Patent · US Active

Optical black level control circuit

US7714913B2 · kind B2 · utility

2Cited by
4References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 21, 2005
Grant dateMay 11, 2010
Priority date
Expiry dateMar 11, 2029

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N25/68
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An optical black level control circuit comprises a digital black level adjusting circuit for generating a black level correction signal by digital processing using a given time constant when an output error between an optical black level and a reference optical black level signal is within a predetermined range so that an error becomes less than a predetermined value and an analog black level adjusting circuit for compensating for said error when said error exceeds the predetermined range.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.