Patent · US Expired

Automatic exposure device

US4540279A · kind A · utility

9Cited by
11References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 27, 1984
Grant dateSep 10, 1985
Priority date
Expiry dateJul 27, 2004

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G15/043
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An automatic exposure device wherein the quantity of light from an exposure lamp is detected by lamp light quantity detecting means, while the reflected light from a region of a document located forwardly of a region of the document being exposed is received by density detecting means, the output signal from said lamp light quantity detecting means being used as an input by reference signal producing means which produces a reference signal, the output signal from said density detecting means and the reference signal being used as inputs by correcting means which corrects the output signal from the density detecting means in accordance with an increase in the quantity of light from the lamp, the output signal from said correcting means being used as an input by lamp control means which controls conducting-angle of the exposure lamp.

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