Patent · US Expired

Zoom lens apparatus

US4596449A · kind A · utility

73Cited by
3References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 13, 1983
Grant dateJun 24, 1986
Priority date
Expiry dateDec 13, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B7/10
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A zoom lens apparatus comprising a moving construction for moving a zoom-ratio adjusting barrel composed of a variator-lens amount and a compensator-lens mount by the rotation along the direction of the optical axis within the fixed barrel; a stepping motor, which is coupled to the moving construction is composed of a rotor having a hollow portion as a light path including the optical axis and a stator to be combined with the rotor, and reversibly rotates in accordance with the pulse signal to be applied; and a circuit means for controlling the operation of the stepping motor with providing advantages and that the reduction gear and clutch mechanism are not required, the outer shape is kept cylindrical, but is not required bigger in size and the price can be made lower.

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