JPH09244016A - Rear projection type liquid crystal projector device - Google Patents

Abstract

(57) [PROBLEMS] To provide a rear projection type liquid crystal projector device capable of preventing deterioration of the contrast of a projected image and improving the image quality. A light source lamp 111 and a parabolic mirror 113.
A first polarizing plate 119 for limiting the passage of substantially parallel light obtained from the parabolic mirror 113, a liquid crystal panel 121, a second polarizing plate 123 for passing only arbitrary polarized light, and a projection lens 127. In a rear projection type liquid crystal projector device including a Fresnel lens 129 and a lenticular lens 131, a third polarizing plate 1 provided at an arbitrary position from the projection lens 127 to the front surface of the lenticular lens 131.
3, the second polarizing plate 123 and the third polarizing plate 13 are provided at arbitrary positions up to the front surface, and the polarization direction of the light passing through the second polarizing plate 123 is converted to change the polarization direction of the third polarizing plate 13. And a retardation plate 11 that matches the polarization direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnifying projection apparatus for reproducing an image on a television or the like, and more particularly to a rear projection type liquid crystal projector apparatus for projecting an image from the back side of a screen by using a liquid crystal panel as an optical shutter. .

[0002]

2. Description of the Related Art In recent years, wide-screen broadcasting of terrestrial television broadcasting has begun following high-definition broadcasting. Also, with the spread of cable television, the upcoming digital television broadcasting, and the introduction of high-resolution software such as digital video discs, a high-quality large-screen image reproducing apparatus is desired. However, the CRT used in the conventional direct-view display device has a limit of about 40-inch due to manufacturing technology, manufacturing cost, product size and weight, and the like. Therefore, there is a front projection type or rear projection type projector system for realizing a larger screen.

Further, these projector systems have a CRT system and a liquid crystal system, respectively, depending on the device forming the original screen to be enlarged and projected, and the liquid crystal system is inferior in the maximum brightness as compared with the CRT system, but the focus is low. It is believed to be superior in terms of performance, equipment weight and volume.

FIG. 14 is a system configuration diagram showing an outline of a conventional rear projection type liquid crystal projector device. FIG. 15 is a sectional view of this rear projection type liquid crystal projector device. In FIG. 14, a conventional rear projection type liquid crystal projector device 101 includes a light source lamp 111 as a light source,
A power supply circuit 113 for supplying power to the light source lamp 111,
A parabolic mirror 115 arranged so that the light source lamp 111 is located at the focal point, and UV for cutting ultraviolet rays and infrared rays
An IR filter 117, a first polarizing plate 119 that constitutes an optical shutter that reproduces an image, a liquid crystal panel 121 and a second polarizing plate 123, a projection lens 127 that magnifies and projects a reproduced image, and a screen. A Fresnel lens 129, a lenticular lens 131, a video input terminal 133 to which a video signal is input, and a signal processing circuit 135 that generates a liquid crystal panel drive signal from the video signal.

The operation of the conventional rear projection type liquid crystal projector device 101 is as follows. First, a light source lamp 1 using a halogen lamp, a metal halide lamp, etc.
11 receives light from the power supply circuit 113 and emits light. The light emitted from the light source lamp 111 is parabolic mirror 1
The light is controlled and reflected by the light beam 15 into substantially parallel light that is emitted to the right.

Next, the UV / IR filter 117 cuts the wavelengths in the ultraviolet and infrared regions, which are unnecessary and harmful for image formation, from the substantially parallel light obtained from the parabolic mirror 115. Then, substantially parallel light in the wavelength range of visible light is incident on the first polarizing plate 119 in order to limit and pass the polarization direction. The substantially parallel light linearly polarized by the first polarizing plate 119 enters a liquid crystal panel 121 including a plurality of liquid crystal cells arranged in a matrix so as to control the respective optical rotatory powers, and a signal processing circuit. The optical rotatory spatial distribution of each liquid crystal cell is given according to the liquid crystal panel drive signal given from 135.

Next, the light having the optical rotatory spatial distribution provided by the liquid crystal panel 121 is made incident on the second polarizing plate 123, and only the light of an arbitrary polarization direction is selectively passed from the second polarizing plate 123. By doing so, the optical rotatory spatial distribution is converted into light having a spatial distribution of light intensity, that is, a bright and dark spatial distribution (light that carries an image).

Next, as shown in FIG. 15, the direction of the light passing through the second polarizing plate 123 is changed by the first reflecting plate 137 provided between the second polarizing plate 123 and the projection lens 127. Then, it is made incident on the projection lens 127. Next, from this projection lens 127 to the Fresnel lens 129
Also, the image is enlarged and projected toward the back surface of the screen configured by the lenticular lens 131.

The Fresnel lens 129 is the projection lens 12
The light emitted from 7 is condensed at the observation position, and the lenticular lens 131 controls and / or diffuses the light passing through the Fresnel lens 129 in an arbitrary direction.

On the other hand, the signal processing circuit 135 generates a liquid crystal panel drive signal for controlling the optical rotatory power of each cell of the liquid crystal panel 121 based on the video signal input to the video input terminal 133.

The rear projection type liquid crystal projector device 101 is housed in a housing in which the front surface of the lenticular lens 131 is exposed, and is observed from the right side of the lenticular lens 131 by an observer having a viewpoint of 141.

[0012]

However, in the conventional rear projection type liquid crystal projector device 101, the lenticular lens 1 is used when the surroundings are bright such as in a normal room.
The ambient light is reflected on 31, so the contrast is reduced,
There was a problem that the image was hard to see.

The present invention has been made in view of the above problems, and an object thereof is to provide a rear projection type liquid crystal projector device capable of preventing deterioration of the contrast of a projected image and improving the image quality. To do.

[0014]

To achieve the above object, the invention according to claim 1 is directed to a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into substantially parallel light, and the parabola. The first polarizing plate that restricts and passes the polarization direction of the substantially parallel light obtained from the surface mirror, and the substantially parallel light that has passed through the first polarizing plate are irradiated, and the respective optical rotatory powers can be controlled. A liquid crystal panel having a plurality of liquid crystal cells arranged in a matrix, a second polarizing plate for selectively passing only light in an arbitrary polarization direction from light passing through the liquid crystal panel, and a second polarizing plate. A projection lens that magnifies and projects the light that has passed through the plate, a Fresnel lens that focuses the light emitted from this projection lens at an arbitrary position, and a lenticular lens that controls and / or diffuses the light that has passed through this Fresnel lens in an arbitrary direction. A rear projection type liquid crystal projector device including: a third projection that is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and reduces reflection by light other than light emitted from the light source lamp. Is provided at an arbitrary position up to the front surfaces of the second polarizing plate and the second polarizing plate, and the polarization direction of light passing through the second polarizing plate is converted to change the polarization direction of the third polarizing plate. The gist of the present invention is to include a polarization direction conversion unit that matches the polarization direction of the polarizing plate.

In the rear projection type liquid crystal projector device according to the first aspect, the light excluding the light emitted from the light source lamp is provided by the third polarizing plate provided at an arbitrary position from the projection lens to the front surface of the lenticular lens. The reflection direction is reduced, and the polarization direction conversion means provided at any position up to the front surfaces of the second polarizing plate and the third polarizing plate converts the polarization direction of the light passing through the second polarizing plate. The polarization direction of the third polarizing plate is adjusted. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

According to a second aspect of the present invention, there is provided a light source lamp, a parabolic mirror which controls and reflects light emitted from the light source lamp into substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate that restricts and passes a polarization direction, and substantially parallel light that has passed through the first polarizing plate is irradiated and arranged in a matrix so that the respective optical rotatory powers thereof can be controlled. A liquid crystal panel including a plurality of liquid crystal cells whose directions are oblique to the image scanning direction; a second polarizing plate that selectively allows only the light in the oblique direction to pass from the light that has passed through the liquid crystal panel; A projection lens that magnifies and projects the light that has passed through the second polarizing plate, a Fresnel lens that condenses the light emitted from this projection lens at an arbitrary position, and controls and / or diffuses the light that has passed through this Fresnel lens in an arbitrary direction. You In a rear projection type liquid crystal projector device including a lenticular lens, the liquid crystal projector is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and has a polarization characteristic of transmitting only light in the same direction as the image scanning direction. A third polarizing plate that reduces reflection by light other than the light emitted from the light source lamp, and the second polarizing plate and the third polarizing plate are provided at arbitrary positions up to the front surface of the third polarizing plate. And a polarization direction conversion means for converting the polarization direction of the light passing through the second polarizing plate to match the polarization characteristic of the third polarizing plate.

In the rear projection type liquid crystal projector device according to the second aspect, the third polarizing plate provided at an arbitrary position from the projection lens to the front surface of the lenticular lens allows light in the same direction as the image scanning direction. Only the light passing through the second light source lamp is reduced, and reflection by light other than the light emitted from the light source lamp is reduced. The polarization direction of the light that has passed through the polarizing plate is converted to match the polarization characteristic of the third polarizing plate. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

Further, according to the invention of claim 3, a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into a substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate for limiting the polarization direction, and a first polarizing plate
A plurality of liquid crystal cells that are irradiated with substantially parallel light that has passed through the polarizing plate and are arranged in a matrix so that their respective optical rotatory powers can be controlled and whose transmission axis direction is oblique to the image scanning direction. A liquid crystal panel, a second polarizing plate for selectively passing only the light in the oblique direction from the light passing through the liquid crystal panel, and a projection lens for enlarging and projecting the light passing through the second polarizing plate, Rear projection type liquid crystal projector device including a Fresnel lens for condensing light emitted from the projection lens at an arbitrary position and a lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction Is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens, and allows only polarized light perpendicular to the image scanning direction to pass through. A third polarizing plate having a polarization characteristic for reducing reflection by light other than light emitted from the light source lamp, and provided at an arbitrary position up to the front surfaces of the second polarizing plate and the third polarizing plate. And a polarization direction conversion means for converting the polarization direction of the light passing through the second polarizing plate to match the polarization characteristic of the third polarizing plate.

According to another aspect of the present invention, there is provided a rear projection type liquid crystal projector device having a polarization characteristic which is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and which transmits only polarized light in a direction perpendicular to the image scanning direction. Have third
The polarizing plate reduces the reflection of light other than the light emitted from the light source lamp, and the polarization direction changing means provided at any position up to the front surfaces of the second polarizing plate and the third polarizing plate allows The polarization direction of the light passing through the second polarizing plate is converted to match the polarization characteristic of the third polarizing plate. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

Further, according to the invention of claim 4, a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into a substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate for limiting the polarization direction, and a first polarizing plate
A plurality of liquid crystal cells that are irradiated with substantially parallel light that has passed through the polarizing plate and are arranged in a matrix so that their respective optical rotatory powers can be controlled and whose transmission axis direction is oblique to the image scanning direction. A liquid crystal panel provided, polarization direction converting means for converting the polarization direction of light passing through the liquid crystal panel to the same direction as the image scanning direction, and only light from the light passing through the polarization direction converting means in the same direction as the image scanning direction. A second polarizing plate that selectively passes light, a projection lens that magnifies and projects the light that has passed through the second polarizing plate, and a Fresnel lens that condenses the light emitted from the projection lens at an arbitrary position, A lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction, and a lenticular lens provided at an arbitrary position from the projection lens to the front surface of the lenticular lens. Have the same polarization characteristics as the second polarizing plate, and summarized in that and a third polarizing plate to reduce the reflection by light except the light emitted from the light source lamp.

In the rear projection type liquid crystal projector device according to the fourth aspect, the polarization direction conversion means causes the polarization direction of light passing through the liquid crystal panel whose transmission axis direction is oblique to the image scanning direction to perform image scanning. The light except the light emitted from the light source lamp is converted by the third polarizing plate, which is converted into the same direction as the second polarizing plate and has the same polarization characteristics as the second polarizing plate, provided at any position from the projection lens to the front surface of the lenticular lens. The reflection due to is reduced. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

Further, according to the invention of claim 5, a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into a substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate for limiting the polarization direction, and a first polarizing plate
A plurality of liquid crystal cells that are irradiated with substantially parallel light that has passed through the polarizing plate and are arranged in a matrix so that their respective optical rotatory powers can be controlled and whose transmission axis direction is oblique to the image scanning direction. A liquid crystal panel provided, polarization direction conversion means for converting the polarization direction of light passing through the liquid crystal panel into a direction vertical to the image scanning direction, and light passing through the polarization direction conversion means for direction perpendicular to the image scanning direction. A second polarizing plate that selectively passes only polarized light; and a projection lens that magnifies and projects the light that has passed through the second polarizing plate,
A Fresnel lens for condensing the light emitted from this projection lens at an arbitrary position, a lenticular lens for controlling and / or diffusing the light passing through this Fresnel lens in an arbitrary direction, and an arbitrary distance from the projection lens to the front surface of the lenticular lens. And a third polarizing plate which is provided at the same position and which has the same polarization characteristics as the second polarizing plate and reduces reflection by light other than the light emitted from the light source lamp.

In the rear projection type liquid crystal projector device according to the fifth aspect, the polarization direction converting means causes the polarization direction of light passing through the liquid crystal panel whose transmission axis direction is oblique to the image scanning direction to perform image scanning. The light emitted from the light source lamp is converted by the third polarizing plate, which is converted to the direction perpendicular to the direction, is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens, and has the same polarization characteristics as the second polarizing plate. The reflection by the excluded light is reduced. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

Further, in the invention according to claim 6, a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate for limiting the polarization direction, and a first polarizing plate
It is equipped with a plurality of liquid crystal cells that are irradiated with substantially parallel light that has passed through the polarizing plate and are arranged in a matrix so that their respective optical rotatory powers can be controlled and whose transmission axis direction is the same direction as the image scanning direction. A liquid crystal panel, a second polarizing plate for selectively passing only the light in the same direction as the image scanning direction from the light passing through the liquid crystal panel, and a projection lens for enlarging and projecting the light passing through the second polarizing plate. A rear projection type liquid crystal including a Fresnel lens for condensing the light emitted from the projection lens at an arbitrary position and a lenticular lens for controlling and / or diffusing the light passing through the Fresnel lens in an arbitrary direction. In the projector device, it is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens, and transmits only polarized light in a direction perpendicular to the image scanning direction. A third polarizing plate having a polarization characteristic for reducing the reflection by light other than the light emitted from the light source lamp, and at an arbitrary position up to the front surfaces of the second polarizing plate and the third polarizing plate. The gist of the present invention is to provide polarization direction conversion means that is provided and that converts the polarization direction of the light that has passed through the second polarizing plate to match the polarization characteristics of the third polarizing plate.

According to a sixth aspect of the present invention, there is provided a rear projection type liquid crystal projector device, wherein the polarized light is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and passes only polarized light in a direction perpendicular to a video scanning direction. The third polarizing plate having the characteristics reduces reflection by light other than the light emitted from the light source lamp, and the polarization direction provided at any position up to the front faces of the second polarizing plate and the third polarizing plate. The conversion means converts the polarization direction of the light passing through the second polarizing plate to match the polarization characteristic of the third polarizing plate. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

Further, in the invention according to claim 7, a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into a substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate for limiting the polarization direction, and a first polarizing plate
A plurality of liquid crystal cells, which are arranged in a matrix so that their respective optical rotatory powers can be controlled while being irradiated with substantially parallel light that has passed through the polarizing plate, and whose transmission axis direction is perpendicular to the image scanning direction. A liquid crystal panel provided, a second polarizing plate that selectively passes only the polarized light in the direction perpendicular to the image scanning direction from the light that has passed through the liquid crystal panel, and the light that has passed through the second polarizing plate is enlarged and projected. A projection lens,
Rear projection type liquid crystal projector device including a Fresnel lens for condensing light emitted from the projection lens at an arbitrary position and a lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction In the above, at the arbitrary position from the projection lens to the front surface of the lenticular lens, there is a polarization characteristic that allows only light in the same direction as the image scanning direction to pass, and reflection by light other than light emitted from the light source lamp is performed. The third polarizing plate to be reduced, and the second polarizing plate and the third polarizing plate are provided at arbitrary positions up to the front surface of the third polarizing plate to convert the polarization direction of the light passing through the second polarizing plate. The gist of the present invention is to provide a polarization direction conversion unit adapted to the polarization characteristic of the third polarizing plate.

In the rear projection type liquid crystal projector device according to the seventh aspect, the liquid crystal projector device is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens, and has a polarization characteristic of transmitting only light in the same direction as the image scanning direction. The third polarizing plate reduces reflection by light other than the light emitted from the light source lamp, and the polarization direction converting means provided at any position up to the front surfaces of the second polarizing plate and the third polarizing plate,
The polarization direction of the light passing through the second polarizing plate is converted to the third direction.
It is adjusted to the polarization characteristics of the polarizing plate. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

Further, the invention according to claim 8 is such that a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into a substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate for limiting the polarization direction, and a first polarizing plate
A plurality of liquid crystal cells, which are arranged in a matrix so that their respective optical rotatory powers can be controlled while being irradiated with substantially parallel light that has passed through the polarizing plate, and whose transmission axis direction is perpendicular to the image scanning direction. A liquid crystal panel provided, polarization direction converting means for converting the polarization direction of light passing through the liquid crystal panel to the same direction as the image scanning direction, and only light from the light passing through the polarization direction converting means in the same direction as the image scanning direction. A second polarizing plate that selectively passes light, a projection lens that magnifies and projects the light that has passed through the second polarizing plate, and a Fresnel lens that condenses the light emitted from the projection lens at an arbitrary position, A lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction, and a lenticular lens provided at an arbitrary position from the projection lens to the front surface of the lenticular lens. Have the same polarization characteristics as the second polarizing plate, and summarized in that and a third polarizing plate to reduce the reflection by light except the light emitted from the light source lamp.

In the rear projection type liquid crystal projector device according to the eighth aspect, the polarization direction converting means causes the polarization direction of light passing through the liquid crystal panel whose transmission axis direction is perpendicular to the image scanning direction to perform image scanning. The light emitted from the light source lamp is removed by the third polarizing plate which is converted to the same direction and is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and which has the same polarization characteristic as the second polarizing plate. Light reflection is reduced. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

Further, the invention according to claim 9 is such that a light source lamp, a parabolic mirror for controlling and reflecting the light emitted from the light source lamp into a substantially parallel light, and a substantially parallel light obtained from the parabolic mirror. A first polarizing plate for limiting the polarization direction, and a first polarizing plate
It is equipped with a plurality of liquid crystal cells that are irradiated with substantially parallel light that has passed through the polarizing plate and are arranged in a matrix so that their respective optical rotatory powers can be controlled and whose transmission axis direction is the same direction as the image scanning direction. A liquid crystal panel, a polarization direction converting means for converting the polarization direction of light passing through the liquid crystal panel into a direction perpendicular to the image scanning direction, and a polarization direction perpendicular to the image scanning direction from the light passing through the polarization direction converting means. A second polarizing plate that selectively passes only the second polarizing plate, a projection lens that magnifies and projects the light that has passed through the second polarizing plate, and a Fresnel lens that condenses the light emitted from the projection lens at an arbitrary position. , A lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction, and an arbitrary position from the projection lens to the front surface of the lenticular lens. Vignetting, have the same polarization characteristics as the second polarizing plate, and summarized in that and a third polarizing plate to reduce the reflection by light except the light emitted from the light source lamp.

In the rear projection type liquid crystal projector device according to the ninth aspect, the polarization direction converting means causes the polarization direction of light passing through the liquid crystal panel whose transmission axis direction is the same direction as the image scanning direction to be the image scanning direction. The light except the light emitted from the light source lamp is converted by the third polarizing plate that is converted to the vertical direction, is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens, and has the same polarization characteristics as the second polarizing plate. The reflection due to is reduced. Therefore, it is possible to prevent the contrast of the projected image from being lowered and improve the image quality.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration diagram showing an outline of a first embodiment of a rear projection type liquid crystal projector device according to the present invention. In the figure, the same parts as those shown in FIG. 14 are designated by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 1, the rear projection type liquid crystal projector device 1 according to the first embodiment has a second polarizing plate 123 and a projection lens in addition to the conventional rear projection type liquid crystal projector device 101 shown in FIG. A normal retardation plate 11 as a polarization direction conversion means is provided between 127, and a third polarizing plate 13 is provided outside the lenticular lens 131, and
When the polarization directions of the second polarizing plate 123 and the third polarizing plate 13 are different from each other, the polarization direction of the light passing through the second polarizing plate 123 is converted by the phase difference plate 11 and the polarization direction of the third polarizing plate 13 is changed. It is adapted to.

The phase difference plate 11 is provided between the second polarizing plate 123 and the projection lens 127, and the phase difference between the component vibrating in the x-axis direction and the component vibrating in the z-axis direction is ¼ wavelength. A λ / 4 wavelength plate, which converts the polarization direction of light that has passed through the second polarization plate 123 (the polarization direction forming an angle of approximately 45 degrees with respect to the image scanning direction) to the polarization direction of the third polarization plate 13. (The same direction as the video scanning direction or the direction perpendicular to the video scanning direction).

As the phase difference plate 11, for example, a plastic sheet phase difference plate which applies a stress to a plastic sheet and produces a phase difference by the photoelastic effect of its residual strain,
A retardation plate made of a crystal exhibiting birefringence that produces a phase difference by controlling the thickness of a birefringent crystal such as quartz or calcite or by joining two crystal plates having a phase difference is used. Alternatively, a substance that causes or changes birefringence due to an electric field or a magnetic field may be used as the retardation plate 11, and the electric field or magnetic field applied to this substance may be changed to adjust the phase difference. The retardation plate 11 is arranged so that the polarization direction after conversion matches the polarization direction of the third polarizing plate 13.

The third polarizing plate 13 is bonded to the outside of the lenticular lens 131, and its polarization direction is the same direction as the image scanning direction (horizontal direction) or the direction vertical to the image scanning direction (vertical direction). It reduces the reflection of light other than the light emitted from the lamp 111, for example, ambient light.

Next, the operation of the first embodiment will be described with reference to FIGS. In addition, here, as shown in FIG.
When the polarization direction of the polarizing plate 13 is the same direction (horizontal direction) as the image scanning direction, and when the polarization direction of the third polarizing plate 13 is vertical to the image scanning direction (longitudinal direction), as shown in FIG. ) Is divided into two and explained. 2 and 4, the light source lamp 111 and the power supply circuit 11 shown in FIG.
3, UV / IR filter 117, and video input terminal 133
The signal processing circuit 135 is omitted.

First, FIGS. 2 and 3 show the case where the polarization direction of the third polarizing plate 13 is the same as the image scanning direction (transverse direction).
Will be mainly described.

In this state, first, the light source lamp 1 shown in FIG.
11 receives light from the power supply circuit 113 and emits light. The light emitted from the light source lamp 111 is parabolic mirror 1
The light is controlled and reflected by the light beam 15 into substantially parallel light that is emitted to the right.

Then, from the substantially parallel light obtained from the parabolic mirror 115, the UV / IR filter 117 cuts wavelengths in the ultraviolet and infrared regions which are unnecessary and harmful for image formation. Then, substantially parallel light in the wavelength range of visible light is incident on the first polarizing plate 119 in order to limit and pass the polarization direction.

The light incident on the first polarizing plate 119 includes light in all directions as indicated by "incident light" in FIG. Therefore, in the first polarizing plate 119, of the incident light, only the light forming an angle of about 45 degrees with respect to the image scanning direction is allowed to pass as shown in the "first polarizing plate" in FIG. Then, the light passing through the first polarizing plate is incident on the liquid crystal panel 121 as shown in FIG.

Then, in the liquid crystal panel 121, the incident light is switched from the voltage on state to the voltage off state as shown in the "liquid crystal panel" of FIG. 3 according to the liquid crystal panel drive signal given from the signal processing circuit 135. It rotates about 90 degrees. Then, the light rotated by about 90 degrees is incident on the second polarizing plate 123 as shown in FIG.

Next, in the second polarizing plate 123, as shown in the "second polarizing plate" of FIG. 3, only the light of the polarization direction which is the same as the transmission axis direction of the liquid crystal panel 121 is selectively transmitted. Then, the light passing through the second polarizing plate 123 is incident on the retardation plate 11 as shown in FIG.

Next, in the retardation plate 11, as shown in the "retardation plate" of FIG. 3, the polarization direction is changed from the polarization direction of the light passing through the second polarizing plate 123 (the direction of the broken line) to the third polarizing plate. 1
The polarization direction of 3 (solid line direction), that is, the same direction as the image scanning direction is converted.

The light whose polarization direction has been converted is incident on the projection lens 127 via a reflection plate (not shown) and projected as an image on the Fresnel lens 129 via a reflection plate (not shown). This projected image is the Fresnel lens 1
The lenticular lens 1 is focused on the observation position by 29.
31 controls and / or diffuses in any direction. That is, the Fresnel lens 129 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 131 widens the viewing angle.

Then, as shown in the "third polarizing plate" in FIG. 3, the third polarizing plate 13 allows only light in the same direction as the image scanning direction to pass therethrough. At this time, since the polarization direction is converted to the same direction as the image scanning direction by the phase difference plate 11, the brightness and contrast of the image do not decrease. Also,
Since the third polarizing plate 13 allows only the light in the same direction as the image scanning direction to pass through, the light excluding the light emitted from the light source lamp 111, for example, the reflection of the polarized light in the direction perpendicular to the image scanning direction among the ambient light. Can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

Next, a case where the polarization direction of the third polarizing plate 13 is vertical to the image scanning direction (longitudinal direction) will be described with reference to FIGS. 3 and 4. The operations of the light source lamp 111, the parabolic mirror 115, the first polarizing plate 119, the liquid crystal panel 121, and the second polarizing plate 123 are such that the polarization direction of the third polarizing plate 13 is the same as the image scanning direction. Since it is the same as the case of the direction (lateral direction), the operation from the retardation plate 11 will be described here.

When the polarization direction of the third polarizing plate 13 is perpendicular to the image scanning direction (longitudinal direction), the retardation plate 11
Then, as shown in the "retardation plate" of FIG.
Polarization direction of light that has passed through the polarizing plate 123 of (the direction of the broken line)
To the polarization direction (solid line direction) of the third polarizing plate 13, that is, the direction perpendicular to the image scanning direction.

The light whose polarization direction is changed is incident on the projection lens 127 via a reflection plate (not shown) and projected as an image on the Fresnel lens 129 via a reflection plate (not shown). This projected image is the Fresnel lens 1
The lenticular lens 1 is focused on the observation position by 29.
31 controls and / or diffuses in any direction. That is, the Fresnel lens 129 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 131 widens the viewing angle.

Then, in the third polarizing plate 13, as shown in "third polarizing plate" in FIG. 5, only the polarized light in the direction perpendicular to the image scanning direction is passed. At this time, the phase difference plate 1
Since the polarization direction is converted to the direction perpendicular to the image scanning direction by 1, the brightness and contrast of the image are not lowered. Further, since the third polarizing plate 13 allows only the polarized light in the direction perpendicular to the image scanning direction to pass therethrough, the light source lamp 111
It is possible to prevent reflection of light other than the light emitted further, for example, of ambient light, which is in the same direction as the image scanning direction. For this reason,
It is possible to prevent the contrast of the screen from being lowered.

As described above, in the first embodiment, since the third polarizing plate 13 is provided outside the lenticular lens 131, light excluding the light emitted from the light source lamp 111,
For example, reflection due to ambient light can be reduced, and the rate of screen contrast reduction can be reduced. Further, in the first embodiment, the polarization direction of the light passing through the second polarizing plate 123 is matched with the polarization direction of the third polarizing plate 13 using the retardation plate 11, so that the liquid crystal panel 121 is It is not necessary to newly manufacture the third polarizing plate 13 in accordance with the polarization direction of the third polarizing plate, and only the phase difference plate 11 and the third polarizing plate 13 are arranged in the conventional rear projection type liquid crystal projector device, which is substantially the same as the conventional one. It is possible to manufacture the rear projection type liquid crystal projector device 1 at a manufacturing cost of the order.

Further, other products such as a liquid crystal panel for a display device of a personal computer and a liquid crystal panel for a liquid crystal television have a transmission axis in order to widen a viewing angle in the same direction as the image scanning direction (horizontal direction). Generally, the direction is oblique to the image scanning direction, but in the first embodiment, the transmission axis direction of the liquid crystal panel 121 used is oblique to the image scanning direction (approximately 45 degrees), and the liquid crystal Since the polarization direction of the light that has passed through the panel 121 and the second polarizing plate 123 is aligned with the polarization direction of the third polarizing plate 13 using the retardation plate 11, the liquid crystal panel of other products can be shared or used. It is possible to share the manufacturing process of the liquid crystal panel of this product.

Next, a second embodiment of the rear projection type liquid crystal projector device according to the present invention will be described with reference to FIGS. The same components as those of the rear projection type liquid crystal projector device 1 of the first embodiment shown in FIG. 1 are designated by the same reference numerals and detailed description thereof is omitted.

In the second embodiment, in addition to the conventional rear projection type liquid crystal projector device 101 shown in FIG. 14, as shown in FIGS. 6 and 8, a liquid crystal panel 121 and a second polarizing plate 1 are provided.
The phase difference plate 11 is provided between the two 23, and the third polarizing plate 13 having the same polarization direction as that of the second polarizing plate 123 is provided outside the lenticular lens 131, and the transmission axis direction of the liquid crystal panel 121 and the second polarizing plate 13 are provided. Polarizing plate 123 and third polarizing plate 13
In which the polarization directions of the light passing through the liquid crystal panel 121 are converted by the retardation plate 11 so as to match the polarization directions of the second polarizing plate 123 and the third polarizing plate 13. Is. In the second embodiment, the polarization directions of the second polarizing plate 123 and the third polarizing plate 13 are the same. 6 and 8, the light source lamp 111, the power supply circuit 113, the UV / IR filter 117, the video input terminal 133, and the signal processing circuit 135 shown in FIG. 1 are omitted.

Next, the operation of the second embodiment will be described with reference to FIGS. In addition, here, as shown in FIG.
When the polarization directions of the polarizing plate 123 and the third polarizing plate 13 are the same direction (horizontal direction) as the image scanning direction, and as shown in FIG. 8, the second polarizing plate 123 and the third polarizing plate 13 The case where the polarization direction is vertical to the image scanning direction (vertical direction) will be described separately.

First, a case where the polarization directions of the second polarizing plate 123 and the third polarizing plate 13 are the same as the image scanning direction (horizontal direction) will be described with reference to FIGS. 6 and 7. The operations of the light source lamp 111, the parabolic mirror 115, and the first polarizing plate 119 are the same as in the case of the first embodiment described above, so the operation from the liquid crystal panel 121 will be described here.

When the polarization directions of the second polarizing plate 123 and the third polarizing plate 13 are the same as the image scanning direction (horizontal direction), the liquid crystal panel 121 is driven by a liquid crystal panel driven by a signal processing circuit (not shown). In response to the signal, as shown in the "liquid crystal panel" in FIG. 7, the incident light is rotated by approximately 90 degrees by changing the voltage on state to the voltage off state. Then, the light that has been rotated by approximately 90 degrees is transmitted to the phase difference plate 1 as shown in FIG.
1 is incident.

Next, in the retardation plate 11, as shown in the “retardation plate” of FIG. 7, the polarization direction is changed from the polarization direction of the light passing through the liquid crystal panel 121 (the direction of the broken line) to the third polarizing plate 13.
The polarization direction (solid line direction), that is, the same direction as the image scanning direction is converted. The light whose polarization direction has been converted is incident on the projection lens 127 via a reflection plate (not shown) and projected as an image on the Fresnel lens 129 via a reflection plate (not shown). The projected image is condensed at the observation position by the Fresnel lens 129, and is controlled and / or diffused in an arbitrary direction by the lenticular lens 131.
That is, the Fresnel lens 129 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 131 widens the viewing angle.

Then, as shown in the "third polarizing plate" in FIG. 7, the third polarizing plate 13 allows only light in the same direction as the image scanning direction to pass therethrough. At this time, since the polarization direction is converted to the same direction as the image scanning direction by the phase difference plate 11, the brightness and contrast of the image do not decrease. Also,
Since the third polarizing plate 13 allows only the light in the same direction as the image scanning direction to pass through, the light excluding the light emitted from the light source lamp 111, for example, the reflection of the polarized light in the direction perpendicular to the image scanning direction among the ambient light. Can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

Next, the case where the polarization directions of the second polarizing plate 123 and the third polarizing plate 13 are vertical to the image scanning direction (longitudinal direction) will be described with reference to FIGS. 8 and 9. The light source lamp 111, the parabolic mirror 115, and the first polarizing plate 1
Since the operation of 19 is the same as that of the first embodiment described above, the operation from the liquid crystal panel 121 will be described here.

When the polarization directions of the second polarizing plate 123 and the third polarizing plate 13 are perpendicular to the image scanning direction (longitudinal direction), the liquid crystal panel 121 is driven by a liquid crystal panel driven by a signal processing circuit (not shown). In response to the signal, as shown in the "liquid crystal panel" in FIG. 9, the incident light is rotated by approximately 90 degrees by changing the voltage on state to the voltage off state. Then, the light that has been rotated by approximately 90 degrees is transmitted to the phase difference plate 1 as shown in FIG.
1 is incident.

Next, in the retardation plate 11, as shown in the “retardation plate” of FIG. 9, the polarization direction is changed from the polarization direction (the direction of the broken line) of the light passing through the liquid crystal panel 121 to the third polarizing plate 13.
The polarization direction (solid line direction), that is, the direction perpendicular to the image scanning direction is converted. The light whose polarization direction has been converted is incident on the projection lens 127 through a reflection plate (not shown), and the Fresnel lens 129 through a reflection plate (not shown).
Is projected as an image on. The projected image is condensed at the observation position by the Fresnel lens 129, and is controlled and / or diffused in an arbitrary direction by the lenticular lens 131. That is, the Fresnel lens 129 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 1
The viewing angle is widened by 31.

Then, in the third polarizing plate 13, as shown in the "third polarizing plate" in FIG. 9, only the polarized light in the direction perpendicular to the image scanning direction is passed. At this time, the phase difference plate 1
Since the polarization direction is converted to the direction perpendicular to the image scanning direction by 1, the brightness and contrast of the image are not lowered. Further, since the third polarizing plate 13 allows only the polarized light in the direction perpendicular to the image scanning direction to pass therethrough, the light source lamp 111
It is possible to prevent reflection of light other than the light emitted further, for example, of ambient light, which is in the same direction as the image scanning direction. For this reason,
The rate of screen contrast reduction can be reduced.

As described above, in the second embodiment, since the third polarizing plate 13 is provided outside the lenticular lens 131, the light excluding the light emitted from the light source lamp 111,
For example, reflection due to ambient light can be reduced, and the rate of screen contrast reduction can be reduced. In addition, in the second embodiment, the polarization direction of the light that has passed through the liquid crystal panel 121 is determined by using the retardation plate 11 and the second polarizing plate 121 and the third polarizing plate 121.
Since the polarization direction of the polarizing plate 13 is adjusted to that of the second polarizing plate 123 and the third polarizing plate 123,
It is not necessary to newly manufacture the polarizing plate 13 according to the polarization direction of the polarizing plate 13, and only the phase difference plate 11 and the third polarizing plate 13 are provided in the conventional rear projection type liquid crystal projector device. Rear projection type liquid crystal projector device 1
Can be manufactured.

Further, other products such as a liquid crystal panel for a display device of a personal computer and a liquid crystal panel for a liquid crystal television have a transmission axis in order to widen a viewing angle in the same direction as the image scanning direction (horizontal direction). The direction is generally oblique to the image scanning direction, but in the second embodiment, the transmission axis direction of the liquid crystal panel 121 used is oblique to the image scanning direction (approximately 45 degrees), and the liquid crystal Since the polarization direction of the light that has passed through the panel 121 is aligned with the polarization directions of the second polarizing plate 123 and the third polarizing plate 13 using the retardation plate 11, the liquid crystal panel of another product is shared or other. The manufacturing process of the product liquid crystal panel can be shared.

Next, a third embodiment of the rear projection type liquid crystal projector device according to the present invention will be described with reference to FIGS. The same components as those of the rear projection type liquid crystal projector device 1 of the first embodiment shown in FIG. 1 are designated by the same reference numerals and detailed description thereof is omitted.

In the third embodiment, in addition to the conventional rear projection type liquid crystal projector device 101 shown in FIG.
As shown in FIG. 12, the retardation plate 11 is provided between the second polarizing plate 123 and the projection lens 127, and the third polarizing plate 13 is provided outside the lenticular lens 131. The direction of polarization of the light passing through the retarder 1
It is converted by 1 to match the polarization direction of the third polarizing plate 13. In the first and second embodiments, the transmission axis direction of the liquid crystal panel 121 is oblique to the image scanning direction, but in the third embodiment, the transmission axis direction of the liquid crystal panel 121 is the image scanning direction. The same direction as or the direction perpendicular to the image scanning direction. 10 and 12, the light source lamp 111, the power supply circuit 113, the UV / IR filter 117, the video input terminal 133, and the signal processing circuit 135 shown in FIG. 1 are omitted.

Next, the operation of the third embodiment will be described with reference to FIGS.
3 will be described. Here, as shown in FIG. 10, the polarization directions of the first polarizing plate 119 and the third polarizing plate 13 are perpendicular to the image scanning direction (vertical direction), and the polarization direction of the second polarizing plate 123 is. In the case of being in the same direction as the image scanning direction (horizontal direction), as shown in FIG. 12, the polarization directions of the first polarizing plate 119 and the third polarizing plate 13 are in the same direction (lateral direction) as the image scanning direction. The case where the polarization direction of the second polarizing plate 123 is perpendicular to the image scanning direction will be described separately.

First, the polarization directions of the first polarizing plate 119 and the third polarizing plate 13 are vertical to the image scanning direction (vertical direction), and the polarizing direction of the second polarizing plate 123 is the same direction as the image scanning direction. The case of (horizontal direction) will be described with reference to FIGS. 10 and 11. The light source lamp 111 and the parabolic mirror 11
Since the operation of No. 5 is the same as that of the above-described first embodiment, the operation from the first polarizing plate 119 will be described here.

The polarization directions of the first polarizing plate 119 and the third polarizing plate 13 are perpendicular to the image scanning direction (vertical direction), and the polarizing direction of the second polarizing plate 123 is the same direction as the image scanning direction (horizontal direction). Direction), the first polarizing plate 119 allows only polarized light, which is perpendicular to the image scanning direction, of incident light to pass therethrough, as shown in “first polarizing plate” in FIG. 11. Then, the light passing through the first polarizing plate is incident on the liquid crystal panel 121 as shown in FIG.

Next, in the liquid crystal panel 121, the incident light is switched from the voltage on state to the voltage off state as shown in the "liquid crystal panel" of FIG. 11 in accordance with the liquid crystal panel drive signal given from the signal processing circuit (not shown). Is rotated about 90 degrees. Then, the light rotated by about 90 degrees is shown in FIG.
The light enters the second polarizing plate 123 as shown in FIG.

Next, in the second polarizing plate 123, as shown in FIG.
As shown in “Second Polarizing Plate”, only light having a polarization direction that is the same as the transmission axis direction of the liquid crystal panel 121 is selectively transmitted. Then, the light that has passed through the second polarizing plate 123 is incident on the retardation plate 11 as shown in FIG.

Next, in the retardation plate 11, as shown in the “retardation plate” of FIG. 11, the polarization direction is changed from the polarization direction of the light passing through the second polarizing plate 123 (the direction of the broken line) to the third polarizing plate. The polarization direction of 13 (solid line direction), that is, the direction perpendicular to the image scanning direction is converted.

The light whose polarization direction has been converted is incident on the projection lens 127 via a reflection plate (not shown) and projected as an image on the Fresnel lens 129 via a reflection plate (not shown). This projected image is the Fresnel lens 1
The lenticular lens 1 is focused on the observation position by 29.
31 controls and / or diffuses in any direction. That is, the Fresnel lens 129 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 131 widens the viewing angle.

Then, in the third polarizing plate 13, as shown in "third polarizing plate" in FIG. 11, only polarized light in the direction perpendicular to the image scanning direction is passed. At this time, the phase difference plate 1
Since the polarization direction is converted to the direction perpendicular to the image scanning direction by 1, the brightness and contrast of the image are not lowered. Further, since the third polarizing plate 13 allows only the polarized light in the direction perpendicular to the image scanning direction to pass therethrough, the light source lamp 111
It is possible to prevent reflection of light other than the light emitted further, for example, of ambient light, which is in the same direction as the image scanning direction. For this reason,
The rate of screen contrast reduction can be reduced.

Next, the polarization directions of the first polarizing plate 119 and the third polarizing plate 13 are the same as the image scanning direction (horizontal direction), and the polarizing direction of the second polarizing plate 123 is perpendicular to the image scanning direction. The case of the direction (vertical direction) will be described with reference to FIGS. 12 and 13. The light source lamp 111 and the parabolic mirror 115
Since the operation of is the same as that of the first embodiment described above, the operation from the first polarizing plate 119 will be described here.

The polarization directions of the first polarizing plate 119 and the third polarizing plate 13 are the same direction (horizontal direction) as the image scanning direction, and the polarization direction of the second polarizing plate 123 is vertical to the image scanning direction (longitudinal direction). Direction), the first polarizing plate 119 transmits only the light in the same direction as the image scanning direction among the incident light, as shown in “first polarizing plate” in FIG. Then, the light passing through the first polarizing plate is incident on the liquid crystal panel 121 as shown in FIG.

Next, in the liquid crystal panel 121, the incident light is switched from the voltage on state to the voltage off state as shown in the "liquid crystal panel" of FIG. 13 according to the liquid crystal panel drive signal given from the signal processing circuit (not shown). Is rotated about 90 degrees. Then, the light rotated by approximately 90 degrees is shown in FIG.
The light enters the second polarizing plate 123 as shown in FIG.

Next, in the second polarizing plate 123, as shown in FIG.
As shown in “Second Polarizing Plate”, only light having a polarization direction that is the same as the transmission axis direction of the liquid crystal panel 121 is selectively transmitted. Then, the light that has passed through the second polarizing plate 123 is incident on the retardation plate 11 as shown in FIG.

Next, in the retardation plate 11, as shown in the "retardation plate" of FIG. 13, the polarization direction is changed from the polarization direction of the light passing through the second polarizing plate 123 (the direction of the broken line) to the third polarizing plate. The polarization direction of 13 (solid line direction), that is, the same direction as the image scanning direction is converted.

The light whose polarization direction has been converted is incident on the projection lens 127 via a reflection plate (not shown) and projected as an image on the Fresnel lens 129 via a reflection plate (not shown). This projected image is the Fresnel lens 1
The lenticular lens 1 is focused on the observation position by 29.
31 controls and / or diffuses in any direction. That is, the Fresnel lens 129 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 131 widens the viewing angle.

Then, in the third polarizing plate 13, as shown in "third polarizing plate" in FIG. 13, only light in the same direction as the image scanning direction is passed. At this time, since the polarization direction is converted to the same direction as the image scanning direction by the phase difference plate 11, the brightness and contrast of the image do not decrease. Also,
Since the third polarizing plate 13 allows only the light in the same direction as the image scanning direction to pass through, the light excluding the light emitted from the light source lamp 111, for example, the reflection of the polarized light in the direction perpendicular to the image scanning direction among the ambient light. Can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

As described above, in the third embodiment, since the third polarizing plate 13 is provided outside the lenticular lens 131, light other than the light emitted from the light source lamp 111,
For example, reflection due to ambient light can be reduced, and a reduction in screen contrast can be prevented. Further, in the third embodiment, the polarization direction of the light passing through the second polarizing plate 123 is adjusted to the polarization direction of the third polarizing plate 13 by using the retardation plate 11, so that the liquid crystal panel 121 is There is no need to manufacture a new one in accordance with the polarization direction of the third polarizing plate 13,
The conventional rear projection type liquid crystal projector device has a retardation plate 11
The rear projection type liquid crystal projector device 1 can be manufactured at the same manufacturing cost as the conventional one by simply disposing the third polarizing plate 13.

In the third embodiment, the first polarizing plate 11
9 and the third polarizing plate 13 have a polarization direction perpendicular to the image scanning direction or the same direction as the image scanning direction, and the liquid crystal panel 121 and the second polarizing plate 123 are the first polarizing plate 1 and the second polarizing plate 123, respectively.
19 and the polarization direction of the third polarizing plate 13 has a transmission axis direction or a polarization direction of about 90 degrees, and the polarization direction of the light passing through the second polarizing plate 123 is converted by the phase difference plate 11 to Although the polarization directions of the third polarization plate 13 are adjusted, the present invention is not limited to this, and the polarization directions of the first polarization plate 119, the second polarization plate 123, and the third polarization plate 13 are not limited thereto. Is perpendicular to the image scanning direction or the same direction as the image scanning direction, and the transmission axis direction of the liquid crystal panel 121 is set to the first polarizing plate 119, the second polarizing plate 123, and the third polarizing plate 123.
The polarizing plate 13 forms an angle of about 90 degrees with the polarization direction of the polarizing plate 13, and the retardation plate 11 is provided between the liquid crystal panel 121 and the second polarizing plate 123 as in the second embodiment.
The polarization direction of the light that has passed through 21 may be converted by the retardation plate 11 to match the polarization directions of the second polarizing plate 123 and the third polarizing plate 13.

The third polarizing plate 13 of the above embodiment is used.
A light-transmitting plate having an arbitrary transmittance may be provided on the outer side or between the lenticular lens 131 and the third polarizing plate 13. In this case, the brightness of the projected image is slightly lowered, but the contrast can be improved.

In the above embodiment, the case where the liquid crystal panel 121 is applied to one rear projection type liquid crystal projector device has been described as an example, but the present invention is not limited to this. In the case where is divided into three sheets of red, green, and blue, the retardation plate 11 is attached to the liquid crystal panel 12.
The same can be applied by providing each one.

[0087]

As described above, according to the first to ninth aspects of the invention, since the third polarizing plate is provided outside the lenticular lens, the deterioration of the contrast of the projected image is prevented. It becomes possible to improve the image quality. Further, according to the inventions of claim 1, claim 2, claim 3, claim 6, and claim 7, the polarization direction of the light that has passed through the second polarizing plate is changed to the third by using the polarization direction conversion means.
Since the liquid crystal panel is adapted to the polarization direction of the polarizing plate, it is not necessary to newly manufacture the liquid crystal panel in accordance with the polarization direction of the third polarizing plate, and the conventional rear projection type liquid crystal projector device is provided with the polarization direction converting means. The present invention can be realized at a manufacturing cost substantially the same as the conventional one by only disposing the third polarizing plate. Further, according to the inventions of claim 4, claim 5, claim 8 and claim 9, the polarization direction of the light transmitted through the liquid crystal panel is converted by the polarization direction conversion means into the second polarizing plate and the third polarizing plate. The liquid crystal panel does not need to be newly manufactured by aligning with the polarization directions of the second polarizing plate and the third polarizing plate because it is aligned with the polarization direction of the liquid crystal panel. Conversion means and third
The present invention can be realized at a manufacturing cost substantially the same as the conventional one simply by disposing the polarizing plate. Further, according to the inventions of claims 2 to 5, the transmission axis direction of the liquid crystal panel is an oblique direction with respect to the image scanning direction, and the transmission axis direction of the liquid crystal panel generally used in other devices. Therefore, the liquid crystal panel or the manufacturing process of the liquid crystal panel can be shared with other devices.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an outline of a first embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 2 is a diagram showing a configuration in a case where a polarization direction of a third polarizing plate is the same as a video scanning direction.

FIG. 3 is a diagram showing a polarization direction of each part shown in FIG. 2 and a transmission axis direction of a liquid crystal panel.

FIG. 4 is a diagram showing a case where the polarization direction of a third polarizing plate is perpendicular to the image scanning direction.

5 is a diagram showing the polarization direction of each part shown in FIG. 4 and the transmission axis direction of the liquid crystal panel.

FIG. 6 is a view showing a second embodiment of a rear projection type liquid crystal projector device according to the present invention (when the polarization directions of the second polarizing plate and the third polarizing plate are the same as the image scanning direction). is there.

7 is a diagram showing a polarization direction of each part shown in FIG. 6 and a transmission axis direction of a liquid crystal panel.

FIG. 8 is a diagram showing a second embodiment of the rear projection type liquid crystal projector device according to the present invention (when the polarization directions of the second polarizing plate and the third polarizing plate are vertical to the image scanning direction). Is.

9 is a diagram showing the polarization direction of each part shown in FIG. 8 and the transmission axis direction of the liquid crystal panel.

FIG. 10 is a rear projection type liquid crystal projector device according to a third embodiment of the present invention (wherein the polarization directions of the first polarizing plate and the third polarizing plate are vertical to the image scanning direction, and the polarization direction of the second polarizing plate is It is a figure showing the case where the direction is the same as the image scanning direction.

11 is a diagram showing a polarization direction of each part shown in FIG. 10 and a transmission axis direction of a liquid crystal panel.

FIG. 12 is a third embodiment of the rear projection type liquid crystal projector device according to the present invention (the polarization directions of the first polarizing plate and the third polarizing plate are the same as the image scanning direction, and the polarizing direction of the second polarizing plate). Is a vertical direction with respect to the video scanning direction).

13 is a diagram showing a polarization direction of each part shown in FIG. 12 and a transmission axis direction of a liquid crystal panel.

FIG. 14 is a system configuration diagram showing an outline of a conventional rear projection type liquid crystal projector device.

FIG. 15 is a sectional view of a conventional rear projection type liquid crystal projector device.

[Explanation of symbols]

 1 Rear Projection Liquid Crystal Projector Device 11 Phase Difference Plate 13 Third Polarizing Plate 111 Light Source Lamp 115 Parabolic Mirror 117 UV / IR Filter 119 First Polarizing Plate 121 Liquid Crystal Panel 123 Second Polarizing Plate 127 Projection Lens 129 Fresnel Lens 131 Lenticular lens

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimitsu Umezawa 1-9-2 Harara-cho, Fukaya-shi, Saitama Prefecture Fukaya Plant, Toshiba Corporation (72) Yutaka Saito 1-9-2 Hara-cho, Fukaya-shi, Saitama Shares Company Toshiba Fukaya Factory (72) Inventor Toshio Obayashi 1-9-2 Hararacho, Fukaya City, Saitama Prefecture Toshiba Fukaya Factory

Claims (12)

[Claims] 1. A light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror that restricts and passes a polarization direction of substantially parallel light obtained from the parabolic mirror. And a liquid crystal panel provided with a plurality of liquid crystal cells arranged in a matrix so that substantially parallel light that has passed through the first polarizing plate is irradiated and the respective optical rotatory powers thereof can be controlled, A second polarizing plate that selectively passes only light of an arbitrary polarization direction from light that has passed through this liquid crystal panel, a projection lens that magnifies and projects light that has passed through this second polarizing plate, and a light emitted from this projection lens. A rear projection liquid crystal projector device including a Fresnel lens for condensing the reflected light at an arbitrary position and a lenticular lens for controlling and / or diffusing the light passing through the Fresnel lens in an arbitrary direction. A third polarizing plate which is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and reduces reflection due to light other than light passing through the liquid crystal panel; the second polarizing plate; A polarization direction conversion unit which is provided at an arbitrary position up to the front surface of the third polarization plate and which converts the polarization direction of the light passing through the second polarization plate to match the polarization direction of the third polarization plate. A rear projection type liquid crystal projector device characterized by comprising: 2. A light source lamp, a parabolic mirror which controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror which restricts and passes a polarization direction of substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers thereof can be controlled, and the transmission axis direction is oblique to the image scanning direction. Direction liquid crystal panel including a plurality of liquid crystal cells, a second polarizing plate for selectively passing only the light in the oblique direction from the light passing through the liquid crystal panel, and the light passing through the second polarizing plate. A projection lens for enlarging and projecting light, a Fresnel lens for condensing the light emitted from this projection lens at an arbitrary position, and a lenticular lens for controlling and / or diffusing the light passing through this Fresnel lens in an arbitrary direction. In a rear projection type liquid crystal projector device configured to include: a polarization characteristic that is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and that allows only light in the same direction as the image scanning direction to pass through, A third polarizing plate for reducing reflection of light other than light passing through the liquid crystal panel; and a second polarizing plate provided at an arbitrary position up to the front faces of the second polarizing plate and the third polarizing plate. A rear projection type liquid crystal projector device, comprising: a polarization direction conversion means for converting the polarization direction of light passing through the plate to match the polarization characteristics of the third polarizing plate. 3. A light source lamp, a parabolic mirror which controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror which restricts and passes a polarization direction of substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers thereof can be controlled, and the transmission axis direction is oblique to the image scanning direction. Direction liquid crystal panel including a plurality of liquid crystal cells, a second polarizing plate for selectively passing only the light in the oblique direction from the light passing through the liquid crystal panel, and the light passing through the second polarizing plate. A projection lens for enlarging and projecting light, a Fresnel lens for condensing the light emitted from this projection lens at an arbitrary position, and a lenticular lens for controlling and / or diffusing the light passing through this Fresnel lens in an arbitrary direction. In a rear projection type liquid crystal projector device configured to include a polarization characteristic that is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and that transmits only polarized light in a direction perpendicular to a video scanning direction, A third polarizing plate that reduces reflection by light other than the light that has passed through the liquid crystal panel, and the second polarizing plate and the third polarizing plate are provided at arbitrary positions up to the front surface of the second polarizing plate. A rear projection type liquid crystal projector device, comprising: a polarization direction conversion unit that converts the polarization direction of light that has passed through the polarizing plate to match the polarization characteristic of the third polarizing plate. 4. A light source lamp, a parabolic mirror which controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror which restricts and passes a polarization direction of substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers thereof can be controlled, and the transmission axis direction is oblique to the image scanning direction. Direction, a liquid crystal panel having a plurality of liquid crystal cells, polarization direction conversion means for converting the polarization direction of the light passing through the liquid crystal panel into the same direction as the image scanning direction, and the image transmitted from the light passing through the polarization direction conversion means. A second polarizing plate that selectively passes only light in the same direction as the scanning direction, a projection lens that magnifies and projects the light that has passed through this second polarizing plate, and the light emitted from this projection lens at an arbitrary position. Focus on A Fresnel lens, a lenticular lens that controls and / or diffuses light that has passed through the Fresnel lens in an arbitrary direction, and a polarization that is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and has the same polarization as the second polarizing plate. A rear projection type liquid crystal projector device comprising: a third polarizing plate having characteristics and reducing reflection by light other than light passing through the liquid crystal panel. 5. A light source lamp, a parabolic mirror which controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror which restricts and transmits a polarization direction of substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers thereof can be controlled, and the transmission axis direction is oblique to the image scanning direction. Direction, a liquid crystal panel having a plurality of liquid crystal cells, a polarization direction conversion means for converting the polarization direction of the light passing through the liquid crystal panel into a direction perpendicular to the image scanning direction, and the light passing through the polarization direction conversion means. A second polarizing plate that selectively passes only polarized light perpendicular to the image scanning direction, a projection lens that magnifies and projects the light that has passed through the second polarizing plate, and a light emitted from this projection lens. Arbitrary position A Fresnel lens for condensing, a lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction, and a second polarizing plate provided at an arbitrary position from the projection lens to the front surface of the lenticular lens. And a third polarizing plate having the same polarization characteristic as the above and reducing reflection by light other than light passing through the liquid crystal panel. 6. A light source lamp, a parabolic mirror that controls and reflects the light emitted from the light source lamp into substantially parallel light, and a first parametric mirror that restricts the polarization direction of the substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers thereof can be controlled, and the transmission axis direction thereof is the same as the image scanning direction. A liquid crystal panel having a plurality of liquid crystal cells, a second polarizing plate for selectively passing only the light in the same direction as the image scanning direction from the light passing through the liquid crystal panel, and the second polarizing plate The projection lens that magnifies and projects the generated light, the Fresnel lens that condenses the light emitted from this projection lens at an arbitrary position, and the lenticular lens that controls and / or diffuses the light that has passed through this Fresnel lens in any direction. In a rear projection type liquid crystal projector device including: a polarization characteristic which is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and which transmits only polarized light in a direction perpendicular to the image scanning direction. A third polarizing plate that reduces reflection due to light other than light that has passed through the liquid crystal panel, and is provided at any position up to the front surfaces of the second polarizing plate and the third polarizing plate, A rear-projection liquid crystal projector device comprising: a polarization direction conversion unit that converts the polarization direction of light that has passed through the second polarizing plate to match the polarization characteristics of the third polarizing plate. 7. A light source lamp, a parabolic mirror that controls and reflects the light emitted from the light source lamp into substantially parallel light, and a first parabolic mirror that restricts the polarization direction of the substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers can be controlled, and the transmission axis direction is perpendicular to the image scanning direction. A liquid crystal panel having a plurality of liquid crystal cells of a certain direction, a second polarizing plate for selectively passing only the polarized light in the direction perpendicular to the image scanning direction from the light passing through the liquid crystal panel, and the second polarizing plate A projection lens that magnifies and projects the light that has passed through, a Fresnel lens that condenses the light emitted from this projection lens at an arbitrary position, and a lens that controls and / or diffuses the light that has passed through this Fresnel lens in an arbitrary direction. In a rear projection type liquid crystal projector device including a circular lens, a polarization characteristic which is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and which transmits only light in the same direction as the image scanning direction is provided. A third polarizing plate that reduces reflection due to light other than light that has passed through the liquid crystal panel, and is provided at any position up to the front surfaces of the second polarizing plate and the third polarizing plate, A rear-projection liquid crystal projector device comprising: a polarization direction conversion unit that converts the polarization direction of light that has passed through the second polarizing plate to match the polarization characteristics of the third polarizing plate. 8. A light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror that restricts and transmits a polarization direction of substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers can be controlled, and the transmission axis direction is perpendicular to the image scanning direction. Direction, a liquid crystal panel having a plurality of liquid crystal cells, polarization direction conversion means for converting the polarization direction of the light passing through the liquid crystal panel into the same direction as the image scanning direction, and the image transmitted from the light passing through the polarization direction conversion means. A second polarizing plate that selectively passes only light in the same direction as the scanning direction, a projection lens that magnifies and projects the light that has passed through this second polarizing plate, and the light emitted from this projection lens at an arbitrary position. Focus on A Fresnel lens, a lenticular lens that controls and / or diffuses light that has passed through the Fresnel lens in an arbitrary direction, and a polarization that is provided at an arbitrary position from the projection lens to the front surface of the lenticular lens and has the same polarization as the second polarizing plate. A rear projection type liquid crystal projector device comprising: a third polarizing plate having characteristics and reducing reflection by light other than light passing through the liquid crystal panel. 9. A light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror that restricts and passes a polarization direction of substantially parallel light obtained from the parabolic mirror. And the substantially parallel light that has passed through this first polarizing plate are radiated and arranged in a matrix so that the respective optical rotatory powers thereof can be controlled, and the transmission axis direction thereof is the same as the image scanning direction. A liquid crystal panel having a plurality of liquid crystal cells, polarization direction conversion means for converting the polarization direction of the light passing through the liquid crystal panel into a direction perpendicular to the image scanning direction, and the image transmitted from the light passing through the polarization direction conversion means. A second polarizing plate that selectively passes only polarized light in the direction perpendicular to the scanning direction, a projection lens that magnifies and projects the light that has passed through this second polarizing plate, and the light emitted from this projection lens is arbitrary. Gathered in position A Fresnel lens for controlling, and a lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction, and provided at an arbitrary position from the projection lens to the front surface of the lenticular lens, the same as the second polarizing plate. A rear projection type liquid crystal projector device comprising: a third polarizing plate having a polarization characteristic and reducing reflection by light other than light passing through the liquid crystal panel. 10. The rear projection type liquid crystal projector device according to claim 1, wherein the polarization direction conversion means is a retardation plate. 11. A light transmitting plate having an arbitrary transmittance is further provided outside the third polarizing plate or between the lenticular lens and the third polarizing plate. The rear projection type liquid crystal projector device according to claim 10. 12. A reflection mirror is further provided between the projection lens and the Fresnel lens, and a polarization direction of light emitted from the projection lens is S polarization with respect to the reflection mirror. The rear projection type liquid crystal projector device according to any one of claims 1 to 11.