Light-receiving element and rotation detector

Abstract

The present application suppresses distortion of a signal for a light-receiving element and reduces wasted space. The light-receiving element has a plurality of light-receiving unit groups (21g) arranged in an arrangement direction at a predetermined arrangement pitch. The light-receiving unit group (21g) has a first light-receiving unit (211) and a second light-receiving unit (212). The first light-receiving unit (211) has a first main phase portion and a first sub phase portion having a width of 1 / 3 of the arrangement pitch. The first light-receiving unit (211) is divided into a first main body portion (211a) and a first divided portion (211b) each having a width of less than 1 / 4 of the arrangement pitch in the arrangement direction. The second light-receiving unit (212) is divided into a second main body portion (212a) and a second divided portion (212b) each having a width of less than 1 / 4 of the arrangement pitch in the direction of arrangement. The first main body portion (211a) and the second main body portion (212a) are arranged in the arrangement direction, and the first divided portion (211b) and the second divided portion (212b) are arranged in the arrangement direction.

Description

Technical Field

[0001] This invention relates to light-receiving elements and rotating detectors. Background Technology

[0002] In the past, in rotation detectors or linear displacement detectors, it is known to use structures that include optical components such as light-emitting parts and light-receiving elements. For example, in the rotation detector described in Patent Document 1, an incremental pattern light-receiving part is formed by combining a photoelectric conversion element and a slit, thereby improving the resolution.

[0003] Furthermore, in the detector described in Patent Document 1, the width of the slit is set to 1 / 3 of the slit pitch, and two slits with such width are arranged offset from each other by 1 / 12 of the slit pitch. This aims to suppress distortion of the signal obtained in the incremental light-receiving section (offset from the sine wave).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5927482 Summary of the Invention

[0007] In the detector described in Patent Document 1, the maximum width of the slit is 5 / 12 of the slit pitch, which is larger than 1 / 4 of the slit pitch. Therefore, when the detector receives two signals with a 90-degree phase difference corresponding to 1 / 4 of the slit pitch, if the two slits corresponding to the two signals are arranged at a 1 / 4 slit pitch interval, the two slits will interfere with each other. Therefore, it is necessary to arrange the two slits at a pitch larger than 1 / 4 of the slit pitch (e.g., a 5 / 4 slit pitch). Consequently, wasted space is generated between the two slits. Therefore, there may be cases where a sufficient number of slits cannot be arranged within the predetermined space.

[0008] The present invention was made to solve such problems, and its purpose is to provide a light-receiving element that can suppress signal distortion and reduce wasted space, and a rotating detector having the light-receiving element.

[0009] One embodiment of the light-receiving element of the present invention includes a plurality of light-receiving portions arranged in a predetermined arrangement direction at a predetermined arrangement pitch. Each of the plurality of light-receiving portions has a first light-receiving portion and a second light-receiving portion, the second light-receiving portion being disposed at a position offset from the first light-receiving portion in the arrangement direction by 1 / 4 of the arrangement pitch. The first light-receiving portion has a first main phase portion and a first sub-phase portion. The first main phase portion has a width of 1 / 3 of the arrangement pitch in the arrangement direction. The first sub-phase portion has a width of 1 / 3 of the arrangement pitch in the arrangement direction. Furthermore, the first sub-phase portion is disposed at a position offset from the first main phase portion in the arrangement direction by 1 / 12 of the arrangement pitch and is adjacent to the first main phase portion in a vertical direction perpendicular to the arrangement direction. The second light-receiving portion has a second main phase portion and a second sub-phase portion. The second main phase portion has a width of 1 / 3 of the arrangement pitch in the arrangement direction. The second sub-phase portion has a width of 1 / 3 of the arrangement pitch in the arrangement direction. Furthermore, the second sub-phase portion is positioned at a location offset from the second main phase portion by 1 / 12 of the arrangement pitch in the arrangement direction and adjacent to the second main phase portion in the vertical direction. The first light-receiving portion is separated into a first main body portion and a first separating portion, each with a width in the arrangement direction less than 1 / 4 of the arrangement pitch. The first main body portion and the first separating portion are arranged separately in the vertical direction. The second light-receiving portion is separated into a second main body portion and a second separating portion, each with a width in the arrangement direction less than 1 / 4 of the arrangement pitch. The second main body portion and the second separating portion are arranged separately in the vertical direction. The first main body portion and the second main body portion are arranged in the arrangement direction, and the gap between the first main body portion and the second main body portion is less than 1 / 4 of the arrangement pitch. The first separating portion and the second separating portion are arranged in the arrangement direction, and the gap between the first separating portion and the second separating portion is less than 1 / 4 of the arrangement pitch.

[0010] One embodiment of the rotating detector of the present invention includes: the aforementioned light-receiving element; a light-emitting portion that emits light; and a rotating plate disposed opposite to the light-receiving element, wherein the light is irradiated onto the plurality of light-receiving portion groups via the rotating plate.

[0011] According to the present invention, a light-receiving element and a rotating detector that can suppress signal distortion and reduce wasted space can be realized. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view showing the structure of the electric motor equipped with the rotary detector of Embodiment 1.

[0013] Figure 2 This is a top view of the rotating plate included in the rotating detector of Embodiment 1.

[0014] Figure 3 The image is an enlarged view of a portion of the patterned portion of the rotating plate of the rotating detector in Embodiment 1.

[0015] Figure 4 This is a top view of the light-receiving element in Embodiment 1.

[0016] Figure 5 This is a top view showing the structure of the light-receiving part assembly of the light-receiving element in Embodiment 1.

[0017] Figure 6 This diagram shows the state in which the first main body and the first separation part of the first light-receiving part of the light-receiving element of Embodiment 1 are arranged on the same circumference.

[0018] Figure 7 This is a top view showing the structure of the first light-receiving part of the light-receiving element in Embodiment 2.

[0019] Figure 8 This is a top view showing the structure of the first light-receiving part of the light-receiving element in Embodiment 3.

[0020] Figure 9 This is a top view showing the structure of the first light-receiving part of the light-receiving element in Embodiment 4. Detailed Implementation

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below represent specific examples of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, and connection methods shown in the following embodiments are illustrative and not intended to limit the present invention. Therefore, the constituent elements of the following embodiments that are not described in the independent claims representing the highest concept of the present invention will be described as arbitrary constituent elements.

[0022] In addition, the figures are schematic diagrams and are not necessarily strictly illustrative. Furthermore, in each figure, structures that are substantially the same as those in other figures are labeled with the same reference numerals, and repeated descriptions are omitted or simplified.

[0023] (Implementation Method 1)

[0024] The light-receiving element and rotating detector of Embodiment 1 will be described.

[0025] [1-1. Overall Structure]

[0026] First, use Figure 1This section describes the overall structure of the light-receiving element and the rotating detector in this embodiment.

[0027] Figure 1 This is a cross-sectional view showing the structure of the motor 1 equipped with the rotary detector 10 of this embodiment. Figure 1 The figure shows a cross section passing through the rotation axis A of motor 1.

[0028] like Figure 1 As shown, the electric motor 1 mainly includes a motor frame 2, a stator 3, a rotor 4, a rotating shaft 5, a bearing 7, and a rotation detector 10.

[0029] The motor frame 2 is a housing that houses the stator 3 and rotor 4, etc. The stator 3 is fixed to the inner surface of the motor frame 2. The rotor 4 is mounted on the motor frame 2 by means of bearings 7 in a manner that allows it to rotate relative to the stator 3.

[0030] The rotating shaft 5 is a rod-shaped member fixed to the inner surface of the rotor 4 and rotates about the rotation axis A. The rotating shaft 5 is fixed to the motor frame 2 by means of a bearing 7 in a manner that allows it to rotate relative to the motor frame 2. For example, when power is supplied to the motor 1, the rotating shaft 5 rotates together with the rotor 4 about the rotation axis A as the center of rotation based on this power. A rotation detector 10 is provided at one end of the rotating shaft 5 along its axial direction. A load (not shown) or the like, driven and rotated by the rotation of the rotating shaft 5, is mounted at the other end of the rotating shaft 5 along its axial direction. For example, the rotating shaft 5 is formed of a magnetic metal such as iron.

[0031] Bearing 7 is a component fixed to the motor frame 2 and supporting the rotating shaft 5 so that it can rotate relative to the motor frame 2. Figure 1 In this case, a bearing 7 is disposed near one end of the rotating shaft 5, but a bearing may also be disposed near the other end of the rotating shaft 5.

[0032] The rotation detector 10 detects the rotation of the object being detected. Specifically, the rotation detector 10 detects the position (rotational position), the direction of rotation, and the rotational speed of the object. In this embodiment, the object being detected is the rotation axis 5. That is, the rotation detector 10 detects the position, direction of rotation, and rotational speed of the rotation axis 5.

[0033] As described above, the rotation detector 10 is disposed at one end of the rotation shaft 5. The rotation detector 10 includes a light-receiving element 20, a light-emitting part 14, and a rotating plate 40. In this embodiment, the rotation detector 10 also includes a substrate 12, a frame 6, a hub 8, a bolt 9, and a screw 13.

[0034] The frame 6 is a cylindrical member mounted to the motor frame 2 in such a way that it covers one end of the rotating shaft 5 along its axial direction and the rotating plate 40. In this embodiment, the frame 6 is fixed to the motor frame 2 together with the base plate 12 using screws 13.

[0035] The rotating plate 40 is a plate fixed to the rotating shaft 5 by means of a hub 8 and rotating about the rotation axis A as the center of rotation. It has a main body 42 and a patterned part 50. The main body 42 has a plate-like shape with its thickness direction along the rotation axis A. Furthermore, the main body 42 has an annular shape when viewed from the direction along the rotation axis A. The main body 42 is mounted at one end of the rotating shaft 5 in the axial direction and rotates together with the rotating shaft 5 about the rotation axis A as the center of rotation. The axis of the main body 42 coincides with the rotation axis A.

[0036] The pattern section 50 is a light modulation section disposed on the path (i.e., the optical path) of light transmitted from the light-emitting section 14 to the light-receiving element 20. In this embodiment, the pattern section 50 is disposed between the end edge of the main body 42 and the rotation axis A, and is positioned opposite to the light-emitting section 14 and the light-receiving element 20. A light modulation pattern is formed on the circumference of the pattern section 50 centered on the rotation axis A. In this embodiment, the pattern section 50 has portions with higher reflectivity and portions with lower reflectivity for light from the light-emitting section 14 formed in a predetermined pattern. The rotating plate 40 is made of stainless steel, for example, and a coating with lower reflectivity is formed on the low-reflectivity portions of the pattern section 50. The detailed structure of the pattern section 50 will be described later.

[0037] Hub 8 is a component to which the rotating plate 40 is fixed. In this embodiment, a through hole is formed in the center of hub 8. Hub 8 is fixed to rotating shaft 5 by bolts 9 inserted into the through hole, and rotates together with rotating shaft 5 about the rotation axis A as the center of rotation.

[0038] Bolt 9 is a component that secures hub 8 to rotating shaft 5. In this embodiment, bolt 9 is an internal hex bolt.

[0039] The substrate 12 is a plate-shaped member disposed separately from the rotating plate 40 at a position opposite to the rotating plate 40. A light-receiving element 20 and a light-emitting part 14 are disposed on the main surface of the substrate 12 opposite to the rotating plate 40. In this embodiment, the substrate 12 is fixed to the motor frame 2 via the frame 6 using screws 13.

[0040] The light-emitting part 14 is a light source that emits light. The light-emitting part 14 is positioned opposite the patterned part 50 of the rotating plate 40. The structure of the light-emitting part 14 is not particularly limited as long as it can emit light. In this embodiment, the light-emitting part 14 is a light-emitting diode (LED) disposed on the substrate 12. More specifically, the light-emitting part 14 is disposed on a light-receiving element 20 disposed on the substrate 12. The light-emitting part 14 may also be included in the light-receiving element 20. That is, the light-receiving element 20 may also include the light-emitting part 14.

[0041] The light-receiving element 20 is an element that receives light from the light-emitting unit 14. Light from the light-emitting unit 14 is irradiated onto the light-receiving element 20 via the rotating plate 40. In this embodiment, the light from the light-emitting unit 14 is reflected by the patterned portion 50 of the rotating plate 40 and then irradiates the light-receiving element 20. The detailed structure of the light-receiving element 20 will be described later.

[0042] [1-2. Structure of the pattern section]

[0043] use Figure 2 and Figure 3 The detailed structure of the patterned portion 50 of the rotating plate 40 of the rotating detector 10 of this embodiment will be explained. Figure 2 This is a top view of the rotating plate 40 included in the rotating detector 10 of this embodiment. Figure 2 This is a top view taken from the side of the rotating plate 40 opposite to the light-receiving element 20, viewed along the direction of the rotation axis A. Figure 3 The image is an enlarged view of a portion of the patterned portion 50 of the rotating plate 40 included in the rotating detector 10 of this embodiment. Figure 3 yes Figure 2 An enlarged view of the interior of dashed box III shown.

[0044] like Figure 2 and Figure 3 As shown, the patterned portion 50 is disposed on the surface of the rotating plate 40 opposite to the light-receiving element 20. The patterned portion 50 is disposed on a circumference centered on the rotation axis A. In this embodiment, the patterned portion 50 includes a first patterned portion 51, a second patterned portion 52, a third patterned portion 53, and a fourth patterned portion 54. The first patterned portion 51, the second patterned portion 52, the third patterned portion 53, and the fourth patterned portion 54 are arranged sequentially starting from the end edge side of the rotating plate 40.

[0045] like Figure 3As shown, the first patterned portion 51 includes a plurality of low-reflectivity regions 51a. The plurality of low-reflectivity regions 51a are formed, for example, by a coating with low reflectivity to light from the light-emitting portion 14. The plurality of low-reflectivity regions 51a form an incremental pattern. The plurality of low-reflectivity regions 51a have the same rectangular (or fan-shaped) shape and are arranged at equal intervals on a circumference centered on the rotation axis A. The number of the plurality of low-reflectivity regions 51a is not particularly limited; in this embodiment, it is 512.

[0046] The second patterned portion 52 includes a plurality of low-reflection regions 52a. These low-reflection regions 52a are formed, for example, by a coating with low reflectivity to light from the light-emitting portion 14. The plurality of low-reflection regions 52a form an absolute pattern. In this embodiment, the plurality of low-reflection regions 52a are randomly arranged on the circumference of the rotating plate 40 centered on the rotation axis A. The light-receiving element 20, by receiving light from the light-emitting portion 14 modulated by the plurality of low-reflection regions 52a, is able to determine the absolute position of the rotating plate 40 in the circumferential direction centered on the rotation axis A.

[0047] The third patterned section 53 includes a plurality of low-reflection regions 53a. These low-reflection regions 53a are formed, for example, by a coating with low reflectivity to light from the light-emitting section 14. The plurality of low-reflection regions 53a form an absolute pattern. In this embodiment, the plurality of low-reflection regions 53a are randomly arranged on the circumference of the rotating plate 40 centered on the rotation axis A, similar to the plurality of low-reflection regions 52a of the second patterned section 52.

[0048] The fourth pattern section 54 includes a plurality of low-reflection regions 54a. These low-reflection regions 54a are formed, for example, by a coating with low reflectivity to light from the light-emitting section 14. The fourth pattern section 54 is used to detect the rotational speed of the rotating plate 40. In this embodiment, the plurality of low-reflection regions 54a have an arc-shaped shape extending circumferentially along the rotation axis A on the rotating plate 40. Each of the plurality of low-reflection regions 54a has an arc-shaped shape with a central angle of 180 degrees. The number of the plurality of low-reflection regions 54a is not particularly limited; in this embodiment, there are four low-reflection regions 54a, each having an arc-shaped shape with a different radius. The four low-reflection regions 54a are arranged at positions 90 degrees apart from each other, centered on the rotation axis A.

[0049] [1-3. Structure of the light-receiving element]

[0050] use Figure 4 Explain the structure of the light-receiving element 20. Figure 4 This is a top view of the light-receiving element 20 in this embodiment. Figure 4 This is a top view observed from the side of the light-receiving element 20 opposite to the rotating plate 40, viewed along the direction of the rotation axis A.

[0051] The light-receiving element 20 is an element having multiple light-receiving portions, which are areas for detecting light. The light-receiving element 20 is, for example, a plate-shaped element having a semiconductor layer. The multiple light-receiving portions of the light-receiving element 20 are formed, for example, by adding impurities to the semiconductor layer. The light-receiving element 20 includes an incremental detection unit 21. In this embodiment, the light-receiving element 20 further includes a first absolute detection unit 23, a second absolute detection unit 22, and a rotational speed detection unit 24.

[0052] The incremental detection unit 21 is a light detection unit that outputs detection signals incrementally. Light from the light-emitting unit 14 is mainly irradiated onto the incremental detection unit 21 via the first patterned portion 51 of the rotating plate 40. The incremental detection unit 21 includes a plurality of light-receiving portion groups 21g arranged at fixed intervals along a predetermined direction. In this embodiment, the plurality of light-receiving portion groups 21g are arranged on a circumference centered on the rotation axis A. The detailed structure of each of the plurality of light-receiving portion groups 21g will be described later. Furthermore, hereafter, the arrangement distance between two adjacent light-receiving portion groups 21g is defined as the arrangement pitch P0, and the direction in which the plurality of light-receiving portion groups 21g are arranged is referred to as the arrangement direction. The arrangement direction is along the circumference centered on the rotation axis A.

[0053] The first absolute detection unit 23 is a detection unit that outputs a detection signal in an absolute manner. Light from the light-emitting unit 14 is mainly irradiated onto the first absolute detection unit 23 via the third patterned portion 53 of the rotating plate 40. The first absolute detection unit 23 has a plurality of first absolute light-receiving portions 23a. The plurality of first absolute light-receiving portions 23a are arranged on a first circumference with a first radius centered on the rotation axis A. The plurality of light-receiving portion groups 21g are disposed only on the outer diameter side (i.e., only on the side away from the rotation axis A) of the plurality of first absolute light-receiving portions 23a. The plurality of light-receiving portion groups 21g are concentric with the first circumference of the first radius on which the plurality of first absolute light-receiving portions 23a are arranged, and are arranged on a second circumference with a second radius larger than the first circumference. The plurality of first absolute light-receiving portions 23a do not overlap with the plurality of light-receiving portion groups 21g.

[0054] The second absolute detection unit 22 is a detection unit that outputs detection signals in an absolute manner. Light from the light-emitting unit 14 is mainly irradiated onto the second absolute detection unit 22 via the second patterned part 52 of the rotating plate 40. The second absolute detection unit 22 has a plurality of second absolute light-receiving parts 22a. The plurality of second absolute light-receiving parts 22a are arranged on a fourth circumference that is concentric with the first circumference and has a fourth radius that is larger than the first radius and smaller than the second radius. The plurality of second absolute light-receiving parts 22a do not overlap with the plurality of light-receiving part groups 21g and the plurality of first absolute light-receiving parts 23a.

[0055] The rotation speed detection unit 24 is a detection unit that outputs a detection signal corresponding to the rotation speed of the rotating plate 40. Light from the light-emitting unit 14 is mainly irradiated onto the rotation speed detection unit 24 via the fourth patterned portion 54 of the rotating plate 40. The rotation speed detection unit 24 has one or more arc-shaped light-receiving portions 24a. The arc-shaped light-receiving portions 24a are concentric with the first circumference (that is, centered on the rotation axis A) and are arranged on a third circumference with a third radius smaller than the first radius. The width of the arc-shaped light-receiving portions 24a in the direction of the third circumference is greater than the width of the plurality of first absolute light-receiving portions 23a in the direction of the first circumference. In this embodiment, the rotation speed detection unit 24 has four arc-shaped light-receiving portions 24a with different radii. The four arc-shaped light-receiving portions 24a do not overlap with the first absolute light-receiving portions 23a.

[0056] In this embodiment, the light-emitting part 14 is disposed on the light-receiving element 20. The light-emitting part 14 is disposed between the first absolute detection part 23 and the second absolute detection part 22.

[0057] [1-4. Structure of the light-receiving part group]

[0058] use Figure 5 This describes the multiple light-receiving parts 21g of the light-receiving element 20. Figure 5 This is a top view showing the structure of the light-receiving part group 21g in this embodiment.

[0059] like Figure 5 As shown, the light-receiving assembly 21g includes a first light-receiving portion 211 and a second light-receiving portion 212. The second light-receiving portion 212 is positioned at a position offset from the first light-receiving portion 211 in the arrangement direction by 1 / 4 of the arrangement pitch P0. In this embodiment, the light-receiving assembly 21g also includes a third light-receiving portion 213 and a fourth light-receiving portion 214. The third light-receiving portion 213 is positioned at a position offset from the first light-receiving portion 211 in the arrangement direction by 1 / 2 of the arrangement pitch P0 and from the second light-receiving portion 212 in the arrangement direction by 1 / 4 of the arrangement pitch P0. The fourth light-receiving portion 214 is positioned at a position offset from the first light-receiving portion 211 in the arrangement direction by 3 / 4 of the arrangement pitch P0 and from the third light-receiving portion 213 in the arrangement direction by 1 / 4 of the arrangement pitch P0. Light from the light-emitting portion 14 is mainly irradiated onto the light-receiving assembly 21g via the first patterned portion 51 of the rotating plate 40. As the rotating plate 40 rotates, the first pattern section 51 periodically modulates the intensity of the light from the light-emitting section 14. Therefore, the intensity of the light irradiating the light-receiving section assembly 21g changes periodically. The phases of the intensity modulation of the light irradiating the second light-receiving section 212, the third light-receiving section 213, and the fourth light-receiving section 214 are offset from the phases of the intensity modulation of the light irradiating the first light-receiving section 211 by 90 degrees, 180 degrees, and 270 degrees, respectively.

[0060] The first light-receiving portion 211 is separated into a first main body portion 211a and a first separating portion 211b, whose width in the arrangement direction D1 is less than 1 / 4 of the arrangement pitch P0. The first main body portion 211a and the first separating portion 211b are arranged separately in a vertical direction D2 perpendicular to the arrangement direction D1. In this embodiment, the arrangement direction D1 is along the circumference of a circle centered on the rotation axis A and passing through the plurality of light-receiving portion groups 21g. The vertical direction D2 is radially within a circle centered on the rotation axis A.

[0061] The second light-receiving part 212 is separated into a second main body part 212a and a second separation part 212b, whose width in the arrangement direction D1 is less than 1 / 4 of the arrangement pitch P0. The second main body part 212a and the second separation part 212b are arranged separately in the vertical direction D2.

[0062] The third light-receiving part 213 is separated into a third main body part 213a and a third separation part 213b, whose widths in the arrangement direction D1 are respectively less than 1 / 4 of the arrangement pitch P0. The third main body part 213a and the third separation part 213b are arranged separately in the vertical direction D2.

[0063] The fourth light-receiving part 214 is separated into a fourth main body part 214a and a fourth separation part 214b, whose widths in the arrangement direction D1 are respectively less than 1 / 4 of the arrangement pitch P0. The fourth main body part 214a and the fourth separation part 214b are arranged separately in the vertical direction D2.

[0064] Here, use Figure 6 Explain the structure of the first light-receiving part 211. Figure 6 This diagram shows the state in which the first main body 211a and the first separation part 211b of the first light-receiving part 211 of this embodiment are arranged on the same circumference.

[0065] like Figure 6 As shown, with the first main body portion 211a and the first separation portion 211b of the first light-receiving portion 211 arranged on the same circumference, the first light-receiving portion 211 has a first main phase portion 211m and a first sub-phase portion 211s. The first main phase portion 211m has a width of 1 / 3 of the arrangement pitch P0 in the arrangement direction D1. The first sub-phase portion 211s has a width of 1 / 3 of the arrangement pitch P0 in the arrangement direction D1. Furthermore, the first sub-phase portion 211s is positioned at a position offset from the first main phase portion 211m by 1 / 12 of the arrangement pitch P0 in the arrangement direction D1 and is adjacent to the first main phase portion 211m in the vertical direction D2.

[0066] Since the first main phase section 211m of the first light-receiving section 211 has a width of 1 / 3 of the arrangement pitch P0 in the arrangement direction D1, the first main phase section 211m outputs a trapezoidal wave-shaped periodic signal when the rotating plate 40 rotates. Similarly, the first sub-phase section 211s also outputs a trapezoidal wave-shaped periodic signal. Furthermore, since the first sub-phase section 211s is positioned at a position offset from the first main phase section 211m by 1 / 12 of the arrangement pitch P0 in the arrangement direction D1, the signal output by the first sub-phase section 211s is phase-shifted by 30 degrees (i.e., 360 degrees / 12) relative to the signal output by the first main phase section 211m. The signal output by the first light-receiving section 211 is the sum of the signal output by the first main phase section 211m and the signal output by the first sub-phase section 211s. Therefore, the waveform of the signal output by the first light-receiving section 211 becomes a waveform composed of two trapezoidal waves, which is closer to a sine wave than a trapezoidal wave, i.e., a waveform with less distortion.

[0067] The second light-receiving portion 212, like the first light-receiving portion 211, has a second main phase portion and a second sub-phase portion when the second main body portion 212a and the second separation portion 212b are arranged on the same circumference. The second main phase portion has a width of 1 / 3 of the arrangement pitch P0 in the arrangement direction D1. The second sub-phase portion also has a width of 1 / 3 of the arrangement pitch P0 in the arrangement direction D1. Furthermore, the second sub-phase portion is positioned at a position offset from the second main phase portion by 1 / 12 of the arrangement pitch P0 in the arrangement direction D1 and is adjacent to the second main phase portion in the vertical direction D2.

[0068] The third light-receiving section 213 also has a third main phase section and a third sub-phase section. The fourth light-receiving section 214 also has a fourth main phase section and a fourth sub-phase section.

[0069] Therefore, the multiple light-receiving units 21g can suppress the distortion of the output signal. Consequently, the light-receiving element 20 can detect the position of the rotating plate 40 in the rotation direction with higher accuracy.

[0070] Furthermore, the first main body portion 211a and the first separation portion 211b of the first light-receiving portion 211, as shown in the figure... Figure 6In the integrated configuration shown, to arrange the first light-receiving section 211 and the second light-receiving section 212 in a non-overlapping manner along the arrangement direction D1, the position of the second light-receiving section 212 in the arrangement direction D1 needs to be offset relative to the first light-receiving section 211 by an amount greater than 1 / 3 of the arrangement pitch P0. Here, to output a signal from the second light-receiving section 212 that is 90 degrees out of phase with respect to the signal output from the first light-receiving section 211, the position of the second light-receiving section 212 needs to be offset relative to the first light-receiving section 211 by 5 / 4 of the arrangement pitch P0 along the arrangement direction D1. Therefore, a wasted space is created between the first light-receiving section 211 and the second light-receiving section 212, within a length of 11 / 12 of the arrangement pitch P0, where no light-receiving section is located.

[0071] In the light-receiving part assembly 21g of this embodiment, as described above, the first light-receiving part 211 is separated into a first main body part 211a and a first separation part 211b, each with a width in the arrangement direction D1 less than 1 / 4 of the arrangement pitch P0, and the first main body part 211a and the first separation part 211b are arranged separately in the vertical direction D2. Furthermore, the second light-receiving part 212 is separated into a second main body part 212a and a second separation part 212b, each with a width in the arrangement direction D1 less than 1 / 4 of the arrangement pitch P0, and the second main body part 212a and the second separation part 212b are arranged separately in the vertical direction D2. Thus, as... Figure 5 As shown, the second main body portion 212a can be positioned at a position offset by 1 / 4 of the arrangement pitch P0 in the arrangement direction D1 relative to the position of the first main body portion 211a. Furthermore, the second separating portion 212b can be positioned at a position offset by 1 / 4 of the arrangement pitch P0 in the arrangement direction D1 relative to the position of the first separating portion 211b. The first main body portion 211a and the second main body portion 212a are arranged in the arrangement direction D1, and the gap between the first main body portion 211a and the second main body portion 212a is less than 1 / 4 of the arrangement pitch P0. Similarly, the first separating portion 211b and the second separating portion 212b are arranged in the arrangement direction D1, and the gap between the first separating portion 211b and the second separating portion 212b is less than 1 / 4 of the arrangement pitch P0. Therefore, wasted space between the first light-receiving portion 211 and the second light-receiving portion 212 can be reduced.

[0072] In addition, in this embodiment, such as Figure 5 As shown, the third light-receiving part 213 and the fourth light-receiving part 214 also have the same structure as the first light-receiving part 211 and the second light-receiving part 212. Therefore, the third light-receiving part 213 and the fourth light-receiving part 214 also achieve the same effect as the first light-receiving part 211 and the second light-receiving part 212.

[0073] (Implementation Method 2)

[0074] The light-receiving element of Embodiment 2 will be described. The light-receiving element of this embodiment differs from the light-receiving element 20 of Embodiment 1 in the shape of the main body and the separating portion of each light-receiving part. Hereinafter, focusing on the differences from the light-receiving element 20 of Embodiment 1, the following will be described. Figure 7 The light-receiving element of this embodiment is described.

[0075] Figure 7 This is a top view showing the structure of the first light-receiving portion 1211 of the light-receiving element in this embodiment. The plurality of light-receiving portion groups of the light-receiving element in this embodiment each have... Figure 7 The first light-receiving portion 1211 is shown. The first light-receiving portion 1211 is also separated into a first main body portion 1211a and a first separation portion 1211b, whose widths in the arrangement direction D1 are respectively less than 1 / 4 of the arrangement pitch P0.

[0076] In this embodiment, the first separation portion 1211b side of the first main body portion 1211a (that is...) Figure 7 The right edge of the first body portion 1211a of the first separation portion 1211b (that is, the right side of the first separation portion 1211b) and the right body portion 1211a side of the first separation portion 1211b (that is, the right side of the first separation portion 1211b) Figure 7 The left edge of the light-receiving element (in the embodiment 1) is inclined relative to the arrangement direction D1 and the vertical direction D2, respectively. The same effect as the light-receiving element 20 of embodiment 1 can be achieved in the light-receiving element including the first light-receiving part 1211 having such a structure.

[0077] Furthermore, in the light-receiving element of this embodiment, when viewed from the vertical direction D2, the first main body portion 1211a and the first separation portion 1211b have overlapping portions. Here, when viewed from the vertical direction D2, the overlapping portion of the first main body portion 1211a and the first separation portion 1211b... Figure 7 The middle part is the portion sandwiched between two dotted lines. In this embodiment, when viewed from the vertical direction D2, a rectangular light-receiving portion can be formed by combining the portion of the first main body portion 1211a that overlaps with the first separating portion 1211b and the portion of the first separating portion 1211b that overlaps with the first main body portion 1211a. In other words, when viewed from the vertical direction D2, the sum of the dimensions of the first main body portion 1211a in the vertical direction D2 at the portion where the first main body portion 1211a and the first separating portion 1211b overlap in the arrangement direction D1 is equal to the maximum dimension of the first main body portion 1211a in the vertical direction D2. For example, the dimension of the first main body portion 1211a in the vertical direction D2 at the portion where the first main body portion 1211a and the first separating portion 1211b overlap in the arrangement direction D1 is... Figure 7The dimension L1 of the portion where the dashed line intersects with the first main body 1211a. Furthermore, the dimension D2 of the first separation portion 1211b in the vertical direction is, for example,... Figure 7 The dimension L2 of the portion where the dashed line intersects with the first separation portion 1211b. Furthermore, the maximum dimension D2 of the first main body portion 1211a in the vertical direction is, for example, [missing information]. Figure 7 The size L0. That is, L1 + L2 = L0. Therefore, the first light-receiving unit 1211 can output the same signal as the first light-receiving unit 211 in Embodiment 1.

[0078] In the case where the first light-receiving portion 1211 is separated into a first main body portion 1211a and a first separation portion 1211b as in this embodiment, the positions of the first main body portion 1211a and the first separation portion 1211b in the arrangement direction D1 may be slightly offset due to manufacturing errors, etc. Even when such a positional offset occurs, in the first light-receiving portion 1211 of this embodiment, the first main body portion 1211a and the first separation portion 1211b have an overlapping portion when viewed from the vertical direction D2. Therefore, it is possible to suppress the decrease in output signal intensity when light shines on a position near the boundary between the first main body portion 1211a and the first separation portion 1211b in the arrangement direction D1. Thus, it is possible to suppress the distortion of the output signal of the first light-receiving portion 1211.

[0079] Furthermore, only the first light-receiving part 1211 has been described for the light-receiving element in this embodiment. However, it is also possible that the second, third, and fourth light-receiving parts of the light-receiving part group of the light-receiving element also have the same structure as the first light-receiving part 1211.

[0080] (Implementation Method 3)

[0081] The light-receiving element of Embodiment 3 will be described. The light-receiving element of this embodiment differs from the light-receiving element of Embodiment 2 in the shape of the main body and the separating portion of each light-receiving part. Hereinafter, focusing on the differences from the light-receiving element of Embodiment 2, the following will be described... Figure 8 The light-receiving element of this embodiment is described.

[0082] Figure 8 This is a top view showing the structure of the first light-receiving portion 2211 of the light-receiving element in this embodiment. The plurality of light-receiving portion groups of the light-receiving element in this embodiment each have... Figure 8 The first light-receiving portion 2211 is shown. The first light-receiving portion 2211 is also separated into a first main body portion 2211a and a first separation portion 2211b, whose widths in the arrangement direction D1 are respectively less than 1 / 4 of the arrangement pitch P0.

[0083] In this embodiment, the first main body portion 2211a has a portion formed on the side of the first separation portion 2211b (that is... Figure 8 The protrusion 2211p on the right side of the first main body portion 2211a (i.e., the first separation portion 2211b has a protrusion formed on the right side of the first main body portion 2211a) Figure 8 The recessed portion 2211q at the left end edge of the middle.

[0084] Furthermore, in the light-receiving element of this embodiment, similar to the light-receiving element of Embodiment 2, when viewed from the vertical direction D2, the first main body portion 2211a and the first separation portion 2211b have overlapping portions. Here, when viewed from the vertical direction D2, the overlapping portion of the first main body portion 2211a and the first separation portion 2211b... Figure 8 The portion is enclosed by two dotted lines. In this embodiment, when viewed from the vertical direction D2, a rectangular light-receiving portion can be formed by combining the portion of the first main body portion 2211a that overlaps with the first separating portion 2211b and the portion of the first separating portion 2211b that overlaps with the first main body portion 2211a. That is, the concave portion 2211q and the convex portion 2211p have the same shape and the same size. Therefore, the area of ​​the concave portion 2211q is equal to the area of ​​the convex portion 2211p. As a result, the first light-receiving portion 2211 can output the same signal as the first light-receiving portion 211 in Embodiment 1.

[0085] In addition, in this embodiment, the first main body portion 2211a has a protrusion 2211p and the first separation portion 2211b has a recess 2211q, but the structure of the first light-receiving portion 2211 is not limited to this. For example, the first main body portion may have a recess formed on the end edge of the first separation portion, and the first separation portion may have a recess formed on the end edge of the first main body portion.

[0086] Furthermore, only the first light-receiving part 2211 has been described for the light-receiving element in this embodiment. However, it is also possible that the second, third, and fourth light-receiving parts of the light-receiving part group of the light-receiving element also have the same structure as the first light-receiving part 2211.

[0087] (Implementation Method 4)

[0088] The light-receiving element of Embodiment 4 will be described. The positional relationship between the convex and concave portions of the light-receiving element in this embodiment differs from that of the light-receiving element in Embodiment 3. Hereinafter, focusing on the differences from the light-receiving element of Embodiment 3, we will use... Figure 9 The light-receiving element of this embodiment is described.

[0089] Figure 9 This is a top view showing the structure of the first light-receiving portion 3211 of the light-receiving element in this embodiment. (As shown) Figure 9As shown, the multiple light-receiving part groups of the light-receiving element in this embodiment each have a first light-receiving part 3211. The first light-receiving part 3211 is also separated into a first main body part 3211a and a first separation part 3211b, whose widths in the arrangement direction D1 are respectively less than 1 / 4 of the arrangement pitch P0.

[0090] In this embodiment, the first main body portion 3211a has a portion formed on the side of the first separation portion 3211b (that is... Figure 9 The protrusion 3211p on the right side of the first main body portion 3211a (i.e., the first separation portion 3211b has a protrusion formed on the right side of the first main body portion 3211a) Figure 9 The recessed portion 3211q at the left end edge of the middle.

[0091] Furthermore, in the light-receiving element of this embodiment, similar to the light-receiving element of Embodiment 3, when viewed from the vertical direction D2, the first main body portion 3211a and the first separating portion 3211b have overlapping portions. Here, when viewed from the vertical direction D2, the overlapping portion of the first main body portion 3211a and the first separating portion 3211b... Figure 9 The middle part is the section sandwiched between two dotted lines.

[0092] In this embodiment, when viewed from the vertical direction D2, even if the portion of the first main body portion 3211a that overlaps with the first separating portion 3211b and the portion of the first separating portion 3211b that overlaps with the first main body portion 3211a are combined, a rectangular light-receiving portion cannot be formed. That is, the position of the convex portion 3211p in the vertical direction D2 does not correspond to the position of the concave portion 3211q in the vertical direction D2. However, the concave portion 3211q and the convex portion 3211p have the same shape and the same size. Therefore, the area of ​​the concave portion 3211q is equal to the area of ​​the convex portion 3211p. Using the first light-receiving portion 3211 having such a convex portion 3211p and a concave portion 3211q can achieve the same effect as the first light-receiving portion 2211 in Embodiment 3.

[0093] Furthermore, the concave portion 3211q and the convex portion 3211p do not necessarily have the same shape and size, provided they have equal areas. For example, in Figure 9 In the example shown, the concave portion 3211q and the convex portion 3211p have rectangular shapes, but their shapes are not limited to rectangles. For example, the concave portion 3211q could be rectangular, and the convex portion 3211p could be parallelogram-shaped, etc. When the first main body portion 3211a and the first separating portion 3211b are arranged in the arrangement direction D1 as described above, the first main body portion 3211a and the first separating portion 3211b can be constructed in such a way that their shapes are equal and their total areas are equal.

[0094] In addition, in this embodiment, the first main body portion 3211a has a protrusion 3211p and the first separating portion 3211b has a recess 3211q, but the structure of the first light-receiving portion 3211 is not limited to this. For example, the first main body portion may have a recess formed on the end edge of the first separating portion, and the first separating portion may have a recess formed on the end edge of the first main body portion.

[0095] Furthermore, only the first light-receiving part 3211 has been described for the light-receiving element in this embodiment. However, it is also possible that the second, third, and fourth light-receiving parts of the light-receiving part group of the light-receiving element also have the same structure as the first light-receiving part 3211.

[0096] (Modified Example)

[0097] The above describes the light-receiving element and rotating detector of the present invention based on the embodiments, but the present invention is not limited to the above embodiments.

[0098] For example, in the embodiments described above, the rotating plate 40 has a patterned portion that reflects a portion of the light from the light-emitting portion 14, but the structure of the patterned portion is not limited to this. For example, the patterned portion may be a slit or the like that through which a portion of the light from the light-emitting portion 14 passes. In this case, the rotating plate is disposed between the light-emitting portion 14 and the light-receiving portion.

[0099] Furthermore, in the above embodiments, the multiple light-receiving groups of the light-receiving element are arranged on a circumference centered on the rotation axis A to detect the rotation amount of the rotating plate, but the structure of the multiple light-receiving groups is not limited to this. For example, the multiple light-receiving groups and the multiple low-reflection areas of the first patterned portion can be arranged in a straight line to form a linear displacement detector (encoder).

[0100] Furthermore, the present invention also includes forms obtained by implementing various modifications to the above embodiments that would be conceived by those skilled in the art, and forms achieved by arbitrarily combining the constituent elements and functions of each embodiment without departing from the spirit of the present invention.

[0101] Industrial availability

[0102] The technology of the present invention can be used in rotary detectors that detect the rotation of electric motors or the like, or in linear displacement detectors that detect the displacement of linearly driven moving tables or the like.

[0103] Explanation of reference numerals in the attached figures

[0104] 1. Electric motor; 2. Motor frame; 3. Stator; 4. Rotor; 5. Rotating shaft; 6. Frame; 7. Bearing; 8. Hub; 9. Bolt; 10. Rotation detector; 12. Substrate; 13. Screw; 14. Light-emitting part; 20. Light-receiving element; 21. Incremental detection part; 21g. Light-receiving part assembly; 22. Second absolute detection part; 22a. Second absolute light-receiving part; 23. First absolute detection part; 23a. First absolute light-receiving part; 24. Rotation speed detection part; 24a. Arc-shaped light-receiving part; 40. Rotating plate; 42. Main body; 50. Pattern part; 51. First pattern part; 51a, 52a, 53a, 54a. Low-reflection area; 52. Second pattern part; 53. Third pattern part; 54. Fourth pattern section; 211, 1211, 2211, 3211, first light-receiving section; 211a, 1211a, 2211a, 3211a, first main body section; 211b, 1211b, 2211b, 3211b, first separation section; 211m, first main phase section; 211s, first sub-phase section; 212, second light-receiving section; 212a, second main body section; 212b, second separation section; 213, third light-receiving section; 213a, third main body section; 213b, third separation section; 214, fourth light-receiving section; 214a, fourth main body section; 214b, fourth separation section; 2211p, 3211p, convex section; 2211q, 3211q, concave section.

Claims

1. A light-receiving element comprising a plurality of light-receiving portions arranged at a predetermined pitch in a predetermined arrangement direction, wherein, The plurality of light-receiving part groups each have a first light-receiving part and a second light-receiving part, the second light-receiving part being disposed at a position offset from the first light-receiving part by 1 / 4 of the arrangement pitch in the arrangement direction. The first light-receiving part has: The first main phase portion has a width of 1 / 3 of the arrangement pitch in the arrangement direction; and The first sub-phase portion, having a width of 1 / 3 of the arrangement pitch in the arrangement direction, is positioned at a position offset from the first main phase portion in the arrangement direction by 1 / 12 of the arrangement pitch and adjacent to the first main phase portion in a vertical direction perpendicular to the arrangement direction. The first main phase portion and the first sub-phase portion are separated into a first main body portion and a first separating portion, the width of which is less than 1 / 4 of the arrangement pitch in the arrangement direction, and the first main body portion and the first separating portion are arranged separately in the vertical direction. The second light-receiving part has: The second main phase portion has a width of 1 / 3 of the arrangement pitch in the arrangement direction; and The second sub-phase portion, having a width of 1 / 3 of the arrangement pitch in the arrangement direction, is positioned relative to the second main phase portion in the arrangement direction at a position offset by 1 / 12 of the arrangement pitch and adjacent to the second main phase portion in the vertical direction. The second main phase portion and the second sub-phase portion are separated into a second main body portion and a second separation portion, each with a width in the arrangement direction less than 1 / 4 of the arrangement pitch. The second main body portion and the second separation portion are arranged separately in the vertical direction. The first main body portion and the second main body portion are arranged in the arrangement direction, and the gap between the first main body portion and the second main body portion is less than 1 / 4 of the arrangement pitch. The first separation portion and the second separation portion are arranged in the arrangement direction, and the gap between the first separation portion and the second separation portion is less than 1 / 4 of the arrangement pitch.

2. The light-receiving element according to claim 1, wherein, When viewed from the vertical direction, the first main body and the first separation part have overlapping portions.

3. The light-receiving element according to claim 2, wherein, The end edge of the first separation portion on the first main body and the end edge of the first main body on the first separation portion are inclined relative to the arrangement direction and the vertical direction, respectively.

4. The light-receiving element according to claim 2, wherein, The first main body portion has a protrusion formed on the end edge of the first separation portion side. The first separation portion has a recess formed on the end edge of the first main body portion.

5. The light-receiving element according to claim 2, wherein, The first main body portion has a recess formed at the end edge on the side of the first separation portion. The first separation portion has a protrusion formed on the end edge of the first main body portion.

6. The light-receiving element according to claim 4, wherein, The area of ​​the concave portion is equal to the area of ​​the convex portion.

7. The light-receiving element according to claim 4, wherein, The recess and the convex part are of the same shape and the same size.

8. The light-receiving element according to claim 2, wherein, When viewed from the vertical direction, a rectangular light-receiving portion is formed by combining the portion of the first main body that overlaps with the first separation portion and the portion of the first separation portion that overlaps with the first main body.

9. The light-receiving element according to claim 2, wherein, When viewed from the vertical direction, the sum of the dimensions of the first main body and the first separation portion in the vertical direction at the position where the first main body overlaps with the first separation portion in the vertical direction is equal to the maximum dimension of the first main body in the vertical direction.

10. A rotating detector, wherein, The rotating detector includes: The light-receiving element as described in claim 1; The light-emitting part, which emits light; and A rotating plate, positioned opposite the light-receiving element. The light is emitted by the rotating plate onto the plurality of light-receiving parts.

Images