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. 13, 1980
Filed:
Apr. 28, 1978
Akiyoshi Suzki, Tokyo, JP;
Ichiro Kano, Yokohama, JP;
Hideki Yoshinari, Yokohama, JP;
Masao Tozuka, Ohmiya, JP;
Ryozo Hiraga, Yokohama, JP;
Yuzo Kato, Yokohama, JP;
Yasuo Ogino, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An improved photoelectric detecting apparatus is disclosed in which a subject surface containing a pattern which diffracts light in a predetermined direction is scanned with spotlight and the diffracted light coming from the pattern is detected by means of photoelectric element so as to read out information of the pattern. The apparatus comprises a first photoelectric element for detecting the light diffracted in the predetermined direction, a second photoelectric element adapted for detecting light diffracted in directions other than the predetermined direction and an operational circuit for operating the signal derived from the first photoelectric element and that derived from the second one. Thus, when there is any diffractive matter such as flaw, dust and the like on the subject surface, diffracted light from the diffractive matter is detected by both the first and second photoelectric elements whereas diffracted light from the pattern is detected only by the first photoelectric element. By operating the outputs of the two photoelectric elements only the necessary information of the pattern can be read out.