JPH06273758A - Liquid crystal projector - Google Patents

Abstract

PURPOSE:To make light transmit through the liquid crystal display part of a liquid crystal panel without impairing light quantity from a light source by a simple constitution. CONSTITUTION:A reflection mirror 3 consisting of a main reflector 3c and sub reflectors 3a, 3b, 3d and 3e is arranged between the light source 1 and the liquid crystal panel 5. A part of luminous flux from the light source and a parabolic mirror is reflected to the liquid crystal display part 9 of the liquid crystal panel 5 by the sub reflectors 3a, 3b, 3d and 3e, and an image of light illuminance is projected on a screen 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 single-panel type liquid crystal projector.

[0002]

2. Description of the Related Art A conventional liquid crystal projector of this type is shown in FIG.

In FIG. 2, reference numeral 1 is a light source composed of a metal halide lamp or the like, and 2 is a circular parabolic mirror for reflecting the light from the light source 1 into uniform parallel light.
Reference numeral 4 is a condenser lens for condensing the light flux created by the parabolic mirror on the liquid crystal panel. Reference numeral 5 denotes a liquid crystal display unit 9 and a liquid crystal display unit 9 which optically modulate the light passing through the condenser lens 4 by a signal from a video signal processing circuit (not shown).
Is a liquid crystal panel including a driving unit in which a driver for driving the device is arranged. A projection lens 6 enlarges and displays an image optically modulated by the liquid crystal panel 5 on the screen 7.

In the conventional liquid crystal projector, the light emitted from the light source 1 is reflected by the parabolic mirror 2, and as a result, the light having a circular cross section is applied to the condenser lens 4. Here, the reflected light from the parabolic mirror 2 is condensed by the condenser lens 4, and the liquid crystal panel 5
To the liquid crystal display unit 9 of the liquid crystal panel 5.
Since the shape is rectangular, as shown in FIGS. 3 and 4, light is also applied to the shaded areas other than the liquid crystal display section 9, and the amount of light projected onto the screen 7 by the liquid crystal panel 5 is reduced.

Here, FIG. 3 is a diagram showing a decrease in the amount of light when the liquid crystal display section 9 is configured to have a wide aspect ratio (16: 9), and FIG. 4 shows the liquid crystal display section 9 in a normal aspect ratio. It is a figure which shows the reduction of the light quantity at the time of comprising in (4: 3).

That is, in the case of the liquid crystal display unit having the shape shown in FIG. 3, the amount of light from the condenser lens 4 is about 46%.
In the case of the liquid crystal display unit having the shape shown in FIG. 4, the light amount is reduced by about 39%.
The image displayed in magnified was dark.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object thereof is to transmit light through a liquid crystal display section of a liquid crystal panel without impairing the amount of light from a light source with a simple structure. To do.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a light source including a metal halide lamp, a condenser lens for condensing light from the light source, a liquid crystal display section for optically modulating light passing through the condenser lens, and a liquid crystal. In a liquid crystal projector comprising a liquid crystal panel having a drive section for driving the liquid crystal panel, and a projection lens for enlarging and displaying the light optically modulated by the liquid crystal panel, a light flux between the light source and the liquid crystal panel. The liquid crystal projector is characterized in that a light flux control unit for controlling the above is provided, and a part of the light flux from the light source is reflected toward the liquid crystal display unit of the liquid crystal panel by the light flux control unit.

Further, the present invention is a liquid crystal projector characterized in that the liquid crystal part constituting the liquid crystal panel has a wide aspect ratio of 16: 9.

Further, the present invention is a liquid crystal projector characterized in that the liquid crystal display section constituting the liquid crystal panel has a normal aspect ratio of 4: 3.

Further, the present invention is a liquid crystal projector in which the light flux controlling section is composed of a plurality of plane reflecting mirrors.

[0012]

According to the present invention, with the above configuration, a part of the light flux from the light source and the parabolic mirror is reflected by the sub-reflecting mirror which constitutes the reflecting mirror, and the light flux is transmitted to the liquid crystal display section of the liquid crystal panel. An image of light intensity is projected on the screen for transmission.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a liquid crystal projector of the present invention.

In FIG. 1, 1 is a light source composed of a metal halide lamp or the like, and 2 is a circular parabolic mirror for reflecting the light from the light source 1 into uniform parallel light.

As shown in FIG. 5, 3 is one main reflector 3
c and three sub-reflecting plates 3a, 3b, 3d, and 3e, which are created by adhering a plurality of flat reflecting plates on metal or resin obtained by cutting or molding these reflecting plates. To be done. The main reflecting mirror 3c is attached at an angle of 45 degrees with respect to the optical axis 10, and the sub-reflecting mirror 3c is attached.
a and 3b are tilted at an angle less than 45 degrees with respect to the optical axis, and the sub-reflecting mirrors 3d and 3e are inclined with respect to the optical axis by 4 degrees.
It is arranged so as to be inclined at an angle that is a few degrees greater than 5 degrees.

Reference numeral 4 denotes a condenser lens for condensing the light flux created by the parabolic mirror 2 on the liquid crystal panel.
Is a liquid crystal display unit 9 which optically modulates the light passing through the condenser lens 4 by a signal from a video signal processing circuit (not shown).
And a drive section in which a driver and the like for driving the liquid crystal display section 9 are arranged. A projection lens 6 enlarges and displays an image optically modulated by the liquid crystal panel 5 on the screen 7.

In the liquid crystal projector constructed as described above, the light emitted from the light source 1 is collimated by the parabolic mirror 2 and applied to the reflecting mirror 3. Here, of the light emitted to the reflecting mirror 3, the sub-reflecting mirrors 3 a, 3
The light radiated to b is reflected as an optical flux 12 to the upper part of the liquid crystal display unit 5 via the condenser lens 4, and the main reflector 3
The light radiated to c is reflected as a light flux 11 to the central portion of the liquid crystal display unit 9 via the condenser lens 4, and the light radiated to the sub-reflecting plates 3d and 3e is radiated as a light flux 13 via the condenser lens 4. It will be reflected to the lower part of the liquid crystal display unit 9.

Next, in the liquid crystal display section 9, the luminous flux 12,
By optically modulating 11 and 13 and projecting them on the screen 7, it is possible to enlarge and display an image with high illuminance.

Incidentally, in addition to the reflecting mirror shown in this embodiment, the one shown in FIG. 6 or 7 is also conceivable.

FIG. 6 shows a reflecting mirror in which sub-reflecting plates are attached to the four sides of the main reflecting plate, and the liquid crystal display 9 is used not only for the upper and lower portions of the shaded portion 8 in FIG. It is configured to pass.

FIG. 7 shows a reflecting mirror integrally formed by a glass mold or the like.

The reflecting mirror is not limited to the above-mentioned shape, and a plurality of divided reflecting plates in which the main reflecting plate is inclined or unevenness is formed on the entire surface of the reflecting mirror to make the illuminance distribution on the screen uniform. You can also use it.

[0024]

Since the present invention is constructed as described above, the luminous flux which has been conventionally blocked by the liquid crystal panel can be guided into the liquid crystal display section by the reflecting mirror, so that the illuminance of the image displayed on the screen can be improved. Can be improved.
Further, even if a light source having a low illuminance other than the metal halide lamp is used, an image having the same illuminance as the conventional one can be obtained on the screen.

[Brief description of drawings]

FIG. 1 is a diagram showing a liquid crystal projector of the present invention.

FIG. 2 is a diagram showing a conventional liquid crystal projector.

FIG. 3 is a diagram showing a decrease in light amount when a liquid crystal display unit is configured to have a normal aspect ratio (4: 3).

FIG. 4 shows a liquid crystal display unit with a wide aspect ratio (16: 9).
It is a figure which shows the reduction of the light quantity in the case of being comprised.

FIG. 5 is a first embodiment of the reflecting mirror.

FIG. 6 is a second embodiment of the reflecting mirror.

FIG. 7 is a third embodiment of the reflecting mirror.

[Explanation of symbols]

 1 Light source 2 Parabolic mirror 3 Reflector 3a Sub-reflector 3b Sub-reflector 3c Main reflector 3d Sub-reflector 3e Sub-reflector 4 Condenser lens 5 Liquid crystal panel 6 Projection lens 9 Liquid crystal display

Claims (4)

[Claims] 1. A light source comprising a metal halide lamp or the like, a condenser lens for condensing light from the light source, a liquid crystal display section for optically modulating the light passing through the condenser lens, and a drive section for driving the liquid crystal. In a liquid crystal projector comprising a liquid crystal panel and a projection lens for enlarging and displaying the light optically modulated by the liquid crystal panel on a screen, a light flux control unit for controlling a light flux is provided between the light source and the liquid crystal panel. A liquid crystal projector, wherein a part of the light flux from the light source is reflected toward the liquid crystal display unit of the liquid crystal panel by the light flux control unit. 2. A liquid crystal display unit constituting a liquid crystal panel is 1
The liquid crystal projector according to claim 1, wherein the liquid crystal projector has a wide aspect ratio of 6: 9. 3. The liquid crystal projector according to claim 1, wherein the liquid crystal part constituting the liquid crystal panel has a normal aspect ratio of 4: 3. 4. The liquid crystal projector according to claim 1, wherein the light flux controller is composed of a plurality of plane reflecting mirrors.