JP3395485B2 - Leakage current inspection device for cathode ray tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak current inspection device for determining whether a cathode ray tube is acceptable or unsuccessful by measuring the magnitude of leak current in a frit seal portion where a panel portion and a funnel portion of a cathode ray tube are joined.

[0002]

2. Description of the Related Art In a cathode ray tube, a leak current at a so-called frit seal portion, which is a joint portion between a panel portion and a funnel portion, is measured. If so, it is determined to be rejected.

Conventionally, such inspection of the leak current is performed by cutting the aluminum tape 1 into an appropriate length as shown in FIG. 6 and manually cutting the aluminum tape 1 with the panel portion 3 and the funnel portion of the cathode ray tube 2. The aluminum tape 1 is attached over the entire outer circumference of the frit seal portion 6 joined with the frit glass 5.
The leak current was measured through a measuring instrument connected between the anode button to which the anode voltage was applied.

As another method, as shown in FIG. 7, an insulating frame 8 fitted on the outer circumference of the frit seal portion 6 is used.
An electrode jig 10 having a felt 9 made of Naslon (trade name), which is a highly conductive fiber, fixed inside is attached to the cathode ray tube 2 and attached to the frit seal portion 6. The leak current was measured through a measuring instrument connected between the buttons.

[0005]

By the way, in the method of FIG. 6, the adhesion of the aluminum tape 1 to the frit seal portion 6 is good, but since the aluminum tape 1 is manually attached every inspection, the workability is poor. And moreover,
There was a problem that the adhesiveness of the aluminum tape 1 was likely to differ.

According to the method shown in FIG. 7, the conductive felt 9 can be fixed to the insulating frame 8 only by adhesion. Therefore, the conductive felt 9 is peeled off during repeated use and the frit seal portion 6 is thus removed. There was an inconvenience that it did not make proper contact with. Also, the conductive felt 9 has a structure such that whisker-like fine fibers come out and an outer carbon film 11 close to the frit seal portion 6, or an explosion-proof tightening wound around the panel portion (not shown). There is also a problem in that the leak current cannot be measured correctly because the band comes into contact with the band to cause a short circuit.

In view of the above points, the present invention provides a leak current inspection apparatus for a cathode ray tube, which can measure leak current correctly and can be repeatedly used, and has excellent durability.

[0008]

SUMMARY OF THE INVENTION A leak current inspection apparatus for a cathode ray tube according to the present invention comprises a ring-shaped electrode portion electrically contacting the outer periphery of a frit seal portion of the cathode ray tube, and an insulation for holding the electrode portion. A conductive woven cloth is formed by bag-folding so that the electrode portion encloses the core material having a shape along the outer circumference of the frit seal portion.

In this leak current inspection device, a conductive woven fabric, which is folded into a bag and fixed to an insulating frame, is used as the electrode portion of the electrode jig attached to the frit seal portion of the cathode ray tube, so that it can be repeatedly used. It can withstand and at the same time can measure leak current correctly without accidentally touching the exterior carbon film or the explosion-proof tightening band.

In addition, since the electrode portion has a structure in which a conductive woven fabric is folded into a bag and a core material having a shape along the frit seal portion is put therein, the size of the cathode ray tube varies due to elastic deformation of the core material. Can be absorbed, and the electrode portion can be surely brought into contact with the entire frit seal portion.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

The leak current inspection apparatus for a cathode ray tube according to the present embodiment applies a high voltage to the anode of the cathode ray tube in order to guarantee the leak resistant current of the frit seal portion which is a joint portion of the funnel portion and the panel portion of the cathode ray tube. This is a device for measuring the magnitude of the leak current value that leaks to the outside of the frit seal portion with an electrode attached to the frit seal portion.

As shown in FIG. 1, the leak current inspection apparatus 21 of the present embodiment includes an electrode jig 22 electrically attached to the outer periphery of the frit seal portion 6 of the cathode ray tube 2 and the electrode jig 22. It comprises a measuring device 23 connected to 22 to measure the leak current, and an isolation chamber 24 for isolating the cathode ray tube 2 to ensure the safety of the measurer during the measurement.

Of these, the present invention is characterized by the structure of the electrode jig 22. As shown in FIGS. 2 to 4, the electrode jig 22 has a ring-shaped electrode portion 26 that comes into contact with the frit seal portion 6 of the cathode ray tube 2 over the entire circumference, and holds and fixes the electrode portion 26 in a sandwiched manner. The insulating frame 27 is attached to the outer circumference of the frit seal portion.

In the electrode portion 26, a conductive woven cloth 29, for example, a cloth made of Naslon (trade name) is folded into a bag so that the bent portion 28 is the inner periphery, and the core material 30 is inside the bent portion 28.
For example, a steel wire made of stainless steel, copper, or the like, in this example, a stainless steel wire is inserted to maintain the shape close to the outer shape of the frit seal portion 6 of the cathode ray tube 2. The core material 30 does not need to have conductivity, and may be any material as long as it maintains a shape corresponding to the outer shape of the frit seal portion 6 and can be elastically deformed as described later.

The conductive woven fabric 29 containing the core material 30 and folded into a bag is laid between the pair of frame portions 27A and 27B constituting the insulating frame body 27 by stacking the folded both ends and sewing them together. It is pinched and fixed. At this time, the electrode portion 26 has the core member 3
The bent portion 28 in which 0 is wrapped is held by the frame body 27 in a state of being protruded inward from the inner circumference of the insulating frame body 27.

When the conductive woven cloth 29 comes into contact with the frit seal portion 6, the electrode portion 26 needs to be brought into close contact with the width W of the frit seal portion 6 as shown in FIG. For this reason, when the contact is made, the bent portion 28 is crushed so that the protruding length L ₁ of the electrode portion 26 becomes 5 mm or less, and the gap t between the conductive woven cloth 29 and the core material 30 is further reduced.
It is formed so that (= t ₁ + t ₂ ) is about ₂ to 3 mm.

The core material 30 has a diameter of, for example, about 0.8 mm, and as shown in FIG. 4, both the long side and the short side are smaller than the outer dimensions of the frit seal portion 6, for example, 2 mm, respectively. The frit seal portion 6 is bent so as to be small, and further has a partial discontinuous portion 32 (so-called cut portion) so as to absorb the variation in the size of the outer shape of the frit seal portion 6.

In the electrode jig 22, as shown in FIG. 2, a lead 33 is led out from the electrode portion 26, and a socket 34 connected to the measuring instrument 23 is attached to the end portion thereof.
Further, when the electrode jig 22 is attached to the frit seal portion 6 on the upper surface of the insulating frame 27, the outer carbon film 11 is brought into contact with the outer carbon film 11 of the funnel portion 4 so that the outer carbon film 11 has a stable ground potential. Conductive contact piece 35 having elasticity
Is provided. The conductive contact piece is connected to the ground terminal via the lead wire 36.

As shown in FIG. 5, the electrode jig 26 is made of metal and is attached to the explosion-proof tightening band 38 which is inserted from the funnel portion 4 side and attached to the cathode ray tube during measurement. When the insulative frame 27 comes into contact with, the electrode portion 26 is positioned exactly at the joint portion between the funnel portion 4 and the panel portion 2, that is, the position of the frit seal portion 6 joined by the frit glass 5, and the frit seal portion 6 is formed so as to be in electrical contact.

On the other hand, the isolation chamber 24 is surrounded by a wall 42 made of transparent vinyl chloride containing wire mesh through a metal three-dimensional frame 41, and has a door in front of which the cathode-ray tube 2 is put in and taken out. A type door 43 is attached. Isolation room 24
A pallet 44 on which the cathode ray tube 2 is placed with the panel portion 3 facing downward is arranged therein, and the pallet 44 can be moved into and out of the isolation chamber 24 via a rail 45. A plurality of rubber pedestals 46 for receiving the cathode ray tube 2 are provided on the pallet 44, and the pallet 44 is manually moved by the grip portion 47. The metal solid frame 41 is grounded.

Next, the measurement of the leak current at the frit seal portion 6 of the cathode ray tube 2 using the leak current inspection device 21 will be described.

The electrode jig 22 is inserted into the frit seal portion 6 of the cathode ray tube 6. The electrode jig 22 includes the insulating frame 2
7 is positioned at a position where it abuts on the mounting portions 39 attached to the four corners of the explosion-proof tightening band 38. At this position, the electrode portion 26 is surely brought into contact with the entire circumference of the frit seal portion 6. In the electrode portion 26, the core material 30 is elastically expanded along the outer shape of the frit seal portion 6,
The bent portion 28 of the conductive woven fabric 29 is brought into close contact with the entire circumference of the frit seal portion 6 by the elastic force of the core material 30.

When the electrode jig 22 is inserted, the conductive contact piece 35 comes into contact with the exterior carbon film 11 of the funnel portion 4, and the electric charge charged on the exterior carbon film 11 is released through the conductive contact piece 35. The exterior carbon film 11 is stabilized at the ground potential.

Next, the socket 34 connected to the electrode portion 26 is connected to the measuring device 23. Isolation room 2 in this state
The cathode ray tube 2 is placed on the pallet 44 drawn out of the container 4, the cathode ray tube 2 is housed in the isolation chamber 24, and the door 43 is closed.

The leak current of the frit seal portion 6 is measured by the measuring device 23 connected between the electrode portion 26 and the anode button 48 to which a high voltage (for example, anode voltage) is applied. As a result of the measurement, if the leak current is less than or equal to the reference value, the cathode ray tube 2 is acceptable, and if it is larger than the reference value, the cathode ray tube 2 is unacceptable.

According to the above-described leak current inspection device 21, the electrode jig 26 has the electrode portion 26 made of the bag-folded conductive woven fabric 29 enclosing the core material 30, so that the electrode portion 26 is fritted. The leak current can be accurately measured by ensuring close contact with the entire circumference of the seal portion 6.

Since the conductive woven cloth 29 is used, a correct leak current can be measured without making a mistaken contact with the exterior carbon film 11 or the explosion-proof tightening band 38 due to a thin fiber such as felt.

Insulating frame 2 by folding conductive woven fabric 29 into bags
Since it is sandwiched and fixed to 7, the electrode portion 26 is not peeled off from the insulating frame 27 even if it is repeatedly used, and the durability is excellent.

The funnel portion 6 is formed by the conductive contact piece 35.
Since the potential of the exterior carbon film 11 is stabilized at the ground potential, the leak current can be measured more accurately without being affected by the potential of the exterior carbon film 11.

The electrode portion 26 is formed by enclosing a core material 30 having a contour shape slightly smaller than the outer shape of the frit seal portion 6, and the electrode jig 22 is formed by expanding the core material 30 with respect to the cathode ray tube 2. Since the cathode ray tube 2 is fitted in, the variation in the size of the cathode ray tube 2 is also absorbed by the elastic deformation of the core material 30, and the electrode portion 26 can be firmly attached to the frit seal portion 6.

When attaching the electrode jig 22 to the cathode ray tube 2,
The insulating frame 27 of the electrode jig 22 has an explosion-proof tightening band 38.
The electrode jig 22 is positioned by abutting on the mounting portions 39 attached to the four corners, and the electrode portion 26 can be surely brought into contact with the frit seal portion 6.

Since the electrode portion 26 uses the conductive woven cloth 29, it is necessary to contact an object having a curvature, and it can be contacted without damaging the surface,
It can also be applied to soft objects. Naslon (trade name)
Since the woven fabric according to is woven with fine stainless steel wire, it can be applied to places where heat resistance is required.

[0034]

According to the leak current inspection apparatus for a cathode ray tube according to the present invention, the leak current can be accurately measured without accidentally contacting the exterior carbon film other than the frit seal portion or the explosion-proof tightening band. .

The variation in size of the cathode ray tube can be absorbed, the electrode portion can be reliably brought into contact with the frit seal portion over the entire circumference, and the leak current over the entire circumference of the frit seal portion can be accurately measured. The electrode part does not peel off even after repeated use, and the device has excellent durability.

The electrode jig can be positioned with respect to the frit seal portion only by inserting the electrode jig into the cathode ray tube and bringing the insulating frame body into contact with the attachment portion attached to the explosion-proof tightening band. Therefore, the measurement work can be facilitated.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a leak current inspection device for a cathode ray tube according to the present invention.

FIG. 2 is a perspective view showing an example of an electrode jig according to the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a plan view showing an example of an electrode section according to the present invention.

FIG. 5 is an explanatory view showing a state in which the electrode jig of the present invention is attached to a frit seal part of a cathode ray tube.

FIG. 6 is a configuration diagram showing an example of a conventional leak current measuring method.

FIG. 7 is a configuration diagram showing another example of a conventional leak current measuring method.

[Explanation of symbols]

2 cathode ray tube 3 panel section 4 funnel section 6 Frit seal part 11 Exterior carbon film 21 Leakage current inspection device 22 Electrode jig 23 Measuring instrument 24 isolation room 26 Electrode part 27 Insulating frame 28 Bent section 29 Conductive woven cloth 30 core material

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 9/42

Claims (2)

(57) [Claims] 1. A ring-shaped electrode portion electrically contacting an outer periphery of a frit seal portion of a cathode ray tube, and an electrode jig including an insulating frame body holding the electrode portion, wherein the electrode portion is the frit. A leak current inspection device for a cathode ray tube, which is formed by bag-folding a conductive woven fabric so as to wrap a core material having a shape along the outer periphery of a seal portion. 2. The cathode wire according to claim 1, wherein the electrode jig is positioned by abutting the insulating frame on a mounting portion attached to a tightening band of the cathode ray tube. Leak current inspection device for pipes.