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:
Sep. 19, 1984
Marcello Boella, Loranze, IT;
Paolo Rivera, Strambino, IT;
Ing. C. Olivetti & C., S.p.A., Ivrea, IT;
Abstract
An optical transducer for detecting the position of a rotary or translatory member comprises a light source, a photodetector group, and a shutter provided with a series of transparent elements spaced by opaque regions and interposed between the light source and the photodetector group. The photodetector group comprises an integrated circuit, on a surface of which is disposed a plurality of photovoltaic cells, each having an area which is a fraction of the area of each transparent element. The cells are divided into four groups to generate as many electrical signals which are out of phase relative to each other by 90.degree. and which are indicative of the position of the shutter with respect to the position of the photodetector group and the light source. The cells are disposed symmetrically with respect to a central radially extending optical axis, and in such a way that the barycenter of the areas of each of the four groups is included in the central optical axis. The sum of the four electrical signals is also used as feedback for controlling the power supply for the light source.