Patent · US Expired

Lens focus control apparatus

US5506654A · kind A · utility

11Cited by
8References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 4, 1994
Grant dateApr 9, 1996
Priority date
Expiry dateFeb 4, 2014

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N23/633
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A lens focus control apparatus and method for use in a camera optical system and which is manually manipulated by a user, includes a lens position detector for detecting current positions of a focus lens and a zoom lens, a memory for storing a movable region value of the focus lens, a current position value of the focus lens and a contrast ratio value therein, and a display. The display indicates the current position of the focus lens, the range of movement of the focus lens, and the movement direction in the movable region of the focus lens. A microcomputer controls the above elements to adjust an exact focus and to display an exact focus direction using the contrast ratio value.

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