JP6610697B2 - Encoder device, drive device, stage device, and robot device - Google Patents

Description

  The present invention relates to an encoder device, a drive device, a stage device, and a robot device.

  A multi-rotation type encoder device that detects rotation information including the number of rotations is mounted on various devices such as a robot device (see, for example, Patent Document 1 below). During the operation of the robot apparatus, the encoder apparatus receives power supply from the main power supply of the robot apparatus, for example, and detects rotation information including the rotation speed and the angular position.

  By the way, when the robot apparatus finishes the predetermined process, the main power supply may be turned off. In this case, the power supply from the main power supply of the robot apparatus to the encoder apparatus is also stopped. The robot apparatus may require information such as an initial posture when the main power source is turned on next time, that is, when the next operation is started. For this reason, the encoder device is required to retain information on the rotational speed even in a state where no electric power is supplied from the outside. Therefore, an encoder device is used that maintains the rotational speed with the power supplied from the battery in a state where the power supply from the main power source cannot be obtained.

JP-A-8-50034

  The encoder device as described above may require battery replacement. Battery replacement is performed during regular maintenance, and the frequency of maintenance may increase depending on the battery life.

  According to the aspect of the present invention, the first magnetic sensor and the second magnetic sensor are provided, the detection unit detects the position information of the rotating shaft of the moving unit, and the relative position of the detecting unit changes based on the rotation of the rotating shaft. A power generation unit having a magnet, a first magnetic sensing unit, and a second magnetic sensing unit, which generates power based on a pulsed current generated by a change in magnetic field due to rotation of the moving unit, and adjusts the power to a predetermined voltage power An encoder device is provided that includes a power adjustment unit that supplies at least part of the power consumed by the detection unit. Moreover, according to the aspect of this invention, it has a 1st sensor and a 2nd sensor, the detection part which detects the positional information on the rotating shaft of a moving part, a 1st magnetic sensing part, and a 2nd magnetic sensing part A power generation unit that generates power based on a pulsed current generated by a change in the magnetic field due to rotation of the moving unit, and adjusts the power to power of a predetermined voltage, and at least part of the power consumed by the detection unit A power adjusting unit to be supplied; and a comparator that compares an output signal output from the first sensor with a predetermined threshold and outputs a high level signal and a low level signal within one rotation of the rotating shaft; The first magnetic sensing unit outputs a first current as a pulsed current during a period during which a high level signal is output, and the second magnetic sensing unit performs a pulse during a period during which a low level signal is output. A second current is output as a current The encoder apparatus is provided. According to the aspect of the present invention, the power supply unit is controlled using the encoder device according to the aspect of the present invention, the power supply unit that supplies power to the moving unit, and the position information detected by the detection unit of the encoder device. And a drive unit including the control unit. According to the aspect of the present invention, there is provided a stage apparatus including a moving object and the driving apparatus according to the aspect of the present invention that moves the moving object. Moreover, according to the aspect of this invention, a robot apparatus provided with the drive device of the aspect of this invention is provided. According to the first aspect of the present invention, a position detecting system including a detecting unit that detects position information of the moving unit, a magnet whose relative position changes as the moving unit moves, and a moving unit A power generation unit that generates power due to a change in magnetic field accompanying movement of the power, and a power adjustment unit that adjusts the power output from the power generation unit to a predetermined voltage power and supplies at least a portion of the power consumed by the position detection system And an electric power supply system including the encoder device.

  According to the second aspect of the present invention, the power supply unit is controlled using the encoder device of the first aspect, the power supply unit that supplies power to the moving unit, and the position information detected by the detection unit of the encoder device. A control unit is provided.

  According to a third aspect of the present invention, there is provided a stage apparatus including a moving object and a driving apparatus according to the second aspect that moves the moving object.

  According to a fourth aspect of the present invention, there is provided a robot apparatus including the driving device according to the second aspect, and a first arm and a second arm that are relatively moved by the driving device.

It is a figure which shows the encoder apparatus which concerns on 1st Embodiment. (A) based on 1st Embodiment is a layout of a magnet and an electric power generation unit, (B) is a figure which shows a magnetic field. It is a circuit block diagram of the magnetic encoder part which concerns on 1st Embodiment. It is a circuit block diagram of the magnetic encoder part which concerns on a modification. It is a figure which shows the encoder apparatus which concerns on 2nd Embodiment. It is an arrangement plan of a power generation unit concerning a 2nd embodiment. It is a circuit block diagram of the magnetic encoder part which concerns on 2nd Embodiment. It is a timing chart which shows operation of a magnetic encoder part at the time of forward rotation concerning a 2nd embodiment. It is a timing chart which shows operation | movement of the magnetic encoder part at the time of reverse rotation which concerns on 2nd Embodiment. It is a figure which shows the encoder apparatus which concerns on 3rd Embodiment. (A) is a layout diagram of a magnetic sensor, and (B) is a circuit configuration diagram of the magnetic sensor according to the third embodiment. It is a circuit block diagram of the magnetic encoder part which concerns on 3rd Embodiment. It is a timing chart which shows operation of a magnetic encoder part at the time of forward rotation concerning a 3rd embodiment. It is a timing chart which shows operation | movement of the magnetic encoder part at the time of reverse rotation which concerns on 3rd Embodiment. It is a figure which shows the encoder apparatus which concerns on 4th Embodiment. It is an arrangement plan of a power generation unit and a magnetic sensor concerning a 4th embodiment. It is a circuit block diagram of the magnetic encoder part which concerns on 4th Embodiment. It is a timing chart which shows operation | movement of the magnetic-type encoder part which concerns on 4th Embodiment. It is a figure which shows the encoder apparatus which concerns on 5th Embodiment. (A) is a perspective view showing a magnet, a power generation unit, and a magnetic sensor according to a sixth embodiment, (B) is a diagram showing a magnetic field formed by the magnet, and (C) is a circuit configuration diagram of the magnetic sensor. It is. It is a figure which shows the circuit structure of the magnetic-type encoder part which concerns on 6th Embodiment. It is a circuit block diagram of the magnetic encoder part which concerns on 7th Embodiment. It is a timing chart which shows operation | movement of the magnetic-type encoder part at the time of forward rotation which concerns on 7th Embodiment. It is a timing chart which shows operation | movement of the magnetic encoder part at the time of reverse rotation which concerns on 7th Embodiment. It is a figure which shows the magnetic encoder part which concerns on a modification. It is a circuit block diagram of the magnetic encoder part which concerns on 8th Embodiment. It is a timing chart which shows operation | movement of the magnetic-type encoder part at the time of forward rotation which concerns on 8th Embodiment. It is a timing chart which shows operation | movement of the magnetic encoder part at the time of reverse rotation which concerns on 8th Embodiment. It is a figure which shows the encoder apparatus which concerns on 9th Embodiment. It is a figure which shows a modification. It is a figure which shows the drive device which concerns on this embodiment. It is a figure which shows the stage apparatus which concerns on this embodiment. It is a figure which shows the robot apparatus which concerns on this embodiment.

[First Embodiment]
A first embodiment will be described. FIG. 1 is a diagram showing an encoder device EC according to the present embodiment. The encoder device EC detects rotation information (position information) of the rotation shaft SF (moving unit) of the motor M (power supply unit). The rotating shaft SF is, for example, a shaft (rotor) of the motor M, and is a working shaft (output shaft) connected to the shaft of the motor M via a power transmission unit such as a transmission and to a load. May be. The rotation information detected by the encoder device EC is supplied to the motor control unit MC. The motor control unit MC controls the rotation of the motor M using the rotation information supplied from the encoder device EC. The motor control unit MC controls the rotation of the rotation shaft SF.

  The encoder device EC is a so-called multi-rotation absolute encoder, and detects rotation information including the rotation speed and the angular position of the rotation shaft SF. The encoder device EC includes a magnetic encoder unit 1 that detects the number of rotations of the rotating shaft SF, and an optical encoder unit 2 that detects the angular position of the rotating shaft SF.

  The magnetic encoder unit 1 includes a magnet 3, a power generation unit 4, and a signal processing unit 5. The magnet 3 is provided on a disc 6 fixed to the rotation shaft SF. Since the disk 6 rotates with the rotation axis SF, the magnet 3 rotates with the rotation of the rotation axis SF (with the rotation axis SF). The power generation unit 4 generates electric power due to a change in the magnetic field accompanying the rotation of the magnet 3. The signal processing unit 5 includes a detection unit 7, a power adjustment unit 8, and a storage unit 9. The detection unit 7 detects rotation information of the rotation shaft SF based on a change in electric power output from the power generation unit 4. The detection unit 7 detects the rotation speed of the rotation axis SF as rotation information. The power adjustment unit 8 adjusts the power output from the power generation unit 4 to a predetermined voltage. The storage unit 9 stores the detection result of the detection unit 7 using the power output from the power adjustment unit 8. The configuration of the magnetic encoder unit 1 will be described in detail later with reference to FIGS.

  The optical encoder unit 2 is an angle detection unit that detects an angular position within one rotation of the rotation axis SF by performing patterning. The optical encoder unit 2 detects the same rotation information of the rotation axis SF as the detection target of the magnetic encoder unit 1. The optical encoder unit 2 includes a light emitting element 11, a scale S, a light receiving sensor 12, and a signal processing unit 13.

  The scale S is provided on a disc 14 fixed to the rotation shaft SF. The scale S includes an incremental scale and an absolute scale. The disc 14 in FIG. 1 is drawn separately from the disc 6, but it may be the same member as the disc 6 or a member integrated with the disc 6. For example, the scale S may be provided on the surface of the disc 6 opposite to the magnet 3. The scale S may be provided on at least one of the inside and the outside of the magnet 3.

  The light emitting element 11 irradiates the scale S with light. The light receiving sensor 12 detects light emitted from the light emitting element 11 and passing through the scale S. In FIG. 1, the optical encoder unit 2 is a transmission type, and the light receiving sensor 12 detects light transmitted through the scale S. The optical encoder unit 2 may be a reflection type. The light receiving sensor 12 supplies a signal indicating the detection result to the signal processing unit 13. The signal processing unit 13 processes the signal supplied from the light receiving sensor 12.

  The signal processing unit 13 includes a detection unit 15, a synthesis unit 16, and an external communication unit 17. The detection unit 15 detects the angular position of the rotation axis SF using the detection result of the light receiving sensor 12. For example, the detection unit 15 detects the angular position of the first resolution using the result of detecting the light from the absolute scale. Further, the detection unit 15 detects an angular position with a second resolution higher than the first resolution by performing an interpolation operation on the angular position with the first resolution using the result of detecting light from the incremental scale. .

  The synthesizing unit 16 acquires the angular position of the second resolution detected by the detecting unit 15. Further, the synthesizing unit 16 acquires the rotation speed of the rotation axis SF from the storage unit 9 of the magnetic encoder unit 1. The synthesizer 16 synthesizes the angular position from the detector 15 and the rotational speed from the magnetic encoder unit 1 to calculate rotation information. For example, when the detection result of the detection unit 15 is θ [rad] and the detection result of the magnetic encoder unit 1 is n rotations, the synthesis unit 16 calculates (2π × n + θ) as rotation information. Such rotation information that can express one or more rotations is sometimes referred to as multi-rotation information.

  The combining unit 16 supplies the multi-rotation information to the external communication unit 17. The external communication unit 17 is communicably connected to the communication unit MC1 of the motor control unit MC by wire or wireless. The external communication unit 17 supplies the digital multi-rotation information to the communication unit MC1 of the motor control unit MC. The motor control unit MC appropriately decodes the multi-rotation information from the external communication unit 17 of the optical encoder unit 2. The motor control unit MC controls the rotation of the motor M by controlling the power (drive power) supplied to the motor M using the multi-rotation information.

  Next, the magnetic encoder unit 1 will be described in more detail. FIG. 2A is a perspective view showing the magnet 3 and the power generation unit 4. FIG. 2B is a diagram showing a magnetic field formed by the magnet 3 in FIG.

  The magnet 3 is configured such that the direction and strength of the magnetic field in the radial direction (radial direction) with respect to the rotation axis SF is changed by rotation. The magnet 3 is an annular member that is coaxial with the rotation axis SF. The main surfaces (front surface and back surface) of the magnet 3 are each substantially perpendicular to the rotation axis SF. As shown in FIG. 2B, the magnet 3 is a permanent magnet magnetized with four poles. The magnet 3 has N poles and S poles arranged in the circumferential direction on the inner peripheral side and the outer peripheral side thereof, and the phase is shifted by 180 ° between the inner peripheral side and the outer peripheral side. In the magnet 3, the boundary between the N pole and the S pole on the inner peripheral side substantially coincides with the boundary between the N pole and the S pole on the outer peripheral side in the circumferential direction (angular position).

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

  Here, in the coordinate system fixed to the magnet 3, the angular position of one boundary between the N pole and the S pole in the circumferential direction is represented by a position 3a, and the angular position rotated 90 ° from the position 3a is represented by a position 3b. An angular position rotated 90 ° from the position 3b is represented by a position 3c, and a position rotated 90 ° from the position 3c is represented by a position 3d. The position 3c is an angular position of another boundary between the N pole and the S pole in the circumferential direction. In FIG. 2B, the direction of the radial direction of the magnetic field (lines of magnetic force) at each position is indicated by an arrow, and the strength of the magnetic field is indicated by the thickness of this arrow.

  In the first section of 180 ° counterclockwise from the position 3a, the N pole is arranged on the outer peripheral side of the magnet 3 and the S pole is arranged on the inner peripheral side of the magnet 3. In the first section, the direction of the magnetic field in the radial direction is generally the direction from the outer peripheral side of the magnet 3 toward the inner peripheral side. In the first section, the strength of the magnetic field is maximum at the position 3b and is minimum near the position 3a and near the position 3c.

  In the second section of 180 ° counterclockwise from the position 3c, the N pole is arranged on the inner peripheral side of the magnet 3 and the S pole is arranged on the outer peripheral side of the magnet 3. In the second section, the direction of the magnetic field in the radial direction is a direction from the inner peripheral side of the magnet 3 toward the outer peripheral side. In the second section, the strength of the magnetic field is maximum at the position 3d and is minimum near the position 3a and near the position 3c.

  Thus, the radial direction of the magnetic field formed by the magnet 3 is reversed at the position 3a and reversed at the position 3c. The magnet 3 forms an alternating magnetic field in which the direction of the radial magnetic field is reversed with the rotation of the magnet 3 with respect to the coordinate system fixed outside the magnet 3. The power generation unit 4 is disposed at a position overlapping the magnet 3 when viewed from the normal direction of the main surface of the magnet 3.

  As illustrated in FIG. 2A, the power generation unit 4 includes a magnetic sensitive unit 20 and a power generation unit 21. The power generation unit 4 is provided in non-contact with the magnet 3. The magnetic sensitive unit 20 and the power generation unit 21 are fixed to the outside of the magnet 3, and the relative positions with respect to the respective positions on the magnet 3 change as the magnet 3 rotates. For example, in FIG. 2B, the position 3d is arranged in the vicinity of the power generation unit 4, and when the magnet 3 makes one turn in the forward direction (counterclockwise) from this state, the vicinity of the power generation unit 4 is moved to the position 3c, The position 3b and the position 3a pass in this order, and the position 3d is disposed again in the vicinity of the power generation unit 4.

  The magnetic sensitive part 20 is a magnetic sensitive wire such as a Wiegand wire. A large Barkhausen jump (Wiegand effect) is generated in the magnetic sensitive part 20 due to a change in the magnetic field accompanying the rotation of the magnet 3. The magnetic sensitive part 20 is a cylindrical member, and the axial direction thereof is set to the radial direction of the magnet 3. When the magnetic field is reversed when an AC magnetic field is applied in the axial direction of the magnetic sensitive unit 20, a domain wall is generated from one end to the other end in the axial direction.

  The power generation unit 21 is a high-density coil or the like that is wound around the magnetic sensing unit 20. In the power generation unit 21, electromagnetic induction occurs due to the occurrence of the domain wall in the magnetic sensitive unit 20, and an induced current flows. When the position 3a or the position 3c of the magnet 3 shown in FIG. 2B passes near the power generation unit 4, a pulsed current is generated in the power generation unit 21.

  The direction of the current generated in the power generation unit 21 changes according to the direction before and after the reversal of the magnetic field. For example, the direction of the current generated when reversing from the magnetic field facing the outside of the magnet 3 to the magnetic field facing the inside is opposite to the direction of the current generated when reversing from the magnetic field facing the inside of the magnet 3 to the magnetic field facing the outside.

  Here, attention is paid to a change in the direction of the magnetic field when the position 3a in FIG. When the position 3a of the magnet 3 that rotates counterclockwise passes through the vicinity of the power generation unit 4, the magnetic field in the magnetic sensing unit 20 changes from the outside to the inside of the magnet 3 and from the inside to the outside of the magnet 3. Invert to the direction. In addition, when the position 3a of the magnet 3 that rotates clockwise passes through the vicinity of the power generation unit 4, the magnetic field in the magnetic sensing unit 20 changes from the inside to the outside of the magnet 3 and from the outside to the inside of the magnet 3. Reverse to the direction. Therefore, when the position 3a of the magnet 3 rotating in the forward direction passes through the vicinity of the power generation unit 4, the direction of the current generated in the power generation unit 21 is the position 3a of the magnet 3 rotating in the reverse direction in the vicinity of the power generation unit 4. The direction of the current generated in the power generation unit 21 when passing through is reversed.

  Thus, electric power is generated in the power generation unit 21 due to the change in the magnetic field in the magnetic sensitive unit 20. This power is used for at least part of the power consumed by the magnetic encoder unit 1. The power (inductive current) generated in the power generation unit 21 can be set by, for example, the number of turns of the high-density coil. In addition, the number of turns of the high-density coil can be set so that the amount of power consumed by the power generation unit 4 out of the power consumed by the magnetic encoder unit 1 is obtained.

  The magnetic sensitive part 20 and the power generation part 21 of FIG. 2 (A) are housed in a case 22. The case 22 is provided with a terminal 23a and a terminal 23b. The high-density coil of the power generation unit 21 has one end electrically connected to the terminal 23a and the other end electrically connected to the terminal 23b. The electric power generated in the power generation unit 21 can be taken out of the power generation unit 4 via the terminal 23a and the terminal 23b.

  FIG. 3 is a diagram illustrating a circuit configuration of the magnetic encoder unit 1. The magnetic encoder unit 1 according to the present embodiment detects the number of rotations of the rotating shaft SF and supplies (covers) at least a part of the power consumed by the detection system and the detection system that stores the detected number of rotations. Power supply system. Here, the detection system will be described first, and then the power supply system will be described.

  In the present embodiment, the rotation speed detection system in the encoder device EC includes a detection unit 7 and a storage unit 9. As shown in FIG. 3, the detection unit 7 includes a current detector 25, a current detector 26, and a counter 27.

  The input terminal 25 a of the current detector 25 is connected to the terminal 23 a of the power generation unit 4. The current detector 25 detects the current I1 flowing from the power generation unit 21. The current I1 corresponds to a current flowing through the power generation unit 4 from the terminal 23b toward the terminal 23a. The output terminal 25 b of the current detector 25 is connected to the first input terminal 27 a of the counter 27. The current detector 25 outputs a voltage from the output terminal 25b when the current input from the input terminal 25a is greater than or equal to the threshold value. For example, the current detector 25 supplies a voltage (signal) corresponding to the current to the first input terminal 27 a of the counter 27 when detecting a pulsed current.

  The input terminal 26 a of the current detector 26 is connected to the terminal 23 b of the power generation unit 4. The current detector 26 detects a current I2 flowing in the direction opposite to the current I1 from the power generation unit 21. The current I2 corresponds to a current flowing through the power generation unit 4 from the terminal 23a toward the terminal 23b. The output terminal 26 b of the current detector 26 is connected to the second input terminal 27 b of the counter 27. The current detector 26 outputs a voltage from the output terminal 26b when the current input from the input terminal 26a is greater than or equal to the threshold value. For example, the current detector 26 supplies a voltage (signal) corresponding to the current to the second input terminal 27 b of the counter 27 when detecting a pulsed current.

  The counter 27 includes, for example, a CMOS logic circuit, and performs a counting process using the voltage supplied via the first input terminal 27a and the voltage supplied via the second input terminal 27b as control signals. For example, the counter 27 increases the counter value when a voltage is output from the current detector 25, and decreases the counter value when a voltage is output from the current detector 26. The counter 27 counts the number of times that the current detector 25 has detected a pulsed current and the number of times that the current detector 26 has detected a pulsed current.

  Such a detector 7 can acquire a counter value corresponding to the number of rotations of the magnet 3 that rotates with the rotation axis SF. The detection unit 7 uses the pulsed power output from the power generation unit 21 as a detection signal, and detects the rotation speed of the rotation shaft SF. The storage unit 9 stores information related to the rotational speed detected by the counter 27. The storage unit 9 includes, for example, a nonvolatile memory 28 and can hold information written while power is supplied even in a state where power is not supplied.

  The encoder device EC according to the present embodiment provides at least a part of the power consumed by the rotation speed detection system by power generation. Therefore, it is possible to omit a battery for covering the power consumption of the detection system, or to extend the life of the battery. As a result, for example, it is possible to reduce the frequency and cost of maintenance. In this embodiment, the battery may or may not be present. When there is a battery in this embodiment, power supply to the battery can be omitted at all times, and the life of the battery can be extended. As a result, the frequency of battery replacement can be reduced. In the present embodiment, when there is no battery, the battery line and the external battery can be omitted, and a reduction in size and cost can be realized. Hereinafter, the power supply system of the encoder device EC will be described.

  The power supply system of the encoder device EC includes a power generation unit 4 and a power adjustment unit 8. The power adjustment unit 8 includes a rectification stack 30, a booster 31, and a regulator 32. The rectification stack 30 is a rectifier that rectifies the current flowing from the power generation unit 21. The booster 31 boosts the voltage of power output from the rectifying stack 30. The regulator 32 adjusts the voltage output from the rectifying stack 30 via the booster 31 to a predetermined voltage.

  The first input terminal 30 a of the rectifying stack 30 is connected to the current detector 25. The signal line connecting the rectifying stack 30 and the current detector 25 is provided in a separate system from the signal line connecting the current detector 25 and the counter 27. The second input terminal 30 b of the rectifying stack 30 is connected to the current detector 26. The signal line connecting the rectifying stack 30 and the current detector 26 is provided in a separate system from the signal line connecting the current detector 26 and the counter 27. The ground terminal 30g of the rectifying stack 30 is connected to a ground line GL to which the same potential as the signal ground SG is supplied. The output terminal 30 c of the rectifying stack 30 is connected to the input terminal 31 a of the booster 31.

  The current I1 from the power generation unit 21 is supplied to the first input terminal 30a of the rectifying stack 30 via the current detector 25. The current I2 from the power generation unit 21 is supplied to the second input terminal 30b of the rectifying stack 30 via the current detector 26. The rectification stack 30 performs full-wave rectification based on these current outputs. The rectification stack 30 supplies the power adjusted by the rectification to the booster 31 via the output terminal 30c.

  The booster 31 includes, for example, a boost type DC / DC converter. The ground terminal 31g of the booster 31 is connected to the ground line GL. The output terminal 31 b of the booster 31 is connected to the input terminal 32 a of the regulator 32. The booster 31 converts the first DC voltage that has been full-wave rectified by the rectifying stack 30 into a second DC voltage that is higher than the first DC voltage. The reference potential of the first DC voltage and the reference potential of the second DC voltage are the same as the potential of the signal ground SG supplied via the ground line GL and the ground terminal 31g. The booster 31 generates a voltage higher than both the voltage required for the counting process of the counter 27 and the voltage required for the writing process of the storage unit 9 as the second DC voltage. For example, the second DC voltage is set to a voltage higher than the voltage at which the switching operation of the CMOS FET is correctly performed when the counter 27 is formed of a CMOS or the like.

  The regulator 32 includes, for example, a low-loss three-terminal regulator. The ground terminal 32g of the regulator 32 is connected to the ground line GL. The output terminal 32b of the regulator 32 is connected to the power supply line PL. The second DC voltage generated by the booster 31 is supplied to the input terminal 32 a of the regulator 32. The regulator 32 generates a predetermined voltage with less nipple (pulsation) based on the second DC voltage generated by the booster 31. The reference potential of the predetermined voltage is the same as the potential of the signal ground SG supplied via the ground line GL and the ground terminal 32g. The predetermined voltage is, for example, 3 V when the counter 27 is configured by a CMOS or the like. The operating voltage of the nonvolatile memory 28 of the storage unit 9 is set to the same voltage as a predetermined voltage, for example. The power adjustment unit 8 sets the potential of the power supply line PL to a predetermined voltage with respect to the potential of the ground line GL at least in a period from when the detection unit 7 detects the rotation speed to when the storage unit 9 writes the rotation speed. Here, the predetermined voltage is a voltage necessary for power supply, and may be a voltage that changes stepwise as well as a constant voltage value.

  The power supply terminal 27p of the counter 27 is connected to the power supply line PL. The ground terminal 27g of the counter 27 is connected to the ground line GL. When the current I1 flows from the power generation unit 21, the power adjustment unit 8 supplies a predetermined voltage to the power supply line PL, and the predetermined voltage is supplied to the counter 27 via the power supply terminal 27p. Further, a detection signal is supplied from the current detector 25 to the first input terminal 27a of the counter 27 substantially simultaneously with or after the power of the predetermined voltage is supplied to the counter 27. The counter 27 performs a counting process using electric power supplied via the power supply terminal 27p and the ground terminal 27g. The rotation speed detection system is appropriately provided with a delay element so that power is supplied from the power adjustment unit 8 to the counter 27 when the detection signal is supplied from the current detector 25 to the counter 27. It is done. In this way, the counter 27 detects the number of rotations and outputs the detected number of rotations to the storage unit 9 while the power supply from the power adjustment unit 8 continues. The magnetic encoder unit 1 operates in the same manner when the current I2 flows from the power generation unit 21.

  A power supply terminal 28p of the nonvolatile memory 28 of the storage unit 9 is connected to the power supply line PL. The ground terminal 28g of the nonvolatile memory 28 is connected to the ground line GL. When the current I1 flows from the power generation unit 21, the power adjustment unit 8 supplies a predetermined voltage to the power supply line PL, and the predetermined voltage is supplied to the storage unit 9 through the power supply terminal 28p. Further, information on the rotational speed is supplied from the counter 27 to the storage unit 9 almost simultaneously with or after the predetermined voltage is supplied to the storage unit 9. The storage unit 9 uses the power supplied via the power supply terminal 28p and the ground terminal 28g to write the rotational speed information. The rotational speed detection system includes a delay element as appropriate so that power is supplied from the power adjustment unit 8 to the storage unit 9 when the rotational speed information is supplied from the counter 27 to the storage unit 9. Provided. In this way, the storage unit 9 writes the rotational speed information while the power supply from the power adjustment unit 8 continues.

  Thus, the magnetic encoder unit 1 of the encoder device EC according to the present embodiment performs dynamic driving (intermittent driving) in a short time after the power generation unit 21 outputs current. After completion of the detection and writing of the rotational speed, the power supply to the rotational speed detection system is cut off, but the count value is retained because it is stored in the nonvolatile memory 28. Such a sequence is repeated every time a predetermined position on the magnet 3 passes in the vicinity of the power generation unit 4 even in a state where the external power supply is cut off. The information on the number of rotations stored in the storage unit 9 is read to the motor control unit MC and the like when the motor M is started next time, and is used for calculating the initial position of the rotation axis SF and the like.

  The encoder device EC configured as described above uses power generation to generate at least part of the power consumed by the rotation speed detection system. Therefore, the encoder device EC can omit the battery for covering the power consumption of the rotation speed detection system, or can extend the life. As a result, the encoder device EC can eliminate or reduce the need for battery replacement.

  By the way, when a magnetosensitive wire such as a Wiegand wire is used, a pulse current output can be obtained from the power generation unit 4 even if the rotation of the magnet 3 is extremely low. Therefore, for example, in a state where power is not supplied to the motor M, the output of the power generation unit 4 can be used as a detection signal even when the rotation of the rotating shaft SF (magnet 3) is extremely low.

  In the present embodiment, the power adjustment unit 8 generates a second DC voltage that is higher than the operating voltage of the counter 27 and the storage unit 9 by a booster, and generates a predetermined voltage based on the second DC voltage. Therefore, an operation margin sufficient for the operation of the counter 27 and the storage unit 9 can be obtained, the malfunction of the counter 27 is avoided, and the malfunction of the storage unit 9 is avoided.

  Next, a modified example will be described. In this modification, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  FIG. 4 is a diagram showing a circuit configuration of the magnetic encoder unit 1 according to this modification. In the magnetic encoder unit 1, the detection unit 7 includes a photocoupler 35 and a photocoupler 36. Each of the photocoupler 35 and the photocoupler 36 has a light emitting element and a light receiving element therein.

  The anode 35 a of the light emitting element of the photocoupler 35 is connected to the terminal 23 a of the power generation unit 4. The cathode 35 c of the light emitting element of the photocoupler 35 is connected to the terminal 23 b of the power generation unit 4. The ground terminal 35g of the light receiving element of the photocoupler 35 is connected to the ground line GL. A power supply terminal 35p of the light receiving element of the photocoupler 35 is connected to the power supply line PL. The output terminal 35 b of the light receiving element of the photocoupler 35 is connected to the first input terminal 27 a of the counter 27.

  When the forward current I1 is output from the power generation unit 21, a current flows through the light emitting element of the photocoupler 35, and the light emitted from the light emitting element causes the power supply terminal 35g and the output terminal 35b of the light receiving element to have a resistance or the like. Energize through. Therefore, a voltage corresponding to the voltage of the power supply line PL is output from the output terminal 35b of the photocoupler 35. The voltage output from the output terminal 35b of the photocoupler 35 takes a preset value less than the voltage of the power supply line PL. When the current I2 in the reverse direction is output from the power generation unit 21, no current flows through the light emitting element of the photocoupler 35. Therefore, the potential of the output terminal 35b of the photocoupler 35 is the same as the potential of the ground terminal 35g. Become. Thus, the photocoupler 35 is a detection unit that binarizes the electric power generated by the current I1 flowing in the forward direction.

  The photocoupler 36 has the same configuration as that of the photocoupler 35, but the connection relationship between the anode and the cathode of the light emitting element is different from that of the photocoupler 35. In the light-emitting element of the photocoupler 36, the anode 36a is connected to the terminal 23b of the power generation unit 4, and the cathode 36c is connected to the terminal 23a. The light receiving element of the photocoupler 36 has a ground terminal 36g connected to the ground line GL and a power supply terminal 36p connected to the power supply line PL. The output terminal 36 b of the light receiving element of the photocoupler 36 is connected to the second input terminal 27 b of the counter 27.

  When the current I2 in the reverse direction is output from the power generation unit 21, a current flows through the light emitting element of the photocoupler 36, and the light emitted from the light emitting element causes the power supply terminal 36g and the output terminal 26b of the light receiving element to have resistance or the like. Energize through. Therefore, a voltage corresponding to the voltage of the power supply line PL is output from the output terminal 36b of the photocoupler 36. When the forward current I1 is output from the power generation unit 21, no current flows through the light emitting element of the photocoupler 36. Therefore, the potential of the output terminal 36b of the photocoupler 36 is the same as the potential of the ground terminal 36g. Become. Thus, the photocoupler 36 is a detection unit that binarizes the electric power generated by the current I2 flowing in the reverse direction.

  In this modification, when a predetermined position of the magnet 3 passes in the vicinity of the power generation unit 4, a current is output from the power generation unit 21, and power is supplied to drive the rotation speed detection system. Also, a preset voltage is output from the output terminal 35b of the photocoupler 35 or the output terminal 36b of the photocoupler 36 as a control signal for a counter that determines whether the counting by the counter 27 is valid or invalid. This voltage can be controlled independently of the current output from the power generation unit 21 because the light emitting element and the light receiving element are electrically isolated in each photocoupler. Therefore, it becomes easy to match the level of the voltage (signal) output from the output terminal of each photocoupler with the operating voltage of the counter 27.

  By the way, to limit the level of the current output from the power generation unit 21, an overvoltage protection circuit such as a diode clipper may be used. However, when a photocoupler is used as shown in FIG. 4, energy loss can be suppressed. . Therefore, the electric power consumed in the rotation speed detection system is easily covered by the power generation of the power generation unit 4.

  In FIG. 4, a capacitor 37 is provided between the rectifying stack 30 and the regulator 32. The first electrode 37 a of the capacitor 37 is connected to a signal line that connects the output terminal 30 b of the rectifying stack 30 and the input terminal 32 a of the regulator 32. The second electrode 37b of the capacitor 37 is connected to the ground line GL. The capacitor 37 is a so-called smoothing capacitor and reduces pulsation to reduce the load on the regulator. The constant of the capacitor 37 is such that, for example, the power supply from the power adjustment unit 8 to the detection unit 7 and the storage unit 9 is maintained during the period from the detection of the rotation number by the detection unit 7 to the writing of the rotation number in the storage unit 9. Is set to

[Second Embodiment]
Next, a second embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  FIG. 5 is a diagram showing an encoder device EC according to the present embodiment. The encoder device EC includes a power generation unit 4 and a power generation unit 40. The power generation unit 40 has the same configuration as the power generation unit 4 described with reference to FIG. The power generation unit 40 is electrically connected to the signal processing unit 5.

  FIG. 6 is a plan view showing the arrangement of the power generation unit 4 and the power generation unit 40. As illustrated in FIG. 6, the power generation unit 40 is disposed at a position different from the power generation unit 4 in the circumferential direction of the rotation shaft SF. In the circumferential direction of the rotation axis SF, the angular position of the power generation unit 40 is set so as to have a phase difference from the angular position of the power generation unit 4. This phase difference is set to be greater than 0 ° and less than 180 °. The phase difference between the angular position of the power generation unit 4 and the angular position of the power generation unit 40 is set to 45 ° to 135 °, for example, and is set to about 90 ° in FIG.

  FIG. 7 is a circuit configuration diagram of the magnetic encoder unit 1 according to the present embodiment. The power generation unit 4 includes a magnetic sensing unit 20 and a power generation unit 21. The power generation unit 40 includes a magnetic sensitive part 41 and a power generation part 42. The power generation unit 42 generates power due to a change in the magnetic field in the magnetic sensitive unit 41.

  In the present embodiment, the power adjustment unit 8 includes a rectification stack 30, a rectification stack 43, a capacitor 37, and a regulator 32. In the power adjustment unit 8, elements other than the rectifying stack 43 are the same as those in FIG. The first input terminal 43 a of the rectifying stack 43 is connected to a terminal 40 a from which a forward current is output from the power generation unit 40. The second input terminal 43 b of the rectifying stack 43 is connected to a terminal 40 b from which current is output in the reverse direction from the power generation unit 40. The ground terminal 43g of the rectifying stack 43 is connected to the ground line GL. The output terminal 43 c of the rectifying stack 43 is connected to a signal line that connects the rectifying stack 30 and the regulator 32. The rectification stack 43 performs full-wave rectification based on the current output from the power generation unit 40. The rectification stack 43 supplies the power adjusted by the rectification to the regulator 32 through the output terminal 43c.

  In FIG. 7, the regulator 32 generates a predetermined voltage based on the output from the rectifying stack 30, and generates the predetermined voltage based on the output from the rectifying stack 43. The regulator 32 is shared by the power feeding system from the rectifying stack 30 and the power feeding system from the rectifying stack 43.

  A regulator 32 that generates a predetermined voltage based on the output from the rectifying stack 30 and another regulator that generates a predetermined voltage based on the output from the rectifying stack 43 may be provided. In FIG. 7, a rectification stack 30 that rectifies the current from the power generation unit 4 and a rectification stack 43 that rectifies the current from the power generation unit 40 are provided separately. May be rectified, and the current from the power generation unit 40 may be rectified.

  In the present embodiment, the rotation speed detection system in the encoder device EC includes a detection unit 7 and a storage unit 9. The detection unit 7 includes a detection unit 45, a detection unit 46, and a counter 27. The detection unit 45 detects the current flowing from the power generation unit 21. The detection unit 46 detects the current flowing from the power generation unit 42. The counter 27 counts the number of times that the detection unit 45 has detected the current and the number of times that the detection unit 46 has detected the current.

  The detection unit 45 includes a current-voltage converter 48 and an analog comparator 49. The current-voltage converter 48 is a converter that converts the current flowing from the power generation unit 21 into a voltage. The analog comparator 49 is a comparator that compares the voltage output from the current-voltage converter 48 with a predetermined voltage.

  The negative electrode 48 a of the current-voltage converter 48 is connected to the terminal 23 a of the power generation unit 4. The positive electrode 48 b of the current-voltage converter 48 is connected to the terminal 23 b of the power generation unit 4. The output terminal 48 c of the current / voltage converter 48 is connected to the input terminal 49 a of the analog comparator 49.

  The power supply terminal 49p of the analog comparator 49 is connected to the power supply line PL. The ground terminal 49g of the analog comparator 49 is connected to the ground line GL. The output terminal 49 c of the analog comparator 49 is connected to the first input terminal 27 a of the counter 27. For example, the analog comparator 49 compares the output voltage of the current-voltage converter 48 with a threshold (for example, a voltage that is half of the predetermined voltage) determined with respect to the predetermined voltage. The analog comparator 49 outputs an H level (high level) signal from the output terminal 48c when the output voltage of the current-voltage converter 48 is equal to or higher than the threshold value, and the output voltage of the current-voltage converter 48 is lower than the threshold value. An L level (low level) signal is output from the output terminal 48c.

  The detection unit 46 has the same configuration as the detection unit 45. The detection unit 46 includes a current / voltage converter 50 and an analog comparator 51. The current-voltage converter 50 is a converter that converts the current flowing from the power generation unit 42 into a voltage. The analog comparator 51 is a comparator that compares the voltage output from the current-voltage converter 50 with a predetermined voltage.

  The current-voltage converter 50 has a negative electrode 50 a connected to the terminal 40 a of the power generation unit 40 and a positive electrode 50 b connected to the terminal 40 b of the power generation unit 40. The output terminal 50 c of the current / voltage converter 50 is connected to the input terminal 51 a of the analog comparator 51.

  The analog comparator 51 has a power supply terminal 51p connected to the power supply line PL, and a ground terminal 51g connected to the ground line GL. The output terminal 51 c of the analog comparator 51 is connected to the second input terminal 27 b of the counter 27. The analog comparator 51 compares the output voltage of the current-voltage converter 50 with a threshold value determined for a predetermined voltage. The analog comparator 51 outputs an H level signal from the output terminal 50c when the output voltage of the current-voltage converter 50 is equal to or higher than the threshold value, and outputs an L level signal from the output terminal 50c when the output voltage is less than the threshold value.

  As described above, the detection unit 45 binarizes the power output from the power generation unit 21, and the detection unit 46 binarizes the power output from the power generation unit 42. The counter 27 uses the H level signal output from the detection unit 45 and the H level signal output from the detection unit 46 as control signals, and counts the number of rotations of the rotary shaft SF. The counter 27 supplies the counted result to the storage unit 9. The storage unit 9 stores information on the rotation speed supplied from the counter 27.

  FIG. 8 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotation axis SF rotates counterclockwise (forward rotation). FIG. 9 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotation shaft SF rotates counterclockwise (reverse rotation).

  The “angular position” in FIGS. 8 and 9 is the magnet 3 in which the angular position of the magnet 3 where the power generation unit 4 is disposed on the position 3d of the magnet 3 (see FIG. 6) is 0 ° and the counterclockwise direction is positive. Indicates the angular position. The “arrangement” in FIGS. 8 and 9 indicates the positional relationship of the magnet 3, the power generation unit 4, and the power generation unit 40 at each angular position. The arrangement of elements when the angular position is 0 ° corresponds to the arrangement shown in FIG. In the magnet 3, the hatched portion corresponds to the N pole in FIG. 6 and the hatched portion corresponds to the S pole.

  8 and 9, the solid line indicates the magnetic field at the position of the power generation unit 4, and the broken line indicates the magnetic field at the position of the power generation unit 40. In the “magnetic field”, the magnetic field from the outside to the inside of the magnet 3 was positive (+), and the magnetic field from the inside to the outside of the magnet 3 was negative (−).

  “Power generation unit 1” in FIGS. 8 and 9 indicates the output of the power generation unit 4, and “Power generation unit 2” indicates the output of the power generation unit 40. In “power generation unit 1” and “power generation unit 2”, the output of current flowing in one direction from each power generation unit was positive (+), and the output of current flowing in the opposite direction was negative (−). “Regulator” in FIG. 8 and FIG. 9 indicates the output of the regulator 32, where the H level is represented by “H” and the L level is represented by “L”.

  “Comparator 1” in FIGS. 8 and 9 indicates the output of the analog comparator 49, and “Comparator 2” indicates the output of the analog comparator 51. In the output of each comparator, “RISE” is a RISE signal indicating that the output of the power generation unit is a forward current. In the output of each comparator, “FALL” is a FALL signal indicating that the output of the power generation unit is a current in the reverse direction. In “RISE” and “FALL”, the H level is represented by “H” and the L level is represented by “L”.

  8 and FIG. 9, “Status” indicates whether the storage unit 9 is in a set state or a reset state. In “Status”, “H” indicates that it is in the set state, and “L” indicates that it is in the reset state. 8 and 9, “write operation” indicates whether or not the storage unit 9 is performing a write operation. In “write operation”, “H” indicates that the write operation is being performed, and “L” indicates that the write operation is not being performed. “Counter” in FIGS. 8 and 9 indicates the number of rotations stored in the storage unit 9.

  First, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates counterclockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse flowing in the reverse direction (negative of “power generation unit 1”) at an angular position of 90 °. Further, the power generation unit 4 outputs a current pulse (positive of “power generation unit 1”) that flows in the forward direction at the angular position 270 °.

  The power generation unit 40 is arranged at a position shifted by 90 ° from the power generation unit 4 in the circumferential direction of the magnet 3. Therefore, the magnetic field felt by the power generation unit 40 is 90 degrees out of phase with the magnetic field felt by the power generation unit 4. The power generation unit 40 outputs a current pulse (negative of “power generation unit 2”) flowing in the opposite direction at an angular position of 180 °. Further, the power generation unit 40 outputs a current pulse (positive of “power generation unit 2”) that flows in the forward direction at an angular position of 0 °.

  When a current pulse is output from the power generation unit 4 at each of the angular position 90 ° and the angular position 270 °, the regulator 32 outputs power of a predetermined voltage. Further, when a current pulse is output from the power generation unit 40 at each of the angular position 0 ° and the angular position 180 °, the regulator 32 outputs power of a predetermined voltage. Each current pulse corresponds to, for example, power having a voltage of about 20 V, and the current flows for about several microseconds. The regulator 32 extends the duration of power supply by dropping the voltage of power generated by each current pulse to a predetermined voltage (for example, 3 V). Further, the period during which the output of the regulator 32 is at the H level is longer than the period from the rising edge to the falling edge of each current pulse.

  At the output of the analog comparator 49 (“Comparator 1”), the RISE signal is maintained at the L level in a state in which no power is supplied, and receives the output of the power generation unit 4 at the angular position 270 ° and becomes the H level. Become. The FALL signal is maintained at the L level in a state where no power supply is received, and becomes the H level upon receiving the output of the power generation unit 4 at the angular position of 90 °. When the counter 27 shown in FIG. 7 detects that the RISE signal from the analog comparator 49 is at the L level and the FALL signal is at the H level, the counter value (number of rotations) is increased (+1). An up signal indicating this is output to the storage unit 9.

  At the output of the analog comparator 51 (“Comparator 2”), the RISE signal is maintained at the L level in a state where no power is supplied, and the output of the power generation unit 40 at the angular position 0 ° is received and becomes the H level. Become. The FALL signal is maintained at the L level in a state where no power supply is received, and becomes the H level in response to the output of the power generation unit 40 at the angular position of 180 °.

  The storage unit 9 is set to the set state when the analog comparator 51 outputs the H level of the RISE signal. When the storage unit 9 receives the up signal from the counter 27 in the set state, the storage unit 9 updates the stored number of rotations to a value increased by one. For example, in the count-up operation, the counter 27 reads the rotation number stored in the storage unit 9 and outputs the rotation number obtained by increasing the rotation number by 1 to the storage unit 9 as an up signal. The storage unit 9 is set to the reset state when the analog comparator 51 outputs the H level of the FALL signal.

  The magnetic encoder unit 1 performs the above-described operation every time power is output from the power generation unit 4 or the power generation unit 40 in accordance with the rotation of the rotation shaft SF. FIG. 8 shows the operation of the magnetic encoder unit 1 during two rotations of the rotating shaft SF. The magnetic encoder unit 1 performs the same operation in the first rotation and the next rotation in FIG. Do. For example, the rotation number stored in the storage unit 9 at the angular position 0 ° of the n-th rotation is n, and at the angular position 90 °, the counter 27 supplies an up signal to the storage unit 9, and the storage unit 9 The stored counter value is updated to n + 1. Similarly, in the next rotation, at the angular position of 90 °, the counter 27 supplies an up signal to the storage unit 9, and the storage unit 9 updates the stored counter value to n + 2.

  Next, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates clockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse (negative of “power generation unit 1”) flowing in the opposite direction at an angular position 270 ° rotated 90 ° clockwise from the angular position 0 °. Further, the power generation unit 4 outputs a current pulse (positive of “power generation unit 1”) that flows in the forward direction at an angular position of 90 ° rotated 270 ° clockwise from the angular position of 0 °.

  The power generation unit 40 outputs a current pulse flowing in the opposite direction (negative of “power generation unit 2”) at an angular position of 0 °. Further, the power generation unit 40 outputs a current pulse (positive of “power generation unit 2”) flowing in the forward direction at an angular position of 180 °.

  When a current pulse is output from the power generation unit 4 at each of the angular position 90 ° and the angular position 270 °, the regulator 32 outputs power of a predetermined voltage. Further, when a current pulse is output from the power generation unit 40 at each of the angular position 0 ° and the angular position 180 °, the regulator 32 outputs power of a predetermined voltage.

  In the output of the analog comparator 49, the RISE signal is maintained at the L level in a state where no power is supplied, and at the angular position 90 °, the output of the power generation unit 4 is received and becomes the H level. The FALL signal is maintained at the L level in a state where no power supply is received, and the output of the power generation unit 4 is received at the angular position 270 ° and becomes the H level. When the counter 27 shown in FIG. 7 detects that the RISE signal from the analog comparator 49 is at the H level and the FALL signal is at the L level, the counter value (the number of rotations) is decreased (−1). A down signal indicating that this is to be performed is output to the storage unit 9.

  In the output of the analog comparator 51, the RISE signal is maintained at the L level in a state where no power is supplied, and the output of the power generation unit 40 is received at the angular position 0 ° and becomes the H level. The FALL signal is maintained at the L level in a state where no power supply is received, and the output of the power generation unit 40 is received at the angular position 180 ° and becomes the H level. The storage unit 9 is set to the set state when the analog comparator 51 outputs the H level of the RISE signal. When the storage unit 9 receives the down signal from the counter 27 in the set state, the storage unit 9 updates the stored number of revolutions to a value reduced by one. For example, in the count-down operation, the counter 27 reads the rotation number stored in the storage unit 9 and outputs the rotation number obtained by reducing the rotation number by 1 to the storage unit 9 as an up signal. The storage unit 9 is set to the reset state when the analog comparator 51 outputs the H level of the FALL signal.

  The magnetic encoder unit 1 performs the above-described operation every time power is output from the power generation unit 4 or the power generation unit 40 in accordance with the rotation of the rotation shaft SF. FIG. 9 shows the operation of the magnetic encoder unit 1 during two rotations of the rotating shaft SF. The magnetic encoder unit 1 performs the same operation in the first rotation and the next rotation in FIG. Do. For example, the rotation number stored in the storage unit 9 at the angular position 0 ° of the (n + 2) th rotation is n + 2, and the counter 27 supplies a down signal to the storage unit 9 at the angular position 90 ° rotated by −270 °. The storage unit 9 updates the stored counter value to n + 1. Similarly in the next rotation, at the angular position of 90 °, the counter 27 supplies a down signal to the storage unit 9, and the storage unit 9 updates the stored counter value to n.

  The magnetic encoder unit 1 according to this embodiment as described above performs a series of operations when there is an output from the power generation unit 21 or the power generation unit 42. Further, the magnetic encoder unit 1 maintains a state in which the operating current becomes zero during a period in which there is no output from either the power generation unit 21 or the power generation unit 42. Thus, the magnetic encoder unit 1 is dynamically driven in response to the predetermined position of the magnet 3 passing through the vicinity of the power generation unit 4 or the power generation unit 40. Therefore, the magnetic encoder unit 1 can omit a battery for extending the power consumed by the detection system and can extend its life.

  Meanwhile, the storage unit 9 is set by the RISE signal from the analog comparator 51, and is reset by the FALL signal. That is, the storage unit 9 is in a writable state when the angular position of the magnet 3 is in a section from 0 ° to 180 °. The detection unit 46 including the analog comparator 51 uses the result of detecting the current from the power generation unit 42 to determine whether or not the angular position of the magnet 3 is in the interval from 0 ° to 180 °. Thus, the magnetic encoder unit 1 according to the present embodiment can detect the rotational speed of the magnet 3 while detecting which section the angular position of the magnet 3 is in.

[Third Embodiment]
Next, a third embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  FIG. 10 is a diagram showing an encoder device EC according to the present embodiment. The encoder device EC includes a power generation unit 4 and a magnetic sensor 55. The magnetic sensor 55 is electrically connected to the signal processing unit 5. The magnetic sensor 55 detects a change in the magnetic field accompanying the rotation of the magnet 3 using the electric power generated by the power generation unit 4.

  FIG. 11A is a plan view showing the arrangement of the magnetic sensor 55. The magnetic sensor 55 is disposed at a position different from the power generation unit 4 in the circumferential direction of the magnet 3. In the circumferential direction of the rotation axis SF, the angular position of the magnetic sensor 55 is set to have a phase difference from the angular position of the power generation unit 4. This phase difference is set to be greater than 0 ° and less than 180 °. The phase difference between the angular position of the power generation unit 4 and the angular position of the magnetic sensor 55 is set to 45 ° to 135 °, for example, and is set to about 90 ° in FIG.

  FIG. 11B is a circuit configuration diagram of the magnetic sensor 55. The magnetic sensor 55 includes a magnetoresistive element 56, a bias magnet (not shown) that applies a magnetic field having a certain strength to the magnetoresistive element 56, and a waveform shaping circuit (not shown) that shapes the waveform from the magnetoresistive element 56. ). The magnetoresistive element 56 has a full bridge shape in which the element 56a, the element 56b, the element 56c, and the element 56d are connected in series. A signal line between the element 56a and the element 56c is connected to the power supply terminal 55p. A signal line between the element 56b and the element 56d is connected to the ground terminal 55g. A signal line between the element 56a and the element 56b is connected to the first output terminal 55a. A signal line between the element 56c and the element 56d is connected to the second output terminal 55b.

  FIG. 12 is a circuit configuration diagram of the magnetic encoder unit 1 according to the present embodiment. The rotation number detection system in the encoder device EC includes a detection unit 7 and a storage unit 9. The magnetic encoder unit 1 includes a detection unit 45 and a detection unit 57. As described in the second embodiment, the detection unit 45 detects the angular position of the magnet 3 by detecting the current from the power generation unit 21. The detection unit 57 includes a magnetic sensor 55 and an analog comparator 58. The detector 57 detects a change in the magnetic field accompanying the rotation of the magnet 3.

  A power supply terminal 55p of the magnetic sensor 55 is connected to the power supply line PL. The ground terminal 55g of the magnetic sensor 55 is connected to the ground line GL. The output terminal of the magnetic sensor 55 is connected to the analog comparator 58. In the present embodiment, the output terminal of the magnetic sensor 55 outputs a voltage corresponding to the difference between the potential of the second output terminal 55b shown in FIG. 11B and the reference potential. The analog comparator 58 outputs an H level signal from the output terminal when the output voltage of the magnetic sensor 55 is equal to or higher than the threshold value, and outputs an L level signal from the output terminal when the output voltage is lower than the threshold value. The power supply terminal 58p of the analog comparator 58 is connected to the power supply line PL. The ground terminal 58g of the analog comparator 58 is connected to the ground line GL. An output terminal 58 b of the analog comparator 58 is connected to the counter 27.

  FIG. 13 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotation axis SF rotates counterclockwise (forward rotation). FIG. 14 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotation shaft SF rotates counterclockwise (reverse rotation). “Angle position”, “arrangement”, and “counter” are the same as those in FIG. In “magnetic field”, the magnetic field that the magnet 3 gives to the magnetic encoder is indicated by a broken line. “Power generation unit”, “Regulator”, and “Comparator 1” indicate the output of the power generation unit 4, the output of the regulator 32, and the output of the analog comparator 49, respectively.

  In “Magnetic field on MR sensor” in FIG. 13, the magnetic field formed by the magnet 3 is indicated by a long broken line, the magnetic field formed by the bias magnet is indicated by a short broken line, and the combined magnetic field is indicated by a solid line. “MR sensor” indicates the output when the magnetic sensor is always driven, the output from the first output terminal 55a in FIG. 11B is indicated by a broken line, and the output from the second output terminal 55b is indicated by a solid line. . “Comparator 2” indicates an output from the analog comparator 58. In the present embodiment, the magnetic sensor 55 is so-called dynamic drive (intermittent drive), and is driven during a period in which power is output from the power generation unit 4 and is not driven during a period in which power is not output from the power generation unit 4. In FIG. 13, the output of the analog comparator 58 when the magnetic sensor 55 is always driven is shown as “always driven”, and the output of the analog comparator 58 when the magnetic sensor 55 is driven intermittently is shown as “intermittent drive”. It was.

  First, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates counterclockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse flowing in the opposite direction (negative of “power generation unit”) at an angular position of 90 °. Further, the power generation unit 4 outputs a current pulse (positive of “power generation unit”) that flows in the forward direction at an angular position of 270 °. When a current pulse is output from the power generation unit 4 at the angular position of 90 ° and the angular position of 270 °, the regulator 32 outputs power of a predetermined voltage.

  In the “magnetic field on the MR sensor”, the direction of the bias magnetic field (short broken line) is constant regardless of the angular position of the magnet 3 and is directed from the center of the magnet 3 to the position 3d (see FIG. 11A). is there.

  The direction of the magnetic field (long broken line) formed by the magnet 3 is a direction rotated 90 ° counterclockwise from the bias magnetic field in a range larger than the angular position 0 ° and smaller than the angular position 180 °. The direction of the combined magnetic field (solid line) is a direction rotated counterclockwise from the bias magnetic field by an angle larger than 0 ° and smaller than 90 ° within a range larger than the angular position 0 ° and smaller than 180 °.

  “The direction of the magnetic field (long broken line) formed by the magnet 3 is 90 ° clockwise from the bias magnetic field in a range larger than the angular position 180 ° and smaller than the angular position 360 ° (0 ° of the next rotation). The direction of the combined magnetic field (solid line) is a direction rotated clockwise from the bias magnetic field by an angle larger than 0 ° and smaller than 90 ° in a range larger than the angular position 180 ° and smaller than the angular position 360 °.

  The output (broken line) from the first output terminal 55a of the magnetic sensor 55 has a negative sine wave shape in the range from the angular position 0 ° to the angular position 180. The output (solid line) from the second output terminal 55b of the magnetic sensor 55 has a positive sine wave shape in the range from the angular position 0 ° to the angular position 180. The output of the analog comparator 58 that is always driven is held at the L level in a state where the output of the second output terminal 55b of the magnetic sensor 55 is negative, and is at the H level in the range from the angular position 0 ° to the angular position 180 °. Become. Actually, since the magnetic sensor 55 and the analog comparator 58 are selectively driven during a period in which electric power is output from the power generation unit 4, the output of the intermittently driven analog comparator 58 is not supplied with electric power. It is held at the L level and becomes the H level during the period in which power is output from the power generation unit 4 in the range from the angular position 0 ° to the angular position 180 °.

  The counter 27 shown in FIG. 12 increments the counter by 1 when it detects that the RISE signal from the analog comparator 49 is L level, the FALL signal is H level, and the output signal of the analog comparator 58 is H level. The storage unit 9 updates the stored number of rotations to a value increased by one.

  Next, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates clockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse flowing in the opposite direction (negative of “power generation unit”) at an angular position 270 ° rotated 90 ° clockwise from the angular position 0 °. Further, the power generation unit 4 outputs a current pulse (positive of “power generation unit”) that flows in the forward direction at an angular position of 90 ° that is rotated 270 ° clockwise from the angular position of 0 °. When a current pulse is output from the power generation unit 4 at each of the angular position 90 ° and the angular position 270 °, the regulator 32 outputs power of a predetermined voltage.

  In the output of the analog comparator 49, the RISE signal is maintained at the L level in a state where no power is supplied, and at the angular position 90 °, the output of the power generation unit 4 is received and becomes the H level. The FALL signal is maintained at the L level and receives the output of the power generation unit 4 at the angular position 270 ° and becomes the H level. 12 detects that the RISE signal from the analog comparator 49 is at the H level, the FALL signal is at the L level, and the output signal from the analog comparator 58 is at the H level, the counter 27 shown in FIG. The storage unit 9 updates the stored number of rotations to a value reduced by 1.

  The magnetic encoder unit 1 according to this embodiment as described above performs a series of operations when there is an output from the power generation unit 21. Further, the magnetic encoder unit 1 maintains a state in which the operating current becomes zero during a period in which there is no output from the power generation unit 21. Thus, the magnetic encoder unit 1 is dynamically driven in response to the predetermined position of the magnet 3 passing through the vicinity of the power generation unit 4. Therefore, the magnetic encoder unit 1 can omit a battery for extending the power consumed by the detection system and can extend its life.

  In the present embodiment, the output of the detection unit 57 including the magnetic sensor 55 and the analog comparator 58 becomes the H level when the angular position of the magnet 3 is in the section from 0 ° to 180 °. That is, the detection unit 57 uses the detection result of the magnetic sensor 55 to determine whether or not the angular position of the magnet 3 is in a section from 0 ° to 180 °. Thus, the magnetic encoder unit 1 according to the present embodiment can detect the rotational speed of the magnet 3 while detecting which section the angular position of the magnet 3 is in.

  By the way, the stronger the magnetic field formed by the magnet 3 in the magnetic sensor 55, the larger the output of the magnetic sensor 55 and the more stable the output from the analog comparator 58. Therefore, the robustness of the magnetic encoder unit 1 increases. Here, since the magnetic sensor 55 is driven during a period in which electric power is output from the power generation unit 4, it is preferable that the magnetic sensor 55 be disposed at a position where the magnetic field formed by the magnet 3 is strong during this period. Further, since the power generation unit 4 generates power when the angular position 90 ° or the angular position 270 ° of the magnet 3 passes in the vicinity of the power generation unit 4, the magnetic sensor 55 is connected to the power generation unit 4 in the circumferential direction of the magnet 3. If the phase difference is not less than 45 ° and not more than 135 °, it is easy to ensure the output, and if it is about 90 °, the output is maximized.

[Fourth Embodiment]
Next, a fourth embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  FIG. 15 is a diagram showing an encoder device EC according to the present embodiment. The encoder device EC includes a power generation unit 4, a power generation unit 40, a magnetic sensor 55, and a magnetic sensor 60. The power generation unit 4, the power generation unit 40, and the power adjustment unit 8 are the same as those in the second embodiment described with reference to FIGS. The magnetic sensor 55 and the magnetic sensor 60 are each electrically connected to the signal processing unit 5. The magnetic sensor 55 and the magnetic sensor 60 detect the change in the magnetic field accompanying the rotation of the magnet 3 using the electric power generated by the power generation unit 4 and the power generation unit 40, respectively. The magnetic sensor 60 has the same configuration as the magnetic sensor 55 described with reference to FIG.

  FIG. 16 is a plan view showing the arrangement of the magnetic sensor 55 and the magnetic sensor 60. The power generation unit 40 is disposed 90 ° away from the power generation unit 4 in the circumferential direction of the magnet 3. The phase difference between the magnetic sensor 55 and the power generation unit 40 in the circumferential direction of the magnet is set in a range of 45 ° to 135 °, for example, and is set to about 45 ° in FIG. In the magnetic sensor 60, the phase difference between the magnetic sensor 60 and the power generation unit 40 in the circumferential direction of the magnet is set in a range of 45 ° to 135 °, for example, and is set to about 135 ° in FIG. In FIG. 16, the magnetic sensor 60 is disposed at an angular position shifted by 90 ° from the magnetic sensor 55, and is disposed at an angular position shifted by −135 ° with the counterclockwise direction being positive from the power generation unit 4.

  FIG. 17 is a circuit configuration diagram of the magnetic encoder unit 1 according to the present embodiment. In the present embodiment, the magnetic encoder unit 1 includes a first detection system that detects the number of rotations using the output from the power generation unit 21 and the output from the power generation unit 42 as detection signals, the output from the magnetic sensor 55, and the magnetic sensor 60. And a second detection system for detecting the rotational speed using the output from the detection signal as a detection signal. The first detection system is the same as in the second embodiment. The second detection system includes a magnetic sensor 55, an analog comparator 58, a magnetic sensor 60, an analog comparator 61, a counter 62, and a storage unit 63.

  A power supply terminal 55p of the magnetic sensor 55 is connected to the power supply line PL. The ground terminal 55g of the magnetic sensor 55 is connected to the ground line GL. The output terminal of the magnetic sensor 55 is connected to the input terminal 58 a of the analog comparator 58. The power supply terminal 58p of the analog comparator 58 is connected to the power supply line PL. The ground terminal 58g of the analog comparator 58 is connected to the ground line GL. The output terminal 58 b of the analog comparator 58 is connected to the first input terminal 62 a of the counter 62.

  The power supply terminal 60p of the magnetic sensor 60 is connected to the power supply line PL. The ground terminal 60g of the magnetic sensor 60 is connected to the ground line GL. The output terminal of the magnetic sensor 60 is connected to the input terminal 61 a of the analog comparator 61. The power supply terminal 61p of the analog comparator 61 is connected to the power supply line PL. The ground terminal 61g of the analog comparator 61 is connected to the ground line GL. The output terminal 61 b of the analog comparator 61 is connected to the second input terminal 62 b of the counter 62.

  The counter 62 includes, for example, a CMOS logic circuit, and performs a counting process using a voltage supplied via the first input terminal 62a and a voltage supplied via the second input terminal 62b as control signals. The power supply terminal 62p of the counter 62 is connected to the power supply line PL. The ground terminal 62g of the counter 62 is connected to the ground line GL. The counter 62 performs a counting process using electric power supplied via the power supply terminal 62p and the ground terminal 62q. The counter 62 supplies the result of the counting process to the storage unit 63.

  The storage unit 63 includes a nonvolatile memory 64 and stores information related to the counting result of the counter 62. The storage unit 63 stores the number of rotations of the magnet 3 counted using the detection result of the magnetic sensor 55 and the detection result of the magnetic sensor 60. A power supply terminal 63p of the storage unit 63 is connected to the power supply line PL. The ground terminal 63g of the storage unit 63 is connected to the ground line GL. The storage unit 63 stores information in the nonvolatile memory 64 using power supplied via the power supply terminal 63p and the ground terminal 63g.

  FIG. 18 is a timing chart showing the operation of the magnetic encoder unit 1. In FIG. 18, “magnetic field on the MR sensor 1” is a magnetic field formed on the magnetic sensor 55. In the “magnetic field on the MR sensor 1”, the magnetic field formed by the magnet 3 is indicated by a long broken line, the magnetic field formed by the bias magnet is indicated by a short broken line, and the combined magnetic field is indicated by a solid line. “MR sensor 1” indicates an output when the magnetic sensor 55 is always driven, an output from the first output terminal 55a (see FIG. 11B) is represented by a broken line, and an output from the second output terminal 55b is indicated. Represented by a solid line. “Comparator 3” indicates an output from the analog comparator 58. In the present embodiment, the magnetic sensor 55 is so-called dynamic drive (intermittent drive), and is driven during a period in which power is output from the power generation unit 4 and is not driven during a period in which power is not output from the power generation unit 4. In FIG. 18, the output of the analog comparator 58 when the magnetic sensor 55 is always driven is shown as “always driven”, and the output of the analog comparator 58 when the magnetic sensor 55 is driven intermittently is shown as “intermittent drive”. It was.

  In FIG. 18, “magnetic field on the MR sensor 2” is a magnetic field formed on the magnetic sensor 60. In the “magnetic field on the MR sensor 2”, the magnetic field formed by the magnet 3 is indicated by a long broken line, the magnetic field formed by the bias magnet is indicated by a short broken line, and the combined magnetic field is indicated by a solid line. “MR sensor 2” indicates an output when the magnetic sensor 60 is constantly driven, an output from the first output terminal is represented by a broken line, and an output from the second output terminal is represented by a solid line. “Comparator 4” indicates an output from the analog comparator 61. In FIG. 18, the output of the analog comparator 61 when the magnetic sensor 60 is constantly driven is shown as “always drive”, and the output of the analog comparator 61 when the magnetic sensor 60 is driven intermittently is shown as “intermittent drive”. It was.

  In the present embodiment, the first detection system that detects the rotational speed using the current output from the power generation unit 21 and the current output from the power generation unit 42 as detection signals operates in the same manner as in the second embodiment. Here, the operation of the second detection system that detects the rotation speed using the output of the magnetic sensor 55 and the output of the magnetic sensor 60 as detection signals will be mainly described. The output of the magnetic sensor 60 and the output of the magnetic sensor 60 have a phase difference of 90 °, and the second detection system detects the rotational speed using this phase difference.

  First, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates counterclockwise will be described. The output of the magnetic sensor 55 (“MR sensor 1”) is in the form of a positive sine wave in the range from the angular position 0 ° to the angular position 180 °. In this angular range, the power generation unit 40 outputs power at an angular position of 45 °, and the power generation unit 4 outputs power at an angular position of 135 °. The magnetic sensor 55 and the analog comparator 49 are driven by electric power supplied at each of the angular position 45 ° and the angular position 135 °. A signal output from the analog comparator 58 (hereinafter referred to as an A-phase signal) is maintained at the L level in a state where no power is supplied, and becomes the H level at each of the angular position 45 ° and the angular position 135 °. .

  Further, the output of the magnetic sensor 60 (“MR sensor 2”) is a positive sine wave in the range from the angular position 270 ° (−90 °) to the angular position 90 °. In this angular range, the power generation unit 4 outputs power at the angular position 315 ° (−45 °), and the power generation unit 40 outputs power at the angular position 45 °. The magnetic sensor 60 and the analog comparator 61 are driven by electric power supplied at each of the angular position 315 ° and the angular position 45 °. A signal output from the analog comparator 61 (hereinafter referred to as a B phase signal) is maintained at the L level in a state where no power is supplied, and is at the H level at each of the angular position 315 ° and the angular position 45 °. . The B phase signal is a signal that is 90 ° out of phase with the A phase signal.

  Here, when the A-phase signal supplied to the counter 62 is at the H level (H) and the B-phase signal supplied to the counter 62 is at the L level, the set of these signal levels is expressed as (H, L ). In FIG. 18, the set of signal levels is (L, H) at an angular position of 315 °, the set of signal levels is (H, H) at an angular position of 45 °, and the set of signal levels is (H, H) at an angular position of 135 °. , L).

  The counter 62 counts the number of rotations while discriminating the rotation direction using the phase difference between the A phase signal and the B phase signal. For example, the counter 62 stores a set of signal levels in the storage unit 63 when one or both of the detected A-phase signal and B-phase signal are at the H level. When one or both of the next detected A-phase signal and B-phase signal are at the H level, the counter 62 reads the previous level set from the storage unit 63, and the previous level set and the current level set. The direction of rotation is determined by comparison with the set.

  For example, when the set of the current signal level is (H, L) and the previous signal level is (H, H), the angle position is 135 ° in the current detection, and the angle in the previous detection. Since the position is 45 °, it can be seen that it is counterclockwise (forward rotation). Further, when the set of the current signal level is (H, L) and the previous signal level is (L, H), the angle position is 135 ° in the current detection, and the angle in the previous detection. Since the position is 315 ° (−45 °), it can be seen that the position is clockwise (reverse rotation).

  When the current level set is (H, L) and the previous level set is (H, H), the counter 62 sends an up signal indicating that the counter is increased to the storage unit 63. Supply. When the storage unit 63 detects an up signal from the counter 62, the storage unit 63 updates the stored number of revolutions to a value increased by one. The counter 62 stores a down signal indicating that the counter is to be down when the current level set is (H, L) and the previous level set is (L, H). To supply. When the storage unit 63 detects a down signal from the counter 62, the storage unit 63 updates the stored number of revolutions to a value reduced by one.

  The magnetic encoder unit 1 according to the present embodiment as described above includes a first detection system that uses the output from the power generation unit 21 and the output from the power generation unit 42 as detection signals, the output from the magnetic sensor 55, and the magnetic sensor 60. The second detection system that uses the output from the detection signal as a detection signal detects the number of rotations. The detection result of the second detection system can be used, for example, for detecting an abnormality by collating with the detection result of the first detection system. The encoder device EC may include an abnormality detection device that detects such an abnormality, or may include an informing device that notifies an abnormality detection result. Further, at least one of the abnormality detection device and the notification device may be a device outside the encoder device EC. Further, when the rotation speed cannot be read from the storage unit 9 due to a failure of the first detection system, the rotation number detected by the second detection system is read from the storage unit 63 and replaced with the detection result of the first detection system. It can also be used.

[Fifth Embodiment]
Next, a fifth embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  FIG. 19 is a diagram showing an encoder device EC according to the present embodiment. In the above-described embodiment, the magnetic encoder unit 1 of the encoder device EC is a stand-alone type device that performs a series of operations without receiving external power supply, but the magnetic encoder unit 1 of FIG. A power supply device 80 that can cover at least part of the power consumed by the detection system that detects the number of rotations of the rotating shaft SF can be connected.

  The power supply device 80 includes a battery 81 and a battery 82. The battery 81 and the battery 82 are a primary battery and a secondary battery, respectively. The battery 81 has an electromotive force of a first voltage (eg, 3.6V), and the battery 82 has an electromotive force of a second voltage (eg, 5.0V) different from the first voltage. The negative electrode of the battery 81 and the negative electrode of the battery 82 are connected to the ground terminal 63 via the ground line GL2.

  The positive electrode of the battery 81 is connected to the first power supply terminal 85 via the fuse 84. The positive electrode of the battery 82 is connected to the second power supply terminal 88 through the switch 86 and the fuse 87. A capacitor 90 is connected between a node 89a between the switch 86 and the fuse 87 and a node 89b of the ground line GL2.

  The encoder device EC includes a circuit 91 that receives power from the power supply device 80. The encoder device EC includes a first power supply terminal 92, a second power supply terminal 93, and a ground terminal 94. The first power supply terminal 92 of the encoder device EC is connected to the first power supply terminal 85 of the power supply device 80. The second power supply terminal 88 of the encoder device EC is connected to the second power supply terminal 93 of the power supply device 80. The ground terminal 94 of the encoder device EC is connected to the ground terminal 94 of the power supply device 80.

  The first power supply terminal 92 is connected to the power supply line PL of the magnetic encoder unit 1 through the diode 95. The second power supply terminal 88 is connected to the power supply line PL of the magnetic encoder unit 1 through the coil 96 and the diode 97. As described above, the power supply device 80 can supply power to the magnetic encoder unit 1.

  Since the encoder device EC according to the present embodiment drives the rotation speed detection system using the electric power generated by the power generation unit, the power supply device 80 can have a long life. As a result, for example, the maintenance frequency of the power supply device 80 can be lowered, and the maintenance frequency of the encoder device EC can be lowered. The power supply device 80 may include at least a part of a power supply system that supplies power to the optical encoder unit 2 and supplies power to the magnetic encoder unit 1 when the optical encoder unit 2 is driven. Also good. This power supply system may be a main power source of various devices such as a robot device on which the encoder device EC is mounted.

[Sixth Embodiment]
Next, a sixth embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. In the encoder device EC according to the present embodiment, the signal processing unit 5 includes a detection unit 7, a power adjustment unit 8, and a storage unit 9, similarly to FIG. The detection unit 7 detects rotation information of the rotation axis SF based on a change in the magnetic field formed by the magnet 3. The detection unit 7 detects the rotation speed of the rotation axis SF as rotation information. The detection unit 7 includes a magnetic sensor 55. The magnetic sensor 55 is electrically connected to the signal processing unit 5. The magnetic sensor 55 detects the magnetic field formed by the magnet 3 using the electric power generated by the power generation unit 4.

  The power adjustment unit 8 adjusts the power output from the power generation unit 4 to a predetermined voltage. The power adjustment unit 8 supplies at least a part of the power consumed by the detection unit 7 and at least a part of the power consumed by the storage unit 9. The storage unit 9 stores the detection result of the detection unit 7 using the power output from the power adjustment unit 8.

  FIG. 20A is a perspective view showing the magnet 3, the power generation unit 4, and the magnetic sensor 55. FIG. 20B is a diagram illustrating a magnetic field formed by the magnet 3. FIG. 20C is a circuit configuration diagram of the magnetic sensor 55. The magnet 3 may have the same configuration as in FIG. The magnet 3 is, for example, an annular member that is coaxial with the rotation axis SF. The magnet 3 may have a bar magnet configuration. The power generation unit 4 may have the same configuration as in FIG. In addition, the direction of the current flowing from the power generation unit 21 can be set in reverse by reversing the winding of the coil. The magnetic sensor 55 may be the same as that shown in FIGS. 11A and 11B, for example.

  FIG. 21 is a diagram illustrating a circuit configuration of the magnetic encoder unit 1. The magnetic encoder unit 1 according to the present embodiment detects the number of rotations of the rotating shaft SF and stores the detected number of rotations, and a power supply system that covers at least part of the power consumed by the detection system. including. Here, the detection system will be described first, and then the power supply system will be described.

  The detection system of the magnetic encoder unit 1 includes a detection unit 7 and a storage unit 9. The detection unit 7 includes a detection unit 126, a detection unit 127, and a counter 128. The detection unit 126 is a magnetic field detection unit that detects a change in the magnetic field formed by the magnet 3. The detection unit 127 is a power detection unit that detects rotation information of the rotation shaft SF based on a change in power output from the power generation unit 21. The counter 128 counts the number of rotations of the rotation shaft SF using the detection result of the detection unit 126 and the detection result of the detection unit 127.

  The detection unit 126 includes a magnetic sensor 55 and an analog comparator 129. A power supply terminal 55p of the magnetic sensor 55 is connected to the power supply line PL. The ground terminal 55g of the magnetic sensor 55 is connected to a ground line GL to which the same potential as the signal ground SG is supplied. The output terminal of the magnetic sensor 55 is connected to the input terminal 129a of the analog comparator 129. The magnetic sensor 55 detects the magnetic field formed by the magnet 3 using the power supplied via the power supply terminal 55p and the ground terminal 55g, and outputs the detection result (detection signal) to the analog comparator 129. In the present embodiment, the output terminal of the magnetic sensor 55 outputs a voltage corresponding to the difference between the potential of the second output terminal 55b shown in FIG. 20C and the reference potential.

  The analog comparator 129 is a comparator that compares the voltage output from the magnetic sensor 55 with a predetermined voltage. A power supply terminal 129p of the analog comparator 129 is connected to the power supply line PL. The ground terminal 129g of the analog comparator 129 is connected to the ground line GL. The analog comparator 129 binarizes the voltage output from the magnetic sensor 55 with the power supplied through the power supply terminal 129p and the ground terminal 129g. The analog comparator 129 outputs an H level (high level) signal from the output terminal when the output voltage of the magnetic sensor 55 is equal to or higher than the threshold value, and outputs an L level (low level) signal from the output terminal when the output voltage is less than the threshold value. Is output. The output terminal 129b of the analog comparator 129 is connected to the first input terminal 128a of the counter 128. The analog comparator 129 supplies an H level or L level signal to the first input terminal 128a of the counter 128 via the output terminal 129b.

  The detection unit 127 includes a current-voltage converter 130 and an analog comparator 131. The current-voltage converter 130 is a converter that converts the current flowing from the power generation unit 21 into a voltage. The negative electrode 130 a of the current-voltage converter 130 is connected to the terminal 23 a of the power generation unit 4. The positive electrode 130 b of the current-voltage converter 130 is connected to the terminal 23 b of the power generation unit 4. The output terminal 133 c of the current / voltage converter 130 is connected to the input terminal 131 a of the analog comparator 31.

  The analog comparator 131 is a comparator that compares the voltage output from the current-voltage converter 130 with a predetermined voltage. The power supply terminal 131p of the analog comparator 131 is connected to the power supply line PL. The ground terminal 131g of the analog comparator 131 is connected to the ground line GL. The analog comparator 131 binarizes the voltage output from the current-voltage converter 130 with the power supplied via the power supply terminal 131p and the ground terminal 131g. The analog comparator 131 outputs an H level (high level) signal from the output terminal 131c when the output voltage of the current-voltage converter 130 is equal to or higher than the threshold value, and outputs an L level (low level) from the output terminal 131c when the output voltage is less than the threshold value. Level) signal. The output terminal 131 c of the analog comparator 131 is connected to the second input terminal 128 b of the counter 128. The analog comparator 131 supplies an H level or L level signal to the second input terminal 128b of the counter 128 via the output terminal 131c.

  The counter 128 includes, for example, a CMOS logic circuit, and performs a counting process using a voltage supplied via the first input terminal 128a and a voltage supplied via the second input terminal 128b as control signals. The power supply terminal 128p of the counter 128 is connected to the power supply line PL. The ground terminal 128g of the counter 128 is connected to the ground line GL. The counter 128 performs a counting process using the power supplied through the power supply terminal 128p and the ground terminal 128g. The counter 128 supplies the counting result to the storage unit 9.

  The storage unit 9 stores information related to the rotation speed detected by the counter 128. The power supply terminal 9p of the storage unit 9 is connected to the power supply line PL. The ground terminal 9g of the storage unit 9 is connected to the ground line GL. The storage unit 9 writes information using power supplied via the power supply terminal 9p and the ground terminal 9g. The storage unit 9 includes a nonvolatile memory 132 and can hold information written while power is supplied even in a state where power is not supplied.

  Generally, the rotation speed detection system receives power supplied from a battery or the like and performs detection and information storage. This battery is replaced during regular maintenance. In an encoder device having such a detection system, when the battery life is shorter than other components, it is necessary to set the maintenance cycle according to the battery life, and the maintenance frequency and cost are high. There is a possibility.

  The encoder device EC according to the present embodiment provides at least a part of the power consumed by the rotation speed detection system by power generation. Therefore, it is possible to omit a battery for covering the power consumption of the detection system, or to extend the life of the battery. As a result, for example, it is possible to reduce the frequency and cost of maintenance. Hereinafter, the power supply system of the encoder device EC will be described.

  The power supply system of the encoder device EC includes a power generation unit 4 and a power adjustment unit 8. The power adjustment unit 8 includes a rectification stack 133, a capacitor 134, and a regulator 135.

  The rectification stack 133 is a rectifier that rectifies the current flowing from the power generation unit 21. The first input terminal 133 a of the rectifying stack 133 is connected to the terminal 23 a of the power generation unit 4. The second input terminal 133 b of the rectifying stack 133 is connected to the terminal 23 b of the power generation unit 4. The ground terminal 133g of the rectifying stack 133 is connected to the ground line GL. The output terminal 133 c of the rectifying stack 133 is connected to the input terminal 135 a of the regulator 135.

  A first current flowing in the forward direction from the power generation unit 21 is supplied to the first input terminal 133 a of the rectifying stack 133. The second input terminal 133b of the rectifying stack 133 is supplied with a second current that flows in the reverse direction (reverse to the first current) from the power generation unit 21. The rectification stack 133 performs full-wave rectification based on these current outputs. The rectification stack 133 supplies the power adjusted by the rectification to the regulator 135 via the output terminal 133c.

  The regulator 135 includes, for example, a low-loss three-terminal regulator. The ground terminal 135g of the regulator 135 is connected to the ground line GL. The output terminal 135b of the regulator 135 is connected to the power supply line PL. The DC power rectified by the rectifying stack 133 is supplied to the input terminal 135a of the regulator 135, and the regulator 135 generates a predetermined voltage with little ripple (pulsation) based on this DC voltage. The reference potential of the predetermined voltage is the same as the potential of the signal ground SG supplied via the ground line GL and the ground terminal 135g. The predetermined voltage is set to the operating voltage of the counter 128, and is set to 3 V, for example, when the counter 128 is configured by a CMOS or the like. The operating voltages of the analog comparator 129, the analog comparator 131, and the nonvolatile memory 132 of the storage unit 9 are set to the same voltage as a predetermined voltage, for example. The power adjustment unit 8 sets the potential of the power supply line PL to a predetermined voltage with respect to the potential of the ground line GL at least in a period from when the detection unit 7 detects the rotation speed to when the storage unit 9 writes the rotation speed.

  The capacitor 134 reduces the pulsation of the power output from the rectifying stack 133. The first electrode 134 a of the capacitor 134 is connected to a signal line that connects the output terminal 133 b of the rectifying stack 133 and the input terminal 135 a of the regulator 135. The second electrode 134b of the capacitor 134 is connected to the ground line GL. This capacitor 134 is a so-called smoothing capacitor, and reduces the load of the regulator by reducing pulsation. The constant of the capacitor 134 is such that, for example, the power supply from the power adjustment unit 8 to the detection unit 7 and the storage unit 9 is maintained during the period from the detection of the rotation number by the detection unit 7 to the writing of the rotation number in the storage unit 9. Is set to

  The magnetic encoder unit 1 according to the present embodiment operates in the same manner as described with reference to FIGS. 14 and 15, for example. The magnetic encoder unit 1 according to this embodiment as described above performs a series of operations when there is an output from the power generation unit 21. Further, the magnetic encoder unit 1 maintains a state in which the operating current becomes zero during a period in which there is no output from the power generation unit 21. Thus, the magnetic encoder unit 1 is dynamically driven in response to the predetermined position of the magnet 3 passing through the vicinity of the power generation unit 4. Therefore, the magnetic encoder unit 1 can omit a battery for supplying power consumed by the detection system, or can have a long life.

  In the present embodiment, the output of the detection unit 126 including the magnetic sensor 55 and the analog comparator 129 becomes the H level when the angular position of the magnet 3 is in the section from 0 ° to 180 °. That is, the detection unit 126 uses the detection result of the magnetic sensor 55 to determine whether or not the angular position of the magnet 3 is in a section from 0 ° to 180 °. Thus, the magnetic encoder unit 1 according to the present embodiment can detect the rotational speed of the magnet 3 while detecting which section the angular position of the magnet 3 is in.

  In the present embodiment, the detection unit 7 includes the detection unit 127 that detects the rotation information based on a change in the power output from the power generation unit 21, but may not include the detection unit 127. In this case, the detection unit 7 can detect the number of rotations of the rotation shaft SF rotating in one direction by using the detection result of the magnetic sensor 55. The detection unit 7 may be any device that drives the sensor using the electric power from the power generation unit 21 and detects the rotation speed based on the detection result of the sensor. For example, this sensor does not have to be a magnetic sensor, and may detect a capacitance.

  By the way, the stronger the magnetic field formed by the magnet 3 on the magnetic sensor 55, the larger the output of the magnetic sensor 55 and the more stable the output from the analog comparator 129. Therefore, the robustness of the magnetic encoder unit 1 increases. Here, since the magnetic sensor 55 is driven during a period in which electric power is output from the power generation unit 4, it is preferable that the magnetic sensor 55 be disposed at a position where the magnetic field formed by the magnet 3 is strong during this period. Since the power generation unit 4 generates power when the angular position 90 ° or the angular position 270 ° of the magnet 3 passes in the vicinity of the power generation unit 4, the magnetic sensor 55 has a phase difference from the power generation unit 4 in the circumferential direction of the magnet 3. If the angle is 45 ° or more and 135 ° or less, it is easy to secure the output, and if it is about 90 °, the output is maximized.

[Seventh Embodiment]
Next, a seventh embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. The encoder device EC according to this embodiment includes the power generation unit 4, the power generation unit 40, the magnetic sensor 55, and the magnetic sensor 60, as in FIGS. 15 and 16. The magnetic sensor 55 and the magnetic sensor 60 detect the change in the magnetic field accompanying the rotation of the magnet 3 using the electric power generated by the power generation unit 4 and the power generation unit 40, respectively.

  FIG. 22 is a circuit configuration diagram of the magnetic encoder unit 1 according to the present embodiment. The power generation unit 40 has the same configuration as the power generation unit 4 described with reference to FIG. The power generation unit 40 includes a magnetic sensitive part 41 and a power generation part 42. The power generation unit 42 generates power due to a change in the magnetic field in the magnetic sensitive unit 41.

  In the present embodiment, the power adjustment unit 8 includes a rectification stack 133, a rectification stack 144, a capacitor 134, and a regulator 135. In the power adjustment unit 8, the elements other than the rectifying stack 144 are the same as in the sixth embodiment. The first input terminal 144a of the rectifying stack 144 is connected to a terminal 40a from which a forward current is output from the power generation unit 40. The second input terminal 144b of the rectifying stack 144 is connected to a terminal 40b from which a current is output in the reverse direction from the power generation unit 40. The ground terminal 144g of the rectifying stack 144 is connected to the ground line GL. The output terminal 144 c of the rectifying stack 144 is connected to a signal line that connects the rectifying stack 133 and the regulator 135. The rectification stack 144 performs full-wave rectification based on the current output from the power generation unit 40. The rectification stack 144 supplies the power adjusted by the rectification to the regulator 135 through the output terminal 144c.

  In FIG. 22, the regulator 135 generates a predetermined voltage based on the output from the rectifying stack 133, and generates the predetermined voltage based on the output from the rectifying stack 144. The regulator 135 is shared by the power feeding system from the rectifying stack 133 and the power feeding system from the rectifying stack 144.

  A regulator 135 that generates a predetermined voltage based on the output from the rectifying stack 133 and another regulator that generates a predetermined voltage based on the output from the rectifying stack 144 may be provided. In FIG. 22, a rectifying stack 133 that rectifies the current from the power generation unit 4 and a rectifying stack 144 that rectifies the current from the power generation unit 40 are provided separately. 4 may be rectified and the current from the power generation unit 40 may be rectified.

  In the present embodiment, the detection unit 7 includes a detection unit 126, a detection unit 145, and a counter 128. The detection unit 126 has the same configuration as that of the sixth embodiment. The detection unit 145 has the same configuration as the detection unit 126 and is a magnetic field detection unit that detects a change in the magnetic field formed by the magnet 3.

  The detection unit 145 includes a magnetic sensor 60 and an analog comparator 146. The power supply terminal 60p of the magnetic sensor 60 is connected to the power supply line PL. The ground terminal 60g of the magnetic sensor 60 is connected to the ground line GL. The output terminal of the magnetic sensor 60 is connected to the input terminal 146a of the analog comparator 146. The magnetic sensor 60 detects the magnetic field formed by the magnet 3 using the power supplied via the power supply terminal 141p and the ground terminal 141g, and outputs the detection result (detection signal) to the analog comparator 146.

  The analog comparator 146 is a comparator that compares the voltage output from the magnetic sensor 60 with a predetermined voltage. The power supply terminal 146p of the analog comparator 146 is connected to the power supply line PL. The ground terminal 146g of the analog comparator 146 is connected to the ground line GL. The analog comparator 146 binarizes the voltage output from the magnetic sensor 60 by the power supplied via the power supply terminal 146p and the ground terminal 146g. The analog comparator 146 outputs an H level signal from the output terminal 146b when the output voltage of the magnetic sensor 55 is equal to or higher than the threshold value, and outputs an L level signal from the output terminal 146b when the output voltage is less than the threshold value. The output terminal 146b of the analog comparator 146 is connected to the second input terminal 128b of the counter 128. The analog comparator 146 supplies an H level or L level signal to the second input terminal 128b of the counter 128 via the output terminal 146b.

  FIG. 23 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates counterclockwise (forward rotation). FIG. 24 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotation axis SF rotates counterclockwise (reverse rotation).

  23 and FIG. 24, the solid line indicates the magnetic field at the position of the power generation unit 4, and the broken line indicates the magnetic field at the position of the power generation unit 40. “Power generation unit 2” indicates the output of the power generation unit 40, the output of the current flowing in one direction from the power generation unit 40 is positive (+), and the output of the current flowing in the opposite direction is negative (−). “Regulator” in FIG. 23 and FIG. 24 indicates the output of the regulator 135, where the H level is represented by “H” and the L level is represented by “L”.

  The “magnetic field on the MR sensor 2” in FIGS. 23 and 24 is a magnetic field formed on the magnetic sensor 60. In the “magnetic field on the MR sensor 2”, the magnetic field formed by the magnet 3 is indicated by a long broken line, the magnetic field formed by the bias magnet is indicated by a short broken line, and the combined magnetic field is indicated by a solid line. “MR sensor 2” indicates an output when the magnetic sensor 60 is constantly driven, an output from the first output terminal is represented by a broken line, and an output from the second output terminal is represented by a solid line. “Comparator 3” indicates an output from the analog comparator 146. The output of the analog comparator 146 when the magnetic sensor 60 is always driven is shown as “always drive”, and the output of the analog comparator 146 when the magnetic sensor 60 is driven intermittently is shown as “intermittent drive”.

  First, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates counterclockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse flowing in the opposite direction (negative of “power generation unit 1”) at an angular position of 135 °. Further, the power generation unit 4 outputs a current pulse (positive of “power generation unit 1”) flowing in the forward direction at the angular position 315 °. The power generation unit 40 outputs a current pulse (positive of “power generation unit 2”) flowing in the forward direction at an angular position of 45 °. Further, the power generation unit 40 outputs a current pulse (negative of “power generation unit 2”) that flows in the opposite direction at the angular position 225 °. Therefore, the regulator 135 supplies a predetermined voltage to the power supply line PL at each of the angular position 45 °, the angular position 135 °, the angular position 225 °, and the angular position 315 °.

  In the present embodiment, the output of the magnetic sensor 55 and the output of the magnetic sensor 60 have a phase difference of 90 °, and the detection unit 7 detects the rotational speed using this phase difference. The output of the magnetic sensor 55 has a positive sine wave shape in the range from the angular position 0 ° to the angular position 180 °. In this angular range, the power generation unit 40 outputs power at an angular position of 45 °, and the power generation unit 4 outputs power at an angular position of 135 °. The magnetic sensor 55 and the analog comparator 129 are driven by electric power supplied at each of the angular position 45 ° and the angular position 135 °. A signal output from the analog comparator 129 (hereinafter referred to as an A-phase signal) is maintained at the L level in a state where no power is supplied, and is at the H level at each of the angular position 45 ° and the angular position 135 °. .

  Further, the output of the magnetic sensor 55 has a positive sine wave shape in the range from the angular position 270 ° (−90 °) to the angular position 90 °. In this angular range, the power generation unit 4 outputs power at the angular position 315 ° (−45 °), and the power generation unit 40 outputs power at the angular position 45 °. The magnetic sensor 55 and the analog comparator 146 are driven by electric power supplied at each of the angular position 315 ° and the angular position 45 °. A signal output from the analog comparator 146 (hereinafter referred to as a B-phase signal) is maintained at the L level in a state where no power is supplied, and becomes the H level at each of the angular position 315 ° and the angular position 45 °. .

  Here, when the A phase signal supplied to the counter 128 is at the H level (H) and the B phase signal supplied to the counter 128 is at the L level, the set of these signal levels is expressed as (H, L ). In FIG. 23, the signal level pair is (L, H) at the angular position 315 °, the signal level pair is (H, H) at the angular position 45 °, and the signal level pair is (H) at the angular position 135 °. , L).

  The counter 128 causes the storage unit 9 to store a set of signal levels when one or both of the detected A-phase signal and B-phase signal are at the H level. When one or both of the next detected A-phase signal and B-phase signal are at the H level, the counter 128 reads the previous level set from the storage unit 9 and the previous level set and the current level set. The direction of rotation is determined by comparison with the set.

  For example, when the previous set of signal levels is (H, H) and the current signal level is (H, L), the angle position is 45 ° in the previous detection, and the angle in the current detection is Since it is 135 degrees, it turns out that it is counterclockwise (forward rotation). When the current level set is (H, L) and the previous level set is (H, H), the counter 128 sends an up signal indicating that the counter is to be increased to the storage unit 9. Supply. When the storage unit 9 detects an up signal from the counter 128, the storage unit 9 updates the stored number of revolutions to a value increased by one.

  Next, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates clockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse (positive of “power generation unit 1”) flowing in the forward direction at an angular position of 135 °. Further, the power generation unit 4 outputs a current pulse (negative of “power generation unit 1”) flowing in the opposite direction at the angular position 315 °. The power generation unit 40 outputs a current pulse flowing in the opposite direction (negative of “power generation unit 2”) at an angular position of 45 °. Further, the power generation unit 40 outputs a current pulse (positive of “power generation unit 2”) flowing in the forward direction at the angular position 225 °. Thus, when the rotation direction of the rotating shaft SF is reversed, the direction of the current output from the power generation unit 4 and the direction of the current output from the power generation unit 40 are reversed.

  Since the power adjustment unit 8 rectifies the current output from each power generation unit, the output of the regulator 135 does not depend on the direction of the current output from each power generation unit. Therefore, similarly to the forward rotation, the regulator 135 supplies a predetermined voltage to the power supply line PL at each of the angular position 45 °, the angular position 135 °, the angular position 225 °, and the angular position 315 °.

  The counter 28 determines the direction of rotation in the same manner as described for forward rotation. Further, when the set of the current signal level is (H, L) and the previous signal level is (L, H), the angle position is 315 ° (−45 °) in the previous detection, Since the angular position is 135 ° (−225 °) in this detection, it is understood that the rotation is clockwise (reverse rotation). The counter 128 stores a down signal indicating that the counter is down when the current level set is (H, L) and the previous level set is (L, H). To supply. When the storage unit 9 detects a down signal from the counter 128, the storage unit 9 updates the stored number of revolutions to a value reduced by one. Thus, the magnetic encoder unit 1 according to the present embodiment can detect the rotation speed while determining the rotation direction of the rotation shaft SF.

  The magnetic encoder unit 1 according to this embodiment as described above performs a series of operations when there is an output from the power generation unit 21 or the power generation unit 42. Further, the magnetic encoder unit 1 maintains a state in which the operating current becomes zero during a period in which there is no output from either the power generation unit 21 or the power generation unit 42. Thus, the magnetic encoder unit 1 is dynamically driven in response to the predetermined position of the magnet 3 passing through the vicinity of the power generation unit 4 or the power generation unit 40. Therefore, the magnetic encoder unit 1 can omit a battery for extending the power consumed by the detection system and can extend its life.

  In the present embodiment, two power generation units are used, but the number of power generation units may be one. FIG. 25 is a diagram illustrating a magnetic encoder unit 1 according to a modification.

  In FIG. 25A, the magnetic sensor 55 is disposed at an angular position rotated about 45 ° counterclockwise from the power generation unit 4. The magnetic sensor 60 is disposed at an angular position rotated about 45 ° clockwise from the power generation unit 4. Further, the magnetic sensor 60 is disposed at an angular position shifted by 90 ° from the magnetic sensor 55.

  In such a configuration, when the position 3c of the magnet 3 passes in the vicinity of the power generation unit 4, the A-phase signal output from the analog comparator 129 is at the H level and B output from the analog comparator 146. The phase signal is at L level. Further, when the position 3c of the magnet 3 passes in the vicinity of the power generation unit 4, the A phase signal is at the L level and the B phase signal is at the H level. Therefore, when the previous set of signal levels is (H, L) and the current signal level is (L, H), it can be seen that a half rotation has been made in the forward or reverse direction. In addition, when the previous set of signal levels is (L, H) and the current signal level is (H, L), it can be seen that a half rotation has been made in the forward or reverse direction. As described above, when the pair of signal levels is different between the previous time and the current time, information on the absolute value of the change amount of the rotational position is obtained. Further, when the signal level is the same between the previous time and the current time, information on the direction of rotation can be obtained. For example, when the previous signal level set and the current signal level set are both (H, L), after the position 3a of the magnet 3 passes the vicinity of the power generation unit 4, the magnet 3 again The position 3a has passed near the power generation unit 4. In this case, it can be seen that the rotation direction of the rotation axis SF is reversed. Therefore, when the A-phase signal and the B-phase signal are obtained for the first time, the direction of rotation (initial value of the direction of rotation) is detected, and thereafter, the pair of signal levels is the same between the previous time and the current time. In this case, switching between count-up and count-down, and when the pair of signal levels is inverted between the previous time and the current time, the counter value is changed to detect the rotation speed in consideration of the direction of rotation. be able to. In order to detect the initial value of the direction of rotation, for example, the output of the power generation unit 4 may be used as a detection signal as described in the sixth embodiment. Similarly to the sixth embodiment, the output of the magnetic sensor 55 and the output of the power generation unit 4 may be used as detection signals, and the rotation speed may be detected in consideration of the direction of rotation. In this case, the magnetic sensor 60 may be used for abnormality detection of the magnetic sensor 55, backup (backup) when the magnetic sensor 55 does not operate, or the like.

  In FIG. 25B, the magnetic sensor 55 is disposed at an angular position rotated about 135 ° counterclockwise from the power generation unit 4. The magnetic sensor 60 is disposed at an angular position rotated about 135 ° clockwise from the power generation unit 4. Further, the magnetic sensor 60 is disposed at an angular position that is shifted by 90 from the magnetic sensor 55. Also in this case, the rotation can be detected as in the example of FIG.

[Eighth Embodiment]
Next, an eighth embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. In the present embodiment, the magnetic encoder unit includes two power generation units and two magnetic sensors, as in the seventh embodiment. The arrangement of the power generation units and the arrangement of the magnetic sensors are the same as in the second embodiment (see FIGS. 15 and 16).

  FIG. 26 is a circuit configuration diagram of the magnetic encoder unit 1 according to the present embodiment. In the present embodiment, the magnetic encoder unit 1 includes a first detection system that detects the rotation speed using the output from the magnetic sensor 55 and the output from the magnetic sensor 60 as detection signals, and the output from the power generation unit 21 and the power generation unit 42. And a second detection system for detecting the rotational speed using the output from the detection signal as a detection signal. The first detection system is the same as in the sixth embodiment. The second detection system detects the rotational speed of the rotation axis SF independently of the first detection system. The second detection system includes a detection unit 150, a detection unit 151, a counter 152, and a storage unit 153.

  The detection unit 150 is a power detection unit that detects rotation information of the rotation shaft SF based on a change in power output from the power generation unit 21. Detection unit 150 includes a current-voltage converter 155 and an analog comparator 156. The current-voltage converter 155 is a converter that converts the current flowing from the power generation unit 21 into a voltage. The negative electrode 155 a of the current-voltage converter 155 is connected to the terminal 23 a of the power generation unit 4. The positive electrode 155 b of the current-voltage converter 155 is connected to the terminal 23 b of the power generation unit 4. The output terminal of the current / voltage converter 155 is connected to the input terminal 156 a of the analog comparator 156.

  The analog comparator 156 is a comparator that compares the voltage output from the current-voltage converter 155 with a predetermined voltage. The power supply terminal 156p of the analog comparator 156 is connected to the power supply line PL. The ground terminal 156g of the analog comparator 156 is connected to the ground line GL. The analog comparator 156 binarizes the voltage output from the current-voltage converter 155 by the power supplied via the power supply terminal 156p and the ground terminal 156g. The analog comparator 156 outputs an H level signal from the output terminal 156b when the output voltage of the current-voltage converter 155 is equal to or higher than the threshold, and outputs an L level signal from the output terminal 156b when the output voltage is less than the threshold. The output terminal 56 b of the analog comparator 156 is connected to the first input terminal 152 a of the counter 152. The analog comparator 156 supplies an H level or L level signal to the first input terminal 152a of the counter 152 via the output terminal 156b.

  The detection unit 151 is a power detection unit that detects rotation information of the rotation axis SF based on a change in power output from the power generation unit 42. The detection unit 151 has the same configuration as the detection unit 150. The detection unit 151 includes a current / voltage converter 157 and an analog comparator 158. The current-voltage converter 157 is a converter that converts the current flowing from the power generation unit 42 into a voltage. The negative electrode 157 a of the current-voltage converter 157 is connected to the terminal 40 a of the power generation unit 40. The positive electrode 157 b of the current-voltage converter 157 is connected to the terminal 40 b of the power generation unit 40. The output terminal 157c of the current / voltage converter 157 is connected to the input terminal 158a of the analog comparator 158.

  The analog comparator 158 is a comparator that compares the voltage output from the current-voltage converter 157 with a predetermined voltage. The power supply terminal 158p of the analog comparator 158 is connected to the power supply line PL. The ground terminal 158g of the analog comparator 158 is connected to the ground line GL. The analog comparator 158 binarizes the voltage output from the current-voltage converter 157 with the power supplied via the power supply terminal 158p and the ground terminal 158g. The analog comparator 158 outputs an H level signal from the output terminal 158b when the output voltage of the current-voltage converter 157 is equal to or higher than the threshold value, and outputs an L level signal from the output terminal 158b when the output voltage is lower than the threshold value. The output terminal 158 b of the analog comparator 158 is connected to the second input terminal 152 b of the counter 152. The analog comparator 158 supplies an H level or L level signal to the second input terminal 152b of the counter 152 via the output terminal 158b.

  The counter 152 counts the number of rotations of the rotation shaft SF using the detection result of the detection unit 150 and the detection result of the detection unit 151. The counter 152 uses the signal output from the analog comparator 156 to the first input terminal 152a and the signal output from the analog comparator 158 to the second input terminal 152b as control signals to count the number of rotations of the rotation axis SF. To do. The power supply terminal 152p of the counter 152 is connected to the power supply line PL. The ground terminal 152g of the counter 152 is connected to the ground line GL. The counter 152 performs counting using the power supplied through the power supply terminal 152p and the ground terminal 152g. The counter 152 supplies the counted result to the storage unit 153.

  The storage unit 153 stores information regarding the number of rotations detected by the counter 152. A power supply terminal 153p of the storage unit 153 is connected to the power supply line PL. The ground terminal 153g of the storage unit 153 is connected to the ground line GL. The storage unit 153 writes information using power supplied via the power supply terminal 153p and the ground terminal 153g. The storage unit 153 includes a nonvolatile memory 159, and can hold information written while power is supplied even in a state where power is not supplied.

  FIG. 27 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates counterclockwise (forward rotation). FIG. 28 is a timing chart showing the operation of the magnetic encoder unit 1 when the rotation axis SF rotates counterclockwise (reverse rotation). Note that the rotational speed detection operation by the first detection system using the magnetic sensor is the same as that in FIGS. 22 and 23 and is omitted in FIGS. 27 and 28. 27 and 28, “angular position”, “arrangement”, “magnetic field”, “power generation unit 1”, “power generation unit 2”, and “regulator” are the same as those in FIG. 22 and FIG.

  27 and 28, “Comparator 1” indicates the output of the analog comparator 156, and “Comparator 2” indicates the output of the analog comparator 158. In the output of each comparator, “RISE” is a RISE signal indicating that the output of the power generation unit is a forward current. In the output of each comparator, “FALL” is a FALL signal indicating that the output of the power generation unit is a current in the reverse direction. In “RISE” and “FALL”, the H level is represented by “H” and the L level is represented by “L”.

  27 and 28, “Status” indicates whether the storage unit 153 is in a set state or a reset state. In “Status”, “H” indicates that it is in the set state, and “L” indicates that it is in the reset state. 27 and 28, “write operation” indicates whether or not the storage unit 153 is performing a write operation. In “write operation”, “H” indicates that the write operation is being performed, and “L” indicates that the write operation is not being performed. “Counter” in FIGS. 27 and 28 indicates the number of rotations stored in the storage unit 53.

  First, the operation of the magnetic encoder unit 1 when the rotating shaft SF rotates counterclockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse flowing in the opposite direction (negative of “power generation unit 1”) at an angular position of 135 °. Further, the power generation unit 4 outputs a current pulse (positive of “power generation unit 1”) flowing in the forward direction at the angular position 315 °.

  The power generation unit 40 is arranged at a position shifted by 90 ° from the power generation unit 4 in the circumferential direction of the magnet 3. Therefore, the magnetic field felt by the power generation unit 40 is 90 degrees out of phase with the magnetic field felt by the power generation unit 4. The power generation unit 40 outputs a current pulse flowing in the opposite direction (negative of “power generation unit 2”) at the angular position 225 °. Further, the power generation unit 40 outputs a current pulse (positive of “power generation unit 2”) flowing in the forward direction at an angular position of 45 °.

  When a current pulse is output from the power generation unit 4 at each of the angular position 135 ° and the angular position 315 °, the regulator 135 outputs power of a predetermined voltage. Further, when a current pulse is output from the power generation unit 40 at each of the angular position 45 ° and the angular position 225 °, the regulator 135 outputs electric power of a predetermined voltage.

  At the output of the analog comparator 156 (“Comparator 1”), the RISE signal is maintained at the L level in a state where no power is supplied, and the output of the power generation unit 4 at the angular position 315 ° is received and becomes the H level. The FALL signal is maintained at the L level in a state where no power is supplied, and becomes the H level in response to the output of the power generation unit 4 at the angular position of 135 ° The counter 152 shown in FIG. When the RISE signal from the analog comparator 156 is at the L level and the FALL signal is detected at the H level, an up signal indicating that the counter value (number of rotations) is increased (+1) is stored in the storage unit 53. Output to.

  At the output of the analog comparator 158 (“Comparator 2”), the RISE signal is maintained at the L level in a state where no power is supplied, and the output of the power generation unit 40 at the angular position of 45 ° is received to the H level. Become. The FALL signal is maintained at the L level in a state where no power supply is received, and becomes the H level in response to the output of the power generation unit 40 at the angular position 225 °.

  The storage unit 153 is set to the set state when the H level of the RISE signal is output from the analog comparator 58 (angular position 45 °). When the storage unit 153 receives an up signal from the counter 152 in the set state (angular position 135 °), the storage unit 153 updates the stored number of rotations to a value increased by one. For example, in the count-up operation, the counter 152 reads the rotation number stored in the storage unit 153 and outputs the rotation number obtained by increasing the rotation number by 1 to the storage unit 153 as an up signal. The storage unit 153 is set to a reset state when the analog comparator 158 outputs the H level of the FALL signal (angular position 225 °).

  The magnetic encoder unit 1 performs the above-described operation every time power is output from the power generation unit 4 or the power generation unit 40 in accordance with the rotation of the rotation shaft SF. FIG. 27 shows the operation of the magnetic encoder unit 1 during the rotation of the rotation axis SF twice. The magnetic encoder unit 1 performs the same operation in the first rotation and the next rotation in FIG. Do. For example, the rotation number stored in the storage unit 153 at the angular position 0 ° of the n-th rotation is n. At the angular position 135 °, the counter 152 supplies an up signal to the storage unit 153, and the storage unit 153 The stored counter value is updated to n + 1. Similarly, in the next rotation, at the angular position of 135 °, the counter 152 supplies an up signal to the storage unit 153, and the storage unit 153 updates the stored counter value to n + 2.

  Next, the operation of the magnetic encoder unit 1 when the rotation shaft SF rotates clockwise will be described with reference to FIG. The power generation unit 4 outputs a current pulse that flows in the opposite direction (negative of “power generation unit 1”) at an angular position 315 ° rotated 45 ° clockwise from the angular position 0 °. Further, the power generation unit 4 outputs a current pulse (positive of “power generation unit 1”) that flows in the forward direction at an angular position of 135 ° that is rotated 225 ° clockwise from the angular position of 0 °.

  The power generation unit 40 outputs a current pulse (positive of “power generation unit 2”) that flows in the forward direction at an angular position 225 ° rotated 135 ° clockwise from the angular position 0 °. Further, the power generation unit 40 outputs a current pulse (negative of “power generation unit 2”) flowing in the opposite direction at an angular position of 45 ° rotated clockwise by 315 ° from the angular position of 0 °.

  When a current pulse is output from the power generation unit 4 at each of the angular position 135 ° and the angular position 315 °, the regulator 135 outputs power of a predetermined voltage. Further, when a current pulse is output from the power generation unit 40 at each of the angular position 45 ° and the angular position 225 °, the regulator 135 outputs electric power of a predetermined voltage.

  At the output of the analog comparator 156 (“Comparator 1”), the RISE signal is maintained at the L level in a state where no power is supplied, and at the angular position 135 °, the output of the power generation unit 4 is received and becomes the H level. . The FALL signal is maintained at the L level in a state where no power supply is received, and the output of the power generation unit 4 is received at the angular position 315 ° and becomes the H level. When the counter 152 shown in FIG. 26 detects that the RISE signal from the analog comparator 156 is at the H level and the FALL signal is at the L level, the counter value (the number of rotations) is decreased (−1). A down signal indicating that this is to be performed is output to the storage unit 153.

  In the output of the analog comparator 158 (“Comparator 2”), the RISE signal is maintained at the L level in a state where no power is supplied, and at the angular position 225 °, the output of the power generation unit 40 is received and becomes the H level. . The FALL signal is maintained at the L level in a state where no power supply is received, and the output of the power generation unit 40 is received at the angular position of 45 ° and becomes the H level. The storage unit 153 is set to the set state when the H level of the RISE signal is output from the analog comparator 158 (angular position 225 °). When the storage unit 153 receives the down signal from the counter 152 in the set state (angular position 135 °), the storage unit 153 updates the stored number of rotations to a value reduced by one. For example, in the count-down operation, the counter 152 reads the rotation number stored in the storage unit 153 and outputs the rotation number obtained by reducing the rotation number by 1 to the storage unit 153 as an up signal. The storage unit 153 is set to the reset state when the analog comparator 158 outputs the H level of the FALL signal (angular position 45 °).

  The magnetic encoder unit 1 performs the above-described operation every time power is output from the power generation unit 4 or the power generation unit 40 in accordance with the rotation of the rotation shaft SF. FIG. 28 shows the operation of the magnetic encoder unit 1 during two rotations of the rotating shaft SF. The magnetic encoder unit 1 performs the same operation in the first rotation and the next rotation in FIG. Do. For example, the number of rotations stored in the storage unit 53 at the angular position 0 ° of the (n + 2) th rotation is n + 2, and the counter 152 supplies a down signal to the storage unit 153 at the angular position 135 ° rotated by −225 °. The storage unit 153 updates the stored counter value to n + 1. Similarly, in the next rotation, at the angular position of 135 °, the counter 152 supplies a down signal to the storage unit 153, and the storage unit 153 updates the stored counter value to n.

  The magnetic encoder unit 1 according to the present embodiment as described above includes a first detection system that uses the output from the magnetic sensor 55 and the output from the magnetic sensor 60 as detection signals, the output from the power generation unit 21, and the power generation unit 42. The second detection system that uses the output from the detection signal as a detection signal detects the number of rotations. The detection result of the second detection system can be used, for example, for detecting an abnormality by collating with the detection result of the first detection system. The encoder device EC may include an abnormality detection device that detects such an abnormality, or may include an informing device that notifies an abnormality detection result. Further, at least one of the abnormality detection device and the notification device may be a device outside the encoder device EC. In addition, when the rotation speed cannot be read from the storage unit 9 due to a failure of the first detection system, the rotation speed detected by the second detection system is read from the storage unit 53 and replaced with the detection result of the first detection system. It can also be used.

[Ninth Embodiment]
Next, a ninth embodiment will be described. In the present embodiment, the elements corresponding to the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  FIG. 29 is a diagram showing an encoder device EC according to the present embodiment. In the above-described embodiment, the magnetic encoder unit 1 of the encoder device EC is a stand-alone type device that performs a series of operations without receiving external power supply, but the magnetic encoder unit 1 of FIG. A power supply device 80 that can cover at least part of the power consumed by the detection system that detects the number of rotations of the rotating shaft SF can be connected. The power supply device 80 may be the same as that shown in FIG.

  Since the encoder device EC according to the present embodiment drives the rotation speed detection system using the electric power generated by the power generation unit, the power supply device 80 can have a long life. As a result, for example, the maintenance frequency of the power supply device 80 can be lowered, and the maintenance frequency of the encoder device EC can be lowered. The power supply device 80 may include at least a part of a power supply system that supplies power to the optical encoder unit 2 and supplies power to the magnetic encoder unit 1 when the optical encoder unit 2 is driven. Also good. This power supply system may be a main power source of various devices such as a robot device on which the encoder device EC is mounted.

  Next, a modified example will be described. FIG. 30A is a diagram illustrating a modification of the magnetic encoder unit 1. In each of the above-described embodiments, the magnet 3 generates an alternating magnetic field by a ring-shaped magnet (see FIG. 2), but the magnet 3 in FIG. 30A generates an alternating magnetic field by a bar magnet. In this modification, the magnet 3 includes a bar magnet 71 a to a bar magnet 71 f provided on a disk-shaped plate 70.

  The plate 70 is fixed to the rotation axis SF and rotates integrally with the rotation axis SF. The bar magnets 71a to 71f are fixed to the plate 70 and rotate integrally with the plate 70 and the rotation shaft SF. Each of the bar magnets 71 a to 71 f is disposed substantially parallel to the radial direction of the plate 70.

  The bar magnets 71a to 71c are arranged with the south pole facing the center (rotation axis SF) of the plate 70 and the north pole facing the radial direction with respect to the rotation axis SF (outside the plate 70). The bar magnet 71a is disposed in the vicinity of the position 3d of the plate 70. The bar magnet 71 b is disposed at the position 3 a of the plate 70. The bar magnet 71 c is disposed in the vicinity of the position 3 b of the plate 70.

  The bar magnets 71d to 71f are arranged with the north pole facing the center (rotation axis SF) of the plate 70 and the south pole facing the radial direction with respect to the rotation axis SF (outside the plate 70). The bar magnet 71d is disposed adjacent to the bar magnet 71c in the vicinity of the position 3b of the plate 70. The bar magnet 71e is disposed at the position 3c of the plate 70. The bar magnet 71f is disposed adjacent to the bar magnet 71a in the vicinity of the position 3d of the plate 70.

  According to such a magnet 3, when the position 3 b or the position 3 d of the plate 70 passes near the power generation unit 4, the direction of the magnetic field in the power generation unit 4 is reversed, and power is output from the power generation unit 4. At this time, one bar magnet passes in the vicinity of the magnetic sensor 55, and a magnetic field in the radial direction of the plate 70 is formed in the magnetic sensor 55. The magnetic sensor 55 can detect the direction of the magnetic field when electric power is output from the power generation unit 4.

  FIG. 30B is a plan view showing a modification of the magnetic encoder unit 1. In FIG. 30B, the magnetic encoder unit 1 includes a power generation unit 4 and a power generation unit 40. The power generation unit 40 is arranged with a phase difference of 180 ° from the power generation unit 4 in the circumferential direction of the magnet 3. In the magnetic encoder unit 1, the position 3 c of the magnet 3 passes near the power generation unit 40 when the position 3 a of the magnet 3 passes near the power generation unit 4. In this way, the power generation unit 4 and the power generation unit 40 generate power almost simultaneously, which makes it easier to cover the power consumed by the detection system and the like.

  FIG. 30C is a side view showing a modification of the magnetic encoder unit 1. In FIG. 30C, the magnetic encoder unit 1 includes a power generation unit 4 and a power generation unit 40. The power generation unit 40 is provided on the opposite side of the power generation unit 4 with respect to the magnet 3. The power generation unit 40 is provided, for example, at the same angular position as the power generation unit 4 in the circumferential direction of the magnet 3. In the encoder device EC, the power generation unit 4 and the power generation unit 40 generate power almost simultaneously, and it is easy to cover the power consumed by the detection system or the like.

  FIG. 30D is a side view showing a modification of the magnetic encoder unit 1. In FIG. 30D, the magnetic encoder unit 1 includes a magnet 3, a power generation unit 4, a magnet 66, and a power generation unit 40. The magnet 3 is disposed on the front surface of the disk 6 shown in FIG. 1 and the like, and the magnet 66 is disposed on the back surface. The power generation unit 4 is disposed in the vicinity of the magnet 3 and generates power by changing the magnetic field formed by the magnet 3. The power generation unit 40 is disposed in the vicinity of the magnet 66 and generates power by changing the magnetic field formed by the magnet 66. As described above, the magnetic encoder unit 1 is a different member in which the magnet 3 paired with the power generation unit 4 and the magnet 66 paired with the power generation unit 40 are different when a plurality of power generation units are provided. Also good.

  Note that, when a plurality of power generation units are provided as in the above-described modification, the power output from the power generation unit 40 may be used as a detection signal for detecting the number of rotations, a detection system, or the like. It may be used only for supply to Further, the number of power generation units provided in the encoder device EC may be three or more. In addition, the power generation unit is provided with a magnetic sensing part and a power generation part on each of the one side and the other side of the magnet 3, and the magnetic sensing part and the power generation part are housed in one casing. May be.

  In each of the above-described embodiments and modifications, the magnet 3 is a quadrupole magnet having two poles in the circumferential direction and two poles in the radial direction, but is not limited to such a configuration and can be changed as appropriate. . For example, the number of circumferential poles may be four or more, and the magnet 3 may be an eight-pole magnet having four poles in the circumferential direction and two poles in the radial direction.

  In the above-described embodiment, the detection unit 7 detects rotation information of the rotation axis SF (moving unit) as position information, but detects at least one of a position, speed, and acceleration in a predetermined direction as position information. Also good. The encoder device EC may include a rotary encoder or a linear encoder. In the encoder device EC, the power generation unit and the detection unit are provided on the rotation shaft SF, and the magnet 3 is provided outside the moving body (eg, the rotation shaft SF), so that the relative position between the magnet and the detection unit moves. It may change as the part moves. The detection unit 7 may not detect position information based on a change in power output from the power generation unit. For example, the detection unit 7 may detect position information using a magnetic sensor. At least one of the power generation unit 21 and the power generation unit 42 may generate electric power due to a phenomenon other than a large Barkhausen jump, for example, by electromagnetic induction accompanying a change in magnetic field accompanying the movement of the moving unit (eg, the rotation axis SF). It may be one that generates electric power. The power supply system may supply at least a part of the power consumed by the detection unit and at least a part of the power consumed by the storage unit that stores the detection result of the detection unit. The power supply system supplies one of at least a part of the power consumed by the detection unit and at least a part of the power consumed by the storage unit that stores the detection result of the detection unit, and does not supply the other. But you can. The storage unit that stores the detection result of the detection unit may be provided outside the position detection system or may be provided outside the encoder device EC.

[Driver]
Next, the drive device will be described. FIG. 31 is a diagram illustrating an example of the driving device MTR. In the following description, components that are the same as or equivalent to those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified. The drive device MTR is a motor device including an electric motor. The drive device MTR includes a rotation shaft SF, a main body (drive portion) BD that rotationally drives the rotation shaft SF, and an encoder device EC that detects rotation information of the rotation shaft SF.

  The rotation shaft SF has a load side end portion SFa and an anti-load side end portion SFb. The load side end portion SFa is connected to another power transmission mechanism such as a speed reducer. The scale S is fixed to the non-load side end portion SFb through a fixing portion. 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 the driving device MTR, the motor control unit MC shown in FIG. 1 or the like controls the main body BD using the detection result of the encoder device EC. Since the drive device MTR has no or low need for battery replacement of the encoder device EC, the maintenance cost can be reduced. 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 device]
Next, the stage apparatus will be described. FIG. 32 is a diagram showing a stage apparatus STG. This stage device STG has a configuration in which a rotary table (moving object) TB is attached to the load side end portion SFa of the rotary shaft SF of the drive device MTR shown in FIG. In the following description, components that are the same as or equivalent to those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

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

  Thus, since the stage apparatus STG has no or low need for battery replacement of the encoder apparatus EC, the maintenance cost can be reduced. The stage apparatus STG can be applied to a rotary table provided in a machine tool such as a lathe.

[Robot equipment]
Next, the robot apparatus will be described. FIG. 33 is a perspective view showing the robot apparatus RBT. FIG. 33 schematically shows a part (joint portion) of the robot apparatus RBT. In the following description, components that are the same as or equivalent to those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified. The robot apparatus RBT includes a first arm AR1, a second arm AR2, and a joint portion JT. The first arm AR1 is connected to the second arm AR2 via the joint portion 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 connection portion 102a. The connecting portion 102a is disposed between the bearing 101a and the bearing 101b in the joint portion JT. The connecting portion 102a is provided integrally with the rotation shaft SF2. The rotation shaft SF2 is inserted into both the bearing 101a and the bearing 101b in the joint portion JT. The end of the rotary shaft SF2 on the side inserted into the bearing 101b passes through the bearing 101b and is connected to the speed reducer RG.

  The 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 it to the rotation shaft SF2. Although not shown in FIG. 33, the load-side end portion SFa of the rotation shaft SF of the drive device MTR is connected to the speed reducer RG. In addition, the scale S of the encoder device EC is attached to the non-load-side end portion SFb of the rotation shaft SF of the drive device MTR.

  When the robot apparatus RBT drives the drive apparatus MTR to rotate the rotation axis SF, the rotation is transmitted to the rotation axis SF2 via the reduction gear RG. Due to the rotation of the rotation shaft SF2, the connecting portion 102a rotates integrally, whereby the second arm AR2 rotates relative to the first arm AR1. At that time, the encoder device EC detects the angular position and the like of the rotating shaft SF. Therefore, the angular position of the second arm AR2 can be detected by using the output from the encoder device EC.

  As described above, the robot apparatus RBT has no or low need for replacing the battery of the encoder apparatus EC, so that the maintenance cost can be reduced. The robot apparatus RBT is not limited to the above configuration, and the drive apparatus MTR can be applied to various robot apparatuses having joints.

  The technical scope of the present invention is not limited to the above-described embodiment or modification. For example, one or more of the requirements described in the above embodiments or modifications may be omitted. In addition, the requirements described in the above embodiments or modifications can be combined as appropriate. In addition, as long as it is permitted by law, the disclosure of all documents cited in the above-described embodiments and the like is incorporated as a part of the description of the text.

  In addition, according to the aspect of the above-described embodiment, the magnet that rotates with the rotation of the rotating shaft, the magnetic sensitive part that causes a large Barkhausen jump due to the change of the magnetic field accompanying the rotation of the magnet, and the magnetic field in the magnetic sensitive part A power generation unit that generates power due to a change, a detection unit that detects rotation information of the rotating shaft based on a change in power output from the power generation unit, and a power adjustment that adjusts the power output from the power generation unit to power of a predetermined voltage An encoder device is provided that includes a storage unit that stores the detection result of the detection unit using the power output from the power adjustment unit.

  In addition, according to the aspect of the above-mentioned embodiment, the magnet which rotates with rotation of a rotating shaft, the magnetic sensitive part which produces a large Barkhausen jump by the change of the magnetic field accompanying rotation of a magnet, and rotation information of a rotating shaft are obtained. A detection unit that detects, a storage unit that stores a detection result of the detection unit, a power generation unit that generates power due to a change in the magnetic field in the magnetic sensing unit, and adjusts the power output from the power generation unit to a predetermined voltage power, An encoder apparatus is provided that includes at least a part of the power consumed by the detection unit and a power adjustment unit that supplies at least a part of the power consumed by the storage unit.

  According to the aspect of the above-described embodiment, the power supply unit is controlled using the encoder device of the above aspect, the power supply unit that supplies power to the rotating shaft, and the rotation information detected by the detection unit of the encoder device. A control unit is provided.

  In addition, according to the aspect of the above-mentioned embodiment, a stage apparatus provided with a moving object and the drive device of the said aspect which moves a moving object is provided.

  According to the aspect of the above-described embodiment, there is provided a robot apparatus including the driving device according to the above aspect, and a first arm and a second arm that are relatively moved by the driving device.

  One aspect of the above-described embodiment is, for example, to reduce or eliminate the need to replace a battery that supplies power to the encoder device. According to the aspect of the above-described embodiment, it is possible to reduce the frequency of replacement of the battery that supplies power to the encoder device, or to omit battery replacement.

DESCRIPTION OF SYMBOLS 1 Magnetic encoder part, 2 Optical encoder part, 3 Magnet, 5 Signal processing part, 7 Detection part, 8 Power adjustment part, 9 Memory | storage part, 20 Magnetic sensing part, 21 Power generation part 35 Photocoupler, 36 Photocoupler, 41 Magnetosensitive part, 42 Power generation part, 55 Magnetic sensor, 60 Magnetic sensor, MTR drive device, RBT robot device, STG stage device

Claims (22)

A detection unit that has a first magnetic sensor and a second magnetic sensor and detects position information of a rotation axis of the moving unit;
A magnet whose relative position changes with the detection unit based on rotation of the rotation shaft;
A power generation unit that includes a first magnetic sensing unit and a second magnetic sensing unit, and generates power based on a pulsed current generated by a change in magnetic field due to rotation of the moving unit;
A power adjustment unit that adjusts the power to a predetermined voltage power and supplies at least a portion of the power consumed by the detection unit;
An encoder device comprising:   The detection unit detects the number of rotations of the rotating shaft based on an output signal of the first magnetic sensor and an output signal of the second magnetic sensor output in a period in which the pulsed current is generated. Item 5. The encoder device according to Item 1. The first magnetic sensor and the first magnetic sensitive part are arranged at angular positions that do not overlap with each other in the rotation direction of the rotary shaft,
The second magnetic sensor and the second magnetic sensitive part are arranged at angular positions that do not overlap each other in the rotation direction of the rotation shaft.
The encoder device according to claim 1 or 2. The first magnetic sensor is arranged at an angular position in a range where the phase difference with respect to the angular position of the first magnetic sensitive part is 45 ° or more and 135 ° or less,
The second magnetic sensor has an angular position that does not overlap with the first magnetic sensor in a rotation direction of the rotation shaft, and a phase difference with respect to the angular position of the second magnetic sensing portion is in a range of 45 ° to 135 °. Placed at an angular position,
The encoder apparatus as described in any one of Claims 1-3. The angular position of the first magnetic sensitive part has a phase difference of 45 ° or more and 135 ° or less with respect to the angular position of the second magnetic sensitive part.
The encoder apparatus as described in any one of Claims 1-4. The output signal of the first magnetic sensor is compared with a predetermined threshold value , a high level signal is output in a first period within one rotation of the rotating shaft , and a low level signal is output in a second period different from the first period. It has a comparator that outputs a signal,
An output signal of the first magnetic sensor is output in the first period .
The encoder apparatus as described in any one of Claims 1-5. The first magnetic sensor and the second magnetic sensor each output an output signal at a timing when the current is generated from the first magnetic sensor and at a timing when the current is generated from the second magnetic sensor.
The encoder apparatus as described in any one of Claims 1-6. The detection unit uses a detection signal based on the pulsed current generated from the first magnetic sensing unit and a detection signal based on the pulsed current generated from the second magnetic sensing unit to detect the second rotation shaft. Detecting the rotation speed of
The encoder apparatus as described in any one of Claims 1-7. Collating the rotational speed of the rotating shaft with the second rotational speed, and detecting an abnormality based on the result of the collation,
The encoder device according to claim 8. The first magnetic sensitive part and the second magnetic sensitive part cause a large Barkhausen jump due to a change in the magnetic field,
The encoder apparatus as described in any one of Claims 1-9. When the detection unit does not receive power supply from the outside, the detection unit receives power supply from the power generation unit or the battery.
The encoder apparatus as described in any one of Claims 1-10. The power adjustment unit
A rectifier that full-wave rectifies the current generated from the power generation unit;
A regulator that adjusts the power rectified by the rectifier to a predetermined voltage power, and
The encoder apparatus as described in any one of Claims 1-11. The power adjustment unit includes a capacitor between the rectifier and the regulator.
The encoder device according to claim 12. The power adjustment unit supplies at least a part of power consumed by a storage unit that stores a detection result of the detection unit.
The encoder apparatus as described in any one of Claims 1-13. A detection unit having a first sensor and a second sensor and detecting position information of a rotation axis of the moving unit;
A power generation unit that includes a first magnetic sensing unit and a second magnetic sensing unit, and generates power based on a pulsed current generated by a change in magnetic field due to rotation of the moving unit;
A power adjustment unit that adjusts the power to a predetermined voltage power and supplies at least a portion of the power consumed by the detection unit;
A comparator that compares an output signal output from the first sensor with a predetermined threshold and outputs a high-level signal and a low-level signal within one rotation of the rotating shaft;
The power generation unit, in the said first current output as pulse current generated by the first sensitive magnetic portion in a high level period of the signal is output, the period during which the signal is output before Symbol low level Outputting a second current as the pulsed current generated by the second magnetic sensing unit ;
Encoder device. The power adjustment unit
A rectifier for rectifying the first current and the second current;
A regulator that adjusts the power rectified by the rectifier to a predetermined voltage power, and
The encoder device according to claim 15. The comparator outputs the high level signal in a first period within one rotation of the rotating shaft, and outputs the low level signal in a second period different from the first period,
The output signal of the first sensor is output in the first period,
The encoder device according to claim 15 or claim 16. An output signal of the second sensor is output in the second period .
The encoder device according to claim 17 . The first sensor is a magnetic sensor,
19. The magnetic sensor according to any one of claims 15 to 18, wherein the magnetic sensor is disposed at a position where the magnetic field is relatively strong in the change of the magnetic field during a period in which the pulsed current is generated from the first magnetosensitive portion. The encoder device according to one item. The encoder device according to any one of claims 1 to 19,
A power supply unit for supplying power to the moving unit;
And a control unit that controls the power supply unit using position information detected by the detection unit of the encoder device. A moving object;
A stage device comprising: the driving device according to claim 20, wherein the moving object is moved.   A robot apparatus comprising the driving apparatus according to claim 20.

Images