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:
Jul. 03, 1984
Filed:
Dec. 08, 1981
Roger Voles, London, GB;
EMI Limited, Hayes, GB;
Abstract
An automatically focussed optical system in which two arrays of photosensitive detectors have different optical spacings respectively in front of and behind the image plane of the system, and sense different portions of the image. Differences in electrical signals generated by adjacent detectors (C,D and E,F) in each set, and indicative of differences in intensity of the corresponding portions, are processed to generate a focus drive signal (Fd) of a value related to an error in the focus of the image. This signal is used to adjust the focus. Two discrete arrays of detectors (FIG. 2B) can be used or alternatively a single array (FIG. 2D) tilted relative to the image plane can be used. In another example (FIG. 2C) a transparent block is inserted adjacent to a part only of a single detector array to thereby lengthen the optical path length of that part relative to the remainder of the array.