JPH11271668A - Lighting optical device and projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the light projection type display device which can light up a liquid crystal panel with lights from light sources very efficiently and uniformly and has good uniformity and high light use efficiency by providing a prism array plate which deflects and puts together the lights from the light sources. SOLUTION: The lights emitted by lamps 30 and 31 are converged by parabolic mirrors 32 and 33 respectively and converted into nearly parallel lights. The respective lights are made incident on a prism array plate 34 consisting of prisms. The pieces of luminous flux from the parabolic mirrors 32 and 33 are split by the prism array plate 34 and the split pieces of luminous flux are put together by turns. The composite luminous flux is made incident on a 1st lens array plate 35 consisting of lenses. Thus, the luminous flux which is split by the prism array plate 34 is made incident on lens elements of the 1st lens array plate 35 to light up the liquid crystal panel 39 uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination optical device for illuminating light from a light source to an image forming means, and to irradiate an image formed on the image forming means with illumination light, and to project an enlarged image on a screen by a projection lens. The present invention relates to a type display device.

[0002]

2. Description of the Related Art In order to obtain a large screen image, a small image forming means for forming an optical image corresponding to a video signal is illuminated with light from a light source, and the optical image is projected on a screen by a projection lens. , An enlarged projection display device is used. For the image forming means, a liquid crystal panel that modulates light using polarization is widely and practically used, which is an active matrix type, in which a polarizing plate is arranged in orthogonal Nicols on both sides of a twisted nematic liquid crystal cell. Have been. An illumination optical device that illuminates a liquid crystal panel with light from a light source uses two lens array plates including a plurality of lenses (for example, Japanese Patent Application Laid-Open No. 3-111806).
The two lens array plates divide a light beam incident on one of the lens array plates disposed on the light source side into a large number, superimpose each of the divided light beams on a liquid crystal panel, and illuminate efficiently and uniformly. is there.

Further, as an illumination optical device of a projection type display device using a liquid crystal panel using polarized light, natural light is transmitted by using a polarized light separating prism as a polarized light separating means and a half-wave plate as a polarized light rotating means. There is disclosed an illumination optical device that constitutes a polarization conversion optical member that converts light into one direction of polarization, improves the light use efficiency of the projection display device, and increases the brightness of the projection display device (for example, disclosed). JP-A-8-304
No. 739). Further, an illumination optical device using a plurality of light sources has been disclosed in order to increase the luminance of a projection display device (for example, Japanese Patent Application Laid-Open No. 6-265887).

FIG. 8 shows a projection type display device in which a conventional illumination optical device using a plurality of light sources is introduced. Radiation light from the two discharge lamps 1 and 2 serving as light sources is condensed by the concave mirrors 3 and 4 and converted into substantially parallel light beams. Each parallel light beam enters the corresponding first lens array plate 5. The first lens array plate 5 is composed of a plurality of rectangular lenses. Each rectangular lens divides the incident light beam into a large number and converges on the plurality of lenses of each second lens array plate 6. Many minute light source images are formed on each lens of the second lens array plate 6.
The second lens array plate 6 superimposes the respective lenses of the first lens array plate 5 on the liquid crystal panels 16, 17, and 18 to form an image.

[0005] The light emitted from the illumination optical device 7 is separated into three primary colors of green, red and blue by dichroic mirrors 8 and 9, and then the liquid crystal panel 16 corresponding to each color light is separated.
The light is incident on 17 and 18. In this way, a large number of split light beams are superimposed on the liquid crystal panel to perform uniform illumination.
The relay lenses 11 and 12 correct the difference in the intensity of illumination light to the liquid crystal panel due to the difference in the illumination optical path length, which is the distance between the second lens array plate and the liquid crystal panel. Field lenses 14, 13, and 15 are liquid crystal panels 16, 1 respectively.
The illumination light to 7 and 18 is focused on the pupil plane 21 of the projection lens 20. The three primary color lights of blue, green, and red emitted from the liquid crystal panels 16, 17, and 18 of the projection lens 20 are combined by the dichroic prism 19, and then enter the projection lens 20. The projection lens 20 enlarges and projects the images of the liquid crystal panels 16, 17, and 18 on a screen (not shown). Since a plurality of light sources are used, a bright projection display device can be configured.

FIG. 8 shows a light source image formed on the pupil plane 21 of the projection lens. Two light sources 1, 2
Is a minute light source image 24 by the lens array plate, and further, light source image groups 22 and 23 are formed.

[0007]

Generally, in order to improve the brightness of a projection display device, the power consumption of a discharge lamp may be increased. When the height is increased, there is a problem that the light emitting portion becomes large and the light use efficiency is reduced. Therefore, the use of a plurality of light sources having relatively low power consumption can improve the brightness of the projection display device more efficiently. In the configuration of a conventional illumination optical device using a plurality of light sources as shown in FIG. 8, two light sources are arranged symmetrically with respect to the optical axis of the projection lens. In such a case, the image of the light source formed on the pupil plane of the projection lens is formed from the two light sources with the optical axis interposed therebetween, as shown in the pupil plane of the projection lens (FIG. 8). become. The projection lens has vignetting, and the peripheral illuminance is lower than the central illuminance on the screen. This is because the light source image on the pupil plane of the projection lens causes vignetting due to vignetting. Therefore, when the light emission characteristics of two light sources arranged with the optical axis interposed therebetween are different,
Since the light source images contributing to the brightness at the periphery of the screen are different, color unevenness of the projected image occurs on the screen. Also,
When one light source is turned off, there arises a problem that the illuminance distribution on the screen becomes uneven.

Further, when such an illumination optical device is introduced into a projection type display device as shown in FIG. 8, one red color light of the three primary colors is formed on the pupil plane of the projection lens. The image of the light source is inverted with respect to the optical axis. Therefore, as for each light source image on the pupil plane of the projection lens, the green and blue light source images of the light source 1 are formed in the region 22 and the red light source image of the light source 1 is formed in the region 23. Also, the green of the light source 2,
The blue light source image is formed in the area 23, and the red light source image of the light source 2 is formed in the area 22. For this reason, if the light emission characteristics of the two light sources are slightly different, vignetting of the projection lens changes the appearance of vignetting of the light source image, resulting in a problem that large color unevenness occurs on the screen.

Therefore, when an illumination optical device and a projection display device are configured by using a plurality of light sources, a light source image formed on each of the light sources on a pupil plane of a projection lens is expressed by:
It was necessary to be as symmetrical as possible with respect to the optical axis. In the configuration shown in FIG. 8, it is necessary to brighten the F-number of the projection lens in order to guide the light from the illumination optical device with high efficiency. Furthermore, for two concave mirrors,
Each of them requires the first and second lens array plates, and has a problem that the cost is increased.

[0010]

In order to solve the above-mentioned problems, a first illumination optical device of the present invention is an illumination optical device for condensing light from a light source and illuminating an image forming means for forming an image. There, a plurality of light sources, a concave mirror that respectively collects the radiated light from the plurality of light sources, the light from the concave mirror is incident, the light from the concave mirror composed of a plurality of prisms, respectively deflected, A prism array plate to be combined, a first lens array plate into which light from the prism array plate is incident and which is composed of a plurality of lenses and divides the light from the prism array plate into a large number of light fluxes, And a second lens array plate to which light from the first lens array plate is incident.

A second illumination optical device of the present invention is an illumination optical device for illuminating image forming means for forming an image by condensing light from a light source, wherein the plurality of light sources and the light from the plurality of light sources are provided. A concave mirror for condensing the emitted light, light from the concave mirror is incident, a prism array plate composed of a plurality of prisms, each of which deviates and combines the light from the concave mirror, and light from the prism array plate. And a first lens array plate composed of a plurality of lenses and dividing the light from the prism array plate into a number of light beams, and a light beam from the first lens array plate composed of a plurality of lenses A second lens array plate, light from the second lens array plate is incident thereon, polarization separating means for separating natural light into two polarized lights having polarization directions orthogonal to each other, and light from the polarization separating means. Entering And it is obtained by a polarization rotation means for rotating the polarization direction of one emitted from the polarization separating means.

A third illumination optical device according to the present invention is an illumination optical device for illuminating image forming means for forming an image by condensing light from a light source, comprising: a plurality of light sources; A concave mirror for condensing emitted light, a plurality of first prism array plates into which light from the concave mirror is incident, and a plurality of first prism array plates each including a plurality of prisms and each of which deviates light from the concave mirror; A second prism array plate, which is composed of a plurality of prisms, respectively deviates and combines light from the plurality of first prism array plates, and the second prism array plate; The first lens array plate, into which light from the prism array plate is incident and configured by a plurality of lenses and splits the light from the light source into a large number of light beams, and the first lens array plate including a plurality of lenses.
And a second lens array plate on which light from the lens array plate is incident.

A fourth illumination optical device according to the present invention is an illumination optical device for illuminating image forming means for forming an image by condensing light from a light source, comprising: a plurality of light sources; A concave mirror for condensing emitted light, a plurality of first prism array plates into which light from the concave mirror is incident, and a plurality of first prism array plates each including a plurality of prisms and each of which deviates light from the concave mirror; A second prism array plate, which is composed of a plurality of prisms, respectively deviates and combines light from the plurality of first prism array plates, and the second prism array plate; The first lens array plate, into which light from the prism array plate is incident and configured by a plurality of lenses and splits the light from the light source into a large number of light beams, and the first lens array plate including a plurality of lenses.
A second lens array plate on which light from the lens array plate is incident, and light from the second lens array plate incident on the second lens array plate;
A polarization separating unit that separates natural light into two polarized light beams whose polarization directions are orthogonal to each other; and a polarization rotation unit that receives light from the polarization separation unit and rotates one polarization direction emitted from the polarization separation unit. It is a thing.

According to a first projection type display device of the present invention, a light source, illumination optical means for condensing light from the light source and illuminating the image forming means, light from the illumination optical means is incident, and a video signal One image forming means for forming an optical image in accordance with
A projection lens for projecting the optical image on the image forming unit onto a screen, wherein the illumination optical unit is constituted by the first to fourth illumination optical units of the present invention.

According to a second projection type display device of the present invention, there are provided a light source, illumination optical means for condensing light from the light source and illuminating the image forming means, and white light from the light source for blue, green and red. A color separation optical unit that separates the light into color component lights, three image forming units on which each color light from the color separation optical unit is incident, and an optical image is formed in accordance with a video signal; and A color combining optical unit that receives blue, green, and red emitted light and combines blue, green, and red light, and a projection lens that projects an optical image on the image forming unit onto a screen. The optical means includes the first to fourth illumination optical means of the present invention.

The light source of the present invention, illumination optical means for condensing light from the light source and illuminating the image forming means, and color separation for separating white light from the light source into light of blue, green and red color components Optical means, each color light from the color separation optical means is incident, a polarization separation prism that separates the incident light into light in two orthogonal polarization directions, light from the polarization separation prism is incident,
Three image forming units in which an optical image is formed in accordance with a video signal, and blue, green, and red light emitted from the image forming unit pass through the polarization splitting prism and enter blue, green, and red. A color synthesizing optical unit for synthesizing color light; and a projection lens for projecting an optical image on the image forming unit onto a screen, wherein the illumination optical unit includes first to fourth illumination optical units of the present invention. It is composed of

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An illumination optical device and a projection display device according to embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) (FIG. 1) shows the configuration of a first illumination optical device according to the present invention. As an image forming unit, a liquid crystal panel that modulates light using polarization or scattering is used.

Reference numerals 30 and 31 denote discharge lamps, 32 and 33 are parabolic mirrors, 34 is a prism array plate composed of a plurality of prisms, 35 is a first lens array plate, 36 is a second lens array plate, and 37 is a second lens array plate. First illumination light optical device of the present invention, 3
8 is a field lens, a liquid crystal panel, 40 is a projection lens, and 41 is a pupil plane of the projection lens. (Figure 1)
Fig. 3 shows aspects of a light source image formed on a pupil plane of a projection lens.

Light emitted from lamps 30 and 31 such as a metal halide lamp, an ultra-high pressure mercury lamp, and a xenon lamp is condensed and converted into substantially parallel light by corresponding parabolic mirrors 32 and 33, respectively. Each light beam enters a prism array plate 34 composed of a plurality of prisms. The prism element of the prism array plate 34 has an apex angle of 6
It is a 0 degree triangular prism. Each prism of the prism array plate 34 totally reflects the light incident from the parabolic mirrors 32 and 33, and deflects each optical axis by 60 degrees. Parabolic mirror 3
The light beams from 2 and 33 are split by the prism array plate 34, respectively, and the split light beams are alternately combined. The light beams alternately combined are incident on a first lens array plate 35 composed of a plurality of lenses. The prism pitch of the prism array plate 34 is two times the lens element pitch of the first lens array plate 35 (the pitch in the prism arrangement direction).
Doubled. This is because the boundary of the light beam reflected by one side of the prism of the prism array plate 34 does not coincide with the inside of the opening of the lens element of the first lens array plate 35. Further, the prism array plate 34 and the first lens array plate are brought into close contact with each other.

In this manner, the first lens array plate 35
The light beam incident on the lens element of FIG.
The luminous flux divided by 4 is uniformly incident so that the liquid crystal panel 39 can be uniformly illuminated.

In the light beam incident on the first lens array plate 35, the light beam from the prism array plate 34 is divided into a number of light beams. A large number of split light beams converge on a second lens array plate 36 composed of a plurality of lenses. Many secondary light source images are formed on the second lens array plate 36. The focal length of the lens elements of the first lens array plate 35 is equal to the distance between the first lens array plate 35 and the second lens array plate 36. The lens elements of the first lens array plate 35 and the lens elements of the second lens array plate 36 have a rectangular opening shape. The focal length of the lens elements of the second lens array plate 36 is determined so that the surface of the first lens array plate 35 and the liquid crystal panel surface 39 have a substantially conjugate relationship. In order to illuminate the light emitted from each lens element of the second lens array plate 36 onto the liquid crystal panel 39, the lens elements of the second lens array plate 36 and the lens elements of the first lens array plate 35 are appropriately polarized. It is cored. Many light beams emitted from the second lens array plate 36 are superimposed on the liquid crystal panel 39 and are uniformly illuminated on the liquid crystal panel 39.

The field lens 38 focuses light illuminated on the liquid crystal panel 39 on the pupil plane 41 of the projection lens 40. The pupil plane 41 of the projection lens 40 and the surface of the second lens array plate 36 have a substantially conjugate relationship.

The appearance of the light source images of the light sources 30 and 31 is shown on the pupil plane 41 of the projection lens 40. In the prism array direction of the prism array plate, minute light source images 42 and 43 of the light sources 30 and 31 are alternately formed.

This pupil plane 41 is projected on a screen (not shown) as a light source. It can be seen that the two light source images are formed symmetrically with respect to the optical axis as compared with the light source images on the pupil plane of the projection lens such as the conventional illumination optical device shown in FIG. It can also be seen that a light source image is formed on the entire pupil plane of the projection lens.

The prism array plate may be manufactured by molding. By using a molded product, a low-cost prism array plate can be configured. In this case, the accuracy of the apex angle of the prism and the flat portion is reduced, but the loss is only slightly increased. Further, the prism array plate may be made of a resin having high heat resistance. If the prism array plate is made of resin,
Further, the cost can be reduced.

As described above, since the light from the plurality of light sources is deflected by the prism array plate and combined, the light source images formed on the pupil plane of the projection lens are arranged substantially symmetrically with respect to the optical axis, and the screen is screened. An illumination optical device having good illuminance uniformity and color uniformity and high light use efficiency can be configured. Further, since a plurality of light sources can be combined without reducing the F-number of the projection lens, a small-sized and low-cost projection display device can be configured.

(Embodiment 2) (FIG. 2) shows the configuration of a second illumination optical device according to the present invention. As the image forming means, a liquid crystal panel that modulates light using polarized light is used.

Reference numerals 50 and 51 denote discharge lamps, 52 and 53 denote parabolic mirrors, 54 denotes a prism array plate, 55 denotes a first lens array plate, and 56 denotes a second lens array plate. It is the same as the illumination optical device. What is different from FIG. 1 is that the polarization separation film 59 as the polarization separation means and the reflection film 60 are provided.
Are provided with a polarization conversion optical member 58 composed of a polarization separation prism array 61 formed by forming a plurality of optical axes and a half-wave plate 62 serving as polarization rotation means, and an auxiliary lens 57. 63 is a second illumination optical device of the present invention.

Reference numeral 65 denotes a liquid crystal panel that modulates light using polarized light, and 64 denotes a field lens.

Reference numeral 66 denotes a projection lens, and 67 denotes a pupil plane of the projection lens. FIG. 2 shows a side view showing the polarization conversion optical member 58 and an enlarged view for explaining the operation of the polarization conversion optical member 58. Also, the figure shows the appearance of the light source image formed on the pupil plane 67 of the projection lens 66.

The light radiated from the lamps 50 and 51 is condensed by the corresponding parabolic mirrors 52 and 53 and converted into substantially parallel light. Each light beam enters a prism array plate 54 composed of a plurality of prisms. The prism elements of the prism array plate 54 are triangular prisms having a vertical angle of 60 degrees. Each prism of the prism array plate 54 totally reflects light incident from the parabolic mirrors 52 and 53, and deflects each optical axis by 60 degrees. The light beams from the parabolic mirrors 52 and 53 are split by the prism array plate 54, and the split light beams are alternately combined. The alternately combined light beams enter a first lens array plate 55 composed of a plurality of lenses. The prism pitch of the prism array plate 54 is twice as large as the lens element pitch of the first lens array plate 55 (the pitch in the prism arrangement direction). This is because the boundary of the light beam reflected by one side of the prism of the prism array plate 54 does not coincide with the inside of the opening of the lens element of the first lens array plate 55. In this manner, the light beam split by the prism array plate 54 is uniformly incident on the light beam incident on the lens elements of the first lens array plate 55, so that the liquid crystal panel 65 can be uniformly illuminated.

In the light beam incident on the first lens array plate 35, the light beam from the prism array plate 34 is divided into a number of light beams. The light enters the first lens array plate 55 and is divided into a number of light beams. The large number of split light beams converge on the second lens array plate 56. Many secondary light source images are formed on the second lens array plate 56. The focal length of the lens elements of the first lens array plate 55 is
5 and the distance between the second lens array plate 56.
The first lens array plate 55 lens element and the second lens array plate 56 lens element have the same rectangular aperture shape and the same focal length. The focal length of the lens elements of the second lens array plate 56 is determined so that the surface of the first lens array plate 55 and the liquid crystal panel surface 65 have a substantially conjugate relationship. The auxiliary lens 57 is a lens for illuminating a light beam emitted from the periphery of the second lens array plate 56 onto the liquid crystal panel 65, and the focal length is a distance between the auxiliary lens surface and the liquid crystal panel surface.

A large number of light beams emitted from the second lens array plate 56 enter a polarization separation prism array 58 in which a plurality of minute polarization separation prisms are arranged in one direction perpendicular to the prism arrangement direction of the prism array plate. The minute polarization separating prism has a lens pitch of about 1 of the second lens array plate 56.
/ 2 pitch. The light incident on one polarization separation prism transmits the P-polarized light through the polarization separation film 59,
S-polarized light is reflected. The reflected S-polarized light enters the adjacent reflection film 60, is reflected again, and enters the half-wave plate 62. The half-wave plate 62 changes the polarization direction of the incident light by 90 °.
It is arranged to rotate and converts incident S-polarized light into P-polarized light. The light obtained by converting natural light into light in one polarization direction by the polarization conversion optical member 58 enters the auxiliary lens 57. Many light beams refracted by the auxiliary lens 57 are superimposed on the liquid crystal panel 69, and illuminate the liquid crystal panel 69 uniformly. By arranging the polarization conversion optical member 58, it is possible to use the lost light in one polarization direction, so that the effective polarized light beam for illuminating the liquid crystal panel can be increased.

The field lens 64 is for condensing the light illuminated on the liquid crystal panel 65 on the pupil surface 67 of the projection lens 66. The pupil plane 67 of the projection lens 66 and the surface of the second lens array plate 56 have a substantially conjugate relationship.

The appearance of the light source images of the light sources 50 and 51 is shown on the pupil plane 67 of the projection lens 66. In the prism array direction of the prism array plate, minute light source images 68 and 69 of polarization components in one direction of the light sources 50 and 51 are alternately formed. Furthermore, a minute light source image 7 of the other polarization component is arranged in the polarization separating prism arrangement direction of the polarization conversion optical member.
0 and 71 are formed.

The pupil plane 67 is projected on a screen (not shown) as a light source. It can be seen that the two light source images are formed symmetrically with respect to the optical axis as compared with the light source images on the pupil plane of the projection lens such as the conventional illumination optical device shown in FIG. Further, it can be seen that a light source image is densely formed on the entire pupil plane of the projection lens.

The prism array plate may be manufactured by molding. By using a molded product, a low-cost prism array plate can be configured. In this case, the accuracy of the apex angle of the prism and the flat portion is reduced, but the loss is only slightly increased. Further, the prism array plate may be made of a resin having high heat resistance. If the prism array plate is made of resin,
Further, the cost can be reduced.

As described above, since the light from the plurality of light sources is deflected by the prism array plate and combined, the light source images formed on the pupil plane of the projection lens are arranged substantially symmetrically with respect to the optical axis, and the screen An illumination optical device having good illuminance uniformity and color uniformity and high light use efficiency can be configured. Further, since a plurality of light sources can be combined without reducing the F-number of the projection lens, a small-sized and low-cost projection display device can be configured. Furthermore, since a polarization conversion optical member for converting natural light into light of one-way polarization is disposed, an illumination optical device having extremely high light use efficiency can be configured.

(Embodiment 3) (FIG. 3) shows a configuration of a third illumination optical device according to the present invention. As an image forming unit, a liquid crystal panel that modulates light using polarization or scattering is used.

80 and 81 are discharge lamps, 82 and 83 are parabolic mirrors, 85 is a second prism array plate, 86 is a first lens array plate, and 87 is a second lens array plate. This is the same as the illumination optical device of 1). The difference from FIG. 1 is that the first prism array plate is
This is a point provided between the second prism array plate 83 and the second prism array plate. Reference numeral 88 denotes a third illumination optical device of the present invention. Reference numeral 90 denotes a liquid crystal panel that modulates light using polarization or scattering, 89 denotes a field lens, and 91 denotes a projection lens.

In the illumination optical device shown in FIG. 1, the ratio of the size of the opening in the prism array direction of the prism array plate to the size of the opening of the parabolic mirror is such that the light beam is deflected by 60 degrees,
It becomes 1. In this case, if the apertures of the prism array plate and the first and second lens array plates are configured to be small, it is necessary to reduce the aperture of the parabolic mirror, and condense light from the lamp of the parabolic mirror. The rate drops.

Therefore, in order to improve the light collection rate, the light beam from the parabolic mirror is adjusted so that the opening of the parabolic mirror is equal to the opening of the prism array plate disposed close to the lens array plate. It comprises a first prism array plate 84 that is deflected by 30 degrees and is incident on a second prism array plate 85.

The light radiated from the lamps 80 and 81 is condensed by the corresponding parabolic mirrors 82 and 83 and converted into substantially parallel light. Each light beam enters a first prism array plate 84 composed of a plurality of prisms. The prism element of the first prism array plate 84 has an apex angle of 9
It is a 0 degree triangular prism. The prism elements of the first prism array plate 84 refract light incident from the parabolic mirrors 82 and 83 without loss, and deflect light from each light source by 30 degrees. In order to deviate the angle by 30 degrees, a medium having a refractive index of about 1.73 of the prism element is used. The first prism array plate 84 is arranged symmetrically with respect to the optical axis of the projection lens. Also, two parabolic mirrors 8
The first prism array plate 84 on which the light beams from the light beams 2 and 83 are incident is constituted by one.
It may be constituted by a plurality of first prism array plates corresponding to the light beams from 2, 83.

The light deflected by the prism elements of the first prism array plate 84 enters the second prism array plate 85. The number of prism elements of the second prism array plate is 1 / the number of prism elements of the first prism array plate.
It consists of two. The ratio of the size of the opening in the prism array direction of the second prism array plate to the size of the opening of the parabolic mirror is 1.1.
5: 1, which is almost the same. Therefore, even if the second prism array plate and the first and second lens array plates are configured to be small, the light collection rate of the light from the lamp of the parabolic mirror can be increased.

The prism element of the second prism array plate 85 refracts the first prism array plate from the parabolic mirrors 82 and 83 and totally reflects the incident light, and deviates each optical axis by 60 degrees. I do. The incident light beams are respectively split by the second prism array plate 85, and the split light beams are alternately combined. The light beams alternately combined are incident on a first lens array plate 86 composed of a plurality of lenses.

The light beam incident on the first lens array plate 86 divides the light beam from the second prism array plate 87 into a number of light beams. A large number of split light beams converge on a second lens array plate 87 composed of a plurality of lenses.
Many secondary light source images are formed on the second lens array plate 87. The lens elements of the first lens array plate 86 and the lens elements of the second lens array plate 87 have a rectangular opening shape.
The focal length of the lens elements of the second lens array plate 87 is determined so that the surface of the first lens array plate 86 and the liquid crystal panel surface 90 have a substantially conjugate relationship. Since the light emitted from each lens element of the second lens array plate 87 is illuminated on the liquid crystal panel 90, the lens elements of the second lens array plate 87 and the lens elements of the first lens array plate 86 are appropriately decentered. Let me. Second lens array plate 8
Many light beams emitted from 6 are superimposed on the liquid crystal panel 90 and are uniformly illuminated on the liquid crystal panel 90.

The field lens 89 is for condensing the light illuminated on the liquid crystal panel 90 on the pupil plane of the projection lens 91. The pupil plane of the projection lens 91 and the surface of the second lens array plate 87 have a substantially conjugate relationship.

The first and second prism array plates may be manufactured by molding. By using a molded product, a low-cost prism array plate can be configured. In this case, the accuracy of the apex angle of the prism and the flat portion is reduced, but the loss is only slightly increased. Further, the second prism array plate may be made of a resin having high heat resistance. First and second
If the prism array plate is made of resin, the cost can be further reduced.

As described above, the light from the plurality of light sources is
The light source image formed on the pupil plane of the projection lens is arranged almost symmetrically with respect to the optical axis, so that the illuminance uniformity and color uniformity on the screen are good. An illumination optical device with high use efficiency can be configured. Further, since a plurality of light sources can be combined without reducing the F-number of the projection lens, a small-sized and low-cost projection display device can be configured. Further, since a first prism array plate for deflecting light from the parabolic mirror by 30 degrees is provided, the size of the opening of the parabolic mirror opening, the second prism array plate, and the first and second lens array plates is large. Thus, an illumination optical device having extremely high light use efficiency can be configured.

(Embodiment 4) (FIG. 4) shows the configuration of a fourth illumination optical device according to the present invention. As the image forming means, a liquid crystal panel that modulates light using polarized light is used.

100 and 101 are discharge lamps, 102 and 1
03 is a parabolic mirror, 104 is a first prism array plate, 1
05 is a second prism array plate, 106 is a first lens array plate, 107 is a second lens array plate, and the above is the same as the illumination optical device of FIG. What is different from FIG. 3 is a polarization separation film 110 serving as polarization separation means, a polarization separation prism array 112 formed by forming a plurality of reflection films 111, and a half-wave plate 113 serving as polarization rotation means. Polarization conversion optical member 109 and auxiliary lens 1
08 is provided. Reference numeral 114 denotes a fourth illumination optical device of the present invention.

Reference numeral 116 denotes a liquid crystal panel that modulates light using polarized light, and 115 denotes a field lens. Reference numeral 117 denotes a projection lens. (FIG. 4) includes the polarization conversion optical member 1.
9 shows an enlarged view for explaining the operation of the polarization conversion member 109.

The lights emitted from the lamps 100 and 101 are condensed by the corresponding parabolic mirrors 102 and 103, respectively, and are converted into substantially parallel lights. Each light beam enters a first prism array plate 104 composed of a plurality of prisms. The prism element of the first prism array plate 104 is a triangular prism having a vertical angle of 90 degrees. Each prism element of the first prism array plate 104 is a parabolic mirror 10
The light incident from the light sources 2 and 103 is refracted without loss, and the light from each light source is deflected by 30 degrees. To deviate 30 degrees, the refractive index of the prism element is approximately 1.73.
Medium is used. The light deflected by the prism of the first prism array plate 104 is transmitted to the second prism array plate 1
05. The ratio of the size of the opening in the prism array direction of the second prism array plate 105 to the size of the opening of the parabolic mirror is 1.15: 1, which is almost the same. Therefore, the second
Even if the prism array plate and the first and second lens array plates are miniaturized, the light collection rate of the parabolic mirror can be increased.

Each prism element of the second prism array plate 105 refracts the first prism array plate 104 from the parabolic mirrors 102 and 103 and totally reflects the incident light, and sets each optical axis to 60 degrees. Deviate. The incident light fluxes are respectively split by the second prism array plate 105, and the split light fluxes are alternately combined. The light beams alternately combined are incident on the first lens array plate 106 including a plurality of lenses.

In the light beam incident on the first lens array plate 106, the light beam from the prism array plate 34 is divided into a number of light beams. The light enters the first lens array plate 55 and is divided into a number of light beams. The large number of split light beams converge on the second lens array plate 56. Many secondary light source images are formed on the second lens array plate 56. The focal length of the lens elements of the first lens array plate 106 is
06 and the distance between the second lens array plate 107. The lens element of the first lens array plate 106 and the lens element of the second lens array plate 107 have the same rectangular aperture shape and the same focal length. The focal length of the lens elements of the second lens array plate 107 is determined so that the surface of the first lens array plate 106 and the liquid crystal panel surface 116 have a substantially conjugate relationship. The auxiliary lens 108 is a lens for illuminating a light beam emitted from the periphery of the second lens array plate 107 onto the liquid crystal panel 116, and the focal length is a distance between the auxiliary lens surface and the liquid crystal panel surface.

A large number of light beams emitted from the second lens array plate 107 enter a polarization separation prism array 109 in which a plurality of minute polarization separation prisms are arranged in one direction perpendicular to the prism arrangement direction of the prism array plate. The minute polarization separating prisms are arranged at a pitch of about １ ／ of the lens pitch of the second lens array plate 107. The light incident on one polarization splitting prism is transmitted by the polarization splitting film 110 as P-polarized light and reflected as S-polarized light. The reflected S-polarized light is incident on the adjacent reflection film 111 and is reflected again, so that the half-wave plate 1
13 is incident. The half-wave plate 113 is arranged so as to rotate the polarization direction of the incident light by 90 °, and converts the incident S-polarized light into P-polarized light. Light obtained by converting natural light into light in one polarization direction by the polarization conversion optical member 109 enters the auxiliary lens 108. Many light beams refracted by the auxiliary lens 108 are superimposed on the liquid crystal panel 116 to uniformly illuminate the liquid crystal panel 116. By arranging the polarization conversion optical member 109, it is possible to use the light in one polarization direction that has been lost, so that the effective polarized light flux for illuminating the liquid crystal panel can be increased.

The field lens 115 is the liquid crystal panel 11
6 is for condensing the light illuminated on 6 onto the projection lens 117. The pupil plane of the projection lens 117 and the surface of the second lens array plate 56 have a substantially conjugate relationship.

As described above, the light from the plurality of light sources is
The light source image formed on the pupil plane of the light projection lens from the light source is arranged almost symmetrically with respect to the optical axis, and the illuminance uniformity and color uniformity are high, An illumination optical device with high use efficiency can be configured. Since a plurality of light sources can be combined without reducing the F-number of the projection lens, a small and low-cost projection display device can be configured. In addition, since a first prism array plate for deflecting light from the parabolic mirror by 30 degrees is provided, the size of the parabolic mirror aperture and the apertures of the second prism array plate and the first and second lens array plates are increased. Thus, an illumination optical device having extremely high light use efficiency can be configured. Furthermore, since a polarization conversion optical member for converting natural light into light of one-way polarization is disposed, an illumination optical device having extremely high light use efficiency can be configured.

(Embodiment 5) (FIG. 5) shows a configuration of a first projection display apparatus according to the present invention.

As the image forming means, a liquid crystal panel that modulates light by using polarization or scattering is used. 80 and 81 are lamps, 82 and 83 are parabolic mirrors, 84 is a first prism array plate, 85 is a second prism array plate, 86 is a first lens array plate, 87 is a second lens array plate, 88 Is a third illumination optical device of the present invention.

Reference numeral 131 denotes a liquid crystal panel, 130 denotes a field lens, 132 denotes a projection lens, and 133 denotes a screen.

The light emitted from the illumination optical device 88 passes through the field lens 130 and enters the liquid crystal panel 131. Blue, green and red color filters are formed in each pixel of the liquid crystal panel 131. The liquid crystal panel 131 is of an active matrix type, and modulates light by controlling a voltage applied to a pixel according to a video signal to form a color image. The field lens 130 is a liquid crystal panel 131
Is focused on the pupil plane of the projection lens 132. The color light transmitted through the liquid crystal panel 131 is enlarged and projected on the screen 133 by the projection lens 132.

As described above, by providing the first prism array plate and the second prism array plate as an illumination optical device using two light sources, light from the two light sources can be very efficiently and uniformly. To the LCD panel.
Therefore, a projection display device having good uniformity and high light use efficiency can be configured. Since the structure is formed using one liquid crystal panel, a small-sized and low-cost projection display device can be formed. Further, as the illumination optical device, the first illumination optical device of the present invention using only the prism array plate that deflects incident light by 60 degrees may be used. Furthermore, in the case where the liquid crystal panel modulates light using polarized light, the second and fourth illumination optical devices of the present invention each including a polarization conversion optical member may be used as the illumination optical device.

(Embodiment 6) (FIG. 6) shows a configuration of a second projection display apparatus according to the present invention. As the image forming means, a liquid crystal panel that modulates light using polarized light is used.

80 and 81 are lamps, 82 and 83 are parabolic mirrors, 84 is a first prism array plate, 85 is a second prism array plate, 86 is a first lens array plate, and 87 is a second lens array plate.
The lens array plate 88 is a third illumination optical device of the present invention.

Reference numerals 140 and 141 denote dichroic mirrors for reflecting blue light and green light, respectively, 142 denotes a color separation optical means composed of dichroic mirrors, and 143, 144, and 1
45 is a mirror, 146 and 147 are relay lenses, 14
9, 148 and 150 are field lenses, 151 and 15
Reference numerals 2 and 153 denote a liquid crystal panel, 156 denotes a dichroic prism which is a color synthesizing means, 154 and 155 denote a dichroic mirror for reflecting blue and red, respectively, constituting a dichroic prism 156, and 157 denotes a projection lens.

The light emitted from the illumination optical device 88 enters the color separation optical means 142. The light incident on the color separation optical means 142 is a blue reflecting dichroic mirror 140,
By the dichroic mirror 141 of green reflection, blue, green,
Separated into red color light. The green and blue color lights pass through the field lenses 149 and 150, respectively, and
1, 153. Red color light is relay lens 14
6, 147 and a mirror, and then enter the liquid crystal panel 152 after passing through the field lens 148. The three liquid crystal panels 151, 152, and 153 are of an active matrix type, and modulate light by controlling a voltage applied to a pixel according to a video signal, and modulate red and red light, respectively.
Form green and blue images. Liquid crystal panels 151, 152,
The color light transmitted through the projection lens 153 is synthesized by a dichroic prism 156 as color synthesis optical means.
57 enlarges and projects the image on a screen (not shown).

As described above, by providing the first prism array plate and the second prism array plate as an illumination optical device using two light sources, light from the two light sources can be very efficiently and uniformly. To the LCD panel.
Therefore, a projection display device having good uniformity and high light use efficiency can be configured. Since it is configured using three liquid crystal panels, a bright and high-definition projection display device can be configured.
Further, as the illumination optical device, the first illumination optical device of the present invention using only the prism array plate that deflects incident light by 60 degrees may be used. Further, the second and fourth illumination optical devices of the present invention each including a polarization conversion optical member may be used as the illumination optical device.

(Embodiment 7) (FIG. 7) shows a configuration of a third projection display apparatus according to the present invention. As an image forming unit, a reflection type liquid crystal panel that modulates light using polarized light is used.

80 and 81 are lamps, 82 and 83 are parabolic mirrors, 84 is a first prism array plate, 85 is a second prism array plate, 86 is a first lens array plate, and 87 is a second lens array plate.
The lens array plate 88 is a third illumination optical device of the present invention.

Reference numerals 180 and 181 denote red-transmitting and green-reflecting dichroic mirrors, 182 denotes color separation optical means constituted by dichroic mirrors, 183 denotes mirrors,
84, 185, 186 are polarization splitting prisms, 187, 1
88 and 189 are reflection type liquid crystal panels, 190 and 191 are half-wave plates, 194 is a dichroic prism which is a color synthesizing means, and 192 and 193 are red reflection and blue reflection dichroic mirrors constituting a dichroic prism 156, respectively. Reference numeral 195 denotes a projection lens.

The light emitted from the illumination optical device 88 enters the color separation optical means 182. The light incident on the color separation optical means 182 is a red-transmitting dichroic mirror 180,
Blue, green,
Separated into red color light. The separated green, red, and blue light components enter the polarization splitting prisms 184, 185, and 186, respectively. The polarization splitting prisms 184, 185, and 186 are prisms having a polarization splitting film composed of a dielectric multilayer film. The polarization splitting film has an incident angle of 45 °, and transmits P-polarized light and reflects S-polarized light with respect to the polarization splitting film surface.
The reflected S-polarized light of green, red, and blue light enters the reflection type liquid crystal panels 187, 188, and 189, respectively. The reflection type liquid crystal panels 187, 188, and 189 are of an active matrix type and include a liquid crystal layer and a reflection film. As the liquid crystal, a homeotropic liquid crystal, a HAN mode liquid crystal, or a 45-degree twisted nematic liquid crystal is used. In a reflective liquid crystal panel, the birefringence of liquid crystal changes when a voltage is applied in accordance with a video signal. The light incident on the reflection type liquid crystal panel passes through the liquid crystal, is reflected by the reflection film, and in the process of transmitting the liquid crystal again, the light changes its polarization state from S-polarized light to P-polarized light due to birefringence, and is emitted. Reflective liquid crystal panel 187
Green P-polarized color light emitted from the
After passing through the dichroic prism 4, the light enters a dichroic prism 194 as a color synthesizing unit. Reflective liquid crystal panel 188, 1
Each of the red and blue P-polarized light emitted from 89 is
After passing through the polarization splitting prisms 185 and 186 and being rotated by the 波長 wavelength plates 191 and 193 to S-polarized light, the light is incident on the dichroic prism 115 serving as a color combining unit. Green by dichroic prism 194,
The red and blue light beams are combined and enlarged and projected on a screen by a projection lens 195.

On the other hand, reflection type liquid crystal panels 187 and 18
The S-polarized light whose polarization state is not changed by 8, 189 is reflected by the polarization splitting prisms 184, 185, 186 and returns to the illumination optical device 88 side. In this way, the optical image formed as a change in the polarization state of light on the reflective liquid crystal panel is enlarged and projected on a screen (not shown), and a full-color projected image is formed.

As described above, by providing the first prism array plate and the second prism array plate as an illumination optical device using two light sources, light from the two light sources can be very efficiently and uniformly. To the LCD panel.
Therefore, a projection display device having good uniformity and high light use efficiency can be configured. Since it is configured using three reflective liquid crystal panels, a bright and high-definition projection display device can be configured. Further, as the illumination optical device, the first illumination optical device of the present invention using only the prism array plate that deflects incident light by 60 degrees may be used. Further, the second and fourth illumination optical devices of the present invention each including a polarization conversion optical member may be used as the illumination optical device.

In the above embodiment, an example in which a liquid crystal panel utilizing polarization or scattering is used as an image forming means has been described. However, an image forming means for forming an optical image corresponding to a video signal as a change in diffraction, reflection, or the like. May be used. In addition, a rear projection type display device may be configured using a transmission screen.

[0077]

As described above, according to the present invention, the illumination optical device for illuminating the image forming means is provided with the prism array plate for deviating and synthesizing the light from the plurality of light sources so that the light from the plurality of light sources can be obtained. An illumination optical device that illuminates the liquid crystal panel very efficiently and uniformly to the liquid crystal panel can be realized. Also,
A bright projection display device with good uniformity and high light use efficiency can be configured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an illumination optical device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an illumination optical device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an illumination optical device according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of an illumination optical device according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a projection display device according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram of a projection display device according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram of a projection display apparatus according to a seventh embodiment of the present invention.

FIG. 8 is a configuration diagram of a conventional illumination optical device and a projection display device.

[Explanation of symbols]

30, 31, 50, 51, 80, 81, 100, 101
Lamps 32, 33, 52, 53, 82, 83, 102, 103
Parabolic mirrors 34, 54 Prism array plates 35, 55, 86, 106 First lens array plates 36, 56, 87, 107 Second lens array plates 37, 63, 88, 114 Illumination optical devices 38, 64, 89, 130,148,149,150
Field lens 39, 65, 90, 131, 151, 152, 153
Liquid crystal panel 40, 66, 91, 132, 157, 195 Projection lens 41, 67 Pupil surface of projection lens 42, 43, 68, 69, 70, 71 Fine light source image 57, 108 Auxiliary lens 58, 109 Polarization conversion optical member 59, 110 Polarization separation film 60, 111 Reflection film 61, 112, 184, 185, 186 Polarization separation prism 62, 113, 190, 191 1/2 wavelength plate 84, 104 First prism array plate 85, 105 Second Prism array plate 133 Screen 140 Blue reflecting dichroic mirror 141,181 Green reflecting dichroic mirror 142,182 Color separation optical means 143,144,145,183 mirror 146,147 Relay lens 154,193 Blue reflecting dichroic mirror 155,192 Dichroic with red reflection Mirror 156,194 dichroic prism 180 red light transmission dichroic mirror 187,188,189 reflective liquid crystal panel

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G09F 9/00 360 G09F 9/00 360D H04N 5/74 H04N 5/74 A 9/31 9/31 C

Claims (23)

[Claims] An illumination optical device for illuminating image forming means for forming an image by condensing light from a light source, comprising: a plurality of light sources; and a concave mirror for condensing light emitted from the plurality of light sources, respectively. A prism array plate, into which light from the concave mirror is incident, deflected light from the concave mirror and composed of a plurality of prisms, and light from the prism array plate, and composed of a plurality of lenses. A first lens array plate that splits light from the prism array plate into a number of light beams, and a second lens array plate that includes a plurality of lenses and into which light from the first lens array plate enters. Illumination optical device provided. 2. An illumination optical apparatus for illuminating image forming means for forming an image by condensing light from a light source, comprising: a plurality of light sources; and a concave mirror for condensing light emitted from the plurality of light sources. A prism array plate, into which light from the concave mirror is incident, deflected light from the concave mirror and composed of a plurality of prisms, and light from the prism array plate, and composed of a plurality of lenses. A first lens array plate that divides light from the prism array plate into a number of light beams, a second lens array plate that includes a plurality of lenses, and into which light from the first lens array plate enters. Light from the second lens array plate enters, and polarization separating means for separating natural light into two polarized lights having polarization directions orthogonal to each other, and light from the polarization separating means enters and exits from the polarization separating means. It was one illumination optical system and a polarization rotating means for rotating the polarization direction of. 3. The illumination optical device according to claim 1, wherein the prisms forming the prism array plate are prisms that deviate light by total reflection. 4. The illumination optical device according to claim 1, wherein the prisms constituting the prism array plate are prisms having an apex angle of 60 degrees. 5. The illumination optical device according to claim 1, wherein the prism array plate comprises a prism which deflects the incident light by approximately 60 degrees. 6. The illumination optical device according to claim 1, wherein an arrangement pitch of the prisms constituting the prism array plate is substantially twice as large as an arrangement pitch of the lenses constituting the first lens array plate. 7. The illumination optical device according to claim 1, wherein the prism array plate and the first lens array plate are in close contact with each other. 8. An illumination optical apparatus for illuminating image forming means for forming an image by condensing light from a light source, comprising: a plurality of light sources; and a concave mirror for condensing light emitted from the plurality of light sources. A light from the concave mirror is incident, a first prism array plate composed of a plurality of prisms and deflecting the light from the concave mirror respectively, and light from the first prism array plate is respectively incident, A second prism array plate which deviates and combines light from the first prism array plate and combines the light from the second prism array plate, and a plurality of lenses. And a first lens array plate that divides light from the light source into a number of light beams, and a plurality of lenses.
And a second lens array plate on which light from the lens array plate is incident. 9. An illumination optical apparatus for illuminating image forming means for forming an image by condensing light from a light source, comprising: a plurality of light sources; and a concave mirror for condensing light emitted from the plurality of light sources. A light from the concave mirror is incident, a first prism array plate composed of a plurality of prisms and deflecting the light from the concave mirror respectively, and light from the first prism array plate is respectively incident, A second prism array plate which deviates and combines light from the first prism array plate and combines the light from the second prism array plate, and a plurality of lenses. And a first lens array plate that divides light from the light source into a number of light beams, and a plurality of lenses.
A second lens array plate on which light from the lens array plate is incident, and light from the second lens array plate incident on the second lens array plate;
A polarization separating unit that separates natural light into two polarized light beams whose polarization directions are orthogonal to each other; and a polarization rotation unit that receives light from the polarization separation unit and rotates one polarization direction emitted from the polarization separation unit. Lighting optics. 10. The prism constituting the first prism array plate is a prism for deflecting light by refraction.
Or the illumination optical device according to 9. 11. The illumination optical device according to claim 8, wherein the prisms constituting the second prism array plate are prisms that deviate light by total reflection. 12. The illumination optical device according to claim 8, wherein the prisms constituting the first prism array plate are right-angle prisms. 13. The illumination optical device according to claim 8, wherein the first prism array plate is a prism that deflects incident light by approximately 30 degrees. 14. The illumination optical device according to claim 8, wherein the prisms constituting the second prism array plate are prisms having a vertical angle of 60 degrees. 15. The illumination optical device according to claim 8, wherein the arrangement pitch of the prisms constituting the second prism array plate is substantially twice as large as the arrangement pitch of the lenses constituting the first lens array plate. 16. The illumination optical device according to claim 8, wherein the number of elements of the prism of the first prism array plate is twice the number of elements of the second prism array plate. 17. The illumination optical device according to claim 1, wherein the prism array plate is manufactured by molding. 18. The illumination optical device according to claim 1, wherein the prism array plate is made of resin. 19. A light source, illumination optical means for condensing light from the light source and illuminating the image forming means, and one of the light from the illumination optical means for forming an optical image in accordance with a video signal. 10. A projection display comprising: an image forming unit; and a projection lens for projecting an optical image on the image forming unit on a screen, wherein the illumination optical unit is the illumination optical unit according to claim 1, 2, 8, or 9. apparatus. 20. A light source, illumination optical means for condensing light from the light source and illuminating the image forming means, and color separation for separating white light from the light source into light of blue, green and red color components. Optical means, and three image forming means on which each color light from the color separation optical means is incident and an optical image is formed according to a video signal;
Receiving blue, green, and red emitted light from the image forming unit;
10. The illumination optical means comprising: a color synthesizing optical means for synthesizing green and red color lights; and a projection lens for projecting an optical image on the image forming means onto a screen. Projection display device. 21. A light source, illumination optical means for condensing light from the light source and illuminating the image forming means, and color separation for separating white light from the light source into light of blue, green and red color components. Optical means, each color light from the color separation optical means is incident, a polarization separation prism that separates the incident light into light of two orthogonal polarization directions, light from the polarization separation prism is incident, and the video signal Three image forming means for forming an optical image in response thereto, and combining blue, green and red emitted lights from the image forming means with blue, green and red color lights which are transmitted through the polarization splitting prism and entered. And a projection lens for projecting an optical image on the image forming unit onto a screen, wherein the illumination optical unit is the illumination optical unit according to claim 1, 2, 8, or 9. Type display device. 22. A projection display device according to claim 19, wherein the image forming means is a liquid crystal panel. 23. The projection display device according to claim 21, wherein the image forming means is a reflection type liquid crystal panel.