JP2605658B2 - Projection display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal light valve of a projection type display device using a liquid crystal panel.

[0002]

2. Description of the Related Art As disclosed in the IEICE Transactions on 80/6 Vo1, J63-CN0.6, a conventional projection type display device has a liquid crystal cell which is formed by projection using thermal writing using a smectic A phase. It was a method of projecting with a light valve of a type display device.

[0003]

However, the prior art has the following problems.

First, since the liquid crystal light valve is of a thermal writing type, the transparent conductive film is energized to adjust the temperature around the light valve and the temperature is adjusted on the high temperature side. On the other hand, heat fluctuation causes a decrease in image quality, and the brightness of the projection light source cannot be increased, so that sufficient image quality cannot be obtained on the screen.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a liquid crystal light valve having excellent contrast and sufficient brightness on a screen.

[0006]

SUMMARY OF THE INVENTION A projection display apparatus according to the present invention.
Is a light modulating means for modulating incident light, and the light modulating means
Projection optical means for projecting modulated light
In the display device, the light modulation unit includes a liquid crystal panel,
A pair of polarizing plates disposed on both sides of the liquid crystal panel.
A comb-shaped spacer is sandwiched between a pair of transparent substrates.
Cooling liquid in the gap formed by the spacer.
The filled cooling means is provided with a light input device out of the pair of polarizing plates.
Characterized in that it is arranged on the incident side of the
You. In addition, the second projection type display device of the present invention can
1 so that the comb teeth of the spacer are formed alternately.
A pair of said comb-shaped spacers are arranged.
You.

[0007]

According to the above structure of the present invention, the liquid crystal light valve is configured such that the cooling panel filled with the cooling liquid is brought into close contact with the liquid crystal panel composed of two transparent substrates by bringing the liquid crystal panel into close contact with the liquid crystal panel. By lowering the amount of heat of the light source applied to the liquid crystal panel and further filling it with a guest-host type cooling liquid, the light source light can be dimmed. The light source is a xenon lamp or a metal halide lamp of 300 W or more. The structure is such that heat is not applied to the liquid crystal panel even when the LCD panel is used.

[0008]

FIG. 1 is a diagram showing the principle of a projection type display device according to an embodiment of the present invention.

The light diverging from the light source 1 is recollimated by the condenser lens 2, irradiates the light to the liquid crystal light valve 3, is enlarged and projected by the projection lens 4, and forms an image on the screen 5.

FIG. 2 is a detailed view of the light source according to the present invention, in which (a) is a configuration diagram of the illumination system, and (b) is a graph showing the spectral characteristics of the reflector.

A lamp 10 is a high color rendering lamp such as a halogen lamp, a xenon lamp, or a metal halide lamp. The light beam 14 is collimated by the condenser lens 13. The elliptical mirror 11 is made of a cold mirror, and is configured such that heat is hardly transmitted to the front surface of the illumination system as shown in the graph (b) to transmit infrared rays.

FIG. 3 is a perspective view of a liquid crystal panel of a liquid crystal light valve according to an embodiment of the present invention. The upper substrate 20 and the lower substrate 21 are each formed of a transparent substrate (glass or quartz plate), and the pixel electrodes 22 are arranged in a matrix and are so-called active matrix panels configured corresponding to the pixel driving transistors 23. is there. The orientation film 24 is a film for orienting the liquid crystal layer 25 on each substrate, and here forms a TN type liquid crystal panel in which the orientation of the upper substrate and the orientation of the lower blocking plate are orthogonal. The common electrode 26 is formed of a solid electrode facing each pixel electrode 22 and having a common potential on the entire surface.

FIG. 4 is an equivalent circuit diagram of a display pixel portion of a liquid crystal light valve according to an embodiment of the present invention.

A source line 40 is connected to the source side of each pixel transistor 42 and a gate line 41
Is connected to the gate of the pixel transistor 42, one electrode 43 of the liquid crystal layer is connected to the drain side of the pixel transistor 42, and the other electrode 44 is connected as a common electrode. The drive circuit of the light valve is Nikkei Electronics NO. 351 (1984) P211.

FIG. 5 is a diagram showing a cooling panel of a liquid crystal light valve according to an embodiment of the present invention.

The upper substrate 50 and the lower substrate 51 are made of a transparent substrate, and the thickness can be controlled by a sealing member 54 such as epoxy resin or silicon.
The gap is controlled to about a few mm, and the cell is filled with a liquid such as cooling oil or ethylene glycol to form a heat dissipating portion larger than the actual display area 56 so that the inside can be convected by heat. Spacer 5
5 is formed in a zigzag shape by screen printing or photolithography. The polarizing plate 52 is laminated and adhered to the lower substrate 51 and protected by a protective glass 53, and the light source for projection enters from the upper substrate 50 side.
1 also provides thermal protection.

FIG. 6 is an assembly view of the liquid crystal light valve according to the embodiment of the present invention.

The mounting substrate 60 is a circuit substrate, which guides the lower substrate to a concave portion cut by the same thickness as the lower substrate 61 of the liquid crystal panel, and a polarizing plate 63 having substantially the same size as the upper substrate 62.
Constitutes a liquid crystal panel. The polarizing plate is brought into close contact with the lower substrate 65 of the cooling panel by a connector 64 so that the cooling panel is brought into close contact with the liquid crystal panel. Since the upper substrate 66 of the cooling panel is the surface on the light incident side of the light source, the surface is coated with an anti-reflection coating to increase the incident efficiency. The Peltier device 67 is embedded on the mounting substrate 60,
The cooling panel is located under the lower substrate 65. Mounting board 6
On the upper side, the wiring 68 for driving the liquid crystal panel, the driving electrode 69 of the Peltier element, and the like are mounted by wire bonding or soldering, so that the mounting can be made very compact.

Also, by filling the cooling liquid of the cooling panel with the liquid crystal of the guest-host type, the upper and lower solid electrodes are energized to the cooling panel, so that the cooling panel can be used as an optical switch by the electro-optic effect. A liquid crystal light valve that combines light control and cooling is also possible.

[0020]

As described above, according to the present invention, an extremely simple cooling panel is brought into close contact with the temperature rise of the light energy emitted from the projection light source of the transmission type liquid crystal light valve, thereby reducing the light emission. Cooling can be performed without impairing the transmittance, and a very thin light valve can be formed.

Further, when the cooling panel is a guest-host type liquid crystal panel, it is possible to control the incident light, and in particular, it is possible to adjust the brightness with the cooling panel. Cooling by the cooling panel is also particularly effective for protecting the polarizing plate of the liquid crystal panel. The heat radiation effect of heat can be enhanced by directly bonding incident light to a polarization plane where light absorption occurs. The cooling effect can be further enhanced by using infrared absorbing glass for the glass substrate of the cooling panel.

[Brief description of the drawings]

FIG. 1 is a principle diagram of a projection display device according to the present invention.

FIGS. 2A and 2B show details of a light source according to the present invention, wherein FIG. 2A is a configuration diagram and FIG.

FIG. 3 is a perspective view of a liquid crystal panel of the liquid crystal light valve of the present invention.

FIG. 4 is an equivalent circuit diagram of a display pixel portion of a liquid crystal light valve.

5A and 5B are a plan view and a side view showing a cooling panel of the liquid crystal light valve of the present invention.

6A and 6B are a plan view and a side view of a liquid crystal light valve of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Condenser lens 3 ... Liquid crystal light valve 4 ... Projection lens 67 ... Peltier element

Continued on the front page (72) Inventor Shunichi Nakamura 3-3-5 Yamato, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (72) Inventor Shuji Ariga 3-5-3 Yamato, Suwa City, Nagano Prefecture Seiko Epson (72) Inventor Akitaka Yajima 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (56) References JP-A-59-231519 (JP, A) JP-A-61-59316 (JP, A) JP-A-62-32422 (JP, A) JP-A-62-76324 (JP, U)

Claims (2)

(57) [Claims] An optical modulator for modulating incident light;
Projection optical means for projecting the light modulated by the modulation means.
In the projection type display device, the light modulating means includes both a liquid crystal panel and the liquid crystal panel.
And a pair of transparent substrates having a pair of polarizing plates
A comb-shaped spacer is interposed between the spacers.
Cooling by filling the gap formed by the cooling liquid with cooling liquid
The means is an incident side of the light incident side polarizing plate of the pair of polarizing plates.
A projection type display device characterized by being arranged in a projector . 2. The comb teeth of said spacers are mutually staggered.
A set of said interdigital spacers is arranged to form
The projection display device according to claim 1, wherein the display device is disposed.
Place.