JPH08190080A - Liquid crystal display device - Google Patents

Abstract

(57) Abstract: To improve the light utilization rate, peripheral light amount ratio, contrast ratio, and image quality of a liquid crystal display. In FIG. 13, a first light refracting means 113 and a second light refracting means 113 are provided in an optical path from a light source means 1 to a liquid crystal panel means 3.
Light refracting means 10, first light reflecting means 117, and third
Is arranged, and the light converging power (the reciprocal of the focal length) of the third light refracting means is algebraically small at its outer peripheral portion and is large at its inner peripheral portion. The light utilization rate can be improved, and the relative illuminance ratio of the outer peripheral portion of the liquid crystal panel can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having excellent light utilization efficiency and image quality.

The present invention is primarily intended for projection liquid crystal display devices, but is also applicable to direct view and fiber types.

[0003]

2. Description of the Related Art In order to construct a liquid crystal display device having an excellent image quality, that is, a contrast ratio, it is necessary to collimate light passing through a liquid crystal panel as much as possible. According to recent research results, for example, in order to obtain a contrast ratio of 200: 1 or more, the divergence angle of light passing through a liquid crystal panel is set to a range of about 0.15 rad pp in the first direction (narrow directivity direction). Limiting and with respect to the second direction (wide directional direction),
It is necessary to limit the range to 0.3 rad pp (about twice the above 0.15).

A parabolic mirror is a typical example of the light collimating means or collimator means in the prior art. A prior art projection liquid crystal display is shown in FIG.

In the figure, 1 is a light source, 2 is a parabolic mirror,
3 is a liquid crystal panel, 4 is a projection lens, and 5 is a screen. The arrows indicate the paths of light rays. In this prior art, there were at least the following problems.

(1) In FIG. 1, the light 6, 6 ′ that directly reaches the liquid crystal panel 3 without passing through the parabolic mirror 2 is
It is not collimated. Therefore, the contrast ratio and the image quality of the reproduced image are deteriorated.

(2) In FIG. 1, the improvement of the light utilization efficiency and the improvement of the peripheral light amount ratio are contradictory to each other. That is, when one is improved, the other is deteriorated. Here, the peripheral light intensity ratio is
The ratio of the peripheral illuminance to the central illuminance of the liquid crystal panel,
Hereinafter, it is abbreviated as RCI (Relative Corner Illuminance).

(3) In FIG. 1, the parabolic mirror 2
Is a rotationally symmetric shape about the optical axis. Therefore, the cross section of the output light is circular, and if the radius is 1, its area is π
Is. On the other hand, the liquid crystal panel 3 has a rectangular shape or a square shape, and the area of the rectangle inscribed in the unit circle is 2 or less. Therefore, in the peripheral portion, about 36% (1-2 / π) loss occurs due to the aspect mismatch.

(4) Since the light source (1) is surrounded by the parabolic mirror (2) and the air circulation path is not in a straight line, it is difficult to increase the efficiency of heat dissipation from the light source.

The result of the inventor's clarification of the cause of the second problem based on the law of nature is shown below. The coordinate system is shown in FIG. Z is taken in the direction of the optical axis of the parabolic mirror 2, and r is the distance from the optical axis. The shape of the parabolic mirror 2 is given by the following equation.

[0011]

[Equation 1]

The light source 1 is focused on the mirror 2 (Z = 0.5).
R ₁ ). Therefore, the output light reflected by the mirror becomes parallel light. The light source is assumed to be isotropic, and its luminous intensity is I [cd]. Therefore, the total luminous flux is 4π
I [lm]. The increment of the luminous flux emitted from the isotropic light source is proportional to the solid angle increment. According to spherical geometry, the solid angle increment is proportional to the cosine increment of the zenith angle θ measured from the optical axis through the light source. The total light flux T and the light utilization factor E (θ _M ) that are converted into parallel light by the parabolic mirror 2 are calculated as follows. However, the shape of the liquid crystal panel is assumed to be a disk shape, and the aspect mismatch loss of (3) above is ignored.

[0013]

[Equation 2]

On the other hand, the illuminance J of the parallel light output from the parabolic mirror 2 is inversely proportional to the square of the distance from the light source to the mirror. Therefore,

[0015]

(Equation 3)

What is meant by the above equation is that the distance from each point on the mirror to the light source is equal to Z + 0.5R ₁ . The following formula is obtained by dividing the output illuminance at each point on the mirror by the illuminance at the center of the mirror (Z = 0 in Formula 3) and standardizing it as J ₁ . The () under the equal sign in the transformation process of the above equation indicates that the equation of that number was used to derive the equal sign. The same applies hereinafter.

[0017]

[Equation 4]

Next, let us consider expressing J ₁ by the zenith angle θ. In FIG. 2, the following equation is obtained using the above-mentioned relationship that the distance between each point on the mirror and the light source is equal to Z + 0.5R ₁ .

[0019]

(Equation 5)

Equations 3 and 8 are shown in FIGS. 3 and 4, respectively. FIG.
As can be seen from the above, when θ _M is 0.5π, that is, 1 right angle, the light utilization rate is 50%. If θ _M is 2π / 3, the light utilization rate is 75%. As can be seen from FIG. 4, θ is 0.
In the case of 5π, the peripheral light amount ratio is 25%. Also, θ is 2
In the case of π / 3, the peripheral light amount ratio becomes as small as 6.3%.

The above-mentioned relation: Although the equations 4 to 8 are analytically obtained, the equations 4 to 8 can be alternatively obtained based on the parabolic geometry. This is shown in FIG. In the figure, the dotted line 2'is the parabola quasi-line. Detailed description of the figure is omitted.

As can be seen from FIGS. 3 and 4, the conventional technique has a problem in that the peripheral light amount ratio is deteriorated when the light utilization rate is improved.

As is well known, in the conventional one-panel type color liquid crystal display, three primary color dyes are used for three primary color pixels. Therefore, only the energy of 1/3 or less (so-called shadow mask loss) of the light energy generated by the white light source can be used. As a measure for compensating for this shadow mask loss and improving the light utilization rate three times, USP 5,161,042 describes three primary colors 3
It has been proposed to arrange the orientation means and the microlens means on the light incident side of the liquid crystal panel means. But,
The above-mentioned proposal has a problem that the parallelism of the light incident on the liquid crystal panel is impaired and the divergence angle of the incident light deteriorates to a value of about 6 times. The quality of the reproduced image, that is, the contrast ratio is inversely proportional to the square of the divergence angle of the incident light and deteriorates. Therefore, the above proposal provides a contrast ratio of about 3
It deteriorates 6 times. Therefore, the above proposal has not been put into practical use yet.

In addition, the present inventor's JP-A-93-3782
4 proposes disposing lenticular lenses on each of the incident side and the emitting side of the liquid crystal panel. However, it could not be useful for solving the problem of deterioration of the contrast ratio.

Further, in the projection type liquid crystal display of the prior art, in FIG. 1, the pixel structure pattern of the liquid crystal panel 3 and the vertical stripe-shaped structure of the lenticular lens which is a constituent element of the screen 5 interfere with each other to prevent moire. There was a problem that occurs. A further independent problem was the problem of ghosting due to internal round-trip light reflection in the Fresnel sheet used in the screen. The inventor has found that the Fresnel ghost disorder particularly occurs at the upper and lower ends on the playback screen based on the reason explained in the detailed example section separately.

The present invention disclosed below is based on the patent applications JPA 81-158062 and JPA-89-3 already filed by the present inventor.
97, JPA-92-54749, and JPA-93-.
It can be constructed by a new idea based on 37824.

[0027]

SUMMARY OF THE INVENTION One of the objects of the present invention is to overcome at least one of the problems of the prior art and to provide a liquid crystal display having an excellent contrast ratio and image quality.

Another object of the present invention is to improve the light utilization rate of liquid crystal displays.

Another object of the present invention is to prevent and improve the deterioration of the peripheral light amount ratio of the liquid crystal display.

Another object of the present invention is to provide a light source device for a projection type liquid crystal display with improved heat dissipation efficiency.

Another object of the present invention is to provide a projection type liquid crystal display with little deterioration in resolution and reduced moire interference.

Another object of the present invention is to provide a projection type liquid crystal display with reduced ghost disturbance.

Another object of the present invention is to provide a direct view type, optical fiber type or projection type liquid crystal display having an excellent light utilization rate by applying the above-mentioned improved liquid crystal display technology.

Another object of the present invention is to provide a liquid crystal display device having a pixel array that is more visually matched to the resolution of the human eye.

Another object of the present invention is to provide a large-sized liquid crystal display device that is resistant to changes in the ambient environment such as temperature and gravity.

[0036]

In order to achieve at least one of the above objects, in the first embodiment of the present invention, first, second and third light refraction means, and A first light reflecting means is provided.

A part of the output light from the light source is input to the first light refraction means, and the output light goes through the second light refraction means to the inner peripheral portion of the liquid crystal panel means. Supplied,
Part of the output light from the light source is input to the first light reflecting means, and the output light is supplied to the outer peripheral portion of the liquid crystal panel means through the third light refracting means, The light deflection angle of the outermost peripheral portion of the third light refracting means is formed algebraically smaller than the deflection angle of the innermost peripheral portion thereof. The deflection angle is the first and second
Is smaller than the sum of the respective light deflection angles of the outermost peripheral portion of the light refracting means, and the direction of the emitted light at the innermost peripheral portion of the third light refracting means and the direction of the second light refracting means. It is formed so that the direction of outgoing light at the outermost peripheral portion substantially coincides.

In another embodiment of the present invention,
In a polar coordinate system having a light source as an origin, a spherical light reflecting means is provided in the western hemisphere, and a light advancing direction changing means (collimator means) is provided in the eastern hemisphere. It is composed of light deflection means.

In another embodiment of the present invention,
In a polar coordinate system having a light source as an origin, a spherical light reflecting means is provided in the western hemisphere, and an air circulation opening means is provided in a high latitude region at the north and south ends of the spherical light reflecting means.

In another embodiment of the present invention, a squarer means is provided in the transmission line of collimator output light.

In another embodiment of the invention,
On the light incident side of the liquid crystal panel means, along the light traveling direction,
Three-primary-color three-direction converting means, three-direction three-positioning means (first lenticular lens means), and light divergence angle reducing means (second
Lenticular lens means), and as a modification, a polarization direction matching means for matching the light diverging directions of the three primary color three-direction converting means with the wide directivity direction of the liquid crystal panel means.

In another embodiment of the present invention,
In a projection type liquid crystal display device, a light diverging means for diverging light in a substantially horizontal direction is arranged between a liquid crystal panel and a projection lens.

In another embodiment of the present invention,
In the projection type liquid crystal display device, Fresnel ghost disturbance reducing means is provided between the liquid crystal panel means and the screen means.

In another embodiment of the present invention,
A three-primary three-direction means using a diffraction grating is shown.

In another embodiment of the present invention,
A three-primary, five-direction directional means using a diffraction grating and a prism array is shown.

In another embodiment of the present invention,
A liquid crystal panel means using a pre-annealed thin glass plate is shown.

In the first embodiment of the present invention, the structure of each of the above means acts to improve the relative illuminance of the outer peripheral portion of the liquid crystal panel means. Further, the combination of the light refraction means and the light reflection means achieves the improvement of the light utilization rate.

In another embodiment of the present invention, the spherical light reflecting means serves to return the light emitted from the light source to the western hemisphere to the light source and re-emit it to the eastern hemisphere. The first direction light deflection means acts so as to deflect light in the latitudinal reduction direction. The second direction light deflector operates so as to deflect the light in the longitude spread reduction direction. By the action of the first-direction light deflecting means and the second-direction light deflecting means, the output light can have a rectangular cross section.
Therefore, the aspect ratio mismatch loss in the prior art can be eliminated, and the light utilization rate can be improved.

In another embodiment of the present invention, the air circulation opening means provided at the north and south ends of the spherical light reflecting means in the western hemisphere correspond to a position where the light source means can be seen straightly. Therefore, the air can be circulated efficiently and the heat dissipation efficiency can be improved.

In another embodiment of the present invention, the aligner means is formed by arranging a large number of black thin plates in a cupboard shape along the traveling direction of light, and the thin plate surface is formed. On the other hand, it acts to absorb light with poor parallelism that enters at a relatively large angle and to reflect light with good parallelism that enters at a relatively small angle. Therefore, it is possible to improve the parallelism of light and reduce the divergence angle of light. Therefore, the contrast ratio can be improved.

In another embodiment of the present invention,
The light divergence angle reducing means has an action of reducing the divergence angle of the three primary color lights by about half. Therefore, 6 in the conventional proposal
The double divergence angle can be reduced to triple the divergence angle. Furthermore, by the polarization direction matching means, the direction of the divergence angle of 3 times is
It is possible to match the wide directivity direction of the liquid crystal panel means. The contrast ratio is about 4 by halving the divergence angle.
Be doubled. By matching the above polarization directions, 45
The contrast ratio is about twice (se
c ² 45 °). In addition, in the conventional proposal, the light utilization factor is improved three times, but the contrast ratio is fatally impaired. In contrast, in the present proposal, the light utilization factor (luminance) is improved without causing contrast deterioration. It can be tripled. Recent research results of the present inventor (SID article M. Ogino, "Projection Displays: Past an
d Future ”, SID 94 DIGEST, P223
~ P226), the display quality merit index is proportional to the product of brightness and contrast ratio. Therefore, the impact of this plan is large.

In another embodiment of the present invention,
The light diverging means allows the horizontal spot size to be increased. Therefore, it is possible to reduce the moire interference caused by the interference between the vertical stripe structure of the screen and the pixel array structure of the liquid crystal panel without causing a light loss.

In another embodiment of the present invention,
The Fresnel ghost disturbance reducing means has the function of aligning the polarization plane of the projection light (the plane including the vibration direction of the electric field and the light traveling direction) in the vertical direction. The light having a plane of polarization in the vertical direction acts as a P-wave at the upper and lower ends of the Fresnel lens forming the screen.

The upper and lower ends of the Fresnel lens have the property that the reflectance for P-wave is extremely small. Therefore, the ghost interference caused by the round-trip light reflection in the Fresnel plate is reduced.

The three-primary-color three-direction directing means using the diffraction grating transmits the positive-order diffracted first-order light output by the diffraction grating toward the liquid crystal panel means, and outputs the negative-polarity directivity by the diffraction grating. The first-order diffracted light is reflected by the mirror,
The reflected output acts so as to become parallel light in the direction of the positive-order diffracted first-order light. Therefore, the positive and negative polarities of the emitted light can be utilized. Therefore, the light utilization efficiency can be improved.

The three-primary-color five-direction converting means separates the input parallel white light into five directions of RGBGR. The light in the five directions is converged by the lenticular lens at each of the five array positions (RGBGR) of the three primary color pixels. Therefore,
The light utilization efficiency can be improved. Furthermore, the pixel array is compatible with the visual psychology of the resolution of the human eye.

The pre-annealed thin glass plate acts to apply a uniform pressure to the liquid crystal layer of the liquid crystal panel means. Therefore, it is possible to configure a liquid crystal display device that has less unevenness in image quality depending on environmental changes.

[0058]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before opening the detailed embodiments of the present invention, in order to facilitate the understanding thereof, the energy conservation law or the flux conservation law in a liquid crystal display found by the inventor will be explained. With the help of this law, the idea of the liquid crystal display of the present invention suitable for each special purpose in various applications becomes possible. The conservation law is shown in the following equation.

[0059]

(Equation 6)

The meaning of the above equation is as follows.

In general, the amount of light flux passing through any one cross-sectional area S ₁ on the traveling path of light is given by the right side of equation (9), and its value follows that of the light passing through S _1. Is equal to the corresponding value in the other cross-sectional area S ₂ that passes through, that is, equation (9 ′). This equation makes it possible to apply the Helmholtz Lagrange's law, which holds only in the image plane of the aberration-free optical system, to a more general interface in the middle of a lossless optical propagation path having an arbitrary aberration. Is extended by the person.

In the above equation, n ₁ and n ₂ are the refractive indexes of the mediums to which the cross-sectional areas S ₁ and S ₂ belong, respectively. dx and dy are
It is the differentiation of each local orthonormal coordinate (x, y) on the cross-sectional area on the optical path. θx is the x-direction latitude component of the light direction θ measured from the normal to the cross-section element, and θy is the y-direction latitude component. In FIG. 6, 1 is a light source, 1'is a cross-sectional area element, a dotted line 1 "is a normal to the cross-sectional area element, and 1 '" is a light direction.
B (x, y, θx, θy) in the above equation is luminance, and its unit is [lm / m ² sr] = [nit]. In this unit, sr is usually called "steradian",
As understood from the equation (9), it is proper to call the “sine area” originally.

For example, the surface of the light emitting portion of the light source has a radius of 3 mm.
If it is spherical and has a Lambertian surface brightness of 100 million nits, the total luminous flux is 100 million nits.
π (3 mm) ² · πsr, that is, about 35500 lm.

Between the light source and the liquid crystal panel, a lossless light collimating means that is rotationally symmetric with respect to the optical axis is assumed, and a disk surface is assumed immediately before the liquid crystal panel, and the illuminance on this disk surface is made uniform. It is assumed that FIG. 7 shows the light source 1 and the disc surface 7.
The light collimating means is not shown. When the distance between the light source 1 and the disc surface 7 is L, the central illuminance E ₀ of the disc surface without the light collimating means is given by the following equation.

[0065]

(Equation 7)

In the above equation, B ₀ is the brightness of the light source, S ₀ is the apparent area of the light source, and r ₀ is the radius of the light source. If a uniform illuminance E ₀ is obtained by the light collimating means to every corner of the disc surface, what is the diameter R ₂ of the disc? This is calculated from the law of conservation of luminous flux as follows.

[0067]

(Equation 8)

That is, the radius of the disk is twice the distance L between the light source and the disk. This is insightable because the surface area of the spherical surface with radius L is equal to the surface area of the disk with radius 2L.

In general, a Lambertian light having a uniform brightness
The total area of the source is S₁Then, the total luminous flux is πS₁And is optional
With the lossless optical system of₂To the light receiving surface of
Assuming that the illuminance is made uniform,
The area of the two-dimensional divergence angle sine is S ₁/ S₂The expression is equal to the ratio
You can deduce from (9). On the other hand, the high contrast ratio
To obtain a reproduced image of high quality, it is necessary to reduce the divergence angle. Follow
You should use a large LCD panel as much as possible.

Now, the next problem is that the light emitted from the isotropic light source 1 in the direction of the zenith angle θ is collimated to the position of the radial distance R from the optical axis on the disk surface 7 by unknown collimation. What kind of function should be used for R to reach it by means?
Is. The answer is shown in FIG.
Relationship, that is, Equation 3 may be used. This is shown in the following equation.

[0071]

[Equation 9]

If the unknown lossless light collimating means is constructed so as to satisfy the above equation, the illuminance on the disk can be made uniform. That is, the peripheral light amount ratio can be made 100%.

Now, here, the size ε of the microscopic light divergence angle at the position of the radius R on the disk is determined. The divergence angle differs in the radial direction, that is, in the meridional direction and in the circumferential direction, that is, in the sagittal direction. Therefore, each is designated as εm (θ) and εs (θ). In FIG. 7, a sphere having a radius L centered on the light source 1 is assumed. Then, in the case of an isotropic light source, the illuminance on the spherical surface is equal to the above-described E ₀ everywhere. The circumference of a circular ring on a spherical surface that shares the zenith angle θ and the width Δθ is equal to 2πLsinθ, and its width is equal to LΔθ. On the other hand, the circular ring on the circular plate 7 corresponding to the circular ring on the spherical surface has a circumferential length of 2πR, that is, 4πL.
It is equal to sin 0.5θ (Equation 12). The width is Δ
2Lsin0.5θ, that is, Lcos0.5θΔθ. Therefore, the unknown light collimating means changes the angle θ to the radial distance R on the disk.
Assuming one-to-one continuous mapping to, the following equation is obtained.

[0074]

[Equation 10]

In the derivation of the above equation, the optical principle that the luminous flux conservation law of the above equation (9) is established for each of the above-mentioned annuli and the brightness is constant in the one-to-one continuous mapping is used. I was there.
When the divergence angle ε is small, the sine of the sine is the angle [rad]
We used the approximation that it is equal to itself. The expression (14) means that the divergence angle is small in the sagittal direction, that is, the circumferential direction because the length is enlarged on the disc, and the divergence angle is small in the meridional direction, that is, the radial direction. This means that the divergence angle becomes large due to the reduction of The above relationship is illustrated in FIG. In the figure, curve 8 shows the sagittal divergence angle, and curve 9 shows the meridional divergence angle.

FIG. 9 shows the divergence angle on the front view of the disk 7. In the figure, the major axis of the ellipse indicating the divergence angle is εm.
(Θ) and the minor axis is equal to εs (θ). When the area of the central circle is equal to the area of the ellipse of the periphery, the illuminance of the periphery becomes equal to the illuminance of the center. In the parabolic mirror system described in the section of the prior art, the divergence angles εm (θ) and εs (θ) in the peripheral portion of the disk are ε (0) cos ² 0.
It was equal to 5θ. That is, divergence angle area cos ⁴ 0.5
It was proportional to θ. This explains the problem of the prior art shown in FIG. 4 from another side.

Εm (θ), εs of the last equation of equation (14)
As can be seen from the form of the (θ) ratio, the square of this ratio is
1 / cos ⁴ 0.5θ, that is, the improvement ratio of the peripheral light amount ratio. In order to maximize the practical effect of the present invention, it is desirable that the improvement ratio is about 1.4 times or more. For this purpose, therefore, the meridional divergence angle of the incident light at the diagonal corner of the liquid crystal panel entrance surface (meaning the entrance surface before passing through the lenticular lens described later) is about 1.2 of the sagittal divergence angle.
It is recommended to double the time. It is assumed that the meaning of the divergence angle was understood by the above explanation.

Next, a method for embodying the unknown light collimating means will be shown in the order of FIGS. Polar coordinates are shown in these figures. The origin is located at the center of the light source, and θ means the zenith angle measured from the optical axis. In these figures, 1 is a light source, 110 is an optical axis, and 7
Is the same disc as in FIG.

In FIG. 10, 114 and 115 are auxiliary lines for designing. Reference numeral 114 corresponds to a portion having a zenith angle of about 60 degrees or less, and 115 corresponds to a portion having a zenith angle of about 60 degrees or more. The length of the radius vector ρ is set according to the following equation, as shown in FIG.

[0080]

[Equation 11]

If the light emitted from the light source 1 in the θ direction is crossed with the auxiliary lines 114 and 115 and then converted into a direction parallel to the optical axis 110 as shown in FIG. The incident illuminance is made uniform. The reason is based on the principle already described in FIG. However, it is extremely difficult to realize the function represented by FIG. 10 by one optical means. Therefore, FIG. 10 is converted into FIG. In FIG. 11, 116 is an auxiliary line, which is
This is a left-right inverted portion of the zenith angle of about 60 degrees or more in FIG.

Next, the function represented by the auxiliary line 114 in FIG. 11 is realized by the first light refraction means and the second light refraction means, and the function represented by the auxiliary line 116 is performed by the first light reflection means. And the third optical refraction means. This is shown in FIG. In the figure, 113 is the first
Of light refraction means, 10 is second light refraction means, and 10 'is third light refraction means.
The light refracting means 117 is a first light reflecting means. Next, the operation will be described. In the figure, a solid line with an arrow indicates an actual ray path. The dotted line is the same as in FIG.

Specifically, the first, second and third light refracting means can be constituted by a light refracting lens or a Fresnel lens. When a Fresnel lens is used, when the known incident angle is α and the outgoing angle is γ according to the above drawing, the prism angle β may be selected according to the following equation. The meaning of each symbol is as shown in FIG.

[0084]

(Equation 12)

In the above equation, n is the refractive index of the medium.

Further, the first light reflecting means indicated by 117 can be specifically realized by a concave mirror. 12 is a main part of the first embodiment of the present invention in which the dotted line part and the auxiliary lines 114 and 116 are removed. By this essential part,
A first embodiment of the present invention is constructed by replacing parts of the prior art light source 1 and parabolic mirror 2 of FIG. The requirements that the main part should have are as follows. In the following description, the light deflection angle of the light refraction means is the angle between the direction of light incident on the light refraction means and the direction of light output from the light refraction means.

(1) The light source means and the liquid crystal panel means are provided, and (2) the first, second and third light refracting means and the first light reflecting means are provided at least in the path from the light source means to the liquid crystal panel means. (3) A part of the output light from the light source means is input to the first light refraction means, and the output light passes through the second light refraction means and the inner peripheral portion of the liquid crystal panel means. Direction, the part of the output light from the light source means is input to the first light reflecting means, and the output light passes through the third light refracting means and then the liquid crystal panel means And (4) the third light refracting means is formed such that the light deflection angle of the outermost peripheral portion is algebraically smaller than the deflection angle of the innermost peripheral portion, 5) The light deflection angle of the innermost peripheral portion of the third light refracting means is equal to the light deflection angle of each outermost peripheral portion of the first and second light refracting means. It is smaller than the sum, and the direction of the emitted light at the innermost peripheral portion of the third light refracting means and the direction of the emitted light at the outermost peripheral portion of the second light refracting means substantially coincide with each other. A liquid crystal display device formed as described above.

As can be seen from the above description, the projection lens 4 and the screen 5 in FIG. 1 are not essential requirements for the first embodiment. Further, as shown in FIG. 12, the second and third light refracting means may be integrally formed.

In the description of FIG. 11, the auxiliary line 114
Although the cutting boundaries of 116 and 116 are described as a zenith angle of about 60 degrees, this angle can be selected as an arbitrary acute angle. The shape of the first light reflecting means is generally aspherical, but a spherical mirror may be used instead.

As described above, it is recommended that the size of the meridional divergence angle of the incident light at the diagonal corner of the liquid crystal panel be about 1.2 times or more the sagittal divergence angle.

Next, FIG. 13 shows modifications of the first embodiment of the present invention. A first modified example in which the drawing is different from FIG. 12 is to add a supporting stem 111 to the light source 1.

The second modification is the second light reflecting means 118.
Is to add. The second light reflecting means is the light source 1
The light utilization efficiency is improved by reflecting the input light from the output light and returning the output light so as to return it to the light source 1. When a metal halide lamp, a xenon lamp, or a magnetron excitation lamp is specifically used as the light source 1, it is desirable to slightly decenter the output reflected light toward the outer peripheral portion of the light source 1. This is because in the seed light source group, blue light tends to be absorbed when the light passes through the plasma inside the light source.

The third modification is the addition of the light shield means 119. As shown in FIG. 13, the light shield means 119 is arranged on the outer peripheral portion of the first light refraction means 113 so as to be along the light emission direction from the light source. The purpose and effect of the light shield means is to prevent the output light from the first light reflection means 117 from being erroneously input to the first light refraction means. As a result, it is possible to prevent an abnormal increase in the light divergence angle, thus improving the contrast ratio of the reproduced image, and thus improving the image quality.

The fourth modification is the third light reflecting means 120.
Is the addition of. As shown in FIG. 13, the means is arranged in the area where the effective surface of the liquid crystal panel 3 does not exist in the light traveling direction of the rear part, and contributes to the improvement of the light utilization rate. The output reflected light 121 of the means is returned in the direction of the light source 1. FIG. 15 shows a front view of the light source side viewed from the liquid crystal panel means. In the figure, reference numeral 120 denotes a third light reflecting means, that is, a shadow portion. Reference numeral 122 denotes a light transmitting portion, the inner peripheral portion of which corresponds to the second light refracting means, and the outer peripheral portion of which corresponds to the third light refracting means. The third light reflecting means includes a third light refracting means and a first light reflecting means.
It may be arranged between the light reflecting means and the light reflecting means.

In FIG. 13, means 10 ', 117, 1
Sealing the gap between 18 and 111 to prevent dust from entering is recommended for use in a dusty environment. It is also effective to fill the closed space with a refrigerant (silicone oil or the like) having a small refractive index. However, in that case, it is desirable that the light source 1 be a well-known double tube type.

In the above-mentioned first embodiment and modification examples of the present invention, the light refracting means means visible light refracting means,
It is desirable to reflect invisible light such as infrared light or ultraviolet light. In particular, it is desirable to provide an invisible light reflecting film on the incident surfaces of the first and second light refracting means, at least. Also,
The light reflection means means visible light reflection means, and it is desirable to transmit invisible light such as infrared light or ultraviolet light.
Such desirable properties can be imparted by applying well-known multilayer film technology. This also holds true for most of the description below.

FIG. 16 shows a modification of the light source means 1.

11 is a spherical light source having stems on both sides, 1
Reference numeral 1'denotes a light source having a light emitting portion which is long in the optical axis direction. When a light source that is long in the optical axis direction is used instead of the light source 1 in FIG. 13, the light source becomes anisotropic with respect to the zenith angle θ, and the amount of peripheral light tends to increase. Therefore, the present invention can be realized more easily.

FIG. 17 shows a modification of the light source arrangement. In the figure, each number is as described above. Reference numeral 123 is a rectangular tube-shaped light guide tube. The direction of the light sources 11 and 11 'is the direction of the short side of the screen,
That is, it is usually effective to improve the light utilization rate by adjusting it in the vertical direction of the screen. In that case, the portion indicated by 117 'of the first light reflecting means in FIG. 17 can be deleted.

Furthermore, FIG. 18 shows a modification of FIG. 13 showing a modification of the first embodiment of the present invention. The first difference of the figure from FIG. 13 is that the first light refracting means and the second light refracting means are embodied by one refracting lens indicated by 113 '. The incident-side interface 113 of the refraction lens forms the first light refracting means, and the exit-side interface 10 thereof forms the second light refracting means.

The second difference is that the third difference is indicated by 120 '.
This is the point where the light reflecting means of (1) is moved to the light incident side of the first light reflecting means. The third light reflecting means is arranged in a region where there is no effective light transmitted to the subsequent liquid crystal panel means. The light reflecting means reflects the light emitted from the light source toward the light source or toward the outer peripheral portion of the light source. Therefore, the light utilization efficiency can be improved. In FIG. 18, 10 'and 11
3 ′ and 3 ′ may be structurally integrated and formed.

FIG. 19 shows still another modification. 18 is different from FIG. 18 in that the outer peripheral portion of the third light refracting means indicated by 10 'is configured to have a negative converging force, that is, a negative light deflection angle.

Third light reflecting means 1 in the configuration of FIG.
A front view of the shape of 20 'based on the Mercator projection as seen from the direction of the light source means 1 is shown in the lower part of FIG. In the figure, the petal-shaped annular portion 120 'of the four-valve is the third light reflecting means.

A dotted line 111 'in the petals of the four valves is the stem portion of the light source means 1. This stem portion is omitted in the sectional view drawn in the upper part of FIG.

FIG. 20 shows another modification of the first embodiment. In the figure, the first, second and third light refracting means in FIG. 19 are formed by a Fresnel lens which is structurally integrated. The meaning of each number in the figure is as described above. The light deflection angle of the innermost peripheral portion of the third light refracting means 10 ′ and the first and second light refracting means 11
Note that the sum of the light deflection angles at the outermost peripheral portions of 3 and 10 changes discontinuously. This property is one of the characteristics common to the first embodiment and its modifications. In the figure, the first light refracting means 113 and the second light refracting means 1
Since the distance to 0 is close, the illuminance on the outer peripheral portion of the second light refracting means tends to be insufficient. However, the illuminance reduction rate is practically acceptable. Alternatively, the decrease in illuminance can be compensated by controlling the light emission light direction of the second light reflecting means 118. In the figure,
A portion 120 ″ indicated by a dotted line beside the third light refracting means 120 ′ corresponds to a short side direction on the reproduced image, that is, a vertical direction in general, in which the third light reflecting means is arranged. 20, the material of the Fresnel lens integrally formed may be a glass material on its light incident side and a synthetic resin on its light emitting side. It is recommended to form a non-visible light reflection film on the entrance surface of the Fresnel lens, because the life of the synthetic resin on the exit side can be extended by doing so.

In FIG. 20, as liquid crystal panel means,
An example of actual dimensions when using a diagonal of 10 inches and an aspect ratio of 4: 3 is as follows.

The diameter of the second light refracting means is about 160 mm, and the maximum diameter of the third light refracting means is about 250 mm.

Each of the above dimensions can be scaled up and down proportionally. In the above example, the length of the short side of the liquid crystal panel is about 1
It is 50 mm, which is smaller than the diameter of the second light refracting means.
Therefore, from the short side direction, the third light reflecting means 120 ', 1
A 20 "gravity bearing structure can be provided and the structure can be provided outside the optical transmission line.

In the above description, the effective portions of the first to third light refracting means and the first light reflecting means have been described on the assumption that they are rotationally symmetric with respect to the optical axis. However, they may generally have a rotationally asymmetric shape. By doing so, the outer edge of the output luminous flux is not circular but rectangular (see FIG.
It is possible to get close to a shape close to 122) of 5).

Next, the countermeasure for the problem in the first embodiment will be supplemented. FIG. 12, 13, 17, 18, 1 described above
At 9 and 20, an annular shade is formed at the boundary between the second light refracting means 10 and the third light refracting means 10 '.
The conditions for reducing this shade to the practical limit on the liquid crystal panel means of FIGS. 13 and 17 are shown in FIG. In the same figure, the portion indicated by diagonal lines 130 corresponds to the above-mentioned shade. The condition for erasing this shadow on the panel surface of the liquid crystal panel means 3 is shown in the following equation.

[0111]

(Equation 13)

In the above equation, D is the distance between the second and third light refracting means and the liquid crystal panel means, and γ (gamma) is the second
It is an angle [rad] at which the main emitting direction of the outer peripheral portion of the light refracting means intersects with the main emitting direction of the inner peripheral portion of the third light refracting means.
G is the width of the shade. As shown in the above equation, set the value of Dγ to 0.5
By selecting G to 1.5 G, the shade interference can be made inconspicuous in practical use.

This is the end of the description of the first embodiment of the present invention. The first embodiment basically belongs to an optical system which is rotationally symmetrical with respect to the optical axis (meaning rotationally symmetrical except for the outer peripheral portion of the output light). The formula (9) discovered by the present inventor is also effective for constructing a rotationally asymmetric collimator optical system. Such modifications will be described later with reference to FIG.

Next, the improvement in the vicinity of the incident surface of the liquid crystal panel 3 which is effectively used in the present invention will be described.

The second embodiment of the present invention is shown in FIG. The figure is a horizontal sectional view. In the figure, 3, 4 and 5 are the same as those described above. Reference numeral 12 is a block in which the light source means and the light traveling direction changing means are put together, and the first embodiment of the present invention described above can be used. However, it is not necessary to be limited thereto. Reference numerals 13, 14, and 15 are three-primary-color three-direction directing means, and specifically, dichroic mirrors for reflecting the RGB primary colors are used. Instead of the dichroic mirrors, the present inventor's JP-A-92-054749
You may use the diffraction grating filter means described in.
Assuming that the angle between the mirrors is 0.5ω as shown in the figure, the angle between the lights emitted from the three primary colors is ω. The value of this ω is
It is selected to be about 1 to 2 times the divergence angle ε (0) described above.
Reference numerals 16 and 16 ′ are polarization direction matching means for matching the light divergence directions of the three primary color three-direction means (13, 14, 15) with the wide directional angle direction of the liquid crystal panel means 3. . Specifically, 16 is a polarizing plate that transmits only light having a polarization plane in a 45-degree oblique direction. The 45-degree oblique direction means the long axis alignment direction of the molecules on the incident side of the liquid crystal layer of the nematic liquid crystal type liquid crystal panel means (3). 16 'is
It is a half-wave plate for rotating the plane of polarization by 45 degrees. As is well known, the plane of polarization can be rotated by 45 degrees by using the half-wave plate with its optical axis (optical anisotropy axis) tilted by 22.5 degrees. Incidentally, the exit side polarizing sheet is usually bonded and integrally formed on the exit surface of the liquid crystal panel (3).
However, the illustration is omitted in this figure. Reference numeral 17 denotes a double-sided lenticular lens, which is provided with three-direction / three-positioning means (first lenticular lens means) 18 on its incident side, and light divergence angle reducing means (second lenticular lens means) 19 on its outgoing side. 20 is a liquid crystal panel means (3)
Pixels. The action of 17, 18, and 19 is shown in FIGS.
3 will be described. Both figures are enlarged views for one cycle. In FIG. 22, 3, 17, 18, 19, and 20 are as described above. Reference numerals 20 'and 20 "respectively denote an incident surface and an emission surface of the liquid crystal panel means 3. Although not shown, a polarizing plate is usually adhered and integrally formed on the emission surface (20") of the liquid crystal panel. A solid line with an arrow in the figure shows a G color light path, and a dotted line with an arrow shows an R, B light path. In a typical application of the present invention, the focal length (f ₁ ) of the light divergence reducing means (19) is set to the distance between the three-direction, three-positioning means (18) and 19 (T _{1 in} FIG. 22). Selected almost equally.
The incident surface (20 ') and the pixel surface (2) of the liquid crystal panel means (3)
0) The distance between the (T ₂₎ is less than T _1, in practice, is chosen smaller than 2/3 of T _1. By doing so, the divergence angle of the emitted light (light passing through the pixel surface of the liquid crystal panel) becomes about 3ω as shown. In practical application, instead of equation (19), as shown in equation (19 ′), T
_By selecting the value of ₁ to be 60% to 120% of the value of f ₁ , one important object of the present invention (improvement of contrast ratio by reduction of divergence angle) can be achieved. This is because by doing so, the increase in the divergence angle of the R and B lights as compared with the G light can be reduced by 60% or more. The focal length f ₀ of the 3-direction 3-positioning means 18 is selected so as to satisfy the equation (19 ″).

[0116]

[Equation 14]

Therefore, the essential constituent feature of this embodiment of the present invention is to satisfy the equations (19 '), (19 ") and the equation (20).

In order to understand the effect of the light divergence angle reducing means (19), FIG. 23 shows a case excluding this. In FIG. 23, the directions of RGB of the light passing through the pixel surface of the liquid crystal panel are not uniform, and the divergence angle thereof is as large as about 6Ω. The divergence angle (3ω) in the present invention is improved by about 1/2 times compared to the divergence angle (6ω) in the conventional technique. The contrast ratio of the reproduced image is inversely proportional to the square of the light divergence angle when passing through the pixel surface of the liquid crystal panel. Therefore, according to the present invention, the contrast ratio can be improved to about 4 times. Further, since the diverging direction of light is matched with the wide directional angle direction of the liquid crystal panel means, the effect of improving the contrast ratio becomes great.

This is the end of the basic description of the second embodiment of the present invention. In FIG. 21, the lenticular lens is shown only for four cycles for the purpose of easy understanding of the figure, but in reality, several hundred cycles or more are formed in one panel. The same applies to subsequent figures. In FIG. 21, the half-wave plate (16 ') may be omitted depending on the application. In that case, the color purity or the contrast ratio is slightly deteriorated.

24 (a), 24 (b) and 24 (c) show a modification of the light divergence angle reducing means (19). FIG. 24A shows the case of a trapezoidal columnar lenticular lens. FIG.
FIG. 24B shows a concave lens on each side of the trapezoid of FIG. FIG. 24 (c) shows a convex lens on each side of the trapezoid of FIG. 24 (a). That is, as shown in FIG.
The divergence of light in the left-right direction is prevented and the divergence of R, G, B lights is reduced. FIG. 24 is effective when the divergence angle ε (0) of the incident light described above is sufficiently smaller than ω. However, it is not effective when ε (0) is almost equal to ω. This is the end of the description of FIGS. 24 (a), (b), and (c).

FIG. 25A shows a further modified example. 21-
24 is a horizontal sectional view, while FIG. 25 (A) is a vertical sectional view. In addition to the configuration of FIG. 22, FIG.
Lenticular lens means 1 for converging light in a vertical direction (a narrow directional angle direction of a liquid crystal panel) for improving the light utilization rate.
7'is added. The requirement of this configuration is that the focal length of the lens means 17 ′ is larger than the focal length of the lens means 18. By doing so, deterioration of the contrast ratio can be suppressed to the minimum and the light utilization rate can be improved.

FIG. 25 (B) shows a modification for applying the present invention to a polarizing glasses type stereoscopic display. 2 in the figure
0 ″ is the exit side polarization plate described above,
Reference numeral 0'denotes a horizontal striped half-wave plate for rotating the plane of polarization by 90 °. As is well known, by using the half-wave plate with the optical anisotropy optical axis inclined by 45 °, the polarization plane can be adjusted to 90 °.
° Can rotate. 1001, 1002, 1003, 100
Reference numeral 4 denotes emitted light corresponding to the first, second, third and fourth scanning lines, respectively. As can be seen from the figure, only the even-numbered outgoing lights have their polarization planes rotated by 90 °. The left eye signal is applied to the pixels corresponding to the odd-numbered scanning lines, and the right eye signal is applied to the pixels corresponding to the even-numbered scanning lines.
Polarizing glasses worn by the viewer are polarizing plates 2 for the left eye.
A polarizing plate passing only light corresponding to 0 ″ is added, and a polarizing plate passing only light passing through the half-wave plates 1000, 1000 ′, ... Is added for the right eye. As a practical method of forming the horizontal stripe-shaped half-wave plates (1000, 1000 ′, ...), a light distribution film-using type molecular alignment direction alignment method well known in the liquid crystal panel manufacturing technology is used. The lenticular lens means 1 has an effect unique to this configuration.
7'and striped half-wave plate (1000, 1000 ',
...), the left-eye emission light and the right-eye emission light can be separated without mutual crosstalk, and thus a high-quality stereoscopic image can be provided.

FIG. 26A shows the third embodiment of the present invention. The feature of this example is that the Fresnel lens means 11 is arranged on the exit side of the liquid crystal panel means (3). The Fresnel lens means (11) can converge the emitted light in the direction of the projection lens means (4), so that the projection lens means (4)
It has the advantage that the diameter of can be reduced.

In FIG. 26 and other figures, the projection lens means (4) is shown as a single lens element for the sake of simplicity, but it is actually composed of a plurality of lens elements. Although not shown, the shape of the squeezing of the projection lens means (4) is recommended to be formed into an ellipse or an ellipse having a major axis in the wide directivity direction of the liquid crystal panel means (3). . This is because by doing so, unnecessary extraordinary light can be prevented from passing, and therefore the contrast ratio (image quality) of the reproduced image can be improved.

A modified example of the Fresnel lens means (11) is shown in FIG. In the figure, 170 is a first Fresnel sheet, 171 is a second Fresnel sheet, 172 is a Fresnel lens surface formed on the exit side of the first Fresnel sheet,
173 is a Fresnel lens surface formed on the incident side of the second Fresnel sheet, 174 is a discontinuous portion of the first Fresnel sheet, 175 is a discontinuous portion of the second Fresnel sheet, 17
Reference numeral 6 is an adhesive portion for attaching both sheets at the peripheral portion. According to this configuration, the angle of view (α) can be expanded to about 30 degrees or more, and thus a compact optical system with a short projection distance can be configured.

FIG. 27 shows a fourth embodiment of the present invention for improving the light utilization efficiency. The inside of the dotted line in the figure is the main part of this embodiment, the light utilization rate improving means, and is a structure for utilizing both the P wave and the S wave. The inside of the dotted line is a symmetrical structure, so only the right half will be described. Reference numeral 21 denotes a polarization beam splitter which transmits P waves and reflects S waves. Reference numeral 22 denotes a half-wave plate for rotating the plane of polarization by 90 degrees, which converts P waves into S waves. Reference numeral 23 is a reflecting mirror. Although this figure shows the format using the S wave, the format using the P wave may be used instead.

In FIG. 27, a dichroic mirror for reflecting a part of the unnecessary spectrum is further provided between the three primary color three-direction directing means (13, 14, 15) and the unit surrounded by the dotted line to improve the color purity. May be placed.

FIG. 28 shows a partial modification of FIG. Two
Reference numeral 1'denotes a polarizing beam splitter, 22 'a half-wave plate for rotating the polarization plane by 90 degrees, and 23' a reflecting mirror.

27 and 28, the light utilization efficiency can be improved about twice. In both figures, the triangular columnar space between the polarization beam splitter and the reflecting mirrors 23, 23 'may be filled with a liquid or gel material and formed integrally with the polarization beam splitters 21, 21'. This is the end of the description of FIGS.

FIG. 29 shows an application example of the present invention to an optical fiber type liquid crystal display. The parts such as the light advancing direction changing means are not shown in this figure. In the figure, 17 and 3 are already described. Reference numeral 24 is an optical fiber group, 25 is an optical fiber input end, and 24 'is an optical fiber output end, that is, an image display section.

In FIG. 29, the fiber light receiving end (25)
It is recommended to connect the liquid crystal panel means 3 and the emission surface of the liquid crystal panel means 3 with a liquid or a silicone gel without an air layer. By doing so, the reflection loss at the interface can be reduced and the contrast ratio of the reproduced image can be improved.

FIG. 30 shows an application example of the present invention to a direct-viewing type liquid crystal display. In the figure, 26 is a lenticular lens means for diverging light in the vertical direction.

FIG. 31 shows a direct-viewing type liquid crystal display of the type obtained by rotating FIG. 30 by 90 degrees. 30 and 31,
The wide-angle direction of the directional characteristics of the liquid crystal panel means (3, 3 ') is
It is the horizontal direction in FIG. 30 and the vertical direction in FIG.

FIG. 32 is an enlarged horizontal sectional view of the embodiment shown in FIG.
Shown in In the figure, 26 'is a lenticular lens means for diverging light in the horizontal direction, 35 is a lenticular lens, 3
6 is a black stripe (black print portion). In this configuration, in order to prevent the occurrence of the interference of the moire pattern due to the interference between the pixel (20) structure of the liquid crystal panel means (3 ') and the lenticular lens (35) structure, the conditional expressions shown in FIG. There is a need. That is, the quotient obtained by dividing the product of the distance (T ₃ ) between the pixel surface and the focal plane of the lenticular lens by the divergence angle (ε) of the incident light by the refractive index (n) of the medium is the array pitch P of the lenticular lens. Must be greater than 0.75 times. If the quotient is equal to the pitch, the Moire disturbance is very small. The same applies to moire interference in FIG.

The structure shown in FIG. 31 has an advantage over the structure shown in FIG. 30 in that deterioration of the contrast ratio due to ambient light 12 on the image display surface of the liquid crystal display can be reduced.
This is the end of the description of FIGS.

This completes the description of the third and fourth embodiments of the present invention and their applications.

Next, when the present invention is combined with a transmissive screen to form a projection type liquid crystal display, the moire interference caused by the interference between the screen vertical stripe structure and the liquid crystal panel vertical stripe structure is reduced. The means will be described.

FIG. 33 shows an example of the structure of a transparent screen.

In the figure, 27 is a lenticular lens for converging and diverging light in the vertical direction, and its pitch is about 0.1 mm.
Below, 28 is a Fresnel lens surface and its pitch is about 0.1.
mm and 29 are lenticular lenses for converging and diverging light in the horizontal direction, the pitch thereof is about 0.5 mm, and 30 is a black stripe surface. The lenticular lens 29 and the vertical stripe pixel structure of the liquid crystal panel interfere with each other to cause moire interference.

FIG. 34 shows a side view of a projection type liquid crystal display in a cabinet. In the figure, reference numerals 12, 3, 4, and 5 are already described. Reference numerals 31, 32, and 33 are light reflecting means.

In order to eliminate the above-mentioned moiré disturbance, in the prior art, it was necessary to mix a large amount of diffusing material into the screen constituent member. Therefore, there is a problem that the projection light is absorbed by the diffusing material and the light utilization rate is reduced. In addition, the focus and contrast ratio are deteriorated due to the mixing of a large amount of the diffusing material, and thus the image quality is deteriorated.

In the projection type liquid crystal display according to the fifth embodiment of the present invention, the light reflecting means 32 of FIG. 34 is formed in a cylindrical shape in the vertical direction or the horizontal direction to reduce the moire interference. Therefore, it is possible to eliminate the use of a large amount of diffusing material and thus improve image quality.

The principle of reducing moire interference is shown in FIG.

In the figure, 32 is a cylindrical light reflecting means, and 34 is a cross section of a light beam. The solid arrows are the upper and lower rays of the bundle of rays,
The dotted arrows are the left and right rays of the bundle of rays.

If the screen is arranged at the converging position of the upper and lower light rays, the vertical resolution does not deteriorate in the reproduction screen on the screen. On the other hand, the horizontal spot size has a width A as shown. By selecting this width A to be about 1.22 times the pitch T of the lenticular lens 29, the moire interference can be greatly reduced. Practically, the horizontal defocus width A is set to 0.8 of the pitch T of the lenticular lens 29.
The effect can be sufficiently obtained by selecting more than twice. FIG. 36 shows the calculated value of the moire interference reduction effect of the cylindrical mirror when the aberration of the projection lens is assumed to be zero.

To make the light reflecting means 32 cylindrical, a moment may be applied. To give a moment,
The deflection of the mirror itself due to gravity may be used, or a moment may be applied by a spring or the like. When the given moment is M, the radius of curvature R of the mirror is given by the following equation based on the material mechanics.

[0147]

(Equation 15)

The relationship between the radius R, the horizontal defocus width A, the projection distance D, and the lateral width W of the light bundle is given by the following equation.

[0149]

[Equation 16]

The above equation can be used to find the required radius value and therefore the required moment value, and this embodiment can be easily embodied. This is the end of the description of the moire interference reduction utilizing the deformation of the mirror. Measures for reducing the BS screen moire interference by devising the liquid crystal panel emission unit are shown in FIGS.

FIG. 38 shows a front view when the present invention is applied to a rear projection type display. In the figure, 5 is a screen, 177 is a cabinet, 178 and 178 'are speaker placement parts, 179 and 179' are optical disk players, and V
It is an arrangement part of a shelf for storing TRs, optical disks, tapes and the like. This example is recommended for use with the examples shown in FIGS. This is because the depth of the cabinet can be made compact by applying the embodiment of FIGS.

Next, the ghost trouble caused by the internal reciprocal reflection of the projection light in the Fresnel sheet used in the transmission screen will be described.

FIG. 39 shows a horizontal sectional view of the Fresnel sheet in the transparent screen shown in FIG. 28 'in the figure
Is a Fresnel sheet, and 28 is a Fresnel lens surface. 1
80 and 180 'are effective projection rays and dotted lines 181 and 181'
Is a ghost disturbing light. Since these disturbing lights are directed in the horizontal oblique direction, they are absorbed by the black stripes (30) described in FIG. Therefore, no ghost interference originally occurs at the left and right ends of the screen. But on the other hand,
Black stripes (3
0) cannot be absorbed. Therefore, a ghost disturbance of the type shown in FIG. 40 is observed on the screen. In the figure, 5'is a screen frame, and four circles are images.
182 and 182 'are ghost interference images.

The inventor tried various experiments focusing on this ghost interference. As a result, they found that the ghost interference was significantly reduced by limiting the polarization direction (electric field) of the incident light to the screen.

Next, the result of the clarification as to why the ghost interference at the upper and lower ends is reduced by limiting the polarization direction of the screen incident light to the vertical direction will be described. FIG. 41 shows the light emitting angle dependence of the interface reflectance of P-wave and S-wave. In the figure, the curve 183 is the reflectance of the S-wave, 184
Is the reflectance of the P-wave. The value of each reflectance is given by the equation (4
It was calculated by 2). The reflectance of the P-wave is zero at the so-called Brewster angle. The Brewster angle, exit angle in FIG. 39 (theta) is tan ~ ^{1 1} / n
It means an angle equal to (about 56 degrees). In fact, in a rear projection display, the emission angles (θ) are usually distributed in the region shown by 185 in FIG. 41 at the upper and lower ends of the screen. The P-wave for the Fresnel sheet at the upper and lower ends of the screen means vertically polarized waves.

Therefore, in light of the optical principle, it is understandable that the ghost interference at the upper and lower ends is reduced by limiting the polarization direction of the screen incident light to the vertical direction.

FIG. 42 shows one embodiment of the present invention made based on the above experiment and consideration. In the figure, 16 ', 1
Reference numerals 6, 17, 3, 11, 4, and 5 are the same as those in FIG. Reference numeral 186 denotes a half-wave plate for rotating a polarization plane of 45 degrees, which is a main part of the present embodiment, and is a liquid crystal panel (3).
And the screen (5). The operating principle will be described with reference to the polarization plane transition shown in FIG. Polarization plane 45
The incident light on the half-wave plate 16 'for rotation is vertically polarized.
The polarization direction of the output light of the polarizing plate 16 is 45 degrees to the right.
The polarization direction of the output light after passing through the polarizing plate (20 ″ in FIG. 22) on the exit surface of the liquid crystal panel 3 is 45 degrees left. The polarization direction of the output light after passing through the half-wave plate (186). Therefore, the polarization direction of the incident light on the screen can be limited to the vertical polarization, and therefore, the ghost interference at the upper and lower ends of the screen can be reduced.

The essential condition to be provided in this embodiment is that the polarization direction of the incident light on the screen is limited to the substantially vertical direction. The use of the half-wave plate (186) in FIG. 42 is one sufficient condition for satisfying the above-mentioned essential conditions in this special embodiment. Because, for example, the input light to the liquid crystal panel (3) is horizontally polarized and the output light is limited to vertically polarized light, the half-wave plate 1
6 ', 186 can be deleted, and the screen upper and lower end ghost interference reduction which is the object of this embodiment can be reduced, and
This is because such a configuration is included as one of easy modifications of this embodiment of the present invention.

Furthermore, by arranging a half-wave plate between the Fresnel sheet and the black stripe sheet of the black stripe type screen shown in FIG. The polarization direction of can be converted to the horizontal direction. That is, it functions as a polarization direction leveling means. By doing so, the light reflection loss at the entrance / exit surface of the black stripe sheet can be reduced by applying the principle described above with reference to FIG. Therefore, the viewing angle in the left-right direction can be expanded, and the applicable fields of the present invention can be expanded. The polarization direction leveling means may be integrally joined to the light emitting side of the black stripe sheet.

A modified example of the three-primary-color three-direction directing means (13, 14, 15) described above with reference to FIG. 21 is indicated by a dotted line 190 in FIG.
Shown in In the figure, 12, 16, 17, 3, and 20 are as described above. 191 is a diffraction grating plate, and 192 is a mirror. The detailed structure and principle thereof are shown in FIG.

Reference numeral 191 'denotes a diffraction grating surface, the diffraction grating array period is p, and the modulation depth is h. Reference numeral 193 is a positive diffraction first order light, and 194 is a negative diffraction first order light. The related formulas are shown below.

[0162]

[Equation 17]

In the above equation, n is the refractive index of the diffraction plate (about 1.5), α is the diffraction angle of the green diffracted first-order light, λ _R , λ _G , and λ.
_B is the wavelength of red, green, and blue, respectively.

Expression (23) is a condition for eliminating the output zero-order light of the diffraction plate (191).

Expression (24) shows the relationship between the diffraction angle (α) of the primary light and the array period (p) of the diffraction grating. Expression (26) shows the relationship between the two-color angle (ω) and the diffraction angle (α). FIG.
This is shown in FIG. As can be understood from FIG. 44, the positive diffraction first-order light and the negative diffraction first-order light have a mirror image relationship with each other with the direction of the incident light as an axis. Therefore, by arranging the mirror (192) in parallel with the direction of the incident light, the outgoing light (195) of the mirror (192) is reflected by the positive diffraction 1
It becomes parallel to the next light (193). That is, the mirror (1
Reference numeral 92) reflects the input negative diffracted first-order light and converts it into output light parallel to the positive diffracted first-order light. The shaded area in FIG. 45 indicates the effective range of the present invention. This is based on the equation (24), and the array period (p) of the diffraction grating is 1.6 μm or less (α ≧ 20 °) 0.65.
This is equivalent to μm or more (α ≦ 55 °). This is because the angle (ω) between the two colors becomes too small or too large when it exceeds this range. With this configuration, the device can be made smaller and less expensive than the configuration of FIG.

The present inventor once found that Japanese Patent Application No. 04-054
In FIG. 12 of 749, the use of a diffraction grating was proposed. However, in this proposal, only the positive diffraction first-order light is used and the negative diffraction first-order light is not used. Therefore,
According to the present invention shown in FIGS. 43 and 44, Japanese Patent Application No. 04-0
The light utilization efficiency can be improved as compared with 54749.

FIG. 52 shows a modification of FIG. 43.
In the figure, the inside of a dotted line 190 'is a three-primary-color three-direction directing means. In FIG. 43, a light transmission type diffraction grating plate is used, whereas in FIG. 52, a reflection type diffraction grating plate 38 is used. 38 'is a diffractive reflection surface. In this example, the conditional expression for eliminating the output zero-order light is expressed by Expression (23).
Instead of, the depth of the diffraction grating: h = λ _G / 4 is used. This is the same as the equation (23) in the physical meaning of giving a phase difference of 180 degrees. Therefore, equation (24)
(26) can be applied as they are. Therefore, the operation principle is the same.

FIG. 53 shows still another modification.
In the figure, 39 is a transparent coating for protecting the diffraction reflection surface (38 ') from dust and the like. When the refractive index of the coating medium is n, the depth of the diffraction grating is h ′ = λ _G
It can be made shallower than / 4n as compared with the previous example. Therefore, its manufacture is facilitated.

FIG. 46 shows still another modification.
In the figure, reference numerals 191 ', 196 and 197 are the main parts of this configuration, and the details thereof are shown in FIG. Reference numeral 198 denotes an intermediate color attenuation filter for improving color purity, which attenuates an orange component or the like generated by mercury contained in the light source. Specifically, a well-known multilayer interference film filter or a colored resin filter can be used. In FIG. 47, reference numeral 191 'is as described above, and the three primary color lights are made into six directions. 197 is a prism array.

The size of the prism angle (β) is selected to be equal to or less than the angle (2α ′) between the positive and negative diffracted blue primary lights. Further, the prism angle (β) is selected so that the outgoing blue color is parallel to each other. Therefore, 196 can be referred to as a three-primary-color five-direction direction unit.

The arrangement of the pixels (20) of the liquid crystal panel means (3) in FIGS. 46 and 47 is RGBG, RGBG,
It is RGBG. The array period of the lenticular lens plate (17) is set equal to the width of the RGBG1 section. The thickness of the lenticular lens plate is selected to be approximately equal to the focal length of the lenticular lens. (However, it is shown compressed in the figure.) By doing so, input light having 5 directions (blue: 1 direction, red: 2 directions, green: 2 directions),
It is possible to lead to the positions of R, G, B, G, and R pixels, respectively. In FIG. 47, the array period of the prism array (197) does not have to match that of the lenticular lens, and may be arbitrarily selected (about 1 mm to 0.1 mm). This is because by providing a distance between the prism array (197) and the lenticular lens, moire interference between the two can be easily eliminated.

According to the configuration of FIG. 46, in addition to the effect of improving the light utilization rate described above, the effect that the pixel arrangement pattern can be matched with the visual psychology can be obtained. As is well known, green is
It contributes most to the resolution of details. Therefore, the above configuration in which the number of green pixels is twice the number of each of red and blue has a preferable property in terms of visual psychology.

It should be noted that the structure of FIG. 47 is not color-separated by the prism (197).
In this configuration, color separation is achieved by the diffraction grating (191 '). Therefore, the prism (197) only refracts light. This is the end of the description of FIGS.

As a modification of the above example, the pixel array is (RG
BBGR), and the positive and negative diffracted blue primary light in FIG. This is referred to as three primary colors in six directions and six directions in six positions.

Next, a method of forming the incident side thin glass plate of the liquid crystal panel means (3) in FIGS. 21, 43 and 46 will be described.

In FIG. 48, 198 is a conventional liquid crystal panel means, 3 is a liquid crystal panel means of the present invention, 20 is a pixel column,
T ₂ is the thickness of the incident side glass plate, and T ₃ is the thickness of the exit side glass plate. In the prior art, in the case of a diagonal size of 10 inches, T ₂ and T ₃ are equal to each other and about 1 mm.
Met. It has been considered that using a thinner glass plate is not suitable due to insufficient image accuracy and deformation due to local temperature distribution abnormality.

The incident side of the liquid crystal panel means (3) of the present invention,
A specific example of the thicknesses T ₂ and T ₃ of the exit side glass plate is about 0.2 mm
And 1 mm. Next, the outline of the forming procedure will be described.

(1) A wiring pattern, a TFT, a charge holding capacitor, and a light distribution film are formed on the light-incident side of the exit side glass plate as in the prior art.

(2) The incident side glass plate is subjected to pre-annealing for providing an even distribution valence heavy adhesion at the time of mounting. Details of the pre-annealed shape will be described later.

(3) A transparent conductive film (ITO) and a light distribution film are formed on the light exit side of the incident side glass plate as in the prior art.

(4) Spherical spacers (diameter of several μm) are uniformly distributed on the surface of the exit side glass plate on the TFT side. Banks for sealing are formed on the four sides of the periphery.

(5) The incident side glass plate is superposed on the emitting side glass plate.

(6) Liquid crystal is injected into the gap between the two glasses and sealed.

Of the above-mentioned forming procedures, the only difference from the prior art is the pre-annealing of item (2). The pre-annealing is described below.

The principle is shown in FIG. 49 for easy understanding. 19 in the figure
9 shows a flat plate in a weightless state. 200 is a flat plate 199
It is shown that when gravity is applied to, it bends due to its own weight. 201 is the shape of the pre-annealed plate in the weightless state. Reference numeral 202 indicates that the plate 201 which has been appropriately pre-annealed becomes a flat plate when gravity is applied.

Even if gravity is applied, the pre-annealing must be further strengthened in order for the thin plate to have an upward adhesive force. The conditions are shown below by mathematical expressions.

According to the material mechanics, there is the following relationship between the curvature θ _{1 of the} thin plate and the weighted area density F ₂ .

[0188]

(Equation 18)

Since the pre-annealing warps the plate only in one dimension (usually the direction of the short side), letting S be the creepage coordinate measured along that dimension, equation (27)
Δθ _{1 in the} inside becomes θ ₁ ″.

[0190]

[Formula 19]

The condition for applying the adhesive force even in the gravitational action state is as follows.

[0192]

(Equation 20)

The following equation is obtained by solving the differential equation of equation (30).

[0194]

[Equation 21]

The curvature θ ₁ is given by the following equation by using the Gaussian complex coordinate (x, jy) = z shown in FIG.

[0196]

[Equation 22]

FIG. 50 is a graph showing the result of computer calculation of the equation (36) by the numerical integration method. Expression (3
6) is a complex number, whose real part is x,
Only the right half of the graph is displayed with the imaginary part as y.

As can be understood from the above description, pre-annealing is applied to the thin plate so that the adhesion pressure, which is determined by the second derivative with respect to the one-dimensional coordinate (s) of the curvature of the thin plate, is larger than the own weight of the thin plate. By doing so, it is possible to always apply a stable contact pressure to the pixel forming portion of the liquid crystal panel means. This manufacturing method is particularly effective when applied to a large-sized panel having a diagonal size of more than 15 inches.

FIG. 51 shows the constituent materials of the double-sided lenticular lens 17. In the figure, 203 is a glass base material having a thickness of about 0.5 to 2 mm, and 204 and 205 are ultraviolet curing resins such as acrylic resin, which are formed on the surface of the glass base material (203), and the thickness thereof is usually about 0. Within 1 mm. Therefore, the coefficient of linear expansion of the double-sided lenticular lens as a whole in the left-right direction in the figure substantially matches that of the glass substrate, and therefore matches that of the liquid crystal panel means. Double-sided lenticular lens 4
Edges (upper and lower edges and left and right edges) are adhesively fixed to the liquid crystal panel means (3).

Therefore, the arrangement phase of the lenticular lenses and the arrangement phase of the pixels in the liquid crystal panel means (3) can be kept substantially unchanged with respect to the temperature change. As an alternative to the four edge bonding, the space between the liquid crystal panel and the double-sided lenticular lens is filled with a medium whose refractive index is smaller than that of the lenticular lens medium (for example, silicone resin) to cover the entire surface. You can glue it.

In FIG. 51, if the base material 203 is made of a resin material, the distance between the base material 203 and the liquid crystal panel means is about 70 ppm.
A difference in linear expansion coefficient of / ° C occurs. Therefore, 0.1% difference in expansion and contraction due to a temperature change of 14 ° C (panel size 100 mm on one side
In that case, a difference of 0.1 mm) occurs. Since this value is almost equal to the pixel size, the color tones are totally wrong at the left and right edges of the screen.

That is, by forming the base material of the lenticular lens (17) as a glass material of the same quality as the liquid crystal panel means (3), it is possible to prevent change in color tone due to temperature change.

As described above, the first embodiment of the present invention belongs to an optical system which is rotationally symmetric with respect to the optical axis. The aspect mismatch loss is considerably improved as compared with the prior art, but the mismatch loss still remains. FIG. 54 shows a basic configuration of a modified example of the collimator for further reducing the aspect mismatch loss and improving the light utilization rate.

In FIG. 54, 1 is a light source and 3 is a liquid crystal panel. For convenience of explanation, description will be given based on a defined polar coordinate system of latitude, longitude, east, west, north, and south with the light source as the origin. Fifty
Reference numeral 1 is a spherical light reflecting means arranged in the western hemisphere, 502 is a first direction light deflecting means, and 503 is a second direction light deflecting means. Reference numerals 502 and 503 form the collimator means of this modification. 504 is simply an ellipsis.

In the figure, spherical light reflecting means (50
1) acts so that the light emitted from the light source (1) to the western hemisphere is returned to the light source (1) and re-emitted to the eastern hemisphere. The first direction light deflector (502) acts to deflect the light in the latitudinal reduction direction. The second direction light deflecting means (503) acts so as to deflect the light in the longitude spread reduction direction. By the action of the first-direction light deflecting means and the second-direction light deflecting means, the cross section of the output light can be made into a substantially rectangular shape. Therefore, the aspect ratio mismatch loss in the prior art can be eliminated and the light utilization rate can be improved.

FIG. 55 shows one specific example of the above basic configuration. The upper half (A) is a front sectional view, and the lower half (B) is an elevation sectional view, that is, an equator sectional view. In the figure, 1 is a light source, 11 is its stem, 3 is a liquid crystal panel, 501 is a spherical light reflecting means arranged in the western hemisphere, 5
Reference numeral 02 denotes a semi-cylindrical first-direction light deflector arranged in the eastern hemisphere, 503 denotes second-direction light deflector arranged in the eastern hemisphere,
504 is an ellipsis symbol. 503 is 503-1, 503
Each of the flat linear Fresnel sheets indicated by -2, 503-3, 503-2 'and 503-3'.
The first direction light deflecting means (502) is a semi-cylindrical Fresnel sheet having a linear Fresnel lens surface (502-1) formed on the outer surface side thereof, as shown in the figure. The cylindrical shape is
A thin flat plate Fresnel sheet manufactured in advance into a flat plate,
It can be easily realized by annealing in a cylindrical shape. Alternatively, it can be formed by adhering a flat Fresnel sheet to the outer surface of a rigid transparent semi-cylindrical body that is separately manufactured.

Above, the explanation of the configuration of FIG. 55 is finished, and then its operation will be explained. In the figure, the solid line with an arrow emitted from the light source (1) indicates the path of the light beam. The angle θ is the latitude component indicating the light emitting direction, h is the latitude distance coordinate on the liquid crystal panel (3), the angle φ is the longitude component indicating the light emitting direction, and k is the longitude distance coordinate on the liquid crystal panel (3). is there.

The first direction light deflecting means (502) refracts and deflects light in the latitudinal direction as shown in the figure. At that time, when the deflection angle of the first direction light deflecting means (502) is selected so as to satisfy the following equation, the illuminance of the incident surface of the liquid crystal panel (3) is compared with that of the incident surface of the means (502) in the latitudinal direction. Can be made more uniform and improved. The reason is that the solid angle measured around the point light source is proportional to the sine of the latitude (θ). (Note: In the so-called Mercator projection, θ is used instead of the right side of Eq. (38), so the planes near the North and South poles are unduly enlarged.)

[0209]

(Equation 23)

Here, θ is the latitude, and h is the liquid crystal panel (3).
It is the upper latitude coordinate.

Above, the description of the first-direction light deflecting means (502) is finished, and then the second-direction light deflecting means (503) will be explained. Since the elevation view (b) of FIG. 55 is vertically symmetrical, only the upper half will be described. The second-direction light deflector (503) is
As shown in the figure, the light is refracted and deflected in the longitude spread reduction direction.
At that time, each Fresnel sheet 503-1, 503-2 ',
The deflection angles are set so that the total of the deflection angles 503-3 'satisfies the following equation.

[0212]

[Equation 24]

Here, φ is the longitude and k is the liquid crystal panel (3).
It is the upper longitude coordinate.

The above equation is based on the fact that the light emission characteristic from the light source is generally rotationally symmetrical in the longitudinal direction.

As shown in the figure, the Fresnel sheet 503
It is a simple design method to make -2 'and 503-3' mirror-symmetrical to each other. That is, Fresnel sheet (50
The light incident on each position of 3-2 ') is emitted parallel to the normal direction of the Fresnel sheet surface, and the Fresnel sheet (50
3-3 ′) becomes incident light, and the emitted light is 1 ′.
It is set so that the light is emitted in the direction indicated by (dotted line). (The design formula of the prism angle of the Fresnel lens has already been described in Equation 17.) In FIG. 55, the point 1'is
The Fresnel sheet (503-2 '/ 3') is located at a mirror-symmetrical position with respect to the light source (1).

As a material of the Fresnel sheet, a methacrylic resin having a large Abbe number, that is, a small chromatic aberration is suitable. The corresponding portion of the Fresnel sheet (503-1) receives the emitted light and refracts and deflects the light toward the liquid crystal panel (3) so that the expression (39) is substantially satisfied.

Above, the explanation of the principle, operation, and construction method of the basic portion of FIG. 55 is completed, and then the supplementary portion will be explained.

In the front sectional view (A) of FIG. 55, the Fresnel sheets (503-2, 2 ', 503-3, 3') are not shown in order to avoid unnecessary complexity in the appearance of the drawing. .

In FIG. 55 (B), equations (39) k to φ
In order to satisfy the relationship, in section D, the rays are slightly tilt-corrected in the longitudinal direction. To eliminate tilt correction,
The Fresnel sheet (503-1) may have a curved plate shape (dotted line 503-1 ') instead of the flat plate shape. That is, the curved plate (5
It is sufficient to arrange so that the light incident coordinates on 03-1 ') satisfy Expression (39). For that purpose, the two-dimensional coordinate pair of the curved plate may be shaped so as to be proportional to (φcotφ, φ). Further, the curved plate may have a shape similar to a polygonal line. By doing so, it can be constructed inexpensively and easily.

50 located at the north and south ends in FIG.
5,505 'are semi-annular light reflecting means.

The 505/505 'is shown only on the front sectional view (A) side in order to avoid unnecessary complexity of the drawing. The reference numeral 505/505 'is for reversing the latitude in the direction of the light emitted in the directions of the north and south poles and effectively utilizing it. The 505/505 'is a half cylinder (502)
The inner cylindrical surface or the north-south end side surface of the semi-cylindrical (502) is arranged close to (or adhered to).

Reference numerals 506-1, -2, -3, and -4 are light guide wall means arranged along the outer edge of the optical path, and mirrors or square walls are used. The light guide wall has a function of preventing the illuminance of the peripheral portion of the liquid crystal panel (3) from being lower than that of the central portion thereof. The squarer type light guide wall means applies the principle of the squarer shown in FIG. 62, which will be described later.

In an application where the distance (D) between the Fresnel sheet (503-1) and the liquid crystal panel (3) is very small compared to the size of the liquid crystal panel (3), the liquid crystal panel (3) is In order to collimate the incident light, it is effective to add lens means to the light incident side of the panel (3). Alternatively, it is effective that the lens means collimates light in the direction of the entrance pupil of the projection lens means arranged on the exit side of the liquid crystal panel (3).

When the value of D is equal to or larger than the size of the liquid crystal panel (3), it is not necessary to add such lens means. This is because the incident light on the liquid crystal panel (3) is already sufficiently parallel.

In FIG. 55, the ratio of the dimension (X) in the longitude direction of the liquid crystal panel (3) to the dimension (Y) in the latitude direction,
That is, the aspect ratio is about 2. Therefore, it is suitable for normal use to make the former correspond to the horizontal width (horizontal width) of the screen and the latter to correspond to the vertical width (vertical width) of the screen.

If the value of the aspect ratio is K, then FIG.
In the arrangement example of, the following equation is given.

[0227]

(Equation 25)

Therefore, in order to further increase the K value, D503
The / D502 ratio should be large.

On the contrary, there are two methods for reducing the K value. The first method is shown in FIG. In the figure,
1, 3, 11, 501, 502, 503, 504 are already described. In this figure, the north-south ray (508-
1, 508-2) is divergent, which is the difference from FIG. As a result, the vertical width (Y) can be increased according to the traveling distance (D), and thus the aspect ratio can be decreased. 507 is
A linear Fresnel sheet for a collimator. If the D value is sufficiently larger than the size of the panel (3), this sheet (507) can be omitted. Also in this example,
It is effective to improve the uniformity of the illuminance of the panel (3) by satisfying the relationship of h to θ in the above-mentioned expression (38). FIG.
Ends the explanation.

In FIG. 56, the latitude direction enlargement in the section D is used, but conversely, the longitude direction reduction in the section D may be used. For that purpose, another Fresnel sheet having different powers in a mirror-symmetrical manner may be added to the emission side of the Fresnel sheet (503-1).

The second method for reducing the aspect ratio is to double the north-south width (vertical width) by using a polarization beam splitter and a mirror. The drawing for that is shown in FIG.
Will also be written. In that case, the aspect ratio is halved, and therefore K ′ in the equation (40 ′) is obtained.

This completes the description of the supplementary portion of FIG.

Next, FIG. 57 shows a local modification of the collimator shown in FIG. 57 is different from FIG. 55 in that
Only 2'and 503'-1 are shown, and the others are slightly omitted, but they are almost the same. 502 'is a first-direction light deflecting means, which is an aspherical semi-toroidal shape. 5
Reference numeral 03'-1 is an aspherical columnar lens forming a part of the second-direction light deflector 503 '. The relationship between h and θ and the relationship between k and φ are as shown in the above equations (38) and (39). Therefore, the operation principle is also the same. However, in this example, unfortunately, the semi-annular light reflecting means (505/505 'in FIG. 55) cannot exert its effect. This is the end of the description of FIG. 57.

Since the Fresnel sheet is lightweight, FIG. 55 is suitable for an optical system having a relatively large size, and FIG. 57 is suitable for an optical system having a relatively small size.

In FIG. 57, the divergence angle of light on the incident surface of the panel (3) (± εy in the latitude direction, ± εx in the longitude direction)
Is given by The reason is that equation (9),
Based on the principle described in relation to (9 ').

[0236]

(Equation 26)

As can be understood from the cos θ factor included in the above equation, as compared with the vicinity of the equator (θ≈0), εx decreases and εy increases with increasing latitude. Therefore, when the latitude (θ _M ) of the use limit is 45 °, the increase ratio of εy can be limited to within about 1.42. This is the end of the explanation of the divergence angle.

Specific numerical values of the divergence angle are shown below. Light source radius a
Is 1.5 mm, the value of the width X in the equation (41) is 27.
In the case of 0 mm, at θ = 0, the value of εx is 0.01
It becomes 7 rad (corresponding to ± 1 degree). Moreover, the value of Y is 110 mm.
And the value of θ _M is 45 °, the value of εy is
It becomes 0.019 rad. That is, a collimator output with extremely good parallelism can be obtained. When calculating the divergence angle of the Fresnel lens output using the equations (9) and (9 '), note the following. That is, it is necessary to pay attention not to the macroscopic area of the exit surface of the Fresnel lens, but to the total of microscopic real exit areas. That is, since the latter is smaller than the former, the divergence angle is larger. With this in mind, an appropriate collimator can be easily constructed using a Fresnel lens. As can be understood from the above description, equation (9),
(9 ') is applicable to an optical system including a Fresnel lens and has a wide range of applications.

Next, another modification of FIG. 54 is shown in FIG.
(Equatorial sectional view).

FIG. 58 is different from FIG. 55 only in the components of the second-direction light deflecting means 503 ″, and is otherwise the same. Fresnel sheet 503 ″ -1, Fresnel sheet pair 503 ″ -2 / 3 and 503 "-2 '/ 3' are shown in FIG.
It is a small modified version of the corresponding element of 5. The main difference is 50
3 "-4 and 503" -4 '. In the present example, the curved arc of the curved light reflecting means is an elliptical arc whose focal point is the light source 1 and its image 1 '. As in FIG. 55, φ in equation (39)
The second direction light deflecting means (50
The deflection angle of 3 ″) is set. Therefore, the illuminance incident on the panel (3) is made uniform and improved. With the above, the description of the configuration and operation of FIG.

In FIG. 58, when the traveling distance D is sufficiently larger than the panel size, the Fresnel sheet (50
The remaining part may be deleted by using only the part within 30 degrees positive and negative of 3 ″ -1). In that case, Fresnel sheet 503 ″ −2/3 and 2 ′ / 3 ′, a bent tube. Instead of directing the light emitted from the circular light reflecting means 503 ″ -4 and 4 ′ to the image position 1 ′, the light is directly emitted toward the panel (3). By satisfying the k relation, the illuminance on the incident surface of the panel can be made uniform and improved.

Generally, a light source having a high light output generates a large amount of heat. An embodiment of the present invention for improving heat dissipation from a light source is shown in FIG. In the figure, the upper half (A) is a front sectional view and the lower half (B) is an equator sectional view.

In FIG. 59, 1 is a light source, 11 is a stem of a light source, 501 is a hemispherical light reflecting means arranged in the western hemisphere, and 501 'and 501 "are semi-cylindrical parts at the north and south ends integrally formed with 501. , 510 are hemispherical light transmitting means for transmitting visible light and absorbing or reflecting a small part of infrared rays, and are arranged in the eastern hemisphere.
It is a semi-cylindrical part at the north and south ends that is formed integrally with 0. 51
1, 511 'are blowers.

High-latitude regions at the north and south ends of the hemispherical light reflecting means (501) (half cylinders 501 ', 501 ", 510', 510")
The inside of) is formed with an opening for air circulation, so that the light source means (1) can be seen in a straight line. Therefore, air can be circulated efficiently. Therefore the light source (1)
It is possible to efficiently dissipate the heat generated from the.

The basic configuration and operation of FIG. 59 have been described above, and supplementary items will be described next.

In FIG. 59, the hemispherical light reflecting means (50
It is recommended that 1) be formed so as to mainly reflect visible light and pass infrared light. Such characteristics can be realized as a so-called cold mirror by forming dielectric thin films having different refractive indexes in a multi-layered manner as is well known. Cold mirror (501), cold filter (5
By virtue of the cooperative action of 10) and the blowers (511, 511 '), the visible light component useful as its output can be efficiently extracted in the eastern hemisphere.

The cold mirror (501) and the cold filter (510) may be integrally formed. By doing so, the structure can be simplified.

This is the end of the description of FIG.

FIG. 60 shows a modification for improving heat dissipation.

The hemispherical cold filter (51
60), a semi-cylindrical cold filter (513) is used instead of 0). Others are the same as those in FIG. 59, and therefore are omitted for simplification of the drawing.

In FIG. 60, reference numerals 513 and 513 'are connection support members. 514 and 514 'are screws,
Only the front sectional view (A) is shown, and the illustration is omitted in the equatorial sectional view. Support member for connection (513, 51
3 ') and screws (514, 514'), the cold mirror (501) and the semi-cylindrical cold filter (512).
Can be connected and supported with. This support method is of course shown in FIG.
It is also applicable to 9.

The semi-cylindrical cold filter is parallel to the air passage. Therefore, as compared with FIG. 59, heat dissipation can be achieved more efficiently.

As the material of the cold filter (512), a so-called heat absorbing glass material or a normal glass material having an infrared light reflecting film formed on the surface thereof can be used. As an example of the latter, a multilayer type or an ITO (indium / tin oxide) film can be used.

FIG. 61 shows a modification for preventing the thermal stress destruction of the cold filter (512) when it is applied to the high light output. This figure is an equator cross-sectional view of the cold filter, and 512-1, 512-2, and 512-3 are elongated flat plate-shaped cold filter members. As shown, these are arranged in a polygonal shape that approximates a half cylinder. On the mutually adjacent side surfaces indicated by 515 and 516, free thermal stress deformation independent of each other is allowed, so that thermal stress fracture can be prevented.

The cold mirror (50
1) and the cold filters (510, 512) are generally referred to as light reflecting means and light transmitting means, respectively.

Next, a part of FIG. 62 shows a second method for reducing the aspect ratio promised as will be described later with reference to FIG. 55 and the equation (40).

FIG. 62 is a perspective view and corresponds to a portion subsequent to the above-mentioned collimator means (FIGS. 54 to 61) of the projection type liquid crystal display of the present invention. In the same figure, for the purpose of simplifying the illustration, the display of the thickness of various thin plate-shaped members is omitted. Moreover, the case where the cross sections of a plurality of thin plate-shaped members arranged adjacently are collectively displayed by a single solid line is also included. The configuration and operation of the figure will be described along the light traveling path.

Reference numeral 1 is a light source. In the western hemisphere of the light source (1), the hemispherical light reflecting means (501) shown in FIG. 55 is arranged. However, in the figure, it is omitted in order to avoid complication of the display. Similarly, the cold filter (51 in FIG. 60)
Also in 2), illustration is omitted. Reference numeral 502 is the already-described first-direction light deflecting means, which deflects light in the latitudinal reduction direction (see FIG. 55). 503-1, 503-2 / 503-3, 503-
Reference numeral 2 '/ 503-3' is an element of the second-direction light deflecting means described above, and deflects light in the longitude spread reduction direction (FIG. 5).
5). Therefore, collimated light is generally obtained at the output of the Fresnel sheet (503-1). 520
Was devised by the present inventor and named a squarer, and its purpose is to remove parasitic harmful light which is not collimated. The structure is simple, and a large number of black rectangular sheets each having a smooth surface are arranged in parallel in a cupboard shape. The principle is based on the property that a sheet that looks black when viewed from the normal direction reflects light like a mirror when viewed from the tangential direction (incident angle of about 85 degrees or more). Generally, the reflectance at the interface between a sheet having a refractive index n and air is given by the following equation for each of P wave and S wave.

[0259]

[Equation 27]

When α ₁ is sufficiently close to 0.5π,
An approximate solution was obtained using the complementary angle θ (0.5π−α ₁ ) instead of α _{1 and} the following formula was obtained from formulas (42) and (43).

[0261]

[Equation 28]

If the arrangement interval of the sheet for the squarer is d and the length of the sheet for the squarer, that is, the traveling distance is 1, the longitude θ
The average number of reflections of light with a radian slope in a cube is equal to lθ / d. Each reflection results in the attenuation shown in equation (44). Therefore, the total attenuation Gp (θ),
Gs (θ) is given by the following equation.

[0263]

[Equation 29]

The above equation (47) is plotted in FIG. As can be seen from the figure, in the numerical example of Expression (47), the parasitic harmful light component with a longitude of about 0.1 rad or more is about 0.5.
It can be seen that it can be attenuated to less than double.

For removing large-latitude harmful light, the arrangement direction of the squarer may be a vertical cupboard shape.

In this embodiment, the crosstalk between the three primary colors in the subsequent three primary color three-direction directing means (13, 14, 15, ..., Similar to the one already described in FIG. 22), that is, color purity deterioration obstacle In order to prevent this, it is selected in the direction (horizontal closet shape) that removes large-longitude harmful light. It is not necessary that the sheet for a straightener is completely black, and a translucent sheet having a light transmittance of about 50% or less can be used instead.

This completes the description of the square regulator (520) of the present invention.

The principle of the aligner can be applied to the light guide wall means (506-1, -2, -3, -4) shown in FIG. That is, for the light guide wall means, a black or semitransparent flat plate means having a smooth surface is used. By doing so, based on the formula (45), only the well-collimated effective light is reflected and guided, and the parasitically badly collimated harmful light (the light whose θ value is about 0.1 rad or more) is absorbed. This is because it can be erased. Also, by configuring as a semi-transparent light guide wall, the light propagation state inside the optical path box can be observed from the outside, so it is easy to find an abnormality in the optical system, and optimal adjustment can be efficiently performed. Have. As described above, the light guide wall means (506-
1, -2, -3, -4 ... (see FIG. 55). The above-mentioned light guide wall means of the squarer type is used for the upper and lower and left and right inner walls of each block in FIG. However, in the optical path wall of the tank 521, a transparent material whose refractive index is smaller than that of the liquid in the tank is used for the inner wall portion, and light is guided by utilizing the so-called total reflection phenomenon of light.

In FIG. 62, reference numeral 521 denotes a liquid filling tank for the polarization beam splitter. A polarizing beam splitter (21 '), a half-wave retarder (22') and a mirror (23 ') are inserted into the liquid in the tank. 21 '~ 2
The operation of 3'is as described above with reference to FIG. In the figure, for convenience of illustration, the arrows of the P-wave and S-wave rays are shown only at the top. As you can see from the figure, 21 '
And 23 ', the aspect ratio K (equation 40)
Can be halved.

Further, 522 and 523 are inserted into the liquid along the incident side wall of the tank (521). 522 is
The 0.25 wavelength retardation plate is arranged with its optical anisotropy axis inclined by 45 degrees from the north-south direction (with the east-west axis as an axis).
By doing so, the polarization of the plane of polarization of the incident light in the north-south direction due to the above-mentioned first / second direction light deflecting means can be circularly polarized and equalized. By doing so, it is possible to prevent the inhibition of the uniformity of gradation on the reproduced image.

Reference numeral 523, which is arranged in parallel with 522, is a multilayer filter plate for improving color purity. The filter plate (523) blocks the orange component in the emission spectrum of the metal halide light source (1) by reflecting it. By doing so, it is possible in particular to improve the color purity of the red and green primaries.

This is the end of the description of the inside of the tank (521).

As is well known, the P-wave means a component in which the direction of the electric field component of the light wave is parallel to the plane containing the traveling direction vector of the incoming / outgoing light. The S wave is a component in which the direction of the electric field component is orthogonal to the plane. Therefore, the S wave (see FIG. 62) output from the tank (521) means a component whose electric field direction is vertical. This component is a P wave when defined from the standpoint of the dichroic mirror (13, 14, 15). Therefore, it is so illustrated in FIG. In this example, reference numerals 13, 14, and 15 are blue, green, and red reflecting dichroic mirrors, respectively, which are collectively referred to as three primary color three-direction directing means in the present invention. A multilayer film is formed on the front side of each dichroic mirror, and a glass plate is exposed in the air on the back side.

Compared with the embodiment described above with reference to FIGS.
The embodiment shown in FIG. 62 has the advantage of being extremely efficient in using S waves and P waves. Because,
27, 28, and 62, since the mirrors 23 and 23 'are used for reflecting S waves, a highly efficient reflection characteristic can be obtained based on the principle shown in FIG. 41 or the equation (42). To be On the other hand, for the dichroic mirror, see FIG.
In No. 28, since it is an S wave, about 5% or more non-dichroic harmful reflection occurs on the back surface of the glass substrate. In FIG. 62, since it is a P wave, its harmful reflection can be 1% or less (see FIG. 41). As understood from the above description, in the configuration shown in FIG. 62, the polarization beam splitter mirror (23 ') is configured for S-wave reflection, and the dichroic mirrors (13, 14) for the three primary color three-direction directing means. , 15) for P-wave reflection has an inherent advantage that the utilization of light can be improved.

The following 16 ', 16, 17'17, 3,
Reference numeral 11 is the same as that described above with reference to FIGS. 25 and 26 (a). These are collectively called a liquid crystal panel set (530). Reference numeral 4 is a projection lens, and 4'is a cylinder for housing it. The light reflected by the three-primary-color three-direction directing means (13, 14, 15) is input to the liquid crystal panel group (530), and its output light is further passed through the projection lens 4 to the subsequent black stripe type screen. It is transmitted and forms a beautiful large image on the screen. This is the end of the basic description of FIG. When using a liquid crystal panel with an effective diagonal length of 33 cm,
The approximate dimensions of the optical system shown in FIG. 62 are 50 cmW × 50 cmD × 30 cmH, excluding the projection lens portion. Further, the mutual angle between the dichroic mirrors 13, 14 and 15 is about 2 degrees, so that the mutual angle between the output lights thereof is about 4 degrees. Therefore, most of the light can be projected by using an effective F value of F / 3.8 of the projection lens (4).

Next, a slight modification of the liquid crystal panel emitting section will be described. FIG. 64 shows a liquid crystal panel (3) and its emission part. In the figure, 20 is a pixel, and 531 is a well-known exit side polarization plate. 532 is incident light, 533 is outgoing light, and 534 is harmful reflected light. In an application field where a large light output is required, there is a problem that the reflected light excites the pixel forming semiconductor element and deteriorates the contrast ratio of the reproduced image. This problem is solved by integrally forming a quarter-wave phase plate indicated by 535 as shown in the figure.
The quarter-wave plate (535) is bonded and integrated so that the direction of the optical anisotropy axis thereof has an inclination of 45 ° with that of the polarizing plate (531). By doing so, the reflected light (53
The plane of polarization of 4) can be rotated by 90 °. (1/4
The reciprocal movement of light through the wave plate substantially acts as a half-wave phase plate. Therefore, the reflected light (534) can be absorbed and erased by the polarizing plate (531). Therefore, deterioration of the contrast ratio can be prevented. As shown in FIG.
Ends the explanation.

Next, FIG. 65 shows a modification of the moire interference reducing means. Regarding the moire interference generated between the Fresnel lens and the lenticular lens in the so-called black stripe type screen, USP 4 of the present inventor has already been mentioned.
No. 725134. By the USP,
Moire interference in CRT projection can be overcome. However, in the projection type liquid crystal display, a very strong moire interference is newly generated due to the interference between the pixel arrangement of the liquid crystal panel and the black stripe arrangement of the screen.

In FIG. 65, 3 is a liquid crystal panel, 20 is a pixel of the liquid crystal panel, 4 is a projection lens, and 5 is a black stripe type screen.

Reference numeral 536 is a transparent plate, and 537 is a horizontal light diverging means for diverging light in a little co-horizontal direction for reducing moire interference. The transparent plate (536) may be shared with the Fresnel sheet (11) shown in FIG.

FIG. 66 shows the operating principle. In the figure, 2
Reference numeral 0 is a pixel of the liquid crystal panel, black circles are green pixels, and the arrangement period thereof is indicated by Tp. Reference numeral 537 denotes a horizontal light diverging unit, and the array period T _L of the lenticular lenses is selected to be equal to or less than the green pixel interval Tp. Reference numeral 538 denotes a conjugate plane of the projection lens (panel-side image plane when starting from the screen and tracing light in the opposite direction ... conjugate plane).
Is. ε ₁ is the divergence angle [rad] of the incident light, and ε ₂ is the light divergence angle [rad] of the horizontal light diverging means (537). t ₀ is the distance between the pixel surface and the light diverging means (537). In a specific example described later, a case where the value of t ₀ is 3 mm is shown. t ₁ is the distance of the conjugate plane measured from the pixel plane, t ₂
Is the distance of the conjugate plane measured from the light diverging means. The position of the conjugate plane can be finely adjusted by a well-known focus adjustment mechanism of the projection lens. Furthermore, depending on the position (center / periphery) on the screen, a slight spread (approximately 0.2 mm-1 mm).

The solid line with an arrow in the figure shows the path of the light beam. The dotted line with an arrow is an extrapolation display of the light divergence range (half-value angle) of the light divergence means (537) on the virtual image space side. T _B is
It is a value obtained by converting the black stripe array period of the black stripe type screen (5) into the liquid crystal panel (3) side in consideration of the magnification of the projection lens (4). Same figure D ₁ , D ₂
Is the spread (half-value width) of the horizontal spot size due to the divergence angles ε ₁ and ε ₂ , respectively. The values of D ₁ and D ₂ depend on the position (t ₁ ) of the conjugate plane. The dependence pattern is shown in FIG. 541 and 542 are each D ₁ / T _B, the graph calculated based on practical numerical example are also shown in the drawing the values of D ₂ / T _B in FIG. 543 is the total value of them. The values of D ₁ and D ₂ are equal to ε ₁ t ₁ and ε ₂ t ₂ , respectively.

The relationship between spot size and frequency response is
It is shown in the following formula.

[0283]

[Equation 30]

In the above equation, G ₁ (f) and G ₂ (f) are
These are frequency responses corresponding to spot sizes D ₁ and D ₂ , respectively. Here, f is a spatial frequency [cycle / mm]. S
The shape of (x) is shown in FIG. 68. This response is well known in the electrical engineering field as a gate spectrum corresponding to a rectangular distribution. The convoluted frequency response of D ₁ and D ₂ is given by the above equation (49) based on the convolution principle. To prevent defocusing of the reproduced image, use the formula (5
It is recommended to meet 1). Here, 0.5 fp is the maximum information frequency that can be restored by the pixel array in FIG. 66 (Shannon's sampling theorem). Including the frequency characteristic G ₃ (f) of the projection lens, the total frequency characteristic is
The above formula (51) is obtained. The recommended condition for reducing the moire disturbance is as shown in the above equation (52). For the idea, refer to the above-mentioned USP 4725134.

The black stripe array frequency (f _B ) is usually set to about twice or more the liquid crystal panel pixel array frequency (fp). That is, it corresponds to about four times or more of the maximum information frequency (0.5 fp). Normally, the response G of the projection lens
The value G ₃ (f _B ) of ₃ (f) at the frequency f _B is about 0.1 or less. Therefore, the condition for satisfying the condition of the expression (52) is that G ₁₂ (f) is 0.1 as shown in the above expression (54).
This is equivalent to

FIG. 69 shows the calculation results of G ₁ (f _B ) and G ₂ (f _B ) based on the above equations in the numerical example of FIG. In the figure, 551 is G ₁ (f _B ) and 552 is G ₂ (f _B ). The product G ₁₂ (f _B ) of G ₁ (f _B ) and G ₂ (f _B ) is shown at 553 in FIG. 554 is G ₁₂ (0.5 fp).

The area that can satisfy the above equation (50, 54) is
From the figure, t ₁ (pixel plane to conjugate plane) value 0.3 to 1.5 m
It turns out that it is m. That is, the focus deterioration of the image is prevented (Equation 50) and the moire interference is reduced (Equation 5).
4) has been shown to be possible.

In practical application of the present invention, particularly in a large field in which the diagonal dimension of the liquid crystal panel exceeds about 15 cm, (1) the Fresnel sheet means is arranged on the light emitting side of the liquid crystal panel (3). And (2) a Fresnel lens surface is formed on the light incident side of the Fresnel sheet, and (3) a light diverging unit for diverging light in the co-horizontal direction is provided inside the Fresnel sheet or the Fresnel sheet. The horizontal FWHM of the spot size on the reproduced image is set to be larger than 0.75 times the black stripe arrangement period of the black stripe screen by the light diverging means. The above 0.75 times means that the upper limit of t ₁ in FIG.
D ₂ / T _B ratio in FIG. 67 corresponding to 5mm 0.75
It corresponds to being. When applying to a small projector with a diagonal dimension of the liquid crystal panel of about 15 cm or less,
The Fresnel lens may be eliminated and the projection lens may be replaced by a larger aperture.

As described above, FIGS.
The explanation of 0 ends.

The present invention has mainly described the optical system. Well-known techniques can be used for the electric circuit system for driving the liquid crystal panel. In particular, regarding the means for reducing the uneven brightness and uneven color remaining on the reproduced image, USP of the present inventor
4969731, USP 5355187 and JP-
It is effective to use the means shown in A-310111.

A technique useful when the present invention is applied to a multi-screen display will be described below. The multi-screen display is one in which unit projectors are arranged in a matrix in the vertical and horizontal directions so that a huge ultra-high-definition image can be displayed as a whole. In the application, it is required to finely adjust the geometric distortion in the seam portion of the image to ensure the continuity of the seam portion.

However, since the base material of the liquid crystal panel is a rigid body (glass plate), its pixel position cannot be locally and continuously moved.

FIG. 71 shows the mechanical distortion compensating means of the present invention.

In the figure, 3 is a liquid crystal panel, 11 is a Fresnel sheet, and 4 is a projection lens, which have already been described.

555 is a transparent flexible plate having a thickness of about 1 to 3 mm. Each peripheral portion of the transparent flexible plate has a mechanism that can be independently bent.

FIG. 72 shows the compensation principle. In the same figure, (a) is a non-bent flat plate state, (b) is a state bent at an angle θ ₁ convex to the liquid crystal panel surface, and (c) is a state bent at an angle θ ₂ concave. Δ in the figure is a distortion correction amount. The magnitude of Δ is approximately proportional to the total [rad] of (θ ₁ + θ ₂ ) and is given by the following equation.

[0297]

[Equation 31]

Therefore, the bending angle adjustment range (θ ₁ + θ ₂ ) is set to about 0.45 rad, the thickness t is 2 mm, and the refractive index n is 1.5.
Then, distortion correction of about 0.3 mm becomes possible. Since the magnitude of the geometric distortion of the projection lens (4) is about 0.3 mm at the diagonal corner of the liquid crystal panel (3), the distortion can be corrected by the above configuration.

In practice, as shown in the perspective view of FIG. 73, four points 555-near the central portion of the long side of the transparent flexible plate (555).
1, -2, -3, -4 are fixedly supported, and 555-6,-
It can be embodied by providing a mechanism capable of finely adjusting the six points of 7, -8, -9 and -10 in the normal direction of the flexible plate (555). This is the end of the description of the application of the present invention to the multi-screen method.

Further, three-direction / three-direction conversion means (see FIGS. 21 and 62)
13, 14, 15 or 191, 1 in FIGS.
92 or 38, 192 of FIGS. 52 and 53) will be described below. In FIG. 74, 3 is a liquid crystal panel 556.
Reference numeral 557 denotes prism means in which a pair of prism plates are combined in mirror symmetry. As the material, 50 in FIG.
Contrary to the cases of 3-2 and -3, a polycarbonate resin or polystyrene resin having a small Abbe number, that is, a large chromatic aberration is used. The prism angle of each prism sheet can be calculated by the above-mentioned formula (17), and the value thereof is about 1.
Substituting 58, it becomes about 60 degrees. A solid line 559 with an arrow in FIG. 74 indicates the direction of a green ray, 558 indicates the direction of a red ray, and 560 indicates the direction of a blue ray. The mutual angle of each color is about the same as the specific numerical value example of FIG. 62 (about 4 degrees).

The structure shown in FIG. 74 can be constructed at a lower cost than the case of the dichroic mirror system shown in FIG.
However, it has a drawback that the optical path length becomes long. A modification in which the optical path length is shortened is shown in FIG. 561 in the figure
Is three-primary-color three-direction directing means, 562 and 563 are prism means in which a pair of prism plates are mirror-symmetrically combined, and 564 is a medium filled between both prism plates (562 and 563). As the material of the prism plates 562 and 563, for example, polycarbonate or polystyrene resin having a large Abbe number is used. As the filling medium (564),
A methacrylic or silicone resin with a small Abbe number is used. By doing so, the chromatic aberration can be emphasized by the action exactly opposite to that of the chromatic aberration correction lens. Therefore, three primary colors in three directions can be achieved with a relatively short optical path length. An ultraviolet curing method can be used as an actual molding method.

This completes the description of the main embodiments and main modifications of the present invention. The present invention is based on TN (Twisted Nema).
Tic) type liquid crystal panel was assumed for opening, but it can be applied to other types of light valves. Further, the embodiment which is not related to the polarized light can be applied by being replaced with a general image source means (for example, an OHP sheet) instead of the liquid crystal panel means.

[0303]

As can be understood from the above description, according to the present invention, it is possible to provide a liquid crystal display having an excellent contrast ratio and image quality by overcoming the problems of the prior art.

Further, it is possible to achieve an improvement in the light utilization rate in the liquid crystal display.

Furthermore, the improvement of the relative peripheral light amount ratio in the liquid crystal display can be achieved.

Further, the two glass plates forming the liquid crystal panel means are formed with different thicknesses, and the TFTs are formed on the thick plate side.
By forming the (thin film semiconductor element), the strength of the liquid crystal panel means can be maintained and the total weight can be reduced.

These techniques are based on direct view type, optical fiber type,
And can be applied to projection type liquid crystal display,
Therefore, its industrial value is high.

[Brief description of drawings]

FIG. 1 is a prior art liquid crystal display.

FIG. 2 is a diagram for explaining the performance of the conventional technique.

FIG. 3 is a diagram for explaining the performance of the conventional technique.

FIG. 4 is a diagram for explaining the performance of the conventional technique.

FIG. 5 is a diagram for explaining the performance of the conventional technique.

FIG. 6 is a coordinate system for explaining the generalized beam conservation principle on which the present invention is based.

FIG. 7 is a diagram illustrating a thought process leading to the present invention.

FIG. 8 is a diagram illustrating a thought process leading to the present invention.

FIG. 9 is a diagram explaining a thought process leading to the present invention.

FIG. 10 is a diagram illustrating a thought process leading to the present invention.

FIG. 11 is a diagram illustrating a thought process leading to the present invention.

FIG. 12 is a sectional view showing the first embodiment of the present invention.

FIG. 13 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 14 is a diagram for explaining a Fresnel lens design method.

FIG. 15 is a diagram showing an aspect ratio of a liquid crystal panel.

FIG. 16 shows a modification of the light source.

FIG. 17 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 18 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 19 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 20 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 21 is a diagram showing a second embodiment of the present invention.

FIG. 22 is an enlarged view of a main part of FIG.

FIG. 23: Prior art.

FIG. 24 is a diagram showing a modification of the second embodiment.

FIG. 25 is a diagram showing a modification of the second embodiment.

FIG. 26 is a diagram showing another embodiment of the present invention.

FIG. 27 is a diagram showing another embodiment for improving the light utilization rate.

FIG. 28 is a modification of FIG. 27.

FIG. 29 is a diagram showing an application of the present invention to a fiber type liquid crystal display.

FIG. 30 is a diagram showing an application of the present invention to a direct-viewing type liquid crystal display.

FIG. 31 is a modification of FIG. 30.

32 is an enlarged horizontal cross-sectional view for explaining the principle of FIG. 31.

FIG. 33 shows an example of a transparent screen.

FIG. 34 is an example of the present invention.

35 is an explanatory diagram of the principle of FIG. 34.

36 is an explanatory diagram of the principle of FIG. 34.

FIG. 37 is a countermeasure for the problem of the first embodiment.

FIG. 38 is a front view of the rear projection type liquid crystal display of the present invention.

FIG. 39 is a horizontal sectional view of a Fresnel sheet.

FIG. 40 is a diagram showing ghost jamming.

FIG. 41 is a graph of reflectance.

FIG. 42 is a perspective view showing a part of the embodiment of the present invention.

FIG. 43 is a view showing a modified example of the three primary color three-direction direction means in the second embodiment of the present invention.

FIG. 44 is a diagram showing details of a main part of FIG. 43.

FIG. 45 is a diagram showing an application range of FIG. 43.

FIG. 46 is a diagram showing another modification of the present invention.

FIG. 47 is a diagram showing a detailed configuration of a main part and a three-primary-color five-direction directional means of FIG.

FIG. 48 is a cross-sectional view of a liquid crystal panel.

FIG. 49 is a diagram showing a basic principle of a liquid crystal panel forming method of the present invention.

FIG. 50 is a graph showing a pre-annealing profile.

FIG. 51 is a horizontal sectional view showing the material of the double-sided lenticular lens.

FIG. 52 is a view showing a modified example of the three-primary-color three-way means.

FIG. 53 is a view showing a modified example of the three-primary-color three-way means.

FIG. 54 is a block diagram showing the basic configuration of an aspect mismatch loss reduction collimator of the present invention.

55 is a sectional view of one specific example of FIG. 54.

FIG. 56 is a sectional view of the aspect ratio reducing means.

57 is a cross-sectional view of another specific example of FIG. 54. FIG.

FIG. 58 is a cross-sectional view of another specific example of FIG. 54.

FIG. 59 is a sectional view of the heat dissipation means of the light source.

FIG. 60 is a sectional view of another heat dissipation means.

61 is a cross-sectional view of the local modification example of FIG. 60.

FIG. 62 is a perspective view of an optical system.

FIG. 63 is a graph for explaining the principle of a squarer.

FIG. 64 is a cross-sectional view of the contrast ratio improving means of the panel emission section.

FIG. 65 is a sectional view of the moire interference reducing means.

66 is an optical path diagram for explaining the principle of FIG. 65.

67 is a graph for explaining the principle of FIG. 66.

68 is a graph for explaining the principle of FIG. 66.

69 is a graph for explaining the principle of FIG. 66.

70 is a graph for explaining the principle of FIG. 66.

FIG. 71 is a cross-sectional view showing the basic configuration of geometric distortion correction means.

72 is a sectional view for explaining the principle of FIG. 71.

73 is a perspective view showing a specific example of FIG. 71. FIG.

FIG. 74 is a cross-sectional view showing a modified example of the three-primary-color three-direction directing means.

FIG. 75 is a cross-sectional view showing another modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Parabolic mirror, 3 ... Liquid crystal panel, 4 ... Projection lens, 5 ... Screen, 7 ... Illuminance measuring surface, 110 ... Optical axis, 114, 115, 116 ... Design auxiliary curve, 113 ... First Light refraction means, 10 ... Second light refraction means, 117 ... First light reflection means, 10 '... Third light refraction means, 118 ... Second light refraction means, 119 ... Light shield means, 120, 120 ??? ... Third light reflecting means, 32 ... cylindrical light reflecting means, 13,14,15 ... 3 primary color three-direction directing means, 18 ... three-direction three-positioning means, 19 ... light divergence angle reducing means, 16,16 ′ ... Optical polarization direction matching means, 191 ... Diffraction grating plate, 192 ... Mirror, 196 ... Three primary color five-direction directing means, 501 ... Spherical light reflecting means, 502 ... First direction light deflecting means, 503 ... Second direction Light deflection means, 503-2 / 503- ... Fresnel sheet pair, 503-2 '/ 503-3' ... Fresnel sheet pair, 503-1 ... Fresnel sheet.

Claims (34)

[Claims] 1. A light source means, a liquid crystal panel means, and a light advancing direction changing means, wherein the light advancing direction changing means is arranged in a path through which light is transmitted from the light source means to the liquid crystal panel means. The traveling direction changing means is composed of at least first, second and third light refracting means and a first light reflecting means, and the first light refracting means has a part of output light from the light source means. Is input and its output light is supplied to the inner peripheral direction of the liquid crystal panel means via the second light refracting means, and a part of the output light from the light source is supplied to the first light reflecting means. Is input, and the output light is supplied to the outer peripheral portion of the liquid crystal panel means through the third light refracting means, and the third light refracting means has the light deflection angle of the outermost periphery of the innermost part. The light deflection angle of the innermost peripheral portion of the third light refracting means is formed algebraically smaller than the light deflection angle of the peripheral portion. The orientation angle is smaller than the sum of the respective light deflection angles of the outermost peripheral portions of the first and second light refracting means, and the emitted light of the innermost peripheral portion of the third light refracting means. And the liquid crystal display device formed so that the direction of the light emitted from the outermost peripheral portion of the second light refracting means substantially coincides with each other. 2. A liquid crystal display device according to claim 1, wherein the first and second light refracting means are formed by an incident side interface and an outgoing side interface of one photorefractive lens means. 3. A liquid crystal display device according to claim 1, wherein the first, second and third light refracting means are integrally formed. 4. A light source means, a liquid crystal panel means, and a light advancing direction changing means, wherein the light advancing direction changing means is arranged in a path through which light is transmitted from the light source means to the liquid crystal panel means. In a polar coordinate system having north-south latitude and east-west longitude with the light emission center of the means as an origin, a spherical light reflecting means is provided in the western hemisphere, and the light traveling direction changing means includes at least the first direction light deflecting means and the second light deflecting means in the east hemisphere The spherical light reflecting means is configured to cause light emitted from the light source means to the western hemisphere to return to the light source means and to be re-emitted from the eastern hemisphere. The liquid crystal display device is formed so that the deflecting means deflects light in the latitudinal reduction direction and the second direction light deflecting means deflects light in the longitude spreading reduction direction. 5. A liquid crystal display device according to claim 4, wherein the first direction light deflecting means is formed by a semi-cylindrical Fresnel sheet. 6. The semi-annular mirror means is disposed inside the tube at the north and south ends of the semi-cylindrical Fresnel sheet, and the reflected output of the semi-annular mirror means is utilized as incident light to the semi-cylindrical Fresnel sheet. A liquid crystal display device configured as described above. 7. The liquid crystal display device according to claim 5, wherein the first direction light deflecting means is formed by a part of a toroidal lens. 8. The light deflector in the second direction according to claim 5,
At least at least a first longitude conversion means and a second longitude conversion means, the first longitude conversion means at least made up of two pairs of linear Fresnel sheets joined in a substantially mirror-symmetrical manner, The second longitude conversion means receives the output of the light source means at the eastern center thereof and outputs light corresponding to the eastern center of the liquid crystal panel means, and the second longitude conversion means further has the east outer periphery thereof. In the section, the liquid crystal display formed so that the output of the light source means receives the light after passing through the first longitude conversion means and outputs the light corresponding to the east outer peripheral portion of the liquid crystal panel means. apparatus. 9. A projection display, comprising a light source means, and in a polar coordinate system having north-south latitude and east-west longitude with an emission center of the light-source means as an origin, a spherical light reflecting means is provided in the western hemisphere, A projection display device having an opening for air circulation in a high latitude area. 10. The projection display device according to claim 9, further comprising a hemispherical light transmitting means having an air circulation opening at the north and south ends of the eastern hemisphere. 11. The semi-cylindrical light transmitting means according to claim 9, further comprising a semi-cylindrical light transmitting means along the north-south direction of the eastern hemisphere, wherein the air circulation opening of the western hemisphere and the semi-cylindrical light transmitting means are 1 at the north-south end thereof.
A projection display device configured to form a pair of air circulation openings. 12. The semi-cylindrical light transmitting means according to claim 11,
A projection display device having a polygonal shape that approximates a half cylinder, and each side being configured by an elongated flat glass plate. 13. A light source means, a liquid crystal panel means, and a light advancing direction changing means, wherein the light advancing direction changing means is arranged in a path through which light is transmitted from the light source means to the liquid crystal panel means, and further, Arranger means is arranged at the output part, and the means is composed of a large number of black thin plates arranged in a cupboard shape along the traveling direction of light, and is relatively large with respect to the surface of the thin plates. A liquid crystal display device formed so as to absorb light having poor parallelism incident at an angle and reflect and guide light having good parallelism incident at a relatively small angle. 14. A light source means, a liquid crystal panel means, and a light advancing direction changing means, wherein the light advancing direction changing means is arranged in a path through which light is transmitted from the light source means to the liquid crystal panel means. The outer edge of the transmission line is provided with a square-shaped light guide wall means, which absorbs light with poor parallelism incident on the wall surface at a relatively large angle and makes it incident on a relatively small angle. A liquid crystal display device formed to reflect and guide good light. 15. A light source means, a liquid crystal panel means, and a light advancing direction changing means, wherein the light advancing direction changing means includes at least a co-polarizing beam splitter, a polarizing beam splitter mirror, and a dichroic mirror. A liquid crystal display device in which a beam splitter mirror is constructed as an S-wave reflection type, and the output S-wave is made incident on the dichroic mirrors as P-wave. 16. A projection type display comprising a black stripe type screen, a projection lens, and a liquid crystal panel means, the light emitting side of said liquid crystal panel means comprising light diverging means for diverging light in a substantially horizontal direction. A moiré disturbance reduction type liquid crystal display device configured such that the half-width of the horizontal spread of the spot size by the diverging means is 0.75 times or more the arrangement period of the black stripes. 17. In a projection type liquid crystal display, a transparent bendable plate means is provided between a liquid crystal panel means and a projection lens means, and a peripheral portion of the transparent bendable plate means is bent and adjusted to adjust a reproduced image on a reproduced image. A projection liquid crystal display device configured to compensate for geometric distortion. 18. The method according to claims 1 to 9 or 14, 15.
An optical fiber type liquid crystal display device in which a light receiving end of an optical fiber means is disposed on the emission side of the liquid crystal panel means. 19. A white light source means, a liquid crystal panel means, and a light advancing direction changing means for guiding the light emitted from the light source means to the liquid crystal panel means, and further, the light advancing direction is provided on the incident side of the liquid crystal panel means. 3 primary colors for separating light of 3 primary colors along different directions into 3 different directions
Orientation means, three-direction three-positioning means for converging the three directions into three different directions, and light divergence angle reducing means for reducing the light divergence angle are provided, and by the light divergence angle reducing means, The direction difference of the three primary color lights is reduced, and the three primary color lights that are substantially in the same direction are guided to each position of the three primary color pixels by the light divergence angle reducing means, and the direction difference is reduced. A liquid crystal display device configured to improve a contrast ratio. 20. The liquid crystal panel means according to claim 19, further comprising polarization direction matching means for causing the light diverging directions of the three primary color three-direction directing means to substantially coincide with the wide directivity direction of the liquid crystal panel means. And a liquid crystal display device provided between the three primary color three-direction directing means. 21. The incident side lenticular lens of one double-sided lenticular lens means according to claim 19, wherein the three-direction three-positioning means and the light divergence angle reducing means are arranged on the light incident side of the liquid crystal panel means. A liquid crystal display device formed by an emission side lenticular lens. 22. The lenticular lens means according to claim 21, further comprising a lenticular lens means disposed on the light incident side of the double-sided lenticular lens means, and the light converging direction thereof is substantially orthogonal to the light converging direction of the double-sided lenticular lens means. Liquid crystal display device. 23. The projection lens means according to claim 19,
A projection type liquid crystal display device comprising screen means, Fresnel lens means on the exit side of the liquid crystal panel means, and the Fresnel lens means for guiding projection light in the direction of the pupil of the projection lens. 24. A polarization beam splitter, a half-wave plate for rotating a polarization plane by 90 degrees, and a reflecting mirror between the light traveling direction changing means and the three primary color three-direction changing means. A liquid crystal display device comprising light utilization rate improving means. 25. An optical fiber type liquid crystal display device according to claim 19 or 22, wherein a light receiving end of an optical fiber means is arranged on the emission side of said liquid crystal panel means. 26. The lenticular lens means according to claim 19 or 22, further comprising lenticular lens means on the exit side of the liquid crystal panel means,
A direct-view liquid crystal display device in which the direction of light divergence by the lenticular lens means is substantially matched with the narrow directivity direction of the liquid crystal panel means. 27. A rear projection type liquid crystal display device according to claim 23, wherein an optical disk storage shelf is provided on at least one of the left and right portions below the screen means. 28. A light source means, a light traveling direction changing means, a liquid crystal panel means, a projection lens means, a transmission type screen means, and a screen upper and lower end Fresnel ghost interference reducing means, wherein the screen upper and lower end Fresnel ghost interference reducing means are provided. A projection type liquid crystal display device comprising a polarization direction verticalizing means arranged between a liquid crystal panel means and the transmissive screen means. 29. A projection type liquid crystal display device according to claim 28, wherein said transmission screen means is further formed so as to include polarization direction leveling means. 30. A white light source means, a liquid crystal panel means, and a light advancing direction converting means for guiding the output of the light source means to the liquid crystal panel means, and further on the incident side of the liquid crystal panel means along the light advancing direction. Means for separating the three primary colors into three directions,
3 directions for converging 3 directions to each position of 3 primary color pixels 3
A positioning means, the three-primary-color three-directions forming means is formed by a diffraction grating plate and a mirror, and only one of the pair of positive and negative diffracted first-order lights emitted from the diffraction grating plate is mirrored. Reflected by,
A liquid crystal display device formed so that the reflected output light is substantially parallel to the other light of the pair of positive and negative diffracted first-order lights. 31. A white light source means, a liquid crystal panel means, and a light advancing direction changing means for guiding the output of the light source means to the liquid crystal panel means, and further to the incident side of the liquid crystal panel means in the light advancing direction. 3 primary color 5 direction conversion means for separating the 3 primary colors into 5 directions, and 5 direction 5 position conversion means for converging the 5 directions to each position of 5 array positions (RGBGR) of the 3 primary color pixels, A liquid crystal display device in which the three-primary-color five-direction directing means is formed by a diffraction grating and a prism array. 32. A white light source means, a liquid crystal panel means, and a light advancing direction converting means for guiding the output of the light source means to the liquid crystal panel means, and further to the incident side of the liquid crystal panel means in the light advancing direction. 3 primary color 6 direction conversion means for separating 3 primary colors along 6 directions, 6 array positions of 3 primary color pixels in 6 directions (RGBBGR)
A liquid crystal display device comprising 6-direction 6-positioning means for converging to each position, and the 3-primary-color 6-direction positioning means being formed by a diffraction grating and a prism array. 33. A white light source means, a liquid crystal panel means, and a light advancing direction changing means for guiding the output of the white light source means to the liquid crystal panel means, and further to the incident side of the liquid crystal panel means in the light advancing direction. Three-primary-three-direction converting means for separating the three primary colors into three directions,
3 directions for converging 3 directions to each position of 3 primary color pixels 3
A liquid crystal display device comprising a positioning means, wherein the three primary color three-direction means is formed by at least one pair of prism sheets joined in a substantially mirror-symmetrical manner. 34. The stripe-shaped half-wave plate means is further arranged on the light-exiting side of the liquid crystal panel means, and the planes of polarization of the light emitted from the lenticular lens means are arranged in two rows by the stripe-shaped half-wave plate means. A liquid crystal display device configured to rotate by 90 degrees for each row.