CN2335151Y

CN2335151Y - High-resolution magnetic rotary encoder with high-sensitivity probe

Info

Publication number: CN2335151Y
Application number: CN 98205666
Authority: CN
Inventors: 赵宏武
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-06-09
Filing date: 1998-06-09
Publication date: 1999-08-25
Anticipated expiration: 2008-06-09

Abstract

The utility model relates to a magnetic rotary encoder, which particularly relates to a magnetic rotary encoder with high resolution and sensitivity for detecting the absolute rotational positions of rotating objects. The utility model is composed of a magnetic drum and a probe. The utility model is characterized in that the probe of the encoder is composed of a plurality of magneto resistor elements which have a certain graph structure and are etched on an insulating substrate, and the magneto resistor elements are arranged at intervals and mutually form bridge circuits. The magneto resistor elements are processed by magnetic spin valve multilayer film materials with giant magneto resistance through microelectronic technique. The magneto resistor elements have an inverse iron magnetic layer structure, an iron magnetic layer structure, a non-magnetic layer structure and an iron magnetic layer structure.

Description

Height explanation magnetic rotary encoder with highly sensitive probe

The utility model relates to a kind of magnetic rotary encoder, and particularly a kind of absolute position of rotation that is used for detecting rotating object has the high resolution and the magnetic rotary encoder of sensitivity.

Utilize resistance value to change with the variation of externally-applied magnetic field, magneto-resistive effect element can be used as Magnetic Sensor and uses; With this magnetoresistive element is that the magnetic rotary encoder of magnetic sensing probe is mainly used in physical quantitys such as control rotating speed, angle and position, this magnetic rotary encoder is simple in structure, anti-adverse environment, the response frequency frequency is wide, be easy to realize absolute position output, also have, characteristics such as cost cheap, low-power consumption and long service life convenient by dress, therefore magnetic encoder is widely used in high-acruracy survey and control field in recent years, and particularly the application at aspects such as numerically-controlled machine, robot, measuring instrument and drive motor seems particularly important.

But the magneto-resistive effect element that is adopted in the magnetic probe of at present nearly all magnetic rotary encoder, what all use is NiFe anisotropic magnetoresistance membraneous materials such as (Co), R/R is little for the magnetoresistive ratio Δ, has only 1-3%, cause a little less than the read output signal of probe, sensitivity is low, simultaneously, anisotropic magnetoresistive element itself intrinsic barkhausen noise, cause the signal to noise ratio (S/N ratio) of its output signal lower; Above-mentioned shortcoming has also limited the raising of magnetic drum above-noted magnetic pole signal density, has reduced the resolution of whole encoder.

In view of this, the resolution of scrambler is improved, make the field of its application be able to further expansion, and it is simple in structure, can't increase under many situations at the scrambler cost, just can bring bigger range of application and increase substantially the degree of accuracy of measuring and controlling, just this novel wound motivation place of grinding.

The utility model designer relies on the practical experience of researching and producing processing and other fields of being engaged in all kinds of electronic measuring instruments for many years, on the basis of feasibility study repeatedly, does a brand-new design and constitutes, and gets this novel generation eventually.

At the deficiencies in the prior art, this novel purpose is a kind of improved magnetic rotary encoder of design, to improve its resolution capability.

Principle of the present utility model is to select to have the magnetic spin valve thin film material of high magnetoresistive ratio as magnetoresistive element, and be linked to be the interference that bridge circuit reduces harmonic signal with certain spacing, adopt the reasonable arrangement architecture of the multipole magnetic pole signal of high record density then, make this scrambler have higher stability and high resolving power and high output signal, the bit error rate and temperature drift are all very little.

Task of the present utility model is finished in such a way, this is novel to be to be made of magnetic drum and probe, it is characterized in that the scrambler probe constitutes by being etched in a plurality of magnetoresistive elements that have certain graphic structure on the dielectric substrate, magnetoresistive element is spaced and forms mutually bridge circuit.Above-mentioned magnetoresistive element is to process through microelectronic technique with the magnetic Spin Valve multilayered film material with giant magnetoresistance effect.Magnetoresistive element has inverse ferric magnetosphere/ferromagnetic layer/non-magnetosphere/ferromagnetic layer structure.

Further illustrate the utility model below in conjunction with accompanying drawing

Fig. 1 is the utility model structural drawing.

The magnetic pole signal schematic representation of Fig. 2 for writing down on the magnetic drum track of the present utility model.

Fig. 3 is the utility model probe magnetic Spin Valve multilayered film material structural representation that magnetoresistive element adopted.

Fig. 4 is the utility model probe magneto-resistor sensing element and track magnetic pole relative position Pareto diagram.

Fig. 5 is the bridge circuit connection layout of the utility model probe magnetoresistive element.

Fig. 6 is the distribution plan of leakage field clocklike that the utility model magnetic drum surface produces.

Fig. 7 is the output signal of the utility model probe magnetoresistive element bridge circuit.

Fig. 8 is the reference signal that the utility model magnetic drum track 4 produces.

The utility model is made of magnetic drum and probe, the magnetic drum 1 of a column type is enclosed within on the axle 2, both combine closely, nothing relatively moves, the magnetic drum outer rim covers one deck magnetic material and makes, and formation is the multichannel magnetic pole track 3-4 of d apart, a magnetic sensing probe 5 constitutes by being etched in a plurality of magnetoresistive element 7-8 that have certain graphic structure on the dielectric substrate 6, magneto-resistor is spaced and forms mutually bridge circuit (referring to Fig. 5), probe and magnetic drum are at a distance of being s, and magneto-resistor sensing element 7-8 is corresponding one by one with the position of magnetic pole track 3-4.

Record the magnetic pole signal on the magnetic drum track 3-4, wherein the magnetic pole signal on the track 3 is a periodic arrangement, and Cycle Length is λ, and 4 of tracks have write down a magnetic pole signal that width is λ, referring to Fig. 2.Magnetoresistive element 7-8 has adopted magnetic Spin Valve multilayered film material, and its structure is referring to Fig. 3, depositing metal films layer 7A-7D on dielectric substrate 6, and wherein 7A is an inverse ferric magnetosphere, and 7B is a ferromagnetic layer, and 7C is a non-magnetosphere, and 7D is a ferromagnetic layer.After lithography process, formation has the arrangement of certain figure, referring to Fig. 4, magneto-resistor bar and track magnetic pole relative position are arranged, wherein the spacing of magnetoresistive element R1 and R2 is λ/2, and the spacing of R3, R4 is 2 λ/3, and the spacing of R3, R4 is λ/2, spacing relation between R5, R6, R7, the R8 is drawn analogous conclusions, and is interconnected into bridge circuit shown in Figure 5 between them mutually.

This novel principle of work is: the magnetic pole signal 3-4 of the periodic arrangement of record around magnetic drum 1, produced leakage field clocklike on its surface, and distribution situation is seen Fig. 6, wherein 9 is distributed magnetic field of

magnetic pole

3, and 10 are distributed magnetic field of magnetic pole 4; When magnetic drum rotates, magnetic field 9-10 is also along with rotation, act on the variation of the leakage field generating period on the magneto-resistor sensing element 7-8 like this, owing to have giant magnetoresistance effect, the resistance value of magnetoresistive element can change with the variation in magnetic field, output signal by its bridge circuit that is linked to be also just changes thereupon, wherein the sinusoidal signal V of AA ' and BB ' output _{AA '}And V _{BB '}Phase differential 90 degree are seen Fig. 7 a, carry out signal Processing through circuit, just can produce V shown in Fig. 7 b _{AA '}And V _{BB '}Pulse output signals.8 of magnetoresistive elements are used to measure the reference signal 11 that track 4 produces and are used as fixed zero, referring to Fig. 8, the position of such corner just has only a definite digital code, make the angle value code elementization, free from error signal adds up and has realized highly sensitive accurate measurement.

This is novel to have simple in structurely, easy to use really, measures accurately highly sensitive advantage.In sum, basis is novel can utilize simple structural design, makes this novel measurement result can increase substantially accuracy, easy to use.Obviously originally novel is the new design of a kind of novelty, progress and dark tool practicality.The above is this novel specific embodiment and the know-why of being used, the equivalence that the novel conception of Ruo Yiben is done changes, when the function that it produced does not exceed spiritual that instructions and accompanying drawing contain yet, all should be in this novel scope, explanation hereby.

Claims

1, a kind of height explanation magnetic rotary encoder with highly sensitive probe, constitute by magnetic drum and probe, it is characterized in that the scrambler probe constitutes by being etched in a plurality of magnetoresistive elements that have certain graphic structure on the dielectric substrate, magnetoresistive element is spaced and forms mutually bridge circuit.

2, the height explanation magnetic rotary encoder with highly sensitive probe according to claim 1 is characterized in that magnetoresistive element is to process through microelectronic technique with the magnetic Spin Valve multilayered film material with giant magnetoresistance effect.

3, the high-resolution magnetic rotary encoder with highly sensitive probe according to claim 1 is characterized in that magnetoresistive element has inverse ferric magnetosphere/ferromagnetic layer/non-magnetosphere/ferromagnetic layer structure.