JPS63225202A - Crt filter - Google Patents

Abstract

PURPOSE:To obtain the CRT filter which does not occur moire phenomenon caused by the open lap of a net constituted by the scanning line of a CRT image surface and the CRT filter by providing with the net on one surface of the filter and by controlling center line average height of the filter at the side of providing with the net to 0.2-5mum. CONSTITUTION:The titled filter provides with the net on one side thereof, and the center line average height of the filter at the side of providing with the net is 0.2-5mum. The net composed of a common fiber is available. And, as the net composed of a metal fiber has an electromagnetic wave shielding and antistatic properties, said net is preferably used for the titled filter. If the size of fiber, the linear density and the directions of the scanning line of the CRT image surface and the net fiber accord with the condition sufficient to obtain glare shielding property of the filter, it is not specified. Thus, the moire phenomenon caused by the scanning line of the CRT image surface and the interference of the net fiber does not generate, and as the titled filter stick to the CRT image surface, the resolution of the CRT image surface due to the titled filter is not reduced.

Description

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

(Prior art) Word processors, personal computers, 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 increasing, and in developed countries, occupational diseases of operators, so-called OA disease, are becoming a social problem. In order to prevent such OA disease, many CRT filters having anti-glare properties have been proposed.

Among CRT filters having anti-glare properties, one that has a high anti-glare effect is one that uses a net having fine eyes.

In addition, nets made of conductive fibers also have electromagnetic shielding properties and antistatic properties. However, CRT filters made of net have the disadvantage that the scanning lines of the CRT screen and the fibers of the net interfere with each other, resulting in the appearance of striped patterns on the screen, a so-called moiré phenomenon.

Many proposals have been made to prevent this moiré phenomenon. For example, if the direction of the fibers constituting the net is C.
A CRT filter (for example, Japanese Patent Publication No. 34-8069) has a net fixed at an angle of about 45° from the scanning line of the RT, and a CRT filter (with a net made only of fibers that runs perpendicular to the scanning line of the CRT screen). For example, Japanese Utility Model Publication No. 33-16409), CRT filters made of a net made of fibers of a specific thickness and having a specific weaving density (for example, Japanese Patent Laid-Open No. 57-1.26054, Japanese Patent Laid-Open No. 61-46903) Publication No. 2), etc. have been proposed.

These CRT filters were fixed by attaching a net to a suitable frame, and did not come into direct contact with the CRT screen and did not cause moiré phenomena. However, each of these CRT filters had drawbacks.For example, the direction of the fibers that make up the net is approximately 45 degrees from the scanning line of the CRT screen.
When cutting the net, fix the net so that
Net yield was poor. In addition, CRT consists of a net made only of fibers that run perpendicular to the scanning lines of the CRT screen.
When the filter was touched by fingers, the opening of the net was easily disturbed. In order to obtain a CRT filter with high light transmittance, it is necessary to use extremely thin fibers for a CRT filter made of a net made of fibers of a specific thickness and having a specific weaving density. It lacked strength when used. Furthermore, although CRT filters with nets have excellent anti-glare properties,
It also had drawbacks such as low light transmittance and reduced resolution of CRT screens. In order to compensate for the low light transmittance and reduced resolution of a CRT filter made of net, it is sufficient to place the CRT filter in close contact with the CRT screen.

However, the above-mentioned CRT filter made of a net has the drawback of causing a moiré phenomenon when placed in close contact with a CRT screen.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to provide a CRT filter that does not cause moiré phenomena due to openings between the scanning lines of a CRT screen and the net that constitutes the CRT filter.

[Means for solving the problem] The present inventors have studied to solve such problems,
This led to the present invention.

That is, the present invention provides a CRT filter having a shape that can be closely attached to a CRT screen, which has a net on one side of the filter, and has a centerline average roughness of 0.2 to 0.2 on the side with the net.
This is a CRT filter characterized in that it is 5μ-.

The center line average roughness in the present invention is defined by JIS B-0651.
A value measured using a measuring instrument according to the law.

In the CRT filter of the present invention, it is necessary to have a net on one side of the filter, and the average roughness of the center line on the side with the net to be 0.2 to 5 μm, and the net to be
CRT filter sandwiched between two films, sheets, boards, etc., center line average roughness of the side with the net is 0.2
A CRT filter of μ- or less causes a moiré phenomenon when brought into close contact with a CRT screen. In addition, a CRT filter with a centerline average roughness of 5μ or more on the side with a net is C
It significantly reduces the resolution of the RT screen and cannot be used as a CRT filter.

In the present invention, a net made of ordinary fibers such as cotton, nylon, silk, carbon fiber, polyester fiber, polyurethane fiber, aramid fiber, polyacetal fiber, and acrylic fiber can be used as the net. In addition, these fibers can be made from gold, silver, copper, aluminum, stainless steel, brass,
Nets made of conductive fibers coated with metals such as nickel, chromium, cobalt, lead, and zinc, and metal fibers such as gold, silver, copper, aluminum, stainless steel, and brass are preferred because they have electromagnetic shielding properties and antistatic properties. .

In the net used in the CRT filter of the present invention, the thickness of the fibers, the weaving density of the net, and the direction of the scanning line of the CRT screen and the fibers of the net need only be under sufficient conditions to obtain anti-glare properties. However, depending on the CRT used, it is preferable that the light transmittance of the manufactured CRT filter is 20% or more; If a net with a low weaving density is used to increase transmittance, the anti-glare properties on the filter surface will be significantly reduced.

Therefore, a net woven using fibers with a thickness of 10 μm to 1100 t1 and a weaving density of 20 to 120 fibers of 7 cm is preferable because it has appropriate light transmittance and antiglare properties.

The material for laminating the net is not particularly limited as long as it is a transparent material; for example, glass, high nitrile resin, vinyl chloride resin, polystyrene, polyetherketone, polyethersulfone, polycarbonate, diethylene glycol bisallyl carbonate. Examples include resins, polyethylene terephthalate, polymethyl methacrylate, polyurethane, nylon, and acrylonitrile-styrene copolymers. These transparent materials may contain general resin additives such as ultraviolet absorbers, dyes, pigments, infrared absorbers, antistatic agents, and antioxidants, as long as the light transmittance is not significantly reduced.

The method for manufacturing the CRT filter of the present invention is to first manufacture a laminate having a centerline average roughness of 0.2 to 5 μm on the net side, and then to adhere it to the CRT screen by vacuum forming, pressure forming, etc. Using a mold with suitable irregularities on the surface, vacuum forming, pressure forming, etc. are used to transfer irregularities with a center line average roughness of 0.2 to 5μ on the net side, and to form a CRT screen. Examples include a method of molding it into a shape that fits tightly.

Methods for laminating the net and the transparent material include hot pressing, casting, hot laminating, bonding using adhesive, etc., but the hot pressing is the most preferable, and the pressure and The center line average of the net side can be adjusted by making at least one side of the temperature lower than the operational conditions for heat pressing the base material, or by laying a board with appropriate irregularities on the net side and transferring the irregularities of the board to the net side. Roughness is 0
．． A 2-5 μm laminate is obtained.

When molding the CRT filter of the present invention into a shape that closely fits the CRT screen by a method such as vacuum forming or pressure forming,
The internet is CRTv! Whether the net is on the side opposite to the CRT screen or the side opposite to the CRT screen, there will be no moiré phenomenon with the scanning lines of the CRT screen, but if the net is on the side opposite to the CRT screen, the CRT filter will The anti-glare properties are excellent.

The method of attaching the CRT filter of the present invention to a CRT screen is to cut it into a size slightly smaller than the inside of the CRT casing and attach it to the CRT screen using adhesive, adhesive, adhesive tape, etc. The CRT filter is cut to a size that completely covers the peripheral area of the CRT filter using an escutcheon, and the CRT filter is fixed to the band using screws, adhesive, adhesive, adhesive tape, etc. to fix the CRT. Can be mentioned.

In addition, if the CRT filter of the present invention is not to be removed again after being attached to a CR/T screen, glue the periphery of the CRT filter to prevent dust or water vapor from entering the gap between the CRT filter and the CRT screen. It is best to seal it using adhesive, adhesive tape, etc.

In the CRT filter of the present invention, it is possible to prevent scratches by providing a hard coat layer. Center line average roughness is 0 by providing a hard coat layer on the net.
．． Even if the strength of the steel decreases to 2μ or less, no moiré phenomenon will occur as long as the surface on the net side before the hard coat layer is provided satisfies the above conditions.

In the present invention, hard coating agents that can be used include:
Examples include thermosetting hard coating agents such as silicone-based, epoxy-based, phenol-based, and melanin-based hard coating agents, and ultraviolet curable hard coating agents such as acrylic and urethane-based hard coating agents. Silica, Wanx, dispersants, sensitizers, ultraviolet absorbers, infrared absorbers, antistatic agents, antifogging agents, pigments, dyes, and the like can be added to the hard coating agent as required.

The thickness of the hard coat layer is preferably 2 to 30 μm, and 2 to 30 μm.
If the thickness is less than .mu.-, sufficient surface hardness cannot be obtained, and if the thickness of the hard coat layer is increased to 30 .mu.- or more, the impact strength of the CRT filter decreases, which is not preferable.

〔Example〕

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

In addition, the center line average roughness is J
Measured with a measuring instrument according to IS B-0651 method, low frequency cutoff value 0.251 m, /IA fixed length 21 I
11) The moiré phenomenon caused by interference between the scanning lines of the CRT screen and the fibers in the CRT filter net was visually observed with the CRT filter attached to a 14-inch color CRT.

Examples 1 to 3 Thickness: 0.5+wm, 2.0ffim, 3 respectively
．． 0LI11 polymethyl methacrylate board with a fiber thickness of 40 μ-2 and a vertical and horizontal weaving density of 20 fibers/cm each.
, 54 pieces/cta, 80 pieces/CI of 7 metallic coppers, and then a black-dyed polyethylene terephthalate net was layered, and heated at 140°C for 5k so that a portion of the net was exposed.
After hot pressing at g/cd pressure for 25 minutes, use an aluminum mold for air pressure forming so that one direction of the scanning line of the CRT screen and the fibers of the net are the same, and the net is in the opposite direction of the CRT screen while it is in close contact with the CRT screen. I got a CRT filter on the side.

Even when this CRT filter was attached to a CRT, there was no moire phenomenon.The table shows the center line average roughness and the presence of moire phenomenon.
Shown in 1.

Comparative Example 1 The same vertical and horizontal weave density as used in Example 3 was 80 pieces/1 between two polymethyl methacrylate plates with a thickness of 1.0-1.
The net was scissored and heated for 25 minutes at a pressure of 160"C 17 kg/aj, and then an aluminum mold for pressure forming was used to make the scanning lines of the CRT screen and the fibers of the net in the same direction, so that it closely adhered to the CRT screen. A CRT filter was obtained.

When this CRT filter was attached to a CRT, the scanning lines on the CRT screen and the fibers in the CRT filter's net interfered, causing a moiré phenomenon. Table 1 shows the center line average roughness and the presence or absence of moire phenomenon.

Comparative Example 2 Thickness is 2. A net with a vertical and horizontal weave density of 80 pieces/1, similar to that used in Example 3, was layered on a polymethyl methacrylate board of Ol, and heat pressed under the same conditions as in Example 3 so that a portion of the net was exposed. A CRT filter was obtained in which the scanning lines of the screen and the fibers of the net were in the same direction, and the flat plate-like net was on the side opposite to the CRT screen. This C
Although the moiré phenomenon did not occur when the RT filter was attached to the CRT, the characters on the CRT screen were not clear because it was not in close contact with the CRT screen. Table 1 shows the center line average roughness and the presence or absence of moire phenomenon.

Examples 4 to 6 The thickness was 0.5 mm, 2.0 mm, and 3. Ovs' high nitrile resin “Zekron” (trademark, Mitsui Toatsu Chemical Co., Ltd.)
A net similar to those in Examples 1 to 3 was layered on a 150"C 15kg/cj pressure for 25 minutes so that a portion of the net was exposed, and CR was applied using an aluminum mold for pressure forming.
A CRT filter was obtained in which the scanning line of the T screen and the direction of the fibers of the net intersected at an angle of 45°, the filter was in close contact with the CRT screen, and the net was on the CRT screen side.

Even when this CRT filter was attached to a CRT, no moiré phenomenon occurred. Table 1 shows the center line average roughness and the presence or absence of moire phenomenon.

Comparative Example 3 Thickness is 2. A net with a vertical and horizontal weaving density of 80/1, similar to that used in Example 3, was layered on the high nitrile resin "Zekron" of the company, and heated at 170°C so that the net was almost completely buried.
Heat pressed at a pressure of 17 kg/cd for 25 minutes, using an aluminum mold for air pressure forming, the scanning line of the CRT screen and the direction of the fibers of the net intersect at an angle of 45 degrees, and the net is in close contact with the CRT screen, with the net facing the CRT screen. A CRT filter was obtained.

When this CRT filter was attached to a CRT, the scanning lines of the CRT screen interfered with the fibers of the CRT filter's net, causing a moiré phenomenon. Table 1 shows the center line average roughness and the presence or absence of moire phenomenon.

Examples 7 to 9 A net with a vertical and horizontal weave density of 80 pieces/1, similar to that used in Example 3, was layered on a polyvinyl chloride plate with a thickness of 2.0 m.
Furthermore, a polyethylene terephthalate film with a centerline roughness of 0.3μ was layered to form a 170″C17kg/
After hot pressing for 25 minutes at d pressure to transfer the unevenness to the side with the net, CRT was formed using an aluminum mold for air pressure forming.
The scanning line of the screen and one direction of the fibers of the net are the same, and C
A CRT filter was obtained that was in close contact with the RT screen and the net was on the opposite side of the CRT screen.

The centerline average roughness was 0.30μ cocoon. Further CR
On the side opposite to the T screen, 53.5 parts by weight of the ultraviolet curable hard coating agent "Orestar
- 10.9 parts by weight of silica powder and 35.6 parts by weight of ethyl acetate as a diluent were mixed and applied so that the thickness of the hard coat layer after curing was 5 μm, 10 μm, and 15 μm, respectively, After drying at 50°C for 5 minutes, 80W/
The surface was hardened by irradiating it with a c++ high-pressure mercury lamp from a distance of 15 cm for 30 seconds. A surface hardness of 41 (pencil hardness) was obtained.

The center line average roughness on the side opposite to the CRT screen was reduced to 0.1 .mu.- or less by providing the hard coat agent layer, but no moiré phenomenon occurred. Table 1 shows the center line average roughness and the presence or absence of moire phenomenon.

〔Effect of the invention〕

When the CRT filter of the present invention is brought into close contact with a CRT screen, the CRT filter of the present invention has a
There is no moiré phenomenon caused by interference between the scanning lines of the RT screen and the fibers of the net. In addition, since it is in close contact with the CRT screen, it does not reduce the resolution of the CRT screen.
The operator who operates the CRT does not feel uncomfortable. Furthermore, the net is held in place by a transparent material, so that the opening of the net will not be disturbed even when touched by fingers, making it sturdy.

The CRT filter of the present invention can be provided with a hard coat layer, and even if the center line average roughness is reduced by providing the hard coat layer on the net, no moiré phenomenon will occur.

Claims (1)

[Claims] 1. A CRT filter that has a shape that can be closely attached to a CRT screen, has a net on one side of the filter, and has a center line average roughness of at least 0.2 to 5 on the side with the net.
A CRT filter characterized by having a diameter of μm.