Patent · US Expired

Variable magnification copying device

US4420248A · kind A · utility

15Cited by
8References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 16, 1981
Grant dateDec 13, 1983
Priority date
Expiry dateMar 16, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B27/526
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A varying magnification copying device of small size and low manufacturing cost in which a region of movement of a zoom lens system for an enlargement copying operation is shared with a region of movement of a half-speed mirror for the equal magnification and reduction copying operations. The zoom lens system is moved along the optical axis thereof by a feed screw rotated by a digitally-controlled stepping motor. The zoom lens system, which includes front and rear frames varying front and rear lens systems, is adjsuted in magnification factor by a cam and cam follower mounted on the rear and front frames, respectively. The cam is rotated by a pinion gear which is engaged with a rack which extends parallel to the feed screw. Movement of the zoom lens system perpendicular to the optical axis is accomplished through a lead cam and cam follower.

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