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, 1994
Filed:
Nov. 19, 1993
Khosro M Rabii, Arlington Heights, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
An RGB preamplifier for a video display includes respective multipliers independently operable for adjusting the contrast of input primary and secondary video signals. The contrast adjusted video signals are added to form a combined display signal, the combined signal being applied to the first inputs of primary and secondary comparators each of which is also supplied with a respective reference DC level. The primary and secondary video signals are alternately nulled at horizontal line rate by nulling the corresponding multipliers. The primary comparator samples the combined signal when the secondary signal is nulled for clamping the DC level of the primary signal in relation to the primary reference DC level and the secondary comparator samples the combined signal when the primary signal is nulled for clamping the DC level of the secondary signal in relation to the secondary reference DC level.