JPH0572650A - Projection type picture display device - Google Patents

Abstract

PURPOSE:To reduce the number of parts by conducting light from the light source of a projection type image display device in three directions to liquid crystal valves provided with color filters by a mirror having the desired radius of curvature. CONSTITUTION:The light from a light source 1 consisting of a high-brightness lamp is conducted forward and left and right. The light conducted left and right is reflected on the first total reflecting mirrors 6 and 9 by the angle of 90 deg. and guided to the liquid crystal light valves obtained by arranging the color filters on the outside of a panel. Then, the white color light conducted forward is converted to the G light by the color filter 17 of a green color and the white color light reflected on the first mirror 6 is similarly converted to the B light by the color filter of a blue color 18 arranged in front of the liquid crystal light valve. Besides, the white color light reflected on the first mirror 9 is converted to the R light by the color filter of a red color 19. Moreover, the G light, the R light and the B light spectrally split by the filters 17-19 are respectively made incident on the liquid crystal light valves for G light. R light and B light 5, 8 and 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type image display device for projecting a color image or the like on a screen at an arbitrary magnification by using a liquid crystal light valve.

[0002]

2. Description of the Related Art FIGS. 8 and 9 are optical system block diagrams of a conventional projection type display device using a transmission type liquid crystal light valve.

In FIG. 8, the light from the light source 1 is separated into R light (red light), G light (green light) and B light (blue light) by a dichroic mirror via a condenser lens 2.

The dichroic mirror comprises an R light reflecting dichroic mirror 3 for reflecting R light and a B light reflecting dichroic mirror 4 for reflecting B light.

The G light passes through the dichroic mirror and goes directly to the G light liquid crystal light valve 5.

The R light reflected by the dichroic mirror is the first total reflection mirror 6 and the second total reflection mirror 7.
The traveling direction is changed by 180 ° and the light enters the liquid crystal light valve 8 for R light.

The B light reflected in the opposite direction to the R light is changed in traveling direction by 180 ° by the first total reflection mirror 9 and the second total reflection mirror 10 and enters the B light liquid crystal light valve 11.

After passing through the liquid crystal light valves, these lights are combined by the dichroic prism 12 and enlarged and projected on the screen 14 by the projection lens 13.

In FIG. 9, the light from the light source is the B light reflecting dichroic mirror 4 and the R light reflecting dichroic mirror 3.
Is decomposed into R light, G light, and B light.

The G light travels 90 degrees by the total reflection mirror 15.
The light that has been changed and dispersed goes to the liquid crystal light valve 5 for G light, the liquid crystal light valve 8 for R light, and the liquid crystal light valve 11 for B light, respectively.

After that, it is magnified by the three projection lenses 13 and combined on the screen 14.

There is also a conventional example in which a TFT substrate is used as a liquid crystal light valve, and a projection type image display device having a high contrast is constituted by three dichroic mirrors and three liquid crystal light valves (Japanese Patent Laid-Open No. 62-133424). ).

[0013]

The optical system shown in FIG. 8 requires one dichroic prism, two dichroic mirrors and four total reflection mirrors, and the optical system shown in FIG. 9 requires two dichroic mirrors. Requires one total reflection mirror.

Since these optical components are expensive and the in-plane uniformity is poor, display unevenness may occur when projected on a screen.

The unit of the optical component which requires the volume shown in FIG. 8 is eight units including the light source, the mirror and the projection lens.

Similarly, the unit of the optical component requiring the volume shown in FIG. 9 is 7 units, and the conventional one tends to be large in the optical component.

Further, the size of the liquid crystal light valve needs to be larger than the size of the liquid crystal light valve in order to diffuse the light.

[0018]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and three liquid crystal light valves each have a built-in color filter for decomposing into R light, G light, and B light, or an external device. Since it is installed more, the number of color filters is three, and the size is the same as the liquid crystal light valve, so that it can be manufactured at a lower cost than the conventional one and is compact.

[0019]

In the projection type image display apparatus according to the present invention, color separation is performed by the above optical system, so that display without hue change is performed without changing the R, G and B wavelength ranges as compared with the conventional one. be able to. In addition, it can be manufactured at low cost and the mold becomes compact. Furthermore, since the light source can emit light in three directions, there is no need for means for splitting the light from the light source into three.

[0020]

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

FIG. 1 is a plan view of an optical system of a projection type image display device according to the first embodiment of the present invention.

In FIG. 1, light from a light source 1 composed of a high-intensity lamp is emitted in the front and left and right directions, and white light emitted in the left and right directions is made by a first total reflection mirror 6, 9 at an angle of 90 °. It is reflected and guided to a liquid crystal light valve with a color filter arranged outside the panel.

The light source is designed so that light is not emitted rearward by the reflector 16, and the white light guided forward is converted into G light by the green color filter 17.

Similarly, the white light reflected by the first total reflection mirror 6 is converted into B light by the blue color filter 18 arranged in front of the liquid crystal light valve, and the first total reflection mirror 9 is generated.
The white light reflected by is converted into R light by the red color filter 19.

G light separated by a color filter,
The R light and the B light respectively enter the G light liquid crystal light valve 5, the R light liquid crystal light valve 8, and the B light liquid crystal light valve 11.

The G light from the G light liquid crystal light valve 5 passes through the dichroic mirror and then enters the projection lens 13.

The R light from the R light liquid crystal light valve 8 is reflected by the second total reflection mirror 10 and then reflected by the R light reflection dichroic mirror 3 to enter the projection lens 13.

The B light from the B light liquid crystal light valve 11 is reflected by the second total reflection mirror 7, and then reflected by the B light reflection dichroic mirror 4 to enter the projection lens 13.

FIG. 1 of the present invention as opposed to the conventional eight units of FIG.
Since it becomes 7 units, it becomes possible to downsize the device.

Color filters having light transmission characteristics as shown in FIGS. 5 to 7 are installed from the outside.

As the dye of the blue color filter of FIG. 5, 4-morpholine-2,5-dibutoxybenzenediazonium tetrafluoroborate, methyl blue or the like is used.

As the dye of the green color filter shown in FIG. 6, resumming green or the like is used.

As the dye of the red color filter of FIG. 7, p-N, N-diethylaminobenzenediazonium tetrafluoroborate, diaside 11 or the like is used.

Reference numerals 3 and 4 are dichroic mirrors,
The light that passed through the liquid crystal light valve is combined.

Reference numeral 13 is a projection lens, which projects the light combined by the dichroic mirror onto the screen 14.

FIG. 2 is a perspective view of the projection type image display device of the first embodiment.

The light source 1 has the appearance shown in FIG. 2 and can emit light in three directions.

Therefore, the white light generated by the light source goes directly to the liquid crystal light valve via the total reflection mirror.

Immediately before passing through the liquid crystal light valve, the light is separated into R, G, and B lights by a color filter installed in the liquid crystal light valve or installed from the outside.

Then, after the color adjustment is performed by the electric signal corresponding to each color, they are combined again by the dichroic mirror.

After that, a projection lens enlarges and projects a color image on the screen 14.

As a second embodiment of the present invention, FIG. 3 shows a perspective view of an optical system using two total reflection mirrors and three projection lenses.

This is a modification of the color synthesizing method of the optical system shown in the first embodiment, in which images are directly synthesized on a screen by using three projection lenses, and is mainly used for rear type. To be done.

Therefore, a good color image can be obtained without damaging the hue of the display image as in the first embodiment.

The projection direction of each color is adjusted by shifting the central axes of the projection lens and the liquid crystal light valve.

FIG. 3 of the present invention is used for the conventional seven units of FIG.
Since it is 6 units, it is possible to further reduce the volume of a small structure in the related art and further reduce the weight.

1 to 3 show a color filter arranged outside the liquid crystal light valve.

FIG. 4 shows a perspective view of a third embodiment of the present invention in which a color filter is incorporated in a liquid crystal light valve and two curved reflecting plates are provided.

In FIG. 4, the right white light (W light) emitted from the light source 1 is collected and reflected by one curved reflecting plate 20, and is inclined in the direction of the preferential viewing angle of the R light liquid crystal light valve 8. Incident.

Similarly, the left W light is incident by the other curved reflecting plate 21 while being inclined in the direction of the preferential viewing angle of the B light liquid crystal light valve 11.

The W light in the center is incident on the liquid crystal light valve 5 for G light, and the R light, G light, and B light transmitted through each liquid crystal light valve.
Light is projected on the screen from a single projection lens.

According to this structure according to the preferential viewing angle, it is possible to maximize the amount of light transmitted through the liquid crystal light valve.

[0053]

As described above in the embodiments, the present invention is a projection type image display device in which a liquid crystal light valve is used to magnify and project a display image on a screen by a projection lens. As a method for disassembling, a color filter installed in the liquid crystal light valve without using a dichroic mirror or a dichroic prism or installed from the outside is used.

Therefore, the optical system is simple and the structure is compact. In addition, since expensive dichroic mirrors and dichroic prisms are not used for color separation of light, it can be manufactured at low cost.

Further, since the light transmission characteristics of the color filter are the same as those of the conventional dichroic mirror or dichroic prism, it is possible to obtain a color image having a good color balance.

[Brief description of drawings]

FIG. 1 is a plan view of a projection type image display device of the present invention using a dichroic mirror.

FIG. 2 is a perspective view of a projection type image display device of the present invention using a dichroic mirror.

FIG. 3 is a perspective view of a projection type image display device of the present invention having three projection lenses.

FIG. 4 is a perspective view of a projection type image display device of the present invention using a curved reflector.

FIG. 5 is a transmission characteristic diagram of a blue color filter.

FIG. 6 is a transmission characteristic diagram of a green color filter.

FIG. 7 is a transmission characteristic diagram of a red color filter.

FIG. 8 is a plan view of a projection-type image display device having one projection lens.

FIG. 9 is a plan view of a projection-type image display device having three projection lenses.

[Explanation of symbols]

 1 Light Source 2 Condenser Lens 3 R Light Reflection Dichroic Mirror 4 B Light Reflection Dichroic Mirror 5 G Light Liquid Crystal Light Valve 6 First Total Reflection Mirror 7 Second Total Reflection Mirror 8 R Light Liquid Crystal Light Valve 9 First Total Reflection mirror 10 Second total reflection mirror 11 Liquid crystal light valve for B light 12 Dichroic prism 13 Projection lens 14 Screen 15 Total reflection mirror 16 Reflector 17 Green color filter 18 Blue color filter 19 Red color filter 20 One curved reflection plate 21 The other Curved reflector

Claims (1)

[Claims] 1. A projection type image display device for color-separating light from a light source, converting the color-separated light into an image through a liquid crystal light valve, and projecting the converted display image at an arbitrary magnification by a projection lens. As a method of color separation, one of R, G, and B color filters is built in each, or three liquid crystal light valves installed from the outside are used, and the light source emits light in three directions. Projection-type image display device.