JP4708537B2 - Image display device and image display system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical unit including an optical system including at least a reflective optical element.
[0002]
[Prior art]
An optical unit used in an image display apparatus such as a liquid crystal projector has a configuration as shown in FIG. This configuration is proposed in Japanese Patent Laid-Open No. 2000-19634.
[0003]
The illumination light emitted from the illumination light source 103 is decomposed into RGB color lights by the mirror groups 104, 105, 140, and 150 to 153 including the dichroic mirrors 104 and 140, and guided to the liquid crystal panels 110 to 112 through the lens 109 . The color image lights modulated by the liquid crystal panels 110 to 112 are color-synthesized by the color synthesis prism 102 and projected from a projection lens 106 onto a screen (not shown) to form a color image.
[0004]
The optical path length of each color light of RGB from the light source 103 to the projection lens 106 is configured to be substantially equal to each other. All the mirror groups are included in the optical housing 101 and fixedly arranged.
[0005]
In addition to this example, the configuration of a liquid crystal projector is disclosed in US Pat. Nos. 5,651,599, 5,676,442, and Japanese Patent Publication No. 7-15537, but in either configuration, a mirror group is included in the optical casing. (Reflective optical element) is stored and held.
[0006]
[Problems to be solved by the invention]
However, in the configuration in which the housing of the optical unit is integrally formed in a box shape as described above and all the reflective optical elements are housed and held inside the housing, the liquid crystal panel, the color combining prism, etc. are surrounded. In many cases, a reflective optical element is arranged, and in order to secure a volume in which the reflective optical element is arranged, the housing has a volume that is slightly larger than the size of the optical system (the housing and the reflective optical It is necessary to leave a gap between the device). Therefore, there is a problem that the optical unit is increased in size and the image display apparatus including the optical unit is also increased in size.
[0007]
[Means for Solving the Problems]
An image display device according to an aspect of the present invention is an image display device in which an optical system is formed inside a housing, and a reflective optical element constituting the optical system forms part of the housing. The reflective optical element includes a dichroic film or a polarization separation film, and a base material that absorbs a light beam transmitted through the dichroic film or the polarization separation film, and is disposed on an outer periphery of the casing. It has the fan which cools a base material with cooling air .
[0008]
An image display device according to another aspect of the present invention is an image display device in which an optical system is formed inside a housing, and a reflective optical element constituting the optical system is a part of the housing. The reflective optical element includes a dichroic film or a polarization separation film, and a base material that transmits a light beam that has passed through the dichroic film or the polarization separation film, and a light beam that has passed through the reflection optical element. And a fan for cooling the absorbing member with cooling air .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
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.
[0015]
In this figure, 1 is a light source lamp such as a metal halide lamp or a mercury lamp, and 2 is a reflector having a parabolic surface or an ellipsoidal surface.
[0016]
Reference numeral 3 denotes an integrator including 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 phase plates 43. A polarization conversion element comprising:
[0017]
Reference numeral 5 denotes a color separation system including a blue reflecting dichroic mirror 51 and a red transmitting dichroic mirror 52. Reference numeral 6 denotes liquid crystal display panels (image display elements: hereinafter referred to as liquid crystal panels) 10R, 10G, It is a condensing lens for condensing on 10B. In the present embodiment, the optical path length is compressed by using the condensing lens 6 together with the concave lenses 61 and 62. Reference numeral 71 denotes a plane mirror, and 72 denotes a plane dichroic mirror (reflection optical element).
[0018]
The flat dichroic mirror 72 is made by evaporating a blue reflecting dichroic film on a transparent glass base material. A polarization separation film may be formed instead of the dichroic film.
[0019]
Reference numeral 8 denotes a relay system, which is configured as a reflection optical system from a mold relay mirror (reflection optical element) 81 having two concave mirrors (reflection surfaces) on the inner side and a mirror 82 arranged opposite to the mold relay mirror 81. Yes.
[0020]
The mold relay mirror 81 is made by mirror-finishing two concave portions of a base material part ( element 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. And the non-red component light which permeate | transmitted the dichroic film | membrane becomes heat | fever in a base material component.
[0021]
The mold relay mirror 81 may be made by depositing a polarization separation film on the concave surface portion.
[0022]
Reference numerals 9G and 9B denote condenser lenses for condensing illumination light (light in the green wavelength region and light in the blue wavelength region ) 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.
[0023]
Reference numeral 11 denotes a color synthesizing prism, in which two dichroic films that reflect light in different wavelength ranges and transmit others 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 this embodiment, the color synthesis prism 11 is configured by combining four prisms in consideration of workability.
[0024]
Reference numeral 12 denotes a projection lens having a positive refractive power and enlarging the color composite image emitted from the color synthesis prism 11 and projecting it on a screen (not shown).
[0025]
Reference numeral 13 denotes a base mount member for fixing and holding the color synthesis prism 11 and the projection lens 12.
[0026]
Each of the above components is fixedly held in the housing 14. The housing 14 is a molded product using a material obtained by adding glass to unsaturated polyester. Openings 141 and 142 are formed in the casing 14, and the flat dichroic mirror 72 and the mold relay mirror 81 are fixed around the openings 141 and 142 so as to block the openings 141 and 142, respectively. Is retained. The plane mirror 71 is fixed to the inside of the housing 14.
[0027]
The flat dichroic mirror 72 is attached to the housing 14 by fixing an elastic spacer to the insertion portion on the outer periphery of the optical path for backlash and then inserting it into a groove formed on the inner surface of the opening 141 in the housing 14. Fixed.
[0028]
The molded relay mirror 81 is coupled and fixed to the peripheral portion of the opening 142 in the housing 14 so as to be positioned. As a method for positioning the mold relay mirror 81, a fitting groove (nested shape portion) 83 is formed on the outer periphery of the opening 142 in the housing 14, and the mold relay mirror 81 having a corresponding shape is fitted. Fixed to the housing 14. At this time, the mold relay mirror 81 is positioned with respect to the housing 14 by fitting a dowel formed on the mold relay mirror 81 into a positioning hole 84 formed in the housing 14.
[0029]
However, positioning may be performed by fitting dowels formed in the casing 14 into positioning holes formed in the mold relay mirror 81, or the mold relay mirror 81 and the casing 14 may be connected to a tool (not shown). It is possible to hold both of them and align them. Then, after positioning the mold relay mirror 81 and the housing 14, fixing with screws, UV curing type, adhesion of epoxy system and cyanobond, thermal welding, spring pressure fixing using a plate spring such as a clip spring 85 or a piano wire, etc. The mold relay mirror 81 is positioned and fixed to the housing 14 using one or a plurality of fixing methods.
[0030]
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.
[0031]
Of the illumination light incident on the blue reflecting dichroic mirror 51, the blue light component is reflected by the blue reflecting dichroic mirror 51, and the other color light components are transmitted through the blue reflecting dichroic mirror 51. The blue light component reflected by the blue reflecting dichroic mirror 51 is reflected by the plane mirror 72 and condensed by the condenser lens 9B, and illuminates the blue liquid crystal panel 10B.
[0032]
The color light component transmitted through the blue reflecting dichroic mirror 51 is incident on the red transmitting dichroic mirror 52. Of the color light components incident on the red transmissive dichroic mirror 52, the green light component is reflected by the red transmissive dichroic mirror 52 and condensed by the condenser lens 9G to illuminate the green liquid crystal panel 10G.
[0033]
Moreover, the red light component transmitted through the red light transmission dichroic mirror 52 is reflected by the first concave mirror of the mold relay mirror 81 (dichroic film), reflected by the concave mirror facing the mirror 82, further a third mold relay mirror 81 The red liquid crystal panel 10R is illuminated by being reflected by a concave mirror (dichroic film) .
[0034]
The color image light components modulated by the liquid crystal panels 10B, 10G, and 10R and transmitted through the liquid crystal panels 10B, 10G, and 10R are combined in the color combining prism 11 and emitted as color combined image light through the projection lens 12. Is done.
[0035]
Here, the molded relay mirror 81 is fixed to the casing 14 such that its outer surface (the surface opposite to the dichroic film) is exposed to the outer surface of the casing, so that the molded relay mirror 81 itself is a part of the casing. Eggplant. In other words, this is the same as forming a dichroic film as a reflective optical element integrally with the housing.
[0036]
The planar dichroic mirror 72 is also fixed to the housing 14 such that the outer surface (the surface opposite to the dichroic film ) is exposed to the outer surface of the housing.
[0037]
That is, since the outside of the molded relay mirror 81 and the planar dichroic mirror 72 is not covered with the casing 14, the optical unit can be downsized compared to the conventional case of covering these mirrors with a gap in the casing. .
[0038]
Moreover, since the base portion of the mold relay mirror 81 is formed along the shape (concave surface) of the two dichroic films to minimize the shape of the mold relay mirror 81, the optical unit can be further miniaturized. it can.
[0039]
In addition, by fixing the flat dichroic mirror 72 and the mold relay mirror 81 so as to close the openings 141 and 142 of the housing 14, the space surrounded by the flat dichroic mirror 72, the mold relay mirror 81 and the housing 14 is The light path of the illumination system of the liquid crystal panels 10R, 10G, and 10B can be formed in which the intrusion of light from the light is blocked.
[0040]
Further, by fixing the mold relay mirror 81 using the opaque base material at a position exposed on the outer surface of the housing as described above, the light transmitted through the dichroic film (or the polarization separation film) is directly absorbed by the base material portion. be able to. Therefore, the heat generated with the unnecessary light processing can be efficiently transferred to the outside of the housing.
[0041]
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 in the mirror member, and the base material and the mirror film (dichroic film or polarization separation film) However, according to the present embodiment, the cooling effect of the mold relay mirror 81 by the air flowing around the outer periphery of the housing can be easily obtained, and the reliability can be improved. Can be increased.
[0042]
For this reason, not only resin but also metal can be used as a base material of the molded relay mirror 81 without any problem.
[0043]
When polycarbonate is used for the base material of the mold relay mirror 81, since the material color is colorless, it becomes possible to efficiently absorb visible region light by adding carbon when making this opaque, 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 dissipate heat.
[0044]
On the other hand, the planar dichroic 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 planar dichroic mirror 72 and the opening 141. The light is emitted out of the body 14. For this reason, as an optical unit, the heat_generation | fever by the unnecessary light in the plane dichroic mirror 72 can be suppressed.
[0045]
FIG. 2 shows an overall configuration of a liquid crystal projector provided with the optical unit.
[0046]
In this figure, reference numeral 15 denotes a projector housing that accommodates 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. An intake fan 19a and an exhaust fan 19b are attached to the projector casing 15 so that the projector casing 15 can be efficiently cooled.
[0047]
In addition, this projector has a power supply system (not shown), a lamp ballast, an image / audio input / output circuit, an image processing circuit, a liquid crystal drive circuit, an audio processing circuit, speakers, operation switches, etc. It is used as a display device that enlarges and projects image information from an image supply device such as a video computer onto a projection screen 16.
[0048]
Further, in this projector, a metal plate (for example, for example) provided with unnecessary light transmitted through the planar dichroic mirror 72 of the optical unit 17 and emitted outside the optical unit 17 in an air passage from the intake fan 19a to the exhaust fan 19b. A power supply unit aluminum case or a light alloy part such as aluminum or magnesium alloy) 18 is applied.
[0049]
A black paint is applied to the metal plate 18 as an antireflection treatment. Unnecessary light hitting the metal plate 18 is converted into heat and radiated to the outside.
[0050]
Conventionally, since the unnecessary light transmitted through the mirror corresponding to the planar dichroic mirror 72 was applied to the inner wall of the casing of the optical unit to absorb and dissipate, the cooling efficiency was not so good. Unnecessary light can be absorbed and radiated efficiently.
[0051]
In addition, taking advantage of the absorption (low spectral transmittance) characteristics in the invisible ultraviolet region of the glass base material, a glass material having a high absorption rate for spectral components that adversely affect liquid crystal properties is used as the glass base material of the flat dichroic mirror 72. It is also possible to select. In this case, by applying a mirror coat to the back side of the glass base material (on the side opposite to the dichroic film surface), unnecessary light that has passed through the dichroic film is reflected in the glass base material, and is transmitted to the outside of the mirror base material. Heat dissipation and light emission processing can be performed simultaneously.
[0052]
In this case, since the transmitted light is reflected and propagates through the glass base material, the glass plate thickness proportional to the amount of light absorption can be thinner for the same light transmission distance than when the filter is simply inserted and arranged orthogonal to the optical path. As a result, the required glass material is reduced, and the cost and weight can be reduced.
[0053]
In the above embodiment, the optical unit used in the image display device has been described. However, the optical unit of the present invention can be used other than the image display device. It is also possible to use an image display element other than the liquid crystal panel.
[0054]
【The invention's effect】
As described above, in the present invention, by reflecting optical element constituting a part of the housing, along with reducing the size of the housing, the light flux transmitted through the dichroic film or a polarization separation film of the reflective optical element Mother By absorbing the luminous flux absorbed by the material or transmitted through the base material by the absorbing member and cooling the base material or the absorbing member with cooling air, it is possible to efficiently dissipate heat generated by unnecessary light .
[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]
DESCRIPTION OF SYMBOLS 1 Light source lamp 2 Relector 3 Integrator 4 Polarization conversion element 5 Color separation system 51,52 Dichroic mirror 6 Condensing lens 71 Plane mirror 72 Plane dichroic mirror 8 Relay system 81 Mold relay mirror 9G, 9B Condenser lens.
10R, 10G, 10B Liquid crystal display panel 11 Color composition prism 12 Projection lens 13 Base mount member 14 Case 15 Projector case 16 Projection screen 17 Optical unit 18 Power supply unit 19a, 19b Fan

Claims (4)

An image display device in which an optical system is formed inside a housing, wherein a reflective optical element constituting the optical system forms part of the housing, and the reflective optical element is a dichroic film or A polarization separation film; and a base material that absorbs a light beam that has passed through the dichroic film or the polarization separation film; and a fan that cools the base material disposed on the outer periphery of the housing with cooling air. An image display device characterized by the above. An image display device in which an optical system is formed inside a housing, wherein a reflective optical element constituting the optical system forms part of the housing, and the reflective optical element is a dichroic film or A polarization separation film; and a base material that transmits the light beam that has passed through the dichroic film or the polarization separation film; and an absorption member that absorbs the light beam that has passed through the reflective optical element; An image display device comprising a fan that performs the above-described operation. Wherein the optical system, an image display apparatus according to claim 1 or 2, characterized in that the light from the light source is an illumination optical system for illuminating the image display element. An image display system comprising: the image display device according to claim 1 ; and an image supply device that supplies image information to the image display device.