Reflection-type optical scale for encoder, reflection-type optical encoder, method for manufacturing reflection-type optical scale for encoder, and reflection-type optical scale assembly for encoder

Abstract

The present invention provides a reflective optical scale for an encoder, comprising: a disc-shaped metal substrate having a first surface and a second surface facing the first surface; and a low reflection layer disposed in a pattern on the first surface side of the metal substrate along the circumferential direction of the metal substrate, in which the metal substrate has a reflectance of 50% or more and a thickness of 0.05 mm to 0.60 mm inclusive on at least the first surface side, the metal substrate has a sag on the outer peripheral edge of the first surface side, and the sag has a thickness of 0.05 mm to 0.60 mm inclusive on the outer peripheral edge of the first surface side. The width of the collapsed edge is less than 500 [mu] m.

Description

Technical Field

[0001] The present disclosure relates to a reflective optical scale for an encoder, a reflective optical encoder, a method for manufacturing a reflective optical scale for an encoder, and a reflective optical scale plateset for an encoder. Background Art

[0002] In the past, optical encoders were used in servo motors with control mechanisms. There are two types of optical encoders: transmissive encoders and reflective encoders. Compared with transmissive encoders, reflective encoders have the following advantages: a short optical path, easy miniaturization and thinning, and no need to position light-emitting elements or light-receiving elements, making them easy to assemble.

[0003] A reflective optical encoder includes a reflective optical scale, a light source such as an LED that irradiates light to the scale, and a light detector that detects reflected light from the scale. In the reflective optical scale, reflective areas (high-reflective areas) and non-reflective areas (low-reflective areas) are alternately arranged, and the reflectivity of light in the reflective area is higher than the reflectivity of light in the non-reflective area (for example, Patent Document 1).

[0004] As a result, the intensity of light reflected from the scale and incident on the photodetector changes depending on the position of the scale. The photodetector detects the intensity of light generated by the position of the scale moving in the length measurement direction. The reflective optical encoder processes the displacement information of the scale position based on the detected intensity of light, thereby being able to obtain position information.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2005-241248 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In the past, reflective optical scales were manufactured by singulating a plated body in which a plurality of reflective optical scales were arranged. In the singulation process, since the processing accuracy is good, singulation is usually performed by etching. However, singulation based on etching is disadvantageous in terms of cost.

[0010] Therefore, the inventor of the present application has tried a method of singulating the plated body of a reflective optical scale by punching. However, the scale singulated by punching will produce a collapsed edge (hereinafter also referred to as a peripheral collapsed edge) at the outer periphery. The inventor of the present application has found that if a peripheral collapsed edge occurs in an area where a low-reflection layer is formed, i.e., a low-reflection area, peeling or cracking of the low-reflection layer may sometimes occur. Therefore, a scheme has been studied in which a low-reflection layer is not pre-configured in the area where the peripheral collapsed edge occurs due to punching. On the other hand, usually, in an optical scale for an encoder, a low-reflection area of ​​a specified size is obtained according to the encoder device. Therefore, if a non-formation area where a low-reflection layer is not formed is provided at the outer peripheral end of the optical scale, the actual scale size will become larger. Therefore, a reflective optical scale for an encoder is required in which the peripheral collapsed edge area caused by punching is reduced.

[0011] The present invention has been accomplished in view of the above-mentioned situation, and its main object is to provide a reflective optical scale for an encoder with a reduced peripheral edge collapse area.

[0012] Means for solving problems

[0013] One embodiment of the present disclosure provides a reflective optical scale for an encoder, which comprises: a disc-shaped metal substrate having a first surface and a second surface opposite to the first surface; and a low-reflection layer, which is arranged in a pattern along the circumferential direction of the metal substrate on the first surface side of the metal substrate, wherein the reflectivity of at least the first surface side of the metal substrate is 50% or more, the thickness of the metal substrate is 0.05 mm or more and 0.60 mm or less, and the metal substrate has a collapsed edge on the outer peripheral edge of the first surface side, and the width of the collapsed edge is 500 μm or less.

[0014] Another embodiment of the present disclosure provides a reflective optical encoder, characterized in that the reflective optical encoder comprises: the reflective optical scale for the encoder; a light source that irradiates measurement light onto the surface of the reflective optical scale for the encoder on the side where the low-reflection layer is arranged; and a light detector that detects reflected light from the reflective optical scale for the encoder.

[0015] Another embodiment of the present disclosure provides a method for manufacturing a reflective optical scale for an encoder, which comprises:

[0016] A process for producing a plate-like body, the plate-like body comprising: a metal substrate to be processed, the metal substrate comprising a first surface and a second surface opposite to the first surface, the reflectivity of at least the first surface side being 50% or more, the metal substrate having a thickness of 0.05 mm or more and 0.60 mm or less; and a low-reflection layer in a pattern arranged in a circumferential shape, the low-reflection layer being plate-like mounted on the first surface side of the metal substrate to be processed, the plate-like body having a peripheral punching predetermined line for the reflective optical scale for the encoder formed on the outer side of the peripheral surface of each low-reflection layer; and

[0017] The singulation step is to singulate the plate-forming body by punching it out at the predetermined periphery punching lines, thereby obtaining a reflective optical scale for an encoder.

[0018] Another embodiment of the present disclosure provides a reflective optical scale plateform for an encoder, the reflective optical scale plateform for an encoder comprising: a metal substrate to be processed, comprising a first surface and a second surface opposite to the first surface, at least the reflectivity of the first surface being greater than 50%, and the thickness of the metal substrate being greater than 0.05 mm and less than 0.60 mm; and a low-reflection layer in a pattern arranged in a circular shape, which is plated and installed on the first surface side of the metal substrate to be processed, the reflective optical scale plateform for an encoder having an outer peripheral punching predetermined line of the reflective optical scale for an encoder formed on the outside of the outer peripheral surface of each low-reflection layer, wherein the distance between the outer peripheral punching predetermined line of the reflective optical scale for an encoder and the outer peripheral surface of the low-reflection layer is greater than 500 μm and less than 1500 μm.

[0019] Effects of the Invention

[0020] The present disclosure has the effect of providing a reflective optical scale for an encoder with a reduced peripheral sagging area. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic top view of a reflective optical scale for an encoder according to the present disclosure.

[0022] Figure 2 This is a partially enlarged cross-sectional view illustrating a reflective optical scale for an encoder of the present disclosure.

[0023] Figure 3 This is a schematic cross-sectional view illustrating a reflective optical scale for an encoder according to the present disclosure.

[0024] Figure 4 This is a schematic perspective view illustrating a reflective optical encoder according to the present disclosure.

[0025] Figure 5This is a schematic top view of a reflective optical scale plateset for an encoder according to the present disclosure.

[0026] Figure 6 This is a schematic cross-sectional view illustrating a punching device used in a singulation step in the method for manufacturing a reflective optical scale for an encoder disclosed in the present invention.

[0027] Figure 7 It is a graph which shows the results of Experimental Examples 1-1 to 1-6 and Experimental Examples 2-1 to 2-5. DETAILED DESCRIPTION

[0028] The present disclosure includes, in an embodiment, a reflective optical scale for an encoder, a reflective optical encoder, a method for manufacturing a reflective optical scale for an encoder, and a reflective optical scale plateform for an encoder. The embodiments of the present disclosure are described below with reference to the accompanying drawings, etc. However, the present disclosure can be implemented in a variety of different ways, and is not limited to the description of the embodiments illustrated below for explanation. In addition, with respect to the accompanying drawings, in order to make the description clearer, the width, thickness, shape, etc. of each part are sometimes schematically shown compared to the actual form, but this is just an example and does not limit the interpretation of the present disclosure. In addition, in this specification and each figure, for figures that have already appeared, the same elements as the previous ones are marked with the same numbers, and the detailed description is sometimes appropriately omitted.

[0029] In this specification, when describing the configuration of other components on a certain component, if simply described as "on..." or "below...", unless otherwise specified, this includes both the case where the other components are configured directly above or directly below the certain component in a manner of contacting the certain component, and the case where the other components are configured above or below the certain component with another component interposed therebetween. In addition, in this specification, when describing the configuration of other components on the surface of a certain component, if simply described as "on the side of..." or "on the surface of...", unless otherwise specified, this includes both the case where the other components are configured directly above or directly below the certain component in a manner of contacting the certain component, and the case where the other components are configured above or below the certain component with another component interposed therebetween.

[0030] In addition, in this specification, the "reflective optical scale for encoder" is sometimes simply referred to as the "optical scale".

[0031] Hereinafter, the reflective optical scale for an encoder, the reflective optical encoder, the method for manufacturing the reflective optical scale for an encoder, and the reflective optical scale plateform for an encoder disclosed in the present invention will be described in detail.

[0032] A. Reflective optical scale for encoder

[0033] Figure 1 This is a schematic top view showing an example of a reflective optical scale for an encoder disclosed in the present invention. Figure 2 (a) is Figure 1 AA enlarged cross-sectional view of part a in the dotted box. Figure 2 (b) is Figure 1 BB is an enlarged cross-sectional view of the dotted box b part.

[0034] Figure 1 and Figure 2 The reflective optical scale 10 for encoder shown has: a disc-shaped metal substrate 1 having a first surface 1a and a second surface 1b opposite to the first surface; and a low-reflection layer 2 arranged in a pattern along the circumferential direction of the metal substrate 1 on the first surface 1a side of the metal substrate 1. In the present disclosure, with respect to the metal substrate 1, at least the reflectivity of the first surface 1a is greater than a specified value, and the thickness of the metal substrate 1 itself is within a specified range. In addition, as Figure 2 As shown in (b), the metal base material 1 has a collapsed edge P at the outer peripheral edge on the first surface 1a side, and the width X of the collapsed edge P is less than or equal to a predetermined value. Figure 1 The reflective optical scale 10 for encoder has a perforated disc shape, and the area where the low reflection layer 2 is provided, namely the low reflection area R2, and the area where the low reflection layer 2 is not provided, namely the high reflection area R1, are alternately arranged in the circumferential direction. The low reflection area R2 has a metal substrate 1 and a low reflection layer 2 in the thickness direction of the reflective optical scale 10 for encoder. The high reflection area R1 has a metal substrate 1. The reflectivity of light in the above-mentioned high reflection area R1 is higher than the reflectivity of light in the above-mentioned low reflection area R2. In addition, the reflectivity of light in the above-mentioned high reflection area R1 and the reflectivity of light in the above-mentioned low reflection area R2 represent the reflectivity at the same wavelength and the same incident angle.

[0035] The reflective optical scale for encoder disclosed in the present invention has a collapsed edge on the outer periphery of the first surface side of the metal substrate, and the width of the collapsed edge is less than a specified value. Such an optical scale having a collapsed edge on the outer periphery of the metal substrate is usually manufactured by punching. Therefore, it is cost-effective compared to an optical scale manufactured by etching. In addition, such an optical scale with a reduced peripheral collapsed edge area of ​​the metal substrate can narrow the width of the non-formed area where the low-reflection layer is not formed, thereby suppressing the expansion of the scale size and suppressing the peeling or cracking of the low-reflection layer. The reflective optical scale for encoder disclosed in the present invention is described in detail below.

[0036] 1. Metal substrate

[0037] (1) Outer periphery collapse

[0038] The metal substrate disclosed in the present invention is disc-shaped, has a first surface and a second surface opposite to the first surface, and has a collapsed edge on the outer periphery of the first surface side. Furthermore, the width of the collapsed edge of the metal substrate disclosed in the present invention is 500 μm or less, preferably 450 μm or less, more preferably 400 μm or less, and particularly preferably 350 μm or less. If the width of the collapsed edge is too large, it will cause overlap with the formation area of ​​the low-reflection layer, which may cause peeling or cracking of the low-reflection layer. On the other hand, the width of the collapsed edge of the metal substrate disclosed in the present invention is, for example, more than 10 μm, more than 100 μm, more than 200 μm, or more than 250 μm. If the width of the collapsed edge is too small, it may cause undulations on the scale.

[0039] Specifically, the width of the collapsed edge of the metal substrate of the present disclosure is, for example, 10 μm to 500 μm, preferably 100 μm to 450 μm, more preferably 200 μm to 400 μm, particularly preferably 250 μm to 350 μm.

[0040] In this manual, if Figure 2 As shown in (b), the width of the collapsed edge refers to the distance X between the point where the first surface 1 a of the metal substrate 1 starts to collapse and the extension line of the outer peripheral surface 1 c of the metal substrate 1 .

[0041] The method for measuring the width of the collapsed edge, i.e., the distance X, is as follows. First, the metal substrate is cut in a direction perpendicular to the first surface using shearing pliers, shearing, laser cutting, or other methods, and the cut surface is ground into a plane using a grinder to obtain a measurement sample. The cut surface of the measurement sample is observed from a direction perpendicular to the cut surface using a microscope, and the distance X between the point where the first surface 1a of the metal substrate 1 begins to collapse and the extension line of the outer peripheral surface 1c of the metal substrate 1 is measured. The point where the first surface 1a of the metal substrate 1 begins to collapse refers to a point that is not parallel to the planar portion of the first surface of the metal substrate 1, specifically, a point that is more than 3 μm away in the vertical direction. In addition, the width of the peripheral collapsed edge is the average value observed and measured at a total of 12 points on the circumference of the scale with a 30° scale.

[0042] The amount of edge collapse of the metal substrate disclosed in the present invention is, for example, less than 500 μm, preferably less than 450 μm, more preferably less than 400 μm, and particularly preferably less than 350 μm. If the amount of edge collapse is too large, it is possible that the scale may be damaged due to insufficient strength. On the other hand, the amount of edge collapse of the metal substrate disclosed in the present invention is, for example, more than 10 μm, preferably more than 200 μm, more preferably more than 250 μm, and particularly preferably more than 300 μm. If the amount of edge collapse is too small, it is possible to cause undulations on the scale.

[0043] Specifically, the amount of edge collapse of the metal substrate of the present disclosure is, for example, 10 μm to 500 μm, preferably 200 μm to 450 μm, more preferably 250 μm to 400 μm, particularly preferably 300 μm to 350 μm.

[0044] In this manual, if Figure 2 As shown in (b), the amount of the collapsed edge refers to the distance Y between the upper end of the outer peripheral surface 1c of the metal substrate 1 (the boundary point between the collapsed edge and the outer peripheral surface 1c) and the extension line of the first surface 1a of the metal substrate.

[0045] As a method for measuring the amount of the collapsed edge, that is, the distance Y, a measurement sample is prepared by the same method as the method for measuring the width of the collapsed edge, and the distance Y is measured. In addition, the upper end of the outer peripheral surface 1c of the metal substrate 1 (the boundary point between the collapsed edge and the outer peripheral surface 1c) refers to a point that is not parallel to the outer peripheral surface 1c of the metal substrate 1, specifically, a point that is separated by 3 μm or more in the planar direction.

[0046] In addition, the ratio (T2 / T1) of the thickness T2 of the metal substrate at the peripheral end to the thickness T1 of the metal substrate described later is, for example, 0.70 or more, or 0.80 or more. If T2 / T1 is too small, the scale may be damaged due to insufficient strength. On the other hand, the above ratio is, for example, 0.90 or less, or 0.87 or less. If T2 / T1 is too large, undulations may occur on the scale.

[0047] Specifically, the ratio (T2 / T1) of the thickness T2 of the metal substrate at the outer peripheral end to the thickness T1 of the metal substrate is preferably 0.70 to 0.90, and more preferably 0.80 to 0.87.

[0048] When the metal substrate of the present disclosure is a perforated disc, it may have a collapsed edge on the inner periphery of the first surface (hereinafter also referred to as an inner peripheral collapsed edge). The width and amount of the inner peripheral collapsed edge may be the same as or different from the width and amount of the outer peripheral collapsed edge.

[0049] (2) Reflectivity

[0050] The reflectivity of at least the first surface of the metal substrate disclosed herein is 50% or more, and may be 55% or more, or 60% or more. The reflectivity is, for example, 100% or less.

[0051] Specifically, the reflectance of the first surface of the metal substrate of the present disclosure is, for example, 50% to 100%, preferably 55% to 100%, and more preferably 60% to 100%.

[0052] It should be noted that the reflectivity mentioned here is, for example, the reflectivity of the detection light used in the optical encoder. When the incident light is any wavelength in the range of 500nm to 1000nm, it is more preferred that the reflectivity is in the above range when the incident angle is in the range of 5° to 70°. As a method for measuring the reflectivity, SolidSpec 3700DUV manufactured by Shimadzu Corporation can be used, and the irradiation beam size is about 6mm×15mm. Both P-polarized light and S-polarized light are measured, and the average of the sum is taken, and the 45° linear polarized light is calculated to calculate the reflectivity. If the reflectivity of the metal substrate is in the above range, the difference between the reflectivity in the high-reflection area and the reflectivity in the low-reflection area is large, so it is possible to prevent erroneous detection of the light detector and improve the detection accuracy of the signal.

[0053] (3) Thickness

[0054] The thickness T1 of the metal substrate disclosed in the present invention is greater than 0.05 mm, preferably greater than 0.1 mm, and more preferably greater than 0.3 mm. If the thickness of the metal substrate is within the above range, the strength of the reflective optical scale used for the encoder becomes sufficient. On the other hand, the thickness T1 of the metal substrate is less than 0.60 mm, preferably less than 0.50 mm, and more preferably less than 0.4 mm. If the thickness of the metal substrate is within the above range, it is easy to make the width of the peripheral collapsed edge within the above range. In addition, the thickness T1 of the metal substrate refers to the average thickness of the metal substrate excluding the collapsed edge area.

[0055] Specifically, the thickness T1 of the metal substrate of the present disclosure is 0.05 mm or more and 0.60 mm or less, preferably 0.10 mm or more and 0.50 mm or less, and more preferably 0.30 mm or more and 0.40 mm or less.

[0056] (4) Others

[0057] Examples of the material of the metal substrate that has the above-mentioned reflectivity and can obtain the above-mentioned outer peripheral sag width include stainless steel (SUS), copper, and aluminum.

[0058] In addition, the metal substrate disclosed in the present invention is disc-shaped, for example, it can be a perforated disc with a center hole, or it can be without a center hole. In the case where the metal substrate is a perforated disc, when viewed from above, the outer diameter is, for example, more than 15 mm, or more than 20 mm. On the other hand, the outer diameter is, for example, less than 70 mm, or less than 60 mm. Specifically, the outer diameter is, for example, more than 15 mm and less than 70 mm, or more than 20 mm and less than 60 mm. In addition, the inner diameter is, for example, more than 5 mm and less than 20 mm. In addition, the difference between the outer diameter and the inner diameter (outer inner diameter difference) is, for example, more than 8 mm and less than 13 mm. If it is within this range, the fluctuation of the scale generated during the punching process can be suppressed.

[0059] 2. Low reflection layer

[0060] The low-reflection layer of the present disclosure is provided in a pattern along the circumferential direction of the metal substrate on the first surface side of the metal substrate. In the present disclosure, regarding the area where the low-reflection layer is provided, i.e., the low-reflection area, the reflectivity at any wavelength in the wavelength region of 500nm to 1000nm is, for example, 10% or less, can be 5% or less, or can be 1% or less. On the other hand, the above-mentioned reflectivity of the low-reflection area is, for example, 0% or more. Specifically, the above-mentioned reflectivity of the low-reflection area of ​​the present disclosure is, for example, 0% or more and 10% or less, preferably 0% or more and 5% or less, and more preferably 0% or more and 1% or less.

[0061] The reflective optical scale for encoder disclosed in the present invention preferably does not have a low-reflection layer in the area from the outer peripheral surface of the metal substrate to 500 μm inside. The metal substrate in the reflective optical scale for encoder of the present invention has a peripheral collapsed edge, and the width of the collapsed edge is less than 500 μm. By not having a low-reflection layer in the area from the outer peripheral surface of the metal substrate to 500 μm inside, peeling or cracking of the low-reflection layer can be suppressed.

[0062] Specifically, if Figure 2 As shown in (b), the distance D1 between the outer peripheral surface 1c of the metal substrate 1 and the outer peripheral surface 2c of the low-reflection layer 2 is preferably 500 μm or more, more preferably 550 μm or more, and particularly preferably 600 μm or more. If the distance D1 is within the above range, peeling or cracking of the low-reflection layer can be easily suppressed. On the other hand, the above distance D1 is, for example, less than 1500 μm, preferably less than 1000 μm, and more preferably less than 900 μm. If the above distance D1 is within the above range, the size expansion of the reflective optical scale for the encoder can be suppressed.

[0063] Specifically, the distance D1 is, for example, not less than 500 μm and not more than 1500 μm, preferably not less than 550 μm and not more than 1000 μm, and more preferably not less than 600 μm and not more than 900 μm.

[0064] In addition, the value of the above-mentioned distance D1 is also applicable to the following reflective optical scale for an encoder, which has: a disc-shaped metal substrate, which has a first surface and a second surface opposite to the above-mentioned first surface; and a low-reflection layer, which is arranged in a pattern along the circumferential direction of the above-mentioned metal substrate on the above-mentioned first surface side of the above-mentioned metal substrate.

[0065] The low-reflection layer disclosed in the present invention is arranged in a pattern along the circumferential direction of the metal substrate on the first surface side of the metal substrate. As the low-reflection layer, as long as the reflectivity of light incident on the area where the low-reflection layer is arranged, i.e., the low-reflection area, is less than the reflectivity of light incident on the high-reflection area, its structure is not particularly limited.

[0066] In the present disclosure, it is preferred to have a three-layer structure having a metal chromium film, and a chromium oxide film and a chromium nitride film formed in different orders on the metal chromium film from the metal substrate side. If it is such a low-reflection layer, the reflectivity of light incident on the low-reflection area can be reduced to less than 10%, preferably less than 5%, and further less than 1% at any wavelength in the wavelength range of 500nm to 1000nm. On the other hand, the above-mentioned reflectivity of the low-reflection area is, for example, greater than 0%. Specifically, the reflectivity of the above-mentioned low-reflection area of ​​the present disclosure is, for example, greater than 0% and less than 10%, preferably greater than 0% and less than 5%, and more preferably greater than 0% and less than 1%.

[0067] It should be noted that the reflectivity of the low-reflection region preferably satisfies the above range at any angle within the range of the incident angle of 5° to 70°. Therefore, the difference between the reflectivity in the high-reflection region and the reflectivity in the low-reflection region can be increased. In addition, 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, high-precision patterning can also be easily performed compared to silicon oxide film.

[0068] In this specification, "chromium oxide film and chromium nitride film formed in different orders on the metal chromium film" means: the metal chromium film, chromium oxide film and chromium nitride film can be formed in this order, or the metal chromium film, chromium nitride film and chromium oxide film can be formed in this order.

[0069] For example, Figure 3 The low reflection layer 2 of the reflective optical scale 10 for encoder shown in (a) has a metal chromium film 2c, a chromium nitride film 2b formed on the metal chromium film 2c, and a chromium oxide film 2a formed on the chromium nitride film 2b from the metal substrate 1 side. On the other hand, Figure 3 The low-reflection layer 2 of the reflective optical scale 10 for an encoder shown in (b) has a metal chromium film 2c, a chromium oxide film 2a formed on the above-mentioned metal chromium film 2c, and a chromium nitride film 2b formed on the chromium oxide film 2a, starting from the metal substrate 1 side.

[0070] The outermost surface of the low reflection region is preferably the surface of the chromium oxide film or chromium nitride film of the low reflection layer, and is particularly preferably the surface of the chromium oxide film, because this can more effectively reduce the reflectivity in the low reflection region.

[0071] Hereinafter, “a low-reflection layer including a metal chromium film, a chromium nitride film, and a chromium oxide film in sequence” is referred to as a low-reflection layer of the first specification, and “a low-reflection layer including a metal chromium film, a chromium oxide film, and a chromium nitride film in sequence” is referred to as a low-reflection layer of the second specification.

[0072] (1) Low reflection layer of the first specification

[0073] The low-reflection layer of this specification is configured with a metal chromium film, a chromium nitride film, and a chromium oxide film in order from the substrate side. The low-reflection region of the low-reflection layer of this specification can reduce the reflectivity at any wavelength within the range of 500nm to 1000nm of the light irradiated from the light source to less than 5%, especially less than 0.5%, and the reflectivity changes relatively smoothly with respect to the wavelength change, making it easy to control the reflectivity. Specifically, the above-mentioned reflectivity can be reduced to more than 0% and less than 5%, especially to more than 0% and less than 0.5%. The following is a detailed description of each layer.

[0074] (a) Metal chromium film

[0075] In this specification, the metal chromium film is provided on the metal substrate. The metal chromium film is a layer composed of metal chromium. The metal chromium film is a layer that does not substantially transmit light irradiated from a light source, and its transmittance is preferably 0.0% or more and 1.0% or less. The transmittance can be measured using a spectrophotometer (MPC-3100) manufactured by Shimadzu Corporation. The film thickness is, for example, 40 nm or more, preferably 70 nm or more.

[0076] Here, the "thickness" of each component refers to the thickness obtained by a general measurement method. As a method for measuring thickness, for example, a stylus method that calculates the thickness by drawing and detecting the unevenness on the surface with a stylus, or an optical method that calculates the thickness based on a spectral reflection spectrum, etc. can be cited. Specifically, the stylus film thickness meter P-15 manufactured by KLA-Tencor Co., Ltd. can be used to measure the thickness. It should be noted that as the thickness, the average value of the thickness measurement results at multiple locations of the component as the object can be used.

[0077] As a method for forming the metal chromium film, for example, a physical vapor deposition method (PVD) such as a sputtering method, an ion plating method, or a vacuum vapor deposition method is used.

[0078] (b) Chromium nitride film

[0079] The chromium nitride film in this specification is arranged between the metal chromium film and the chromium oxide film. Unlike chromium oxynitride, chromium oxynitride carbide, etc., the main components of the chromium nitride film are chromium and nitrogen, and it does not contain impurities other than chromium and nitrogen.

[0080] The x representing the atomic ratio of Cr to N in the chromium nitride (CrNx) film is preferably 0.4 or more and 1.1 or less.

[0081] In addition, regarding the chromium nitride film, the ratio of chromium to nitrogen is within a range of 80% to 100% with the entire film being 100 atomic %, and a purity within a range of 90% to 100% is preferred. Impurities may include, for example, hydrogen, oxygen, carbon, and the like.

[0082] The thickness of the chromium nitride film (T N ) is preferably in the range of 5 nm to 100 nm, and particularly preferably in the range of 10 nm to 80 nm. O ), when the wavelength is 850nm, T N With T O The total of is preferably 40 nm or more. When the wavelength is 550 nm, T N With T O The total of is preferably 20 nm or more. If the film thickness is within this range, the reflectivity in the low reflection region can be easily reduced to 10% or less, particularly 5% or less, compared to the case outside the above range. Furthermore, in order to easily reduce the reflectivity in the entire region from green to infrared (about 500 nm or more and 1000 nm or less), the film thickness (T N ) is preferably in the range of greater than 10 nm and less than 80 nm.

[0083] As a method for forming chromium nitride, for example, a physical vapor deposition method (PVD) such as a reactive sputtering method, an ion plating method, and a vacuum evaporation method is used. When using the reactive sputtering method, nitrogen can be introduced into argon (Ar) gas, and a chromium nitride film can be formed by a reactive sputtering method using a Cr target. At this time, the composition of the chromium nitride film can be controlled by controlling the ratio of Ar gas and nitrogen gas.

[0084] (c) Chromium oxide film

[0085] The chromium oxide film is formed on the chromium nitride film, and its main components are chromium and oxygen. Unlike chromium oxynitride, chromium oxynitride carbide, etc., it does not substantially contain impurities other than chromium and oxygen.

[0086] The y representing the atomic ratio of Cr to O in the chromium oxide (CrOy) film is preferably 1.4 or more and 2.1 or less.

[0087] Specifically, in the chromium oxide film, the ratio of chromium to oxygen is in the range of 80 to 100% based on 100 atomic % of the entire film, and a purity in the range of 90% to 100% is preferred.

[0088] As impurities, hydrogen, nitrogen, carbon, etc. may also be contained.

[0089] The film thickness of the chromium oxide film is not particularly limited, but is preferably in the range of 5 nm to 100 nm, and particularly preferably in the range of 10 nm to 80 nm. O ) and the thickness of the chromium nitride film (T N ) is preferably within the range described in the above “(1) Low-reflection layer of the first specification (b) Chromium nitride film”. O ), in order to easily reduce the reflectivity in the entire area of ​​green to infrared (about 500 to 1000nm), it is preferably in the range of 10nm to 65nm.

[0090] As a method for forming chromium oxide, for example, a physical vapor deposition method (PVD) such as a reactive sputtering method, an ion plating method, and a vacuum evaporation method is used. When using the reactive sputtering method, oxygen can be introduced into argon (Ar) gas, and a chromium oxide film can be formed by a reactive sputtering method using a Cr target. At this time, the composition of the chromium oxide film can be controlled by controlling the ratio of Ar gas to oxygen.

[0091] (2) Second specification low reflection layer

[0092] The low-reflection layer of this specification is configured with a metal chromium film, a chromium oxide film, and a chromium nitride film in order from the metal substrate side. The low-reflection region of the low-reflection layer of this specification can reduce the reflectivity at any wavelength within the range of 500nm to 1000nm of the wavelength of light irradiated from the light source to 5% or less, especially to 1% or less. Specifically, the above reflectivity can be reduced to 0% or more and 5% or less, especially to 0% or more and 1% or less. The following is a detailed description of each layer.

[0093] (a) Metal chromium film

[0094] The metal chromium film in this specification is formed on a substrate. The details of the metal chromium film are the same as those in the above-mentioned "(1) Low reflection layer of the first specification (a) Metal chromium film", and therefore the description here is omitted.

[0095] (b) Chromium oxide film

[0096] The chromium oxide film in this specification is arranged between the metal chromium film and the chromium nitride film. The film thickness is not particularly limited, for example, preferably in the range of 5nm to 60nm, particularly preferably in the range of 10nm to 50nm. Furthermore, it is preferred to satisfy the relationship with the film thickness of the chromium nitride film described later. This is because the reflectivity at any wavelength in the wavelength range of the low reflection region of 500nm to 1000nm can be more reliably reduced to 10% or less, particularly 5% or less.

[0097] Furthermore, regarding the film thickness (T O ), in order to easily reduce the reflectivity of the entire area from green to infrared (about 500 to 1000nm), it is preferably in the range of 5nm to 35nm.

[0098] The other physical properties, composition and details of the formation method of the chromium oxide film are the same as those in the above-mentioned "(1) Low-reflection layer of the first specification (c) Chromium oxide film", and therefore the description here is omitted.

[0099] (c) Chromium nitride film

[0100] The chromium nitride film of this specification is formed on the chromium oxide film. The film thickness of the chromium nitride film of this specification is not particularly limited, for example, it is preferably in the range of 5 nm to 100 nm, and particularly preferably in the range of 10 nm to 80 nm. Furthermore, in the range of the film thickness (T O ), when the wavelength is 850nm, T N With T O The total of is preferably 30 nm or more. When the wavelength is 550 nm, T N With T O The total of is preferably 15 nm or more. In addition, regarding the film thickness (T N ), in order to easily reduce the reflectivity in the entire area from green to infrared (about 500nm and 1000nm), it is preferably in the range of 10nm and 60nm.

[0101] The method for forming the low-reflection layer disclosed in the present invention is not particularly limited, and can be manufactured by selective etching or lift-off. Specifically, a metal chromium film is formed on a metal substrate, for example, by sputtering, and then a chromium nitride film and a chromium oxide film are formed. Then, the metal chromium film, the chromium nitride film, and the chromium oxide film are patterned by photolithography and etching, thereby being able to manufacture a patterned low-reflection layer.

[0102] As another method, a resist pattern is formed on a metal substrate, and a metal chromium film, a chromium nitride film, and a chromium oxide film are formed using a known vacuum film forming method such as a sputtering method. Then, the resist pattern is removed to peel 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 chromium nitride film and the chromium oxide film.

[0103] The low reflection region of the present disclosure has a reflectance of, for example, 10% or less, 5% or less, or 1% or less at any wavelength within a wavelength range of 500 nm to 1000 nm or less.

[0104] Specifically, the above-mentioned reflectivity of the low-reflection area of ​​the present disclosure is, for example, 0% or more and 10% or less, preferably 0% or more and 5% or less, and more preferably 0% or more and 1% or less. In addition, the reflectivity of the low-reflection area preferably satisfies the above-mentioned range at any angle within the range of the incident angle of 5° or more and 70° or less. The outermost surface of the low-reflection area is preferably the surface of the chromium oxide film or chromium nitride film of the low-reflection layer, and is particularly preferably the surface of the chromium oxide film. This is because the reflectivity in the low-reflection area can be more effectively reduced.

[0105] 3. Other layer structures

[0106] The reflective optical scale for encoder disclosed in the present invention may have other layers in addition to the metal substrate and the low-reflection layer. For example, the reflective optical scale for encoder disclosed in the present invention may also have a protective layer between the metal substrate and the low-reflection layer.

[0107] The protective layer has transparency and preferably has the function of protecting the metal substrate. By providing the protective layer, when etching the low-reflection layer in a pattern, there is no need to worry that the surface of the metal substrate becomes rough and the surface roughness becomes larger. Therefore, diffuse reflection of light can be suppressed. The protective layer can be provided in the entire area of ​​the metal substrate when viewed from above, or it can be provided in a partial area.

[0108] The material of the protective layer is not particularly limited as long as it has transparency and can protect the high reflective layer, and may be any of an organic material and an inorganic material.

[0109] The organic material preferably includes a resin. As the resin used for the protective layer, there is no particular limitation as long as it is a resin that can obtain a transparent protective layer. For example, ionizing radiation curing resins cured by irradiation with ionizing radiation such as ultraviolet rays and electron beams, thermosetting resins cured by heating, etc. can be listed. Specifically, preferably novolac resins, polyolefin resins, polyester resins, urethane resins, polyimide resins, acrylic resins, epoxy resins. As novolac resins, phenol novolac resins are preferred. This is because: its electrical properties are excellent and the adverse conditions caused by charging can be suppressed. As acrylic resins, trifunctional or higher acrylates such as pentaerythritol tetraacrylate and dipentaerythritol tetraacrylate are preferred. This is because it can improve photocurability. As epoxy resins, epoxy acrylate resins with fluorene structures are preferred. This is because it can improve heat resistance, close adhesion, and chemical resistance. As epoxy resins, phenolphthalein (cardo) epoxy resins are also preferred. This is because it can impart excellent transparency, heat resistance, surface hardness, and flatness. The organic material may contain a polymerization initiator, various additives, and the like in addition to the resin.

[0110] Examples of inorganic materials include inorganic compounds. Examples of inorganic compounds include oxides, oxynitrides, nitrides, oxycarbides, and oxycarbide-nitrides of metal elements or non-metal elements such as silicon, aluminum, magnesium, calcium, potassium, tin, sodium, titanium, boron, yttrium, zirconium, cerium, and zinc. Silicon dioxide (SiO 2 ). The inorganic compound may be used alone or in any combination.

[0111] 4. Reflective optical scale for encoder

[0112] The reflective optical scale for encoder disclosed in the present invention is usually used as an optical scale for rotary encoder. The reflective optical scale for encoder is disc-shaped, for example, it can be a perforated disc with a center hole, or it can be without a center hole. In the case where the reflective optical scale for encoder disclosed in the present invention is a perforated disc, when viewed from above, the outer diameter is, for example, greater than 15 mm, or greater than 20 mm. On the other hand, the outer diameter is, for example, less than 70 mm, or less than 60 mm. Specifically, the outer diameter is, for example, greater than 15 mm and less than 70 mm, or greater than 20 mm and less than 60 mm. In addition, the inner diameter is, for example, greater than 5 mm and less than 20 mm. In addition, the difference between the outer diameter and the inner diameter (outer inner diameter difference) is, for example, greater than 8 mm and less than 13 mm. If it is within this range, the fluctuation of the scale generated during the punching process can be suppressed.

[0113] In addition, the reflective optical scale for encoder disclosed in the present invention can be manufactured by the "C. Manufacturing method of reflective optical scale for encoder" described later.

[0114] B. Reflective optical encoder

[0115] In the present disclosure, a reflective optical encoder is provided, characterized in that the reflective optical encoder comprises: the above-mentioned reflective optical scale for encoder; a light source, which irradiates measuring light to the surface of the side of the reflective optical scale for encoder on which the above-mentioned low-reflection layer is arranged; and a light detector, which detects reflected light from the above-mentioned reflective optical scale for encoder.

[0116] Figure 4 1 is a schematic three-dimensional diagram showing an example of a reflective optical encoder having a reflective optical scale for an encoder of the present disclosure. The reflective optical encoder 100 of the present disclosure includes a reflective optical scale for an encoder 10, a light source 21, and a light detector 22. Figure 4 In the embodiment, a fixed gap 23 is arranged between the light detector 22 and the reflective optical scale 10 for encoder. The encoder disclosed in the present invention has the reflective optical scale for encoder with reduced peripheral collapse, and therefore, based on the above reasons, is advantageous in terms of cost, and can also suppress peeling or cracking of the low-reflection layer, thus having good encoder characteristics.

[0117] 1. Reflective optical scale for encoder

[0118] The reflective optical scale for encoder is the same as that described in the above-mentioned "A. Reflective optical scale for encoder", so the description here is omitted.

[0119] 2. Light source

[0120] As the light source, for example, it is an LED (light emitting diode), a laser, etc. The wavelength λ of the light irradiated from the light source is, for example, in the green to infrared (about 500nm and 1000nm). The incident angle of the light relative to the optical scale 10 is, for example, 5° and 70°.

[0121] 3. Light detector

[0122] The photodetector detects light reflected by the optical scale and includes, for example, a light receiving element (eg, a photoelectric conversion element) such as a photodiode or an imaging element.

[0123] 4. Others

[0124] The reflective optical encoder disclosed in the present invention may also include a fixed gap between the light detector and the reflective optical scale for the encoder. By providing a fixed gap, the change in the amount of light received by the light detector becomes larger, which can improve the detection sensitivity. The fixed gap may also be provided between the light source and the reflective optical scale for the encoder.

[0125] C. Method for manufacturing a reflective optical scale for an encoder

[0126] In the present invention, a method for manufacturing a reflective optical scale for an encoder is provided, which comprises: a process of making a plateform, wherein the plateform has a metal substrate to be processed and a patterned low-reflection layer, wherein the metal substrate to be processed has a first surface and a second surface opposite to the first surface, wherein at least the reflectivity of the first surface is greater than 50%, and the thickness of the metal substrate to be processed is greater than 0.05 mm and less than 0.60 mm, wherein the low-reflection layer is plated and installed on the first surface side of the metal substrate to be processed and is arranged in a circular shape, wherein a peripheral punching predetermined line of the reflective optical scale for an encoder is formed on the plateform at an outer side than the peripheral surface of each low-reflection layer; and a singulation process of singulating the plateform by punching out the plateform at the peripheral punching predetermined line, thereby obtaining a reflective optical scale for an encoder.

[0127] Figure 5 It is a schematic top view of the plate-like body 50 produced in the above-mentioned plate-like body production process. The plate-like body 50 disclosed in the present invention comprises: a metal substrate 51 to be processed, the reflectivity of at least the first surface of which is greater than a specified value and the thickness is within a specified range; and a patterned low-reflection layer 2, which is plate-mounted on the first surface side of the metal substrate 51 to be processed and is arranged in a circumferential shape. The plate-like body 50 disclosed in the present invention has a peripheral punching predetermined line L for a reflective optical scale for an encoder formed on the outside of each low-reflection layer 2. In the singulation process, the plate-like body 50 is singulated by punching at the peripheral punching predetermined line L, thereby obtaining a reflective optical scale for an encoder.

[0128] 1. Platemaking process

[0129] In this process, a plateform is produced, which comprises: a metal substrate to be processed, of which at least the first surface has a reflectivity of more than 50% and a thickness of more than 0.05 mm and less than 0.60 mm; and a patterned low-reflection layer, which is plated and installed on the first surface side of the metal substrate to be processed and is arranged in a circular shape, and a predetermined peripheral punching line for a reflective optical scale for an encoder is formed on the outside of the outer peripheral surface of each low-reflection layer.

[0130] The reflectivity and thickness of the first surface of the processed metal substrate are the same as those of the first surface of the above-mentioned metal substrate. The size of the processed metal substrate when viewed from above is not particularly limited as long as it is a size that can be used to mount a patterned low-reflection layer.

[0131] The low-reflection layer is the same as the low-reflection layer described in the above-mentioned "A. Reflective optical scale for encoder". In addition, the method of installing a patterned low-reflection layer on the first side of the processed metal substrate is the same as the method of forming the low-reflection layer described in the above-mentioned "A. Reflective optical scale for encoder".

[0132] like Figure 5 As shown, the plate-like body disclosed in the present invention is formed with a peripheral punching predetermined line L of the reflective optical scale for encoder at the outer side of the outer peripheral surface of each low-reflection layer 2. The distance D2 between the peripheral punching predetermined line L of the reflective optical scale for encoder and the outer peripheral surface of the low-reflection layer 2 is preferably 500 μm or more, more preferably 550 μm or more, and particularly preferably 600 μm or more. If the above-mentioned distance D2 is within the above-mentioned range, it is difficult to produce peripheral collapse in the area where the low-reflection layer is formed during the punching process, so the peeling or cracking of the low-reflection layer can be suppressed. On the other hand, the distance D2 is, for example, less than 1500 μm, preferably less than 1000 μm, and more preferably less than 900 μm. If the above-mentioned distance D2 is within the above-mentioned range, the size expansion of the reflective optical scale for encoder can be suppressed. Specifically, the distance D2 is, for example, more than 500 μm and less than 1500 μm, preferably more than 550 μm and less than 1000 μm, and more preferably more than 600 μm and less than 900 μm.

[0133] Furthermore, an inner peripheral punching planned line for punching out a center hole of the reflective optical scale for an encoder may be formed on a plate-like body for manufacturing a perforated disk-shaped reflective optical scale for an encoder.

[0134] 2. Singulation process

[0135] In this step, the plate-forming body produced in the plate-forming body producing step is punched out at the outer peripheral punching planned lines to separate the pieces, thereby obtaining a reflective optical scale for an encoder.

[0136] Figure 6 1 is a schematic diagram showing an example of a punching device used in the singulation step of the method for manufacturing a reflective optical scale for an encoder disclosed in the present invention. Figure 6 (a) and Figure 6As shown in (b), the plate-mounted plate body 50 is placed on a lower stage 62 with a lower blade 61, the lower stage 62 is moved upward, and the upper stage 63 with an upper blade 64 is moved downward, and the plate-mounted body 50 is pressed between them, thereby punching the plate-mounted body 50 to obtain the reflective optical scale 10 for each encoder. At this time, the position of the upper blade is aligned with the outer peripheral punching predetermined line and the inner peripheral punching predetermined line. In addition, it is preferred that the pressing component 65 of the metal substrate is arranged at a position opposite to the upper blade 64. By the pressing component 65, the metal substrate is clamped in pairs with the upper blade 64 during the punching process, and a punching process with less burrs and collapsed edges can be performed.

[0137] In the present disclosure, by setting the width of the gap in this process to, for example, 0.020 mm or less, preferably 0.017 mm or less, and more preferably 0.015 mm or less, it is easy to make the width of the above-mentioned peripheral collapsed edge of the reflective optical scale for the encoder fall within the above-mentioned range. On the other hand, the width of the gap is, for example, 0.003 mm or more, preferably 0.004 mm or more, and more preferably 0.006 mm or more. By making the width of the gap within the above-mentioned range, the burden on the blade of the punching device can be reduced. In addition, as Figure 6 As shown in (b), the width of the gap refers to the distance C between the end surface of the upper blade 64 and the end surface of the lower blade 61 in the width direction. Specifically, the width of the gap is, for example, 0.003 mm to 0.020 mm, preferably 0.004 mm to 0.017 mm, and more preferably 0.006 mm to 0.015 mm.

[0138] The reflective optical scale for encoder obtained in this process is the same as the reflective optical scale for encoder described in the above-mentioned "A. Reflective optical scale for encoder".

[0139] D. Reflective optical scale for encoder

[0140] In the present disclosure, a reflective optical scale plateform for an encoder is provided, the reflective optical scale plateform for an encoder comprising: a metal substrate to be processed, which has a first surface and a second surface opposite to the first surface, at least the reflectivity of the first surface is greater than 50%, and the thickness of the metal substrate to be processed is greater than 0.05 mm and less than 0.60 mm; and a patterned low-reflection layer, which is plated and installed on the first surface side of the metal substrate to be processed, arranged in a circular shape, and a peripheral punching predetermined line of the reflective optical scale for the encoder is formed on the outside of the outer peripheral surface of each of the low-reflection layers, wherein the distance between the peripheral punching predetermined line of the reflective optical scale for the encoder and the outer peripheral surface of the low-reflection layer is greater than 500 μm and less than 1500 μm.

[0141] According to the encoder reflective optical scale imposition body disclosed in the present invention, by making the distance between the peripheral punching predetermined line of the encoder reflective optical scale and the peripheral surface of the above-mentioned low-reflection layer within a specified range, the peripheral collapse edge generated during the punching process is unlikely to occur in the area where the low-reflection layer is formed, thereby suppressing the peeling or cracking of the low-reflection layer. In addition, the size expansion of the encoder reflective optical scale can be suppressed.

[0142] The reflective optical scale plateform for encoder disclosed in the present invention is the same as that described in the above-mentioned "C. Method for manufacturing reflective optical scale for encoder", so the description here is omitted.

[0143] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are illustrative, and any configuration having substantially the same configuration and achieving the same function and effect as the technical concept described in the claims of the present disclosure is included in the technical scope of the present disclosure.

[0144] Example

[0145] Hereinafter, experimental examples are shown to further illustrate the present disclosure.

[0146] (Experimental Example 1-1)

[0147] A SUS substrate with a thickness of 0.3 mm was prepared. Figure 6 The punching device shown in the figure was used to punch out the SUS substrate to be processed, and a SUS substrate with a hole disk shape having an outer diameter of 23.5 mm and an inner diameter of 15.0 mm was obtained. At this time, the width C of the gap was set to 0.004 mm. The width of the outer periphery of the SUS substrate with a hole disk shape was measured. The results are shown in Figure 7 (a).

[0148] (Experimental Example 1-2)

[0149] In addition, a perforated disc-shaped SUS substrate was obtained in the same manner as in Experimental Example 1-1 except that the width of the gap was changed to 0.015 mm. The width of the outer peripheral collapse of the perforated disc-shaped SUS substrate obtained was measured. The results are shown in Figure 7 (a).

[0150] (Experimental Example 1-3)

[0151] A perforated disc-shaped SUS substrate was obtained in the same manner as in Experimental Example 1-1 except that the thickness of the SUS substrate to be processed was changed to 0.4 mm. The width of the outer peripheral collapse of the perforated disc-shaped SUS substrate obtained was measured. The results are shown in Figure 7 (a).

[0152] (Experimental Examples 1-4)

[0153] A SUS substrate having a hole in the form of a disk was obtained in the same manner as in Experimental Example 1-1 except that the thickness of the SUS substrate to be processed was changed to 0.4 mm and the width of the gap was changed to 0.009 mm. The width of the outer peripheral collapse of the SUS substrate having a hole in the form of a disk was measured. The results are shown in Figure 7 (a).

[0154] (Experimental Example 1-5)

[0155] A perforated disc-shaped SUS substrate was obtained in the same manner as in Experimental Example 1 except that the thickness of the SUS substrate to be processed was changed to 0.4 mm and the width of the gap was changed to 0.012 mm. The width of the peripheral sag of the perforated disc-shaped SUS substrate obtained was measured. The results are shown in Figure 7 (a).

[0156] (Experimental Example 1-6)

[0157] A perforated disc-shaped SUS substrate was obtained in the same manner as in Experimental Example 1 except that the thickness of the SUS substrate to be processed was changed to 0.4 mm and the width of the gap was changed to 0.015 mm. The width of the outer peripheral collapse of the perforated disc-shaped SUS substrate obtained was measured. The results are shown in Figure 7 (a).

[0158] according to Figure 7 The result of (a) confirmed that the width of the peripheral sag does not change according to the width of the gap. On the other hand, when comparing Experimental Examples 1-1 to 1-2 with Experimental Examples 1-3 to 1-6, it was confirmed that the thicker the metal substrate, the larger the width of the peripheral sag.

[0159] (Experimental Example 2-1)

[0160] A SUS substrate with a thickness of 0.3 mm was prepared. Figure 6 The punching device shown in the figure was used to punch out the SUS substrate to be processed, and a SUS substrate with a hole disk shape having an outer diameter of 23.5 mm, an inner diameter of 15.0 mm, and an outer and inner diameter difference of 8.5 mm was obtained. The width of the outer peripheral collapse edge of the obtained SUS substrate with a hole disk shape was measured. The results are shown in Figure 7 (b).

[0161] (Experimental Example 2-2)

[0162] By the same method as in Experimental Example 2-1, a SUS substrate having a hole disk shape with an outer diameter of 21.96 mm, an inner diameter of 9.16 mm, and an outer and inner diameter difference of 12.8 mm was obtained. The width of the outer peripheral collapse edge of the obtained SUS substrate having a hole disk shape was measured. The results are shown in Figure 7 (b).

[0163] (Experimental Example 2-3)

[0164] A SUS substrate having a hole and a disc shape with an outer diameter of 23.5 mm, an inner diameter of 15.0 mm, and an outer and inner diameter difference of 8.5 mm was obtained by the same method as in Experimental Example 2-1 except that the thickness of the SUS substrate to be processed was 0.4 mm. The width of the outer peripheral edge collapse of the obtained SUS substrate was measured. The results are shown in Figure 7 (b).

[0165] (Experimental Example 2-4)

[0166] A SUS substrate having a hole and a disc shape with an outer diameter of 25.3 mm, an inner diameter of 13.8 mm, and an outer and inner diameter difference of 11.5 mm was obtained by the same method as in Experimental Example 2-1 except that the thickness of the SUS substrate to be processed was 0.4 mm. The width of the outer peripheral collapse of the obtained SUS substrate was measured. The results are shown in Figure 7 (b).

[0167] (Experimental Example 2-5)

[0168] A SUS substrate having a hole and a disc shape with an outer diameter of 21.96 mm, an inner diameter of 9.16 mm, and an outer and inner diameter difference of 12.8 mm was obtained by the same method as in Experimental Example 2-1 except that the thickness of the SUS substrate to be processed was 0.4 mm. The width of the outer peripheral collapse of the obtained SUS substrate was measured. The results are shown in Figure 7 (b).

[0169] According to the above Figure 7 The result of (b) confirmed that the peripheral sag has nothing to do with the difference in the outer and inner diameters of the SUS substrate. On the other hand, it was confirmed that the thicker the metal substrate, the larger the peripheral sag.

[0170] That is, the present disclosure can provide the following inventions. [1]

[0172] A reflective optical scale for an encoder comprises: a disc-shaped metal substrate having a first surface and a second surface opposite to the first surface; and a low-reflection layer arranged in a pattern along the circumferential direction of the metal substrate on the first surface side of the metal substrate, wherein, with respect to the metal substrate, at least the reflectivity of the first surface is greater than 50%, and the thickness is greater than 0.05 mm and less than 0.60 mm, and the metal substrate has a collapsed edge on the outer peripheral edge of the first surface side, and the width of the collapsed edge is less than 500 μm. [2]

[0174] The reflective optical scale for an encoder according to [1], wherein the metal substrate is a SUS substrate. [3]

[0176] The reflective optical scale for an encoder according to [1] or [2], wherein the metal substrate is in the shape of a perforated disk having a center hole. [4]

[0178] The reflective optical scale for an encoder according to [3], wherein the metal substrate has a collapsed edge at the inner peripheral edge of the first surface side, and the width of the collapsed edge is 500 μm or less. [5]

[0180] The reflective optical scale for an encoder according to [3] or [4], wherein the difference between the outer and inner diameters of the perforated disc-shaped metal substrate is greater than or equal to 8 mm and less than or equal to 13 mm. [6]

[0182] A reflective optical scale for an encoder according to any one of [1] to [5], wherein the ratio (T2 / T1) of the thickness (T2) of the metal substrate at the outer peripheral end to the thickness (T1) of the metal substrate is greater than 0.70 and less than 0.90. [7]

[0184] A reflective optical scale for an encoder according to any one of [1] to [6], wherein a distance (D1) between an outer peripheral surface of the metal substrate and an outer peripheral surface of the low-reflection layer is greater than or equal to 500 μm and less than or equal to 1500 μm. [8]

[0186] The reflective optical scale for an encoder according to any one of [1] to [7], wherein the amount of edge collapse of the metal substrate is greater than or equal to 10 μm and less than or equal to 500 μm. [9]

[0188] A reflective optical scale for an encoder, comprising: a disc-shaped metal substrate having a first surface and a second surface opposite to the first surface; and a low-reflection layer arranged in a pattern along the circumferential direction of the metal substrate on the first surface side of the metal substrate, wherein a distance (D1) between an outer peripheral surface of the metal substrate and an outer peripheral surface of the low-reflection layer is greater than 500 μm and less than 1500 μm.

[10]

[0190] A reflective optical encoder, characterized in that the reflective optical encoder comprises: a reflective optical scale for an encoder as described in any one of [1] to [9]; a light source, which irradiates measurement light onto the surface of the reflective optical scale for the encoder on the side where the low-reflective layer is arranged; and a light detector, which detects reflected light from the reflective optical scale for the encoder.

[11]

[0192] A method for manufacturing a reflective optical scale for an encoder, wherein the method for manufacturing a reflective optical scale for an encoder comprises:

[0193] A process of making a plate-like body, the plate-like body comprising: a metal substrate to be processed, which has a first surface and a second surface opposite to the first surface, the reflectivity of at least the first surface of the metal substrate to be processed is 50% or more, and the thickness of the metal substrate to be processed is 0.05 mm or more and 0.60 mm or less; and a low-reflection layer in a pattern arranged in a circumferential shape, which is plate-mounted on the first surface side of the metal substrate to be processed, the plate-like body having a peripheral punching predetermined line for the reflective optical scale for the encoder formed on the outer side of the outer peripheral surface of the low-reflection layer; and

[0194] In the singulation step, the plate-forming body is punched out at the predetermined periphery punching lines to be singulated, thereby obtaining a reflective optical scale for an encoder.

[12]

[0196] A reflective optical scale platework for an encoder, comprising: a processed metal substrate having a first surface and a second surface opposite to the first surface, wherein the reflectivity of at least the first surface side of the processed metal substrate is 50% or more, and the thickness of the processed metal substrate is 0.05 mm or more and 0.60 mm or less; and a patterned low-reflection layer arranged in a circumferential shape, which is platework-mounted on the first surface side of the processed metal substrate, wherein the platework body is formed with a predetermined peripheral punching line of the reflective optical scale for the encoder at a position outside the outer peripheral surface of the low-reflection layer,

[0197] in,

[0198] The distance between the outer peripheral punching planned line of the reflective optical scale for the encoder and the outer peripheral surface of the low-reflection layer is 500 μm or more and 1500 μm or less.

[0199] Description of symbols

[0200] 1…Metal substrate;

[0201] 2… low reflection layer;

[0202] P…collapse edge;

[0203] 10…Reflective optical scale for encoder;

[0204] 50…Reflective optical scale plate for encoder;

[0205] 100…Reflective optical encoder.

Claims

1. A reflective optical scale for an encoder, comprising: a disc-shaped metal substrate having a first surface and a second surface opposite to the first surface; and a low reflection layer arranged in a pattern along the circumferential direction of the metal substrate on the first surface side of the metal substrate, in, The metal substrate has a reflectivity of at least 50% on the first surface side and a thickness of 0.05 mm to 0.60 mm. The metal substrate has a collapsed edge at an outer peripheral edge on the first surface side, and a width of the collapsed edge is 500 μm or less.

2. The reflective optical scale for an encoder according to claim 1, wherein: The metal substrate is a stainless steel substrate.

3. The reflective optical scale for an encoder according to claim 1, wherein: The metal substrate is in the shape of a perforated disk with a central hole.

4. The reflective optical scale for an encoder according to claim 3, wherein: The metal substrate has a collapsed edge at an inner peripheral edge on the first surface side, and a width of the collapsed edge is 500 μm or less.

5. The reflective optical scale for an encoder according to claim 3, wherein: The difference between the outer and inner diameters of the perforated disk-shaped metal substrate is 8 mm or more and 13 mm or less.

6. The reflective optical scale for an encoder according to claim 1, wherein: A ratio (T2 / T1) of the thickness (T2) of the metal substrate at the outer peripheral end to the thickness (T1) of the metal substrate is 0.70 or more and 0.90 or less.

7. The reflective optical scale for an encoder according to claim 1, wherein: A distance (D1) between an outer peripheral surface of the metal substrate and an outer peripheral surface of the low-reflection layer is 500 μm or more and 1500 μm or less.

8. The reflective optical scale for an encoder according to claim 1, wherein: The amount of edge collapse of the metal substrate is 10 μm or more and 500 μm or less.

9. A reflective optical scale for an encoder, comprising: a disc-shaped metal substrate having a first surface and a second surface opposite to the first surface; and a low reflection layer arranged in a pattern along the circumferential direction of the metal substrate on the first surface side of the metal substrate, in, A distance (D1) between an outer peripheral surface of the metal substrate and an outer peripheral surface of the low-reflection layer is 500 μm or more and 1500 μm or less.

10. A reflective optical encoder, characterized in that: The reflective optical encoder comprises: The reflective optical scale for an encoder according to any one of claims 1 to 9; a light source for irradiating measurement light onto a surface of the reflective optical scale for encoder on a side where the low-reflection layer is disposed; and A light detector detects reflected light from the reflective optical scale for the encoder.

11. A method for manufacturing a reflective optical scale for an encoder, wherein: The manufacturing method of the reflective optical scale for the encoder comprises: A process of making a plate-like body, wherein the plate-like body comprises: a metal substrate to be processed, which comprises a first surface and a second surface opposite to the first surface, wherein the reflectivity of at least the first surface side of the metal substrate to be processed is 50% or more, and the thickness of the metal substrate to be processed is 0.05 mm or more and 0.60 mm or less; and a low-reflection layer in a pattern arranged in a circumferential shape, which is plate-like mounted on the first surface side of the metal substrate to be processed, wherein the plate-like body is formed with a predetermined peripheral punching line of the reflective optical scale for the encoder at a position outside the peripheral surface of each of the low-reflection layers; as well as In the singulation step, the plate-forming body is punched out at the predetermined periphery punching lines to be singulated, thereby obtaining a reflective optical scale for an encoder.

12. A reflective optical scale plateform for an encoder, comprising: a metal substrate to be processed, which has a first surface and a second surface opposite to the first surface, the reflectivity of at least the first surface side of the metal substrate to be processed is 50% or more, and the thickness of the metal substrate to be processed is 0.05 mm or more and 0.60 mm or less; and a low-reflection layer in a circular pattern, which is plateformed and installed on the first surface side of the metal substrate to be processed, the plateform body is formed with a predetermined peripheral punching line of the reflective optical scale for the encoder on the outer side of the outer peripheral surface of each low-reflection layer, in, The distance between the outer peripheral punching planned line of the reflective optical scale for the encoder and the outer peripheral surface of the low-reflection layer is 500 μm or more and 1500 μm or less.

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