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. 20, 1991
Filed:
Mar. 28, 1990
Johannes L Bogaerts, Eindhoven, NL;
Eduard Camerik, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The device comprises on the one hand an elongate scale (7) consisting of a succession of magnetic north poles and south poles, and on the other hand a measuring head (9) with at least a first and a second magnetic field sensor (21, 23) which are subjected to the effect of a magnetic field which alternates as a function of time due to the alternating passage of north poles and south poles during a displacement (15) of the scale in its longitudinal direction with respect to the measuring head. The two magnetic field sensors (21, 23) are arranged so that they are always situated opposite one and the same point on the scale (7), the first sensor (21) being sensitive to variations in the magnetic field component extending parallel to the longitudinal direction of the scale (7), the second sensor (23) being sensitive to variations in the component extending parallel to the connecting line (19) between the scale (7) and the measuring head (9). Because the points where the direction of these magnetic field components is reversed correspond to different points on the scale (7), the output signals of the two sensors (21, 23) are phase-shifted with respect to one another, so that the direction of the displacement can be readily determined.