JPS5663203A - Magnetic scale - Google Patents

Abstract

PURPOSE: To ensure an easy detection for the position of a object to be detected without setting the reference position, by installing the magnetic reader having plural number of sensing elements are arranged with every bit and the position code component containing the magnetized substance which forms the position code on the substrate which can move relatively and against to the magentic reader.

CONSTITUTION: A plural number of sensing elements 3 having the magnetic resistance effect are arranged every bit to the magnetic reader 4 which is moved in a body with the object to be detected. The magnetic position code component 7, containing the magnetized substance 6 distributed at the position along the shifting direction 2 of the element 3, forms position code. The current of a constant level is supplied successively from the constant current source 10 via the multipexer 11. And the differential output between the output of the constant current and the reference voltage given from the reference power source 12 is extracted out of the differential amplifier 13. And this output of the amplifier 13 passes through the discriminating circuit 14 and the tatching circuit 15 synchronized with the multiplexer 11, and thus the position of the reader 4 is displayed part 16. Thus the position of the object to be detected can be detected easily without setting the reference position.

COPYRIGHT: (C)1981,JPO&Japio