The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 27, 1982
Filed:
Oct. 15, 1980
Richard L Hockenbrock, Mundelein, IL (US);
James W Schwartz, Deerfield, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
Apparatus and method is disclosed for spot-knocking a cathode ray picture tube by beneficial arcing between selected electrodes of an electron gun sealed in the evacuated envelope of the tube. The invention is particularly useful in spot-knocking certain cathode ray picture tubes having a resistive arc-suppression means and static elimination system. The picture tube has an inherent capacitance that can store energy in an amount capable of inducing destructive arcing during spot-knocking. In one embodiment of the invention, a bipolar potential is applied across the electrodes to be spot-knocked, resulting in the amount of energy in the induced arcing, for a given applied potential, being very much less than would be the case if a unipolar potential were applied. Other embodiments include resistive means and spark gap means for discharging the voltage between lead-in pins before a destructive arc can occur therebetween.