Patent · US Expired

Color filter unit

US4974937A · kind A · utility

5Cited by
1References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 8, 1990
Grant dateDec 4, 1990
Priority date
Expiry dateMar 8, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B26/007
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A filter unit includes a plurality of filter members, a filter drive mechanism, and a switching mechanism. One of the filter members is continuously engaged with the filter drive mechanism, so that it is moved toward and away from an optical path extending between an exposure light source and an image recording medium. On the other hand, remaining filter members are selectively engageable with the filter drive mechanism. This selective engagement is provided by the switching mechanism. After remaining one of the filters is selected and engaged with the filter drive mechanism, the selected filter is moved toward the optical path. In this instance, the filter member always engageable with the filter drive mechanism is retracted from the optical path.

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