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:
Jan. 18, 1994
Filed:
Feb. 18, 1992
Joannes G Bremer, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The measuring device (1) comprises a scale graduation element (3) provided with a number of tracks (9, 13), a pick-up device (5) which comprises a number of sensing elements (4, 6) provided with sensors, which number corresponds to the number of tracks (9, 13), and also comprises a signal processing system (7). The tracks (9, 13) include an incremental track (9) and an absolute track (13). Both tracks are formed as a succession of strip-shaped parts (11, 15), each of which has a property which can be detected by the sensors of the sensing elements (4, 6). This property is dependent on the location on the scale graduation element (3). This property is preferably bivalent. In the signal processing system (7) signals originating from the sensing element (4) associated with the incremental track (9) and signals originating from the sensing element (6) associated with the absolute track (13) are combined. On the absolute track (13) the property is distributed in a pseudo-random fashion between the strip-shaped parts (15) so that the combination of signals for a pitch (17) of the incremental track (9) produces a specific value for each pitch (17). Consequently, the measurement value produced by the signal processing system (7) is absolute.