Rotation detector and rotation detection method

Abstract

Provided is a rotation detector capable of suppressing occurrence of false detection. A rotation detector (14) includes: a magnet (20) that rotates together with a rotation shaft; a plurality of power generation elements (22, 24) that generate power by changes in a magnetic field generated by the magnet (20) rotating together with the rotation shaft; and a plurality of magnetic sensors (26, 28) provided corresponding to the plurality of power generation elements (22, 24). The rotation detector (14) further includes: an information processing section (56) that determines a rotation position of the rotation shaft using the plurality of magnetic sensors (26, 28); and a power supply section (46) that supplies power generated by each of the plurality of power generation elements (22, 24) only to a magnetic sensor corresponding to the power generation element among the plurality of magnetic sensors (26, 28).

Description

Technical Field

[0001] This disclosure relates to a rotation detector and a rotation detection method, and more particularly to a rotation detector and a rotation detection method for detecting the rotation of a rotating shaft of a rotating body. Background Technology

[0002] Previously, rotation detectors for detecting the rotation of a motor's rotating shaft were known. For example, Patent Document 1 discloses a rotation detector comprising a circular plate-shaped magnet disposed on the shaft, and three power generating units composed of magnetic wires and pickup coils, each of the three power generating units being disposed on one side of a plurality of sides of a virtual triangle formed on the end face side of the magnet.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6336232 Summary of the Invention

[0006] However, in the rotary detector of Patent Document 1, there is a problem that the power generated by the generator cannot be properly supplied, resulting in false detection.

[0007] This disclosure was made to solve such a problem, and its purpose is to provide a rotating detector and a rotating detection method that can suppress the occurrence of false detections.

[0008] One aspect of this disclosure relates to a rotation detector comprising: a magnet that rotates together with a rotation axis; a plurality of power generating elements that generate electricity through changes in the magnetic field produced by the rotation of the magnet together with the rotation axis; and a plurality of magnetic sensors disposed corresponding to the plurality of power generating elements. The rotation detector further comprises: an information processing unit that uses the plurality of magnetic sensors to determine the rotational position of the rotation axis; and a power supply unit that supplies power generated by each of the plurality of power generating elements only to the magnetic sensor corresponding to that power generating element.

[0009] One aspect of this disclosure relates to a rotation detection method using a rotation detector. The rotation detector comprises: a magnet that rotates together with a rotation axis; a plurality of power generating elements that generate electricity through changes in the magnetic field produced by the rotation of the magnet together with the rotation axis; a plurality of magnetic sensors disposed corresponding to the plurality of power generating elements; and a power supply unit that supplies power generated by each of the plurality of power generating elements only to the magnetic sensor corresponding to that power generating element among the plurality of magnetic sensors. The rotation detection method includes: determining, based on power generation information indicating which of the plurality of power generating elements has generated electricity and detection information indicating the detection result of the magnetic sensor corresponding to that power generating element among the plurality of magnetic sensors, which is located in a plurality of regions arranged in the rotation direction of the rotation axis, a reference position in the rotation direction of the rotation axis is located in; and storing the region among the plurality of regions where the reference position is determined to be located.

[0010] According to this disclosure, a rotating detector and a rotating detection method capable of suppressing false detections can be provided. Attached Figure Description

[0011] Figure 1 This is a diagram showing a motor equipped with the rotary detector according to the first embodiment.

[0012] Figure 2 It is shown Figure 1 A diagram of the substrate and rotating plate of the rotating detector.

[0013] Figure 3 It is shown Figure 1 A block diagram of the functional structure of the rotating detector.

[0014] Figure 4 This is used to describe the case where the rotating shaft rotates clockwise. Figure 1 A diagram illustrating an example of how a rotation detector determines an action.

[0015] Figure 5 This is used to describe the situation where the rotating shaft rotates counterclockwise. Figure 1 A diagram illustrating an example of how a rotation detector determines an action.

[0016] Figure 6 This is a diagram illustrating the rotating detector according to the second embodiment.

[0017] Figure 7 It is shown Figure 6 A block diagram of a portion of the functional structure of a rotating detector.

[0018] Figure 8 It is shown Figure 6A block diagram of another part of the functional structure of the rotation detector. Detailed Implementation

[0019] The embodiments of this disclosure will now be described. Furthermore, each of the embodiments described below illustrates a specific example of this disclosure. Therefore, the numerical values, constituent elements, the arrangement and connection methods of the constituent elements, and the processes and their order shown in the following embodiments are merely examples and are not intended to limit this disclosure. Therefore, any constituent element in the following embodiments that is not described in the independent claim representing the highest-level concept of this disclosure will be described as an arbitrary constituent element.

[0020] In addition, the figures are schematic diagrams and may not be strictly illustrated. Furthermore, in all figures, substantially identical structures are labeled with the same reference numerals, and repetitive descriptions are omitted or simplified.

[0021] (First Implementation)

[0022] Figure 1 This is a diagram showing a motor 1 equipped with the rotary detector 14 according to the first embodiment. Figure 2 It is shown Figure 1 A diagram of the substrate 18 and the rotating plate 16 of the rotating detector 14. Figure 2 (a) shows substrate 18, Figure 2 (b) shows the rotating plate 16. Furthermore, in Figure 1 The image shows a cross-section of the housing 12, the magnet 20, and the reflective pattern 44. Additionally, in... Figure 1 In the middle, the following was omitted. Figure 2 The diagram shows the power generation element 22 and the control circuit 32. Additionally, in... Figure 2 In the middle, the following was omitted. Figure 1 The diagram shows the optical sensor 30.

[0023] like Figure 1 As shown, the motor 1 includes a main body 4, a rotor 6, a stator 8, a rotating shaft 10, a housing 12, and a rotation detector 14. Furthermore, the direction of the rotation axis refers to the direction in which the rotation axis A of the rotating shaft 10 extends (see reference). Figure 1 (arrow X).

[0024] The rotor 6 and the stator 8 are housed in the main body 4. The rotor 6 rotates relative to the stator 8.

[0025] The rotating shaft 10 extends along the rotation axis and is cylindrical or rod-shaped. The axis of the rotating shaft 10 coincides with the rotation axis A. The rotating shaft 10 is fixed to the rotor 6 and rotates about the rotation axis A. For example, when power is supplied to the motor 1, the rotating shaft 10 rotates together with the rotor 6 about the rotation axis A as the center of rotation, based on this power. The direction of rotation of the rotating shaft 10 (refer to...) Figure 2 Arrow Z) aligns with the circumferential direction centered on the rotation axis A. A rotation detector 14 is provided at one end of the rotation axis 10. A load (not shown) or similar device, which is driven to rotate by the rotation of the rotation axis 10, is installed at the other end of the rotation axis 10. For example, the rotation axis 10 is formed of a magnetic metal such as iron.

[0026] The housing 12 is mounted on the main body 4 such that it covers one end of the rotating shaft 10 in the direction of the rotation axis and the rotating detector 14. For example, the housing 12 is formed of a magnetic metal such as iron.

[0027] The rotation detector 14 is used to detect the rotation of the rotating shaft 10. For example, the rotation detector 14 is used to detect the rotational position of the rotating shaft 10, the rotational direction of the rotating shaft 10, and the rotational speed of the rotating shaft 10. For example, the rotation detector 14 is an absolute encoder. As described above, the rotation detector 14 is disposed at one end of the rotating shaft 10 along its rotational axis. Figure 1 and Figure 2 As shown, the rotation detector 14 includes a rotating plate 16, a substrate 18, a magnet 20, multiple power generation elements 22 and 24, multiple magnetic sensors 26 and 28, an optical sensor 30, and a control circuit 32.

[0028] The rotating plate 16 extends in a direction orthogonal to the axis of rotation. Specifically, the rotating plate 16 is a circular plate with a main surface extending in a direction orthogonal to the axis of rotation, and is circular when viewed from the axis of rotation. The rotating plate 16 is mounted at one end of the rotating shaft 10 in the direction of the axis of rotation. The axis of rotation of the rotating plate 16 coincides with the axis of rotation A. The rotating plate 16 rotates together with the rotating shaft 10.

[0029] The substrate 18 extends in a direction orthogonal to the rotation axis. Specifically, the substrate 18 is a circular plate having a main surface extending in a direction orthogonal to the rotation axis, and is circular when viewed from the rotation axis direction. The substrate 18 is disposed at a distance from one end of the rotation shaft 10 and the rotation plate 16 in the rotation axis direction, and faces the rotation plate 16. The axis of the substrate 18 coincides with the rotation axis A. The substrate 18 is fixed to the inner surface of the housing 12 and does not rotate with the rotation shaft 10.

[0030] The magnet 20 rotates together with the rotation shaft 10. Specifically, when the rotation shaft 10 rotates, the magnet 20 rotates together with the rotation shaft 10 and the rotating plate 16. The magnet 20 is annular and arranged along the rotation direction of the rotation shaft 10. The magnet 20 is plate-shaped with the rotation axis direction as its thickness direction. The magnet 20 is disposed on the main surface of the rotating plate 16 on the side opposite to the substrate 18. The magnet 20 has an N pole and an S pole arranged in the rotation direction of the rotation shaft 10 in conjunction with the N pole. One half of one side of the magnet 20 is magnetized as the N pole, and the other half of the magnet 20 is magnetized as the S pole.

[0031] Each of the multiple power generation elements 22 and 24 generates electricity by changing the magnetic field generated when the magnet 20 rotates together with the rotating shaft 10.

[0032] Multiple power generation elements 22 and 24 are configured to have a phase difference in the rotation direction of the rotation axis 10. Specifically, the multiple power generation elements 22 and 24 are arranged at an angular interval greater than or equal to the angular interval between a first position and a second position in the rotation direction of the rotation axis 10. The first position is the position where one of the power generation elements 22 and 24 generates power when the rotation axis 10 rotates clockwise, and the second position is the position closest to the first position among more than one positions where that one power generation element generates power when the rotation axis 10 rotates counterclockwise. Furthermore, clockwise refers to clockwise when viewed from the side of the substrate 18 opposite to the rotating plate 16 in the rotation axis direction, and counterclockwise refers to counterclockwise when viewed from the side of the substrate 18 opposite to the rotating plate 16 in the rotation axis direction. The same applies in the following description.

[0033] Figure 4 This diagram illustrates an example of the determination action of the rotation detector 14 when the rotating shaft 10 rotates clockwise. For example, Figure 4 Position i shown is an example of the first position where one of the multiple power generation elements 22, 24 generates electricity when the rotation axis 10 rotates clockwise. Additionally, Figure 4 The position viii shown is an example of the second position closest to position i among positions vi and viii, where one power generation element 22 generates electricity when the rotation axis 10 rotates counterclockwise. The angular interval between position i and position viii in the rotation direction of the rotation axis 10 is 30 degrees, and the multiple power generation elements 22 and 24 are arranged with an angular interval of more than 30 degrees in the rotation direction of the rotation axis 10. In this embodiment, the multiple power generation elements 22 and 24 are arranged with an angular interval of 120 degrees in the rotation direction of the rotation axis 10.

[0034] Furthermore, for example, the angular interval between power generation element 22 and power generation element 24 in the rotation direction of the rotation axis 10 is radially centered on the rotation axis A (see reference). Figure 2 The angle formed by the center line of the magnetic induction section 34 of the power generation element 22 extending in the long side direction and passing through the center line of the magnetic induction section 38 of the power generation element 24 extending radially around the axis of rotation A and passing through the center in the long side direction.

[0035] The power generation element 22 extends tangentially to the rotation direction of the rotation axis 10 and is disposed on the main surface of the substrate 18 opposite to the rotation axis 10 (opposite to the rotating plate 16). The power generation element 22 has a magnetic induction section 34 and a coil 36 wound around the magnetic induction section 34. The magnetic induction section 34 is a magnetic material extending tangentially to the rotation direction of the rotation axis 10 and located on the side of the substrate 18 opposite to the rotating plate 16. For example, the magnetic induction section 34 is a magnetic material exhibiting the large Backhausen effect, and is a Wiegand wire extending tangentially to the rotation direction of the rotation axis 10. A Wiegand wire is a magnetic material whose magnetization direction is aligned towards the long side when a magnetic field of a predetermined value or higher is applied along its long side. When the direction of the magnetic flux flowing along the long side of the Wiegand wire changes, the magnetization direction of the Wiegand wire abruptly reverses, inducing voltage pulses at both ends of the coil wound around the Wiegand wire. In this way, the power generation element 22 generates electricity.

[0036] The power generation element 24 extends tangentially to the rotation direction of the rotation axis 10 and is disposed on the main surface of the substrate 18 opposite to the rotation axis 10 (opposite to the rotating plate 16). The power generation element 24 has a magnetic induction section 38 and a coil 40 wound around the magnetic induction section 38. The magnetic induction section 38 is a magnetic material extending tangentially to the rotation direction of the rotation axis 10 and located on the side of the substrate 18 opposite to the rotating plate 16. For example, the magnetic induction section 38 is a magnetic material exhibiting the large Backhausen effect, and is a Wiegand wire extending tangentially to the rotation direction of the rotation axis 10. The power generation element 24 generates electricity in the same manner as the power generation element 22.

[0037] Multiple magnetic sensors 26 and 28 are respectively disposed corresponding to multiple power generation elements 22 and 24. Magnetic sensor 26 is disposed corresponding to power generation element 22 and operates based on the electricity generated by power generation element 22. Magnetic sensor 28 is disposed corresponding to power generation element 24 and operates based on the electricity generated by power generation element 24. The multiple magnetic sensors 26 and 28 are disposed on the main surface of the substrate 18 on the rotation axis 10 side (rotation plate 16 side).

[0038] The plurality of magnetic sensors 26, 28 are configured to have a phase difference in the rotation direction of the rotating shaft 10. Specifically, each of the plurality of magnetic sensors 26, 28 is arranged in the same position in the rotation direction of the rotating shaft 10 as the corresponding power generation element in the plurality of power generation elements 22, 24.

[0039] The magnetic sensor 26 is positioned at the same location as the power generation element 22 in the rotational direction of the rotation axis 10. For example, the magnetic sensor 26 is configured such that its center is located on the centerline of the long side of the magnetic induction section 34 of the power generation element 22, which extends radially about the rotation axis A. The magnetic sensor 26 is arranged radially with the power generation element 22 and positioned outside the power generation element 22.

[0040] The magnetic sensor 28 is positioned at the same location as the power generation element 24 in the rotational direction of the rotation axis 10. For example, the magnetic sensor 28 is configured such that its center is located on the centerline of the long side of the magnetic induction section 38 of the power generation element 24, which extends radially about the rotation axis A. The magnetic sensor 28 is arranged radially with the power generation element 24 and positioned outside the power generation element 24.

[0041] The optical sensor 30 is an optical encoder having a light-emitting element 42 and a reflective pattern 44, and used to detect the amount of rotation of the rotating shaft 10.

[0042] The light-emitting and light-receiving element 42 is disposed on the main surface of the rotating plate 16 side of the substrate 18, based on an external power supply 150 (see reference). Figure 3 The light-emitting and light-receiving element 42 operates using electricity (as shown in the functional block diagram). The light-emitting and light-receiving element 42 faces the reflective pattern 44 in the direction of the rotation axis and emits light towards the reflective pattern 44. Additionally, the light-emitting and light-receiving element 42 receives light reflected by the reflective pattern 44. The light reflected by the reflective pattern 44 varies depending on the rotational position of the rotation axis 10. The optical sensor 30 detects the amount of rotation of the rotation axis 10 based on the light reflected by the reflective pattern 44. In this embodiment, the light-emitting and light-receiving element 42 corresponds to both a light-emitting element and a light-receiving element.

[0043] A reflective pattern 44 is disposed on the main surface of the rotating plate 16 on the side of the substrate 18. The reflective pattern 44 is disposed along the rotation direction of the rotation axis 10 and is annular. For example, the reflective pattern 44 has a reflective region that easily reflects light and a non-reflective region that is difficult to reflect light. For example, the reflective region and the non-reflective region are disposed alternately along the rotation direction of the rotation axis 10.

[0044] The control circuit 32 is disposed on the main surface of the substrate 18 on the side of the rotation axis 10 (rotation plate 16 side) and is electrically connected to the power generation element 22.

[0045] Figure 3 It is shown Figure 1 A block diagram of the functional structure of the rotation detector 14.

[0046] like Figure 3 As shown, the rotating detector 14 also includes a power supply unit 46, a polarity determination unit 47, a magnetic pole determination unit 51, a signal processing unit 55, an information processing unit 56, a storage unit 58, and a communication unit 60.

[0047] The power supply unit 46 supplies power generated by each of the multiple power generation elements 22 and 24 only to the magnetic sensor corresponding to that power generation element among the multiple magnetic sensors 26 and 28. For example, the power supply unit 46 supplies power generated by the power generation element 22 only to magnetic sensor 26 among the multiple magnetic sensors 26 and 28, and supplies power generated by the power generation element 24 only to magnetic sensor 28 among the multiple magnetic sensors 26 and 28.

[0048] The power supply unit 46 has multiple full-wave rectifiers 62 and 64, sensor power storage units 66 and 67, multiple switches 72, 74 and 76, multiple internal power supplies 78 and 80, multiple power monitoring units 82, 84, 86, 88 and 89, multiple voltage regulation units 90 and 92, multiple discharge units 94, 96 and 98, and multiple switches 100 and 102.

[0049] The full-wave rectifier 62 is connected to the power generation element 22 and is used to rectify the voltage pulses generated by the power generation element 22. The full-wave rectifier 64 is connected to the power generation element 24 and is used to rectify the voltage pulses generated by the power generation element 24.

[0050] The sensor power storage unit 66 stores the power generated by each of the plurality of power generating elements 22, 24 and supplied to the magnetic sensors corresponding to those power generating elements among the plurality of magnetic sensors 26, 28. When the power generating element 22 generates power, the sensor power storage unit 66 stores the power generated by the power generating element 22 and supplied to the magnetic sensor 26. Additionally, when the power generating element 24 generates power, the sensor power storage unit 66 stores the power generated by the power generating element 24 and supplied to the magnetic sensor 28.

[0051] The power storage unit 67 is used to store the power generated by each of the plurality of power generation elements 22, 24 and supplied to components other than the plurality of magnetic sensors 26, 28. The power storage unit 67 has a first storage unit 68 for storing the power generated by the power generation element 22 and supplied to components other than the magnetic sensor 26, and a second storage unit 70 for storing the power generated by the power generation element 24 and supplied to components other than the magnetic sensor 28.

[0052] Switch 72 is an example of a disconnector capable of electrically disconnecting the sensor power storage unit 66 from the power storage unit 67. When neither the power generation element 22 nor the power generation element 24 is generating power, switch 72 is in an open state, disconnecting the power, thus disconnecting the sensor power storage unit 66 from the power storage unit 67. During the period when either the power generation element 22 or the power generation element 24 is generating power, switch 72 is in an on state, capable of transmitting power. When the power generation element 22 is not generating power, switch 74 is in an open state, disconnecting the power; during the period when the power generation element 22 is generating power, switch 74 is in an on state, capable of transmitting power. When the power generation element 24 is not generating power, switch 76 is in an open state, disconnecting the power; during the period when the power generation element 24 is generating power, switch 76 is in an on state, capable of transmitting power.

[0053] The internal power supply 78 is used to receive the power stored in the sensor power storage unit 66 and supply that power to the magnetic sensor 26 or magnetic sensor 28. The internal power supply 80 is used to receive the power stored in the power storage unit 67 and supply that power to components other than the multiple magnetic sensors 26, 28, such as the information processing unit 56.

[0054] Power monitoring unit 82 monitors the power between sensor power storage unit 66 and voltage regulation unit 90. Power monitoring unit 84 monitors the power between voltage regulation unit 90 and internal power supply 78. Power monitoring unit 86 monitors the power between full-wave rectifier unit 62 and first storage unit 68. Power monitoring unit 88 monitors the power between full-wave rectifier unit 64 and second storage unit 70. Power monitoring unit 89 monitors the power between voltage regulation unit 92 and internal power supply 80.

[0055] Voltage regulator 90 uses ground potential as a reference potential and takes the voltage between the terminals of the capacitor in sensor power storage unit 66 as an input voltage to output a constant voltage. The output voltage of voltage regulator 90 is supplied to internal power supply 78. Voltage regulator 92 uses ground potential as a reference potential and takes the voltage between the terminals of the capacitor in first storage unit 68 or second storage unit 70 as an input voltage to output a constant voltage. The output voltage of voltage regulator 92 is supplied to internal power supply 80. For example, multiple voltage regulators 90 and 92 are LDO (Low Drop Out) regulators.

[0056] The discharge unit 94 releases the power stored in the sensor power storage unit 66 when the power generating elements 22 and 24 are not generating power. The discharge unit 96 releases the power stored in the first storage unit 68 when the power generating element 22 is not generating power. The discharge unit 98 releases the power stored in the second storage unit 70 when the power generating element 24 is not generating power.

[0057] When the power generation element 22 is not generating power, switch 100 switches to an off state, cutting off power from the internal power supply 78 to prevent it from being supplied to the magnetic sensor 26. During the period when the power generation element 22 is generating power, switch 100 switches to an on state, enabling power from the internal power supply 78 to be supplied to the magnetic sensor 26. When the power generation element 24 is not generating power, switch 102 switches to an off state, cutting off power from the internal power supply 78 to prevent it from being supplied to the magnetic sensor 28. During the period when the power generation element 24 is generating power, switch 102 switches to an on state, enabling power from the internal power supply 78 to be supplied to the magnetic sensor 28.

[0058] The polarity determination unit 47 determines the polarity of the electricity generated by each of the plurality of power generation elements 22 and 24. The polarity determination unit 47 includes: a first determination unit 48, which determines the polarity of the electricity generated by the power generation element 22; and a second determination unit 50, which determines the polarity of the electricity generated by the power generation element 24.

[0059] The magnetic pole determination unit 51 determines the magnetic pole detected by each of the plurality of magnetic sensors 26 and 28. The magnetic pole determination unit 51 includes: a first determination unit 52, which determines the magnetic pole detected by the magnetic sensor 26; and a second determination unit 54, which determines the magnetic pole detected by the magnetic sensor 28.

[0060] The signal processing unit 55 is powered by electricity from an external power source 150 and sends the detection results of the optical sensor 30 to the information processing unit 56.

[0061] The information processing unit 56 uses multiple magnetic sensors 26 and 28 to determine the rotational position of the rotating shaft 10. The determination of the rotational position of the rotating shaft 10 by the information processing unit 56 will be described later.

[0062] The storage unit 58 stores the rotational position and direction of rotation of the rotating shaft 10. For example, the storage unit 58 is composed of a non-volatile memory such as FRAM (registered trademark).

[0063] The communication unit 60 connects the information processing unit 56 and the signal processing unit 55 in a manner that enables wired communication or wireless communication.

[0064] Figure 4 This is used to illustrate the case where the rotating shaft 10 rotates clockwise. Figure 1 A diagram showing an example of the action determined by the rotation detector 14. Figure 4 (a) shows the state where the reference position B is at position i. Figure 4 (b) shows the state where reference position B is located at position ii. Figure 4(c) shows the state where the reference position B is at position iii. Figure 4 (d) shows the state where the reference position B is located at position iv.

[0065] Figure 5 This is used to illustrate the case where the rotating shaft 10 rotates counterclockwise. Figure 1 A diagram showing an example of the action determined by the rotation detector 14. Figure 5 (a) shows the state where the reference position B is at position v. Figure 5 (b) shows the state where the reference position B is at position vi. Figure 5 (c) shows the state where the reference position B is at position vii. Figure 5 (d) shows the state where the reference position B is in position viii.

[0066] Reference position B is the reference position in the rotation direction of the rotating shaft 10. In this embodiment, the center of the N pole in the rotation direction of the rotating shaft 10 is taken as the reference position.

[0067] First, refer to Figure 4 Let's illustrate the case where the rotating shaft 10 rotates clockwise. In this case, when the reference position B is at position i, position ii, position iii, and position iv, one of the power generation elements 22 and 24 generates electricity.

[0068] For example, rotating the rotation axis 10 clockwise, thus... Figure 4 When the reference position B is at position i, as shown in (a), the direction of the magnetic field in the long side direction of the power generation element 22 is reversed by the magnetic field of the magnet 20, and thus the power generation element 22 generates electricity. On the other hand, when the reference position B is at position i, the direction of the magnetic field in the long side direction of the power generation element 24 is not reversed by the magnetic field of the magnet 20, and thus the power generation element 24 does not generate electricity.

[0069] Power is generated by the power generation element 22, and the magnetic sensor 26 operates based on the power from the power generation element 22. When the reference position B is at position i, the magnetic sensor 26 is facing the S pole. Therefore, when the reference position B is at position i, the magnetic sensor 26 outputs a signal indicating that it is facing the S pole.

[0070] The rotating shaft 10 is further rotated clockwise, thus... Figure 4When the reference position B is located at position ii, as shown in (b), the direction of the magnetic field in the long side direction of the power generation element 24 is reversed by the magnetic field of the magnet 20, and thus the power generation element 24 generates electricity. On the other hand, when the reference position B is located at position ii, the direction of the magnetic field in the long side direction of the power generation element 22 is not reversed by the magnetic field of the magnet 20, and thus the power generation element 22 does not generate electricity.

[0071] Power is generated by the power generation element 24, and the magnetic sensor 28 operates based on the power from the power generation element 24. When the reference position B is at position ii, the magnetic sensor 28 is facing the S pole. Therefore, when the reference position B is at position ii, the magnetic sensor 28 outputs a signal indicating that it is facing the S pole.

[0072] The rotating shaft 10 is further rotated clockwise, thus... Figure 4 When reference position B is in position iii as shown in (c), the direction of the magnetic field in the long side direction of the power generation element 22 is reversed by the magnetic field of the magnet 20, thereby generating electricity. On the other hand, when reference position B is in position iii, the direction of the magnetic field in the long side direction of the power generation element 24 is not reversed by the magnetic field of the magnet 20, thereby not generating electricity.

[0073] Power is generated by the power generation element 22, and the magnetic sensor 26 operates based on the power from the power generation element 22. When the reference position B is in position iii, the magnetic sensor 26 is facing the N pole. Therefore, when the reference position B is in position iii, the magnetic sensor 26 outputs a signal indicating that it is facing the N pole.

[0074] The rotating shaft 10 is further rotated counterclockwise, thus... Figure 4 When the reference position B is at position iv as shown in (d), the direction of the magnetic field in the long side direction of the power generation element 24 is reversed by the magnetic field of the magnet 20, and thus the power generation element 24 generates electricity. On the other hand, when the reference position B is at position iv, the direction of the magnetic field in the long side direction of the power generation element 22 is not reversed by the magnetic field of the magnet 20, and thus the power generation element 22 does not generate electricity.

[0075] Power is generated by the power generation element 24, and the magnetic sensor 28 operates based on the power from the power generation element 24. When the reference position B is at position iv, the magnetic sensor 28 is facing the N pole. Therefore, when the reference position B is at position iv, the magnetic sensor 28 outputs a signal indicating that it is facing the N pole.

[0076] Next, refer to Figure 5Let's illustrate the case where the rotating shaft 10 rotates counterclockwise. In this case, when the reference position B is at position v, position vi, position vii, and position viiii, one of the power generation elements 22 and 24 generates electricity.

[0077] For example, rotating the rotation axis 10 counterclockwise, thus... Figure 5 When the reference position B is at position v, as shown in (a), the direction of the magnetic field along the long side of the power generation element 24 is reversed by the magnetic field of the magnet 20, and thus the power generation element 24 generates electricity. On the other hand, when the reference position B is at position v, the direction of the magnetic field along the long side of the power generation element 22 is not reversed by the magnetic field of the magnet 20, and thus the power generation element 22 does not generate electricity.

[0078] Power is generated by the power generation element 24, and the magnetic sensor 28 operates based on the power from the power generation element 24. When the reference position B is at position v, the magnetic sensor 28 is facing the N pole. Therefore, when the reference position B is at position v, the magnetic sensor 28 outputs a signal indicating that it is facing the N pole.

[0079] The rotating shaft 10 is further rotated counterclockwise, thus... Figure 5 When the reference position B is at position vi, as shown in (b), the direction of the magnetic field in the long side direction of the power generation element 22 is reversed by the magnetic field of the magnet 20, and thus the power generation element 22 generates electricity. On the other hand, when the reference position B is at position vi, the direction of the magnetic field in the long side direction of the power generation element 24 is not reversed by the magnetic field of the magnet 20, and thus the power generation element 24 does not generate electricity.

[0080] Power is generated by the power generation element 22, and the magnetic sensor 26 operates based on the power from the power generation element 22. When the reference position B is at position vi, the magnetic sensor 26 is facing the N pole. Therefore, when the reference position B is at position vi, the magnetic sensor 26 outputs a signal indicating that it is facing the N pole.

[0081] The rotating shaft 10 is further rotated counterclockwise, thus... Figure 5 When the reference position B is at position vii, as shown in (c), the direction of the magnetic field along the long side of the power generation element 24 is reversed by the magnetic field of the magnet 20, and thus the power generation element 24 generates electricity. On the other hand, when the reference position B is at position vii, the direction of the magnetic field along the long side of the power generation element 22 is not reversed by the magnetic field of the magnet 20, and thus the power generation element 22 does not generate electricity.

[0082] Power is generated by the power generation element 24, and the magnetic sensor 28 operates based on the power from the power generation element 24. When the reference position B is at position vii, the magnetic sensor 28 is facing the S pole. Therefore, when the reference position B is at position vii, the magnetic sensor 28 outputs a signal indicating that it is facing the S pole.

[0083] The rotating shaft 10 is further rotated counterclockwise, thus... Figure 5 When the reference position B is in position viii as shown in (d), the direction of the magnetic field in the long side direction of the power generation element 22 is reversed by the magnetic field of the magnet 20, and the power generation element 22 generates electricity. On the other hand, when the reference position B is in position viii, the direction of the magnetic field in the long side direction of the power generation element 24 is not reversed by the magnetic field of the magnet 20, and the power generation element 24 does not generate electricity.

[0084] Power is generated by the power generation element 22, and the magnetic sensor 26 operates based on the power from the power generation element 22. When the reference position B is in position viii, the magnetic sensor 26 is facing the S pole. Therefore, when the reference position B is in position viii, the magnetic sensor 26 outputs a signal indicating that it is facing the S pole.

[0085] For example, the information processing unit 56 determines which of the multiple regions I to IV arranged in the rotation direction of the rotation shaft 10 the reference position B is located in, based on power generation information indicating that the power generation element among the multiple power generation elements 22 and 24 has generated power, and detection information indicating the detection results of the magnetic sensors corresponding to the power generation element among the multiple magnetic sensors 26 and 28. The storage unit 58 stores the region among the multiple regions I to IV that the information processing unit 56 has determined to be the location of the reference position B.

[0086] For example, power generation information is a two-bit message that displays 1 when power generation element 22 is generating power and 0 when power generation element 24 is generating power. Similarly, detection information is a two-bit message that displays 1 when magnetic sensor 26 detects the S pole and when magnetic sensor 28 detects the S pole, and 0 when magnetic sensor 26 detects the N pole and when magnetic sensor 28 detects the N pole.

[0087] Furthermore, for example, each of the multiple regions I to IV is a region sandwiched between two adjacent straight lines that are arranged at equal intervals in the rotation direction of the rotation axis 10, each extending radially around the rotation axis A. In this embodiment, the region containing positions i and viii is designated as region I, the region containing positions ii and vii is designated as region II, the region containing positions iii and vi is designated as region III, and the region containing positions iv and v is designated as region IV.

[0088] As described above, when the reference position B is at position i, the power generation element 22 generates electricity, and the magnetic sensor 26 detects the S pole. Additionally, when the reference position B is at position viii, the power generation element 22 generates electricity, and the magnetic sensor 26 detects the S pole. That is, in these cases, (detection information, power generation information) = (1, 1). Therefore, when (detection information, power generation information) = (1, 1), the information processing unit 56 determines that the reference position B is near position i or position viii, and that the reference position B is located in region I.

[0089] Furthermore, when reference position B is located at position ii, the power generation element 24 generates electricity, and the magnetic sensor 28 detects the S pole. Also, when reference position B is located at position vii, the power generation element 24 generates electricity, and the magnetic sensor 28 detects the S pole. In other words, in these cases, (detection information, power generation information) = (1, 0). Therefore, when (detection information, power generation information) = (1, 0), the information processing unit 56 determines that reference position B is located near position ii or position vii, and that reference position B is located in region II.

[0090] Furthermore, when reference position B is located at position iii, the power generation element 22 generates electricity, and the magnetic sensor 26 detects the N pole. Also, when reference position B is located at position vi, the power generation element 22 generates electricity, and the magnetic sensor 26 detects the N pole. That is, in these cases, (detection information, power generation information) = (0, 1). Therefore, when (detection information, power generation information) = (0, 1), the information processing unit 56 determines that reference position B is located near position iii or position vi, and that reference position B is located in region III.

[0091] Furthermore, when reference position B is located at position iv, the power generation element 24 generates electricity, and the magnetic sensor 28 detects the N pole. Similarly, when reference position B is located at position v, the power generation element 24 generates electricity, and the magnetic sensor 28 detects the N pole. In other words, in these cases, (detection information, power generation information) = (0, 0). Therefore, when (detection information, power generation information) = (0, 0), the information processing unit 56 determines that reference position B is located near position iv or position v, and that reference position B is located in region IV.

[0092] Furthermore, if the area where the current determination of reference position B is located is not adjacent to the area where the previous determination of reference position B is located, the information processing unit 56 causes the storage unit 58 to store an error.

[0093] For example, whenever either the power generation element 22 or the power generation element 24 generates electricity, the information processing unit 56 determines the rotation position of the rotating shaft 10 and stores the rotation position in the storage unit 58. If the current determination is that the region where the reference position B is located is region I, and the previous determination was that the region where the reference position B is located is region III, the storage unit 58 stores an error.

[0094] Furthermore, if the region where the current reference position B is located in one of the multiple regions I to IV is not adjacent to the region where the previous reference position B was located, the information processing unit 56 causes the storage unit 58 to store the case where the region where the previous reference position B was located has changed to the region where the current reference position B is located.

[0095] For example, if the current determination is that the region where the reference position B is located is region I, and the previous determination was that the region where the reference position B is located is region III, the information processing unit 56 causes the storage unit 58 to store the situation that the change has occurred from region III to region I.

[0096] In addition, the information processing unit 56 determines the rotation direction of the rotating shaft 10 based on power generation information, detection information, and polarity information indicating the polarity determined by the polarity determination unit 47.

[0097] For example, polarity information is a two-bit message that shows 1 when the polarity of the power generated by power generation element 22 is negative and 0 when the polarity of the power generated by power generation element 22 is positive. In other words, for example, polarity information is a two-bit message that shows 0 when the polarity of the power generated by power generation element 24 is negative and 1 when the polarity of the power generated by power generation element 24 is positive.

[0098] For example, the polarity of the electricity generated by the power generation element 22 when the reference position B is at position i is reversed compared to the polarity of the electricity generated by the power generation element 22 when the reference position B is at position viii. For example, when the polarity of the electricity generated by the power generation element 22 is set to positive when the reference position B is at position i and negative when the reference position B is at position viii, the information processing unit 56 can determine that the rotation axis 10 rotates clockwise when the polarity information is 0, and can determine that the rotation axis 10 rotates counterclockwise when the polarity information is 1.

[0099] Furthermore, if the region where the current reference position B is located in one of the multiple regions I to IV is adjacent to the region where the previous reference position B was located, and the change from the polarity determined by the polarity determination unit 47 in the previous case to the polarity determined by the polarity determination unit 47 in the current case is abnormal, the information processing unit 56 causes the storage unit 58 to store an error.

[0100] Table 1 shows... Figure 1 Table 1 shows the relationship between the power generation positions of the multiple power generation elements 22, 24 of the rotation detector 14 and the rotation direction of the rotation axis 10. As shown in Table 1, for example, when the reference position B is at position i, the polarity information is 0; when the reference position B is at position ii, the polarity information is 0; when the reference position B is at position iii, the polarity information is 1; and when the reference position B is at position iv, the polarity information is 1. Furthermore, for example, when the reference position B is at position v, the polarity information is 0; when the reference position B is at position vi, the polarity information is 0; when the reference position B is at position vii, the polarity information is 1; and when the reference position B is at position viiii, the polarity information is 1.

[0101] [Table 1]

[0102] Rotation position Rotation direction - area Polarity information i CW-I 0 ii CW-II 0 iii CW-III 1 iV CW-IV 1 v CCW-IV 0 Vi CCW-III 0 Vii CCW-II 1 Viii CCW-I 1

[0103] For example, if the reference position B is currently determined to be located in region I, and the previous determination was that the reference position B was located in region II, and the polarity information changes from 1 to 1, then it is known that the rotation axis 10 rotates counterclockwise to move the reference position B from region II to region I, and the information processing unit 56 can determine that the detection of the rotation position of the rotation axis 10 is normal. On the other hand, if the reference position B is currently determined to be located in region I, and the previous determination was that the reference position B was located in region II, and the polarity information changes from 0 to 0, then it is known that the rotation axis 10 rotates clockwise to move the reference position B from region II to region I, and the information processing unit 56 fails to determine that the reference position B is located in regions III and IV, and can determine that the detection of the rotation position of the rotation axis 10 is abnormal. Therefore, if the reference position B is determined to be in region I in this instance and in region II in the previous instance, and the polarity information changes from 0 to 0, the information processing unit 56 determines that the change from the polarity determined by the polarity determination unit 47 in the previous instance to the polarity determined by the polarity determination unit 47 in this instance is abnormal, and the storage unit 58 stores an error.

[0104] Furthermore, when the optical sensor 30 changes from a power-off state (where it does not receive power from the power source 150) to a power-on state (where it receives power from the power source 150), the information processing unit 56 determines the rotation position of the rotating shaft 10 based on the rotation position of the rotating shaft 10 determined by the multiple magnetic sensors 26 and 28 in the power-off state, and the amount of rotation of the rotating shaft 10 detected by the optical sensor 30 after it changes to the power-on state.

[0105] For example, the information processing unit 56 determines the rotation position of the rotating shaft 10 by adding the rotation position of the rotating shaft 10 determined by multiple magnetic sensors 26, 28 before the optical sensor 30 changes from an unpowered state to a powered state, to the amount of rotation of the rotating shaft 10 detected by the optical sensor 30 after it changes to a powered state.

[0106] In addition, the information processing unit 56 updates the count value used to calculate the rotational speed of the rotating shaft 10 based on the region in multiple regions I to IV where the reference position B is located this time, the polarity determined by the polarity determination unit 47 this time, the region in multiple regions I to IV where the reference position B was located previously, and the polarity determined by the polarity determination unit 47 previously.

[0107] Table 2 is for illustration. Figure 1 The table shows an example of the update action of the count value of the rotation detector 14.

[0108] [Table 2]

[0109]

[0110] As shown in Table 2, for example, if the previous polarity information is 1, the previous detection information is 0, the previous power generation information is 0, the current polarity information is 0, the current detection information is 1, and the current power generation information is 1, it is known that the rotating axis 10 rotates clockwise to move the reference position B from region IV to region I, and the information processing unit 56 decrements the count value by 1.

[0111] Additionally, for example, if the previous polarity information is 0, the previous detection information is 0, the previous power generation information is 0, the current polarity information is 0, the current detection information is 1, and the current power generation information is 1, and it is known that the rotating axis 10 rotates clockwise to move the reference position B from region IV to region I, the information processing unit 56 decrements the count value by 1.

[0112] Additionally, for example, if the previous polarity information is shown as 1, the previous detection information is shown as 1, the previous power generation information is shown as 1, the current polarity information is shown as 0, the current detection information is shown as 0, and the current power generation information is shown as 0, and it is known that the rotating axis 10 rotates counterclockwise to move the reference position B from region I to region IV, the information processing unit 56 increments the count value by 1.

[0113] Additionally, for example, if the previous polarity information shows 0, the previous detection information shows 1, the previous power generation information shows 1, the current polarity information shows 0, the current detection information shows 0, and the current power generation information shows 0, and it is known that the rotating axis 10 rotates counterclockwise to move the reference position B from region I to region IV, the information processing unit 56 increments the count value by 1.

[0114] As described above, the information processing unit 56 can calculate the rotational speed of the rotating shaft 10 by updating the count value.

[0115] The above describes the rotation detector 14 according to the first embodiment.

[0116] The rotation detector 14 according to this embodiment includes: a magnet 20 that rotates together with a rotation axis 10; a plurality of power generation elements 22 and 24 that generate electricity through changes in the magnetic field generated by the rotation of the magnet 20 together with the rotation axis 10; and a plurality of magnetic sensors 26 and 28 corresponding to the plurality of power generation elements 22 and 24. The rotation detector 14 according to this embodiment also includes: an information processing unit 56 that uses the plurality of magnetic sensors 26 and 28 to determine the rotational position of the rotation axis 10; and a power supply unit 46 that supplies the power generated by each of the plurality of power generation elements 22 and 24 only to the magnetic sensor corresponding to that power generation element among the plurality of magnetic sensors 26 and 28.

[0117] Accordingly, the power generated by the multiple power generation elements 22 and 24 can be supplied only to the magnetic sensor corresponding to that power generation element among the multiple magnetic sensors 26 and 28. Therefore, the power consumption generated by each of the multiple power generation elements 22 and 24 can be suppressed, and the power can be used to drive the magnetic sensor corresponding to that power generation element more reliably. Thus, the occurrence of false detections caused by the magnetic sensor corresponding to that power generation element not being driven can be suppressed.

[0118] Furthermore, in the rotation detector 14 according to this embodiment, the information processing unit 56 determines the rotational position of the rotation axis 10. The rotation detector 14 also includes a storage unit 58, which stores the region among multiple regions I to IV where the reference position B is determined by the information processing unit 56. The determination of the rotation axis 10 is performed by determining which region among the multiple regions I to IV arranged in the rotational direction of the rotation axis 10 is located based on power generation information indicating that the power generation elements 22 and 24 have generated power, and detection information indicating the detection results of the magnetic sensors 26 and 28 corresponding to the power generation elements.

[0119] Accordingly, the rotational position of the rotating shaft 10 can be determined using power generation information and detection information without using the polarity of the power generated by each of the multiple power generation elements 22 and 24. Therefore, even when the power generated by each of the multiple power generation elements 22 and 24 is small and the polarity of the power cannot be determined, the rotational position of the rotating shaft 10 can still be determined, and the occurrence of false detection can be suppressed.

[0120] Furthermore, in the rotation detector 14 of this embodiment, if the area where the current reference position B is located in one of the multiple areas I to IV is not adjacent to the area where the previous reference position B was located, the information processing unit 56 causes the storage unit 58 to store an error.

[0121] Therefore, in the event that a false detection occurs because the area where the reference position B is located is not adjacent to the area where the reference position B was located in the previous detection, due to the failure of multiple magnetic sensors 26 and 28 to be driven, the false detection can be stored, thus making it easy to identify the occurrence of false detection.

[0122] Furthermore, in the rotation detector 14 according to this embodiment, if the area where the current reference position B is located in one of the multiple areas I to IV is not adjacent to the area where the previous reference position B was located, the information processing unit 56 causes the storage unit 58 to store the case that a change has occurred from the area where the previous reference position B was located to the area where the current reference position B is located.

[0123] Therefore, it is easy to identify which region the false detection occurred from when the reference position B changed to which region, and thus, it is easy to determine the cause of the false detection.

[0124] In addition, the rotation detector 14 according to this embodiment also includes a polarity determination unit 47, which determines the polarity of the electricity generated by each of the plurality of power generation elements 22 and 24. The information processing unit 56 determines the rotation direction of the rotation shaft 10 based on the power generation information, the detection information and the polarity information indicating the polarity determined by the polarity determination unit 47.

[0125] Therefore, in addition to determining the rotational position of the rotating shaft 10, the rotational direction of the rotating shaft 10 is also determined, thereby making it easy to identify the occurrence of false detection.

[0126] Furthermore, in the rotation detector 14 of this embodiment, if the area where the current reference position B is located in one of the multiple areas I to IV is adjacent to the area where the previous reference position B was located, and the change from the polarity determined by the polarity determination unit 47 in the previous case to the polarity determined by the polarity determination unit 47 in the current case is abnormal, the information processing unit 56 causes the storage unit 58 to store an error.

[0127] Therefore, in the event of false detection due to multiple magnetic sensors 26 and 28 not being driven, error information indicating that false detection has occurred can be stored, thus making it easy to identify the occurrence of false detection.

[0128] In addition, in the rotation detector 14 of this embodiment, the information processing unit 56 updates the count value used to calculate the rotational speed of the rotating shaft 10 based on the region in multiple regions I to IV where the current reference position B is located, the polarity determined by the polarity determination unit 47 this time, the region in multiple regions I to IV where the previous reference position B was located, and the polarity determined by the polarity determination unit 47 last time.

[0129] Therefore, the count value used to calculate the rotational speed of the rotating shaft 10 can be updated more accurately, thus suppressing false detections.

[0130] Furthermore, the rotation detector 14 according to this embodiment also includes an optical sensor 30, which has a light-emitting element 42 that operates based on power from the power source 150. The optical sensor 30 is used to detect the amount of rotation of the rotation shaft 10. When the optical sensor 30 changes from an unpowered state (not receiving power from the power source 150) to a powered state (receiving power from the power source 150), the information processing unit 56 determines the rotation position of the rotation shaft 10 based on the rotation position of the rotation shaft 10 determined by multiple magnetic sensors 26 and 28 in the unpowered state, and the amount of rotation of the rotation shaft 10 detected by the optical sensor 30 after changing to the powered state.

[0131] Accordingly, in the unpowered state, multiple magnetic sensors 26 and 28 can be used to determine the rotational position of the rotating shaft 10. Furthermore, when switching from an unpowered state to a powered state, the rotational position of the rotating shaft 10 can be determined by adding the rotational amount of the rotating shaft 10 detected by the optical sensor 30 after switching to a powered state to the rotational position determined by the multiple magnetic sensors 26 and 28 in the unpowered state. Therefore, false detections can be further suppressed.

[0132] Furthermore, in the rotary detector 14 according to this embodiment, the power supply unit 46 includes a sensor power storage unit 66, a power storage unit 67, and a switch 72. The sensor power storage unit 66 stores power generated by each of the plurality of power generating elements 22, 24 and supplied to the magnetic sensors corresponding to those power generating elements in the plurality of magnetic sensors 26, 28. The power storage unit 67 stores power generated by each of the plurality of power generating elements 22, 24 and supplied to components other than the plurality of magnetic sensors 26, 28. The switch 72 can electrically disconnect the sensor power storage unit 66 from the power storage unit 67.

[0133] Accordingly, the power generated by each of the multiple power generation elements 22 and 24 can be supplied more reliably to the corresponding magnetic sensors among the multiple magnetic sensors 26 and 28, thereby further suppressing the occurrence of false detections caused by the magnetic sensor not being driven.

[0134] Furthermore, in the rotation detector 14 according to this embodiment, multiple power generation elements 22 and 24 are arranged at angular intervals, exceeding the angular interval between a first position and a second position, in the rotation direction of the rotation axis 10. The first position is the position where one of the power generation elements 22 and 24 generates electricity when the rotation axis 10 rotates clockwise, and the second position is the position closest to the first position among more than one position where that one power generation element generates electricity when the rotation axis 10 rotates counterclockwise. Each of the multiple magnetic sensors 26 and 28 is arranged in the same position as the corresponding power generation element in the multiple power generation elements 22 and 24 in the rotation direction of the rotation axis 10.

[0135] Accordingly, it is easy to make the magnetic pole detected by the magnetic sensor 26 when the power generation element 22 generates electricity at a certain position different from the magnetic pole detected by the magnetic sensor 26 when the power generation element 22 generates electricity at other positions. Therefore, it is easy to determine the rotation position of the rotating shaft 10 and suppress the occurrence of false detection.

[0136] (Second Implementation)

[0137] Figure 6 This is a diagram showing the rotation detector 14a according to the second embodiment.

[0138] like Figure 6 As shown, the main difference between the rotary detector 14a and the rotary detector 14 is that it also has a power generation element 104 and a magnetic sensor 106.

[0139] The power generation element 104 has the same structure as power generation elements 22 and 24, therefore a detailed description of power generation element 104 is omitted. Multiple power generation elements 22, 24, and 104 are arranged at equal intervals in the rotation direction of the rotating shaft 10.

[0140] The magnetic sensor 106 has the same structure as the magnetic sensor 26 and the magnetic sensor 28, so a detailed description of the magnetic sensor 106 is omitted. The magnetic sensor 106 is arranged in the same position as the power generation element 104 in the rotation direction of the rotation shaft 10, and is arranged in the radial direction of the rotation shaft 10 with the power generation element 104 and is located outside the power generation element 104.

[0141] In this way, by also providing a power generation element 104 and a corresponding magnetic sensor 106, when the rotation axis 10 rotates clockwise, one of the multiple power generation elements 22, 24, and 104 can generate electricity at positions i to vi, and when the rotation axis 10 rotates counterclockwise, one of the multiple power generation elements 22, 24, and 104 can generate electricity at positions vii to xii. Therefore, it is possible to determine which of the six regions, from region I to region VI, the reference position B is located in, and the position of the rotation axis 10 can be detected more precisely than that of the rotation detector 14.

[0142] Figure 7 It is shown Figure 6 A block diagram of a portion of the functional structure of the rotation detector 14a. Figure 8 It is shown Figure 6 A block diagram of another part of the functional structure of the rotation detector 14a.

[0143] like Figure 7 and Figure 8 As shown, the rotary detector 14a differs from the rotary detector 14 mainly in that it has a power supply unit 46a that is different from the power supply unit 46, a polarity determination unit 47a that is different from the polarity determination unit 47, and a magnetic pole determination unit 51a that is different from the magnetic pole determination unit 51.

[0144] The main difference between the power generation and power supply unit 46a and the power generation and power supply unit 46 is that it has a full-wave rectifier unit 112, a third storage unit 114, a switch 116, a power monitoring unit 118, a discharge unit 120, and a switch 122.

[0145] The power supply unit 46a can supply the power generated by the power generation element 104 to the magnetic sensor 106 corresponding to the power generation element 104 among the plurality of magnetic sensors 26, 28, 106.

[0146] The polarity determination unit 47a differs from the polarity determination unit 47 mainly in that it also has a third determination unit 108 for determining the polarity of the electricity generated by the power generation element 104. The third determination unit 108 is able to determine the polarity of the electricity generated by the power generation element 104.

[0147] The magnetic pole determination unit 51a differs from the magnetic pole determination unit 51 mainly in that it also has a third determination unit 110 for determining the magnetic pole detected by the magnetic sensor 106. The third determination unit 110 is able to determine the magnetic pole detected by the magnetic sensor 106.

[0148] (Other implementation methods, etc.)

[0149] As described above, embodiments have been illustrated as examples of the technology disclosed in this application. However, the technology disclosed herein is not limited to these, and can also be applied to embodiments or variations obtained by appropriate changes, substitutions, additions, omissions, etc., as long as they do not depart from the spirit of this disclosure.

[0150] In the above embodiments, the magnet 20 is described as being in a ring shape, but it is not limited to this. For example, the magnet may not be ring-shaped, but may be in the shape of a disc or a rod, etc.

[0151] Furthermore, in the above embodiment, the case where the optical sensor 30 has a reflective pattern 44 was described, but it is not limited to this. For example, the optical sensor may also have a transmissive pattern that allows light to pass through, and the rotational position of the rotating shaft can be detected by receiving light that has passed through the transmissive pattern.

[0152] Furthermore, in the above embodiment, it was described that each of the multiple magnetic sensors 26 and 28 is arranged in the same position as the corresponding power generation element in the multiple power generation elements 22 and 24 in the rotation direction of the rotation axis 10, but this is not a limitation. For example, each of the multiple magnetic sensors may be arranged in a position offset by 180 degrees from the corresponding power generation element in the rotation direction of the rotation axis.

[0153] Furthermore, in the above embodiment, the magnetic sensors 26 and 28 are described as being arranged radially with respect to the power generation elements 22 and 24, and positioned further outward than the power generation elements 22 and 24. However, the magnetic sensors 26 and 28 are not necessarily required to be positioned outside the power generation elements 22 and 24; they can also be positioned inside the power generation elements 22 and 24. Here, it is required that the magnetic sensors 26 and 28 accurately read the magnetic poles of the magnet 20. Therefore, the magnetic sensors 26 and 28 are preferably positioned with a large S / N ratio in order to detect the magnetic flux of the magnet 20. Thus, when observing the magnetic sensors 26 and 28 along the rotation axis A, the magnetic sensors 26 and 28 are positioned in a position that does not overlap with the power generation elements 22 and 24. As a result, the magnetic sensors 26 and 28 have the advantage of being less affected by changes in magnetic flux caused by the power generation of the power generation elements 22 and 24. When the magnetic sensors 26 and 28 are arranged on the outside of the power generation elements 22 and 24, the magnetic sensors 26 and 28 can be arranged even in the case of a substrate with a central opening. Therefore, the central part of the rotation detector 14 can be easily hollowed out.

[0154] Furthermore, in the above embodiment, the case where multiple power generation elements 22, 24 are disposed on the main surface of the substrate 18 opposite to the rotating plate 16 is described, but this is not a limitation. For example, multiple power generation elements may also be disposed on the main surface of the substrate on the rotating plate side.

[0155] Furthermore, in the above embodiment, the case where multiple magnetic sensors 26, 28 are disposed on the main surface of the substrate 18 on the side of the rotating plate 16 is described, but it is not limited to this. For example, multiple magnetic sensors may also be disposed on the main surface of the substrate on the side opposite to the rotating plate.

[0156] Furthermore, in the above embodiment, the case where the magnet 20 is disposed on the main surface of the rotating plate 16 opposite to the substrate 18 is described, but it is not limited to this. For example, the magnet may also be disposed on the main surface of the rotating plate on the substrate side.

[0157] Industrial availability

[0158] The rotation detector disclosed herein can be used for rotation detection of the rotating shaft of a motor that drives a load to rotate.

[0159] Explanation of reference numerals in the attached figures

[0160] 14, 14a: Rotation detector; 16: Rotating plate; 18: Substrate; 20: Magnet; 22, 24, 104: Power generation element; 26, 28, 106: Magnetic sensor; 30: Optical sensor; 32: Control circuit; 34, 38: Magnetic induction unit; 36, 40: Coil; 42: Light-emitting and light-receiving element; 44: Reflective pattern; 46, 46a: Power supply unit; 47, 47a: Polarity determination unit; 48, 52: First determination unit; 50, 54: Second determination unit; 51, 51a: Magnetic pole determination unit; 55: Signal processing unit; 5 6: Information processing unit; 58: Storage unit; 60: Communication unit; 62, 64, 112: Full-wave rectification unit; 66: Sensor power storage unit; 67: Power storage unit; 68: First storage unit; 70: Second storage unit; 72, 74, 76, 100, 102, 116, 122: Switch; 78, 80: Internal power supply; 82, 84, 86, 88, 89, 118: Power monitoring unit; 90, 92: Voltage adjustment unit; 94, 96, 98, 120: Discharge unit; 108, 110: Third determination unit; 114: Third storage unit.

Claims

1. A rotating detector, comprising: A magnet that rotates together with the axis of rotation; Multiple power generation elements generate electricity by changing the magnetic field produced when the magnet rotates together with the rotating shaft; Multiple magnetic sensors are provided corresponding to the multiple power generation elements; The information processing unit uses the plurality of magnetic sensors to determine the rotational position of the rotating shaft; as well as The power supply unit supplies power generated by each of the plurality of power generation elements only to the magnetic sensor corresponding to that power generation element among the plurality of magnetic sensors.

2. The rotating detector according to claim 1, wherein, The information processing unit determines, based on power generation information indicating which of the plurality of power generation elements has generated electricity and detection information indicating the detection results of the magnetic sensors corresponding to the power generation elements, which are among the plurality of magnetic sensors, which determine the reference position of the rotating shaft in the rotation direction is located in which of the plurality of regions arranged in the rotation direction of the rotating shaft, and thereby determines the rotation position of the rotating shaft. The rotation detector also includes a storage unit that stores the region among the plurality of regions where the information processing unit determines the reference position to be located.

3. The rotating detector according to claim 2, wherein, If the region where the reference position is determined to be located in the current instance is not adjacent to the region where the reference position was previously determined to be located, the information processing unit causes the storage unit to store the error.

4. The rotating detector according to claim 2 or 3, wherein, If the region where the reference position is determined to be located in the current instance is not adjacent to the region where the reference position was previously determined to be located, the information processing unit causes the storage unit to store the case where a change has occurred from the region where the reference position was previously determined to be located to the region where the reference position is currently determined to be located.

5. The rotating detector according to claim 2 or 3, wherein, It also includes a polarity determination unit, which determines the polarity of the electricity generated by each of the plurality of power generation elements. The information processing unit determines the rotation direction of the rotating shaft based on the power generation information, the detection information, and polarity information indicating the polarity determined by the polarity determination unit.

6. The rotating detector according to claim 5, wherein, If the region where the reference position is determined to be located in the current region is adjacent to the region where the reference position was determined to be located in the previous region, and the change from the polarity determined by the polarity determination unit in the previous region to the polarity determined by the polarity determination unit in the current region is abnormal, the information processing unit causes the storage unit to store an error.

7. The rotating detector according to claim 5, wherein, The information processing unit updates the count value used to calculate the rotational speed of the rotating shaft based on the region in the plurality of regions where the reference position is currently determined, the polarity determined by the polarity determination unit in the current determination, the region in the plurality of regions where the reference position was previously determined, and the polarity determined by the polarity determination unit in the previous determination.

8. The rotating detector according to any one of claims 1 to 3, wherein, It also includes an optical sensor, which has a light-emitting element and a light-receiving element that operate based on power from a power source. This optical sensor is used to detect the amount of rotation of the rotating shaft. When the optical sensor changes from an unpowered state (where it does not receive power from the power source) to a powered state (where it receives power from the power source), the information processing unit determines the rotation position of the rotating shaft based on the rotation position of the rotating shaft determined by the plurality of magnetic sensors in the unpowered state and the amount of rotation of the rotating shaft detected by the optical sensor after the change to the powered state.

9. The rotating detector according to any one of claims 1 to 3, wherein, The power supply unit includes: a sensor power storage unit for storing power generated by each of the plurality of power generating elements and supplied to the magnetic sensor corresponding to the power generating element among the plurality of magnetic sensors; a power storage unit for storing power generated by each of the plurality of power generating elements and supplied to components other than the plurality of magnetic sensors; and a disconnection unit capable of electrically disconnecting the sensor power storage unit from the power storage unit.

10. The rotating detector according to any one of claims 1 to 3, wherein, The plurality of power generating elements are arranged at angular intervals, exceeding the angular interval between the first position and the second position, in the rotational direction of the rotating shaft. The first position is the position where one of the power generating elements generates electricity when the rotating shaft rotates clockwise, and the second position is the position closest to the first position among more than one positions where that single power generating element generates electricity when the rotating shaft rotates counterclockwise. Each of the plurality of magnetic sensors is positioned in the same position as the corresponding power generation element in the plurality of power generation elements or offset from the power generation element by 180 degrees in the direction of rotation of the rotating shaft.

11. A rotation detection method, which is a rotation detection method using a rotation detector, wherein, The rotation detector includes: a magnet that rotates together with a rotation axis; a plurality of power generation elements that generate electricity through changes in the magnetic field produced by the rotation of the magnet together with the rotation axis; and a plurality of magnetic sensors disposed corresponding to the plurality of power generation elements. And a power supply unit that supplies power generated by each of the plurality of power generation elements only to the magnetic sensor corresponding to that power generation element among the plurality of magnetic sensors. The rotation detection method includes: Based on the power generation information of the power generation element that has generated electricity among the plurality of power generation elements, and the detection information of the detection result of the magnetic sensor corresponding to the power generation element among the plurality of magnetic sensors, it is determined which region among the plurality of regions arranged in the rotation direction of the rotating shaft the reference position of is located in. as well as The region identified as the location of the reference position is stored among the plurality of regions.

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