JP2018115895A - Encoder device, drive device, stage device, and robot device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable encoder device. An encoder device has a first pattern indicating an angular position of a rotating body, a first detection unit that detects light from the first pattern, and an angular position of the rotating body based on the detection results of the first detection unit. A first processing unit that calculates information, a second pattern in which the optical characteristic value gradually changes in the rotation direction of the rotating body, a second detection unit that detects light from the second pattern, and a second detection unit. It includes a second processing unit that calculates multi-rotation information of the rotating body based on the detection result. [Selection diagram] Fig. 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).

JP-A-8-50034

  According to the first aspect of the present invention, the first pattern indicating the angular position of the rotator, the first detector that detects light from the first pattern, and the rotator based on the detection result of the first detector. A first processing unit that calculates the angular position information of the second, a second pattern in which the optical characteristic value gradually changes in the rotation direction of the rotating body, a second detection unit that detects light from the second pattern, and a second There is provided an encoder device comprising: a second processing unit that calculates multi-rotation information of a rotating body based on a detection result of the detection unit.

  According to the second aspect of the present invention, the position information of the moving unit is calculated based on the first pattern indicating the position information of the moving unit and the detection result of the first detection unit that detects light from the first pattern. The position of the moving unit based on the first processing unit, the second pattern in which the optical characteristic value gradually changes in the moving direction of the moving unit, and the detection result of the second detecting unit that detects light from the second pattern There is provided an encoder apparatus comprising: a second processing unit that calculates information; and a comparison unit that compares the position information of the moving unit calculated by the first processing unit and the position information of the moving unit calculated by the second processing unit. The

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

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

  According to a fifth aspect of the present invention, there is provided a robot apparatus including a third driving device 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 scale of the encoder apparatus which concerns on 1st Embodiment. It is a figure which shows the 2nd process part which concerns on 1st Embodiment. It is a figure which shows the signal generation part which concerns on 1st Embodiment. It is a figure which shows the electric power supply part which concerns on 1st Embodiment. It is a figure which shows the operation | movement at the time of electric power supply from a 1st power supply in 1st Embodiment. It is a figure which shows the operation | movement at the time of electric power supply from a 2nd power supply in 1st Embodiment. It is a figure which shows the comparison part which concerns 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 a moving unit (eg, rotating body, moving body). The encoder device EC is, for example, a rotary encoder. The moving part (rotating body) in the rotary encoder is, for example, the rotation axis SF of the motor M (drive device, power supply part), and the movement of the moving part 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 rotational position information includes one or both of multi-rotation information and angular position information. The multi-rotation information is information indicating the number of rotations of the rotating body (for example, the rotation axis SF). The angular position information is information indicating an angular position (rotation angle) of less than one rotation of the rotating body (for example, the rotation axis SF).

  The rotating shaft SF is, for example, a shaft (rotor) of the motor M. The rotation axis SF may be an action axis (output axis). The action shaft is connected to the shaft of the motor M via a power transmission unit such as a transmission and is connected to a load. 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 includes a position detection unit 1 and a power supply unit 2. The position detection unit 1 detects rotation position information of the rotation axis SF. The encoder device EC is, for example, a multi-rotation absolute encoder. The encoder device EC can detect rotational position information including multi-rotation information and angular position information. The position detection unit 1 includes a multi-rotation information detection unit 3 and an angle detection unit 4. The angle detection unit 4 detects angular position information of the rotation axis SF. The multi-rotation information detection unit 3 detects multi-rotation information of the rotation axis SF.

  For example, the encoder device EC detects rotational position information of the rotating shaft SF in each of a normal state and a backup state in which the power supply sources consumed by the encoder device EC are different. For example, at least a part of the position detection unit 1 (for example, the multi-rotation information detection unit 3 and the angle detection unit 4) detects the rotation position information of the rotation axis SF by the power supplied from the first power supply PW1 in the normal state. To do. The first power supply PW1 is, for example, a main power supply of a device (eg, drive device, stage device, robot device) on which the encoder device EC is mounted. In the normal state, the power of the first power supply PW1 is turned on, the first power supply PW1 is turned on, and power is supplied from the first power supply PW1 to the device on which the encoder device EC is mounted. And at least one of a state in which power is supplied from the first power supply PW1 to the encoder device EC.

  For example, the first power supply PW1 is, in a normal state, power consumed for driving the rotation axis SF and a detection operation of the position detection unit 1 (for example, an operation for calculating and detecting angular position information and multi-rotation information). Supply the power consumed. At least a part of the position detection unit 1 receives power supply from the first power supply PW1 and detects rotational position information of the rotation shaft SF. The motor control unit MC controls the rotation of the rotating shaft SF by adjusting the electric power from the first power supply PW1 and supplying it to the motor M based on the detection result of the position detection unit 1.

  At least a part of the position detection unit 1 (eg, the multi-rotation information detection unit 3) is supplied with power from a second power source (eg, battery 6) different from the first power source PW1 in a backup state different from the normal state. Can be operated by. The backup state includes, for example, a state where the power supply from the first power supply PW1 is cut off, a state where the power of the first power supply PW1 is not turned on, a state where the first power supply PW1 is off, and an encoder device EC Includes at least one state in which power is not supplied from the first power source PW1 to the device on which the power is mounted, and a state in which power is not supplied from the first power source PW1 to the encoder device EC.

  For example, the power supply unit 2 intermittently (selectively, intermittently) supplies power to at least a part of the position detection unit 1 (for example, the multi-rotation information detection unit 3) in the backup state. In the backup state, the position detection unit 1 receives power supply from the power supply unit 2 and detects at least a part (for example, multi-rotation information) of the rotation position information of the rotation axis SF. For example, the multi-rotation information detection unit 3 intermittently receives the power supply from the second power source (for example, the power supply unit 2) and intermittently detects the multi-rotation information. The multi-rotation information detected by the multi-rotation information detection unit 3 in the backup state is, for example, when power supply from the first power supply PW1 is started and switched from the backup state to the normal state (for example, when the drive device is started). The rotation of the rotating shaft SF by the motor control unit MC is used for control.

  The multi-rotation information detection unit 3 detects multi-rotation information of the rotation shaft SF in each of a normal state in which power is supplied from the first power source PW1 and a backup state in which power is supplied from the second power source. For example, the encoder device EC switches from the normal state to the backup state when the power supply of the first power supply PW1 is stopped. The encoder device EC switches from the backup state to the normal state when the power supply of the first power supply PW1 is started. When the encoder device EC is switched between the normal state and the backup state, the multi-rotation information detection unit 3 continues to detect multi-rotation information (continues calculation). For example, the angle detection unit 4 does not detect (calculate) angle information in a backup state in which power supply from the first power supply PW1 is cut off. For example, the second power supply does not supply power to the angle detection unit 4 in the backup state. The angle detection unit 4 is, for example, a state in which power supply is cut off in the backup state, and does not detect angular position information.

  In the present embodiment, the multi-rotation information detection unit 3 can detect the angular position information of the rotation axis SF. For example, the multi-rotation information detection unit 3 detects multi-rotation information and angular position information in a normal state. The angular position information detected by the multi-rotation information detection unit 3 is used, for example, for comparison with the angular position information detected by the angle detection unit 4. For example, the multi-rotation information detection unit 3 detects angular position information as comparison information (reference information) with respect to the angular position information detected by the angle detection unit 4. For example, the multi-rotation information detection unit 3 does not detect angular position information in a state where the angle detection unit 4 does not detect angular position information (for example, a backup state).

  For example, the position detection unit 1 generates a notification signal (notification information) based on a comparison result between the angle position information detected by the angle detection unit 4 and the angle position information detected by the multi-rotation information detection unit 3. Output to the outside. For example, the position detection unit 1 generates notification information when the difference between the angle position information detected by the angle detection unit 4 and the angle position information detected by the multi-rotation information detection unit 3 is not within a predetermined range. The notification information is, for example, information (signal) for notifying an external device of a warning or an error with respect to an external device (eg, motor control unit MC) of the encoder device EC.

  Hereinafter, each part of the encoder device EC will be described. The angle detector 4 detects position information (angular position information, absolute or relative position information) within one rotation of the scale S (eg, code plate). The scale S is, for example, a disk-shaped member (eg, a member made of glass, metal, resin, or the like). The scale S is fixed to the rotation axis SF and rotates in conjunction with the rotation axis SF. The angle detection unit 4 is an optical encoder. For example, the angle detection unit 4 detects the angular position information of the rotation axis SF by reading the patterning information of the scale S with a light receiving element. The patterning information of the scale S detected by the angle detection unit 4 is, for example, a light / dark pattern based on one or both of a transmission pattern (eg, a slit) and a reflection pattern on the scale S.

  The angle detection unit 4 includes a first pattern 10, an irradiation unit 11, a first detection unit 12, and a first processing unit 13. The 1st pattern 10 is a pattern which shows the angular position of a rotating body (for example, rotation axis SF). The first pattern 10 includes, for example, one or both of an absolute pattern ABS and an incremental pattern INC. The absolute pattern ABS indicates the angular position (eg, absolute position) of the rotating body (scale S, rotating shaft SF). The incremental pattern INC indicates the amount of change in angle (eg, relative position) in the rotation direction of the rotation axis SF. The incremental pattern INC includes a structure (periodic structure) that is periodically arranged in the rotation direction of the rotation axis SF.

  The irradiation unit 11 (light emitting unit) irradiates light to the absolute pattern ABS and the incremental pattern INC. The irradiation unit 11 includes, for example, a light emitting element (eg, a solid light source) such as an LED (light emitting diode). The first detector 12 (light detector) detects light from the absolute pattern ABS and light from the incremental pattern INC, respectively. The first detection unit 12 includes a light receiving element (photoelectric conversion element) such as an FD (photodiode).

  The angle detection unit 4 is, for example, a reflection type. The first detection unit 12 individually detects the light irradiated from the irradiation unit 11 and reflected by the absolute pattern ABS, and the light irradiated from the irradiation unit 11 and reflected by the incremental pattern INC. The first processing unit 13 detects (eg, calculates) angular position information of the rotation axis SF based on the detection result of the first detection unit 12. For example, the first processing unit 13 detects the angular position information of the first resolution using the result of detecting the light from the absolute pattern ABS. Further, the first processing unit 13 performs an interpolation operation on the angular position information of the first resolution using the result of detecting the light from the incremental pattern INC, so that the angle of the second resolution higher than the first resolution is obtained. Detect location information.

  The angle detector 4 may be a transmissive type. In this case, the 1st detection part 12 detects separately the light irradiated from the irradiation part 11, and permeate | transmitted the absolute pattern ABS, and the light irradiated from the irradiation part 11, and permeate | transmitted the incremental pattern INC.

  The multi-rotation information detection unit 3 optically detects multi-rotation information of the same rotation axis SF as the detection target of the angle detection unit 4. The multi-rotation information detection unit 3 is, for example, an optical encoder. The multi-rotation information detection unit 3 detects the multi-rotation information of the rotation axis SF by reading patterning information of the scale S with a light receiving element, for example.

  The multi-rotation information detection unit 3 includes a second pattern 15, an irradiation unit 16, a second detection unit 17, and a second processing unit 18. The second pattern 15 is, for example, a shading pattern. The second pattern 15 has an optical characteristic value that changes in the movement direction (eg, rotation direction) of the rotation axis SF (eg, stepwise, linear, or non-linear change). The second pattern 15 includes a pattern in which an optical characteristic value gradually changes in a moving direction (eg, rotation direction) of a rotating body (eg, rotation axis SF, scale S) (eg, a gray scale pattern). The optical characteristic value includes, for example, at least one of reflectance, transmittance, and light absorption. For example, the second pattern 15 includes a pattern in which the optical characteristic value gradually increases or decreases in at least a part of the rotation direction. In the second pattern 15, for example, one or both of the light amount and intensity of light (for example, reflected light, transmitted light, scattered light) irradiated to the outside upon receiving light from the irradiation unit 16 is gradually increased in the rotation direction. Has changing characteristics. For example, the second pattern 15 is provided on the same member (eg, scale S, first rotating body) as the absolute pattern ABS and the incremental pattern INC.

  The second pattern 15 may be provided on a member different from the first pattern 10 (for example, the absolute pattern ABS, the incremental pattern INC). For example, at least a part of the first pattern 10 (eg, the absolute pattern ABS) is provided on the first rotating body (eg, the first scale), and the second pattern 15 is different from the first rotating body. It may be provided on two rotating bodies (for example, the second scale). Note that the patterning information of the scale S detected by the multi-rotation information detection unit 3 may be, for example, a light / dark pattern based on one or both of a transmission pattern (eg, a slit) and a reflection pattern on the scale S.

  The irradiation unit 16 (light emitting unit) irradiates the second pattern 15 with light. The irradiation unit 16 includes, for example, a light emitting element (eg, a solid light source) such as an LED (light emitting diode). The second detection unit 17 (light detection unit) detects light from the second pattern 15. The second detection unit 17 includes a light receiving element (photoelectric conversion element) such as an FD (photodiode). The multi-rotation information detection unit 3 is, for example, a reflection type. The second detection unit 17 detects the light emitted from the irradiation unit 11 and reflected by the second pattern 15. The second processing unit 18 detects (eg, calculates) the multi-rotation information of the rotation axis SF based on the detection result of the second detection unit 17. The multi-rotation information detection unit 3 may be a transmission type. In this case, the second detection unit 17 detects light emitted from the irradiation unit 16 and transmitted through the second pattern 15. Note that the illumination unit 16 is not configured to be independent of the illumination unit 11 but may be configured to share (combine) the illumination unit 11. In this case, for example, the illumination unit 11 and the illumination unit 16 share a light emitting unit (eg, one light emitting unit), and the light receiving unit 12 and the light receiving unit 17 are the same chip (eg, one integrated circuit board). Formed on top.

  FIG. 2 is a diagram illustrating a scale of the encoder device according to the present embodiment. FIG. 2A is a plan view of the scale S in a plane perpendicular to the rotation axis SF. The absolute pattern ABS, the incremental pattern INC, and the second pattern 15 are each annular. The absolute pattern ABS, the incremental pattern INC, and the second pattern 15 are arranged concentrically around the rotation axis SF. The absolute pattern ABS is, for example, arranged outside the incremental pattern INC with respect to the rotation axis SF. The first detection unit 12 includes a light receiving unit 12a (light receiving region) that detects light from the absolute pattern ABS, and a light receiving unit 12b (light receiving region) that detects light from the incremental pattern INC.

  For example, the second pattern 15 is disposed inside the incremental pattern INC with respect to the rotation axis SF. In the second pattern 15 in FIG. 2A, the reflectance is expressed in gray scale. In the second pattern 15 in FIG. 2A, a portion close to white is a portion having a relatively high reflectance, and a portion close to black is a portion having a relatively low reflectance.

  The second pattern 15 includes, for example, a plurality of patterns (for example, a first phase pattern 15a and a second phase pattern 15b) whose phases are shifted from each other in the rotation direction. The pattern 15a and the pattern 15b have different optical characteristic value distribution phases in the rotation direction of the rotation axis SF. FIG. 2B is a graph showing a distribution of optical characteristic values of the second pattern 15 in the rotation direction of the rotation axis SF. In FIG. 2B, the optical characteristic value on the vertical axis is, for example, reflectance.

  In FIG. 2B, the optical characteristic value Va of the pattern 15a and the optical characteristic value Vb of the pattern 15b change continuously with respect to the angular position. The optical characteristic value Va of the pattern 15a and the optical characteristic value Vb of the pattern 15b each change in a sine wave shape with respect to the angular position. Note that the second pattern 15 may be configured such that the optical characteristic value Va and the optical characteristic value Vb change to a linear shape. The optical characteristic value Va of the pattern 15a and the optical characteristic value Vb of the pattern 15b are, for example, a one-cycle distribution in the range of one rotation (360 °).

  The optical characteristic value Va of the pattern 15a becomes maximum at a position Pb (eg, 90 °) and becomes minimum at a position Pd (eg, 270 °). The phase of the pattern 15b differs from the phase of the pattern 15a by about 90 °, for example. The optical characteristic value Vb of the pattern 15b becomes maximum at a position Pc (eg, 180 °) and becomes minimum at a position Pa (eg, 0 °, 360 °). Note that the distribution of optical characteristic values shown in FIG. 2B is an example and can be changed as appropriate. For example, the distribution of the optical characteristic values of the second pattern 15 may be a linear distribution (for example, a straight line or a triangular wave shape) with respect to the angular position, or may be a non-linear distribution with respect to the angular position. Further, the optical characteristic value of the second pattern 15 may change discontinuously (eg, three or more steps) in three or more stages.

  The second detection unit 17 (see FIG. 2A) individually detects the light from the pattern 15a and the light from the pattern 15b. The second detection unit 17 includes a light receiving unit 17a (light receiving region) and a light receiving unit 17b (light receiving region). The light receiving unit 17a detects light emitted from the irradiation unit 16 and passing through the pattern 15a. The detection result of the light receiving unit 17a is used as an A phase signal, for example. The light receiving unit 17b detects light emitted from the irradiation unit 16 and passing through the pattern 15b. The detection result of the light receiving unit 17b is used as, for example, a B phase signal.

  FIG. 3 is a diagram illustrating a second processing unit according to the present embodiment. The second detection unit 17 supplies a signal (detection signal) indicating the detection result to the second processing unit 18. The second processing unit 18 calculates position information of the rotating body (for example, the rotation axis SF, the scale S) based on the detection result of the second detection unit 17. For example, the second processing unit 18 calculates multi-rotation information as position information of the rotating body (eg, the rotation axis SF, the scale S) based on the detection result of the second detection unit 17. The second processing unit 18 may calculate the angular position information as the position information of the rotating body (eg, the rotation axis SF, the scale S) based on the detection result of the second detection unit 17, or may perform multiple rotations. Information and angular position information may be calculated.

  The detection signal of the second detection unit 17 includes, for example, the detection result of the light receiving unit 12a (hereinafter referred to as the first detection signal) and the detection result of the light receiving unit 12b (hereinafter referred to as the second detection signal) illustrated in FIG. )including. The second processing unit 18 includes a calculation unit 21, a binarization unit 22, and a counting unit 23. The detection results (first detection signal and second detection signal) of the second detection unit 17 are supplied to the calculation unit 21 and the binarization unit 22, respectively.

  The calculation unit 21 calculates angular position information of the rotation axis SF based on the detection signal from the second detection unit 17. For example, the calculation unit 21 detects (calculates) the angular position information of the rotation axis SF with a resolution lower than that of the first processing unit 13 (see FIG. 1). In addition, the second processing unit 18 (for example, the binarizing unit 22 and the counting unit 23), for example, converts the detection result of the second detection unit 17 into a gradation value, and calculates multi-rotation information of the rotation axis SF. To do. For example, the binarization unit 22 compares the level of the detection signal of the second detection unit 17 with a threshold value and binarizes the detection signal.

  FIG. 3B is a diagram illustrating examples of detection signals and threshold values. The distribution of the level of the first detection signal Sa with respect to the angular position is a distribution (eg, sinusoidal distribution) corresponding to the optical characteristic value of the pattern 15a. Further, the distribution of the level of the second detection signal Sb with respect to the angular position is a distribution (eg, sinusoidal distribution) corresponding to the optical characteristic value of the pattern 15b. The threshold value Vth is set to, for example, an average value (amplitude) of detection signal levels.

  FIG. 3C is a diagram illustrating the level of the binarized first detection signal Sa. The level of the binarized first detection signal Sa is a high level (H) in a range from the position Pa to the position Pc via the position Pb (for example, a range of 0 ° to 180 °). The binarized first detection signal Sa has a low level (L) in a range from the position Pc to the position Pa via the position Pd (for example, a range of 180 ° to 360 °).

  FIG. 3D is a diagram illustrating the level of the binarized second detection signal Sb. The level of the binarized second detection signal Sb is a range from the position Pa to the position Pb (eg, a range from 0 ° to 90 °) and a range from the position Pd to the position Pa (eg, 270 ° to 360 °). (Range) is low level (L). The level of the binarized second detection signal Sb is a high level (H) in a range from the position Pb to the position Pd via the position Pc (for example, a range from 90 ° to 270 °).

  The counting unit 23 calculates multi-rotation information (counts the number of rotations) using the binarized first detection signal Sa and the binarized second detection signal Sb. For example, the counting unit 23 uses the detection result (first detection signal Sa) detected by the second detection unit 17 (light receiving unit 17a) and the pattern 15b detected by the second detection unit 17 (light receiving unit 17b). Using the detected result (second detection signal Sb), the direction (movement direction, rotation direction) of the rotation axis SF is determined, and multi-rotation information is detected. Hereinafter, the set of the binarized first detection signal Sa and the binarized second detection signal Sb at each angular position is referred to as a signal level set, and the signal level set (H, L).

  For example, the set of signal levels is (H, L) in a range from position Pa to position Pb (eg, a range from 0 ° to 90 °). The set of signal levels is (H, H) in the range from the position Pb to the position Pc (eg, the range from 90 ° to 180 °). The set of signal levels is (L, H) in the range from the position Pc to the position Pd (eg, the range from 180 ° to 270 °). The set of signal levels is (L, L) in a range from the position Pd to the position Pa (eg, a range from 270 ° to 360 °).

  For example, when the set of signal levels based on the previous detection result is (H, H) and the set of signal levels based on the current detection result is (L, H), the counting unit 23 counts from the previous detection to the current level. It is determined that the rotation axis SF has rotated in the first direction (eg, clockwise in FIG. 2A) until detection. For example, when the set of signal levels based on the previous detection result is (H, H) and the set of signal levels based on the current detection result is (H, L), the counting unit 23 starts from the previous detection. It is determined that the rotation axis SF has rotated in a second direction opposite to the first direction (eg, counterclockwise in FIG. 2A) until the current detection. For example, when the set of signal levels is (H, H), the counting unit 23 increments (+1) or decrements (−1) the counter value according to the direction of rotation, and sets the counter value as multi-rotation information. Output.

  The second processing unit 18 converts, for example, the detection result of the second detection unit 17 into gradation values of three or more levels, and at least a part of the rotation position information of the rotation axis SF (eg, multi-rotation information). May be calculated. In addition, the second processing unit 18 calculates, for example, at least a part (for example, angular position information) of the rotation position information of the rotation axis SF without converting the detection result of the second detection unit 17 into a gradation value. Also good. In addition, as described above, the second processing unit 18 detects a detection result (eg, a detection signal) obtained by detecting the second pattern 15 (eg, a pattern whose optical characteristic value gradually changes in the moving direction). Includes a processing circuit for processing the above by an arithmetic operation.

  Returning to the description of FIG. 1, the encoder device EC according to the present embodiment includes a storage unit 24, a comparison unit 25, a synthesis unit 26, and a communication unit 27. The storage unit 24 is, for example, a nonvolatile memory. Information (eg, multi-rotation information) output from the second processing unit 18 is stored. The synthesizing unit 26 acquires the angular position information of the second resolution detected by the first processing unit 13. Further, the synthesizing unit 26 acquires multi-rotation information of the rotation axis SF from the storage unit 24. The synthesizing unit 26 synthesizes the angular position information from the first processing unit 13 and the multi-rotation information from the multi-rotation information detection unit 3, and calculates the rotational position information of the rotation axis SF. For example, when the detection result of the first processing unit 13 is θ [rad] and the detection result of the multi-rotation information detection unit 3 is n rotations, the combining unit 26 uses (2π × n + θ) [ rad] is calculated. The rotation position information may be information obtained by combining multi-rotation information and angular position information of less than one rotation.

  The synthesizing 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 4. 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 comparison unit 25 compares information based on the detection result of the first detection unit 12 and information based on the detection result of the second detection unit 17 (performs a comparison process). For example, the comparison unit 25 is calculated by the second processing unit 18 based on the angular position information calculated by the first processing unit 13 based on the detection result of the first detection unit 12 and the detection result of the second detection unit 17. The angle position information is compared, and notification information (notification signal) indicating the comparison result is generated.

  The comparison unit 25 includes, for example, the position information (eg, angular position information) of the rotating body (eg, rotation axis SF) calculated by the first processing unit 13 and the rotation body (eg, rotation axis) calculated by the second processing unit 18. SF) position information (eg, angular position information) is determined whether or not a predetermined condition is satisfied. The predetermined condition is, for example, a comparison value (e.g., difference, difference) between the angular position information of the rotation axis SF calculated by the first processing unit 13 and the angular position information of the rotation axis SF calculated by the second processing unit 18. The ratio is within a predetermined range (eg, allowable range, allowable error range).

  For example, the comparison unit 25 determines whether or not the operation of the encoder device EC is normal by comparing the processing result of the first processing unit 13 and the processing result of the second processing unit 18. For example, the comparison unit 25 determines that the operation of the encoder device EC is normal when the processing result of the first processing unit 13 and the processing result of the second processing unit 18 satisfy the predetermined condition, and the determination Output results (eg, results of normal or abnormal operation).

  The encoder device EC outputs information (eg, rotational position information) including position information (eg, angular position information) of the rotating body calculated by the first processing unit 13 based on the determination result of the comparison unit 25. For example, when the comparison unit 25 determines that the operation of the encoder device EC is normal, the synthesizing unit 26 generates rotational position information without using the angular position information calculated by the second processing unit 18. For example, the second processing unit 18 calculates angular position information as reference information to be compared with the processing result of the first processing unit 13. When the comparing unit 25 determines that the operation of the encoder device EC is normal, the combining unit 26 generates rotational position information that does not include the reference information.

  For example, when the difference between the angular position information calculated by the first processing unit 13 and the angular position information calculated by the second processing unit 18 exceeds a predetermined value, the comparison unit 25 detects an error in the detection state of the encoder device EC. Notification information (eg, error information, error signal) indicating the occurrence of a warning or notification information (warning information, warning signal) indicating a warning is generated. The notification information is, for example, information that notifies the occurrence of at least one malfunction of the irradiation unit 11, the first detection unit 12, the first processing unit 13, the irradiation unit 16, the second detection unit 17, and the second processing unit 18. But you can. For example, when an operation failure (for example, a decrease in the amount of light or an unexpected turn-off) occurs in the irradiating unit 11 or the irradiating unit 16, the angle position information from the first processing unit 13 and the angle from the second processing unit 18 are detected. The difference or ratio with the position information falls outside the allowable range, and the comparison unit 25 generates notification information notifying the occurrence of an abnormality (eg, malfunction). Similarly, when an operation failure occurs in the first detection unit 12 or the second detection unit 17 and when an operation failure occurs in the first processing unit 13 or the second processing unit 18, the comparison unit 25 is also abnormal (for example, Notification information for generating the occurrence of malfunction) is generated. For example, the comparison unit 25 outputs the generated notification information to the communication unit 27. For example, the comparison unit 25 outputs the notification information to the outside of the encoder device EC (for example, the motor control unit MC) via the communication unit 27.

  The multi-rotation information detection unit 3 may include a second multi-rotation detection unit separately from the first multi-rotation detection unit (for example, the second pattern 15 and the detection unit 17). The second multi-rotation detection unit may be an optical encoder or an encoder of another detection method (eg, magnetic type). The magnetic encoder may detect the magnetic field of the magnet 31 and detect multi-rotation information based on the detection result. For example, the comparison unit 25 may compare the detection result (eg, multi-rotation information) of the first multi-rotation detection unit with the detection result (eg, multi-rotation information) of the second multi-rotation detection unit. . The comparison unit 25 may compare a plurality of pieces of angular position information obtained from the detection results of different sensors, and may compare a plurality of pieces of multi-rotation information obtained from the detection results of different sensors. Further, the second processing unit 18 calculates the angular position information as the position information of the rotating body (eg, the rotation axis SF) based on the detection result of the second detection unit 17, and does not calculate the multi-rotation information. Also good.

  The encoder device EC may not output the notification information generated by the comparison unit 25 to the outside of the encoder device EC. For example, the encoder device EC may turn on a warning light or emit a warning sound (eg, alarm sound) based on the notification information generated by the comparison unit 25, for example.

  For example, the comparison unit 25 performs the comparison process in a state where the first processing unit 13 calculates angular position information and the second processing unit 18 calculates angular position information. For example, the comparison unit 25 performs the above-described comparison process in a normal state in which power is supplied from the first power supply PW1 to the position detection unit 1.

  For example, the comparison unit 25 does not perform the comparison process in a state where one or both of the first processing unit 13 and the second processing unit 18 does not calculate the angular position information. For example, in the backup state in which the power supply from the first power supply PW1 is cut off, the first detection unit 12 does not perform detection, and the first processing unit 13 does not calculate angular position information. In the backup state, for example, the first processing unit 13 does not calculate the angular position information, and the comparison unit 25 does not execute the comparison process. In the backup state, for example, the second detection unit 17 receives power from a second power source (for example, the battery 6) and performs detection. In the backup state, the second detection unit 17 performs detection. In the backup state, for example, the second processing unit 18 calculates the multi-rotation information based on the detection result of the second detection unit 17 described above, and does not calculate the angular position information. In the backup state, the encoder device EC may be configured such that, for example, the second processing unit 18 does not calculate the angular position information, and the comparison unit 25 does not execute the above-described comparison processing.

  For example, the comparison unit 25 receives the power supply from the first power supply PW1 in a normal state, and executes the above comparison process. For example, the comparison unit 25 performs the comparison process using the power supplied from the first power supply PW1 in the normal state. For example, the power supply unit 2 does not supply power to the comparison unit 25 in the backup state. For example, the comparison unit 25 does not perform the comparison process when the power supply is cut off in the backup state.

  Next, the power supply unit 2 will be described. The power supply unit 2 supplies power to at least a part of the position detection unit 1 (for example, the multi-rotation information detection unit 3) in at least the backup state of the normal state and the backup state. The power supply unit 2 includes a magnet 31, a signal generation unit 32, a switching unit 33, and a battery 6. FIG. 4 is a diagram illustrating the signal generator 32 according to the present embodiment. 4A shows a perspective view of the magnet 31 and the signal generation unit 32, and FIG. 4B shows a plan view of the magnet 31 and the signal generation unit 32 viewed from the direction of the rotation axis SF. .

  The signal generation unit 32 generates an electrical signal (detection signal) by movement (eg, rotation) of a movement unit (eg, rotation axis SF). This electric signal includes, for example, a waveform in which power (current, voltage) changes with time. For example, the signal generator 32 generates a detection signal as an electrical signal by a magnetic field that changes in accordance with the rotation of the rotation axis SF. For example, the magnet 31 and the signal generator 32 are relatively moved by the rotation of the rotation axis SF, and the magnetic field formed by the magnet 31 at the position of the signal generator 32 is changed. Occur.

  The magnet 31 is fixed with respect to the rotation axis SF, for example. The magnet 31 is fixed to the scale S, for example. The signal generating unit 32 is arranged so that the angular position relative to the magnet 31 is changed by the rotation of the rotating shaft SF. For example, when the relative position between the signal generator 32 and the magnet 31 reaches a predetermined position, the signal generator 32 generates a pulsed electric signal.

  The signal generator 32 may generate a detection signal (for example, a pulsed electric signal) other than a change in the magnetic field. The magnet 31 may be provided on a member different from the scale S. For example, the magnet 31 may be provided on the third rotating body, and the third rotating body may be fixed to the rotation shaft SF. The third rotating body may be provided with a part of the absolute pattern ABS, the incremental pattern INC, and the second pattern 15.

  The magnet 31 is configured to change the direction and strength of the magnetic field in the radial direction (the radial direction of the scale S) with respect to the rotation axis SF by rotation. The magnet 31 is, for example, an annular member that is coaxial with the rotation axis SF. The main surfaces (front surface and back surface) of the magnet 31 are each substantially perpendicular to the rotation axis SF. As shown in FIG. 4B, the magnet 31 is a permanent magnet magnetized to 8 poles. The magnet 31 has N poles and S poles arranged in the circumferential direction on the inner peripheral side and the outer peripheral side, and the phase is shifted by 90 ° between the inner peripheral side and the outer peripheral side. In the magnet 31, 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 FIG. 4B, the symbol Qa is the position of one boundary between the N pole and the S pole in the circumferential direction in the coordinate system fixed to the magnet 31. Reference sign Qb is a position rotated 90 ° clockwise from the position Qa. Reference sign Qc is a position rotated 90 ° clockwise from the position Qb. The symbol Qd is a position rotated 90 ° clockwise from the position Qc. For example, the position Qa to the position Qd correspond to the position Pa to the position Pd shown in FIG.

  The orientation of the magnetic field formed by the magnet 31 in the radial direction of the scale S is reversed at each of the position Qa, the position Qb, the position Qc, and the position Qd. The magnet 31 forms an AC magnetic field in which the direction of the magnetic field in the radial direction of the scale S is reversed with the rotation of the magnet 31 with respect to the coordinate system fixed outside the magnet 31. The signal generator 32 is disposed at a position overlapping the magnet 31 when viewed from the normal direction of the main surface of the magnet 31.

  In the present embodiment, the signal generator 32 is provided in non-contact with the magnet 31. The signal generation unit 32 includes a magnetic sensing unit 41 and a power generation unit 42. The magnetic sensing unit 41 and the power generation unit 42 are fixed to the outside of the magnet 31, and the relative positions with respect to the respective positions on the magnet 31 change as the magnet 31 rotates.

  The magnetic sensitive part 41 is a magnetic sensitive wire (magnetic material) such as a Wiegand wire. A large Barkhausen jump (Wiegand effect) is generated in the magnetic sensitive part 41 due to a change in the magnetic field accompanying the rotation of the magnet 31. The magnetic sensitive part 41 is a columnar member, and the axial direction thereof is set to the radial direction of the magnet 31. In the magnetic sensitive 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 power generation unit 42 is a high density coil or the like that is wound around the magnetic sensing unit 41. In the power generation unit 42, electromagnetic induction occurs due to the occurrence of the domain wall in the magnetic sensing unit 41, and an induced current flows. When the position Qa, position Qb, position Qc, or position Qd of the magnet 31 shown in FIG. 4B passes in the vicinity of the magnetic sensitive section 41, a pulsed current (electric signal) is generated in the power generation section 42. To do. The 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 can supply power from the outside (for example, the first power supply PW1 in FIG. 1). It is possible to operate even if there is no.

  The direction of the current generated in the 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 31 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 31 to the magnetic field facing the outside. The power (inductive current) generated in the power generation unit 42 can be set by, for example, the number of turns of the high-density coil.

  As shown in FIG. 4A, the magnetic sensitive part 41 and the power generation part 42 are accommodated in a case 43. The case 43 is provided with a terminal 43a and a terminal 43b. The high-density coil of the 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 power generation unit 42 can be taken out of the signal generation unit 32 via the terminals 43a and 43b.

  The configuration of the signal generator 32 described above is an example, and the configuration can be changed as appropriate. For example, the signal generator 32 may generate electric power by electromagnetic induction that does not use a large Barkhausen jump (Wiegand effect). Moreover, the number of the signal generation parts 32 with which the encoder apparatus EC is equipped can be changed suitably, for example, may be two or more. The arrangement of the signal generator 32 can be changed as appropriate.

  Returning to the description of FIG. 1, the battery 6 in the present embodiment supplies at least a part of the power consumed by the position detector 1 based on the detection signal generated by the signal generator 32 in the backup state. It may be configured. The battery 6 (battery) 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 battery 6 of this embodiment is a button type battery, for example.

  In the case of the above configuration, the switching unit 33 switches the presence / absence of power supply from the battery 6 to the position detection unit 1 using the detection signal generated by the signal generation unit 32 as a control signal. For example, the switching unit 33 starts power supply from the battery 6 to the position detection unit 1 when the level of the electric signal generated by the signal generation unit 32 is equal to or higher than a threshold value. For example, the switching unit 33 starts the power supply from the battery 6 to the position detection unit 1 when the signal generation unit 32 generates a detection signal equal to or greater than the threshold value.

  Further, the switching unit 33 stops the power supply from the battery 6 to the position detection unit 1 when the level of the electric signal generated by the signal generation unit 32 becomes less than the threshold value. For example, the switching unit 33 stops the power supply from the battery 6 to the position detection unit 1 when the detection signal generated by the signal generation unit 32 becomes less than the threshold value. For example, in the state where the power supply from the first power supply PW1 is cut off (backup state), when a pulsed electric signal is generated in the signal generating unit 32, the switching unit 33 has a level (potential) of the electric signal. When rising from the low level to the high level, power supply from the battery 6 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 battery 6 Power supply 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 with a regulator or the like and the power from the battery 6 in combination or switching.

  FIG. 5 is a diagram illustrating a circuit configuration of the power supply unit and the multi-rotation information detection unit according to the present embodiment. The power supply unit 2 includes a rectifier stack 51 and a regulator 52 as the switching unit 33 in FIG. The rectification stack 51 is a rectifier that rectifies the current flowing from the signal generator 32. The first input terminal 51 a of the rectifying stack 51 is connected to the terminal 43 a of the signal generating unit 32. The second input terminal 51 b of the rectifying stack 51 is connected to the terminal 43 b of the signal generator 32. The ground terminal 51g of the rectifying stack 51 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 3, the potential of the ground line GL becomes the reference potential of the circuit. The output terminal 51 c of the rectifying stack 51 is connected to the control terminal 52 c of the regulator 52.

  In the backup state, the regulator 52 adjusts the power supplied from the battery 6 to the position detection unit 1 according to the on state and the off state of the regulator. The regulator 52 includes a switching element 53 (switch) provided in a power supply path between the battery 6 and the position detection unit 1. The regulator 52 controls the operation of the switching element 53 by using an electric signal (detection signal) generated by the signal generator 32 as a control signal (eg, an enable signal).

  The positive electrode of the battery 6 is connected to the input terminal 52 a of the regulator 52. The negative electrode of the battery 6 is connected to the ground line GL. The output terminal 52b of the regulator 52 is connected to the power supply line PL. The ground terminal 52g of the regulator 52 is connected to the ground line GL. The control terminal 52c of the regulator 52 is an enable terminal. The regulator 52 maintains the potential of the output terminal 52b at a predetermined voltage in a state where a voltage equal to or higher than the threshold is applied to the control terminal 52c. The output voltage of the regulator 52 (the above-mentioned predetermined voltage) is, for example, 3 V when the counting unit 23 is configured by CMOS or the like. The operating voltage of the storage unit 24 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 53 switches between conduction and interruption of the circuit 54 that supplies power to the position detection unit 1. The circuit 54 constitutes a power supply path that connects, for example, a first electrode (positive electrode) and a second electrode (negative electrode) of a second power source (for example, the battery 6). Circuit 54 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 6, and the potential thereof becomes the reference potential of the circuit 54. For example, the switching element 53 switches whether or not power is supplied from the battery 6 to the position detection unit 1 via the circuit 54.

  The regulator 52 uses the electrical signal supplied from the signal generator 32 to the control terminal 52c as a control signal (enable signal), and conducts between the terminals of the switching element 53 (eg, source electrode, drain electrode) (ON state). ) And insulation state (off state). For example, the switching element 53 includes a MOS, a TFT, and the like. The control terminal 52c is connected to the gate electrode of the switching element 53, for example.

  The gate electrode (control terminal) of the switching element 53 is charged by an electrical signal (detection signal) generated by the signal generator 32. The switching element 53 switches the circuit 54 to conduction according to the voltage of the gate electrode. For example, the switching element 53 blocks the circuit 54 in a state where the potential of the gate electrode is the reference potential of the circuit 54. Further, in the switching element 53, when the voltage of the gate electrode becomes equal to or higher than a predetermined value, the source electrode and the drain electrode are in a conductive state (ON state). When the source electrode and the drain electrode of the switching element 53 are turned on, electric power is supplied from the battery 6 to the circuit 54 via the power supply line PL and the ground line GL. The power supply unit 2 may include an acquisition unit that acquires the on state and the off state of the regulator 52.

  The multi-rotation information detection unit 3 includes an analog comparator 55, an analog comparator 56, and a counting unit 23 as the second processing unit 18 illustrated in FIG. The power supply terminal 16p of the irradiation unit 16 is connected to the power supply line PL. The ground terminal 16g of the irradiation unit 16 is connected to the ground line GL. The output terminal 17 c of the second detection unit 17 (light receiving element) is connected to the input terminal 55 a of the analog comparator 55. The output terminal 17c outputs a voltage corresponding to the detection result of the light receiving unit 17a shown in FIG. The output terminal 17 d of the second detection unit 17 is connected to the input terminal 56 a of the analog comparator 56. The output terminal 17d outputs a voltage corresponding to the detection result of the light receiving unit 17b shown in FIG.

  The analog comparator 55 and the analog comparator 56 are the binarization unit 22 shown in FIG. The analog comparator 55 binarizes the voltage output from the output terminal 17 c of the second detection unit 17. The analog comparator 55 is a comparator, for example, and compares the voltage output from the output terminal 17c with a predetermined voltage. A power supply terminal 55p of the analog comparator 55 is connected to the power supply line PL. The ground terminal 55g of the analog comparator 55 is connected to the ground line GL. The output terminal 55 b of the analog comparator 55 is connected to the first input terminal 23 a of the counting unit 23. The analog comparator 55 outputs an H level signal from the output terminal 55b when the output voltage of the output terminal 17c of the second detection unit 17 is equal to or higher than the threshold value. The analog comparator 55 outputs an L level signal from the output terminal 55b when the output voltage of the output terminal 17c of the second detection unit 17 is less than the threshold value.

  The analog comparator 56 binarizes the voltage output from the output terminal 17d of the second detection unit 17. The analog comparator 56 is a comparator, for example, and compares the voltage output from the output terminal 17d with a predetermined voltage. The power supply terminal 56p of the analog comparator 56 is connected to the power supply line PL. The ground terminal 56g of the analog comparator 56 is connected to the ground line GL. The output terminal 56 b of the analog comparator 56 is connected to the second input terminal 23 b of the counting unit 23. The analog comparator 56 outputs an H level signal from the output terminal 56b when the output voltage of the output terminal 17d of the second detection unit 17 is equal to or higher than the threshold value. The analog comparator 56 outputs an L level signal from the output terminal 56b when the output voltage of the output terminal 17d of the second detection unit 17 is less than the threshold value.

  The counting unit 23 counts the multi-rotation information of the rotation axis SF using the power supplied from the battery 6. The counting unit 23 includes, for example, a CMOS logic circuit. The counting unit 23 operates using electric power supplied via the power supply terminal 23p and the ground terminal 23g. The power supply terminal 23p of the counting unit 23 is connected to the power supply line PL. The ground terminal 23g of the counting unit 23 is connected to the ground line GL. The counting unit 23 performs a counting process using the voltage supplied via the first input terminal 23a and the voltage supplied via the second input terminal 23b as control signals.

  The storage unit 24 stores at least a part (for example, multi-rotation information) of the rotational position information detected by the second processing unit 18 (for example, the counting unit 23) using the power supplied from the battery 6 (writing). Action). The storage unit 24 stores the count result (multi-rotation information) by the counting unit 23 as the rotational position information detected by the second processing unit 18. The power supply terminal 24p of the storage unit 24 is connected to the power supply line PL. The ground terminal 24g of the storage unit 24 is connected to the ground line GL. The storage unit 24 includes, for example, a non-volatile memory, and can hold information written while power is supplied even in a state where power is not supplied.

  In the present embodiment, a capacitor 59 is provided between the rectifying stack 51 and the regulator 52. The first electrode 59 a of the capacitor 59 is connected to a signal line that connects the rectifying stack 51 and the control terminal 52 a of the regulator 52. The second electrode 59b of the capacitor 59 is connected to the ground line GL. The capacitor 59 is, for example, a smoothing capacitor, and reduces pulsation to reduce the load on the regulator. The constant of the capacitor 59 is, for example, the power from the battery 6 to the second processing unit 18 and the storage unit 24 during the period from when the rotational position information is detected by the second processing unit 18 until the rotational position information is written in the storage unit 24. Set to maintain supply.

  Next, the operation of the encoder device EC according to the embodiment will be described. FIG. 6 is a diagram illustrating the operation of the encoder device when power is supplied from the first power supply in the present embodiment. FIG. 7 is a diagram illustrating an operation of the encoder device when power is supplied from the second power source in the present embodiment.

  As shown in FIG. 6, the first power supply PW1 supplies power to the position detection unit 1 in a normal state. The irradiation unit 11 irradiates light to the first pattern 10 (eg, an absolute pattern ABS, an incremental pattern INC) using power supplied from the first power supply PW1. The first detection unit 12 detects light from the first pattern 10 using electric power supplied from the first power supply PW1. The first detection unit 12 outputs a detection signal indicating the detection result to the first processing unit 13. The 1st process part 13 processes the detection signal from the 1st detection part 12 using the electric power supplied from the 1st power supply PW1, and calculates angular position information. The first processing unit 13 outputs the calculated angular position information to each of the comparison unit 25 and the synthesis unit 26.

  The irradiation unit 16 irradiates the second pattern 15 with light using the power supplied from the first power supply PW1. The second detection unit 17 detects light from the second pattern 15 using the power supplied from the first power supply PW1. The second detection unit 17 outputs a detection signal indicating the detection result to the second processing unit 18. The second processing unit 18 processes the detection signal from the second detection unit 17 using the power supplied from the first power supply PW1, and calculates angular position information and multi-rotation information. The multi-rotation information calculated by the second processing unit 18 is stored (output), for example, in the storage unit 24, and is output (read) from the storage unit 24 to the combining unit 26. The angular position information calculated by the second processing unit 18 is stored (output), for example, in the storage unit 24, and is output (read) from the storage unit 24 to the comparison unit 25.

  The combining unit 26 outputs rotational position information including the angular position information output from the first processing unit 13 and the multi-rotation information output from the second processing unit 18. The comparison unit 25 compares the angular position information output from the first processing unit 13 with the angular position information output from the second processing unit 18. Since the encoder device EC according to the embodiment compares the angular position information output from the first processing unit 13 with the angular position information output from the second processing unit 18, for example, it detects a defect such as an error. Can be reliable. For example, the comparison unit 25 generates notification information when the difference in angular position information between the first processing unit 13 and the second processing unit 18 exceeds a predetermined value (eg, allowable range). This notification information is used, for example, to notify the user or the like of the occurrence of an error, and contributes to improving the reliability of the device.

  The encoder device EC includes a first angle detection unit (eg, irradiation unit 11, first detection unit 2, first processing unit 13) and a second angle detection unit (eg, irradiation unit 16, second detection). The rotation position information may be output using the detection result of the other angle detection unit when malfunction occurs in one of the angle detection units among the unit 17 and the second processing unit 18). Such an encoder device EC outputs rotational position information even when a malfunction occurs in the first angle detection unit or the second angle detection unit described above, which contributes to improvement in the reliability of the device.

  As shown in FIG. 7, the first power supply PW1 does not supply power to the position detector 1 in the backup state. In addition, the second power source PW2 (eg, the battery 6 and the power supply unit 2) supplies power to the position detection unit 1 in at least a part of a period in which the first power source PW1 does not supply power to the position detection unit 1, for example. To do. For example, the second power source PW2 intermittently supplies power in the above period. For example, the second power supply PW2 supplies power when the rotation axis SF reaches a predetermined angular position. For example, the second power supply PW2 does not supply power when the rotation axis SF is at a position other than the predetermined angular position. In this case, for example, at least part of the encoder device EC (for example, the battery 6 in FIG. 1) is limited in operation, so that consumption is reduced.

  In addition, the second power supply PW2 supplies power to, for example, a part of the position detection unit 1 (hereinafter referred to as a supply target). For example, the second power supply PW2 supplies power to the multi-rotation information detection unit 3. The second power supply PW2 does not supply power to, for example, the portion of the position detection unit 1 excluding the supply target. For example, the second power supply PW2 does not supply power to the angle detection unit 4. In this case, for example, at least a part of the encoder device EC (for example, the battery 6 and the angle detection unit 4 in FIG. 1) is limited in operation, so that consumption is reduced.

  The irradiation unit 16 irradiates the second pattern 15 with light using the power supplied from the second power source PW2. The second detection unit 17 detects light from the second pattern 15 using power supplied from the second power supply PW2. The second detection unit 17 outputs a detection signal indicating the detection result to the second processing unit 18. The second processing unit 18 processes the detection signal from the second detection unit 17 using the power supplied from the second power supply PW2, and calculates at least multi-rotation information among the rotational position information. For example, the second processing unit 18 calculates multi-rotation information and does not calculate angular position information. In this case, the processing of the multi-rotation information detection unit is reduced and power consumption is reduced. The storage unit 24 stores the multi-rotation information output from the second processing unit 18 using the power supplied from the second power supply PW2. The storage unit 24 holds the multi-rotation information even when the power supply from the first power supply PW1 and the power supply from the second power supply PW2 are cut off.

  In the present embodiment, for example, when the optical characteristic value of the second pattern 15 is a one-cycle distribution (for example, a distribution pattern that changes in one cycle) in the range of one rotation (360 °), multiple rotations are performed. The information detection unit 3 can also use a portion (for example, the second pattern 15) used for detecting the multi-rotation information for generating the angular position information. This angular position information is used, for example, as one or both of angular position information indicating the angular position of the rotation axis SF and comparison information (reference information) with respect to the angular position information calculated by the angle detection unit 4. The encoder apparatus EC according to the present embodiment can simplify the apparatus configuration as compared with, for example, a case where a part used for detecting multi-rotation information and a part used for generating the comparison information are provided separately. .

  The encoder device EC according to the present embodiment has a short period (eg, when a detection signal is generated) after an electric signal is generated in the signal generation unit 32 or a period (or irregular) preset by a host controller. In a short time after the trigger signal that can be output from the host controller or the encoder device EC is generated, power is supplied from the battery 6 to the multi-rotation information detection unit 3, and the multi-rotation information detection unit 3 is dynamically driven (intermittent drive). ) After the detection and writing of the multi-rotation information is completed, the power supply to the multi-rotation information detection unit 3 is cut off, but the count value is retained because it is stored in the storage unit 24. Such a sequence is repeated every time a predetermined position on the magnet 31 passes in the vicinity of the signal generator 32 even in a state where the external power supply is cut off.

  The multi-rotation information stored in the storage unit 24 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 6 supplies at least part of the power consumed by the position detection unit 1 (for example, the multi-rotation information detection unit 3) in accordance with the electrical signal generated by the signal generation unit 32. Therefore, the battery 6 can have a long life. Maintenance (eg, replacement) of the battery 6 can be eliminated, and the frequency of maintenance can be reduced. For example, when the life of the battery 6 is longer than the life of the other part of the encoder device EC, the replacement of the battery 6 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 32 even if the rotation of the magnet 31 is extremely low. Therefore, for example, in a state where power is not supplied to the motor M, the output of the signal generation unit 32 can be used as an electrical signal even when the rotation of the rotating shaft SF (magnet 31) is extremely low.

  In addition, the 2nd process part 18 does not need to detect multi-rotation information using the detection result which the 2nd detection part 17 detected the 2nd pattern 15, and to detect angle position information. In this case, the comparison unit 25 may compare the multi-rotation information based on the detection result of the second detection unit 17 with the multi-rotation information by the second multi-rotation detection unit. Moreover, the 2nd process part 18 does not need to detect angular position information using the detection result which the 2nd detection part 17 detected the 2nd pattern 15, and does not detect multi-rotation information. The encoder device EC may not include the comparison unit 25.

  A part of the multi-rotation information detection unit 3 may be shared with the angle detection unit 4. The power supply unit 2 may use the power of the detection signal generated by the signal generation unit 32 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 32 generates a detection signal when a predetermined positional relationship with the magnet 31 is obtained. The encoder device EC (multi-rotation information detection unit 3) may include the signal generation unit 32 as a sensor that detects position information of the rotation axis SF (magnet 31).

  Note that the power supply unit 2 may continuously supply power in the backup state. Further, the power supply unit 2 may supply power to a part (eg, at least a part of the angle detection unit 4) different from the multi-rotation information detection unit 3 in the backup state. The multi-rotation information detection unit 3 may calculate the angular position information in the backup state as in the normal state. For example, in the backup state, the multi-rotation information detection unit 3 and the angle detection unit 4 may each calculate angular position information. In this case, the comparison unit 25 may compare the angular position information calculated by the multi-rotation information detection unit 3 in the backup state with the angular position information calculated by the angle detection unit 4 in the backup state.

  The combining unit 26 may generate rotational position information including the angular position information calculated by the multi-rotation information detecting unit 3. For example, the synthesizing unit 26 uses the angular position information calculated by the multi-rotation information detecting unit 3 instead of the angular position information calculated by the angle detecting unit 4 when a malfunction of the angle detecting unit 4 is detected. It may be used to generate rotational position information. For example, when the multi-rotation information detection unit 3 that detects the second pattern 15 described above is used to detect the angular position information of the rotating body, the encoder device EC in the present embodiment includes an optical multi-rotation information detection unit 3 and Multiplexing (in this case, duplication) of a detection unit (for example, angle detection unit 4) that detects angular position information by the optical angle detection unit 4 can be configured, and the reliability of the apparatus can be improved. Is possible. Further, for example, the angle detector 4 in the present embodiment may be a magnetic angle detector using a Hall element, an MR element, or the like. Even if such a magnetic angle detector is used and the multi-rotation information detector 3 for detecting the second pattern 15 described above is used for detecting the angular position information of the rotating body, this embodiment The encoder device EC in FIG. 1 multiplexes (in this case, duplex) a detection unit (eg, angle detection unit 4) that detects angular position information by means of an optical multi-rotation information detection unit 3 and a magnetic angle detection unit. Thus, the reliability of the apparatus can be improved.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIG. 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. 8A is a diagram illustrating a comparison unit according to the present embodiment. The comparison unit 25 detects a detection result (hereinafter, first pattern) in which the second detection unit 17 (for example, the first light receiving unit 17a) detects the first phase pattern 15a (for example, a pattern having shading) in the second pattern 15. A detection signal) and a detection result (hereinafter referred to as a first detection signal) when the second detection unit 17 (for example, the second light receiving unit 17b) detects a second phase pattern 15b (for example, a pattern having shading) in the second pattern 15. Notification information regarding the operation of the encoder device EC is generated and output based on the relationship with the two detection signals).

  The first detection signal Sa (see FIG. 3B) is, for example, sinusoidal. The second detection signal Sb (see FIG. 3B) has a sine wave shape that is out of phase with the first detection signal Sa. For example, when the first detection signal Sa and the second detection signal Sb are 90 ° out of phase, the second detection signal Sb corresponds to a cosine wave.

  FIG. 8B is a diagram illustrating the relationship between the level of the first detection signal and the level of the second detection signal. As described above, when the first detection signal and the second detection signal are 90 ° out of phase, the Lissajous LF (Lissajous figure) between the first detection signal and the second detection signal is a circle. For example, when the level of the first detection signal is SL1 and the level of the second detection signal is SL2, the points of the coordinates (SL1, SL2) that combine these levels are arranged on the line of the Lissajous LF. Is assumed.

  A symbol AR in FIG. 8B is an allowable range in which an error is added to the Lissajous LF. For example, the comparison unit 25 determines whether or not the point of the coordinates (SL1, SL2) is within the allowable range AR. For example, when the comparison unit 25 determines that the point of the coordinates (SL1, SL2) is not within the allowable range AR, the comparison unit 25 generates information (signal) indicating an error or a warning as the notification information (notification signal). For example, the comparison unit 25 can notify the defect of the irradiation unit 16 to the outside by notification information, which contributes to improving the reliability of the apparatus.

[Driver]
Next, the drive device according to the embodiment will be described. FIG. 9 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 will be given the same reference numerals, and description thereof will be 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.

  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 the encoder device according to the above-described embodiment.

  The encoder device EC includes, for example, a magnet 31 and a detection unit MD that rotate relatively with the rotation of the rotation shaft SF. The detection unit MD is, for example, a magnetic detection unit such as a Hall element or an MR element. The detection unit MD detects a magnetic field formed by the magnet 31. In the magnet 31 (see FIG. 2), the direction and strength of the magnetic field formed in the detection unit MD vary depending on the rotation angle of the rotation axis SF. The encoder device EC detects multi-rotation information of the rotation axis SF based on the detection result of the detection unit MD. For example, the encoder device EC may compare the multi-rotation information by the second processing unit 18 and the multi-rotation information by the detection unit MD as described above by the comparison unit 25 illustrated in FIG. 1 and the like. The magnet that forms the magnetic field detected by the detection unit MD may be provided separately from the magnet 31.

  The encoder device EC includes a first angle detection unit (for example, the irradiation unit 11, the first detection unit 12, and the first processing unit 13 in FIG. 1) and a second angle detection unit (for example, the irradiation in FIG. 1). One or both of the unit 16, the second detection unit 17, and the second processing unit 18) may be provided. The encoder device EC includes a first multi-rotation detection unit (for example, the irradiation unit 16, the second detection unit 17, and the second processing unit 18 in FIG. 1) and a second multi-rotation detection unit (for example, the detection in FIG. 9). Part MD) or both. Each of the first angle detector, the second angle detector, the first multi-rotation detector, and the second multi-rotation detector may be an optical encoder or a magnetic encoder. Other detection methods (eg, capacitance type) encoders may also be used. A combination of detection methods of the first angle detection unit, the second angle detection unit, the first multi-rotation detection unit, and the second multi-rotation detection unit is arbitrary.

  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. The drive device MTR according to the embodiment may be a linear motor or a planar motor, and the encoder device EC according to the embodiment may be a linear encoder. The drive device MTR is not limited to a motor device, and may be another drive device having a shaft portion that rotates using hydraulic pressure or pneumatic pressure.

[Stage device]
Next, the stage apparatus will be described. FIG. 10 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. In the following description, components that are the same as or equivalent to those in the above-described embodiment will be given the same reference numerals, and description thereof will be 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 apparatus STG can be applied to, for example, a rotary table provided in a machine tool such as a lathe. Note that 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).

[Robot equipment]
Next, the robot apparatus will be described. FIG. 11 is a perspective view showing the robot apparatus RBT. FIG. 11 schematically shows a part (joint part) of the robot apparatus RBT. In the following description, components that are the same as or equivalent to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted or simplified. The robot apparatus RBT includes a first arm AR1, a second arm AR2, and a joint portion JT. The first arm AR1 is connected to the second arm AR2 via the joint portion JT.

  The first arm AR1 includes an arm portion 101, a bearing 101a, and a bearing 101b. The second arm AR2 has an arm portion 102 and a connection portion 102a. The connecting portion 102a is disposed between the bearing 101a and the bearing 101b in the joint portion JT. The connecting portion 102a is provided integrally with the rotation shaft SF2. The rotation shaft SF2 is inserted into both the bearing 101a and the bearing 101b in the joint portion JT. The end of the rotary shaft SF2 on the side inserted into the bearing 101b passes through the bearing 101b and is connected to the speed reducer RG.

  The reducer RG is connected to the drive device MTR, and reduces the rotation of the drive device MTR to, for example, 1/100 and transmits it to the rotation shaft SF2. Although not shown in FIG. 11, 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. 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, 2 ... Electric power supply part, 3 ... Multi-rotation information detection part, 4 ... Angle detection part, 6 ... Battery, S ... Scale, 10 ... First pattern, 11... Irradiation unit, 12... First detection unit, 15... Second pattern, 15 a... First phase pattern, 15 b. ..Second detection unit, 18 ... second processing unit, 25 ... comparison unit, EC ... encoder device, MTR ... drive device, PW1 ... first power supply, PW2 ... first 2 power supplies, RBT ... Robot device, STG ... Stage device

Claims (16)

A first pattern indicating the angular position of the rotating body;
A first detector for detecting light from the first pattern;
A first processing unit that calculates angular position information of the rotating body based on a detection result of the first detection unit;
A second pattern in which the optical characteristic value gradually changes in the rotation direction of the rotating body;
A second detector for detecting light from the second pattern;
An encoder device comprising: a second processing unit that calculates multi-rotation information of the rotating body based on a detection result of the second detection unit.   The encoder apparatus according to claim 1, wherein the second pattern includes a pattern in which the optical characteristic value gradually increases or decreases. The first processing unit calculates the angular position information in a state where power is supplied from a first power source,
The second processing unit calculates the multi-rotation information in a state where power is supplied from the first power source or in a state where power is supplied from a second power source different from the first power source.
The encoder device according to claim 1 or 2. The second processing unit calculates angular position information of the rotating body based on a detection result of the second detection unit in a state where power is supplied from the first power source.
The encoder apparatus according to claim 3, further comprising a comparison unit that compares the angular position information of the rotating body calculated by the first processing unit and the angular position information of the rotating body calculated by the second processing unit. The second processing unit includes:
In the state of receiving power supply from the first power source, the angular position information of the rotating body is calculated based on the detection result of the second detection unit,
5. The encoder device according to claim 3, wherein multi-rotation information of the rotating body is calculated based on a detection result of the second detection unit in a state where power supply from the first power source is cut off.   The said 2nd processing part detects the angular position information of the said rotary body with a resolution | decomposability lower than the said 1st processing part based on the detection result of the said 2nd detection part, The any one of Claims 1-5 The encoder device according to one item.   The encoder device according to any one of claims 1 to 6, wherein the second pattern includes a plurality of patterns whose phases are shifted from each other in a rotation direction of the rotating body.   The second processing unit detects a detection result of the second detection unit detecting a first phase pattern among the plurality of patterns, and a second detection unit detects the second phase pattern among the plurality of patterns. The encoder apparatus according to claim 7, wherein the direction of the rotating body is determined using the detected result. A first pattern indicating position information of the moving unit;
A first processing unit that calculates position information of the moving unit based on a detection result of a first detection unit that detects light from the first pattern;
A second pattern in which the optical characteristic value gradually changes in the moving direction of the moving unit;
A second processing unit that calculates position information of the moving unit based on a detection result of a second detection unit that detects light from the second pattern;
An encoder device comprising: a comparison unit that compares the position information of the moving unit calculated by the first processing unit with the position information of the moving unit calculated by the second processing unit. The comparison unit determines whether the position information of the moving unit calculated by the first processing unit and the position information of the moving unit calculated by the second processing unit satisfy a predetermined condition,
The encoder apparatus according to claim 9, wherein information including position information of the moving unit calculated by the first processing unit is output based on a determination result of the comparison unit. The moving unit is a rotating body,
The comparison unit is notified based on a calculation result of the angular position information of the rotating body based on the detection result of the first detection unit and the angular position information of the rotating body based on the detection result of the second detection unit. The encoder apparatus according to claim 9 or 10, which generates information. The moving unit is a rotating body,
A multi-rotation information detection unit for detecting multi-rotation information of the rotating body;
The comparison unit compares multi-rotation information of the rotating body based on a detection result of the second detection unit and multi-rotation information of the rotating body by the multi-rotation information detection unit. The encoder device according to any one of the above. The moving unit is a rotating body,
The second pattern includes a plurality of patterns whose phases are shifted from each other in the rotation direction of the rotating body,
The comparison unit detects a detection result obtained by detecting the first phase pattern among the plurality of patterns by the second detection unit, and a detection obtained by detecting the second phase pattern among the plurality of patterns by the second detection unit. The encoder device according to any one of claims 9 to 12, wherein the notification information is generated based on a relationship with a result. The encoder device according to any one of claims 1 to 13,
And a driving unit that supplies a driving force to the rotating body. A drive device according to claim 14,
And a stage that is moved by the driving device. A drive device according to claim 14,
And an arm that is moved by the driving device.