Patent · US Expired

Apparatus and process for photographically duplicating intelligence existing on photoplastic film

US4147429A · kind A · utility

6Cited by
4References
41Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 31, 1978
Grant dateApr 3, 1979
Priority date
Expiry dateJan 31, 1998

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G16/00
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Process and apparatus for duplicating on microfiche the intelligence appearing on a photoplastic microfiche master by irradiating the duplicate through the master with high intensity moderately collimated light. Photoplastic film having a relatively thick thermoplastic layer is used as the master. The master and the duplicate are separated by a gap of predetermined size, which gap can be filled by air, plastic, glass or any other transparent medium. Multiple light sources isolated from one another, are used and provision is made for absorbing and dissipating some of the heat before the light reaches the master. Means are provided for assuring relatively uniform light intensity across the entire recording face and for assuring consistent irradiation of the duplicate irrespective of lamp age or line voltage variations.

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