Patent · US Expired

Exposure apparatus for printing system

US4639127A · kind A · utility

16Cited by
23References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 10, 1985
Grant dateJan 27, 1987
Priority date
Expiry dateDec 10, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B2227/325
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Apparatus is described for exposing a layer of photosensitive material to form an image thereon, by passing the photosensitive layer under a row of closely spaced light shutter apertures which are selectively opened and closed. The total light falling on each pixel area at the photosensitive layer is increased by using apertures which are long and thin, and concentrating the light passing therethrough onto a pixel at the photosensitive layer. Two rows of staggered apertures are used. The photosensitive layer is on a transparent substrate, and a reflector lies on a side of the substrate opposite the light apertures, so light passing through the photosensitive layer and substrate is reflected back through the layer to pass twice therethrough. The entire sheet is pre-exposed to light of a level less than a threshold, with the light subsequently passing through each light aperture being sufficient to raise the total exposure beyond the threshold.

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