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:
Apr. 27, 1982
Filed:
Jun. 03, 1980
Takanori Tanaka, Tokyo, JP;
Masanobu Morishita, Tokyo, JP;
Nippon Electric Co., Ltd., Tokyo, JP;
Abstract
An iris controls the amount of light transmitted through television camera lens to an integrated semiconductor matrix of light responsive elements. A characteristic of the matrix is that photo-charges may overflow the light responsive elements if the light falling on the matrix becomes too bright. The normal iris control responds to a loss of picture contrast caused by the overflow of charges and attempts to increase contrast by increasing the amount of light passing through the lens. The invention compares the output from the light responsive elements with a reference signal representing black areas in the picture. When the comparison exceeds a given difference, a special iris control overrides the normal iris control in order to reduce the amount of light passing through the lens. The reference signal may be taken from one or more of the light responsive elements which are shielded from light passing through the lens. Or, the reference signal may be taken during periods between picture frames when the video signal does not record any light.