JP2002090505A - Lens array unit, illuminating optical system and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an optical system and to enhance its reliability and productivity. SOLUTION: A first lens array 320 with plural first microlenses arranged in a matrix shape and a second lens array 340 with plural second microlenses arranged in a matrix shape in correspondence to the respective first microlenses are formed in one united body by way of a triangular prism 310 whose section comprises one major side and two minor sides and a reflective surface which totally reflects light is formed on a face formed by the major side of the prism 310.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector for obtaining an image by irradiating light from an illumination optical system to an electro-optical device such as a liquid crystal panel.

[0002]

2. Description of the Related Art FIG. 11 is a perspective view showing an example of the appearance of a general projector. Here, the projector 50
1 has a rectangular parallelepiped shape including an upper case 503 defining an upper surface thereof, on which operation buttons 502 are arranged, a lower case 504 defining a lower surface thereof, and a front case 505 defining a front surface thereof.
The tip of the projection lens 506 protrudes.

A known optical system in such a projector has, for example, a configuration as shown in FIG.
That is, the light source 510, the illuminance distribution of light from the light source 510 is made uniform, and the liquid crystal panel
An illumination optical system 520 for causing the light to enter the 50R, 550G, and 550B, and a color light separation optical system 530 that separates the light beam W emitted from the illumination optical system 520 into red, green, and blue color light beams R, G, and B. And a relay optical system 540 for guiding the blue light beam B among the respective color light beams separated by the color light separation optical system 530 to the corresponding liquid crystal panel 550B, and a light modulator 3 for modulating each color light beam according to the given image information. Liquid crystal panels 550R, 550G, 550B
A cross dichroic prism 560 as a color light combining optical system for combining the modulated color light beams; and a projection lens 506 for enlarging and projecting the combined light beam on a projection surface.

An illumination optical system 520 divides light emitted from a light source 510 into a plurality of partial light beams by a first lens array 521, and divides the light into a polarization conversion element array 523 via a second lens array 522. After being incident, the polarization directions of the respective partial light beams are aligned by the polarization conversion element array 523, the liquid crystal panels 550R,
The image is superimposed on the image forming areas 550G and 550B.

The illumination optical system 520 operates in this manner to uniformly illuminate each of the liquid crystal panels 550R, 550G, and 550B with one type of polarized light, to brighten every corner when displaying an image by a projector or the like, and to make the entire area high. This contributes to providing a sharp contrast image.

[0006]

By the way, with the recent miniaturization of projectors, it is required that the illumination optical system be configured as compact as possible. Also,
For an electro-optical device such as a liquid crystal panel on which a light beam from an illumination optical system enters, it is required to reduce the illumination margin as much as possible to improve the light utilization rate and to make the illuminance distribution uniform. Further, there is a demand for a configuration that allows easy adjustment of the optical axis of the optical components constituting the illumination optical system and that can be positioned with high accuracy. The present invention has been made to solve these problems, and employs the following configuration.

[0007]

SUMMARY OF THE INVENTION A lens array unit according to the present invention corresponds to a first lens array having a plurality of first small lenses arranged in a matrix and each of the first small lenses. And a second lens array having a plurality of second small lenses arranged in a matrix, and a triangular prism-shaped transparent section having a cross section of one long side and two short sides between these lens arrays. The light-transmitting member is integrally formed with a light-reflecting surface, and a reflection surface that totally reflects light is formed on a surface formed by long sides of the light-transmitting member. According to this, since the two lens arrays and the light reflecting element are unitized, the productivity (assembly) and the optical axis alignment accuracy of the optical system using the lens array unit are improved. Further, by improving the optical axis alignment accuracy, it is also possible to reduce the illumination margin and improve the uniformity of the light utilization factor and the illuminance distribution. Further, the unitization can contribute to downsizing of the device.

In the above case, the first lens array,
The productivity is further improved by integrally molding the second lens array and the translucent member.

Further, in order to integrally form the first lens array and the second lens array, the optical axes of the corresponding lenses of these lens arrays are aligned to form one long side and two short sides. Each lens array can be fixed and fixed to the surface formed by each short side of the triangular prism constituted by the sides with an adhesive or the like.

In the above case, the first lens array may be formed with a parallel lens such as a concave lens on the back side of the surface on which the lens array is formed. One of the second lens arrays may be fixed to the triangular prism via an ultraviolet cut filter. Thus, it is possible to further reduce the size of the optical system using the lens array unit.

The illumination optical system according to the present invention is directed to an illumination optical system that divides light emitted from a light source into a plurality of partial light beams and aligns the polarization directions of the partial light beams. A polarization conversion element array arranged on the light emission side of the lens array unit. Thus, a compact illumination optical system can be realized.

In the above case, a collimating lens and an ultraviolet cut filter are arranged between the light source and the light incident side of the lens array unit so that only light in a required wavelength range is incident on the lens array unit. You may make it do.

Further, in the above case, the optical components constituting the illumination optical system are positioned using a positioning portion formed on a light guide for supporting these optical components. This makes it easy to mount the optical component. Further, when the lens array unit is fixed to the light guide, the lens array unit is stabilized, and occurrence of optical axis shift can be prevented. In this case, the lens array unit may be directly fixed to the light guide, fixed via an elastic member, or a combination thereof. Further, a light-shielding member for adjusting the amount of light incident on the polarization conversion element array is provided, and the light-shielding member is arranged on the positioning portion of the light guide so that the supporting position thereof can be adjusted. Can be adjusted appropriately. In these cases, by manufacturing the light guide from a metal or a heat-resistant resin, it is possible to stably hold the optical components constituting the illumination optical system at predetermined positions.

Further, by using the lens array unit or the illumination optical system having the above configuration for the projector, it is possible to obtain a small and highly reliable projector.

[0015]

Next, embodiments of the present invention will be described based on examples.

FIG. 1 is a schematic plan view showing an optical system of a projector (projection display device) showing one embodiment of the present invention. This optical system includes a light source unit 20, an optical unit 3
0, and three main parts of the projection lens 40.
Note that such an optical system is housed in an outer case as described above and shown in FIG.

The optical unit 30 includes an integrator optical system 300 to be described later and dichroic mirrors 382, 3
86, color light separation optical system 380 having reflection mirror 384
And a relay optical system 390 having an incident-side lens 392, a relay lens 396, and reflection mirrors 394 and 398. Further, three field lenses 400, 402,
404, three liquid crystal panels 410R, 410G, 41
0B, and a cross dichroic prism 420 as a color light combining optical system. Also, the light source unit 20
Are disposed on the incident surface side of the integrator optical system 300, and the projection lens 40 is disposed on the exit surface side of the cross dichroic prism 420.

FIG. 2 shows an illumination area 3 of the projector.
It is an enlarged view of the illumination optical system which illuminates one liquid crystal panel.
In FIG. 2, for the sake of simplicity, only the main components for explaining the function of the illumination optical system are shown. The illumination optical system includes a light source unit 20 and an integrator optical system 300 provided in the optical unit 30. The integrator optical system 300 includes an ultraviolet cut filter (UV cut filter) 3 for cutting ultraviolet rays.
01, a concave lens 302, a triangular prism-shaped light-transmitting member (here, a triangular prism 3) whose cross section (shape) is formed by one long side and two short sides and a surface formed by the long side is a light total reflection surface.
10) and first and second lens arrays 320 and 340 fixed to a surface formed by the short sides of the triangular prism 310, a light shielding plate 350, and a polarization conversion element array 3.
60 and a superimposing lens 370.

The light source unit 20 includes a light source lamp 210 and a concave mirror 212. Radial light (radiation light) emitted from the light source lamp 210 is converted by the concave mirror 212 into condensed light condensed at a predetermined focal position. The concave lens 302 has a curved shape and converts the condensed light from the light source unit 20 into light substantially parallel to the optical axis. Here, as the light source lamp 210, a halogen lamp, a metal halide lamp, a high-pressure mercury lamp, or the like can be used.
It is preferable to use an ellipsoidal mirror, but if the light emitted from the light source lamp 210 is made substantially parallel as a parabolic mirror, the concave lens 302 can be omitted and the configuration of the illumination optical system can be simplified. .

The unpolarized light emitted from the light source lamp 210 is supplied to the ultraviolet cut filter 301 and the concave lens 302.
, And is incident on the first lens array 320, where it is split by the plurality of small lenses 321 into a plurality of partial light beams 202. Subsequently, the partial light beam 202 is reflected by the total light reflection surface 311 of the triangular prism 310, and enters the direction of the second lens array 340. The second lens array 340 includes two polarization conversion element arrays 361 and 36.
The partial light beam 202 acts to converge the partial light beam 202 in the vicinity of the polarization splitting film of the polarization conversion element array 360 formed by combining the two. The plurality of partial luminous fluxes incident on the polarization conversion element arrays 361 and 362 are converted into one type of linearly polarized light and emitted therefrom. And these polarization conversion element arrays 3
A plurality of partial light beams emitted from the liquid crystal panels 410R, 410G, 4
Superimposed on 10B.

FIG. 3 is a front view (A) and a side view (B) showing the appearance of the first lens array 320. In the first lens array 320, small lenses 321 having a rectangular contour are arranged in N × 2 rows (here, N = 4) in the x direction;
The small lenses 321 are arranged in a matrix of M rows (here, M = 10) in the y direction.
The shape is set to be substantially similar to the shape of 10B. For example, if the aspect ratio (the ratio between the horizontal and vertical dimensions) of the image forming area of the liquid crystal panel is 4: 3, the aspect ratio of each small lens 321 is also set to 4: 3.

The second lens array 340 includes the first lens array 340.
The first lens array 320 has a function of guiding a plurality of partial light beams emitted from the lens array 320 of the first lens array 320 to be condensed near the polarization separation film of the polarization conversion element array 360.
Are composed of the same number of small lenses 341 as the number of lenses that constitute.

These lens arrays 320 and 340 are
As described above, the triangular prism 310 having a cross section having one long side and two short sides is fixed to each surface formed by the short side of the triangular prism 310 with an adhesive such as an ultraviolet curing type or a thermosetting type. The prism 310 and the lens arrays 320 and 340 are integrated (integrally formed).

The polarization conversion element array 360 has two polarization conversion element arrays 361 and 362 arranged symmetrically with respect to the optical axis. FIG. 4 shows the appearance of the polarization conversion element array 361. FIG. The polarization conversion element array 361 includes a polarization beam splitter array 363.
And a λ / 2 retardation plate 364 (shown by oblique lines in the figure) selectively disposed on a part of the light exit surface of the polarizing beam splitter array 363. The polarizing beam splitter array 363 has a shape in which a plurality of columnar translucent members 365 each having a parallelogram cross section are sequentially bonded. A polarization separating film 366 is provided on the interface of the light transmitting member 365.
And the reflection film 367 are formed alternately. The λ / 2 retardation plate 364 is a polarization separation film 366 or a reflection film 367.
Is selectively affixed to the mapping part in the x direction of the light emission surface of the light. In this example, a λ / 2 retardation plate 364 is attached to the x-direction mapped portion of the light exit surface of the polarization separation film 366.

The polarization conversion element array 361 has a function of converting an incident light beam into one type of linearly polarized light (for example, s-polarized light or p-polarized light) and emitting the same. FIG. 5 is an explanatory diagram showing the operation of the polarization conversion element array 361. When non-polarized light (incident light having a random polarization direction) including an s-polarized component and a p-polarized component is incident on the incident surface of the polarization conversion element array 361, the incident light is
66 separates the light into s-polarized light and p-polarized light. The s-polarized light is reflected almost vertically by the polarization splitting film 366,
The light is emitted after being further reflected by the reflection film 367. On the other hand, the p-polarized light passes through the polarization separation film 366 as it is. A λ / 2 retardation plate 364 is disposed on the exit surface of the p-polarized light transmitted through the polarization separation film 366.
The polarized light is converted into s-polarized light and emitted. Therefore, most of the light that has passed through the polarization conversion element array 361 is emitted as s-polarized light. When light emitted from the polarization conversion element array 361 is desired to be p-polarized light, the λ / 2 retardation plate 364 may be disposed on the emission surface from which the s-polarized light reflected by the reflection film 367 is emitted. Good.
Further, as long as the polarization directions can be aligned, a λ / 4 retardation plate may be used, or a desired retardation plate may be provided on both the exit surfaces of the p-polarized light and the s-polarized light.

In the polarization conversion element array 361, one adjacent polarization separation film 366 and one reflection film 36
7, and one block composed of one λ / 2 retardation plate 364 can be regarded as one polarization conversion element 368. In the polarization conversion element array 361, such polarization conversion elements 368 are arranged in a plurality of rows in the x direction. Note that the polarization conversion element array 362 has exactly the same configuration as the polarization conversion element array 361, and a description thereof will be omitted.

FIG. 6 is a front view of the light shielding plate 350. The light shielding plate 350 includes two polarization conversion element arrays 361 and 36.
Of the two light incident surfaces, the light is incident only on the light incident surface corresponding to the polarization separation film 366, and has a configuration in which an opening 351 is provided in a substantially rectangular metal plate. .

Incidentally, the optical components constituting the illumination optical system are positioned and supported by predetermined positioning portions of light guides disposed above and below the optical components, together with other optical components constituting the optical unit 30. . The light guide is made of a metal such as magnesium (Mg) or aluminum (Al) or a heat-resistant resin such as unsaturated polyester (BMC) or polyphenylene sulfide (PPS), and stably holds each optical component constituting the optical unit 30. In order to easily mount these optical components, positioning grooves and projections are provided at predetermined positions.

FIG. 7 is a partial sectional view showing an example of positioning an optical component by the light guide 430. The light guide 430 includes an upper light guide and a lower light guide, and a concave portion or a convex portion for positioning an optical component is formed at a predetermined position. An ultraviolet cut filter 301, a concave lens 302, a lens array unit 330 including a triangular prism 310 and first and second lens arrays 320 and 340, a light shielding plate 350, a polarization conversion element array 360, and the like are provided in these concave and convex portions. By positioning them by storing or abutting them, their mounting work is facilitated. If the bottom surface of the lens array unit 330 is directly fixed to one of the upper and lower light guides 430 with an adhesive or the like, the lens array unit 330 is securely fixed. Can be prevented. Further, the light-shielding plate 350 is used to
Although it is positioned in contact with the space 30, it is configured to be movable in parallel to the polarization conversion element array 360 so that the position can be adjusted.

FIG. 8 is a partial cross-sectional view showing a modification of FIG. 7, in which a heat-resistant elastic member 440 such as silicon is fixed on the upper surface of the lens array unit 330 with an adhesive or the like. In this configuration, the lens array unit 330 is sandwiched between the upper and lower light guides 430. Note that, even in this case, the lens array unit 3
If the bottom surface of the light guide 430 and the lower light guide 430 are directly fixed by bonding or the like, the fixing of the lens array unit 330 is further ensured.

In FIG. 1, the color light separating optical system 380 is
The illumination device includes first and second dichroic mirrors 382 and 386, and emits light emitted from the illumination optical system into red, green, and blue light.
It has the function of separating light into colored light. The first dichroic mirror 382 transmits the red light component of the light emitted from the superimposing lens 370 and reflects the blue light component and the green light component. The red light transmitted through the first dichroic mirror 382 is reflected by the reflection mirror 384, passes through the field lens 400, and reaches the liquid crystal panel 410R for red light. This field lens 400
Converts each partial light beam emitted from the superimposing lens 370 into a light beam parallel to its central axis (principal ray). Field lenses 402 and 404 provided in front of the other liquid crystal panels 410G and 410B operate in a similar manner.

Further, the first dichroic mirror 382
Of the blue light and the green light reflected by the, the green light is reflected by the second dichroic mirror 386 and passes through the field lens 402 to reach the liquid crystal panel 410G for green light. On the other hand, the blue light is reflected by the second dichroic mirror 3
86, the relay optical system 390, that is, the incident side lens 392, the reflection mirror 394, and the relay lens 39
6, through the reflection mirror 398, and further through the field lens 404 to the liquid crystal panel 410B for blue light. The reason why the relay optical system 390 is used for blue light is that the optical path length of blue light is longer than the optical path lengths of other color lights, so that a reduction in light use efficiency due to light diffusion or the like is prevented. To do that. That is, the incident side lens 39
The partial light beam incident on 2
04.

The three liquid crystal panels 410R, 410G, 4
10B has a function as an electro-optical device that modulates incident light in accordance with given image information (image signal). Thereby, the three liquid crystal panels 410R, 41
Each color light incident on 0G and 410B is modulated in accordance with given image information to form an image of each color light. In addition,
A polarizing plate (not shown) is provided on the light incident surface side and the light emitting surface side of the three liquid crystal panels 410R, 410G, and 410B. The liquid crystal panel and the polarizing plate are referred to as a liquid crystal light valve.

The three liquid crystal panels 410R, 410G, 4
The modulated lights of three colors emitted from 10B enter the cross dichroic prism 420. The cross dichroic prism 420 has a function as a color light combining optical system that forms a color image by combining three color modulated lights. In the cross dichroic prism 420, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an approximately X-shape at the interface between the four right-angle prisms. The modulated light of three colors is synthesized by these dielectric multilayer films to form synthesized light for projecting a color image. This cross dichroic prism 420
Are emitted in the direction of the projection lens 40. The projection lens 40 has a function of projecting the combined light on a projection screen, and displays a color image on the projection screen.

In the projector according to the present embodiment, which employs an optical system for returning light from a light source, the first optical system constituting the illumination optical system is provided.
By integrating the lens array 320 and the second lens array 340, the size and size of the device can be reduced. In addition, by integrating the first lens array 320 and the second lens array 340 in advance,
At the time of assembling the apparatus, the optical axis of the illumination optical system can be easily and accurately adjusted, and thus the reliability and productivity of the assembled product are improved.

Incidentally, the ultraviolet cut filter 301 and the concave lens 3 constituting the illumination optical system described in the above-described embodiment.
02, triangular prism 310, first lens array 320
Alternatively, all of the second lens array 340 may be integrated (formed integrally). FIG. 9 shows an example of such a case, in which a compound lens array 32 is configured as a condensing lens having a concave lens on the entrance side and a lens array for obtaining a partial light beam on the exit side.
2 is fixed to the light incident surface of the triangular prism 310 via the ultraviolet cut filter 301, and the second lens array 340 is fixed to the light emitting surface of the triangular prism 310. Fixing of the triangular prism 310 to the ultraviolet cut filter 301 and the complex lens array 322, and the triangular prism 310 and the second lens array 3
Here, the fixing of 40 can also be performed by using an ultraviolet-curing or thermosetting adhesive. According to this, the integration ratio of the optical components constituting the illumination optical system is increased, and further downsizing of the projector can be achieved. Further, the ultraviolet cut filter 301 is moved to the second lens array 340 side,
The second lens array 340 and the triangular prism 310
You may make it fix via the ultraviolet cut filter 301. Instead of providing the ultraviolet cut filter 301, the concave lens 302, the triangular prism 310, the first
And one of the second lens arrays 320 and 340,
Alternatively, all may be formed of UV absorbing glass.

Further, a lens array unit comprising a triangular prism 310 and first and second lens arrays 320 and 340, which constitute the illumination optical system described in the above embodiment, is integrated as shown in a plan view of FIG. It may be a molded product. In this case, the integrally formed lens array unit 3
A surface formed by the long sides of 32 is configured as a light total reflection surface 333, like the total reflection surface 311 of the triangular prism 310. According to this, since the lens array unit 332 is supplied as a single component from the beginning, the adjustment of the optical axis of the first lens array 320 and the second lens array 340 and the mounting work are not required, so that the projector Productivity improvement and cost reduction are further promoted.

Further, in the above embodiment, an example in which the present invention is applied to a projector using a transmissive liquid crystal panel has been described. However, the present invention is also applied to a projector using a reflective liquid crystal panel. It is possible. Further, as described later, the electro-optical device is not limited to a liquid crystal panel. Here, “transmissive” means that an electro-optical device such as a liquid crystal panel transmits light, and “reflective” means that an electro-optical device such as a liquid crystal panel reflects light. It is a type. In a projector employing a reflection type electro-optical device, a dichroic prism is used as a color light separating means for separating light into three colors of red, green and blue, and synthesizes modulated three colors of light. And may also be used as a color light combining means that emits light in the same direction.

The electro-optical device for light modulation is not limited to a liquid crystal light valve using a liquid crystal panel, but may be, for example, a device using a micro mirror. Also, the prism that is a color light combining optical system is not limited to a dichroic prism in which two types of color selection surfaces are formed along the bonding surface of the four triangular prisms, but a dichroic prism with one type of color selection surface and a polarization type. It may be a beam splitter. Alternatively, the prism may be such that a light-selecting surface is arranged in a substantially hexahedral light-transmitting box and a liquid is filled therein.

Further, as the projector, there are a front projection type projector that projects from a direction in which a projected image is observed, and a rear projection type projector that projects from a side opposite to the direction in which a projected image is observed. The configurations shown in the embodiments can be applied to any of them.

[0041]

According to the present invention, the two lens arrays and the light reflecting element for treating the light source light as a plurality of partial light beams are integrally formed, so that the light of the optical system using this lens array unit is formed. Axis adjustment can be performed easily and with high precision, and the illumination optical system and projector using this can be downsized, the illumination margin for electro-optical devices such as liquid crystal panels can be reduced, the light utilization rate and the illuminance distribution can be uniform. Improvements in productivity and product productivity are achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an optical system of a projector according to an embodiment of the present invention.

FIG. 2 is an enlarged view of an illumination optical system constituting the optical system of FIG.

FIGS. 3A and 3B are a front view (A) and a side view (B) of a first lens array forming an illumination optical system. FIGS.

FIG. 4 is a perspective view showing the appearance of a polarization conversion element array.

FIG. 5 is an explanatory view showing the operation of the polarization conversion element array.

FIG. 6 is a front view of a light shielding plate.

FIG. 7 is a partial cross-sectional view showing an example of mounting optical components constituting the illumination optical system according to the present invention.

FIG. 8 is a partial cross-sectional view showing another example of mounting optical components constituting the illumination optical system according to the present invention.

FIG. 9 is a plan view showing one embodiment of a lens array unit constituting the illumination optical system according to the present invention.

FIG. 10 is a plan view showing another embodiment of the lens array unit constituting the illumination optical system according to the present invention.

FIG. 11 is a perspective view showing an example of the appearance of a general projector.

FIG. 12 is a configuration diagram showing an optical system of a known projector.

[Explanation of symbols]

 202 Partial light beam 210 Light source lamp 212 Concave mirror 300 Integrator optical system 301 UV cut filter 302 Concave lens 310 Triangular prism 311 Total light reflecting surface of triangular prism 320 First lens array 321 First small lens 322 Composite lens array 330, 332 Lens array Unit 333 Total light reflecting surface of lens array unit 332 340 Second lens array 341 Second small lens 350 Light shielding plate 360, 361, 362 Polarization conversion element array 364 Phase difference plate 366 Polarization separation film 367 Reflection film 368 Polarization conversion element 370 Superimposing lens 380 Color light separation optical system 382 First dichroic mirror 384 Reflection mirror 386 Second dichroic mirror 390 Relay optical system 394,398 Reflection mirror 400,402,4 4 field lens 410R, 410G, 410B liquid crystal panel 420 cross dichroic prism

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 21/00 G03B 21/00 E 5G435 G09F 9/00 360 G09F 9/00 360D H04N 5/74 H04N 5 / 74 A F-term (reference) 2H052 BA02 BA03 BA09 BA14 2H088 EA14 EA15 HA13 HA18 HA21 HA25 HA28 MA04 MA06 MA20 2H091 FA05X FA05Z FA07Z FA08X FA08Z FA14Z FA26X FA26Z FA29Z FA41Z FA50Z LA12 LA16 LA18 MA08 A08 BA08 EA26 5G435 AA17 AA18 BB12 DD05 FF05 GG02 GG03 GG04 GG08 GG09 GG16 GG23 GG46 LL15

Claims (16)

[Claims] 1. A first lens array having a plurality of first small lenses arranged in a matrix, and a plurality of second lens arrays arranged in a matrix corresponding to each of the first small lenses. A second lens array having a small lens is integrally formed between these lens arrays via a triangular prism-shaped light-transmitting member having a cross section composed of one long side and two short sides. A lens array unit, wherein a reflection surface that totally reflects light is formed on a surface formed by long sides of the optical member. 2. The lens array unit according to claim 1, wherein the first lens array, the second lens array, and the translucent member are integrally formed. 3. A cross section of the first lens array and the second lens array having one long side and two short sides with the optical axes of the corresponding lenses of the lens arrays being aligned. 2. The lens array unit according to claim 1, wherein the lens array unit is fixed to a surface formed by each short side of the triangular prism. 4. The lens array unit according to claim 3, wherein the first lens array and the second lens array are fixed to the triangular prism with an adhesive. 5. The lens array unit according to claim 3, wherein the first lens array is formed by forming a parallelizing lens behind a surface on which the lens array is formed. 6. The lens array unit according to claim 5, wherein the first lens array has a concave lens on the light incident side and a lens array on the light emitting side. 7. The lens array according to claim 3, wherein one of the first lens array and the second lens array is fixed to the triangular prism via an ultraviolet cut filter. unit. 8. An illumination optical system that divides light emitted from a light source into a plurality of partial light beams and aligns the polarization directions of the partial light beams, wherein the lens array unit according to any one of claims 1 to 7 is provided. And a polarization conversion element array arranged on the light emission side of the lens array unit. 9. The illumination optical system according to claim 8, wherein a collimating lens and an ultraviolet cut filter are arranged between the light source and the light incident side of the lens array unit. 10. The optical component constituting the illumination optical system is positioned using a positioning portion formed on a light guide supporting these optical components. Illumination optical system as described. 11. The illumination optical system according to claim 10, wherein the lens array unit is fixed to the light guide. 12. The light guide according to claim 11, wherein the lens array unit is directly fixed to the light guide.
Illumination optical system as described. 13. The illumination optical system according to claim 11, wherein said lens array unit is fixed to said light guide via an elastic member. 14. A light-shielding member for adjusting the amount of light incident on the polarization conversion element array, and the light-shielding member is arranged at a positioning portion of the light guide so that a supporting position thereof can be adjusted. 11. The illumination optical system according to 10. 15. The illumination optical system according to claim 10, wherein the light guide is made of a metal or a heat-resistant resin. 16. A projector comprising the lens array unit or the illumination optical system according to claim 1.