Browse Prior Art Database

VIDEO SIGNAL WHITE LEVEL CORRECTOR

IP.com Disclosure Number: IPCOM000025029D
Original Publication Date: 1983-Jun-30
Included in the Prior Art Database: 2004-Apr-04

Publishing Venue

Xerox Disclosure Journal

Abstract

A video signal white level corrector is disclosed wherein a digital memory is used to store a correction signal which is applied to a signal multiplier to remove white level shading which results from optic and beam misalignment of a scanner. Video signals are applied to a multiplier 10, the output therefrom being the corrected video signal. The correction signal is stored for future use in a digital memory 14 after being compared to a reference voltage at comparator 20. In a first or Wore" mode, the output from the comparator 20 is coupled to an integrator 22, the output of which increases or decreases the gain of multiplier 10. In a second or "operate" mode, the output from the digital memory is coupled to integrator 22 to also control the gain of multiplier 10.