JP2018059875A - Encoder device, driving device, stage device, and robot apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly-reliable encoder device.SOLUTION: An encoder device (EC) includes: a position detection part (1) that detects a piece of position information of a moving part (SF); a first storage part (3A) storing the position information of the moving part detected by the position detection part; a second storage part (3B) different from the first storage part, which can store the position information of the moving part; and a storage management part (4) that manages to store the position information of the moving part in either one storage part of the first storage part and the second storage part.SELECTED DRAWING: Figure 1

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 distinguishes the number of rotations of a rotary shaft 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, for example, a main power supply of the robot apparatus, and includes rotational position information including multi-rotation information indicating the number of rotations and angular position information indicating an angular position of less than one rotation. Is detected.

  When the robot apparatus finishes the predetermined process, its main power 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 supply is turned on next time (for example, when the next operation is started). For this reason, the encoder device is required to retain the multi-rotation information even in a state where power is not supplied from the outside. Therefore, an encoder device that retains multi-rotation information with power supplied from a battery in a state where power supply from the main power source cannot be obtained is used.

JP-A-8-50034

  According to the first aspect of the present invention, a position detection unit that detects position information of the moving unit, a first storage unit that stores position information of the moving unit detected by the position detection unit, and position information of the moving unit A second storage unit that is different from the first storage unit, and a storage management unit that stores position information of the moving unit in one of the first storage unit and the second storage unit, An encoder device is provided.

  According to a second aspect of the present invention, there is provided a drive device including the encoder device according to the first aspect and a drive unit that supplies a driving force to the moving unit.

  According to a third aspect of the present invention, there is provided a stage apparatus including the driving device according to the second aspect and a stage moved by the driving device.

  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 an arm that is moved by the driving device.

It is a figure which shows the encoder apparatus which concerns on 1st Embodiment. It is a figure which shows the memory | storage part and memory | storage management part which concern on 1st Embodiment. It is a figure which shows operation | movement of the memory | storage part and memory | storage management part which concern on 1st Embodiment. It is a figure which shows the modification of the memory | storage part which concerns on 1st Embodiment. It is a figure which shows the magnet which concerns on 1st Embodiment, a signal generation part, and a magnetic sensor. It is a figure which shows the circuit structure of the encoder apparatus which concerns on 1st Embodiment. It is a figure which shows operation | movement of the encoder apparatus which concerns on 1st Embodiment. It is a figure which shows the memory | storage part and memory | storage management part which concern on 2nd Embodiment. It is a figure which shows operation | movement of the memory | storage part and memory | storage management part which concern on 2nd Embodiment. It is a figure which shows the drive device which concerns on embodiment. It is a figure which shows the stage apparatus which concerns on embodiment. It is a figure which shows the robot apparatus which concerns on 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 position information (moving position information) of the moving unit. The encoder device EC is, for example, a rotary encoder. The moving unit is, for example, a rotation axis SF of a motor M (power supply unit), and the movement of the moving unit is, for example, rotation around a predetermined axis. Further, the position information of the moving unit is, for example, rotation position information of the rotation axis SF.

  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 rotational position information detected by the encoder device EC is supplied to the motor control unit MC. The motor control unit MC controls the rotation of the motor M using the rotational position information supplied from the encoder device EC. The motor control unit MC controls the rotation of the rotation shaft SF. The encoder device EC may be, for example, a linear encoder, and may detect position information (moving position information) of a moving unit (moving axis) of a power drive unit such as a linear motor or a planar motor.

  The encoder device EC includes a position detection unit 1, a power supply unit 2, a storage unit 3, and a storage management unit 4. The position detector 1 detects rotational position information (for example, information including multi-rotation information) of the rotational axis SF. The power supply unit 2 supplies power to at least a part of the position detection unit 1 (for example, the processing unit 13 and the signal processing unit 25) and the storage unit 3. The power supply unit 2 includes, for example, a signal generation unit 6, a switching unit 7, and a battery 8. The signal generation unit 6 may be configured to be included in the position detection unit 1 described above. The storage unit 3 includes a first storage unit 3A and a second storage unit 3B. The first storage unit 3A stores the rotation position information of the rotation axis SF detected by the position detection unit 1. The second storage unit 3B is a storage unit different from the first storage unit 3A, and can store rotational position information of the rotation axis SF. The storage management unit 4 stores the position information of the moving unit in one of the first storage unit 3A and the second storage unit 3B.

  For example, the first storage unit 3A and the second storage unit 3B are provided at different positions. For example, the first storage unit 3A (eg, the first storage device, the first storage unit) and the second storage unit 3B (eg, the second storage device, the second storage unit) are separate storage units (a plurality of storage units). Storage units) or separate storage areas (storage units) within a single storage unit. For example, the first storage unit 3A may be provided in a first device (eg, the position detection unit 1), and the second storage unit 3B may be provided in a second device different from the first device.

  The first storage unit 3A and the second storage unit 3B have different power supply sources, for example. For example, the second storage unit 3B stores the rotational position information during a period in which power is supplied from the first power supply 9 to the position detection unit 1. Further, for example, the second storage unit 3B stores the rotational position information during a period in which power is supplied from the first power supply 9 to the second storage unit 3B. In addition, the first storage unit 3A stores rotational position information during a period in which power is supplied from the second power source (eg, power supply unit 2) different from the first power source 9 to the position detection unit 1, for example. For example, the first storage unit 3A stores rotational position information during a period in which power is supplied from a second power source (eg, power supply unit 2) different from the first power source 9 to the first storage unit 3A.

  Note that the first storage unit 3A and the second storage unit 3B may be provided in the same storage device and may have different storage areas. In addition, the first storage unit 3A and the second storage unit 3B may have different or the same operation or mechanism for storing information, for example. For example, the first storage unit 3A is a storage unit (eg, a non-volatile memory) that holds information in a state where power supply to the first storage unit 3A is interrupted, and the second storage unit 3B is a second storage unit. A storage unit (for example, a volatile memory) that does not hold information in a state where the power supply to the unit 3B is cut off may be used. The first storage unit 3A and the second storage unit 3B may have different characteristics or the same characteristics (eg, writing speed, reading speed, operating voltage, durability, number of writable times, storage capacity), for example. Good.

  Moreover, the timing at which information is written may be different between the first storage unit 3A and the second storage unit 3B, for example. For example, the first storage unit 3A may store the rotational position information in a state where the second storage unit 3B does not store the rotational position information. On the other hand, for example, the second storage unit 3B may store the rotational position information in a state where the first storage unit 3A does not store the rotational position information. Further, the first storage unit 3A and the second storage unit 3B may have different priorities (priorities) in which information is written according to a control signal, for example. For example, the first storage unit 3A may store the rotational position information when the storage destination is not specified. Further, when the second storage unit 3B is specified as a storage destination by the control signal, the first storage unit 3A may not store the rotational position information, and the second storage unit 3B may store the rotational position information.

  The storage management unit 4 includes, for example, a storage monitoring unit 4A and a control unit 4B (storage control unit). The storage monitoring unit 4A monitors at least one storage state of the first storage unit 3A and the second storage unit 3B. Based on the monitoring result (for example, the storage state of the monitored storage unit) of the storage monitoring unit 4A, the control unit 4B sets the storage unit (storage destination) that stores the rotational position information of the rotation shaft as the first storage unit 3A. It selects from the 2nd memory | storage part 3B, and a memory | storage part is switched as needed. For example, the control unit 4B supplies (eg, outputs, transmits) a control signal (eg, storage control signal) that defines a storage unit that stores the rotational position information of the rotation axis SF to the position detection unit 1, and the position detection unit. 1 transmits and stores the rotational position information of the rotation axis SF to a storage destination (eg, the first storage unit 3A, the second storage unit 3B) determined in the control signal.

  Further, the storage management unit 4 (eg, control unit 4B) determines whether or not power is supplied from the power supply unit 2 (eg, battery 8) to the position detection unit 1, and the storage state (eg, rotational position information) of the storage unit 3. According to the storage destination setting). For example, the control unit 4B stores rotational position information (eg, multi-rotation information) in the first storage unit 3A (eg, when the storage location of the rotational position information is set in the first storage unit 3A (first 1), a control signal for permitting power supply from the battery 8 to the position detection unit 1 is transmitted to the power supply unit 2. Further, the control unit 4B stores the rotational position information in the second storage unit 3B (for example, when the storage location of the rotational position information is set in the second storage unit 3B (second setting condition)). Then, a control signal for prohibiting power supply from the battery 8 to the position detection unit 1 is transmitted to the power supply unit 2. For example, the control unit 4B transmits a control signal for cutting off the power supply from the battery 8 to the position detection unit 1 to the power supply unit 2 under the second setting condition, and another power source different from the battery 8 ( For example, a control signal for switching the power supply source so as to supply power to the position detection unit 1 from the capacitor 30 described later can be transmitted to the power source or the like. Note that the storage management unit 4 (eg, the control unit 4B) does not need to switch the power supply from the power supply unit 2 (eg, the battery 8) to the position detection unit 1.

  Hereinafter, each part of the encoder device EC will be described. The position detection unit 1 detects rotation position information of the rotation axis SF. The encoder device EC in this embodiment is a multi-rotation absolute encoder, and includes rotational position information including multi-rotation information indicating the number of rotations of the rotation shaft SF and angular position information indicating an angular position (rotation angle) of less than one rotation. Is detected. The position detection unit 1 includes a multi-rotation information detection unit 1A that detects multi-rotation information of the rotation axis SF, and an angle detection unit 1B that detects an angular position of the rotation axis SF.

  At least a part of the position detection unit 1 (for example, the angle detection unit 1B), for example, in the normal state supplied from the first power supply 9, the rotational position information of the rotation axis SF is obtained by the power supplied from the first power supply 9. To detect. The first power source 9 is, for example, a main power source of a device (for example, a driving device, a stage device, or a robot device) on which the encoder device EC is mounted, and supplies power consumed for driving the rotary shaft SF in a normal state. . For example, the motor control unit MC controls the rotation of the rotation shaft SF by adjusting the power from the first power supply 9 and supplying it to the motor M based on the detection result of the encoder device EC.

  The position detection unit 1 operates with power supplied from the first power supply 9 in a state where the power of the first power supply 9 is turned on (a state where the first power supply 9 is turned on, a normal state). Further, in a state where the first power supply 9 is turned on to the position detection unit 1, the angle detection unit 1B (or its circuit) can operate. For example, when the first power source 9 enters the normal state when the position detection unit 1 is turned on, the angle detection unit 1B starts detection (eg, calculation) of the angular position information, and similarly the multi-rotation information detection unit 1A. Also starts detecting multi-rotation information (eg, detection by sensor, processing of detection result, calculation).

  In addition, at least a part of the position detection unit 1 (for example, the multi-rotation information detection unit 1A) is in a state where the supply of power from the first power source 9 is cut off (for example, the first power source 9 is not turned on). In the state, the state in which the first power source 9 is turned off, and the backup state), the operation is performed by the power supplied from the second power source (for example, the battery 8 and the power supply unit 2) different from the first power source 9. For example, in a state where power supply from the first power supply 9 is cut off to the position detection unit 1, the power supply unit 2 is connected to at least a part of the position detection unit 1 (for example, the multi-rotation information detection unit 1A). On the other hand, electric power is intermittently (intermittently and selectively) supplied based on the detection signal, and the position detector 1 receives at least the rotational position information of the rotating shaft SF when electric power is supplied from the electric power supplier 2. A part (eg, multi-rotation information) is detected.

  In addition, the multi-rotation information detection unit 1A (or its circuit) can operate in a state where the first power source 9 is not turned on. For example, when the first power source 9 is not turned on and the power is supplied from the second power source (for example, the battery 8), the multi-rotation information detection unit 1A detects (calculates) the multi-rotation information. Continuing, the angle detector 1B stops detecting (calculating) the angular position information. As described above, the multi-rotation information detection unit 1A is based on the detection signal, regardless of the on / off state (normal state and backup state) of the power source (the first power source 9, the second power source such as the battery 8). Detection is performed.

  The multi-rotation information detection unit 1A is, for example, a magnetic detection unit, and detects multi-rotation information by magnetism. The multi-rotation information detection unit 1A includes, for example, a magnet 11, a magnetic sensor 12, and a processing unit 13.

  The magnet 11 is provided, for example, on a scale S fixed to the rotation shaft SF. The scale (in this case, a disk) S is, for example, a disk and rotates together with the rotation axis SF, so that the magnet 11 rotates (moves) in conjunction with the rotation axis SF. The magnetic sensor 12 is fixed to the outside of the rotation axis SF, and the relative positions of the magnet 11 and the magnetic sensor 12 are changed by the rotation of the rotation axis SF. The strength and direction of the magnetic field on the magnetic sensor 12 formed by the magnet 11 changes according to the rotation of the rotation axis SF. The magnet 11 may include a plurality of magnets (eg, two), at least one of which may be disposed on a different scale different from the scale S and rotate together with the rotation axis SF.

  The magnetic sensor 12 detects the magnetic field formed by the magnet 11, and the processing unit 13 is based on the result of the magnetic sensor 12 detecting the magnetic field formed by the magnet, and position information (for example, multi-rotation information) of the rotation axis SF. Is detected (calculated). The processing unit 13 is, for example, a multi-rotation processing unit that processes multi-rotation information. For example, the processing unit 13 supplies a storage instruction (data write command) of position information (eg, multi-rotation information) to the storage unit 3, and the storage unit 3 detects the processing unit 13 based on the storage instruction. The processed position information is stored.

  The magnet 11 only needs to be able to move relative to the magnetic sensor 12 or the signal generator 6. For example, the magnetic sensor 12 is provided on the scale S and the magnet 11 is provided outside the scale S. Also good. The position detection unit 1 may include at least a part of the storage unit 3 (eg, the first storage unit 3A). For example, the encoder device EC includes a processing substrate unit K (shown later in FIG. 10) on which at least a part of wiring and electronic components included in the position detection unit 1 is provided, and at least a part of the storage unit 3 is a processing substrate unit. K may be provided. The processing substrate unit K is, for example, a printed circuit board. Further, the position detection unit 1 may include at least a part of the storage management unit 4 (for example, the storage monitoring unit 4A). For example, at least a part of the storage management unit 4 may be provided on the processing substrate unit K.

  The angle detection unit 1B is an optical or magnetic encoder, and detects position information (angular position information, absolute or relative position information) within one rotation of the scale S. For example, when the angle detection unit 1B is an optical encoder, the angular position information within one rotation of the rotation axis SF is detected by reading the patterning information of the scale (in this case, a disk) S with a light receiving element. To do. The patterning information of the scale S is, for example, a light / dark pattern by a slit (transmission pattern) or a reflection pattern on the scale S. The angle detection unit 1B detects the same angular position information of the rotation axis SF as the detection target of the multi-rotation information detection unit 1A.

  The angle detection unit 1B includes a scale S, a light emitting element 21, a light receiving sensor 22, and a processing unit 23. The scale S is fixed to the rotation shaft SF. The scale S includes an incremental pattern INC and an absolute pattern ABS. For example, the incremental pattern INC and the absolute pattern ABS are provided on the same side of the scale S as the magnet 11. For example, the incremental pattern INC and the absolute pattern ABS are arranged outside the magnet 11 in the radial direction (eg, radial direction) with respect to the rotation axis SF. The absolute pattern ABS is arranged outside the incremental pattern INC, for example, in a radial direction (eg, radial direction) with respect to the rotation axis SF.

  Note that one or both of the incremental pattern INC and the absolute pattern ABS may be provided on the same surface as the magnet 11 or on the opposite surface of the scale S. Further, one or both of the incremental pattern INC and the absolute pattern ABS may be provided on at least one of the inside and the outside with respect to the position of the magnet 11. The magnet 11 may be provided on a member different from the scale S. For example, the scale S is a first moving body (eg, first rotating body) fixed to a moving body (eg, rotating shaft SF), and the magnet 11 is a moving body (eg, rotating shaft SF). It may be provided in a second moving body (for example, a second rotating body) fixed to. The first moving body may be integrated (unitized) with the second moving body.

  The light emitting element 21 (irradiation unit, light emission unit) irradiates light to the incremental pattern INC and absolute pattern ABS of the scale S. The light receiving sensor 22 (light detection unit) detects light emitted from the light emitting element 21 and passing through the incremental pattern INC, and light emitted from the light emitting element 21 and passing through the absolute pattern ABS. In FIG. 1, the angle detector 1 </ b> B is a reflection type, and the light receiving sensor 22 detects light reflected by the scale S. The angle detector 1B may be a transmissive type. In this case, the light receiving sensor 22 detects light transmitted through the scale S.

  The light receiving sensor 22 supplies a signal indicating the detection result to the processing unit 23. The processing unit 23 detects the angular position of the rotation axis SF using the detection result of the light receiving sensor 22. For example, the processing unit 23 detects the angular position information of the first resolution using the result of detecting the light from the absolute pattern ABS. Further, the processing unit 23 uses the result of detecting the light from the incremental pattern INC to perform an interpolation operation on the angular position information of the first resolution, so that the angular position information of the second resolution higher than the first resolution. Is detected.

  In the present embodiment, the encoder device EC includes a signal processing unit 25. The signal processing unit 25 processes the signal output from the processing unit 13 and the signal output from the processing unit 23. For example, the signal output from the processing unit 13 is stored in the storage unit 3, and the signal processing unit 25 reads the signal output from the processing unit 13 from the storage unit 3 and processes the signal via the storage unit 3. . The signal processing unit 25 includes a synthesis unit 26 and a communication unit 27. For example, at least a part of the signal processing unit 25 is provided on the processing substrate unit 54. At least a part of the signal processing unit 25 may be provided in a part different from the processing substrate unit 54.

  The synthesizing unit 26 acquires the angular position information of the second resolution detected by the processing unit 23. Further, the synthesizing unit 26 acquires multi-rotation information of the rotation axis SF from the storage unit 3. The synthesizing unit 26 synthesizes the angular position information from the processing unit 23 and the multi-rotation information from the multi-rotation information detection unit 1A, and calculates the rotational position information of the rotation axis SF. For example, when the detection result of the processing unit 23 is θ [rad] and the detection result of the multi-rotation information detection unit 1A is n rotations, the synthesis unit 26 uses (2π × n + θ) [rad] as the rotation position information. Is calculated. The rotation position information may be information obtained by combining multi-rotation information and angular position information of less than one rotation.

  Then, the combining unit 26 transmits the calculated rotational position information to the communication unit 27. The communication unit 27 (external communication unit, external connection interface) is communicably connected to the communication unit MC1 of the motor control unit MC by wire or wireless. The communication unit 27 supplies the digital rotational position information to the communication unit MC1 of the motor control unit MC. The motor control unit MC appropriately decodes the rotational position information from the communication unit 27 of the angle detection unit 1B. 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 rotational position information.

  The power supply unit 2 is in a state where supply of power from at least the first power supply 9 is cut off (for example, a state where the first power supply 9 is not turned on, a state where the first power supply 9 is turned off, a backup state) In step 1, power is supplied. At least a part of the power supply unit 2 (eg, the battery 8) is, for example, a second power source 33 (shown in FIG. 3 and the like later) different from the first power source 9. For example, the power supply unit 2 supplies power intermittently in the backup state. For example, the position detection unit 1 (eg, multi-rotation information detection unit 1A) intermittently receives power supply from the power supply unit 2 in the backup state, thereby intermittently rotating position information (eg, multi-rotation information). Is detected.

  The signal generator 6 generates (outputs) an electric signal (detection signal) by a change in magnetic field accompanying movement (eg, rotation) of the movement unit (eg, rotation axis SF). This electric signal includes, for example, a waveform in which power (current, voltage) changes with time. In the signal generator 6, for example, a detection signal is generated as an electric signal by a magnetic field that changes as the rotating shaft SF rotates. For example, a detection signal is generated in the signal generation unit 6 by a change in the magnetic field formed by the magnet 11 used by the multi-rotation information detection unit 1A to detect the multi-rotation information of the rotation axis SF. The signal generation unit 6 is arranged so that the angular position relative to the magnet 11 is changed by the rotation of the rotation axis SF. For example, when the relative position between the signal generator 6 and the magnet 11 reaches a predetermined position, the signal generator 6 generates a pulsed electric signal.

  The battery 8 supplies at least a part of the power consumed by the position detection unit 1 in accordance with the detection signal generated by the signal generation unit 6 in the backup state. The battery 8 is a primary battery such as a button-type battery or a dry battery, but may be a secondary battery such as a lithium ion secondary battery.

  The switching unit 7 switches presence / absence of power supply from the battery 8 to the position detection unit 1 using the detection signal generated by the signal generation unit 6 as a control signal. For example, the switching unit 7 starts the supply of power from the battery 8 to the position detection unit 1 when the level of the electric signal generated by the signal generation unit 6 is equal to or higher than the threshold value. For example, the switching unit 7 starts supplying power from the battery 8 to the position detection unit 1 when the signal generation unit 6 generates a detection signal equal to or greater than the threshold value.

  In addition, the switching unit 7 stops the supply of power from the battery 8 to the position detection unit 1 when the level of the electric signal generated by the signal generation unit 6 becomes less than the threshold value. For example, the switching unit 7 stops the supply of power from the battery 8 to the position detection unit 1 when the detection signal generated by the signal generation unit 6 becomes less than the threshold value. For example, when a pulsed electric signal is generated in the signal generator 6 in a state where the power supply from the first power supply 9 is interrupted (backup state), the switching unit 7 determines the level (potential) of the electric signal. Is started from the low level to the high level, the supply of power from the battery 8 to the position detection unit 1 is started, and after a predetermined time has elapsed since the level (potential) of the electric signal has changed to the low level, The power supply from the battery 8 to the position detection unit 1 is stopped.

  The power supply unit 2 may supply the position detection unit 1 with power obtained by adjusting the voltage of the detection signal with a regulator or the like. For example, the power supply unit 2 may supply the position detection unit 1 with the power obtained by adjusting the voltage of the detection signal using a regulator or the like and the power from the battery 8 in combination or switching. The power supply unit 2 may supply power continuously. The power supply unit 2 may supply power without depending on the generation of the detection signal (regardless of the generation of the detection signal). In this case, the encoder device EC may not include at least a part of the power supply unit 2 (eg, the signal generation unit 6 and the switching unit 7). Further, at least a part of the power supply unit 2 (eg, the second power supply 33) may be a power supply external to the encoder device EC.

  FIG. 2 is a diagram illustrating a storage unit and a storage management unit according to the present embodiment. The storage unit 3 includes a non-volatile or volatile first storage unit 3A and a non-volatile or volatile second storage unit 3B. Here, the first storage unit 3A is assumed to be a non-volatile storage unit, but the first storage unit 3A may be a volatile storage unit. Here, the second storage unit 3B is a volatile storage unit, but the second storage unit 3B may be a non-volatile storage unit. In the present embodiment, the storage unit 3 includes a nonvolatile memory 31 as the first storage unit 3A illustrated in FIG. 1, and includes a capacitor 32 as the second storage unit 3B illustrated in FIG.

  The nonvolatile memory 31 can receive power from, for example, the second power source 33 (eg, the power supply unit 2 and the battery 8). The nonvolatile memory 31 can write information and read information by receiving power supply from the second power supply 33, for example. Further, the first storage unit 3A can hold information in a state where the power supply from the second power source 33 is interrupted. The nonvolatile memory 31 may be able to receive power from the first power supply 9 or may not be able to receive power from the first power supply 9.

  The capacitor 32 (capacitor) includes, for example, an electric double layer capacitor (electric double layer capacitor). The capacitor 32 can receive power from the first power supply 9, for example. The capacitor 32 is charged with power supplied from the first power supply 9. The capacitor 32 holds 1-bit information depending on, for example, whether or not charges are accumulated between a pair of electrodes. The capacitor 32 may be switchable at a plurality of levels (for example, 3 or more) of charge between a pair of electrodes, and may be capable of holding information of 2 bits or more. For example, when the charge between the pair of electrodes can be switched at four levels (eg, 0, H1, H2, H3), the capacitor 32 can hold 2-bit information by the charge between the pair of electrodes. The read circuit that reads information from the capacitor 32 reads the information held in the capacitor 32 by, for example, a voltage corresponding to the level of the charge held between the pair of electrodes in the capacitor 32.

  For example, the capacitor 32 is provided with a number of pairs of electrodes (for example, cells) corresponding to the information amount of stored rotational position information (for example, multi-rotation information). The capacitor 32 may be a part of the DRAM, for example. For example, the capacitor 32 can receive information from the first power supply 9 to write information and read information. For example, after the power supply from the first power supply 9 is interrupted, the capacitor 32 is not able to hold information for a long time because the charge between the pair of electrodes is discharged. On the other hand, the capacitor 32 can store information because it can accumulate electric charge between a pair of electrodes by receiving power supply from a power source such as the first power source 9, for example. The second storage unit 3B may not include the capacitor 32, and may include, for example, at least one of a latch circuit, a volatile memory, or a nonvolatile memory.

  In the present embodiment, the storage management unit 4 includes a voltage sensor 34 as the storage monitoring unit 4A of FIG. The voltage sensor 34 monitors the voltage between the electrodes of the capacitor 32 constantly or periodically (for example, a predetermined time, the timing at which the detection signal is generated, etc.) as the storage state of the capacitor 32 (second storage unit 3B). . For example, in a state where electric power is supplied from the first power supply 9 to the capacitor 32, the charge is accumulated (charged) between at least one pair of electrodes of the capacitor 32 and becomes a voltage equal to or higher than the threshold value. Further, for example, in the state where the power supply from the first power supply 9 to the capacitor 32 is cut off, the charge between the pair of electrodes of the capacitor 32 is discharged due to the passage of time or the storage operation, so that a voltage lower than the threshold (eg, 0 V )become. For example, the voltage sensor 34 repeatedly detects the voltage between the pair of electrodes of the capacitor 32, and supplies (eg, outputs and transmits) the detection result to the control unit 4B. For example, the voltage sensor 34 may be a part of a circuit that reads information from the second storage unit 3B (eg, the capacitor 32).

  For example, the control unit 4B selects a storage unit that stores rotational position information (eg, multi-rotation information) in the storage unit 3 based on the voltage (monitoring result) between the electrodes of the capacitor 32 detected by the voltage sensor 34. Control signals (for example, enable signal and setting signal) are output. For example, the control unit 4B outputs a control signal to the position detection unit 1. The control signal includes, for example, a switching signal for switching the storage destination between the first storage unit 3A (eg, nonvolatile memory 31) and the second storage unit 3B (eg, capacitor 32). For example, when the storage unit 3 is set to store the rotational position information in the second storage unit 3B (capacitor 32) in the normal state or the backup state, the position detection unit 1 receives a control signal (in this case, from the control unit 4B). By receiving the switching signal), the storage location of the rotational position information is switched from the second storage unit 3B to the nonvolatile memory 31. On the other hand, for example, when the rotation position information is set to be stored in the nonvolatile memory 31 in the storage unit 3 in the normal state or the backup state, the position detection unit 1 receives a control signal (in this case, from the control unit 4B). By receiving the switching signal), the storage location of the rotational position information is switched from the nonvolatile memory 31 to the second storage unit 3B (capacitor 32).

  The control signal may include a permission signal (access permission signal) for permitting access to the first storage unit 3A (eg, nonvolatile memory 31) or the second storage unit 3B (eg, capacitor 32). The control signal does not permit (inhibit) access to the first storage unit 3A (eg, the non-volatile memory 31) or the second storage unit 3B (eg, the capacitor 32) (eg, access non-permission signal). May be included. The control unit 4B may output the control signal to the storage unit 3, and the storage unit 3 may include a setting unit that sets a storage destination based on the control signal. Such a setting unit is provided in a device from which a control signal is output from the control unit 4B, and may be provided in the position detection unit 1, or may be provided in the storage unit 3, and may be provided in the position detection unit 1 and the storage. It may be provided in a device different from any of the units 3.

  FIG. 3 is a diagram illustrating operations of the storage unit and the storage management unit according to the present embodiment. FIG. 3A shows a state (normal state) in which the power of the first power source 9 is turned on. For example, the first power supply 9 can supply power to each of the position detection unit 1 and the capacitor 32. The capacitor 32 is capable of holding rotational position information (for example, multi-rotation information) transmitted from the position detection unit 1 by receiving power supply from the first power supply 9. For example, when the voltage between the electrodes of the capacitor 32 detected by the voltage sensor 34 is equal to or higher than the threshold value, the control unit 4B sets the storage location of the rotational position information in the capacitor 32. This threshold is set to a level at which the capacitor 32 can hold information or a level at which information can be read from the capacitor 32, for example. For example, in a state where power is supplied from the first power supply 9 to the capacitor 32, the voltage between the electrodes of the capacitor 32 detected by the voltage sensor 34 is equal to or higher than the threshold value, and the control unit 4 </ b> B stores the rotational position information in the capacitor 32. (Hold).

  In addition, the storage management unit 4 (eg, the control unit 4B), the second power supply 33 different from the first power supply 9 based on the storage state (eg, interelectrode voltage) of the second storage unit 3B (eg, capacitor 32). Whether or not power is supplied from the (eg, battery 8) to the position detection unit 1A is switched. For example, when the voltage between the electrodes of the capacitor 32 (monitoring result) detected by the voltage sensor 34 is equal to or greater than a threshold value, the control unit 4B outputs a control signal for prohibiting power supply from the second power source 33 to the position detection unit 1. Transmit to the second power source 33. The second power supply 33 (eg, battery 8) is consumed (eg, battery 8) by not supplying power to the position detection unit 1 in a state where power is supplied from the first power supply 9 to the position detection unit 1, for example. Consumption) is suppressed.

  For example, the control unit 4B regulates (eg, prohibits) a write operation to the first storage unit 3A (eg, the nonvolatile memory 31) in a state where the power of the first power supply 9 is turned on. For example, the control unit 4B reduces the number of times of writing (eg, writing frequency) of the first storage unit 3A (eg, nonvolatile memory 31) in a state where the power of the first power supply 9 is turned on. The write operation to the second storage unit 3B (eg, the capacitor 32) is permitted (not regulated).

  FIG. 3B shows a state where the power of the first power supply 9 is not turned on (backup state). The capacitor 32 is cut off from the power supply from the first power supply 9 and does not hold the rotational position information. The second power supply 33 can supply power to the position detection unit 1 and the nonvolatile memory 31. The non-volatile memory 31 can receive the power supply from the second power supply 33 and write the rotational position information. For example, when the voltage between the electrodes of the capacitor 32 detected by the voltage sensor 34 is less than the threshold value, the control unit 4B sets the storage location of the rotational position information in the nonvolatile memory 31. For example, in the state where the power supply from the first power supply 9 to the capacitor 32 is cut off, the voltage between the electrodes of the capacitor 32 detected by the voltage sensor 34 is less than the threshold value, and the control unit 4B sets the rotational position information to nonvolatile. It is stored (held) in the memory 31.

  For example, the control unit 4B regulates (eg, prohibits) a write operation to the second storage unit 3B (eg, the capacitor 32) in a state where the power of the second power source 33 can be turned on. For example, the control unit 4B permits a write operation to the first storage unit 3A (eg, the non-volatile memory 31) in a state where the power of the second power supply 33 can be turned on (not regulated or not prohibited). The storage management unit 4 (for example, the control unit 4B) permits power supply from the second power source 33 to the position detection unit 1 when the voltage between the electrodes of the capacitor 32 detected by the voltage sensor 34 is less than the threshold value. A control signal is transmitted to the second power source 33.

  As described above, when the first power supply 9 is turned off (in the backup state), the charge accumulated in the capacitor 32 by the first power supply 9 decreases, so that the voltage between the electrodes of the capacitor 32 decreases, and the first power supply 9 decreases. 2 The storage state of the storage unit 3B (for example, the voltage between the electrodes, the charge of the capacitor 32 (charge accumulation state)) changes. When the voltage between the electrodes of the capacitor 32 detected by the voltage sensor 34 falls below the threshold value (when a change occurs in the storage state of the second storage unit 3B (in this case, a decrease in voltage)), the control unit 4B Based on the storage state of the second storage unit 3B, the switching signal is output to the position detection unit 1, and the storage destination is switched from the capacitor 32 to the nonvolatile memory 31. Further, when the first power supply 9 is turned on (normal state), the charge accumulated in the capacitor 32 by the first power supply 9 increases, so that the voltage between the electrodes of the capacitor 32 rises. When the voltage between the electrodes of the capacitor 32 detected by the voltage sensor 34 rises above the threshold value, the control unit 4B (when a change in the storage state of the second storage unit 3B occurs (in this case, an increase in voltage)). Then, the switching signal is output to the position detection unit 1, and the storage destination is switched from the nonvolatile memory 31 to the capacitor 32.

  For example, the storage management unit 4 (eg, the control unit 4B) may output a notification signal (notification information) indicating the storage state to the host controller (eg, the motor control unit MC1) via the communication unit 27. Good. The storage state includes, for example, information (eg, operation information) indicating an operation state of the storage unit 3 (eg, voltage between electrodes of the capacitor 32), information indicating setting of a storage destination (storage setting information), and storage in the storage unit 3. Information (storability information) and at least one of information indicating the usage state of the storage unit 3 (e.g., exhaustion state, number of times information is written). For example, the storage management unit 4 may transmit a notification signal to an external device (for example, the motor control unit MC1 in FIG. 1) via the communication unit 27. The notification signal may include, for example, one or both of the storage state of the first storage unit 3A (eg, the number of times information is written to the nonvolatile memory) and the storage state of the second storage unit 3B. For example, when switching the storage destination, the storage management unit 4 may notify one or both of the storage state of the storage destination before switching and the storage state of the storage destination after switching. In addition, when the storage management unit 4 switches the storage destination from the second storage unit 3B (for example, the capacitor 32) to the first storage unit 3A, a notification signal indicating that the storage destination has been changed (indicating that the storage unit has been switched). Information) may be output. In addition, the storage management unit 4 may output a notification signal indicating the current storage destination.

  FIG. 4 is a diagram illustrating a modification of the storage unit according to the present embodiment. In the storage unit 3 of FIG. 4A, the second storage unit 3B includes a volatile memory 29 and a capacitor 30 (power storage unit, third power source). The volatile memory 29 stores rotational position information (for example, multi-rotation information) detected by the position detection unit 1. 4 is charged by the power supplied from the power source (in this case, the first power source 9), and the second storage unit 3B (in this case, the volatile memory 29) is charged. Functions as a power storage unit (third power source) for supplying power. For example, the capacitor 30 stores power supplied from the first power supply 9 and supplies the stored power to the volatile memory 29. For example, the capacitor 30 performs a write operation (for example, the volatile memory 29) in at least a storage state (for example, a state in which electric power supplied from a power source (for example, the first power source 9) is stored in a normal state or a backup state). , The information consumption) is supplied to the volatile memory 29.

  The memory monitoring unit 4A (for example, the voltage sensor 34) monitors whether or not power is supplied to the volatile memory 29 by monitoring the voltage between electrodes of the capacitor 30 (monitoring result) (monitoring result). ). The storage monitoring unit 4A (eg, voltage sensor 34) monitors the storage state (eg, operable state) of the volatile memory 29 by, for example, monitoring the voltage between the electrodes of the capacitor 30 that supplies power to the volatile memory 29. Whether or not the rotational position information can be stored is generated) and a monitoring result is generated.

  The second storage unit 3B may include a nonvolatile memory instead of the volatile memory 29. Further, the capacitor 30 may not supply power to the volatile memory 29, and the volatile memory 29 may receive power from the first power supply 9 without going through the capacitor 30. For example, the volatile memory 29 and the capacitor 30 may be arranged in parallel in the power supply path from the first power supply 9. Even in this case, the storage state of the volatile memory 29 can be monitored by monitoring the voltage between the electrodes of the capacitor 30.

  In addition, the second storage unit 3B may include a power storage unit (third power source) such as a secondary battery instead of the capacitor 30. In addition, the power storage unit (eg, capacitor 30) that supplies power to the second storage unit 3B (eg, volatile memory 29) may be provided outside the second storage unit 3B (eg, processing substrate unit). . For example, in FIG. 4B, the second storage unit 3B includes the volatile memory 29 and does not include the capacitor 30 (power storage unit, third power source). The capacitor 30 is provided, for example, in a power supply path from the first power supply 9 to the second storage unit 3B.

  3 or 4 is charged by the electric power supplied from the first power supply 9, and the electric power is supplied to the position detection unit 1 (for example, the multi-rotation information detection unit 1A). Good. The capacitor 30 (power storage unit, third power source) may supply at least a part of the power consumed by the position detection unit 1 (eg, the multi-rotation information detection unit 1A). For example, in a state where the power supply from the first power supply 9 is cut off, the position detection unit 1 uses the power supplied from the capacitor 30 (power storage unit, third power supply) to obtain rotational position information (eg, multi-rotation information). It may be detectable.

  FIG. 5 is a diagram showing the magnet 11, the magnetic sensor 12, and the signal generating unit 6 according to the present embodiment. 5A shows a perspective view of the magnet 11, the magnetic sensor 12, and the signal generator 6, and FIG. 5B shows the magnet 11, the magnetic sensor 12, and the signal generator viewed from the direction of the rotation axis SF. The top view of the part 6 was shown. FIG. 5C shows a circuit configuration of the first magnetic sensor 12a.

  The magnet 11 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 11 is, for example, an annular member that is coaxial with the rotation axis SF. The main surface (front surface and back surface) of the magnet 11 is substantially perpendicular to the rotation axis SF. As shown in FIG. 5B, the magnet 11 is a permanent magnet magnetized with four poles. The magnet 11 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 11, 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).

  In the following description, 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 11, the angular position of one boundary between the N pole and the S pole in the circumferential direction is represented by a position 11a, and the angular position rotated 90 ° from the position 11a is represented by a position 11b. An angular position rotated 90 ° from the position 11b is represented by a position 11c, and a position rotated 90 ° from the position 11c is represented by a position 11d. The position 11c is an angular position of another boundary between the N pole and the S pole in the circumferential direction.

  In the first section of 180 ° counterclockwise from the position 11 a, the N pole is disposed on the outer peripheral side of the magnet 11, and the S pole is disposed on the inner peripheral side of the magnet 11. 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 11 toward the inner peripheral side. In the first section, the strength of the magnetic field is maximum at the position 11b and is minimum near the position 11a and near the position 11c.

  In the second section of 180 ° counterclockwise from the position 11 c, the N pole is disposed on the inner peripheral side of the magnet 11, and the S pole is disposed on the outer peripheral side of the magnet 11. 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 11 toward the outer peripheral side. In the second section, the strength of the magnetic field is maximum at the position 11d and is minimum near the position 11a and near the position 11c.

  Thus, the radial direction of the magnetic field formed by the magnet 11 is reversed at the position 11a and reversed at the position 11c. The magnet 11 forms an alternating magnetic field in which the direction of the radial magnetic field is reversed with the rotation of the magnet 11 with respect to the coordinate system fixed outside the magnet 11. The signal generator 6 is arranged at a position overlapping the magnet 11 when viewed from the normal direction of the main surface of the magnet 11.

  In the present embodiment, the signal generator 6 includes a first signal generator 6a and a second signal generator 6b. The first signal generator 6a and the second signal generator 6b are units that generate electrical signals, respectively, and are provided in non-contact with the magnet 11. The first signal generation unit 6 a includes a first magnetic sensing unit 41 and a first power generation unit 42. The first magnetic sensing unit 41 and the first power generation unit 42 are fixed to the outside of the magnet 11, and relative positions with respect to the respective positions on the magnet 11 change as the magnet 11 rotates. For example, in FIG. 5B, the position 11b of the magnet 11 is arranged at a position of 45 ° counterclockwise from the first signal generator 6a, and the magnet 11 is rotated in the reverse direction (clockwise) from this state. After one rotation, the position 11b, the position 11c, the position 11d, and the position 11a pass through the vicinity of the first signal generating unit 6a in this order.

  The first magnetic sensitive part 41 is a magnetic sensitive wire (magnetic material) such as a Wiegand wire. A large Barkhausen jump (Wiegand effect) occurs in the first magnetic sensing part 41 due to a change in the magnetic field accompanying the rotation of the magnet 11. The first magnetic sensitive part 41 is a cylindrical member, and the axial direction thereof is set to the radial direction of the magnet 11. In the first magnetic sensing part 41, when an AC magnetic field is applied in the axial direction and the magnetic field is reversed, a domain wall is generated from one end to the other end in the axial direction.

  The first power generation unit 42 is a high-density coil or the like that is wound around the first magnetic sensing unit 41. In the first power generation unit 42, electromagnetic induction occurs due to the occurrence of the domain wall in the first magnetic sensing unit 41, and an induced current flows. The signal generator 6 generates a detection signal when the magnet 11 is disposed at a predetermined position. For example, when the position 11 a or the position 11 c of the magnet 11 shown in FIG. 5B passes near the signal generator 6, a pulsed current (electric signal) is generated in the first power generator 42. Further, the first power generation unit 42 can output a detection signal including a detection pulse such as a positive pulse or a negative pulse using a large Barkhausen jump, and is supplied from the outside (for example, the first power supply 9 in FIG. 1). It can operate without power supply.

  The direction of the current generated in the first power generation unit 42 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 11 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 11 to the magnetic field facing the outside. The power (inductive current) generated in the first power generation unit 42 can be set by, for example, the number of turns of the high-density coil.

  As shown in FIG. 5A, the first magnetic sensitive part 41 and the first power generation part 42 are housed in a case 43. The case 43 is provided with a terminal 43a and a terminal 43b. The high-density coil of the first power generation unit 42 has one end connected to the terminal 43a and the other end connected to the terminal 43b. The electric power generated in the first power generation unit 42 can be taken out of the first signal generation unit 6a via the terminal 43a and the terminal 43b.

  The second signal generator 6b is disposed at an angular position that forms an angle greater than 0 ° and smaller than 180 ° from the angular position where the first signal generator 6a is disposed. The angle between the angular position of the first signal generator 6a and the angular position of the second signal generator 6b is selected from a range of 45 ° to 135 °, and is about 90 ° in FIG. 5B. The second signal generator 6b has the same configuration as the first signal generator 6a. The second signal generation unit 6 b includes a second magnetic sensing unit 45 and a second power generation unit 46. The second magnetic sensing unit 45 and the second power generation unit 46 are the same as the first magnetic sensing unit 41 and the first power generation unit 42, respectively, and description thereof is omitted. The second magnetic sensing unit 45 and the second power generation unit 46 are housed in a case 47. The case 47 is provided with a terminal 47a and a terminal 47b. The electric power generated by the second power generation unit 46 can be taken out of the second signal generation unit 6b via the terminal 47a and the terminal 47b.

  The configuration of the signal generator 6 described above is an example, and the configuration can be changed as appropriate. For example, the signal generator 6 may generate electric power by electromagnetic induction that does not use the large Barkhausen jump (Wiegand effect). Moreover, the number of the power generation units with which the signal generation part 6 is equipped can be changed suitably, for example, one may be sufficient and three or more may be sufficient. Further, the arrangement of the signal generator 6 can be changed as appropriate.

  The magnetic sensor 12 includes a first magnetic sensor 12a and a second magnetic sensor 12b. The first magnetic sensor 12a is arranged at an angular position greater than 0 ° and less than 90 ° with respect to the first magnetic sensing unit 41 (first signal generation unit 6a) in the rotation direction of the rotation axis SF. The second magnetic sensor 12b is disposed at an angular position greater than 90 ° and less than 180 ° with respect to the first magnetic sensitive unit 41 (first signal generation unit 6a) in the rotation direction of the rotation axis SF.

  As shown in FIG. 5C, the first magnetic sensor 12 a includes a magnetoresistive element 48, a bias magnet (not shown) that applies a magnetic field with a certain strength to the magnetoresistive element 48, and the magnetoresistive element 48. And a waveform shaping circuit (not shown) for shaping the waveform. The magnetoresistive element 48 has a full bridge shape in which an element 49a, an element 49b, an element 49c, and an element 49d are connected in series. A signal line between the element 49a and the element 49c is connected to the power supply terminal 48p. A signal line between the element 49b and the element 49d is connected to the ground terminal 48g. A signal line between the element 49a and the element 49b is connected to the first output terminal 48a. A signal line between the element 49c and the element 49d is connected to the second output terminal 48b. The second magnetic sensor 12b has the same configuration as the first magnetic sensor 12a.

  The first magnetic sensor 12a is an AMR sensor using the magnetoresistive effect in FIG. 5C, for example. The first magnetic sensor 12a is not limited to the example of FIG. 5C, and may be another sensor (eg, TMR sensor) using the magnetoresistive effect, and may not include a bias magnet. In addition, the first magnetic sensor 12a may be a sensor (for example, a Hall element) using the Hall effect.

  FIG. 6 is a diagram illustrating a circuit configuration of the position detection unit 1 (eg, multi-rotation information detection unit 1A) and the power supply unit 2 according to the present embodiment. The power supply unit 2 includes a first signal generation unit 6 a, a rectification stack 61, a second signal generation unit 6 b, a rectification stack 62, and a battery 8. The power supply unit 2 includes a regulator 63 as the switching unit 7 in FIG.

  The rectification stack 61 is a rectifier that rectifies the current flowing from the first signal generator 6a. The first input terminal 61a of the rectification stack 61 is connected to the terminal 43a of the first signal generator 6a. The second input terminal 61b of the rectification stack 61 is connected to the terminal 43b of the first signal generator 6a. The ground terminal 61g of the rectifying stack 61 is connected to a ground line GL to which the same potential as the signal ground SG is supplied. During the operation of the multi-rotation information detection unit 1A, the potential of the ground line GL becomes the reference potential of the circuit 60. The output terminal 61 c of the rectifying stack 61 is connected to the control terminal 63 c of the regulator 63.

  The rectification stack 62 is a rectifier that rectifies the current flowing from the second signal generator 6b. The first input terminal 62a of the rectification stack 62 is connected to the terminal 47a of the second signal generator 6b. The second input terminal 62b of the rectification stack 62 is connected to the terminal 47b of the second signal generator 6b. The ground terminal 62g of the rectifying stack 62 is connected to the ground line GL. The output terminal 62 c of the rectifying stack 62 is connected to the control terminal 63 c of the regulator 63.

  In the backup state, the regulator 63 adjusts the power supplied from the battery 8 to the position detection unit 1 according to the on state and the off state of the regulator 63. The regulator 63 includes a switch (for example, a switching element 64) provided in a power supply path between the battery 8 and the position detection unit 1. The regulator 63 controls the operation of the switching element 64 using an electric signal (detection signal) generated by the signal generator 6 as a control signal (eg, an enable signal).

  An input terminal 63 a of the regulator 63 is connected to the battery 8. The output terminal 63b of the regulator 63 is connected to the power supply line PL. The ground terminal 63g of the regulator 63 is connected to the ground line GL. The control terminal 63c of the regulator 63 is an enable terminal, and the regulator 63 maintains the potential of the output terminal 63b at a predetermined voltage in a state where a voltage higher than the threshold is applied to the control terminal 63c. The output voltage of the regulator 63 (the above-mentioned predetermined voltage) is, for example, 3 V when the counting unit 67 is configured by a CMOS or the like. The operating voltage of the storage unit 3 (eg, the first storage unit 3A) is set to the same voltage as a predetermined voltage, for example. The predetermined voltage is a voltage necessary for power supply, and may be a constant voltage value or a voltage that changes stepwise.

  The switching element 64 (switch) switches between conduction and interruption of the circuit 60 that supplies power to the position detection unit 1. The circuit 60 forms, for example, a power supply path that connects a first electrode (positive electrode) and a second electrode (negative electrode) of a second power supply (eg, battery 8), and includes a power supply line PL and a ground line GL. For example, the ground line GL is connected to the negative electrode of the battery 8, and the potential thereof becomes the reference potential of the circuit 60. For example, the switching element 64 switches whether or not power is supplied from the battery 8 to the position detection unit 1 via the circuit 60.

  The regulator 63 uses the electrical signal supplied from the signal generator 6 to the control terminal 63c as a control signal (enable signal), and conducts between the first terminal 64a and the second terminal 64b of the switching element 64 (ON). State) and insulation state (off state). For example, the switching element 64 includes a MOS, a TFT, etc., the first terminal 64a and the second terminal 64b are a source electrode and a drain electrode, and the control terminal 64c is a gate electrode.

  The control terminal 64c is charged by an electric signal (detection signal) generated by the signal generator 6. The switching element 64 switches the circuit 60 to conduction according to the voltage of the control terminal 64c. For example, the switching element 64 blocks the circuit 60 in a state where the potential of the control terminal 64 c is the reference potential of the circuit 60. Moreover, the switching element 64 will be in a conduction | electrical_connection state (on state) between the 1st terminal 64a and the 2nd terminal 64b because the voltage of the control terminal 64c becomes more than predetermined value. Switch circuit 60 to conduction. When the first terminal 64a and the second terminal 64b are turned on, power is supplied from the battery 8 to the circuit 60 via the power supply line PL and the ground line GL. The power supply unit 2 may include means for acquiring the on state and off state of the regulator 63.

  The multi-rotation information detection unit 1A includes a first magnetic sensor 12a and a second magnetic sensor 12b. For example, the multi-rotation information detection unit 1A includes an analog comparator 65, an analog comparator 66, and a counting unit 67 as the processing unit 13 illustrated in FIG. The first magnetic sensor 12a and the second magnetic sensor 12b are sensors that detect the rotation axis SF, respectively. The first magnetic sensor 12a and the second magnetic sensor 12b detect the rotation axis SF by detecting a magnetic field formed by the magnet 11 attached to the rotation axis SF. In the backup state, each of the first magnetic sensor 12 a and the second magnetic sensor 12 b detects the magnetic field formed by the magnet 11 using the power supplied from the battery 8.

  The power terminal 55p of the first magnetic sensor 12a is connected to the power line PL. The ground terminal 55g of the first magnetic sensor 12a is connected to the ground line GL. The output terminal 55 c of the first magnetic sensor 12 a is connected to the input terminal 65 a of the analog comparator 65. The output terminal 55c outputs, for example, a voltage corresponding to the difference between the potential of the second output terminal 48b shown in FIG. 5C and the reference potential.

  The analog comparator 65 is a binarization unit that binarizes the voltage output from the first magnetic sensor 12a. The analog comparator 65 is a comparator, for example, and compares the voltage output from the first magnetic sensor 12a with a predetermined voltage. The power supply terminal 65p of the analog comparator 65 is connected to the power supply line PL. The ground terminal 65g of the analog comparator 65 is connected to the ground line GL. The output terminal 65 b of the analog comparator 65 is connected to the first input terminal 67 a of the counting unit 67. The analog comparator 65 outputs an H level signal from the output terminal when the output voltage of the first magnetic sensor 12a 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 second magnetic sensor 12b and the analog comparator 66 have the same configuration as the first magnetic sensor 12a and the analog comparator 65. The power terminal 56p of the second magnetic sensor 12b is connected to the power line PL. The ground terminal 56g of the second magnetic sensor 12b is connected to the ground line GL. The output terminal 56 c of the second magnetic sensor 12 b is connected to the input terminal 66 a of the analog comparator 66. The power supply terminal 66p of the analog comparator 66 is connected to the power supply line PL. The ground terminal 66g of the analog comparator 66 is connected to the ground line GL. The output terminal 66 b of the analog comparator 66 is connected to the second input terminal 67 b of the counting unit 67. The analog comparator 66 outputs an H level signal from the output terminal when the output voltage of the second magnetic sensor 12b is equal to or higher than the threshold value, and outputs an L level signal from the output terminal 66b when the output voltage is lower than the threshold value.

  The counting unit 67 counts the multi-rotation information of the rotation axis SF using the power supplied from the battery 8. The counting unit 67 includes, for example, a CMOS logic circuit. The counting unit 67 operates using electric power supplied via the power supply terminal 67p and the ground terminal 67g. The power supply terminal 67p of the counting unit 67 is connected to the power supply line PL. The ground terminal 67g of the counting unit 67 is connected to the ground line GL. The counting unit 67 performs a counting process using the voltage supplied via the first input terminal 67a and the voltage supplied via the second input terminal 67b as control signals.

  The storage unit 3 (eg, the first storage unit 3A) stores at least a part (eg, multi-rotation information) of the rotational position information detected by the processing unit 13 using the power supplied from the battery 8 (writing). Action). The storage unit 3 (for example, the first storage unit 3A) stores the count result (multi-rotation information) by the counting unit 67 as the rotational position information detected by the processing unit 13. The power supply terminal 3p of the first storage unit 3A of the storage unit 3 is connected to the power supply line PL. The ground terminal 3g of the first storage unit 3A of the storage unit 3 is connected to the ground line GL. Note that the multi-rotation information detection unit 1A may include means for acquiring the on state and the off state of the regulator 63.

  In the present embodiment, a capacitor 69 is provided between the rectifying stack 61, the rectifying stack 62, and the regulator 63. The first electrode 69 a of the capacitor 69 is connected to a signal line that connects the rectifying stack 61, the rectifying stack 62, and the control terminal 63 c of the regulator 63. The second electrode 69b of the capacitor 69 is connected to the ground line GL. The capacitor 69 is a smoothing capacitor, for example, and reduces pulsation to reduce the load on the regulator. The constant of the capacitor 69 is, for example, the power from the battery 8 to the processing unit 13 and the first storage unit 3A during the period from the detection of the rotational position information by the processing unit 13 to the writing of the rotational position information to the first storage unit 3A. Set to maintain supply.

  Next, regarding the operation of the second power source 33 (eg, the power supply unit 2) and the multi-rotation information detection unit 1A in a state where the power of the first power source 9 is not turned on, the rotation axis SF rotates counterclockwise ( The operation of the multi-rotation information detection unit 1A when performing forward rotation will be representatively described. FIG. 7 is a timing chart showing the operation of the multi-rotation information detection unit 1A when the rotation axis SF rotates counterclockwise (forward rotation).

  In “magnetic field” in FIG. 7, the solid line indicates the magnetic field at the position of the first signal generator 6 a, and the broken line indicates the magnetic field at the position of the second signal generator 6 b. The “first signal generator” and the “second signal generator” respectively indicate the output of the first signal generator 6a and the output of the second signal generator 6b, and output the current flowing in one direction. The output of current flowing in the opposite direction was positive (+), and negative (-). The “enable signal” indicates a potential applied to the control terminal 63a of the regulator 63 by an electric signal generated by the signal generator 6, and the high level is represented by “H” and the low level is represented by “L”. “Regulator” indicates the output of the regulator 63, the high level is represented by “H”, and the low level is represented by “L”.

  “First magnetic sensor” and “second magnetic sensor” in FIG. 7 indicate the outputs of the first magnetic sensor 12a and the second magnetic sensor 12b with solid lines, respectively. In the “first magnetic sensor” and the “second magnetic sensor”, a dotted line is an output in the case of being always driven. “First analog comparator” and “second analog comparator” indicate outputs from the analog comparator 65 and the analog comparator 66, respectively.

  The first signal generator 6a outputs a current pulse flowing in the reverse direction (negative of the “first signal generator”) at an angular position of 135 °. In addition, the first signal generator 6a outputs a current pulse that flows in the forward direction (positive of the “first signal generator”) at the angular position 315 °. The second signal generator 6b outputs a current pulse (positive of the “second signal generator”) that flows in the forward direction at an angular position of 45 °. The second signal generator 6b outputs a current pulse flowing in the reverse direction (negative of the “second signal generator”) at the angular position 225 °. Therefore, the enable signal switches to a high level at each of the angular position 45 °, the angular position 135 °, the angular position 225 °, and the angular position 315 °. Further, the regulator 63 corresponds to a state in which the enable signal is maintained at a high level, and a predetermined voltage is applied 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 °. Supply.

  In the present embodiment, the output of the first magnetic sensor 12a and the output of the second magnetic sensor 12b have a phase difference of 90 °, and the processing unit 13 detects rotational position information using this phase difference. To do. The output of the first magnetic sensor 12a has a positive sine wave shape in the range from the angular position 0 ° to the angular position 180 °. In this angular range, the regulator 63 outputs power at an angular position of 45 ° and an angular position of 135 °. The first magnetic sensor 12a and the analog comparator 65 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 65 (hereinafter referred to as an A-phase signal) is maintained at the L level in a state where power is not supplied, and is at the H level at each of the angular position 45 ° and the angular position 135 °. .

  The output of the second magnetic sensor 12b has a positive sine wave shape in the range from the angular position 270 ° (−90 °) to the angular position 90 °. In this angle range, the regulator 63 outputs power at an angular position of 315 ° (−45 °) and an angular position of 45 °. The second magnetic sensor 12b and the analog comparator 66 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 66 (hereinafter referred to as a B-phase signal) is maintained at the L level in a state where power is not supplied, and is at the H level at each of the angular position 315 ° and the angular position 45 °. .

  Here, when the A-phase signal supplied to the counting unit 67 is at the H level (H) and the B-phase signal supplied to the counting unit 67 is at the L level, a set of these signal levels is expressed as (H, L ). In FIG. 7, 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 counting unit 67 causes the storage unit 3 to store a set of signal levels when one or both of the A-phase signal and the B-phase signal detected by the magnetic sensor 12 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 counting unit 67 reads the previous level set from the storage unit 3 and reads 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 counting unit 67 outputs an up signal indicating that the counter is to be increased to the first storage unit. Supply to 3A. When the first storage unit 3A detects an up signal from the counting unit 67, the first storage unit 3A updates the stored multi-rotation information to a value increased by one. The multi-rotation information detection unit 1A according to the present embodiment can detect multi-rotation information while determining the rotation direction of the rotation axis SF.

  In the present embodiment, the storage management unit 4 stores the position information of the moving unit in one of the first storage unit 3A and the second storage unit 3B. For example, in the first storage unit 3A, the number of times information is written decreases as the position information is stored in the second storage unit 3B (for example, the number of information write operations to the first storage unit 3A decreases). Therefore, the occurrence of an operation failure (for example, an operation error due to a limitation on the number of writing times) is suppressed for a long time. The encoder device EC has high reliability because, for example, occurrence of malfunctions in the first storage unit 3A is suppressed.

  In the encoder device EC according to the present embodiment, power is supplied from the battery 8 to the multi-rotation information detection unit 1A within a short time after the electrical signal is generated in the signal generation unit 6, and the multi-rotation information detection unit 1A Dynamic drive (intermittent drive). After the end of the detection and writing of the multi-rotation information, the power supply to the multi-rotation information detection unit 1A is cut off, but the count value is retained because it is stored in the first storage unit 3A. Such a sequence is repeated every time a predetermined position on the magnet 11 passes in the vicinity of the signal generator 6 even in a state where the external power supply is cut off.

  The multi-rotation information stored in the first storage unit 3A is read, for example, by the motor control unit MC when the motor M is started next time, and is used for calculating the initial position of the rotation axis SF and the like. . In such an encoder device EC, the battery 8 supplies at least a part of the power consumed by the position detector 1 (for example, the multi-rotation information detector 1A) in accordance with the electrical signal generated by the signal generator 6. Therefore, the battery 8 can have a long life. Further, when switching the presence / absence of power supply from the battery 8 in accordance with the control signal of the control unit 4B, for example, the power supply from the battery 8 is stopped in a state where the power is supplied from the first power supply 9 (normal state). Battery life can be extended. Since the battery 8 has a long life, for example, maintenance (e.g., replacement) of the battery 8 can be eliminated or the frequency of maintenance can be reduced. For example, when the life of the battery 8 is longer than the life of the other part of the encoder device EC, the replacement of the battery 8 can be made unnecessary.

  Further, when a magnetosensitive wire such as a Wiegand wire is used, a pulse current output can be obtained from the signal generator 6 even if the rotation of the magnet 11 is extremely low. Therefore, for example, in the state where power is not supplied to the motor M, the output of the signal generator 6 can be used as an electrical signal even when the rotation of the rotating shaft SF (magnet 11) is extremely low.

  The multi-rotation information detection unit 1A is a magnetic detection unit in the above embodiment, but receives transmission light or reflection light through a transmission type or reflection type optical detection unit (eg, a scale). An optical sensor). In this case, a part of the multi-rotation information detection unit 1A may be shared with the angle detection unit 1B. The power supply unit 2 may use the power of the detection signal generated by the signal generation unit 6 as a power source. For example, the power supply unit 2 may adjust the voltage of the detection signal to a predetermined voltage with a regulator or the like, and supply the power of the detection signal to the position detection unit 1. In the above-described embodiment, the signal generation unit 6 generates a detection signal when a predetermined positional relationship with the magnet 11 is reached. The encoder device EC (multi-rotation information detection unit 1A) may include the signal generation unit 6 as a sensor that detects position information of the rotation shaft SF (magnet 11).

[Second Embodiment]
A second embodiment will be described. In the present embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. FIG. 8 is a diagram illustrating a storage unit and a storage management unit according to the present embodiment. The first storage unit 3A is, for example, a nonvolatile memory. The first storage unit 3 </ b> A includes a position information storage unit 35 and a write count storage unit 36. The position information storage unit 35 stores (stores) rotational position information (eg, rotational position information such as multi-rotation information) detected by the position detection unit 1. The write count storage unit 36 stores (stores) the number of times information (eg, rotational position information) has been written in the position information storage unit 35 (hereinafter referred to as the write count). For example, the first storage unit 3 </ b> A includes a counting unit that counts the number of times of writing, and stores the number of times of writing counted by the counting unit in the writing number storage unit 36. Note that the counting unit may be provided outside the first storage unit 3A (eg, the storage monitoring unit 4A). Further, the write count storage unit 36 may be provided outside the first storage unit 3A.

  The second storage unit 3B is, for example, a nonvolatile memory. The second storage unit 3B may be a storage area of a storage device different from the first storage unit 3A, or a different storage area in the same storage device as the first storage unit 3A (eg, a first storage area and a second storage having different addresses). Range). The second storage unit 3B includes a position information storage unit 37 and a write count storage unit 38. The position information storage unit 37 stores (stores) rotational position information (eg, rotational position information such as multi-rotation information) detected by the position detection unit 1. The write count storage unit 38 stores (stores) the number of times information (eg, rotational position information) has been written in the position information storage unit 37 (hereinafter referred to as the write count). For example, the second storage unit 3B includes a counting unit that counts the number of writings, and stores the number of writings counted by the counting unit in the writing number storage unit 38. Note that the counting unit may be provided outside the second storage unit 3B (eg, the storage monitoring unit 4A). Further, the write count storage unit 38 may or may not be provided outside the second storage unit 3B.

  In the present embodiment, the storage monitoring unit 4A monitors the number of rotation position information writing operations (monitoring results) to the first storage unit 3A as the storage state of the first storage unit 3A. For example, the storage monitoring unit 4A repeatedly acquires the write count from the write count storage unit 36 of the first storage unit 3A. The storage management unit 4 switches the storage unit that stores the rotational position information from the first storage unit 3A to the second storage unit 3B, based on the number of rotation position information writing operations (number of times of writing). For example, the storage management unit 4 selects the second storage unit 3B as the storage location of the rotational position information of the rotation axis SF when the number of writes in the first storage unit 3A reaches a predetermined value. For example, the control unit 4B compares the write count acquired by the storage monitoring unit 4A from the write count storage unit 36 of the first storage unit 3A with a predetermined value, and if this write count is equal to or greater than the predetermined value, 2 A control signal in which the storage unit 3B is set as the storage destination of the rotational position information is output. This control signal may be the switching signal described in the first embodiment, or may be a permission signal or a non-permission signal.

  FIG. 9 is a diagram illustrating operations of the storage unit and the storage management unit according to the present embodiment. In FIG. 9A, the storage location of the rotational position information is set in the first storage unit 3A. The position information storage unit 35 of the first storage unit 3A stores the rotational position information detected by the position detection unit 1. The writing number storage unit 36 of the first storage unit 3A updates the counted number of writings every time rotational position information is written in the position information storage unit 35 (at each writing timing). The storage monitoring unit 4A acquires the number of writes from the write number storage unit 36. For example, when the number of writes acquired by the storage monitoring unit 4A from the write number storage unit 36 is less than a predetermined value, the control unit 4B sets the storage destination in the first storage unit 3A. For example, when the number of writes acquired by the storage monitoring unit 4A from the write count storage unit 36 is equal to or greater than a predetermined value, the control unit 4B sets a storage destination to the second storage unit 3B. (Eg, a switching signal) is output to the position detector 1.

  In FIG. 9B, the position detection unit 1 accesses the second storage unit 3B defined as a storage destination in the control signal. The position information storage unit 37 of the second storage unit 3B stores the rotational position information detected by the position detection unit 1. In addition, the storage management unit 4 (eg, control unit 4B) may output a notification signal (notification information, warning information) indicating the above-described storage state (eg, write count), for example. For example, the storage management unit 4 may transmit a notification signal to an external device (for example, the motor control unit MC1 in FIG. 1) via the communication unit 27. The storage management unit 4 may output a notification signal indicating the current storage destination, or may output a notification signal indicating switching of the storage unit (information indicating that the storage unit has been switched).

  The storage management unit 4 selects a storage unit as a storage destination based on the storage state (eg, the number of writings) of the first storage unit 3A and the storage state (eg, the number of writings) of the second storage unit 3B. May be. For example, the storage monitoring unit 4A monitors the number of writes in the first storage unit 3A and the number of writes in the second storage unit 3B constantly or periodically (eg, a predetermined time, the timing at which the detection signal is generated, etc.). Then, the control unit 4B may select, as the storage destination, a storage unit with a small number of writings out of the first storage unit 3A and the second storage unit 3B. Further, the storage unit 3 may include three or more storage units (eg, the first storage unit 3A, the second storage unit 3B, the third storage unit,...). The storage management unit 4 may select the third storage unit as the storage destination of the position information of the moving unit when the number of times of writing in the second storage unit 3B reaches a predetermined value.

[Driver]
Next, the drive device according to the embodiment will be described. FIG. 10 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 rotary shaft SF, a main body (drive unit) BD that rotationally drives the rotary shaft SF, and an encoder device EC that detects rotational position information of the rotary shaft SF.

  In FIG. 10, the signal generator 6 is arranged on the same side of the scale S as the light emitting element 21 and the light receiving sensor 22. The arrangement of the magnet 11, the signal generator 6, the scale S, the light emitting element 21, and the light receiving sensor 22 is not limited to the arrangement shown in FIG. 13, but may be the arrangement shown in FIG. 1, for example, or any other arrangement. Good. For example, the signal generator 6 may be disposed on the surface opposite to the light emitting element 21 and the light receiving sensor 22 with respect to the scale S.

  The encoder device EC includes a processing substrate unit K on which at least a part of the position detection unit 1 shown in FIG. 1 is provided. At least a part of the storage unit 3 in FIG. 1 may be provided in the processing substrate unit K. Further, at least a part of the power supply unit 2 in FIG. 1 may be provided in the processing substrate unit K.

  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. The drive device MTR, for example, can operate stably because the reliability of the encoder device EC is high. For example, the drive device MTR has no or low need for replacement of the storage unit 3 of the encoder device EC, so that 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 according to the embodiment will be described. FIG. 11 is a diagram showing a stage apparatus STG. This stage device STG has a configuration in which a stage (a rotary table TB, a moving object) is attached to the load side end portion SFa of the rotation shaft SF of the drive device MTR shown in FIG. The stage apparatus STG may have a configuration in which the stage is linearly moved in one direction by a one-dimensional linear motor, for example. Further, the stage apparatus STG may be configured to move the stage in two directions by a plurality of one-dimensional linear motors or two-dimensional linear motors (eg, planar motors). 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 stage device STG drives the driving device MTR to rotate the rotation shaft SF. This rotation is transmitted to the rotary table TB, and the encoder device EC detects the angular position of the rotary shaft SF and the like at that time. By using the output from the encoder device EC, the angular position of the rotary table TB can be detected. 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.

  The stage apparatus STG can operate stably because the reliability of the encoder apparatus EC is high, for example. The stage device STG has no or low need for replacement of the storage unit 3 of the encoder device EC, for example, so that 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 according to the embodiment will be described. FIG. 12 is a perspective view showing the robot apparatus RBT. FIG. 12 schematically shows a part (joint portion) of the robot apparatus RBT. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description 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. 12, 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.

  For example, the robot apparatus RBT can operate stably because the reliability of the encoder apparatus EC is high. For example, the robot apparatus RBT has no or low need for replacement of the storage unit 3 of the encoder apparatus EC, so that the maintenance cost can be reduced. Note that the robot apparatus RBT is not limited to the above configuration, and the driving apparatus MTR can be applied to various robot apparatuses (for example, a double-arm multi-axis robot) having a plurality of joints. In the case of a robot apparatus having a plurality of joints, the encoder apparatus EC of the present embodiment is arranged at each joint (each axis) or a part of the robot apparatus.

  The technical scope of the present invention is not limited to the aspects described in the above-described embodiments. One or more of the requirements described in the above embodiments and the like may be omitted. In addition, the requirements described in the above-described embodiments and the like 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.

DESCRIPTION OF SYMBOLS 1 ... Position detection part, 3A ... 1st memory | storage part, 3B ... 2nd memory | storage part, 4 ... Memory | storage management part, 4A ... Memory | storage monitoring part, 6 ... Signal generation part, 8 ... Battery, 9 ... First power source, 31 ... Non-volatile memory, 32 ... Capacitor, 33 ... Second power source, 34 ... Voltage sensor, EC ... Encoder device, SF ... Rotating shaft, MTR ... Drive device, RBT ... Robot device, STG ... Stage device

Claims (17)

A position detection unit for detecting position information of the moving unit;
A first storage unit that stores position information of the moving unit detected by the position detection unit;
Position information of the moving unit can be stored, a second storage unit different from the first storage unit,
An encoder device comprising: a storage management unit that stores position information of the moving unit in one of the first storage unit and the second storage unit.   The storage management unit includes a storage monitoring unit that monitors at least one storage state of the first storage unit and the second storage unit, and the one storage unit is based on a monitoring result of the storage monitoring unit. The encoder device according to claim 1, wherein the encoder device is selected. The storage monitoring unit monitors the number of times the position information is written to the first storage unit as the storage state of the first storage unit,
The encoder device according to claim 2, wherein the storage management unit switches the storage unit that stores the position information from the first storage unit to the second storage unit based on the number of times the position information is written.   4. The storage management unit according to claim 3, wherein when the number of write operations in the first storage unit reaches a predetermined value, the storage management unit selects the second storage unit as a location information storage destination of the moving unit. 5. Encoder device. The second storage unit includes a capacitor charged by power supplied from a first power source,
The memory monitoring unit monitors the voltage between the electrodes of the capacitor as the memory state of the second memory unit,
The encoder device according to claim 2, wherein the storage management unit switches the storage unit that stores the position information from the second storage unit to the first storage unit based on a voltage between electrodes of the capacitor.   The encoder apparatus according to claim 5, wherein whether or not power is supplied to the position detection unit from a second power supply different from the first power supply is switched based on a voltage between the electrodes of the capacitor.   The encoder according to claim 5 or 6, wherein the storage management unit outputs a control signal for switching whether or not to limit a write operation of the first storage unit according to a voltage between the electrodes of the capacitor. apparatus.   The encoder device according to any one of claims 2 to 7, wherein the storage management unit notifies a storage state of the first storage unit. The second storage unit stores the position information during a period in which power is supplied from the first power source to the position detection unit,
The said 1st memory | storage part memorize | stores the said positional information in the period when electric power is supplied to the said position detection part from the 2nd power supply different from the said 1st power supply. The encoder device described in 1.   The position detection unit detects angular position information and multi-rotation information as the position information based on electric power supplied from a first power source, and detects the multi-rotation information in a state where power supply from the first power source is cut off. The encoder device according to any one of claims 1 to 9.   The position detection unit detects the position information by power supplied from a first power source, and is supplied from a second power source different from the first power source in a state where power supply from the first power source is interrupted. The encoder device according to any one of claims 1 to 10, wherein the position information is detected by electric power. A capacitor charged with electric power supplied from the first power source and holding electric power consumed for storing the position information;
12. The position detection unit can detect the position information based on power supplied from the capacitor in a state where power supply from the first power source is cut off. 13. The encoder device described in 1. A signal generating unit that generates a detection signal by a change in magnetic field accompanying the movement of the moving unit;
13. The switch according to claim 9, further comprising: a switching unit that switches presence / absence of power supply from the second power source different from the first power source to the position detection unit based on the generation of the detection signal. Encoder device.
Coder device. The signal generator is
A magnet that moves in conjunction with the moving part;
The encoder apparatus according to claim 13, further comprising: a magnetic sensitive section that causes a large Barkhausen jump by a change in a magnetic field accompanying the movement of the magnet. The encoder device according to any one of claims 1 to 14,
And a driving unit that supplies a driving force to the moving unit. A drive device according to claim 15;
And a stage that is moved by the driving device. A drive device according to claim 15;
And an arm that is moved by the driving device.

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