The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 01, 1991
Filed:
May. 16, 1989
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
There is disclosed a device for correcting and compensating variations of the back focal length caused by temperature changes in a photographic lens system which incorporates at least one lens component made of a plastic material. The device includes a lens drive which axially moves the lens system to obtain a fully focused image of an object to be photographed, and a temperature sensor which senses surrounding temperature conditions and produces output signals representing the sensed temperature condition. A lens control is also provided in the device, and functions in response to the output signals from the temperature sensor to control the lens drive in a manner to compensates any temperature-related variation of the back focal length of the lens system.