Patent · US Expired

Field flattener lens element assembly

US4365877A · kind A · utility

9Cited by
6References
12Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 6, 1981
Grant dateDec 28, 1982
Priority date
Expiry dateAug 6, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B1/42
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A film support element assembly is disclosed, primarily for supporting film in relation to a projection aperture in a motion picture projector having a rolling loop film transport mechanism. In a preferred embodiment the film support element is a so-called "field flattener" and has a cylindrically curved surface over which successive frames in the film are laid by the mechanism. Wiper elements are provided above and below the film path and the lens element can be displaced to bring a fresh portion of the surface into the film path. At the same time, the wiper elements remove debris from the surface. The wiper elements are removable for disposal of collected debris.

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