JPH075419A - Projection type color liquid crystal optical device - Google Patents

Abstract

PURPOSE:To provide the projection type color liquid crystal optical device which makes a uniform, high-contrast and high-luminance display and is compact and lightweight. CONSTITUTION:This device has a light source system 1, dichroic mirrors 21 and 22 which form a specific angle beta, reflection type liquid crystal optical elements 31-33 which have reflecting surfaces having condenser lenses attached onto the front surfaces, and a projection optical system 4; and the normal of a dichroic mirror surface and an optical axis of reflection have an angle alphaand the optical axis of a reflecting surface and an optical axis of incidence has an angle 2.gamma. The divergent light emitted by a light source 11 is separated by colors into color lights, which are made parallel by the condenser lenses, modulated by the reflection type liquid crystal optical elements, and reflected and modulated, so that the lights are multiplexed and projected from a projection lens 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type color liquid crystal optical device having a light source system, a color separation / synthesis optical system (two dichroic mirrors), three reflection type liquid crystal optical elements and a projection optical system. Regarding

[0002]

2. Description of the Related Art A liquid crystal optical element is initially a dynamic scattering type (D
A liquid crystal optical element using a liquid crystal of (SM) was also proposed, but DSM has a drawback that the current consumption is large because the current value flowing in the liquid crystal is high. Currently, a twist nematic (TN) liquid crystal is used. Has become the mainstream, and has appeared in the market as a pocket TV. The TN liquid crystal has a very small leakage current and a low power consumption, and is therefore suitable for applications using a battery as a power source. However, since the polarizing plate is used, there is a drawback that the display is dark.

Furthermore, in recent years, nematic liquid crystals have been dispersed and held in a solidified matrix, and the refractive index of the solidified matrix is almost the same as the refractive index of the liquid crystal used when a voltage is applied or not applied. Attention has been paid to a transmission / scattering type liquid crystal optical element formed by sandwiching the liquid crystal solidified composite thus prepared. This transmission scattering type liquid crystal optical element,
Since no polarizing plate is used, there is an advantage that bright display is possible. For this reason, a bright projected image can be obtained especially when used in a projection type optical device, and therefore, it is attracting attention.

[0004]

When this transmission / scattering type liquid crystal optical element is used as a reflection type element by forming a light reflection layer on one surface of the element, light is used as a light modulation functional layer as compared with the case of using it as a transmission type element. Since it reciprocates, the action length is twice as large, and as a result, the element has a high scattering power at the time of scattering. Therefore, when this transmission / scattering type liquid crystal optical element is used as a reflection type optical device, a significant difference between the transmission state and the scattering state occurs, and high contrast display may be possible as compared with the case of the transmission type optical device.

Further, a color projection type liquid crystal optical device using this transmission / scattering type liquid crystal optical element as a reflection type element, particularly a white light source is divided into three colors of blue (B), green (G) and red (R). After that, the color projection type liquid crystal optical device using the three reflection type liquid crystal optical elements that modulate each color light can achieve good full color projection by adjusting the light scattering property of the reflection type liquid crystal optical elements. It is useful.

Further, the electrodes of the back electrode substrate are composed of divided pixel electrodes, and each pixel electrode is a full color projection type using a reflection type liquid crystal display element driven by an active element such as a TFT provided for each pixel. Display devices have been proposed. When an active element and a storage capacitor are formed for each pixel,
The reflective type eliminates the reduction of the pixel aperture ratio due to the formation of the storage capacitor, and it is easy to obtain a high aperture ratio as compared with the transmissive type, and the degree of freedom in designing active elements such as TFTs is generally increased.

Conventionally, a color projection type liquid crystal optical device using a transmission / scattering type liquid crystal optical element as a reflection type element, for example, in Japanese Patent Publication No. 61-502286, forms blue, green and red color filters in a mosaic pattern. A projection type liquid crystal display device using the single reflection type display element is described. However, there is no description about a color projection system using three reflection type optical elements for separating the white light source into three colors of BGR and then modulating each color light.

A color projection type liquid crystal using a transmission-scattering type liquid crystal optical element as a reflection type element and using three reflection type optical elements for modulating each color light after separating a white light source into three colors of BGR. Regarding the display device, the configuration of the optical system thereof is described in FIG. 5 of JP-A-4-142528 or FIG. 1 of JP-A-4-232917.
In all of these known examples, an elliptical mirror is used as a condenser mirror of the light source system, and the divergent light emitted from the light source system is collimated by one convex lens, and then three reflection-scattering liquid crystal optical elements are used as reflection types. It is incident on the device.

Here, as a color separation / synthesis system, 45 ° to each other.
A dichroic prism that intersects at is used by being disposed between the collimating convex lens and the reflective element. This conventional example is shown in FIGS. FIG. 18 is a plan view of an optical system in which the light source system and the projection lens are omitted, and FIG. 19 is a side view of the whole. As a result, a space is required between the projection lens 142 and the collimating convex lens 130 and between the light source system 101 and the collimating convex lens 130, which causes an increase in the volume of the color projection type liquid crystal display device.

Further, as compared with a flat plate type dichroic mirror that is generally used in a color projection type liquid crystal display device using a transmission type liquid crystal optical element, a dichroic prism is easier to perform optical adjustment and has a shorter optical path length. Although it has the advantage that it can be done, there is a problem that it becomes expensive as the weight increases.

Further, the reflective liquid crystal optical elements 131, 132, 133
Since the incident light and the reflected light of are incident and reflected at a certain angle with respect to the reflective surface of the reflective liquid crystal optical element instead of having the same optical axis, the light is reflected corresponding to the effective surface of the reflective liquid crystal optical element. In order to use without loss, the effective surfaces of the color separation / combination system 102 and the collimating convex lens 130 require a larger area than the reflective surface of the reflective liquid crystal optical element, which causes an increase in volume and weight. .

Furthermore, the collimating convex lens 130 is a BGR.
In the case of a projection type display device, it is necessary to have a complicated structure in which two or more kinds of lenses are combined in order to reduce the chromatic aberration when the projection type display device is used. On the other hand, instead of the dichroic prisms intersecting each other at 45 ° as a color separation / combination system, a configuration shown in FIGS. 20 and 21 in which flat plate dichroic mirrors intersect each other at 45 ° may be considered.

FIG. 20 is a plan view and FIG. 21 is a side view.
However, the illustration of the reflective liquid crystal optical element for the light reflected and separated by the dichroic mirror 202 is omitted in the side view. In this case, the weight and cost can be reduced as compared with the case where the dichroic prism is used, but there is a problem that the shadow at the intersection of the dichroic mirrors 202 is easily projected on the screen. This is a serious problem as a cause of deterioration of the display quality of the projection type display device.

Further, in the conventional color projection type liquid crystal display device using the transmission type liquid crystal optical element, since two kinds of dichroic mirrors are generally used for the color separation system and the color combination system, respectively, a total of four dichroic mirrors are used. There was a degree of freedom to adjust the color purity of the three colors of BGR by using one dichroic mirror. However, in the case of a color projection type liquid crystal display device using a reflection type liquid crystal optical element, as shown in FIGS. 18 to 21, it is necessary to adjust the color purity of the three colors of BGR by two types of dichroic mirrors. Under such restrictions, when a white light source having a high color rendering property and a high luminous efficiency such as a metal halide lamp, a xenon lamp, a halogen lamp is used as a light source for projection, excellent color purity of the three colors of BGR cannot be achieved.

A reflective display element using a viscoelastic material as a light modulating material instead of the liquid crystal solidified composite is, for example, SPI.
E VOL. 1255, "Large-Screen
Projection Display (1990),
page 69-78 "(Large Screen Projection Display). The reflective display element applies a voltage to the viscoelastic body by an active element formed for each pixel electrode, and the viscoelastic body reflecting surface is deformed by the applied voltage to form a diffraction grating. When incident light is applied to it, diffracted light is generated.

Here, in order to display a projected image with a high contrast ratio, a dark field schlieren optical system using a schlieren stop or schlieren rod that blocks non-diffracted light is used. This is different from the case where the liquid crystal solidified substance composite is used as a transmission / scattering type display element, because it is in a transparent state (non-diffraction state) when no voltage is applied, and therefore it is dark to display a black level when no voltage is applied. -Field Schlieren optics will be used.

22 to 24 show the three types of optical systems described in the above document. FIG. 22 shows the case where a schlieren stop is used as the undiffracted light removal system.
3 shows the case where a schlieren rod is used as the non-diffraction light removal system, and FIG.
Using a stop, using a condenser lens on the light source side and the projection side,
This is the case where the incident light on the dichroic mirror for color separation / synthesis is parallel light. Here, the light source LS, the light source condensing lens LC, the dichroic mirrors 21 and 22, the lens L1,
L2, L3, and light modulation display elements E1, E2, E3
And the projection lens L4 and the like.

In these cases, the viscoelastic body is not deformed when no voltage is applied, and all 0th-order diffracted light (non-diffracted light) is blocked by the Schlieren stop or Schlieren rod.
No light is projected on the screen. Therefore, while the black level of the image can be suppressed to a low value, the bright level cannot be a bright projection image unless the diffraction intensity is sufficient. In addition, since the projected light is a diffracted light component, the directivity is not uniform, and when the optical path length to the projection lens is long, the light is dissipated in the optical path on the way and the amount of light projected on the screen is reduced. Further, a projection lens having a large aperture is required to efficiently collect the diffracted light on the screen.

Therefore, in the dark field schlieren optical system used in the reflection type display device using the viscoelastic body, the diffracted light whose directivity is disturbed is used as the projection light, so that in a normal optical system, it reaches the projection lens. There is a problem that a large amount of light is dissipated up to this point and a large amount of light is dissipated by the aperture of the projection lens, and the light reaching the screen is reduced. In addition, a large color separation / synthesis system (dichroic mirror) and a large-diameter projection lens are required to reduce such a loss of light amount, which necessitates an increase in the size of the entire device and also reduces productivity. became.

Although the literature describes the advantages and disadvantages of the three types of optical systems shown in FIGS. 22 to 24, all of them include such problems, and it is finally concluded which form is preferable. Not not. Therefore, a projection type color liquid crystal optical device using a transmission / scattering type liquid crystal optical element as a reflection type liquid crystal optical element is desired to be small and lightweight and have high color purity.

Also, J. E. Gunser (J.
E. Gunther) et al., “High Vi
safety Color Projection
Display (final technical)
report), HAC reference num
"ber F2317 (1986)" (high visibility color projection display) uses three reflective liquid crystal display elements using single crystal silicon as an active element and DSM liquid crystal as a light modulating means, and a color separation / synthesis optical system. A projection type display device using a prism block (a structure in which three prisms are combined) is disclosed as the above (see FIG. 31).

In this case, since the incident angle of light on the surface of the dichroic mirror is 45 ° or less, the sharpness of color separation and synthesis is higher than that of the dichroic mirror and dichroic prism with 45 ° incidence, and therefore the color purity of the projected light is high. It will be expensive. However, three prisms are required, and the optical path length between the condenser lens and the display element becomes longer than that of the 45 ° incidence cross type color separation / combination system shown in FIGS.

Generally, a white light source such as a metal halide lamp, a xenon lamp, a halogen lamp, etc., which has a long emission brightness and a long emission life, is not a perfect point light source. Is hard to collect. Further, even if the light diverged from the reflector is collimated by a lens, it does not become a collimated light with directivity. As described above, when the incident light on the liquid crystal display element is not a perfect parallel light, the light scattered from the side surface of the prism on the way to the liquid crystal display element, or the light totally reflected on the side surface of the prism and disturbing the directivity is generated. Then, the amount of light incident on the liquid crystal display element increases.

With respect to the light reflected by the reflecting surface of the liquid crystal display element and passing through the prism and finally projected, is part of the normally reflected light that should be originally projected scattered from the side surface of the prism? Or, the light may be totally reflected by the side surface of the prism and may not be able to enter the projection lens. Further, since the incident light having the disordered directivity does not contribute to the brightness of the projected light because it is regularly reflected when the liquid crystal display element is in the transparent state and does not enter the projection lens, it does not contribute when the liquid crystal display element is in the scattering state. It produces light that is incident on the projection lens, thus increasing the dark level.

As a result, the brightness of the projected light is reduced and the contrast ratio is deteriorated. This is because the side surface of the prism is large, and when the liquid crystal display element is in the scattering state, the scattered light is totally reflected by the side surface of the prism and the ratio of staying inside the prism increases.

Therefore, even if a practical light source is used, it is necessary to prepare a prism that is sufficiently larger than the display surface of the liquid crystal display element in order to exhibit desired characteristics. Increase. Also, Red
Since the light incident on the (red) liquid crystal display element is color-separated by the dichroic mirror surface and then totally reflected by the prism surface, it is necessary to make the incident light on the prism parallel light. As a result, there is a problem that the projection lens system including the collimating lens becomes large and the volume of the entire apparatus increases.

Furthermore, since the incident angle of the incident light on the liquid crystal display element and the incident angle of the reflected light on the liquid crystal display element are different with respect to the dichroic mirror surface shown in FIG. 31,
Spectral characteristics of the dichroic mirrors at the same dichroic mirror surface position are different, which may result in deterioration of light utilization efficiency and generation of stray light.

Further, in Japanese Patent Laid-Open No. 4-113344, a light source system has a light source, an elliptical mirror, a diaphragm, and a condenser lens, and the elliptic mirror serves as a condenser mirror and the light source is arranged at a first focal point position thereof. , The light from the light source is condensed at the second focal position, the light passing through the aperture of the diaphragm arranged at the second focal position is condensed by the condensing lens and is incident on the transmission / scattering type display element. A projection type display device is described which is provided with a projection optical system which collects light emitted from a transmission / scattering type display element and disposes a second diaphragm having an opening at its focal position. In addition, there is a description of the configuration when a reflective liquid crystal display element is used.

Further, JP-A-4-142528 and JP-A-4-305637 relate to a reflection type display device in which the above-mentioned projection type display device, a color separation / combination system and three transmission / scattering type display elements are combined. Examples have been described.

[0030]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a projection type color liquid crystal optical device which is small in size, light in weight and high in color purity.

First, the basic constitution of the present invention is to provide three reflective liquid crystal optical elements arranged in a Δ (delta) shape at an angle of approximately 60 ° on a horizontal plane (a specific one plane) and a liquid crystal optical element of about 60 °. A color separation / combination optical system composed of two color separation / combination means (specifically, a flat plate type dichroic mirror) arranged in a V shape with an included angle β, and further from a light source system to a liquid crystal optical element and a projection optical system. By the way, in the direction of the plane vertical to the horizontal plane, light is obliquely emitted upward (downward) from the light source system, passes through the color separation / combination optical system, and is reflected by the reflective liquid crystal optical element. This is an optical arrangement in which light is emitted upward (downward) and tilted projection is performed. Figure 2
FIG. 7 shows a perspective view of an embodiment of the present invention. In the configuration of FIG. 27, the light source system (the light source 11, the elliptical mirror 12, the concave cone-shaped reflector)
15b), color separation / combination optical system (dichroic mirrors 21, 2
2), light modulation means (reflection type liquid crystal optical elements 31A, 32A, 33A
Are each provided with a liquid crystal polymer composite layer (LCPC) as an electrically controllable light modulation function layer, and a reflection function layer.
31C, 32C, and 33C are built in each).
In addition, a part of the optical path before and after the reflection function layer is enlarged and shown in FIG.
Shown in. Here, the central optical axis 5 and the optical axis AX are shown, and the separated color light travels along the optical axis AX. In these figures, there is a relation of β = α1 + α2 (see FIG. 1). Further, the two dichroic mirrors 21 and 22 are basically two vertical planes with respect to the plane (H _P ),
Even if it is slightly inclined, it is possible in practice. In addition, in FIG.
In order to compare the plan view of the example of the present invention with the conventional example shown in FIG. 31, the respective constituent elements are set under substantially the same conditions, and are further schematically shown at substantially the same scale ratio.

According to the present invention, there is provided a projection type color liquid crystal optical device provided with a light source system, a color separation / combination optical system, a light modulator, and a projection optical system.
Color separation / combination means and second color separation / combination means, and the light modulation means is provided with three condensing means, three liquid crystal optical elements, and three reflective functional layers. The device has a nematic liquid crystal dispersed and held in a solidified matrix between a front substrate with a transparent front electrode and a back substrate with a back electrode, and the solidified matrix of the solidified matrix is applied when voltage is applied or not applied. The refractive index and the nematic liquid crystal are made to substantially coincide with each other, and the liquid crystal solidified composite layer operating in the transmission / scattering mode is sandwiched, and the color separation / combination optical system has two color separation / combination means on a certain horizontal plane. The angle β made by
The projection optical system is arranged in a range of 70 °, and the projection optical system is arranged on a plane substantially perpendicular to the horizontal plane so that the optical axis from the light source system to the projection optical system forms a tilted projection, and obliquely upward from the light source (downward). ) The emitted light is allowed to travel along the optical axis via the color separation / combination optical system and the light modulator, and the first color separation / combination means has an incident angle α1 with respect to the optical axis.
Is provided in a range of 20 ° to 35 °, and the second color separation / combination means has an incident angle α2 with respect to the optical axis of 20 ° to 35 °.
The light is divided into three color lights by the color separating / combining means, is condensed by the condensing means corresponding to each color light, and is modulated by the liquid crystal optical element corresponding to each color light. Is reflected by the reflection function layer corresponding to 1) so that the incident angle γ becomes 1 ° to 20 °, is condensed by the condensing means corresponding to each color light, and is color-combined by the color separation / combination optical means, and is projected to the projection optical system. Provided is a first projection type color liquid crystal optical device which is characterized by being made incident.

Here, it is not necessary that α1 and α2 always match completely. The angle formed on the horizontal plane is defined as the angle when two flat plate type dichroic mirrors are projected on a certain plane, or the angle in the cross section on that plane. For example, it refers to the angle β appearing in the plan view of FIG. 1.

Further, in the first projection type color liquid crystal optical device, the incident angle α1 and the incident angle α2 are made substantially equal, and the incident angle γ is set in the range of 2 ° to 10 °. A second projection type color liquid crystal optical device is provided. Further, in the second projection type color liquid crystal optical device, it is more preferable that the incident angle α1 is set to 30 ° (β = 60 °).

Also, in the first or second projection type color liquid crystal optical device, the third projection is characterized in that the light converging means is attached to or close to the front surfaces of the three liquid crystal optical elements, respectively. A type color liquid crystal optical device is provided.

Further, in the projection type color liquid crystal optical device according to any one of the first to third aspects, a third projection type liquid crystal optical device is provided with three reflective functional layers respectively provided in three liquid crystal optical elements. A color liquid crystal optical device is provided.

In the projection type color liquid crystal optical device according to any one of the first to fourth aspects, the three condensing means are composed of three liquid crystal optical elements and the first color separation / synthesis means or the second color separation / synthesis means. Arranged respectively with any one of the means,
And the charge transfer plate (CT
P) is used as a back substrate, and the reflective functional layer is CTP.
And a liquid crystal solidified composite layer, the fifth projection type color liquid crystal optical device is provided.
Here, CTP refers to a structure in which a large number of thin conductive wires are densely embedded in a substrate.

In the projection type color liquid crystal optical device according to any one of the first to fifth aspects, the light source system includes an elliptical mirror, a light source and an aperture stop, and the light source emits light in the vicinity of the first focal point of the elliptic mirror. The aperture stop is disposed so that the aperture of the aperture stop is located near the second focal point of the elliptical mirror, and the conical prism or the conical reflector is disposed near the aperture. A sixth projection type color liquid crystal optical device is provided. With this configuration, it is possible to efficiently obtain a preferable light source light having a collimation angle of 6 ° to 10 ° from the light source.

In the projection type color liquid crystal optical device according to any one of the first to sixth aspects, the front substrate has the transparent electrodes formed on the transparent insulating substrate, and the back substrate has a plurality of row wirings. A plurality of column wirings, active elements are provided in the vicinity of intersections of the row wirings and the column wirings, and a dielectric multilayer mirror is provided so as to cover a part or all of the row wirings, the column wirings, and the active elements. A seventh projection type color liquid crystal display device is provided which is formed and further uses a transparent electrode formed on the dielectric multilayer film mirror layer as a back electrode for pixel display.

The double electrode structure of transparent (pixel) electrodes arranged on or above the mirror of the TFT substrate can be applied to a single liquid crystal optical element.

In any one of the first to seventh projection type color liquid crystal optical devices described above, a transparent electrode is formed on a transparent insulating substrate on the front substrate, and a plurality of row wirings are formed on the back substrate. A plurality of column wirings, an active element for driving a pixel electrode in the vicinity of an intersection of the row wirings and the column wirings, a third electrode is further provided, and the third electrode is the row wirings. An electric potential between the third electrode and the front electrode, the electric potential between the third electrode and the front electrode being arranged so as to cover a part or all of the column wiring and the active element and / or substantially cover a gap between adjacent pixel electrodes. Provides an eighth projection type color liquid crystal display device characterized by being equal to or less than the threshold value of the liquid crystal solidified composite layer.

With this structure, it is possible to solve the functional problem that occurs in the space between adjacent pixels, which is peculiar to the liquid crystal optical element having the liquid crystal solidified composite. Then, good aperture ratio and low voltage driving can be obtained from the preferable electric efficiency for the liquid crystal solidified composite layer. This structure can also be applied to various applications using an ordinary single liquid crystal optical element.

In the projection type color liquid crystal optical device according to any one of the first to eighth aspects, at least one of the color separating / combining means has a difference in spectral transmission characteristic depending on an incident angle depending on a position on the optical surface. A ninth projection type color liquid crystal display device is provided which is provided with a function of compensating for. Specifically, a distribution is provided for the difference in the spectral transmission characteristics within the surface of the dichroic mirror.

In the projection type color liquid crystal optical device according to any one of the first to ninth aspects, the reflective functional layer has a relatively high refractive index with respect to the translucent dielectric thin film. Provided is a tenth projection type color liquid crystal optical device, characterized in that a dielectric multi-layer film mirror in which low light-transmitting dielectric thin films are alternately laminated is used.

Further, in the projection type color liquid crystal optical device according to any one of the first to tenth aspects, fine irregularities are formed on the interface of the front substrate or the surface of the transparent electrode surface. An eleventh projection type color liquid crystal optical device is provided.

Further, in the projection type color liquid crystal optical device according to any one of the above first to eleventh aspects,
Provided is a twelfth projection type color liquid crystal optical device, which is provided with a wavelength selective reflection property for compensating the color purity of the color separation / synthesis means. Further, in the projection type color liquid crystal optical device according to any one of the first to twelfth aspects, the color purity of the color separation / synthesis unit is set in any one of the light condensing unit, the reflective functional layer, and the liquid crystal optical element. A thirteenth projection-type color liquid crystal optical device having a wavelength-selective absorption property for compensation is provided.

Explaining an example of the present invention, a light source system, two first and second dichroic mirrors for color separation / combination, three liquid crystal optical elements, a reflection function layer, and a projection optical system are provided. The projection type color liquid crystal optical device is provided, wherein an optical axis from the light source system to the projection optical system is provided, and the dichroic mirrors are a first flat plate type dichroic mirror and a second flat plate type dichroic mirror. And an angle α1 formed by the normal line of the first flat plate dichroic mirror surface is 20 ° to 35 °, and an angle α2 formed by the optical axis and the normal line of the second flat plate dichroic mirror surface is 20 °
The liquid crystal optical element is electrically arranged at an angle β of 40 ° to 70 °, which is 35 °, and the angle β formed by the first flat plate dichroic mirror surface and the second flat plate dichroic mirror surface on the horizontal plane is 40 ° to 70 °. It has a function of controlling the transmission / scattering state, a reflective function layer is provided on the back side of the liquid crystal optical element, and all three liquid crystal optical elements have an angle γ formed by the optical axis of the reflecting surface and the optical axis of the incident light. Arranged at an angle of 1 ° to 20 °, preferably 2 ° to 10 °, the incident light on the reflecting surface has a plane defined by the optical axis of the incident light and the optical axis of the reflected light, and a first flat plate type. The light emitted from the light source is arranged so that the plane parallel to the plane including the normal line of the dichroic mirror and substantially parallel to the plane including the normal line of the second flat plate type dichroic mirror is orthogonal to the plane. Flat plate dichroic mirror and Or is the three are color separated color light by a second action of the flat plate type dichroic mirror,
The light is emitted from either the first flat plate type dichroic mirror or the second flat plate type dichroic mirror, and is collected by the light collecting means, the liquid crystal optical element (the modulation function layer thereof), and the reflection function layer, which are associated with each color light. Light, modulated, reflected, remodulated (that is, passed through the modulation function layer twice), and condensed again, each color light is further converted into a first flat plate dichroic mirror and / or a second flat plate dichroic. Colors are combined by the function of the mirror and projected through the projection lens. When the condensing means is arranged on the back surface of the liquid crystal optical element, each color light passes through the condensing means only once. Further, it is possible to use a condensing reflecting means in which the condensing means and the reflection function layer are integrated.

Further, in the fifth projection type color liquid crystal optical device described above, the reflecting surface formed between the CTP and the liquid crystal solidified composite has an electrode divided into pixels. This invention provides a projection type color liquid crystal optical device.

In the sixth projection type color liquid crystal optical device, a second aperture stop is provided at a position where an optical conjugate image of the aperture arranged near the second focal point of the elliptic mirror is generated. A fifteenth projection type color liquid crystal optical device is provided. Further, in the fifteenth projection type color liquid crystal optical device, the aperture size of the aperture stop arranged near the second focus of the elliptic mirror and the aperture size of the second aperture stop are both variable. A sixteenth projection type color liquid crystal optical device is provided. Further, the present invention will be described in detail.

In the projection type liquid crystal optical device of the present invention, the liquid crystal optical element used is preferably a reflection type liquid crystal optical element in which a liquid crystal solidified composite capable of electrically controlling the scattering state and the transmitting state is sandwiched. To use. Therefore, a polarizing plate is not required, a bright light source can be used, and the light transmittance at the time of transmission can be significantly improved.

In addition, the liquid crystal optical element sandwiching the liquid crystal solidified composite complex can avoid the problems such as the alignment process essential for the reflection type TN type liquid crystal optical element and the destruction of the active element due to static electricity generated at that time. The manufacturing yield of liquid crystal optical elements can be greatly improved.

Furthermore, since this liquid crystal solidified composite is in the form of a film after solidification, problems such as short-circuiting between substrates due to pressurization of substrates and breakage of active elements due to movement of spacers are unlikely to occur.

Further, this liquid crystal solidified composite has a specific resistance equivalent to that of the conventional TN liquid crystal, and it is not necessary to provide a large storage capacitance for each pixel electrode unlike the DSM liquid crystal, and each pixel electrode does not need to be provided. It is easy to design the provided active elements, and
The power consumption of the liquid crystal optical element can be kept low. Therefore, it is possible to manufacture the conventional TN liquid crystal optical element only by removing the alignment film forming step from the manufacturing step, which facilitates the production. Further, in the liquid crystal solidified composite, it is possible to adapt the average particle diameter of the encapsulated liquid crystal in each cell, their shape and (ellipsoidal shape), and the density depending on the dominant wavelength range of the colored light used. it can. For example, R _B <R _G
A cell of each liquid crystal optical element can be formed as <R _R. Moreover, the substrate thickness can be optimized for each color light.

The specific resistance of the liquid crystal solidified composite is 5 ×
It is preferably 10 ⁹ Ωcm or more. Further, in order to minimize the voltage drop due to leakage current or the like, the specific resistance is more preferably 10 ¹⁰ Ωcm or more, and in this case, it is not necessary to give a large storage capacitance to each pixel electrode.

FIG. 1 is a plan view showing the basic constitution of the projection type liquid crystal optical device of the present invention, and FIG. 2 is a side view showing the basic constitution of the projection type liquid crystal optical device of the present invention. However, in FIG. 2, the reflection type liquid crystal element block 3 on which the light reflected and separated by the two types of dichroic mirrors 21 and 22 is incident.
Omitting 1 and 32, the reflection type liquid crystal element block 33 for the light transmitted through the two dichroic mirrors and its light rays are described. The arrangement and light rays of the other two reflective liquid crystal elements 31, 32 are mirror image symmetrical with respect to the arrangement of the reflective liquid crystal element block 33 and the light rays described with respect to the reflecting surfaces of the dichroic mirrors 21, 22. .

In FIG. 1 and FIG. 2, the light source system 1 is a lamp 11
The ellipsoidal mirror 12 and the aperture stop 13 are provided, and the light emitted from the lamp 11 is reflected by the ellipsoidal mirror 12 and then collected near the aperture stop 13. Here, the lamp 11 is near the first focus of the elliptical mirror 12,
The aperture stop 13 is installed near the second focal point of the elliptical mirror 12. The light passing through the aperture diaphragm 13 is included in the visible light of the lamp 1 by the first flat plate type dichroic mirror 21.
Light in one of the GR wavelength bands is reflected and light in the other wavelength band is transmitted.

Further, the light of the remaining wavelength band transmitted through the first flat plate type dichroic mirror 21 is incident on the second flat plate type dichroic mirror 22, and the light of any wavelength band of BGR is reflected and remains. Light in the wavelength band of is transmitted. In this way, the flat plate type dichroic mirror 21 and the second flat plate type dichroic mirror 22 are used for the BG.
The lights split into the three colors of R are collected lenses 31B, 32B, and 33, respectively.
After being incident on B, it is collimated and enters the transmission / scattering reflective liquid crystal optical elements 31A, 32A, and 33A.

For the sake of convenience, the combination of the condenser lenses 31B, 32B and 33B and the transmissive / scattering reflective liquid crystal optical elements 31A, 32A and 33A will be referred to as reflective liquid crystal optical element blocks 31, 32 and 33.
These incident lights are reflected by the liquid crystal optical element blocks 31, 32,
The directivity is optically modulated by 33, and the degree of scattering changes depending on the voltage applied to the liquid crystal solidified composite layer. The reflected light that has not been scattered is again focused by the lenses 31B, 32B, and 33B in the vicinity of the focal position.

Here, the lights separated into the three colors of BGR are color-synthesized by the first and second flat plate type dichroic mirrors 21 and 22, and the condenser lenses 31B, 32B and 33B open the aperture of the light source optical system. A conjugate image corresponding to the diaphragm shape is formed near the focal position of the condenser lens. The condensed reflected light passes through a diaphragm 41, which is a device for reducing diffused light, installed near the focal positions of the condenser lenses 31B, 32B, and 33B, and a screen (not shown) is shown by a lens 42 of the projection optical system. Projected on.

In FIGS. 1 and 2, the projection optical system 4 is the light source system 1
Although the case of being on the upper side of is described, the vertical relationship may be reversed. In order to provide the tilt projection mechanism in the projection type display device, the vertical relationship between FIG. 1 and FIG. 2 is preferable when the observer's eye height of the screen projection image is higher than the display device.
When the eye level of the observer is lower than the display device, it is preferable that the light source system 1 is located above the projection optical system 4.

On the other hand, the light scattered by the reflective liquid crystal optical element is not condensed by the condenser lens in the vicinity of its focal position and is blocked by the diaphragm which is a device for reducing diffused light, and therefore passes through the projection lens. And then it is not projected on the screen.

In the light source system 1 of the present invention, an ellipsoidal mirror (ellipsoidal mirror) is most preferable as the condenser mirror 12, but a parabolic mirror,
It may be a combination of a spherical mirror, a lens and the like.
Further, instead of a simple spheroidal shape, a multi-mirror structure may be adopted in which rotator surfaces having different elliptical shapes are overlapped for each position in the rotation axis direction in consideration of equalizing the light amount in the surface of the reflective liquid crystal optical element. Further, a configuration may be adopted in which an elliptic mirror and a spherical mirror are combined to improve the light collection rate.

The lamp 11 may be a halogen lamp, a metal halide lamp, a xenon lamp or the like, but a metal halide lamp is preferable in terms of luminous efficiency and life.
Further, a transmissive diaphragm having an opening near the focal position of the condenser mirror may be used, or a diaphragm using a reflecting mirror having a reflecting surface corresponding to the opening may be used. Generally, the light emitting portion of the lamp has a non-uniform light emission distribution, and due to the influence of the shadow of the lamp tube wall, the light distribution distribution of the emitted light tends to be non-uniform.

In particular, when an elliptic mirror is used as a condenser mirror,
Since a small amount of light is emitted in the angle region of 10 ° or less with respect to the optical axis, a shade having a small amount of light is likely to occur in the central portion within the surface of the reflective liquid crystal optical element. To improve the problem of uneven light intensity,
In order to improve the light collection efficiency, a concave type instead of an aperture stop and a concave or convex cone-shaped prism near the focal position of the focusing mirror, or a stop using a reflecting mirror with a reflecting surface corresponding to the opening Alternatively, it is effective to install a convex cone-shaped reflector. 1 and 2 show a light source system in which the conical prism 14 is used.

FIG. 3 shows a structural example of a light source system using the conical prism 14, and FIG. 4 shows a structural example of a light source system using the conical reflector 15a (convex type). When the cone-shaped prism 14 is used, the convex cone-shaped prism having the apex angle θa1 of the light emitting surface of 90 ° to 175 ° or the apex angle θa2 of 185 ° to 27.
A concave cone prism with a 0 ° is preferred. The apex angle of the conical prism is placed on the optical axis, and the arrangement is made symmetrical with respect to the optical axis as shown in FIG. θa1 and θa2 have a complementary relationship, and can optically perform the same function in relation to the uneven surface. The illustration of the concave-cone prism is omitted.

When the cone-shaped reflector 15a is used,
A convex cone-shaped reflector having an apex angle θb1 of 150 ° to 177 ° or a concave cone-shaped reflector having an apex angle θb2 of 183 ° to 210 ° is preferable. The apex angle of the cone-shaped reflector is placed in the vicinity of the optical axis, and its symmetry axis is set to the optical axis of the incident light and is 4
Place with an inclination of 5 ° or less. θb1 and θb2 have a complementary angle relationship, and can optically perform the same function in relation to the uneven surface.

In the case of a conical prism which is a transmission type optical element, it is preferable that an antireflection film or a heat ray cut filter is formed on the surface. In the case of a cone-shaped reflector,
A metal mirror made of aluminum or the like or a dielectric multilayer film mirror is formed as a reflecting surface. When a dielectric multilayer film mirror is used, it is preferably a cold mirror that transmits heat rays.

In addition to the above-mentioned cone-shaped prism or cone-shaped reflector, a diffusion plate or a lens array may be arranged near the aperture stop of the light source optical system to make the light distribution uniform. Further, a cooling system may be added to the light source optical system, or an infrared cut filter, an ultraviolet cut filter, or the like may be combined.

Further, the above-mentioned cone-shaped prism or cone-shaped reflector is not limited to the case where only an elliptic mirror is used as a condensing mirror, and a combination of an elliptic mirror and a spherical mirror having a structure for improving the condensing rate is combined. It is also effective in the case of a different configuration.

FIG. 25 shows the specific structure of the case where a conical prism is used. Unlike Fig. 3, elliptical mirror
The depth of 12a is set to be approximately the same as the first focal length where the light emitting part of the lamp is arranged, and the spherical mirror 12b whose center of curvature is near the first focal point of the elliptical mirror 12a is located on the second focal point side of the elliptic mirror. Arrange to do. The spherical mirror 12b covers the elliptic mirror 12a in the vicinity of the first focal point of the elliptic mirror 12a, and has a shape of the spherical mirror 12b having an opening for emitting light between the first focal point and the second focal point of the elliptic mirror 12a.

With such a combination, the luminous flux density emitted from the light source system to the reflection type liquid crystal optical element block is further improved as compared with the case where only the elliptic mirror is used as the converging mirror, so that the light utilization efficiency is increased. To do.

Next, the color separation / synthesis optical system will be described. In the dichroic mirror that uses the optical interference effect of the dielectric multilayer film, the spectral characteristics of the reflectance and the transmittance of the dichroic mirror are those of S-polarized light and P-polarized light as the light incident angle increases from 0 ° (normal incidence) to oblique incidence. The difference in spectral characteristics increases. 18 and 19 in which a dichroic mirror or a dichroic prism is arranged at an incident angle of 45 °.
In the case of the conventional projection type liquid crystal optical device shown in FIGS. 20 and 21, the difference is remarkable.

There is no problem in the case of a TN liquid crystal optical element which uses only one linearly polarized light by using a polarizing plate, but a projection type liquid crystal optical element of the present invention which uses both polarized lights as projection light is used. In an optical device, the polarization dependence of the spectral characteristics of such a dichroic mirror is
This is a problem because it causes deterioration of the spectral action in the color separation and synthesis of the dichroic mirror, that is, the color purity of BGR is reduced.

In the first flat plate type dichroic mirror and the second flat plate type dichroic mirror of the color separation / combination system of the present invention, the angles α1 and α2 formed by the optical axis of the optical system and the perpendicular to the surface of the dichroic mirror are 20 °. The dichroic mirrors are sequentially arranged at an angle of 35 ° from each other without intersecting each other. Therefore, the conventional 45 °
Compared with the incident dichroic mirror, the difference in the spectral characteristics between the S-polarized light and the P-polarized light is reduced, a sharp color separation action is obtained, and as a result, the color purity of each color light of BGR is improved.

In particular, in the structure of the present invention, the incident light on the dichroic mirror is divergent or convergent light,
The incident angle varies depending on the in-plane position of the dichroic mirror. Therefore, the angle formed by the optical axis of the optical system and the perpendicular to the surface of the dichroic mirror becomes larger around the dichroic mirror surface, and the polarization dependence of the spectral characteristics becomes remarkable.

Therefore, when the incident light on the dichroic mirror is divergent or convergent, the incident angle α is 45.
In the conventional configuration of °, the color distribution of the projected light on the screen becomes remarkable, which is not suitable for a projection type display device or the like in which the required specifications of the color reproducibility of the displayed image are strict, but the configuration of the present invention can be improved.

Further, by adopting the arrangement of the present invention as shown in FIGS. 1 and 2, the dichroic of each light beam is different from the case where the angle α formed by the optical axis of the optical system and the perpendicular of the dichroic mirror surface is 45 °. The average value of the incident angle to the mirror becomes small, the effective area of the dichroic mirror can be reduced, the optical path length passing through the dichroic mirror is shortened, and the optical axis shift corresponding to the thickness of the dichroic mirror is reduced. There are advantages such as.

Further, since the dichroic mirrors 21 and 22 are sequentially arranged without intersecting each other, there is no problem that the shadow of the intersecting portion which is a problem in the intersecting dichroic mirror is projected on the screen.

By arranging so that the angle β formed by the mirror surface of the first dichroic mirror 21 and the mirror surface of the second dichroic mirror 22 is in the range of 40 ° to 70 °, parallel (β = Since the optical path length can be shortened as compared with the case of arranging the optical path at 0 °), the volume of the entire projection-type optical device can be reduced, and the amount of light scattered in the middle of the optical path can be reduced, leading to improvement in light utilization efficiency.

The plane defined by the optical axis of the incident light and the optical axis of the reflected light on the reflective surface of the reflective liquid crystal element,
And a plane defined by the normal line of the second dichroic mirror (planes that are parallel to the normal planes of the two dichroic mirror surfaces) are arranged substantially orthogonal to each other.

This is because, compared to the case where two planes are arranged so as to be parallel to each other, such an arrangement makes the average value of the incident angle of each light ray on the dichroic mirror small, and the dichroic mirror is effective. This is because the area can be reduced, and the spectral characteristics of the color separation / synthesis of the dichroic mirror due to oblique incidence are less deteriorated.

In the projection type optical device according to the present invention, as shown in FIG.
As shown in FIG. 2, the incident angle differs in the in-plane position of the dichroic mirror, and the difference in the spectral characteristic of the dichroic mirror occurs due to the difference in the incident angle. Therefore, when a dichroic mirror having a uniform spectral characteristic in a normal plane is used, the in-plane color distribution of screen projection light becomes non-uniform.

In order to improve such a problem, the first and second flat plate type dichroic mirrors 21 and 22 are designed to reduce the difference in the spectral transmittance corresponding to the difference in the light incident angle at the in-plane position. In addition, the film thickness of the dielectric multilayer film is adjusted so that the spectral transmittance in the plane of the dichroic mirror has a distribution that varies depending on the in-plane position.

In the case of the projection type liquid crystal optical device of the present invention, the difference in the incident angle of light to the dichroic mirrors 21 and 22 is in the direction determined by the line of intersection between the plane defined by the normal line of the two dichroic mirrors and the dichroic mirror surface. Since it is remarkable, a distribution may be provided in this direction.

The film thickness distribution forming technique for such a dielectric multilayer film is a technique which is usually performed by changing the shape of the film thickness correction plate in the vacuum evaporation method, and the productivity is deteriorated due to this. Is rarely seen.

1 and 2 showing the projection type color liquid crystal optical device of the present invention, the red wavelength light R is reflected by the first flat plate type dichroic mirror 21, and the blue wavelength light B is then reflected by the second flat plate type. The dichroic mirror 22 reflects and the green wavelength light G is transmitted. Regarding the spectral characteristics of the dichroic mirror, an edge type filter such as R reflection or B reflection has a higher degree of freedom in design than a notch type filter such as G reflection, and it is easy to improve color purity. And

In a projection type display device using a reflection type display element, dichroic mirror surfaces having two kinds of spectral characteristics are usually used, and the same type of dichroic mirror surfaces act for color separation and color combination. In a projection type display device using a transmissive display element, two kinds are usually required for a color separation system and two kinds for a color synthesis system, but in the case of the present invention, two kinds of dichroic mirrors are used. Color separation and composition are possible.

In the case of the cross type dichroic mirror or dichroic prism, the number of parts is increased as compared with the structure of the color separation / synthesis system of the present invention, and it is necessary to join each part with high accuracy. Further, in order to manufacture the prism, it is necessary to precisely process and polish the optical glass, which is inferior in productivity. On the contrary, since the dichroic mirror of the present invention uses the same members as the conventional flat plate type dichroic mirror, good quality and quantity can be easily obtained.

When the same dichroic mirror surface is used twice for color separation and color combination, the final spectral transmission (reflection) characteristic is equivalent to almost one squared case. Therefore, the color purity can be improved as compared with the case of single transmission. However, when the sharpness of the spectral characteristic at the color separation wavelength in the case of single transmission is low, light in the intermediate wavelength range between the transmission wavelength range and the reflection wavelength range is deleted and is not used as projection light. Therefore, the conventional 4
When the sharpness of the spectral characteristic at the color separation wavelength is low as in the case of a 5 ° incident dichroic mirror, the amount of projection light also decreases as the color purity decreases.

In the case of the projection type display device of the present invention, in FIG. 1, since the incident angles of the incident light on the flat plate type dichroic mirrors 21 and 22 are 20 ° to 35 °, which are smaller than 45 °, the random polarization is reduced. High sharpness for color separation and color synthesis is maintained even for light. as a result,
The loss of light in the intermediate wavelength range between the transmission wavelength range and the reflection wavelength range is also suppressed to a low level, high color purity is obtained, and the amount of projected light is increased. When the projection type display device of the present invention is used, a color separation / synthesis system composed of only two dichroic mirrors of two types can achieve a color purity of projection light equal to or higher than that of a CRT.

In the present invention, the device for reducing diffused light may be arranged in front of or behind the projection lens of the projection optical system or between a plurality of lenses constituting the projection lens in combination with the projection optical system. As shown in FIGS. 1 and 2, the device for reducing the diffused light may be the second aperture stop 41 corresponding to the conjugate image of the shape of the aperture stop 13 of the light source system described above, or has a corresponding effective surface. It may be a reflector.

The second aperture stop may be installed separately from the projection lens or may be integrated like a camera lens. In terms of shortening the optical path length and downsizing, a conjugate image corresponding to the shape of the aperture stop of the light source optical system is imaged at the pupil position of the projection lens, and the second aperture stop is installed at that position. It is preferable that the and the diffused light removing system are integrated. Also, without using a special aperture,
The diameter of the projection lens may be selected to eliminate diffused light.

As the projection optical system, a conventional projection optical system including a lens or the like is used, but the projection optical system is used in combination with a device for reducing diffused light. The device that reduces this diffused light is the light that has traveled straight through and reflected from the incident light of the light that has passed through the liquid crystal optical element (the pixel portion is transmitted through the transmissive portion and is reflected by the reflective film on the back side). It does not matter as long as it takes out (light coming in) and reduces the light reflected without going straight (light scattered in the part where the liquid crystal solidified substance complex is in a scattering state).

In particular, it is preferable to reduce the diffused light, which is the light reflected without going straight, without reducing the light that goes straight and is reflected. In order to improve the visibility of the projected light, it was placed near the aperture stop 13 of the light source optical system and the projection lens that is the scattered light removal system so that the amount of projected light and the contrast ratio can be adjusted according to the surrounding brightness. It is preferable to use a mechanism in which the second aperture diaphragm 41 can be interlocked with each other so that the aperture area can be varied.

18 to 21 and 31 which are conventional examples.
In the projection type display device shown in Fig. 1, the image of the reflection type liquid crystal display element is formed on the screen by the projection lens and the condenser lens, and the liquid crystal display element and the color separation / synthesis system, the condenser lens and the projection lens are formed. Are separated.

On the other hand, in the optical system of the present invention shown in FIG. 1, three condensing lenses 31B, 32B and 33B are provided for each liquid crystal display element instead of the single condensing lenses 130 and 230 in the conventional example. It is divided and used. As a result, it is possible to make the size significantly smaller than the conventional example in which the color separation / synthesis system is arranged between the condenser lens and the projection lens, and the color separation / synthesis system is arranged between the condenser lens and the liquid crystal display element. Become. In addition, almost no light that enters the condenser lens from the light source system is dissipated by the time it reaches the liquid crystal display element, and stray light is less likely to occur along the optical path, resulting in a bright, high-contrast projected image. To be

Next, various structural examples of the reflective liquid crystal optical element according to the present invention are shown in FIGS. The reflective function layers 337 and 339 of the reflective liquid crystal optical element may be metal reflective films of aluminum, silver, chrome, etc., or a transparent dielectric thin film having a relatively high refractive index and a transparent film having a relatively low refractive index. It may be a dielectric multilayer film reflecting surface formed by alternately stacking optical dielectric thin films.

As the low refractive index transparent dielectric thin film, Si is used.
There are O ₂ , MgF ₂ , Na ₃ AlF _6, etc., and as the high refractive index transparent dielectric thin film, TiO ₂ , ZrO ₂ , Ta ₂ O are used.
₅ , ZnS, ZnSe, ZnTe, Si, Ge, Y ₂ O
₃ and Al ₂ O ₃ etc. are used, the dielectric multilayer mirror has the flexibility to adjust the spectral reflection characteristics by changing the material, the number of layers or the film thickness, compared with the metal reflective film, and the number of layers is increased. Therefore, there is a feature that a high reflectance close to 100% can be achieved.

As shown in FIG. 5, a reflective function layer 339 may be provided between the back electrode substrate 333 and the liquid crystal solidified composite 332. In this case, if a metal film is used, the back electrode and the reflection function layer can be used in common, but in the case of the dielectric multilayer mirror, the transparent electrode film needs to be a constituent element of the multilayer film. In addition, FIG.
As shown in FIG. 7, the reflection function layer 337 may be formed on the side of the back electrode substrate 333 of the transmissive liquid crystal optical element where the transparent back electrode 336 is not formed.
The substrate 338 on which 7 is formed may be installed behind the back electrode substrate 333.

In the case of a display element in which the reflective liquid crystal optical element is composed of pixels which are sufficiently smaller than the thickness of the back electrode substrate 333, in order to prevent the deterioration of the resolution of the projected image due to the formation of double images, The configuration of FIG. 5 in which a reflective function layer is formed between the electrode substrate 333 and the liquid crystal solidified composite 332 is preferable.

In the structure of FIG. 5, since the back electrode substrate 333 does not need to be a light-transmitting material, Si, which can be integrated with a semiconductor circuit on the substrate, other than glass or plastic,
A semiconductor substrate such as Ge or GaAs capable of forming a light emitting element, or a sintered body such as ceramics may be used.

Further, in the structure of FIG. 5, it is necessary that the reflection function layer 339 also has the function of the back electrode. When the reflective function layer is a metal electrode reflective film of aluminum, silver, chrome, etc.,
Although it also serves as a back electrode and also serves as a reflecting surface, the soft surface thereof is likely to cause scratches due to a gap control spacer or the like, which may cause a decrease in reflectance.

On the other hand, the dielectric multilayer film and In ₂ O ₃ --SnO
_When a reflective film formed by combination with a transparent electrode such as ₂ (ITO) or SnO ₂ is formed between the back electrode substrate and the liquid crystal solidified composite, the flatness and durability are superior to those of the metal film. As with the dichroic mirror, since it has wavelength selective reflectivity, it has the effect of improving the color purity of each color light.

In particular, when a white lamp having a high color rendering property is used and the above-mentioned first flat plate type dichroic mirror and the second dichroic mirror are used to perform color separation and synthesis into RGB three colors, a wavelength band of 570 nm to 590 nm is obtained. It is known that the above-mentioned light significantly deteriorates the color purity when mixed in the green or red wavelength band.

Although such unnecessary wavelength band light cannot be separated in principle by the two dichroic mirrors, a reflection type liquid crystal optical element formed with a dielectric multilayer film having a spectral characteristic of transmitting light in this wavelength range is used. It is effective because the use can improve the deterioration of green or red color purity. As another measure, a light absorption type filter may be used. For example, if a colored glass filter that absorbs light having a wavelength of 590 nm or less is disposed between the liquid crystal optical element for R color light and the dichroic mirror in order to exclude light in the 570 nm to 590 nm wavelength range mixed in the R color light. Good.

When the reflection function layer 339 is patterned and used as a pixel electrode in the structure of the reflection type liquid crystal optical element of FIG. 5, active elements such as TFT, thin film diode and MIM are provided and connected as necessary. To do. Note that in order to reduce undesired reflection, such an active element may be provided on the back electrode substrate 333, and the surface of the back electrode substrate in contact with the liquid crystal solidified composite may be made as flat as possible to reduce diffuse reflection. preferable.

When a dielectric multilayer film is used as the reflective function layer of the back electrode, there are two types of positional relationship between the back electrode on the back electrode substrate and the reflective film of the dielectric multilayer film. That is, one is the case where a reflective film of a dielectric multilayer film is formed on the back electrode substrate on which the back electrode is formed. The other is a case where the back electrode is formed on the back electrode substrate on which the reflection film of the dielectric multilayer film is formed.

The former can be applied to all back electrode substrates and back electrodes, but the latter is active when an active element is formed for each pixel in the substrate using a Si single crystal for the back substrate. It is necessary to establish electrical connection with the circuit node of the element (for example, any of the electrodes having a three-terminal structure). Specifically, it is preferable to electrically connect the pixel driving electrode and the pixel electrode on the dielectric multilayer film. However, since an active element such as a TFT is usually formed on a glass substrate, there is no problem in forming a TFT on a dielectric multilayer film formed on a substrate such as glass. In the latter case, the back electrode is a transparent electrode.

Since the applied voltage directly acts on the liquid crystal solidified composite, the back electrode is preferably formed on the reflective film of the dielectric multilayer film from the viewpoint of low voltage driving. In this case, when an active element is formed on each of the back electrodes (used as pixel electrodes), the uppermost layer of the dielectric multilayer reflective film in contact with the active element is made of a material that does not react at the interface. Preferably. For this purpose, specifically, SiO ₂ , TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , A
It is preferably an oxide dielectric such as l ₂ O ₃ .

On the other hand, when a reflective film of the dielectric multilayer film is formed on the back electrode substrate on which the back electrode and the active element are formed, a part of the applied voltage is consumed in the reflective film of the dielectric multilayer film. . As a result, the effective driving voltage rises, but the dielectric multilayer film has an advantage of acting as a protective film for the electrodes and active elements.

In order to reduce the voltage loss in the dielectric multi-layer film and improve the pixel aperture ratio, after forming the contact hole in the dielectric multi-layer film, the pixel electrode is formed on the dielectric multi-layer film. By doing so, it is effective to electrically connect the pixel driving electrode of the active element and the pixel electrode on the dielectric multilayer film.

When an active element is formed on each of the back electrodes, it also functions as a light-shielding film so that the light incident on the reflective liquid crystal optical element does not reach the active element directly. As a result, even when an active element such as amorphous Si having a large photoconductive effect is used, it is possible to reduce the generation of photoinduced current without separately providing a light shielding layer.

In order to further increase the degree of light shielding, a light shielding film may be formed on the back electrode substrate side on the dielectric multilayer film at each active element position. In order to suppress the generation of additional capacitance, the light-shielding film is preferably made of a non-metal having a low conductivity, and a photosensitive black polymer, Si, Ge, CdTe, or the like is used.
In this case, since the dielectric multilayer film serves as a protective film for the active element, the reliability of the active element is high even when an alkaline developer is used in patterning by wet etching. On the other hand, a metal light-shielding film such as Cr may be formed only on each active element position on the back electrode substrate side via an insulating film, and a reflecting surface of the dielectric multilayer film may be formed thereon.

In the configuration of the reflective liquid crystal optical element shown in FIGS. 5 and 6, the liquid crystal solidified composite layer can be heated or cooled directly from the back electrode substrate 333 side, so that the temperature adjustment is easy, It is possible to maintain the optimum operating temperature. Specifically, the temperature of the back electrode substrate may be forcibly adjusted by combining a heater, a Peltier element, a radiator plate, a cooling fan, a thermometer, and the like.

In the structure of the reflective liquid crystal optical element of FIG. 5, a back electrode substrate in which transparent electrodes are uniformly formed on a transparent substrate.
A photoconductive film may be formed on 333, and a dielectric multi-layer film mirror may be further formed on the photoconductive film to form an optical writing type spatial light modulator. In this case, the back electrode and the photoconductive layer are used without being patterned.

Amorphous S is used as the photoconductive layer material.
i, polycrystalline Si, single crystal Si, BSO (Bi ₁₂ Si
O _20), GaAs, CdS, may be used or Se. Further, when the incident light intensity of the reflective liquid crystal display element is high and a part of the light transmitted through the dielectric multilayer film mirror excites the photoconductive layer, a non-conductive film is formed between the dielectric multilayer film mirror and the photoconductive layer. It is preferable to form a light-absorbing layer having a positive polarity.

When such an optical writing type spatial light modulator is used as a reflection type liquid crystal display element, it is necessary to introduce light from the photoconductive layer side as an optical writing means.
Normally, a CRT, a transmissive liquid crystal display device (LCD), or the like is used for image input.

The image produced by the CRT or LCD may be imaged on the photoconductive layer surface using a lens. Also,
For downsizing, a fiber array plate (FAP) may be used as the face plate of the image generating element and the back electrode substrate of the spatial light modulator, and they may be coupled with a refractive index matching oil or an adhesive material. . In this case, in order to prevent the deterioration of resolution due to the joining of two FAPs, the face plate of a CRT or LCD and the back electrode substrate of the spatial light modulator are made to be a common FAP in a form in which the configuration is further simplified. preferable.

Further, in the structure of the reflection type liquid crystal optical element of FIG. 5, CTP may be used as the back electrode substrate. C
An example of a spatial light modulator using TP is, for example, “Applied Optics Vol. 31, No. 20, 199”.
2, page 3971-3979: Charge-tr
transfer-plate spatial light
t Modulator "(Charge Transfer Plate Spatial Light Modulator)
It is described in.

The CTP has a structure in which a large number of thin conductive wires are densely embedded in an insulating material substrate, and a two-dimensional charge distribution or voltage distribution formed on one surface of the CTP is transmitted to the other surface of the CTP. Have a function. A dielectric multilayer mirror can be formed on one side of the CTP and used as the back electrode substrate 333 of the reflective liquid crystal display device.

As a voltage applying method, a photoconductive material such as the above-described amorphous Si film is formed on the surface on which the dielectric multilayer film mirror is not formed, and a transparent electrode is formed on the photoconductive material to form a front electrode substrate. By applying a constant AC voltage between the electrodes of 331, a reflective spatial light modulator of optical image writing type is realized.

As another voltage applying method, an active matrix substrate may be bonded to one side of the CTP via bump bonds, or an electric gun used in a CRT and an electron lens may be combined on one side of the CTP to charge the CTP. By scanning the surface, the image information voltage may be directly applied to the liquid crystal solidified composite layer through the CTP.

When a voltage is applied to the liquid crystal solidified composite layer via CTP, the voltage is applied only to the conductive wire portion in the CTP. Therefore, when the area occupied by the conductive wire is small, the effective pixel effective surface decreases, As a result, the light utilization efficiency decreases.
In order to avoid such a problem, it is preferable to form a pixel electrode on one surface of the CTP and to fabricate a dielectric multilayer mirror on it. With this configuration,
Since the voltage applied from the opposite side of the CTP is applied to the pixel electrode via the conductor of the CTP, if a large occupied area of the pixel electrode is secured, the light utilization efficiency does not decrease.

The front electrode substrate 331 of the reflective liquid crystal optical element is
It is a transparent substrate made of glass, plastic or the like, and a transparent electrode 335 made of In ₂ O ₃ —SnO ₂ (ITO), SnO ₂ or the like is formed on the inner surface thereof, and is usually a solid electrode. Further, when the front electrode substrate 331 has a surface in contact with air, it is preferable to reduce the regular reflection component by forming an antireflection film 334 on the interface.

In the reflective liquid crystal optical element, the front electrode substrate
When the transparent electrode interface of 331 and the reflective function layer are parallel,
Since the regular reflection of incident light generated at the interface of the transparent electrode is superimposed on the light reflected by the reflective functional layer, the black level of the projected light does not have a small value, and as a result, only a low contrast ratio is obtained.

As one of the measures for improving the deterioration of the contrast ratio due to the regular reflection at the front electrode interface, it is effective to make the front electrode interface and the reflective functional layer non-parallel. Specifically, as shown in FIG.
The irregularities are formed on the interface of (1) to diffusely reflect the light, and the light is blocked by the second aperture stop of the scattered light removing system so that it does not reach the screen. Further, it also has a function of alleviating the hysteresis phenomenon of the applied voltage vs. transmission characteristic (VT curve) peculiar to the liquid crystal solidified substance composite.

As the shape of the fine irregularities formed for such a purpose, a sawtooth shape constituted by a small number of flat surfaces and an inclined surface is preferable instead of a rectangular shape having many flat surfaces. Examples of the method for producing the fine unevenness include polishing using fine particles, sandblasting for spraying the fine particles, corrosion method (etching) by chemicals, fusion of silica particles, and the like.

The polishing method is suitable for uniformly forming a fine uneven surface having a high light diffusion property on the entire surface of the substrate, but fine unevenness is formed only on the operating surface of the front electrode substrate of the liquid crystal optical element. When the surface is a transparent flat surface, the sandblast method is suitable. In particular, when the liquid crystal optical element is a display element composed of pixel electrodes and patterning of a light-shielding film such as a black matrix is required on the front electrode substrate and alignment with the pixel on the back electrode substrate side is required, Except for the display surface, a transparent flat surface is preferably used for easy alignment. Further, it is preferable that the sealing portion also has a flat surface in order to prevent mixing of bubbles and the like.

Alternatively, as shown in FIG. 9, SiO ₂ , TiO ₂ , and ZrO having different refractive indexes from the surface transparent electrode film 435.
A multilayer antireflection film in which a single layer of an inorganic substance such as ₂ , MgF ₂ , Al ₂ O ₃ , CeF ₃ or an organic substance such as polyimide or a multilayer interference dielectric film 434 is combined may be used.

As another measure, as shown in FIG. 10, a substrate 438, which is a reflection means having a reflection function layer 437, is separately installed behind the transmissive liquid crystal optical element, and the transmissive liquid crystal optical element has a reflective function. The layer 437 is tilted so that the light reflected at the interface of the transmissive liquid crystal optical element is blocked by the aperture stop of the scattered light removing system and does not reach the screen.

In particular, in the case of a display element in which the reflection type liquid crystal optical element is composed of pixels smaller than the thickness of the back electrode substrate, the back electrode substrate and the liquid crystal solidified compound composite are provided so as not to deteriorate the resolution. In order to form a reflective function layer between the
Alternatively, it is preferable to reduce the interface regular reflection by using a multilayer antireflection film having ITO as a constituent element.

In the projection type liquid crystal optical device of FIGS. 1 and 2, the divergent light emitted from the light source system 1 is a color separation / synthesis optical system.
2 (2 flat plate type dichroic mirrors) and the reflective liquid crystal optical elements 31A, 32A, 33A are arranged between the reflective liquid crystal optical elements 31A, 32A, 33A so that the light is almost collimated. , 32A, 33A, the reflected light is again collected by the same condenser lenses 31B, 32B, 33B, and an image conjugate with the aperture 13 near the second focus of the elliptical mirror is formed near the second focus of the elliptic mirror. It is generated so that it does not overlap the opening position.

For these three condenser lenses 31B, 32B and 33B, a plano-convex spherical lens is usually used, and it is preferable that the convex surface faces the reflection type liquid crystal optical element as a structure for reducing aberrations.
However, in this case, surface reflection occurs at both surfaces of the lens and at the interface of the reflective liquid crystal optical element with air on the light incident side, and therefore it is preferable to form an antireflection film on these surfaces.

Also, these three plano-convex lenses 31B, 32B, 33B
When the plane of is arranged to face the reflective liquid crystal optical element,
By bonding the lens and the reflective liquid crystal optical element with an optical adhesive or a refractive index matching oil, reflection at the two interfaces can be greatly reduced. In this case, a reflective liquid crystal optical element
It is not necessary to form an antireflection film on the interfaces of 31A, 32A, and 33A with air, and it is sufficient to form the antireflection film only on the convex surface of the lens. 1 and 2 show the case of such a configuration.

In the projection type liquid crystal optical device of the present invention, another structure relating to the reflection type liquid crystal optical element is shown in FIGS. That is, the electrodes of the front electrode substrate 531 and the back electrode substrate 533 that sandwich the liquid crystal solidified composite compound are transparent electrodes, and the reflective light-collecting function layer 537 is provided on the side of the back electrode substrate 533 where the transparent electrode is not formed. As a result, it is a reflective liquid crystal optical element that integrates both the action of focusing and the action of reflection. In this case,
Therefore, the condenser lenses 31B, 32B and 33B in FIG. 2 are not necessary. This reflective type light collecting functional layer is collectively called a light collecting reflecting means.

The reflective condensing functional layer is provided by forming the reflective functional layer on a non-planar surface such as a spherical surface or an ellipsoidal surface. In the case of a spherical mirror, if the aperture stop of the light source optical system is installed near the center of the spherical body, the incident light will be reflected by the spherical mirror and then the aperture of the light source optical system will be located near the center of the spherical body. It is condensed as a conjugate image of the diaphragm. In the case of an ellipsoidal mirror, if the aperture stop of the light source optical system is installed near the first focal point of the ellipsoid, the incident light is reflected by the ellipsoidal mirror and then near the second focal point of the ellipsoid. It is condensed as a conjugate image of the aperture stop.

Here, for the transmissive liquid crystal optical element consisting of the front electrode substrate and the back electrode substrate sandwiching the liquid crystal solidified composite, the above-mentioned condensing mirror has the back electrode substrate 533 as shown in FIG.
May be integrated with each other, or may be separated as shown in FIG. In the case of integration, a reflection function layer may be formed on the convex surface of the plano-convex lens and the transparent electrode 536 may be formed on the plane to form the back electrode substrate 533, or a plano-convex reflection in which a reflecting mirror is formed on the convex surface of the plano-convex lens. A mirror may be bonded to the transmissive liquid crystal optical element.

As shown in FIG. 12, the integrated type has a smaller interface reflection than the separated type, which is advantageous in light utilization efficiency and contrast ratio. Further, it is preferable to form an antireflection film on the interface with the air other than the reflective layer. In the case of the display element in which the transparent electrode of the reflective liquid crystal optical element shown in FIGS. 11 and 12 is composed of pixels, the liquid crystal solidified composite layer 532 as the light modulation layer and the condensing reflective functional layer 537 are provided. If they are separated by more than the pixel length, a double image occurs in the projected image, which is not preferable.

Therefore, in such a case, it is necessary to shorten the distance between the liquid crystal solidified composite layer 532 and the reflective functional layer 537 by forming the reflecting surface into a Fresnel lens shape or the like. In the projection type liquid crystal optical device using the reflection type liquid crystal optical element shown in FIGS. 11 and 12, the other components are the same as in FIG.
Is the same as in FIG.

The operation of the projection type color liquid crystal optical device of the present invention will be described using a liquid crystal optical element sandwiching a liquid crystal solidified composite in a scattering state in the absence of applied voltage. In the transmissive portion of the reflective liquid crystal optical element, light is transmitted, reflected by the reflective film, and returned (regular reflection) to be emitted. Since this straight light is the light that passes through the device that reduces the diffused light,
Brightly displayed on the projection screen.

On the other hand, in the scattered portion, the light is scattered and emitted as diffused light. Most of this light will not be able to pass through the device that attenuates the diffuse light, so it will appear dark on the projection screen. In the scattering state part of the reflective liquid crystal optical element of the present invention, the scattered light reaching the back side is reflected and passes through the scattering part again, and is further scattered, resulting in high scattering in the thin liquid crystal solidified composite layer. Noh is obtained. Further, when the transmission type liquid crystal optical element is made to have the same scattering ability, the liquid crystal solidified composite layer can be made thin, so that the driving voltage can be reduced.

In the present invention, the liquid crystal solidified substance composite is composed of a solidified substance matrix in which a large number of fine pores are formed and a liquid crystal filled in the pores thereof, and either when a voltage is applied or when no voltage is applied. In that state, the refractive index of the solidified matrix is made to substantially match the refractive index of the liquid crystal used. In this case, it is preferable to use a liquid crystal solidified substance composite in which the refractive index anisotropy Δn of the liquid crystal used is 0.18 or more. In particular, it is preferable to use a nematic liquid crystal having a positive dielectric anisotropy so that the refractive index of the solidified matrix thereof substantially matches the ordinary refractive index (n _o ) of the liquid crystal used.

The liquid crystal solidified composite is sandwiched between the front electrode substrate and the back electrode substrate, and the liquid crystal solidified composite is sandwiched between the back electrode substrate and the liquid crystal solidified composite or on the side where the electrode surface of the back electrode substrate is not formed. A reflective liquid crystal optical element provided with a reflective function layer. The refractive index of the liquid crystal changes depending on the applied state of the voltage between the electrodes of this reflective liquid crystal optical element, and the relationship between the refractive index of the solidified matrix and the refractive index of the liquid crystal changes, and When they coincide with each other, they are in a transmissive state (regular reflection and light is emitted), and when they have different refractive indices, they are in a scattering state (diffused light is emitted).

The liquid crystal solidified substance composite comprising the solidified substance matrix having a large number of fine pores formed therein and the liquid crystal filled in the pores is as if liquid crystals were enclosed in liquid bubbles such as microcapsules. Although it is a structure, individual microcapsules do not have to be completely independent, and liquid bubbles of individual liquid crystals may communicate with each other through a slit like a porous body.

The liquid crystal solidified substance composite provided in the reflection type liquid crystal optical element used in the present invention is prepared by mixing the liquid crystal and the curable compound constituting the solidified substance matrix into a solution form or a latex form. , Light cure, heat cure,
The solidified material matrix may be separated by curing by removing the solvent, reaction hardening, or the like so that the liquid crystal is dispersed in the solidified material matrix.

This curable compound is preferably a photocurable or thermosetting type because it can be cured in a closed system. In particular, the use of a photocurable curable compound is preferable because it can be cured in a short time without being affected by heat. As a specific manufacturing method, a cell is formed using a sealing material as in a conventional normal TN type liquid crystal optical element, and an uncured mixture of liquid crystal and a curable compound is injected through an injection port, and the injection port is opened. After sealing, it can be cured by irradiation with light or heating.

In the case of a reflective liquid crystal optical element according to the present invention, a sealant is not used, and, for example, a liquid crystal and a curable compound are provided on one of the front electrode substrate and the back electrode substrate. It is also possible to supply an uncured mixture, then stack the other electrode substrate and cure it by light irradiation or the like.

Of course, thereafter, a sealing material may be applied to the periphery to seal the periphery. According to this manufacturing method, the uncured mixture of the liquid crystal and the curable compound may be simply supplied by roll coating, spin coating, printing, coating with a dispenser, etc., so that the injection step is simple and the productivity is extremely high. Good.

The uncured mixture of the liquid crystal and the curable compound contains ceramic particles for controlling the substrate gap, plastic particles, spacers such as glass fibers, pigments, dyes, viscosity modifiers, and other materials for the performance of the present invention. You may add the additive which does not have a bad influence. By fixing the element, which is in a scattering state when no voltage is applied, in a state where a sufficiently high voltage is applied only to a specific part during this curing step, that part can be kept in a light transmitting state at all times. If there is something to be displayed, such a normal transmission part may be formed. Conversely, in the case of an element that is in a transmissive state when no voltage is applied, the ordinary scattering portion can be similarly formed.

The higher the transmittance in the transmissive state of the reflection type liquid crystal display element using this liquid crystal solidified composite, the better, and the haze value in the scattered state is preferably 80% or more. In the present invention, the refractive index of the solidified material matrix (after curing) is the same as the refractive index of the liquid crystal used in either the voltage applied state or the non-voltage applied state, and in the opposite state, the solidified material matrix has a refractive index. , So that it does not match the refractive index of the liquid crystal used. As a result, light is transmitted when the refractive index of the solidified material matrix and the refractive index of the liquid crystal match, and light is scattered (cloudy) when they do not match. The scattering property of this element is higher than that of the conventional DSM reflective liquid crystal display element, and a display with a high contrast ratio can be obtained.

[0151] In the present invention, particularly, in a voltage applied state, the refractive index of the solidified matrix (after curing) is preferably made to coincide with the liquid crystal n _o used. As a result, since a transmissive state is achieved when a voltage is applied, the transmissivity at the time of transmitting light is increased and the light is uniformly transmitted, so that the display contrast ratio is improved.

The liquid crystal dispersed and held in the solidified matrix is preferably independent particles or particles in which some of them are connected. This is effective in achieving both high scattering power and high transparency when driven at a low voltage. Scattering is caused by the presence of an interface between the liquid crystal and the solidified matrix.

Therefore, the larger the area of this interface, the better the scattering property. In order to increase the area of this interface with a certain optimum liquid crystal particle diameter, the amount of liquid crystal separated from the solidified matrix material such as resin is independently increased. That is,
It is important to increase the liquid crystal particle density.

However, when the amount of liquid crystals separated from the solidified matrix is increased, the respective liquid crystal particles come into communication with each other, and further, the liquid crystal comes to have a structure in which all the liquid crystals are in communication with each other. The loss of the liquid crystal interface separated from the matrix leads to a decrease in the scattering ability.

Refractive index anisotropy Δn (= n _{e of} the liquid crystal used)
-N _o) is the contribution to scattering, obtain a high scattering property,
It is preferable that it is larger than a certain level, specifically, Δn ≧
0.18 is preferable, and Δn ≧ 0.20 is more preferable. Furthermore, the range of 0.25 ≧ Δn ≧ 0.21 is preferable. Moreover, the range of 13 ≧ Δε ≧ 5 is preferable. Furthermore, the range of 11.6 ≧ Δε ≧ 5 is preferable. Further, n _o of the liquid crystal used is preferably set to substantially match the refractive index of the solidified matrix (n _p), high transparency when an electric field is applied to obtain the time. More specifically, n _o -0.03 <n _p
<It is preferable to satisfy the relationship of n _o +0.05.

Further, in order to improve the scattering property, it is effective to increase the volume fraction Φ of the operable liquid crystal of the liquid crystal solidified composite, and Φ> 20% is preferable, and the higher scattering property is obtained. Φ> 35% is preferred, and Φ> 4
5% is preferable. On the other hand, if Φ is too large, the structural stability of the liquid crystal-solidified composite deteriorates, so Φ <70% is preferable.

In the liquid crystal solidified substance composite of the reflective liquid crystal optical element according to the present invention, the liquid crystal molecules are aligned under the influence of the solidified substance matrix wall surface when no voltage is applied.
Not arranged in a fixed direction. Therefore, when the refractive indexes of the two are different in this state, a scattering state (that is, a cloudy state) is shown.

Such a reflection type liquid crystal optical element which shows a scattering state when no voltage is applied is a display element having a pixel electrode, and when this is used as a projection type display device, light is scattered in a portion having no electrode. Even if the light shielding film is not provided on the portion other than the pixel portion of the back electrode, the light does not reach the projection screen, and thus appears black. As a result, in order to prevent light from leaking from the portion other than the pixel, it is not necessary to shield the portion other than the pixel with a light shielding film or the like, and there is also an advantage that the step of forming the light shielding film is unnecessary.

When the wiring electrode of the pixel is formed, a weak electric field is generated in the liquid crystal solidified composite layer between itself and the counter electrode, and incident light passes through the liquid crystal solidified composite layer,
There may be a case where black display is not performed due to reflection by the wiring electrode. As a countermeasure, a light shielding film may be formed on the back electrode substrate or the front electrode substrate corresponding to the wiring electrode position. In particular, when the definition of the display surface pixel is improved and the area occupied by the pixel electrode portion is reduced, the component that is superimposed on the projected light by the reflected light from the liquid crystal solidified composite layer other than the pixel electrode portion is increased, This causes a decrease in contrast ratio. In this case, the light shielding film may be a metal film such as aluminum or chromium, or may be a light absorbing substance.

In the case of the chromium light-shielding film on the front electrode substrate, since it has a high reflectance at the interface between glass and chromium, the regular reflection light is projected on the screen and the contrast ratio is significantly deteriorated. Therefore, in order to reduce this interface reflection, it is preferable to form an antireflection film of chromium oxide or the like between the chromium light shielding film and the glass. Further, in order to reduce the internal reflection light on the liquid crystal solidified composite layer side, an antireflection film combined with chromium oxide or a transparent electrode may be formed on the chromium light shielding film on the liquid crystal solidified composite layer side. On the other hand, on the other hand, in the case of a light-shielding film using a light-absorbing substance such as a black photosensitive polymer, the interface reflection can be ignored and the influence of reflected light can be ignored.

When a light-shielding film is formed on the front electrode substrate side, as a measure for maintaining the light-shielding property and efficiently reducing the interface reflection projection light reaching the screen, as shown in FIG. It is preferable to form fine concavities and convexities on the front electrode surface of the electrode substrate and to fabricate the light shielding film thereon. With such a configuration, even if the interface reflected light exists, the regular reflected light that reaches the screen is significantly reduced and removed by the scattered light removing system, so that a high contrast ratio can be maintained.

On the other hand, when the metal light-shielding film is formed on the back electrode substrate side, it is preferable that the electric potential of the wiring electrode portion is shielded by setting the potential thereof to the same level as that of the front electrode substrate.

A voltage is applied between electrodes of desired pixels of this liquid crystal display element. In the pixel part where this voltage is applied,
Liquid crystal is arranged in parallel to the electric field direction, shows the transmission state by the liquid crystal n _o and n _p of solidified matrix coincide, becomes the light in the desired pixel is transmitted, it is displayed brightly on a projection screen It

By curing such an element in such a state that a sufficiently high voltage is applied only to a specific portion during this curing step, that portion can be kept in a light transmitting state at all. If desired, such a normally permeable portion may be formed.

In the present invention, when the back electrode of the reflective liquid crystal optical element is patterned as a pixel electrode and a TFT is used as an active element for each pixel electrode, Si may be suitable as the semiconductor material. In particular, polycrystalline Si is amorphous Si
As described above, since the photosensitivity is low, malfunction does not occur even if the light from the light source is not strictly shielded by the light shielding film, which is preferable. When this polycrystalline Si is used as a projection type liquid crystal optical device as in the present invention, a strong projection light source can be used and a bright display can be obtained.

Further, in the case of the conventional TN liquid crystal optical element, a light-shielding film is often formed between pixels in order to suppress light leakage from between pixels. At the same time, a light-shielding film can be simultaneously formed on the active element portion, and forming the light-shielding film on the active element portion does not significantly affect the entire process. That is, even if polycrystalline Si is used as the active element and the light shielding film is not formed in the active element portion, the number of steps cannot be reduced if the light shielding film needs to be formed between the pixels.

On the other hand, in the present invention, as described above,
By using the solidified matrix liquid crystal and solidified matrix composite that is adapted to substantially match the liquid crystal n _o of refractive index use, on a projection screen that is projected light is scattered at the portion where no voltage is applied Since it becomes black, it is not necessary to form a light shielding film between pixels.

When a dielectric multilayer film is used as the reflection function layer, the optical performance is determined by the material, the number of layers and the film thickness. However, if the thickness becomes thicker, the voltage drop there becomes larger and the driving efficiency of the liquid crystal deteriorates. For example SiO ₂
The reflectance of a 1.5 μm-thick multilayer film including a film and a TiO ₂ film is about 99%, and the remaining 1% is leakage light. At this time, the voltage drop is about 0.5 to 0.6 V although there are other factors. By doubling the number of layers with the same material, it is theoretically possible to achieve a reflectance of 99.99%.

In addition, the high refractive index of a light absorbing material in the visible wavelength range
Si film and SiO ₂ Form a multi-layered film
By doing so, the reflectance does not reach 99%, but a thin film
With a thickness of less than 0.01%, a reflective film and a light-shielding film are produced.
You can have Alternatively, Si on the TFT
O₂ After forming a multi-layer film of Si film and Si film, SiO₂ Membrane and T
iO₂ By forming a multi-layered film, 99% or more
Has a light-shielding property with a transmittance of 0.01% or less.
It is also possible.

The reflectance is not uniquely determined, but
When used as a projection type liquid crystal optical device, the desired screen light amount and the light intensity of the light source to be used are related, and thus the combination may be made in an optimum combination. Polycrystalline S as active element
When i is used, since polycrystalline Si has relatively low photosensitivity, malfunction due to light is unlikely to occur. For this reason, the strictness of the light-shielding property is not required even if the light-shielding film is not formed in the active element portion, so that the step of forming the light-shielding film can be eliminated or simplified, and the productivity is improved.

Even if amorphous Si, which has a higher photosensitivity than polycrystalline Si, is used, a light-shielding film is formed on the semiconductor portion thereof, and the dielectric multilayer film is used as a reflective function layer to form the back electrode substrate and the liquid crystal solidified composite. And a small amount of light leaking from the dielectric multilayer film (for example, the reflectance is 99 to 99.95%).
In case of), it can be used.

Regardless of whether polycrystalline Si or amorphous Si is used as the active element, by forming a dielectric multilayer reflection function layer on the surface of the back electrode substrate on which the pixel electrode and the active element are formed, incident light In most cases, the amount of light reflected by the multilayer film and incident on the active element is small, and it can be said that the dielectric multilayer film itself functions as a light-shielding film and has a light-shielding effect.

When stray light generated by light incident on a surface other than the operating surface of the liquid crystal optical element and scattered light by the liquid crystal solidified composite layer is projected on the screen, the contrast ratio is deteriorated or a ghost image or a bright spot is generated. Cause. In order to reduce such stray light, the area other than the operation surface of the liquid crystal optical element and the areas that do not interfere with the optical path of the projected light in the various optical elements and the housing such as the holder that configure the projection type liquid crystal optical device are selected. It is preferable to carry out light absorbing black processing.

Specifically, black paint is applied to the glass surface area around the operating surface of the front electrode substrate of the liquid crystal optical element and the substrate side surface. Also, black paint is applied to the side surface and the back surface of the back electrode substrate. Furthermore, it is preferable to apply a black paint to the area that does not interfere with the projected light even in the optical elements such as the condenser lens, the condenser reflection means, and the dichroic mirror.

Next, the structure inside the cell of the liquid crystal optical element will be described. In the present invention, it is preferable to use a photocurable compound as the uncured curable compound that constitutes the above-mentioned liquid crystal solidified composite, and it is particularly preferable to use a photocurable vinyl compound. Specifically, a photocurable acrylic compound is exemplified. Particularly, those containing an acrylic oligomer which is polymerized and cured by light irradiation are preferable.

[0176] The liquid crystal used in the present invention may be a nematic liquid crystal, the liquid crystal such as refractive index of the solidified matrix agrees with the liquid crystal n _o is preferred. This liquid crystal
Although it may be used alone or as a composition, it can be said that it is advantageous to use the composition in order to satisfy various performance requirements such as operating temperature range and operating voltage.

In the case of using a photocurable compound, the liquid crystal used in the liquid crystal solidified substance complex preferably dissolves the photocurable compound uniformly, and the cured product after photoexposure does not dissolve. Alternatively, it is preferably made difficult to dissolve. Further, when the composition is used, it is preferable that the solubility of each liquid crystal is as close as possible.

In the case of producing a liquid crystal solidified composite, the substrate and the counter electrode substrate are arranged so that their electrode surfaces face each other like a conventional ordinary liquid crystal optical element, and the periphery is sealed with a sealing material, The uncured liquid mixture for liquid crystal solidified composite may be injected from the injection port to seal the injection port, or the uncured mixture of the curable compound and the liquid crystal is supplied on one electrode substrate. Alternatively, the other electrode substrate may be laminated to manufacture.

In the liquid crystal optical element of the present invention, a dichroic dye, a simple dye or a pigment may be added to the liquid crystal, or a colored curable compound may be used. In the present invention, using a liquid crystal as a solvent as a liquid crystal solidified composite,
By curing the photocurable compound by light exposure,
There is no need to evaporate a simple solvent or water that is unnecessary during curing. Therefore, since it can be cured in a closed system, the conventional manufacturing method of injecting into a cell can be adopted as it is, it is highly reliable, and it also has the effect of adhering two substrates with a photocurable compound. Will be more likely.

By thus forming the liquid crystal solidified substance composite, there is a low risk of the upper and lower electrodes being short-circuited, and it is not necessary to strictly control the alignment and the substrate gap as in a normal TN liquid crystal optical element. A liquid crystal optical element capable of controlling the transmission state and the scattering state can be manufactured with extremely high productivity. The ratio of the straight-ahead component and the scattered component that reach the projection screen can be controlled by the diameter of the spot, mirror, etc., which is a device that reduces diffused light, and the focal length of the lens to obtain the desired display contrast and display brightness. It can be set so that

When a device for reducing diffused light such as an aperture is used, it is preferable that the light incident on the liquid crystal optical element from the light source for projection is more parallel in order to increase the brightness of the display. It is preferable to configure a light source optical system by combining a light source having a brightness and as close as possible to a point light source, a concave mirror, a condenser lens, and the like. For this purpose, by using a light source having high directivity such as laser light, it is possible to obtain more parallel light, which is effective in obtaining a high contrast ratio.

Further, a heat sink, a temperature controller such as a heater or a Peltier element is installed on the surface of the back electrode substrate together with a thermometer, and is used in combination with a cooling fan to use the liquid crystal and solidified substance composite in its optimum operating temperature range. The temperature can be adjusted.

In the projection type color liquid crystal optical device of the present invention, the light from the light source for projection is separated into three colors by the two types of flat plate type dichroic mirrors and is made incident on the three reflection type liquid crystal optical elements. It suffices if the reflected and emitted light is color-synthesized by the same two types of flat plate type dichroic mirrors and then projected. Therefore, it includes not only a color display device that projects an image on a large-sized projection screen but also a reflective light modulator and a lighting device.

[0184]

In the present invention, since a liquid crystal solidified substance composite is used as a reflection type liquid crystal optical element, high scattering characteristics can be obtained even with a thin liquid crystal solidified substance composite, and a high contrast ratio is obtained as a characteristic of the element itself. Is obtained.

Further, the dichroic mirror for color separation / synthesis is composed of two types of two plate type dichroic mirrors,
Two dichroic mirror surfaces are sequentially arranged without intersecting each other so that the angles α1 and α2 formed by the optical axis of the optical system and the perpendicular of the dichroic mirror surface are 20 ° to 35 °. Since the arrangement is such that the angle β is 40 ° to 70 °, the dichroic mirror has excellent spectral characteristics for color separation / combination, and the color separation / combination system can be miniaturized.

Further, the arrangement of the above-mentioned respective components makes it possible to miniaturize the optical system including the light source system, the color separation / synthesis system, and the reflection type liquid crystal display element. Further, a projection lens having a diaphragm corresponding to the size of the aperture image at a position where the light reflected by the reflective liquid crystal optical element is condensed and an image conjugate with the aperture at the second focal point of the elliptic mirror is generated. By using, the miniaturization of the entire projection type color liquid crystal optical device is achieved.

Further, by making the aperture stop at the second focus position of the elliptic mirror and the aperture stop of the projection lens variable in conjunction with each other, the brightness and contrast ratio of the projection light on the screen can be adjusted according to the ambient brightness. It can be adjusted and the visibility is improved.

Further, the two types of dichroic mirrors have different spectral transmittances in the in-plane position so as to reduce the difference in the spectral transmittance corresponding to the difference in the light incident angle at the in-plane position. Since the cone-shaped prism or the cone-shaped reflector has a distribution and is arranged in the vicinity of the aperture stop arranged at the second focus position of the elliptic mirror in the light source system for projection, the surface of the screen projection light is A projection type liquid crystal optical device having excellent uniformity of internal light intensity distribution and color distribution can be obtained.

The reflective function layer of the reflective liquid crystal optical element is a dielectric layer formed by laminating a translucent dielectric thin film having a relatively high refractive index and a translucent dielectric thin film having a relatively low refractive index. Since the reflection film formed of the body multilayer film is used, an optical reflection surface having good flatness can be obtained and high reflectance can be obtained as compared with the reflection film formed of a metal film, and as a result, a high contrast ratio can be obtained.

Further, since the spectral reflectance can be arbitrarily adjusted according to the structure of the reflection film formed of the dielectric multilayer film and has the wavelength selective reflection property, the reflection type optical filter similar to the light absorption type color filter is used. The effect of is obtained. In particular, a dichroic mirror for color separation / synthesis is provided between the light source optical system and the reflection type liquid crystal optical element, and the color separation lights are incident on three different reflection type liquid crystal optical elements, and the plurality of liquid crystal optical elements At least one of the reflective functional layers of the above is a reflection type liquid crystal having high color purity and light utilization rate by having a spectral reflectance having wavelength selective reflectivity that compensates for the decrease in color purity due to the dichroic mirror for color separation and synthesis. An optical element is obtained.

Further, as the back electrode substrate of the reflection type liquid crystal optical element, CTP which is a structure in which a large number of thin conductive wires are densely embedded in an insulating material substrate is used, and the reflection surface is composed of CTP and a liquid crystal solidified composite. The reflection type light modulation element portion and the electric field applying element portion are formed by the CTP.
And a structure in which they are separated and coupled via a photoconductor, and in particular, an optical writing means or a CR using a photoconductor as an electric field applying means for image information
A projection type liquid crystal display device using a charge writing means or the like using T can be obtained.

[0192]

【Example】

(Embodiment 1) Next, an embodiment of the present invention will be described with reference to the drawings. The structure of the reflective liquid crystal display cell of this example is shown in FIG. Glass substrate (Corning "705
9 ") IT patterned as pixels on one surface
Three transparent back electrode substrates were prepared in which an O transparent electrode 636 was provided, and a polycrystalline silicon TFT 639 was arranged on the back electrode 636 for each pixel.

Further, on each of the back electrode substrates, SiO ₂ having a refractive index of 1.45 and TiO ₂ having a refractive index of 2.35 are alternately arranged to have respective optical film thicknesses nd = λ / 4 (λ: wavelength in each RGB). 20 layers are laminated with a reflectance of 99 in each of the RGB wavelength bands.
A back electrode substrate 633 was prepared by forming a reflective film of a dielectric multilayer film 637 with a percentage of not less than 100% on the entire display surface by a vacuum deposition method.

Of the incident light, TF is transmitted through the dielectric multilayer film.
A light-shielding film 640 was formed on the dielectric multilayer film at a position corresponding to the TFT of each pixel on the back electrode substrate in order to completely block the leakage light incident on T and suppress the deterioration of the image quality due to the photosensitivity of the TFT. . The light-shielding film used here is not a Cr metal film which is usually used by forming a film on a front electrode substrate in a transmissive active matrix liquid crystal display element, but a black and electrically insulating film in which fine carbon particles are dispersed in a photosensitive polymer. Highly sensitive photosensitive polymer (Fuji Hunt Electronics Technology Co., Ltd .: CK-2000) was used.

In this case, if a metal film is used for the light-shielding film, T
Since the dielectric multi-layer film mirror interposed between the FT and the metal film acts as a capacitor, the characteristics of the TFT are deteriorated. Further, in the case of the reflective type, the incident light is reflected by the reflection on the metal surface, so that the TFT portion is not shielded from light corresponding to black.

On the other hand, one surface of the glass substrate is formed with fine irregularities to the extent that regular reflected light is reduced and transmitted light is not extremely reduced, and an ITO transparent electrode 635 is further formed thereon.
The front electrode substrate 631 was used. Peripheral portions of the back electrode substrate 633 and the front electrode substrate 631 were sealed with a sealing material to fabricate three RGB reflective cells.

The cell shape is a diagonal of 4.4 inches, the number of pixels is 480 vertical × 640 horizontal, and each pixel size is 140 μm × 1.
It was 40 μm. Also, in this reflective cell,
Since it is not necessary to form the light-shielding film required on the conventional TN liquid crystal optical element on the front electrode substrate, the aperture ratio of the pixel is as high as 58% in the state of the transmissive cell before forming the reflective film. Shows. Further, it is also possible to form a TFT cell having a diagonal dimension, a vertical and horizontal dimension larger than that, or a pixel density higher than that.

Further, by forming a reflection film of a dielectric multilayer film to form a reflection type cell, the storage capacitor portion can also be used as an opening portion, so that a large value of 67% was obtained. Conventional transmissive TN with the same TFT configuration
In the case of using the type liquid crystal optical element, the aperture ratio was as low as 40% due to the formation of the light shielding film.

A solution in which a nematic liquid crystal having Δn of about 0.24 and Δε of about 16 was uniformly dissolved in the above cell with an acrylate monomer, a bifunctional urethane acrylate oligomer and a photo-curing initiator was injected into the cell and exposed to ultraviolet light. The liquid crystal-solidified composite was cured by, and three reflective liquid crystal display cells having a liquid crystal content of 68 wt% were produced.

When the applied voltage that gives a transmittance of 90% of the saturated transmittance is defined as a drive voltage, the drive voltage of each of these reflection type liquid crystal optical elements was 6V. Further, black paint 641 for absorbing light was applied to the surface of the back electrode substrate of the reflective liquid crystal optical element to reduce back reflection of transmitted light. Then, a heat sink with a built-in heater, to which a thermocouple for temperature measurement was attached, was adhered from above, and an air-cooling fan was provided behind it. In the actual projection display state, while monitoring the temperature of this thermocouple, the temperature of each reflective liquid crystal optical element is 35 ° C ±
The heater was forcibly heated and air-cooled so that the temperature was kept in the range of 5 ° C.

As shown in FIGS. 1 and 2, these three RGB reflective liquid crystal display elements 31A, 32A, and 33A have front electrode substrates on which plano-convex spherical lenses 31B and 32B having a focal length of 180 mm are provided.
The plane side of 33B was joined with an optical adhesive to form reflection type liquid crystal display element blocks 31, 32 and 33. An antireflection film corresponding to each wavelength band is formed on the convex surface of the lens, and the reflectance is suppressed to 0.1% or less.

Next, the reflection type liquid crystal display element block 3
1, 32, and 33 are the light source system 1 of FIG. 1 and FIG.
A projection type color liquid crystal optical device was constructed in combination with a projection type device equipped with a projection lens system 4. Projection light source optical system
1, the light source 11 uses a metal halide lamp with a power of 250 W and an arc length of 5 mm, and an elliptical mirror with a cold mirror 12
It was collected at. The light emitting portion of the light source 11 is arranged near the first focal point of the elliptic mirror, and the conical prism 14 is arranged near the second focal point of the elliptic mirror.

The cone-shaped prism is oriented so that the light is incident from the bottom surface and the light is emitted to the apex angle side. After processing and polishing the optical glass so that the apex angle is 120 °, the antireflection film is formed on the surface. Was formed. Further, an aperture stop 13 having a variable aperture diameter was installed on the light emitting side of the cone-shaped prism.

In the optical system, if the bisecting axis of the optical axis of the incident light to the reflective liquid crystal display element and the optical axis of the reflected light from the reflective liquid crystal display element is defined as the central optical axis 5, color separation / combination is performed. The two types of two plate type dichroic mirrors 21 and 22 which are means are arranged such that the angle formed by the normal line and the central optical axis 5 is 30 °, and the angle β formed by the two mirror surfaces is Are sequentially arranged so that the angle becomes 60 ° without crossing.

Further, the reflective liquid crystal display element was arranged so that the angle γ formed by the perpendicular of the reflective surface and the optical axes of the incident light and the reflected light was 6 °. Further, the plane defined by the optical axis of the incident light and the optical axis of the reflected light on the reflection surface of the reflective liquid crystal optical element and the plane defined by the normal line of the two dichroic mirrors were arranged so as to be orthogonal to each other.

In the projection type color liquid crystal optical device of this embodiment, in FIG. 1 and FIG. 2, the red wavelength light R is reflected by the first flat plate dichroic mirror 21, and the blue wavelength light B is reflected by the second flat plate dichroic. It is configured so that the green wavelength light G is reflected by the mirror 22 and is transmitted. Regarding the spectral characteristics of the dichroic mirror, an edge type filter such as R reflection or B reflection has a higher degree of freedom in design than a notch type filter such as G reflection, and it is easy to improve color purity. And

The first flat plate type dichroic mirror 21 is
The second flat plate dichroic mirror 22 has a spectral characteristic of a short wavelength transmission type that reflects orange (R) having a visible wavelength of 575 nm or more in the light from the light source system and transmits other wavelength light. Of the light from the light transmitted through the first flat plate type dichroic mirror, one having a long wavelength transmission type spectral characteristic of reflecting blue (B) having a visible wavelength of 500 nm or less and transmitting other wavelength light was used. The light transmitted through the first and second flat plate type dichroic mirrors was green (G).

As shown in FIG. 1, the light emitted from the light source system 1 becomes divergent light and is emitted to the reflection type liquid crystal optical element blocks 31, 32 and 33. The angle of incidence on the dichroic mirrors 21 and 22 depends on the in-plane position.

That is, in the plan view of FIG. 1, in the first flat plate type dichroic mirror 21, the incident angle of the incident light ray becomes a value smaller than α1 toward the upper side of the dichroic mirror in the figure, and in the second flat plate type dichroic mirror 22, The lower the dichroic mirror in the figure is, the smaller the incident angle of incident light is below α2.

As described above, the film thickness distribution of the dielectric multi-layer film that determines the spectral characteristics of the dichroic mirror is set so that the spectral characteristics of the in-plane are the same even when the incident angles to the dichroic mirror are different in the plane. In the flat plate type dichroic mirror of No. 1, the film is formed so that the lower side is thicker than the upper side, and in the second flat plate type dichroic mirror, the upper side is thicker than the lower side.

Incident light and reflected light of the reflective liquid crystal optical element are
Since the plan view of FIG. 1 passes through the same projecting light path, the influence of oblique incidence is the same for incident light and reflected light, and the spectral characteristics of the dichroic mirror are effective. Further, in the side view of FIG. 2, the incident light and the reflected light of the reflective liquid crystal optical element have different incident angles, but the inclination angle of the angular dispersion center is 6 °, which is smaller than 30 ° in the plan view of FIG. , Its influence on the spectral characteristics is small. Therefore, the film thickness distribution of the dielectric multilayer film of the dichroic mirror may be formed in the in-plane direction in the plan view of FIG.

As described above, B.
The color purity of G is not a problem, but as it is, yellow (wavelength of 575 nm to 595 nm) is mixed into R, so that a highly pure red color is not obtained and the color becomes orange. In particular, when a metal halide lamp is used, a strong light emitting peak is likely to occur in this wavelength range, and the color purity is significantly deteriorated. Therefore, the reflective film made of the dielectric multilayer film of the reflective liquid crystal display element 31A for R has a short wavelength transmission type spectral characteristic that reflects visible light wavelengths of 595 nm or more and transmits light of at least 575 nm to 590 nm in total. Was used as the dichroic filter.

Incidentally, in order to correct the difference in the optical path length of the BGR due to the transmission / reflection of the dichroic mirror, the condenser lenses 31B, 32 joined to the respective reflection type liquid crystal display cells 31A, 32A, 33A.
B and 33B have different thickness. That is, for R, B
The thicker condensing lens was used in the order of G and G.

The divergent light emitted from the opening 13 near the second focus of the elliptical mirror of the light source system is color-separated into RGB by the dichroic mirrors 21 and 22 for color separation / synthesis in this way, and then each reflection type. The light is collimated by the condenser lenses 31B, 32B, 33B joined to the liquid crystal display elements 31A, 32A, 33A, and enters the reflective liquid crystal display elements 31A, 32A, 33A. The reflected light from the reflecting surface of the reflective liquid crystal display element is condensed again by the same condenser lens, and the image conjugate with the opening near the second focal point of the elliptic mirror does not overlap the opening at the second focal point position of the elliptic mirror. Generated in position.

The projection optical system is composed of a projection lens and a diffused light removing system, and the diaphragm 41, which is a device for reducing diffused light, has a structure in which its aperture diameter is variable, and the inside of the projection lens 42 is composed of a plurality of lenses. The projection optical system 4 is arranged so that the image conjugate with the aperture 13 at the second focal position of the elliptic mirror corresponds to the variable diaphragm position of the projection lens. The projection optical system 4 including the diaphragm 41 as a component projects the light onto a projection screen (not shown).

At this time, the directivity of the incident light to the reflection type liquid crystal display device is determined by the diameter Ψ of the variable aperture diaphragm 13 of the light source optical system 1 and the focal length f of the condenser lenses 31B, 32B, 33B. It can be expressed by δ1 (= 2 tan ⁻¹ (Ψ / 2f)). Further, the diameter φ of the variable aperture stop 41 for removing diffused light of the projection optical system 4 and the converging angle δ2 which is the divergence angle of the directivity of the light projected by the focal length f of the condensing lenses 31B, 32B and 33B. Determined.

Variable aperture stop 13 of light source system 1 and projection optical system
The variable second aperture stop 41 of 4 can adjust and vary the respective aperture diameters so that the divergence angle δ1 of the light flux emitted from the light source optical system and the converging angle δ2 are substantially equal. It is preferable because it does not deteriorate the contrast ratio.

By using the projection type color liquid crystal display device having such a configuration, the variable aperture stop 13 of the light source system and the variable second aperture stop 41 of the projection optical system are changed under the condition of δ1 = δ2. Then, the contrast ratio and the luminous flux on the projection screen were measured while changing the angle δ1 = δ2. The results are shown in Table 1.
Summarized in.

Table 1 shows the results of measurement using a reflective optical element in which a dielectric multilayer film was formed as a reflective surface on a transparent electrode film as the back electrode substrate, and the reflective liquid crystal optical element in which a TFT array was formed. The performance when using is obtained by optical calculation.

[0220]

[Table 1]

When the room in which the projection screen is installed is bright, the amount of light at the black level of the image increases due to the influence of ambient light. Therefore, in order to obtain a high-contrast display with good visibility, the angle δ1 (= δ2 ) Is set to about 10 ° to 12 °, and a large projected light flux is preferably set. On the other hand, when the room is dark, there is no influence of ambient light, the amount of light at the black level of the image is directly recognized, and unnecessary screen brightness becomes dazzling and reduces visibility.
It is preferable that (= δ2) is set to about 4 ° to 6 °, the contrast ratio is made high, and the black level gradation is reproduced.

By using the two variable apertures in this embodiment, it was possible to easily adjust the brightness and contrast ratio of the screen projection image according to the brightness of the surrounding environment. Further, the light amount distribution on the screen was highly uniform with 50% or more around the center and around the center, and the in-plane color distribution was also uniform.

Further, the RGB color purity of the projected image showed a color purity of CRT or higher, and the standard color purity of NTSC including the chromaticity coordinates of white was achieved.

In this embodiment, polycrystalline Si having high light resistance is used as the active matrix, but amorphous Si may be used if the light shielding film is made thick to increase the light shielding degree. Alternatively, an active matrix in which a transistor is formed for each pixel on a Si single crystal wafer may be used. In this case, the color purity of the R light cannot be improved by transmitting unnecessary light by using the filter action of the dielectric multilayer film mirror, and therefore, the light of the wavelength range of 575 nm to 590 nm is separately included in the optical path of the R light. It is necessary to provide a filter that cuts.

(Embodiment 2) In Embodiment 1, when an aluminum film is used as the back electrode and the reflection film instead of the back electrode and the reflection film, the angle δ1 (= δ2) = 6 ° and the contrast ratio is 90, the luminous flux was 600 lumens. In addition, the color purity of red was poor and it became orange. However, the yellow component (565 nm to 585 nm) is reduced by changing the film thickness configuration of the dielectric multilayer film forming the first dichroic mirror 21 to deteriorate the sharpness of the color separation spectral characteristic, and as a result, the CRT level is reduced. RGB color purity was obtained.

Reference Example 1 In Example 2, after a color filter that transmits visible light of 590 nm or more and absorbs short wavelength light is applied to the entire flat surface of the R condenser lens 31B, the reflective liquid crystal is applied. It is bonded to the display element 31A. As a result, the color purity of red is improved to that of Example 1 as compared with Example 2.

Reference Example 2 In Example 1, the light source system 1
A conical reflector 15a was used in place of the conical prism 14 of FIG. The glass block is processed and polished into a cone shape so that the apex angle θb1 is 160 °, and a cold mirror that reflects visible light and transmits infrared light is formed on the surface of the cone. Such a cone-shaped reflector is arranged near the second focal point position of the elliptic mirror 12, and the optical axis of the incident light from the elliptic mirror 12 and the optical axis of the outgoing light to the color separation / combination system 2 are six.
The light source system 1 is arranged so as to form an angle of 0 °. As a result, characteristics similar to those of the first embodiment can be obtained.

Reference Example 3 In Example 1, in order to reduce light reflected from portions other than the pixel electrode on the back electrode substrate and sufficiently shield active elements, a metal film was used instead of the electrically insulating photosensitive polymer light shielding film. Is formed on the surface of the dielectric multilayer film mirror other than the display pixel electrode, and wiring is performed so that the electrode potential thereof matches the transparent electrode potential of the front electrode substrate. 28 and 29 show enlarged views of the structure of such a reflective liquid crystal display element. 28 is a plan view, and FIG. 29 is a section line X1- of FIG.
It is sectional drawing in X2.

As a result, all the portions other than the display pixel electrode are in a scattering state corresponding to the applied voltage of 0 V, so that the display is dark and the contrast ratio is improved, and the photo-induced current is generated even with strong incident light. The deterioration of the projected image is improved. At this time, if an antireflection film is laminated on the metal film in contact with the liquid crystal solidified composite layer, the dark level of the portion other than the display pixel electrode is further lowered, and the contrast ratio is improved.

Reference Example 4 An example in which an amorphous silicon TFT active matrix is used as the reflective liquid crystal display element in Example 1 will be described below.

A reflection type T formed on one surface of a glass substrate
A cross-sectional view of the FT array is shown in FIG. First, the glass substrate
Form the gate electrode of the TFT array on 833, and
A gate insulating layer, an amorphous silicon semiconductor layer, and a protective insulating layer are deposited and patterned on this, and then a source electrode 862 and a drain electrode 836A are deposited and patterned to form a wiring. Fabricate electrodes and active devices.

A light-shielding film is formed on the back electrode substrate at a position corresponding to each TFT 839 in order to completely block the leaked light entering the TFT out of the incident light and suppress the deterioration of the image quality due to the photosensitivity of the TFT. You may. In order to obtain a reflective liquid crystal display device, SiO ₂ having a refractive index of 1.45 and a refractive index of 2.1 are formed on the back electrode substrate on which the above-mentioned TFT array is formed.
23 layers of Ta ₂ O ₅ are alternately laminated with an optical film thickness of nd = λ / 4 (λ: wavelength in each RGB), and a dielectric multilayer film having a reflectance of 98% or more in each RGB wavelength band. 837
The reflective surface is formed on the entire display surface. At this time, the total film thickness of each dielectric multilayer film 837 is about 1.6 to 2.1 μm.

Further, a contact hole 861 is formed at the position of the dielectric multilayer film 837 corresponding to the drain electrode 836A of each TFT.
After forming, the ITO is formed and patterned as the transparent pixel electrode 836B, and three reflective back electrode substrates 833 are manufactured. At this time, the drain electrode 836A formed on the back electrode substrate side and the transparent pixel electrode 836B formed on the dielectric multilayer film 837 ensure electrical continuity and the transparent pixel electrode 836B is formed.
The TFT and the wiring electrodes of most of the pixels are not located between them, and the TFTs and the wiring electrodes of most of the pixels are hidden under the transparent pixel electrode 836B.

The dielectric multilayer mirror 837 has excellent heat resistance,
Since the optical characteristics do not change even after the heating process after film formation, high reflectance can be maintained. On the other hand, in the case of an aluminum mirror, it is known that the flatness of the surface remarkably deteriorates and the effective reflectance decreases when a heating process after film formation is performed.

The film thickness of the dielectric multilayer mirror 837 is 1
Since it is as large as μm or more, even if the transparent pixel electrode is overlapped with the data wiring or the gate wiring, the overlapping capacitance is small, so that a large obstacle in driving the TFT such as a blunt electric signal waveform can be avoided. Further, as in Example 1, a light absorbing black paint 841 is applied on the back surface of the back electrode substrate in order to reduce back surface reflection of residual transmitted light.

Further, as the front electrode substrate 831, fine irregularities are formed by a sand blast method in which an abrasive is sprayed only on the portion corresponding to the display surface, and the ITO transparent electrode 83 is formed thereon.
A glass substrate was used in which the regular reflection light at the interface was reduced by depositing 5. The light-shielding property may be enhanced by forming a light-shielding film on the transparent electrode surface of the front electrode substrate 831 at a position corresponding to the portion other than the transparent pixel electrode 836B and the TFT.

Peripheral portions of the back electrode substrate 833 and the front electrode substrate 831 are sealed with a sealing material to produce three RGB reflective cells. The cell shape is a diagonal of 2.1 inches and the number of pixels is 4 vertically.
80 pixels x 640 pixels, each pixel size is about 67μm x 67
μm. Further, the pixel occupying area (aperture ratio) of the transparent pixel electrode 836B formed on the dielectric multilayer film 837 through the contact hole is as high as about 85%, which is higher than that of the conventional TN type liquid crystal optical element. A dramatically large aperture ratio can be realized.

Then, in the same manner as in Example 1, a liquid crystal solidified composite is injected and exposed to produce three reflective liquid crystal display elements. The driving voltage of each of these reflective liquid crystal display elements is a low driving voltage of about 5.5V.

Further, as in Example 1, a black paint 841 for absorbing light was applied to the back surface of the back electrode substrate of the reflection type liquid crystal display element, and a thermocouple for temperature measurement was attached to the black paint 841 from the top of the built-in heater. The heat radiation plate is attached and an air-cooling fan is provided behind it so that the temperature of the liquid crystal display element can be adjusted.

Compared with the projection type liquid crystal display device of Example 1, the configuration of the optical system is the same except that the following components are different. 1 and 2, plano-convex spherical lenses 31B, 32B, 33
A plano-convex spherical lens with a focal length of 120 mm is used as B,
In the light source system 1, the light source 11 has a power of 150 W and an arc length of 4 mm.
Use the metal halide lamp of.

In this reference example, in order to remove the yellow color (Y: wavelength 575 nm to 595 nm) mixed in the red color (R), a colored glass filter (HOYA (stock) was used between the condenser lens 31B and the liquid crystal display element 31A. ): Wear a sharp cut filter R-60).

Using the projection type color liquid crystal display device having such a configuration, the variable aperture stop 13 of the light source system 1 and the variable second aperture stop 41 of the projection optical system are provided under the condition of δ1 = δ2. The contrast ratio and the luminous flux on the projection screen were optically calculated by changing the angle δ1 = δ2. The results are shown in Table 2.

[0243]

[Table 2]

Compared with the first embodiment, it is possible to realize high light utilization efficiency, although a small liquid crystal display element and a low power consumption lamp are used.

Reference Example 5 In the configuration of Reference Example 4, Si is used instead of the dielectric multilayer mirror 837 and the transparent pixel electrode 836B.
An N insulator layer and an aluminum reflective electrode layer are used.

As shown in FIG. 26, S is formed on the TFT array.
An iN insulator layer 837 is formed to a thickness of about 2 μm, a contact hole is formed, and then an aluminum reflective electrode layer 836B is formed to secure electrical continuity with the drain electrode 836A. After the aluminum film is formed, the surface is flattened by polishing and then patterned as a pixel electrode. The structure of this reflective liquid crystal display device is, for example, 5 of the proceedings of the 1989 IEICE Autumn National Convention.
Pp. 30, "Reflective High Density TFT Array of Liquid Crystal Projection Television for HDTV". Other configurations are the same as those in Reference Example 4.

As a result, the aluminum mirror has a lower reflectance than the dielectric multilayer film mirror, and it is difficult to obtain a flat specular reflection surface. Therefore, the light utilization efficiency and the contrast ratio are shown in Reference Example 4. The same characteristics can be obtained except that it is slightly inferior.

Reference Example 6 In Reference Example 4, after a light-shielding film (black matrix) is formed on a flat glass surface as a front electrode substrate 831, it has an antireflection effect of a three-layer structure of ITO / SiO ₂ / ITO. A transparent electrode film is formed. As a result, the same characteristics can be obtained as compared with Reference Example 4 in which the front electrode substrate having a fine uneven surface is used, except that the contrast ratio is reduced by about 30%.

Reference Example 7 In Reference Example 4, the light source system 1
A diffuser plate is used instead of the conical prism 14 of FIG. As a result, as compared with the reference example 4, the luminous flux near the center of the screen is reduced, and thus the same characteristics are obtained except that the light utilization efficiency is reduced to about half.

Reference Example 8 In Reference Example 4, the light source system 1
Instead of a single elliptic mirror, an elliptic mirror and a spherical mirror as shown in FIG. A cold mirror is formed on each reflecting surface, and the light emitting portion of the light source 11 is arranged in the vicinity of the first focal point of the elliptic mirror and is adjusted so as to substantially coincide with the center of curvature of the spherical mirror. Further, the conical prism 14 is arranged near the second focus of the elliptical mirror. as a result,
The light utilization efficiency is improved as compared with Reference Example 4.

(Comparative Example 1) Instead of the optical system of Example 1, the conventional optical system shown in FIGS. 20 and 21 having a single condenser lens and a 45 ° incidence cross type flat plate dichroic mirror as its constituent elements. In the case of using, the contrast ratio is about the same, but the screen light flux and the color purity are inferior to those in the first embodiment, and the volume of the entire optical system becomes twice or more as large as that in the first embodiment. Since the shadow corresponding to the intersection of the dichroic mirrors is projected in the center of, the light intensity distribution is not uniform.

(Comparative Example 2) In the case of using the conventional optical system shown in FIGS. 18 and 19 having a single condensing lens and a 45 ° incident dichroic prism as constituent elements instead of the optical system of Example 1. , The contrast ratio is similar,
The screen light flux, the uniformity of the light amount distribution, and the color purity are inferior to those in the first embodiment, and the volume of the entire optical system becomes twice as large as that in the first embodiment.

(Comparative Example 3) In the case of using the conventional optical system shown in FIG. 31 having a single condenser lens and a prism block color separation / combination system as components instead of the optical system of Example 1, Although the purity is about the same, the screen light flux, the uniformity of the light amount distribution, and the contrast ratio are inferior to those of the first embodiment, and the volume of the entire optical system becomes twice as large as that of the first embodiment.

Reference examples showing Examples 1 and 2 above and various embodiments are shown in Table 4 (Examples B1 and B2, and Reference example b).
1 to b8 and Comparative Examples B1 to B3).

In addition, a solid electrode is provided instead of a pixel electrode for image display, which is used in a full-color lighting device or the like.
Regarding the liquid crystal optical device having a simpler structure, performance comparison was performed by optical calculation, and the result was obtained (reference examples A1 to A).
6, Comparative Examples A1 to A3) are shown in Table 3.

Table 5 shows the approximate performance values and conditions of each component in this optical calculation. Although it is difficult to completely simulate the actual optical operation of an elliptic mirror or a reflective liquid crystal optical element, an approximate solution that can be practically used has been obtained.

[0257]

[Table 3]

[0258]

[Table 4]

[0259]

[Table 5]

Reference Example 9 A reflective spatial light modulator is used as shown in FIG. 14 in place of the reflective liquid crystal display element in which the TFT of Example 1 is formed for each pixel. Back electrode substrate
FAP is used as 643. The FAP is a glass substrate obtained by slicing and polishing a glass fiber having a relatively large refractive index as a core and a glass having a relatively small refractive index as a clad and bundling and fusing optical fibers having a diameter of 10 μm.

As a transparent electrode 646, S is formed on one surface of this FAP.
A film of nO ₂ is formed. In addition, amorphous Si
Photoconductive film 649 (film thickness 10 μm), Cd as the light shielding film 650
Te films (film thickness 1 μm) are sequentially formed. Finally, 40 layers of SiO ₂ having a refractive index of 1.45 and TiO ₂ having a refractive index of 2.35 are alternately laminated at each optical film thickness nd = λ / 4 (λ: central wavelength in each RGB wavelength band). A back electrode substrate 643 is obtained by forming a reflective film of the dielectric multilayer film 647 on the RGB wavelength band so that the reflectance is 99.9% or more.

On the other hand, as in Example 1, the front electrode substrate 631 has an ITO transparent electrode on a surface on which fine irregularities are formed on one surface of the glass substrate to reduce the regular reflected light and not to extremely reduce the transmitted light. 635 is used. The peripheral portions of the back electrode substrate 643 and the front electrode substrate 631 are sealed with a sealing material to produce a reflection type cell having three RGB cell shapes and a diagonal of 5 inches.

Similar to the first embodiment, Δn is about 0.2.
4. A solution in which a nematic liquid crystal having Δε of about 16 is uniformly dissolved with an acrylate monomer, a bifunctional urethane acrylate oligomer, and a photo-curing initiator is injected into the cell, and the liquid crystal solidified substance complex is cured by exposure to ultraviolet light, and the liquid crystal amount is 68w
Three reflective spatial light modulators with t% are produced.

The front electrode substrates of these three reflective spatial light modulators are bonded to the plane of the plano-convex spherical lens, as in the first embodiment. In addition, F, which is the back electrode substrate of the reflective spatial light modulator,
A CRT with a diagonal effective display surface of 4.5 inches using FAP as a face plate is joined to AP to be a writing input image.

In this way, the reflective liquid crystal display elements 31, 32,
33 is made and incorporated into the same projection type device as in Example 1.
As a result, in Example 1, only light corresponding to a TFT aperture ratio of 67% can be used, but as a result of the configuration of this reference example,
The aperture ratio is effectively improved and the projected light flux can be increased by about 20%.
Other optical characteristics are almost the same as those in the first embodiment.

In this reference example, an amorphous Si photoconductive film is used as the photoimage writing material, but a CdS film, amorphous Se, BI ₁₂ SiO ₂₀ single crystal or the like may be used as the photoconductive material.

In addition to the CdTe film as the light-shielding film, S
It is also possible to use a dielectric multilayer film mirror in which i and SiO ₂ are alternately laminated so that the optical film thickness (refractive index × film thickness) is λ / 4 with respect to the central wavelength λ of the light shielding wavelength band. A black and highly electrically insulating photosensitive polymer in which the described fine carbon particles are dispersed in the photosensitive polymer may be used. Any substance having a high electric insulating property and a high light absorption rate can be used.

Reference Example 10 As the reflective spatial light modulator of Reference Example 9, a reflective liquid crystal display element utilizing CTP is used. In this reference example, as shown in FIG.
A dielectric multilayer mirror 737 similar to that of the first embodiment is formed on one side of 0 and used as the back electrode substrate 750 of the reflective liquid crystal display element.

On the other hand, the front electrode substrate 731 is similar to the first embodiment in that the ITO transparent electrode is formed on one surface of the glass substrate on which fine irregularities are formed to the extent that regular reflection light is reduced and transmitted light is not extremely reduced. 735 is used. The periphery of the back electrode substrate 750 and the front electrode substrate 731 is sealed with a sealing material to produce a reflection type cell having three RGB cell shapes and diagonally 2 inches.

As in the first embodiment, Δn is about 0.2.
4. A solution in which a nematic liquid crystal having Δε of about 16 is uniformly dissolved with an acrylate monomer, a bifunctional urethane acrylate oligomer, and a photo-curing initiator is injected into the cell, and the liquid crystal solidified substance complex is cured by exposure to ultraviolet light, and the liquid crystal amount is 68w
Three reflective liquid crystal elements with t% are manufactured. Various methods are conceivable as a voltage input method corresponding to an image on one surface of the CTP750 of this reflective liquid crystal element.

For example, a CTP in which a photoconductive material such as an amorphous Si film is formed on the surface of the CTP750 on which the dielectric multilayer film mirror is not formed in advance, and a transparent electrode is formed thereon is used as a back electrode. Used as a substrate, front electrode substrate
By applying a constant AC voltage between the electrode 735 and the electrode 735 of 731, a reflective spatial light modulator of the optical image writing type similar to that of Reference Example 9 is realized. In this case, by using a light-absorbing substance as the insulating material for CTP, Reference Example 9
Functions as a light-shielding film.

As another example, as shown in FIG. 16, CT
The active matrix substrate 733 may be bonded to one side of P via bump bonds 760. With this configuration, the applied voltage to the pixel 736 of the active matrix is CT
It is directly applied to the liquid crystal solidified substance composite layer 732 through P. Therefore, unlike the first embodiment, the active matrix substrate itself does not need to have the reflection type configuration, and the configuration of the active matrix substrate may be exactly the same as the transmission type configuration.
Further, unlike the reference example 9, it is not necessary to form a photoconductive layer and an input image for optical writing is not required, so that the structure is simplified.

As another reference example, as shown in FIG. 17, an electron gun 774 used for a CRT is provided on one side of the CTP 750.
The image information voltage may be directly applied to the liquid crystal solidified substance composite layer 732 through the CTP by scanning the charge on the CTP surface in combination with the electron lens 773.

Although only a negative charge can be supplied from the electron gun 774, as shown in FIG. 17, the mesh electrode 772 is arranged close to this CTP surface, and the applied voltage is adjusted to adjust the insulator of the CTP surface. Since the secondary charge emission characteristics of substance 771 can be manipulated, it is also possible to supply a positive charge to the CTP surface. At this time, it is preferable to form an insulator material having a large secondary charge emission coefficient, such as MgO or CaF ₂ , on the CTP surface in order to supply positive charges at a high speed.

Further, in the case of writing with an electron gun, since the CRT manufacturing process is used, the manufacturing procedure of the reflection type liquid crystal display element is different from the others. That is, the CT shown in FIG.
After manufacturing a CRT using P750 as a face plate, a reflective cell using the CTP as a back electrode substrate is manufactured, and a liquid crystal solidified composite is further injected and exposed to form.

In the case of the spatial light modulator of Reference Example 9, a CRT and a liquid crystal display element were separately required as the image generating means for writing, but by using the reflection type liquid crystal display element having the structure as shown in FIG. Since the CRT charge amount information can be directly applied as a voltage to the liquid crystal solidified composite layer without converting the charge energy into luminescence by the phosphor, the structure is simplified, and the deterioration of the resolution and energy due to the luminescence conversion by the phosphor is reduced. The loss can be reduced.

When CTP is used as the back electrode substrate, the area of the conductor portion occupying the back electrode substrate surface becomes the effective pixel electrode surface, so that the occupied area of the conductor portion is preferably as large as possible. Since there is a limit to the area occupied by the conductor portion in actual CTP fabrication, it is preferable to form the pixel electrode on the reflection surface side of the CTP in order to increase the pixel electrode area even when the conducting wire is relatively thin.

That is, the metal film or the transparent electrode film may be formed on the surface of the CTP and then patterned into a pixel shape. When a silver film or aluminum film having a high reflectance is used as the pixel electrode, it also functions as a reflective layer. On the other hand, in the case of a transparent pixel electrode, high reflectance and durability are achieved by forming a dielectric multilayer reflective layer on the entire surface thereof.

Reference Example 11 Instead of the reflective liquid crystal display element of Example 1, a reflective liquid crystal optical element as shown in FIG. 11 is used. The condensing mirror substrate 533, which is a back electrode substrate, is a glass having an ellipsoidal surface close to a spherical surface, on the plane side of which fine irregularities are formed, and a transparent electrode 536 is formed thereon. On the elliptical surface side, a dielectric multilayer film mirror 537 corresponding to each wavelength region of RGB is formed. Its spectral characteristics are the same as in Example 1.

The front electrode substrate 531 is the same as in the first and second embodiments.
IT is formed on the surface of the glass substrate on which fine irregularities are formed to the extent that regular reflection light is reduced and transmitted light is not extremely reduced.
An O transparent electrode 535 was used. The peripheral portions of the back electrode substrate 533 and the front electrode substrate 531 are sealed with a sealing material to form a reflective cell having three RGB cell shapes and a diagonal of 3 inches, and a compatible material of liquid crystal and photocurable resin is prepared. Injection-exposure is carried out to form a liquid crystal solidified substance complex, which is used as a reflective liquid crystal optical element.

The reflection type liquid crystal optical element thus manufactured is incorporated into the same projection type apparatus as in Example 1 and used as an illuminating apparatus. As a result, the extinction ratio is 1000: 1 or more by adjusting the voltage applied to the three reflective liquid crystal optical elements by making the two types of aperture diaphragms of the light source system and the projection system variable, and adjusting the full color at high speed. It is possible to obtain a small illuminating device that can emit light.

[0282]

In the projection type color liquid crystal optical device of the present invention, as the liquid crystal material sandwiched between the front electrode substrate and the back electrode substrate, a liquid crystal solidified substance capable of electrically controlling the scattering state and the transmitting state is used. Since a reflective liquid crystal optical element sandwiching the composite is used, no polarizing plate is required, and the transmittance of light at the time of transmission can be significantly improved compared to the conventional TN type liquid crystal optical element, which is bright. A projected image is obtained.

The reflection type liquid crystal optical element used in the present invention is capable of controlling high scattering property and high transmission property by changing the voltage application state, and has a substrate gap smaller than that of the transmission type. Since it can be narrow, it can be driven at a low voltage,
Even in the case of driving using a driving IC for a conventional TN type liquid crystal optical element, a display having a high contrast ratio and high brightness can be realized.

In particular, in the present invention, since the reflecting film of the dielectric multilayer film is used as the reflecting film of the back electrode substrate, the problem of the deterioration of the optical mirror surface due to the reaction with the substrate interface material is unlikely to occur and the reflectance is high. It is easy to obtain a flat mirror surface without light absorption. Further, since it has no conductivity, there is no problem of short circuit with the wiring electrode.

Further, selective reflectivity can be imparted by the constitution of the multilayer film. Therefore, it can function as a reflection-type color filter that does not absorb light. As a result, it is possible to obtain a bright projection display with a good contrast ratio while taking advantage of the fact that a thin substrate space can be provided, which makes it possible to drive at a low voltage.

Further, since fine irregularities are formed on the transparent electrode surface in contact with the liquid crystal solidified composite layer of the front electrode substrate in the reflective element to reduce regular reflection, the liquid crystal solidified composite layer is in a scattering state. Superimposition of the interface reflected light on the projection image at the time is reduced, and high contrast projection can be realized.

Further, since the reflective liquid crystal optical element used in the present invention does not need to use a polarizing plate, the optical characteristics have little wavelength dependence, and the color correction of the light source is almost unnecessary. Also has. Further, the problem of alignment treatment such as rubbing which is indispensable for the TN liquid crystal optical element and destruction of the active element due to the generation of static electricity accompanying it can be avoided, so that the manufacturing yield of the liquid crystal optical element can be greatly improved.

Furthermore, since this liquid crystal solidified composite is in the form of a film after being cured, problems such as short circuit between substrates due to pressurization of substrates and breakage of active elements due to movement of spacers are unlikely to occur.

Further, this liquid crystal solidified composite has a specific resistance equivalent to that of the conventional TN liquid crystal optical element, and the conventional D
Unlike the SM liquid crystal optical element, it is not necessary to provide a large storage capacitor for each pixel electrode, the active element can be easily designed, the ratio of the effective pixel electrode area can be easily increased, and the power consumption of the liquid crystal optical element can be reduced. Can be kept.

Further, the manufacturing process is easy because the manufacturing process of the TN liquid crystal optical element can be carried out only by removing the alignment film forming process. Further, a liquid crystal optical element using this liquid crystal solidified composite has a feature that the response time is short, and it is easy to display a moving image. Further, since the electro-optical characteristic (VT curve) of this liquid crystal optical element is a comparatively gentle characteristic as compared with the TN liquid crystal optical element, it can be easily applied to gradation display.

[0291] Further, since the liquid crystal optical element for use in the present invention, by so as to substantially match the liquid crystal n _o of using the refractive index of the solidified matrix, which light is scattered at the portion where no voltage is applied, Even if the portions other than the pixels are not strictly shielded by the light-shielding film, light leakage is small at the time of projection, and there is no problem even if the gap between adjacent pixels is not shielded.

Therefore, in particular, the polycrystalline S is used as an active element.
By using the active element according to i, a high-luminance projection light source can be used by simply providing no light-shielding film or a simple light-shielding film on the active element portion, and a high-luminance projection-type liquid crystal optical device can be easily obtained. be able to. Further, in this case, the light-shielding film may not be provided at all, or only a simple light-shielding film may be required, which further simplifies the production process. However, when the illuminance of incident light on the reflection type display element is very large, it is relatively necessary to take measures against light shielding of the active element.

Further, the dichroic mirror for color separation / synthesis is composed of two types of two plate type dichroic mirrors,
The two dichroic mirror surfaces are sequentially arranged without intersecting each other so that the angle α formed by the optical axis of the optical system and the normal line of the dichroic mirror surface is 20 ° to 35 °, and the angle formed by the two types of dichroic mirror surfaces. β is 40 ° to 7
Since they are arranged so as to be 0 °, the spectral characteristics of the color separation / synthesis of the dichroic mirror are excellent. as a result,
Full-color projection light with high color purity was obtained, and the color separation / synthesis system was downsized.

By the arrangement configuration of each of the above-mentioned components,
An optical system including a light source system, a color separation / synthesis system, and a reflective liquid crystal display element can be miniaturized.

Further, at the position where the light reflected by the reflective liquid crystal optical element is condensed and an image conjugate with the aperture at the second focal point of the elliptic mirror is produced, a diaphragm corresponding to the size of the aperture image is placed. By using the projection lens included therein, downsizing of the entire projection type liquid crystal optical device can be achieved.

Furthermore, the contrast ratio and brightness of the projected image can be adjusted by linking the aperture of the light source system and the aperture of the projection system to make the aperture variable, and the visibility according to the brightness of the surrounding environment can be adjusted. Higher display is possible.

Further, the two types of dichroic mirrors have different spectral transmittances in the in-plane position so as to reduce the difference in spectral transmittance corresponding to the difference in light incident angle at the in-plane position. Since the cone-shaped prism or the cone-shaped reflector has a distribution and is arranged in the vicinity of the aperture stop arranged at the second focus position of the elliptical mirror in the projection light source system, the in-plane of the projection light of the screen It is possible to obtain projection type liquid crystal optics having excellent uniformity of light intensity distribution and color distribution.

Further, by using CTP having a reflective film formed on one surface as the back electrode substrate of the reflective liquid crystal optical element, it becomes easy to apply a voltage corresponding to image information. In particular, it is effective for a reflection type liquid crystal optical element using a CRT as an electric image supplying means.

The back electrode substrate of the reflective liquid crystal display element of the present invention has a plurality of row wirings, a plurality of column wirings, and a plurality of column wirings on the substrate.
An active element is provided in the vicinity of the intersection, a dielectric multilayer mirror is formed on the entire surface, and a transparent electrode for pixel display is patterned on the active element, and a contact hole is formed in the dielectric mirror layer. The pixel transparent electrode is electrically connected to the active element through.

As a result, since there is no close relationship between the active element and the back electrode substrate material and the pixel structure, the degree of freedom in selecting the device structure is increased and a large aperture ratio can be achieved. Therefore, a brighter projected image can be obtained.

In addition to the above, the present invention can be applied in various ways within the range of not impairing the effects of the present invention.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of a projection type color liquid crystal optical device of the present invention.

FIG. 2 is a side view showing a configuration of a projection type color liquid crystal optical device (some components are omitted) of the present invention.

FIG. 3 is a cross-sectional view showing an example of the configuration of a light source system using the conical prism of the present invention.

FIG. 4 is a cross-sectional view showing an example of the configuration of a light source system using the cone-shaped reflector of the present invention.

FIG. 5 is a sectional view showing an example of a liquid crystal optical element provided with a reflective back electrode of the present invention.

FIG. 6 is a cross-sectional view of a liquid crystal optical element provided with a reflective surface on the back surface of the back substrate of the present invention.

FIG. 7 is a cross-sectional view showing an example in which a reflection means having a reflection function layer of the present invention and a liquid crystal optical element are arranged with a space therebetween.

FIG. 8 is a cross-sectional view of a liquid crystal optical element of the present invention provided with a first means (uneven surface) for reducing interface reflection.

FIG. 9 is a sectional view of a liquid crystal optical element of the present invention provided with a second means (antireflection film) for reducing interface reflection.

FIG. 10 is a cross-sectional view of a liquid crystal optical element of the present invention provided with a third means (inclination) for reducing interface reflection.

FIG. 11 is a sectional view of a liquid crystal optical element in which a condenser mirror is provided on the back substrate of the present invention.

FIG. 12 is a cross-sectional view showing an example of the present invention in which a condensing reflecting means and a liquid crystal optical element are arranged so as to be spatially separated from each other.

FIG. 13 is a cross-sectional view showing an example of a liquid crystal optical element of the present invention in which a reflective film is provided between an active element and a light shielding film.

FIG. 14 is a sectional view showing an example of the liquid crystal optical element of the present invention provided with a photoconductive layer and a reflective film.

FIG. 15 is a cross-sectional view showing an example of a liquid crystal optical element using CTP having a dielectric multilayer mirror formed on one surface as a back electrode substrate.

FIG. 16 is a cross-sectional view showing an example of a liquid crystal optical element that is bonded to an active element substrate by bump bonding, using a CTP having a dielectric multilayer mirror formed on one surface as a back electrode substrate.

FIG. 17 is a cross-sectional view showing an example of a liquid crystal optical element that uses a CTP having a dielectric multilayer mirror formed on one surface as a back electrode substrate and supplies an electrified image by a CRT.

FIG. 18 is a plan view showing a conventional example of a projection type liquid crystal optical device using a dichroic prism.

FIG. 19 is a side view showing a conventional example of a projection type liquid crystal optical device using a dichroic prism.

FIG. 20 is a plan view showing a conventional example of a projection type liquid crystal optical device using a crossed flat plate dichroic mirror.

FIG. 21 is a side view showing a conventional example of a projection type liquid crystal optical device using a crossed flat plate dichroic mirror.

FIG. 22 is a plan view showing a first conventional example of a projection type optical device using a reflective display element utilizing deformation of a viscoelastic body and a sequentially arranged flat plate dichroic mirror.

FIG. 23 is a plan view showing a second conventional example of a projection type optical device using a reflective display element utilizing deformation of a viscoelastic body and a sequentially arranged flat plate dichroic mirror.

FIG. 24 is a plan view showing a third conventional example of a projection type optical device using a reflective display element utilizing deformation of a viscoelastic body and a sequentially arranged flat plate dichroic mirror.

FIG. 25 is a cross-sectional view showing an example of the configuration of a light source system of the present invention in which an elliptical mirror and a spherical mirror are combined, and a conical prism is used.

FIG. 26 is a cross-sectional view showing a double electrode structure of the present invention in which a pixel electrode of an active element is electrically connected to a transparent pixel electrode on a dielectric multilayer film mirror through a contact hole.

FIG. 27 is a perspective view schematically showing an example of a projection type color liquid crystal optical device of the present invention.

FIG. 28: Black matrix on / TFT of the present invention
The top view of (3rd electrode structure).

FIG. 29: Black matrix on / TFT of the present invention
Sectional drawing of (3rd electrode structure).

FIG. 30 is a plan view of an example of a projection type color liquid crystal optical device of the present invention.

FIG. 31 is a plan view showing a conventional example of a projection type liquid crystal optical device using a TFT driven DSM liquid crystal display element and a dichroic prism block.

FIG. 32 is a perspective view schematically showing an optical path before and after a reflection function layer of the projection type color liquid crystal optical device of the present invention.

[Explanation of symbols]

 1: Light source system 2: Color separation / synthesis optical system 4: Projection optical system 42: Projection lens 5: Central optical axis 11: Light source 12: Elliptical mirror 13: Aperture stop 14: Conical prism 15a, 15b: Conical reflection Body 21, 22: Dichroic mirror 31, 32, 33: Reflective liquid crystal optical element block 31A, 32A, 33A: Reflective liquid crystal optical element 31B, 32B, 33B: Condensing lens 41: Second aperture stop

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nariyuki Serizawa 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Asahi Glass Co., Ltd. (72) Inventor Yoshiyuki Takada 1150, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Asahi Glass Central Research Institute Co., Ltd. (72) Inventor Masaya Keyada, 1160 Matsubara, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Prefecture EG Technology Co., Ltd. (72) Yoshinori Hirai, 1150, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Asahi Glass Central Research Institute Co., Ltd.

Claims (15)

[Claims] 1. A projection type color liquid crystal optical device provided with a light source system, a color separation / combination optical system, a light modulator, and a projection optical system, wherein the color separation / combination optical system has a first color. The separation / combination means and the second color separation / combination means are provided, and the light modulation means is provided with three condensing means, three liquid crystal optical elements, and three reflective functional layers. The nematic liquid crystal is dispersed and held in the solidified matrix between the front substrate with the transparent front electrode and the back substrate with the back electrode, and the refractive index of the solidified matrix is either applied or not applied with voltage. And the nematic liquid crystal have almost the same refractive index, and the liquid crystal solidified composite layer operating in the transmission / scattering mode is sandwiched, and the color separation / synthesis optical system has two color separation / synthesis means on a certain horizontal plane. The angle β is arranged in the range of 40 ° to 70 °, and the projection The science system is arranged almost vertically to the horizontal plane so that the optical axis from the light source system to the projection optical system forms a projection, and the light emitted obliquely upward (downward) from the light source is the optical axis. Along the optical path through the color separation / combination optical system and the light modulator, and the first color separation / combination means has an incident angle α1 of 2 with respect to the optical axis.
The second color separation / combination unit is provided with an incident angle α2 with respect to the optical axis in the range of 20 ° to 35 °, and the light is divided into three color lights by the color separation / combination unit. The separated light is condensed by the condensing means corresponding to each color light, and is modulated by the liquid crystal optical element corresponding to each color light, and the incident angle γ is 1 ° to 1 ° by the reflection function layer corresponding to each color light.
A projection type color liquid crystal optical device characterized by being reflected at 20 °, condensed by a condensing unit corresponding to each color light, color-combined by a color separation / combination optical unit, and made incident on a projection optical system. . 2. The projection type color liquid crystal optical device according to claim 1, wherein the incident angle α1 and the incident angle α2 are made substantially equal, and the incident angle γ is in the range of 2 ° to 10 °. Projection type color liquid crystal optical device. 3. The projection type color liquid crystal optical device according to claim 1 or 2, wherein the condensing means is attached to or near the front faces of the three liquid crystal optical elements. Optical device. 4. The projection type color liquid crystal optical device according to claim 1, wherein the three reflective functional layers are provided in three liquid crystal optical elements, respectively. Optical device. 5. The projection type color liquid crystal optical device according to claim 1, wherein the three condensing means are three liquid crystal optical elements, and the first color separating / combining means or the second color separating means. A charge transfer plate (CTP), each of which is disposed between the transfer means and any one of the synthesizing means.
Is used as a back substrate, and the reflective function layer is disposed between the CTP and the liquid crystal solidified composite layer. 6. The projection type color liquid crystal optical device according to claim 1, wherein the light source system comprises an elliptic mirror, a light source and an aperture stop, and the light emitting portion of the light source is near the first focal point of the elliptic mirror. Is disposed, the aperture stop is disposed so that the aperture of the aperture stop is located near the second focus of the elliptic mirror, and the conical prism or the conical reflector is disposed near the aperture. Projection type color liquid crystal optical device. 7. The projection type color liquid crystal optical device according to claim 1, wherein the front substrate has a transparent electrode formed on a transparent insulating substrate, and the back substrate has a plurality of row wirings. A plurality of column wirings and active elements are provided near intersections of the row wirings and the column wirings, and a dielectric multilayer mirror is formed so as to cover the row wirings, the column wirings, or a part or all of the active elements. Further, the projection type color liquid crystal display device is characterized in that the transparent electrode formed on the dielectric multilayer mirror layer is used as a back electrode for pixel display. 8. The projection type color liquid crystal optical device according to claim 1, wherein the front substrate has a transparent electrode formed on a transparent insulating substrate, and the back substrate has a plurality of row wirings. A plurality of column wirings, an active element for driving a pixel electrode in the vicinity of an intersection of the row wirings and the column wirings, and a third electrode, wherein the third electrode is the row wiring, The electric potential between the third electrode and the front electrode is set so as to cover a part or all of the column wiring and the active element and / or substantially cover a gap between adjacent pixel electrodes. A projection type color liquid crystal display device characterized in that the liquid crystal solidified substance composite layer has a threshold value or less. 9. The projection type color liquid crystal optical device according to claim 1, wherein at least one of the color separating / combining means has a spectral transmission characteristic depending on an incident angle depending on a position on the optical surface. A projection type color liquid crystal display device having a function of compensating for a difference. 10. The projection type color liquid crystal optical device according to claim 1, wherein the reflective functional layer has a translucent dielectric thin film having a relatively high refractive index and a relatively low refractive index. A projection type color liquid crystal optical device comprising a dielectric multi-layered film mirror in which translucent dielectric thin films are alternately laminated. 11. The projection type color liquid crystal optical device according to claim 1, wherein fine projections and depressions are formed on the interface of the front substrate or on the surface of the transparent electrode surface. Type color liquid crystal optical device. 12. The projection type color liquid crystal optical device according to claim 1, wherein the reflective functional layer is provided with wavelength selective reflectivity for compensating the color purity of the color separation / synthesis means. Characteristic projection-type color liquid crystal optical device. 13. The projection type color liquid crystal optical device according to claim 1, wherein any one of the light condensing means, the reflection function layer, and the liquid crystal optical element is provided with a color of the color separating / combining means. A projection type color liquid crystal optical device having a wavelength selective absorption property for compensating for purity. 14. The projection type color liquid crystal optical device according to claim 5, wherein the reflection surface formed between the CTP and the liquid crystal solidified composite has electrodes divided into pixels. Liquid crystal optical device. 15. The projection type color liquid crystal optical device according to claim 6, wherein the second aperture stop is provided at a position where an optical conjugate image of the aperture of the aperture stop arranged near the second focal point of the elliptic mirror is generated. A projection type color liquid crystal optical device characterized by being provided.