JPH0222976B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube, particularly to a grounding structure for an external conductive film provided on the outer peripheral surface of a funnel portion thereof.

A cathode ray tube generally has a conductive film made of a conductive paint or the like on the outer circumferential surface of its funnel portion to form a capacitance between the tube and the inside. This external conductive film is
When a cathode ray tube is in use, it is necessary to ground it, and the conventional method for this grounding is to connect a metal band or mounting bracket attached to the outer surface of the panel and connect it to the outside surface of the panel.

However, in all conventional grounding methods of this type, only a small portion of the external conductive film is connected to the metal band, etc., resulting in high grounding resistance and inability to sufficiently suppress unnecessary radiation. There were flaws.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a cathode ray tube whose external conductive film has a low ground resistance and can effectively prevent unnecessary radiation.

In order to achieve such an object, the cathode ray tube according to the present invention has an external conductive film extending below the metal band provided on the outer surface of the panel, and at least An adhesive tape made of a conductive tape base material having an adhesive material on the panel side and having contact portions exposed on the surface of the adhesive material distributed over the entire circumference is interposed.

That is, between the external conductive film and the metal band,
Since there are many contact points over almost the entire circumference, the connection resistance is low, and therefore the grounding resistance can be reduced. Hereinafter, the cathode ray tube according to the present invention will be explained in detail using Examples.

1 and 2 are a front view and a side view showing an embodiment of a cathode ray tube according to the present invention.
In the figure, a bulb 1 consists of a panel portion 1a and a funnel portion 1b, and a metal band 2 is provided on the outer surface of the panel portion 1a. This metal band 2 has a function of fixing the cathode ray tube mounting lug 3, and each mounting lug 3 can be welded to the metal band 2 or sandwiched between the metal band 2 and the outer surface of the panel part. It is fixed by Further, a conductive paint film 5 is formed on the outer peripheral surface of the funnel portion 1b except for a part near the anode terminal 4, and one end thereof extends to below the metal band 2. . An adhesive tape 6 is provided between the metal band 2 and the conductive paint film 5, as shown in FIG. Generally, such an adhesive tape is provided to prevent the metal band 2 from damaging the glass surface of the bulb 1 and to enhance the effect of reinforcing the panel portion 1a, and is usually made of an insulating material. On the other hand, the adhesive tape 6
As shown in FIG. 3, it is composed of a conductive tape base material 6a having protrusions 6a over almost the entire surface of the panel and an adhesive material 6c filling the gaps between the protrusions 6a. When forming this adhesive tape 6, as shown in FIG. A large number of protrusions 6a are formed on the surface. next,
An adhesive material 6c is applied to the entire main surface. In this case, the adhesive material 6c is also attached to the top of the protrusion 6a as shown in FIG. When tightened with the metal band 2, the protrusion 6
Since the portion a is locally pressed, the top of the protrusion 6a is crushed and at the same time the adhesive material 6c in that portion is removed and flows into the gap between the protrusions 6a. As a result, as shown in FIG. 3, the protrusions 6a come into contact with the conductive paint film 5, and are adhered to the outer surface of the panel on which the conductive paint film 5 is attached by the adhesive 7c.

In the above-described embodiment, the case where the protrusions 6a and the adhesive material 6c are provided only on one side has been described, but it goes without saying that these may be formed on both sides of the tape base material 6b. In addition, the protrusion 6a
The shape of the adhesive material 6c is not limited to a round shape, but may be of any shape, such as a wave shape or a lattice shape, as long as a concave portion to which the adhesive material 6c is attached and a convex portion exposed on the surface of the adhesive material 6c can be formed. It's okay.

Furthermore, instead of providing the projections 6a, a mesh-like tape base material may be used. In this case, the mesh may be a conductive flat tape having a large number of through holes, or a mesh made of soft metal wires woven into a woven fabric. An example of the latter is shown in Part 6.
As shown in the figure. In the figure, the tape base material 7 constituting the adhesive tape is woven from metal wires 7a,
If adhesive is applied to both sides or one side of the panel and wound onto the external conductive film 5 on the outer surface of the panel, and the metal band 2 is tightened from above, the adhesive is pushed and the metal wire 7
a, and the metal wire 7a escapes into the gap of the conductive paint film 5.
and metal band 2 to electrically conduct them. In this case, thread made of an organic material such as cotton or synthetic fiber may be mixed with the metal wire 7a.

As explained above, according to the cathode ray tube according to the present invention, the external conductive film extends below the metal band provided on the outer surface of the panel part, and an adhesive is provided at least on the panel side between the metal band and the panel. The panel is made of Adhesive tape can be attached to the outer surface, and the external conductive film and the metal band can be electrically connected over almost the entire circumference. Therefore, it is possible to effectively protect the panel from the metal band, reduce the connection resistance between the external conductive film and the metal band, and sufficiently reduce the grounding resistance of the external conductive film to effectively prevent unnecessary radiation. It has the excellent effect of being able to

[Brief explanation of drawings]

1 and 2 are front and side views showing one embodiment of a cathode ray tube according to the present invention, FIG. 3 is a side sectional view thereof, and FIGS. 4 and 5 are adhesives shown in FIG. 3 during the manufacturing process. A perspective view and a sectional view showing the tape, and FIG. 6 is a perspective view showing a tape base material in another embodiment according to the present invention. DESCRIPTION OF SYMBOLS 1... Valve, 1a... Panel part, 1b... Funnel part, 2... Metal band, 5... Conductive paint film, 6... Adhesive tape, 6a... Protrusion, 6b, 7
... Tape base material, 6c ... Adhesive material, 7a ... Metal wire.

Claims (1)

[Scope of Claims] 1. An external conductive film attached to the outer peripheral surface of the funnel portion of the bulb extends to below a metal band attached to the outer surface of the panel portion, and the metal band and the outer conductive film below the An adhesive tape is interposed in between, and the adhesive tape is composed of a tape base material made of a conductor and an adhesive material attached to at least one main surface of the tape base material on the panel side, and A cathode ray tube, characterized in that a part of the tape base material is exposed on the surface over almost the entire circumference and brought into contact with the external conductive film. 2. The adhesive tape is characterized by being composed of a tape base material made of a soft metal that has protrusions distributed over almost the entire circumference of the main surface, and an adhesive material that fills the gaps between the protrusions. A cathode ray tube according to claim 1. 3. The cathode ray tube according to claim 1, wherein the adhesive tape has a tape base material made of mesh. 4. The cathode ray tube according to claim 3, wherein the mesh is constituted by a flat plate made of soft metal with a large number of through holes distributed on its main surface. 5. The cathode ray tube according to claim 3, wherein the mesh is made of a woven fabric made of soft metal wires. 6. The cathode ray tube according to claim 3, wherein the mesh is made of a woven fabric made of soft metal wire and organic fiber.