JP2002244203A - Two-plate transmission type liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-plate transmission type liquid crystal projector which can be simplified and easily designed by using a transmission type liquid crystal panel having sufficiently accumulated technical know-how. SOLUTION: Light 50 with a 1st polarization angle which is emitted by a light-beam emitting means 1 is split by a dischroic mirror 4 into a 1st light beam 51 and a 2nd light beam 52. The 1st light beam 51 has its traveling direction changed by a 1st total reflecting mirror 81 and is made incident on a 1st liquid crystal panel 91. The 1st light beam 51 transmitted through the 1st liquid crystal panel 91 is made incident on a beam splitter 120A. The 2nd light beam 51 transmitted through the dichroic mirror 4 has its traveling direction changed by a 2nd total reflecting mirror 81 and is made incident on a 2nd liquid crystal panel 92. The 2nd light beam 52 transmitted through the 2nd liquid crystal panel 92 is made incident on the beam splitter 120A. The beam splitter 120A puts the 1st light beam 51 and the 2nd light beam 52 together and the composite light is made incident on a projection lens 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector, and more particularly, to a structure of a two-panel transmissive liquid crystal projector using two transmissive liquid crystal panels.

[0002]

2. Description of the Related Art As a liquid crystal projector using a transmissive liquid crystal panel, a single-panel liquid crystal projector using one liquid crystal panel and a three-panel liquid crystal projector using three liquid crystal panels have been put to practical use. Single-panel LCD projectors have the advantage of being smaller in size than three-panel LCD projectors, but have the drawback of poor light use efficiency and low screen brightness, so they can only be used in a limited range. In general, a three-panel liquid crystal projector is employed.

FIG. 8 shows a conventional liquid crystal projector 100E using three transmissive liquid crystal panels. The device configuration of the liquid crystal projector 100E includes a light source 1 for a liquid crystal projector (hereinafter, simply referred to as a light source 1) as a light ray generating means.
A fly-eye lens 2 and a PS separation / combination 3 are provided. The light source 1 emits unpolarized white light including red light (R), green light (G), and blue light (B). Since the light emitted from the light source 1 has a distribution in which the amount of light increases toward the center, the light is made uniform by the fly-eye lens 2. In order to align the light emitted from the fly-eye lens 2 to the first polarization angle, a PS separation / combination 3 is arranged on the exit side of the fly-eye lens 2.

[0004] The dichroic mirror 41 separates only the light 51 of the first color from the light 50 emitted from the PS separation / combination 3 and adjusted to the first polarization angle. The direction of the separated light 51 of the first color is changed to the first liquid crystal panel 91 by the total reflection mirror 81.

[0005] Of the light emitted from the PS separation / combination 3 and not separated by the dichroic mirror 41, only the light 52 of the second color is the dichroic mirror 42.
Are separated. The separated second color light 52 is projected onto the second liquid crystal panel 92.

The third color light 53 emitted from the PS separation / combination 3 and transmitted through the dichroic mirror 42 is projected on a third liquid crystal panel 93 by total reflection mirrors 82 and 83.

In each of the liquid crystal panels 91, 92, and 93, a first color light 51, a second color light 52, and a third color light 52 are provided in each liquid crystal panel in response to a signal from a control circuit (not shown). Is modulated. Liquid crystal panel 91,
Polarizing filters 10 are provided on the exit sides of 92 and 93, respectively.
Lights that are not displayed on the screen are cut off.

The light 51 of the first color, the light 52 of the second color, and the light 53 of the third color emitted from the polarizing filters 101, 102, and 103 are combined by the prism 6 and combined. The light is projected onto the projection lens 7, and three colors are simultaneously displayed on the screen.

Next, a conventional liquid crystal projector using two reflective liquid crystal panels is disclosed in Japanese Patent Application Laid-Open No. 2000-147656. FIG. 9 shows this liquid crystal projector 1
00F is shown. The light 50 from the light beam generating means 20 that has a uniform polarization distribution at the first polarization angle is subjected to color separation by the dichroic mirror 4. The light 51 of the first color transmitted through the dichroic mirror 4 is polarized by the polarization angle rotating unit 110 to a second polarization angle and reflected. The reflected light 51 of the first color again passes through the dichroic mirror 4 and further passes through the polarization beam splitter 12.
0, and is polarized by the first reflective liquid crystal panel 91. The light 51 of the first color having the first polarization angle is reflected by the polarization beam splitter 120 toward the projection lens 7 and projected on the screen via the projection lens 7.

The light beams 52 and 53 of the second and third colors reflected by the dichroic mirror 4 are reflected by the polarization beam splitter 120 toward the color adjustment valve 130. The lights 52 and 53 of the second and third colors are time-separated by the color adjustment valve 130,
The light 52 of the third color and the light 53 of the third color are alternately modulated by the second reflective liquid crystal panel 92. The modulated second color light 52 and third color light 53 are reflected toward the polarizing beam splitter 120 and projected on the screen via the projection lens 7.

[0011]

In the liquid crystal projector 100E using the above-mentioned transmissive liquid crystal panel, white light is separated into red light (R), green light (G), and blue light (B). Therefore, there is a problem that the device size of the liquid crystal projector becomes large. Also, unnecessary light that is not displayed on the screen is absorbed by the polarizing filter provided on the emission side of the liquid crystal panel. Therefore, when displaying a black screen, the amount of light absorbed by the optical element from the light source to the polarizing filter is reduced. Except for this, all the light emitted from the light source becomes a heat generating factor of the polarizing filters. Therefore, a cooling design is required for each polarizing filter. As a result, there is a problem that the device design of the liquid crystal projector becomes complicated. For example, when a 150 W light source is used, the amount of heat generated by the polarizing filter is as high as 12 W.

Further, the liquid crystal projector 100F using the reflection type liquid crystal panel has an advantage that it can be made smaller than the liquid crystal projector 100D using three transmission type liquid crystal panels. In addition, since the unnecessary light is returned to the light source, a polarizing filter is not required, so that the cooling design of the liquid crystal projector can be easily performed. However, in the case of the liquid crystal projector 100E, know-how on optical design for the reflective liquid crystal panel is not sufficiently accumulated, and it is considered that many unknown problems are inherent. Further, the reflection type liquid crystal panel does not have sufficient optical characteristics with respect to the transmission type liquid crystal panel.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, and to simplify the device and facilitate the design by using a transmissive liquid crystal panel having sufficient technical know-how. An object of the present invention is to provide a two-panel transmissive liquid crystal projector that is made possible.

[0014]

According to one aspect of the two-panel transmissive liquid crystal projector based on the present invention, the first
A light beam generating means for emitting a light beam including a first light beam and a second light beam having a polarization angle of?, A dichroic mirror for separating the light beam into a first light beam and a second light beam, (1) a liquid crystal panel, a color adjustment valve to which the second light ray is incident, a second liquid crystal panel to which a second light ray emitted from the color adjustment valve is incident, and a first light ray transmitted through the first liquid crystal panel A beam splitter for combining the second light beam transmitted through the second liquid crystal panel, and a projection lens to which the combined light is incident.

Preferably, in the above invention, the first light beam includes light of a first color, the second light beam includes light of a second and a third color, and the color adjustment valve includes: The light of one of the second and third colors of the second light beam is selected and emitted.

According to the two-panel transmissive liquid crystal projector, two transmissive liquid crystal panels, which already have a good track record of optical characteristics and have sufficient optical design know-how, are used. The time series division of the light of the second and third colors is controlled, and the transmission and reflection of the first light beam and the second light beam are controlled by the beam splitter, thereby eliminating the need for a polarizing plate. Further, since unnecessary emission of light can be concentrated on the side of the beam splitter, the cooling design of the two-panel transmission type liquid crystal projector can be facilitated.

In another aspect of the two-panel transmissive liquid crystal projector based on the present invention, a light beam generating means for emitting a light beam having a first polarization angle, and a first light beam having a first polarization angle are provided. A first color adjustment valve for separating the light into a second light beam having a second polarization angle; and a first color adjusting valve for guiding the first light beam to a first optical path and guiding the second light beam to a second optical path. A beam splitter, a first dichroic mirror disposed in a first optical path, through which the first light beam passes, a first liquid crystal panel, into which the first light beam passing through the first dichroic mirror is incident, and a second liquid crystal panel, Placed in the light path,
A second dichroic mirror through which the second light beam passes;
A second liquid crystal panel on which the second light beam transmitted through the second dichroic mirror is incident, a first light beam transmitted through the first liquid crystal panel, and a second light beam transmitted through the second liquid crystal panel are combined. Beam splitter, and a projection lens into which the combined light is incident.

Preferably, in the above invention, the first light beam includes light of first and second colors, and
The light beam includes light of a third color, and the first dichroic mirror selects one of the first and second colors of light of the first light beam.

Preferably, in the above invention, the first light beam includes light of a first color, the second light beam includes light of a second color and a third color, and the first color adjustment valve. Accordingly, one of the second and third colors of light of the second light ray is selected.

Preferably, in the above invention, the first light beam includes light of a first color, the second light beam includes light of a second and a third color, and the first light beam includes a second dichroic mirror. The light of one of the second and third colors of the second light ray is selected.

According to the two-panel transmissive liquid crystal projector, by adjusting the operation time of each of the first color adjustment valve and the second color adjustment valve 131, red light (R), green light (G), The balance of the amount of blue light (B) can be adjusted, and an optimal hue can be realized. Further, light unnecessary for the screen is reflected outside the optical path except that a part of the light is absorbed by the second color adjustment valve, so that the cooling design of the two-plate transmission type liquid crystal projector is also facilitated.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a two-panel transmission type liquid crystal projector in each embodiment based on the present invention will be described.
This will be described with reference to the drawings.

(Embodiment 1) Hereinafter, a two-panel transmissive liquid crystal projector 100A according to Embodiment 1 will be described.
This will be described with reference to FIG. FIG. 1 is a schematic diagram showing a structure of a two-panel transmission type liquid crystal projector 100A in the present embodiment.

(Apparatus Configuration) Referring to FIG. 1, a two-panel transmission type liquid crystal projector 100A includes
It has a dichroic mirror 4. A first total reflection mirror 81 and a transmission-type first liquid crystal panel 91 are provided in the first optical path.
Is arranged. In the second optical path, a color adjusting valve 130, a second total reflection mirror 82, and a transmission type second liquid crystal panel 92 are arranged. In addition, the first optical path and the second optical path
The beam splitter 120A and the projection lens 7 are arranged in a region where the optical path and the optical path meet.

The light 50 having the first polarization angle emitted from the light beam generating means 1 is separated by the dichroic mirror 4 into a first light beam 51 and a second light beam 52. The traveling direction of the first light beam 51 reflected by the dichroic mirror 4 is changed by the first total reflection mirror 81 and is incident on the first liquid crystal panel 91. The first light transmitted through the first liquid crystal panel 91
The light beam 51 enters the beam splitter 120A.

On the other hand, the traveling direction of the second light ray 52 transmitted through the dichroic mirror 4 is changed by the second total reflection mirror 81 and is incident on the second liquid crystal panel 92. The second light beam 52 transmitted through the second liquid crystal panel 92 enters the beam splitter 120A.

In the beam splitter 120A, the first
The light beam 51 and the second light beam 52 are combined, and the combined light is incident on the projection lens 7.

(Principle of Operation) The principle of operation of the two-panel transmissive liquid crystal projector 100A having the above-described configuration will be described. In the light beam generating means 1, white light including unpolarized red light (R), green light (G), and blue light (B) emitted from the liquid crystal projector light source is radiated, and a fly-eye lens and a PS separation light are emitted. Light 50 having a uniform distribution by the combination and being aligned at the first polarization angle is formed and emitted.

The light emitted from the light beam generating means 1 is separated by the dichroic mirror 4 into only a first light beam 51 having light of a first color. The direction of the separated first light beam 51 is changed by the first total reflection mirror 81 and is incident on the first liquid crystal panel 91. In the first liquid crystal panel 91, each liquid crystal display cell, for example, polarizes incident light from a first polarization angle to a second polarization angle when in an ON state, and maintains the first polarization angle of incident light when OFF. Then, the incident light is emitted from the liquid crystal panel 91.

The beam splitter 120A is manufactured so as to reflect the second polarization angle and pass through the first polarization angle. Therefore, when the first liquid crystal panel 91 is in the ON state, the incident light is polarized at the second polarization angle, is reflected by the beam splitter 120A, and only the first light beam 51 polarized at the second polarization angle is projected. Head for. In addition,
When the first light ray 51 has the first polarization angle, the reflection surface 121a is provided so that the first light ray 51 passes through the beam splitter 120A and is radiated to the outside from the side of the beam splitter 120A.

Next, the second light beam 52 including the second and third colors that has passed through the dichroic mirror 4 is time-divisionally operated by the color adjustment valve 130 so that only one of the colors passes. You. Color adjustment valve 130
A second ray 5 containing light of a second or third color that has passed through
2 is a second liquid crystal panel 92 by the second total reflection mirror 82
Reflected to

When the color adjustment valve 130 has a function of polarizing the second light ray 52 passing through the color adjustment valve 130 from the first polarization angle to the second polarization angle, For example, when the liquid crystal display cell is in the ON state, the second light ray 52 is polarized from the second polarization angle to the first polarization angle, and when the liquid crystal display cell is in the OFF state, the second light ray 52 is kept at the second polarization angle. The light beam 52 is configured to be emitted from the liquid crystal panel 92. An example of such a color adjustment valve is a color switch.

When the color adjustment valve 130 has a function of maintaining the second light ray 52 passing through the color adjustment valve 130 at the first polarization angle, each liquid crystal display cell of the second liquid crystal panel 92 For example, when in the ON state, the second light ray 52 is kept at the first polarization angle, and when in the OFF state, the second light ray 52 is polarized from the first polarization angle to the second polarization angle, so that the second light ray 52 becomes The light is emitted from the liquid crystal panel 92. An example of such a color adjustment valve is a color wheel using a color filter.

Since the beam splitter 120A is manufactured so as to reflect the second polarization angle and pass through the first polarization angle, the first polarization angle transmitted when the second liquid crystal panel 92 is in the ON state. Is incident on the projection lens 7 only.

In the color adjustment valve 130, the time division operation for the light of the second and third colors is performed in synchronization with the display operation of the second liquid crystal panel 92, so that the two colors are always displayed on a screen (not shown). Can be displayed,
It can be recognized as a full color display by the afterimage effect.

The light of the second or third color, which is unnecessary light, becomes heat in the color adjustment valve 130 and is cooled. Further, the light of the first color that is not displayed and the light of the second color
Alternatively, the non-display light of the third light is radiated laterally from the beam splitter 120A. For example, when the screen is black, the color adjustment valve 13
At 0, one light amount is consumed, and two light amounts are consumed in the form of heat generation on the side of the beam splitter 120A.

(Operation / Effect) As described above, according to the two-panel transmissive liquid crystal projector 100A of the present embodiment, a transmissive liquid crystal panel which has a good track record of optical characteristics and has sufficient optical design know-how is provided. The color adjustment valve 130 controls the time-series division of the second and third colors of light of the second light beam 52, and the beam splitter 120
By controlling the transmission and reflection of the first light beam 51 and the second light beam 52 by A, a polarizing plate is made unnecessary. Further, since unnecessary emission of light can be concentrated on the side of the beam splitter, the cooling design of the two-panel transmission type liquid crystal projector 100A can be facilitated.

Embodiment 2 Hereinafter, a two-panel transmissive liquid crystal projector 100B according to Embodiment 2 will be described.
This will be described with reference to FIG. FIG. 2 is a schematic diagram showing a structure of a two-panel transmissive liquid crystal projector 100B in the present embodiment. Note that the basic configuration of the two-panel transmissive liquid crystal projector 100B is the same as that of the two-panel transmissive liquid crystal projector 100A in the first embodiment, and therefore the same or corresponding parts are denoted by the same reference numerals and detailed description. Is omitted.

(Apparatus Configuration) 2 in the first embodiment
In the plate-type transmissive liquid crystal projector 100A, the reflection surface 121a is configured to emit unnecessary light to the side by the beam splitter 120A, but as shown in FIG.
The reflection surface 1 of the beam splitter 120B is configured to reflect unnecessary light in the directions of the first and second liquid crystal panels 91 and 92.
21b can also be configured.

(Function / Effect) As described above, according to the two-panel transmission type liquid crystal projector 100B in the present embodiment, unnecessary light returns to the light beam generating means 1, but a part of the light is used as an optical component such as a liquid crystal panel. Is reflected and absorbed. With this configuration, it is possible to facilitate the cooling design of the two-panel transmissive liquid crystal projector 100B, as in the case of the first embodiment.

In the first and second embodiments, the beam splitters 120a and 120b are formed so as to reflect the second polarization angle and pass the first polarization angle. Can be configured to reflect light and pass the second polarization angle. In this case, it should be noted that it is necessary to change the rotation of the polarization angle of each liquid crystal panel and color adjustment valve.

(Embodiment 3) Hereinafter, a two-panel transmission type liquid crystal projector 100C according to Embodiment 3 will be described.
This will be described with reference to FIG. FIG. 3 is a schematic diagram showing a structure of a two-panel transmission type liquid crystal projector 100C in the present embodiment. Note that the basic configuration of the two-panel transmissive liquid crystal projector 100C is the same as that of the two-panel transmissive liquid crystal projector 100A in the first embodiment, and therefore the same or corresponding parts are denoted by the same reference numerals and detailed description. Is omitted.

(Apparatus configuration) 2 in the first embodiment
In the plate-type transmissive liquid crystal projector 100A, the color adjustment valve 130 is disposed behind the dichroic mirror 4, and the second light beam 52 including the second and third colors is separated by the color adjustment valve 130. In the plate-type transmission type liquid crystal projector 100C, as shown in FIG. 3, a color adjusting valve 130 is disposed between the dichroic mirror 4 and the light beam generating means 1.

At this time, the first color light and the second color light, or the first color light and the third color light pass through the color adjustment valve 130 in a time series. The control valve 130 is controlled.

The ultra-high pressure mercury lamp used as a light source has low red characteristics, and it is desirable to use red as the first color, blue as the second color, and green as the third color. In general, human eyes perceive blue as weaker than other colors. Therefore, when the color balance of the light source is substantially uniform, it is preferable to increase the amount of blue light. In such a case, it is desirable that the first color be blue.

(Operation / Effect) As described above, in the two-panel transmissive liquid crystal projector 100C of the present embodiment,
The same operation and effect as in the first embodiment can be obtained.

Embodiment 4 Hereinafter, a two-panel transmissive liquid crystal projector 100D according to Embodiment 4 will be described.
This will be described with reference to FIG. FIG. 4 is a schematic diagram showing a structure of a two-panel transmissive liquid crystal projector 100D according to the present embodiment.

(Device Configuration) Referring to FIG. 4, this two-panel transmission type liquid crystal projector 100A includes
It has a first color adjustment valve 131 and a first beam splitter 121.

In the first optical path, a first dichroic mirror 41, a first total reflection mirror 81, and a transmission type first
A liquid crystal panel 91 is provided.

A second color adjustment valve 1 is provided in the second optical path.
32, a second dichroic mirror 42, a second total reflection mirror 82, and a transmissive second liquid crystal panel 92 are arranged. In the confluence area of the first optical path and the second optical path,
The beam splitter 120A and the projection lens 7 are arranged.

In the light beam generating means 1, unpolarized red light (R) emitted from the liquid crystal projector light source,
White light including green light (G) and blue light (B) is radiated, and light 50 having a uniform distribution by the fly-eye lens and PS separation / combination and aligned with the first polarization angle is formed and emitted. Is done.

The light 50 emitted from the light beam generating means 1 is
The light enters the first color adjustment valve 131. The first color adjustment valve 131 polarizes the polarization angles of the first color and the second color (or only the first color) by 90 ° and converts the first light ray 51 and the second light ray 52 into a second polarization angle. Form.

On the emission side of the first color adjustment valve 131, a first beam splitter 121 is arranged. The light beam 51 having the second polarization angle is reflected by the first beam splitter 121 and bent to the first optical path. The light beam 52 having the first polarization angle travels straight through the first beam splitter 121 and travels along the second optical path.

The dichroic mirror 41 is provided on the first optical path.
Are disposed to reflect unnecessary light out of the optical path. In the second optical path, a second color adjustment valve 132 that operates in conjunction with the first color adjustment valve 131 and a second dichroic mirror 42 are arranged, and allow only one light to pass.

Light of one color, which has passed through the first optical path and the second optical path, respectively enters the first liquid crystal panel 91 and the second liquid crystal panel 92, is modulated, and then enters the beam splitter 120A. And synthesized. The combined light passes through the projection lens 7 and is projected on a screen.
At this time, unnecessary light that is not modulated by the liquid crystal panels 91 and 92 is guided out of the optical path by the beam splitter.

(Control method) Next, the control method
A control method of the color adjustment valve 130 and the second color adjustment valve 131 of the plate-type transmissive liquid crystal projector 100D will be described with reference to FIGS. The light of the first, second, and third colors will be described as red light (R), green light (G), and blue light (B), respectively.

The beam splitter 121 reflects the light having the second polarization angle and transmits the light having the first polarization angle (the light having the first polarization angle is reflected and the light having the second polarization angle is It is also possible to configure so as to transmit light. In this case, the first optical path and the second optical path are interchanged.

[First Mode] As shown in FIG.
In the mode (1), red light (R) and green light (G) are polarized as the first light ray 51 by the first color adjustment valve 130 to the second polarization angle, and blue light (B) is converted into the first light ray 52 as the first light ray 52.
Is maintained. The red light (R) and the green light (G) are bent by the first beam splitter 121 to the first optical path. The green light (G) is reflected out of the optical path by the first dichroic mirror 41, and only the red light (R) is reflected by the first total reflection mirror 81 and enters the first liquid crystal panel 91. The blue light (B) is incident on the second liquid crystal panel 92 without any action by the second color adjustment valve 131.

[Second Mode] As shown in FIG.
In the mode (1), red light (R) is polarized as the first light ray 51 by the first color adjustment valve 130 to the second polarization angle, and blue light (B) and green light (G) are emitted as the second light ray 52 into the first light ray. Is maintained. The red light (R) is bent by the first beam splitter 121 to the first optical path. The red light (R) passes through the first dichroic mirror 41 and
The light is reflected by the total reflection mirror 81 and enters the first liquid crystal panel 91. Of the second light rays 52, blue light (B) is reflected out of the optical path by the second dichroic mirror 42, and only green light (G) is reflected by the second total reflection mirror 82 and enters the second liquid crystal panel 92.

[Third Mode] As shown in FIG.
In the mode (1), blue light (B) is polarized as the first light ray 51 by the first color adjustment valve 130 to the second polarization angle, and red light (R) and green light (G) are emitted as the second light ray 52 in the first direction. Is maintained. The blue light (B) is bent by the first beam splitter 121 to the first optical path. The blue light (B) passes through the first dichroic mirror 41 and
The light is reflected by the total reflection mirror 81 and enters the first liquid crystal panel 91. Of the second light rays 52, the red light (R) is reflected out of the optical path by the second dichroic mirror 42, and only the green light (G) is reflected by the second total reflection mirror 82 and enters the second liquid crystal panel 92.

(Operation / Effect) As described above, in the two-panel transmission type liquid crystal projector 100D according to the present embodiment,
In the first mode, the first liquid crystal panel 91 emits red light (R), the second liquid crystal panel 92 emits blue light (B), and in the second mode, the first light
The liquid crystal panel 91 projects red light (R), the second liquid crystal panel 92 projects green light (G), and in the third mode, the first liquid crystal panel 91 projects blue light (B) and the second liquid crystal panel 92 projects green light (G). I do.
In addition, by adjusting the operation time of each of the first color adjustment valve 130 and the second color adjustment valve 131, the balance of the light amounts of red light (R), green light (G), and blue light (B) can be adjusted. And an optimum color tone can be realized. Light unnecessary for the screen is reflected out of the optical path except for a part of the light being absorbed by the second color adjustment valve 131.
00D cooling design is also facilitated.

In this embodiment, the first dichroic mirror 41 and the second dichroic mirror 42 are used, but a color adjusting valve can be used instead of the dichroic mirror. In this case, the second
Color adjustment valve 131 and second dichroic mirror 4
2 can be integrated.

The embodiments disclosed herein are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0064]

According to the two-panel transmissive liquid crystal projector based on the present invention, a transmissive liquid crystal panel which has abundant experience in optical characteristics and has sufficient accumulation of optical design know-how is provided.
And the second beam of the second ray is
By controlling the time-series division of the light of the third color and controlling the transmission and reflection of the first light beam and the second light beam by the beam splitter, the polarizing plate becomes unnecessary.
Further, since the emission of unnecessary light can be concentrated on the side of the beam splitter, it is possible to facilitate the cooling design of the two-panel transmission type liquid crystal projector.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a two-panel transmissive liquid crystal projector 100A according to a first embodiment based on the present invention.

FIG. 2 is a configuration diagram of a two-panel transmissive liquid crystal projector 100B according to a second embodiment based on the present invention.

FIG. 3 is a configuration diagram of a two-panel transmissive liquid crystal projector 100C according to a third embodiment based on the present invention.

FIG. 4 is a configuration diagram of a two-panel transmissive liquid crystal projector 100D according to a fourth embodiment based on the present invention.

FIG. 5 is a configuration diagram showing a first mode of a two-panel transmissive liquid crystal projector 100D according to a fourth embodiment based on the present invention.

FIG. 6 is a configuration diagram showing a second mode of a two-panel transmissive liquid crystal projector 100D according to a fourth embodiment based on the present invention.

FIG. 7 is a configuration diagram illustrating a third mode of a two-panel transmissive liquid crystal projector 100D according to a fourth embodiment of the present invention.

FIG. 8 is a configuration diagram of a three-panel transmissive liquid crystal projector according to the related art.

FIG. 9 is a configuration diagram of a two-panel reflective liquid crystal projector according to the related art.

[Explanation of symbols]

1 light beam generating means, 4 dichroic mirror, 7 projection lens, 41 first dichroic mirror, 42 second dichroic mirror, 50 light, 51 first light beam,
52 second ray, 81 first total reflection mirror, 82 second
Total reflection mirror, 91 first liquid crystal panel, 92 second liquid crystal panel, 100A, 100B, 100C, 100D 2
Plate type transmissive liquid crystal projector, 120A beam splitter, 121 first beam splitter, 121a, 12
1b Reflection surface, 130 color adjustment valve, 131 first color adjustment valve, 132 second color adjustment valve.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 EA15 HA13 HA20 HA21 HA24 HA28 MA20 2H091 FA05X FA05Z FA08X FA08Z FA10X FA14Y FA41X FA41Z LA04 LA11

Claims (6)

[Claims] 1. A light beam generating means for emitting a light beam including a first light beam and a second light beam having a first polarization angle; and a dichroic mirror for separating the light beam into the first light beam and the second light beam. A first liquid crystal panel on which the first light beam is incident, a color adjustment valve on which the second light beam is incident, and performs time-series division of light included in the second light beam, and a light emitted from the color adjustment valve. A second liquid crystal panel on which a second light ray is incident; a beam splitter for combining a first light ray transmitted through the first liquid crystal panel and a second light ray transmitted through the second liquid crystal panel; A projection lens into which light is incident, 2
Plate-type transmissive liquid crystal projector. 2. The method according to claim 2, wherein the first light beam includes light of a first color, the second light beam includes light of second and third colors, and the color adjustment valve includes a second light beam of the second light beam. The two-panel transmissive liquid crystal projector according to claim 1, wherein one of the two colors or the third color light is selected and emitted. 3. A light beam generating means 1 for emitting a light beam having a first polarization angle; and separating the light beam into a first light beam having a first polarization angle and a second light beam having a second polarization angle. A first color adjustment valve that guides the first light beam to a first optical path and directs the second light beam to a second light beam.
A first beam splitter for guiding the first light beam to the first light path, a first dichroic mirror through which the first light beam passes, and a first light beam through which the first light beam passes through the first dichroic mirror. A liquid crystal panel, a second dichroic mirror disposed in a second optical path and transmitting the second light beam, a second liquid crystal panel receiving the second light beam transmitted through the second dichroic mirror, and the first liquid crystal panel. A second beam splitter for combining the first light beam transmitted through the liquid crystal panel and the second light beam transmitted through the second liquid crystal panel; and a projection lens into which the combined light is incident.
Plate-type transmissive liquid crystal projector. 4. The first light beam includes light of a first color and a second color, the second light beam includes a light of a third color, and the first dichroic mirror generates a light beam of the first light beam. 4. The two-panel transmissive liquid crystal projector according to claim 3, wherein one of the first and second colors of light is selected. 5. The first light beam includes light of a first color, the second light beam includes light of second and third colors, and the second light beam is controlled by the first color adjustment valve. Second
4. The two-panel transmissive liquid crystal projector according to claim 3, wherein any one of the third color lights is selected. 6. The first light beam includes light of a first color, the second light beam includes light of a second and a third color, and the second dichroic mirror generates a light beam of the second light beam. 4. The two-panel transmissive liquid crystal projector according to claim 3, wherein light of any one of the second and third colors is selected.