JPH09269470A - Lighting device for projection type liquid crystal projector - Google Patents

Abstract

(57) An object of the present invention is to provide a lighting device for a projection type liquid crystal projector that can obtain high-quality lighting at low cost by using a fly-eye lens. A light source lamp (11), a parabolic mirror (15) that controls and reflects light emitted from the light source lamp (11) into substantially parallel light, and the light obtained by the parabolic mirror (15) is divided into a plurality of parts.
A first fly-eye lens 21 that focuses each of the divided lights in the optical axis direction to form an image, and a first fly-eye lens 21 collects and forms an image in the optical axis direction. And a second fly-eye lens 23 that diffuses each of the lights in accordance with the light collection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting system for a projection type liquid crystal projector using a light source lamp and a liquid crystal light valve.

[0002]

2. Description of the Related Art In recent years, wide-screen broadcasting of terrestrial television broadcasting has begun following high-definition broadcasting. Also, with the spread of cable television, the upcoming digital television broadcasting, and the introduction of high-resolution software such as digital video discs, a high-quality large-screen image reproducing apparatus is desired. However, the CRT used in the conventional direct-view display device has a limit of about 40-inch due to manufacturing technology, manufacturing cost, product size and weight, and the like. Therefore, there is a front projection type or rear projection type projector system for realizing a larger screen.

Further, these projector systems have a CRT system and a liquid crystal system, respectively, depending on the device forming the original screen to be enlarged and projected, and the liquid crystal system is inferior in terms of maximum brightness to the CRT system. , Is considered superior in terms of focus performance, device weight and volume.

FIG. 4 is a block diagram showing an outline of a conventional projection type liquid crystal projector. In FIG. 4, a conventional projection type liquid crystal projector 101 includes a light source lamp 11 as a light source.
1 and a power supply circuit 11 for supplying power to the light source lamp 111
3, a parabolic mirror 115 arranged so that the light source lamp 111 is located at the focal point, a first polarizing plate 117, a color filter 119, a liquid crystal panel 121, and a second polarizing plate 1.
A liquid crystal light valve 125 having 23, a projection lens 127 for enlarging and projecting an image, a screen 129, an image input terminal 131 to which an image signal is input, and a signal processing circuit 133 for generating a liquid crystal panel drive signal from the image signal. And is configured.

This conventional projection type liquid crystal projector 101
The operation of is as follows. First, the light source lamp 111 using a halogen lamp, a metal halide lamp, etc.
A predetermined power is supplied from the power supply circuit 113 to emit light.
The light emitted from the light source lamp 111 is controlled and reflected by the parabolic mirror 115 into substantially parallel light emitted in the right direction.

Then, the substantially parallel light obtained from the parabolic mirror 115 is incident on the first polarizing plate 117 in order to limit the polarization direction. The substantially parallel light linearly polarized by the first polarizing plate 117, after passing through a color filter 119 for colorization, is provided with a plurality of liquid crystal cells arranged in a matrix so that the respective optical rotatory powers thereof can be controlled. Incident on the liquid crystal panel 121 equipped with the signal processing circuit 13
A spatial distribution of optical rotatory power for each liquid crystal cell according to the liquid crystal panel drive signal given from 3 is given.

Next, the light having the optical rotatory spatial distribution provided by the liquid crystal panel 121 is made incident on the second polarizing plate 123, and only the light of an arbitrary polarization direction is selectively passed from the second polarizing plate 123. By doing so, the optical rotatory spatial distribution is converted into light having a spatial distribution of light intensity, that is, a spatial distribution of light and dark.

Next, the light that has passed through the second polarizing plate 123 is made incident on the projection lens 127, and enlarged and projected from the projection lens 127 toward the screen 129.

The light emitting state of the light source lamp 111 is as follows.
Due to the influence of gravity, it has a vertically unbalanced emission intensity and color balance, and with this configuration as it is, the image quality is unbalanced vertically and horizontally. Also, depending on the lamp manufacturer and product, a protrusion called a chip for gas filling is arranged near the light emitting part, so diffuse reflection occurs here,
The collimated light is not obtained, and as a result, a large decrease in brightness occurs. Further, the brightness curve with respect to the distance from the optical axis obtained by the parabolic mirror 115 is extremely steep as shown in FIG. 5, which hinders obtaining a desired image quality.

As a means for solving this problem, the improvement means using a fly-eye lens is currently most commonly used. In this method, as shown in FIG. 6, the light emitted from the parabolic mirror 115 is subdivided into a plurality of pieces by the first fly-eye lens 141, and the subdivided lens array has a one-to-one correspondence. The second fly-eye lens 143 is used to provide directivity and illuminates the entire surface of the liquid crystal light valve 125, thereby averaging the luminance imbalance due to the above-mentioned factors and obtaining a high-quality light source illumination. . For example,
Of the light obtained from the parabolic mirror 115, the light in the hatched area in FIG. 6 is incident on the first fly-eye lens 141 and is condensed on the corresponding second fly-eye lens 143. The second fly-eye lens 143 gives directionality and irradiates the entire surface of the liquid crystal light valve 125.

The first fly-eye lens 141 and the second fly-eye lens 141
The fly-eye lens 143 is subdivided by a lens array as shown in FIG. 7A having the same aspect ratio as the illumination image shown in FIG. 7B.

[0012]

The illumination device of such a projection type liquid crystal projector is sufficient as a light source device such as an exposure device, which requires uniformity, but is slow with respect to the light beam incident angle. However, there are considerable limitations as an illuminating device of a liquid crystal projector in which the light passing through the liquid crystal light valve is further enlarged and radiated by a projection lens.

The reason for this will be described with reference to FIG. The parabolic mirror 115 is required to have an arbitrary size depending on the power and efficiency of the light source lamp 111. However, since the manufacturing cost is almost proportional to the area of the opening, the cost will be a problem if it is made larger than necessary. Therefore, the minimum required size is the most desirable shape.

The first fly-eye lens 141 and the second
The fly-eye lens 143 of FIG. 1 is arbitrarily divided according to the parabolic mirror 115 and the liquid crystal light valve 125. When the illumination system is viewed from the liquid crystal light valve 125, each lens array of the second fly-eye lens 143. It is an illumination system with multiple light sources that emit light from almost the center position.

Therefore, at each position of the liquid crystal light valve 125, light beams are incident from the multiple light sources according to the illumination optical system within the range of the angle θ, but the projection lens needs to take almost all the light beams into the entrance pupil. is there. This is because the uneven brightness is averaged only after all the light fluxes have been captured and irradiated, and the desired light utilization efficiency is achieved. On the other hand, the projection lens NA (image side numerical aperture; numerical)
It goes without saying that aperture) is also limited by shape and cost.

Now, the NA of the required projection lens will be calculated assuming that the parabolic mirror 115 and the liquid crystal light valve 125 have the same diagonal dimension. If the effective opening of the parabolic mirror 115 is 100φ, the distance between the electrodes of the light source lamp 111, which is most commonly used at present, is about 3 mm, so that the luminous flux emitted from the parabolic mirror 115 is already ± 5. It has a luminous flux divergence angle a of about degree. Here, the first fly-eye lens 141 and the second fly-eye lens 143 are also 100
If φ is divided into 10 equal parts, since the light source seen from the optical axis position of the liquid crystal light valve 125 is a light source existing in the range of 90φ, the second fly-eye lens 143 and the liquid crystal light valve 125 are separated from each other. The incident angle ψ at the ideal light source when the distance is L is expressed by the equation (1).

Ψ = ± tan ⁻¹ {(90/2) / L} (1) Here, when L = 200 mm, ψ = ± 12.7 degrees. By simply adding ± 5 degrees due to the above-described light beam divergence angle a to this, θ = ± 17.7 degrees. Therefore, NA required for the projection lens is 0.3 (Fno = 1.6). This is a very expensive and very large, i.e. unrealistic projection lens.

In order to solve this problem, it is necessary to secure an unrealistic optical path length or to provide a sufficiently large parabolic mirror 115 for the liquid crystal light valve 125. In order to reduce the size of a liquid crystal panel that is desired, a sacrifice directly related to the aperture ratio, that is, the light utilization efficiency is required. Therefore, it is necessary to avoid many restrictions in developing a product that satisfies all these conditions. It was

The present invention has been made in view of the above problems, and it is possible to obtain high-quality illumination at low cost even when a fly-eye lens is used, and to downsize the fly-eye lens. An object of the present invention is to provide an illuminating device for a projection type liquid crystal projector that can be used.

[0020]

In order to achieve the above object, the invention according to claim 1 allows light emitted from a light source lamp to pass through a first fly-eye lens divided into arbitrary areas, and The light passing through the fly-eye lens forms an image in the vicinity of the second fly-eye lens having a lens array configuration corresponding to the lens array of the first fly-eye lens,
The lens array of the second fly-eye lens includes liquid crystal panels arranged in a matrix, and is configured to illuminate the entire liquid crystal light valve that controls the amount of light transmission by controlling the optical rotation of the liquid crystal panel. In the illumination device of the projection type liquid crystal projector, the first fly-eye lens decenters each lens array so that the light passing through each lens array is imaged in the optical axis direction, and the second fly-eye lens is arranged. The gist of the eye lens is to configure each lens array corresponding to the decentering amount of the lens array of the first fly-eye lens.

In the illuminating device of the projection type liquid crystal projector according to claim 1, the first fly-eye is arranged so that the light passing through each lens array of the first fly-eye lens forms an image in the optical axis direction. Each lens array of the lenses is decentered, and the lens array of the second fly-eye lens is configured in correspondence with the decentering amount of the lens array of the first fly-eye lens. As a result, even when a fly-eye lens is used, high-quality illumination can be obtained at low cost, and the fly-eye lens can be downsized.

Further, a condenser lens is provided between the liquid crystal light valve and the second fly's eye lens so that the light flux emitted from the second fly's eye lens to the liquid crystal light valve becomes substantially parallel to the optical axis. It may be provided between them. Further, the condenser lens may form a plurality of chief rays generated by the second fly-eye lens at an entrance pupil position of the projection lens. Further, the first fly-eye lens and the second fly-eye lens are
A group of lens arrays having the same aspect ratio as the projected image and having a plurality of types of areas is used. The first fly-eye lens and the second fly-eye lens are a group of lens arrays having the same aspect ratio as the projected image, and these lens arrays have the same focal length symmetrically about the optical axis. In addition, those arranged in the same area and symmetrically decentered about the optical axis are used. Further, as the first fly-eye lens and the second fly-eye lens, those which are aggregates of lens arrays having the same aspect ratio and plural kinds of areas such that they become substantially circular when combined are used.
Further, the first fly-eye lens has a first face on one surface.
The fly-eye lens may be used as the fly-eye lens, and a single spherical surface or an aspherical surface having an eccentric function may be processed on the semi-opposing surface of the fly-eye lens processing surface. Further, the first fly-eye lens is provided with a convex lens processing for condensing the light obtained from the parabolic mirror on the light source lamp side, and further, a plurality of light is condensed by the convex lens processed surface. The fly-eye lens processing for splitting is performed on the second fly-eye lens side, and the second fly-eye lens has a concave lens processing for diffusing the light split by the first fly-eye lens as the first fly-eye lens processing. It is also possible to use a fly-eye lens that is provided on the fly-eye lens side and further has a fly-eye lens process that splits the light diffused by the concave lens processed surface on the exit side.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of a lighting device of a projection type liquid crystal projector according to the present invention. In the figure, the same components as those shown in FIG. 4 are denoted by the same symbols, and detailed description is omitted.

As shown in FIG. 1, the illuminating device 1 of the projection type liquid crystal projector according to the first embodiment has a light source lamp 11 as a light source and a parabolic surface for limiting and reflecting the light emitted from the light source lamp 11 into substantially parallel light. The first fly-eye lens 21 that splits the light obtained from the mirror 15 and the parabolic mirror 15 into a plurality of lights and forms an image of each of the split lights in the optical axis direction.
And a second fly-eye lens 23 that diffuses a plurality of chief rays generated by the first fly-eye lens 21 in accordance with the respective eccentricity amounts of the first fly-eye lens 21.
A condenser lens 25 for controlling the light diffused by the second fly-eye lens 23 into substantially parallel light; a first polarizing plate;
A liquid crystal light valve 125 including a color filter, a liquid crystal panel, and a second polarizing plate.

The illumination device 1 of the projection type liquid crystal projector of the first embodiment divides the substantially parallel light obtained by the parabolic mirror 15 into a plurality of light beams by the first fly-eye lens 21. The luminance unbalance is averaged by a plurality of chief rays generated by 21, and an image is formed in the optical axis direction, and is diffused by the second fly-eye lens 23 according to the eccentricity of the first fly-eye lens 21, The light is controlled to be substantially parallel light by the condenser lens 25 so that the light is incident on the entire liquid crystal light valve 125. Therefore, the second fly-eye lens 23 can be downsized. still,
The light emitted from the liquid crystal light valve 125 enters a projection lens (not shown), is enlarged by the projection lens, and is displayed as an image on a screen (not shown).

The first fly-eye lens 21 and the second fly-eye lens 23 have a diameter L1 of a virtual light source distribution shown in FIG. The virtual light source outline L2 (the diameter of the circle in which all the fly-eye lenses 21 are inserted) is determined from conditions such as the diameter) and the light resistance.

The first fly-eye lens 21 is composed of a plurality of lens arrays which are decentered so as to form an image of incident light in the optical axis direction, and the second fly-eye lens 23.
Is composed of a plurality of lens arrays that are decentered so as to diffuse corresponding to the amount of decentering of the first fly-eye lens 21.

Further, the first fly-eye lens 21 and the second fly-eye lens are a group of convex lenses having the same aspect ratio as that of the liquid crystal panel, and the light obtained from the parabolic mirror 15 is required to the minimum. In order to control the most efficiently so as to have sufficient light utilization efficiency with the lens array configuration of FIG.
It is combined so that it becomes close to a circle as shown in.

Further, the first fly-eye lens 21 and the second fly-eye lens 23 have the optical axis of the light source lamp 11 so that the unbalanced brightness in the vertical and horizontal directions caused by the structure of the light source is averaged. They are arranged symmetrically around the center. That is, as shown in FIG. 2, lens A in quadrant a
a and lens Ab in quadrant b and lens Ac in quadrant c and quadrant d
The lens Ad has an optical axis symmetrical structure, and the lens Ba in the quadrant a, the lens Bb in the quadrant b, the lens Bc in the quadrant c, and the lens Bd in the quadrant d have an axial symmetric structure and the lens Ca in the quadrant a. Lens Cb in quadrant b and lens Cc in quadrant c
And the lens Cd in the quadrant d have an optical axis symmetrical structure, and the lens Da in the quadrant a, the lens Db in the quadrant b, the lens Dc in the quadrant c, and the lens Dd in the quadrant d have an axial symmetric structure.
The lens Ea in the quadrant a, the lens Eb in the quadrant b, the lens Ec in the quadrant c, and the lens Ed in the quadrant d have an optical axis symmetrical structure.

When the second fly-eye lens 23 is viewed from the liquid crystal light valve 125, it is equivalent to being illuminated by a plurality of virtual light sources dispersed in an arbitrary range around the optical axis. By disposing the condenser lens 25 so that the principal ray is parallel to the optical axis at an arbitrary position, the telecentricity (a state where all the principal rays are parallel to the optical axis) is improved.

In the first embodiment, since each lens array of the first fly-eye lens 21 and the second fly-eye lens 23 is decentered in the optical axis direction, it is seen from the optical axis position on the liquid crystal panel surface. The diameter L1 of the virtual light source distribution of the second fly-eye lens 23 is reduced to 45φ. Furthermore, a focal length of 4 on the 10 mm light source side of the liquid crystal light valve 125
By arranging a 22 mm condenser lens 25, the emitted light is controlled to be substantially parallel light.

In this way, the uneven brightness due to the reflecting mirror (parabolic mirror 15) having the distance from the optical axis as a parameter is reduced by the first fly-eye lens 21 and the second fly-eye lens 23. In addition, the first fly-eye lens 21 and the second fly-eye lens 23 are configured to have four quadrants having a symmetrical structure with respect to the optical axis, and the minimum required lens array configuration has sufficient light utilization efficiency. By irradiating them with optical axis symmetry, they are averaged so as to cancel out the unbalanced luminance with respect to the optical axis, that is, up and down, left and right, so that uneven light emission caused by the light source lamp 11 is reduced. To do.

Further, the NA required for the projection lens of the first embodiment is improved to ψ = ± tan ⁻¹ {(45/2) / L} = ± 6.1 degrees. Even if the divergence angle of the luminous flux of ± 5 degrees is added, θ = ± 11.1 degrees, and NA = 0.19.
(Conventional 0.3), 2.6 when expressed by Fno (Conventional 1.
6) and a great improvement. Therefore, the cost is remarkably reduced and the shape is remarkably downsized.

As described above, in the illumination device 1 of the projection type liquid crystal projector of the first embodiment, the light emitted from the light source lamp 11 is limitedly reflected by the parabolic mirror 15 to be substantially parallel light, and the first
Light is split by the first fly-eye lens 21, the luminance imbalance is averaged by a plurality of chief rays generated by the first fly-eye lens 21, and an image is formed in the optical axis direction by the second fly-eye lens 23. The first fly-eye lens 21 diffuses according to the eccentricity amount, and is controlled by the condenser lens 25 to be substantially parallel light, and the liquid crystal light valve 125.
Since the light is made incident on the whole, high-quality illumination can be obtained at low cost even if the first fly-eye lens 21 and the second fly-eye lens 23 are used, and the second fly-eye lens 23 is used. It can be miniaturized.

FIG. 3 is a view showing a second embodiment of the illuminating device of the projection type liquid crystal projector according to the present invention. In the figure, the same components as those shown in FIG. 4 are denoted by the same symbols, and detailed description is omitted.

As shown in FIG. 3, if the viewing angle of the liquid crystal light valve 125 is acceptable, the condenser lens 25 further shortens the focal length so that the principal ray is imaged at the entrance pupil position 127a of the projection lens 127. It is also possible to have a field lens function together. For this reason, in the illumination device of the projection type liquid crystal projector of the second embodiment, the light emitted from the light source lamp 11 is limitedly reflected by the parabolic mirror 15 to be substantially parallel light, and divided into a plurality by the first fly-eye lens 21. The luminance imbalance is averaged by the plurality of chief rays generated by the first fly-eye lens 21, and an image is formed in the optical axis direction.
The light is diffused in accordance with the eccentricity of the first fly-eye lens 21, and the light diffused by the second fly-eye lens 23 is controlled by the condenser lens 25 to be incident on the liquid crystal light valve 125 and projected. An image is formed at the entrance pupil position 127a of the lens 127.

Further, when the liquid crystal light valve 125 is relatively large or a sufficient optical path length cannot be obtained, as shown in FIG. 3, the light source lamp 1 of the first fly-eye lens 21 is used.
A first fly-eye lens 31 in which a convex lens processing 31a is applied to the first side and a fly-eye lens processing 31b is applied to the second fly-eye lens 23 side of the first fly-eye lens 21 and a second fly-eye lens 23 is provided with concave lens processing 33a on the side of the first fly-eye lens 21 and
Liquid crystal light valve 125 of the second fly-eye lens 21
A second fly-eye lens 33 having a fly-eye lens processing 33b on its side may be used.

In this case, the convex lens processing 31a and the fly-eye lens processing 31b of the first fly-eye lens 31 may be provided independently, or the concave lens processing 33a and the fly-eye lens processing 33b of the second fly-eye lens 33 may be provided separately. It may be provided independently.

Further, a normal fly-eye lens processing as the first fly-eye lens 21 is performed on one surface of the first fly-eye lens 21, and a semispherical surface or an aspherical surface having a decentering function on its half-opposite surface. You may make it process.

As described above, in the illuminating device of the projection type liquid crystal projector of the second embodiment, the light emitted from the light source lamp 11 is limitedly reflected by the parabolic mirror 15 to be substantially parallel light, and
Is divided into a plurality by the fly-eye lens 21 and the luminance imbalance is averaged by a plurality of chief rays generated by the first fly-eye lens 21, and an image is formed in the optical axis direction. The light that is diffused according to the eccentricity of the first fly-eye lens 21 and that is diffused by the second fly-eye lens 23 is controlled by the condenser lens 25 to enter the liquid crystal light valve 125, and at the same time, the projection lens. Since the image is formed at the entrance pupil position 127a of 127, the function of the field lens can be provided in addition to the effect of the first embodiment, and the cost can be further reduced.

[0041]

As described above, according to the present invention, each lens array of the first fly-eye lens is formed so that the light passing through each lens array of the first fly-eye lens forms an image in the optical axis direction. Is decentered, and the lens array of the second fly-eye lens is configured corresponding to the decentering amount of the lens array of the first fly-eye lens. Therefore, even when the fly-eye lens is used, High-quality illumination can be obtained at low cost, and the fly-eye lens can be downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of an illumination device of a projection type liquid crystal projector according to the present invention.

FIG. 2 is a diagram showing a configuration example of a fly-eye lens.

FIG. 3 is a diagram showing a schematic configuration of a second embodiment of an illumination device of a projection type liquid crystal projector according to the present invention.

FIG. 4 is a diagram showing a schematic configuration of a conventional projection type liquid crystal projector.

FIG. 5 is a distribution diagram showing luminance characteristics with respect to a distance from an optical axis of a parabolic mirror.

FIG. 6 is a diagram showing a schematic configuration of an illumination optical system using a conventional fly-eye lens.

FIG. 7 is a diagram showing an example of division of a conventional fly-eye lens.

FIG. 8 is a diagram for explaining a problem of an illumination optical system using a conventional fly-eye lens.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Illumination device for projection type liquid crystal projector 11 Light source lamp 15 Parabolic mirror 21 First fly-eye lens 23 Second fly-eye lens 25 Condensing lens 125 Liquid crystal light valve

Claims (8)

[Claims] 1. Light emitted from a light source lamp is passed through a first fly-eye lens divided into arbitrary areas, and the light passed through the first fly-eye lens is a lens array of the first fly-eye lens. An image is formed in the vicinity of a second fly-eye lens having a lens array configuration corresponding to, and the lens array of the second fly-eye lens includes liquid crystal panels arranged in a matrix to control optical activity of the liquid crystal panel. In the illumination device of the projection type liquid crystal projector configured to illuminate the entire liquid crystal light valve for controlling the amount of light transmission, the first fly-eye lens is configured such that the light passing through each lens array is an optical axis. Decentering each lens array so as to form an image in a direction, and the second fly-eye lens is a lens array of the lens array of the first fly-eye lens. Lighting device of the projection type liquid crystal projector, characterized by constituting each of the lens array so as to correspond to the amount. 2. A condensing lens is provided between the liquid crystal light valve and the second fly-eye lens so that a light flux emitted from the second fly-eye lens to the liquid crystal light valve is substantially parallel to an optical axis. The illumination device for a projection type liquid crystal projector according to claim 1, wherein the illumination device is provided between them. 3. The projection type liquid crystal projector according to claim 2, wherein the condenser lens forms an image of a plurality of chief rays generated by the second fly-eye lens at an entrance pupil position of the projection lens. Lighting equipment. 4. The first fly-eye lens and the second fly-eye lens are a group of lens arrays having a plurality of areas with the same aspect ratio as the projected image. Any one of claim 1 to claim 3
An illumination device for a projection type liquid crystal projector according to the item. 5. The first fly-eye lens and the second fly-eye lens are a group of lens arrays having the same aspect ratio as the projected image, and these lens arrays are centered around the optical axis. 5. The projection type liquid crystal projector according to claim 1, wherein the projection type liquid crystal projectors are symmetrically arranged with the same focal length and the same area, and are symmetrically decentered about the optical axis. Lighting equipment. 6. The first fly's eye lens and the second fly's eye lens are aggregates of lens arrays having the same aspect ratio and a plurality of types of areas, which are combined into a substantially circular shape when combined. An illumination device for a projection type liquid crystal projector according to any one of claims 1 to 5. 7. The fly-eye lens processing as the first fly-eye lens is applied to one surface of the first fly-eye lens, and a semi-facing surface of the fly-eye lens processed surface is provided.
4. The projection type liquid crystal projector illumination device according to claim 1, wherein a single spherical or aspherical surface having an eccentric function is applied. 8. The first fly-eye lens is provided with a convex lens processing for condensing light obtained from the parabolic mirror on the light source lamp side, and further, the light condensed by the convex lens processed surface. Is applied to the side of the second fly-eye lens, and the second fly-eye lens is processed with a concave lens for diffusing the light split by the first fly-eye lens. The first fly-eye lens side is provided, and further, the fly-eye lens processing for dividing the light diffused by the concave lens processed surface is provided on the emission side. An illumination device for a projection type liquid crystal projector according to any one of claims 1.