JP3536353B2 - Reflector, reflective polarizer and reflective liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection plate having a novel reflected light amount distribution characteristic, a reflection type polarizing plate using the same, and a liquid crystal display device.

[0002]

2. Description of the Related Art As a reflection type liquid crystal display device, a reflection plate is arranged in the structure of a first polarization plate / liquid crystal cell / second polarization plate / reflection plate (TN type, STN type) or a liquid crystal cell / reflection type. It is known that a reflector is arranged in a plate structure (GH type).

[0003]

In any of these, the visibility is low when viewed from an angle avoiding the glare phenomenon due to the light rays reflected from the outermost surface of the display device, that is, the surface of the first polarizing plate or the liquid crystal cell. Has the problem.
The present inventors have conducted intensive studies to solve such problems, and as a result, have found that such problems can be solved by using a reflector having a novel reflected light amount distribution characteristic, and have reached the present invention. .

[0004]

According to the present invention, a metal is vapor-deposited on a surface of a base material having a surface shape showing a maximum point of reflectance at a position deviated by 2 degrees or more from a regular reflection angle in a reflected light amount distribution curve. Therefore, the reflection light amount distribution curve of the metal vapor deposition surface has a maximum point of reflectance at a position (θ ′) deviated from the regular reflection angle by 2 degrees or more, and relates to a reflection plate in which 0 degrees <θ ′ <90 degrees. Is. In the present invention, a metal is vapor-deposited on the surface of a base material having a surface shape showing a maximum point of reflectance at a position deviated from the regular reflection angle by 2 degrees or more in a reflected light amount distribution curve,
The reflected light amount distribution curve when light is incident on the metal vapor deposition surface such that the regular reflection angle is more than 0 degree and less than 90 degrees is within the range of more than 0 degree and less than 90 degrees. It also relates to a reflector having a maximum point of reflectance at a position deviated from the angle by 2 degrees or more. By using the reflector of the present invention, it is possible to obtain a reflective liquid crystal display device which is bright and has good visibility when viewed from an angle avoiding the glare phenomenon. Further, according to the present invention, a metal is vapor-deposited on a surface of a base material having a surface shape showing a maximum point of reflectance at a position deviated from a regular reflection angle by 2 degrees or more in a reflected light amount distribution curve. Also in the distribution curve, the reflection plate having the maximum point of reflectance at a position deviated from the regular reflection angle by 2 degrees or more is also related to the reflection type polarizing plate laminated on the polarizing plate on the metal vapor deposition surface side.

The present invention will be described in detail below. The reflector of the present invention has a maximum point of the reflectance at a position deviated by 2 degrees or more from the regular reflection angle in the reflected light amount distribution curve. That is, the reflector of the present invention has a reflected light amount distribution curve different from that of the conventional reflector, and the incident angle of light to the reflector is θ (0 ° <θ <90 °), and the amount of reflected light is Is measured, the angle at which the reflectance is maximized is θ '(0 degree <θ'<
90 degrees), there is a maximum point that satisfies the condition of | θ−θ ′ | ≧ 2 degrees. The incident angle θ is not particularly limited and may be a value in the range of 0 ° <θ <90 °, and preferably a value in the range of 30 ° ≦ θ ≦ 80 °.

Examples of such a reflected light amount distribution curve include the following cases. The reflectance is maximum at the regular reflection angle (θ), and the maximum point of the reflectance exists at a position deviated from the regular reflection angle (θ) by 2 degrees or more (see FIG. 1).
The position where the reflectance is maximum deviates from the regular reflection angle by less than 2 degrees, and the maximum reflectance point exists at the position deviated from the regular reflection angle by 2 degrees or more (see FIG. 2). The position where the reflectance is maximum deviates from the regular reflection angle by 2 degrees or more (Fig. 3).
And FIG. 4). The order of << is preferable.

The reflector of the present invention is manufactured by vapor-depositing a metal having a high reflectance property such as aluminum or silver on the surface of a substrate having a reflected light amount distribution curve of | θ-θ '| ≧ 2 degrees. can do. A base material having a reflected light amount distribution curve of | θ−θ ′ | ≧ 2 degrees can be produced by modifying the base material surface by the following method, for example.

A: To a substrate having a smooth or uneven surface, from the angle of 45 ° or more with respect to the surface normal, drop or blow fine particles of a silicate compound or a metal compound. Method: -A method of irradiating a plasma, or a method of-irradiating a laser; B: a substrate having an uneven surface, from an angle of 45 degrees or more with respect to a normal to the surface, a compound such as an inorganic compound C: When coating a substrate having a smooth surface with an organic / inorganic fine particle dispersion, a method of inclining the substrate immediately after coating, or a method of blowing air from one direction immediately after coating, etc. .

Examples of the type of substrate include plastic films such as polyethylene terephthalate film, polyester film, polycarbonate film, polyacrylic film and polyolefin film, metal plates such as aluminum plate and copper plate, and glass plate.

The base material used for the above A or B and having an uneven surface can be manufactured, for example, by the following method. -A method of extruding a resin mixed with organic / inorganic fine particles, -a method of sandblasting the surface of a base material, -a method of coating a base material with a coating liquid containing inorganic / organic fine particles, and the like.

The thickness of the substrate having a reflected light amount distribution curve of | θ−θ ′ | ≧ 2 degrees is not particularly limited, but for example,
It is about 10 μm to 5 mm. The method of depositing a metal having a high reflectance and the thickness of the deposited layer are not limited as long as the reflected light amount distribution characteristic of the substrate surface does not change due to the deposition and | θ−θ ′ | ≧ 2 degrees is satisfied. There is no. For example, a vacuum vapor deposition method, a sputtering method, an ion plating method, or the like, which is generally used for forming a metal thin film, can be appropriately selected and used depending on the type of the substrate. The reflector may have translucency.

By using a substrate having a reflected light amount distribution curve of | θ-θ '| ≧ 2 degrees obtained by the above method and forming a negative shape of the surface shape on a roll, the following process is performed. | Θ− using a roll transfer method using a roll
A plastic substrate having a reflected light amount distribution curve of θ ′ | ≧ 2 degrees can be efficiently manufactured.

When a plastic film such as a PET film is produced by the solvent casting method, the surface of the casting belt is
By forming in advance a negative shape of a surface shape showing a reflected light amount distribution curve of | θ−θ ′ | ≧ 2 degrees, it is possible to efficiently use | θ−θ ′ | ≧ 2 degrees by the solvent casting method. It is possible to produce a plastic substrate having a reflected light amount distribution curve.

Using as a stylus a metal plate having a negative shape of the surface shape showing a reflected light amount distribution curve of | θ−θ ′ | ≧ 2 degrees, and pressing a plastic substrate having a smooth surface against it. Also, | θ-θ '|
A plastic substrate having a reflected light amount distribution curve of ≧ 2 degrees can be efficiently produced.

When silver is vapor-deposited as a metal having a high reflectance characteristic, it is preferable to provide a protective film on the silver vapor-deposited layer in order to prevent deterioration of the vapor-deposited layer. The protective film is not particularly limited, and examples thereof include a coating film of acrylic resin, epoxy resin, polyester resin, urethane resin or alkyd resin.For example, it can be applied by a usual method such as roll coating, gravure coating, spray coating and the like. Can be engineered. Further, an inorganic thin film such as SiO ₂ can also be used. The thickness of the protective film is not particularly limited, but is in the range of 5 nm to 10 μm, for example.

The reflection plate of the present invention can be made into a reflection type polarization plate suitable for a reflection type liquid crystal display device such as a TN type or STN type by bonding it to a polarization plate. A reflective liquid crystal display device having a layer structure of polarizing plate / liquid crystal cell / (polarizing plate / reflecting plate) equipped with such a reflective polarizing plate, when viewed from an angle avoiding glare, It is bright and has excellent visibility.

When the reflection plate of the present invention is used in a GH type liquid crystal display device, it may be attached to the lower side of the liquid crystal cell, or the lower glass plate or plastic plate constituting the liquid crystal cell. Instead of this, the reflector of the present invention may be used. By either method, it is possible to obtain a GH type liquid crystal display device having a layer structure of glass / liquid crystal layer / reflector, which is bright and has excellent visibility when viewed from an angle avoiding the glare phenomenon.

[0018]

The reflector of the present invention has a novel reflection characteristic that it has a maximum point of reflectance at a position deviated from the regular reflection angle by 2 degrees or more in the reflected light amount distribution curve. By mounting on the device, it is possible to obtain a reflective liquid crystal display device which is bright and has excellent visibility when viewed from an angle avoiding the glare phenomenon.

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The distribution curve of the amount of reflected light on the surface was measured with an automatic goniophotometer (GP-200 manufactured by Murakami Color Co., Ltd.).

Example 1 An aluminum plate was placed at an angle of 60 ° from the horizontal, and NG # 80 sand was dropped from the top to obtain an aluminum plate (thickness: 1 mm) with a modified surface. When light was incident at an angle of 45 degrees with respect to the surface normal and the reflected light amount distribution curve was measured, the angle at which the reflectance was maximum was 43 degrees. Aluminum was vapor-deposited on this aluminum plate with a thickness of about 70 nm while maintaining the distribution characteristic of the reflected light amount to form a reflector (angle at which the maximum reflectance is 43 degrees). This reflective plate is attached to a polarizing plate (SG-1852A manufactured by Sumitomo Chemical Co., Ltd.) via an acrylic adhesive to form a reflective polarizing plate (polarizing plate / [aluminum vapor deposition layer / aluminum plate]).
And

This reflective polarizing plate is laminated on a TN type liquid crystal cell, and a polarizing plate (S manufactured by Sumitomo Chemical Co., Ltd.
G-1852A) is laminated to form a polarizing plate / liquid crystal cell / polarizing plate /
A reflective TN liquid crystal display device having a layer structure of [aluminum vapor deposition layer / aluminum plate] was assembled. When this reflective liquid crystal display device was driven, it was bright and excellent in visibility when viewed from an angle avoiding the glare phenomenon.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a reflected light amount distribution curve of a reflector of the present invention.

FIG. 2 is a diagram showing an example of a reflected light amount distribution curve of a reflector of the present invention.

FIG. 3 is a diagram showing an example of a reflected light amount distribution curve of a reflector of the present invention.

FIG. 4 is a diagram showing an example of a reflected light amount distribution curve of a reflector of the present invention.

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Claims (6)

(57) [Claims] 1. A metal vapor-deposited on a surface of a base material having a surface shape showing a maximum point of reflectance at a position deviated from the regular reflection angle by 2 degrees or more in a reflected light amount distribution curve, and the metal vapor-deposited surface is reflected. light intensity distribution curve, 'have a maximum point of reflectance, 0 ° <theta position displaced from the regular reflection angle 2 degrees or more (theta)' <9
A reflector characterized by being 0 degree . 2. From the regular reflection angle in the reflected light amount distribution curve
A surface shape showing a maximum point of reflectance at a position displaced by 2 degrees or more
A metal is vapor-deposited on the surface of the substrate having the metal vapor-deposited surface.
The position where the regular reflection angle exceeds 0 degree and is smaller than 90 degree
The distribution curve of the reflected light quantity when light is incident is
Regular reflection angle within the range of more than 0 degree and less than 90 degrees
Must have a maximum point of reflectance at a position more than 2 degrees away from
Reflector characterized by. 3. From the regular reflection angle in the reflected light quantity distribution curve
A surface shape showing a maximum point of reflectance at a position displaced by 2 degrees or more
A metal is vapor-deposited on the surface of the substrate having the metal vapor-deposited surface.
2 or more from the regular reflection angle in the reflected light amount distribution curve of
Reflector, the gold having a maximum point of the reflectivity displacement position
A reflective polarizing plate, which is laminated on the polarizing plate on the metal vapor deposition surface side . 4. A reflective TN liquid crystal display device comprising the reflective polarizing plate according to claim 3 . 5. A reflective STN liquid crystal display device comprising the reflective polarizing plate according to claim 3 . 6. A reflection type GH liquid crystal display device comprising the reflection plate according to claim 1 or 2 .