JPH11119149A - Liquid crystal projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a device compact by providing a reflection mirror in which plural elliptic surfaces are integrally formed, a light emitting tube, a composite mirror group, a liquid crystal and a projection lens. SOLUTION: Light emitting tubes 1a, 1b are aligned/fixed to concave mirrors 2a, 2b made of parabolic surfaces or elliptic surfaces. The concave mirrors 2a, 2b have elliptic surfaces, integrally formed and light emitting parts 1c, 1d are fixed in the vicinity of a first focal position of the ellipse. An illuminating light beam is refracted insides by first prisms 3a, 3b. The beams passes through first flyeye lenses 5a, 5b having second prisms 4a, 4b in one surface and a lens group in the other surface. Lamp arc has a positional relation of being formed its image by each lens of a second flyeye lens 7. At this time, a light ray is bent by 90 deg. by a right-angle prism 8. A light beam of only S wave synthesized by two lamps is resolved to red, blue and green colors by mirrors 11-15, made incident on three liquid crystal panels 16 and incident on a projection lens 18 after being sythesized by a X prism 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projection device for enlarging and projecting an image of a liquid crystal panel, and more particularly to a liquid crystal projection device having a plurality of light sources (hereinafter referred to as a multipoint type).

[0002]

2. Description of the Related Art Conventionally, devices for enlarging and projecting an image on a liquid crystal panel using a light source such as a metal halide have been put on the market. In this method, light emitted from a light source is condensed on a liquid crystal panel via a mirror or the like, and is projected on a screen through a projection lens.

[0003] As a type, a single liquid crystal panel single panel system and three liquid crystal panels are color-separated by a dichroic mirror or the like.
There are two types of three-panel system for color synthesis and illumination.

[0004] Recently, a high-intensity screen is required so that a projected image can be viewed on a large screen even in a bright room, and a three-panel system is mainly used.

[0005] Lamps such as metal halide lamps as light sources have been increased in output, and liquid crystal panels and polarizing plates have also become light and heat resistant materials.

Further, the polarization direction of the light is previously unified to either the P or S wave by using a polarization conversion element for the illumination light, and the liquid crystal portion is illuminated about 1.5 times as high as the conventional one without using this element. There are many projection devices that aim to increase brightness.

[0007] Further, the arc length of the lamp is also short, and a point light source is used to improve the light utilization rate. Generally one lamp
The lighting type is the mainstream of each company, but an illumination system of, for example, a plurality of lighting type lamps has been proposed to improve the brightness.

For example, in a two-lighting type, two lamps are reflected by a mirror at 90 degrees with a mirror according to the configuration of Japanese Patent Application Laid-Open No. H5-29320 (FIG. 12) to guide illumination light to a liquid crystal panel after color separation. As disclosed in H4-155189 (FIG. 13), a method of illuminating a liquid crystal panel with two light sources using a prism after color separation has been reported.

Japanese Patent Application Laid-Open No. H5-346 discloses a multiple light source system using an integrator optical system for uniformly illuminating light.
As shown in FIG. 557 (FIG. 14), there has been proposed a system in which respective integrator lenses are arranged on respective lamps and illumination light is obliquely superimposed on a liquid crystal panel.

[0010]

However, in a liquid crystal projection apparatus of this type, when a typical two-lighting type lamp is used, each lamp light is bent at a right angle by a reflecting mirror or a prism, so that a large space is required. The volume of the body becomes large. Also, since the incidence of the two lamp lights becomes oblique light, it is necessary to use a PS separation element (polarization conversion element) which is a method of separating the reflected (S wave) transmission (P wave) at 45 degrees by a dielectric band film. difficult. Further, when one lamp is broken, only the other lamp becomes oblique light, so that illumination unevenness (color unevenness) occurs on the liquid crystal surface. Further, a plurality of lamps (FIG. 8) require integrated illumination for uniformizing light over the entire screen with two fly-eye lenses, which increases the size of the main body and increases the cost. Further, as disclosed in Japanese Patent Application Laid-Open No. H5-29320, the lamp is located at a distant position, and a plurality of lamp boxes are required, which causes a problem at the time of replacement.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a compact multi-lamp type liquid crystal projector.

[0012]

In order to solve the above-mentioned problems, a liquid crystal projection device according to the present invention comprises: a reflecting mirror integrally formed with a plurality of elliptical surfaces and paraboloids; A plurality of arc tubes which are aligned and fixed in the vicinity of the focal position; a group of combining mirrors for separating and synthesizing the color light from the arc tube; a liquid crystal for controlling the transmission of the color light; It is characterized by comprising a lens, a light source holding member for holding the reflecting mirror, and a main body containing the light source holding member, the composite mirror group, the liquid crystal, and the projection lens.

[0013] Further, two elliptical reflecting mirrors, two arc tubes fixedly aligned near a first focal position of each of the reflecting mirrors, and collecting light near the second focal position by the reflecting mirrors, Two mirror-symmetric first prisms for refracting light so as to be close to the inside of the corresponding reflecting mirror, and each of the first prisms which correct the refracted light condensed on one side in parallel and are bent by the first prism Two concentric concave surfaces formed of a second prism that refracts convergent light in parallel, and two mirror-symmetrical two surfaces integrally formed with a plurality of lenses that collect light-emitting tube images on the other surface. A first fly-eye lens, a second fly-eye lens in which a plurality of lenses are respectively formed at positions where the two first fly-eye lenses form an arc tube image, and color light from the arc tube is separated. Synthetic compound to be synthesized Group, a liquid crystal for controlling transmission of the color light, a projection lens for enlarging a transmitted light image in the liquid crystal, a light source holding member for holding the reflecting mirror, the light source holding member, the composite mirror group, The first and second fly-eye lenses, the first prism, the liquid crystal, and a main body including the projection lens are included. Each of the two first prisms is a mirror-symmetric triangular prism, and one side that forms a right angle is joined to and integrated with surfaces having the same length.

Further, two first fly-eye lenses are integrally formed at mirror-symmetric positions. The ellipse was changed to a parabolic surface, and the irregular concave surface was changed to a flat surface.

Further, a light source comprising a plurality of integrally formed reflecting mirrors and a plurality of arc tubes is detachably mounted by a single light source holding member.

The two mirror-symmetric first prisms have concave surfaces on one side to make convergent light reflected by the two elliptical mirrors parallel, and two surfaces on the first prism from the two elliptical mirrors. Light was refracted so as to be closer to the inside of each, and the three first surfaces were joined together by joining the two first prisms.

According to the above contents, it is possible to combine them into one light before entering the integrator optical system,
The capacity is not as large as before. Also, since parallel light is incident on the integrator, a polarization conversion element composed of a right-angle prism can be introduced into the subsequent optical path.

Further, since the prism, the lens array, the concave mirror and the like are integrated and arranged, the cost is not increased. Further, the present invention provides a liquid crystal projection device having a feature that even if one lamp becomes unlit, it can be illuminated with another lamp, and the lamp house unit can be integrated so that maintenance is easy.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first invention according to the present invention is directed to a reflecting mirror having a plurality of elliptical surfaces and paraboloids integrally formed, and a plurality of reflecting mirrors aligned and fixed near respective focal positions of the reflecting mirrors. An arc tube, a combination mirror group for separating and synthesizing the color light from the arc tube, and a liquid crystal for controlling the transmission of the color light,
A projection lens for enlarging a transmitted light image in the liquid crystal, a light source holding member for holding the reflecting mirror, the light source holding member,
This is a compact liquid crystal projector comprising the synthetic mirror group, the liquid crystal, and a main body containing the projection lens, and comprising a lamp concave mirror and a plurality of arc tubes.

Further, according to a second aspect of the present invention, two elliptical reflecting mirrors are aligned and fixed in the vicinity of a first focal position of each of the reflecting mirrors, and the light is collected near the second focal position by the reflecting mirror. Two arc tubes, two mirror-symmetrical first prisms for refracting light so as to be close to the inside of an adjacent reflecting mirror, and correcting the refracted light condensed on one side in parallel to the first prism. Two mirror surfaces formed integrally with a plurality of lenses that collectively converge the light converged by the prisms and that form a second prism that refracts the converged light in parallel, and a plurality of lenses that collect light from the arc tube image on the other surface. Two first fly-eye lenses forming a symmetrical shape, a second fly-eye lens forming a plurality of lenses at positions where an arc tube image is formed by the two first fly-eye lenses, respectively, Distributes the color light from the tube A combining mirror group for combining, a liquid crystal for controlling transmission of the color light, a projection lens for enlarging a transmitted light image in the liquid crystal, a light source holding member for holding the reflecting mirror, the light source holding member, and the combining mirror Group, the first and second fly-eye lenses, the first prism, the liquid crystal, and a main body including the projection lens, thereby uniformly irradiating two illumination lights, and thereafter by a right-angle prism. A system using the constituted PS polarization conversion element was made possible.

Further, in the third invention, the two first prisms are mirror-symmetrical triangular prisms, and one side forming a right angle is joined and integrated by a surface having the same length. It can be realized only by increasing the number of parts. . In addition, the two first fly-eye lenses are integrally formed at mirror-symmetric positions, thereby simplifying the integrator parts. The same effect was obtained by changing the ellipse to a paraboloid and changing the deformed concave to a plane. Further, the light source comprising a plurality of integrally formed reflecting mirrors and a plurality of arc tubes is detachably mounted by one light source holding member, so that it can be replaced by one lamp house. That is, according to the above-mentioned contents, the light can be collected into one light before being incident on the integrator optical system, and the capacity is not increased as compared with the conventional case. Further, since parallel light is incident on the integrator, a polarization conversion element can be introduced into the subsequent optical path. In addition, since the prism, the lens array, the concave mirror and the like are configured and arranged to be integrated, the cost does not increase. Further, the present invention provides a liquid crystal projection device having features such as being able to be illuminated with another lamp even if one lamp is turned off, and being easy to maintain because the lamp house unit can be integrated.

An embodiment of the present invention will be described below with reference to FIGS. (Embodiment 1) FIG. 1 is a plan view showing the entire optical system of a two-lighting type liquid crystal projection device according to a first embodiment of the present invention. 2 is a plan view of a single lamp type, FIG. 3 is a front view of FIG. 2, and FIG.
FIG. 5 is a plan view showing a lamp system, FIG. 5 is a front view of FIG. 4, FIG. 6 is a plan view of a four lamp system, and FIG. 7 is a front view of FIG.

As shown in FIG. 1, in the overall layout of the optical system, a lamp unit as an illumination source includes a plurality of arc tubes 1.
a and 1b are aligned and fixed to parabolic or elliptical concave mirrors 2a and 2b.

In the embodiment shown in FIG. 1, the concave mirrors 2a and 2b have elliptical surfaces, and are integrally molded as shown in FIGS. 4 and 6, and the respective light emitting portions 1c and 1d are fixed near the first focal position of the ellipse. . The arcs of the light emitting sections 1c and 1d are close to a point light source of about 1 mm.

The reflected light is first refracted by the two first prisms 3a and 3b, each consisting of a triangular prism, to the inside of each of them.

FIGS. 8, 9 and FIG. 10, which is an enlarged view of FIG. Assuming that the refractive indexes of the two first prisms 3a, 3b are n1, the main optical axis is n1 = sin θ1 / si
nθ2.

The light emitted from the first prism has second prisms 4a and 4b on one surface and passes through first fly-eye lenses 5a and 5b comprising a plurality of lens groups 6 on the other surface.

In this relationship, if the refractive index of the second prisms 4a and 4b is n2, the relationship is n2 = sin θ4 / sin θ3, and the first prisms 3a and 3b and the second prism 4
The angles of the prism interfaces a and 4b are set such that their main optical axes are parallel in the second prism.

For example, in this embodiment, the angle is set to about 30 degrees. FIG. 8 shows the case where the interfaces 4a and 4b of the second prism are straight, and FIG. 9 shows the case where the interfaces 4a and 4b of the second prism are formed.
4b is a concave surface.

When the reflecting mirror is parabolic, the peripheral light is substantially parallel to each other. Therefore, the second prism is shown in FIG. 8, and when the reflecting mirror is elliptical, the second prism is not connected to the second prism as shown in FIG. It has a spherical surface and a slightly concave surface so that ambient light before entering the fly-eye lens is substantially parallel.

The second fly-eye lens 7 is divided corresponding to the plurality of lens groups 6, and the lamp arc has a positional relationship of forming an image on each lens of the second fly-eye lens 7. I have.

In the embodiment, the light beam is bent by 90 degrees by the right-angle prism 8. The rectangular prism 8 has a glass plate 9 having a total reflection surface on the other surface bonded to the interface where the dielectric band film 8a is formed.

Therefore, the S-wave is reflected by the dielectric band film 8a, and the P-wave is reflected by the total reflection surface, and irradiates the second fly-eye lens 7, respectively. Therefore, the second fly-eye lens 7 has twice the number of lenses as the first fly-eye lens.

The second fly-eye lens 7 is provided with a plurality of phase difference plates 10 for shifting the phase of only the P wave by 90 degrees and converting the phase into an S wave component.

The details of the principle of the polarization conversion element will be omitted. The combined light of only the S-wave from the two lamps is then separated into red, blue and green by a plurality of mirrors 11, 12, 13, 14, and 15, and is incident on three liquid crystal panels 16 and X prism 17 The light is then incident on the projection lens 18. The entire optical components are assembled on the optical chassis 20.

The lamp is attached to the lamp box 21 and a handle 22 is provided so that the lamp box 21 can be easily pulled out.

The insertion and removal of the lamp is performed from the left side of FIG. 3 and FIG. That is, the light source including the plurality of integrally formed reflecting mirrors and the plurality of arc tubes is configured to be able to be inserted and removed by one light source holding member.

(Embodiment 2) FIG. 11 is a plan view showing an optical layout of a liquid crystal projection device of a two-lighting type according to a second embodiment of the present invention.

The overall structure is similar to that of FIG. 8, except that the first surfaces of the two first prisms 3a and 3b through which the light passes are concave surfaces 3c and 3d, and the elliptical concave mirrors 2a and 2b pass through the second surfaces. The light condensed near the focal point is made parallel, and the next interface 3
Each illumination light is slightly refracted to the inside by e and 3f. The following is the same as in the first embodiment.

[0040]

As described above, according to the present invention, even a multi-lamp type lamp can be combined into one light before entering the integrator optical system, and the capacity is not as large as that of the conventional lamp.

Since parallel light is incident on the integrator, a polarization conversion element composed of a right-angle prism can be introduced into the subsequent optical path.

The structure and arrangement allow the prism, lens array, concave mirror, and the like to be integrated, so that cost does not increase. Even if one light goes out, it can be illuminated with another light.
Since the lamp house unit can be integrated, a liquid crystal projector having features such as easy maintenance can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical layout of a liquid crystal projection device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a single lamp type.

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a plan view of a two-lamp system in which a plurality of lamp units are integrally molded.

FIG. 5 is a front view of FIG. 4;

FIG. 6 is a plan view of a four-lamp system in which a plurality of lamp units are integrally molded.

FIG. 7 is a front view of FIG. 6;

FIG. 8 is a plan view of the principle of the illumination system when the concave mirror is a parabolic surface.

FIG. 9 is a plan view of the principle of the illumination system when the concave mirror has an elliptical surface;

FIG. 10 is an enlarged view of FIG. 8;

FIG. 11 is a plan view of an optical layout of a two-lighting type liquid crystal projection device according to a second embodiment of the present invention.

FIG. 12 is a plan view showing an optical layout of a conventional liquid crystal projection device.

FIG. 13 is a plan view showing an optical layout of a conventional liquid crystal projection device.

FIG. 14 is a plan view showing an optical layout of a conventional liquid crystal projection device.

[Explanation of symbols]

 1a, 1b Arc tube 2a, 2b Concave mirror 3a, 3b First prism 5 First fly-eye lens 7 Second fly-eye lens 8 Right angle prism

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI H04N 9/31 H04N 9/31 C

Claims (7)

[Claims] 1. A reflecting mirror having a plurality of concave surfaces, an arc tube respectively arranged near a focal position of each concave surface, a synthetic mirror group for separating and synthesizing color light from the arc tube, A liquid crystal projection device comprising a liquid crystal to be controlled and a projection lens for enlarging a transmitted light image of the liquid crystal. 2. A liquid crystal projection device according to claim 1, wherein a light source comprising a plurality of integrally formed reflecting mirrors and a plurality of arc tubes is detachably mounted by one light source holding member. 3. A plurality of elliptical reflecting mirrors, an arc tube arranged near a focal position of each of the reflecting mirrors, a plurality of symmetric first prisms for refracting light for condensing, and An irregular concave surface composed of a second prism for correcting the refracted light to be emitted in parallel and refracting each of the convergent light bent by the first prism in parallel is formed, and the arc tube image is collected on the other surface. A plurality of symmetrical first fly-eye lenses integrally formed with a plurality of lenses to be illuminated; and a plurality of lenses at positions where the two first fly-eye lenses form an arc tube image. A second fly's eye lens formed by combining, a combining mirror group that separates and combines the color light from the arc tube, a liquid crystal that controls the transmission of the color light, and a projection lens that enlarges a transmitted light image in the liquid crystal, Light source holding the reflector Holding member, the light source holding member, the composite mirror group, the first and second fly-eye lenses,
A liquid crystal projection device comprising the first prism, the liquid crystal, and a main body including the projection lens. 4. The liquid crystal projection device according to claim 3, wherein each of the plurality of first prisms is a symmetrical triangular prism, and one side forming a right angle is joined and integrated on a surface having the same length. 5. The liquid crystal projection device according to claim 3, wherein the plurality of first fly-eye lenses are integrally formed at symmetric positions. 6. The liquid crystal projection device according to claim 3, wherein the plurality of elliptical reflecting mirrors are formed into a plurality of parabolic reflecting mirrors, and the plurality of deformed concave surfaces of the second prism are formed into a plurality of planes and integrated. . 7. The plurality of mirror-symmetric first prisms is one.
The surfaces form a concave surface to make the convergent light reflected by the plurality of elliptical reflecting mirrors parallel, the two surfaces refract light from the plurality of elliptical reflecting mirrors toward each other, and the three surfaces are flat surfaces. 4. The liquid crystal projection device according to claim 3, wherein said plurality of first prisms are joined and integrated.