JPS63121001A - Crt filter - Google Patents

Abstract

PURPOSE:To prevent generation of bleeding in the display of the corner part of a screen and deterioration of resolution by forming the cathode ray tube (CRT) filter so as to be in closely contact with CRT. CONSTITUTION:The CRT filter has glossiness Gs (60 deg.) of 5-40 at the filter surface thereof and has the shape capable of being in closely contact with the CRT surface. The material of the CRT filter is exemplified by polyvinyl chloride, high nitrile resin, polyether, etherketone, etc., and further preferably, the high nitrile resin in points of sticking property and moldability. And, arbitrarily, said material may comprise a UV ray absorber, an antistatic agent, a dyestuff and a pigment, etc. Thus, the titled filter is easily equipped for CRT, without depressing the resolution, and with a small space, and a reflected ray does not come into the eyes, thereby preventing disturbance caused by external light.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a CRT filter.

[Conventional technology]

O of word processing sensor, personal computer etc.
CRT display devices such as A-devices and analytical devices have become so widespread that they have become indispensable in offices, homes, and factories. Along with this, the number of operators who come into close contact with CRTs for long periods of time is also increasing, and occupational diseases among operators have become a social problem in developed countries. In order to prevent such negative effects, a CRT filter is usually attached to cover the CRT section. These C
RT is usually used in a bright room, so CR
Even when using a T-filter, indoor light or sunlight tends to reflect on the screen and appear in the image forming area, which can cause eye fatigue.

Various proposals have been made as ways to improve these points. For example, ■method of roughening the surface of a CRT filter (for example, Japanese Patent Application Laid-Open No. 55-12107, Japanese Utility Model Application No. 61-6
No. 0291, etc.), ■ A method of attaching a light-absorbing mesh to the front of the filter (for example, Utility Model Publication No. 60-107)
(No. 80, U.S. Patent No. 4.253.737), ■ A method of providing an enhancement treatment by providing a multilayer reflective layer, ■ A method of installing a front plate with a curved surface at an angle (for example, Utility Model Publication No. 40-1
8252) and the like are known.

However, each of these methods has its own merits and demerits, and it is currently not possible to obtain a satisfactory result. That is, although the method (2) of roughening the CRT filter surface can effectively reduce specular reflection,
In the area around C117, the surface of the filter could not be strongly roughened because it would deteriorate the resolution due to transmitted light. In the method (2) of attaching a light-absorbing mesh to the front of the filter, even the transmitted light is absorbed, resulting in a large loss of transmitted light In. Although the method (2) of providing a multilayer reflective layer and performing a transmission enhancement treatment can reduce the specular reflectance, it has the disadvantage that it is less effective against reflected light having a large angle of incidence. The method (2) in which a front plate with a curved surface is installed at an angle requires a large space to install the curved plate at an angle, and there are problems such as the need to use a light shielding plate.

[Problem that the invention seeks to solve]

As described above, the present invention provides a CRT filter that does not deteriorate the resolution, can be easily installed, requires only a small space, and prevents reflected light from entering the eyes and prevents reflections. This is what we are trying to provide.

[Means for solving problems]

The present inventors have studied to solve such problems,
The present invention has now been completed.

That is, in the CRT filter according to the present invention, the glossiness Gs ((i0') of the filter surface is 5 to 40, and the CI'
? It is characterized by having a shape that can be brought into close contact with the T-plane.

The gloss level Gs (60”) in the present invention is defined by JIS K
-7105.

Examples of materials for the CRT filter of the present invention include polyvinyl chloride, high nitrile resin, polyetheretherketone, polyethersulfone, polycarbonate,
High nitrile resins, such as diethylene glycol bisallyl carbonate resin, polyethylene terephthalate, polymethyl methacrylate, and acrylonitrile-styrene copolymer, are particularly preferred in terms of adhesiveness and moldability.

The material of the CRT filter according to the present invention may optionally contain ultraviolet absorbers, antistatic agents, dyes, pigments, and the like.

As a method for manufacturing a CRT filter, the CRT filter according to the present invention can be obtained by ordinary molding methods such as injection molding, vacuum molding, and pressure molding.

Glossiness Gs (60”) of CRT filter surface is 5 to 4
As a method for adjusting to 0, a known method can be used.

For example, methods of roughening the surface of the filter using sand, etc., methods of applying paint containing finely powdered silica etc. to the surface of the filter, methods of blending finely powdered silica etc. to the resin material, injection molding, vacuum A method of applying grains to the surface of the mold used for molding and pressure forming and transferring the grains to the surface of the CRT filter, using a sheet of original fabric or temporary material obtained by roughening the surface in advance or transferring the grains. Examples include a method for manufacturing a CRT filter.

The surface of the CRT filter of the present invention may be coated with a surface hardening agent, an antistatic agent, an ultraviolet absorber, etc., so long as the gloss level (G5C60') of the surface of the CRT filter is maintained within a range of 5 to 40. Further, in order to prevent electromagnetic waves and static electricity generated by a CRT, it is also possible to laminate R-electrode fibers or the like inside the filter.

〔Example〕

The present invention will be explained below with reference to Examples.

In addition, the gloss level Gs (60') is based on JIS K-7105.
The resolution was measured by attaching an acid filter to a 14-inch CRT and visually observing the resolution of characters on the screen.

Example 1 A CRT was manufactured using a polyvinyl chloride sheet with a thickness of 2 mm and an aluminum mold for pressure forming with a wrinkled surface.
A CRT filter with a shape that can be closely attached to a surface was manufactured. Table 1 shows the glossiness Gs ((ioo)) and resolution.

Example 2 A high nitrile resin sheet (Mitsui Toatsu Chemical Co., Ltd. (LIL!!!, trade name: Balenox)) with a thickness of 1 mm was used instead of a polyvinyl chloride sheet, and scissors were used between press plates with wrinkles on the surface. A raw sheet with low gloss was obtained by heat pressing. Using this sheet, a CRT filter with a shape that could be closely attached to the CRT surface was manufactured by vacuum forming.Gloss Gs (60') and resolution are shown in Table 1.

Comparative Example 1 C1'? with a gloss level Gs (60 @) of 2 was prepared in the same manner as in the example except that an aluminum mold for pressure forming with a more grained surface was used. A T filter was manufactured.

The resolution was poor and the characters on the CRT could not be distinguished. Table 1 shows the glossiness Gs (60'') and resolution.

Comparative Example 2 A sheet large enough to cover a CRT screen was cut out from the original sheet of Example 2 and C1? It was used as a T filter. The resolution was poor and the characters on the CRT could not be distinguished. Table 1 shows the glossiness GS (60') and resolution.

Comparative Example 3 A cmT filter was produced directly from the polyvinyl chloride sheet of Example 1 in the same manner as in Example 2, without applying wrinkles. This filter had problems as a CRT filter, as it reflected strong indoor light and made it difficult to read the characters on the CRT. Table 1 shows glossiness Gs (60°) and resolution.
Shown below.

Table 1 [Effects of the Invention] Since the CRT filter of the present invention has a shape that allows it to come into close contact with the CRT, the glossiness of the filter Gs (60”)
Despite its low resolution, it prevents the display from blurring in the corners of the screen and does not reduce the resolution.It also has an excellent design and does not lose the curved surface of a conventional CRT screen and does not create an awkward window. .

Since there is no reflection from the CRT screen, the operator can work without eye fatigue or the resulting mental pain.

Claims (1)

[Claims] 1. Glossiness Gs (60°) of filter surface is 5 to 40
A CRT filter characterized in that it has a shape that allows it to come into close contact with a CRT surface.