Encoder

Abstract

An encoder (10) comprises: a rotating plate (20) that rotates; a radiation unit (30) that radiates light to the rotating plate (20); and a light-receiving unit (40) that receives the light which was radiated from the radiation unit (30) and passed through the rotating plate (20), and that outputs a signal corresponding to the received light. The rotating plate (20) has a plurality of reflective surfaces (21) arranged in the direction of rotation of the rotating plate (20). Each of the plurality of reflective surfaces (21) has a radial curvature being the curvature in a radial direction about a rotation axis (A) of the rotating plate (20). The light radiated from the radiation unit (30) to the reflective surfaces is reflected toward the light-receiving unit (40), and the plurality of reflective surfaces (21) have two or more radial curvatures that are different from each other.

Description

[Technical Field]

[0001] The present disclosure relates to encoders. [Background technology]

[0002] Conventionally, encoders that detect the position of a detection target such as a motor have been known. As an example of an encoder, Patent Document 1 discloses a movement information measuring device that includes a light source, a moving body that has a curved surface in the movement direction, and a light receiving element that receives reflected light or transmitted light that is collected from the curved surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-181018 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the movement information measuring device of Patent Document 1, it is difficult to differentiate the position onto which light reflected from one of the multiple curved surfaces is irradiated from the position onto which light reflected from curved surfaces other than the one curved surface in a direction perpendicular to the direction of movement of the moving object, making it difficult to detect the position of the detection object.Furthermore, with a conventional rotary encoder having multiple reflective surfaces aligned in the rotation direction, it is difficult to differentiate the position onto which light reflected from one of the multiple reflective surfaces is irradiated from the position onto which light reflected from reflecting surfaces other than the one reflective surface in a radial direction centered on the rotation axis, making it difficult to detect the position of the detection object.

[0005] The present disclosure has been made to solve such problems, and has an object to provide an encoder that can easily detect the position of a detection target. [Means for solving the problem]

[0006] An encoder according to one aspect of the present disclosure comprises a rotating rotating plate, an irradiation unit that irradiates light onto the rotating plate, and a light receiving unit that receives the light irradiated from the irradiation unit and passed through the rotating plate and outputs a signal corresponding to the received light, wherein the rotating plate has a plurality of reflective surfaces aligned in the rotation direction of the rotating plate, each of the plurality of reflective surfaces having a radial curvature that is a radial curvature centered on the rotation axis of the rotating plate, and reflects the light irradiated onto the reflective surface from the irradiation unit toward the light receiving unit, and the plurality of reflective surfaces have two or more radial curvatures that are different from each other.

[0007] Moreover, an encoder according to one aspect of the present disclosure includes a substrate that moves linearly, an irradiation unit that irradiates light onto the substrate, and a light receiving unit that receives the light irradiated from the irradiation unit and passed through the substrate and outputs a signal corresponding to the received light, wherein the substrate has a plurality of reflective surfaces aligned in the direction of movement of the substrate, each of the plurality of reflective surfaces having an orthogonal curvature that is a curvature in an orthogonal direction that is perpendicular to the direction of movement, and reflects the light irradiated onto the reflective surface from the irradiation unit toward the light receiving unit, and the plurality of reflective surfaces have two or more orthogonal curvatures that are different from each other. [Effects of the Invention]

[0008] According to the present disclosure, an encoder that can easily detect the position of a detection target can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an encoder according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing the radial direction travel state of light reflected by the first reflecting surface of the encoder of FIG. 1 and the radial direction travel state of light reflected by the second reflecting surface. [Figure 3] FIG. 3 is a diagram showing the traveling state of light reflected by the first reflecting surface of the encoder of FIG. 1 in the rotation direction and the traveling state of light reflected by the second reflecting surface in the rotation direction. [Figure 4]FIG. 4 is a perspective view showing an encoder according to the second embodiment. [Figure 5] FIG. 5 is a diagram showing a light receiving section of an encoder according to the third embodiment. [Figure 6] FIG. 6 is a diagram showing a light receiving section of an encoder according to the fourth embodiment. [Figure 7] FIG. 7 is a diagram showing a light receiving section of an encoder according to the fifth embodiment. [Figure 8] FIG. 8 is a diagram showing a light receiving section of an encoder according to the sixth embodiment. [Figure 9] FIG. 9 is a diagram showing a light receiving section of an encoder according to the seventh embodiment. [Figure 10] FIG. 10 is a perspective view showing an encoder according to the eighth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concept of the present disclosure will be described as optional components.

[0011] Note that each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, the scales and the like do not necessarily match in each figure. Furthermore, in each figure, the same reference numerals are used for substantially the same configurations, and redundant explanations will be omitted or simplified.

[0012] (First embodiment) FIG. 1 is a perspective view showing an encoder 10 according to a first embodiment. FIG. 1(b) is an enlarged view of a portion surrounded by a two-dot chain line in FIG. 1(a). Note that FIG. 1 omits the illustration of some of the multiple reflecting surfaces 21. FIG. 2 is a diagram showing the radial progression of light reflected by the first reflecting surface 22 and the radial progression of light reflected by the second reflecting surface 23 of the encoder 10 of FIG. 1. FIG. 2(a) is an end view of the first reflecting surface 22 as viewed from the rotational direction, and FIG. 2(b) is an end view of the second reflecting surface 23 as viewed from the rotational direction. FIG. 3 is a diagram showing the rotational progression of light reflected by the first reflecting surface 22 and the rotational progression of light reflected by the second reflecting surface 23 of the encoder 10 of FIG. 1. FIG. 3(a) is a view of the light receiving unit 40 as viewed from the axial direction, and FIG. 3(b) is an end view of the first reflecting surface 22 and the second reflecting surface 23 as viewed from the radial direction. In Fig. 3(a), dots are added to the portions of the light receiving section 40 where light is irradiated. The same applies to Figs. 5 to 9 described below. An encoder 10 according to a first embodiment will be described with reference to Figs. 1 to 3.

[0013] The axial direction is the direction in which the rotation axis A extends (see arrow X in Figure 1, etc.), the rotation direction is the rotation direction centered on the rotation axis A (see arrow Y in Figure 1, etc.), and the radial direction is the radial direction centered on the rotation axis A (see arrow Z in Figure 1, etc.).

[0014] As shown in FIG. 1, the encoder 10 is an optical rotary encoder. Specifically, the encoder 10 is a light-reflecting rotary encoder. The encoder 10 detects the rotation of a detection object. Specifically, for example, the encoder 10 detects the position (rotational position) of the detection object, the rotation direction of the detection object, the number of rotations of the detection object, etc. In this embodiment, the detection object is the rotating shaft 1 of a motor. That is, the encoder 10 detects the position of the rotating shaft 1, the rotation direction of the rotating shaft 1, the number of rotations of the rotating shaft 1, etc. The encoder 10 includes a rotating plate 20, an irradiation unit 30, and a light-receiving unit 40.

[0015] The rotating plate 20 is a rotating substrate. The rotating plate 20 is attached to the end of the rotating shaft 1 and rotates together with the rotating shaft 1 around the rotation axis A. The rotating plate 20 is plate-shaped with its thickness direction aligned with the axial direction and extends in a direction perpendicular to the rotation axis A. For example, the rotating plate 20 rotates both clockwise and counterclockwise when viewed from the axial direction. Note that the rotating plate 20 may also rotate only in one of the clockwise and counterclockwise directions when viewed from the axial direction. For example, the rotating plate 20 is made of metal, resin, glass, ceramic, or the like. The rotating plate 20 has a plurality of reflective surfaces 21.

[0016] The plurality of reflecting surfaces 21 are aligned in the rotation direction of the rotating plate 20. The plurality of reflecting surfaces 21 are provided over the entire circumference of the rotating plate 20 in the rotation direction. In other words, the plurality of reflecting surfaces 21 are aligned in the circumferential direction centered on the rotation axis A, and are provided over the entire circumference in the circumferential direction. For example, each of the plurality of reflecting surfaces 21 is formed by chrome plating or the like.

[0017] The rotating plate 20 is provided at a position different from the irradiating section 30 and the light receiving section 40 in the axial direction, and the plurality of reflecting surfaces 21 are provided on the main surface of the rotating plate 20 on the irradiating section 30 and light receiving section 40 side.

[0018] Each of the plurality of reflecting surfaces 21 reflects light irradiated onto the reflecting surface from the irradiating unit 30 toward the light-receiving unit 40. The light emitted from the irradiating unit 30 is not irradiated onto all of the plurality of reflecting surfaces 21 at the same time, but is irradiated onto some of the plurality of reflecting surfaces 21 at the same time. The reflecting surface 21 onto which the light emitted from the irradiating unit 30 is irradiated varies depending on the rotational position of the rotating plate 20. When light is irradiated onto the reflecting surface 21 from the irradiating unit 30, each of the plurality of reflecting surfaces 21 reflects the light irradiated onto the reflecting surface 21 toward the light-receiving unit 40.

[0019] Each of the plurality of reflecting surfaces 21 has a radial curvature, which is a curvature in the radial direction. The plurality of reflecting surfaces 21 have two or more radial curvatures that are different from each other. In this embodiment, the plurality of reflecting surfaces 21 have two radial curvatures that are different from each other. That is, in this embodiment, the plurality of reflecting surfaces 21 include a first reflecting surface 22 that has a first radial curvature and a second reflecting surface 23 that has a second radial curvature that is different from the first radial curvature, and each of the plurality of reflecting surfaces 21 is either the first reflecting surface 22 or the second reflecting surface 23.

[0020] 2(a), in this embodiment, the first radial curvature is greater than 0%, and the first reflecting surface 22 is a concave curved surface that is concave in the axial direction in a cross section perpendicular to the rotation direction. The first reflecting surface 22 reflects light emitted from the emitting unit 30 toward the light receiving unit 40, and irradiates the light onto a predetermined range on the light receiving unit 40.

[0021] 2(b), in this embodiment, the second radial curvature is greater than 0%, and the second reflecting surface 23 is a concave curved surface that is concave in the axial direction in a cross section perpendicular to the rotation direction. The second radial curvature is greater than the first radial curvature. That is, the second reflecting surface 23 is curved more sharply than the first reflecting surface 22. In other words, the first reflecting surface 22 is curved more gently than the second reflecting surface 23. The second reflecting surface 23 reflects the light emitted from the emitting unit 30 toward the light receiving unit 40, and irradiates the light onto a predetermined range on the light receiving unit 40.

[0022] As described above, since the second radial curvature is larger than the first radial curvature, the radial range of the light receiving unit 40 irradiated with light reflected by the second reflecting surface 23 is smaller than the radial range of the light irradiated with light reflected by the first reflecting surface 22.

[0023] In this way, since the plurality of reflecting surfaces 21 have two mutually different radial curvatures, the radial range onto which light is irradiated at the light receiving unit 40 can be varied depending on the rotational position of the rotating plate 20. Furthermore, since each of the plurality of reflecting surfaces 21 has a radial curvature, the light irradiated onto each of the plurality of reflecting surfaces 21 can be efficiently collected onto the light receiving unit 40.

[0024] As shown in FIGS. 1 and 3(b), each of the plurality of reflecting surfaces 21 has a rotational curvature, which is the curvature in the rotational direction of the rotating plate 20. In this embodiment, the plurality of reflecting surfaces 21 have a single rotational curvature. That is, in this embodiment, the rotational curvature of each of the plurality of reflecting surfaces 21 is equal to the rotational curvature of the reflecting surfaces 21 other than the reflecting surface 21 in question. Specifically, in this embodiment, the rotational curvature of the first reflecting surface 22 is equal to the rotational curvature of the second reflecting surface 23.

[0025] In this embodiment, the rotational curvature is greater than 0%, and each of first reflecting surface 22 and second reflecting surface 23 is a concave curved surface that is concave in the axial direction in a cross section perpendicular to the radial direction.

[0026] In this way, since each of the plurality of reflecting surfaces 21 has a rotational curvature, it is possible to further reduce the range of the rotational direction in which light is irradiated at the light receiving unit 40. Furthermore, since each of the plurality of reflecting surfaces 21 has a rotational curvature, it is possible to efficiently collect the light irradiated to each of the plurality of reflecting surfaces 21 onto the light receiving unit 40.

[0027] 1, the irradiation unit 30 irradiates light onto the rotating plate 20. For example, the irradiation unit 30 is configured with a light-emitting element such as an LED (Light Emitting Diode). For example, the light irradiated from the irradiation unit 30 is visible light such as white light, or infrared light.

[0028] The light receiving unit 40 receives light emitted from the irradiation unit 30 and transmitted through the rotating plate 20, and outputs a signal corresponding to the received light. Specifically, the light receiving unit 40 receives light reflected from each of the plurality of reflecting surfaces 21, and outputs a signal corresponding to the received light. As shown in FIG. 3(a), the light receiving unit 40 has a plurality of region rows each consisting of a plurality of light receiving regions aligned in the rotational direction, and the plurality of region rows are aligned in the radial direction. The plurality of region rows includes a first region row, a second region row, and a third region row.

[0029] The first region row is configured with a plurality of first light-receiving regions 41a, 41b, and 41c aligned in the rotational direction. The light-receiving unit 40 outputs a signal corresponding to the intensity of light received by each of the plurality of first light-receiving regions 41a, 41b, and 41c. For example, each of the plurality of first light-receiving regions 41a, 41b, and 41c is a light-receiving region of a light-receiving element such as a photodiode. Note that, for example, each of the plurality of first light-receiving regions 41a, 41b, and 41c may also be a light-receiving region of an image sensor.

[0030] The dimensions of each of the first light receiving regions 41a, 41b, and 41c in the rotation direction are smaller than the dimensions of each of the second light receiving regions 42a, 42b, and 42c and the dimensions of each of the third light receiving regions 43a, 43b, and 43c.

[0031] The second region row is configured with multiple second light-receiving regions 42a, 42b, and 42c aligned in the rotational direction. The second region row is aligned with the first region row in the radial direction. In the radial direction, the second light-receiving region 42a is aligned with the first light-receiving region 41a, the second light-receiving region 42b is aligned with the first light-receiving region 41b, and the second light-receiving region 42c is aligned with the first light-receiving region 41c. The light-receiving unit 40 outputs a signal corresponding to the intensity of light received by each of the multiple second light-receiving regions 42a, 42b, and 42c. For example, each of the multiple second light-receiving regions 42a, 42b, and 42c is a light-receiving region of a light-receiving element such as a photodiode. Note that, for example, each of the multiple second light-receiving regions 42a, 42b, and 42c may be a light-receiving region of an image sensor.

[0032] The third region row is configured with multiple third light-receiving regions 43a, 43b, and 43c aligned in the rotational direction. The third region row is aligned with the first and second region rows in the radial direction. In the radial direction, the third light-receiving region 43a is aligned with the first light-receiving region 41a and the second light-receiving region 42a, the third light-receiving region 43b is aligned with the first light-receiving region 41b and the second light-receiving region 42b, and the third light-receiving region 43c is aligned with the first light-receiving region 41c and the second light-receiving region 42c. The light-receiving unit 40 outputs a signal corresponding to the intensity of light received by each of the multiple third light-receiving regions 43a, 43b, and 43c. For example, each of the multiple third light-receiving regions 43a, 43b, and 43c is a light-receiving region of a light-receiving element such as a photodiode. For example, each of the plurality of third light receiving regions 43a, 43b, and 43c may be a light receiving region of an image sensor.

[0033] The plurality of reflecting surfaces 21 have a rotational curvature so that an incremental signal is output from the light receiving unit 40. For example, the rotational curvature can narrow the range of the rotational direction in which light is irradiated at the light receiving unit 40. As a result, as the rotating plate 20 rotates, light can be periodically irradiated onto each of the plurality of first light receiving areas 41 a, 41 b, 41 c, and signals are periodically output from the light receiving unit 40, and the signals output from the light receiving unit 40 become incremental signals. This makes it possible to detect the relative position of the detection target.

[0034] Furthermore, the multiple reflecting surfaces 21 have two radial curvatures so that an absolute signal is output from the light receiving unit 40. Specifically, the first reflecting surface 22 has a first radial curvature so that light reflected from the first reflecting surface 22 is irradiated onto the first region row, the second region row, and the third region row, and the second reflecting surface 23 has a second radial curvature so that light reflected from the second reflecting surface 23 is irradiated onto the first region row but not onto the second region row and the third region row. This makes it possible to change the light irradiation pattern onto the multiple second light receiving regions 42a, 42b, 42c and the multiple third light receiving regions 43a, 43b, 43c depending on the arrangement order of the first reflecting surface 22 and the second reflecting surface 23 in the rotational direction.

[0035] For example, by arranging three first reflecting surfaces 22 in the rotational direction, light can be irradiated simultaneously onto all of the multiple second light-receiving areas 42a, 42b, and 42c. Furthermore, by arranging the first reflecting surface 22, the second reflecting surface 23, and the first reflecting surface 22 in that order in the rotational direction, light can be irradiated simultaneously onto the multiple second light-receiving areas 42a and 42c, while preventing light from being irradiated onto the second light-receiving area 42b. In this way, by changing the light irradiation pattern onto the multiple second light-receiving areas 42a, 42b, and 42c depending on the rotational position of the rotating plate 20, the signal output from the light-receiving unit 40 becomes an absolute signal. This allows the absolute position of the detection target to be detected.

[0036] For example, in the state shown in FIG. 3, light is irradiated onto multiple first light receiving areas 41a, 41b, and 41c, so the light receiving unit 40 outputs "1" for the first light receiving area 41a, "1" for the first light receiving area 41b, and "1" for the first light receiving area 41c.

[0037] 3, light is not irradiated onto the second light-receiving region 42a and the second light-receiving region 42c, but light is irradiated onto the second light-receiving region 42b, so the light-receiving unit 40 outputs "0" for the second light-receiving region 42a, "1" for the second light-receiving region 42b, and "0" for the second light-receiving region 42c. For example, the combination of these signals output by the light-receiving unit 40 is a signal that can identify the absolute position of the detection target, and is an absolute signal.

[0038] 3, light is not irradiated onto the third light-receiving region 43a and the third light-receiving region 43c, but light is irradiated onto the third light-receiving region 43b, so the light-receiving unit 40 outputs "0" for the third light-receiving region 43a, "1" for the third light-receiving region 43b, and "0" for the third light-receiving region 43c. For example, the combination of these signals output by the light-receiving unit 40 is a signal that can identify the absolute position of the detection target, and is an absolute signal.

[0039] The encoder 10 according to the first embodiment has been described above.

[0040] The encoder 10 of the first embodiment comprises a rotating rotating plate 20, an irradiation unit 30 that irradiates light onto the rotating plate 20, and a light receiving unit 40 that receives the light irradiated from the irradiation unit 30 and passed through the rotating plate 20, and outputs a signal corresponding to the received light. The rotating plate 20 has a plurality of reflective surfaces 21 arranged in the rotation direction of the rotating plate 20, and each of the plurality of reflective surfaces 21 has a radial curvature that is a radial curvature centered on the rotation axis A of the rotating plate 20, and reflects the light irradiated onto the reflective surface from the irradiation unit 30 toward the light receiving unit 40, and the plurality of reflective surfaces 21 have two mutually different radial curvatures.

[0041] According to this, the multiple reflecting surfaces 21 have two mutually different radial curvatures, so that the amount of light irradiated to the light receiving unit 40 can be prevented from decreasing, while the radial range onto which light is irradiated at the light receiving unit 40 can be easily varied depending on the rotational position of the rotating plate 20, thereby making it easy to detect the position of the detection object.

[0042] Furthermore, in the encoder 10 according to the first embodiment, each of the plurality of reflecting surfaces 21 has a curvature in the rotational direction.

[0043] This prevents the amount of light irradiated to the light receiving unit 40 from decreasing, while easily reducing the range of rotational directions in which light is irradiated to the light receiving unit 40, making it even easier to detect the position of the object to be detected.

[0044] Furthermore, in the encoder 10 according to the first embodiment, the plurality of reflecting surfaces 21 have a single curvature in the rotational direction.

[0045] According to this, the rotation of the rotary plate 20 allows the light receiving section 40 to be regularly irradiated with light, so that the position of the detection object can be detected more easily.

[0046] Furthermore, in the encoder 10 according to the first embodiment, the light receiving section 40 has a plurality of region rows each configured by arranging a plurality of light receiving regions in the rotational direction, and the plurality of region rows are arranged in the radial direction.

[0047] This allows the light receiving unit 40 to output signals of various patterns by irradiating light onto only one of the multiple area rows or onto all of the multiple area rows, making it even easier to detect the position of the object to be detected.

[0048] Furthermore, in the encoder 10 according to the first embodiment, the plurality of reflecting surfaces 21 have two or more radial curvatures so that the light receiving section 40 outputs an absolute signal.

[0049] This allows the absolute position of the detection object to be identified, making it even easier to detect the position of the detection object.

[0050] (Second embodiment) Fig. 4 is a perspective view showing an encoder 10a according to the second embodiment. Fig. 4(b) is an enlarged view of the part surrounded by the two-dot chain line in Fig. 4(a). Note that Fig. 4 does not show some of the multiple reflecting surfaces 21a. The encoder 10a according to the second embodiment will be described with reference to Fig. 4.

[0051] As shown in FIG. 4, encoder 10a differs from encoder 10 primarily in that encoder 10a includes a rotating plate 20a that is different from rotating plate 20. In the example shown in FIG.

[0052] Rotating plate 20a differs from rotating plate 20 mainly in that rotating plate 20a has a plurality of reflecting surfaces 21a that are different from the plurality of reflecting surfaces 21. The plurality of reflecting surfaces 21a differs from the plurality of reflecting surfaces 21 mainly in that the plurality of reflecting surfaces 21a has a third reflecting surface 24 instead of the first reflecting surface 22.

[0053] The third reflecting surface 24 has a radial curvature of 0%. That is, in this embodiment, the two radial curvatures include a 0% curvature. The third reflecting surface 24 is not curved in a cross section perpendicular to the rotation direction.

[0054] Furthermore, third reflecting surface 24 has a rotational curvature of 0%. That is, in this embodiment, multiple reflecting surfaces 21a have two rotational curvatures, and two of the rotational curvatures include a 0% curvature. Third reflecting surface 24 is not curved in a cross section perpendicular to the radial direction.

[0055] That is, in this embodiment, the third reflecting surface 24 is a flat surface.

[0056] The plurality of reflecting surfaces 21 a may include a first reflecting surface 22 , a second reflecting surface 23 , and a third reflecting surface 24 .

[0057] The encoder 10a according to the second embodiment has been described above.

[0058] In the encoder 10a according to the second embodiment, the two radial curvatures include a 0% curvature.

[0059] This makes it possible to easily form a plurality of reflecting surfaces 21a.

[0060] (Third embodiment) 5 is a diagram showing a light receiving section 50 of an encoder according to the third embodiment. The encoder according to the third embodiment will be described with reference to FIG.

[0061] As shown in FIG. 5, the encoder of the third embodiment differs from encoder 10 mainly in that it includes a light receiving unit 50 different from light receiving unit 40 and a plurality of reflecting surfaces (not shown) different from the plurality of reflecting surfaces 21.

[0062] The light receiving section 50 differs from the light receiving section 40 mainly in that it does not have a third region row.

[0063] For example, in the third embodiment, the multiple reflective surfaces have two or more radial curvatures so that incremental signals are output from the light receiving unit 50. For example, the multiple reflective surfaces are arranged such that reflective surfaces with radial curvatures that allow light to be irradiated onto the second region row and reflective surfaces with radial curvatures that prevent light from being irradiated onto the second region row are alternately arranged. As a result, as the rotating plate rotates, light can be periodically irradiated onto each of the multiple second light receiving regions 42a, 42b, and 42c, and analog signals are periodically output from the light receiving unit 50, and the signals output from the light receiving unit 50 become incremental signals. This makes it possible to detect the relative position of the detection target.

[0064] The encoder according to the third embodiment has been described above.

[0065] In the encoder according to the third embodiment, the multiple reflecting surfaces have two or more radial curvatures so that the light receiving section 50 outputs incremental signals.

[0066] This allows the relative position of the detection target to be identified, making it even easier to detect the position of the detection target.

[0067] (Fourth embodiment) 6 is a diagram showing a light receiving section 60 of an encoder according to a fourth embodiment. The encoder according to the fourth embodiment will be described with reference to FIG.

[0068] As shown in FIG. 6, the encoder of the fourth embodiment differs from encoder 10 mainly in that it includes a light receiving unit 60 different from light receiving unit 40 and a plurality of reflecting surfaces (not shown) different from the plurality of reflecting surfaces 21.

[0069] The light receiving section 60 differs from the light receiving section 40 mainly in that the light receiving section 60 has more region rows than the light receiving section 40. Specifically, the light receiving section 60 includes a first region row, a second region row, a third region row, a fourth region row, a fifth region row, a sixth region row, and a seventh region row.

[0070] The first region row is configured with a plurality of first light receiving regions 61 lined up in the rotational direction. The second region row is configured with a plurality of second light receiving regions 62 lined up in the rotational direction. The third region row is configured with a plurality of third light receiving regions 63 lined up in the rotational direction. The fourth region row is configured with a plurality of fourth light receiving regions 64 lined up in the rotational direction. The fifth region row is configured with a plurality of fifth light receiving regions 65 lined up in the rotational direction. The sixth region row is configured with a plurality of sixth light receiving regions 66 lined up in the rotational direction. The seventh region row is configured with a plurality of seventh light receiving regions 67 lined up in the rotational direction.

[0071] The plurality of reflecting surfaces in the fourth embodiment differ from the plurality of reflecting surfaces 21 mainly in that they have four or more radial curvatures. Specifically, of the plurality of reflecting surfaces, a first reflecting surface has a radial curvature such that it irradiates light onto the first to seventh region rows. The second reflecting surface has a radial curvature such that it irradiates light onto the first to fifth region rows but does not irradiate light onto the sixth and seventh region rows. Furthermore, of the plurality of reflecting surfaces, a third reflecting surface has a radial curvature such that it irradiates light onto the first to third region rows but does not irradiate light onto the fourth to seventh region rows, and the fourth reflecting surface has a radial curvature such that it irradiates light onto the first region row but does not irradiate light onto the second to seventh region rows.

[0072] In this way, the light receiving section 60 may have four or more region rows, and the plurality of reflecting surfaces may have four or more radial curvatures.

[0073] The encoder according to the fourth embodiment has been described above.

[0074] (Fifth embodiment) 7 is a diagram showing a light receiving section 70 of an encoder according to a fifth embodiment. The encoder according to the fifth embodiment will be described with reference to FIG.

[0075] As shown in FIG. 7, the encoder of the fifth embodiment differs from encoder 10 mainly in that it includes a light receiving unit 70 different from light receiving unit 40 and a plurality of reflecting surfaces (not shown) different from the plurality of reflecting surfaces 21.

[0076] The light receiving unit 70 has a first region row, a second region row, and a third region row. The first region row is configured with a plurality of first light receiving regions 71 lined up in the rotational direction, the second region row is configured with a plurality of second light receiving regions 72 lined up in the rotational direction, and the third region row is configured with a plurality of third light receiving regions 73 lined up in the rotational direction.

[0077] The first region row differs from the first region row in the light receiving unit 40 mainly in that the dimensions of each of the multiple first light receiving regions 71 in the rotation direction are smaller than the dimensions of each of the multiple first light receiving regions 41a, 41b, 41c.

[0078] The second region row differs from the second region row in the light receiving unit 40 mainly in that the dimensions of each of the multiple second light receiving regions 72 in the rotation direction are smaller than the dimensions of each of the multiple second light receiving regions 42a, 42b, 42c.

[0079] The third region row differs from the third region row in the light receiving unit 40 mainly in that the dimensions of each of the multiple third light receiving regions 73 in the rotation direction are smaller than the dimensions of each of the multiple third light receiving regions 43a, 43b, 43c.

[0080] In this way, by making the plurality of first light receiving regions 71, the plurality of second light receiving regions 72, and the plurality of third light receiving regions 73 smaller, the position of the detection object can be detected more precisely than with the encoder 10.

[0081] For example, the light receiving unit 70 may output a signal indicating the light receiving intensity of the light received by each of the multiple first light receiving areas 71. For example, as shown in (a) of Fig. 7, when the rotating plate rotates from a state in which light is irradiated onto one first light receiving area 71 of the multiple first light receiving areas 71, passes through the state shown in (b) of Fig. 7, and then changes to a state in which light is irradiated onto a first light receiving area 71 adjacent to the one first light receiving area 71 of the multiple first light receiving areas 71, as shown in (c) of Fig. 7, the position of the detection target can be detected more precisely based on the light receiving intensity of the light received by these two first light receiving areas 71.

[0082] The encoder according to the fifth embodiment has been described above.

[0083] (Sixth embodiment) 8 is a diagram showing a light receiving section 80 of an encoder according to the sixth embodiment. The encoder according to the sixth embodiment will be described with reference to FIG.

[0084] As shown in FIG. 8(a), the encoder according to the sixth embodiment differs from the encoder according to the fifth embodiment mainly in that the encoder according to the sixth embodiment includes a light receiving section 80 that is different from the light receiving section 70.

[0085] The light receiving section 80 differs from the light receiving section 70 mainly in that the light receiving section 80 has a second region row that is different from the second region row of the light receiving section 70.

[0086] The second region row is configured by a plurality of first light receiving regions 81a, 81b, 81c, 81d, 81e, and 81f arranged in the rotation direction.

[0087] The first light receiving region 81a is provided so that its radial dimension gradually decreases toward one side in the rotation direction. The first light receiving region 81b is provided so that its radial dimension gradually increases toward one side in the rotation direction. The first light receiving region 81a and the first light receiving region 81b face each other in the radial direction.

[0088] The first light receiving region 81c is provided so that its radial dimension gradually decreases toward one side in the rotation direction. The first light receiving region 81d is provided so that its radial dimension gradually increases toward one side in the rotation direction. The first light receiving region 81c and the first light receiving region 81d face each other in the radial direction.

[0089] The first light receiving region 81e is provided so that its radial dimension gradually decreases toward one side in the rotation direction. The first light receiving region 81f is provided so that its radial dimension gradually increases toward one side in the rotation direction. The first light receiving region 81e and the first light receiving region 81f face each other in the radial direction.

[0090] In the encoder according to the sixth embodiment, when the rotating plate rotates and the irradiation spot on the light-receiving unit 80 moves in the rotation direction, the ratio between the light intensity received by the first light-receiving region 81a and the light intensity received by the first light-receiving region 81b, and the ratio between the light intensity received by the first light-receiving region 81c and the light intensity received by the first light-receiving region 81d, etc. change, as shown in (b) of Fig. 8. Therefore, for example, the position of the detection target can be detected based on the ratio between the light intensity received by the first light-receiving region 81a and the light intensity received by the first light-receiving region 81b.

[0091] The encoder according to the sixth embodiment has been described above.

[0092] (Seventh embodiment) 9 is a diagram showing a light receiving section 90 of an encoder according to the seventh embodiment. The encoder according to the seventh embodiment will be described with reference to FIG.

[0093] As shown in (a) of Figure 9, the encoder of the seventh embodiment differs from encoder 10 mainly in that it has a light receiving unit 90 different from light receiving unit 40 and multiple reflecting surfaces (not shown) different from multiple reflecting surfaces 21.

[0094] The light receiving unit 90 has a first region row, a second region row, and a third region row. The first region row is configured with a plurality of first light receiving regions 91 lined up in the rotational direction, the second region row is configured with a plurality of second light receiving regions 92a, 92b, 92c, and 92d lined up in the rotational direction, and the third region row is configured with a plurality of third light receiving regions 93a, 93b, 93c, and 93d lined up in the rotational direction.

[0095] The third light receiving regions 93a, 93b, 93c, and 93d are arranged so as to be shifted in the rotational direction with respect to the second light receiving regions 92a, 92b, 92c, and 92d.

[0096] For example, in the state shown in (a) of Figure 9, light is irradiated onto the multiple second light receiving areas 92b, 92c, and light is not irradiated onto the multiple second light receiving areas 92a, 92d, so the light receiving unit 90 outputs "0" for the second light receiving area 92a, "1" for the second light receiving area 92b, "1" for the second light receiving area 92c, and "0" for the second light receiving area 92d.

[0097] Also, in the state shown in (a) of Figure 9, light is irradiated onto the third light receiving area 93b, and light is not irradiated onto the multiple third light receiving areas 93a, 93c, and 93d, so the light receiving unit 90 outputs "0" for the third light receiving area 93a, "1" for the third light receiving area 93b, "0" for the third light receiving area 93c, and "0" for the third light receiving area 93d.

[0098] In this case, for example, the absolute signal may be the logical product of the four signals "0", "1", "1", "0" output from the light receiving unit 90 based on the light received by the multiple second light receiving areas 92a, 92b, 92c, and 92d and the four signals "0", "1", "0", and "0" output from the light receiving unit 90 based on the light received by the multiple third light receiving areas 93a, 93b, 93c, and 93d.

[0099] Specifically, for example, the logical product of a signal "0" output from the light receiving unit 90 based on the light received by the second light receiving region 92a and a signal "0" output from the light receiving unit 90 based on the light received by the third light receiving region 93a is "0." Similarly, the logical product of a signal "1" output from the light receiving unit 90 based on the light received by the second light receiving region 92b and a signal "1" output from the light receiving unit 90 based on the light received by the third light receiving region 93b is "1." Similarly, the logical product of a signal "1" output from the light receiving unit 90 based on the light received by the second light receiving region 92c and a signal "0" output from the light receiving unit 90 based on the light received by the third light receiving region 93c is "0." Furthermore, the logical product of the signal "0" output from the light receiving unit 90 based on the light received by the second light receiving region 92d and the signal "0" output from the light receiving unit 90 based on the light received by the third light receiving region 93d is "0".

[0100] The four signals "0", "1", "0", and "0" obtained by logical ANDing in this way may be used as absolute signals.

[0101] In other words, the multiple reflecting surfaces may have two or more radial curvatures so that the four signals obtained by the logical product in this way, "0", "1", "0", "0", become absolute signals.

[0102] For example, as shown in (b) of Figure 9, the light receiving intensity of light received by the second light receiving area 92b, the light receiving intensity of light received by the second light receiving area 92c, and the light receiving intensity of light received by the third light receiving area 93b may be compared, and the signal output from the light receiving unit 90 based on the light received by the area row associated with the greatest light receiving intensity may be used as an absolute signal.

[0103] The encoder according to the seventh embodiment has been described above.

[0104] (Eighth embodiment) Fig. 10 is a perspective view showing an encoder 100 according to an eighth embodiment. Fig. 10(b) is an enlarged view of a portion surrounded by a two-dot chain line in Fig. 10(a). Note that Fig. 10 omits illustration of some of the multiple reflecting surfaces 121. The encoder 100 according to the eighth embodiment will be described with reference to Fig. 10.

[0105] As shown in FIG. 10 , the encoder 100 is an optical linear encoder. Specifically, the encoder 100 is a light-reflecting linear encoder. The encoder 100 detects the movement of a detection object. Specifically, for example, the encoder 100 detects the position and movement direction of the detection object. For example, the detection object is a linear motor. The encoder 100 includes a substrate 120, an irradiation unit 30, and a light-receiving unit 40.

[0106] The substrate 120 is a substrate that moves linearly. For example, the substrate 120 is attached to a linear motor and moves together with the linear motor. For example, the substrate 120 is made of metal, resin, glass, ceramic, or the like. The substrate 120 has a plurality of reflective surfaces 121.

[0107] The plurality of reflecting surfaces 121 are aligned in the movement direction of the substrate 120 (see arrow Y1 in FIG. 10). For example, each of the plurality of reflecting surfaces 121 is formed by chrome plating or the like. The plurality of reflecting surfaces 121 are provided on the main surface of the substrate 120 on the irradiation unit 30 and light receiving unit 40 sides.

[0108] Each of the plurality of reflecting surfaces 121 reflects light irradiated onto the reflecting surface from the irradiating unit 30 toward the light receiving unit 40. The light emitted from the irradiating unit 30 is not irradiated onto all of the plurality of reflecting surfaces 121 at the same time, but is irradiated onto some of the plurality of reflecting surfaces 121 at the same time. The reflecting surface 121 onto which the light emitted from the irradiating unit 30 is irradiated varies depending on the position on the substrate 120. When light is irradiated onto the reflecting surface 121 from the irradiating unit 30, each of the plurality of reflecting surfaces 121 reflects the light irradiated onto the reflecting surface 121 toward the light receiving unit 40.

[0109] Each of the multiple reflecting surfaces 121 has an orthogonal curvature, which is the curvature in an orthogonal direction (see arrow Z1 in FIG. 10) that is perpendicular to the movement direction of the substrate 120. The multiple reflecting surfaces 121 have two or more orthogonal curvatures that are different from each other. In this embodiment, the multiple reflecting surfaces 121 have two orthogonal curvatures that are different from each other. That is, in this embodiment, the multiple reflecting surfaces 121 include a first reflecting surface 122 that has a first orthogonal curvature and a second reflecting surface 123 that has a second orthogonal curvature that is different from the first orthogonal curvature, and each of the multiple reflecting surfaces 121 is either the first reflecting surface 122 or the second reflecting surface 123.

[0110] In this embodiment, the first orthogonal curvature is greater than 0%, and first reflecting surface 122 is a concave curved surface that is concave in a cross section perpendicular to the movement direction. First reflecting surface 122 reflects light irradiated from irradiating unit 30 toward light receiving unit 40, and irradiates the light onto a predetermined range on light receiving unit 40.

[0111] Furthermore, in this embodiment, the second orthogonal direction curvature is greater than 0%, and second reflecting surface 123 is a concave curved surface that is recessed in a cross section perpendicular to the movement direction. The second orthogonal direction curvature is greater than the first orthogonal direction curvature. That is, second reflecting surface 123 is curved more sharply than first reflecting surface 122. In other words, first reflecting surface 122 is curved more gently than second reflecting surface 123. Second reflecting surface 123 reflects light irradiated from irradiating unit 30 toward light receiving unit 40, and irradiates the light onto a predetermined range on light receiving unit 40.

[0112] Each of the plurality of reflecting surfaces 121 may have a curvature in the movement direction.

[0113] As described above, since the second orthogonal curvature is greater than the first orthogonal curvature, the range in the orthogonal direction at the light receiving unit 40 onto which the light reflected by the second reflecting surface 123 is irradiated is smaller than the range in the orthogonal direction onto which the light reflected by the first reflecting surface 122 is irradiated.

[0114] In this way, the plurality of reflecting surfaces 121 have two mutually different orthogonal curvatures, which makes it possible to vary the orthogonal range onto which light is irradiated at the light receiving unit 40. Furthermore, since each of the plurality of reflecting surfaces 121 has an orthogonal curvature, the light irradiated onto each of the plurality of reflecting surfaces 121 can be efficiently collected onto the light receiving unit 40.

[0115] The irradiating section 30 irradiates light onto the substrate 120. The light receiving section 40 receives the light irradiated from the irradiating section 30 and transmitted through the substrate 120, and outputs a signal corresponding to the received light.

[0116] The encoder 100 according to the eighth embodiment has been described above.

[0117] The encoder 100 of the eighth embodiment comprises a substrate 120 that moves linearly, an irradiation unit 30 that irradiates light onto the substrate 120, and a light receiving unit 40 that receives the light irradiated from the irradiation unit 30 and passed through the substrate 120, and outputs a signal corresponding to the received light, the substrate 120 has a plurality of reflective surfaces 121 aligned in the direction of movement of the substrate 120, each of the plurality of reflective surfaces 121 having an orthogonal curvature that is a curvature in an orthogonal direction perpendicular to the direction of movement, and reflects the light irradiated onto the reflective surface from the irradiation unit 30 towards the light receiving unit 40, the plurality of reflective surfaces 121 having two mutually different orthogonal curvatures.

[0118] According to this, the multiple reflecting surfaces 121 have two mutually different orthogonal curvatures, which prevents the amount of light irradiated to the light receiving unit 40 from decreasing, while easily varying the orthogonal range onto which light is irradiated at the light receiving unit 40 depending on the position of the substrate 120, thereby making it easy to detect the position of the detection object.

[0119] (Other embodiments, etc.) The encoder according to the present disclosure has been described above based on the embodiments, but the present disclosure is not limited to the above embodiments.

[0120] In the above-described embodiment, the case where the plurality of reflecting surfaces 21 have two mutually different radial curvatures has been described, but this is not limiting. For example, the plurality of reflecting surfaces may have three or more mutually different radial curvatures.

[0121] In the above-described embodiment, the case where the plurality of reflecting surfaces 21 have a single rotational curvature has been described, but this is not limiting. For example, the plurality of reflecting surfaces 21 may have two or more rotational curvatures that are different from one another. Also, for example, the plurality of reflecting surfaces may not have a rotational curvature.

[0122] In the above-described embodiment, the case where the plurality of reflecting surfaces 121 have two mutually different orthogonal curvatures has been described, but the present invention is not limited to this. For example, the plurality of reflecting surfaces may have three or more mutually different orthogonal curvatures.

[0123] In the above-described embodiment, the light receiving unit 40 has a plurality of region rows, but the present invention is not limited to this. For example, the light receiving unit may have a single region row instead of a plurality of region rows.

[0124] In addition, this disclosure also includes forms obtained by making various modifications to the above-mentioned embodiments that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions of each embodiment within the scope of the present disclosure. [Industrial Applicability]

[0125] The encoder according to the present disclosure is useful for devices and apparatuses such as motors that rotate or move linearly. [Explanation of symbols]

[0126] 10,10a,100 encoder 20,20a Rotating plate 21,21a,121 Reflective surface 22,122 1st reflective surface 23,123 Second reflective surface 24 Third reflecting surface 30 irradiation department 40, 50, 60, 70, 80, 90 Light-receiving area 41a,41b,41c,61,71,81a,81b,81c,81d,81e,81f,91 First Light-receiving Area 42a, 42b, 42c, 62, 72, 92a, 92b, 92c, 92d Second light-receiving area 43a, 43b, 43c, 63, 73, 93a, 93b, 93c, 93d Third light-receiving area 64 Fourth Light-receiving Area 65 Fifth Light-receiving Area 66. The 6th Light-receiving Area 67. The 7th Light-receiving Area 120 substrate

Claims

1. A rotating rotating plate; an irradiation unit that irradiates the rotary plate with light; a light receiving unit that receives light that has been irradiated from the irradiating unit and passed through the rotating plate, and outputs a signal corresponding to the received light, the rotary plate has a plurality of reflecting surfaces aligned in a rotation direction of the rotary plate, Each of the plurality of reflecting surfaces has a radial curvature that is a curvature in a radial direction centered on a rotation axis of the rotating plate, and reflects light irradiated onto the reflecting surface from the irradiating unit toward the light receiving unit, the plurality of reflecting surfaces have two or more radial curvatures that are different from each other; Encoder.

2. The two or more radial curvatures include a 0% curvature. The encoder of claim 1 .

3. Each of the plurality of reflecting surfaces has a rotational curvature that is a curvature in the rotational direction. The encoder of claim 1 .

4. the plurality of reflecting surfaces have a single curvature in the rotational direction; The encoder of claim 3 .

5. the light receiving unit has a plurality of area rows each including a plurality of light receiving areas arranged in the rotation direction, The plurality of region rows are aligned in the radial direction. An encoder according to any one of claims 1 to 4.

6. the plurality of reflecting surfaces have the two or more radial curvatures so that an absolute signal is output from the light receiving unit; An encoder according to any one of claims 1 to 4.

7. the plurality of reflecting surfaces have the two or more radial curvatures so that incremental signals are output from the light receiving unit; An encoder according to any one of claims 1 to 4.

8. a linearly moving substrate; an irradiation unit that irradiates the substrate with light; a light receiving unit that receives light that has been irradiated from the irradiating unit and passed through the substrate, and outputs a signal corresponding to the received light; the substrate has a plurality of reflective surfaces aligned in a moving direction of the substrate; Each of the plurality of reflecting surfaces has an orthogonal curvature that is a curvature in an orthogonal direction perpendicular to the moving direction, and reflects light irradiated onto the reflecting surface from the irradiating unit toward the light receiving unit; the plurality of reflecting surfaces have two or more curvatures in the orthogonal direction that are different from each other; Encoder.

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