Patent · US Expired

Color separating circuit for producing red and black signals

US4577218A · kind A · utility

18Cited by
1References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 18, 1983
Grant dateMar 18, 1986
Priority date
Expiry dateMar 18, 2003

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/488
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A reading device having two different reading elements for scanning the same portion of an original in different wavelength ranges. A color separating circuit comprises a signal level adjusting circuit for adjusting the levels of picture signals provided by the reading elements so that the levels are equal to each other when white picture data is read. An arithmetic unit obtains a level difference between the picture signals which have been subjected to level adjustment by the signal level adjusting circuit. A/D converters are used for digitizing an output signal of the arithmetic unit and the picture signals provided by the reading elements. A color separation logic circuit subjects three different picture signals outputted by the A/D converters to logic operation for color separation.

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