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:
Nov. 01, 1977
Filed:
Jun. 01, 1976
Robert L Caswell, Placentia, CA (US);
Rockwell International Corporation, El Segundo, CA (US);
Abstract
An intensity control system for a cathode ray tube (CRT) is disclosed. The system provides precise intensity control for a CRT whose control characteristics are only slowly varying. Precise intensity control is provided by measuring the cathode ray tube beam current. The beam current is set at a desired value without producing an image on the tube face. Thus, tube intensity can be set without fogging photoresponsive media which is in position for exposure by images on the cathode ray tube screen. The intensity may be set to a value determined by a manually adjustable intensity control. The intensity is preferably set by iterative threshold comparison of the actual beam current with the value corresponding to the setting of the intensity control. A unique threshold comparison circuit provides precise comparison between the reference level set by the intensity control and the actual beam current.