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:
Dec. 21, 2004
Filed:
Dec. 04, 2003
Tadashi Sasaki, Saitama, JP;
Masao Wada, Tokyo, JP;
Tetsuji Inoue, Tokyo, JP;
Ryoji Kumaki, Tokyo, JP;
Shinobu Nakamura, Tokyo, JP;
Haruo Tominaga, Tokyo, JP;
Hiroyuki Horiguchi, Tokyo, JP;
Hideaki Sugiura, Tokyo, JP;
Masayuki Sugawara, Tokyo, JP;
Other;
Abstract
In a focusing state determining device for determining a focusing state of a taking lens, an object light entering the taking lens is captured by focusing state determination imaging elements provided separately from a video imaging element, and the focusing state is determined according to luminance signals outputted from the focusing state determination imaging elements. Any error of determination of the focusing state induced by saturation of the luminance signals in imaging an object of high luminance is prevented by adjusting the gains of the image signals outputted from the focusing state determination imaging elements or the charge accumulation times of the focusing state determination imaging elements. High-frequency components are determined from the luminance signals obtained from the focusing state determination imaging elements (A, B, C), and the focus evaluation value is determined by integration thereof. An automatic gain control circuit ( ) adjusts the gains of the luminance signals so that the maximum levels of the luminance signals may not reach the saturation levels.