JPS63159803A - Crt filter - Google Patents

Abstract

PURPOSE:To prevent the electric charge and scratching of a CRT screen and to prevent the degradation in resolution thereof by providing a filter which is a thin film made of a synthetic resin, is laminated with a metal-coated synthetic resin fiber net having a prescribed mesh opening and has >=4H pencil hardness on the CRT screen. CONSTITUTION:For example, PVC is used as a synthetic resin material and in some cases, UV and IR absorbents, antistatic agent, dye and pigment are added thereto. The net is superposed on such synthetic resin sheet or film. The net is the synthetic resin fiber net which has the mesh opening to prevent generation of interference fringes with the scanning lines of the CRT or generates the interference fringes but to the extent of generating substantially no after-images and is deposited with a metal such as copper on the surface. The mesh opening is selected by the performance of the CRT and the patterns on the CRT and the purpose thereof. Such laminated sheet is adhered by vacuum forming onto the CRT. The sheet thickness is specified to 0.3-5mm and the net is used by grounding the same. The filter having >=4H pencil hardness is completed if a UV curing type resin is coated on the surface.

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 also increasing, and occupational diseases among operators have become a social problem in developed countries. A common symptom of this occupational disease is fatigue of the optic nerve, and although the scientific cause and effect relationship has not been fully elucidated, it is necessary to take into account exposure to electromagnetic waves, static electricity, ultraviolet rays, etc.

To prevent such negative effects, the CRT part is usually equipped with a CRT filter that has a metal film deposited on its surface, a CRT filter that has a layered conductive fiber net, or a CRT filter that has lead added to a transparent resin. The installation prevents the negative effects of exposure to electromagnetic waves, static electricity, ultraviolet rays, etc.

Also, U.S. Patent No. 425373 and U.S. Pat. No. 59-106
No. 176 proposes a removable screen filter that can be brought into close contact with the CRT surface.

Usually used CRTs have a curved display area, so when a flat CRT filter is attached, the display often appears blurred at a corner of the screen, which may cause the CRT to have a curved display. The reality is that operators who come into contact with the CRT filter have to remove the CRT filter while working.

Furthermore, conventionally proposed CRT filters require a special frame to be attached so that they can be removed.
CRT filters also become expensive.

On the other hand, if glass is used as a material for a CRT filter shaped like a CRT filter, the surface of the CRT filter will have excellent hardness, but it will be easily broken by impact and difficult to mold, making it less preferable to use plastic as the material. A product with excellent impact resistance can be obtained, and it can also be easily molded into a shape that closely fits a CRT. However, the surface hardness of plastics is inferior to that of glass, and the surface of the CRT filter has problems such as being easily scratched when cleaning it or accidentally scratching it with a pencil or the like.

In addition, CRT filters that have a metal film deposited on the observation surface side or a net made of conductive fibers are laminated with a net made of conductive fibers may cause CR when the surface of the filter is touched by a hand.
The static electricity generated by the T often causes mischief. Furthermore, when cleaning the surface of the CRT filter,
The metal film on the surface and the net made of conductive fibers wear out,
It had problems such as peeling and loss of conductivity and anti-glare properties.

(Problems to be Solved by the Invention) The present inventors have developed a CRT that has excellent antistatic properties and scratch resistance, and does not reduce the resolution of the CRT.
It attempts to provide a filter.

(Means for solving the problems) The present inventors have studied to solve these problems,
The present invention has now been completed.

That is, the CRT filter according to the present invention is a synthetic resin CRT filter having a shape capable of accommodating the CRT tip portion and adhering closely to the CRT surface.
The filter does not produce interference fringes with the CRT scanning line, or even if interference fringes do occur, the interference fringes have openings that do not substantially cause afterimages, and a net whose surface is coated with metal is laminated on the CRT side of the filter. The CRT filter is characterized in that the pencil hardness of the observation surface side of the CRT filter is 4H or higher.

Examples of the synthetic resin materials used in the present invention include polyvinyl chloride, high nitrile resin, polyether ether ketone, polyether sulfone, polycarbonate, diethylene glycol bisallyl carbonate resin, polyethylene terephthalate, polymethyl methacrylate, and acrylonitrile-styrene copolymer. Examples include merging.

In addition, ultraviolet absorbers, infrared absorbers, antistatic agents, dyes, pigments, etc. may be added to the synthetic resin material used in the present invention, if necessary.

It has an opening that does not produce interference fringes with the CRT scanning line laminated with the sheet or film made of these synthetic resins, or even if interference fringes do occur, the interference fringes do not substantially cause an afterimage, and the surface thereof is coated with metal. The net has a mesh structure made of synthetic resin fibers, and the opening of the net and the size of the filaments are appropriately selected depending on the performance of the cathode ray tube, the size and shape of the image on the cathode ray tube, and the purpose. This net surface is further coated with metal. Copper, iron, nickel, etc. or alloys such as stainless steel can be used as the metal, and the coating is performed by coating, vapor deposition, sputtering, ion blating, VD, etc. A laminated sheet in which the resin layers on both sides of the net have different thicknesses is obtained by a conventional method using a metal-coated net and a sheet or film made of synthetic resin.

Using this laminated sheet, a CRT filter is obtained by vacuum forming, pressure forming, etc., in which the CRT is located on the side where the resin layer is thinner, and the CRT filter has a shape that can be brought into close contact with the CRT surface.

The thickness of the CRT filter of the present invention is 0.3 mm to 5 m.
If the thickness is less than 0.3 m, the static electricity charged on the net cannot be sufficiently insulated and the strength of the filter will be poor. If the thickness of the CRT filter is 5 mm or more, birefringence will appear and the resolution will be adversely affected. This causes a decrease in the amount of water. It is sufficient for the net whose surface is coated with metal to be slightly exposed on the CRT side or to have a resin layer with a thickness of 0.10+m or less on the net. If the net is too exposed, the resolution of the CRT filter will drop significantly.

It is preferable that the CRT filter of the present invention is used by grounding a net whose surface is coated with metal, so that electromagnetic waves and static electricity can be more effectively prevented.

For grounding, there are no particular restrictions on how to attach a grounding guide to the net.For example, when attaching a guide to a net, the surface of which has been coated with metal may be laminated. A method in which a part of the net is layered so that it protrudes from the sheet and used as a guide, a method in which conductive paint is applied to the cross section around the filter and used as a guide, a method in which a part of the resin layer of the filter is removed using an appropriate solvent. Methods include melting and using it as a removal guide, and if conductive fibers are exposed on the surface, CRT
One method is to sandwich the edge of the filter with a metal washer.

Since no vapor-deposited metal film or fiber net is exposed on the observation surface side of the CRT filter of the invention, a surface hardening agent can be applied using a conventional method to achieve a pencil hardness of 411 or higher. If the pencil hardness is less than 411, the scratch resistance is insufficient.

The type of surface hardening agent varies depending on the resin of the material, but if the material is polyvinyl chloride, high nitrile resin, etc., which have a low heat distortion temperature, an ultraviolet curing type surface hardening agent is preferable.

The surface hardening agent may be applied by either a spraying method or a dipping method.Also, in order to increase the adhesive strength between the surface hardening agent and the base resin of the CRT filter, the surface on the viewing side of the CRT filter may be roughened in advance. Then, a surface hardening agent may be applied thereon.

(Example) Details will be shown below with reference to Examples.

In addition, pencil hardness is measured according to JIS K-5400,
Scratch resistance was determined by rubbing the viewing side of the CRT filter with stainless steel wool and visually observing the presence or absence of scratches.Resolution was determined by visually observing the CRT filter attached to a 14-inch CRT.Static electricity was determined by: The CRT filter can be installed on a CRT at a temperature of 20°C and a humidity of 60%.
After using it for a minute, use an A4 size paper (thickness 0.1mm).
) near the CRT filter to check for static electricity.

Example 1 A polyvinyl chloride sheet with a thickness of 1.1+wm and a polyethylene telecrate net (opening T
YLER standard sieve (70 mesh) was laminated by hot pressing method, and a CRT filter with a thickness of 111 liters and a shape that could be closely attached to the CRT with the net slightly exposed on the CRT side was obtained using a pneumatic molding machine equipped with an aluminum mold. Ta.

Apply an ultraviolet curing type surface hardener "Orestar
After drying for a minute, irradiate ff1l.

The surface was cured by irradiating ultraviolet rays of 00IIJ/c+m'' for 15 seconds.Furthermore, a conductive paint was applied to the periphery of the filter, and a grounding guide was attached to the CRT.

Table 1 shows the pencil hardness, scratch resistance, resolution, and presence or absence of static electricity.

Example 2 A net similar to Example 1 was sandwiched between high nitrile resin sheets (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name "Zekron") with a thickness of 1 m and 0.0511 uw, and a laminated sheet was obtained by hot pressing. I got it. Using the same method as in Example 1, the overall thickness was reduced to 0.
A CRT filter with a shape that can be closely attached to a 9m CRT with a resin thickness of 0.041 on the CRT side is installed, and an ultraviolet curing surface hardening agent "Liocure X-8606" is installed on the observation surface side.
13" (trademark, manufactured by Toyo Ink Co., Ltd.) 50 parts by weight, diluting thinner "Liocure AH-01 thinner" (trademark, manufactured by Toyo Ink Co., Ltd.) 50 parts by weight were mixed and applied.
After drying for 10 minutes at °C, irradiation i11000MJ/cL
The surface was hardened by irradiating it with 1" ultraviolet light for 15 seconds.
It was grounded and attached to a CRT in the same manner as in Example 1. Table 1 shows the pencil hardness, scratch resistance, resolution, and presence or absence of static electricity.

Example 3 Polymethyl methacrylate sheet “Acrylite E’ (trademark, manufactured by Mitsubishi Rayon Co., Ltd.) with a thickness of 2II11
A net similar to that in Example 1 was placed on top of the net and hot pressed to obtain a stacked stone sheet. Using the same method as in Example 1, the total thickness was 1,
91 to obtain a CRT filter with a shape that allows the net to be slightly exposed on the CRT side and adhere closely to the CRT, and an ultraviolet curing type surface hardening agent "Hidec RC5100" (trademark, manufactured by Dainippon Ink Co., Ltd., solid content 33) on the observation surface side. 6% by weight)
After drying at 0℃ for 10 minutes, irradiation 11000MJ/cm
The surface was cured by irradiating it with ultraviolet rays for 15 seconds.C
Open a hole at the end of the RT filter using a washer and bolt C.
I sandwiched the RT filter, grounded it, and attached it to the CRT. In addition to scratch resistance, anti-glare properties have also been improved. Table 1 shows the pencil hardness, scratch resistance, resolution, and presence or absence of static electricity.

Comparative Example 1 CR was applied to the CRT filter of Example 1 without applying a surface hardening agent.
It was used as a T filter. The resolution was fine and no static electricity was generated, but the scratch resistance was poor and the surface was easily scratched. Table 1 shows the pencil hardness, scratch resistance, resolution, and presence or absence of static electricity.

Comparative Example 2 C as it is from a polyvinyl chloride sheet with a thickness of 2 mm
Example 1 Cut out a sheet large enough to cover the RT screen
After applying the surface hardening agent and curing it in the same manner as above,
It was attached to. There was no problem with scratch resistance, but static electricity was easily generated. Table 1 shows the pencil hardness, scratch resistance, resolution, and presence or absence of static electricity.

(Effects of the Invention) Since the CRT filter of the present invention does not have a metal film or a net made of conductive fibers exposed on the surface that does not come into contact with the CRT, if your hand or the like touches the surface of the filter, you will receive an electric shock due to static electricity. Never.

In addition, it has an excellent surface hardness, so when cleaning the surface of a CRT filter, it will not damage the surface of the filter. A CRT configured in a shape that allows it to come into close contact with a CRT
Since it has a partial filter, there is no discomfort when it is attached to a CRT, and it also prevents the phenomenon that the resolution decreases in the corner of the screen, so the operator can avoid eye fatigue.
You can work without feeling any mental pain based on this.

Claims (1)

[Claims] 1. In a synthetic resin CRT filter having a shape capable of accommodating the tip of a CRT and coming into close contact with the CRT surface, whether or not the CRT filter produces interference fringes with CRT scanning lines. Also, a net with openings that do not substantially cause interference fringes and afterimages and whose surface is coated with metal is laminated on the CRT side of the filter, and the pencil hardness of the observation surface side of the CRT filter is 4H or higher. C characterized by
The RT filter 2 is a CRT filter according to claim 1, characterized in that a grounding guide is attached to a net whose surface is coated with metal.