JPH10288757A - Illuminator and projecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a deflection coverting part small by providing a deflection converting element array converting plural luminous fluxes from a collimating optical system into polarized lights individually. SOLUTION: It is preferably that a light source 1 is a point light source but the light source 1 may have a spread. When the spread is present in the light source 1, since spreads are generated in luminous fluxes from a first convex lens array 4, a second convex lens array 6 on which convex lenses corresponding to respective lenses of the first convex lens array 4 are arranged is provided in the vicinity of converged positions of respective luminouis fluxes by the first convex lens array 4. Since the first convex lens array 4 is provided in the optical path of the converged light and then, sizes of secondary light sources to be generated by the array 4 are made small, as a result, the size of a deflection converting element array 7 can be made small in accordance with the sizes of the secondary optical sources. Thus, the whole of this device can be made small by making outside diameters of a convex lens 5, the second convex lens array 6, the deflection converting element array 7 smaller than the outside diameter of a light collecting mirror 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device and a projecting device, and more particularly, to an image of a liquid crystal display device (liquid crystal panel).
The projection lens is suitable for a liquid crystal projector that performs enlarged projection on a screen or a wall.

[0002]

2. Description of the Related Art Conventionally, various liquid crystal projectors have been proposed in which a liquid crystal panel is illuminated by a light beam from a light source and an image based on transmitted light or reflected light from the liquid crystal panel is enlarged and projected on a screen or a wall by a projection lens. Have been.

A TN type liquid crystal panel from which a high-contrast image can be obtained relatively easily utilizes the polarization characteristics of liquid crystal. For this purpose, a polarizer and an analyzer are usually provided before and after the liquid crystal panel. Such a polarizing filter has a characteristic of transmitting polarized light having a specific polarization direction of incident light and blocking polarized light having a polarization direction orthogonal to the polarization direction. Therefore, at least half of the light from the light source of the liquid crystal projector is cut off by the polarizer, and the brightness of the projected image is not sufficient.

FIG. 23 is a schematic view of a main part of a projector proposed in Japanese Patent Application Laid-Open No. 61-90584 which has solved the problem of brightness.

The liquid crystal projector shown in FIG.
The light beam from the infrared cut filter 208 and the lens 20
7, the light is incident on a polarization separation element 202 that separates the randomly polarized light into two orthogonal polarization components (P-polarized light and S-polarized light). A half-wave plate 203 is provided on the optical path of S-polarized light, which is reflected light, of the light beam that has passed through the polarization splitter 202. The polarization direction of the polarized light passing through the half-wave plate is rotated by 90 °, and the polarized light is emitted in the same manner as the transmitted P-polarized light. Then, the optical paths of the two polarized lights from the polarization splitting element 202 are folded on the liquid crystal panel 205 using the bending mirror 209 and the prism 204, and the light source 2
All light from 01 is available.

[0006] In the liquid crystal projector shown in FIG.
6 is required, and has the disadvantage that it is large and expensive. In addition, since the light beam is split into two, the illumination light beam becomes approximately twice as large as the conventional one. In order for all the light beams to pass through the projection lens, the aperture diameter (F _NO ) of the projection lens is required to be twice or more as compared with the conventional case, and there is also a problem in design.

On the other hand, the illuminating device for a liquid crystal projector disclosed in Japanese Patent Application Laid-Open No. H8-304739 achieves a thinner polarization converter by arraying a polarization splitting element, a bending mirror, and a half-wave plate. In addition, the size of the illuminating light beam is maintained at the same level as that of the related art, so that the conventional projection lens can be used.

[0008]

However, at present,
There is a demand for an illumination device and a projection device having a polarization converter smaller than that of Japanese Patent Application Laid-Open No. 8-304739.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an illuminating device in which the polarization conversion unit can be made smaller than before, and a projection device such as a liquid crystal projector in which the polarization conversion unit can be made smaller than before.

[0010]

The lighting device according to the present invention comprises (1)
-1) a condensing optical system that converts light from a light source into convergent light, a first convex lens array that receives the convergent light, a collimating optical system that makes a plurality of light beams from the first convex lens array parallel to each other, and A polarization conversion element array that individually converts the plurality of light beams from the collimating optical system into polarized light,
And characterized in that:

(1-2) a condensing optical system for converting light from a light source into convergent light, a collimating optical system for converting the convergent light to parallel light, a first convex lens array receiving the parallel light, and the first A polarization conversion element array for individually converting a plurality of light beams from the convex lens array into polarized light.

Particularly, in the constitutions (1-1) and (1-2), (1-2-
1) A second convex lens array is provided between the collimating lens system and the polarization conversion element array, each convex lens corresponding to each one of the plurality of light beams.

(1-2-2) The condensing optical system includes an elliptical mirror, and the light source is located at a focal position of the elliptical mirror.

(1-2-3) The condensing optical system includes a parabolic mirror, and the light source is located at a focal position of the parabolic mirror. Having a convex lens that receives a parallel light beam.

(1-2-4) The collimating optical system includes a concave lens.

(1-2-5) An optical system for superposing the plurality of polarized light beams from the polarization conversion element array on the surface to be illuminated. And so on.

A projection device according to the present invention comprises: (2-1) a liquid crystal panel illuminated by the illumination device according to any one of the constitutions (1-1) and (1-2); It is characterized in that image light is projected by a projection optical system.

In particular, (2-1-1) each element of the polarization conversion element array has a polarization splitter, an optical path bending mirror, and a half-wave plate.

(2-1-2) An optical system for superposing the plurality of polarized light beams from the polarization conversion element array on the liquid crystal panel is provided.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a first embodiment of the present invention. In the figure, reference numeral 230 denotes a part or all of the lighting device, and 1 denotes a radiation light source such as a metal halide lamp. 2
Reference numeral denotes a parabolic mirror, which is a reflector having a paraboloidal reflection surface. The parabolic mirror reflects a light beam from the light source 1 and converts the light beam into a parallel light. Lens 3
Has a positive refractive power.

Reference numeral 4 denotes a first convex lens array, which comprises a plate having a plurality of lenses 4a having a positive refractive power. Reference numeral 5 denotes a concave lens having a negative refractive power. 6
Denotes a second convex lens array, which is composed of a plate having a lens 6a having a positive refractive power corresponding to each lens 4a of the first convex lens array 4. Reference numeral 7 denotes a polarization conversion element array having the configuration shown in FIG. 2, and emits unpolarized (randomly polarized) light incident on each polarization conversion element as linearly polarized light polarized in a specific direction. The polarization directions of the polarized lights emitted from the respective polarization conversion elements coincide with each other, as shown in FIG.

Reference numeral 8 denotes a condenser lens having a positive refractive power. Reference numeral 9 denotes a condenser lens, which collects illumination light on an entrance pupil (aperture stop) of a projection lens 11 via a panel 10. Reference numeral 10 denotes an image display element formed of a liquid crystal panel. The projection lens 11 has a positive refractive power, and enlarges and projects an image formed by the image display element 10 on a screen or a wall.

The concave lens 5 makes a plurality of non-parallel light beams from the first convex lens array parallel to each other so that the corresponding light beam in each polarization conversion element 7 is incident only on the light receiving portion 7i of the element 7 and has an optical axis. And in parallel.

In this embodiment, the light source 1 is desirably a point light source, but the light source 1 may have a spread. When the light source 1 has a spread, the light flux from the first convex lens array 4 also spreads. Therefore, each of the first convex lens array 4 A second convex lens array 6 in which convex lenses (field lenses) corresponding to the lenses are arranged is provided.

In the present embodiment, by providing the first convex lens array 4 in the optical path of the convergent light, the size of the secondary light source generated thereby is reduced, so that the size of the polarization conversion element array 7 is also reduced. Since it can be reduced according to the size of the secondary light source, the concave lens 5, the second
The outer diameter of each of the convex lens array 6 and the polarization conversion element array 7 is made smaller than the outer diameter of the condenser mirror, thereby reducing the size of the entire apparatus.

Here, what is described as a convex lens indicates a lens having a positive refractive power. Therefore, in the present invention, a Fresnel lens having a positive refractive power and a refractive index distribution type lens having a positive refractive power, which does not have a so-called convex surface, can also be used. Further, what is described as a concave lens indicates a lens having a negative refractive power. Therefore, in the present invention, a Fresnel lens having a negative refractive power and a gradient index lens having a negative refractive power, which does not have a so-called concave surface, can also be used.

Next, the configuration of the polarization conversion element array 7 will be described with reference to FIG. The polarization conversion element array 7 is an array of polarization conversion elements corresponding to the individual lenses 6 a of the second convex lens array 6.
a and the optical path of the S-polarized light reflected by the polarization separation surface 7a is 90
It has a reflecting surface 7b to be bent, and a half-wave plate (λ / 2 plate) 7c provided in the optical path of P-polarized light transmitted through the polarization separating surface 7a or the optical path of reflected S-polarized light. FIG.
In the optical path of the S-polarized light reflected by the polarization separation surface 7a, λ /
Two plates 7c are provided.

Next, an optical path from the light source 1 according to the present embodiment will be described with reference to FIGS. 2 and 3,
The light emitted from the light source 1 is reflected by the parabolic mirror 2 in the direction in which the image display element 10 is present, becomes parallel light, enters the first lens array 4 via the convex lens 3, and is split into a plurality of light fluxes. The plurality of light beams form a plurality of converging points in a range smaller than the outer diameter of the parabolic mirror 2 near the biconvex lens array 6. The concave lens 5 guides the light beams from the first convex lens array 4 to the second convex lens array 6 after making the plurality of light beams parallel to each other and aligning the directions of the respective light beams incident on the polarization conversion element array 7. Each light beam transmitted through the second convex lens array 6 is incident on a corresponding polarization conversion element of the polarization conversion element array 7.

The luminous flux incident on each polarization conversion element is separated by the polarization separation surface 7a into S-polarized light and P-polarized light whose polarization directions are orthogonal to each other (← →,...). The reflected S-polarized light (← →) has the same polarization direction as the P-polarized light reflected by the reflection surface 7b, transmitted through the half-wave plate 7c, and transmitted through the polarization separation surface 7a by the half-wave plate. It is converted to light (•). Accordingly, a plurality of light beams having the same polarization direction are emitted from the polarization conversion element array 7.
A plurality of light beams from the polarization conversion element array 7 are
And the condenser lens 9 are combined on the image display element 10.

The light beam transmitted through the image display element 10 is guided to a projection lens 11, and the image formed by the image display element 10 by the lens 11 is formed on a screen, a wall, or the like.

FIGS. 4 and 5 are enlarged explanatory views of a part of FIG. FIGS. 4 and 5 show the optical path in a normal case where the light flux from the light source 1 is spread. If the luminous flux from the light source 1 spreads, the angle of the light emitted from the parabolic mirror 2 becomes non-uniform, and the luminous flux condensed by the first convex lens array 4 also spreads, and the imaging point also widens.

Therefore, in the present embodiment, the light from each lens of the first convex lens array 4 is actuated by the action of each lens 601 of the second convex lens array 6 provided near the converging point of the plurality of light from the first convex lens array 4. , The directions of a plurality of light beams having different traveling directions are aligned, and the spread of the light beam is suppressed.

In this embodiment, the convex lens 3 and the first
The convex lens array 4 may be an integrated lens La1 as shown in FIG. 6, or a lens L having a configuration in which each lens of the first convex lens array 4 is decentered in the center direction as shown in FIG.
a2 alone may be used.

Further, the concave lens 5 and the second convex lens array 6 may be only the lens La3 having a configuration in which each lens of the second lens array 6 is decentered in the peripheral direction as shown in FIG. Further, the second convex lens array 6 may be provided between the polarization conversion element array 7 and the condenser lens 8 as shown in FIG.
Only the lens La4 having a configuration in which each lens of the second convex lens array 6 is decentered in the center direction, such as 0, may be used.

In this embodiment, as shown in FIG. 22, a color separation system 101 composed of a plurality of dichroic mirrors or the like is provided between the condenser lens 8 and the image display element 10, and the image display element 1
By providing a color synthesizing system 109 composed of a dichroic prism or the like between
It can also be used as it is in a three-panel liquid crystal projector using three 0s for RGB.

FIG. 11 is a schematic view of a main part of a second embodiment of the present invention. In the figure, 230 is a part or all of the lighting device, FIG.
Elements that are the same as the elements indicated by are given the same reference numerals. In this embodiment, the lens 3 is omitted as compared with the first embodiment in FIG.
Instead of the parabolic mirror 2, the light flux from the light source 1 placed at the focal position by an elliptical mirror, which is a reflector 2 having a reflecting surface composed of an elliptical surface, is converted into a convergent light beam, and the convergent light beam is converted into a first convex lens array. The only difference is that the light is incident on No. 4 and other configurations are the same.

FIG. 12 is a schematic view of a main part of a third embodiment of the present invention. In the figure, reference numeral 1 denotes a radiation light source such as a metal halide lamp. Reference numeral 2 denotes an elliptical mirror which is a reflector having a reflecting surface formed of an elliptical surface. The mirror 2 reflects and condenses the light beam from the light source 1 located at the focal position to convert the light beam into a convergent light beam. I have. The concave lens 5 has a negative refractive power.

Reference numeral 4 denotes a first convex lens array, which comprises a plate in which a plurality of convex lenses 4a having a positive refractive power are arranged. Reference numeral 6 denotes a second convex lens array, which comprises a plate in which a plurality of convex lenses 6a having a positive refractive power corresponding to the individual lenses 4a of the first lens array 4 are arranged. Reference numeral 71 denotes a polarization conversion element array having the configuration shown in FIG.
The incident non-polarized (randomly polarized) light is converted into linearly polarized light polarized in a specific direction and emitted. Reference numeral 8 denotes a condenser lens having a positive refractive power. Reference numeral 9 denotes a condenser lens, which condenses illumination light on the entrance pupil (aperture stop) of the projection lens 11 via the liquid crystal panel 10. 1
Numeral 0 is an image display element composed of a liquid crystal panel. The projection lens 11 has a positive refractive power, and enlarges and projects a projection image formed by the image display element 10 on a screen or a wall.

Next, the configuration of the polarization conversion element array 71 will be described with reference to FIG. Each polarization conversion element of the polarization conversion element array 71 is provided corresponding to each lens 6a of the second convex lens array 6, and this element converts the polarization separation surface 71a and the S-polarized light reflected by the polarization separation surface 71a. A reflecting surface 71b for bending the optical path, and a first half-wave plate 71 provided on the optical path of the p-polarized light transmitted through the polarization splitting surface 71a.
c, and a second half-wave plate (λ / 2 plate) 71d provided in the optical path of the S-polarized light. As a result, the emitted light beams are emitted with the same polarization state.

Next, the optical path of this embodiment will be described with reference to FIGS. 13 and 14, the light emitted from the light source 1 is reflected by the elliptical mirror 2 in a specific direction (the direction in which the image display element 10 is located), converted into convergent light, and incident on the concave lens 5. The concave lens 5 converts convergent light into parallel light. The parallel light from the concave lens 5 is incident on the first convex lens array 4 and is divided into a plurality of light beams by the array 4. The plurality of light beams are smaller than the outer diameter of the elliptical mirror 2 which is a close magnification of the second convex lens array 6. The light is incident on the second convex lens array 6 while forming a plurality of condensing points in a small range. The plurality of light beams transmitted through the second convex lens array 6 are incident on the polarization conversion element array 71. The luminous flux incident on each polarization conversion element of the polarization conversion element array 71 is
1a separates the light into S-polarized light and P-polarized light whose polarization directions are orthogonal to each other (← →,...).
The S-polarized light (← →) reflected by the reflector is reflected by the reflection surface 71b and transmitted through the second half-phase plate 71d, thereby being converted into obliquely polarized linearly polarized light (/) and emitted. I do. The P-polarized light (•) transmitted through the polarization splitting surface 71a transmits through the first half-wave plate 71c,
The light is emitted in a linearly polarized state (/) deflected in an oblique direction (the same direction as the S-polarized light).

Thus, a plurality of light beams having the same polarization direction are emitted from the polarization conversion element array 71.
A plurality of light beams from the polarization conversion element array 71 are combined on the image display element 10 by the condenser lens 8 and the condenser lens 9.

The light beam transmitted through the image display element 10 is guided to the projection lens 11 to form an image formed by the image display element 10 on a screen or a wall by the projection lens 11.

In this embodiment, the concave lens 5 and the first convex lens array 4 may be constituted by an integrated lens La5 as shown in FIG. Further, as shown in FIG. 16, each lens of the first lens array may be constituted by a lens La6 decentered in the center direction.

FIG. 17 is a schematic view of a main part of a fourth embodiment of the present invention. In the figure, reference numeral 230 denotes a part or all of the lighting device, and 1 denotes a radiation light source such as a metal halide lamp. 2 is a parabolic mirror whose reflecting surface is a parabolic reflector,
The light flux from the light source 1 at the focal position is reflected and converted into parallel light, and is incident on the first convex lens array 81.
The first convex lens array 81 is a lens 8 having a positive refractive power.
It comprises a plate in which a plurality of 1a are arranged.

Reference numeral 5 denotes a concave lens having a negative refractive power. Reference numeral 6 denotes a second convex lens array. Reference numeral 82 denotes a polarization conversion element array which has the configuration shown in FIG. 18 and converts incident non-polarized light (randomly polarized light) into linearly polarized light polarized in a specific direction and emits it. 8 is a condenser lens. Reference numeral 9 denotes a condenser lens, which collects illumination light on an entrance pupil (aperture stop) of the projection lens 11.

Reference numeral 10 denotes an image display element comprising a liquid crystal panel. The projection lens 11 has a positive refractive power, and enlarges and projects a projection image formed by the image display element 101 on a screen surface.

Next, the configuration of the polarization conversion element array 82 will be described with reference to FIG. Polarization conversion element array 82
As shown in FIG. 18, one plate-shaped member 82d composed of a surface having a mountain shape and a flat surface and four rod-shaped prisms 8 are formed.
2b and two half-phase plates 82c, a polarization splitting surface 82a is provided on one surface of each rod-shaped prism 82b, and the polarization splitting surface 82a separates the S-polarized light or the P-polarized light into two light paths. Each member is joined and provided in the form of providing a one-half wavelength plate 82c.

In FIG. 18, a half-wave plate 82c is sandwiched between a rod-shaped prism and a mountain-shaped plate-like member to form a half-wave plate.
The wavelength plate 82c is configured to receive S-polarized light. With such a configuration, the polarization separation surfaces 82a are not formed at equal intervals, but each lens of the first convex lens array 81 is formed as shown in FIG.
As shown in FIG. 9, the optical axis O of the lens 81a is
By being configured to be decentered with respect to the center of “a”, it becomes possible to make the condensing point of each lens 81a of the first convex lens array 81 correspond to the corresponding polarization separation surface 82a as shown in FIG.

In FIG. 20, the light emitted from the light source 1 is reflected by the parabolic mirror 2 in a certain direction and converted into parallel light, and is incident on the first convex lens array 81. These light beams form a plurality of converging points in a range smaller than the outer diameter of the reflector 2 near the second convex lens array 6.
The concave lens 5 converts a plurality of light beams from the first convex lens array 5 into light beams parallel to each other, and guides the light beams to the second convex lens array 6. The light beam transmitted through the second convex lens array 6 is incident on the polarization conversion element array 82.

The light beam incident on each polarization conversion element of the polarization conversion element array 82 is separated by the polarization separation surface 82a into S-polarized light and P-polarized light whose polarization directions are orthogonal to each other (← →,
..), Of which the S-polarized light (← →) reflected by the polarization splitting surface 82a is reflected by the reflection surface 82e, and
2c, the light is converted into linearly polarized light (•) polarized in the same direction as the P-polarized light transmitted through the polarization splitting surface 82a, and a plurality of linearly polarized lights having the same polarization direction from the polarization conversion element 82. Emit it as light. The plural light beams from the polarization conversion element 82 are combined on the image display element 10 by the condenser lens 8 and the condenser lens 9.

The light beam transmitted through the image display device 10 is guided to the projection lens 11. An image formed on the image display element 10 is formed on a screen or a wall by the projection lens 11.

FIG. 21 is a schematic view of a main part of a fifth embodiment of the present invention. This embodiment is different from the fourth embodiment in FIG.
Other configurations are the same except that the shape of the concave lens array 91 and the polarization conversion element array 92 are different, and that the arrangement of the polarizing plate 93 between the condenser lens 9 and the image display element 10 is different. . Here, the polarization conversion element array 92 is a half of the array 82 of the fourth embodiment in the array direction.

The polarization conversion element array 9 in the present embodiment
Reference numeral 2 does not correspond to all the individual lenses constituting the second convex lens array 91, but performs polarization conversion only for the light beam passing through the central lens row of the second lens array 91. This is because the intensity of the parallel light flux from the parabolic mirror 2 is concentrated at the central portion, and therefore, a polarization conversion is performed so that only the central portion of the parallel light beam is a predetermined linearly polarized light. The portion is converted to linearly polarized light.

At this time, in the second convex lens array 91, the size a21 of the central lens receiving the light of the central portion for performing the polarization conversion is set to be larger than the size a22 of the peripheral lens, so that the polarization conversion is more efficiently performed. To be able to.

In such a configuration, a light beam which is not subjected to polarization conversion illuminates the liquid crystal panel 10 in a non-polarized state as it is, so that a polarizing plate 93 is provided near the panel. With such a configuration, the number of components used for the polarization conversion element 92 can be reduced to, for example, half, and downsizing is facilitated.

The lighting devices of Embodiments 2 to 4 described above can also be applied to the liquid crystal projector of FIG.

[0057]

According to the present invention, as described above, by setting each element, an illumination device that can make the polarization conversion unit smaller than the conventional one, and a liquid crystal projector and the like that can make the polarization conversion unit smaller than the conventional one. A projection device can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is an explanatory view of a part of FIG.

FIG. 3 is an explanatory diagram of an optical path according to the first embodiment of the present invention.

FIG. 4 is an enlarged explanatory view of a part of FIG. 3;

FIG. 5 is an enlarged explanatory view of a part of FIG. 4;

FIG. 6 is an explanatory view of another embodiment of a part of FIG. 1;

FIG. 7 is an explanatory view of another embodiment of a part of FIG. 1;

FIG. 8 is an explanatory view of another embodiment of a part of FIG. 1;

FIG. 9 is an explanatory view of another embodiment of a part of FIG. 11;

FIG. 10 is an explanatory view of another embodiment of a part of FIG. 1;

FIG. 11 is a schematic view of a main part of a second embodiment of the present invention.

FIG. 12 is a schematic view of a main part of a third embodiment of the present invention.

FIG. 13 is an explanatory diagram of an optical path according to a third embodiment of the present invention.

14 is an explanatory view of a part of FIG.

FIG. 15 is an explanatory view of another embodiment of a part of FIG. 13;

FIG. 16 is an explanatory view of another embodiment of a part of FIG. 13;

FIG. 17 is a schematic view of a main part of a fourth embodiment of the present invention.

FIG. 18 is an explanatory view of a part of FIG. 17;

FIG. 19 is an explanatory view of a part of FIG. 17;

FIG. 20 is an explanatory diagram of an optical path according to a fourth embodiment of the present invention.

FIG. 21 is a schematic view of a main part of a fifth embodiment of the present invention.

FIG. 22 is a schematic diagram of a three-panel color liquid crystal projector to which the lighting device 230 of the present invention is applied.

FIG. 23 is a schematic view of a main part of a conventional lighting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source lamp 2 Reflector (reflection mirror) 3 Lens 4, 21, 81 First convex lens array 5 Concave lens 6 Second convex lens array 7, 22, 31, 41, 71, 82 Polarization conversion element 8 Condensing lens 9 Condenser lens 10 Image Display element 11 Projection lens 11a Entrance pupil 7a Polarization separation surface 7b Reflection mirror 7c λ / 2 plate

Claims (10)

[Claims] A focusing optical system for converting light from a light source into convergent light; a first convex lens array receiving the convergent light; a collimating optical system for parallelizing a plurality of light beams from the first convex lens array with each other; A polarization conversion element array for individually converting the plurality of light beams from the collimating optical system into polarized light. 2. A condensing optical system that converts light from a light source into convergent light, a collimating optical system that converts the convergent light into parallel light, a first convex lens array receiving the parallel light, and a first convex lens array. A polarization conversion element array for individually converting a plurality of light beams into polarized light. 3. A second convex lens array, wherein each convex lens corresponds to each of the plurality of light fluxes, between the collimating optical system and the polarization conversion element array. 3. The lighting device according to claim 1, wherein 4. The illuminating device according to claim 3, wherein said focusing optical system includes an elliptical mirror, and said light source is located at a focal position of said elliptical mirror. 5. The condensing optical system includes a parabolic mirror, the light source is located at a focal position of the parabolic mirror, and the condensing optical system receives a parallel light beam from the parabolic mirror. The lighting device according to claim 3, further comprising: 6. The illumination device according to claim 3, wherein the collimating optical system includes a concave lens. 7. The illumination device according to claim 3, further comprising an optical system that superimposes the plurality of polarized lights from the polarization conversion element array on a surface to be illuminated. 8. A projection device, characterized in that a liquid crystal panel illuminated by the illumination device according to claim 1 and image light from the illuminated liquid crystal panel is projected by a projection optical system. 9. The projection apparatus according to claim 8, wherein each element of the polarization conversion element array includes a polarization splitter, an optical path bending mirror, and a half-wave plate. 10. The projection apparatus according to claim 7, further comprising an optical system that superimposes the plurality of polarized lights from the polarization conversion element array on the liquid crystal panel.