Optical scale for encoder, optical scale multifaceted body for encoder, and optical encoder

Abstract

To provide an encoder optical scale that ensures traceability.SOLUTION: An encoder optical scale comprising an optical pattern having two regions with different reflectance or transmittance is provided with a two-dimensional code.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an optical scale for an encoder, an optical scale polygon body for an encoder, and an optical encoder. [Background technology]

[0002] Conventionally, optical encoders are used in servo motors and the like equipped with a control mechanism. An optical encoder is equipped with an optical scale, a light source such as an LED that irradiates the optical scale with light, and a photodetector that detects the transmitted light or reflected light from the optical scale. Optical encoders require high accuracy. Therefore, traceability is important so that the manufacturing history of the optical encoder can be traced in case of a malfunction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 201024 Summary of the Invention [Problem to be solved by the invention]

[0004] Traceability is also required for optical scales used in optical encoders. Conventionally, methods for identifying optical scales include a method in which the identification information is letters, numbers, or symbols, and the method of identifying them with the human eye or a method of character recognition using OCR (Optical Character Recognition). However, identifying them with the human eye poses problems of misreading and input errors, as well as issues in terms of efficiency and cost. In addition, OCR has the advantage of being efficient and cost-effective because characters are read by a machine, but there is a concern of misreading.

[0005] The present invention has been made in consideration of the above circumstances, and has as its main object to provide an optical scale for an encoder that can ensure traceability. [Means for solving the problem]

[0006] One embodiment of the present disclosure provides an optical scale for an encoder having an optical pattern with two regions having different reflectance or transmittance, the optical scale for an encoder having a two-dimensional code.

[0007] Another embodiment of the present disclosure provides an optical scale polygonal body for an encoder having an optical scale for an encoder having an optical pattern with two regions of different reflectance or transmittance attached to multiple surfaces, wherein the optical scale for the encoder has a two-dimensional code, the optical scale polygonal body for the encoder has one or more unit areas, and in the unit areas, the two-dimensional code is different for each optical scale for the encoder.

[0008] Another embodiment of the present disclosure provides an optical encoder comprising: an optical scale for an encoder as described above; a light source that irradiates a surface of the optical scale for an encoder with measurement light; and a photodetector that detects reflected light or transmitted light from the optical scale for an encoder. Effect of the Invention

[0009] The optical scale for encoder according to the present disclosure has the effect of ensuring traceability. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic plan view illustrating an optical scale for an encoder according to the present disclosure. [Diagram 2] FIG. 1 is a schematic plan view illustrating an optical scale for an encoder according to the present disclosure. [Diagram 3] 1 is a schematic plan view illustrating an example of an optical scale polygonal body for an encoder according to the present disclosure; [Figure 4]FIG. 10 is a schematic plan view illustrating an example of an optical scale polygonal body for an encoder according to the present disclosure, and is a partially enlarged view of FIG. 3 or FIG. 9. [Diagram 5] 1 is a schematic cross-sectional view illustrating an optical scale for an encoder according to the present disclosure. [Figure 6] 1 is a schematic cross-sectional view illustrating an optical scale for an encoder according to the present disclosure. [Figure 7] 1 is a schematic cross-sectional view illustrating an optical scale for an encoder according to the present disclosure. [Figure 8] 1 is a schematic diagram illustrating a punching device used in a singulation step in a manufacturing method for an optical scale for an encoder in the present disclosure. FIG. [Figure 9] 1 is a schematic plan view illustrating an example of an optical scale polygonal body for an encoder according to the present disclosure; [Figure 10] 1 is a schematic plan view showing a state in which an optical scale for an encoder according to the present disclosure is accommodated in a housing member. FIG. [Figure 11] 1 is a schematic perspective view illustrating an optical encoder according to the present disclosure. [Figure 12] 1 is a schematic perspective view illustrating an optical encoder according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure can be implemented in many different forms, and is not to be interpreted as being limited to the description of the embodiments exemplified below. In addition, in order to make the explanation clearer, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual form, but these are merely examples and do not limit the interpretation of the present disclosure. In addition, in this specification and each figure, elements similar to those described above with respect to the previous figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0012] In this specification, when describing an aspect in which another component is disposed on a certain component, the term "above" or "below" includes both cases in which another component is disposed directly above or below a certain component so as to be in contact with the component, and cases in which another component is disposed above or below a certain component with another component interposed therebetween, unless otherwise specified. In addition, in this specification, when describing an aspect in which another component is disposed on the surface of a certain component, the term "on the surface side" or "on the surface" includes both cases in which another component is disposed directly above or below a certain component so as to be in contact with the component, and cases in which another component is disposed above or below a certain component with another component interposed therebetween, unless otherwise specified.

[0013] In addition, in this specification, the "optical scale for encoder" may be simply referred to as the "optical scale".

[0014] The optical scale for an encoder, the optical scale polygonal body for an encoder, and the optical encoder according to the present disclosure will be described in detail below.

[0015] A. Optical scale for encoders The optical scale for an encoder in the present disclosure is an optical scale for an encoder having an optical pattern with two regions with different reflectance or transmittance, and has a two-dimensional code. The optical scale for an encoder in the present disclosure may be a reflective optical scale for an encoder having an optical pattern with two regions with different reflectance, i.e., a reflective region (high reflection region) and a non-reflective region (low reflection region), or may be a transmissive optical scale for an encoder having an optical pattern with two regions with different transmittance, i.e., a transmissive region and a non-transmissive region (light-shielding region).

[0016] Fig. 1 is a schematic plan view showing an example of a reflective optical scale for an encoder in the present disclosure. As illustrated in Fig. 1, the reflective optical scale for an encoder 10 has an optical pattern 13 having two regions with different reflectances, i.e., a high reflection region 11 and a low reflection region 12. The reflective optical scale for an encoder 10 has a two-dimensional code 14 in a region other than the optical pattern region in which the optical pattern 13 is arranged.

[0017] Fig. 2 is a schematic plan view showing an example of a transmissive optical scale for an encoder in the present disclosure. As illustrated in Fig. 2, the transmissive optical scale for an encoder 20 has an optical pattern 23 having two regions with different transmittances, i.e., a transmissive region 21 and a light-shielding region 22. The transmissive optical scale for an encoder 20 has a two-dimensional code 24 in a region other than the optical pattern region in which the optical pattern 23 is arranged.

[0018] In the present disclosure, the manufacturing history of the optical scale for encoders is linked to the two-dimensional code, thereby ensuring traceability. The two-dimensional code can improve the reading accuracy. Thus, the traceability can be improved. Furthermore, the two-dimensional code can record a lot of information in a small space. The size of characters that can be recognized by the human eye is about 2 mm to 3 mm, but the size of the entire two-dimensional code can be made smaller than that. Thus, in the optical scale for encoders, the two-dimensional code can be easily arranged in an area other than the optical pattern area. Furthermore, since the two-dimensional code is read by a machine, efficiency can be improved and labor costs can be reduced.

[0019] When manufacturing an optical scale, a multi-surface mounting body having optical scales mounted on multiple surfaces may be used.

[0020] Fig. 3 is a schematic plan view showing an example of an encoder optical scale multi-faceted body on which encoder optical scales are attached on multiple faces, and Fig. 4 is a partial enlarged view of Fig. 3. In the present disclosure, an encoder optical scale (encoder optical scale 10 or encoder transmissive optical scale 20) is produced by individualizing an encoder optical scale multi-faceted body 50 as shown in Figs. 3 and 4.

[0021] In the present disclosure, the two-dimensional code can include information for identifying the position of the optical scale for the encoder on the multi-faceted optical scale for the encoder. In FIG. 3, 100 optical scales for the encoder (reflective optical scale for the encoder 10 or transmissive optical scale for the encoder 20) are multi-faceted on the multi-faceted optical scale for the encoder body 50, so that the two-dimensional code can identify which position of the optical scale for the encoder (reflective optical scale for the encoder 10 or transmissive optical scale for the encoder 20) is located among the 100. The two-dimensional code includes information indicating row numbers and column numbers in, for example, 10 rows x 10 columns. By having the two-dimensional code in the optical scale for the encoder, even if the optical scale for the encoder is separated from the multi-faceted optical scale for the encoder body, it is easy to identify which position of the multi-faceted optical scale for the encoder body it was manufactured at.

[0022] The substrate in the multi-faceted encoder optical scale body may have undulations or warping. In addition, in the multi-faceted encoder optical scale body, there may be errors from the design values ​​in the pattern dimensions, reflectance, or transmittance in two regions with different reflectance or transmittance. In such a case, the characteristics of the encoder optical scale change depending on the position in the multi-faceted encoder optical scale body. In such a case, since the position of the encoder optical scale in the multi-faceted encoder optical scale body is specified by the two-dimensional code, even after the encoder optical scale is separated from the multi-faceted encoder optical scale body, the characteristics that differ depending on the position in the multi-faceted encoder optical scale body can be grasped. For example, the encoder optical scale can be used after grasping the characteristics that differ depending on the position in the multi-faceted encoder optical scale body. In addition, for example, when undulations, warping, errors, etc. are not allowed, good and defective products can be smoothly sorted according to the position in the multi-faceted encoder optical scale body. Therefore, by linking the characteristics that vary depending on the position on the optical scale polygonal body for encoder with the two-dimensional code, quality control can be carried out efficiently.

[0023] Here, for example, when forming two regions with different transmittances or reflectances using photolithography, the photomask is used repeatedly. Therefore, even if the same photomask is used to manufacture the optical scale, the state of the optical scale may change depending on conditions such as the number of times the photomask is used. Therefore, identifying the time of manufacture may be important from the viewpoint of traceability.

[0024] Conventionally, when two regions with different transmittances or reflectances are formed by using photolithography, the size of the polygonal body in plan view is, for example, 5 inches square, and in this case, the number of optical scales provided on the polygonal body is relatively small, about several tens to about 20. Therefore, in this case, the photomask is used repeatedly many times for mass production. Therefore, from the viewpoint of traceability, it is important to identify the manufacturing time such as the number of times the photomask has been used, and the position of the optical scale on the polygonal body has not been considered much. In addition, even if information for identifying the position of the optical scale on the polygonal body is given, the amount of information for identifying the position of the optical scale on the polygonal body is small, so that it is sufficient to use characters that can be distinguished by human eyes or recognized by OCR as the identification information, and there was no need to use a two-dimensional code with a large amount of information.

[0025] On the other hand, when a hundred or more or several hundreds of optical scales for encoders are attached to the optical scale polygonal body for encoders, the optical scales for encoders are manufactured in large quantities at one time, and therefore it is desirable to ensure traceability. In addition, when the number of optical scales for encoders in the optical scale polygonal body for encoders is large, the substrate in the optical scale polygonal body for encoders becomes large, and the substrate itself may be prone to undulation or warping. Furthermore, the photomask used in the manufacturing process also becomes large, and the pattern dimensions may be prone to variation. Therefore, it is important from the viewpoint of traceability to identify the position of the optical scale for encoder in the optical scale polygonal body for encoders. In the present disclosure, as described above, the position of the optical scale for encoder in the optical scale polygonal body for encoders can be identified by the two-dimensional code. Therefore, the present disclosure is useful when the number of optical scales for encoders in the optical scale polygonal body for encoders is large and the optical scale polygonal body for encoders is large.

[0026] In addition, in the present disclosure, as described later, when a patterned low-reflection layer is arranged on the first surface of the highly reflective substrate, and the region where the low-reflection layer is arranged is a low-reflection region, and the region where the low-reflection layer is not arranged is a high-reflection region, an optical pattern and a two-dimensional code can be formed simultaneously. In addition, in the present disclosure, as described later, when a patterned high-reflection layer is arranged on the first surface of the low-reflection substrate, and the region where the high-reflection layer is arranged is a high-reflection region, and the region where the high-reflection layer is not arranged is a low-reflection region, an optical pattern and a two-dimensional code can be formed simultaneously. In addition, in the present disclosure, as described later, when a patterned light-shielding layer is arranged on the first surface of the transparent substrate, and the region where the light-shielding layer is arranged is a light-shielding region, and the region where the light-shielding layer is not arranged is a transmission region, an optical pattern and a two-dimensional code can be formed simultaneously. Therefore, an optical scale for an encoder having a two-dimensional code can be manufactured without increasing the manufacturing process.

[0027] Hereinafter, the optical scale for an encoder according to the present disclosure will be described in detail with respect to each component.

[0028] 1. 2D Code In the present disclosure, the two-dimensional code is linked to the manufacturing history of the optical scale for encoder.

[0029] The optical scale for an encoder in the present disclosure is preferably manufactured by dividing an optical scale polygonal body for an encoder, and therefore, the two-dimensional code preferably includes information for identifying the position of the optical scale for an encoder on the optical scale polygonal body for an encoder.

[0030] Furthermore, when the encoder optical scale is manufactured using photolithography, the two-dimensional code may include information for identifying a photomask. The information for identifying the photomask is information unique to the photomask. In the encoder optical scale polygonal body, the information for identifying the photomask is the same.

[0031] The two-dimensional code may also include information indicating the manufacturer, manufacturing date, lot number, etc.

[0032] The two-dimensional code may be, for example, a matrix type two-dimensional code or a stack type two-dimensional code. Among them, the matrix type two-dimensional code is preferable. The matrix type two-dimensional code can increase the amount of information and is easy to read. Generally, the stack type two-dimensional code is rectangular, whereas the matrix type two-dimensional code is square. Therefore, compared with the stack type two-dimensional code, the matrix type two-dimensional code is easier to arrange in an area other than the optical pattern area. Specific examples include QR Code (registered trademark), micro QR code, rMQR code, data matrix, Veri Code, Aztec Code, and Maxi Code. Among them, QR Code (registered trademark), micro QR code, rMQR code, and data matrix are preferable, micro QR code, rMQR code, and data matrix are more preferable, and data matrix is ​​even more preferable. QR Code (registered trademark) is highly versatile. Furthermore, the micro QR code, rMQR code, and data matrix can reduce the size of the two-dimensional code, so that the two-dimensional code can be easily arranged in an area other than the optical pattern area in the optical scale for encoder.

[0033] In the optical scale for encoder in the present disclosure, the position of the two-dimensional code is not particularly limited, but it is preferable that the two-dimensional code is arranged in an area other than the optical pattern area. The optical pattern area is an area in which the optical pattern is arranged. The optical pattern is composed of two areas with different reflectances or transmittances. The optical pattern refers to a pattern used in an optical encoder to detect the displacement of the optical scale for encoder.

[0034] As for the position of the two-dimensional code, for example, as shown in FIG. 2, it is preferable that the end of the two-dimensional code 24 is separated from the end of the optical scale 20 for encoder by a distance d1. The distance d1 is preferably 0.2 mm or more, and more preferably 0.5 mm or more. In this case, as shown in FIG. 4, the end of the two-dimensional code 14 or 24 is separated from the planned cutting line L by a distance d1 in the optical scale polygonal body 50 for encoder. If the distance d1 is within the above range, the effect of cutting on the two-dimensional code can be suppressed. Specifically, the effect of cutting on reading the two-dimensional code can be suppressed. On the other hand, the upper limit of the distance d1 is not particularly limited as long as the two-dimensional code is arranged in an area other than the optical pattern area.

[0035] As for the position of the two-dimensional code, for example, as shown in Fig. 2, it is preferable that the end of the two-dimensional code 24 is separated by a distance d2 from the end of the optical pattern region where the optical pattern 23 is arranged. The distance d2 is preferably 3 mm or more, and more preferably 10 mm or more. On the other hand, the upper limit of the distance d2 is not particularly limited as long as the two-dimensional code is arranged in a region other than the optical pattern region and the distance d1 is within a predetermined range.

[0036] In the two-dimensional code, the size of the cells is preferably 300 μm or less, may be 200 μm or less, or may be 100 μm or less. If the size of the cells is within the above range, the size of the two-dimensional code can be relatively small, depending on the type of the two-dimensional code. Therefore, the two-dimensional code can be easily arranged in an area other than the optical pattern area. On the other hand, the size of the cells is preferably 10 μm or more, may be 20 μm or more, or may be 30 μm or more. If the size of the cells is within the above range, the two-dimensional code can be read without enlarging it, and the efficiency can be improved. In addition, if the size of the cells is too small, it may be difficult to form the two-dimensional code. Specifically, the size of the cells is preferably 10 μm or more and 300 μm or less, may be 20 μm or more and 200 μm or less, or may be 30 μm or more and 100 μm or less.

[0037] In addition, in a two-dimensional code, the width of a bar is the same as the size of the cell described above.

[0038] The size of the two-dimensional code is preferably, for example, 3000 μm or less, may be 2000 μm or less, or may be 1500 μm or less. If the size of the two-dimensional code is within the above range, the two-dimensional code can be easily arranged in an area other than the optical pattern area. On the other hand, the size of the two-dimensional code is preferably, for example, 100 μm or more, may be 300 μm or more, or may be 500 μm or more. If the size of the two-dimensional code is within the above range, the two-dimensional code can be read without enlarging it, depending on the type of the two-dimensional code, and the efficiency can be improved. In addition, if the size of the two-dimensional code is too small, it may be difficult to form the two-dimensional code. Specifically, the size of the two-dimensional code is preferably 100 μm or more and 3000 μm or less, may be 300 μm or more and 2000 μm or less, or may be 500 μm or more and 1500 μm or less.

[0039] For example, as shown in FIG. 5(a), when a patterned low-reflection layer 2 is disposed on the first surface 1a of the highly reflective substrate 1, and the region where the low-reflection layer 2 is disposed is the low-reflection region 12, and the region where the low-reflection layer 2 is not disposed is the high-reflection region 11, it is preferable that the two-dimensional code is formed simultaneously with the optical pattern 13. That is, it is preferable that the material of the two-dimensional code is the same as the material of the optical pattern. In the above case, for example, as shown in FIG. 5(b), in the two-dimensional code 14, the code portion 15 may be a portion where the low-reflection layer 2 is disposed, and the background portion 16 may be a portion where the low-reflection layer 2 is not disposed. Also, although not shown, in the two-dimensional code, the code portion may be a portion where the low-reflection layer is not disposed, and the background portion may be a portion where the low-reflection layer is disposed.

[0040] In addition, although not shown, when a patterned high reflection layer is arranged on the first surface of the low reflection substrate, and the area where the high reflection layer is arranged is a high reflection area, and the area where the high reflection layer is not arranged is a low reflection area, it is preferable that the two-dimensional code is formed at the same time as the optical pattern. That is, it is preferable that the material of the two-dimensional code is the same as the material of the optical pattern. In the above case, in the two-dimensional code, the code part may be a part where the high reflection layer is arranged, and the background part may be a part where the high reflection layer is not arranged. In addition, in the two-dimensional code, the code part may be a part where the high reflection layer is not arranged, and the background part may be a part where the high reflection layer is arranged.

[0041] Also, for example, as shown in FIG. 6(a), when a patterned light-shielding layer 32 is arranged on the first surface 31a of the transparent substrate 31, and the region where the light-shielding layer 32 is arranged is the light-shielding region 22, and the region where the light-shielding layer 32 is not arranged is the transmission region 21, it is preferable that the two-dimensional code is formed simultaneously with the optical pattern 23. That is, it is preferable that the material of the two-dimensional code is the same as the material of the optical pattern. In the above case, for example, as shown in FIG. 6(b), in the two-dimensional code 24, the code portion 25 may be a portion where the light-shielding layer 32 is arranged, and the background portion 26 may be a portion where the light-shielding layer 32 is not arranged. Also, although not shown, in the two-dimensional code, the code portion may be a portion where the light-shielding layer is not arranged, and the background portion may be a portion where the light-shielding layer is arranged.

[0042] 2. Other identifying information The reflective optical scale for an encoder according to the present disclosure may further have identification information other than the two-dimensional code. Examples of the other identification information include the manufacturer, the date of manufacture, and the lot number. Examples of the other identification information include letters, numbers, and symbols. The other identification information may be discerned by human eyes, or may be character-recognized by OCR.

[0043] In the optical scale for an encoder according to the present disclosure, the position of the other identification information is not particularly limited, but it is preferable that the other identification information be disposed in an area other than the optical pattern area.

[0044] Other identification information can be formed simultaneously with the optical pattern, similar to the above-mentioned two-dimensional code.

[0045] 3. Reflective Optical Scale for Encoders The reflective optical scale for an encoder in the present disclosure has an optical pattern having two regions with different reflectances, i.e., a high reflection region and a low reflection region. The configuration of the reflective optical scale for an encoder in the present disclosure is not particularly limited as long as it has an optical pattern having a high reflection region and a low reflection region. The reflective optical scale for an encoder may have a high reflection substrate having a first surface and a second surface opposite to the first surface, and a patterned low reflection layer arranged on the first surface side of the high reflection substrate. The reflective optical scale for an encoder may also have a low reflection substrate having a first surface and a second surface opposite to the first surface, and a patterned high reflection layer arranged on the first surface side of the low reflection substrate. Each aspect will be described below.

[0046] (1) First aspect of the reflective optical scale for encoder A first aspect of a reflective optical scale for an encoder in the present disclosure has a highly reflective substrate having a first surface and a second surface opposite the first surface, and a patterned low-reflective layer arranged on the first surface side of the highly reflective substrate.

[0047] FIG. 5(a) is an enlarged cross-sectional view of the dotted frame a in FIG. 1 along the line AA. As illustrated in FIG. 1 and FIG. 5(a), the reflective optical scale 10 for an encoder has a disk-shaped highly reflective substrate 1 having a first surface 1a and a second surface 1b facing the first surface 1a, and a low-reflection layer 2 arranged in a pattern along the circumferential direction of the highly reflective substrate 1 on the first surface 1a side of the highly reflective substrate 1. The reflective optical scale 10 for an encoder has a holed disk shape, and low-reflection regions 12 in which the low-reflection layer 2 is arranged and high-reflection regions 11 in which the low-reflection layer 2 is not arranged are arranged alternately in the circumferential direction. The low-reflection region 12 has a highly reflective substrate 1 and a low-reflection layer 2 in the thickness direction of the reflective optical scale 10 for an encoder. The high-reflection region 11 has a highly reflective substrate 1. The reflectance in the high-reflection region 11 is higher than the reflectance in the low-reflection region 12. The reflectance in the high reflection region 11 and the reflectance in the low reflection region 12 indicate reflectances at the same wavelength and at the same incident angle.

[0048] Hereinafter, the reflective optical scale for an encoder according to this embodiment will be described in detail with respect to each component.

[0049] (a) Highly reflective base material The highly reflective substrate in this embodiment has a high reflectance. The reflectance of the first surface of the highly reflective substrate is, for example, 50% or more, may be 55% or more, or may be 60% or more. The reflectance is, for example, 100% or less. Specifically, the reflectance of the first surface of the highly reflective substrate is 50% or more and 100% or less, may be 55% or more and 100% or less, or may be 60% or more and 100% or less. If the reflectance is within the above range, the difference between the reflectance in the high reflection region and the reflectance in the low reflection region is large, so that erroneous detection by the photodetector can be prevented and the detection accuracy of the signal can be improved.

[0050] In this specification, the reflectance refers to the reflectance of the detection light used in the optical encoder. In the case where the wavelength of the incident light is in the range of 500 nm to 1000 nm in the highly reflective substrate, it is more preferable that the reflectance is within the above range when the incident angle is in the range of 5° to 70°.

[0051] The reflectance is measured using a SolidSpec 3700DUV manufactured by Shimadzu Corporation. The irradiation beam size is approximately 6 mm x 15 mm. Both P-polarized and S-polarized light are measured, and the sum is averaged to calculate the 45° linear polarization and calculate the reflectance.

[0052] The highly reflective substrate may be a metal substrate, and may have a supporting substrate and a metal layer disposed on one surface of the supporting substrate.

[0053] The material of the metal substrate preferably satisfies the above reflectance, and examples thereof include stainless steel (SUS), copper, and aluminum.

[0054] The thickness of the metal base material is, for example, 0.1 mm or more, may be 0.3 mm or more, or may be 0.35 mm or more. The thickness of the metal base material is, for example, 1.1 mm or less, may be 0.5 mm or less, or may be 0.45 mm or less. Specifically, the thickness of the metal base material is, for example, 0.1 mm or more and 1.1 mm or less, may be 0.3 mm or more and 0.5 mm or less, or may be 0.35 mm or more and 0.45 mm or less.

[0055] Examples of materials for the support substrate include glass and resin. Glass has a small linear expansion coefficient and can suppress dimensional changes caused by temperature changes in the usage environment.

[0056] The material of the metal layer preferably satisfies the above-mentioned reflectance, and examples thereof include chromium, silver, aluminum, rhodium, gold, copper, and alloys containing these metals as main components. Among these, a metal chromium film is preferable.

[0057] The thickness of the metal layer is, for example, 0.05 μm or more, and may be 0.1 μm or more. The thickness of the metal layer is, for example, 0.3 μm or less, and may be 0.2 μm or less. Specifically, the thickness of the metal layer is, for example, 0.05 μm or more and 0.3 μm or less, and may be 0.1 μm or more and 0.2 μm or less.

[0058] Here, the "thickness" of each component refers to the thickness obtained by a general measurement method. Examples of thickness measurement methods include a stylus method in which the thickness is calculated by tracing the surface with a stylus to detect unevenness, and an optical method in which the thickness is calculated based on the spectral reflectance spectrum. Specifically, the thickness is measured using a stylus-type film thickness meter "P-15" manufactured by KLA-Tencor. The thickness is calculated by averaging the thickness measurements at multiple points on the component. For example, in the case of a metal substrate, the average thickness measurement value at two points symmetrical to the center of the disk-shaped metal substrate may be used.

[0059] In the case of a rotary encoder, the highly reflective substrate is disk-shaped. The highly reflective substrate may be, for example, a perforated disk-shaped substrate having a central hole, or may not have a central hole. On the other hand, in the case of a linear encoder, the highly reflective substrate is rectangular.

[0060] When the highly reflective substrate is a perforated disk shape, the outer diameter of the highly reflective substrate in plan view may be, for example, 15 mm or more, or 20 mm or more. On the other hand, the outer diameter of the highly reflective substrate may be, for example, 70 mm or less, or 60 mm or less. Specifically, the outer diameter of the highly reflective substrate may be, for example, 15 mm or more, 70 mm or less, or 20 mm or more, or 60 mm or less.

[0061] In the above case, the inner diameter of the highly reflective substrate is, for example, 5 mm or more and 20 mm or less in plan view.

[0062] In the above case, the difference between the outer diameter and the inner diameter, that is, the outer / inner diameter difference, is, for example, 8 mm or more and 13 mm or less.

[0063] When the highly reflective substrate is a metal substrate or has a resin substrate, the highly reflective substrate may have a sagging on the outer peripheral edge on the first surface side. FIG. 5(c) is an enlarged cross-sectional view of the line BB in the dotted frame b in FIG. 1. In FIG. 5(c), the highly reflective substrate 1 has a sagging P on the outer peripheral edge on the first surface 1a side. The reflective optical scale for an encoder having a sagging on the outer peripheral edge on the first surface side of the highly reflective substrate is usually manufactured by punching a polygonal body. In the case of punching a polygonal body, unlike etching a polygonal body, there is no need to provide a bridge connecting the optical scale for an encoder and a frame, so no bridge marks are generated. Therefore, the occurrence of partial distortion can be suppressed. In addition, there is no need to reduce the thickness of the metal substrate to reduce costs and improve accuracy. Therefore, the metal substrate can be thickened, and waviness and warping can be suppressed. In addition, it is more advantageous in terms of cost than etching a polygonal body.

[0064] Furthermore, when the highly reflective substrate is a metal substrate or has a resin substrate and is a perforated disk, it may have a sagging on the inner peripheral edge on the first surface side.

[0065] (b) Low reflective layer The low reflective layer in this embodiment is disposed in a pattern on the first surface side of the highly reflective substrate.

[0066] The reflectance in the low reflection region may be lower than that in the high reflection region. Specifically, the reflectance in the low reflection region may be lower than that of the first surface of the high reflection substrate. In the low reflection region, the reflectance at any wavelength in the range of 500 nm to 1000 nm is, for example, 10% or less, may be 5% or less, or may be 1% or less. On the other hand, the reflectance in the low reflection region is, for example, 0% or more. Specifically, the reflectance in the low reflection region is 0% or more and 10% or less, may be 0% or more and 5% or less, or may be 0% or more and 1% or less. If the reflectance is within the above range, the difference between the reflectance in the high reflection region and the reflectance in the low reflection region can be increased.

[0067] In the low reflection region, when the wavelength of incident light is anywhere in the range of 500 nm or more and 1000 nm or less, it is more preferable that the reflectance at an incident angle anywhere in the range of 5° or more and 70° or less is within the above range.

[0068] The low-reflection layer is not particularly limited in its configuration as long as it satisfies the above-mentioned reflectance. In particular, the low-reflection layer preferably has a metal chromium film, and a chromium oxide film and a chromium nitride film arranged in random order on the surface of the metal chromium film opposite to the highly reflective substrate from the highly reflective substrate side. With such a three-layered low-reflection layer, the reflectance of the low-reflection region can be reduced to the above-mentioned range. Moreover, if only metal chromium is prepared, a chromium oxide film and a chromium nitride film can be easily formed by using reactive sputtering or the like. Furthermore, with the above-mentioned low-reflection layer, high-definition patterning can be easily performed compared to a silicon oxide film.

[0069] In this specification, "a chromium oxide film and a chromium nitride film arranged in any order on the surface of the metal chromium film opposite the highly reflective substrate" means that the metal chromium film, the chromium oxide film, and the chromium nitride film may be arranged in this order, or the metal chromium film, the chromium nitride film, and the chromium oxide film may be arranged in this order.

[0070] For example, in Fig. 7(a), the low-reflection layer 2 has, from the highly reflective substrate 1 side, a metal chromium film 2c, a chromium nitride film 2b, and a chromium oxide film 2a. On the other hand, in Fig. 7(b), the low-reflection layer 2 has, from the highly reflective substrate 1 side, a metal chromium film 2c, a chromium oxide film 2a, and a chromium nitride film 2b.

[0071] In the low reflection layer, the film located on the outermost surface opposite to the highly reflective substrate is preferably a chromium oxide film or a chromium nitride film, and more preferably a chromium oxide film, because the reflectance of the low reflection region can be more effectively reduced.

[0072] Hereinafter, the "low-reflective layer in which a metal chromium film, a chromium nitride film, and a chromium oxide film are arranged in this order" will be referred to as a first specification low-reflective layer, and the "low-reflective layer in which a metal chromium film, a chromium oxide film, and a chromium nitride film are arranged in this order" will be referred to as a second specification low-reflective layer.

[0073] (i) Low-reflection layer of the first specification In the low-reflection layer of this specification, a metal chromium film, a chromium nitride film, and a chromium oxide film are arranged in this order from the highly reflective substrate side. In the low-reflection region having the low-reflection layer of this specification, the reflectance at any wavelength within the range of 500 nm to 1000 nm can be reduced to 5% or less, especially 0.5% or less. In addition, the change in reflectance with respect to the change in wavelength is gradual, making it easy to control the reflectance.

[0074] (i-1) Metal chromium film In this specification, the metal chromium film is disposed on the first surface of the highly reflective substrate. The metal chromium film is a layer made of metal chromium. The metal chromium film is a layer that does not substantially transmit light irradiated from a light source, and preferably has a transmittance of 0.0% or more and 1.0% or less. The transmittance is measured using a spectrophotometer "MPC-3100" manufactured by Shimadzu Corporation. The thickness of the metal chromium film is, for example, preferably 40 nm or more, more preferably 70 nm or more.

[0075] The metal chromium film can be formed by a physical vapor deposition (PVD) method such as sputtering, ion plating, or vacuum deposition.

[0076] (i-2) Chromium nitride film The chromium nitride film in this specification is disposed between the metallic chromium film and the chromium oxide film. Unlike chromium oxide nitride and chromium oxide nitride carbide, the chromium nitride film is mainly composed of chromium and nitrogen and contains substantially no impurities other than chromium and nitrogen.

[0077] In the chromium nitride (CrNx) film, x, which represents the atomic ratio of Cr to N, is preferably 0.4 or more and 1.1 or less.

[0078] When the ratio of all elements contained in the chromium nitride film is taken as 100 atomic %, the ratio of chromium and nitrogen is preferably 80 atomic % or more and 100 atomic % or less, and more preferably 90 atomic % or more and 100 atomic % or less. The chromium nitride film may contain impurities such as hydrogen, oxygen, and carbon.

[0079] Chromium nitride film thickness (T N ) is preferably, for example, 5 nm or more and 100 nm or less, and more preferably 10 nm or more and 80 nm or less. O ) in relation to the wavelength of 850 nm, T N and T O It is preferable that the sum of T is 40 nm or more. N and T O The sum of the thickness and the thickness is preferably 20 nm or more. With such a thickness, the reflectance of the low reflection region can be easily reduced to a desired range, compared with a case where the thickness is outside the above range. Furthermore, the thickness of the chromium nitride film is preferably 10 nm or more and 80 nm or less. It becomes easy to reduce the reflectance in the entire range from green to infrared, that is, the reflectance in the range of about 500 nm to 1000 nm.

[0080] Chromium nitride can be formed by physical vapor deposition (PVD) methods such as reactive sputtering, ion plating, and vacuum deposition. When using reactive sputtering, nitrogen is introduced into argon (Ar) gas, and a chromium nitride film can be formed by reactive sputtering using a Cr target. In this case, the composition of the chromium nitride film can be controlled by controlling the ratio of Ar gas and nitrogen gas.

[0081] (i-3) Chromium oxide film The chromium oxide film in this specification is disposed on the opposite side of the chromium nitride film to the metallic chromium film. The chromium oxide film is mainly composed of chromium and oxygen, and unlike chromium oxide nitride and chromium oxide nitride carbide, it contains substantially no impurities other than chromium and oxygen.

[0082] In the chromium oxide (CrOy) film, y, which represents the atomic ratio of Cr to O, is preferably 1.4 or more and 2.1 or less.

[0083] Specifically, when the ratio of all elements contained in the chromium oxide film is taken as 100 atomic %, the ratio of chromium and oxygen is preferably 80 atomic % or more and 100 atomic % or less, and more preferably 90 atomic % or more and 100 atomic % or less. The chromium oxide film may contain impurities such as hydrogen, nitrogen, and carbon.

[0084] The thickness of the chromium oxide film is not particularly limited, and is preferably 5 nm to 100 nm, more preferably 10 nm to 80 nm. The sum of the thickness of the chromium oxide film and the thickness of the chromium nitride film is as described above. Furthermore, the thickness of the chromium oxide film is preferably 10 nm to 65 nm. It becomes easy to reduce the reflectance in the entire range from green to infrared, that is, the reflectance in the range of about 500 nm to 1000 nm.

[0085] Chromium oxide can be formed by physical vapor deposition (PVD) such as reactive sputtering, ion plating, and vacuum deposition. When using reactive sputtering, oxygen is introduced into argon (Ar) gas, and a chromium oxide film can be formed by reactive sputtering using a Cr target. In this case, the composition of the chromium oxide film can be controlled by controlling the ratio of Ar gas to oxygen gas.

[0086] (ii) Second specification low-reflection layer In the low-reflection layer of this specification, a metal chromium film, a chromium oxide film, and a chromium nitride film are arranged in this order from the highly reflective substrate side. In the low-reflection region having the low-reflection layer of this specification, the reflectance at any wavelength within the range of 500 nm to 1000 nm can be reduced to 5% or less, especially 1% or less.

[0087] (ii-1) Metal chromium film The metal chromium film in this specification is similar to the metal chromium film in the low reflection layer in the first specification described above, and therefore a description thereof will be omitted here.

[0088] (ii-2) Chromium oxide film The chromium oxide film in this specification is disposed between the metallic chromium film and the chromium nitride film.

[0089] The thickness of the chromium oxide film is not particularly limited, and is preferably 5 nm to 60 nm, more preferably 10 nm to 50 nm. As described later, the sum of the thickness of the chromium oxide film and the thickness of the chromium nitride film is preferably within a predetermined range. Furthermore, the thickness of the chromium oxide film is preferably 5 nm to 35 nm, since it is easy to reduce the reflectance in the entire range from green to infrared, that is, the reflectance in the range from 500 nm to 1000 nm.

[0090] The physical properties, composition and method of formation of the chromium oxide film are similar to those of the chromium oxide film in the low reflection layer of the first specification, and therefore a description thereof will be omitted here.

[0091] (ii-3) Chromium nitride film The chromium nitride film in this specification is disposed on the opposite side of the chromium oxide film to the metallic chromium film.

[0092] Chromium nitride film (T N The thickness of the chromium oxide film (T O ) in relation to the wavelength of 850 nm, T N and T O It is preferable that the sum of is 30 nm or more. When the wavelength is 550 nm, T N and T O The sum of these is preferably 15 nm or more. Furthermore, the thickness of the chromium nitride film is preferably 10 nm or more and 60 nm or less. This makes it easy to reduce the reflectance over the entire range from green to infrared, that is, the reflectance over the range of about 500 nm to 1000 nm.

[0093] The method for forming the chromium nitride film is the same as that for the chromium nitride film in the low reflection layer of the first specification described above, and therefore a description thereof will be omitted here.

[0094] (iii) Method for forming a low reflection layer The method for forming the low reflective layer is not particularly limited, but the low reflective layer can be formed by selective etching or lift-off.

[0095] In the case of selective etching, for example, a metal chromium film is first formed on the first surface of a highly reflective substrate by sputtering or the like, and then a chromium nitride film and a chromium oxide film are formed. Next, the metal chromium film, the chromium nitride film, and the chromium oxide film are patterned by photolithography and etching.

[0096] In the case of the lift-off method, for example, a resist pattern is first formed on the first surface of a highly reflective substrate, and a metal chromium film, a chromium nitride film, and a chromium oxide film are formed by a known vacuum film forming method such as sputtering. The resist pattern is then removed to lift off the metal chromium film, the chromium nitride film, and the chromium oxide film formed directly on the resist pattern, thereby obtaining a pattern of the metal chromium film, the chromium nitride film, and the chromium oxide film.

[0097] (c) Other configurations The reflective optical scale for an encoder of this embodiment may have other layers in addition to the high reflection substrate and the low reflection layer. For example, the reflective optical scale for an encoder of this embodiment may have a protective layer between the high reflection substrate and the low reflection layer.

[0098] The protective layer is preferably transparent and has a function of protecting the highly reflective substrate. By providing the protective layer, there is no risk that the surface of the highly reflective substrate becomes rough and the surface roughness increases during etching when forming the low reflection layer in a pattern. Therefore, diffuse reflection of light can be suppressed. The protective layer may be provided over the entire area of ​​the highly reflective substrate in a plan view, or may be provided in a partial area.

[0099] The material for the protective layer is not particularly limited as long as it is transparent and can protect the highly reflective substrate, and may be either an organic material or an inorganic material.

[0100] The organic material preferably contains a resin. The resin used in the protective layer is not particularly limited as long as it is a resin that can provide a transparent protective layer, and examples thereof include ionizing radiation curable resins that are cured by irradiation with ionizing radiation such as ultraviolet rays or electron beams, and thermosetting resins that are cured by heating. Specifically, novolac resins, polyolefin resins, polyester resins, urethane resins, polyimide resins, acrylic resins, and epoxy resins are preferred. Of the novolac resins, phenol novolac resins are preferred. This is because they have excellent electrical properties and can suppress problems caused by charging. Of the acrylic resins, trifunctional or higher acrylates such as pentaerythritol tetraacrylate and dipentaerythritol tetraacrylate are preferred. This is because they can enhance photocurability. Of the epoxy resins, epoxy acrylate resins having a fluorene structure are preferred. This is because they improve heat resistance, adhesion, and chemical resistance. Of the epoxy resins, cardo epoxy resins are also preferred. This is because they can provide excellent transparency, heat resistance, surface hardness, and flatness. The organic material may contain, in addition to the resin, a polymerization initiator, various additives, and the like.

[0101] The inorganic material may be an inorganic compound. Examples of the inorganic compound include oxides, oxynitrides, nitrides, oxycarbides, and oxycarbonitrides of metal elements or nonmetal elements such as silicon, aluminum, magnesium, calcium, potassium, tin, sodium, titanium, boron, yttrium, zirconium, cerium, and zinc. In particular, silicon dioxide (SiO 2 The inorganic compound may be used alone or in the form of a mixture of the above-mentioned materials in any ratio.

[0102] (2) Second aspect of the reflective optical scale for encoder A second aspect of the reflective optical scale for an encoder in the present disclosure has a low-reflection substrate having a first surface and a second surface opposite the first surface, and a patterned highly-reflective layer arranged on the first surface side of the low-reflection substrate.

[0103] Hereinafter, the reflective optical scale for an encoder according to this embodiment will be described in detail with respect to each component.

[0104] (a) Low reflection base material The low-reflection substrate in this embodiment has a low reflectance similar to that of the low-reflection region in the first embodiment of the reflective optical scale for an encoder.

[0105] The low-reflection substrate may be a single-layer low-reflection substrate, or may have a transparent substrate and a low-reflection layer disposed on the surface of the transparent substrate opposite to the highly reflective layer.

[0106] The material of the low reflection substrate is not particularly limited as long as it has low reflectivity, and may be either an organic material or an inorganic material.

[0107] Similarly, the material of the low reflection layer is not particularly limited as long as it has low reflectivity, and may be either an organic material or an inorganic material. The organic material preferably contains a resin. The resin used in the low reflection layer is not particularly limited as long as it is a resin that can obtain a low reflection layer, and examples thereof include ionizing radiation curable resins that are cured by irradiation with ionizing radiation such as ultraviolet rays and electron beams, and thermosetting resins that are cured by heating. Specifically, novolac resins, polyolefin resins, polyester resins, urethane resins, polyimide resins, acrylic resins, and epoxy resins are preferred. Among the novolac resins, phenol novolac resins are preferred. This is because they have excellent electrical properties and can suppress problems caused by charging. Among the acrylic resins, trifunctional or higher acrylates such as pentaerythritol tetraacrylate and dipentaerythritol tetraacrylate are preferred. This is because they can enhance photocurability. As the epoxy resin, epoxy acrylate resins having a fluorene structure are preferred. This is because they improve heat resistance, adhesion, and chemical resistance. As the epoxy resin, cardo epoxy resins are also preferred. This is because it is possible to impart heat resistance, surface hardness, and flatness. The organic material may contain, in addition to the resin, a polymerization initiator, various additives, and the like.

[0108] When the low-reflection layer contains an inorganic material, the low-reflection layer is the same as the low-reflection layer in the first embodiment of the reflective optical scale for an encoder. Among them, the low-reflection layer is preferably the low-reflection layer of the first specification or the low-reflection layer of the second specification described above.

[0109] The transparent substrate is the same as the transparent substrate in the reflective optical scale for encoder described below.

[0110] In the case of a rotary encoder, the low-reflection substrate is disk-shaped. The low-reflection substrate may be, for example, a perforated disk-shaped substrate having a central hole, or may not have a central hole. On the other hand, in the case of a linear encoder, the low-reflection substrate is rectangular.

[0111] When the low-reflection substrate is a perforated disk, the outer and inner diameters of the low-reflection substrate in a plan view are similar to the outer and inner diameters of the high-reflection substrate in the first embodiment of the reflective optical scale for an encoder.

[0112] When the low-reflection substrate has a resin substrate, the low-reflection substrate may have a sagging on the outer peripheral edge on the first surface side. When the low-reflection substrate has a resin substrate and is a perforated disk shape, the low-reflection substrate may have a sagging on the inner peripheral edge on the first surface side.

[0113] (b) Highly reflective layer The highly reflective layer in this embodiment is disposed in a pattern on the first surface side of the low reflection substrate.

[0114] The reflectance of the high reflection region may be higher than that of the low reflection region. Specifically, the reflectance of the high reflection region may be higher than that of the low reflection substrate. The reflectance of the high reflection region is the same as the reflectance of the first surface of the high reflection substrate in the first embodiment of the reflective optical scale for an encoder.

[0115] The highly reflective layer is not particularly limited in its configuration as long as it satisfies the above reflectance, and may be, for example, a metal film. The metal film is preferably made of a metal having a high reflectance. Examples of metals include chromium, silver, aluminum, rhodium, gold, copper, and alloys mainly composed of these metals. Among them, a metal chromium film is preferable. The metal chromium film is a layer made of metal chromium. The thickness of the metal film is, for example, 0.05 μm or more and 0.3 μm or less, and may be 0.1 μm or more and 0.2 μm or less.

[0116] 4. Transmissive Optical Scale for Encoders The transmissive optical scale for an encoder in the present disclosure has an optical pattern having two regions with different transmittances, i.e., a transmissive region and a light-shielding region. The configuration of the transmissive optical scale for an encoder in the present disclosure is not particularly limited as long as it has an optical pattern having a transmissive region and a light-shielding region, but it preferably has a transparent substrate having a first surface and a second surface opposed to the first surface, and a patterned light-shielding layer disposed on the first surface side of the transparent substrate.

[0117] 6(a) is an enlarged cross-sectional view of the dotted frame a in FIG. 2 along the line AA. As illustrated in FIG. 2 and FIG. 6(a), the transmissive optical scale 20 for an encoder has a disk-shaped transparent base material 31 having a first surface 31a and a second surface 31b facing the first surface 31a, and a light-shielding layer 32 arranged in a pattern along the circumferential direction of the transparent base material 31 on the first surface 31a side of the transparent base material 31. The transmissive optical scale 20 for an encoder has a holed disk shape, and light-shielding regions 22 in which the light-shielding layer 32 is arranged and transmissive regions 21 in which the light-shielding layer 32 is not arranged are arranged alternately in the circumferential direction. The light-shielding region 22 has the transparent base material 31 and the light-shielding layer 32 in the thickness direction of the transmissive optical scale 20 for an encoder. The transmissive region 21 has a transparent base material 31. The transmittance in the transmissive region 21 is higher than the transmittance in the light-shielding region 22. The transmittance in the light-transmitting region 21 and the transmittance in the light-shielding region 22 indicate the transmittance at the same wavelength.

[0118] Hereinafter, each configuration of the reflective optical scale for an encoder according to the present disclosure will be described.

[0119] (1)Transparent base material The transparent substrate in the present disclosure has high transmittance. The total light transmittance of the transparent substrate is, for example, 80% or more, may be 85% or more, or may be 90% or more. The total light transmittance is measured in accordance with JIS K7361-1:1997.

[0120] Examples of materials for the transparent substrate include glass and resin. Glass has high strength and a small linear expansion coefficient, so dimensional changes caused by temperature changes in the usage environment can be suppressed. Resins that satisfy the above transmittance are preferable, and examples of such resins include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), polyethylene (PE), polycarbonate (PC), acrylic resin, polyvinyl chloride, polyvinyl alcohol, polyimide, polyetherimide, polyether ether ketone, epoxy resin, silicone resin, and phenol resin.

[0121] The thickness of the transparent substrate is not particularly limited as long as it satisfies the above-mentioned transmittance, and is, for example, 0.1 mm or more and 2 mm or less.

[0122] In the case of a rotary encoder, the transparent substrate is disk-shaped, and may be, for example, a disk-shaped substrate having a central hole or may not have a central hole, whereas in the case of a linear encoder, the transparent substrate is rectangular.

[0123] (2) Light shielding layer The light-shielding layer in the present disclosure is disposed in a pattern on the first surface side of the transparent substrate.

[0124] The transmittance in the light-shielding region may be lower than the transmittance in the light-transmitting region. The optical density of the light-shielding region is, for example, 2.5 or more, or may be 3.0 or more, 3.5 or more, or 4.0 or more.

[0125] In this specification, optical density refers to transmission density. Optical density is measured using an optical densitometer. An optical densitometer is a measuring instrument that irradiates a sample (object to be measured) with light and measures the intensity of the transmitted light. Specifically, a Takano OD reflectance measuring instrument manufactured by Takano Corporation is used to irradiate the sample with light in a perpendicular direction to perform the measurement.

[0126] The configuration of the light-shielding layer is not particularly limited as long as it satisfies the above optical density. The configuration of the light-shielding layer may be the same as the configuration of the low reflection layer, for example.

[0127] 5. Manufacturing method of optical scale for encoder The manufacturing method of the optical scale for an encoder in the present disclosure preferably includes a polygonal body fabrication process for fabricating an optical scale for an encoder polygonal body having an optical scale for an encoder attached to multiple surfaces, and a singulation process for individualizing the optical scale for an encoder polygonal body.

[0128] The optical scale polygonal body for an encoder will be described later, so a description thereof will be omitted here.

[0129] The method of dividing the optical scale polygonal body for the encoder into individual pieces varies depending on the substrate of the optical scale polygonal body for the encoder. When the substrate of the optical scale polygonal body for the encoder is a highly reflective substrate, and the highly reflective substrate is a metal substrate, punching and etching can be used. When the substrate of the optical scale polygonal body for the encoder is a highly reflective substrate, and the highly reflective substrate has a glass substrate, when the substrate of the optical scale polygonal body for the encoder is a low reflective substrate, and the low reflective substrate has a glass substrate, and when the substrate of the optical scale polygonal body for the encoder is a transparent substrate, and the transparent substrate is a glass substrate, mechanical cutting can be used. When the substrate of the optical scale polygonal body for the encoder is a highly reflective substrate, and the highly reflective substrate has a resin substrate, when the substrate of the optical scale polygonal body for the encoder is a low reflective substrate, and the low reflective substrate has a resin substrate, and when the substrate of the optical scale polygonal body for the encoder is a transparent substrate, and the transparent substrate is a resin substrate, punching can be used.

[0130] As described above, punching a polygonal body is different from etching a polygonal body in that there is no need to provide a bridge connecting the optical scale for an encoder and the frame, and therefore no bridge marks are generated. This makes it possible to suppress the occurrence of partial distortion. In addition, there is no need to reduce the thickness of the metal base material in order to reduce costs and improve accuracy. This allows the metal base material to be made thicker, suppressing waviness and warping. In addition, this is more advantageous in terms of cost than etching a polygonal body.

[0131] Furthermore, when the size of the optical scale polygonal body for the encoder is large, when singulating the optical scale polygonal body for the encoder, rather than singulating the optical scale polygonal body for the encoder all at once, the optical scale polygonal body for the encoder may be divided into multiple pieces in advance and then singulated.

[0132] 8(a) to 8(b) are schematic diagrams showing an example of a punching device used in the singulation process. First, as shown in FIG. 8(a), the encoder optical scale polygonal body 50 is placed on a lower stage 62 having a lower blade 61. Next, as shown in FIG. 8(b), the lower stage 62 is moved upward and the upper stage 63 having an upper blade 64 is moved downward and pressed in, thereby punching out the encoder optical scale polygonal body 50. In addition, it is preferable that a pressing member 65 is disposed at a position opposite to the upper blade 64. During punching, the metal base material is sandwiched between the upper blade 64 and the pressing member 65, and punching can be performed with less burrs and sagging. In this manner, individual encoder reflective optical scales 10 are obtained.

[0133] 6. Applications of optical scales for encoders The optical scale for an encoder according to the present disclosure may be used in a rotary encoder or a linear encoder.

[0134] B. Multi-faceted optical scale for encoder The optical scale polygonal body for an encoder in the present disclosure is an optical scale polygonal body for an encoder having an optical pattern with two areas of different reflectance or transmittance attached to it in a multifaceted manner, wherein the optical scale for an encoder has a two-dimensional code, the optical scale polygonal body for an encoder has one or more unit areas, and in the unit areas, the two-dimensional code is different for each optical scale for an encoder.

[0135] Fig. 3 and Fig. 9 are schematic plan views showing an example of an encoder optical scale polygonal body in the present disclosure, and Fig. 4 is a partial enlarged view of Fig. 3 and Fig. 9. As shown in Fig. 3 and Fig. 9, in the encoder optical scale polygonal body 50, an encoder optical scale (an encoder reflective optical scale 10 or an encoder transmissive optical scale 20) having an optical pattern having two regions with different reflectance or transmittance is multifaceted. As shown in Fig. 4, the encoder optical scale (an encoder reflective optical scale 10 or an encoder transmissive optical scale 20) has a two-dimensional code 14 or 24.

[0136] In Fig. 3, the encoder optical scale polygonal body 50 has one unit area U1, and in the unit area U1, the two-dimensional code 14 or 24 is different for each encoder optical scale (the encoder reflective optical scale 10 or the encoder transmissive optical scale 20). Specifically, in Fig. 3, a total of 100 encoder optical scales (the encoder reflective optical scale 10 or the encoder transmissive optical scale 20) are arranged in 10 rows and 10 columns. In the unit area U1, the two-dimensional codes 14 or 24 of the 100 encoder optical scales (the encoder reflective optical scale 10 or the encoder transmissive optical scale 20) are different from each other.

[0137] 9, the encoder optical scale polygonal body 50 has two unit areas U1 and U2, and in the unit area U1, the two-dimensional code 14 or 24 is different for each encoder optical scale (the encoder reflective optical scale 10 or the encoder transmissive optical scale 20), and similarly, in the unit area U2, the two-dimensional code 14 or 24 is different for each encoder optical scale (the encoder reflective optical scale 10 or the encoder transmissive optical scale 20). Specifically, in FIG. 8, a total of 320 encoder optical scales (encoder reflective optical scales 10 or encoder transmissive optical scales 20) are arranged in 20 rows and 16 columns. In the unit area U1, 160 optical scales for encoders (reflective optical scales for encoders 10 or transmissive optical scales for encoders 20) are arranged in 10 rows and 16 columns, and similarly, in the unit area U2, 160 optical scales for encoders (reflective optical scales for encoders 10 or transmissive optical scales for encoders 20) are arranged in 10 rows and 16 columns. In the unit area U1, the two-dimensional codes 14 or 24 of the 160 optical scales for encoders (reflective optical scales for encoders 10 or transmissive optical scales for encoders 20) are different from each other. Similarly, in the unit area U2, the two-dimensional codes 14 or 24 of the 160 optical scales for encoders (reflective optical scales for encoders 10 or transmissive optical scales for encoders 20) are different from each other.

[0138] In Figures 3 and 9, in order to make it easier to illustrate and to understand, a total of 100 optical scales for encoders are shown arranged in 10 rows and 10 columns, or a total of 320 optical scales for encoders are shown arranged in 20 rows and 16 columns, but the number of optical scales for encoders in the optical scale polygonal body for encoders is not limited to this.

[0139] In the present disclosure, since the two-dimensional code is different for each optical scale for an encoder in a unit area, the position of the optical scale for an encoder on the polygonal optical scale body for an encoder can be specified, thereby achieving the same effects as those of the optical scale for an encoder described above.

[0140] An optical scale for an encoder produced by dividing the optical scale polygonal body for an encoder in the present disclosure will be described. FIG. 10 is a schematic diagram showing a state in which the optical scale for an encoder is contained in a containing member. As shown in FIG. 10, the optical scale for an encoder (the reflective optical scale for an encoder 10 or the transmissive optical scale for an encoder 20) is contained in a containing member 70 for each unit area. FIG. 10 shows an example in which the optical scale polygonal body for an encoder shown in FIG. 3 is divided into individual pieces. The containing member 70 has 100 containing sections 71, and the optical scale for an encoder (the reflective optical scale for an encoder 10 or the transmissive optical scale for an encoder 20) is contained in the containing section 71.

[0141] In Fig. 3, the optical scale polygonal body 50 for an encoder has one unit area U1, so 100 optical scales for an encoder are accommodated in one accommodation member. On the other hand, in Fig. 9, the optical scale polygonal body 50 for an encoder has two unit areas U1 and U2, so the optical scales are accommodated in the accommodation members for each unit area U1 and U2, that is, the optical scales for an encoder are accommodated in two accommodation members, with 160 pieces for each unit area.

[0142] When the encoder optical scale polygonal body according to the present disclosure has a plurality of unit areas, the encoder optical scale has the same two-dimensional code in one unit area and the other unit areas. In contrast, in the unit areas, the two-dimensional code is different for each encoder optical scale, so that traceability can be ensured by storing the encoder optical scale in a storage member for each unit area.

[0143] It is preferable that information indicating the unit area is displayed on the storage member.

[0144] In the encoder optical scale polygonal body of the present disclosure, the number of encoder optical scales is, for example, preferably 50 or more, may be 200 or more, or may be 400 or more. In this way, the present disclosure is useful when the number of encoder optical scales in the encoder optical scale polygonal body is large. On the other hand, the upper limit of the number of encoder optical scales in the encoder optical scale polygonal body is not particularly limited, but is, for example, 3000 or less due to constraints of the manufacturing device.

[0145] The size of the encoder optical scale polygonal body in the present disclosure in a plan view is not particularly limited, but the length of one side of the encoder optical scale polygonal body is preferably 150 mm or more, more preferably 300 mm or more, and even more preferably 350 mm or more. As described above, the present disclosure is useful when the encoder optical scale polygonal body has a large size in a plan view. The upper limit of the size of the encoder optical scale polygonal body in the present disclosure in a plan view is not particularly limited, but due to the constraints of the manufacturing device, for example, the length of one side of the encoder optical scale polygonal body is 920 mm or less.

[0146] The optical scale polygonal body for an encoder in the present disclosure may further have identification information other than the two-dimensional code. Examples of the other identification information include the manufacturer, the date of manufacture, and the lot number. Examples of the other identification information include letters, numbers, and symbols. The other identification information may be discerned by human eyes, or may be character-recognized by OCR.

[0147] In the encoder optical scale polygonal body of the present disclosure, the position of the other identification information is not particularly limited. The other identification information may be disposed on each encoder optical scale, or may be disposed in an area other than the encoder optical scale.

[0148] In the case of an encoder optical scale body having multiple reflective optical scales, the method for forming a patterned low-reflection layer on the first surface of the highly reflective substrate is the same as the method for forming a low-reflection layer described above. In the case of an encoder optical scale body having multiple transmissive optical scales, the method for forming a patterned light-shielding layer on the first surface of the transparent substrate is the same as the method for forming a light-shielding layer described above.

[0149] C. Optical Encoder The optical encoder of the present disclosure comprises the above-mentioned optical scale for the encoder, a light source that irradiates measurement light onto the surface of the optical scale for the encoder, and a photodetector that detects reflected light or transmitted light from the optical scale for the encoder.

[0150] The optical encoder in the present disclosure may be a reflective encoder or a transmissive encoder.

[0151] Fig. 11 is a schematic perspective view showing an example of an optical encoder in the present disclosure, which is an example of a reflective encoder. The optical encoder 100A includes a reflective optical scale 10 for an encoder, and a light source 81 and a photodetector 82 arranged on the same plane as the reflective optical scale 10 for an encoder. In Fig. 11, a fixed slit 83 is arranged between the photodetector 82 and the reflective optical scale 10 for an encoder.

[0152] Fig. 12 is a schematic perspective view showing another example of an optical encoder according to the present disclosure, which is an example of a transmissive encoder. The optical encoder 100B includes a transmissive optical scale 20 for an encoder, a light source 91 arranged on one surface side of the transmissive optical scale 20 for an encoder, and a photodetector 92 arranged on the other surface side of the transmissive optical scale 20 for an encoder. In Fig. 12, a lens 93 is arranged between the light source 91 and the transmissive optical scale 20 for an encoder.

[0153] According to the present disclosure, since the above-mentioned optical scale for an encoder is provided, the same effects as those of the above-mentioned optical scale for an encoder are achieved.

[0154] Hereinafter, the optical encoder according to the present disclosure will be described in detail with respect to each of its components.

[0155] 1. Optical scale for encoders The optical scale for the encoder has been described above in "A. Optical scale for the encoder" and so a description thereof will be omitted here.

[0156] 2.Light source Examples of light sources include LEDs (light emitting diodes) and lasers. The wavelength λ of light emitted from the light source is, for example, in the blue to infrared region, that is, about 400 nm to 1000 nm. In the case of a reflective encoder, the angle of incidence of light on the optical reflective scale is, for example, 5° to 70°.

[0157] 3. Photodetector The photodetector detects light reflected by or transmitted through the optical scale. The photodetector includes a light receiving element such as a photodiode or an image sensor. Examples of the light receiving element include a photoelectric conversion element.

[0158] 4.Other In the case of a reflective encoder, the optical encoder according to the present disclosure may include a fixed slit between the photodetector and the optical reflective scale for the encoder. By providing the fixed slit, the change in the amount of light received by the photodetector increases, and the detection sensitivity can be improved. The fixed slit may be provided between the light source and the optical scale for the encoder.

[0159] In the case of a transmissive encoder, the optical encoder according to the present disclosure may include a lens between the light source and the optical transmissive scale for the encoder. By providing the lens, the light from the light source can be converted from diffused light to parallel light.

[0160] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits similar effects is included in the technical scope of the present disclosure.

[0161] That is, the present disclosure provides the following inventions. [1] An optical scale for an encoder having an optical pattern having two regions with different reflectance or transmittance, An optical scale for encoders having a two-dimensional code. [2] The optical scale for an encoder according to [1], wherein the two-dimensional code is arranged in an area other than the optical pattern area in which the optical pattern is arranged. [3] A disk-shaped highly reflective substrate having a first surface and a second surface opposite to the first surface; a patterned low-reflection layer disposed on the first surface side of the highly reflective substrate; The optical scale for an encoder according to [1] or [2], [4] A disc-shaped transparent substrate having a first surface and a second surface opposite to the first surface; a patterned light-shielding layer disposed on the first surface side of the transparent substrate; The optical scale for an encoder according to [1] or [2], [5] An optical scale for an encoder described in any one of [1] to [4], wherein the material of the two-dimensional code is the same as the material of the optical pattern. [6] A multi-faceted optical scale body for an encoder, the multi-faceted optical scale for an encoder having an optical pattern with two regions having different reflectance or transmittance, The optical scale for an encoder has a two-dimensional code, The encoder optical scale polygonal body has one or more unit areas, A polygonal optical scale body for an encoder, in which the two-dimensional code is different for each of the optical scales for an encoder in the unit area. [7] An optical scale for an encoder according to any one of [1] to [5], a light source that irradiates a surface of the optical scale for an encoder with measurement light; a photodetector for detecting reflected light or transmitted light from the optical scale for encoder; An optical encoder comprising: [Explanation of symbols]

[0162] 1 … Highly reflective base material 2…Low reflective layer 10... Optical reflective scale for encoder 11… High reflective area 12…Low reflection area 13...Optical pattern 14... 2D code 20... Optical transmission scale for encoder 21…Transmission area 22…shading area 23...Optical pattern 24... 2D code 31…Transparent base material 32... Light shielding layer 50... Optical scale multi-faceted body for encoder 100A, 100B... Optical Encoder U1, U2... Unit area

Claims

1. An optical scale for an encoder having an optical pattern having two regions with different reflectance or transmittance, An optical scale for encoders having a two-dimensional code.

2. 2. The optical scale for an encoder according to claim 1, wherein the two-dimensional code is arranged in an area other than an optical pattern area in which the optical pattern is arranged.

3. a highly reflective substrate having a first surface and a second surface opposite to the first surface; a patterned low-reflection layer disposed on the first surface side of the highly reflective substrate; 2. The optical scale for an encoder according to claim 1, wherein

4. a transparent substrate having a first surface and a second surface opposite to the first surface; a patterned light-shielding layer disposed on the first surface side of the transparent base material; 2. The optical scale for an encoder according to claim 1, wherein

5. The optical scale for an encoder according to claim 1 , wherein a material of the two-dimensional code is the same as a material of the optical pattern.

6. An optical scale for an encoder having an optical pattern with two regions having different reflectances or transmittances, the optical scale for an encoder having a multi-surface attachment, The optical scale for an encoder has a two-dimensional code, the encoder optical scale polygonal body has one or more unit areas, A polygonal optical scale body for an encoder, in which the two-dimensional code is different for each optical scale for an encoder in the unit area.

7. An optical scale for an encoder according to any one of claims 1 to 5; a light source that irradiates a surface of the optical scale for an encoder with a measurement light; a photodetector for detecting reflected light or transmitted light from the optical scale for an encoder; An optical encoder comprising:

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