JPH11196355A - Display device with optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a loss or unevenness in light quantity and to obtain uniform image forming performance. SOLUTION: An illuminating optical device 11 is provided with a 1st optical block 1 including a 1st lens array 21 having plural cell lenses 21a to 21d having shapes approximately similar to optical modulation elements 45, 49, 53, a 2nd optical block 2 including a 2nd lens array 23 corresponding to the 1st lens array 21 in the block 1 and having plural cell lenses 23a to 23d having shapes approximately similar to the elements 45, 49, 53 and a 1st light converging component for converging a beam passed through the array 23 to the elements 45, 49, 53 and a 2nd light converging element arranged in the vicinity of the elements 45, 49, 53 in order to form an image of a beam projected from the block 2 on a prescribed position. The cell lenses 21a to 21d of the array 21 consist of respectively different aspheric surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device having an optical device capable of efficiently irradiating light to a light modulation element (display device) such as a liquid crystal display panel.

[0002]

2. Description of the Related Art Recently, display devices such as a projector device, a television receiver, and a computer display using an optical element such as a liquid crystal display panel, which is a so-called light valve, which is a light modulation device, have been widely used. It is widespread. A display device using such a liquid crystal display panel or the like disperses light emitted from a light source into three primary colors, enters the liquid crystal display panel, modulates the light with a video signal input to the liquid crystal display panel, and combines the light. As a result, a color video signal is generated. The color video signal is enlarged and projected on a screen via a projection lens.

In such an optical system, it is required that a light beam emitted from a light source can be efficiently and uniformly irradiated on a liquid crystal display panel. However, since the light emitting surface of the light source has a surface area, it is difficult to use the light source as an ideal point light source, and a light beam generated by an actual light source has a large divergence angle. For this reason, it is difficult to efficiently irradiate the light beam emitted from the light source to the liquid crystal display panel.
As a means for efficiently irradiating the light flux emitted from the light source having such a large divergence angle to the liquid crystal display panel, for example, using a lens array having a structure in which many small lenses are arranged in a lattice shape, It is generally known to converge a light beam reaching a liquid crystal display panel and to make the distribution of illuminance uniform.

A general example using such a lens array will be described with reference to FIG. In the light source 510, for example, a metal halide lamp 510a is disposed at the focal position of the parabolic mirror, and a light beam substantially parallel to the optical axis of the parabolic mirror is emitted from the opening. In the light beam emitted from the light source 510, the infrared region (IR) and the ultraviolet region (UV)
The unnecessary light beam is blocked by the UV-IR cut filter 511, and only the effective light beam is transmitted to the rear first optical block 50.
It is led to 1.

[0005] The first optical block 501 includes liquid crystal display panels 517 and 5 which are light modulation elements (light spatial modulation elements).
The optical element includes a first lens array 512 in which a plurality of convex cell lenses 512a having an outer shape substantially similar to the aspect ratio of the effective apertures 21 and 527 are arranged in a lattice.

[0006] The second lens array 513 of the second optical block 502 disposed behind the first optical block 501.
Is formed with a plurality of convex cell lenses 513a on the incident side, and one convex surface 5 serving as a first condensing component on the exit side.
13b. Second lens array 513
Dichroic mirrors 514 and 519 for separating light emitted from the light source 510 into red, green and blue colors are disposed between the effective apertures of the liquid crystal display panels 517, 521 and 527. In the example shown in this figure, first, the red light R is reflected by the dichroic mirror 514, and the green light G and the blue light B are transmitted. This dichroic mirror 514
The red light R reflected by the mirror 515 has its traveling direction bent by 90 ° by the mirror 515, is converged by the condenser lens 516, and enters the red liquid crystal display panel 517.

On the other hand, the green light G and the blue light B transmitted through the dichroic mirror 514 are reflected by the dichroic mirror 51.
9 will be separated. That is, the green light G is reflected, the traveling direction is bent by 90 °, and guided to the green liquid crystal display panel 521 via the condenser lens 520. Then, the blue light B passes through the dichroic mirror 519 and goes straight, and is guided to the blue liquid crystal display panel 527 via the relay lenses 522 and 524, the condenser lens 526, and the mirrors 523 and 525.

[0008] A polarizing plate (not shown) for aligning the polarization direction of the incident light into a predetermined direction is provided on the incident side of the liquid crystal display panels 517, 521, and 527, and a predetermined polarization plane of the emitted light is provided behind. Polarizing plate that transmits only light with
Are arranged to modulate the intensity of light by the voltage of a circuit for driving the liquid crystal.

The liquid crystal display panels 517, 521, 5
The light of each color modulated by the light 27 is combined by the dichroic prism 518 as a light combining means. In this dichroic prism 518, the red light R
Is reflected by the reflecting surface 518a, and the blue light B is reflected by the reflecting surface 518b in the direction in which the projection lens 530 is arranged.
Then, the green light G passes through the reflection surfaces 518a and 518b, so that each of the RGB lights is combined into one optical axis, and is enlarged and projected by a projection lens 530 on a screen (not shown).

Next, the configuration of the lens arrays 512 and 513 of the first optical block 501 and the second optical block 502 will be described in more detail with reference to FIGS. First, FIG. 18 mainly shows an example of forming a light beam based on the optical characteristics of the first optical block 501. The light beam L emitted from the light source is split by each cell lens 512a of the first lens array 512, Optical block 501
Then, an image corresponding to each cell lens 512a of the first lens array 512 is formed near the second optical block 502. After that, the light flux is changed to the first condensing component 513b.
As a result, the light is guided to the condenser lens 520 which is the second condensing component. At this time, the image point formed by the cells on the outer peripheral portion of the first lens array 512 becomes an object point having a peripheral angle of view with respect to the condenser lens 520 which is the second condensing component. Thus, each cell lens 5 of the first lens array 512
The image formed in the vicinity of the second optical block 502 by 12a is re-formed in the vicinity of the entrance pupil E of the projection lens 530 by the condenser lens 520, which is the second condensing component.

FIG. 19 mainly shows an example of the formation of a light beam by the second optical block 502. The second lens array 502
By appropriately setting the outer dimensions of each cell lens 513a and the distance between the first lens array 512,
The divergence angle θ that can be captured by the illumination system is controlled.
The luminous flux within the captured divergence angle is guided to the condenser lens 520, which is the second condensing component, at the convex surface 513b, which is the first condensing component, and combines the first condensing component and the second condensing component. The liquid crystal display panel 521 is efficiently and uniformly irradiated with the combined light condensing component. However, this action causes the following problem. That is, the luminous flux passing through the central portion of the convex surface 513b is shifted to the position P1 near the liquid crystal display panel 521.
The light flux passing through the peripheral portion of the convex surface 513b is focused at a position P2 close to the second lens array 502. That is, the position where the image is formed shifts from the liquid crystal display panel 521 side to the second optical block 502 side from the central portion to the peripheral portion of the convex surface 513b.

As described above, for example, the liquid crystal display panel 521
Is modulated by a liquid crystal display panel 520 having polarizing plates on the front and rear surfaces, and then enters a color combining element such as a dichroic prism 518. The first
Light incident on the condenser lens 520, which is the second condensing component, via the convex surface 513b, which is the condensing component, is separated into red light R, green light G, and blue light B by an optical element (not shown) such as a dichroic mirror. The green light G of the rays. The dichroic prism 518 is formed by bonding four prisms via reflection surfaces 518a and 518b formed of a thin film having predetermined reflection characteristics.

Although only the optical path of the green light G is shown by a solid line, the red light R and the blue light B are similarly light-modulated by the liquid crystal display panels of each color, and then cross-dichroic as shown by the arrows. The light enters the prism 518 from different directions.

The green light G modulated by the liquid crystal display panel 521 passes through the dichroic prism 518 as it is, and the red light R incident on the dichroic prism 518.
Is a reflecting surface 518a, and the incident blue light B is reflected by the reflecting surface 518a.
b. That is, the respective lights of RGB are combined by the cross dichroic prism 518 to generate a color video signal, which is incident on the projection lens 530.

As described above, the convex lenses 512a and 513a
By providing the lens arrays 512 and 513 arranged in a lattice in the back of the light source, light emitted from the light source can be more efficiently emitted than when only the condenser lens is arranged.
In addition, it is possible to uniformly irradiate the effective aperture of the liquid crystal display panel 521.

[0016]

However, such a first optical block 501 and a second optical block 50 of the related art are used.
In No. 2, each of the first lens array 512 and the second lens array 513 is configured by arranging lens cells of exactly the same shape in a lattice shape. As a problem when the lens array having such a configuration is used, first, as shown in FIG. 18, the imaging position of each cell lens 512a of the first lens array 512 and its aberration are completely the same. is there. At this time, each cell lens 51 of the first lens array 512
The light beam imaged by 2a is condensed by the convex lens 513b, which is the first condensing component, and the condenser lens 5, which is the second condensing component.
20, since the angles of the light beams incident on the condenser lens 520 are different from each other as shown by the broken line and the solid line in FIG. 18, the off-axis aberration of the condenser lens 520 due to the condenser lens 520 as shown in FIG. 18 and FIG. In the vicinity of the pupil E of the projection lens 530, as shown by the areas AR1 and AR2, for example, the light flux does not have a uniform imaging performance, and a loss of light amount and unevenness of light amount occur.

As a second problem, as shown in FIG. 19, each cell lens 513a of the second lens array 513
The light fluxes in different ranges among the light fluxes imaged in the vicinity of the liquid crystal display panel 521 are formed by a light condensing component obtained by combining the convex surface 513b as the first light condensing component and the condenser lens 520 as the second light condensing component. Acts only on. As a result, as shown in FIGS. 19 and 20B, each cell lens 513a of the second lens array 513 is affected by different aberrations due to the combined condensed light component, and the liquid crystal display panel 521 forms a uniform image. Performance is not achieved, and loss of light amount and unevenness of light amount occur. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems and to provide a display device including an optical device capable of preventing loss of light amount and unevenness of light amount to obtain uniform imaging performance.

[0018]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light source, a light modulator from which a light beam from the light source is radiated through an optical device for illumination, and a method for projecting the modulated light beam. The illumination optical device includes a first optical block including a first lens array having a plurality of cell lenses having substantially similar shapes to the light modulation element, and a first optical block. A second lens array corresponding to the first lens array of the block and having a plurality of cell lenses; and a second light-collecting component for condensing the light beam passing through the second lens array toward the light modulation element. An optical block and a second
A second condensing component disposed near the light modulation element for imaging a light beam emitted from the optical block at a predetermined position; and a cell lens of the first lens array of the first optical block. Is achieved by a display device comprising an optical device characterized by different aspheric surfaces.

In the present invention, the light modulation element of the display device includes:
A light beam from a light source is emitted through an optical device for illumination. The projection lens of the display device projects the modulated light beam. The first optical block of the illumination optical device includes a first lens array. The first lens array has a plurality of cell lenses. The second optical block has a second lens array. This second
The lens array has a plurality of cell lenses. This second lens array corresponds to the first lens array of the first optical block. The first condensing component of the second optical block condenses the light beam passing through the second lens array toward the light modulation element side. The second condensing component is arranged near the light modulation element in order to form a light beam emitted from the second optical block at a predetermined position, for example, at a position of a pupil of a projection lens. In this case, the cell lenses of the first lens array of the first optical block are made of different aspheric surfaces. Accordingly, since the cell lenses of the first lens array are formed not from the same spherical surface but from different aspherical surfaces, the cell lenses pass through the first lens array and the second lens array and the first and second light-collecting components. The formed light beam can form an image uniformly near the pupil of the projection lens, for example.
As a result, loss of light amount and unevenness of light amount in the projection lens can be prevented.

According to the present invention, there is provided a light source comprising: a light source;
A light modulator from which a light beam from a light source is irradiated via an optical device for illumination, and a display device including a projection lens for projecting the modulated light beam.The optical device for illumination includes a light modulator A first optical block including a first lens array having a plurality of cell lenses having substantially similar shapes; a second lens array corresponding to the first lens array of the first optical block and having a plurality of cell lenses; A second optical block including a first light-collecting component for condensing the light beam passing through the two-lens array toward the light modulation element, and forming an image of the light beam emitted from the second optical block at a predetermined position. And a second condensing component disposed in the vicinity of the light modulation element, wherein the cell lens of the second lens array of the second optical block has a different aspherical surface. By display device It is achieved.

In the display device of the present invention, a light beam from a light source is applied to the light modulation element of the display device through an optical device for illumination. The projection lens of the display device is
The modulated light beam is projected. The first optical block of the illumination optical device includes a first lens array. The first lens array has a plurality of cell lenses having a substantially similar shape to the light modulation element. The second optical block has a second lens array. This second lens array has a plurality of cell lenses. This second
The lens array corresponds to the first lens array of the first optical block. The first condensing component of the second optical block is
The light beam passing through the second lens array is focused on the light modulation element side. The second condensing component is arranged near the light modulation element in order to form a light beam emitted from the second optical block at a predetermined position. In this case,
The second lens array of the second optical block is made from different aspheric surfaces. Accordingly, since the second lens array of the second optical block is made of a different aspheric surface instead of the same spherical surface, the first lens array, the second lens array, the first light-collecting component, and the second light-collecting component are formed. The luminous flux passing through the component is not, for example, away from the light modulation element,
A uniform image can be formed on the light modulation element. In the present invention, it is preferable that both the first lens array of the first optical block and the second lens array of the second optical block have different aspherical surfaces, thereby obtaining both of the above-mentioned uniform imaging functions. Can be.

[0022]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 is an external view showing a projection type television set 100 including a projection type display device having a preferred embodiment of the optical device of the present invention, and FIG. 2 is a view showing the projection type display device 1 of FIG. 1 shows a liquid crystal type rear projection type television set 100 including a liquid crystal projector device. FIG. 2 shows the internal structure of the television set 100. First, the schematic structure of the television set 100 will be described. In FIG. 1 and FIG.
It includes a screen 102, a mirror 103, and the projection display device 1. The projection light 5 that the projection display apparatus 1 intends to project using the light of the light source 3 is reflected by the mirror 103 and projected from the back surface 104 of the screen 102. The image projected on the screen 102 can be viewed by the user U on the screen 102 as a color image or a monochrome image.

In the following description of the embodiment, a device capable of displaying a color image on the screen 102 will be described. 3 and 4 includes an optical device 11, a light source 3, and a projection lens 13. The light source 3 and the projection lens 13 are detachably attached to the main body 11a of the optical device 11.

The light source 3 has, for example, a parabolic reflector 3a and a lamp 3b as shown in FIG. As the lamp 3b, a metal halide lamp, a halogen lamp, or the like can be used. On the other hand, the projection lens 13 converts the combined light (color image light) 13A guided from the optical device 11 into
It has a mechanism that can adjust the focus with respect to the back surface 104 of the screen 102 in FIG.

Next, the optical system in the optical device 11 will be described with reference to FIG. The filter 15, the first optical block 1, and the second optical block 2 are arranged near the light source 3. The filter 15, the first optical block 1, and the second optical block 2 are arranged orthogonal to and parallel to the optical axis OP of the light (light flux) LP emitted from the light source 3.

First optical block 1 and second optical block 2
Is, for example, a large number of rectangular lenses gathered in a plane, equalizes the light LP passing through the filter 15, supplies illumination light to the liquid crystal display panels 45, 49, and 53, and supplies a projection lens. Send to 13. Filter 15, 1st
The light L passing through the optical block 1 and the second optical block 2 is
The light L includes red light (R), green light (G), and blue light (B), and the light L is converted to red light (R), green light (G), and blue light by an optical system described below. After the division into (B), predetermined light modulation is given, and these three primary colors are formed again, so that the combined light 13A, which is color image light, is combined with the projection lens 13 side.

Along the optical axis OP, dichroic mirrors 25 and 27, a relay lens 29 and a mirror 31 are arranged. Another optical axis OP1 in a direction orthogonal to this optical axis OP
Along the line, mirrors 37 are arranged corresponding to the dichroic mirrors 25. Optical axis OP2 parallel to optical axis OP
Along the mirror 37, a condenser lens (second condensing component) 51, and the liquid crystal display panel 5 as a light modulating member.
3 are arranged.

Further, along an optical axis OP3 parallel to the optical axis OP1, a condenser lens (second condensing component) 47 and a liquid crystal display panel 49 as a light modulating member are arranged corresponding to the dichroic mirror 27. . Optical axis OP1, optical axis O
A relay lens 33 and a mirror 35 are arranged corresponding to the mirror 31 along an optical axis OP4 parallel to P3. The optical axis OP5 passing through the mirror 35 coincides with the optical axis OP2. Along the optical axis OP5, a condenser lens (second light-collecting component) 43 and a liquid crystal display panel 45 as a light modulating member are arranged. Are located.

These liquid crystal display panels 53, 49, 45
Corresponding to the dichroic prism (also referred to as a photosynthetic member or a synthetic optical element or a cross prism) 4
1 is arranged. This dichroic prism 41
, The projection lens 13 is located. The dichroic mirrors 25 and 27 are mirrors having a light reflection characteristic of reflecting light according to a wavelength and a light transmission characteristic of transmitting light.

The red light (R) of the light L in FIG. 4 is reflected by the dichroic mirror 25 and sent to the mirror 37 side, and the green light (G) and the blue light (B) of the light L are transmitted to the dichroic mirror 25. Transmit through the dichroic mirror 2
It is sent to 7 side. The green light (G) is reflected by the dichroic mirror 27 and sent to the condenser lens 47 and the liquid crystal display panel 49. The blue light (B) passes through the dichroic mirror 27, passes through the relay lens 29, is reflected by the mirror 31, and passes through the relay lens 33, and is reflected by the mirror 35, so that the condenser lens 43 and the liquid crystal display panel are displayed. Go through 45.

On the other hand, the red light (R) is reflected by the mirror 37, and is condensed by the condenser lens 51 and the liquid crystal display panel 53.
Pass through.

Next, the dichroic prism 41 shown in FIG. 4 will be described. This dichroic prism 4
Reference numeral 1 denotes a prism that combines red light (R), blue light (B), and green light (G) to create a combined light 13A. The dichroic prism 41 is a prism formed by bonding four prisms 41A, 41B, 41C, 41D having a triangular cross section with an adhesive. Each prism 41A,
One or two surfaces 41B, 41C, and 41D are provided with an optical thin film 41 having light transmission characteristics and light reflection characteristics.
a, 41b are formed. The optical thin films (optical multilayer films) 41a and 41b having such predetermined light transmission characteristics and light reflection characteristics are formed by prisms 41A and 41B.
1B, 41C and 41D are formed on the surfaces to be bonded. Each of the prisms 41A to 41D of the dichroic prism 41 is made of plastic or glass and has a triangular cross section.

Next, in FIG. 4, a path until the light LP generated by the lamp 3 b of the light source 3 reaches the screen 102 will be briefly described. The light LP generated by the lamp 3b is
Unnecessary light (infrared and ultraviolet) is removed through the filter 15 to become light L. The red light R of the light L is reflected by the dichroic mirror 25, and after being reflected by the mirror 37,
The light passes through the condenser lens 51 and the liquid crystal display panel 53 and is reflected by the optical thin film 41 a of the dichroic prism 41.

On the other hand, the green light G and blue light B components of the light L pass through the dichroic mirror 25, and the green light G among them is reflected by the dichroic mirror 27, passes through the condenser lens 47 and the liquid crystal display panel 49, and becomes a dichroic prism. It passes through 41 optical thin films 41a and 41b. The blue light B passing through the dichroic mirror 27 passes through the relay lens 29, is reflected by the mirror 31, and
The light passes through 3 and is further reflected by the mirror 35. This blue light B
Passes through the condenser lens 43 and the liquid crystal display panel 45, and passes through the optical thin film 41b of the dichroic prism 41.
Reflected by

As described above, the dichroic prism 41
The red light R, green light G, and blue light B gathered in the optical thin film 4
The liquid crystal display panels 53, 49, and 4 are combined according to the light transmission characteristics and the light reflection characteristics of the liquid crystal display panels 53, 49, and 4a.
5 is enlarged and projected from the projection lens of the projection lens 13 onto the rear surface of the projection screen 102 so as to include the information of the image being displayed.

Next, the first optical block 1 and the second
The optical block 2 will be described with reference to FIGS. First, referring to FIG. 4, FIG. 5 and FIG. 6, the first optical block 1 and the second optical block 2 are arranged with respect to the optical axis OP.
They are vertically and spaced apart. The first optical block 1 and the second optical block 2 are arranged in parallel with the filter 15 and are located between the filter 15 and the dichroic mirror 25. Lamp 3 of light source 3 in FIG.
The light LP generated by the b is substantially parallel light,
And enters the first optical block 1. And this light LP
Passes through the first optical block 1 and the second optical block 2 and reaches the dichroic mirror 25 as light L.

The first optical block 1 has a first lens array 21 as shown in FIGS. This first
The lens array 21 is, for example, as shown in FIG.
It has cell lenses 21a to 21d arranged in a lattice. These cell lenses 21a to 21d are composed of at least two types of different aspheric surfaces. For example, the aspherical shapes of the cell lenses 21a and 21d are different from the aspherical shapes of the cell lenses 21b and 21c. However, the shapes of the aspheric surfaces of all the cell lenses 21a to 21d may be different from each other depending on the positions of the cell lenses.

On the other hand, the second optical block 2 is shown in FIGS.
Has a second lens array 23 as shown in FIG. The second lens array 23 has a plurality of cell lenses 23a to 23d as shown in FIG. The cell lenses 23a to 23d are located at positions corresponding to the cell lenses 21a to 21d of the first lens array 21 in FIG. As shown in FIG. 9B, the cell lenses 23a to 23d are composed of, for example, at least two types of different aspheric surfaces. For example, the aspherical shapes of the cell lenses 23a and 23d are different from the aspherical shapes of the cell lenses 23b and 23c. However, the aspherical shapes of all the cell lenses 23a to 23d may be different from each other depending on the positions of the cell lenses.

The aspect ratio (the ratio of the horizontal length to the vertical length) of the cell lenses 21a to 21d in FIG.
6: 9. The aspect ratio of the cell lens 21a is different from that of the liquid crystal display panel 4 of FIG.
5, 49, 53 aspect ratio and screen 1 of FIG.
The aspect ratio is approximately equal to 02.

Each of the cell lenses 21a to 21 shown in FIGS.
5d and FIG. 6 if each of the cell lenses 21a to 21d and 23a to 23d is a different aspherical surface by preferably forming at least two types of different aspherical surfaces. As illustrated, a uniform imaging state can be obtained by freely controlling the aberration of the imaging position of the light beam. The second optical block 2 has a first condensing component 23f in addition to the second lens array 23 described above. The first light condensing component 23f has a convex shape, and the second lens array 23
And are formed integrally. This second optical block 2,
Between the liquid crystal display panels 45, 49, and 53, condenser lenses 43, 47, and 51, which are second light-collecting components, are disposed.

FIGS. 5 and 6 show an example for explaining that a uniform imaging state is obtained by the optical functions of the first optical block 1 and the second optical block 2 as described above.
FIG. 5 mainly shows the first lens array 2 of the first optical block 1.
One cell lens 21a, 21b, 21c, 21d is composed of at least two types of different aspherical surfaces, and more preferably, has different shapes from each other.
This shows that an image can be uniformly and successfully formed on the entrance pupil E of the projection lens 13. In contrast, FIG.
Is formed by the fact that the cell lenses 23a, 23b, 23c and 23d of the second lens array 23 of the second optical block 2 are composed of at least two types of different aspherical surfaces and have different shapes from each other. Position FP is
The example which can be formed on the liquid crystal display panel 49 is shown.
5 and 6 show an example of the green light G as an example,
As an optical system, a first optical block 1, a second optical block 2, a condenser lens 47, a liquid crystal display panel 49
And a dichroic prism 41.

The image forming characteristics and the like of the first optical block 1 and the second optical block 2 to be described below can be similarly exerted not only for the green light G but also for the red light R and the blue light B. The characteristic functions of the first optical block 1 and the second optical block 2 will be described with reference to FIGS. In FIG. 5, the aspherical shapes of the cell lenses 21a to 21d of the first optical block are as follows:
By optimizing so as to cancel out aberrations generated in the optical system after the first optical block 1 mainly caused by the condenser lens 47, which is the second light-collecting component, the second light-condensing component as shown by a solid line or a broken line in FIG. The image formed near the second lens array by the one lens array can be formed on the pupil E of the projection lens 13. Thereby, the projection lens 13
A more uniform imaging state can be obtained with respect to the entrance pupil E, and efficient and uniform illumination without loss of light amount and unevenness of light amount can be obtained.

Next, the function of the cell lens 23a of the second optical block 2 will be mainly described with reference to FIG. The light L passes through the cell lens 21a of the first optical block 1 and passes through the second
Through the cell lenses 23a to 23d of the optical block 2,
By being condensed by the first condensing component 23f, the light passes through the condenser lens 47 and forms an image on the liquid crystal display panel 49. As described above, the aspherical shape of the cell lenses 23a to 23d of the second optical block 2 is mainly changed by the first condensing component 23f.
By optimizing the shape so as to correct the spherical aberration, it is possible to form a uniform image on the liquid crystal display panel 49 well, unlike the related art.

Thus, the first lens array and the second lens
The lens array is composed of the same spherical cell lens. However, as compared with this conventional configuration, the aspherical cell lens 23 of the second lens array 23 in the embodiment of FIG.
By using a to 23d, an aberration generated by a combined light-collecting component synthesized by the first light-collecting component 23f and the condenser lens 47 is properly corrected, and an image forming position corresponding to each cell lens of the second lens array is obtained. The FP can be uniformly set on the liquid crystal display panel 49. As a result, a more uniform imaged state can be obtained in the vicinity of the liquid crystal display panel 49, and illumination can be obtained with high efficiency and uniform illumination without loss of light quantity and without unevenness in light quantity. Each of the cell lenses 23a to 23d of the second lens array 23 has at least two or more types of different aspheric surfaces, and has different aspheric shapes depending on their positions.

5 and 6, the cell lenses 21a to 21a in the first optical block 1 and the second optical block 2 are shown.
1d and 23a to 23d are each composed of at least two types of aspherical surfaces, and more preferably, adjacent cell lenses 21a to 21d or adjacent cell lenses 2
3a to 23d have different aspherical shapes. However, the present invention is not limited to this, and it is possible to employ only the cell lenses 21a to 21d of the embodiment of the present invention only in the first optical block, and conversely, the cell lens of the embodiment of the present invention only in the second optical block. 23a to 23d can also be adopted. In any case, the embodiment shown in FIGS. 5 and 6 is the best mode in which the first optical block 1 and the second optical block 2 are most preferable.

Although the green light G has been described with reference to FIGS. 6 and 7, the same applies to the red light R and the blue light B.
Such a function can be exhibited for the primary colors (RGB).

FIG. 10 is an optical path diagram simply showing a combination of FIG. 6 and FIG. Again, the projection lens 1
When an image is formed on the third pupil (entrance pupil) E, the first
The cell lens 21a of the optical block 1 functions. vice versa,
When an image is formed on the liquid crystal display panel 49, the second
Cell lens 2 of second lens array 23 of optical block 2
3a functions.

Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 11 shows that the polarization conversion element 131 is inserted between the first optical block 1 and the second optical block 2 of the optical device 11 shown in the embodiment of FIG. The polarization conversion element 131 converts, for example, only the P-wave into the second optical block by combining the P-wave and the S-wave after the light LP from the light source 3 passes through the filter 15 and passes through the first optical block 1. 2 is irradiated. By doing so, the light flux from the light source 3 can be more efficiently and uniformly applied to the liquid crystal display panel as a light valve. This polarization conversion element 131
One of the two types of polarization planes of the light LP radiated from the ordinary light source 3 is separated and converted. That is, the plane of polarization can be generally divided into a P-polarized component (P-wave) and an S-polarized component (S-wave). In this type of display device, before the luminous flux emitted from the light source 3 is incident on the liquid crystal display panel, such a polarization conversion element 131 is used to correspond to a polarizing plate provided on the front surface of the liquid crystal display panel. Then, the light is converted into only light having one of the polarization planes of the P wave and the S wave and irradiated.

As a polarization conversion element which is a means for obtaining a P wave or an S wave, a polarization beam splitter (Polarizi) is used.
ng Beamsplitters (hereinafter referred to as PBS) is used. Then, for example, random polarization (P
(+ S wave), for example, the P wave is transmitted and the S wave is reflected. Then, there is a method in which the S wave is reflected by the end face of the prism and returned to parallel light, and for example, only the S wave is converted into a P wave by passing through a 1 / 2λ plate. By using such a polarization conversion element, light emitted from a light source can be efficiently and uniformly applied to a liquid crystal display panel by effectively utilizing light that has been absorbed by a conventional polarizing plate. It has become.

Next, reference will be made to FIGS. 12A, 12B and 12C. The second optical block 2 in FIG.
Each of the cell lenses 23a to 23d of the lens array 23 is formed on the light source 3 side in FIG. Each of the cell lenses 23a to 23d in FIG. 12A is integrally formed with one first condensing component 23f. FIG.
(B) The cell lenses 23a to 23d of the second lens array 23 of the second optical block 2 are formed integrally with one large first condensing component 23f. The cell lenses 23a to 23d of the second lens array 23 of the second optical block 2
23d faces the first optical block 1 side. FIG.
(C) shows still another embodiment of the second optical block 2, and an air space H is provided between the second lens array 23 and the first light condensing component 23 f of the second optical block 2. Is formed.

FIG. 13 shows the light source 3 and the polarization conversion element 23.
1, first optical block 1, second optical block 2, condenser lens (second condensing component) 47, liquid crystal display panel 49
2 shows an example of a dichroic prism 41. In this example, the polarization conversion element 231 is disposed between the first optical block 1 and the light source 3. This polarization conversion element 231
Has a function similar to that of the polarization conversion element 131 shown in FIG. 11, and can convert the light LP into only a P-wave or an S-wave and transmit it to the first optical block 1 side.

In the embodiment shown in FIG.
Reference numeral 31 is arranged between the first optical block 1 and the second optical block 2. In the embodiment of FIG. 15, the second lens array 23 of the second optical block 2 and the first condensing component 23
f is arranged at an air interval H, and the polarization conversion element 431 is arranged in the air space H.

Next, FIGS. 16 (A), (B) and (C)
For example, an example of a light combining means that can be used in place of the dichroic prism 41 as the light combining element in FIG. 4 is shown. FIG. 16A shows a so-called L-shaped light combining means, which is a combination of prisms 400, 401, and 402, and a light modulation element or a liquid crystal display panel 403 corresponding to these prisms 400, 401, and 402. , 4
04, 405 are arranged. The light combining means in FIG. 16B is similarly composed of prisms 600, 601 and 602. These prisms 600, 601, 60
2, three liquid crystal display panels 700, 701, 7
02 is arranged. The photosynthesis means in FIG.
It is composed of two dichroic mirrors 800 and 801 and three liquid crystal display panels 900, 901 and 902.

In the embodiment of the present invention, such a light combining means as shown in FIGS. 16A to 16C can be used in place of the dichroic prism 41 shown in FIG.

The present invention is not limited to the above embodiment. In the above embodiment, the liquid crystal display panel is 3
An example of a so-called three-panel type, particularly a rear projection type display device, is shown. However, the present invention is not limited to this, and a so-called single-panel type using only one liquid crystal display panel can be adopted. Further, the light valve or the light modulation element is not limited to the liquid crystal display panel, and other types of display panels can be used. The present invention is not limited to a rear-projection type display device that projects synthesized light from the back side of a screen as shown in FIG. 1, but can be applied to a projector of a type called a front projector that projects synthesized light directly on a screen. .

[0057]

As described above, according to the present invention,
Uniform imaging performance can be obtained by preventing loss of light amount and unevenness of light amount.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an example of a display device of the present invention.

FIG. 2 is a diagram showing an internal structure of the display device of FIG.

FIG. 3 is a diagram showing a projection type display device provided in the display devices of FIGS. 1 and 2;

FIG. 4 is a diagram showing a structure of an optical device of the projection display device.

FIG. 5 is a diagram illustrating a first optical block, a second optical block, and other optical elements, and mainly illustrates a state in which the first optical block forms an image.

FIG. 6 is a view mainly showing a state where the second optical block forms an image on the liquid crystal display panel side.

FIG. 7 is a diagram showing an arrangement example of cell lenses of a first optical block and cell lenses of a second optical block.

FIG. 8 is a view for explaining an example in which each cell lens of the first optical block, the liquid crystal display panel, and the screen have the same aspect ratio.

FIG. 9 is a sectional view showing the shapes of the cell lens of the first optical block and the cell lens of the second optical block.

FIG. 10 is a diagram showing an example of a light beam formed by a first optical block and a second optical block and an image thereof.

FIG. 11 is a diagram showing another embodiment of the present invention.

FIG. 12 is a diagram showing another embodiment of the present invention.

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

FIG. 14 is a diagram showing another embodiment of the present invention.

FIG. 15 is a diagram showing another embodiment of the present invention.

FIG. 16 is a diagram showing another embodiment of the present invention.

FIG. 17 is a diagram showing an example of an optical system of a conventional projection type projector.

18 is a diagram showing a problem in the conventional optical system of FIG.

FIG. 19 is a diagram showing a problem in the conventional optical system of FIG. 17;

FIG. 20 is a diagram illustrating a problem in a conventional optical system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st optical block, 1 ... Projection display apparatus
2 ... second optical block, 3 ... light source, 13 ...
Projection lens, 21... First lens array, 21a to 2
1d: cell lens, 23: second lens array,
23a to 23d: cell lens, 23f: first condensing component of the second optical block, 45, 49, 53 ... liquid crystal display panel (light modulation element, light valve), 131
..Polarization conversion elements

Claims (16)

[Claims] 1. A display device comprising: a light source; a light modulation element to which a light beam from the light source is irradiated via an optical device for illumination; and a projection lens for projecting the modulated light beam. The optical device includes: a first optical block including a first lens array having a plurality of cell lenses having substantially similar shapes to the light modulation element; and a plurality of cell lenses corresponding to the first lens array of the first optical block. A second lens array, and a first lens that condenses a light beam passing through the second lens array toward a light modulation element.
A second optical block including a condensed component; and a second condensed component disposed near the light modulation element for imaging a light beam emitted from the second optical block at a predetermined position. The cell lens of the first lens array of the first optical block is
A display device comprising an optical device, wherein the display device includes different aspheric surfaces. 2. A display device comprising the optical device according to claim 1, wherein the cell lenses of the first lens array of the first optical block include at least two types of aspherical surfaces or different aspherical surfaces. 3. A display device comprising: a light source; a light modulating element to which a light beam from the light source is irradiated via an optical device for illumination; and a projection lens for projecting the modulated light beam. The optical device includes: a first optical block including a first lens array having a plurality of cell lenses having substantially similar shapes to the light modulation element; and a plurality of cell lenses corresponding to the first lens array of the first optical block. A second lens array, and a first lens that condenses a light beam passing through the second lens array toward a light modulation element.
A second optical block including a condensed component; and a second condensed component disposed near the light modulation element for imaging a light beam emitted from the second optical block at a predetermined position. The cell lens of the second lens array of the second optical block is
A display device comprising an optical device, wherein the display device includes different aspheric surfaces. 4. A display device comprising the optical device according to claim 3, wherein the cell lenses of the second lens array of the second optical block are made of at least two types of aspherical surfaces or different aspherical surfaces. 5. A display device comprising the optical device according to claim 2, wherein the cell lenses of the second lens array of the second optical block are made of at least two types of aspherical surfaces or different aspherical surfaces. 6. A display device comprising the optical device according to claim 4, wherein the cell lenses of the first lens array of the first optical block are made of at least two types of aspherical surfaces or different aspherical surfaces. 7. The method according to claim 7, wherein the first light-collecting component of the second optical block is a second light-collecting component.
A display device comprising the optical device according to claim 1, wherein the display device is formed integrally with a lens array. 8. The method according to claim 1, wherein the first condensing component of the second optical block is the second
A display device comprising the optical device according to claim 3, wherein the display device is formed integrally with a lens array. 9. The method according to claim 1, wherein the first condensing component of the second optical block is a second condensing component.
A display device comprising the optical device according to claim 1, wherein the display device is formed integrally with each cell lens of the lens array. 10. A display device comprising the optical device according to claim 3, wherein the first condensing component of the second optical block is formed integrally with each cell lens of the second lens array. 11. A display device comprising the optical device according to claim 1, wherein the second lens array of the second optical block and the first light-collecting component are spaced apart from each other. 12. A display device comprising the optical device according to claim 3, wherein the second lens array and the first light-collecting component of the second optical block are spaced apart from each other. 13. A display device comprising the optical device according to claim 1, wherein a polarization conversion element is disposed between the light source and the first optical block. 14. A display device comprising the optical device according to claim 3, wherein a polarization conversion element is disposed between the light source and the first optical block. 15. A display device comprising the optical device according to claim 1, wherein a polarization conversion element is disposed between the first optical block and the second optical block. 16. A display device comprising the optical device according to claim 3, wherein a polarization conversion element is disposed between the first optical block and the second optical block.