JPH0722002B2 - Cathode ray tube - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cathode ray tube in which high voltage charging and specular reflection on the outer surface of a face panel of a glass bulb are prevented.

[Conventional technology]

Generally, a cathode ray tube installed in a terminal device of a television receiver or a computer is used with a high voltage of about 10 to 30 kV applied as an anode voltage. Easy to be charged.

When charged to a high voltage, there is a danger of electric shock when a human body contacts the face panel part, and dust in the air charged to the opposite charge or dust or contaminants floating in other air may get on the face panel part. Adhesion causes deterioration of brightness of an image displayed on the cathode ray tube face panel, and there is a problem that it becomes difficult to see.

On the other hand, since the outer surface of the face panel of the cathode ray tube is a smooth mirror surface, indoor fluorescent lamps, objects, people, etc. are reflected on the outer surface of the panel, and are reflected on the surface of the face panel, and ambient light from the surroundings. The image that is reflected and displayed on the cathode ray tube face panel becomes very difficult to see. Especially, in cathode ray tubes for displays incorporated in various terminal devices such as computers and word processors, which are rapidly becoming widespread in recent years, face the operator at a close distance of 30 to 40 cm and input data to the processing device. Since a light pen is sometimes used as a means, the human body is likely to come into contact with the outer surface of the cathode ray tube face panel, and eye fatigue becomes a problem because it keeps seeing small characters and figures for a long time. Preventing high-voltage charging of the panel surface and specular reflection is an important issue.

Further, when a display device is installed for process control in a production site of a dusty factory, deterioration of brightness becomes a serious problem due to adhesion of dust and contaminants floating in the air to the cathode ray tube face panel.

In order to solve the above-mentioned problems, the following method is used.

For example, first, to prevent specular reflection, the outer surface of the face panel is directly sandblasted or etched by 1 to 0.5.
A non-glare process is performed in which unevenness having a fine pitch of μm is provided and external light is diffusely reflected on the outer surface to blur the reflected image.

Next, for example, by spraying an organic tin oxide solution onto the face panel surface that has been subjected to non-glare treatment as an antistatic treatment, and firing it, an extremely thin transparent conductive film is formed, which is grounded when the cathode ray tube is used. In order to prevent the specular reflection of the surface of the face panel and the antistatic effect, the method of obtaining the antistatic effect is performed.

Alternatively, as another alternative method, a cathode ray tube is preliminarily configured by a face panel whose outer surface is mirror-finished, and then, for example, a conductive metal such as lithium (Li) is made into fine powder and mixed with silicon. The outer surface of the face panel is fixed to the ground potential when using a cathode ray tube by spray-coating the outer surface of the face panel with an alkoxide solution and baking it to form a silicon (SiO ₂ ) film that is transparent and has fine irregularities. A method for obtaining an antistatic effect and a specular antireflection effect with an uneven coating formed on the outer surface is used.

FIG. 4 is a partially cutaway perspective view of an example of a conventional cathode ray tube in which an antistatic transparent conductive film is formed on the outer surface of a face panel having an outer surface subjected to a non-glare treatment.

As shown in FIG. 4, the panel outer peripheral portion of the face panel 11
A reinforcing metal band 16 for preventing cathode ray tube implosion provided with a mounting seat 15 is attached to 13 via a buffer tape 14. Funnel part 17 continuous to the outer peripheral part 13 of the face panel
An outer conductive film 18 made of graphite is applied to the outer surface of the cathode, and is held at the ground potential together with the explosion-proof reinforcing metal band 16 during operation of the cathode ray tube 1. The cushioning tape 14 is made of glass by attaching the tightening metal band 16 to the outer peripheral portion of the face panel.
In order to buffer the compressive force applied to 13 and to prevent displacement of the tightening metal band 16, etc., it is wound around the face panel outer peripheral portion 14 at a predetermined position and is conventionally made of an insulating material. Therefore, the tightening metal band 16 and the face panel outer peripheral portion 13 are electrically insulated from each other. For this reason, the transparent conductive film 12 extended to the outer peripheral portion 14 of the panel is applied.
Also, for example, a conductive tape 19 is hung on and attached to the transparent conductive film 12 and the tightening metal band 16 so as to be at the ground potential during the operation of the cathode ray tube.

[Problems to be Solved by the Invention]

However, in the above method, it is necessary to separately attach the conductive tape 19, which requires extra attaching man-hours and is complicated in practical use. Moreover, the attached conductive tape 19 peels off during operation or handling of the cathode ray tube 1. Sometimes. When the conductive tape 19 peels off,
The conductive film 12 of the face panel 11 electrically floats during operation, and the high voltage induced therein is charged, and when the operator touches it, the charged electric charge is concentrated discharged at the contact point and is extremely shocked by electric shock. It has the drawback of being dangerous.

Alternatively, when a high voltage is applied to the cathode ray tube 1, electrostatic discharge occurs from the conductive film 12 to the tightening metal band 16, resulting in noise,
There is also a drawback that it becomes extremely dangerous depending on the usage environment.

An object of the present invention is, in a cathode ray tube having an antistatic film on the outer surface of a face panel, capable of reliably and easily electrically connecting the outer surface of the face panel to a tightening metal band for explosion-proof reinforcement, and , To provide a cathode ray tube that can guarantee the reliability and safety of the equipment using the cathode ray tube.

[Means for Solving the Problems]

According to the present invention, in a cathode ray tube having an antistatic conductive film on the outer surface of a face panel, the width of a tightening metal band for explosion proof reinforcement that is adhered to the outer peripheral portion of the face panel via a buffer material tape is used. Wider than the width of the material tape, near the edge of the tightening metal band, outside the abutting portion of the cushioning material tape, and inside the tightening metal band, a plurality of convex projections or cut and raised parts. And the conductive metal is formed by applying either one of a convex projection and a cut-and-raised part when the tightening metal band is fitted to the outer peripheral portion of the face panel. Contacting the membrane.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention.

As shown in FIG. 1, on the outer surface of the face panel 11,
A non-glare treatment is applied in advance, and an antistatic transparent conductive film 12 is further formed thereon.

An explosion-proof reinforcing metal band 26, which is provided with a mounting seat 25 and is relatively wider than the width of the cushioning tape 14, contacts the face panel outer peripheral portion 13 outside the width of the cushioning tape 14 along the edge. A plurality of convex protrusions 26E that protrude inward are formed, and the height of the protrusions is less than or equal to the thickness of the cushioning tape 14 and, as a whole, a predetermined inner circumference that is less than or equal to the outer circumference of the face panel. Both ends of the tightening metal band 26 are welded and fixed to have a frame shape so as to have a length. The buffer material tape 14 is wound around the outer peripheral portion 13 of the face panel of the cathode ray tube 2 in advance, and the tightening metal band 26 is directly heated and expanded by a flame of a burner, for example, on the buffer material tape 14. When the tightening metal band 26 is returned to room temperature, the outer circumference of the face panel can be tightened. However, since the plurality of convex protrusions 26E protruding toward the face panel outer peripheral portion 13 side are formed on the edge of the tightening metal band 26, when the tightening metal band 26 returns to room temperature, the convex protrusions 26E are formed. 26E firmly contacts the transparent conductive film 12 extended and applied up to the outer peripheral portion 13 of the face panel.

FIG. 2 is a sectional view taken along the line AA ′ shown in FIG.

It can be seen from FIG. 2 that the projections 26E of the tightening metal band 26 are securely and easily electrically connected to the transparent conductive film 12. Further, in this case, since the cushioning material tape 14 is sandwiched between the upper and lower two convex protrusions 26E, when the tightening metal band 26 is fitted to the face panel outer peripheral portion 13, there is no displacement with respect to the face panel 11.

FIG. 3 is a partial perspective view of a tightening metal band showing another embodiment of the present invention.

As shown in FIG. 3, at the edge of the tightening metal band 36 wider than the cushioning material tape 14 that does not contact the cushioning material tape 14, a plurality of cut and raised portions are formed so as to abut the outer peripheral portion 13 of the face panel. 36E is formed, and the highest portion from the inner surface of the tightening metal band 36 of the cut and raised 36E is the cushioning tape 14
It is set to a height not less than the thickness of. When the frame-shaped tightening metal band 36 is fitted to the panel outer peripheral portion 13 in the same manner as described above, the tip of the cut-and-raised portion 36E is applied to the transparent conductive film 12 extended and extended to the panel outer peripheral portion 13. They are pressed into contact with each other to ensure that they are electrically connected.

When the cathode ray tube 2 is used, the tightening metal band 26 (36) and the outer conductive film 18 applied to the funnel portion 17 are electrically connected to each other and grounded by a commonly used means. The transparent conductive film 12 formed on 11 is also a fastening metal band 26.
It will be grounded through (36). Even if a convex protrusion or a cut-and-raised part is formed on the tightening metal band as described above, the explosion-proof performance is not deteriorated because the width of the part where it is formed is widened.

Although the above description has been made on a so-called shrink fitting metal band for explosion-proof, the present invention is not limited to the embodiment of the explosion-proof system, and includes, for example, a rim band whose frame is divided into two. Needless to say, it can be applied to a rim band that is tightened with a tension band.

Alternatively, the antistatic conductive film is not limited to the transparent conductive film applied to the non-glare panel surface, and the present invention is also applicable to a film forming method or the like for obtaining non-glare and an antistatic effect with a silicon oxide film containing conductive metal fine powder. Not wait to be applicable.

〔The invention's effect〕

As described above, according to the present invention, the conductive film extended from the outer surface of the face panel to the outer peripheral portion and the explosion-proof reinforcing metal band can be easily and easily connected to each other without using any electrical connection means. The electrical connection can be made uniquely and surely. Therefore, when the cathode ray tube is used, if the tightening metal band and the outer conductive film are electrically connected to each other and grounded by the conventionally used means, even if the operator touches the face panel, it is possible to prevent electric shock. Further, there is an effect that the electrostatic discharge of sparks between the conductive film on the outer periphery of the face panel and the tightening metal band is eliminated, and the reliability and safety of the device using the cathode ray tube can be guaranteed.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA ′ shown in FIG. 1, and FIG. 3 is a tightening showing another embodiment of the present invention. FIG. 4 is a partially cutaway perspective view of an example of a conventional cathode ray tube in which an antistatic transparent conductive film is formed on the outer surface of a face panel whose outer surface is non-glare treated. . 1,2 …… Cathode ray tube, 11 …… Face panel, 12 …… Transparent conductive film, 13 …… Panel periphery, 14 …… Cushioning tape, 1
5,25 …… Mounting seat, 16,26,36 …… Tightening metal band, 26E…
… Convex protrusions, 36E… cut and raised, 17 …… funnels, 18…
… External conductive film, 19 …… conductive tape.

Claims (1)

[Claims] 1. In a cathode ray tube having an antistatic conductive film on the outer surface of a face panel, the width of an explosion-proof reinforcing tightening metal band adhered to the outer peripheral portion of the face panel via a buffer tape is set to the above-mentioned range. It is wider than the width of the cushioning tape, is outside the abutting portion of the cushioning tape near the edge of the fastening metal band, and has a plurality of convex protrusions or cut and raised inside the fastening metal band. And one of the convex protrusion and the cut-and-raised portion when the tightening metal band is fitted to the outer peripheral portion of the face panel is extendedly applied to the outer peripheral portion of the face panel. A cathode ray tube characterized by being brought into contact with a conductive film.