JPH10133180A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion of dust to a liquid crystal display element, to enable heat radiation with only the forced air cooling and to enable the miniaturization around a liquid crystal display section by inserting incident transparent glass and exist transparent glass into respective incident/exit partition plates and fixing the transparent glass to the liquid crystal display element by a transparent gelatinous adhesive material. SOLUTION: The incident transparent glass 1 formed by subjecting the incident side surface 1a to an antireflection filed treatment and the exit transparent glass 2 formed by constituting a polarizer 3 and a phase plate 4 on the exist side surface are respectively inserted into the incident/exit partition plates 7, 8 and are fixed to the liquid crystal display element 20 by the transparent gelatinous adhesive material 5. The compsn. of the material 5 is composed mainly of a silicon material which is cured by the contact reaction of a two- component mixing type and is made gelatinous (gel) after curing. The gel does not exert an influence, such as application of stresses, on the element 20 even if the gel itself shrinks. The thickness of the gel is set at a thickness at which the transmittance changes extremely less, preferably at <=0.1mm even despite of the occurrence of yellowing by liquid and heat.

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 for enlarging and projecting an output signal from a personal computer and an image such as a CD or a video on a screen, and other liquid crystal display devices. About.

[0002]

2. Description of the Related Art Conventionally, as a liquid crystal display device, for example, a liquid crystal projector, an optical image signal formed on a light valve is irradiated by an illuminating means, and the optical image is enlarged and projected on a screen by a projecting means. There is. Many light valves using a liquid crystal display element have been proposed as light valves for such display devices. Twisted nematic (TN), one of the liquid crystal display devices
The liquid crystal display device has a structure in which a liquid crystal is injected between a pair of transparent substrates having a transparent electrode film. By disposing two polarizers and combining the action of rotating the plane of polarization by the electro-optic effect of the liquid crystal and the action of selecting the polarization component of the polarizer, the amount of transmitted incident light is controlled to display image information. It has become.

[0003] Such display devices are not only used for displaying images such as video signals, but also for displaying images output from personal computers, and are increasingly used for presentations. Presentations using these liquid crystal projectors are generally performed in a dark room. The manuscripts were difficult to see due to the dark surroundings, and I was dissatisfied with the presentation while introducing the products. For this reason, the power of the light valve can be increased,
A liquid crystal display device such as a liquid crystal projector has been proposed in which the amount of light reaching a screen is greatly improved, for example, by optically modifying a reflector around a light valve or by combining polarized light incident on a liquid crystal display element.

[0004]

For example, in the above-mentioned liquid crystal projector, the temperature of the optical components constituting the optical system rises due to the light emitted from the light valve. In particular, in the liquid crystal display element, since a circuit is incorporated in a pixel region through which light passes, there is a temperature rise due to heat absorption here. Further, as described above, the liquid crystal display element has the polarizers arranged one after the other, and the polarizer and the liquid crystal display element are particularly closely fixed on the emission side. For this reason, in a state where the electro-optical twist of the liquid crystal is perpendicular to the output polarizer, that is, in the case of an image where light is restricted, the light hitting the polarizer is almost changed to heat, but the heat is applied to the liquid crystal display element. Temperature rise.

Conventionally, in a liquid crystal display device such as a liquid crystal projector having a relatively small amount of light, the temperature rise of the liquid crystal display element due to the light is relatively small, and the excessive temperature of the liquid crystal display element is increased by forced air cooling using a so-called cooling fan. There was no rise.

However, in a liquid crystal display device such as a liquid crystal projector in which the amount of light is increased as described above, cooling by forced air cooling is not sufficient, and liquid cooling using a refrigerant has been proposed. For example, liquid cooling disclosed in JP-A-3-91716 will be described with reference to FIG. FIG. 4 shows a cross section of only the liquid crystal display element of the liquid crystal projector. One surface of the liquid crystal display element 20 is in contact with the cooling device 25 via the transparent glass 21a. The cooling device 25 includes the transparent glass 21 and the radiator 23,
A refrigerant 22 is sealed in a space surrounded by these. A fan 26 is provided below the cooling device 25. In the conventional liquid crystal display element having the above-mentioned structure, even if the temperature of the liquid crystal display element rises due to the light 24 from the light bubble, the heat of the liquid crystal display element does not
a to the refrigerant 22. The refrigerant 22 warmed by heat rises due to the decrease in density, and natural convection occurs in the refrigerant. The heat carried by the convection flows to the radiator 23
Heat exchange with the outside air is performed. At this time, the fan 26
, Heat exchange from the radiator is more effectively promoted. By the above heat cycle, heat generated in the liquid crystal display element is removed. The liquid cooling is advantageous in characteristics such as specific heat, density, viscosity, and the like, as compared with forced air cooling, and thus has high heat radiation efficiency. Therefore, it is suitable for cooling a liquid crystal display element of a liquid crystal projector having a large luminous flux. However, the above-mentioned liquid cooling is not sufficiently considered in the following points.

First, the first point is that a device such as a radiator becomes larger in comparison with forced air cooling, which is disadvantageous in terms of miniaturization and weight reduction of a product and cost.

The second point is that the connection between the liquid crystal panel and the cooler is
It is a solid combination of the liquid crystal panel glass and the cooler transparent glass. The interface between the glasses is in a state in which the solid contact and the air layer are interposed, which is disadvantageous in terms of heat transfer efficiency.

The third point is that interference fringes due to refraction of light are likely to occur due to the presence of an air layer at the interface between individuals as described above. For this reason, the glass surface of the liquid crystal panel and the transparent glass may require anti-reflection measures,
Since the interference fringes are projected on the projected screen, generation of the interference fringes in the panel liquid crystal display element must be prevented.

The fourth point is that it is necessary to take measures against dust adhering to the emission side of the liquid crystal display element. Since dust adhering to the liquid crystal display element is projected on a screen, some countermeasures are required. As a general countermeasure, either a transparent glass is formed at a place away from the emission surface of the liquid crystal display element, and a transparent structure is provided between the transparent glass and the liquid crystal display element, or the focal length of the projection lens is set to be small. In many cases, such a method is applied. In the former closed structure method, forced air-cooling cooling by a fan is difficult to be performed because the heat generated by the polarizing plate is closed structure. Therefore, the heat is transferred to the liquid crystal display element and is radiated from the cooling device, thereby lowering the efficiency.

On the other hand, the latter is a method of increasing the F value of the projection lens to reduce the depth of focus. As a result, a slight shift from the pixel of the liquid crystal display element prevents the dust adhering to the glass surface from being focused. However, this method not only raises the cost of the projection lens, but also increases the weight and outer shape because the diameter of the projection lens increases.

[0012]

In the present invention, in order to solve the above-mentioned problems, a transparent glass is used which is fixed to the entrance surface and the exit surface of the liquid crystal display element with a transparent adhesive. The properties of the transparent adhesive in the solidified state are rich in elasticity, and when an external force is applied to the transparent glass, or when stress occurs due to expansion of each member due to heat, the transparent adhesive affects the liquid crystal display element. It has no such properties. The thickness of the transparent adhesive is set to a thickness that does not affect the transmittance of the adhesive even if yellowing due to heat or ultraviolet rays caused by the light valve occurs.

[0013] Further, the transparent glass for both the incoming and outgoing light is set to a thickness such that dust cannot be recognized when the pixel is in focus. Further, the incident-side transparent glass has an antireflection film formed only on the surface to be bonded, and the surface to be bonded of the output-side transparent glass has a polarizer and a phase plate slightly larger than the transparent glass.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the apparatus according to the present invention will be described below with reference to the drawings. Components having the same functions as those of the components disclosed in the above-described conventional example are denoted by the same reference numerals.

FIG. 1 is a sectional view showing an example of the configuration of each part of the liquid crystal display element used in the present invention, and FIG. 2 is a plan view seen from the incident side in FIG. 1 and 2, reference numeral 1 denotes an incident transparent glass in which a light incident surface 1a is subjected to an anti-reflection film treatment, 2 denotes an outgoing transparent glass in which a polarizer 3 and a phase plate 4 are sequentially formed,
5 and 6 are transparent adhesives, 7 is an incident parting plate detachably attached to the holding frame 9 of the liquid crystal display element 20, 8 is an emission parting plate detachably held on the holding frame, and 10 is a holding frame. Reference numeral 9 denotes a panel plate in which components around the liquid crystal display element are integrally held and fixed by screws 11. In the above configuration, the composition of the transparent adhesives 5 and 6 is mainly composed of a silicon-based material and is cured by a two-liquid mixing type catalytic reaction. The transparent adhesive becomes gelatinous (hereinafter referred to as gel) after curing. Even if the gel itself shrinks, the gel does not exert an effect of giving stress to the liquid crystal display element 20. Further, the expansion of the input / output transparent glass constituting the periphery due to heat and the expansion of the liquid crystal display element itself have little effect on the liquid crystal display element itself. The thickness of the gel is set to a very small thickness with a very small change in transmittance even when yellowing due to light or heat occurs, and preferably set to 0.1 mm or less.

The thickness of the incident transparent glass is set such that even if dust adheres to the surface thereof, it is almost invisible when the picture element is focused. In addition, the gel is adhered to the liquid crystal display element and inserted into the parting lines 7a and 8a of the input / output parting plate so as not to be separated due to the falling vibration of the product and fixed to the liquid crystal display element. You. The parting lines 7a, 8a of the entrance / exit parting plates 7, 8 are the entrance / exit transparent glass 1,
2 has a function of accurately arranging 2 at a predetermined position. An antireflection film is formed on the light incident surface 1a of the incident side transparent glass 1 to prevent light loss on the surface.

On the other hand, the outgoing transparent glass is a light outgoing surface 2a.
, A polarizer 3 and a phase plate 4 are sequentially stacked. The size of the polarizer 3 and the phase plate 4 is formed larger than the size of the emission transparent glass 2. As a result, the polarizer 3 and the phase plate 4 can be made sufficiently larger than the picture element display area 12, thereby preventing the occurrence of picture missing. Further, the total thickness m of the output transparent glass 2, the polarizer 3, and the phase plate 4 is m.
Numeral 1 is smaller than the distance m0 between the panel plate 10 and the liquid crystal display element 20, and the thickness d1 of the emission transparent glass 2 is larger than the distance d0 between the emission parting plate 8 and the liquid crystal display element 20. As a result, the phase plate 4 is formed so as to be recessed from the panel plate surface 10a. Therefore, when assembling the liquid crystal display unit 15 into a device (not shown), it is necessary to assemble the phase plate surface of a relatively soft material without damaging it. Can be. The thickness of m1 is set to a thickness that is hardly seen when the picture element is focused even if dust adheres to the surface of the phase plate.

The size w1 of the polarizer 3 and the phase plate 4
Is set to be larger than the size w0 of the emission side transparent glass 2. Therefore, there is no problem if the light passing through the outgoing transparent glass 2 is parallel light, but even in the case of light having an angle that passes through the edge of the outgoing transparent glass 2, anomalies are caused by the polarizing plate 3 and the phase plate 4. The screen that does not cause the problem is obtained. The function of the liquid crystal projector having the liquid crystal display element section 15 of the present invention having the above-described configuration will be described with reference to FIG.

FIG. 3 is a schematic diagram showing the entire optical system of a liquid crystal projector according to one embodiment of the present invention. In FIG.
Numeral 0 denotes a light source such as a metal halide, 31 denotes a reflecting mirror for condensing light emitted from the light source 30 in a certain direction, and 32 and 33 denote multi-lenses condensed by a number of cell lenses. 34-39
Denotes a separation optical system, and is a mirror group for separating light into three primary colors RGB. 40R, 40G, 40B are each RG
Lenses for condensing B on the liquid crystal display element, 41R, 41G,
41B is an incident side polarizer, and 15R, 15G and 15B are the liquid crystal display unit 15 described above. Reference numeral 42 denotes a combining optical system that combines RGB separated by the separating optical system. 43 is a projection lens, and 44 is a screen. In the liquid crystal projector of the present invention having the above configuration, the light emitted from the light source 30 is condensed on the multi-lenses 32 and 33 by the reflecting mirror 31 and enters the separation / combination system. The multi lens 32,
The liquid crystal display element 33 has a function of uniformly entering light to every corner of the picture element display area 12, and has a function of making the illuminance uniform at any place on the screen 44. The light that has exited the multi-lens is separated by a separating / combining optical system 34-39.
GB, condenser lenses 40R, 40G, 4
OB and the respective liquid crystal display units 15R, 15G, 15B via the incident polarizers 41R, 41G, 41B. The polarization plane is electro-optically rotated by the liquid crystal display element, and image information is displayed on the screen 44 via the projection lens 43.

The above-mentioned optical components in each section absorb light from the light source and store heat, but the heat generation at the output-side polarizer 3 is extremely large. In particular, in a black screen in which the rotation of the polarization plane in the liquid crystal display element is scarce, light is blocked by the output polarizer 3, so that heat is stored in the output polarizer 3 and the temperature rises. However, since the polarizer 3 touches the outside air through the phase plate 3 having almost no thickness, the heat can be sufficiently released by forced air cooling from the fan 26. It is much more efficient than a conventional liquid crystal display element in which air is used as a heat insulating layer and is in a sealed state as in the prior art.

On the other hand, since forced cooling air also hits the surface of the transparent glass on the incident side, heat generated in the circuit portion of the liquid crystal panel and the like is radiated to the outside by heat conduction of the incident transparent glass.

[0022]

According to the liquid crystal display device of the present invention disclosed above, since the transparent glass is fixed to the liquid crystal display element with a gel-like adhesive, not only the adhesion of dust to the liquid crystal display element can be prevented, but also the liquid crystal display can be prevented. The heat generated in the element itself and the heat of the output polarizer can also be radiated only by forced air cooling by heat conduction. For this reason, the area around the liquid crystal display unit can be reduced in size, and a large-scale device such as liquid cooling is not required. In addition, since the liquid crystal display element is fixed to the liquid crystal display element with an adhesive having a gel-like elasticity, stress due to heat of each component is relieved. External forces are also reduced.

Since the size of the transparent glass, the polarizer and the phase plate is taken into consideration in the configuration on the emission side, there is no vignetting due to the polarizer and the phase plate. At the same time
These thicknesses are also taken into consideration, so that scratch defects on the surface of the phase plate are unlikely to occur.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a liquid crystal display unit of the device of the present invention.

FIG. 2 is a plan view of the apparatus of FIG. 1 as viewed from an incident side.

FIG. 3 is a schematic diagram of the apparatus of the present invention.

FIG. 4 is a sectional view of a liquid crystal display section of a conventional device.

[Explanation of symbols]

 Reference numerals 1, 2, transparent glass 3, emission side polarizer 4, phase plate 5, 6, transparent gel adhesive 15, liquid crystal display unit 20, liquid crystal display element

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaharu Exit 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref.

Claims (4)

[Claims] 1. A means for irradiating an emitted light from a light source onto a surface to be illuminated, a spectral means for splitting the light into RGB, a synthesizing means for synthesizing the same, a liquid crystal display element for modulating light, and the liquid crystal display. A liquid crystal display device having projection means for projecting light emitted from the element, comprising: an incident transparent glass having an incident-side surface treated with an antireflection film; and an output transparent glass having a polarizing plate and a phase plate on the exit-side surface. Glass, an incoming / outgoing parting plate for blocking unnecessary light, a holding frame for a liquid crystal display element, and a panel plate, and the incident transparent glass and the outgoing transparent glass are inserted into respective incoming / outgoing parting plates. A liquid crystal display unit comprising a liquid crystal display unit fixed to a liquid crystal display element with a transparent gelatinous adhesive. 2. A means for irradiating light emitted from a light source onto a surface to be illuminated, a spectral means for splitting the light into RGB, a synthesizing means for synthesizing the same, a liquid crystal display element for modulating light, and the liquid crystal display. A liquid crystal display device having projection means for projecting light emitted from an element, comprising: an incident transparent glass; an incident parting plate; a holding frame of the liquid crystal display element; and a panel plate. Insert into the parting board,
A liquid crystal display device comprising a liquid crystal display section in which the incident transparent glass is fixed to a liquid crystal display element with a transparent gelatinous adhesive. 3. The relationship between the thickness d1 of the outgoing transparent glass, the distance d0 between the outgoing parting plate and the liquid crystal display element is d0 <d1, the total thickness m1 of the transparent glass, the polarizer and the phase plate, and the liquid crystal display from the panel plate. A liquid crystal display device comprising: a liquid crystal display section in which the component whose distance m0 to the element satisfies the relationship of m0> m1 is fixed to a liquid crystal display element with a transparent gelatinous adhesive. 4. The liquid crystal display according to claim 1, wherein the liquid crystal display element portion has a relationship between the size w0 of the outgoing transparent glass and the size w1 of the polarizer and the phase plate such that w0 <w1. apparatus.