Patent · US Expired

Copying apparatus with moveable screen and method

US5055877A · kind A · utility

0Cited by
7References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 3, 1990
Grant dateOct 8, 1991
Priority date
Expiry dateJan 3, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G2215/0174
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A copying apparatus in which a screen for improving gradation characteristics of a copied image can be retractably projected into an optical path, including a device for setting, when the screen is placed in the optical path and retracted from the optical path, a developing voltage to a first value and a second value, respectively such that the first value is lower than the second value.

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