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:
Jul. 14, 1992
Filed:
May. 09, 1990
Applicant:
Inventors:
Andrew J Morrish, Eastleigh, GB;
Julian D Williams, Marchwood, GB;
David J Eagle, Chandlers Ford, GB;
Adrian M Clitheroe, Fareham, GB;
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
315107 ; 315 94 ; 315106 ; 315291 ;
Abstract
A CRT display system is described wherein a measure of the beam current generated within the CRT is derived and the voltage across the cathode heater modified as a function of this measure. In this way the optimum voltage across the heater coils is maintained, thus preventing 'cathode stripping' at times of peak beam currents, and optimizing the CRT's working lifetime.