JPH09171785A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the potential at the surface of a bulb at earth potential, and remove the fear of leakage, by connecting a tension band with an external conductive film by a conductive tape, arranging an insulating member in the position of a flit seal line. SOLUTION: A bulb 1 is fastened with a tension band 3 for reinforcement of a cathode-ray tube, and screw holes 2 for connection are provided at the four corners. An external conductive film 4 is applied to surround the rear of the bulb 1. This cathode-ray tube is provided with a flit seal line 6 where a panel part 1a and a funnel part 1b are joined with each other. Then the band 3 and the conductive film 4 arc bonded and connected by a conductive tape 5, and also a high withstand-voltage insulating material 7 is installed between the tape 5 and the line 6, thus this is made into leakage preventive structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground structure of an external conductive film applied to the funnel portion of a cathode ray tube.

[0002]

2. Description of the Related Art Generally, a funnel portion of a cathode ray tube is coated with an external conductive film to form a capacitance with an electrode inside a bulb. In addition, a metal band is fastened to the side of the panel for safety against the implosion of the glass bulb. When operating the cathode ray tube, it is necessary to ground both of them.

In the prior art, the ground wire in a tensioned state is brought into line contact with the exterior graphite film which is the outer conductive film of the cathode ray tube.

In the above-mentioned prior art, since the ground wire in a tensioned state is brought into line contact with the exterior graphite film of the funnel portion,
A long ground wire is required and a tension spring is also required, which is disadvantageous in terms of cost. In addition, the workability of attaching to the cathode ray tube has been largely entangled with each other due to the structure of the ground wire, which has hindered automation.

To improve this, Japanese Patent Laid-Open No. 3-102746.
As disclosed in Japanese Patent Laid-Open Publication No. JP-A-2003-264, there is one in which a cathode ray tube tension band (metal band) and an external conductive film are adhesively connected with a conductive tape.

[0006]

In this case, there remains concern about the long-term reliability of the adhesive. Further, in the cathode ray tube, the funnel portion and the panel portion are joined by a frit seal, but since the conductive tape directly contacts this portion, there is a risk of leakage.

The present invention solves the above problems,
It is intended to provide a cathode ray tube that is free from the risk of leakage.

[0008]

The cathode ray tube of the present invention comprises:
The outer conductive film of the funnel and the reinforcing tension band provided near the pipe surface are electrically connected by a conductive tape, and between the conductive tape that hits the frit seal line and the pipe surface. It is characterized by arranging an insulating member. Also, by stacking on the conductive tape,
It is characterized in that an insulating member is arranged.

According to such a constitution of the present invention, it is possible to provide a cathode ray tube without a risk of leakage in the frit seal line.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention electrically connects an external conductive film of a funnel portion and a reinforcing tension band provided in the vicinity of the tube surface with a conductive tape. In addition, an insulating member is disposed between the conductive tape that hits the frit seal line and the tube surface. According to such a configuration, there is no risk of leakage in the frit seal line. Can be provided.

According to a fifth aspect of the present invention, the outer conductive film of the funnel portion and the reinforcing tension band provided near the tube surface are electrically connected by a conductive tape, and the frit is used. A cathode ray tube characterized in that a first insulating member is arranged between the conductive tape corresponding to a seal line and a tube surface, and a second insulating member is further arranged on the conductive tape. According to such a configuration, it is possible to provide a CRT in which there is no risk of leakage in the frit seal line even under severe conditions, for example, an environment in which salt water is sprayed.

A cathode ray tube according to an embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a perspective view of a cathode ray tube according to a first embodiment of the present invention, and FIG. 2 is a perspective view of a conductive tape and an insulating member constituting the cathode ray tube of FIG.

In FIGS. 1 and 2, the bulb 1 is fastened with a tension band (metal band) 3 for reinforcing the cathode ray tube. Screw holes 2 are provided at the four corners for connection with a cabinet or the like. On the other hand, the outer conductive film 4 is applied so as to surround the rear surface of the bulb 1. Further, there is a frit seal line 6 where the panel portion 1a and the funnel portion 1b are joined.

In such a general CRT, the tension band 3 and the outer conductive film 4 are bonded and connected by the conductive tape 5, and the conductive tape 5 and the frit seal line 6 are connected. A high withstand voltage insulating member 7 is provided to provide a leak prevention structure. This insulating member 7 is
It may be arranged so as to be sandwiched between the conductive tape 5 and the frit seal line 6 of the valve 1. Alternatively, as shown in FIG. An insulating member 7 wider than the tape 5 may be attached. With this configuration, it is possible to eliminate the risk of leakage in the frit seal line 6. Further, since the conductive tape 5 and the insulating member 7 are attached to each other, automation can be facilitated. Further, in order to prevent the conductive tape 5 from falling off, spot welding is applied to the attachment portion on the tension band 3 side. 8 is a spot weld.

As shown in FIG. 1, using the screw holes 2 of the tension band 3, the connection wires 9 with terminals are fastened with the screws 10 and are connected so as to be electrically energized. Can be withdrawn.

The conductive tape used in the present invention is composed of a conductive adhesive and a tape in advance. Further, the reliability is doubled by attaching a plurality of the conductive tapes.

(Embodiment 2) FIG. 3 is a perspective view of a cathode ray tube according to a second embodiment of the present invention, and FIG. 4 is a perspective view of a conductive tape and an insulating member constituting the cathode ray tube of FIG.

Also in this case, the structure is basically the same as that of the first embodiment, except that the second insulating member is arranged so as to overlap the conductive tape.

That is, the outer conductive film 4 of the funnel portion 1b.
And the conductive tape 5 which electrically connects the reinforcing tension bands 3 provided in the vicinity of the tube surface 1a with a conductive tape 5 and which abuts the frit seal line 6,
It is characterized in that the first insulating member 7 is arranged between the tube surface 1a and the second insulating member 11 so as to overlap the conductive tape 5.

The first insulating member is a resin tape, and the second insulating member is a resin tape with an adhesive.

It goes without saying that the first and second insulating members may be resin tapes with an adhesive.

Further, the same applies to the case where the first insulating member may be a resin tape with an adhesive and the second insulating member may be a coating type resin.

Further, the first insulating member may be a simple resin tape and the second insulating member may be a coating type resin.

The coating resin may be one of arbitrary members such as silicon resin, epoxy resin, acrylic resin, ultraviolet curable resin (UV resin) and butyl rubber.

The coating thickness is from 5 μm to
The thickness is about 50 μm, preferably about 25 μm.

Furthermore, in the first and second embodiments,
Similarly, the width, length, and thickness of the insulating member, the application range of the coating resin, and the like may be set arbitrarily.

[0028]

Next, specific examples of the present invention will be described.

(Example 1) Insulating member: A pressure resistant insulating tape is used. This is thickness 7
Polyester tape having a thickness of 5 μm to 200 μm, preferably 125 μm.

Conductive tape: A structure in which a nickel-plated iron foil is used as a base material and a special acrylic adhesive in which metal particles are dispersed is coated. The thickness including the adhesive layer is about 40 to 50 microns, and the contact resistance is about 0.007Ω / (25mm) ↑ 2. As a commercially available product, Sumitomo 3M Co., Ltd./Conductive iron foil tape F
E-20CX or the like may be used.

With the above-mentioned constitution, heat cycle test (-40 degrees Celsius to +80 degrees Celsius)
Degree): No breakdown voltage abnormality for 8000 hours continuously ・ Constant temperature and humidity test (+80 degrees Celsius, 85% humidity): No breakdown voltage breakdown for 8000 hours continuously (Example 2) Insulating member: Using pressure-resistant insulation tape. This is thickness 2
The pressure-sensitive adhesive layer made of an acrylic resin member is applied to a polyester base material having a thickness of about 5 μm to 150 μm, preferably about 75 μm to a thickness of about 40 μm. As a commercially available product, Sumitomo 3M Co., Ltd. product / electrical insulating tape 1350 may be used.

Conductive Tape: A nickel-plated iron foil as a base material coated with a special acrylic pressure-sensitive adhesive having metal particles dispersed therein. The thickness including the adhesive layer is about 40 to 50 microns, and the contact resistance is about 0.007Ω / (25mm) ↑ 2. As a commercially available product, Sumitomo 3M Co., Ltd./Conductive iron foil tape F
E-20CX or the like may be used.

With the above-mentioned constitution, heat cycle test (-40 degrees Celsius to +80 degrees Celsius)
Degree): No breakdown voltage abnormality for 8000 hours continuously ・ Constant temperature and humidity test (+80 degrees Celsius, 85% humidity): No breakdown voltage abnormality for continuous 8000 hours (Example 3) First insulating member: Sumitomo 3M Co., Ltd./ Electrical Insulation Tape 1350 Conductive Tape: Sumitomo 3M Co., Ltd. Product / Conductive Iron Foil Tape FE-20CX Second Insulating Member: Sumitomo 3M Product / Electrical Insulation Tape 1350 40 degrees to +80 degrees Celsius
Degree): Continuous 8,000 hours no breakdown voltage abnormality ・ Constant temperature and humidity test (+ 80 ° C, humidity 85%): Continuous 8,000 hours breakdown voltage no abnormality ・ Salt spray test: Continuous 72 hours breakdown voltage no abnormality

[0034]

As described above, according to the cathode ray tube of the present invention, the tension band and the external conductive film are electrically connected by arranging an insulating member at the position of the frit seal line and connecting them with a conductive tape. The connection can be made, the potential of the valve surface can be kept at the ground potential, and the risk of frit leak can be eliminated. In addition, this eliminates the need for the ground wire and springs that were previously used,
Cost effectiveness and automation are possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a CRT according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration example of a conductive tape and an insulating member used for the cathode ray tube according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a CRT according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a configuration example of a conductive tape and an insulating member used for the cathode ray tube according to the second embodiment of the present invention.

[Explanation of symbols]

 1 Valve 2 Screw Hole 3 Tension Band 4 External Conductive Film 5 Conductive Tape 6 Frit Seal Line 7 Pressure Resistant Insulating Tape (First Insulating Member) 8 Spot Welding Part 9 Terminal Connecting Wire 10 Screw 11 Pressure Insulating Tape (Secondary) Insulation material)

Claims (7)

[Claims] 1. A conductive tape for electrically connecting an external conductive film of a funnel portion and a reinforcing tension band provided in the vicinity of the pipe surface with a conductive tape and hitting a frit seal line, and a pipe. A cathode ray tube characterized by placing an insulating member between the surface and the surface. 2. The cathode ray tube according to claim 1, wherein the insulating member is a resin tape. 3. The cathode ray tube according to claim 2, wherein the resin tape is a resin tape with an adhesive material. 4. The cathode ray tube according to claim 2, wherein the connecting portion of the conductive tape to the reinforcing tension band is spot-welded. 5. An external conductive film of the funnel portion and a reinforcing tension band provided in the vicinity of the pipe surface are electrically connected by a conductive tape, and the conductive tape hits a frit seal line, and the pipe. A cathode ray tube characterized in that a first insulating member is arranged between the surface and the surface, and a second insulating member is further arranged so as to overlap the conductive tape. 6. The cathode ray tube according to claim 5, wherein the first edging member is a resin tape and the second edging member is a resin tape with an adhesive. 7. The cathode ray tube according to claim 5, wherein the first edging member is a resin tape and the second edging member is a coating type resin.