JP2000111838A - Illumination device of projector and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the degradation in the contrast of a liquid crystal light valve by increasing the components near a zero degree as a cone angle distribution of an illumination region and to obtain high diffraction efficiency when a liquid crystal display element having a hologram color filter is used. SOLUTION: This illumination device has a light source 1, a polarization beam splitter 5 which splits light to P wave light and S wave light of two optical paths, total reflection mirrors 8a, 8b, a half-wave plate 6 and a superposition lens 11 which emits the luminous flux of the optical path transmitted through the polarization beam splitter 5 with substantially no refraction of the central part thereof and condenses the exit light of the entire luminous flux in the form of superposing the same on the irradiation region 12. A first lens array 4 is arranged between the light source 1 and the polarization beam splitter 5 and a second lens array 7 and two third lens arrays 9 and 10 are arranged between the polarization beam splitter 5 and the superposition lens 11 to parallel the main rays emitted from the respective ommatidium lenses of the second lens array 7 and the third lens arrays 9 and 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for a projection device, which converts non-constantly polarized light emitted from a light source into one kind of linearly polarized light beam to produce illumination light, and a projection device using the same. In particular, the present invention relates to a technique suitable for using a liquid crystal display element as a light valve.

[0002]

2. Description of the Related Art As an illumination device for a projection device of this type, the present applicant has proposed a device disclosed in Japanese Patent Application No. Hei 9-361630, and FIG. FIG.

[0003] In FIG. 4, a light source 21 emits light of indeterminate polarization, and this light flux enters a collimator lens 23 via a condenser lens 22. The collimator lens 23 emits the incident light as parallel light, and the emitted light is guided to the polarization beam splitter 25 via the first lens array 24. The polarization beam splitter 25 has one polarization splitting surface 25a having an angle of 45 degrees with respect to the incident light, and the P-polarized component light transmitted through the polarization splitting surface 25a and the polarization splitting surface 2a.
It is split into S-polarized component light reflected at 5a.

The P-polarized component light transmitted through the polarization splitting surface 25a is guided to a half-wave plate 26, where it is converted into S-polarized component light and emitted to a second lens array 27. The optical path of the S-polarized component light reflected by the polarization splitting surface 25a is changed by the total reflection mirror 28 to be an optical path substantially parallel to the optical path of the transmitted light of the polarization splitting surface 25a. The S-polarized component light whose optical path has been changed is emitted to the third lens array 29.

[0005] First to third lens arrays 24, 27, 29
Are fly-eye lens plates, each of which is configured by arranging a plurality of single-lenses in a predetermined arrangement. Generally, each monocular lens is configured to have the same aspect ratio as the illumination area of the light valve. The third lens array 29 is the first lens array 2
The first lens array 24 and the second lens array 27 are arranged at an optical position substantially equal to the optical distance between the fourth lens array 27 and the second lens array 27.
In addition, the first lens array 24 and the third lens array 29 constitute different optical integrators. Each single lens of the first lens array 24 condenses a light beam on each corresponding single lens of the second lens array 27 and on each corresponding single lens of the third lens array 29. Further, the principal rays of each light beam emitted from each single lens of the second lens array 27 and the third lens array 29 are in a parallel state.

The emitted light of the S-polarized light component from the second lens array 27 and the third lens array 29 is
0, and the second lens array 2
The light emitted from 7 and the light emitted from the third lens array 29 are both refracted and condensed on the illumination area 31 as the irradiation position. Here, each light beam emitted from each single lens of the second lens array 27 and the third lens array 29 is collected while being superimposed on the illumination area 31.

By configuring the illuminating device of the projection apparatus in this way, when a liquid crystal display element having a hologram color filter is used as a liquid crystal light valve, each of the second lens array 27 and the third lens array 29 Since all the light beams emitted from the lens are superimposed on the illumination area 31, the illumination light having a large cone angle in the diffraction / spectral direction by the hologram color filter and a small cone angle in the direction orthogonal to the diffraction / spectral direction. An illumination light having an angle can be emitted, and a display image with a good contrast ratio can be obtained.

By the way, the liquid crystal used in the light valve is, for example, a liquid crystal of a vertical alignment type, in which the major axes of the liquid crystal molecules are arranged in a direction perpendicular to the substrate, and the alignment is controlled in response to the application of an electric field. Light modulation is performed by changing the birefringence state of light. That is, as shown in FIG. 5 (a), the liquid crystal molecules 40 in the absence of an electric field are arranged perpendicular to the substrate 41, so that birefringence does not occur in the light entering the liquid crystal, and the light in the S-polarized plane is If it enters, it exits with the S-polarized plane, and does not leak light in the projection direction. The image at this time displays black information.

As shown in FIG. 5B, when an electric field is applied, the long axis of the liquid crystal molecules 40 falls in a direction parallel to the substrate 41,
Birefringence occurs and the light on the S-polarized plane rotates to elliptically polarized light,
Light in the P-polarized plane leaks in the projection direction. And the liquid crystal molecules 4
When 0 is tilted until it becomes parallel to the substrate 41, it is the most tilted state. At this time, the largest birefringence occurs in the light entering the liquid crystal, and the light is modulated. The image at this time displays white information.

That is, if the major axis of the liquid crystal molecules 40 is parallel to the optical axis of the incident light, no birefringence occurs. If the major axis of the liquid crystal molecules 40 and the optical axis of the incident light are at an angle, birefringence occurs. Therefore,
As shown in FIG. 5C, even when no electric field is applied, if the incident light is incident on the liquid crystal molecules 40 at an angle instead of being parallel, birefringence occurs due to the action equivalent to that when the electric field is applied. And
Light leaks in the projection direction, and the projected image becomes an image with a low black level and a low contrast ratio.

From the above, it can be seen that when a liquid crystal display element is used as a light valve, the illumination light from the illumination device has a cone angle distribution in the illumination area that is important.

[0012]

However, in the above prior art, the light beam from the second lens array 27 and the light beam from the third lens array 29 are refracted in the direction of the central axis C by the superimposing lens 30 at substantially the same ratio. Since the light is condensed and condensed, the cone angle distribution of the light in the illumination region 31 is substantially as shown in FIG. That is,
The characteristic of the cone angle distribution is that there are few components near zero degree, and when a light beam having such a cone angle distribution is irradiated on the liquid crystal display element, as shown in FIG. Even if there is, there is a problem that an image having a low contrast ratio has many angle components in which birefringence occurs.

Further, when a liquid crystal display device having a hologram color filter is used as a liquid crystal light valve, there are the following problems. That is, the diffraction efficiency with respect to the incident angle of the hologram color filter has characteristics as shown in FIG. 7, and shows the highest diffraction efficiency at a predetermined incident angle φ, and the diffraction efficiency decreases as the incident angle changes. Therefore, when the hologram color filter is irradiated with a light beam having a cone angle distribution as shown in FIG. 6, sufficient diffraction efficiency cannot be obtained, and the image becomes dark.

Accordingly, the present invention has been made to solve the above-mentioned problem, and when a liquid crystal display element having a hologram color filter is used as a liquid crystal light valve, the direction of diffraction and spectral distribution by the hologram color filter is reduced. Is an illumination light with a large cone angle,
In the direction orthogonal to the diffraction / spectral direction, illumination light having a small cone angle can be emitted, and the component near zero degree is increased as the cone angle distribution of the illumination area to increase the contrast ratio of the liquid crystal light valve. It is an object of the present invention to provide an illuminating device and a projection device of a projection device which prevent a decrease and use a liquid crystal display device having a hologram color filter and obtain a high diffraction efficiency.

[0015]

According to a first aspect of the present invention, there is provided a light source that emits a light beam, and transmits one of the P-polarized component light and the S-polarized component light of the light beam emitted from the light source. A polarization splitting means for reflecting the other component light on the polarization splitting surface, and splitting the reflected light into two light paths, and the other component light split into two light paths, wherein the principal ray of each light beam is One of two optical path bending means for bending each of the two light paths so as to be substantially parallel to the light flux of one of the component lights, and one of the two light paths of the one component light and the other component light emitted from the polarization splitting means. A 波長 wavelength plate that is arranged on one side and aligns two types of component light into any one type of linearly polarized light, and all light beams whose polarization planes are aligned are incident, and
A central portion of a light beam in an optical path that has passed through the polarization splitting unit is emitted with little refraction, and has a superimposing lens that collects outgoing light of all the light beams in a superimposed state on an irradiation area, and the light source and the light source. A first lens array arranged between the polarization splitting means and the plurality of monocular lenses, and between the polarization splitting means and the superimposing lens, and on an optical path of light transmitted by the polarization splitting means; A second lens array comprising a plurality of single-lenses, and between the polarized light separating means and the superimposing lens, and disposed on two optical paths of reflected light of the polarized light separating means, respectively. A second lens array including two third lens arrays, each of which is disposed at a position substantially equal to an optical distance between the first lens array and the second lens array and includes a plurality of single-lenses. Principal ray of the light beam emitted from the ommatidium lenses constituting the two of the third lens array is a lighting device of a projection apparatus characterized by being configured to be substantially parallel.

According to a second aspect of the present invention, in the illumination device of the projection device according to the first aspect, the first lens array, the second lens array, and the two third lens arrays have the same configuration. An illumination device for a projection device characterized by the above.

According to a third aspect of the present invention, there is provided a light source for emitting a light beam;
One of the P-polarized component light and the S-polarized component light of the light beam emitted from this light source is transmitted, the other component light is reflected by the polarization splitting surface, and the reflected light is transmitted to two optical paths. Polarization splitting means for splitting, and two optical path bending means for bending the principal ray of each light flux, which is the other component light split into two optical paths, so as to be substantially parallel to the light flux of the one component light, It is arranged on one of the optical path of one component light and the other optical path of the other component light emitted from the polarization separation means, and aligns the two types of component light into any one type of linearly polarized light. The two-wavelength plate and all the luminous fluxes whose polarization planes are aligned are incident, and the central part of the luminous flux in the optical path that has passed through the polarization splitting means is emitted with almost no refraction, thereby irradiating outgoing light of all the luminous fluxes. Focus on the area Having a superimposing lens, disposed between the light source and the polarization splitting means, a first lens array consisting of a plurality of single lenses, between the polarization splitting means and the superposition lens, and A second lens array comprising a plurality of single-lenses arranged on the optical path of the transmitted light of the polarized light separating means, between the polarized light separating means and the superimposing lens, and reflected light of the polarized light separating means 2
And two third lens arrays each including a plurality of single-lenses, each being disposed on an optical path, each being disposed at a position substantially equal to an optical distance between the first lens array and the second lens array. An illuminating device configured such that principal rays of light beams emitted from the single-lenses constituting the second lens array and the two third lens arrays are substantially parallel, and illumination emitted from the illuminating device. An active matrix type liquid crystal display element is provided, in which light is incident on a hologram color filter that diffracts and disperses the three primary color lights of the additive color mixture, and modulates light emitted from the hologram color filter based on display image information. A projection device characterized by projecting a light beam emitted from a liquid crystal display element onto a screen.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an illumination device of a projection device according to an embodiment of the present invention. In FIG. 1, a light source 1 emits light of indeterminate polarization, and this light flux enters a collimator lens 3 via a condenser lens 2. The collimator lens 3 emits the incident light as parallel light, and the emitted light is guided via the first lens array 4 to a polarization beam splitter 5 which is a polarization separation unit. The polarization beam splitter 5 has two polarization separation surfaces 5a and 5b having an angle of ± 45 degrees with respect to the incident light, and the two polarization separation surfaces 5a and 5b.
P-polarized component light passing through and two polarization separation surfaces 5a and 5b
Are split into S-polarized component lights of two optical paths, each of which is reflected.

The P-polarized component light transmitted through the polarization splitting surfaces 5a and 5b is guided to the half-wave plate 6, where it is converted into S-polarized component light and emitted to the second lens array 7. The optical paths of the respective S-polarized component lights reflected by the polarization splitting surfaces 5a and 5b are respectively changed by the total reflection mirrors 8a and 8b, which are optical path bending means, to form an optical path substantially parallel to the optical path of the transmitted light of the polarization splitting surface 5a. Is done. Each S-polarized component light whose optical path has been changed is emitted to two third lens arrays 9 and 10, respectively. When the S-polarized component light is converted into the P-polarized component and emitted to the second lens arrays 9 and 10, the half-wave plate 6 is arranged in front of the second lens arrays 9 and 10.

First to third lens arrays 4, 7, 9, 10
Are fly-eye lens plates, each of which is configured by arranging a plurality of single-lenses in a predetermined arrangement. Generally, each monocular lens is configured to have the same aspect ratio as the illumination area of the light valve. In this embodiment, the first to third lens arrays 4, 7, 9, 10 each have the same configuration (number, size, arrangement, etc. of single-lenses). Therefore, the manufacturing is easy and the cost is reduced.

The third lens arrays 9 and 10 are arranged at optical positions substantially equal to the optical distance between the first lens array 4 and the second lens array 7, respectively. 1 and 2 constitute an optical integrator, and the first lens array 4 and the two third lens arrays 9 and 10 constitute another optical integrator. Each single lens of the first lens array 4 collects a light beam with respect to each corresponding single lens of the second lens array 7 and each corresponding single lens of the third lens arrays 9 and 10. The main rays of each light beam emitted from each single lens of the second lens array 7 and the two third lens arrays 9 and 10 are made parallel.

The outgoing light of the S-polarized light component from the second lens array 7 and the two third lens arrays 9 and 10 is guided to the superimposing lens 11, and is emitted from the second lens array 7 by the superimposing lens 11. The light and the light emitted from the third lens arrays 9 and 10 are refracted and condensed on the illumination area (irradiation position) 12. Here, the optical path of the light emitted from the second lens array 7 (the optical path of the light transmitted through the polarization separation surfaces 5a and 5b) is the center, and the two optical paths of the light emitted from the two third lens arrays 9 and 10 are located on both sides. (2 of the reflected light from the polarization separation surfaces 5a and 5b)
The superimposing lens 11 emits the light beam from the second lens array 7 without substantially refracting the central portion of the light beam, and the light beams emitted from the third lens arrays 9 and 10 on both sides are transmitted along the central axis C. It is configured to be refracted and emitted to the same extent in the direction. Also, the second lens array 7
Each light beam emitted from each single lens of the third lens arrays 9 and 10 is condensed in a state of being superimposed on the illumination area 12.

A liquid crystal display element (not shown) as a liquid crystal light valve is arranged in the illumination area 12, and for example, a liquid crystal display element having a hologram color filter is arranged. In the case of a reflection type active matrix type liquid crystal display device, illumination light emitted from an illumination device is incident on a hologram color filter that diffracts and disperses the three primary colors of additive color mixture. The emitted light is modulated based on the display image information and projected onto a screen (not shown).

In the above configuration, each single lens of the first to third lens arrays 4, 7, 9, and 10 has the same configuration.
Light emitted from each monocular lens of the first lens array 4 is made incident on each monocular lens of the second and third lens arrays 7, 9, and 10 having the same configuration, and all light beams emitted from each monocular lens are output. When the brightness (F-number) in the vertical direction in FIG. 1 in the illumination area 12 is compared with the brightness (F-number) in the direction perpendicular to the plane of FIG. Is brighter than the brightness in the vertical direction.

Therefore, when a liquid crystal display element having a hologram color filter is used as the liquid crystal light valve, all the light beams emitted from each single lens of the second lens array 7 and the two third lens arrays 9 and 10 are used. Are superimposed on the illumination area 12, so that illumination light having a large cone angle is emitted in the diffraction / spectral direction by the hologram color filter, and illumination light having a small cone angle is emitted in the direction orthogonal to the diffraction / spectral direction. And a display image with a good contrast ratio can be obtained.

The light quantity of the light beam emitted from the light source 1 such as a lamp is generally the largest at the central portion, and the central portion of the light beam in the optical path transmitted through the polarizing beam splitter 5 from the superimposing lens 11 is emitted with almost no refraction. Accordingly, the cone angle distribution characteristics of light in the illumination area 12 of the illumination device are as shown in FIG.

That is, as the cone angle distribution of the illumination area 12, the light of the component near zero degree increases, and as a result,
A decrease in the contrast ratio of the liquid crystal light valve is prevented,
Further, when a liquid crystal display element having a hologram color filter is used as a liquid crystal light valve, high diffraction efficiency is obtained, and an image with high luminance is obtained.

Further, in this embodiment, since the boundary between the two polarization splitting surfaces 5a and 5b is located at a position where the luminous flux of the incident light is just split into two, the upper and lower split light amounts are almost the same. As shown in FIG. 2, the cone angle distribution becomes bilaterally symmetric.

By the way, if the superimposing lens 11 on which each light beam emitted from each single lens constituting the second and third lens arrays 7, 9, 10 has a spherical aberration, Even if the principal rays of the light beams are parallel to each other, the light beams emitted from the superimposing lens 11 are non-parallel, and the second and third lens arrays 7,
The so-called image shift problem that the image forming points of the individual eye lenses 9 and 10 deviate from the illumination area 12 occurs.

When there is such an image shift, the optical axis of each single lens constituting the second and third lens arrays 7, 9, and 10 is shifted, or the second and third lenses are shifted. The problem can be solved by, for example, increasing the distance between the arrays 7, 9, 10 and the superimposing lens 11. If a Fresnel lens having no spherical aberration is used as the superimposing lens 11, the above-described problem itself does not occur.

FIG. 3 is a schematic configuration diagram of an illumination device of a projection device according to another embodiment of the present invention. In FIG. 3, in the other embodiments, the same components as those in the above embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted. Only different components will be described.

That is, in the other embodiment, the polarization beam splitter 5 is formed of a plate-like member. Therefore, there is an advantage that the material cost, the processing cost, and the like are reduced as compared with the case of the glass material or the like as in the above embodiment.
The other embodiments also have the same operation and effects as those of the above embodiment.

According to each of the above-described embodiments, the first to third lens arrays 4, 7, 9, and 9 are provided on the assumption that incident light from the collimator lens 3 is parallel light.
10 can have the same configuration, and each light beam emitted from each single lens of the second lens array 7 and the third lens arrays 9 and 10 has a principal ray substantially parallel to each other. However, the incident light from the collimator lens 3 is
In the case of a converged light beam or a divergent light beam, the size of each monocular lens of the first lens array 4 is different from the size of each monocular lens of the second and third lens arrays 7, 9, 10. You. However, the other conditions, the number of single-lenses, and the arrangement are the same.

Further, according to each of the above embodiments, the half-wave plate 6 is arranged on the optical path of the transmitted light of the polarization beam splitter 5 so as to irradiate the luminous flux of the S polarization plane. １ ／ wavelength plate 6 in two optical paths of reflected light 5
May be arranged to irradiate a light beam of the P polarization plane. However, when the half-wave plate 6 is arranged in the optical path of the transmitted light of the polarization beam splitter 5 as in each of the above-described embodiments, the half-wave plate 6 may be arranged at one place. Simplification, cost reduction, etc.

Further, according to the above embodiments, the optical path bending means is constituted by the total reflection mirrors 8a and 8b. However, the optical path bending means may be any means capable of changing the optical path.

[0037]

As described above, according to the first aspect of the present invention, a light source that emits a light beam and one of the P-polarized component light and the S-polarized component light of the light beam emitted from the light source A polarization splitting unit that transmits light, reflects the other component light on the polarization splitting surface, and splits the reflected light into two light paths, and the other component light split into two light paths, Two optical path bending means for bending the principal ray so as to be substantially parallel to the light flux of the one component light,
It is arranged on one of the optical path of one component light and the other optical path of the other component light emitted from the polarization separation means, and aligns the two types of component light into any one type of linearly polarized light. The two-wavelength plate and all the luminous fluxes whose polarization planes are aligned are incident, and the central part of the luminous flux in the optical path that has passed through the polarization splitting means is emitted with almost no refraction, thereby irradiating outgoing light of all the luminous fluxes. A first lens comprising a plurality of single-lenses disposed between the light source and the polarization splitting means and having a superimposing lens for condensing light in a state of being superimposed on the region;
A second lens array including a plurality of single-lenses disposed between the lens array, the polarization separating unit and the superimposing lens, and on an optical path of light transmitted by the polarization separating unit; A position between the first lens array and the second lens array between the first lens array and the second lens array, between the first lens array and the superimposing lens, on the two optical paths of the reflected light of the polarization splitting means. , Each of which has two third lens arrays composed of a plurality of single-lenses, and mainly emits a light beam emitted from each single lens constituting the second lens array and the two third lens arrays. Since the light beams are configured to be substantially parallel, when a liquid crystal display element having a hologram color filter is used as the liquid crystal light valve, the second lens array and the second lens array are used.
Since all the light beams emitted from each single lens of the three third lens arrays are superimposed on the illumination area, the illumination light having a large cone angle with respect to the diffraction / spectral direction by the hologram color filter is combined with the above-described diffraction / spectral direction. In the orthogonal direction, illumination light having a small cone angle can be respectively emitted, and a display image with a good contrast ratio can be obtained. In addition, the amount of light flux emitted from a light source such as a lamp generally has a central portion. Mostly, since the central portion of the light beam in the optical path that has passed through the polarization splitting means from the superimposing lens is emitted with little refraction, the component near the zero degree increases as the cone angle distribution of the illumination area, and as a result, The contrast ratio of the liquid crystal light valve is prevented from lowering, and the hologram is used as a liquid crystal light valve. When using a liquid crystal display device having a color filter, high diffraction efficiency can be obtained.

According to a second aspect of the present invention, in the illumination device of the projection apparatus according to the first aspect, the first lens array, the second lens array, and the two third lens arrays have the same configuration. Therefore, in addition to the effects of the first aspect of the present invention, the same lens array can be used, so that the manufacture is easy and the cost is reduced.

According to the third aspect of the present invention, a light source for emitting a light beam, and one of the P-polarized component light and the S-polarized component light of the light beam emitted from the light source is transmitted, and the other component is transmitted. The light is reflected by the polarization separation surface, and the reflected light
Polarization splitting means for splitting the light into two light paths, and two optical path bending means for bending the principal ray of each light flux so as to be substantially parallel to the light flux of the one component light. And one of the two component light beams emitted from the polarization splitting means on the optical path of one component light beam and the other component light beam, and aligns the two types of component light into any one type of linearly polarized light. The half-wave plate and all the luminous fluxes whose polarization planes are aligned are made incident, and the central part of the luminous flux in the optical path that has passed through the polarization splitting means is emitted with almost no refraction. A first lens array comprising a plurality of single-lens lenses disposed between the light source and the polarization splitting means, and a polarization splitting means. Superimposed ren And, disposed on the optical path of the transmitted light of the polarized light separating means, a second lens array consisting of a plurality of single-lens, and between the polarized light separating means and the superposition lens, In addition, each of the first and second light sources is arranged on two optical paths of the reflected light of the polarization splitting means, and
It has two third lens arrays, each of which is disposed at a position substantially equal to the optical distance between the lens array and the second lens array, and includes a plurality of single-lenses, wherein the second lens array and the two third lens arrays are provided. An illuminating device configured such that principal rays of a light beam emitted from each of the single-lens lenses constituting the lens array are substantially parallel to each other; and an illuminating light emitted from the illuminating device is diffracted into three primary color lights of additive color mixture. It has an active matrix type liquid crystal display element that enters the hologram color filter to be split and modulates the light emitted from the hologram color filter based on the display image information, and projects the light beam emitted from the liquid crystal display element onto the screen. Therefore, all the light beams emitted from each single lens of the second lens array and the two third lens arrays are superimposed on the illumination area. Therefore, it is possible to emit illumination light having a large cone angle in the diffraction / spectral direction by the hologram color filter, and to emit illumination light having a small cone angle in the direction orthogonal to the diffraction / spectral direction. A display image having a contrast ratio can be obtained, and the amount of light flux emitted from a light source such as a lamp is generally the largest at the central portion, and the central portion of the light beam in the optical path transmitted from the superimposing lens through the polarization separating means is almost refracted. Since the light is emitted without incident, the light of the component near zero degree as the cone angle distribution of the illumination area increases, and high diffraction efficiency can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating cone angle distribution characteristics of light in an illumination area of the illumination device.

FIG. 3 is a schematic configuration diagram of an illumination device of a projection device according to another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of an illumination device of the projection device according to the prior art.

FIGS. 5A to 5C are diagrams respectively showing the relationship between the direction of the long axis of the liquid crystal molecules and the incident light in the illumination device according to the prior art.

FIG. 6 is a diagram showing cone angle distribution characteristics of light in an illumination area of the illumination device according to the prior art.

FIG. 7 is a diagram showing a characteristic of diffraction efficiency with respect to an incident angle of a hologram color filter of the illumination device according to the prior art.

[Explanation of symbols]

 Reference Signs List 1 light source 4 first lens array 5 polarization beam splitter (polarization separation means) 5a, 5b polarization separation surface 6 1/2 wavelength plate 7 second lens array 8a, 8b total reflection mirror (optical path bending means) 9, 10 third lens Array 11 Superimposed lens 12 Illumination area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 EA12 HA12 HA15 HA20 HA21 HA23 HA24 HA25 HA28 MA02 2H091 FA02Z FA10Z FA11Z FA14Z FA19Z FA21Z FA26Z FA29Z FA41Z FD06 LA17 MA07 2H099 AA12 BA09 CA01 DA05

Claims (3)

[Claims] 1. A light source that emits a light beam, and transmits one of the P-polarized light component light and the S-polarized light component light of the light beam emitted from the light source, and reflects the other light component on a polarization separation surface. Polarization splitting means for splitting the reflected light into two light paths, and the other of the two component light paths, wherein the principal ray of each light beam is substantially parallel to the one component light beam. Two optical path bending means for bending each of them, and one of two optical paths of one component light and the other component light emitted from the polarization splitting means. A half-wave plate for aligning with any one type of linearly polarized light, and all light beams whose polarization planes are aligned are incident thereon, and the central portion of the light beam on the optical path transmitted through the polarization separation unit is hardly refracted. Emitted and illuminates the emitted light of all luminous fluxes A first lens array including a plurality of single-lenses disposed between the light source and the polarization splitting unit, and a superimposed lens that is arranged between the light source and the polarization splitting unit. A second lens array comprising a plurality of single-lenses disposed between the lens and the polarized light separating means and on the optical path of the transmitted light of the polarized light separating means; and A plurality of single-lenses arranged respectively on two optical paths of reflected light of the polarization splitting means and arranged at positions substantially equal to an optical distance between the first lens array and the second lens array; And two third lens arrays composed of the first lens array and the third lens array. The principal rays of the light beams emitted from the single lenses constituting the second lens array and the two third lens arrays are substantially parallel to each other. An illumination device for a projection device, comprising: 2. The illumination device of the projection device according to claim 1, wherein the first lens array, the second lens array, and the two third lens arrays have the same configuration. The lighting device of the device. 3. A light source that emits a light beam, and transmits one of the P-polarized component light and the S-polarized component light of the light beam emitted from the light source, and reflects the other component light on a polarization splitting surface. Polarization splitting means for splitting the reflected light into two light paths, and the other of the two component light paths, wherein the principal ray of each light beam is substantially parallel to the one component light beam. Two optical path bending means for bending each of them, and one of two optical paths of one component light and the other component light emitted from the polarization splitting means. A half-wave plate for aligning with any one type of linearly polarized light, and all light beams whose polarization planes are aligned are incident thereon, and the central portion of the light beam on the optical path transmitted through the polarization separation unit is hardly refracted. Emitted and illuminates the emitted light of all luminous fluxes A first lens array including a plurality of single-lenses disposed between the light source and the polarization splitting unit, and a superimposed lens that is arranged between the light source and the polarization splitting unit. A second lens array comprising a plurality of single-lenses disposed between the lens and the polarized light separating means and on the optical path of the transmitted light of the polarized light separating means; and And a plurality of optical elements arranged on two optical paths of the reflected light of the polarization splitting means and arranged at optical positions substantially equal to the optical distance between the first lens array and the second lens array. It has two third lens arrays composed of eye lenses, and the principal rays of the light beam emitted from each single lens constituting the second lens array and the two third lens arrays are substantially parallel. An illumination device configured as described above, and illumination light emitted from the illumination device is incident on a hologram color filter that diffracts and disperses the three primary color lights of additive color mixture, and emits light from the hologram color filter based on display image information. A projection device, comprising: an active matrix type liquid crystal display element that modulates a light beam; and projecting a light beam emitted from the liquid crystal display element onto a screen.