JP6172396B1 - Motor encoder and motor - Google Patents

Abstract

An axial dimension of a motor encoder is shortened. A motor encoder includes a disk rotating with a motor shaft, a main board disposed opposite to the disk and having an opening formed therein, and the main board on the opposite side of the disk. A sub-substrate 13 disposed on the surface 12b of the sub-substrate 13 so as to cover at least a part of the opening 12a, a light source 14 disposed on the surface 13a on the disk 11 side of the sub-substrate 13 in the opening 12a and emitting light to the disk 11. A light receiving element 15 that receives the reflected light from the disk 11 is provided on the surface 13a of the sub-substrate 13 on the disk 11 side in the opening 12a.

Description

  The disclosed embodiment relates to a motor encoder and a motor.

  Patent Document 1 describes a motor having a motor body and an encoder including a multi-rotation detection unit and a rotational position detection unit.

International Publication No. 2013/094042 (FIG. 11)

  In order to reduce the axial dimension of a motor encoder, further optimization of the device configuration is desired.

  The present invention has been made in view of such problems, and an object thereof is to provide a motor encoder and a motor capable of reducing the axial dimension.

In order to solve the above problems, according to one aspect of the present invention, a housing, a disk that rotates together with a motor shaft in the housing, and a shaft in the housing that is more axial than a wall on one side in the axial direction of the housing. is arranged to face the axial one side of the direction the other side a and the disc, the opening is connected to the first substrate which is formed, on the first substrate so as to cover at least a part of the previous SL openings and second substrate are arranged in the axial direction other side of the surface to be pre-Symbol the disk side of the second substrate, a light source for emitting light to the disc, the axial direction becomes the front Symbol the disk side of the second substrate A light receiving element that is disposed on the other surface and receives reflected light from the disk, a plurality of first terminal portions provided on the surface of the first substrate, and a plurality provided on the surface of the second substrate. of A plurality of two terminal portions and a plurality of solders arranged on one side in the axial direction of the first substrate and the second substrate connected to each other and connecting the first terminal portion and the second terminal portion; A motor encoder having a connecting portion is applied.

  According to another aspect of the present invention, a motor having a motor shaft, a motor electromagnetic unit that rotates the motor shaft, and the motor encoder is applied.

  According to still another aspect of the present invention, a disk that rotates with a motor shaft, a first substrate that is disposed to face the disk, a light source that emits light to the disk, and reflected light from the disk A motor encoder having a second substrate including a light receiving element that receives light and means for disposing the second substrate on a surface of the first substrate opposite to the disk is applied.

  According to the present invention, the axial dimension of a motor encoder or the like can be shortened.

It is an axial direction sectional view showing an example of the composition of the motor provided with the encoder for motors concerning an embodiment. It is the II-II arrow line view of FIG. 1 showing an example of a structure of an optical module. It is explanatory drawing showing an example of the structure of the terminal part of a sub board | substrate, and the terminal part of a main board | substrate. It is explanatory drawing showing an example of the structure of the opening vicinity of a sub board | substrate and a main board | substrate. It is a VV arrow line view of FIG. 1 showing an example of arrangement | positioning of the magnet in a magnetic body. FIG. 6 is a view taken along the line VI-VI in FIG. 1 illustrating an example of the configuration of the magnetic member. It is explanatory drawing of the state which removed the magnetic member from FIG. 6 showing an example of a structure of a magnetic field detection part. It is explanatory drawing which expanded an example of the one magnetic field detection part in FIG. 6, etc. showing an example of a structure of a magnetic member. It is explanatory drawing showing an example of the rotation detection operation | movement of a magnetic detection mechanism. It is explanatory drawing showing an example of the path | route of the magnetic path in a magnetic detection mechanism. It is explanatory drawing showing an example of the rotation detection operation | movement of a magnetic detection mechanism. It is explanatory drawing showing an example of the path | route of the magnetic path in a magnetic detection mechanism. It is explanatory drawing showing an example of the rotation detection operation | movement of a magnetic detection mechanism. It is explanatory drawing showing the distance between the main board | substrate and the disk in the encoder for motors of a comparative example. It is explanatory drawing showing the distance between the main board | substrate and disk in the encoder for motors of embodiment.

  Hereinafter, an embodiment will be described with reference to the drawings.

<1. Overall configuration of motor>
First, an example of the overall configuration of the motor 100 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the motor 100 includes a motor shaft 102, a motor electromagnetic unit 110, and a motor encoder 10 (hereinafter referred to as “encoder 10”).

  The motor electromagnetic unit 110 outputs a rotational force by rotating the motor shaft 102 around its axis AX. In this specification, the torque output side of the motor electromagnetic unit 110 is referred to as “load side”, and the opposite side is referred to as “anti-load side”.

  Here, for convenience of the description of the structure of the motor 100, in the following, directions such as up and down are determined as follows and used appropriately. That is, in FIG. 1, the anti-load side direction, that is, the Z-axis positive direction is defined as “up”, and the reverse load side direction, that is, the Z-axis negative direction is defined as “down”. However, the direction such as up and down varies depending on the installation mode of the motor 100 and does not limit the positional relationship of each component of the motor 100.

  The configuration of the motor electromagnetic unit 110 is not particularly limited as long as it can rotate the motor shaft 102. For example, the configuration is as follows. That is, the motor electromagnetic unit 110 includes the stator 103 and the rotor 104. The rotor 104 is disposed on the inner peripheral side of the stator 103. The rotor 104 is fixed to the outer periphery of the motor shaft 102 so as to have the same axis as the motor shaft 102. The motor shaft 102 is rotatably supported by bearings 107 and 108 in which outer rings are fitted to brackets 105 and 106. The stator 103 is fixed to the inner periphery of the frame 101 and is disposed so as to face the outer periphery of the rotor 104 in the radial direction with a magnetic gap therebetween.

  The motor electromagnetic unit 110 having the above configuration can rotate the motor shaft 102 around the axis AX by rotating the rotor 104 around the axis AX relative to the stator 103.

  The configuration of the motor electromagnetic unit 110 described above is merely an example, and a configuration other than the above may be used. For example, the motor electromagnetic unit 110 is not limited to a so-called “inner rotor type” in which a rotor is disposed on the inner peripheral side of the stator, and the rotor is disposed on the outer peripheral side of the stator. It may be configured as a so-called “outer rotor type”.

<2. Encoder>
Next, an example of the configuration of the encoder 10 according to the present embodiment will be described with reference to FIGS. As shown in FIG. 1, the encoder 10 is disposed adjacent to, for example, the upper side of the motor electromagnetic unit 110. The encoder 10 is covered by a covered cylindrical housing 2 provided adjacent to the bracket 105, for example. The housing 2 is fixed to the upper surface of the bracket 105 with, for example, bolts. The encoder 10 includes an optical detection mechanism 20 and a magnetic detection mechanism 30.

(2-1. Optical detection mechanism)
An example of the configuration of the optical detection mechanism 20 will be described with reference to FIGS. As shown in FIG. 1, the optical detection mechanism 20 includes a disk 11, a main substrate 12 (an example of a first substrate), a sub substrate 13 (an example of a second substrate), a light source 14, a light receiving element 15, and the like.

  As shown in FIG. 1, the disk 11 is configured to rotate together with the motor shaft 102. That is, the disk 11 is fixed to the surface 18c on the main board 12 side of the magnetic body 18 connected to the motor shaft 102 so as to be substantially concentric with the axis AX of the motor shaft 102.

  The disk 11 is formed of a material that transmits light, such as glass or transparent resin. A reflective slit is formed by disposing a material that reflects light (for example, aluminum) on the upper surface of the disk 11 by vapor deposition or the like.

  The material and manufacturing method of the disk 11 are not particularly limited. For example, the disk 11 can be formed of a material that reflects light, such as metal. In this case, a reflective slit is formed in a portion where the material is not disposed by disposing a material with low reflectance (for example, chromium oxide) on the portion of the disk 11 where light is not reflected by coating or the like. In addition, a reflective slit may be formed by making the part which does not reflect light into a rough surface by sputtering etc., and reducing a reflectance.

  The magnetic body 18 has, for example, an annular shape, and has an annular collar portion 18 a at a substantially central portion in the radial direction of the surface 18 d on the opposite side to the main substrate 12. The magnetic body 18 is coupled to the motor shaft 102 by fitting the concave portion 18 b inside the collar portion 18 a to the opposite end portion of the motor shaft 102. The motor shaft 102 extends upward through the magnetic detection mechanism 30.

  A plurality of tracks (not shown) in which a plurality of reflective slits (not shown) are arranged along the circumferential direction are formed on the surface of the disk 11 on the main substrate 12 side. Each reflecting slit reflects light emitted from the light source 14. As an arrangement pattern of the reflection slits in the track, for example, an “incremental pattern” in which the reflection slits are regularly repeated at a predetermined pitch, or the position and ratio of the reflection slits are uniquely determined within one rotation of the disk 11. Absolute pattern "etc. are mentioned, However It does not specifically limit.

  The main board 12 is supported by the housing 2 by a support member (not shown), and is disposed so as to face the disk 11. The main substrate 12 is formed with an opening 12 a (notched) penetrating in the vertical direction at a position deviated from the axis AX of the motor shaft 102. Note that some electronic devices on the main board 12 are connected to some electronic devices on the board 31 of the magnetic field detection unit 17 by, for example, a cable.

  The sub-board 13 is arranged so as to block the opening 12a on the surface 12b of the main board 12 opposite to the disk 11. At this time, the light source 14, the plurality of light receiving elements 15 and the like disposed on the surface 13a on the disk 11 side of the sub-substrate 13 are accommodated in the opening 12a. In this example, the sub-board 13 covers the entire opening 12a, but may be arranged so as to cover a part of the opening 12a.

  The main board 12 and the sub board 13 are connected by a plurality of connecting portions 19. The plurality of connecting portions 19 connect the edge portion of the sub-board 13 and the peripheral portion of the opening 12 a on the surface 12 b on the opposite side of the disk 11 of the main board 12. For example, solder can be used as the connecting portion 19. In the example shown in FIG. 2, a plurality of terminal portions 26 are provided on both sides of the sub-board 13 in the disk rotation direction (left and right direction in FIG. 2) and on the inner peripheral edge in the disk radial direction (up and down direction in FIG. 2). Is provided. As shown in FIG. 3, each terminal portion 26 has a semicylindrical recess 26a. On the other hand, as shown in FIG. 3, a terminal portion 27 is formed on the surface 12b of the main substrate 12 at a position corresponding to the terminal portion 26 around the opening 12a, for example, in a thin film shape. The sub board 13 is placed on the surface 12 b of the main board 12 so that the terminal part 26 overlaps the terminal part 27. In this state, the solder is melted in the vicinity of the concave portion 26a of the terminal portion 26, and the molten solder is guided onto the terminal portion 27 by the concave portion 26a. In this way, the connecting portion 19 is formed, and the terminal portion 26 and the terminal portion 27 are mechanically and electrically connected.

  In addition, the structure of the above-mentioned terminal parts 26 and 27 and the connection part 19 is an example, and is not limited to this structure. For example, an arm-shaped metal terminal may protrude outward from the edge of the sub-board 13 and the metal terminal and the terminal portion 27 of the main board 12 may be joined by soldering, or the sub-board 13 and the main board 12 may be joined. May be connected by soldering using lead wires or the like. Further, for example, a flip-chip bonding method may be employed in which a plurality of terminal portions are formed on the surface of the sub-substrate 13 and are directly connected to the terminal portions on the sub-substrate 13 side by solder bumps formed on the terminal portions 27 of the main substrate 12. . Furthermore, it is good also as a structure which connects the terminal part of the sub board | substrate 13 and the terminal part of the main board | substrate 12 using a connector etc., without performing soldering.

  The light source 14 is disposed on the surface 13 a of the sub substrate 13 on the disk 11 side inside the opening 12 a of the main substrate 12, and emits light to the disk 11. A plurality of light receiving elements 15 are arranged on the surface 13a of the sub-substrate 13 inside the opening 12a, and receive the reflected light from the disk 11. The plurality of light receiving elements 15 constitutes a plurality of light receiving arrays PA1, PA2, PI1, PI2 arranged around the light source 14 along the disk rotation direction. The sub board 13, the light source 14, the plurality of light receiving elements 15, and the like are modularized as an optical module 21.

  In the example shown in FIG. 2, the optical module 21 includes a light source 14, a plurality of light receiving arrays PA 1, PA 2, PI 1, PI 2 corresponding to a plurality of tracks on the disk 11, And an adjustment light receiving element PD.

  As the light source 14, for example, an LED (Light Emitting Diode) can be used. The light source 14 is configured as a point light source in which no optical lens or the like is particularly disposed, and emits diffused light from the light emitting unit. By using the point light source in this way, the light source 14 can irradiate light substantially uniformly on a plurality of tracks of the disk 11 passing through the opposed positions. In addition, since the light is not condensed and diffused by the optical element, errors due to the optical element are not easily generated, and the straightness of the emitted light to the irradiation region can be improved.

  The plurality of light receiving arrays PA1, PA2, PI1, PI2 are arranged around the light source 14. Specifically, the light receiving arrays PI1 and PI2 are arranged inside and outside the disk radial direction with the light source 14 interposed therebetween, and the light receiving arrays PA1 and PA2 are arranged inside the disk radial direction with the light receiving arrays PI1 and PI2 interposed therebetween. And on the outside. These light receiving arrays PA1, PA2, PI1, PI2 are configured by arranging a plurality of light receiving elements 15 in an array at a predetermined pitch along the disk rotation direction.

  Each of the light receiving arrays PI1 and PI2 receives light reflected by the reflecting slit of the corresponding incremental pattern of the disk 11 by the light receiving element 15 and outputs an incremental signal. In this example, the incremental signal generated by the light receiving array PI2 corresponding to the reflective slit having a small pitch has a higher resolution than the incremental signal of the light receiving array PI1 corresponding to the reflective slit having a large pitch. Each of the light receiving arrays PA1 and PA2 receives light reflected by the reflecting slit of the corresponding absolute pattern of the disk 11 by the light receiving element 15 and outputs an absolute signal.

  The adjustment light receiving elements PD are arranged on both sides of the light receiving array PI1 in the disk rotation direction, and receive light reflected by the slit track of the increment pattern corresponding to the light receiving array PI1. The two light-receiving elements for adjustment PD are formed so that the amount of received light is substantially constant so that the amount of received light can be adjusted using the signal of the light-receiving element for adjustment PD.

  Further, as shown in FIGS. 2 and 4, a plurality of sub-substrates 13, light receiving elements 15, and the like are electrically connected to a surface 13 a on the disk 11 side of the sub-substrate 13 inside the opening 12 a of the main substrate 12. A bonding wire 28 is disposed. The plurality of bonding wires 28 are accommodated in the opening 12a.

  An IC chip 23 is disposed on the surface 13 a of the sub-board 13 on the disk 11 side inside the opening 12 a of the main board 12. The light receiving element 15 and the adjustment light receiving element PD are formed on the semiconductor wafer 24 of the IC chip 23. On the semiconductor wafer 24 of the IC chip 23, an integrated circuit 25 having predetermined functions such as an operational amplifier and a comparator is formed in addition to the light receiving element 15 and the adjustment light receiving element PD. The integrated circuit 25 is formed on a vacant area on the semiconductor wafer 24, in this example, on both sides of the light receiving array PA1.

  A position data generation unit (not shown) included in the encoder 10 has two bit patterns each including a bit pattern representing the absolute position from the optical module 21 at the timing of measuring the absolute position of the motor electromagnetic unit 110 (motor shaft 102). An absolute signal, a high incremental signal, and a low incremental signal are acquired. Then, the position data generation unit calculates the absolute position of the motor electromagnetic unit 110 represented by these signals based on the acquired signals, and generates position data representing the calculated absolute position.

  The configuration of the optical detection mechanism 20 is merely an example, and a configuration other than the above may be used. For example, the disk 11 is connected to the motor shaft 102 via the magnetic body 18, but may be directly connected to the motor shaft 102 without passing through the magnetic body 18. The optical detection mechanism 20 is disposed adjacent to the upper side of the motor electromagnetic unit 110. However, another configuration such as an electromagnetic brake is disposed on the upper side of the motor electromagnetic unit 110, and the upper side of the motor electromagnetic unit 110 is disposed. You may arrange | position through the said other structure. The light receiving arrays PA1 and PA2 that output the absolute signal may be only one of the light receiving arrays, or the light receiving array that outputs the incremental signal may have a single resolution.

(2-2. Magnetic detection mechanism)
Next, an example of the configuration of the magnetic detection mechanism 30 will be described with reference to FIGS. 1 and 5 to 13. As shown in FIG. 1, the magnetic detection mechanism 30 includes a magnet 16, a magnetic field detection unit 17, a substrate 31, and the like.

(2-2-1. Substrate, magnet)
The substrate 31 is formed in an annular shape and is fixed to the lower end portion of the housing 2. The substrate 31 has a hole 31a through which the motor shaft 102 penetrates in a non-contact manner in the radial center.

  The magnet 16 is supported so as to rotate together with the motor shaft 102 on the opposite side of the disk 11 from the main substrate 12. Specifically, as shown in FIG. 5, four magnets 16 are fixed to the surface 18 d of the magnetic body 18 on the side opposite to the main board 12.

  The four magnets 16, that is, the magnets 16a, 16b, 16c, and 16d are, for example, plate-like permanent magnets. The four magnets 16a to 16d are arranged in the circumferential direction at positions close to the outer peripheral portion of the surface 18d of the magnetic body 18. Here, the four magnets 16a to 16d are arranged, for example, at equal intervals (90 ° intervals) in the circumferential direction. The four magnets 16a to 16d are arranged so that the N and S polarities are alternately different in the circumferential direction. For example, the magnet 16a has an N pole, the magnet 16b has an S pole, the magnet 16c has an N pole, and the magnet 16d has an S pole. These magnets 16 a to 16 d form a magnetic field in a region between the magnetic body 18 and the substrate 31.

  5 represents a rotation locus circle of the four magnets 16 (magnets 16a to 16d) when the magnetic body 18 rotates around the axis AX. A circumferential dimension D1 of each magnet 16 (a tangential dimension at a point on the rotation locus circle R overlapping the center of each magnet 16) is set to a predetermined value.

  Note that the number of magnets 16 is not limited to four, and may be another number. In that case, what is necessary is just to change suitably also about the number, arrangement | positioning, etc. of the magnetic field detection part 17 and the magnetic members 33 and 34. FIG. The magnet 16 may be a magnet (such as an electromagnet) that is not a permanent magnet.

(2-2-2. Magnetic field detector)
The magnetic field detector 17 is disposed on the opposite side of the disk 11 from the main substrate 12, specifically, on the opposite side of the magnetic body 18 from the main substrate 12.

  As shown in FIGS. 6 and 7, the magnetic field detection unit 17 includes a magnetic element 35 and a coil 36. The magnetic element 35 is formed in a wire shape, a rod shape, or a long plate shape (in this example, a long plate shape), and the coil 36 is wound around the magnetic element 35.

  Three magnetic field detectors 17 are provided on the surface of the substrate 31 on the magnetic body 18 side. The three magnetic field detection units 17, that is, the magnetic field detection units 17a, 17b, and 17c are arranged on the surface of the substrate 31 on the magnetic body 18 side so as to be spaced apart from each other in the circumferential direction, for example, at regular intervals (120 ° intervals) in the circumferential direction. Are lined up. In each of the magnetic field detection units 17a to 17c, the length direction of the magnetic element 35 is parallel to the tangent line at the intersection point where the radial line passing through the midpoint of the length direction and the rotation locus circle R of the magnet 16 intersect (length). The position is determined to be perpendicular to the radial line passing through the midpoint of the direction. Both ends in the length direction of the magnetic element 35 of each of the magnetic field detectors 17a to 17c are positioned such that the distance from the axis AX is equal and overlaps the rotation locus circle R. Each magnetic field detection part 17a-17c detects the magnetic field formed by the magnets 16a-16d.

  In addition, the arrangement | positioning shape of the magnetic field detection parts 17a-17c is not limited to a triangle shape seeing from the axial center AX direction, Other shapes may be sufficient. Further, the number of magnetic field detectors 17 is not limited to three, and may be other numbers. In that case, what is necessary is just to change suitably also about the number of magnets 16, arrangement, etc.

  The magnetic element 35 produces a large Barkhausen effect. Here, the “large Barkhausen effect” is a phenomenon in which the magnetization direction of the magnetic element 35 is rapidly reversed when the intensity of the applied external magnetic field exceeds a certain intensity, and is also referred to as a large Barkhausen jump.

  The magnetic element 35 is not particularly limited as long as it produces a large Barkhausen effect. For example, a wire-like magnetic element (for example, a composite magnetic wire, a Wiegand wire, an amorphous wire, etc.), a rod-like magnetic element A plate-like magnetic element or the like can be used. However, for convenience of explanation, a case where the magnetic element 35 is a composite magnetic wire will be described below.

  In each of the magnetic field detectors 17a to 17c employing such a composite magnetic wire as the magnetic element 35, when an external magnetic field is applied to the magnetic element 35, thereby changing the magnetization direction of the outer peripheral portion of the magnetic element 35, A pulsed electrical signal is output as a detection signal from the coil 36 wound around the magnetic element 35. In the magnetic detection mechanism 30, what corresponds to the external magnetic field applied to the magnetic element 35 is a magnetic field formed by the magnet 16a and the magnet 16b, a magnetic field formed by the magnet 16b and the magnet 16c, and a magnet 16c and a magnet 16d. And a magnetic field formed by the magnet 16d and the magnet 16a. When attention is paid to any one of the magnetic elements 35, the four magnetic fields are sequentially applied to the magnetic element 35 by rotating the magnetic body 18. Further, these four magnetic fields are not large magnetic fields that can change the magnetization directions of both the central portion and the outer peripheral portion of the magnetic element 35, but can change only the magnetization directions of the outer peripheral portion of the magnetic element 35. The magnetic field is as large as possible. From the positional relationship between the magnetic element 35 and the magnets 16a to 16d, the direction of the magnetic field is switched every time the magnetic field applied to the magnetic element 35 is switched. Therefore, each time the magnetic field is switched, the outer peripheral portion of the magnetic element 35 is changed. As the magnetization direction changes, a detection signal is output from the coil 36 wound around the magnetic element 35.

  Further, in the magnetic detection mechanism 30, the magnets 16a to 16d are arranged at intervals of 90 °, for example, whereas the magnetic field detectors 17a to 17c are arranged at intervals of 120 °, for example. Therefore, the timing at which the detection signal is output from each of the magnetic field detectors 17a to 17c does not overlap while the magnetic body 18 rotates. By performing predetermined processing using detection signals output at different timings from the magnetic field detectors 17a to 17c, the multi-rotation amount (rotation speed and rotation direction) of the motor 100 can be detected.

(2-2-3. Magnetic member)
As shown in FIG. 1, the magnetic detection mechanism 30 includes magnetic members 33 and 34 that cover the magnetic field detection unit 17. As shown in FIG. 6, the magnetic members 33 and 34 are provided with respect to each magnetic field detection part 17a-17c. The magnetic members 33 and 34 are formed of, for example, a magnetic material such as iron, and one of the magnetic members 33 covers one side in the length direction of each of the magnetic field detectors 17a to 17c, and the other magnetic member 34 includes The other side in the length direction of the magnetic field detectors 17a to 17c is covered.

  FIG. 8 is an enlarged view of one magnetic field detection unit and the like in FIG. As shown in FIG. 8, the magnetic members 33 and 34 provided in the magnetic field detector 17 a are disposed on the surface of the substrate 31 on the magnetic body 18 side and are fixed to the substrate 31. The magnetic members 33 and 34 are arranged so as not to contact with each other and with the magnetic field detector 17a. Further, the magnetic members 33 and 34 are arranged so as not to contact any of the magnetic members 33 and 34 of the other magnetic field detectors 17b and 17c.

  The magnetic member 33 includes a flat plate portion 33a and a side plate portion 33b, and is disposed on one side in the length direction of the magnetic field detector 17a (left side in FIG. 8). The flat plate portion 33a extends in parallel with the substrate 31 on the side opposite to the substrate 31 of the magnetic field detection unit 17a, and the magnetic field from the immediate vicinity of the center of the magnetic field detection unit 17a to the length direction one end (left end). The magnetic field detector 17a is covered with an area that exceeds the width direction of the detector 17a. One end of the side plate portion 33b is fixed to the substrate 31, and the flat plate portion 33a is fixed to the substrate 31 via the side plate portion 33b. The side plate part 33b covers the side on the substantially circumferential direction side at one end in the length direction of the magnetic field detection part 17a.

  The magnetic member 34 is formed in a shape symmetrical to the magnetic member 33 with respect to a radial line passing through the center in the length direction of the magnetic field detector 17a. The magnetic member 34 includes a flat plate portion 34a and a side plate portion 34b, and is disposed on the other side in the length direction of the magnetic field detection portion 17a (right side in the drawing).

  The side portion 33A of the flat plate portion 33a of the magnetic member 33 and the side portion 34A of the flat plate portion 34a of the magnetic member 34 are close to each other and face each other with a predetermined dimension D2. The dimension D2 of the gap and the dimension D1 of each of the magnets 16a to 16d are set so that D1 is larger than D2. The surface of the magnetic field detection unit 17a facing the magnetic body 18 is substantially covered by the flat plate portion 33a of the magnetic member 33 and the flat plate portion 34a of the magnetic member 34. The magnetic field detection unit 17a includes the flat plate portion 33a and the flat plate portion 34a. It is exposed to the magnetic body 18 only in the region between the opposing side portions 33A and 34A.

  The magnetic members 33 and 34 of the other magnetic field detectors 17b and 17c have the same configuration as the magnetic members 33 and 34 of the magnetic field detector 17a.

  The magnetic members 33 and 34 are not limited to the shape described above, and any other magnetic members may be used as long as they cover at least the portion facing the magnet 16 at the end in the length direction of the magnetic field detector 17. It is good also as the shape of this.

(2-2-4. Rotation detection operation of magnetic detection mechanism)
The rotation detection operation of the magnetic detection mechanism 30 will be described with reference to FIGS. 9, FIG. 11 and FIG. 13 are IX-IX arrow views in FIG. 1, but the illustration of the motor shaft 102, the magnetic body 18 and the like is omitted for convenience of explanation.

  First, a basic rotation detection operation of the magnetic detection mechanism 30 will be described with reference to FIGS. 9 and 13. When the magnets 16a, 16b, 16c, and 16d rotate clockwise or counterclockwise together with the magnetic body 18 as the motor 100 rotates, a magnetic field formed between the magnetic body 18 and the substrate 31 by the magnets 16a to 16d is generated. Rotate. Since the magnetic field detectors 17a, 17b, and 17c are stationary in the rotating magnetic field in this way, the polarity of the magnetic field applied to each of the magnetic field detectors 17a to 17c changes with rotation. Thereby, in each magnetic field detection part 17a-17c, the magnetization direction of the outer peripheral part of the magnetic element 35 changes, and the pulse-shaped detection signal is output from the coil 36. FIG. Based on this detection signal, the multi-rotation amount of the motor 100 can be detected.

  Here, paying attention to the magnetic field detector 17a, this operation will be specifically described. For example, it is assumed that the substrate 31 rotates counterclockwise when the magnetic element 35 of the magnetic field detection unit 17a is magnetized in the direction from the other end toward the one end. As a result, as shown in FIG. 9, when the N-pole magnet 16a approaches one end of the magnetic field detection unit 17a and the S-pole magnet 16b approaches the other end of the magnetic field detection unit 17a, the magnet 16a changes to the magnet. The magnetization direction of the outer peripheral portion of the magnetic element 35 of the magnetic field detector 17a is reversed by the magnetic field toward 16b. As a result, the magnetization direction of the magnetic element 35 is the direction from one end to the other end. Then, due to the reversal of the magnetization direction of the magnetic element 35, a pulse-like detection signal that rises sharply in the positive direction is output from the coil 36 wound around the magnetic element 35, for example.

  Subsequently, the counterclockwise rotation of the magnetic body 18 continues, and as shown in FIG. 13, the south pole magnet 16d approaches one end of the magnetic field detector 17a, and the north pole magnet 16a becomes the magnetic field detector 17a. When approaching the other end of the magnetic field, the magnetization direction of the outer peripheral portion of the magnetic element 35 of the magnetic field detector 17a is reversed by the magnetic field from the magnet 16a toward the magnet 16d. As a result, the magnetization direction of the magnetic element 35 is the direction from the other end to the one end. Then, due to the reversal of the magnetization direction of the magnetic element 35, a pulse-like detection signal that rises sharply, for example, in the negative direction is output from the coil 36 wound around the magnetic element 35.

  Subsequently, when the magnetic body 18 continues to rotate, the N-pole magnet 16c approaches one end of the magnetic field detector 17a, and the S-pole magnet 16d approaches the other end of the magnetic field detector 17a, the magnet 16c Due to the magnetic field directed toward the magnet 16d, the magnetization direction of the magnetic element 35 of the magnetic field detection unit 17a changes from one end to the other end, and a pulse-like detection signal that rises sharply in the positive direction is output from the coil 36, for example. The

  Further, when the magnetic body 18 continues to rotate, the S-pole magnet 16b approaches one end of the magnetic field detector 17a, and the N-pole magnet 16c approaches the other end of the magnetic field detector 17a, the magnet 16c Due to the magnetic field directed toward the magnet 16b, the magnetization direction of the magnetic element 35 of the magnetic field detection unit 17a changes from the other end to the one end, and a pulsed detection signal that rises sharply in the negative direction is output from the coil 36, for example. .

  The magnetic field detectors 17b and 17c also operate in the same manner as the above magnetic field detector 17a.

(2-2-5. Magnetic field induction function by magnetic member)
Next, the magnetic field induction function by the magnetic members 33 and 34 will be described with reference to FIGS. The magnetic members 33 and 34 of the magnetic field detectors 17a to 17c have a function of inducing a magnetic field applied to the magnetic field detectors 17a to 17c by the magnets 16a to 16d and forming a predetermined magnetic path.

  As shown in FIG. 9, the magnetic body 18 rotates, for example, counterclockwise, the N-pole magnet 16a approaches one end of the magnetic field detector 17a, and the S-pole magnet 16b is the other end of the magnetic field detector 17b. Suppose that it approaches the part. At this time, as shown in FIG. 10, the magnetic member 33 is interposed between the magnet 16a and one end of the magnetic field detector 17a, while between the magnet 16b and the other end of the magnetic field detector 17a. A magnetic member 34 is interposed. Therefore, most of the magnetic flux from the magnet 16a toward the magnet 16b first enters the magnetic member 33 instead of one end of the magnetic field detection unit 17a from the magnet 16a. It advances in the flat plate portion 33a of the magnetic member 33 toward the side. Since the magnetic member 33 and the magnetic member 34 are separated from each other at the intermediate portion in the longitudinal direction of the magnetic field detector 17a, the magnetic flux that has traveled through the flat plate portion 33a of the magnetic member 33 approaches the magnetic member 34, but the magnetic member 34. It does not enter directly, but enters the portion near one end side (left side in FIG. 10) of the intermediate portion of the magnetic field detector 17a. The magnetic flux that has entered the portion closer to one end in the intermediate portion of the magnetic field detection unit 17a travels toward the other end side of the intermediate portion of the magnetic field detection unit 17a, and the other end side of the intermediate portion of the magnetic field detection unit 17a (FIG. (Middle right) Reach the closest part. The magnetic flux that has reached the portion near the other end of the intermediate portion of the magnetic field detector 17a leaves the magnetic field detector 17a and enters the magnetic member 34. The magnetic flux that has entered the magnetic member 34 travels through the flat plate portion 34a of the magnetic member 34 toward the magnet 16b, and reaches the magnet 16b from the magnetic member 34.

  As described above, when the magnet 16a approaches one end of the magnetic field detection unit 17a and the magnet 16b approaches the other end of the magnetic field detection unit 17b, a magnetic field directed from the magnet 16a to the magnet 16b is caused by the magnetic members 34 and 34. As shown by a solid arrow curve in FIG. 10, the magnetic field detection unit 17a is guided to the middle part of the magnetic field detection unit 17a. A magnetic path that proceeds in the order of the magnet 16b is formed. As a result, since most of the magnetic field is applied to the intermediate part of the magnetic field detection unit 17a, the magnetic flux density of the intermediate part of the magnetic field detection unit 17a is compared with the magnetic flux density of one end and the other end of the magnetic field detection unit 17a. And get higher.

  Further, a wide area including a portion facing the magnetic body 18 at one end and the other end of the magnetic field detector 17a is covered with the flat plate portions 33a and 33b of the magnetic members 33 and 34, and one of the magnetic field detectors 17a. The end face (left end face) and the other end face (right end face) are covered with the side plate portions 33b and 34b of the magnetic members 33 and 34. Thus, when the N-pole magnet 16a approaches one end of the magnetic field detection unit 17a and the S-pole magnet 16b approaches the other end of the magnetic field detection unit 17a, the magnetic field detection unit 17a is surrounded by the magnetic field. In the inner space covered with the members 33 and 34, a magnetic path of magnetic flux from one end side to the other end side of the magnetic field detection unit 17a is formed as shown by a broken arrow curve in FIG. This magnetic flux is applied not only to the intermediate portion of the magnetic element 35 but also to one end and the other end of the magnetic element 35. In this case, most of the magnetic flux from the magnet 16a to the magnet 16b travels along the magnetic path indicated by the solid arrow curve in FIG. 10, so the density of the magnetic flux indicated by the broken arrow curve is the solid arrow curve. It is smaller than the magnetic flux density indicated by Therefore, by applying the magnetic flux indicated by the broken arrow curve to the magnetic field detector 17a, the magnetic flux density at the intermediate portion of the magnetic field detector 17a is maintained higher than the magnetic flux density at the one end and the other end. The magnetic flux density of the whole detection part 17a can be increased.

  By applying the magnetic flux as described above to the magnetic field detection unit 17a, the outer peripheral portion of the magnetic element 35 of the magnetic field detection unit 17a is from the direction indicated by the white arrow in FIG. Magnetized in the direction toward the other end. Therefore, when the magnetization direction of the outer peripheral portion of the magnetic element 35 is the direction from the other end portion of the magnetic element 35 to the one end portion, the magnetization direction of the outer peripheral portion of the magnetic element 35 is reversed, For example, a pulse-shaped detection signal that rises sharply in the positive direction is output from the coil 36 wound around the magnetic element 35.

  Subsequently, as shown in FIG. 11, when the magnetic body 18 further rotates 45 ° counterclockwise from the state of FIGS. 9 and 10, and the N-pole magnet 16a approaches the intermediate portion of the magnetic field detection unit 17a, As shown in FIG. 12, since the distance between the magnet 16a and the magnetic member 33 is shorter than the distance between the magnet 16a and the magnetic field detector 17a, most of the magnetic flux from the magnet 16a toward the magnet 16d. Enters the magnetic member 33 from the magnet 16a, not the intermediate portion of the magnetic field detector 17a. The magnetic flux that has entered the magnetic member 33 travels through the magnetic member 33 toward the magnet 16d. Thereby, it can suppress that magnetic flux approachs the magnetic field detection part 17a. In addition, as shown in FIG. 11, the magnetic member 33 on the magnetic field detection unit 17a side and the magnetic member 34 on the magnetic field detection unit 17c side are separated from each other via a gap, so that a large amount of magnetic flux travels through the magnetic member 33. The portion does not enter the magnetic member 34 on the magnetic field detector 17c side.

  When the magnet 16a approaches the intermediate portion of the magnetic field detection unit 17a, the distance between the magnet 16a and the magnetic member 34 is larger than the distance between the magnet 16a and the magnetic field detection unit 17a as shown in FIG. Therefore, most of the magnetic flux from the magnet 16a to the magnet 16b enters the magnetic member 34 from the magnet 16a, not the intermediate portion of the magnetic field detection unit 17a. The magnetic flux that has entered the magnetic member 34 travels through the magnetic member 34 toward the magnet 16b. Thereby, it can suppress that magnetic flux approachs the magnetic field detection part 17a. Further, as shown in FIG. 11, the magnetic member 34 on the magnetic field detection unit 17a side and the magnetic member 33 on the magnetic field detection unit 17b side are separated from each other via a gap, so that a large amount of magnetic flux travels through the magnetic member 34. The portion does not enter the magnetic member 33 on the magnetic field detector 17b side.

  Thus, when the magnet 16a approaches the intermediate part of the magnetic field detection unit 17a, the magnetic flux from the magnet 16a toward the magnets 16d and 16b is guided so as to avoid the magnetic members 33 and 34 from entering the magnetic field detection unit 17a. Is done. As a result, most of the magnetic flux in the magnetic field does not enter the magnetic field detector 17a. Therefore, the magnetization direction of the outer periphery of the magnetic element 35 of the magnetic field detector 17a does not change, and the white arrow indicating the magnetization direction in FIG. 12 is the same as the white arrow indicating the magnetization direction in FIG. Become. Therefore, a pulse-like detection signal is not output from the coil 36 wound around the magnetic element 35.

  Subsequently, as shown in FIG. 13, the magnetic body 18 further rotates 45 ° counterclockwise from the state of FIGS. 11 and 12, the S-pole magnet 16 d approaches one end of the magnetic field detector 17 a, and When the N-pole magnet 16a approaches the other end of the magnetic field detector 17a, the magnetic field from the magnet 16a toward the magnet 16d is induced by the magnetic members 34 and 33, and the solid line arrow curve and the broken line arrow in FIG. The magnetic path indicated by the curve is traced in the reverse direction. That is, most of the magnetic flux from the magnet 16a toward the magnet 16d proceeds in order from the magnet 16a to the magnetic member 34, the intermediate portion of the magnetic field detection unit 17a, and the magnetic member 33, and reaches the magnet 16d. As a result, most of the magnetic flux from the magnet 16a toward the magnet 16d is applied to the intermediate portion of the magnetic field detection unit 17a. It becomes higher than the magnetic flux density of the part. Furthermore, a magnetic path is formed by a relatively small magnetic flux from the other end side to the one end side of the magnetic field detection unit 17a in an inner space around the magnetic field detection unit 17a and covered with the magnetic members 33 and 34. The As a result, the magnetic flux density of the entire magnetic field detector 17a increases while the magnetic flux density at the intermediate portion of the magnetic field detector 17a is maintained higher than the magnetic flux density at one end or the other end of the magnetic field detector 17a. .

  By applying such a magnetic flux to the magnetic field detector 17a, the outer periphery of the magnetic element 35 of the magnetic field detector 17a is magnetized in the direction from the other end of the magnetic element 35 toward one end. Therefore, when the magnetization direction of the outer periphery of the magnetic element 35 is the direction from one end of the magnetic element 35 to the other end, the magnetization direction of the outer periphery of the magnetic element 35 is reversed, For example, a pulse-shaped detection signal that rises sharply in the negative direction is output from the coil 36 wound around the magnetic element 35.

  As described above, according to the magnetic field induction function of the magnetic members 33 and 34, when the magnets 16 having different polarities approach the one end and the other end of the magnetic field detector 17a, the magnetic flux formed by these magnets 16 is increased. The magnetic flux can be induced so as to pass through the intermediate portion rather than the one end and the other end of the magnetic field detector 17a. Moreover, when the magnet 16 approaches the intermediate part of the magnetic field detection part 17a, it can suppress that the magnetic flux formed by this magnet 16 enters into the magnetic field detection part 17a.

  As a result, when a pair of magnets 16 having different polarities approach one end and the other end of the magnetic field detector 17a, the magnetic flux density mainly in the intermediate portion of the magnetic element 35 of the magnetic field detector 17a can be increased. it can. On the other hand, when the magnet 16 approaches the intermediate portion of the magnetic field detection unit 17a, the magnetic flux density of the magnetic element 35 of the magnetic field detection unit 17a can be lowered over the whole. Therefore, the magnetic flux density of the magnetic element 35 of the magnetic field detector 17a can be increased only when the magnets 16 having different polarities approach the one end and the other end of the magnetic field detector 17, respectively. Therefore, the magnetization direction of the magnetic element 35 can be changed only when the magnets 16 having different polarities approach the one end and the other end of the magnetic field detector 17a. That is, it is possible to prevent the magnetization direction of the magnetic element 35 of the magnetic field detection unit 17a from changing during a period in which the magnets 16 having different polarities are not close to the one end and the other end of the magnetic field detection unit 17a, respectively. .

  In the present embodiment, when the encoder 10 includes the magnetic detection mechanism 30 including the magnetic field detection unit 17 that generates the large Barkhausen effect as illustrated, the battery-less encoder can be realized. Detailed explanation of the configuration, operation, and functions of. However, the configuration of the magnetic detection mechanism 30 is not limited to this example. If the magnetic detection mechanism can detect a multi-rotation amount (for example, a magnetic detection mechanism including a magnetoresistive element such as an MR element), Embodiments can achieve the same effects. Furthermore, even in an encoder without a magnetic detection mechanism, the axial dimension of the encoder can be shortened, so that this embodiment can achieve the same effect.

  In the above configuration, the opening 12a is formed in the main substrate 12, and the light source 14 and the light receiving element 15 of the sub-substrate 13 emit light to the disk 11 and receive reflected light through the opening 12a. This corresponds to an example of means for disposing the substrate on the surface of the first substrate opposite to the disk.

<3. Examples of effects according to this embodiment>
As described above, the encoder 10 of the present embodiment includes the disk 11 that rotates together with the motor shaft 102, the main board 12 that is disposed to face the disk 11 and has the opening 12a, and the disk 11 of the main board 12. The sub-substrate 13 is disposed on the surface 12b opposite to the substrate 12 so as to cover at least part of the opening 12a, and is disposed on the surface 13a of the sub-substrate 13 on the disk 11 side in the opening 12a. It has a light source 14 and a light receiving element 15 that is disposed on the surface 13a of the sub-substrate 13 on the disk 11 side in the opening 12a and receives reflected light from the disk 11. Thereby, there exists the following effect.

  That is, generally, the ratio of the optical gap between the light source 14 or the light receiving element 15 of the optical module 21 and the disk 11 is relatively high in the axial dimension of the reflective encoder. Therefore, as in the encoder 10 ′ of the comparative example shown in FIG. 14A, the sub board 13 is arranged on the surface 12c of the main board 12 on the disk 11 side, and the light source 14 and the light receiving light are received on the surface 13a of the sub board 13 on the disk 11 side. When the element 15 or the like is disposed, the distance L between the main substrate 12 and the disk 11 (the distance between the upper surface of the main substrate 12 and the upper surface of the disk 11) increases, and the axial dimension of the encoder 10 ′ increases. . However, if the optical gap G (distance between the light source 14 and the disk 11) is changed in order to reduce the thickness of the encoder 10 ', a complete review of the optical system design of the encoder 10' is required. Equivalent cost and development time may be required.

  In the encoder 10 of the present embodiment, as shown in FIG. 14B, the sub board 13 is disposed on the surface 12 b opposite to the disk 11 of the main board 12, and the disk 11 side of the sub board 13 is located in the opening 12 a of the main board 12. A light source 14 and a light receiving element 15 are arranged on the surface 13a of the light source. As a result, the light source 14 and the light receiving element 15 can be arranged inside the opening 12a of the main substrate 12, so that the distance L between the main substrate 12 and the disk 11 can be set as compared with the comparative example without changing the optical gap G. Can be greatly shortened. As a result, the axial dimension of the encoder 10 can be shortened without causing an increase in cost or development period.

  Further, in the present embodiment, the sub-board 13 is disposed so as to close the opening 12a, and the encoder 10 has a peripheral portion of the opening 12a on the surface 12b opposite to the edge of the sub-board 13 and the disk 11 of the main board 12. In the case where the plurality of connecting portions 19 are connected, the following effects are obtained.

  For example, when the sub board 13 is soldered to the main board 12, in the encoder 10 ′ of the comparative example shown in FIG. 14A, soldering is performed on the surface 12c on the disk 11 side of the main board 12 where the light source 14 and the light receiving element 15 are exposed. And foreign matters such as flux are likely to adhere to the light source 14 and the light receiving element 15. If foreign matter such as flux adheres to the light source 14 or the light receiving element 15, the detection accuracy of the encoder may be affected. For this reason, in order to prevent adhesion of foreign matter, for example, it is preferable to install a cover that covers the light source 14 and the light receiving element 15 when performing soldering.

  In the present embodiment, the sub board 13 is arranged so as to block the opening 12a on the surface 12b of the main board 12 opposite to the disk 11, and the edge of the sub board 13 and the peripheral portion of the opening 12a on the surface 12b side. Are connected by a plurality of connecting portions 19. As a result, while the sub-substrate 13 closes the opening 12a, the light source 14 and the light receiving element 15 can be connected on the surface 12b opposite to the surface 12c on the disk 11 side of the main substrate 12 exposed through the opening 12a. The workability of the connecting work is improved, for example, a clearance with other parts can be secured. In addition, since solder can be used as the connecting portion 19, it is possible to prevent foreign matters such as flux that may be generated from the solder from adhering to the light source 14 and the light receiving element 15, and to prevent the detection accuracy from being lowered. Further, since the parts such as the cover for preventing the adhesion of foreign matters are not necessary, the manufacturing process can be simplified and the cost can be reduced.

  In the present embodiment, the encoder 10 is disposed on the opposite side of the disk 11 from the magnet 16 that is supported so as to rotate together with the motor shaft 102 on the opposite side of the disk 11 from the main board 12. When the magnetic field detection unit 17 that detects the magnetic field of the magnet 16 is provided, the following effects can be obtained.

  That is, the amount of multiple rotations of the motor 100 can be detected by detecting the magnetic field of the magnet 16 by the magnetic field detector 17. Further, in the encoder 10 that detects the amount of multi-rotation, the detection accuracy may be affected, for example, by an induced electromotive force generated in the electronic circuit of the optical module 21 due to leakage magnetic flux from the motor electromagnetic unit 110 or the magnet 16. . In the present embodiment, since the optical module 21 is disposed at a deep position in the opening 12a of the main board 12, the optical module 21 is arranged on the disk 11 of the main board 12 like the encoder 10 ′ of the comparative example shown in FIG. 14A, for example. The influence of the leakage magnetic flux can be reduced as compared with the case where it is arranged so as to protrude to the side.

  In the present embodiment, the magnetic field detection unit 17 includes the magnetic element 35 and the coil 36 that generate the large Barkhausen effect, and is arranged so that the length direction is parallel to the tangential direction of the rotation locus circle R of the magnet 16. The following effects can be achieved.

  That is, with the above configuration, it is possible to generate a voltage using the pulse signal output from the magnetic field detection unit 17, start an electronic circuit using the voltage, and detect the amount of multi-rotation. Therefore, even when the power supply voltage is not supplied from the external power supply, the power consumption can be self-generated, so that a battery-less encoder without a backup power supply (for example, a battery) can be realized.

  In the present embodiment, the encoder 10 is connected to the motor shaft 102, the disk 11 is fixed to the surface 18 c on the main substrate 12 side, and the magnet 16 is fixed to the surface 18 d on the side opposite to the main substrate 12. In addition, when the magnetic body 18 is provided, the following effects are obtained.

  That is, with the above configuration, the disk 11 and the magnet 16 can be supported by the magnetic body 18 that is a common support, and therefore, the thickness can be further reduced as compared with the case where the support is individually provided. In addition, the number of parts and cost can be reduced. Furthermore, since the magnetic flux 18 can reduce the leakage magnetic flux leaking from the motor electromagnetic unit 110 and the magnet 16 to the optical module 21 side, the influence of the leakage magnetic flux on the detection accuracy can be further reduced. In addition, by fixing the magnet 16 to the magnetic body 18, the magnetic path of the magnet 16 can be formed and the magnetic field can be concentrated, so that the detection accuracy by the magnetic field detector 17 can be improved.

  In the present embodiment, the encoder 10 is disposed on the surface 13a of the sub substrate 13 on the disk 11 side in the opening 12a of the main substrate 12, and the integrated circuit 25 having the light receiving element 15 and a predetermined function on the semiconductor wafer 24. In the case where the IC chip 23 is formed, the following effects are obtained.

  That is, when the main board 12 is a double-sided mounting type board on which electronic components are mounted on both sides of the board, the sub board 13 is disposed on the surface 12b of the main board 12 opposite to the disk 11, and the main board 12 There is a problem in that the mounting area of the surface 12b of the main substrate 12 is reduced by adopting a configuration in which light is emitted to and received from the disk 11 through the opening 12a.

  In the present embodiment, an IC chip 23 in which a light receiving element 15 and an integrated circuit 25 having a predetermined function are formed on a semiconductor wafer 24 is mounted on a sub-substrate 13 so that, for example, circuit functions such as an operational amplifier and a comparator are optically applied. The module 21 can be provided. As a result, the optical module 21 can be provided with a function of an electronic component mounted at a position corresponding to the optical module 21 on the surface 12b of the main board 12, thereby reducing the mounting area of the main board 12. The influence can be reduced.

  In the present embodiment, the encoder 10 is disposed on the surface 13 a of the sub-board 13 on the disk 11 side inside the opening 12 a of the main board 12, and electrically connects the sub-board 13 and the light receiving element 15. When the bonding wire 28 is provided, the following effects are obtained.

  That is, since the bonding wire 28 is generally very thin and weak in strength, if the sub-board 13 is arranged on the surface 12c on the disk 11 side of the main board 12 like the encoder 10 'of the comparative example shown in FIG. 14A, the surface 12c As shown in FIG. 14A, for example, a protective member (for example, the frame substrate 9) is preferably installed around the bonding wire 28 exposed on the disk 11 side to protect the bonding wire 28.

  In this embodiment, since the bonding wire 28 can be accommodated inside the opening 12a of the main substrate 12, the bonding wire 28 can be protected without using the frame substrate 9. Therefore, since the frame substrate 9 is not necessary, the configuration can be simplified and the cost can be reduced.

  Moreover, according to the motor 100 of this embodiment, since the encoder 10 which can shorten an axial direction dimension is provided, the whole motor can be reduced in an axial direction.

  In addition, in the above description, when there are descriptions such as “vertical”, “parallel”, and “plane”, the descriptions are not strict. That is, the terms “vertical”, “parallel”, and “plane” are acceptable in design and manufacturing tolerances and errors, and mean “substantially vertical”, “substantially parallel”, and “substantially plane”. .

  In addition, in the above description, when there are descriptions such as “same”, “equal”, “different”, etc., in terms of external dimensions and sizes, the descriptions are not strict. That is, the terms “identical”, “equal”, and “different” mean that “tolerance and error in manufacturing are allowed in design and that they are“ substantially identical ”,“ substantially equal ”, and“ substantially different ”. .

  In addition to those already described above, the methods according to the above embodiments may be used in appropriate combination.

  In addition, although not illustrated one by one, the above-described embodiment is implemented with various modifications within a range not departing from the gist thereof.

10 Motor encoder 11 Disc 12 Main board (an example of the first board)
12a Opening 12b Surface 13 Sub-substrate (an example of a second substrate)
13a surface 14 light source 15 light receiving element 16 magnet 17 magnetic field detection unit 18 magnetic body 18c surface 18d surface 19 connecting unit 24 semiconductor wafer 23 IC chip 25 integrated circuit 28 bonding wire 35 magnetic element 36 coil 100 motor 102 motor shaft 110 motor electromagnetic unit R Rotation locus circle

Claims (8)

A housing;
A disk that rotates with the motor shaft in the housing;
In the housing, a first substrate having an opening formed on the other side in the axial direction than the wall surface on the one side in the axial direction of the housing and facing the one side in the axial direction of the disk;
A second substrate coupled to the first substrate so as to cover at least a part of the previous SL openings,
Disposed in the axial direction other side of the surface to be pre-Symbol the disk side of the second substrate, a light source for emitting light to said disk,
Disposed in the axial direction other side of the surface to be pre-Symbol the disk side of the second substrate, a light receiving element for receiving reflected light from the disk,
A plurality of first terminal portions provided on a surface of the first substrate;
A plurality of second terminal portions provided on a surface of the second substrate;
The first terminal portion and the second terminal portion, which are exposed and provided on one side in the axial direction opposite to the disk of the connected first substrate and the second substrate, and are stacked at right angles. Connecting a plurality of connecting parts made of solder;
A motor encoder characterized by comprising: The second substrate is
Arranged to close the opening,
The plurality of connecting portions are:
The second terminal portion provided on the edge of the second substrate is connected to the first terminal portion provided on the peripheral portion of the opening on the surface of the first substrate opposite to the disk. motor encoder according to claim 1, <br/> be characterized by that. A magnet supported to rotate with the motor shaft on the opposite side of the disk from the first substrate;
3. The motor encoder according to claim 1, further comprising a magnetic field detection unit that is disposed on a side of the disk opposite to the first substrate and detects a magnetic field of the magnet. The magnetic field detector is
4. The motor encoder according to claim 3, further comprising a magnetic element and a coil that generate a large Barkhausen effect, wherein the length direction is parallel to a tangential direction of a rotation locus circle of the magnet. The magnetic shaft is further connected to the motor shaft, the disk is fixed to the surface on the first substrate side, and the magnet is fixed to the surface opposite to the first substrate. The motor encoder according to claim 4. 2. The IC chip according to claim 1, further comprising an IC chip disposed on a surface of the second substrate on the disk side in the opening, wherein the light receiving element and an integrated circuit having a predetermined function are formed on a semiconductor wafer. The encoder for motors of any one of -5. 2. The apparatus according to claim 1, further comprising a plurality of bonding wires disposed on a surface of the second substrate on the disk side inside the opening and electrically connecting the second substrate and the light receiving element. The motor encoder according to claim 6. A motor shaft;
A motor electromagnetic unit for rotating the motor shaft;
A motor comprising: the motor encoder according to claim 1.

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