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:
Aug. 09, 1977
Filed:
May. 30, 1975
Dieter Handtmann, Sindelfingen, DT;
Jean-Pierre Lavanchy, Neuchatel, CH;
Robert Bosch GmbH, Stuttgart, DT;
Abstract
An instrument for giving electrical indications of the distance between two reference points includes a light source, a primary light-sensitive detector and a secondary light-sensitive control detector. Both detectors may be photodiodes. In one embodiment, the light from the source is reflected from a reference plane and is intercepted by the primary detector and by the secondary control detector. The secondary control detector is part of a control loop which adjusts the intensity of the light source in such a manner that the photo current through the secondary control detector remains constant, thus providing compensation for changes in brightness and sensitivity due to aging, soiling and other influences.