Magnetic displacement sensor containing zero-setting GMR chip

Abstract

The magnetic displacement sensor includes magnetic grid rule band and GMR chip. The GMR chip uses giant magnetoresistance GMR nano magnetic film as magnetic sensor made of magnetoresistance sensitive material, and contains zero-setting resistor. The GMR chip is fixed on printed circuit board (PCB), and can implement electric signal connection with aftertreatment circuit by means of aluminium silicon wire binding mode. The GMR chip and PCB board are formed into movable rule, and when the movable rule is transversely moved on the fixed rule, the magnetic field intensity change of magnetic grid which is detected by GMR chip can be converted into electric signal, and is transferred to the aftertreatment circuit, finally the displacement quantity of movable rule moved relatively to fixed rule can be obtained by signal treatment circuit.

Description

technical field [0001] The invention relates to a device for measuring the length of a magnetic grating ruler with a zero-adjustable GMR chip, which is a displacement sensor using the GMR chip and belongs to the technical field of sensors. Background technique [0002] In industrial applications such as automatic control, machinery manufacturing, vehicles and ships, a large number of sensors for measuring length and angular position or a system composed of various displacement sensors are required. Generally speaking, these sensors are required to have the characteristics of high sensitivity, high resolution, fast response, good stability, small size, and low power consumption. [0003] At present, there are four main types of common length measuring sensors: [0004] 1. A grating-type displacement detection device using a grating as a code, such as an "optical displacement detection device" described in patent 97122401.3 CN1183546A (Mitutoyo Corporation). The disadvantage...

AI Technical Summary

Problems solved by technology

The disadvantage of this type of displacement sensor is that the miniaturization of the active components is difficult

[0007] 4. A magnetic grid type displacement sensor that uses a magnetoresistive sensor to detect the magnetic field change of the magnetic grid to achieve displacement measurement, such as patent US5036276 (Seiko Epson), EP0624778B1 (Heidenhain), patent 98107990.3 CN1199856A (Brown and Sharp Tesar), Patent 200410009165.1 CN1584504A (Beijing University of Science and Technology), the above inventions are all based on traditional magneto-resistance devices, which are magneto-sensitive components made using the anisotropic magneto-resistance effect (AMR) of ferromagnetic materials. Their biggest shortcoming is magneto-resistance The rate of change is low and the sensitivity is low, so the improvement of measurement accuracy will be greatly limited

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