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:
Mar. 17, 1987
Filed:
Aug. 08, 1984
Osamu Maehara, Kanagawa, JP;
Yoshitaka Nakajima, Kanagawa, JP;
Kabushiki Kaisha Ono Sokki, Tokyo, JP;
Abstract
An angle transducer which photo-electrically measures the rotation angle of a shaft by utilizing, a polarizer disc is arranged as follows: the polarizer disc is secured to the shaft to be measured or to the detection shaft of the angle transducer. Two pairs of photo-electric conversion elements are in opposition to light sources across the polarizer disc. The first and second polarizer plates are interposed between the photo-electric conversion elements of each pair. The transmission axes of the first and second polarizer plates differ from each other by 45 degrees. The quantities of light emitted by the light sources or the outputs of the photo-electric conversion elements are modulated by carrier waves of two phases differing 90 degrees from each other. The amplitudes of the outputs correspond to the sine and cosine functions of the double angle of the rotation angle of the shaft to be measured. These outputs form modulated waves of two phases differing 90 degrees from each other. The sum of the modulated waves of two phases, and the difference between the sum and a signal obtained by multiplication of the two phase carrier waves by a predetermined value, are computed by addition and subtraction computers to obtain a phase signal of a sine wave the phase of which is proportional to the rotation angle of the shaft being measured.