JPH11231263A - Polarizedlight illuminating device and projection type image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable efficient illumination by applying the rotating operation of a polarizing plane through a polarized light converting part only to one side polarized light and providing a polarized light illuminating device with the state of putting the direction of polarization in order with the direction of the other side polarized light. SOLUTION: Concerning a projection type image display device, a polarized light illuminating device 200 has a light source part 201, optical integrator system 202 and polarized light separating part 203 along with the optical axis of a system and light emitted from the light source part 201 passes the optical integrator system 202, polarized light separating part 203 and polarized light converting part 204 and reaches a rectangular illumination area 205. Concerning such a projection type image display device, the polarized light converting part 204 applies the rotating operation of the polarizing plane only to one side polarized light through the polarized light illuminating device 200 and provides the state of putting the direction of polarization in order with that of the other polarized light. Therefore, since the polarized light having the uniform direction of polarization is guided to first - third liquid crystal valves, the rate of light utilization is improved and light projection images can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarized light illuminating apparatus for uniformly illuminating a rectangular area using polarized light having a uniform polarization direction. The present invention also relates to a projection type image display device which modulates polarized light emitted from the polarized light illuminating device by a light valve and projects an image on a screen in an enlarged manner.

[0002]

2. Description of the Related Art As an optical system for uniformly illuminating a rectangular illumination area such as a liquid crystal light valve, an integrator optical system using two lens plates has been conventionally known, and a projection type using a liquid crystal light valve is known. It has already been put to practical use as a lighting device for an image display device.

In a general projection type image display device using a liquid crystal light valve of a type that modulates polarized light, only one type of polarization direction light can be used, so that the light use efficiency is not necessarily sufficient. Did not. For the purpose of improving light use efficiency in this projection type image display device, for example, Japanese Patent Application Laid-Open No. 9-146064 proposes a novel optical system in which a polarization conversion method is combined with an integrator optical system.

FIG. 18 shows an illumination optical system disclosed in this publication. As shown in FIG. 18, a polarized light illumination device 100 includes a light source 101 and an integrator optical system 102.
, A polarization separation unit 103, and a λ / 2 retardation plate 104 as a polarization conversion element. Integrator optical system 1
Reference numeral 02 denotes a first lens plate 105 and a second lens plate 106. Of the light emitted from the light source 101, the S-polarized light with respect to the polarization separation unit is the first lens plate 10.
5. The light is reflected by the polarization beam splitter 107 of the polarization beam splitter, which is a polarization beam splitter, to form a light source image on the second lens plate 106. The P-polarized light passes through the first lens plate 105 and the polarization splitting surface 107 of the polarizing beam splitter, which is a polarization splitting portion, and is reflected by the total reflection surface 108 to the polarization splitting portion. A light source image is formed on the plate 106. The part of the light source image formed on the second lens plate 106 by the P-polarized light is a λ / 2 retardation plate 1.
The light is condensed out of the second lens plate 106 so that all the light can be S-polarized light.

[0005]

In the polarized light illuminating apparatus thus configured, it is possible to align light in two polarization directions to one polarization direction. Each light source image formed on the second lens plate 106 after being reflected by the polarization splitting surface 107 and the total reflection surface 108 of the splitter has a certain distance (d in the figure) determined by the thickness and the refractive index of the parallel flat plate. It will shift uniformly.

[0006] If the shift amount d is too small, the polarization conversion efficiency deteriorates. If the shift amount d is too large, the F number of this illumination system becomes small. When this illumination device is applied to a projection type image display device or the like, another optical system is used. Is large and expensive. Furthermore, if only the configuration of the conventional polarization conversion optical system typified by Japanese Patent Application Laid-Open No. 9-146064 is used, the size of the light valve in the illuminated portion can be reduced when actually applied to the projection type image display device as described above. Considering the application to microlenses used in recent years for transmission and transmission type liquid crystal panels and the like, the F-number of the illumination system becomes too small, and it has been difficult to effectively use light as a whole device. Therefore, Japanese Patent Application Laid-Open No. 5-346
A proposal has been made to reduce the size of the second lens plate by optimizing the aperture area of the minute lens in accordance with a light source image formed on the second lens plate as in 557.

An object of the present invention is to make it possible to illuminate efficiently by aligning the polarization directions of light having two polarization directions,
Furthermore, by realizing this without restricting the design of the original illumination system as in the conventional means and without sacrificing the size of the set, projection is performed particularly in the case of a projection type image display device. The size and cost of the lens can be reduced. Another object of the present invention is to provide a brighter projected image by increasing the light utilization factor when a projection lens having the same brightness is used.

[0008]

According to a first aspect of the present invention, there is provided a polarized light illuminating apparatus comprising a light source for emitting light having a random polarization direction and a plurality of rectangular lenses.
An integrator optical system composed of a lens plate and a second lens plate which is an aggregate of a plurality of microlenses, and light emitted from the light source is transmitted through the first lens plate to the second lens plate.
In the illumination device, which is projected as a secondary light source image on the entrance surface of each lens constituting the lens plate, and illuminates an object to be illuminated using light emitted from the second lens plate, Polarization separating means for separating the randomly polarized light emitted from the light source into two polarized lights whose polarization directions are orthogonal to each other and separating them into two substantially parallel lights, and a polarization converter for aligning the polarization directions of the two polarized lights. And a polarization beam splitter comprising a polarization separation film surface and a total reflection surface provided obliquely to light emitted from the first lens plate. The lens plate is a set of rectangular lenses in which the light source images form approximately rows on the second lens plate and the aperture and the center of curvature are set to be shifted so that the light source images are arranged. Is formed on the second lens plate A collection of microlenses having openings corresponding to the size of the light source image, wherein a row of light source images formed on the second lens plate includes a system axis from the light source to the second lens plate Are arranged in a direction perpendicular to the plane, and the number thereof is smaller than the number of rows in the same direction formed by the microlenses on the first lens plate when viewed only in one polarization direction. Features.

A polarized light illuminating device according to claim 2, wherein the second lens is an aggregate of a light source for emitting light having a random polarization direction, a first lens plate comprising a plurality of rectangular lenses, and a plurality of minute lenses. An integrator optical system composed of a plate, and the emitted light from the light source is provided as a secondary light source image on the entrance surface of each lens constituting the second lens plate via the first lens plate. In an illumination device that is projected and illuminates an object to be illuminated using the light emitted from the second lens plate, the randomly polarized light emitted from the light source is separated into two polarized lights whose polarization directions are orthogonal to each other. And a polarization splitting unit for splitting the light into two substantially parallel light beams and a polarization conversion unit for aligning the polarization directions of the two polarized light beams, wherein the first lens plate has a light source image on the second lens plate. Approximate rows of light source image An aggregate of rectangular lenses set by shifting the opening and the center of curvature to sequence, the second
Is an aggregate of minute lenses having an opening corresponding to the size of the light source image formed on the second lens plate, and the polarized light separating unit emits light from the first lens plate. The polarization beam splitter has a polarization beam splitter surface and a total reflection surface that are provided obliquely to light, and the polarization beam separation film surface and the total reflection surface are parallel to each other, and the interval therebetween is different in the plane. Features.

[0010] A polarized light illuminating device according to claim 3, wherein the second lens is an aggregate of a light source for emitting light having a random polarization direction, a first lens plate composed of a plurality of rectangular lenses, and a plurality of minute lenses. An integrator optical system composed of a plate, and the emitted light from the light source is provided as a secondary light source image on the entrance surface of each lens constituting the second lens plate via the first lens plate. In an illumination device that is projected and illuminates an object to be illuminated using the light emitted from the second lens plate, the randomly polarized light emitted from the light source is separated into two polarized lights whose polarization directions are orthogonal to each other. A polarization splitting unit that splits the light into two substantially parallel light beams; and a polarization conversion unit that aligns the polarization directions of the light beams in the two polarization directions, wherein the polarization splitting unit emits the light emitted from the first lens plate. Installed diagonally to Equipped with a polarizing separating film surface and the total reflection surface and,
In addition, the polarizing beam splitter is a polarizing beam splitter in which the surface of the polarized light separating film and the total reflection surface are parallel to each other and the distance between the surfaces is different in the plane. The first lens plate forms a light source image on the second lens plate. A set of rectangular lenses set so that the aperture and the center of curvature are shifted so that the light source images are arranged,
The second lens plate is an aggregate of minute lenses having openings corresponding to the size of the light source image formed on the second lens plate, and is formed on the second lens plate. The rows of the light source images are arranged in a direction perpendicular to a plane including the system axis from the light source to the second lens plate, and the number thereof is equal to the number on the first lens plate when viewed only in one polarization direction. The number of rows in the same direction formed by the microlenses is less than the number of rows.

Here, in the inventions 1, 2 and 3, the polarization separation means is a polarization beam splitter which forms a polarization reflection film surface and a total reflection surface by sandwiching the polarization separation film between a prism and a plane-parallel plate. Alternatively, the polarization separation means is a polarization beam splitter that forms a polarization separation film surface and a total reflection surface with a plane parallel plate in which a sheet having polarization selectivity is attached to an incident surface, or The means is characterized in that it is a polarizing beam splitter in which a highly refractive inorganic material film is thinned so as to have polarization selectivity, and the polarizing beam splitter is constituted by a plane-parallel plate having a polarization-separating film surface and a total reflection surface provided on an incident surface.

In the inventions 2 and 3, the plane-parallel plates forming the polarization splitting means are formed by stacking a plurality of plane-parallel plates having different sizes, or the plane-parallel plates forming the polarization splitting means are parallel plates having different thicknesses. It is configured by arranging flat plates. In the inventions 1, 2, and 3, the polarization conversion means is a λ / 2 plate, and is disposed near the second lens plate.

The polarized light illuminating device according to claim 1, 2 or 3, is used as an illuminating means, and a light valve arranged at least near an illuminated surface of the polarized light illuminating device, and an image on the light valve is enlarged and projected. It is possible to configure a projection-type image display device including a projection lens provided so as to be capable of being provided.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The polarized light illuminating device according to the present invention realizes this with a simple structure while keeping the polarized light of all polarized light in the same polarization direction and keeping the second lens plate to the minimum size. This can minimize the cost increase and the size of the entire apparatus. Hereinafter, embodiments will be described with reference to the drawings. (First Embodiment) FIG. 1 is a schematic configuration diagram of a first embodiment. The polarized light illuminating device 200 of this example has a light source unit 201, an integrator optical system 202, and a polarization separation unit 203 along the system optical axis, and light emitted from the light source unit 201 emits light from the integrator optical system 202 and the polarization separation unit 203. , Through the polarization converter 204 to the rectangular illumination area 205.

The light source unit 201 includes a light source 211 and a reflector 212. Polarized light emitted from the light source and having a random polarization direction is reflected in one direction by the reflector 212 and enters the integrator optical system 202.
The shape of the reflecting surface of this reflector 212 is parabolic,
An elliptical surface or a spherical surface can be used depending on the design of the optical system.

The first lens plate 213 is a composite lens body of rectangular minute lenses as shown in FIG. The incident light here is condensed by individual minute lenses. The light source image formed by the minute lens is
3. The polarization converter 204 is set to be formed on the second lens plate 214.

In FIG. 1, the polarization splitting unit 203 is configured by a triangular pyramid prism 215 and a parallel plane plate 216 closely contacting each other with a polarization splitting surface 217 interposed therebetween. The randomly polarized light from the light source incident on the polarized light separating surface 217 reflects the S-polarized light component on the polarized light separating surface 217 and reaches the second lens plate 214. On the other hand, the P-polarized light transmitted through the polarization separation surface 217 is transmitted through the parallel plane plate 216 and reflected by the total reflection surface 218, and is again reflected by the parallel plane plate 2
16, the light passes through the triangular pyramid prism 215 and reaches the second lens plate 214. At this time, the light passes through the λ / 2 plate 219 provided on the second lens plate 214, whereby the polarization direction is changed and S It becomes polarized light. The s-polarized light having the light source image formed on the second lens plate 214 with the polarization directions aligned in this manner is applied to each micro lens 220 on the second lens plate 214.
Thereby, each microlens image on the first lens plate 213 is enlarged and projected on the illumination target surface 221. In this way, uniform illumination is realized while aligning random light from the light source in one polarization direction.

However, in the first embodiment, looking at the arrangement of the microlenses on the first lens plate 213 as shown in FIG. 2, the system optical axes 222a and 222b folded by the polarization separation section 203 are not aligned. When viewed in a direction (row direction in FIG. 2) orthogonal to the plane including the data, a six-row configuration is provided.
On the other hand, the arrangement of microlenses on the second lens plate necessary for illuminating only the light in the S-polarized direction on the illumination target surface 221 is configured as shown in FIG. The lens array has a four-row configuration in the direction described above with reference to FIG. FIG. 4 shows the first lens plate 213 on the outer shape of the first lens plate 213.
The second lens plate 214 is condensed by each of the upper microlenses.
The light source image formed above is shown in an overlapping manner. In the present invention, by appropriately setting the center of curvature of each microlens on the first lens plate 213, as shown in FIG. 4, the formation positions of light source images having different sizes are shown in FIG. It was arranged as follows. Thus, even if the number of rows formed by each microlens on the second lens plate 214 is set to be smaller than the number of rows formed by each microlens on the first lens plate 213, the light utilization rate is not impaired. Make up the device. Here, the light source image formed by the light that was originally P, which was reflected by the total reflection surface 218 of the polarization separation unit 203 and passed through the polarization conversion unit 204 to become S-polarized light, mainly has the thickness, refractive index, It is formed on the second lens plate 214 as shown in FIG. 6 with a shift amount d1 determined by the incident angle of the light passing therethrough.

As described above, according to this embodiment, the second polarized light from the light source is aligned with one polarized light while
Since the lens plate 214 can be made smaller than the conventional example, it is possible not only to reduce the size of the apparatus, but also to suppress the illumination F-number to a large value (the incident angle to the surface to be illuminated 221).

In the present embodiment, the polarization separation section 203
Although a prism is used, it is applicable if reflection and transmission can be selected depending on the polarization direction.It can be applied to a thin film of a high refractive index material formed on a parallel plane plate, or a sheet with a polarization separation function recently developed. It can be realized even if it is attached to a parallel plane plate. Speaking of the total reflection surface, there is no problem when the total reflection can be sufficiently expected from the relationship between the refractive index of the glass and the air and the incident angle, but if this is insufficient, a reflection layer is provided on the total reflection surface 218 side of the parallel plane plate. It is also possible to secure the performance by providing it.

In this embodiment, the polarization converter 2
04 is formed on the second lens plate 214, but it is not always necessary to integrate both of them, and it is sufficient that the polarization conversion unit 204 is arranged on an optical path through which only P-polarized light passes. Therefore, as long as it is near the second lens plate 214, it can be arranged on the illuminated surface 221 side without any problem.

Further, in this embodiment, all the randomly polarized light from the light source is converted into S-polarized light with respect to the polarization separation surface 217. However, if the position where the polarization converter 204 is attached is changed, all the light is converted into P-polarized light. Can easily be obtained as light. Further, if different retardation plates are set for both optical paths, it is needless to say that linear polarization other than the P and S polarization directions, or any circular polarization or elliptical polarization can be obtained.

In the present embodiment, the integrator optical system 202 includes a first lens plate 213 and a second lens plate 2.
14, but as shown in FIG.
3 can be used together.

It is also apparent that it is desirable to use a means for eliminating ultraviolet rays and infrared rays in the apparatus in this embodiment also in order to improve reliability.

FIG. 8 shows an example in which the device of the above embodiment is applied to a projection type image display device. The projection type image display device 300 shown in the figure includes a light source unit 201 that emits randomly polarized light in one direction, and the random polarized light emitted from the light source unit 201 receives an integrator optical system 202 and a polarization separation unit 203. , The light is separated into two types of polarized light, and one direction of the separated polarized light is converted by the polarization converter 204 into a single polarization direction.

In the light beam emitted from the polarized light illuminating device 200, first, red light is transmitted through the red transmission dichroic mirror 301, and blue and green light are reflected.

The red light is reflected by the reflection mirror 302 and reaches the first liquid crystal light valve 303. On the other hand, of the blue light and the green light, the green light is a green reflecting dichroic mirror 3.
04, the second liquid crystal light valve 305
Reach Blue light is a green reflective dichroic mirror 304
After the light is transmitted through the third liquid crystal light by a light guide means 350 configured by adding a reflection mirror 307 and a reflection mirror 309 to a relay lens system including the entrance side lens 306, the relay lens 308, and the exit side lens 310. Valve 3
It is led to 11. Here, the first, second, and third liquid crystal light valves 303, 305, and 311 modulate color light, respectively, and input the color light modulated according to the video signal corresponding to each color to the dichroic prism 313 (color combining means). . The dichroic prism 313 has a red reflective dielectric multilayer film and a blue reflective dielectric multilayer film in a cross shape, and synthesizes respective modulated light fluxes. The light beam synthesized here passes through the projection lens 314 (projection means) and passes through the screen 3.
15 to form an image.

In the projection type image display apparatus 300 thus configured, a liquid crystal panel of a type that modulates one kind of polarized light is used. Therefore, when the conventional random polarized light is guided to the liquid crystal light valve, half of the random polarized light is absorbed by the polarizer and converted into heat, so that the light utilization rate is low and the heat generated by the polarizer is suppressed. There was a problem that a large-sized and noisy cooling device was required, but the projection-type image display device 300 of this example can largely solve such a problem.

That is, the projection type image display device 30 of this embodiment
In the case of 0, in the polarized light illuminating device 200, only one polarized light is rotated by the polarization conversion unit 204 so that the other polarized light and the polarized light are aligned. Therefore, the polarized light having the same polarization direction is guided to the first, second, and third liquid crystal light valves 303, 305, and 311. Therefore, the light utilization factor is improved, and a bright projected image can be obtained. In addition, since light absorption by the polarizing plate can be reduced, temperature rise in the polarizing plate can be suppressed. This makes it possible to reduce the size and noise of the cooling device.

Further, according to this embodiment, the second lens plate 21
4 can be configured to have a small area. Therefore, the F-number of the projection lens is determined by the relationship between the apparent size of the second lens plate and the distance from the panel to the second lens plate.
If the apparent size of the lens plate can be reduced, the F-number can be reduced, that is, there is no need to brighten the projection lens. Can be sufficiently realized.

When a projection type image display apparatus is constructed using a small panel, a microlens is arranged near the panel opening to improve the apparent aperture ratio. Since it is essential to increase the F number, performance improvement according to the present invention is expected from this viewpoint. (Embodiment 2) FIG. 9 is a schematic configuration diagram of Embodiment 2. The polarized light illuminating device 400 of this example has a light source unit 201, an integrator optical system 410, and a polarization separation unit 411 along the system optical axis, and the light emitted from the light source unit 201 receives the light emitted from the light source unit 201, the polarization separation unit 411. , Through the polarization converter 204 to the rectangular illumination area 205.

The light source section 201 includes a light source 211 and a reflector 212. Polarized light emitted from the light source and having a random polarization direction is reflected in one direction by the reflector 212 and enters the integrator optical system 410.
The shape of the reflecting surface of this reflector 212 is parabolic,
An elliptical surface or a spherical surface can be used depending on the design of the optical system.

The first lens plate 401 is a composite lens body of rectangular minute lenses as shown in FIG. The incident light here is condensed by individual minute lenses. The light source image formed by this micro lens is
1. The polarization converter 204 is set to be formed on the second lens plate 402.

In FIG. 9, the polarization splitting section 411 includes a parallel plane plate 404a having a size different from that of the reflection type polarizing sheet 403,
404b and 404c are configured in close contact. The randomly polarized light from the light source incident on the polarization separation surface 40
5, the S-polarized light component is reflected by the polarization splitting surface 405 and reaches the second lens plate 402.
On the other hand, the P-polarized light transmitted through the polarization separation surface 405 is transmitted through the parallel plane plate 404a, or 404a and 404b, or 404a, 404b, and 404c, and is totally reflected by the total reflection surface 40.
6a, or 406b or 406c, the polarization direction is changed by being transmitted again through the parallel plane plate and the polarization splitting surface 405 and transmitted through the λ / 2 plate 219 provided on the second lens plate 402. It becomes S-polarized light. In this manner, the polarization directions are aligned and the second lens plate 402
The S-polarized light having the light source image formed on the surface to be illuminated 221 by the microlenses 407 on the second lens plate 402
The respective microlens images on the lens plate 401 are enlarged and projected. In this way, uniform illumination is realized while aligning random light from the light source in one polarization direction.

In the second embodiment, looking at the arrangement of each micro lens on the first lens plate 401 as shown in FIG. 2, it includes the system optical axes 222a and 222b folded by the polarization separation section 411. When viewed in a direction perpendicular to the plane (up and down direction in FIG. 2), there are six rows. The light condensed by the lenses in the first and sixth rows is reflected by the polarization separation surface 405 of the polarization separation unit 411, and the S-polarized light component is reflected.
Through the λ / 2 plate 219 provided on the second lens plate 402 after being reflected by the total reflection surface 406a. The light condensed by the lenses in the second and fifth rows is reflected by the polarization splitting surface 405 of the polarization splitting section 411 so that the S-polarized light component is reflected.
The light is transmitted through the λ / 2 plate 219 provided on the second lens plate 402 after being transmitted through the second lens plate 402 after being transmitted through the first lens plate 402 and reflected by the total reflection surface 406 b. Further, the light condensed by the lenses in the third and fourth rows is reflected by the polarization splitting surface 405 of the polarization splitting unit 411 so that the S-polarized light component is reflected.
04a, 404b and 404c and the total reflection surface 406
The light reflected by c is transmitted through the λ / 2 plate 219 provided on the second lens plate 402. Here, the first lens plate 4
The light source image formed on the second lens plate 402 by the microlens on the light source 01 is shifted depending on whether it is reflected on the polarization splitting surface 405 or on the total reflection surface. Since this shift amount is proportional to the thickness of the parallel plane plate from the polarization splitting surface 405 to the total reflection surface, the lenses in the first and sixth rows in FIG. 2 form a light source image formed on the second lens plate. The deviation amount (d
2) is small, and the displacement amount (d4) of the light source image formed by the lenses in the third and fourth rows on the second lens plate is the largest. Therefore, in Embodiment 2, as shown in FIG. 10, among the microlenses on the second lens plate 403, the light source images formed by the lenses of the first and sixth rows of the first lens plate 402 shown in FIG. In the portion provided in the portion, the effective portion forms a row of microlenses having a width of about d2, and in the portion provided in the light source image portion formed by the lenses in the second and fifth rows, the effective portion has a width of about d3. Of the light source image portions formed by the lenses in the third and fourth rows, the microlenses whose effective portions are approximately d4 form a row. Thus, FIG.
Although the size of the light source image shown in (1) increases near the system axis, in the present embodiment, the width and pitch of the lens array are changed in accordance with the change in the size of the lens. By changing the distance, the effective portion of the second lens plate 402 can be formed small without lowering the light utilization rate. Here, the arrangement in the vertical direction in FIG. 10 is minimized in accordance with the size of the light source image formed in the same row.

As described above, according to the present embodiment, while the randomly polarized light from the light source is aligned in one polarization direction,
Since the lens plate 402 can be configured to be small, not only can the device be miniaturized, but also the illumination F-number can be increased (the illumination surface 2).
21) can be suppressed.

In this embodiment, the polarization splitting section 411 is used.
Although a reflective polarizing sheet 403 was used for the present invention, it is applicable if reflection and transmission can be selected depending on the polarization direction, and a prism having a thin film of a high refractive index material formed on a plane parallel plate or the prism of the first embodiment may be used. Needless to say, it can be realized even with the used one. Speaking of the total reflection surface, there is no problem when the total reflection can be sufficiently expected from the relationship between the refractive index of the glass and the air and the incident angle. It is also possible to provide a reflective layer to ensure the performance.

In this embodiment, the polarization converter 2
04 is formed on the second lens plate 402, but it is not always necessary to integrate both of them, and it is sufficient that the polarization conversion unit 204 is disposed on an optical path through which only P-polarized light passes. Therefore, as long as it is near the second lens plate 402, there is no problem even if it is arranged on the illuminated surface 221 side.

Further, in the present embodiment, all the randomly polarized light from the light source is converted into S-polarized light with respect to the polarization splitting surface 405. Can easily be obtained as light. Further, if different retardation plates are set for both optical paths, it is needless to say that linear polarization other than the P and S polarization directions, or any circular polarization or elliptical polarization can be obtained.

In this embodiment, the integrator optical system 410 includes a first lens plate 401 and a second lens plate 4.
Although it is made of 02, it can also be configured by using a condensing lens together.

In the present embodiment, the polarization separation surface 4
Although a plurality of parallel flat plates are overlapped between 05 and the total reflection surface, the same function can be achieved by arranging parallel flat plates having different thicknesses as shown in FIG. Further, even when the thickness is the same, parallel flat plates made of materials having different refractive indexes can be arranged. Of course, there is a disadvantage in terms of cost, but it goes without saying that a component can be used as long as the thickness of one component varies depending on the location. In the examples of FIGS. 9 and 11, the polarization splitting surface 405 side is the same plane and the total reflection surface side is provided with a step. However, this is not always the case, and the total reflection surface side may be the same surface. It is clear that the configuration can be made by providing steps on both the total reflection surface and the polarization separation surface. Further, in the second embodiment, the thickness between the polarization separation surface 405 and the total reflection surface is the same in the vertical direction with respect to the paper surface of FIG. 9, but also in the vertical direction with respect to the paper surface in the same manner as the reflection surface direction. By changing the thickness, the second
Needless to say, the effective area of the lens plate 402 can be reduced.

FIG. 12 shows an example in which the device of the above embodiment is applied to a projection type image display device. The projection-type image display device 500 shown in the figure includes a light source unit 201 that emits randomly polarized light in one direction, and the random polarized light emitted from the light source unit 201 receives an integrator optical system 410 and a polarization separation unit 411. To separate two types of polarized light, and in one direction of the separated polarized light, the polarization converter 204
The polarization direction is changed so that the polarization direction is adjusted to one polarization direction.

In the light beam emitted from the polarized light illuminating device 400, red light is transmitted through the red transmission dichroic mirror 301, and blue and green light are reflected.

The red light is reflected by the reflection mirror 302 and reaches the first liquid crystal light valve 303. On the other hand, of the blue light and the green light, the green light is a green reflecting dichroic mirror 3.
04, the second liquid crystal light valve 305
Reach Blue light is a green reflective dichroic mirror 304
After the light is transmitted through the third liquid crystal light by a light guide means 350 configured by adding a reflection mirror 307 and a reflection mirror 309 to a relay lens system including the entrance side lens 306, the relay lens 308, and the exit side lens 310. Valve 3
It is led to 11. Here, the first, second, and third liquid crystal light valves 303, 305, and 311 modulate color light, respectively, and input the color light modulated according to the video signal corresponding to each color to the dichroic prism 313 (color combining means). . The dichroic prism 313 has a red reflective dielectric multilayer film and a blue reflective dielectric multilayer film in a cross shape, and synthesizes respective modulated light fluxes. The light beam synthesized here passes through the projection lens 314 (projection means) and passes through the screen 3.
15 to form an image.

In the projection type image display device 300 configured as described above, a type of liquid crystal panel that modulates one type of polarized light is used. Therefore, when the conventional random polarized light is guided to the liquid crystal light valve, half of the random polarized light is absorbed by the polarizer and converted into heat, so that the light utilization rate is low and the heat generated by the polarizer is suppressed. There was a problem that a large-sized and noisy cooling device was required, but the projection-type image display device 300 of this example can largely solve such a problem.

That is, the projection type image display device 50 of this embodiment
In the case of 0, in the polarized light illuminating device 400, the polarization converter 204 applies a rotating action of the polarization plane to only one polarized light so that the other polarized light and the polarized light are aligned. Therefore, the polarized light having the same polarization direction is guided to the first, second, and third liquid crystal light valves 303, 305, and 311. Therefore, the light utilization factor is improved, and a bright projected image can be obtained. In addition, since light absorption by the polarizing plate can be reduced, temperature rise in the polarizing plate can be suppressed. This makes it possible to reduce the size and noise of the cooling device.

Further, according to the present embodiment, the second lens plate 40
2 can be made small. Therefore, the F-number of the projection lens determines the apparent size of the apparent second lens plate from the relationship of the distance from the panel to the second lens plate,
If the apparent size of the second lens plate can be reduced, the F-number becomes smaller, that is, it is not necessary to brighten the projection lens. Therefore, a projection lens used in a conventional apparatus that does not perform polarization conversion, or a projection lens similar thereto Thus, it is possible to sufficiently realize the high brightness of the projected image.

When a projection type image display device is constructed using a small panel, a microlens is arranged near the panel opening to improve the apparent aperture ratio. Since it is essential to increase the F number, performance improvement according to the present invention is expected from this viewpoint. (Third Embodiment) FIG. 13 is a schematic configuration diagram of a third embodiment. The polarized light illuminating device 600 of this example has a light source unit 201, an integrator optical system 610, and a polarization separation unit 611 along the system optical axis, and light emitted from the light source unit 201 receives the light emitted from the light source unit 201 and the polarization separation unit 203. ,
The light reaches the rectangular illumination area 205 through the polarization converter 204.

The light source unit 201 includes a light source 211 and a reflector 212. Polarized light emitted from the light source and having a random polarization direction is reflected in one direction by the reflector 212 and enters the integrator optical system 610.
The shape of the reflecting surface of this reflector 212 is parabolic,
An elliptical surface or a spherical surface can be used depending on the design of the optical system.

The first lens plate 601 is a composite lens body of rectangular minute lenses as shown in FIG. The incident light here is condensed by individual minute lenses. The light source image formed by the minute lens is
1, the polarization converter 204 and the second lens plate 602 are set.

In FIG. 13, the polarization splitting section 611 is composed of a triangular pyramid prism 215 and parallel plane plates 603 a and 603 b adhered to each other with a polarization splitting surface 604 interposed therebetween. The randomly polarized light from the light source incident here is polarized
4, the S-polarized light component is reflected by the polarization splitting surface 604 and reaches the second lens plate 602.
On the other hand, the P-polarized light transmitted through the polarization separation surface 604 is transmitted through the parallel plane plates 603a or 603a and 603b, is reflected by the total reflection surface 605a or 605b, and is transmitted again through the parallel plane plates 603a and 603b and the triangular pyramid prism 215. To reach the second lens plate 602,
The polarization direction is changed by transmitting through the λ / 2 plate 219 provided on the lens plate 602 of FIG. The S-polarized light having the light source image formed on the second lens plate 602 with the polarization directions aligned in this manner is applied to the first lens plate 601 on the illuminated surface 221 by the microlenses 606 on the second lens plate 602. Each of the above microlens images is enlarged and projected. In this way, uniform illumination is realized while aligning random light from the light source in one polarization direction.

However, in the third embodiment, looking at the arrangement of the microlenses on the first lens plate 601 as shown in FIG. 2, the system optical axes 222a and 222b folded by the polarization splitting section 611 are aligned. When viewed in a direction (vertical direction in FIG. 2) that is orthogonal to the plane including the image, a six-row configuration is provided. On the other hand, the arrangement of microlenses on the second lens plate required to illuminate only the light in the S polarization direction on the illumination target surface 221 is configured as shown in FIG. The lens array has a four-row configuration in the direction described above with reference to FIG.
FIG. 4 shows a light source image formed on the second lens plate 601 by being condensed by the microlenses on the first lens plate 601 on the outer shape of the first lens plate 601. In the present invention, by appropriately setting the center of curvature of each microlens on the first lens plate 601, as shown in FIG. 4, the formation positions of light source images of different sizes are shown in FIG. 15 for S-polarized light. It was arranged as follows. Thus, even if the number of rows formed by each microlens on the second lens plate 602 is set smaller than the number of rows formed by each microlens on the first lens plate 601, the light utilization rate is not impaired. Make up the device. Here, the polarization separation unit 61
The light source image formed by the light P originally reflected by the total reflection surface 605a or 605b and converted into S-polarized light through the polarization conversion unit 204 is mainly composed of the parallel flat plate 603a or the plate thickness and refractive index of 603a and 603b. The shift amounts d5 and d6 determined by the incident angles of the light passing therethrough are formed on the second lens plate 602 as shown in FIG. Specifically, the light condensed by the lenses in the first and fourth rows in FIG. 14 is reflected by the polarization splitting surface 604 of the polarization splitting unit 611, and the component of the S-polarized light is reflected by the parallel splitting plane. Face plate 60
3a, and is reflected by the total reflection surface 605a.
Through the λ / 2 plate 219 provided on the lens plate 602 of FIG. The light condensed by the lenses in the second and third rows is reflected on the polarization splitting surface 604 of the polarization splitting section 611 so that the S-polarized light component is reflected, and the P-polarized light is transmitted through the parallel plane plates 603a and 603b. Then, the light is reflected by the total reflection surface 605b and passes through the λ / 2 plate 219 provided on the second lens plate 602. Here, the light source image formed on the second lens plate 602 by the microlenses on the first lens plate 601 is formed so as to be shifted depending on whether it is reflected on the polarization splitting surface 604 or reflected on the total reflection surface. As described above, this shift amount is proportional to the thickness of the parallel plane plate from the polarization splitting surface 604 to the total reflection surface. Therefore, the lenses in the first and fourth rows in FIG. (D) of the light source image formed at
5) is small, and the shift amount (d6) of the light source image formed by the lenses in the third and fourth rows on the second lens plate is large. Therefore, in the third embodiment, as shown in FIG. 16, among the micro lenses on the second lens plate 602, FIG.
In the first and fourth rows of lenses, microlenses having a width of about d5 form a row, and similarly in the second and third rows, microlenses having a width of about d6 form a row. .

As described above, according to this embodiment, the second polarized light from the light source is aligned with one polarization direction while the second polarized light is aligned.
Since the lens plate 602 can be configured to be small, not only can the device be miniaturized, but also the illumination F number can be increased (the surface to be illuminated 2).
21) can be suppressed.

In the present embodiment, the polarization separation section 611
Although a prism is used, it is applicable if reflection and transmission can be selected depending on the polarization direction.It can be applied to a thin film of a high refractive index material formed on a parallel plane plate, or a sheet with a polarization separation function recently developed. It can be realized even if it is attached to a parallel plane plate. Speaking of the total reflection surface, there is no problem if the total reflection can be sufficiently obtained from the relationship between the refractive index of the glass and the air and the incident angle. It is also possible to secure performance by providing a layer.

In the present embodiment, the polarization converter 2
04 is formed on the second lens plate 602, but it is not always necessary to integrate both of them, and it is sufficient that the polarization conversion unit 204 is disposed on an optical path through which only P-polarized light passes. Therefore, as long as it is near the second lens plate 602, there is no problem even if it is arranged on the illuminated surface 221 side.

Further, in the present embodiment, all the randomly polarized light from the light source is converted into S-polarized light with respect to the polarization splitting surface 604. Can easily be obtained as light. Further, if different retardation plates are set for both optical paths, it is needless to say that linear polarization other than the P and S polarization directions, or any circular polarization or elliptical polarization can be obtained.

In this embodiment, the integrator optical system 610 includes the first lens plate 601 and the second lens plate 6.
Although it is made of 02, it can also be configured by using a condensing lens together.

It is also apparent that it is desirable to use a means for eliminating ultraviolet rays and infrared rays in the apparatus in this embodiment also in order to improve reliability.

In the present embodiment, the polarization separation surface 6
Although a plurality of plane-parallel plates are overlapped between 04 and the total reflection surface, the same function can be achieved by arranging plane-parallel plates having different thicknesses. Further, even when the thickness is the same, parallel flat plates made of materials having different refractive indexes can be arranged. Of course, there is a disadvantage in terms of cost, but it goes without saying that a component can be used as long as the thickness of one component varies depending on the location. In the example of FIG.
The four sides are the same plane and a step is provided on the total reflection surface side. However, this is not always the case, and the total reflection surface side can be configured as the same surface, or both the total reflection surface and the polarization separation surface can be used. Obviously, the configuration can be made even if a step is added to the step. In the third embodiment, the thickness between the polarization splitting surface 604 and the total reflection surface is the same in the vertical direction with respect to the paper surface of FIG. 13, but also in the vertical direction with respect to the paper surface in the same manner as the reflection surface direction. It goes without saying that the effective area of the second lens plate 602 can be further reduced by changing the thickness.

FIG. 17 shows an example in which the device of the above embodiment is applied to a projection type image display device. The projection type image display device 700 shown in the figure includes a light source unit 201 that emits randomly polarized light in one direction, and the random polarized light emitted from the light source unit 201 receives an integrator optical system 610 and a polarization separation unit 611. To separate two types of polarized light, and in one direction of the separated polarized light, the polarization converter 204
The polarization direction is changed so that the polarization direction is adjusted to one polarization direction.

In the light beam emitted from the polarized light illuminating device 600, first, red light is transmitted through the red transmission dichroic mirror 301, and blue and green light are reflected.

The red light is reflected by the reflection mirror 302 and reaches the first liquid crystal light valve 303. On the other hand, of the blue light and the green light, the green light is a green reflecting dichroic mirror 3.
04, the second liquid crystal light valve 305
Reach Blue light is a green reflective dichroic mirror 304
After the light is transmitted through the third liquid crystal light by a light guide means 350 configured by adding a reflection mirror 307 and a reflection mirror 309 to a relay lens system including the entrance side lens 306, the relay lens 308, and the exit side lens 310. Valve 3
It is led to 11. Here, the first, second, and third liquid crystal light valves 303, 305, and 311 modulate color light, respectively, and input the color light modulated according to the video signal corresponding to each color to the dichroic prism 313 (color combining means). . The dichroic prism 313 has a red reflective dielectric multilayer film and a blue reflective dielectric multilayer film in a cross shape, and synthesizes respective modulated light fluxes. The light beam synthesized here passes through the projection lens 314 (projection means) and passes through the screen 3.
15 to form an image.

In the projection type image display device 700 thus configured, a type of liquid crystal panel that modulates one type of polarized light is used. Therefore, when the conventional random polarized light is guided to the liquid crystal light valve, half of the random polarized light is absorbed by the polarizer and converted into heat, so that the light utilization rate is low and the heat generated by the polarizer is suppressed. There was a problem that a large-sized and noisy cooling device was required, but the projection-type image display device 300 of this example can largely solve such a problem.

That is, the projection type image display device 70 of this embodiment
In the case of 0, in the polarized light illuminating device 600, the polarization converter 204 applies a rotating action of the polarization plane to only one polarized light so that the other polarized light and the polarized light are aligned. Therefore, the polarized light having the same polarization direction is guided to the first, second, and third liquid crystal light valves 303, 305, and 311. Therefore, the light utilization factor is improved, and a bright projected image can be obtained. In addition, since light absorption by the polarizing plate can be reduced, temperature rise in the polarizing plate can be suppressed. This makes it possible to reduce the size and noise of the cooling device.

Further, according to the present embodiment, the second lens plate 60
2 can be made small. Therefore, the F-number of the projection lens determines the apparent size of the apparent second lens plate from the relationship of the distance from the panel to the second lens plate,
If the apparent size of the second lens plate can be reduced, the F-number becomes smaller, that is, it is not necessary to brighten the projection lens. Therefore, a projection lens used in a conventional apparatus that does not perform polarization conversion, or a projection lens similar thereto Thus, it is possible to sufficiently realize the high brightness of the projected image.

In the case where a projection type image display apparatus is constructed using a small panel, a micro lens is arranged near the panel opening to improve the apparent aperture ratio. Since it is essential to increase the illumination F-number, performance improvement according to the present invention is expected from this viewpoint. Although the first, second and third embodiments have been described using the first lens plates arranged orthogonally in FIG. 2, even in a staggered arrangement in which the micro lenses are arranged with a half pitch shift, the radius of curvature of each lens This can be handled by optimizing the settings.

In the first, second and third embodiments, the three-panel type in which the liquid crystal light valves are arranged for each color has been described as an example. However, the random light can be arbitrarily applied to the single-panel projection type image display. The same advantage can be obtained without converting the illumination F-number and reducing the illumination F-number, so that the application range is not necessarily limited by the number of light valves.

[0068]

As described above, in the illumination device using the integrator optical system, the surface to be illuminated is made such that the randomly polarized light from the light source is polarized in one direction using polarization separation and polarization conversion means. The size of the second lens plate can be reduced while performing uniform illumination. Therefore, the size of the entire device can be realized without changing the size of the conventional device having no polarization conversion function, and the illumination F number can be suppressed to a large value (the incident angle to the surface to be illuminated).
Therefore, in a projection type image display device using a light valve utilizing polarization such as a liquid crystal light valve by the polarization illuminating device of the present invention, polarized light having a uniform polarization direction can be supplied to the liquid crystal panel, so that the light use efficiency is improved. In addition, the brightness of the projected image can be improved. Further, since the heat absorption by the polarizing plate is reduced, the temperature rise in the polarizing plate is suppressed, so that the cooling device can be reduced in size and noise can be reduced. Furthermore, since a large illuminating F number (small incident angle) is required for a microlens that increases the aperture ratio of a liquid crystal light valve or the like which is being developed in a pseudo manner, development in this application can be expected. In addition, according to the present invention, in the first invention, the cost is not increased at all with the polarization conversion optical system conventionally proposed, and in the second and third inventions, only further increasing the number of parallel plane plates while making further improvements. A major feature is that the performance can be improved without a large increase in cost because it can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a polarized light illumination device according to a first embodiment.

FIG. 2 is an external view of a first lens plate according to the first embodiment.

FIG. 3 is a diagram illustrating a microlens array for light that is S-polarized light before polarization conversion of a second lens plate according to the first embodiment;

FIG. 4 is a diagram showing a light source image formed by each microlens on a second lens plate overlaid on the outer shape of the first lens plate according to the first embodiment;

FIG. 5 is a diagram showing light source images formed on a microlens array for S-polarized light before polarization conversion of the second lens plate according to the first embodiment;

FIG. 6 is a diagram illustrating an appearance of a second lens plate according to the first embodiment and a light source image formed on each microlens;

FIG. 7 is another configuration diagram of the polarized light illumination device of the first embodiment.

FIG. 8 is a configuration diagram of a projection-type image display device using the polarized light illumination device of the first embodiment.

FIG. 9 is a configuration diagram of a polarized light illumination device according to a second embodiment.

FIG. 10 is a diagram showing an appearance of a second lens plate according to a second embodiment and a light source image formed on each microlens;

FIG. 11 is another configuration diagram of the polarized light illumination device of the second embodiment.

FIG. 12 is a configuration diagram of a projection-type image display device using the polarized light illumination device of the second embodiment.

FIG. 13 is a configuration diagram of a polarized light illumination device according to a third embodiment.

FIG. 14 is a diagram showing a microlens array for light that is S-polarized light before polarization conversion of the second lens plate according to the third embodiment.

FIG. 15 is a diagram illustrating light source images formed on a microlens array for S-polarized light before polarization conversion of a second lens plate according to the third embodiment.

FIG. 16 is a diagram showing an appearance of a second lens plate and a light source image formed on each microlens according to the third embodiment.

FIG. 17 is a configuration diagram of a projection-type image display device using the polarized light illumination device of the third embodiment.

FIG. 18 is a configuration diagram of a polarized light illuminating device according to a conventional example (Japanese Patent Application Laid-Open No. 9-146064).

[Explanation of symbols]

100, 200, 400, 600 Polarized light illumination device 101, 211 Light source 102, 202, 410, 610 Integrator optical system 103, 203, 411, 611 Polarization separation unit 104, 219 λ / 2 phase difference plate 105, 213, 401, 601 First lens plate 106, 214, 402, 602 Second lens plate 107, 217, 405, 604 Polarization separation surface 108, 218, 406a, 406b, 406c, 60
5a, 605b Total reflection surface 201 Light source section 212 Reflector 215 Triangular pyramid prism 216, 404a, 404b, 404c, 603a, 6
03b Parallel plane plate 220, 407, 606 Each micro lens 221 on the second lens plate 221 Illuminated surface 222a, 222b System optical axis 223 Condensing lens 300, 500, 700 Projection image display device 301 Red transmission dichroic mirror 302, 307, 309 Reflection mirror 303 First liquid crystal light valve 304 Green reflection dichroic mirror 305 Second liquid crystal light valve 306 Incident side lens 308 Relay lens 310 Exit side lens 311 Third liquid crystal light valve 313 Dichroic prism 314 Projection lens 315 Screen 350 Light guide means 403 Reflective polarizing sheet

Claims (10)

[Claims] 1. A light source for emitting light having a random polarization direction, an integrator optical system including a first lens plate including a plurality of rectangular lenses and a second lens plate as an aggregate of a plurality of minute lenses. The light emitted from the light source is projected as a secondary light source image on the incident surface of each lens constituting the second lens plate via the first lens plate, and the second lens In an illumination device for illuminating an object to be illuminated using light emitted from a plate, random polarized light emitted from the light source is separated into two polarized lights whose polarization directions are orthogonal to each other, and is converted into two substantially parallel lights. Polarization splitting means for splitting the light having the two polarization directions, and polarization converting means for aligning the polarization directions of the light having the two polarization directions, wherein the polarization splitting means is provided at a slant with respect to the light emitted from the first lens plate. Separation membrane surface and total reflection surface A polarizing lens splitter, wherein the first lens plate is a rectangular lens set with the aperture and the center of curvature shifted so that the light source images form approximately rows on the second lens plate and the light source images are arranged. Wherein the second lens plate is an aggregate of minute lenses having an opening corresponding to the size of the light source image formed on the second lens plate, and wherein the second lens plate The rows of light source images formed thereon are arranged in a direction orthogonal to a plane including a system axis from the light source to the second lens plate, and the number thereof is the first when viewed only in one polarization direction. Wherein the number of rows in the same direction formed by the microlenses on the lens plate is less. 2. A light source for emitting light having a random polarization direction, and an integrator optical system including a first lens plate including a plurality of rectangular lenses and a second lens plate as an aggregate of a plurality of minute lenses. The light emitted from the light source is projected as a secondary light source image on the incident surface of each lens constituting the second lens plate via the first lens plate, and the second lens In an illumination device for illuminating an object to be illuminated using light emitted from a plate, random polarized light emitted from the light source is separated into two polarized lights whose polarization directions are orthogonal to each other, and is converted into two substantially parallel lights. A polarization separation unit for separating the light having the two polarization directions, and a polarization conversion unit for aligning the polarization directions of the light having the two polarization directions.
Is a group of rectangular lenses set so that the aperture and the center of curvature are shifted so that the light source images are arrayed by forming an approximate row on the lens plate, and the second lens plate is provided on the second lens plate. A microlens assembly having an opening corresponding to the size of the formed light source image, wherein the polarization splitting means is a polarization splitting film provided obliquely to light emitted from the first lens plate A polarized light illuminating device comprising a polarizing beam splitter having a surface and a total reflection surface, wherein the polarization separation film surface and the total reflection surface are parallel to each other, and the distance between the surfaces is different within the surface. 3. A light source for emitting light having a random polarization direction, an integrator optical system including a first lens plate including a plurality of rectangular lenses and a second lens plate as an aggregate of a plurality of minute lenses. The light emitted from the light source is projected as a secondary light source image on the incident surface of each lens constituting the second lens plate via the first lens plate, and the second lens In an illumination device for illuminating an object to be illuminated using light emitted from a plate, random polarized light emitted from the light source is separated into two polarized lights whose polarization directions are orthogonal to each other, and is converted into two substantially parallel lights. Polarization splitting means for splitting the light having the two polarization directions, and polarization converting means for aligning the polarization directions of the light having the two polarization directions, wherein the polarization splitting means is provided at a slant with respect to the light emitted from the first lens plate. Separation membrane surface and total reflection surface In addition, the polarizing beam splitter is a polarizing beam splitter in which the surface of the polarized light separating film and the total reflection surface are parallel and the distance between the surfaces is different in the plane. And a set of rectangular lenses that are set so that the aperture and the center of curvature are shifted so that the light source images are arranged. The second lens plate is a collection of the light source images formed on the second lens plate. A row of light source images formed on the second lens plate, which is an aggregate of microlenses having an opening corresponding to the size, and orthogonal to a plane including a system axis from the light source to the second lens plate; And the number thereof is smaller than the number of rows in the same direction formed by the microlenses on the first lens plate when viewed only in one polarization direction. Polarized light illumination device. 4. The polarization beam splitter according to claim 1, wherein the polarization beam splitting means is a polarization beam splitter having a polarization beam splitting film interposed between a prism and a plane-parallel plate to form a polarization beam splitting film surface and a total reflection surface. , A polarized light illumination device. 5. A polarization beam splitter comprising: a plane-parallel plate having a polarization-selective sheet adhered to an incident surface; and a polarization splitting film surface and a total reflection surface. The polarized light illumination device according to 1, 2, or 3. 6. A polarization beam splitter, wherein said polarization beam splitting means comprises a plane-parallel plate having a high refraction inorganic material film thinned so as to have polarization selectivity and applied to an incident surface thereof to constitute a polarization beam splitting film surface and a total reflection surface. The method according to claim 1, wherein
2. The polarized light illumination device according to 2, 3. 7. The polarized light illuminating device according to claim 2, wherein the parallel plane plate constituting the polarization separation means is formed by stacking a plurality of parallel plane plates having different sizes. 8. The polarized light illuminating device according to claim 2, wherein the parallel plane plates constituting the polarization splitting means are formed by arranging parallel plane plates having different thicknesses. 9. The polarized light illuminating device according to claim 1, wherein said polarization conversion means is a λ / 2 plate, and is disposed near the second lens plate. 10. The polarized light illuminating device according to claim 1, 2 or 3 as an illuminating means, wherein at least a light valve arranged near an illuminated surface of the polarized light illuminating device and an image on the light valve are displayed. A projection type image display device comprising a projection lens provided to be capable of enlarged projection.