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. 16, 1983
Filed:
Oct. 27, 1980
Horst Burkhardt, Truchtlaching, DE;
Hans-Rudolf Kober, Traunreut, DE;
Dr. Johannes Heidenhain GmbH, Traunreut, DE;
Abstract
A photoelectric measuring apparatus includes a measuring scale and a scanning unit including at least one photosensitive element for generating a scanning signal in response to light incident on the scanned region of the scale. First and second light sources are included, as well as a mechanism for selecting either of the first and second light sources such that light from the selected light sources is directed at the scanned region of the scale. A slider mechanism, a turntable, a movable mirror, or a movable prism can be used to select either the first or second light sources. In addition, a circuit is disclosed which provides separate first and second balancing circuits for the respective light sources, such that rebalancing the measuring instrument is not required when the selecting mechanism is used to select a different light source.