JPH1039138A - Glass polarizing plate or phase-contrast plate for liquid crystal projector and liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polarizing plate having improved durability by sticking a transparent glass sheet to at least one side of a polarizing film. SOLUTION: A polarizing film is formed and a glass sheet and a glass molded article are separately stuck to both sides of the polarizing film with an adhesive to obtain the objective polarizing plate. Any of UV-curing and thermosetting adhesives may be used as the adhesive. The polarizing film is preferably a PVA-base dye-contg. polarizing film. In a liq. crystal projector, such polarizing plates 5f are disposed on the incidence sides of liq. crystal cells 6B, 6R, 6G. Visible radiation emitted from a light source 1 is resolved with 1st and 2nd dichroic resolving mirrors 4, 4' after passing through a condenser 2 and a UV cutting filter 3 to obtain the three primary colors. The resultant red, green and blue rays are made incident on the polarizing plates 5f and only rays each polarized in a certain direction are made incident on the liq. crystal cells 6B, 6R, 6G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass polarizer or retarder for a liquid crystal projector and a liquid crystal projector, and more particularly to a glass polarizer or retarder having good durability and optical characteristics for a liquid crystal projector and using the same. Liquid crystal projector.

[0002]

2. Description of the Related Art A liquid crystal projector for enlarging and projecting a display image of a liquid crystal display device has been developed. In this projector, an image is enlarged and displayed by arranging a light source behind a liquid crystal display element and enlarging and projecting the light of the light source transmitted through the liquid crystal display element with a lens. Since the light source used in this type of device has a very high brightness, it contains a large amount of ultraviolet light and the temperature inside the device becomes high. In order to avoid deterioration of the liquid crystal display element under such severe operating conditions, an ultraviolet cut filter is separately provided between the light source and the liquid crystal display element. In addition, the cooling efficiency is increased by separating the polarizing plate portion and the liquid crystal cell portion of the liquid crystal display element, and the polarizing plate uses an ultraviolet absorber to avoid the influence of ultraviolet rays that cannot be cut completely. Similar treatment is performed when a phase difference plate is used.

[0003]

However, even if an ultraviolet absorber is used for a polarizing plate or a retardation plate, the deterioration is unavoidable when used for a long time, and the polarizing plate or the retardation plate with further improved durability is used. The development of is desired.

[0004]

The present inventors have made various studies to solve the above-mentioned problems, and as a result, have found that in a liquid crystal projector, an ultraviolet cut filter is separately provided between a light source and a polarizing plate or a retardation plate. It was found that using a glass polarizing plate or retardation plate with a polarizing film or retardation film attached to a flat surface of glass surprisingly further improves durability and further improves optical characteristics, The present invention has been completed. That is, the present invention provides (1) a glass polarizing plate for a liquid crystal projector in which a glass plate is attached to at least one surface of a polarizing film, and (2) the polarizing film is a dye-based polarizing film based on polyvinyl alcohol. A glass polarizing plate for a liquid crystal projector, (3) a liquid crystal projector using the glass polarizing plate of (1) or (2), and (4) a liquid crystal projector having an ultraviolet cut filter, between the light source and the glass polarizing plate. (3) the liquid crystal projector having the ultraviolet cut filter, (5) a glass retarder for a liquid crystal projector having a glass plate attached to at least one surface of a retardation film,
(6) The retardation film using a glass retardation plate for a liquid crystal projector according to (5) and a glass retardation plate according to (7), (5) or (6), which is a retardation film based on polyvinyl alcohol. (8) The liquid crystal projector of (7), wherein the liquid crystal projector has an ultraviolet cut filter, and the ultraviolet cut filter is arranged between the light source and the glass phase difference plate, (9) a dichroic dye as a polarizer A glass polarizing plate in which a glass plate is adhered to one side of a polarizing film using
0) The glass polarizing plate according to (9), wherein the polarizing film is a dye-based polarizing film based on polyvinyl alcohol.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A glass polarizing plate for a liquid crystal projector according to the present invention comprises a polarizing film and a transparent glass plate attached to at least one surface. A transparent glass molded product is attached to the other surface. As the polarizing film, for example, iodine or 2
Examples of the polarizing film include a polarizing film using a coloring pigment as a polarizer and a transparent PVA-based film as a base material, and a polarizing film using a dichroic dye is preferable. Examples of the PVA (polyvinyl alcohol) film include a PVA film and a polyvinyl butyral film, and a PVA film is preferable. The thickness of the polarizing film is 1
It is preferably about 0 to 50 μm, and more preferably about 25 to 35 μm. still,
An elliptically polarizing film obtained by bonding a polarizing film and a retardation film is also included in the polarizing film according to the present invention.

The polarizing film has a thickness of, for example, about 28 μm, and converts incident light into linearly polarized light and emits it. As the polarizing film, a so-called H formed by stretching a PVA thin film while heating it, immersing it in a solution called H ink containing a large amount of iodine (potassium iodide), and absorbing iodine, is used.
A film formed by absorbing iodine on a film, a polyvinyl butyral film, a film formed by absorbing a dichroic dye on a uniaxially stretched PVA film, or the like can be used.

A glass phase difference plate for a liquid crystal projector according to the present invention is obtained by attaching a transparent glass plate to at least one surface of a phase difference film. A transparent glass molded product is attached to the other surface. As the base material of the retardation film, for example, PVA
Base film and polycarbonate film. Examples of the PVA-based film include a PVA film and a polyvinyl butyral film, and a PVA film is preferable. The thickness of the retardation film is 30 to 100 μm, preferably about 50 to 80 μm.

As the material of the glass plate used in the present invention, for example, inorganic glass such as soda glass and borosilicate glass is preferable. The size of the glass plate may be a desired size, for example, one side or a diameter is 5 to 300 mm, preferably about 20 to 200 mm, and the shape thereof is not particularly limited, such as a rectangle, a square, and a circle. Is preferred. The thickness of the glass plate is 0.5 to 5 mm, preferably about 0.7 to 2.3 mm.

As the material of the glass molded product used in the present invention, for example, inorganic glass such as soda glass and borosilicate glass is preferable. Examples of the glass molded product include a glass plate, a lens, a prism, and the like. A lens having a polarizing film attached thereto can be used as a condenser lens with a (pre) polarizing plate in a liquid crystal projector.
Further, a prism having a polarizing film or a retardation film attached thereto can be used as a polarizing plate or a polarizing beam splitter with a retardation plate or a dichroic prism with a polarizing plate in a liquid crystal projector. The size of the lens or the prism may be a desired size.

[0010] The glass polarizing plate and the retardation plate used in the present invention are produced by a known method. For example, a polarizing plate is prepared by forming a polarizing film by a wet method or a dry method, and then bonding a glass plate to one surface of the polarizing film and a glass molded product to the other surface with an adhesive. It is obtained by bonding a glass plate to one surface of a retardation film uniaxially stretched by a method and a glass molded product to the other surface with an adhesive. As the adhesive, for example, any of an ultraviolet curable adhesive and a thermosetting adhesive can be used. When an elliptically polarizing film is used as the polarizing film, it is normal to stick the retardation film side to the glass molded product, but the polarizing film side may be stuck to the glass molded product.

An AR (anti-reflection) layer may be provided on the outer surface of the glass polarizing plate or retardation plate used in the present invention. AR
As the layer, for example, a substance such as silicon dioxide or titanium oxide can be formed by vapor deposition or sputtering, or can be formed by applying a thin fluorine-based substance.

The liquid crystal projector of the present invention uses the above-mentioned glass polarizing plate or retardation plate, and preferably has an ultraviolet cut filter disposed between the light source and the above-mentioned glass polarizing plate or retardation plate. FIG. 1 shows the basic configuration of the liquid crystal projector of the present invention. Light emitted from a light source such as a metal halide lamp passes through an ultraviolet cut filter,
Then, the light passes through the above-mentioned glass polarizing plate or retardation plate and is applied to the color liquid crystal display device. Light passing through the liquid crystal display element,
That is, the display image of the liquid crystal display element is enlarged by the projection lens and projected on the screen.

The liquid crystal cell is, for example, of an active matrix type, and is formed by sealing liquid crystal between a transparent substrate on which electrodes and TFTs are formed and a transparent substrate on which counter electrodes are formed.

The glass polarizing plate on the light incident side is an elliptically polarizing plate with the retardation film side facing the light source side and using a dichroic dye as a polarizer. An antireflection multilayer film (antireflection film) is formed on the outer surface of the glass plate. As the polarizing plate on the light emission side, a normal polarizing plate is attached to a liquid crystal cell with an adhesive.

The light incident side polarizing plate is exposed to intense light.
Therefore, the temperature increases. If the liquid crystal cell and the light incident side polarizing plate are in close contact, as in a normal liquid crystal display element,
The heat of the light incident side polarizing plate is transmitted to the liquid crystal cell, and the liquid crystal in the liquid crystal cell exceeds the NI point, so that display cannot be performed.
In order to avoid this, the liquid crystal cell and the light incident side polarizing plate are arranged apart from each other, and air or gas is circulated by a cooling fan or the like to prevent the liquid crystal cell from being heated (a water cooling system may be used).

[0016]

EXAMPLES Next, the present invention will be described in detail with reference to Examples. Example 1 A 70 μPVA film (without an ultraviolet absorber, manufactured by Kuraray Co., Ltd.) is dyed with a dichroic dye, and then uniaxially quadrupled by a wet method. A transparent glass plate having a size of 30 mm × 40 mm and one side of which is subjected to an AR treatment is adhered to both surfaces of a polarizing film (thickness: 30 μ) obtained by stretching via a thermosetting adhesive, and is cured by heating. A glass polarizing plate is obtained by bonding.

Example 2 A 70 μPVA film (without using an ultraviolet absorber, manufactured by Kuraray Co., Ltd.) was uniaxially stretched to 1.1 times by a wet method, and an ultraviolet curing type adhesive was applied to both surfaces of a retardation film (film thickness: 70 μm). 30m through the agent
A transparent glass plate having a size of mx 40 mm and one surface of which is subjected to an AR treatment is adhered, cured by irradiating ultraviolet rays, and the glass plate is bonded to obtain a glass phase difference plate.

Example 3 A transparent glass plate having a size of 30 mm × 40 mm and one side of which is subjected to an AR treatment is bonded to one side of the retardation film obtained by the method of Example 2 via an ultraviolet curing adhesive. Example 1
A transparent glass plate having a size of 30 mm × 40 mm and AR-treated on one side is bonded to one side of the polarizing film obtained by the method described above through an ultraviolet curable adhesive. Then, the two plates are bonded together so that the side of the retardation film and the side of the polarizing film are aligned to obtain a glass elliptically polarizing plate.

Example 4 One side of the polarizing film obtained by the method of Example 1 was placed on one side of 30 mm × 40 mm with an A
The transparent glass plate subjected to the R treatment is adhered. Then, the polarizing plate with the glass of the present invention was obtained by attaching the other surface of the polarizing film to the flat portion of the lens having one flat surface via an ultraviolet curable adhesive.

Example 5 Three retardation films having different retardation values (1/2 wavelength plate, blue; retardation value 225 nm, green) on three surfaces of a dichroic cubic prism for synthesis having a size of 30 mm × 40 mm. Phase difference value: 275 nm, for red; phase difference value: 305 nm)
Is bonded via an ultraviolet-curable adhesive. Example 1
A transparent glass plate having a size of 30 mm × 40 mm and AR-treated on one side is bonded to one side of the polarizing film obtained by the method described above through an ultraviolet curable adhesive. Then, the three retardation film surfaces of the former glass member and the three polarizing film surfaces of the latter glass member are bonded together to obtain a glass elliptically polarizing plate.

Embodiment 6 FIG. 1 shows an example of a liquid crystal projector of the present invention using the glass polarizing plate of Embodiment 1. In this example, the glass polarizing plate is disposed on the incident side of the liquid crystal cell. The visible light emitted from the light source (metal halide lamp) 1 is
The light passes through an ultraviolet cut filter (which also has an infrared cut function) 3 and passes through a first dichroic mirror 4 for decomposition.
Blue (B) is separated by the above, and separated into green (G) and red (R) by the second separating dichroic mirror 4 'to obtain three primary colors. The R, G, and B light beams are incident on the polarizing plate with glass 5f of the present invention, and only the light beams of a predetermined direction are incident on the liquid crystal cells 6B, 6R, and 6G. A polarizing plate is attached to the emission side of the liquid crystal cell. The R, G, and B light beams that have passed through the emission-side polarizing plate 5r are sequentially combined by the first combining dichroic mirror 7 and the second combining dichroic mirror 7 ', and projected onto the screen 10 via the projection lens 9. Is done.

Example 7 In Example 6, the liquid crystal projector of the present invention is obtained by using the polarizing plate with glass plate of Example 4 instead of the polarizing plate with glass plate of Example 1. Here, since the glass polarizing plate of the fourth embodiment serves as a condenser lens, the condenser lens 2 may not be used.

Example 8 In FIG. 1, behind the exit-side polarizing plate 5r, a glass retardation plate (1/2 wavelength plate, for blue; retardation value of 225 nm, for green; Phase difference value 275 nm, for red;
With a retardation value of 305 nm), the liquid crystal projector of the present invention is obtained. In this projector, the output polarized light is rotated in the vertical direction and projected on the screen 10 (polarizing screen), so that an image with high contrast is obtained.

The present invention is not limited to the above embodiment, and can be arbitrarily changed in application. For example, the polarizing plate may include a low-reflection film or the like, and the configuration of the liquid crystal projector, the configuration of the liquid crystal display element, and the like can be arbitrarily changed.

[0025]

According to the present invention, when an ultraviolet cut filter is arranged between a light source and a polarizing plate or a retardation plate, the durability of the polarizing plate or the retardation plate can be improved even when very strong light is irradiated. Also, since no ultraviolet absorber is used, there is no absorption of light near ultraviolet, and light can be used effectively.
Further, since the smoothness of the flat portion of the glass to which the polarizing film is attached can be more strictly controlled, a polarizing plate having higher smoothness and better optical characteristics such as a small difference in optical characteristics depending on the location can be obtained. Further, by using the glass polarizing plate or the phase difference plate of the present invention, a liquid crystal projector capable of stably displaying a high-contrast image for a long time can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a liquid crystal projector according to a sixth embodiment of the present invention.

[Explanation of symbols]

 1: Light source (metal halide lamp) 2: Condensing lens 3: UV / IR cut filter 4, 4 ': Dichroic mirror for decomposition 5f: Incident side polarizing plate 5r: Outgoing side polarizing plate 6R: 6G, 6B: TFT liquid crystal cell 7 , 7 ': dichroic mirror for synthesis 8: mirror 9: projection lens 10: screen

Claims (10)

[Claims] 1. A glass polarizing plate for a liquid crystal projector, wherein a glass plate is attached to at least one side of a polarizing film. 2. The glass polarizing plate for a liquid crystal projector according to claim 1, wherein the polarizing film is a dye-based polarizing film based on polyvinyl alcohol. 3. A liquid crystal projector using the glass polarizing plate according to claim 1. 4. The liquid crystal projector according to claim 3, wherein the liquid crystal projector has an ultraviolet cut filter, and the ultraviolet cut filter is arranged between the light source and the glass polarizing plate. 5. A glass phase difference plate for a liquid crystal projector having a glass plate attached to at least one surface of a phase difference film. 6. The glass phase difference plate for a liquid crystal projector according to claim 5, wherein the phase difference film is a phase difference film containing polyvinyl alcohol as a base material. 7. A liquid crystal projector using the glass phase difference plate according to claim 5. 8. The liquid crystal projector according to claim 7, wherein the liquid crystal projector has an ultraviolet cut filter, and the ultraviolet cut filter is arranged between the light source and the glass phase difference plate. 9. A glass polarizing plate comprising a polarizing plate using a dichroic dye as a polarizer and a glass plate attached to one side of a polarizing film. 10. The glass polarizing plate according to claim 9, wherein the polarizing film is a dye-based polarizing film based on polyvinyl alcohol.