Patent · US Expired

Exposure process for use in a variable magnification copying machine

US4436415A · kind A · utility

2Cited by
3References
24Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 21, 1981
Grant dateMar 13, 1984
Priority date
Expiry dateDec 21, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G15/041
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A photosensitive member is subject to a slitwise exposure. An imaging lens system is displaced in accordance with the magnitude of a magnification being utilized during a copying process which is switched. Disposed adjacent to the end face of a lens in the imaging lens system is at least one rectangular light shield member so that its lengthwise dimension corresponds to a slitwise scan direction. The light shield member is movable into or out of a light flux which is utilized for purpose of exposure, and is integral with the imaging lens system as the latter is displaced in accordance with a magnification being utilized during a particular copying process. During a light shielding operation, the light shield member is adapted to be disposed within or wedged partly into the light flux of exposure. As the copying magnification is switched, the amount of exposure light which is cut off by the light shield member changes, whereby the distribution of exposure light in the slit-shaped exposure station is made uniform as viewed lengthwise of the exposure station.

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