Electric lamp or space discharge component or device manufacturi – Process – Including use of electric arc or current for removing an...
Reexamination Certificate
2000-01-07
2001-10-02
Ramsey, Kenneth J. (Department: 2879)
Electric lamp or space discharge component or device manufacturi
Process
Including use of electric arc or current for removing an...
Reexamination Certificate
active
06296538
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of cathode ray tube manufacture. More specifically, the present invention relates to a device and method for preventing arcing that punctures the neck glass of a cathode ray tube during the evaluation of frit strength and vacuum integrity.
BACKGROUND OF THE INVENTION
Cathode ray tubes (“CRTs”) are well known in modern society. The CRT is the principal component in such common devices as television and computer monitors. As shown in
FIG. 1
, a CRT (
100
) typically includes a relatively flat display portion (
101
) (upper portion as seen in FIG.
1
). When one is watching television or looking at a computer monitor, that person is looking at the flat display portion (
101
) of a cathode ray tube.
During manufacture, an electro-luminescent material is coated over the display portion (
101
) of the CRT. The display portion (
101
) is then joined to the funnel (
102
) using a glass paste compound known as frit to complete the cathode ray tube shown, for example, in FIG.
1
). An electron gun (
106
) is then placed at the end of the CRT's “neck” (
102
). When the CRT is operated, a yoke (not shown) creating an electromagnetic field causes the stream of electrons (
105
) emitted from the electron gun (
106
) to scan in lines across the surface of the display portion (
101
).
Where the stream of electrons (
105
) hits the electro-luminescent material, the electro-luminescent material emits light. Thus, by rapidly switching the electron stream (
105
) on and off, or by varying the power of the electron stream as it sweeps across the display portion of the CRT, an image can be formed in the light emitted by the electro-luminescent material. This is the general principle on which CRTs operate.
After the display portion (
101
) of the tube is joined to the funnel (
102
) and the joint between the two is sealed with frit, the completed tube is evacuated. Then, the strength of the frit seal and the integrity of the vacuum are evaluated. This evaluation is known as “frit knocking” and is performed with a high voltage being applied from within the cathode ray tube (
100
).
Unfortunately, it is not uncommon for the high voltage (
105
) to arc (
107
) out of the neck (
102
) of the CRT (
100
) and into the support fixture (
120
). This may result in a puncture of the CRT neck (
102
) at the point where the arcing (
107
) occurred. This degrades the quality of the CRT or renders it unusable.
Consequently, there is a need in the art for a device and method that prevents the arcing of the high voltage so as to avoid punctures in the neck of the CRT during the frit knocking, i.e., the evaluation of the frit integrity.
SUMMARY OF THE INVENTION
It is an object of the present invention to meet the above-described needs and others. Specifically, it is an object of the present invention to provide an apparatus and method for preventing the arcing of the high voltage used to evaluate the frit seal of a cathode ray tube so as to avoid punctures in the neck of the CRT during frit knocking.
Additional objects, advantages and novel features of the invention will be set forth in the description which follows or may be learned by those skilled in the art through reading these materials or practicing the invention. The objects and advantages of the invention may be achieved through the means recited in the attached claims.
To achieve these stated and other objects, the present invention may be embodied and described as a cathode ray tube processing device having a saddle for receiving and supporting the cathode ray tube during frit knocking using a high voltage; and an isolation diaphragm disposed on the saddle so as to be between the saddle and the cathode ray tube when the cathode ray tube is supported by the saddle. The isolation diaphragm prevents arcing of the high voltage through the cathode ray tube to the saddle.
Preferably, the diaphragm is made of a non-conductive material, such as silicone. Preferably, the diaphragm is about 2 mm thick as measured between the saddle and the cathode ray tube.
The diaphragm should be adhered to the saddle with a non-conductive adhesive. The diaphragm has a funnel shape conforming to the interior opening of the saddle and the neck portion of a cathode ray tube. In this way, the saddle and diaphragm receive and support the cathode ray tube.
The present invention also encompasses a method of manufacturing a cathode ray tube using the diaphragm described above. In other words, the present invention expressly encompasses a method of preventing arcing of an internal high voltage through the cathode ray tube to a saddle supporting the cathode ray tube during frit knocking using the high voltage. The arcing is prevented with an isolation diaphragm disposed on the saddle so as to be between the saddle and the cathode ray tube when the cathode ray tube is supported by the saddle.
REFERENCES:
patent: 4214798 (1980-07-01), Hopen
patent: 4272701 (1981-06-01), Gallaro et al.
patent: 4398897 (1983-08-01), Nubani et al.
patent: 4473774 (1984-09-01), Hernqvist
patent: 4940440 (1990-07-01), Rehkopf et al.
Chamberlain Michael J.
Murtishaw David Allen
Kananen Ronald P.
Rader Fishman & Grauer
Ramsey Kenneth J.
Sony Corporation
LandOfFree
Insulation diaphragm for getter flash turntable and method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Insulation diaphragm for getter flash turntable and method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Insulation diaphragm for getter flash turntable and method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2580523