JP7372604B2 - Encoder device, drive device, stage device, and robot device - Google Patents

Description

The present invention relates to an encoder device, a method of using the encoder device, a drive device, a stage device, and a robot device.

As a conventional encoder device, one is known that detects multiple rotations even without a power source by driving a power-free multiple rotation detection circuit with self-power generation means using a Wiegand wire or other magnetic power generation element (for example, , see Patent Document 1).

JP2017-26397A

According to the first aspect, there is a position detection unit that detects position information of the moving unit, a magnet that moves due to the movement of the moving unit, and an electrical signal generation unit that generates an electric signal by a change in magnetic field caused by the movement of the magnet. and a circuit section that outputs an output of the electrical signal generating section that changes depending on a control signal from the position detecting section to the position detecting section.

According to the second aspect, there is provided a position detecting section that is supplied with power from a power source and detects position information of the moving section, a magnet that moves as the moving section moves, and an electric signal generated by a change in a magnetic field caused by the movement of the magnet. and a power supply section that supplies power to the position detection section using the electric signal, and when the power supply from the power supply is cut off, the position detection section An encoder device is provided that detects position information based on an electric signal before power is supplied from its power supply unit.

According to a third aspect, there is provided a drive device including the encoder device according to the first or second aspect and a power supply section that supplies power to a moving section thereof.
According to a fourth aspect, there is provided a stage device that includes a moving object and the drive device of the third aspect that moves the moving object.
According to a fifth aspect, there is provided a robot device including the drive device of the third aspect and an arm that is relatively moved by the drive device.

According to the sixth aspect, there is provided a position detecting section that is supplied with power from a power source and detects position information of the moving section, a magnet that moves as the moving section moves, and an electric signal generated by a change in the magnetic field caused by the movement of the magnet. 1. A method of using an encoder device comprising an electric signal generating section that generates an electrical signal, and a power supply section that supplies power to the position detecting section using the electric signal, the position detecting section receiving power from the power source. A method of use is provided which includes detecting the location information when the power supply is cut off until power is supplied from the power supply by means of the electrical signal.

FIG. 1 is a diagram showing an encoder device according to a first embodiment. (A) is a perspective view showing the magnet, electric signal generation unit, and magnetic sensor in Fig. 1, (B) is a plan view showing the magnet etc. in Fig. 2 (A), and (C) is a perspective view showing the magnet, etc. in Fig. 2 (A). FIG. 2 is a circuit diagram showing a magnetic sensor. (A) is a plan view showing the magnet and electric signal generation unit of FIG. 2(A), (B) and (C) are respectively sectional views of FIG. 3(A), and (D) is a plan view showing a modified example; (E) is a side view of FIG. 3(D). 2 is a diagram showing the configuration of a power supply system and a multi-rotation information detection section of the encoder device of FIG. 1. FIG. FIG. 2 is a diagram showing the operation of the encoder device of FIG. 1 during forward rotation. It is a flowchart which shows an example of operation at the time of high-speed rotation. (A), (B), (C), (D), and (E) are diagrams each showing predetermined signals corresponding to the operation of FIG. 6; FIG. 7 is a diagram showing the configuration of a power supply system and a multi-rotation information detection section of an encoder device according to a second embodiment. 12 is a flowchart illustrating an example of an operation when the power is turned off according to the second embodiment. (A), (B), (C), (D), and (E) are diagrams each showing predetermined signals corresponding to the operation of FIG. 9; It is a figure showing an example of a drive device. It is a figure showing an example of a stage device. FIG. 1 is a diagram showing an example of a robot device.

[First embodiment]
A first embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 shows an encoder device EC according to this embodiment. In FIG. 1, an encoder device EC detects rotational position information of a rotating shaft SF (moving section) of a motor M (power supply section). The rotating shaft SF is, for example, the shaft (rotor) of the motor M, but it is also an operating shaft (output shaft) that is connected to the shaft of the motor M via a power transmission unit such as a transmission and is also connected to a load. You can. The rotational position information detected by the encoder device EC is supplied to the motor control unit MC. The motor control unit MC controls the rotation (eg, rotational position, rotational speed, etc.) of the motor M using the rotational position information supplied from the encoder device EC. The motor control unit MC controls the rotation of the rotating shaft SF.

The encoder device EC includes a position detection system (position detection unit) 1 and a power supply system (power supply unit) 2. The position detection system 1 detects rotational position information of the rotation axis SF. The encoder device EC is a so-called multi-rotation absolute encoder, and detects rotational position information including multi-rotation information indicating the number of rotations of the rotary shaft SF and angular position information indicating an angular position (rotation angle) less than one rotation. . The encoder device EC includes a multi-rotation information detection section 3 that detects multi-rotation information about the rotation axis SF, and an angle detection section 4 that detects the angular position of the rotation axis SF.

At least a part of the position detection system 1 (for example, the angle detection unit 4) is activated when the power (for example, the main power supply) of the device (for example, the drive device, the stage device, the robot device) on which the encoder device EC is mounted is turned on. It operates by receiving power from this device in the normal state. In addition, at least a part of the position detection system 1 (for example, the multi-rotation information detection unit 3) is operated in a state where the power (for example, the main power supply) of the device in which the encoder device EC is mounted is not turned on (in an emergency state, It operates by receiving power from the power supply system 2 in a backup state, etc.). For example, in a state where the power supply from the device in which the encoder device EC is installed is cut off, the power supply system 2 provides intermittent ( The position detection system 1 detects at least part of the rotational position information (for example, multi-rotation information) of the rotating shaft SF when the power is supplied from the power supply system 2 (intermittently).

The multi-rotation information detection unit 3 detects multi-rotation information using, for example, magnetism. The multi-rotation information detection section 3 includes, for example, a magnet 11, a magnetic detection section 12, a detection section 13, and a storage section 14. The magnet 11 is provided on a disc 15 fixed to the rotating shaft SF. Since the disk 15 rotates together with the rotating shaft SF, the magnet 11 rotates in conjunction with the rotating shaft SF. The magnet 11 is fixed outside the rotating shaft SF, and the relative positions of the magnet 11 and the magnetic detection section 12 change with the rotation of the rotating shaft SF. The strength and direction of the magnetic field formed by the magnet 11 on the magnetic detection unit 12 change depending on the rotation of the rotating shaft SF. The magnetic detection unit 12 detects the magnetic field formed by the magnet 11, and the detection unit 13 detects position information of the rotating shaft SF based on the result of the magnetic detection unit 12 detecting the magnetic field formed by the magnet. The storage unit 14 stores position information detected by the detection unit 13.

The angle detection unit 4 is an optical or magnetic encoder, and detects position information (angular position information) within one rotation of the scale. For example, in the case of an optical encoder, the angular position within one rotation of the rotation axis SF is detected by reading scale patterning information with a light receiving element. The scale patterning information is, for example, bright and dark slits on the scale. The angle detection unit 4 detects angular position information of the same rotation axis SF as the detection target of the multi-rotation information detection unit 3. The angle detection section 4 includes a light emitting element 21, a scale S, a light receiving sensor 22, and a detection section 23.

The scale S is provided, for example, on a disc 5 fixed to the rotating shaft SF. The scale S includes an incremental scale and an absolute scale. The scale S may be provided on the disc 15 or may be a member integrated with the disc 15. For example, the scale S may be provided on the surface of the disc 15 opposite to the magnet 11. The scale S may be provided on at least one of the inside and outside of the magnet 11.

The light emitting element 21 (irradiation section, light emitting section) irradiates the scale S with light. The light receiving sensor 22 (light detecting section) detects the light emitted from the light emitting element 21 and passing through the scale S. In FIG. 1, the angle detection section 4 is of a transmission type, and the light receiving sensor 22 detects the light transmitted through the scale S. Note that the angle detection section 4 may be of a reflective type. The light receiving sensor 22 then supplies a signal indicating the detection result to the detection unit 23. The detection unit 23 uses the detection result of the light receiving sensor 22 to detect the angular position of the rotation axis SF. For example, the detection unit 23 detects the angular position at the first resolution using the result of detecting light from the absolute scale. Further, the detection unit 23 detects an angular position with a second resolution higher than the first resolution by performing an interpolation calculation on the angular position with the first resolution using the result of detecting the light from the incremental scale. .

In this embodiment, the encoder device EC includes a signal processing section 25. The signal processing unit 25 calculates and processes the detection results by the position detection system 1. The signal processing section 25 includes a combining section 26 and an external communication section 27. The synthesizing unit 26 acquires the angular position information of the second resolution detected by the detecting unit 23. Furthermore, the synthesis unit 26 acquires multi-rotation information about the rotation axis SF from the storage unit 14 of the multi-rotation information detection unit 3 . The synthesis section 26 synthesizes the angular position information from the detection section 23 and the multi-rotation information from the multi-rotation information detection section 3, and calculates rotational position information. For example, when the detection result of the detection unit 23 is θ (rad) and the detection result of the multi-rotation information detection unit 3 is n rotations, the synthesis unit 26 uses (2π×n+θ) (rad) as the rotational position information. Calculate. The rotational position information may be information that is a set of multi-rotation information and angular position information for less than one rotation.

The synthesis section 26 supplies the rotational position information to the external communication section 27. The external communication section 27 is communicably connected to the communication section MCC of the motor control section MC by wire or wirelessly. The external communication section 27 supplies digital rotational position information to the communication section MCC of the motor control section MC. The motor control unit MC appropriately decodes the rotational position information from the external communication unit 27 of the angle detection unit 4. The motor control unit MC controls the rotation of the motor M by controlling the electric power (driving electric power) supplied to the motor M using the rotational position information.

The power supply system 2 includes first and second electrical signal generation units 31A and 31B, a battery 32, and a switching section 33. The electric signal generation units 31A and 31B each generate an electric signal by rotating the rotation shaft SF. This electrical signal includes, for example, a waveform in which power (current, voltage) changes over time. The electric signal generating units 31A and 31B each generate electric power as an electric signal using, for example, a magnetic field that changes based on the rotation of the rotating shaft SF. For example, the electric signal generation units 31A and 31B generate electric power by changes in the magnetic field formed by the magnet 11, which is used by the multi-rotation information detection section 3 to detect the multi-rotation position of the rotating shaft SF. The electric signal generating units 31A and 31B are arranged so that their angular positions relative to the magnet 11 change with the rotation of the rotating shaft SF. The electrical signal generating units 31A, 31B generate pulsed electrical signals, for example, when the relative positions of the electrical signal generating units 31A, 31B and the magnet 11 reach respective predetermined positions.

The battery 32 supplies at least a portion of the power consumed by the position detection system 1 based on the electrical signals generated by the electrical signal generation units 31A and 31B. The battery 32 includes, for example, a primary battery 36 such as a button type battery or a dry battery, and a rechargeable secondary battery 37 (see FIG. 4). The secondary battery of the battery 32 can be charged, for example, by electric signals (eg, current) generated by the electric signal generating units 31A and 31B. The battery 32 is held in a holding section 35. The holding portion 35 is, for example, a circuit board on which at least a portion of the position detection system 1 is provided. The holding unit 35 holds, for example, the detection unit 13, the switching unit 33, and the storage unit 14. The holding portion 35 is provided with, for example, a plurality of battery cases capable of accommodating the batteries 32, electrodes connected to the batteries 32, wiring, and the like.

The switching unit 33 switches whether or not power is supplied from the battery 32 to the position detection system 1 based on the electrical signals generated by the electrical signal generation units 31A and 31B. For example, the switching unit 33 starts supplying power from the battery 32 to the position detection system 1 when the level of the electric signals generated by the electric signal generation units 31A and 31B becomes equal to or higher than a threshold value. For example, the switching unit 33 starts supplying power from the battery 32 to the position detection system 1 when the electric signal generation units 31A and 31B generate power equal to or higher than the dark value. Further, the switching unit 33 stops supplying power from the battery 32 to the position detection system 1 when the level of the electric signal generated by the electric signal generation units 31A and 31B becomes less than a threshold value. For example, the switching unit 33 stops supplying power from the battery 32 to the position detection system 1 when the power generated by the electric signal generation units 31A and 31B becomes less than a threshold value. For example, when a pulsed electrical signal is generated in the electrical signal generation units 31A and 31B, the switching unit 33 changes the level (power) of this electrical signal from a low level (hereinafter referred to as L level) to a high level (hereinafter referred to as L level). ), the battery 32 starts supplying power to the position detection system 1, and after a predetermined period of time has passed since the level (power) of this electrical signal changes to the L level, the battery 32 starts supplying power to the position detection system 1. The power supply to the position detection system 1 is stopped. Furthermore, the encoder device EC is configured to use electrical signals (pulse signals) generated by the electrical signal generation units 31A and 31B as a switching signal (trigger signal) in supplying power from the battery 32 to the position detection system 1.

2(A) is a perspective view showing the magnet 11, electric signal generating units 31A, 31B, and two magnetic sensors 51, 52 which are the magnetic detection parts 12 in FIG. 1, and FIG. 2(B) is a perspective view showing the magnet 11 in FIG. A) is a plan view of the magnet 11 etc. viewed from a direction parallel to the rotation axis SF, and FIG. 2C is a circuit diagram of the magnetic sensor 51. Note that in FIG. 2(A) and the like, the rotation axis SF in FIG. 1 is represented by a straight line.
In FIGS. 2(A) and 2(B), due to rotation, the magnet 11 directs a magnetic field in the axial direction (also referred to as the axial direction), which is a direction parallel to a straight line (axis of symmetry) passing through the center of the rotation axis SF. and is configured to vary in strength. The magnet 11 is, for example, an annular member coaxial with the rotating shaft SF. As an example, the magnet 11 has a first circle consisting of fan-shaped north poles 16A, south poles 16B, north poles 16C, and south poles 16D each having an opening angle of 90° and arranged in order so as to surround the rotation axis SF. Consists of an annular magnet, and S poles 17A, N poles 17B, S poles 17C, and N poles 17D, which have the same shape as the N poles 16A to S poles 16D and are bonded to one surface of the N poles 16A to S poles 16D, respectively. and a second annular magnet. The magnet 11 is a permanent magnet that is magnetized to have four pairs of polarities along the circumferential direction (also referred to as the circumferential direction or the rotational direction) around the rotating shaft SF to generate magnetic force. The main surfaces of the magnet 11, the front surface (the surface opposite to the motor M in FIG. 1) and the back surface (the surface on the same side as the motor M), are each substantially perpendicular to the rotation axis SF. In other words, in the magnet 11, the angle between the N poles 16A to S poles 16D on the front side and the S poles 17A to N poles 17D on the back side (for example, the positions of the N and S poles of each other) is 90° ( The boundary between the N and S poles of N pole 16A to S pole 16D and the boundary of S pole and N pole of S pole 17A to N pole 17D are shifted by 180° in phase. (angular position) are almost the same. Note that the first annular magnet and the second annular magnet are one magnet that is continuously integrated in the moving direction (here, circumferential direction, rotational direction) or axial direction and has multiple polarities. However, it may be a hollow magnet with a space inside the magnet.

Here, for convenience of explanation, counterclockwise rotation is referred to as forward rotation, and clockwise rotation is referred to as reverse rotation when viewed from the tip side of the rotating shaft SF (the side opposite to the motor M in FIG. 1). Further, the angle of forward rotation is expressed as a positive value, and the angle of reverse rotation is expressed as a negative value. Note that, when viewed from the rear end side of the rotating shaft SF (motor M side in FIG. 1), counterclockwise rotation may be defined as forward rotation, and clockwise rotation may be defined as reverse rotation.

Here, in the coordinate system fixed to the magnet 11, the angular position of the boundary between the S pole 16D and the N pole 16A in the circumferential direction is represented by a position 11a, and the angular positions sequentially rotated by 90 degrees from the position 11a (the N pole and the S pole ) are represented by positions 11b, 11c, and 11d, respectively.
In a first section extending 90° counterclockwise from the position 11a, an N pole is arranged on the front side of the magnet 11, and an S pole is arranged on the back side of the magnet 11. In this first section, the axial direction of the magnetic field of the magnet 11 is approximately parallel to the axial direction AD1 (see FIG. 3(C)) from the front side to the back side of the magnet 11. In the first section, the strength of the magnetic field is maximum between positions 11a and 11b, and minimum near positions 11a and 11b.

In the second section 90° counterclockwise from the position 11b (the section where the S pole is arranged on the front side of the magnet 11 and the N pole is arranged on the back side of the magnet 11), the axial direction of the magnetic field of the magnet 11 is determined. is approximately opposite to the direction from the back side to the front side of the magnet 11 (for example, the axial direction AD1 (direction in FIG. 3(C)). In the second section, the strength of the magnetic field is and the position 11c, and the minimum in the vicinity of positions 11b and 11c.Similarly, the third section of 90° counterclockwise from the position 11c, and the third section of 90° counterclockwise from the position 11d. In the four sections, the axial direction of the magnetic field of the magnet 11 is approximately from the front side to the back side of the magnet 11, and from the back side to the front side.

In this way, the axial direction of the magnetic field formed by the magnet 11 is sequentially reversed at positions 11a to 11d. The magnet 11 forms an alternating current magnetic field in which the direction of the axial magnetic field is reversed as the magnet 11 rotates with respect to a coordinate system fixed outside the magnet 11. The electric signal generating units 31A and 31B are arranged on the outer surface of the magnet 11 in a direction intersecting the normal direction of the main surface of the magnet 11.

In this embodiment, the electric signal generation units 31A and 31B are spaced apart from each other in a radial direction (also referred to as a radial direction) of the magnet 11 perpendicular to the rotation axis SF or in a direction parallel to the radial direction. Provided for contact. The first electrical signal generating unit 31A includes a first magnetically sensitive section 41A, a first power generating section 42A, a first set of first magnetic bodies 45A, and a first set of second magnetic bodies 46A. Note that one of the first magnetic body 45A and the second magnetic body 46A can be omitted. The first magnetically sensitive part 41A, the first power generation part 42A, the first magnetic body 45A, and the second magnetic body 46A are fixed to the outside of the magnet 11, and are moved to different positions on the magnet 11 as the magnet 11 rotates. The relative position with the For example, in FIG. 2B, a position 11b of the magnet 11 is placed at a position 45° counterclockwise from the first electrical signal generation unit 31A, and from this state the magnet 11 is moved forward (counterclockwise). ), positions 11a, 11d, 11c, and 11b pass in this order near the electrical signal generating unit 31A.

The first magnetically sensitive portion 41A is a magnetically sensitive wire such as a Wiegand wire. A large Barkhausen jump (Wiegand effect) occurs in the first magnetically sensitive portion 41A due to changes in the magnetic field accompanying the rotation of the magnet 11. The first magnetically sensitive portion 41A is a cylindrical member with a rectangular projected image, and its axial direction is set in the circumferential direction of the magnet 11. Hereinafter, the axial direction of the first magnetically sensitive part 41A, that is, the direction perpendicular to the circular (or polygonal, etc.) cross section of the first magnetically sensitive part 41A is also referred to as the length direction of the first magnetically sensitive part 41A. Further, for example, the length of the magnetically sensitive portion in the direction (axial direction, length direction, longitudinal direction) perpendicular to the cross section of the magnetically sensitive portion (for example, the first magnetically sensitive portion 41A) is parallel to the cross section of the magnetically sensitive portion. The length of the magnetically sensitive portion is longer than the length of the magnetically sensitive portion in the direction (lateral direction). An alternating magnetic field is applied to the first magnetically sensitive portion 41A in its axial direction (lengthwise direction), and when the alternating magnetic field is reversed, a domain wall is generated from one end in the axial direction to the other end. As described above, the length direction (axial direction) of the magnetically sensitive portion (for example, the first magnetically sensitive portion 41A, etc.) in this embodiment is also referred to as the easy magnetization direction, which is the direction in which magnetization is easily directed.

The first and second magnetic bodies 45A, 46A are made of a ferromagnetic material such as iron, cobalt, nickel, or the like. The first and second magnetic bodies 45A and 46A can also be called yokes. The first magnetic body 45A is provided between the front surface of the magnet 11 and one end of the first magnetically sensitive section 41A, and the second magnetic body 46A is provided between the back surface of the magnet 11 and the other end of the first magnetically sensitive section 41A. is provided in between. The tips of the first and second magnetic bodies 45A, 46A are arranged at the same angular position in the circumferential direction on the front and back surfaces of the magnet 11. The polarities of the magnets 11 at the tips of the first and second magnetic bodies 45A, 46A are always opposite to each other, and when the tip of the first magnetic body 45A is near the north pole 16A (or south pole 16B), The tip of the second magnetic body 46A is located near the S pole 17A (or N pole 17B). Therefore, the first and second magnetic bodies 45A, 46A direct magnetic lines of force from two portions of mutually different polarities (for example, the N pole 16A and the S pole 17A) of the magnet 11 located at the same position in the circumferential direction of the magnet 11. 1 is guided in the length direction of the magnetically sensitive portion 41A. The magnet 11, the first magnetic body 45A, the first magnetically sensitive part 41A, and the second magnetic body 46A form a magnetic circuit MC1 (see FIG. ) is formed. Note that a step (not shown) is provided at the peripheral edge of the disk 15 in FIG. is ensured.

The first power generation section 42A is a high-density coil arranged around the first magnetically sensitive section 41A. In the first power generation section 42A, electromagnetic induction occurs due to the generation of domain walls in the first magnetically sensitive section 41A, and an induced current flows. When the positions 11a to 11d of the magnet 11 shown in FIG. electrical signal, power) is generated.

The direction of the current generated in the first power generation section 42A changes depending on the direction before and after the magnetic field is reversed. For example, the direction of the current generated when the magnetic field is reversed from the magnetic field facing the front side of the magnet 11 to the magnetic field facing the back side is the direction of the current generated when the magnetic field is reversed from the magnetic field facing the back side of the magnet 11 to the magnetic field facing the front side. It becomes the opposite. The electric power (induced current) generated in the first power generation section 42A can be set, for example, by the number of turns of the high-density coil.

As shown in FIG. 2(A), the first magnetically sensitive section 41A, the first power generating section 42A, and the portions of the first and second magnetic bodies 45A and 46A on the first magnetically sensitive section 41A side are housed in a case 43A. has been done. Case 43A is provided with terminals 42Aa and 42Ab. The high-density coil of the first power generation section 42A has one end and the other end electrically connected to the terminals 42Aa and 42Ab, respectively. The electric power generated by the first power generation section 42A can be taken out to the outside of the first electric signal generation unit 31A via the terminals 42Aa and 42Ab.

The second electrical signal generation unit 31B is arranged at an angular position that is greater than 0° and smaller than 180° from the angular position where the first electrical signal generation unit 31A is arranged. The angle between the electrical signal generation units 31A and 31B is selected from a range of, for example, 22.5° or more and 67.5° or less, and is approximately 45° in FIG. 2(B). The second electrical signal generation unit 31B has the same configuration as the first electrical signal generation unit 31A. The second electric signal generation unit 31B includes a second magnetically sensitive section 41B, a second power generation section 42B, a second set of first magnetic bodies 45B, and a second set of second magnetic bodies 46B. The second magnetically sensitive part 41B, the second power generating part 42B, and the first and second magnetic bodies 45B and 46B of the second set are the first magnetically sensitive part 41A, the first power generating part 42A, and the first magnetic body of the first set, respectively. 1. It is the same as the second magnetic bodies 45A and 46A, and the explanation thereof will be omitted. The second magnetically sensitive section 41B, the second power generating section 42B, and the portions of the first and second magnetic bodies 45B and 46B on the second magnetically sensitive section 41B side are housed in a case 43B. Case 43B is provided with terminals 42Ba and 42Bb. The electric power generated by the second power generation section 42B can be taken out to the outside of the second electric signal generation unit 31B via the terminals 42Ba and 42Bb. Note that at least a portion of the magnetically sensitive portions (for example, the first magnetically sensitive portion 41A and the second magnetically sensitive portion 41B) are spaced apart from each other on the outside of the magnet 11 in the radial direction of the magnet 11 or in the parallel direction thereof. For example, when the magnet 11 has one surface and the other surface perpendicular to the rotation axis SF (that is, the surface on which a plurality of polarities of the magnet are arranged), They are orthogonal to each other and are spaced apart from the side surface of the magnet 11 along the moving direction of the magnet (or the side surface parallel to the axial direction of the rotating shaft SF).

The magnetic detection unit 12 includes magnetic sensors 51 and 52. The magnetic sensor 51 is arranged at an angular position greater than 0° and less than 180° with respect to the second magnetically sensitive portion 41B (second electric signal generation unit 31B) in the rotation direction of the rotation axis SF. The magnetic sensor 52 is arranged at an angular position greater than 22.5 degrees and less than 67.5 degrees (approximately 45 degrees in FIG. 2B) with respect to the magnetic sensor 51 in the rotational direction of the rotation axis SF.

As shown in FIG. 2C, the magnetic sensor 51 includes a magnetoresistive element 56, a bias magnet (not shown) that applies a magnetic field of a constant strength to the magnetoresistive element 56, and a waveform from the magnetoresistive element 56. and a waveform shaping circuit (not shown) that shapes the waveform. The magnetoresistive element 56 has a full bridge shape in which elements 56a, 56b, 56c, and 56d are connected in series. A signal line between elements 56a and 56c is connected to a power terminal 51p, and a signal line between elements 56b and 56d is connected to a ground terminal 51g. The signal line between the elements 56a and 56b is connected to the first output terminal 51a, and the signal line between the elements 56c and 56d is connected to the second output terminal 51b. The magnetic sensor 52 has the same configuration as the magnetic sensor 51, and its description will be omitted.

Next, the operation of the first electrical signal generation unit 31A of this embodiment will be explained. In the following, the first magnetically sensitive section 41A and the first power generating section 42A of the first electric signal generating unit 31A in FIG. 2(B) will be integrally described as the magnetically sensitive member 47. The length direction of the magnetically sensitive member 47 is the same as the lengthwise direction of the first magnetically sensitive part 41A, and the center of the magnetically sensitive member 47 in the lengthwise direction is the same as the center of the first magnetically sensitive part 41A. be. Note that the operation of the second electrical signal generation unit 31B is similar to that of the first electrical signal generation unit 31A, so the explanation thereof will be omitted.

3(A) is a plan view showing the magnet 11 and the electric signal generating unit 31A in FIG. 2(A), and FIGS. 3(B) and (C) are cross-sectional views of the magnet 11 in FIG. 3(A). be. In FIGS. 3A and 3B, the magnet 11 has a flat plate shape along the rotation direction around the rotation axis SF (hereinafter also referred to as the θ direction), and has a plurality of different polarities in the θ direction (N pole 16A to It has two different polarities (N pole 16A and S pole 17A) in the thickness direction (which is also the axial direction AD1 (axial direction) of the rotating shaft SF in this embodiment) perpendicular to the θ direction. etc.). Therefore, the axial direction AD1 can also be referred to as the orientation direction (magnetization direction) of the portions of the magnet 11 with mutually different polarities (N pole 16A, S pole 17A, etc.). As the magnet 11 rotates in the θ direction, the direction and strength of the magnetic field in the axial direction or orientation direction AD1 change.

Moreover, the magnetically sensitive member 47 (or magnetically sensitive part) is arranged near the outer surface of the magnet 11 so that its length direction is parallel to the front surface (one surface or the back surface) of the flat magnet 11. There is. In FIG. 3A, when the length direction of the magnetically sensitive member 47 is defined as a direction LD1, the length direction LD1 is parallel to the surface of the magnet 11. In the present embodiment, the length direction LD1 of the magnetically sensitive member 47 is approximately parallel to the θ direction (circumferential direction) and in the magnetization direction of the magnet 11 (for example, a specific direction in which the direction of the magnetic pole is fixed). It is substantially orthogonal to a certain axial direction (axial direction) AD1. Furthermore, as shown in FIG. 3(C), among the lines of magnetic force of the magnet 11, approximately the center in the longitudinal direction of the magnetically sensitive member 47 (for example, the longitudinal length of the magnetically sensitive member 47 or the magnetically sensitive parts 41A, 41B) The length direction of the magnetically sensitive member 47 is arranged so as to be substantially perpendicular to the tangential direction (in this case, the direction parallel to the axial direction AD1) of the line of magnetic force MF1 passing through the magnetic field MF1. Note that the length direction LD1 of the magnetically sensitive member 47 is arranged to be substantially orthogonal to the thickness direction that is orthogonal to the θ direction. In addition, the first and second magnetic bodies 45A and 46A transmit lines of magnetic force from two portions of mutually different polarities (for example, the N pole 16A and the S pole 17A) of the magnet 11 located at the same angular position in the θ direction to the magnetically sensitive member 47. It is guided in the length direction LD1 of the magnetically sensitive member 47 via one end 47a and the other end 47b.

Magnetic field components unnecessary for pulse generation in the electric signal generation unit 31A, including lines of magnetic force generated on the side surface of the magnet 11, are perpendicular to the length direction of the magnetically sensitive member 47, and the unnecessary magnetic field components are generated by the rotation of the magnet 11. This does not adversely affect the generation of a domain wall from one end of the magnetically sensitive member 47 to the other end due to a large Barkhausen jump (Wiegand effect) in the length direction of the magnetically sensitive member 47 caused by the reversal of the alternating current magnetic field. Therefore, even if the magnetically sensitive member 47 is arranged near the magnet 11 and the electric signal generating unit 31A is miniaturized, the axial alternating magnetic field generated by the rotation of the magnet 11 can be generated without being affected by unnecessary magnetic field components. By reversing , it is possible to efficiently generate stable, high-output pulses using the electrical signal generating unit 31A.

FIG. 4 shows the circuit configuration of the power supply system 2 and multi-rotation information detection section 3 of the encoder device EC according to this embodiment. In FIG. 4, the power supply system 2 includes a first electrical signal generation unit 31A, a rectification stack 61, a second electrical signal generation unit 31B, a rectification stack 62, and a battery 32. Further, the power supply system 2 includes a regulator (smoothing section) 63 as the switching section 33 shown in FIG.

The rectifier stack 61 is a rectifier that rectifies the current flowing from the first electrical signal generating unit 31A. The first input terminal 61a of the rectifier stack 61 is connected to the terminal 42Aa of the first electrical signal generation unit 31A. The second input terminal 61b of the rectifier stack 61 is connected to the terminal 42Ab of the first electrical signal generation unit 31A. A ground terminal 61g of the rectifier stack 61 is connected to a ground line GL to which the same potential as the signal ground SG is supplied. When the multi-rotation information detection section 3 operates, the potential of the ground line GL becomes the reference potential of the circuit. The output terminal 61c of the rectifier stack 61 is connected to the input part of the buffer circuit 74, and the output part of the buffer circuit 74 is connected to the control terminal 63a of the regulator 63 and the first input part of the AND circuit 72.

The rectifier stack 62 is a rectifier that rectifies the current flowing from the second electrical signal generation unit 31B. The first input terminal 62a of the rectifier stack 62 is connected to the terminal 42Ba of the second electrical signal generation unit 31B. The second input terminal 62b of the rectifier stack 62 is connected to the terminal 42Bb of the second electrical signal generation unit 31B. A ground terminal 62g of the rectifier stack 62 is connected to the ground line GL. An output terminal 62c of the rectifier stack 62 is connected to an input of a buffer circuit 74. The output signal (hereinafter referred to as an enable signal) 7B of the buffer circuit 74 is a signal that becomes L level when the signal at the input section is below a predetermined threshold value, and becomes H level when the signal becomes larger than the threshold value. A capacitor 69A is connected between the output terminals 61c, 62c of the rectifier stacks 61, 62 and the ground line GL for temporarily accumulating pulse signals (pulse current) generated at the output terminals 61c, 62c. Hereinafter, the pulse signals generated at the output terminals 61c and 62c will be referred to as WW output 7A (meaning Wiegand wire output). Furthermore, a switching element 70 for discharging is connected between the output terminals 61c, 62c and the ground line GL, and a discharging signal 7D is supplied from the counter 67 to the control terminal of the switching element 70. When the switching element 70 is, for example, a MOS FET, the output terminals 61c and 62c are connected to the drain electrode D, the source electrode S is connected to the ground line GL, and the control terminal becomes the gate electrode G. When the discharge signal 7D becomes high level, the switching element 70 becomes conductive, and the WW output 7A (potential of the capacitor 69A) generated at the output terminals 61c and 62c rapidly decreases to the reference potential. In the following, making the switching element 70 conductive and setting the WW output 7A to the reference potential is also referred to as discharging the electrical signal generation units 31A and 31B or discharging the WW output 7A.

The regulator 63 adjusts (smoothes) the power supplied from the battery 32 to the position detection system 1 . The regulator 63 may include a switch 64 provided in the power supply path between the battery 32 and the position detection system 1. The regulator 63 controls the operation of the switch 64 based on the electrical signals generated by the electrical signal generating units 31A and 31B.
An input terminal 63b of the regulator 63 is connected to the battery 32 via a power switch 38. The output terminal 63c of the regulator 63 is connected to the power supply line PL and the second input section of the AND circuit 72. A ground terminal 63g of the regulator 63 is connected to the ground line GL. An input side capacitor 69B (second capacitor) is connected between the input terminal 63b of the regulator 63 and the ground line GL, and an output side capacitor 69C (first capacitor) is connected between the output terminal 63c and the ground line GL. It is connected. The control terminal 63a of the regulator 63 is an enable terminal, and the regulator 63 changes the potential of the output terminal 63c (power line PL potential) is maintained at a predetermined voltage. The output voltage (the above-mentioned predetermined voltage) of the regulator 63 is, for example, 3V when the counter 67 is composed of CMOS or the like. The operating voltage of the nonvolatile memory 68 of the storage unit 14 is set to, for example, the same voltage as the predetermined voltage. Note that the predetermined voltage is a voltage necessary for power supply, and may be not only a constant voltage value but also a voltage that changes in steps.

The switch 64 has a first terminal 64a connected to an input terminal 63b, and a second terminal 64b connected to an output terminal 63c. The regulator 63 uses an enable signal 7B supplied to the control terminal 63a from the buffer circuit 74 (electrical signal generation units 31A, 31B) as a control signal to control the voltage between the first terminal 64a and the second terminal 64b of the switch 64. Switch between conductive state and insulated state. For example, the switch 64 includes a switching element such as a MOS, TFT, or FET, the first terminal 64a and the second terminal 64b are a source electrode and a drain electrode, and a gate electrode is connected to the control terminal 63a. In the switch 64, when the gate electrode is charged by the electric signal (power) generated by the electric signal generation units 31A and 31B and the potential of the gate electrode exceeds a threshold value, the source electrode and the drain electrode become conductive ( on). Note that the switch 64 may be provided outside the regulator 63, and may be an external device such as a relay.

Furthermore, the AND circuit 72 outputs a signal 7E (second signal) that becomes H level when the enable signal 7B is H level and the output signal of the regulator 63 is higher than a predetermined threshold (H level) to the delay circuit 73. do. The delay circuit 73 supplies a reset signal 7R generated using the signal 7E to the counter 67 and the nonvolatile memory 68. The reset signal 7R is a signal that goes to the H level after a predetermined delay time after the input signal 7E goes to the H level, and then goes to the L level when the signal 7E goes to the L level. The reset signal 7R can also be regarded as a second signal equivalent to the signal 7E. The counter 67 and the nonvolatile memory 68 stop their counting operation while the reset signal 7R is at L level. Hereinafter, stopping the counting operation of the counter 67 and the nonvolatile memory 68 will also be referred to as initializing or resetting the counter 67 and the nonvolatile memory 68. A signal relay circuit 75 is composed of a buffer circuit 74, an AND circuit 72, and a delay circuit 73.

The multi-rotation information detection unit 3 includes magnetic sensors 51 and 52 and analog comparators 65 and 66 as the magnetic detection unit 12. The magnetic detection unit 12 detects the magnetic field formed by the magnet 11 using electric power supplied from the battery 32. Further, the multi-rotation information detection section 3 includes a counter 67 as the detection section 13 shown in FIG. 1, and a nonvolatile memory 68 as the storage section 14.
A power terminal 51p of the magnetic sensor 51 is connected to a power line PL. A ground terminal 51g of the magnetic sensor 51 is connected to a ground line GL. The output terminal 51c of the magnetic sensor 51 is connected to the input terminal 65a of the analog comparator 65. In this embodiment, the output terminal 51c of the magnetic sensor 51 outputs a voltage corresponding to the difference between the potential of the second output terminal 51b and the reference potential shown in FIG. 2(C). The analog comparator 65 is a comparator that compares the voltage output from the magnetic sensor 51 with a predetermined voltage. A power terminal 65p of the analog comparator 65 is connected to a power line PL. A ground terminal 65g of the analog comparator 65 is connected to the ground line GL. An output terminal 65b of the analog comparator 65 is connected to a first input terminal 67a of the counter 67. The analog comparator 65 outputs from the output terminal 65b a signal that becomes H level when the output voltage of the magnetic sensor 51 is equal to or higher than the threshold value, and becomes L level when the output voltage is less than the threshold value. Note that the analog comparator 65 is configured to have two input terminals, and the output terminals 51a and 51b of the magnetic sensor 51 in FIG. 2(C) are connected to the two input terminals. 51b may be compared.

The magnetic sensor 52 and the analog comparator 66 have the same configuration as the magnetic sensor 51 and the analog comparator 65. A power terminal 52p and a ground terminal 52g of the magnetic sensor 52 are connected to a power line PL and a ground line GL, respectively. An output terminal 52c of the magnetic sensor 52 is connected to an input terminal 66a of an analog comparator 66. A power terminal 66p and a ground terminal 66g of the analog comparator 66 are connected to a power line PL and a ground line GL, respectively. An output terminal 66b of the analog comparator 66 is connected to a second input terminal 67b of the counter 67. The analog comparator 66 outputs from the output terminal 66b a signal that becomes H level when the output voltage of the magnetic sensor 52 is equal to or higher than the threshold value, and becomes L level when the output voltage is less than the threshold value.

The counter 67 counts the multiple rotation information of the rotating shaft SF using the power supplied from the battery 32. Counter 67 includes, for example, a CMOS logic circuit. The counter 67 operates using power supplied through a power terminal 67p connected to the power line PL and a ground terminal 67g connected to the ground line GL. The counter 67 performs a counting process using the voltage supplied via the first input terminal 67a and the voltage supplied via the second input terminal 67b as detection signals. Furthermore, after the counting process and the writing process to the nonvolatile memory 68 are completed, the counter 67 sets the discharge signal 7D to H level to turn on the switching element 70 and discharge the charge accumulated in the capacitor 69A. By doing so, the electric signal generating units 31A and 31B are discharged (the level of the WW output 7A is lowered). As a result, the enable signal 7B becomes L level, and the regulator 63 is turned off. Note that, hereinafter, discharging the electrical signal generation units 31A and 31B is also referred to as resetting the WW output 7A.

The nonvolatile memory 68 stores (performs a write operation) at least a portion of the rotational position information (for example, multi-rotation information) detected by the detection unit 13 using the power supplied from the battery 32 . The nonvolatile memory 68 stores the result of counting by the counter 67 (multi-rotation information) as the rotational position information detected by the detection unit 13. A power terminal 68p and a ground terminal 68g of the nonvolatile memory 68 are connected to a power line PL and a ground line GL, respectively. The counter 67 and the nonvolatile memory 68 stop the counting operation and the writing operation to the storage section during the period when the reset signal 7R output from the delay circuit 73 is at L level. Further, the counter 67 and the non-volatile memory 68 perform a counting operation and write to or read from the storage unit while the voltage of the power line PL is above a predetermined threshold and the reset signal 7R is at H level. conduct. The delay time of the reset signal 7R (the time from the rise of the output signal 7E of the AND circuit 72 until the rise of the reset signal 7R) is the time when the voltage of the power supply line PL exceeds the predetermined threshold and the magnetic detection unit 12 and the counter The time is set to slightly exceed the time required for the device 67 to operate correctly. The storage unit 14 in FIG. 1 includes a nonvolatile memory 68, and is capable of retaining information written while power is being supplied even when power is not being supplied.

In this embodiment, a capacitor 69A is provided between the rectifier stacks 61, 62 and the ground line GL. The capacitor 69A is a so-called smoothing capacitor and reduces ripples in the input signal to the buffer circuit 74. Further, an input capacitor 69B is connected between the input terminal 63b of the regulator 63 and the ground line GL, and an output capacitor 69C is connected between the output terminal 63c of the regulator 63 and the ground line GL. The input capacitor 69B and the output capacitor 69C are smoothing capacitors for stabilizing the operation of the regulator 63 (improving load response, improving ripple, preventing oscillation, etc.). The constants of the capacitors 69B and 69C are determined, for example, by the constants from the battery 32 to the magnetic detection unit 12 and the nonvolatile memory 68 during the period from when the magnetic detection unit 12 detects rotational position information to when the rotational position information is written to the nonvolatile memory 68. The power supply may be maintained. Note that the input capacitor 69B can be omitted. Further, the charge in the output capacitor 69C is gradually discharged by a small leakage current.

When the output capacitor 69C is empty, it is necessary to charge the output capacitor 69C when the regulator 63 is turned on during intermittent operation by the electric signal generating units 31A and 31B, and therefore the voltage of the battery 32 is momentarily reduced. descend to After the output capacitor 69C is charged, the voltage of the battery 32 is restored and the regulator 63 operates stably. Regarding this, for example, after the counting operation in the counter 67 is completed, it is also possible to adopt a configuration in which the output of the output capacitor 69C is discharged to set the reset signal 7R to a low level. However, in this configuration, when the rotating shaft SF rotates at high speed and the interval at which the regulator 63 is turned on becomes short, the next WW output 7A rises and the regulator 63 is turned on before the voltage of the battery 32 is sufficiently restored. is turned on, the voltage of the battery 32 gradually drops, and the voltage of the power line PL becomes always lower than the threshold value, which may prevent the magnetic detection unit 12 and the like from operating accurately. Further, the time it takes for the voltage of the battery 32 to recover becomes more significant when the internal resistance of the battery 32 increases. On the other hand, in this embodiment, after the counting operation in the counter 67 is completed, the switching element 70 discharges the WW output 7A of the electrical signal generation units 31A, 31B, so that the rotating shaft SF rotates at high speed. Even if the power supply line PL is turned off, the voltage of the power supply line PL will surely reach the H level (details will be described later).

Further, the battery 32 includes a primary battery 36 such as a button type battery, and a rechargeable secondary battery 37, for example. The secondary battery 37 is electrically connected to the power supply section MCE of the motor control section MC. The power supply unit MCE can drive the motor M in FIG. 1 with electric power obtained from, for example, an AC power source (not shown), and can also supply DC voltage obtained from the electric power to the secondary battery 37 of the battery 32. During at least part of the period during which the power supply unit MCE of the motor control unit MC can supply power (for example, the period when the main power supply is in an on state), power is supplied from the power supply unit MCE to the secondary battery 37, and this power supplies the secondary battery 37. Next battery 37 is charged. During a period in which the power supply unit MCE of the motor control unit MC cannot supply power (for example, a period in which the main power supply is off), the supply of power from the power supply unit MCE to the secondary battery 37 is cut off.

Further, the secondary battery 37 may be electrically connected to a transmission path for electrical signals from the electrical signal generation units 31A and 31B. In this case, the secondary battery 37 can be charged by the electric power of the electric signals from the electric signal generation units 31A and 31B. For example, the secondary battery 37 is electrically connected to a circuit between the rectifier stack 61 and the regulator 63. The secondary battery 37 can be charged by the power of the electric signal generated by the electric signal generation units 31A and 31B by the rotation of the rotation shaft SF when the power supply from the power supply unit MCE is cut off. . Note that the secondary battery 37 may be charged by electric power generated by a generator (not shown) when the rotating shaft SF is rotated by being driven by the motor M.

The encoder device EC according to the present embodiment selects which of the primary battery 36 and the secondary battery 37 will supply power to the position detection system 1 in a state where the supply of power from the outside is cut off. The power supply system 2 includes a power supply switch (power supply selection section, selection section) 38, and the power supply switch 38 supplies power to the position detection system 1 from either the primary battery 36 or the secondary battery 37. Switch (select) A first input terminal of the power switch 38 is electrically connected to the positive electrode of the primary battery 36 , and a second input terminal of the power switch 38 is electrically connected to the secondary battery 37 . The output terminal of the power supply switch 38 is electrically connected to the input terminal 63b of the regulator 63.

The power supply switch 38 selects the primary battery 36 or the secondary battery 37 as the battery that supplies power to the position detection system 1, based on the remaining amount of the secondary battery 37, for example. For example, when the remaining capacity of the secondary battery 37 is equal to or higher than the threshold value, the power supply switch 38 causes the secondary battery 37 to supply power, and does not cause the primary battery 36 to supply power. This threshold value is set based on the power consumed by the position detection system 1, and is set, for example, to be greater than or equal to the power that should be supplied to the position detection system 1. For example, if the power consumed by the position detection system 1 can be covered by the power from the secondary battery 37, the power switch 38 causes the secondary battery 37 to supply power, and the primary battery 36 to supply power. I won't let you. Further, when the remaining amount of the secondary battery 37 is less than the threshold value, the power switch 38 does not cause the secondary battery 37 to supply power, but causes the primary battery 36 to supply power. For example, the power supply switch 38 may also serve as a charger that controls charging of the secondary battery 37, and uses information about the remaining amount of the secondary battery 37 used for charging control to control the charging of the secondary battery 37. It may be determined whether the remaining amount is equal to or greater than a threshold value.

By using the secondary battery 37 in this way, the consumption of the primary battery 36 can be delayed. Therefore, in the encoder device EC, there is no maintenance (eg, replacement) of the battery 32, or the frequency of maintenance is low.
Note that the battery 32 may include at least one of a primary battery 36 and a secondary battery 37. Further, in the above embodiment, power is supplied alternatively from the primary battery 36 or the secondary battery 37, but power may be supplied from the primary battery 36 and the secondary battery 37 in parallel. For example, depending on the power consumption of each processing section (for example, magnetic sensor 51, counter 67, nonvolatile memory 68) of the position detection system 1, the primary battery 36 supplies power to the processing section, and the secondary battery 37 supplies power. A processing unit that supplies the information may be defined. Note that the secondary battery 37 may be charged using at least one of the power supplied from the power supply unit MEC and the power of the electric signal generated by the electric signal generation units 31A and 31B.

Next, the normal basic operations of the power supply system 2 and the multi-rotation information detection section 3 will be explained. FIG. 5 is a timing chart showing the operation of the multi-rotation information detection unit 3 when the rotating shaft SF rotates counterclockwise (forward rotation). The timing chart showing the operation of the multi-rotation information detection unit 3 when the rotation axis SF rotates counterclockwise (reverse rotation) is the chart in FIG. 4 reversed in time, so its explanation is omitted. do.

In "magnetic field" in FIG. 5, the solid line indicates the magnetic field at the position of the first electric signal generation unit 31A, and the broken line indicates the magnetic field at the position of the second electric signal generation unit 31B. "First electrical signal generation unit" and "second electrical signal generation unit" respectively indicate the output of the first electrical signal generation unit 31A and the output of the second electrical signal generation unit 31B, and output of a current flowing in one direction. is defined as positive (+), and the output of the current flowing in the opposite direction is defined as negative (-). The "enable signal" indicates the enable signal 7B (potential) applied to the control terminal 63a of the regulator 63 by the electrical signals generated by the electrical signal generation units 31A and 31B, and the H level is expressed as "H" and the L level is expressed as "H". Represented by "L". "Regulator output" indicates the output of the regulator 63 (potential of power supply line PL), H level is expressed as "H", and L level is expressed as "L".

“Magnetic field on the first magnetic sensor” and “magnetic field on the second magnetic sensor” in FIG. 5 are magnetic fields formed on the magnetic sensors 51 and 52. The magnetic field formed by the magnet 11 is shown by a long broken line, the magnetic field formed by the bias magnet is shown by a short broken line, and their combined magnetic field is shown by a solid line. "First magnetic sensor" and "second magnetic sensor" respectively indicate the output when the magnetic sensors 51 and 52 are constantly driven, and the output from the first output terminal is indicated by a broken line, and the output from the second output terminal is indicated by a broken line. The output is shown as a solid line. "First analog comparator" and "second analog comparator" indicate outputs from analog comparators 65 and 66, respectively. The output when the magnetic sensor and analog comparator are driven all the time is shown in "Constant Drive", and the output when the magnetic sensor and analog comparator are driven intermittently is shown in "Intermittent Drive".

When the rotation axis SF rotates counterclockwise, the first electrical signal generation unit 31A outputs current pulses (+ of "first electrical signal generation unit") flowing in the forward direction at angular positions of 45° and 225°. do. Further, the first electrical signal generating unit 31A outputs current pulses (- in "first electrical signal generating unit") flowing in opposite directions at angular positions of 135° and 315°. The second electrical signal generating unit 31B outputs current pulses (- in "second electrical signal generating unit") flowing in opposite directions at angular positions of 90° and 270°. Further, the second electrical signal generating unit 31B outputs current pulses (- in "second electrical signal generating unit") flowing in the forward direction at angular positions of 180° and 0° (360°). Therefore, the enable signal switches to H level at each of the angular positions 45°, 90°, 135°, 180°, 225°, 270°, 315°, and 0°. In addition, the regulator 63 operates at angular positions of 45°, 90°, 135°, 180°, 225°, 270°, 315°, and 0°, respectively, corresponding to the state in which the enable signal is maintained at the H level. , supplies a predetermined voltage to the power line PL.

In this embodiment, the output of the magnetic sensor 51 and the output of the magnetic sensor 52 have a phase difference of 90 degrees, and the detection unit 13 detects rotational position information using this phase difference. The output of the magnetic sensor 51 has a positive sine wave shape in the range from angular position 22.5° to angular position 112.5°. In this angular range, the regulator 63 outputs power at angular positions of 45° and 90°. The magnetic sensor 51 and the analog comparator 65 are driven by power supplied at angular positions of 45° and 90°, respectively. The signal output from the analog comparator 65 (hereinafter referred to as the A-phase signal) is maintained at the L level when no power is being supplied, and becomes the H level at each of the angular positions of 45° and 90°.

Further, the output of the magnetic sensor 52 has a positive sine wave shape in the range of angular positions from 157.5° to 247.5°. In this angular range, the regulator 63 outputs power at angular positions of 180° and 225°. The magnetic sensor 52 and analog comparator 66 are driven by power supplied at angular positions of 180° and 225°, respectively. The signal output from the analog comparator 66 (hereinafter referred to as a B-phase signal) is maintained at L level when no power is supplied, and becomes H level at each of the angular positions of 180° and 225°.

Here, when the A-phase signal supplied to the counter 67 is at the H level (H) and the B-phase signal supplied to the counter 67 is at the L level, a set of these signal levels (H, L ). In FIG. 5, the signal level set at angular position 180° is (L, H), the signal level set at angular position 225° is (H, H), and the signal level set at angular position 270° is (H). , L).

Counter 67 stores a set of signal levels in nonvolatile memory 68 when one or both of the detected A-phase signal and B-phase signal is at H level. When one or both of the A-phase signal and B-phase signal detected next is at H level, the counter 67 reads the previous level set from the non-volatile memory 68 and combines the previous level set and the current level. The direction of rotation of the rotation axis SF is determined by comparing with the set of .

For example, if the previous set of signal levels was (H, H) and the current signal level was (H, L), the previous detection was at an angular position of 225°, and the current detection was at an angle of 225°. Since the position is 270°, it can be seen that the rotation is counterclockwise (forward rotation). If the current level set is (H, L) and the previous level set is (H, H), the counter 67 sends an up signal to the nonvolatile memory 68 indicating that the counter is to be increased. supply to. When the nonvolatile memory 68 detects the up signal from the counter 67, it updates the stored multi-rotation information to a value incremented by one. Further, in the case of reverse rotation, the counter 67 supplies a down signal to the nonvolatile memory 68 indicating that the counter is to be down. At this point, the nonvolatile memory 68 updates the stored multi-rotation information to a value that is decreased by one. In this way, the multi-rotation information detection unit 3 according to the present embodiment can detect multi-rotation information while determining the rotation direction of the rotating shaft SF.

Next, an example of the operation (intermittent operation sequence) when the rotary shaft SF is rotated at high speed in the encoder device EC of this embodiment will be described with reference to the flowchart of FIG. 6 and the waveform diagram of FIG. 7. When the rotating shaft SF is rotated at high speed, the period TE of the enable signal shown in FIG. 5 becomes shorter.
First, in step 102 of FIG. 6, the WW output 7A of the electrical signal generating unit 31A or 31B of FIG. 4 is generated, and the enable signal 7B of the buffer circuit 74 (see FIG. 7(C)) becomes H level. The WW output 7A occurs intermittently in short cycles as shown in FIG. 7(A), but below, as shown in FIGS. 7(B) to (E), the operation of the WW output 7A within one cycle will be explained. I will explain about it. Furthermore, although the signals generated by the electrical signal generating units 31A and 31B are in the form of pulses as shown in FIG. 5, the WW output is 7A decreases to the reference potential relatively slowly. Then, in step 104, the regulator 63 is turned on (activated) in response to the enable signal 7B, and the potential of the power line PL connected to the output terminal 63c of the regulator 63 rises as shown by the dotted waveform (Fig. (See (B)). At this time, the signal 7E of the AND circuit 72 becomes H level.

Further, in step 106, the reset signal 7R of the delay circuit 73 becomes H level after a predetermined time δt (see FIG. 7(B)), and in step 108, the counter 67 and the nonvolatile memory 68 start operating, At step 110, counter 67 writes rotation information (up signal or down signal as described above) to non-volatile memory 68. Data 7RD in FIG. 7(B) shows an example of a signal exchanged between the counter 67 and the nonvolatile memory 68. Then, in step 112, the counter 67 sets the discharge signal 7D to H level (see FIG. 7(E)), and in response, the switching element 70 becomes conductive, and the WW output 7A decreases (is discharged). In step 114, the enable signal 7B of the buffer circuit 74 becomes L level, and in step 116, the output 7E of the AND circuit 72 becomes L level (see FIG. 7(D)), and the regulator 63 is turned off (stops operating). , the potential of power supply line PL decreases. Then, in step 118, the reset signal 7R goes to L level (see FIG. 7(B)), and the counter 67 and nonvolatile memory 68 stop operating. Thereafter, when the WW output 7A rises, the operation returns to step 102 and the operations of steps 104 to 118 are repeated.

According to this operation, as shown in FIG. 7A, even if each pulse signal of the WW output 7A is generated intermittently in a short cycle, the WW output 7A is generated every time the processing of the counter 67 is completed. By resetting and turning off the regulator 63, the potential of the power line PL connected to the output terminal of the regulator 63 (dotted curve) hardly decreases. Therefore, it is possible to suppress a drop in the voltage of the battery 32 when the pulse signal of the WW output 7A is generated and the regulator 63 is turned on, and the voltage of the battery 32 can be reliably restored to the original voltage. Therefore, even if the rotating shaft SF rotates at high speed, power can be accurately supplied and cut off from the battery 32 to the position detection system 1 (multi-rotation information detection unit 3), and the power consumption of the battery 32 can be reduced. As a result, rotation information about the rotating shaft SF can be obtained with high precision. This eliminates maintenance (for example, replacement) of the battery 32 or reduces the frequency of maintenance of the battery 32.

As described above, the encoder device EC according to the present embodiment includes the position detection system 1 (position detection section) that detects rotational position information of the rotation shaft SF (moving section), and the position detection system 1 (position detection section) that detects rotational position information of the rotation shaft SF (moving section). an electric signal generating unit 31A (electrical signal generator) that generates a WW output 7A (electrical signal) due to changes in the magnetic field caused by the rotation of the magnet 11, and a discharge signal 7D (control signal) from the position detection system 1. The signal relay circuit 5 (circuit section ).

According to the present embodiment, for example, after the position detection process in the position detection system 1 is completed, the electric signal generation unit 31A is discharged by the discharge signal 7D (the WW output 7A is lowered), and the regulator 63 is turned off. By doing so, subsequent power consumption of the battery 32 can be prevented. Furthermore, since the output of the electrical signal generation unit 31A is discharged instead of the output of the regulator 63, a decrease in the output of the regulator 63 (potential of the power source of the position detection system 1) can be suppressed. Therefore, when the rotating shaft SF rotates at high speed, the amount of charge from the regulator 63 to the position detection system 1 can be reduced each time each WW output 7A (pulse signal) is generated, and the voltage of the battery 32 decreases. By reducing the amount, the time required for the voltage of the battery 32 to recover can be shortened. Therefore, even when the rotating shaft SF is rotating at high speed, the power consumption of the battery 32 can be reduced and power can be supplied to the position detection system 1, and rotation information of the rotating shaft SF can be obtained with high precision. be able to.

Further, in this embodiment, an output capacitor 69C is provided. This capacitor 69A stabilizes the operation of the regulator 63 (improves load response, etc.). Furthermore, since the output capacitor 69C is not discharged, when the rotating shaft SF rotates at high speed, the amount of charge from the regulator 63 to the output capacitor 69C each time each WW output of 7A is generated can be reduced, and the voltage of the battery 32 can be reduced. By reducing the amount of drop in voltage, the time required for the voltage of the battery 32 to recover can be shortened.

The signal relay circuit 75 also sends a reset signal 7R (a second signal equivalent to the signal 7E) from the WW output 7A after the potential of the power line PL of the position detection system 1 to the counter 67 of the position detection system 1 and The counter 67 and the nonvolatile memory 68 are initialized by the reset signal 7R (stopping the counting operation). This prevents malfunctions due to unstable signals due to a drop in potential.
Further, according to the present embodiment, magnetic field components unnecessary for pulse generation in the electric signal generation unit 31A, including magnetic lines of force generated on the side surface of the magnet 11, are perpendicular to the length direction of the magnetically sensitive member 47, and are unnecessary. This magnetic field component does not adversely affect the generation of a domain wall from one end of the magnetically sensitive member 47 in the length direction to the other end due to the reversal of the alternating current magnetic field due to the rotation of the magnet 11. Therefore, even if the magnetically sensitive member 47 is arranged near the magnet 11 and the electric signal generating unit 31A is miniaturized, the axial alternating magnetic field generated by the rotation of the magnet 11 can be generated without being affected by unnecessary magnetic field components. By reversing , it is possible to efficiently generate a high WW output 7A (pulse signal) with high reliability (stable output) using the electrical signal generation unit 31A.

Further, in the encoder device EC, power is supplied from the battery 32 to the multi-rotation information detection section 3 within a short time after the electric signal is generated in the electrical signal generation unit 31A, and the multi-rotation information detection section 3 is dynamically driven. (intermittent drive). After the detection and writing of the multi-rotation information is completed, the power supply to the multi-rotation information detection section 3 is cut off, but the count value is stored in the storage section 14 and is therefore retained. Such a sequence is repeated every time a predetermined position on the magnet 11 passes near the electric signal generating unit 31A even when the external power supply is cut off. Further, the multi-rotation information stored in the storage unit 14 is read out by the motor control unit MC etc. when the motor M is started next time, and is used to calculate the initial position of the rotation axis SF. In such an encoder device EC, the battery 32 supplies at least a portion of the power consumed by the position detection system 1 according to the electric signal generated by the electric signal generation unit 31A, so that the battery 32 has a long life. be able to. Therefore, maintenance (for example, replacement) of the battery 32 can be eliminated or the frequency of maintenance can be reduced. For example, if the lifespan of the battery 32 is longer than the lifespan of other parts of the encoder device EC, the battery 32 may not need to be replaced.

By the way, if a magnetically sensitive wire such as a Wiegand wire is used, even if the magnet 11 rotates at an extremely low speed, a pulsed current (electrical signal) can be output from the electrical signal generating unit 31A. Therefore, even when the rotating shaft SF (magnet 11) rotates at an extremely low speed, for example in a state where no power is supplied to the motor M, the output of the electrical signal generating unit 31A can be used as an electrical signal. Note that an amorphous magnetostrictive wire or the like can also be used as the magnetically sensitive wire (first magnetically sensitive portion 41A). In this case, for example, the encoder device EC performs full-wave rectification on the electrical signal (current) generated from the electrical signal generation unit (e.g., 31A, 31B) using the rectifier stack (e.g., rectifier) described above. The configuration may be such that the generated power is supplied to the multi-rotation information detection section 3 or the like.

[Second embodiment]
A second embodiment will be described with reference to FIGS. 8 to 10. Note that in FIGS. 8, 9, and 10, parts corresponding to those in FIGS. 4, 6, and 7 are designated by the same reference numerals, and detailed explanation thereof will be omitted. FIG. 8 shows an encoder device ECA according to this embodiment. In FIG. 8, an OR circuit 71 having three input sections is provided in place of the buffer circuit 74 in FIG. The WW output 7A generated at the output terminals 61c, 62c of the rectifier stacks 61, 62 connected to the electric signal generating units 31A, 31B is supplied to the first input section of the OR circuit 71. Further, a switching signal 7ND indicating switching between normal operation and backup operation is supplied from the power supply section MCE of the motor control section MC to the second input section of the OR circuit 71 and the switching signal input section of the counter 67. Furthermore, a processing completion signal 7TC is supplied from the counter 67 to the third input portion of the OR circuit 71 to indicate that the counting operation has been completed. When at least one of the WW output 7A, the switching signal 7ND, and the processing completion signal 7TC becomes H level (high level), the output of the OR circuit 71 becomes H level, and the WW output 7A, the switching signal 7ND, and the processing completion signal 7TC become H level. When all of them become L level (low level), the output of the OR circuit 71 becomes L level. The output of the OR circuit 71 is supplied to the first input portion of the AND circuit 72 and the control terminal 63a of the regulator 63 as an enable signal 7B. The output signal 7E of the AND circuit 72 is supplied to the counter 67 and the nonvolatile memory 68 as a reset signal 7R via the delay circuit 73. The OR circuit 71, the AND circuit 72, and the delay circuit 73 constitute a signal relay circuit 75A.

Basically, as in the first embodiment, the power supply unit MCE drives the motor M shown in FIG. is supplied to the secondary battery 37. Further, in the present embodiment, as an example, in normal operation, the power supply unit MCE sets the switching signal 7ND to H level, supplies DC voltage to the secondary battery 37 of the battery 32, and the power of the secondary battery 37 is used as the power source. The signal is supplied to the input terminal 63b of the regulator 63 via the switch 38. At this time, since the enable signal 7B of the OR circuit 71 is at the H level, the regulator 63 is continuously turned on, and the potential of the power supply line PL is continuously at the H level. Therefore, the magnetic detection section 12, the counter 67, and the nonvolatile memory 68 operate continuously. Furthermore, since the switching signal 7ND is also supplied to the counter 67, the counter 67 can recognize that the current state is normal operation since the switching signal 7ND is at the H level. In this case, the counter 67 takes in the outputs of the analog comparators 65 and 66 at a predetermined sampling rate, for example, obtains rotation information for multiple rotations of the rotating shaft SF, and writes the obtained information into the nonvolatile memory 68.

In the backup operation, for example, the power supply unit MCE (main power supply) is turned off, the driving of the motor M (rotating shaft SF) in FIG. 1 is stopped, and the supply of power from the power supply unit MCE to the battery 32 is stopped. At this time, the power supply unit MCE sets the switching signal 7ND to L level. This allows the counter 67 to recognize that the normal operation has been switched to the backup operation. In the backup operation, in order to suppress the power consumption of the battery 32, the regulator 63 is turned on during the period when the WW output 7A of the electric signal generating units 31A and 31B is equal to or higher than a predetermined threshold, and the magnetic Power is supplied to the detection unit 12, the counter 67, and the nonvolatile memory 68 to obtain rotation information about the rotating shaft SF.

However, when transitioning from normal operation to backup operation, there is a possibility that power cannot be supplied to the magnetic detection unit 12 and the like at the timing when the WW output 7A first rises. Therefore, in this embodiment, when the switching signal 7ND is set to the L level, the counter 67 sets the processing completion signal 7TC to the H level, turns on the regulator 63, and powers the magnetic detection section 12, etc. be supplied. Note that during normal operation, the processing completion signal 7TC may always be at the H level, for example. Thereafter, after the rotation information is obtained, the counter 67 sets the switching signal 7ND to the L level. After this, it is possible to smoothly shift to the backup operation described above. The configuration of this embodiment other than this is the same as that of the first embodiment, so the description thereof will be omitted.

Next, an example of the operation in the encoder device ECA of this embodiment when the power supply unit MCE (main power supply) is turned off from a state in which the rotary shaft SF is rotating at high speed and the normal operation is shifted to the backup operation will be explained. , will be explained with reference to the flowchart of FIG. 9 and the waveform diagram of FIG. 10. This operation is performed, for example, when the power supply MCE is on and the rotating shaft SF is rotating at high speed, the power supply MCE is turned off due to an emergency stop, etc., and from that state the rotating shaft SF changes from high-speed rotation to a stopped state due to inertia. Occurs when there is a transition.

First, in step 120 of FIG. 9, the power supply unit MCE (main power supply) is turned off, and the switching signal 7ND becomes L level (see FIG. 10(A)). In response, in step 122, the counter 67 sets the processing completion signal 7TC to H level (see FIG. 10(B)). Thereafter, in step 104, the enable signal 7B of the OR circuit 71 becomes H level, the regulator 63 is activated, the potential of the power line PL becomes H level, and the signal 7E of the AND circuit 72 becomes H level. Then, in step 106, the reset signal 7R becomes H level after a predetermined time has elapsed (see FIG. 10(C)), the counter 67 and the nonvolatile memory 68 start operating in step 108, and in step 110, the counter 67 and the nonvolatile memory 68 start operating. 67 writes rotation information (the above-mentioned up signal or down signal) into the nonvolatile memory 68. This completes the backup of rotation information when the power is turned off.

Thereafter, in step 124, the counter 67 sets the processing completion signal 7TC to the L level (see FIG. 10(B)), and in step 112, the counter 67 sets the discharge signal 7D to the H level (see FIG. 10(B)). In response, the switching element 70 becomes conductive and the WW output 7A decreases (the electrical signal generating units 31A and 31B are discharged). Then, the enable signal 7B of the OR circuit 71 becomes L level, and in step 116, the regulator 63 is turned off (stops operating), and the output 7E of the AND circuit 72 becomes L level. Then, in step 118, the reset signal 7R becomes L level (see FIG. 10(C)), and the counter 67 and nonvolatile memory 68 stop operating. Operation then moves to step 102 of FIG. Then, when the WW output 7A rises, the operations of steps 104 to 118 in FIG. 6 are repeated.

According to this operation, even if the WW output 7A rises immediately before or after the power supply section MCE (main power supply) is turned off while the rotating shaft SF is rotating at high speed, the counter 67 does not process the The completion signal 7TC ensures that the enable signal 7B of the OR circuit 71 becomes H level, the regulator 63 is turned on, power is supplied to the magnetic detection section 12, etc., and rotation information of the rotation shaft SF is determined and stored in the nonvolatile memory. 68. Then, when the WW output 7A rises thereafter, the rotation information of the rotating shaft SF is obtained by efficiently using the power of the battery 32, similarly to the intermittent operation sequence of the first embodiment. Therefore, even if the rotating shaft SF rotates at high speed, the normal operation can smoothly transition to the intermittent operation sequence.

As described above, the encoder device ECA according to the present embodiment includes the position detection system 1 (position detection unit) that is supplied with power from the power supply unit MCE and detects rotational position information of the rotation shaft SF (moving unit), and A magnet 11 that rotates with the rotation of the shaft SF, an electric signal generation unit 31A (electric signal generation unit) that generates a WW output of 7A (electrical signal) due to changes in the magnetic field due to the rotation of the magnet 11, and a battery 32 that generates a WW output of 7A. A regulator 63 (power supply unit) that supplies power from the position detection system 1 (or power supply unit MCE) to the position detection system 1 is provided. Furthermore, when the power supply from the power supply unit MCE is cut off (when the power supply unit or the power supply unit MCE is turned off), the position detection system 1 of the encoder device ECA is supplied with power from the regulator 63 with WW output 7A. The rotational position information is detected until the rotational position is reached.

Furthermore, the method of using the encoder device ECA according to the present embodiment is such that when the position detection system 1 is cut off from the power supply from the power supply unit MCE (when the power is turned off), the position detection system 1 uses the regulator 63 with the WW output 7A. The process includes steps 122, 108, 110, and 124 in which rotational position information is detected before power is supplied from the controller.
According to this embodiment, even if the power supply unit MCE is turned off while the rotating shaft SF is rotating at high speed, the regulator 63 is turned on by the processing completion signal 7TC of the counter 67, and the magnetic detection of the position detection system 1 is detected. Electric power is supplied to the unit 12 and the like, and rotation information about the rotating shaft SF is obtained and stored. Therefore, even if the power supply unit MCE is turned off, the rotation information of the rotating shaft SF at that time is accurately obtained and stored, and then the operation of the regulator 63 is controlled using the WW output 7A of the electric signal generation unit 31A. Able to smoothly transition to the movement sequence.
Further, the electric signal generating unit 31A has a magnetically sensitive portion 41A whose magnetic characteristics change according to changes in the magnetic field accompanying the rotation of the magnet 11, and generates WW output 7A based on the magnetic characteristics of the magnetically sensitive portion 41A. , a signal relay circuit 75A (signal output section) is provided, and when the power supply section MCE is turned off, the regulator 63 is operated to smooth the output of the battery 32 and supply it to the position detection system 1 (step 120, 122, 104). The effects of the magnetically sensitive portion 41A and the signal relay circuit 75A are similar to those of the first embodiment.

In this embodiment, since the counter 67 outputs the processing completion signal 7TC for operating the regulator 63, the outputs of the electrical signal generation units 31A and 31B can be used smoothly. Note that the element that outputs the processing completion signal 7TC does not necessarily have to be the counter 67.
Furthermore, in each of the above-described embodiments, as shown in FIG. The electric signal generating unit 31A can be further miniaturized because the electric signal generating unit 31A is disposed near the portions of the south pole 16D) and the back surface (the south pole 17A to the north pole 17D) having the same angular position and different polarities. Note that, as in the electrical signal generation unit 31C of the modified example shown in FIGS. (for example, the N pole 16A or the S pole 16B), and the tip of the second magnetic body 46C on the other end side of the magnetically sensitive member 47 is placed near a portion of the surface of the magnet 11 with a different polarity (for example, the S pole 16D). or N pole 16A, etc.). In this case, the first and second magnetic bodies 45C, 46C transmit lines of magnetic force from two portions of mutually different polarities (for example, the N pole 16A and the S pole 16D) of the magnet 11 located at different positions in the rotation direction to the magnetically sensitive member 47. It is guided in the length direction. Also in the electric signal generating unit 31C, since the magnetic circuit MC2 is formed from the magnet 11 to pass through the first magnetic body 45C, the magnetically sensitive member 47, and the second magnetic body 46C, unnecessary magnetic fields on the sides of the magnet 11 The magnetically sensitive member 47 can efficiently output stable pulses without being affected by the reversal of the alternating current magnetic field caused by the rotation of the magnet 11. Note that the configuration of the magnet 11 is arbitrary, and the configuration of the electric signal generation units 31A and 31B is also arbitrary.

Moreover, although the two electrical signal generation units 31A and 31B are provided in the above embodiment, the encoder devices EC and ECA may be provided with only one electrical signal generation unit 31A. Furthermore, the encoder devices EC, ECA may include three or more electrical signal generation units.
Note that when a plurality of electrical signal generating units are provided as in the above-described embodiment, the electric power output from the electrical signal generating unit 31A may be used as a detection signal for detecting multi-rotation information. However, it may also be used for supplying to a detection system or the like.

In the first embodiment described above, the magnet 11 is an eight-pole magnet having four poles in the circumferential direction and two poles in the thickness direction, but the structure is not limited to this and can be changed as appropriate. For example, the magnet 11 may have two or more poles in the circumferential direction.
In the above-described embodiment, the position detection system 1 detects the rotational position information of the rotating shaft SF (moving part) as the position information, but it also detects at least one of the position, velocity, and acceleration in a predetermined direction as the position information. You may. Encoder devices EC and ECA may include rotary encoders or linear encoders. Furthermore, in the encoder devices EC and ECA, the power generation section and the detection section are provided on the rotating shaft SF, and the magnet 11 is provided outside the moving body (for example, the rotating shaft SF), so that the relative position of the magnet and the detecting section can be adjusted. It may be something that changes as the moving part moves. Further, the position detection system 1 does not need to detect the multi-rotation information of the rotating shaft SF, and the multi-rotation information may be detected by a processing section outside the position detection system 1.

In the embodiment described above, the electrical signal generating units 31A and 31B generate electric power (electrical signals) when they are in a predetermined positional relationship with the magnet 11. The position detection system 1 uses changes in the electric power (signals) generated in the electric signal generation units 31A and 31B as a detection signal to obtain position information (for example, multi-rotation information or angular position information) of the moving part (for example, the rotating shaft SF). (including rotational position information) may be detected (counted). For example, the electric signal generation units 31A, 31B may be used as sensors (position sensors), and the position detection system 1 is configured by the electric signal generation units 31A, 31B and one or more sensors (for example, a magnetic sensor, a light receiving sensor). , position information of the moving unit may be detected. Further, when the number of electrical signal generation units is two or more, the position detection system 1 may detect position information using two or more electrical signal generation units as sensors. For example, the position detection system 1 may use two or more electric signal generating units as sensors to detect the position information of the moving part without using a magnetic sensor, or may detect the position information of the moving part without using a light receiving sensor. Information may also be detected. Furthermore, similarly to the magnetic sensor described above, the position detection system 1 may use two or more electrical signal generation units as sensors to determine the rotational direction of the rotating shaft SF based on the two or more electrical signals. good.

Furthermore, the electrical signal generation units 31A and 31B may supply at least a portion of the power consumed by the position detection system 1. For example, the electrical signal generation units 31A and 31B may supply power to a processing section of the position detection system 1 whose power consumption is relatively low. Further, the electricity supply system 2 does not need to supply power to a part of the position detection system 1. For example, the power supply system 2 may intermittently supply power to the detection unit 13 and not supply power to the storage unit 14. In this case, power may be supplied to the storage unit 14 intermittently or continuously from a power source, battery, or the like provided outside the power supply system 2. The power generation section may generate power due to a phenomenon other than the large Barkhausen jump, and does not need to supply power to the moving section (for example, the rotating shaft SF) and a part of the position detection system 1, for example. For example, the power supply system 2 may intermittently supply power to the detection unit 13 and not supply power to the storage unit 14. In this case, power may be supplied to the storage unit 14 intermittently or continuously from a power source, battery, or the like provided outside the power supply system 2. The power generation section may generate power by a phenomenon other than the large Barkhausen jump, and may generate power, for example, by electromagnetic induction caused by changes in the magnetic field accompanying movement of the moving section (for example, the rotating shaft SF). The storage unit that stores the detection results of the detection unit may be provided outside the position detection system 1, or may be provided outside the encoder devices EC and ECA.

[Drive device]
An example of a drive device will be described. FIG. 11 is a diagram showing an example of the drive device MTR. In the following description, components that are the same or equivalent to those of the above-described embodiment are given the same reference numerals and the description will be omitted or simplified. This drive device MTR is a motor device including an electric motor. The drive device MTR includes a rotation shaft SF, a main body portion (drive portion) BD that rotationally drives the rotation shaft SF, and an encoder device EC that detects rotational position information of the rotation shaft SF. Note that an encoder device ECA may be provided instead of the encoder device EC.

The rotating shaft SF has a load side end SFa and an anti-load side end SFb. The load side end SFa is connected to another power transmission mechanism such as a reduction gear. A scale S is fixed to the opposite-load side end SFb via a fixing part. Along with fixing the scale S, an encoder device EC is attached. The encoder device EC is an encoder device according to the above-described embodiment, modification, or combination thereof.

In this drive device MTR, a motor control section MC shown in FIG. 1 controls the main body section BD using the detection result of the encoder device EC. Since the drive device MTR does not require or has little need to replace the battery of the encoder device EC, maintenance costs can be reduced. Note that the drive device MTR is not limited to a motor device, and may be another drive device having a shaft portion that rotates using hydraulic pressure or pneumatic pressure.

[Stage equipment]
An example of a stage device will be described. FIG. 12 shows the stage device STG. This stage device STG has a configuration in which a rotary table (moving object) TB is attached to the load side end SFa of the rotating shaft SF of the drive device MTR shown in FIG. In the following description, components that are the same or equivalent to those of the above-described embodiment are given the same reference numerals and the description will be omitted or simplified.

When the stage device STG drives the drive device MTR to rotate the rotating shaft SF, this rotation is transmitted to the rotating table TB. At that time, the encoder device EC detects the angular position of the rotating shaft SF. Therefore, by using the output from encoder device EC, the angular position of rotary table TB can be detected. Note that a speed reducer or the like may be disposed between the load side end SFa of the drive device MTR and the rotary table TB.

Since the stage device STG has little or no need to replace the battery of the encoder device EC, maintenance costs can be reduced. Note that the stage device STG can be applied to, for example, a rotary table included in a machine tool such as a lathe.
[Robot device]
An example of a robot device will be described. FIG. 13 is a perspective view showing the robot device RBT. Note that FIG. 13 schematically shows a part (joint part) of the robot device RBT. In the following description, components that are the same or equivalent to those of the above-described embodiment are given the same reference numerals and the description will be omitted or simplified. This robot device RBT has a first arm AR1, a second arm AR2, and a joint JT. The first arm AR1 is connected to the second arm AR2 via a joint JT.

The first arm AR1 includes an arm portion 101, a bearing 101a, and a bearing 101b. The second arm AR2 has an arm portion 102 and a connecting portion 102a. The connecting portion 102a is arranged between the bearing 101a and the bearing 101b in the joint JT. The connecting portion 102a is provided integrally with the rotating shaft SF2. The rotating shaft SF2 is inserted into both the bearing 101a and the bearing 101b at the joint JT. The end of the rotating shaft SF2 that is inserted into the bearing 101b passes through the bearing 101b and is connected to the reducer RG.

The speed reducer RG is connected to the drive device MTR, and reduces the rotation of the drive device MTR to, for example, 1/100, and transmits the speed to the rotating shaft SF2. Although not shown in FIG. 13, the load-side end SFa of the rotating shaft SF of the drive device MTR is connected to the speed reducer RG. Furthermore, a scale S of an encoder device EC is attached to the opposite-load side end SFb of the rotating shaft SF of the drive device MTR.

When the robot device RBT drives the drive device MTR to rotate the rotating shaft SF, this rotation is transmitted to the rotating shaft SF2 via the reducer RG. The connection portion 102a rotates integrally with the rotation of the rotation shaft SF2, and thereby the second arm AR2 rotates with respect to the first arm AR1. At that time, the encoder device EC detects the angular position of the rotating shaft SF. Therefore, the angular position of the second arm AR2 can be detected by the output from the encoder device EC.

Since the robot device RBT does not require or has little need to replace the battery of the encoder device EC, maintenance costs can be reduced. Note that the robot device RBT is not limited to the above configuration, and the drive device MTR can be applied to various robot devices including joints.

1...Position detection system, 3...Multi-rotation information detection section, 4...Angle detection section, 11, 11A...Magnet, 12...Magnetic detection section, 13...Detection section, 14...Storage section, 21...Light emitting element (irradiation section) , 22... Light receiving sensor (light detection section), 31A, 31B... Electric signal generation unit, 32... Battery, 33... Switching section, 36... Primary battery, 37... Secondary battery, 41A, 41B... Magnetism sensitive section, 42A, 42B...Power generation section, 43A, 43B...Case, 45A...First magnetic body, 46A...Second magnetic body, 47...Magnetically sensitive member, 51, 52...Magnetic sensor, 63...Regulator, 67...Counter, 70...Switching element, 71...OR circuit, 72...AND circuit, 73...delay circuit, 75, 75A...signal relay circuit, EC, ECA...encoder device, SF...rotary shaft, AR1...first arm, AR2...second arm, MTR ...Drive device, RBT...Robot device, STG...Stage device

Claims (12)

a position detection unit that detects position information of the moving unit;
a magnet that moves as the moving part moves;
an electric signal generating section that generates an electric signal by a change in the magnetic field due to the movement of the magnet;
An encoder device comprising: a circuit section that outputs an output of the electrical signal generating section that changes depending on a control signal from the position detecting section to the position detecting section. comprising an accumulation section that accumulates the charge output from the electric signal generation section,
2. The encoder device according to claim 1, wherein the output of the electrical signal generating section changes when the charge in the storage section is discharged by the control signal. The circuit unit outputs the electric signal to the position detection unit after the potential of the position detection unit is lowered by the output of the electric signal generation unit,
The encoder device according to claim 1 or 2, wherein the position detection section is initialized by the electric signal after the potential of the position detection section has decreased. comprising a power supply unit that supplies power to the position detection unit according to the electric signal,
4. The encoder device according to claim 3, wherein the circuit section outputs the electric signal after the potential of the position detecting section has decreased to the position detecting section when the potential of the power supply section is equal to or higher than a reference value. 5. The circuit section includes a delay section that outputs the electric signal to the position detection section after the potential of the position detection section has decreased after a predetermined time has elapsed since the potential of the power supply section has increased. encoder device. The encoder according to any one of claims 1 to 4, wherein the position detection unit outputs the control signal to change the output of the electric signal generation unit when the detection process of the position information of the moving unit is completed. Device. The encoder device according to any one of claims 1 to 6, wherein the electric signal is intermittently and repeatedly output by movement of the moving section. The moving part includes a rotating shaft,
The magnet includes a ring-shaped or sector-shaped part,
The encoder device according to any one of claims 1 to 7, wherein a plurality of the electric signal generation units are arranged along the magnet. The position detection unit includes an angle detection unit that detects angular position information within one rotation of the rotation axis;
The encoder device according to claim 8 , further comprising a multi-rotation information detection unit that detects multi-rotation information of the rotating shaft as the position information. An encoder device according to any one of claims 1 to 9 ,
A drive device comprising: a power supply unit that supplies power to the moving unit. a moving object,
A stage device comprising: the drive device according to claim 10 , which moves the moving object. The drive device according to claim 10 ;
A robot device comprising: an arm that is relatively moved by the drive device.

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