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:
Sep. 19, 1989
Filed:
Dec. 09, 1987
Takashi Azumi, Yokohama, JP;
Toshio Murakami, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An automatic focusing apparatus for a video camera converts the quantity of reflected light reflected by an object into an electric signals by light receiving elements. The electric signals are detected and the detected signals are integrated by integrators once every fixed period. A decision is made on the basis of the respective outputs of the integrators whether or not the video camea is in focus. The detectors and the integrators have offset voltages, respectively. The outputs of the integrators are sampled and held and are compared with a reference voltage equal to a voltage for resetting the integrators. Signals representing the result of the comparison are fed back to the detectors or to the integrators to regulate the offset voltages of the detectors and the integrators.