JP6380589B2 - Optical encoder unit - Google Patents

Description

  The present invention relates to an optical encoder unit using an optical sensor including a light emitting unit and a light receiving unit.

  In general, an optical encoder includes a light emitting unit that emits light, a light receiving unit that detects light emitted from the light emitting unit, and a rotor unit that includes a polarizing plate and the like. In this type of optical encoder, the positional relationship between the light emitting unit and the light receiving unit is important. In particular, in the case of a transmission type encoder, the light emitting unit and the light receiving unit are arranged in the axial direction of the polarizing plate via the polarizing plate. It is necessary to arrange them facing each other. For this reason, in order to establish as an optical sensor, it is necessary to position the light emitting part and the light receiving part at predetermined positions. In order to solve this problem, a light receiving element (light receiving unit) for detecting light, a first circuit board on which the light receiving element is mounted, and a predetermined interval from the first circuit board are conventionally provided. Optical circuit comprising a second circuit board, a light emitting element (light emitting part) for irradiating light to the light receiving element, and a holder for holding the light emitting element, the first circuit board and the second circuit board in one structure. An encoder has been proposed (see, for example, Patent Document 1).

JP 2001-027551 A

  However, in the technique described in Patent Document 1, the light emitting element and the first circuit board having the light receiving element are separate components, and the relationship between the irradiation range of light emitted from the light emitting element and the light receiving range by the light receiving element in assembly is determined. There is a problem that the positioning for doing so must be performed. Furthermore, in the technique described in Patent Document 1, since the positioning of the light emitting element, the first circuit board, and the second circuit board is performed using a holder that is a separate part, the number of parts increases, and the device configuration is increased. There is a problem that becomes complicated.

  It is an object of the present invention to provide an optical encoder unit that has a simple configuration and that allows easier positioning of a light emitting unit and a light receiving unit.

  In order to achieve the above object, an optical encoder unit according to the present invention includes a light emitting unit that emits light, a light receiving unit that detects light emitted from the light emitting unit, a first part provided with the light emitting unit, and a light receiving unit. The second portion to be provided is integrally formed and includes a flexible substrate and a cylindrical housing. The light emitting unit and the light receiving unit each have a bare chip, and the bare chip is flip-chip on the substrate. The board is mounted so that the first part and the second part are parallel to each other, the light emitting part and the light receiving part are arranged to face each other, and the light receiving part is interposed between the light emitting part and the light receiving part. Then, a change in light caused by the rotation of the optical scale whose polarization direction changes due to the rotation is detected, and the casing includes a first casing that operably supports the optical scale, and one of the first part and the second part. A second housing fixed, and the second housing is There are two support portions provided so as to face each other, and the two support portions are an arc-shaped inner peripheral portion that comes into contact with a circular outer peripheral edge of one of the two support portions, and a cylinder of the first housing And an arcuate outer peripheral portion along the inner peripheral surface.

  According to this configuration, the light emitting unit and the light receiving unit can be easily positioned by a simple operation such as bending the substrate so that the first part provided with the light emitting unit and the second part provided with the light receiving unit are parallel to each other. It can be carried out. In addition, since the light emitting unit and the light receiving unit are provided on the same substrate, the configuration of the optical encoder unit can be simplified. Further, the substrate is bent so that the first portion and the second portion are parallel, and the light emitting portion and the light receiving portion are opposed to each other, thereby adjusting the position for accommodating the light receiving portion in the light emitting region of the light emitting portion and the light emitting portion. In addition, it is possible to more easily design the position angle when the light receiving unit is provided on the substrate.

  Further, the substrate and the optical encoder unit can be reduced in size as compared with the case where the light emitting unit and the light receiving unit are configured by package parts. Further, since the bare chip is flip-chip mounted on the substrate, for example, wire bonding and resin sealing required for the face-up type bare chip are not required, and the configuration of the optical encoder unit is simplified. Further, since there is no wire or sealing resin, the distance between the first part and the second part can be reduced while maintaining the distance between the light emitting part and the light receiving part, and the substrate and the optical encoder unit can be made compact. Can be realized.

  Further, the substrate may have a connection portion that connects the first portion and the second portion, and the connection portion may have a wiring that is connected to the light emitting portion or the light receiving portion. According to this configuration, the wiring connected to the light emitting part or the light receiving part and the connecting part can be integrated, and the connecting part and the substrate having the wiring can be made more compact.

  In addition, the substrate may be configured to be bent at the boundary between the first portion and the connection portion and at the boundary between the second portion and the connection portion. According to this configuration, since the bent portion of the substrate can be clarified, the light emitting portion and the light receiving portion can be easily positioned by bending the substrate.

  In addition, the connecting portion is a direction perpendicular to the extending direction of the connecting portion between the first portion and the second portion, as compared with the first portion and the second portion, and a direction along the plate surface of the substrate. The width may be small. According to this configuration, the area of the substrate can be made smaller than when the width of the substrate including the first portion and the second portion sandwiching the connection portion is made uniform. For this reason, a board | substrate can be reduced more.

  Further, the other of the first part or the second part may be supported in a hollow manner by the connecting portion, and the other may be configured to be smaller than the other. According to this configuration, the detection region between the light emitting unit and the light receiving unit can be provided by supporting one of the first part and the second part in a hollow state by the connecting part alone with the connection part. Moreover, the weight of the said one can be made lighter because the said one is smaller than the other. For this reason, in addition to making it possible to make requirements such as strength required for the connection portion easier, the center of gravity of the entire substrate can be brought closer to the other side which is the base. Therefore, the support by the connection portion can be realized more easily.

  Moreover, the board | substrate may be provided with the harness part containing the wiring connected to a light emission part and a light-receiving part. According to this structure, the wiring connected to the structure of the optical encoder unit containing a light emission part and a light-receiving part can be collectively provided in the board | substrate provided with a harness part. That is, by providing the harness portion, it is not necessary to individually draw out wiring from components (circuits or the like) that require wiring. For this reason, it is not necessary to handle the substrate and the wiring separately, and the optical encoder unit can be handled more easily.

  In addition, according to the configuration of the optical encoder unit of the present invention, since the light emitting unit and the light receiving unit can be easily positioned, an optical encoder unit with a simplified apparatus configuration can be realized.

  According to the present invention, the light emitting unit and the light receiving unit can be easily positioned by a simple operation such as bending the substrate so that the first part provided with the light emitting unit and the second part provided with the light receiving unit are parallel to each other. It can be carried out. In addition, since the light emitting unit and the light receiving unit are provided on the same substrate, the configuration of the optical encoder unit can be simplified.

FIG. 1 is a configuration diagram of an optical encoder unit according to this embodiment. FIG. 2 is an external perspective view of the optical encoder unit. FIG. 3 is an explanatory diagram illustrating an example of the arrangement of the light emitting unit, the optical scale, and the light receiving unit. FIG. 4 is a block diagram of the optical encoder according to the present embodiment. FIG. 5 is an explanatory diagram showing an example of an optical scale pattern. FIG. 6 is a perspective view illustrating an example of an optical sensor. FIG. 7 is a plan view of the optical sensor showing a state before the substrate is bent. FIG. 8 is a partially enlarged view of the optical sensor. FIG. 9 is a perspective view illustrating an example of a stator body. FIG. 10 is a perspective view showing an example of a stator chassis. FIG. 11 is a plan view showing an example of a substrate before circuit mounting. FIG. 12 is a diagram illustrating an example of assembling a stator for providing an optical scale in a detection area. FIG. 13 is an explanatory diagram for explaining an example of the light receiving unit. FIG. 14 is an explanatory diagram for explaining an example of the first light receiving unit of the light receiving unit. FIG. 15 is an explanatory diagram for describing an example of a third light receiving unit of the light receiving unit. FIG. 16 is an explanatory diagram for explaining separation of polarization components by the optical scale. FIG. 17 is an explanatory diagram for explaining the separation of polarization components by the optical scale. FIG. 18 is an explanatory diagram for explaining separation of polarization components by the optical scale. FIG. 19 is a functional block diagram of the optical encoder. FIG. 20 is an explanatory diagram for explaining the rotation angle of the optical scale and the change in the light intensity of the polarization component of each light receiving unit. FIG. 21 is an explanatory diagram for explaining the relationship between the rotation angle of the optical scale and the Lissajous angle.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

  FIG. 1 is a configuration diagram of an optical encoder unit 31 according to the present embodiment. FIG. 2 is an external perspective view of the optical encoder unit 31. FIG. 1 is a schematic cross-sectional view of FIG. FIG. 3 is an explanatory diagram illustrating an example of the arrangement of the light emitting unit 41, the optical scale 11, and the light receiving unit 35. FIG. 4 is a block diagram of the optical encoder 2 according to the present embodiment. FIG. 5 is an explanatory diagram showing an example of a pattern of the optical scale 11. The optical encoder unit 31 includes a rotor 10 having a shaft 12 connected to a rotary machine such as a motor, a stator 20, and an optical sensor 40 capable of reading a signal pattern.

  As shown in FIG. 1, the rotor 10 includes a shaft 12 that serves as a rotation axis, and an optical scale 11 that is attached to an end of the shaft 12. The optical scale 11 has a disk shape or a polygonal shape, and is made of, for example, silicon, glass, a polymer material, or the like. The optical scale 11 may be annular or hollow. The optical scale 11 shown in FIG. 5 has a signal track T1 on one plate surface. Even if the optical scale 11 is tilted, it does not affect the polarization separation function when the tilt angle is small. That is, even if the optical scale 11 is inclined with respect to a plane orthogonal to the rotation center Zr (FIG. 1), it functions as a polarization separation element.

  The stator 20 is made of a light-shielding member that surrounds the bearings 26 a and 26 b that support the shaft 12, the shaft 12, the optical scale 11 attached to the end of the shaft 12, and the optical sensor 40. For this reason, external optical noise can be suppressed inside the stator 20. As shown in FIG. 2, the stator 20 includes a body 21, a chassis 22, and a cover 23. The body 21 rotatably supports the shaft 12 via bearings 26a and 26b. The inner periphery of the body 21 is fixed to the outer rings of the bearings 26a and 26b, and the outer periphery of the shaft 12 is fixed to the inner rings of the bearings 26a and 26b. When the shaft 12 is rotated by rotation from a rotating machine such as a motor, the optical scale 11 is rotated about the rotation center Zr in conjunction with the shaft 12. As will be described in detail later, the optical sensor 40 is fixed to the chassis 22 and accommodated in the body 21. When the rotor 10 rotates, the signal track T1 (FIG. 5) of the optical scale 11 is in relation to the optical sensor 40. Move relatively. Next, the optical sensor 40 will be described.

  FIG. 6 is a perspective view showing an example of the optical sensor 40. FIG. 7 is a plan view of the optical sensor 40 showing a state before the substrate 50 is bent. FIG. 8 is a partially enlarged view of the optical sensor 40. FIG. 9 is a perspective view showing an example of the body 21 of the stator 20. FIG. 10 is a perspective view showing an example of the chassis 22 of the stator 20. FIG. 11 is a plan view showing an example of a substrate before circuit mounting. FIG. 12 is a diagram showing an example of assembling the stator 20 for providing the optical scale 11 in the detection area. The optical sensor 40 includes a light emitting unit 41 that generates light, a light receiving unit 35 that detects light generated by the light emitting unit 41 across a detection region, and a substrate 50 on which the light emitting unit 41 and the light receiving unit 35 are provided. . The detected area is an area between the light emitting unit 41 and the light receiving unit 35.

  As shown in FIGS. 6 and 7, the substrate 50 is one substrate including a semicircular arc-shaped first portion 51 and a disk-shaped second portion 52. In the present embodiment, the light emitting unit 41 is provided in the first portion 51, and the light receiving unit 35 is provided in the second portion 52. The substrate 50 is made of, for example, a flexible printed circuit (FPC), and various circuits including the light emitting unit 41 and the light receiving unit 35 (for example, the circuits 60 to 62 shown in FIG. 6) are mounted thereon. More specifically, FPC uses an insulator made of, for example, a polyimide film or a photo solder resist film as a base film, and forms an adhesive layer and a conductor layer on the base film. A wiring board having flexibility in which a portion other than (including) is covered with an insulator. The conductor layer is made of an electrical conductor such as copper, and is provided with signal lines and power lines that are connected to components such as various circuits according to the pattern of the conductor layer. The specific configuration of the flexible substrate that can be employed in the present invention is not limited to this, and can be changed as appropriate. The circuits 60 to 62 constitute, for example, a preamplifier AMP, a differential arithmetic circuit DS, a filter circuit NR, a multiplier circuit AP, and the like shown in FIG.

  The substrate 50 has a connection portion 53 that connects the first portion 51 and the second portion 52. Specifically, as shown in FIGS. 6 and 7, the connecting portion 53 is between the first portion 51 and the second portion 52, and the outer peripheral portion of the arc of the first portion 51 and the arc of the second portion 52. It is provided so that the outer peripheral part may be connected. The connection part 53 has wiring (not shown) connected to the light emitting part 41 (or the light receiving part 35). In the present embodiment, the connection unit 53 includes a signal line, a power line, and a GND line (ground line) connected to the light emitting unit 41. Specifically, the wiring of the connection unit 53 is provided as a signal line, a power line, and a GND line mounted on, for example, an FPC. For this reason, these signal lines, power lines, and GND lines can be shared with the light receiving unit 35. In addition, although the circuit is not provided in the connection part 53 of this embodiment, components, such as a circuit, can also be provided in the connection part 53. FIG.

  As shown in FIGS. 6 and 7, the connecting portion 53 of the present embodiment has a connecting portion 53 between the first portion 51 and the second portion 52 as compared with the first portion 51 and the second portion 52. The width in the direction perpendicular to the extending direction of the substrate 50 and along the plate surface of the substrate 50 is small.

  The substrate 50 includes a harness part 54 including wiring connected to the light emitting part 41 and the light receiving part 35. Specifically, as shown in FIGS. 6 and 7, the harness portion 54 is provided so as to extend from the first portion 51 to the opposite side of the connection portion 53. The harness section 54 includes signal lines and power lines connected to various circuits provided on the light emitting section 41, the light receiving section 35, and the substrate 50. Specifically, the wiring of the harness portion 54 is provided as, for example, a signal line and a power line mounted on the FPC. In the present embodiment, the wiring of the light emitting unit 41 is provided in the first portion 51, the connection portion 53, and the harness portion 54. In addition, the wiring of the light receiving unit 35 is provided in the second portion 52 and the harness portion 54. By adopting such a configuration, it is not necessary to newly connect a harness portion to the substrate 50, so that improvement in connection reliability is expected. In addition, when the first portion 51 and the second portion 52 are separate bodies (separate substrates), it is necessary to pull out the harness portion from each substrate, but in this configuration, all wiring from the first portion 51 is required. Therefore, it is possible to improve the embeddability.

  Moreover, the harness part 54 is connected with the connector CNT as shown, for example in FIG. The connector CNT is an interface that connects the optical encoder unit 31 and another device (for example, the arithmetic device 3). The optical encoder unit 31 is connected to the arithmetic device 3 via the connector CNT. That is, the harness portion 54 functions as a wiring that connects various circuits provided on the substrate 50 and another device (for example, the arithmetic device 3). In addition, you may provide components, such as a circuit, in the harness part 54. FIG.

  The substrate 50 is provided so that the first portion 51 and the second portion 52 are parallel to each other. Specifically, as shown in FIGS. 1 and 6, the substrate 50 is bent into a shape (a U-shape) in which the light emitting unit 41 and the light receiving unit 35 face each other. In the present embodiment, the substrate 50 is bent at a boundary 55 a between the first portion 51 and the connection portion 53 and a boundary 55 b between the second portion 52 and the connection portion 53 as predetermined positions. That is, the substrate 50 of this embodiment is bent so that the first portion 51 and the second portion 52 are perpendicular to the connection portion 53, and the first portion 51 and the second portion 52 are opposed to each other. Exist. The light emitting unit 41 and the light receiving unit 35 are positioned so as to face each other on a normal line (not shown) penetrating the first portion 51 and the second portion 52 when the substrate 50 is bent at a right angle at the boundaries 55a and 55b. The first portion 51 and the second portion 52 are provided in advance. For this reason, the light emission part 41 and the light-receiving part 35 can be arrange | positioned in a predetermined position only by bending the boundary 55a, 55b which is a predetermined bending location. In this configuration, the parallel is not only a state in which the first portion 51 and the second portion 52 are completely parallel, but also an inclination that allows the light receiving portion 35 to sufficiently detect the light emitted from the light emitting portion 41. Shall be included.

  The surface on the side where the light emitting unit 41 is provided in the first portion 51 and the surface on the side where the light receiving unit 35 is provided in the second portion 52 are the same surface on the substrate 50. Since the surface on the side where the light emitting unit 41 is provided and the surface on the side where the light receiving unit 35 is provided are opposed to each other, the positional relationship between the light emitting unit 41 and the light receiving unit 35 is as shown in FIG. The light emitted by the light emitting unit 41 has a positional relationship that can be detected by the light receiving unit 35. Further, a region between the light emitting unit 41 and the light receiving unit 35 facing each other is a detection target region.

  One of the first portion 51 or the second portion 52 is supported hollowly by the connection portion 53, and one is smaller than the other. Specifically, as shown in FIG. 6, the first portion 51 provided with the light emitting portion 41 is supported in a hollow manner by the connecting portion 53. Further, as shown in FIGS. 6 and 7, the first portion 51 is smaller than the second portion 52. More specifically, the diameter of the arc-shaped first portion 51 in the present embodiment is substantially the same as the diameter of the circular second portion 52. However, the first portion 51 has a semicircular arc shape, and a semicircular cutout 51a is provided on the inner peripheral side of the semicircular FPC. For this reason, the area of the first portion 51 occupying the substrate 50 is smaller than the area of the second portion 52.

  In the present embodiment, as shown in FIG. 8, the light emitting unit 41 includes a light emitting element bare chip 63, and the light receiving unit 35 includes a light receiving element bare chip 65. In general, since the bare chip is smaller than the package component, the substrate 50 and the optical sensor 40 can be downsized by adopting the bare chip for the light emitting unit 41 and the light receiving unit 35.

  As a method for mounting the bare chip on the substrate, there is a technique of wire bonding to the chip surface electrode and connecting to the substrate. However, the optical sensor 40 of this configuration is bent so that the first portion 51 and the second portion 52 of the substrate 50 are parallel to each other, and the light emitting portion 41 provided in the first portion 51 and the light receiving provided in the second portion 52. The part 35 is opposed. Further, the optical scale 11 is interposed in the detection area between the light emitting unit 41 and the light receiving unit 35. For this reason, when the method of mounting the bare chip by wire bonding is adopted, the wire is very thin, several tens (μm), and is weak against external force. Therefore, when the wire is exposed, the optical scale 11 at the time of assembling the optical sensor 40 There is a concern about wire breakage due to the interference. Further, even when the wire portion is protected with a sealing resin, since the target to be sealed is an optical element, it is difficult to seal with a resin so as to cover the light emitting element bare chip 63 and the light receiving element bare chip 65. There is.

  For this reason, in this configuration, the light emitting element bare chip 63 and the light receiving element bare chip 65 include bumps 64 and 66 formed of solder on the arrangement surfaces 63a and 65a on the substrate 50, respectively. On the other hand, on the substrate 50, land portions 67 and 68 are provided at target arrangement positions on the arrangement target surfaces 51b and 52b of the first portion 51 and the second portion 52, respectively. When the light emitting element bare chip 63 and the light receiving element bare chip 65 are mounted on the substrate 50, the substrate 50 is performed before being bent as shown in FIG. That is, the arrangement target surfaces 51b and 52b which are the same side surfaces of the substrate 50 and the arrangement surfaces 63a and 65a of the light emitting element bare chip 63 and the light receiving element bare chip 65 are opposed to the arrangement target surfaces 51b and 52b. A light emitting element bare chip 63 and a light receiving element bare chip 65 are respectively arranged. In this case, the positions of the bumps 64 and 66 of the light emitting element bare chip 63 and the light receiving element bare chip 65 are made to coincide with the positions of the land portions 67 and 68 (FIG. 8) provided on the arrangement target surfaces 51b and 52b. In this state, the substrate 50, the light emitting element bare chip 63, and the light receiving element bare chip 65 are put into a reflow furnace and heated, whereby the bumps 64, 66 of the light emitting element bare chip 63 and the light receiving element bare chip 65 are placed on the arrangement target surfaces 51b, 52b. By welding to the provided land portions 67 and 68, the light emitting element bare chip 63 and the light receiving element bare chip 65 are soldered and mounted (flip chip mounting). This eliminates the need for wire bonding and resin sealing required for face-up type bare chips, and simplifies the configuration of the optical sensor 40. Further, since there is no wire or sealing resin, the arrangement target surfaces of the first portion 51 and the second portion 52 are maintained while maintaining the distance (detected region) between the light emitting element bare chip 63 and the light receiving element bare chip 65. The distance between 51b and 52b can be made small, and size reduction of the board | substrate 50 and the optical sensor 40 is realizable. Further, since the light emitting element bare chip 63 and the light receiving element bare chip 65 are mounted on the substrate 50, the first portion 51 and the second portion 52 of the substrate 50 are bent at the aforementioned boundaries 55a and 55b so as to be parallel. The light emitting element bare chip 63 and the light receiving element bare chip 65 can be easily positioned.

  As shown in FIGS. 9 and 10, the body 21 has an opening 21 a for attaching the chassis 22 provided with the substrate 50 to the body 21. The chassis 22 supports the substrate 50 by contacting at least a part of the surface (back surface) opposite to the side where the light receiving unit 35 is provided in the second portion 52 of the substrate 50. Specifically, an integrated circuit (for example, an IC of a QFN package) as a component constituting the optical encoder unit 31 is provided on the back surface of the substrate 50. The chassis 22 supports the substrate 50 by covering the integrated circuit on the back surface from the outside and contacting the outer peripheral portion of the back surface of the substrate 50. The connection portion 53 of the substrate 50 bent in a U-shape is positioned so as to stand up from the second portion 52 supported by the chassis 22. Thus, in this embodiment, the substrate 50 is fixed to the chassis 22. The cover 23 is a member that forms a part of the cylindrical outer peripheral surface of the stator 20. The cover 23 is provided on the opening 21 a side of the body 21, that is, on the opposite side of the notch 21 b where the harness portion 54 extends from the chassis 22. In the state where the body 21 and the chassis 22 are assembled, the cover 23 is further assembled so as to cover the opening 21a, so that the body 21, the chassis 22 and the cover 23 form a cylindrical stator 20, and the stator 20 The inside is shielded from external light noise.

  In the optical encoder unit 31, when the shaft 12 of the rotor 10 described above rotates, the optical scale 11 moves relative to the light receiving unit 35 in the R direction, for example, as shown in FIG. Thereby, the signal track T <b> 1 of the optical scale 11 moves relative to the light receiving unit 35. In the optical scale 11, the polarization direction Pm of the polarizer in the plane is in a predetermined direction, and the polarization direction Pm is changed by rotation. The light receiving unit 35 receives incident light (transmitted light) 73 that is incident after the light source light 71 of the light emitting unit 41 is transmitted through the optical scale 11 and can read the signal track T1 of the optical scale 11 shown in FIG. .

  The optical encoder 2 includes the optical encoder unit 31 and the arithmetic device 3 described above, and the optical encoder unit 31 and the arithmetic device 3 are connected as shown in FIG. The arithmetic device 3 is connected to a control unit 5 of a rotating machine such as a motor.

  In the optical encoder 2, the light receiving unit 35 detects incident light 73 that is incident on the optical scale 11 through the light source light 71. The calculation device 3 calculates the relative position between the rotor 10 of the optical encoder unit 31 and the light receiving unit 35 from the detection signal of the light receiving unit 35, and uses the information on the relative position as a control signal to control the rotating unit 5 such as a motor. Output to.

  The arithmetic device 3 is a computer such as a personal computer (PC), for example, and includes an input interface 4a, an output interface 4b, a CPU (Central Processing Unit) 4c, a ROM (Read Only Memory) 4d, and a RAM (Random Access Memory). 4e and an internal storage device 4f. The input interface 4a, output interface 4b, CPU 4c, ROM 4d, RAM 4e, and internal storage device 4f are connected by an internal bus. Note that the arithmetic device 3 may be configured by a dedicated processing circuit.

  The input interface 4a receives an input signal from the light receiving unit 35 of the optical encoder unit 31, and outputs it to the CPU 4c. The output interface 4 b receives a control signal from the CPU 4 c and outputs it to the control unit 5.

  A program such as BIOS (Basic Input Output System) is stored in the ROM 4d. The internal storage device 4f is, for example, an HDD (Hard Disk Drive), a flash memory, or the like, and stores an operating system program and application programs. The CPU 4c implements various functions by executing programs stored in the ROM 4d and the internal storage device 4f while using the RAM 4e as a work area.

  The internal storage device 4f stores a database in which the polarization direction Pm of the optical scale 11 and the output of the light receiving unit 35 are associated with each other. Alternatively, the internal storage device 4f stores a database in which a value of distance D described later is associated with position information of the optical scale 11.

  In the signal track T1 shown in FIG. 5, an array of fine metal wires (wires) g called a wire grid pattern is formed on the optical scale 11 shown in FIG. The optical scale 11 linearly arranges adjacent fine metal wires g as signal tracks T1 in parallel. For this reason, the optical scale 11 has the same polarization axis regardless of the position where the light source light 71 is irradiated, and the polarization direction of the polarizer in the plane is in one direction.

  In addition, the optical scale 11 having the fine metal wires g called wire grid patterns can improve heat resistance as compared with a light-induced polarizing plate. In addition, since the optical scale 11 is a line pattern that does not have a portion that intersects locally, the optical scale 11 can be highly accurate and have few errors. Moreover, since the optical scale 11 can be stably manufactured by batch exposure or nanoimprint technology, the optical scale 11 can be made highly accurate and less error-prone. The optical scale 11 may be a light-induced polarizing plate.

  The plurality of fine metal wires g are arranged without intersecting. Between adjacent metal fine wires g is a transmission region d through which all or part of the light source light 71 can be transmitted. When the width of the fine metal wire g and the interval between the adjacent fine metal wires g, that is, the width of the fine metal wire g and the width of the transmission region d are sufficiently smaller than the wavelength of the light source light 71 of the light emitting unit 41, the optical scale 11 71 incident light 73 can be polarized and separated. For this reason, the optical scale 11 has a polarizer in which the in-plane polarization direction Pm is uniform. In the rotating circumferential direction of the optical scale 11, the polarization axis of the incident light 73 incident on the light receiving unit 35 changes according to the rotation of the optical scale 11. In the present embodiment, the change in the polarization axis repeats the increase / decrease twice for one rotation of the optical scale 11.

  The optical scale 11 does not need to be finely divided into segments having different polarization directions. And since the optical scale 11 has the uniform polarization direction Pm, there is no boundary of the area | region from which the polarization direction Pm differs, and it can suppress disorder of the polarization state of the incident light 73 by this boundary. The optical encoder 2 of the present embodiment can reduce the possibility of causing false detection or noise.

  FIG. 13 is an explanatory diagram for explaining an example of the light receiving unit 35. FIG. 14 is an explanatory diagram for describing an example of the first light receiving unit PD1 of the light receiving unit 35. FIG. 15 is an explanatory diagram for explaining an example of the third light receiving unit PD3 of the light receiving unit 35 according to the present embodiment. As illustrated in FIGS. 3 and 13, the light receiving unit 35 includes a first light receiving unit PD1 having a polarizing layer PP1, a second light receiving unit PD2 having a polarizing layer PP2, and a polarization on the surface 30b of the unit base 30. A third light receiving part PD3 having a layer PP3 and a fourth light receiving part PD4 having a polarizing layer PP4 are included. The first light receiving part PD1 to the fourth light receiving part PD4 are configured to include the light receiving element bare chip 65 (see FIG. 8). In this case, when the light receiving element bare chip 65 is mounted on the second portion 52 of the substrate 50, the first light receiving part PD1 to the fourth light receiving part PD4 are positioned and mounted in advance so that the polarization directions thereof are different from each other. As shown in FIG. 13, the first light receiving part PD1, the second light receiving part PD2, the third light receiving part PD3, and the fourth light receiving part PD4 are equidistant from the arrangement center S0 of the surface 30b of the unit base member 30 in plan view. Has been placed.

  The light emitting unit 41 is, for example, a light emitting diode or a semiconductor laser light source. As shown in FIG. 3, the light source light 71 emitted from the light emitting unit 41 passes through the optical scale 11 described above, and enters the polarizing layer PP1, the polarizing layer PP2, the polarizing layer PP3, and the polarizing layer PP4 as the incident light 73. The light passes through and enters the first light receiving part PD1, the second light receiving part PD2, the third light receiving part PD3, and the fourth light receiving part PD4.

  As shown in FIG. 3, it is preferable that the distances from the first light receiving part PD1, the second light receiving part PD2, the third light receiving part PD3, and the fourth light receiving part PD4 to the arrangement center S0 are equal. With this structure, it is possible to reduce the calculation load on the CPU 4c which is the calculation means.

  Further, the first light receiving part PD1 is arranged at a point-symmetrical position with respect to the third light receiving part PD3 via the arrangement center S0, and the second light receiving part PD2 is point-symmetrical with the fourth light receiving part PD4 via the arrangement center S0. Is arranged. The first light receiving unit PD1 is arranged at a distance W from the third light receiving unit PD3 via the arrangement center S0, and the second light receiving unit PD2 is arranged at a distance W from the fourth light receiving unit PD4 through the arrangement center S0. Has been. Note that there is a width w that the first light receiving part PD1, the third light receiving part PD3, the second light receiving part PD2, and the fourth light receiving part PD4 have, and there is a restriction that the distance W is not smaller than the width 2w. In the present embodiment, the virtual axis on the surface 30b of the unit substrate 30 that passes through the first light receiving part PD1, the placement center S0, and the third light receiving part PD3 is the x axis, and the second light receiving part PD2, the placement center S0, and the first light receiving part PD2. The virtual axis on the surface 30b of the unit base material 30 passing through the four light receiving parts PD4 is taken as the y axis. In FIG. 13, the x axis is orthogonal to the y axis on the surface 30 b of the unit substrate 30. As shown in FIG. 3, let D be the distance between the emission surface of the light emitting section 41 and the arrangement center S0. The xy plane formed by the x-axis and the y-axis is orthogonal to the z-axis connecting the emission surface of the light emitting unit 41 and the arrangement center S0.

  As shown in FIG. 3, each of the first light receiving unit PD1, the second light receiving unit PD2, the third light receiving unit PD3, and the fourth light receiving unit PD4 is arranged around the light emitting unit 41 when viewed in plan from the z-axis direction. Has been. It is preferable that the distances from the first light receiving part PD1, the second light receiving part PD2, the third light receiving part PD3, and the fourth light receiving part PD4 to the arrangement center S0 are equal. With this structure, it is possible to reduce the calculation load on the CPU 4c which is the calculation means.

  As shown in FIG. 14, the first light receiving portion PD1 includes a silicon substrate 34, a light receiving semiconductor 37, and a first polarizing layer 39a. As shown in FIG. 15, the third light receiving portion PD3 includes a silicon substrate 34, a light receiving semiconductor 37, and a second polarizing layer 39b. For example, the silicon substrate 34 is an n-type semiconductor, the light receiving semiconductor 37 is a p-type semiconductor, and a photodiode formed by a PN junction with the silicon substrate 34 and the light receiving semiconductor 37 can be configured. The first polarizing layer 39a and the second polarizing layer 39b can be formed of a light-induced polarizing layer or a wire grid pattern in which fine metal wires are arranged in parallel. The first polarizing layer 39a separates the incident light 73 incident from the light source light 71 into the optical scale 11 shown in FIG. 3 in the first polarization direction, and the second polarizing layer 39b separates the incident light 73 into the second polarized light. Separate in direction. It is preferable that the polarization axis of the first separated light and the polarization axis of the second separated light are relatively different by 90 °. With this configuration, the CPU 4c of the arithmetic device 3 can easily calculate the polarization angle.

  Similarly, with reference to FIGS. 14 and 15, the second light receiving portion PD2 includes a silicon substrate 34, a light receiving semiconductor 37, and a first polarizing layer 39a. As shown in FIG. 15, the fourth light receiving portion PD4 includes a silicon substrate 34, a light receiving semiconductor 37, and a second polarizing layer 39b. For example, the silicon substrate 34 is an n-type semiconductor, the light receiving semiconductor 37 is a p-type semiconductor, and a photodiode formed by a PN junction with the silicon substrate 34 and the light receiving semiconductor 37 can be configured. The first polarizing layer 39a and the second polarizing layer 39b can be formed of a light-induced polarizing layer or a wire grid pattern in which fine metal wires are arranged in parallel. The first polarizing layer 39a separates the incident light 73 incident from the light source light 71 into the optical scale 11 shown in FIG. 3 in the first polarization direction, and the second polarizing layer 39b separates the incident light 73 into the second polarized light. Separate in direction. It is preferable that the polarization axis of the first separated light and the polarization axis of the second separated light are relatively different by 90 °. With this configuration, the CPU 4c of the arithmetic device 3 can easily calculate the polarization angle.

  The first light receiving unit PD1, the second light receiving unit PD2, the third light receiving unit PD3, and the fourth light receiving unit PD4 receive the incident light 73 through the polarization layers PP1, PP2, PP3, and PP4 that separate the different polarization directions, respectively. . For this reason, it is preferable that the polarization axis separated by the polarizing layer PP1 and the polarization axis separated by the polarizing layer PP2 are relatively different by 45 °. It is preferable that the polarization axis separated by the polarizing layer PP2 and the polarization axis separated by the polarizing layer PP3 are relatively different by 45 °. It is preferable that the polarization axis separated by the polarizing layer PP3 and the polarization axis separated by the polarizing layer PP4 are relatively different by 45 °. It is preferable that the polarization axis separated by the polarization layer PP4 and the polarization axis separated by the polarization layer PP1 are relatively different by 45 °. With this configuration, the CPU 4c of the arithmetic device 3 can easily calculate the polarization angle.

  16, FIG. 17 and FIG. 18 are explanatory diagrams for explaining the separation of polarization components by the optical scale 11 according to the present embodiment. As shown in FIG. 16, incident light polarized in the polarization direction Pm is incident by the signal track T1 of the optical scale 11. In FIG. 16, the sensing range includes foreign matter D1 and foreign matter D2. The polarization direction Pm of incident light can be expressed by the light intensity PI (−) of the first polarization direction component and the light intensity PI (+) of the second polarization direction component. As described above, the first polarization direction and the second polarization direction are preferably different from each other by 90 °, and are, for example, a + 45 ° component and a −45 ° component with respect to the reference direction. . 16, 17 and 18, the axial direction of the wire grid is shown parallel to the paper surface. However, even if the wire grid is inclined at the same angle with respect to the paper surface, it is polarized when the inclination angle is small. The separation function is not affected. That is, even if the optical scale 11 is inclined with respect to the rotation axis, it functions as a polarization separation element.

  As shown in FIG. 17, the first light receiving unit PD1 detects incident light through the first polarizing layer 39a that separates the incident light in the first polarization direction, and thus the light intensity PI (− of the component in the first polarization direction). ) Is detected. As shown in FIG. 18, since the third light receiving unit PD3 detects incident light through the second polarizing layer 39b that separates the incident light in the second polarization direction, the light intensity PI (+ of the component in the second polarization direction) ) Is detected. Similarly, as shown in FIG. 17, since the second light receiving unit PD2 detects incident light via the first polarizing layer 39a that separates the incident light in the first polarization direction, the light intensity of the component in the first polarization direction is detected. PI (-) is detected. As shown in FIG. 18, the fourth light receiving unit PD4 detects incident light via the second polarizing layer 39b that separates the incident light in the second polarization direction. Therefore, the light intensity PI (+ of the component in the second polarization direction) ) Is detected.

  FIG. 19 is a functional block diagram of the optical encoder 2 according to the present embodiment. FIG. 20 is an explanatory diagram for explaining the rotation angle of the optical scale 11 and the light intensity change of the polarization component of each light receiving unit according to the present embodiment. As shown in FIG. 19, the light emitting unit 41 emits light based on the reference signal and irradiates the optical scale 11 with the light source light 71. Incident light 73 that is transmitted light is received by the light receiving unit 35. The differential arithmetic circuit DS performs differential arithmetic processing using the detection signal output from the light receiving unit 35 and amplified by the preamplifier AMP. The preamplifier AMP can be omitted according to the output level of the light receiving unit 35.

  The differential arithmetic circuit DS detects the light intensity PI (−) of the first polarization direction component (first separated light) and the second polarization direction component (second separated light), which are detection signals of the light receiving unit 35. ) Of the light intensity PI (+). The respective outputs of the first light receiving part PD1, the second light receiving part PD2, the third light receiving part PD3, and the fourth light receiving part PD4 corresponding to the light intensity PI (−) and the light intensity PI (+) are, for example, As shown in FIG. 19, the light intensities I1, I2, I3, and I4 are out of phase according to the rotation of the optical scale 11.

The differential arithmetic circuit DS calculates the optical intensity from the light intensity PI (−) of the component in the first polarization direction and the light intensity PI (+) of the component in the second polarization direction according to the expressions (1) and (2). The differential signals Vc and Vs depending on the rotation of the scale 11 are calculated.
Vc = (I1-I3) / (I1 + I3) (1)
Vs = (I2-I4) / (I2 + I4) (2)

  In this way, the differential operation circuit DS calculates the light intensity sum [I1 + I3] and the light intensity difference [I1-I3] based on the light intensity I1 and the light intensity I3, and the light intensity difference [I1 -I3] is divided by the sum of light intensities [I1 + I3] to calculate a differential signal Vc. Further, the differential operation circuit DS calculates the light intensity sum [I2 + I4] and the light intensity difference [I2-I4] based on the light intensity I2 and the light intensity I4, and the light intensity difference [I2-I4]. ] Is calculated by dividing the light intensity by the sum [I2 + I4] of the light intensity. The differential signals Vc and Vs calculated by the equations (1) and (2) do not include a parameter affected by the light intensity of the light source light 71, and the output of the optical encoder unit 31 is the light receiving unit. It is possible to reduce the influence of the distance between the optical scale 11 and the optical scale 11 and the variation in the light intensity of the light emitting unit 41. The differential signals Vc and Vs are a function of the rotation angle (hereinafter referred to as the polarization angle) β of the polarization axis of the optical scale 11 that is the rotation angle of the optical scale 11. However, the above-described division is not necessary when an automatic power control (APC) that controls the light amount of the light source provided in the light emitting unit 41 to be constant is provided.

  As shown in FIG. 19, the differential signals Vc and Vs are input to the filter circuit NR and noise is removed. Next, the multiplication circuit AP can calculate the Lissajous pattern shown in FIG. 21 from the differential signals Vc and Vs, and can specify the absolute angle of the rotation angle of the rotor 10 rotated from the initial position. Since the differential signals Vc and Vs are differential signals having a phase shift of λ / 4, a Lissajous pattern with the cosine curve of the differential signal Vc on the horizontal axis and the sine curve of the differential signal Vs on the vertical axis is used. The Lissajous angle is determined according to the calculation and the rotation angle. For example, the Lissajous pattern shown in FIG. 21 makes two turns when the rotor 10 makes one revolution. The arithmetic device 3 has a function of storing whether the rotation position of the optical scale 11 is in the range of 0 ° or more and less than 180 ° or in the range of 180 ° or more and less than 360 °. Thereby, the optical encoder 2 can be an absolute encoder capable of calculating the absolute position of the rotor 10.

  Next, a method for manufacturing the optical encoder unit 31 will be described. First, the optical sensor 40 having the substrate 50 in which the first portion 51 where the light emitting portion 41 is provided and the second portion 52 where the light receiving portion 35 is provided is formed. Specifically, for example, as shown in FIG. 11, a semicircular arc-shaped first portion 51, a circular second portion 52, a connection portion 53 that connects the first portion 51 and the second portion 52, An FPC having a harness portion 54 extending from the first portion 51 to the opposite side of the connection portion 53 is formed. In this step, wiring such as signal lines and power lines connected to various circuits mounted on the substrate 50 in a later step is formed in the FPC.

  Next, various circuits constituting the optical sensor 40 are provided on the substrate 50. Specifically, as shown in FIG. 7, the light emitting portion 41 is provided in the first portion 51 of the substrate 50, and the light receiving portion 35 is provided in the second portion 52 of the substrate 50. In the present embodiment, each of the light emitting unit 41 and the light receiving unit 35 includes a light emitting element bare chip 63 and a light receiving element bare chip 65, and the light emitting element bare chip 63 and the light receiving element bare chip 65 are bent as shown in FIG. Implemented before it is made. Specifically, the positions of the bumps of the light emitting element bare chip 63 and the light receiving element bare chip 65 are made to coincide with the positions of the land portions provided on the arrangement target surfaces 51b and 52b on the same side of the substrate 50, and light emission is performed. The element bare chip 63 and the light receiving element bare chip 65 are arranged on the arrangement target surfaces 51b and 52b. In this state, the substrate 50, the light emitting element bare chip 63, and the light receiving element bare chip 65 are placed in a reflow furnace and heated, so that bumps of the light emitting element bare chip 63 and the light receiving element bare chip 65 are provided on the arrangement target surfaces 51b and 52b. The light emitting element bare chip 63 and the light receiving element bare chip 65 are soldered and mounted (flip chip mounting) by being welded to the land portions. In the present embodiment, four light receiving element bare chips 65 are mounted on the second portion 52 in, for example, a two-row by two-column grid pattern. In this case, it is preferable to arrange the polarization layers of the light receiving element bare chip 65 so that the polarization directions thereof are different by 45 °, for example. In addition to this, various components constituting the sensor are provided in this step in accordance with the wiring provided in the previous step.

  Next, the substrate 50 is bent so that the light emitting unit 41 and the light receiving unit 35 face each other. Specifically, for example, as shown in FIG. 6, the first portion 51 and the second portion 52 are bent in a U shape so as to be parallel. Thereby, the light-emitting part 41 (light-emitting element bare chip 63) and the light-receiving part 35 (light-receiving element bare chip 65) mounted in advance are arranged to face each other in a positioned state.

  Next, an opening through which the substrate 50 can be inserted is provided in the direction along the plate surface of the optical scale 11 at the position where the optical scale 11 is provided on the cylindrical outer peripheral surface of the stator 20. The optical scale 11 is provided in the detection area as 50 enters. In this case, the board | substrate 50 approachs by being inserted from the harness part 54 side with respect to an opening part. Further, a semicircular arc-shaped first portion 51 enters the side of the optical scale 11 where the rotor 10 extends, and a circular second portion 52 extends on the side of the optical scale 11 where the rotor 10 does not extend. enter in. More specifically, as shown in FIG. 12, the chassis 22 to which the second portion 52 is fixed and the body 21 on which the rotor 10 is rotatably provided are connected to the first portion 51, the second portion 52, and the optical device. It is assumed that the scale 11 is substantially parallel and the optical scale 11 is positioned in the detection area between the first portion 51 and the second portion 52. That is, the first portion 51, the second portion 52, and the optical scale 11 are in a positional relationship along a predetermined plane. With this positional relationship, the body 21 and the chassis 22 are assembled by bringing the body 21 and the chassis 22 into close contact with each other along a predetermined plane so that the chassis 22 enters from the opening 21a of the body 21. Thereby, the optical scale 11 is provided in the detection area. The harness portion 54 extends from a cutout portion 21 b provided on the opposite side of the opening 21 a of the body 21. Thereafter, the cover 23 is attached so as to cover the opening 21 a of the body 21. In FIG. 12, illustration of some circuits such as the light receiving unit 35 is omitted, but in practice, various circuits including the light receiving unit 35 are already mounted. The chassis 22 and the cover 23 may be integrated.

  As described above, according to the present embodiment, the light emitting unit 41 that emits light, the light receiving unit 35 that detects the light emitted from the light emitting unit 41, the first portion 51 provided with the light emitting unit 41, and the light receiving unit. The second portion 52 provided with the first portion 35 is integrally formed and has a flexible substrate 50. The substrate 50 is bent so that the first portion 51 and the second portion 52 are parallel to each other. 41 and the light receiving unit 35 are arranged to face each other, so that the light emitting unit 41 and the light receiving unit 35 are positioned by a simple operation such as bending the substrate 50 so that the first portion 51 and the second portion 52 are parallel to each other. It can be done easily. Further, since the light emitting unit 41 and the light receiving unit 35 are provided on the same substrate 50, the configuration of the optical sensor 40 can be simplified. Further, the substrate 50 is bent at the boundaries 55a and 55b so that the first portion 51 and the second portion 52 are parallel, and the light emitting portion 41 and the light receiving portion 35 are opposed to each other, so that the light emitting portion 41 has a light emitting region. The position adjustment for accommodating the light receiving unit 35 and the design regarding the position angle when the light emitting unit 41 and the light receiving unit 35 are provided on the substrate 50 can be more easily performed.

  Further, according to the present embodiment, the light emitting unit 41 includes the light emitting element bare chip 63, the light receiving unit 35 includes the light receiving element bare chip 65, and these bare chips are flip-chip mounted on the substrate 50. The substrate 50 and the optical sensor 40 can be downsized as compared with the case where the light emitting unit 41 and the light receiving unit 35 are configured by package parts. Further, since the light emitting element bare chip 63 and the light receiving element bare chip 65 are flip-chip mounted on the substrate 50, for example, wire bonding and resin sealing required for the face-up type bare chip are unnecessary, and the optical sensor 40 The configuration is simplified. Furthermore, since there is no wire or sealing resin, the distance between the first portion 51 and the second portion 52 can be reduced while maintaining the light emitting portion 41 and the light receiving portion 35, and the substrate 50 and the optical sensor 40 can be reduced. Can be reduced in size.

  Further, according to the present embodiment, the substrate 50 includes the connection portion 53 that connects the first portion 51 and the second portion 52, and the connection portion 53 is a wiring that is connected to the light emitting portion 41 or the light receiving portion 35. Therefore, the wiring connected to the light emitting part 41 or the light receiving part 35 and the connecting part 53 can be integrated, and the connecting part 53 and the substrate 50 having the wiring can be made more compact.

  In addition, according to the present embodiment, the substrate 50 is bent at the boundary 55a between the first portion 51 and the connection portion 53 and at the boundary 55b between the second portion 52 and the connection portion 53. Therefore, the positioning of the light emitting unit 41 and the light receiving unit 35 by bending the substrate 50 can be easily performed.

  In addition, according to the present embodiment, the connection portion 53 has the first portion 51 and the second portion sandwiching the connection portion 53 because the width of the connection portion 53 is smaller than that of the first portion 51 and the second portion 52. The area of the substrate can be made smaller than when the width of the substrate including the portion 52 is made uniform. For this reason, a board | substrate can be reduced more.

  In addition, according to the present embodiment, the first portion 51 is supported hollow by the connection portion 53, and the first portion 51 is smaller than the second portion 52. A detection area between the light emitting unit 41 and the light receiving unit 35 can be provided by being supported in a hollow shape. Further, since the first portion 51 is smaller than the second portion 52, the weight of the first portion 51 can be further reduced. For this reason, in addition to making it possible to make requirements such as strength required for the connection portion 53 easier, it is possible to bring the center of gravity of the entire substrate closer to the second portion 52 side that is the base. Therefore, the support by the connecting portion 53 can be realized more easily.

  In addition, according to the present embodiment, the substrate 50 is bent into a shape (for example, a U-shape) in which the light emitting unit 41 and the light receiving unit 35 face each other, so ) Can be arranged along a part of the substrate 50 (for example, the second portion 52, etc.).

  Further, according to the present embodiment, since the substrate 50 is a flexible substrate, a component including the light emitting unit 41 and the light receiving unit 35 is mounted on the substrate 50 in a state where the first portion 51 and the second portion 52 are on the same plane. Then, a series of operations of processing the substrate 50 to provide a detection area between the light emitting unit 41 and the light receiving unit 35 can be performed more easily.

  Further, according to the present embodiment, the substrate includes the harness portion 54 including the wiring connected to the light emitting portion 41 and the light receiving portion 35, so that the optical encoder unit 31 including the light emitting portion 41 and the light receiving portion 35 on the substrate can be used. Wirings connected to the configuration can be collectively provided. That is, by providing the harness portion 54, it is not necessary to individually draw out wiring from components (circuits or the like) that require wiring. For this reason, it is not necessary to handle the substrate and the wiring separately, and the sensor can be handled more easily.

  In addition, according to the present embodiment, since the optical sensor 40 and the optical scale 11 that is interposed between the light emitting unit 41 and the light receiving unit 35 and whose polarization direction is changed by rotation are provided, the light emitting unit 41 and the light receiving unit are provided. The optical encoder unit 31 can be easily positioned with respect to the portion 35 and the apparatus configuration can be simplified.

  The positional relationship between the first portion 51 and the second portion 52 may be reversed. That is, the light emitting part 41 and the first part 51 may be provided on the chassis 22 side, and the light receiving part 35 and the second part 52 may be provided on the side supported by the connection part 53 so as to sandwich the detection area.

  Moreover, the 1st part 51 and the 2nd part 52 do not need to be parallel. The relationship between the first part 51 and the second part 52 is that a detection area can be provided between the light emitting part 41 and the light receiving part 35, and the detection target generated by the light emitting part 41 provided in the first part 51. Can be detected by the light receiving unit 35 provided in the second portion 52, and the detailed arrangement of the first portion 51 and the second portion 52 can be appropriately changed.

  The connection part 53 does not need to have wiring. In this case, the connection part 53 supports either the 1st part 51 or the 2nd part 52 in hollow, for example. Moreover, it is not essential that the said one is smaller than the other. The first portion 51 and the second portion 52 may be the same size, or the side supported by the connection portion 53 may be large. Moreover, the stator 20 etc. may have a support part for supporting at least one of the connection part 53 and the 1st part 51 in this embodiment. Moreover, you may provide the structure (For example, latching parts, such as an adhesive agent, a tape, a protrusion, etc.) for fixing at least one of the connection part 53 and the 1st part 51 in this embodiment to the support part which concerns.

  The bending position of the substrate 50 is not limited to the boundary 55 a between the first portion 51 and the connection portion 53 and the boundary 55 b between the second portion 52 and the connection portion 53. For example, a connecting portion 53 including a fold may be provided between the first portion 51 and the second portion 52 separately. The substrate 50 is not limited to a flexible substrate. In the substrate of the present invention, a detection region can be provided between the light emitting unit 41 and the light receiving unit 35, and a detection target generated by the light emitting unit 41 provided in the first portion 51 is provided in the second portion 52. Any substrate can be used as long as it can be detected by the light receiving unit 35 and the first portion 51 and the second portion 52 are integrated. For example, a substrate made of a material that can be bent by a process such as heating is adopted, and the process is applied to the part between the first part and the second part (for example, a connection part) and bent. You may make it make 1 part and 2nd part oppose. Moreover, you may employ | adopt the board | substrate which has both a part which is hard to deform | transform, and a part which is easy to deform | transform like a rigid flexible substrate. In this case, the first part and the second part are used by using the part that is not easily deformed and the part that is easily deformed as a part between the first part and the second part (for example, a connection part). The second portion can be opposed.

  The harness portion 54 may be omitted as appropriate. Moreover, the extension part which functions as a harness part may be two or more.

DESCRIPTION OF SYMBOLS 2 Optical encoder 10 Rotor 11 Optical scale 12 Shaft 20 Stator 21 Body 22 Chassis 23 Cover 31 Optical encoder unit 35 Light-receiving part 40 Optical sensor 41 Light-emitting part 50 Board | substrate 51 1st part 52 2nd part 53 Connection part 54 Harness part 55a 55b Boundary (predetermined position)
63 Light emitting element bare chip 64, 66 Bump 65 Light receiving element bare chip

Claims (6)

A light emitting unit that emits light;
A light receiving portion for detecting light emitted from the light emitting portion;
A first portion where the light emitting portion is provided and a second portion where the light receiving portion is provided, and a flexible substrate;
A cylindrical housing,
The light emitting unit and the light receiving unit each have a bare chip, and the bare chip is flip-chip mounted on the substrate,
Bend the substrate so that the first part and the second part are parallel, and arrange the light-emitting part and the light-receiving part facing each other,
The light receiving unit is interposed between the light emitting unit and the light receiving unit to detect a change in light caused by rotation of an optical scale whose polarization direction is changed by rotation,
The housing includes a first housing that operably supports the optical scale, a second housing to which one of the first portion or the second portion is fixed, and an opening that the first housing has. And a cover for closing
The second housing has two support portions provided so as to face each other with the one in between.
The two support portions, possess an arcuate inner peripheral portion in contact with the circular outer peripheral edge the one having, an arcuate outer peripheral portion along the cylindrical inner peripheral surface of the first housing ,
The opening is bent so that the first portion and the second portion are parallel to each other, and the one side is fixed to the second housing, and the two support portions are An optical encoder unit provided so as to be insertable along a radial direction of a rotation shaft of an optical scale .   The said board | substrate has a connection part which connects the said 1st part and the said 2nd part, and the said connection part has the wiring connected to the said light emission part or the said light-receiving part. The optical encoder unit described in 1.   The optical encoder unit according to claim 2, wherein the substrate is bent at a boundary between the first portion and the connection portion and a boundary between the second portion and the connection portion.   The connecting portion is in a direction perpendicular to the extending direction of the connecting portion between the first portion and the second portion, as compared to the first portion and the second portion, and 4. The optical encoder unit according to claim 2, wherein a width in a direction along the plate surface is small.   The other of said 1st part or said 2nd part is supported by the said connection part in hollow, and said other is smaller than one, The Claim 1 characterized by the above-mentioned. Optical encoder unit.   The optical encoder unit according to any one of claims 1 to 5, wherein the substrate includes a harness portion including a wiring connected to the light emitting portion and the light receiving portion.

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