Patent · US Expired

Image signal processing with a variable threshold

US4539600A · kind A · utility

14Cited by
0References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 28, 1981
Grant dateSep 3, 1985
Priority date
Expiry dateAug 28, 2001

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/403
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An image signal processing apparatus particularly suitable for use in a facsimile system for converting an analog image signal obtained by photoelectrically reading an original into a binary image signal for further processing is provided. The present image signal processing apparatus comprises a digital-to-analog converter and a digital data input unit, preferably a microcomputer, connected to the converter. Thus, the level of the reference voltage to be supplied to the comparator for converting the analog image signal into the binary image signal may be finely adjusted appropriately without complication in structure.

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