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:
May. 02, 1989
Filed:
May. 02, 1988
Paul W Ernest, Arlington, MA (US);
Allan C Green, Framingham, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
A method and apparatus for exposure control of electronic imaging cameras capable of video and still modes of operation and having an automatic variable aperture diaphragm to control image light passing to a sensor during the video mode of operation. Relatively short exposure time intervals are attained in the still mode of operation by attenuating light passing to the sensor during the video mode so that the aperture to which the variable aperture diaphragm is set is increased over that to which it would normally be adjusted during video operation. Upon conversion to the still mode, the filter attenuation is rapidly removed resulting in a correct aperture setting for the relatively shorter still mode exposure time intervals. In the video mode, electronic shutter operation is effected in the conventional manner. In the still mode of operation, the exposure time interval is established either by a combination of electronic shutter operation and mechanical shutter operation or by mechanical operation alone. A shutter mechanism is disclosed in which the light attenuating and exposure terminating functions are combined.