JP2002055389A - Optical unit, picture display device and picture display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate trouble that an optical unit gets larger in constitution where all the catoptric elements are housed and held inside a casing of the optical unit. SOLUTION: In this optical unit constituted by holding an optical system including at least the catoptric element 81 so as to form an optical path in the inside of the casing 14, the element 81 is integrally provided in the housing. In the optical unit constituted by holding the optical system including at least the element 81 so as to form the optical path in the inside of the casing 14, the surface of the element 81 on an opposite side of the reflection surface thereof is exposed to the outside of the casing 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical unit having an optical system including at least a reflective optical element.

[0002]

2. Description of the Related Art An optical unit used for an image display device such as a liquid crystal projector has a structure as shown in FIG. This configuration is described in Japanese Patent Laid-Open No. 2000-19 / 2000.
634 has been proposed.

[0003] The illumination light emitted from the illumination light source 103 is transmitted to a mirror group 10 including dichroic mirrors 104 and 140.
4, 105, 140 and 150 to 153, the light is decomposed into RGB color lights,
To 112. Then, the liquid crystal panels 110 to 11
Each color image light modulated by 2
02, and are projected from the projection lens 106 onto a screen or the like (not shown) to form a color image.

[0004] The optical path lengths of the RGB color lights from the light source 103 to the projection lens 106 are configured to be substantially equal to each other. In addition, all of the above mirror groups are fixedly disposed so as to be included in the optical housing 101.

[0005] In addition to this example, US Pat.
No. 599, No. 5676442 and Tokuhei 7-155
No. 37 discloses a configuration of a liquid crystal projector, but in any case, a mirror group (reflection optical element) is housed and held in an optical housing.

[0006]

However, as described above, in the configuration in which the housing of the optical unit is integrally formed in a box shape and all the reflection optical elements are housed and held inside the housing, the liquid crystal panel is not provided. In order to secure a volume for disposing the reflective optical element, which is often arranged so as to surround the optical system and the color combining prism, etc., the housing should have a volume slightly larger than the size of the optical system. It is necessary to leave a gap between the body and the reflective optical element). Therefore, there is a problem that the size of the optical unit increases, and the size of the image display device including the optical unit also increases.

[0007]

According to a first aspect of the present invention, an optical system including at least a reflection optical element is held so as to form an optical path inside a housing. In such an optical unit, the reflective optical element is provided integrally with a housing.

According to the second aspect of the present invention, in the optical unit configured to hold at least an optical system including a reflective optical element so as to form an optical path inside a housing, the reflective surface of the reflective optical element The opposite surface is exposed outside the housing.

That is, in the first invention, the reflection optical element is integrally provided on the housing itself, and in the second invention, the reflection optical element is used as a part of the housing, and the housing itself is used. Since it has a configuration equivalent to providing a reflective surface,
The size of the optical unit can be reduced as compared with the conventional case where the outside of the reflective optical element is covered with a housing with a gap.

The present invention is particularly effective in an optical unit in which a reflective optical element is arranged so as to surround an image display element, a color synthesizing prism, and the like, and the external dimensions of the housing are determined by the position of the reflective optical element. is there.

Further, in the first aspect of the present invention, a portion of the housing where the reflective optical element is provided (element installation portion).
May be shaped in accordance with the shape of the reflective optical element,
In the invention of the above, the surface opposite to the reflection surface of the reflection optical element is formed in a shape following the shape of the reflection surface, thereby minimizing the element installation portion or the reflection optical element, and making the optical unit smaller. Can be achieved.

Further, by forming the element installation portion of the casing and the main body portion of the reflection optical element using a polymer material or a metal material, the strength of these portions is increased and the accuracy of the reflection surface is improved. It becomes possible. In particular, by using polycarbonate or a composite material containing polycarbonate as the polymer material, both strength and heat resistance can be ensured.

[0013] Further, the element installation portion of the housing is formed separately from the other portions of the housing, or the reflection optical element is fixed to the housing, so that the element installation portion and the reflection optical element can be used. It is possible to secure the easiness of the work at the time of manufacturing such as depositing and attaching the reflecting surface, and it is possible to easily inspect the reflecting optical element and replace it as a part.

[0014]

FIG. 1 shows a configuration of an optical unit provided in a liquid crystal projector (image display device) according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a light source lamp such as a metal halide lamp or a mercury lamp, and 2 denotes a reflector having a paraboloid or an ellipsoid.

Reference numeral 3 denotes an integrator composed of a first lens array 31 and a second lens array 32. Reference numeral 4 denotes a plurality of polarization separation surfaces 41, a plurality of reflection surfaces 42 corresponding to the polarization separation surfaces 41, and a plurality of phases. This is a polarization conversion element including the plate 43.

Reference numeral 5 denotes a color separation system including a blue reflection dichroic mirror 51 and a red transmission dichroic mirror 52. Reference numeral 6 denotes a liquid crystal display panel (image display element: hereinafter, referred to as a liquid crystal panel) 10R which diffuses the light from the polarization conversion element 4. ,
It is a condenser lens for condensing light on 10G and 10B.
In this embodiment, the optical path length is compressed by using the condenser lens 6 together with the concave lenses 61 and 62. Also, 7
1 is a plane mirror, and 72 is a plane dichroic mirror (reflection optical element).

The plane dichroic mirror 72 is formed by depositing a blue reflecting dichroic film on a transparent glass base material. Note that a polarization separation film may be formed instead of the dichroic film.

Reference numeral 8 denotes a relay system, which comprises a molded relay mirror (reflection optical element) 81 having two concave mirrors (reflection surfaces) inside, and a mirror 82 arranged opposite to the molded relay mirror 81 as a reflection optical system. It is configured.

The molded relay mirror 81 is formed by mirror-finishing two concave portions of a base material (main body) formed of an opaque polycarbonate resin, and depositing a dichroic film on these concave portions. These dichroic films reflect light in the red wavelength range and transmit light on the longer wavelength side than the red wavelength range. Then, the non-red component light transmitted through the dichroic film becomes heat in the base material component.

Incidentally, the molded relay mirror 81 may be formed by depositing a polarization separation film on the concave portion.

Reference numerals 9G and 9B denote condenser lenses for condensing illumination light (light in the green wavelength range and light in the blue wavelength position) on the liquid crystal panels 10G and 10B. The liquid crystal panel 10R is a liquid crystal panel for red, the liquid crystal panel 10G is a liquid crystal panel for green, and the liquid crystal panel 10B is a liquid crystal panel for blue.

Reference numeral 11 denotes a color synthesizing prism, in which two dichroic films for reflecting light in different wavelength ranges and transmitting the other light are formed. The color synthesizing prism 11 basically uses a prism configuration similar to a so-called 3P prism for a 3CCD camera for projection. However, in the present embodiment, the color combining prism 11 is configured by combining four prisms in consideration of workability.

Reference numeral 12 denotes a projection lens which has a positive refracting power and enlarges the color composite image emitted from the color composite prism 11 and projects it on a screen (not shown).

Reference numeral 13 denotes a base mount member for fixing and holding the color combining prism 11 and the projection lens 12.

The above components are fixedly held by the housing 14. The housing 14 is a molded product using a material obtained by adding glass to unsaturated polyester. This housing 14
Are formed with openings 141 and 142, respectively, and a plane dichroic mirror 72 and a molded relay mirror 81 are formed around the openings 141 and 142, respectively.
Are fixedly held so as to close the openings 141 and 142. Further, the plane mirror 71 is fixed inside the housing 14.

The plane dichroic mirror 72 is
After the elastic spacer is fixed to the insertion portion on the outer periphery of the optical path for play, it is fixed to the housing 14 by being inserted into a groove formed on the inner surface of the opening 141 of the housing 14.

The molded relay mirror 81 is positionably connected and fixed to a portion around the opening 142 in the housing 14. The method for positioning the molded relay mirror 81 is to form a fitting groove (nested portion) 83 on the outer periphery of the opening 142 in the housing 14 and fit the molded relay mirror 81 having a corresponding shape. It is fixed to the housing 14. At this time, the dowel formed on the molded relay mirror 81 is fitted into the positioning hole 84 formed on the housing 14, whereby the molded relay mirror 81 is positioned with respect to the housing 14.

However, the positioning may be performed by fitting a dowel formed in the housing 14 into a positioning hole formed in the molded relay mirror 81, or the molded relay mirror 81 and the housing 14 may be improperly positioned. The two may be aligned by holding them with the illustrated tool. Then, after the positioning of the molded relay mirror 81 and the housing 14, screwing, U
Adhesion of V-curing type, epoxy and cyano bond, etc.
The mold relay mirror 81 is positioned and fixed to the housing 14 using a single or a plurality of fixing methods such as heat welding, a plate spring such as a clip spring 84 or a spring wire using a piano wire.

In the optical unit configured as described above, the white illumination light emitted from the light source lamp 1 (and the reflector 2) is reflected by the plane mirror 71 and enters the color separation system through the polarization conversion element 4.

The blue light component of the illumination light incident on the blue reflection dichroic mirror 51 is reflected by the blue reflection dichroic mirror 51, and the other color light components pass through the blue reflection dichroic mirror 51. The blue light component reflected by the blue reflection dichroic mirror 51 is
And is condensed by the condenser lens 9B to illuminate the blue liquid crystal panel 10B.

The color light component transmitted through the blue reflecting dichroic mirror 51 is converted into a red transmitting dichroic mirror 52.
Incident on. Of the color light components incident on the red transmission dichroic mirror 52, the green light component is reflected by the red transmission dichroic mirror 52, collected by the condenser lens 9G, and illuminates the green liquid crystal panel 10G.

Further, a red transmission dichroic mirror 52
Is reflected by the first concave mirror of the molded mirror relay 81, reflected by the concave mirror of the opposing mirror 82, and further reflected by the third concave mirror of the molded mirror relay 81 to cause the red liquid crystal panel 10R to be reflected. Light up.

Then, each of the liquid crystal panels 10B, 10G, 1
The liquid crystal panels 10B, 10G, 1
The image light components of each color transmitted through the OR are combined with the color combining prism 11.
And is emitted as color-combined image light through the projection lens 12.

Here, the molded relay mirror 81 is fixed to the housing 14 such that the outer surface thereof (the surface opposite to the dichroic film) is exposed to the outer surface of the housing, whereby the molded relay mirror 81 itself is mounted on the housing. Part of. In other words, this is the same as forming a dichroic film as a reflective optical element integrally with the housing.

The flat mirror 72 is also fixed to the housing 14 such that its outer surface (surface opposite to the mirror surface) is exposed to the outer surface of the housing.

That is, since the outside of the molded relay mirror 81 and the flat mirror 72 is not covered with the casing 14, the size of the optical unit can be reduced as compared with the conventional case in which these mirrors are covered with a gap in the casing. Can be.

Further, since the base material of the molded relay mirror 81 is formed along the shape (concave surface) of the two dichroic films to minimize the molded relay mirror 81, the size of the optical unit can be further reduced. Can be planned.

By fixing the flat mirror 72 and the molded relay mirror 81 so as to cover the openings 141 and 142 of the casing 14, the space surrounded by the planar mirror 72, the molded relay mirror 81 and the casing 14 is reduced.
Liquid crystal panels 10R, 1 that block the intrusion of light from outside
An optical path of an illumination system of 0G and 10B can be formed.

Further, by fixing the molded relay mirror 81 using the opaque base material at the position exposed on the outer surface of the housing as described above, the light transmitted through the dichroic film (or the polarization splitting film) is transmitted through the base material portion. Can be absorbed directly. Therefore, the heat generated due to the unnecessary light processing can be efficiently transmitted to the outside of the housing.

Here, in the configuration in which the mirror member using the opaque base material is sealed inside the housing, the temperature of the mirror member rises due to the heat generated by the mirror member, and the adhesion strength between the base material and the mirror film deteriorates. However, according to the present embodiment, the effect of cooling the molded relay mirror 81 by the air flowing around the housing can be easily obtained, and the reliability can be improved.

Therefore, not only resin but also metal can be used as a base material of the molded relay mirror 81 without any problem.

When polycarbonate is used as the base material of the molded relay mirror 81, the color of the material is colorless, so that carbon is added when the material is made opaque so that light in the visible region can be efficiently absorbed. And the base material strength is also improved. By using such a molded relay mirror 81, it is possible to more effectively reduce the outer dimensions and radiate heat.

On the other hand, the flat mirror 72 is fixed at a position exposed on the outer surface of the housing so that light in a long wavelength region other than blue light passes through the transparent glass base material of the flat mirror 72 and the opening 141. The light is emitted outside the housing 14. For this reason, as the optical unit, heat generation due to unnecessary light in the plane mirror 72 can be suppressed.

FIG. 2 shows the overall configuration of a liquid crystal projector having the above-mentioned optical unit.

In this figure, reference numeral 15 denotes a projector housing for housing the optical unit 17, and reference numeral 16 denotes a projection screen. The projector housing 15 is formed in a box shape, and is made using a magnesium alloy. The projector housing 15 includes an intake fan 19.
a and an exhaust fan 19b are attached so that the inside of the projector housing 15 can be efficiently cooled.

The projector includes a power supply system (not shown), a lamp ballast, an image / sound input / output circuit, an image processing circuit, a liquid crystal driving circuit, a sound processing circuit, a speaker, an operation switch, and the like. , TV, video,
It is used as a display device for enlarging and projecting image information from an image supply device such as a computer onto the projection screen 16.

In the projector, unnecessary light transmitted through the flat dichroic mirror 72 of the optical unit 17 and emitted to the outside of the optical unit 17 is supplied to the intake fan 19.
a to a metal plate (for example, an aluminum case of a power supply unit or a part made of a light alloy such as aluminum or a magnesium alloy) provided in a passage of air from the a to the exhaust fan 19b.

A black paint is applied to the metal plate 18 as an anti-reflection treatment. Unwanted light hitting the metal plate 18 is converted into heat and radiated to the outside world.

Conventionally, unnecessary light transmitted through a mirror corresponding to the plane dichroic mirror 72 is applied to the inner wall of the housing of the optical unit to absorb and radiate heat. Therefore, the cooling efficiency is not very good. According to this, it is possible to efficiently absorb and radiate unnecessary light.

Also, taking advantage of the absorption (low spectral transmittance) characteristic in the non-visible ultraviolet region of the glass base material, the glass base material of the plane dichroic mirror 72 has a high absorption rate for spectral components which have a bad influence on the liquid crystal properties. It is also possible to select a glass material. In this case, by applying a mirror coat on the back side of the glass base material (the side opposite to the dichroic film surface), unnecessary light transmitted through the dichroic film reflects inside the glass base material and proceeds to the outside of the mirror base material. Heat radiation and light emission processing can be performed simultaneously.

In this case, since the transmitted light reflects in the glass base material, the thickness of the glass plate proportional to the amount of light absorption is thinner at the same light transmission distance than when the filter is simply inserted orthogonally to the optical path. Only needs to be done. As a result, required glass materials are reduced, and cost reduction and weight reduction can be achieved.

In the above embodiment, the optical unit used for the image display device has been described. However, the optical unit of the present invention can be used for devices other than the image display device. Further, an image display element other than the liquid crystal panel can be used.

[0054]

As described above, in the first invention of the present application, the reflection optical element is provided integrally with the housing itself, and in the second invention of the present application, the reflection optical element is mounted on the housing. The optical unit has a smaller size compared to the conventional case where the outside of the reflective optical element is covered with a housing with a gap between the housing and the housing. Can be Therefore, the size of the image display device including the optical unit can be reduced.

Particularly, it is possible to obtain a large size-reducing effect in an optical unit in which a reflective optical element is arranged so as to surround an image display element, a color synthesizing prism, and the like, and the external dimensions of the housing are determined by the position of the reflective optical element. Can be.

Further, in the first aspect of the present invention, a portion of the housing where the reflective optical element is provided (element installation portion).
May be shaped in accordance with the shape of the reflective optical element,
In the invention of the present invention, if the surface opposite to the reflection surface of the reflection optical element is formed in a shape along the shape of the reflection surface, the element installation portion or the reflection optical element is minimized,
The size of the optical unit can be further reduced.

Further, by forming the element installation portion of the housing and the main body portion of the reflection optical element using a polymer material or a metal material, the strength of these portions is increased and the accuracy of the reflection surface is improved. be able to. In particular, if polycarbonate or a composite material containing polycarbonate is used as the polymer material, both strength and heat resistance can be ensured.

Further, the element installation portion of the housing is formed separately from other portions of the housing, or the reflection optical element is fixed to the housing, so that the reflection surface installation portion or the reflection optical element is provided. This makes it possible to secure the ease of work at the time of manufacturing such as depositing or attaching a reflective surface on the surface, and to easily inspect the reflective surface and replace it as a part.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical unit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a liquid crystal projector including the optical unit.

FIG. 3 is a schematic configuration diagram of a conventional optical unit.

[Explanation of symbols]

 Reference Signs List 1 light source lamp 2 reflector 3 integrator 4 polarization conversion element 5 color separation system 51, 52 dichroic mirror 6 condenser lens 71 plane mirror 72 plane dichroic mirror 8 relay system 81 molded relay mirror 9G, 9B condenser lens. 10R, 10G, 10B Liquid crystal display panel 11 Color synthesis prism 12 Projection lens 13 Base mount member 14 Housing 15 Projector housing 16 Projection screen 17 Optical unit 18 Power supply unit 19a, 19b Fan

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/31 H04N 9/31 C // G02F 1/1335 520 G02F 1/1335 520 F term (reference) 2H088 EA14 EA15 HA13 HA20 HA21 MA20 2H091 FA05Z FA10Z FA17Z FB02 FB08 FC02 FC17 FD06 FD13 LA02 LA04 LA09 LA11 MA07 5C058 BA35 EA02 EA11 EA26 5C060 BC05 DA04 GA02 GB01 GB06 HC01 HC09 HC21 5G04 AA12 AA17 DD12 AA12 AA13 DD GG03 GG04 GG08 GG28 GG44 GG46 LL15

Claims (27)

[Claims] An optical unit configured to hold an optical system including at least a reflective optical element so as to form an optical path inside a housing, wherein the reflective optical element is provided integrally with the housing. An optical unit, characterized in that: 2. The optical unit according to claim 1, wherein a portion of the housing where the reflective optical element is provided inside has a shape conforming to the shape of the reflective optical element. 3. The optical unit according to claim 2, wherein the reflective optical element has a curved shape. 4. The optical unit according to claim 1, wherein the reflection optical element has a dichroic film or a polarization separation film. 5. The device according to claim 1, wherein a portion of the housing where the reflective optical element is provided is configured separately from other portions of the housing. Optical unit. 6. The optical unit according to claim 5, wherein a portion of the housing where the reflection optical element is provided is formed of a polymer material. 7. The optical unit according to claim 6, wherein the polymer material is polycarbonate or a composite material containing polycarbonate. 8. The optical unit according to claim 5, wherein a portion of the housing where the reflection optical element is provided is formed of a metal material. 9. The optical unit according to claim 1, wherein the optical system is an illumination optical system that guides illumination light from a light source to an image display device. 10. The illumination optical system according to claim 1, wherein the light from the light source is R
10. The optical unit according to claim 9, wherein the optical unit is decomposed into each color light of GB and led to three image display elements provided for each color light. 11. The relay system according to claim 10, wherein the reflection optical element constitutes a relay system for guiding a color light having a longer optical path to an image display element than the other color lights among the respective color lights. Optical unit. 12. The image display device according to claim 9, further comprising a projection optical system for projecting an image displayed on said image display element.
12. The optical unit according to any one of items 1 to 11. 13. An optical unit configured to hold an optical system including at least a reflective optical element so as to form an optical path inside a housing, and a surface of the reflective optical element opposite to a reflective surface. Is exposed to the outside of the housing. 14. The optical unit according to claim 1, wherein the surface of the reflection optical element opposite to the reflection surface has a shape conforming to the shape of the reflection surface. 15. The optical unit according to claim 14, wherein the reflection surface is a curved surface. 16. The reflection surface according to claim 13, wherein the reflection surface is a dichroic film or a polarization separation film.
The optical unit according to any one of the above. 17. The method according to claim 13, wherein an opening is formed in the housing, and the reflection optical element is fixed to the housing so as to cover the opening. Optical unit. 18. The optical unit according to claim 13, wherein a surface of the reflection optical element opposite to the reflection surface is exposed to the outside of the housing so as to be air-cooled. . 19. The optical unit according to claim 13, wherein the reflection optical element has a reflection surface formed on an inner surface of an element body formed of a polymer material. . 20. The optical unit according to claim 19, wherein polycarbonate or a composite material containing polycarbonate is used as said polymer material. 21. The optical unit according to claim 13, wherein the reflection optical element has a reflection surface provided on an inner surface of an element body formed of a metal material. . 22. The optical unit according to claim 13, wherein the optical system is an illumination optical system that guides illumination light from a light source to an image display device. 23. The illumination optical system, comprising:
23. The optical unit according to claim 22, wherein the optical unit is decomposed into each color light of GB and guided to three image display elements provided for each color light. 24. The apparatus according to claim 23, wherein the reflection optical element forms a relay system for guiding a color light having a longer optical path to an image display element than the other color lights among the respective color lights. Optical unit. 25. A system according to claim 2, further comprising a projection optical system for projecting an image displayed on said image display device.
25. The optical unit according to any one of 2 to 24. 26. An image display device comprising the optical unit according to claim 1. Description: 27. The image display device according to claim 26,
An image display system comprising: an image supply device that supplies image information to the image display device.