Focusing device for cameras

US4389107A · kind A · utility

Assignee

• VEB Pentacon Dresden Kamera und Kinowerke · DE

Inventors

• Michael Lenk · Pirna, DE
• Gottfried Konig · Bad Laasphe, DE

Key dates

• Filing date: May 15, 1981
• Grant date: Jun 21, 1983
• Expiry date: May 15, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B7/34
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An arrangement for the automatic critical focusing of optical systems in mirror reflex cameras provided with a partially transmitting reflex mirror, an image field lens arranged in the viewfinder ray path as well as a range-finder image plane, which is equivalent to the film plane. The range-finder image plane, which contains image-forming and deflecting optical components, is arranged in the optical axis of the viewfinder system. By these means a reduction of the expenditure of optical components as well as of the required assembly and adjustment expenditure for automatic critical focusing devices is achieved.