TW201819845A - Reading head device for sensing absolute position capable of improving the problem of digital hall sensor being unable to correctly sense the magnetism of encoded magnetic zones - Google Patents

Abstract

A reading head device for sensing an absolute position includes an encoding element and a reading element. The encoding element includes an absolute row track and an incremental row track. The absolute row track has a plurality of magnetic zone boundaries. The incremental row track has a plurality of magnetic pole boundaries. The distance between two adjacent magnetic pole boundaries is noted as P. The distance between two adjacent magnetic zone boundaries is noted as 2P. The reading element includes a first and a second magnetic flux sensing groups corresponding to the absolute row track, a third magnetic sensor corresponding to the incremental row track, and a fourth magnetic sensor corresponding to the incremental row track. The first magnetic sensor of the first magnetic sensing group and the second magnetic sensor of the second magnetic sensing group are staggered by a P distance. The third magnetic sensor is aligned with one of the first and second magnetic sensors. The distance between the third magnetic sensor and the fourth magnetic sensor is (N-0.5)*P, where N is a positive integer.

Description

Absolute position sensing read head device

The present invention relates to a position sensing read head, in particular to an absolute position sensing read head device.

Referring to FIG. 1, a conventional absolute position sensing read head device 1 includes a coding element 11, a reading element 12, and a processing unit 13. The encoding element 11 includes an absolute row of tracks 111 and an incremental row of tracks 112 extending side by side along a moving direction X. The absolute column track 111 has a plurality of magnetic field boundaries 114 that are arranged at equal distances along the moving direction X and divide the absolute column track 111 into a plurality of coded magnetic regions 113. The incremental column track 112 has a plurality of magnetic pole boundaries 115 arranged equidistantly along the moving direction X. The magnetic pole boundaries 115 distinguish the incremental column track 112 into a plurality of staggered arrays of a first incremental magnetic zone 116 and a complex number. Second incremental magnetic zone 117. Each of the first incremental magnetic regions 116 and each of the second incremental magnetic regions 117 have different magnetic properties. The reading element 12 is spaced apart from the encoding element 11 and includes a plurality of digital hall sensors 121 (digital hall sensors) corresponding to the absolute column tracks 111 and arranged equidistantly along the moving direction X, and a pair of The magnetic tracks 112 should be incremented and be magnetoresistive sensors 122. The processing unit 13 is electrically connected to the digital Hall sensors 121 and the magnetoresistive sensors 122.

The encoding element 11 can move relative to the reading element 12 along the moving direction X. The digital Hall sensors 121 are used to sense the magnetic field of the encoded magnetic region 113 of the absolute column track 111. For the processing unit 13 to decode to obtain the current absolute position information, the magnetoresistive sensor 122 is configured to sense the magnetic movement of the first incremental magnetic region 116 and the second incremental magnetic region 117 of the incremental column magnetic track 112. The amount of change is used by the processing unit 13 to obtain the displacement information of the encoding element 11.

Referring to FIG. 2, however, when the digital Hall sensors 121 of the absolute position sensing read head device 1 are located at the magnetic field boundaries 114 respectively, the digital Hall sensors 121 are susceptible to The isomagnetic zone boundary 114 is located between two opposite magnetic transition change zones and the magnetic value (magnetic flux) is too small, instead of being able to sense the correct magnetic field of the encoded magnetic zone 113, so that the encoded magnetic zones 113 that are respectively sensed are not all located in On the same side of the boundary 114 of the magnetic zones, that is, the magnetic code sensed by the digital Hall sensors 121 is not the current absolute position code, thereby causing the misidentification of the absolute position.

It is therefore an object of the present invention to provide an absolute position sensing read head device that overcomes at least the disadvantages described in the prior art.

Therefore, the absolute position sensing read head device of the present invention includes a coding element, a reading element, and a processing unit.

The encoding element includes an absolute row of tracks and an incremental row of tracks extending side by side in a moving direction. The absolute column track has a magnetic zone boundary where plural numbers are equidistantly arranged along the moving direction and the absolute column track is divided into a plurality of coded magnetic zones. The incremental column track has a plurality of magnetic pole boundaries arranged equidistantly along the moving direction. The magnetic pole boundaries distinguish the incremental column tracks into a plurality of staggered arrays of a first incremental magnetic zone and a plurality of second incremental magnetic zones. Each of the first and second incremental magnetic regions has different magnetic properties. The distance between two adjacent magnetic pole boundaries is P, and the distance between two adjacent magnetic zone boundaries is 2P. The offset distance between the magnetic zone boundaries of the absolute row track and the magnetic pole boundaries of the incremental row track is ρ, 0 ≦ ρ ≦ 2P. When ρ is equal to 0, the boundaries of the magnetic domains are aligned with several of the boundaries of the magnetic poles, respectively.

The reading element is spaced apart from the encoding element, and includes a first magnetic induction group and a second magnetic induction group corresponding to an absolute column track, a third magnetic sensor corresponding to an incremental column track, and A pair of fourth magnetic sensors should be arranged in increments of magnetic tracks and spaced from the third magnetic sensor along the moving direction. The first magnetic induction group has a plurality of first magnetic sensors arranged at equal intervals along the moving direction at a pitch of 2P. The second magnetic induction group has a plurality of second magnetic sensors arranged alternately with the first magnetic sensors at a P pitch along the moving direction. The displacement distance between the third magnetic sensor, the first magnetic sensor, and the second magnetic sensor adjacent to each other along the moving direction is ρ and the same as that of the incremental magnetic track and the absolute magnetic track. Offset direction. When ρ is equal to 0, the third magnetic sensor is aligned with one of the first magnetic sensors and the second magnetic sensors, and the distance between the third magnetic sensor and the fourth magnetic sensor is ( N-0.5) * P, where N is a positive integer.

The processing unit is electrically connected to the first magnetic sensor group, the second magnetic sensor group, the third magnetic sensor, and the fourth magnetic sensor, and a magnetic value range corresponding to each magnetic pole boundary is set.

The encoding element is movable relative to the reading element along the moving direction.

When the third magnetic sensor and the fourth magnetic sensor respectively sense the magnetism of each of the first incremental magnetic zone and each of the second incremental magnetic zone, or respectively sense the magnetic value range and When the magnetism of each second incremental magnetic zone, or the magnetism of each second incremental magnetic zone is sensed, or the magnetism of each second incremental magnetic zone and the magnetic value range of each magnetic pole boundary are sensed separately, The processing unit selects the magnetic combination of the encoded magnetic regions sensed by one of the first magnetic induction group and the second magnetic induction group as a basis for decoding the absolute position;

When the third magnetic sensor and the fourth magnetic sensor respectively sense the magnetic properties of each of the second incremental magnetic areas and each of the first incremental magnetic areas, or the magnetic value ranges and When the magnetism of each first incremental magnetic zone is sensed separately, or when the magnetism of each first incremental magnetic zone and the magnetic value range of each magnetic pole boundary are sensed separately, The processing unit selects the magnetic combination of the encoded magnetic regions sensed by the other of the first magnetic induction group and the second magnetic induction group as a basis for decoding the absolute position.

The reading selection of the first magnetic induction group and the second magnetic induction group in the above two absolute position reading modes is based on the actual relative positions of the third magnetic sensor and the fourth magnetic sensor, and the third The relative positions of the magnetic sensors, the first magnetic sensors and the second magnetic sensors are determined.

The effect of the present invention lies in the specificity of the absolute magnetic track, the incremental magnetic track, the first magnetic induction group, the second magnetic induction group, the third magnetic sensor, and the fourth magnetic sensor. The relative position configuration makes it possible to select the first magnetic induction group or the second magnetic induction group which is not adjacent to the boundaries of the magnetic regions by the combination of the magnetic changes sensed by the third magnetic sensor and the fourth magnetic sensor. The magnetic combination of the encoded magnetic zone sensed by the magnetic induction group is used as the basis for decoding the absolute position, to avoid misjudgment of the signal of the magnetic sensor at the magnetic pole junction, to achieve the correct reading of the absolute position.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

Referring to FIG. 3, a first embodiment of an absolute position sensing read head device according to the present invention includes a coding element 2, a reading element 3, and a processing unit 4.

The encoding element 2 includes an absolute row of magnetic tracks 21 and an incremental row of magnetic tracks 22 extending side by side along a moving direction X. The absolute column track 21 has a plurality of magnetic field boundaries 210 arranged at equal distances along the moving direction X and dividing the absolute column track 21 into a plurality of coded magnetic regions 211. The incremental column track 22 has a plurality of magnetic pole boundaries 220 arranged equidistantly along the moving direction X. The magnetic pole boundaries 220 distinguish the incremental column track 22 into a plurality of staggered arrays of a first incremental magnetic zone 221 and a complex number. Second incremental magnetic zone 222. Each of the first incremental magnetic regions 221 and each of the second incremental magnetic regions 222 have different magnetic properties. The interval between two adjacent magnetic pole boundaries 220 is P, and the interval between two adjacent magnetic zone boundaries 210 is 2P. The magnetic domain boundaries 210 are respectively aligned with several of the magnetic pole boundaries 220.

The reading element 3 is spaced from the encoding element 2 and includes a first magnetic induction group 31 and a second magnetic induction group 32 corresponding to the absolute column magnetic track 21, and a pair of first magnetic induction groups 22 corresponding to the incremental column magnetic track 22. Three magnetic sensors 33, a pair of fourth magnetic sensors 34 corresponding to the incremental column tracks 22 and spaced apart from the third magnetic sensor 33 along the moving direction X, and a pair of corresponding incremental column tracks 22 and The fifth magnetic sensor 35 is a magnetoresistive sensor. The first magnetic induction group 31 has a plurality of first magnetic sensors 311 arranged at equal intervals along the moving direction X at a pitch of 2P. The second magnetic sensor group 32 includes a plurality of second magnetic sensors 321 staggered along the moving direction X with the first magnetic sensors 311 at a P pitch. The third magnetic sensor 33 is aligned with one of the first magnetic sensors 311 and the second magnetic sensors 321. The distance between the third magnetic sensor 33 and the fourth magnetic sensor 34 is (N-0.5) * P, and N is a positive integer. In this embodiment, the first magnetic sensors 311 and the second magnetic sensors 321 are digital Hall sensors, and the third magnetic sensor 33 and the fourth magnetic sensor 34 are analog types. Hall sensors, but not limited to this.

The processing unit 4 is electrically connected to the first magnetic sensor group 31, the second magnetic sensor group 32, the third magnetic sensor 33, the fourth magnetic sensor 34, and the fifth magnetic sensor 35. The processing unit 4 sets a magnetic value range corresponding to each magnetic pole boundary 220 according to the magnitude of the magnetic field at each magnetic pole boundary 220 sensed by the third magnetic sensor 33 and the fourth magnetic sensor 34. In this embodiment, the magnetic value range is ± 30 Gauss (Gs).

The encoding element 2 can move relative to the reading element 3 along the moving direction X. The first magnetic induction group 31 and the second magnetic induction group 32 are respectively used to sense and read the encoding of the absolute column magnetic track 21 The magnetic field 211 is magnetic for the processing unit 4 to decode to obtain the current absolute position information. The fifth magnetic sensor 35 is used to sense the first incremental magnetic field 221 and the second incremental magnetic field 22 of the incremental column track 22. The magnetic movement variation of the magnetic region 222 is used by the processing unit 4 to obtain the displacement information of the encoding element 2.

When the third magnetic sensor 33 and the fourth magnetic sensor 34 respectively sense the magnetism of each of the first incremental magnetic area 221 and the second incremental magnetic area 222, or respectively sense the The magnetic value range and the magnetism of each second incremental magnetic region 222, or both the magnetism of each second incremental magnetic region 222, or the magnetism of each second incremental magnetic region 222 and each magnetic pole are sensed, respectively. When the magnetic value range of the boundary 220 is reached, the processing unit 4 selects the magnetic combination of the encoded magnetic regions 211 sensed by one of the first magnetic induction group 31 and the second magnetic induction group 32 as a basis for decoding the absolute position.

When the third magnetic sensor 33 and the fourth magnetic sensor 34 respectively sense the magnetic properties of the second incremental magnetic areas 222 and the first incremental magnetic areas 221 or the magnetic pole boundaries 220 respectively. The magnetic value range and the magnetism of each first incremental magnetic region 221, or the magnetism of each first incremental magnetic region 221, or the magnetism of each first incremental magnetic region 221 and each magnetic pole, respectively When the magnetic value range of the boundary 220 is reached, the processing unit 4 selects the magnetic combination of the encoded magnetic region 220 sensed by the other of the first magnetic induction group 31 and the second magnetic induction group 32 as the basis for decoding the absolute position.

The reading selection of the first magnetic induction group 31 and the second magnetic induction group 32 in the above two absolute position reading modes is based on the actual relative positions of the third magnetic sensor 33 and the fourth magnetic sensor 34. And the relative positions of the third magnetic sensor 33 and the first magnetic sensor 311 and the second magnetic sensor 321 are determined. The following is a description of the third magnetic sensor 33 and the fourth magnetic sensor 34. Different relative positions are matched with different relative positions of the third magnetic sensor 33, the first magnetic sensor 311, and the second magnetic sensor 321 to perform reading judgment on the absolute position of the absolute position sensing head device Mechanism description.

[Specific example 1]

When N is a positive even number, that is, the distance between the third magnetic sensor 33 and the fourth magnetic sensor 34 is 1.5P, 3.5P, 5.5P, etc., and the third magnetic sensor 33 and the first When the magnetic sensors 311 and the second magnetic sensors 321 have the same relative position, the reading options of the first magnetic induction group 31 and the second magnetic induction group 32 in the two absolute position reading modes are the same. of. Referring to FIG. 3, in this specific example, a distance between the third magnetic sensor 33 and the fourth magnetic sensor 34 is 1.5P, and the third magnetic sensor 33 is aligned with the first magnetic sensors 311. The position of the magnetic sensor located on the far left is used to explain the reading and judging mechanism of the absolute position of the absolute position sensing head device.

When the third magnetic sensor 33 and the fourth magnetic sensor 34 respectively sense the magnetic properties of the first incremental magnetic area 221 and the second incremental magnetic area 222 (see FIG. 3), or respectively, The magnetic value range of each magnetic pole boundary 220 and the magnetism of each second incremental magnetic region 222 (see FIG. 4), or the magnetism of each second incremental magnetic region 222 (see FIG. 5), or both When the magnetism of each second incremental magnetic region 222 and the magnetic value range of each magnetic pole boundary 220 are measured (see FIG. 6), the processing unit 4 selects the first magnetic induction group 31 or the second magnetic induction group 32 The detected magnetic combination of the encoded magnetic regions 211 is used as the basis for decoding the absolute position.

When the third magnetic sensor 33 and the fourth magnetic sensor 34 respectively sense the magnetic properties of the second incremental magnetic areas 222 and the first incremental magnetic areas 221 (see FIG. 7), or respectively The magnetic value range of each magnetic pole boundary 220 and the magnetism of each first incremental magnetic region 221 (see FIG. 8), or the magnetism of each first incremental magnetic region 221 (see FIG. 9), respectively, or When measuring the magnetism of each first incremental magnetic region 221 and the magnetic value range of each magnetic pole boundary 220 (see FIG. 10), the processing unit 4 selects the first magnetic induction group 31 or the second magnetic induction group 32 for sensing. The magnetic combination of the obtained encoded magnetic regions 211 is used as the basis for decoding the absolute position.

Accordingly, the absolute position sensing read head device of the present invention selects the first magnetic induction group 31 or the second magnetic induction through a combination of the magnetic changes sensed by the third magnetic sensor 33 and the fourth magnetic sensor 34. The magnetic combination of the encoded magnetic region 211 sensed by the sensing group 32 is used as the basis for decoding the absolute position, so as to avoid misjudgment of the signal of the magnetic sensor at the magnetic pole junction to achieve the correct reading of the absolute position.

[Specific example 2]

When N is a positive odd number, that is, the distance between the third magnetic sensor 33 and the fourth magnetic sensor 34 is 0.5P, 2.5P, 4.5P, etc., and the third magnetic sensor 33 and the first When the magnetic sensors 311 and the second magnetic sensors 321 have the same relative position, the reading options of the first magnetic induction group 31 and the second magnetic induction group 32 in the two absolute position reading modes are the same. of. Referring to FIG. 11, in this specific example, a distance between the third magnetic sensor 33 and the fourth magnetic sensor 34 is 2.5P, and the third magnetic sensor 33 is aligned with the first magnetic sensors 311. The position of the magnetic sensor located on the far left is used to explain the reading and judging mechanism of the absolute position of the absolute position sensing head device.

When the third magnetic sensor 33 and the fourth magnetic sensor 34 respectively sense the magnetic properties of the first incremental magnetic area 221 and the second incremental magnetic area 222 (see FIG. 11), or respectively The magnetic value range of each magnetic pole boundary 220 and the magnetism of each second incremental magnetic region 222 (see FIG. 12), or the magnetism of each second incremental magnetic region 222 (see FIG. 13), or both When the magnetism of each second incremental magnetic region 222 and the magnetic value range of each magnetic pole boundary 220 are measured (see FIG. 14), the processing unit 4 selects the first magnetic induction group 31 or the second magnetic induction group 32 for sensing. The magnetic combination of the obtained encoded magnetic regions 211 is used as the basis for decoding the absolute position.

When the third magnetic sensor 33 and the fourth magnetic sensor 34 respectively sense the magnetic properties of the second incremental magnetic areas 222 and the first incremental magnetic areas 221 (see FIG. 15), or respectively, The magnetic value range of each magnetic pole boundary 220 and the magnetic properties of each first incremental magnetic zone 221 (see FIG. 16), or the magnetic properties of each first incremental magnetic zone 221 and the magnetic value of each magnetic pole boundary 220 are sensed separately. Range (see FIG. 17), or when the magnetism of each first incremental magnetic area 221 is sensed (see FIG. 18), the processing unit 4 selects the first magnetic induction group 31 or the second magnetic induction group 32 The detected magnetic combination of the encoded magnetic regions 211 is used as the basis for decoding the absolute position.

Accordingly, the absolute position sensing read head device of the present invention selects the first magnetic induction group 31 or the second magnetic induction through a combination of the magnetic changes sensed by the third magnetic sensor 33 and the fourth magnetic sensor 34. The magnetic combination of the encoded magnetic region 211 sensed by the sensing group 32 is used as the basis for decoding the absolute position, so as to avoid misjudgment of the signal of the magnetic sensor at the magnetic pole junction to achieve the correct reading of the absolute position.

[Specific example 3]

Referring to FIG. 19, it is substantially the same as the specific example 1. The difference is that the absolute column track 21 and the incremental column track 22 are misaligned along the moving direction X, and the magnetic regions of the absolute column track 21 The offset distance between the boundary 210 and the magnetic pole boundaries 220 of the incremental track 22 is ρ, where 0 ≦ ρ ≦ 2P. The offset distance between the third magnetic sensor 33 and the leftmost one of the neighboring first magnetic sensors 311 along the moving direction X is ρ, and the incremental row magnetic track 22 and the absolute row magnetic track are the same. 21's misalignment direction. Because the dislocation directions and dislocation pitches of the absolute row magnetic track 21 and the incremental row tracks 22 are the same as the dislocation directions and dislocation pitches of the third magnetic sensor 33 and the adjacent first magnetic sensor 311, The relative position of each magnetic sensor and corresponding magnetic track corresponding to the specific example 2 can be maintained under the position. Therefore, the reading position determination mechanism of the absolute position of the processing unit 4 is the same as that of the specific example 1. Therefore, it is also possible to have The advantages and effects are the same as those of the specific example 1.

It can be known from the above description that the absolute position sensing read head device of the present invention uses the absolute row magnetic track 21, the incremental row magnetic track 22, the first magnetic induction group 31, the second magnetic induction group 32, and the third The specific relative position configuration of the magnetic sensor 33 and the fourth magnetic sensor 34 enables non-proximity to be selected by the combination of the sensed magnetic changes of the third magnetic sensor 33 and the fourth magnetic sensor 34. The magnetic combination of the encoded magnetic field 211 sensed by the first magnetic induction group 31 or the second magnetic induction group 32 of the magnetic field boundaries 210 is used as the basis for decoding the absolute position, so as to avoid the false judgment of the signal of the magnetic sensor at the magnetic pole boundary In order to achieve correct reading of the absolute position, in addition, the third magnetic sensor 33 and the fourth magnetic sensor 34 are analog Hall sensors, respectively, and the magnetic flux density of the incremental column magnetic track 22 is measured. The distribution is helpful for the magnetic flux sensing at the magnetic pole boundaries 220 with smaller changes in the magnetic flux, and can more effectively assist the correct reading of the absolute position.

In addition, the width of the encoded magnetic field 211 of the absolute column track 21 of the absolute position sensing read head device of the present invention is twice the first and second incremental magnetic fields 221 of the incremental column track 22 The widths of 222 and 222 are compared with the configuration of each encoding magnetic area 211 and each of the first and second incremental magnetic areas 221 and 222 being the same width. The advantage is that with the same encoding, a longer track (2 times) can be obtained. ) Furthermore, the above descriptions are based on the reading element 3 being fixed, and the coding element 2 moving as an illustration. In practice, as long as the coding element 2 and the reading element 3 are fixed, the other may be Relative to the fixed one, it can indeed achieve the purpose of the invention.

Referring to FIG. 20, a second embodiment of an absolute position sensing read head device according to the present invention is substantially the same as the first embodiment, except that:

The absolute column magnetic track 21 and the incremental column magnetic track 22 extend along an axis L in a surrounding direction R and are arranged side by side in the radial direction. The magnetic field boundaries 210 are arranged at equal angles along the circumferential direction R and the absolute column magnetic track 21 is divided into the encoded magnetic fields 211. The magnetic pole boundaries 220 are arranged at equal angles along the circumferential direction R to distinguish the incremental column magnetic track 22 into the first incremental magnetic areas 221 and the second incremental magnetic areas 222 that are staggered. The angular distance between two adjacent magnetic pole boundaries 220 is A. The angular distance between two adjacent magnetic field boundaries 210 is 2A. The magnetic domain boundaries 210 are respectively aligned radially with the magnetic pole boundaries 220.

The first magnetic sensors 311 are arranged at equal angular distances of 2A along the surrounding direction R. The second magnetic sensors 32 and the first magnetic sensors 311 are staggered at an angular distance A along the surrounding direction R and the first magnetic sensors 311. The third magnetic sensor 33 is aligned with one of the first magnetic sensors 311 and the second magnetic sensors 321 in a radial direction. The distance between the third magnetic sensor 33 and the fourth magnetic sensor 34 is (N-0.5) * A, and N is a positive integer.

The encoding element 2 can rotate relative to the reading element 3 in the axial direction of the axis L.

The above-mentioned configuration of the encoding element 2 and the reading element 3 also applies the same absolute position reading mode described in the first embodiment, so as to achieve the same advantages and effects as the first embodiment.

Of course, the absolute column magnetic track 21 and the incremental column magnetic track 22 of the second embodiment may also be misaligned along the surrounding direction R, so that the magnetic field boundaries 210 of the absolute column magnetic track 21 and the incremental column magnetic track 21 The misalignment angular distance of the magnetic pole boundaries 220 of the rail 22 is α, where 0 ≦ α ≦ 2A, and the third magnetic sensor 33 is adjacent to the first magnetic sensors 311 and the second magnetic sensors 321. One of the misalignment angular distances along the circumferential direction R is α and the same misalignment direction of the incremental row magnetic track 22 and the absolute row magnetic track 21, thereby maintaining the same magnetic sensors and corresponding ones in each position. The relative position of the magnetic track and the reading and judging mechanism of the absolute position of the processing unit 4 can be kept the same, and thus the above advantages and effects can also be achieved.

Referring to FIG. 21, a third embodiment of an absolute position sensing read head device according to the present invention is substantially the same as the second embodiment, except that the absolute row magnetic track 21 and the incremental row magnetic track 22 follow The orbiting direction R extends around the axis L and is arranged side by side along the extending direction of the axis L, and the reading element 3 is disposed on the peripheral side of the encoding element 2, that is, adjacent to the absolute column track 21 and the incremental column track. 22. In this way, the third embodiment can also achieve the same advantages and effects as the second embodiment.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited in this way, any simple equivalent changes and modifications made in accordance with the scope of the patent application and the content of the patent specification of the present invention are still Within the scope of the invention patent.

2‧‧‧ coding element

21‧‧‧ absolute column track

210‧‧‧ magnetic field boundary

211‧‧‧coded magnetic zone

22‧‧‧ incremental column track

220‧‧‧ magnetic pole boundary

221‧‧‧The first incremental magnetic zone

222‧‧‧Second incremental magnetic zone

3‧‧‧Reading element

31‧‧‧The first magnetic induction group

311‧‧‧The first magnetic sensor

32‧‧‧Second magnetic induction group

321‧‧‧Second magnetic sensor

33‧‧‧Third magnetic sensor

34‧‧‧Fourth magnetic sensor

35‧‧‧Fifth magnetic sensor

4‧‧‧ processing unit

X‧‧‧ direction of movement

R‧‧‧ Surrounding direction

L‧‧‧ axis

Other features and effects of the present invention will be clearly presented in the embodiment with reference to the drawings, in which: FIG. 1 is a schematic diagram illustrating the component configuration of a conventional absolute position sensing read head device; FIG. 2 is a Schematic diagram of a complex digital Hall sensor of an existing absolute position sensing read head device located at the boundary of a plurality of magnetic zones of an absolute column track; FIGS. 3 to 10 are schematic diagrams illustrating the absolute position sensing of the present invention. A component arrangement pattern of a first embodiment and a specific example 1 of the scanning head device, and a pattern with different relative positions between a coding element and a reading element; FIGS. 11 to 18 are schematic diagrams illustrating Element configuration of a specific example 2 of the first embodiment, and a state of different relative positions between a coding element and a reading element; FIG. 19 is a schematic diagram, a specific example 3 of the first embodiment FIG. 20 is a schematic diagram illustrating the component configuration of a second embodiment of the absolute position sensing read head device of the present invention; and FIG. 21 is an incomplete perspective view illustrating the absolute position of the present invention A component configuration of a third embodiment of the sensing head device.

Claims (10)

An absolute position sensing read head device includes: a coding element including an absolute row of tracks and an incremental row of tracks extending side by side and arranged side by side, the absolute row of tracks having a plurality of rows along the direction of movement, etc. Arrange the distance and divide the absolute column track into the magnetic field boundary of the complex coded magnetic field, the incremental column track has a plurality of magnetic pole boundaries arranged equidistantly along the moving direction, and the magnetic pole boundaries divide the incremental column track Divided into a staggered array of multiple first and second incremental magnetic regions, each of the first and second incremental magnetic regions has different magnetic properties, and the distance between two adjacent magnetic pole boundaries is P The distance between the boundaries of two adjacent magnetic zones is 2P, and the dislocation distance between the boundaries of the magnetic zones of the absolute column tracks and the magnetic pole boundaries of the incremental column tracks is ρ, 0 ≦ ρ ≦ 2P, when ρ When equal to 0, the boundaries of the magnetic regions are aligned with several of the boundaries of the magnetic poles, respectively; and a reading element is arranged at a distance from the encoding element, and includes a first magnetic induction group corresponding to an absolute row of tracks and A second magnetic induction group, a pair of incremental magnetic tracks A third magnetic sensor, and a pair of fourth magnetic sensors arranged in increments of the magnetic track and spaced from the third magnetic sensor along the moving direction, the first magnetic group having a plurality of 2P along the moving direction The first magnetic sensors arranged at equal distances from each other, the second magnetic sensor group has a plurality of second magnetic sensors arranged alternately with the first magnetic sensors at a P pitch along the moving direction, and the third magnetic sensors and The dislocation distance between the first magnetic sensor and the second magnetic sensor adjacent to each other along the moving direction is ρ and the dislocation direction of the incremental column track and the absolute column track is the same. When ρ is equal to 0 When the third magnetic sensor is aligned with one of the first magnetic sensors and the second magnetic sensors, the distance between the third magnetic sensor and the fourth magnetic sensor is (N-0.5) * P, N are positive integers; wherein the coding element can move relative to the reading element along the moving direction. The absolute position sensing read head device according to claim 1, further comprising a processing unit electrically connected to the first magnetic sensor group, the second magnetic sensor group, the third magnetic sensor, and the fourth magnetic sensor. , The processing unit sets a magnetic value range corresponding to each magnetic pole boundary; when the third magnetic sensor and the fourth magnetic sensor respectively sense the first incremental magnetic zone and the second incremental magnetic zone, Magnetism, or the magnetic value range of each magnetic pole boundary and the magnetic properties of each second incremental magnetic area, or the magnetic properties of each second incremental magnetic area, or the second incremental magnetic areas, respectively When measuring the magnetism of the magnetic region and the magnetic value range of each magnetic pole boundary, the processing unit selects the magnetic combination of the encoded magnetic regions sensed by one of the first magnetic induction group and the second magnetic induction group as the absolute position Decoding basis; when the third magnetic sensor and the fourth magnetic sensor respectively sense the magnetic properties of the second incremental magnetic area and the first incremental magnetic area, or respectively sense the magnetic properties of the magnetic pole boundaries The range of values and the magnetic properties of each first incremental magnetic zone, or the The magnetic unit, or when the magnetic value ranges of the first incremental magnetic zones and the magnetic value ranges of the magnetic pole boundaries are sensed separately, the processing unit selects the first magnetic induction group and the second magnetic induction group to sense The magnetic combination of the encoded magnetic zone is used as the basis for decoding the absolute position; the reading selection of the first magnetic induction group and the second magnetic induction group under the two absolute position reading modes is based on the actual third magnetic sensor. The relative position to the fourth magnetic sensor and the relative positions of the third magnetic sensor to the first magnetic sensor and the second magnetic sensor are determined. The absolute position sensing read head device according to claim 2, wherein the first magnetic sensors and the second magnetic sensors are digital Hall sensors, and the third magnetic sensor and the The fourth magnetic sensor is an analog Hall sensor. The absolute position sensing read head device according to claim 1, wherein the width of the encoded magnetic field is twice the width of the incremental magnetic field. The absolute position sensing read head device according to claim 1, wherein the reading element further includes a fifth magnetic sensor corresponding to the incremental column magnetic track and electrically connected to the processing unit, the fifth magnetic sensor It is a magnetoresistive sensor, and is used to sense the magnetic movement changes of the first incremental magnetic zone and the second incremental magnetic zone of the incremental column track. An absolute position sensing read head device includes: a coding element including an absolute column magnetic track and an incremental column magnetic track extending side by side and extending side by side around an axis, the absolute column magnetic track having a plurality of along the The magnetic field boundaries are arranged at equal angles in the circumferential direction and the absolute column tracks are divided into complex coded magnetic zones. The incremental column tracks have a plurality of magnetic pole boundaries arranged at equal angles in the circumferential direction. The column tracks are divided into a plurality of staggered first and second incremental magnetic zones. Each of the first and second incremental magnetic zones has different magnetic properties. The angular distance is A, the angular distance between the two adjacent magnetic field boundaries is 2A, and the misalignment angular distance between the magnetic field boundaries of the absolute column track and the magnetic pole boundaries of the incremental column track is α, 0 ≦ α ≦ 2A, when α is equal to 0, the magnetic field boundaries are respectively aligned with some of the magnetic pole boundaries in the radial direction; and a reading element is arranged at a distance from the coding element, and includes a magnetic field corresponding to the absolute column. A first magnetic induction group and a second magnetic induction group of the track, a A third magnetic sensor that should increase the number of magnetic tracks, and a pair of fourth magnetic sensors that should increase the number of magnetic tracks and be spaced from the third magnetic sensor along the surrounding direction. The first magnetic induction group has A plurality of first magnetic sensors arranged equidistantly at an angular distance of 2A along the surrounding direction, and the second magnetic sensing group having a plurality of second magnetic inductors staggeredly arranged at an angular distance of A with the first magnetic sensors along the surrounding direction The third magnetic sensor, the first magnetic sensor and the second magnetic sensor are adjacent to each other, and the offset angular distance along the surrounding direction is α and the same. The incremental row magnetic track and the absolute row When α is equal to 0, the third magnetic sensor is radially aligned with one of the first magnetic sensors and the second magnetic sensors, and the third magnetic sensor is aligned with the first magnetic sensor. The pitch of the four magnetic sensors is (N-0.5) * A, and N is a positive integer; and wherein, the encoding element can rotate relative to the reading element in an axial extension direction of the axis. The absolute position sensing read head device according to claim 6, further comprising a processing unit electrically connected to the first magnetic sensor group, the second magnetic sensor group, the third magnetic sensor, and the fourth magnetic sensor. , The processing unit sets a magnetic value range corresponding to each magnetic pole boundary; when the third magnetic sensor and the fourth magnetic sensor respectively sense the first incremental magnetic zone and the second incremental magnetic zone, Magnetism, or the magnetic value range of each magnetic pole boundary and the magnetic properties of each second incremental magnetic area, or the magnetic properties of each second incremental magnetic area, or the second incremental magnetic areas, respectively When measuring the magnetism of the magnetic region and the magnetic value range of each magnetic pole boundary, the processing unit selects the magnetic combination of the encoded magnetic regions sensed by one of the first magnetic induction group and the second magnetic induction group as the absolute position Decoding basis; when the third magnetic sensor and the fourth magnetic sensor respectively sense the magnetic properties of the second incremental magnetic area and the first incremental magnetic area, or respectively sense the magnetic properties of the magnetic pole boundaries The range of values and the magnetic properties of each first incremental magnetic zone, or the The magnetic unit, or when the magnetic value ranges of the first incremental magnetic zones and the magnetic value ranges of the magnetic pole boundaries are sensed separately, the processing unit selects the first magnetic induction group and the second magnetic induction group to sense The magnetic combination of the encoded magnetic zone is used as the basis for decoding the absolute position; the reading selection of the first magnetic induction group and the second magnetic induction group under the two absolute position reading modes is based on the actual third magnetic sensor. The relative position to the fourth magnetic sensor and the relative positions of the third magnetic sensor to the first magnetic sensor and the second magnetic sensor are determined. The absolute position sensing read head device according to claim 7, wherein the first magnetic sensors and the second magnetic sensors are digital Hall sensors, and the third magnetic sensor and the The fourth magnetic sensor is an analog Hall sensor. The absolute position sensing read head device according to claim 6, wherein the width of the encoded magnetic field is twice the width of the incremental magnetic field. The absolute position sensing read head device according to claim 6, wherein the reading element further includes a fifth magnetic sensor corresponding to the incremental column magnetic track and electrically connected to the processing unit, the fifth magnetic sensor It is a magnetoresistive sensor, and is used to sense the magnetic movement changes of the first incremental magnetic zone and the second incremental magnetic zone of the incremental column track.