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

Abstract

The invention provides an optical scale for an encoder, an optical scale makeup body for an encoder, and an optical encoder. An optical scale for an encoder has an optical pattern having two regions having different reflectance or transmittance, in which the optical scale for an encoder has a two-dimensional code.

Description

Technical Field

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

[0002] In the past, optical encoders were used in servo motors with control mechanisms. Optical encoders include an optical scale, a light source such as an LED that irradiates light to the optical scale, and a light detector that detects transmitted light or reflected light from the optical scale. Optical encoders require high precision. Therefore, it is important to be able to trace the manufacturing history of the optical encoder in the event of a malfunction.

[0003] Patent Document 1: International Publication No. 2021 / 201024

[0004] The optical scale used in the optical encoder also requires traceability. In the past, as a method of identifying an optical scale, there are known methods: a method of identifying information as text, numbers, and numbers and distinguishing by the human eye; and a method of recognizing text by OCR (Optical Character Recognition). However, in the case of distinguishing by the human eye, there are problems with misreading and input errors, or issues with efficiency and cost. In addition, in the case of OCR, since the text is read by a machine, it is advantageous in terms of efficiency and cost, but there is a concern about misreading. Summary of the invention

[0005] The present invention has been made in view of the above-mentioned situation, and its main object is to provide an optical scale for an encoder that can ensure traceability.

[0006] One embodiment of the present disclosure provides an optical scale for an encoder, which has an optical pattern as follows: the optical pattern has two areas with different reflectivity or transmittance, wherein the optical scale for the encoder has a two-dimensional code.

[0007] Another embodiment of the present disclosure provides an optical scale plateform for an encoder, wherein a plurality of optical scales for encoders are installed on the plateform, and the optical scale for encoder has an optical pattern as follows: the optical pattern has two areas with different reflectivity or transmittance, wherein the optical scale for encoder has a two-dimensional code, and the optical scale plateform for encoder has more than one unit area, and in the unit area, the two-dimensional code is different for each optical scale for encoder.

[0008] Another embodiment of the present disclosure provides an optical encoder, comprising: the above-mentioned optical scale for encoder; a light source that irradiates measurement light onto the surface of the above-mentioned optical scale for encoder; and a light detector that detects reflected light or transmitted light from the above-mentioned optical scale for encoder.

[0009] The optical scale for the encoder disclosed in the present invention has the effect of ensuring traceability. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic top view of an optical scale for an encoder according to the present disclosure.

[0011] Figure 2 This is a schematic top view of an optical scale for an encoder according to the present disclosure.

[0012] Figure 3 This is a schematic top view of an optical scale plateset for an encoder according to the present disclosure.

[0013] Figure 4 is a schematic top view of an optical scale imposition body for an encoder disclosed in the present invention, and is Figure 3 or Fig. 9 A partial enlarged view of .

[0014] Figure 5 This is a schematic cross-sectional view illustrating an optical scale for an encoder according to the present disclosure.

[0015] Figure 6 This is a schematic cross-sectional view illustrating an optical scale for an encoder according to the present disclosure.

[0016] Figure 7 This is a schematic cross-sectional view illustrating an optical scale for an encoder according to the present disclosure.

[0017] Figure 8 This is a schematic diagram illustrating a punching device used in a singulation step in a method for manufacturing an optical scale for an encoder disclosed in the present invention.

[0018] Fig. 9 This is a schematic top view of an optical scale plateset for an encoder according to the present disclosure.

[0019] Fig.10 This is a schematic top view showing a state in which the optical scale for the encoder of the present invention is stored in a storage component.

[0020] Fig.11 This is a schematic perspective view illustrating an optical encoder according to the present disclosure.

[0021] Fig.12 This is a schematic perspective view illustrating an optical encoder according to the present disclosure.

[0022] Description of symbols

[0023] 1…Highly reflective substrate;

[0024] 2… low reflection layer;

[0025] 10…Optical reflective scale for encoder;

[0026] 11…highly reflective area;

[0027] 12…low reflection area;

[0028] 13…Optical Pattern;

[0029] 14…QR code;

[0030] 20…Optical transmission scale for encoder;

[0031] 21…transmission area;

[0032] 22…shaded area;

[0033] 23…Optical Pattern;

[0034] 24…QR code;

[0035] 31… transparent substrate;

[0036] 32…shading layer;

[0037] 50…Optical scale plate for encoder;

[0038] 100A, 100B…optical encoder;

[0039] U1, U2…unit area. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings and the like. However, the present disclosure can be implemented in a variety of different ways, and is not limited to the description of the embodiments described below for interpretation. 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 only an example and does not limit the interpretation of the present disclosure. In addition, in this specification and the drawings, for the drawings that have already appeared, the same reference numerals are used for the same elements as the previous ones, and the detailed description is sometimes appropriately omitted.

[0041] In this specification, when describing the configuration of other components on a certain component, if simply described as "above" or "below", unless otherwise specified, this includes both the case where the other component is configured directly above or directly below the certain component in a manner of contacting the certain component, and the case where the other component is 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 ... surface side" or "on the ... surface", unless otherwise specified, this includes both the case where the other component is configured directly above or directly below the certain component in a manner of contacting the certain component, and the case where the other component is configured above or below the certain component with another component interposed therebetween.

[0042] In addition, in this specification, the "optical scale for encoder" is sometimes simply referred to as the "optical scale".

[0043] Hereinafter, the optical scale for encoder, the optical scale plateform for encoder, and the optical encoder disclosed in the present invention will be described in detail.

[0044] A. Optical scale for encoder

[0045] The optical scale for encoder disclosed in the present invention has an optical pattern as follows: the optical pattern has two areas with different reflectivity or transmittance, wherein the optical scale for encoder has a two-dimensional code. The optical scale for encoder disclosed in the present invention can be a reflective optical scale for encoder having an optical pattern as follows: the optical pattern has two areas with different reflectivity, namely, a reflective area (high reflective area) and a non-reflective area (low reflective area). The optical scale for encoder disclosed in the present invention can also be a transmissive optical scale for encoder having an optical pattern as follows: the optical pattern has two areas with different transmittance, namely, a transmissive area and a non-transmissive area (light-shielding area).

[0046] Figure 1 1 is a schematic top view showing an example of a reflective optical scale for an encoder disclosed in the present invention. Figure 1 As shown, the encoder reflective optical scale 10 has an optical pattern 13 having two regions with different reflectivities, namely a high reflection region 11 and a low reflection region 12. The encoder reflective optical scale 10 has a two-dimensional code 14 in a region other than the optical pattern region where the optical pattern 13 is arranged.

[0047] Figure 2 1 is a schematic top view showing an example of a transmissive optical scale for an encoder disclosed in the present invention. Figure 2As shown, the transmissive optical scale 20 for encoder has an optical pattern 23 having two regions with different transmittances, namely a transmissive region 21 and a light shielding region 22. The transmissive optical scale 20 for encoder has a two-dimensional code 24 in a region other than the optical pattern region where the optical pattern 23 is arranged.

[0048] In the present disclosure, by associating the manufacturing history of the optical scale for the encoder with a QR code, traceability can be ensured. The QR code can improve the reading accuracy. Therefore, traceability can be improved. In addition, the QR code can record a lot of information in a space-saving manner. The size of the text that can be recognized by the human eye is about 2mm to 3mm, but if it is a QR code, the overall size of the QR code can be made smaller than this. Therefore, in the optical scale for the encoder, the QR code can be easily configured in an area outside the optical pattern area. In addition, since the QR code is read by a machine, efficiency can be achieved and labor costs can be reduced.

[0049] When manufacturing an optical scale, a plate assembly in which a plurality of optical scales are mounted is sometimes used.

[0050] Figure 3 This is a schematic top view showing an example of an optical scale jigsaw assembly for encoders in which a plurality of optical scales for encoders are mounted on a jigsaw. Figure 4 yes Figure 3 In the present disclosure, the optical scale for encoder (reflective optical scale 10 for encoder or transmissive optical scale 20 for encoder) is obtained by Figure 3 and Figure 4 The encoder shown is produced by singulating the optical scale plate body 50.

[0051] In the present disclosure, the two-dimensional code may include information for identifying the position of the optical scale for encoder in the optical scale for encoder imposition body. Figure 3 In the embodiment, since 100 optical scales for encoders (reflective optical scale 10 for encoders or transmissive optical scale 20 for encoders) are assembled and installed in optical scale plateform 50 for encoders, it is possible to determine which position of the 100 positions the optical scale for encoders (reflective optical scale 10 for encoders or transmissive optical scale 20 for encoders) is located by a two-dimensional code. The two-dimensional code contains information indicating row numbers and column numbers in, for example, 10 rows × 10 columns. By providing the optical scale for encoders with a two-dimensional code, it is possible to easily determine at which position of the optical scale plateform for encoders it was manufactured, even if the optical scale for encoders is monolithicized from the optical scale plateform for encoders.

[0052] Regarding the substrate in the optical scale plateform for encoder, sometimes the substrate itself has undulations or warping. In addition, in the optical scale plateform for encoder, in two areas with different reflectivity or transmittance, there is sometimes an error with the design value regarding the pattern size, or reflectivity or transmittance. In such a case, the characteristics of the optical scale for encoder change according to the position in the optical scale plateform for encoder. In such a case, by using a two-dimensional code to determine the position of the optical scale for encoder in the optical scale plateform for encoder, even after the optical scale for encoder is monolithicized from the optical scale plateform for encoder, different characteristics can be grasped according to the position in the optical scale plateform for encoder. For example, the optical scale for encoder can be used on the basis of grasping different characteristics according to the position in the optical scale plateform for encoder. In addition, for example, in the case where undulations, warping, errors, etc. are not allowed, qualified products and unqualified products can be smoothly distinguished according to the position in the optical scale plateform for encoder. Therefore, by associating the characteristics that differ depending on the position in the optical scale plateform of the encoder with the two-dimensional code, quality management can be performed efficiently.

[0053] Here, for example, when two regions with different transmittance or reflectance are formed by photolithography, the photomask is repeatedly used. Therefore, even if the same photomask is used to manufacture an optical scale, the state of the optical scale may change depending on conditions such as the number of times the photomask is used. Therefore, from the perspective of traceability, it is sometimes important to determine the manufacturing time point.

[0054] In the past, when photolithography was used to form two areas with different transmittances or reflectances, the size of the plateform when viewed from above was, for example, 5 inches square. In this case, the number of optical scales provided on the plateform was about several dozen to more than twenty, which was relatively small. Therefore, in this case, for mass production, the number of times the photomask was repeatedly used increased. Therefore, from the perspective of traceability, it becomes important to determine the manufacturing time point such as the number of times the photomask was used, and the position of the optical scale in the plateform is hardly considered. In addition, even if information for identifying the position of the optical scale in the plateform is given, since the amount of information for identifying the position of the optical scale in the plateform is small, it is sufficient to use text that can be discerned by the human eye or recognized by OCR as identification information, and there is no need to use a two-dimensional code with a large amount of information.

[0055] On the other hand, in the case where more than one hundred or hundreds of optical scales for encoders are plated and installed on the optical scale plateform for encoders, the optical scales for encoders are produced in large quantities at one time, so it is expected to ensure traceability. In addition, if the number of optical scales for encoders in the optical scale plateform for encoders is large, the substrate in the optical scale plateform for encoders becomes larger, so sometimes the substrate itself is prone to undulation or warping. Furthermore, the photomask used in manufacturing also becomes larger, so sometimes the pattern size is prone to deviation. Therefore, from the viewpoint of traceability, it is important to determine the position of the optical scale for encoder in the optical scale plateform for encoders. In the present disclosure, as described above, the position of the optical scale for encoder in the optical scale plateform for encoders can be determined by a two-dimensional code. Therefore, the present disclosure is useful when the number of optical scales for encoders in the optical scale plateform for encoders is large and the optical scale plateform for encoders is large.

[0056] In addition, in the present disclosure, when a patterned low-reflection layer is configured on the first surface of a high-reflection substrate as described later, and the area where the low-reflection layer is configured is a low-reflection area, and the area where the low-reflection layer is not configured is a high-reflection area, an optical pattern and a two-dimensional code can be formed simultaneously. In addition, in the present disclosure, when a patterned high-reflection layer is configured on the first surface of a low-reflection substrate as described later, and the area where the high-reflection layer is configured is a high-reflection area, and the area where the high-reflection layer is not configured is a low-reflection area, an optical pattern and a two-dimensional code can be formed simultaneously. In addition, in the present disclosure, when a patterned shading layer is configured on the first surface of a transparent substrate as described later, and the area where the shading layer is configured is a shading area, and the area where the shading layer is not configured is a transmission area, an optical pattern and a two-dimensional code can be formed simultaneously. Therefore, an optical scale for an encoder with a two-dimensional code can be manufactured without increasing the manufacturing process.

[0057] The optical scale for the encoder disclosed in the present invention will be described below according to each structure.

[0058] 1. QR code

[0059] In the present disclosure, the manufacturing history of the optical scale for the encoder is associated with a two-dimensional code.

[0060] The optical scale for encoder of the present disclosure is preferably manufactured by monolithicizing the optical scale for encoder. Therefore, the two-dimensional code preferably includes information for identifying the position of the optical scale for encoder in the optical scale for encoder.

[0061] In addition, when the optical scale for encoder is manufactured by photolithography, the two-dimensional code may also include information for identifying the photomask. The information for identifying the photomask is information inherent to the photomask. In the optical scale for encoder imposition body, the information for identifying the photomask is the same.

[0062] In addition, the two-dimensional code may include information indicating the manufacturer, date of manufacture, batch number, etc.

[0063] As a two-dimensional code, for example, it can be a matrix two-dimensional code or a stacked two-dimensional code. Among them, a matrix two-dimensional code is preferred. The matrix two-dimensional code can increase the amount of information and is easy to read. In addition, in general, the stacked two-dimensional code is a rectangle, and on the contrary, the matrix two-dimensional code is a square, so compared with the stacked two-dimensional code, the matrix two-dimensional code is easily configured in the area outside the optical pattern area. Specifically, QR code (registered trademark), micro QR code, rMQR code, data matrix, Veri code (Veri Code), Aztec code (Aztec Code), Maxi Code can be listed. Among them, QR code (registered trademark), micro QR code, rMQR code, data matrix are preferred, micro QR code, rMQR code, data matrix are more preferred, and data matrix is ​​further preferred. The versatility of QR code (registered trademark) is high. In addition, since micro QR code, rMQR code, and data matrix can reduce the size of the two-dimensional code, the two-dimensional code can be easily configured in the area outside the optical pattern area in the optical scale for encoder.

[0064] In the optical scale for encoder disclosed in the present invention, the position of the two-dimensional code is not particularly limited, and the two-dimensional code is preferably arranged in an area outside the optical pattern area. In addition, the optical pattern area is an area where an optical pattern is arranged. The optical pattern is composed of two areas with different reflectivity or transmittance. The optical pattern refers to a pattern used in an optical encoder to detect the displacement of the optical scale for encoder.

[0065] In addition, regarding the location of the QR code, for example Figure 2 As shown, it is preferred that the end of the two-dimensional code 24 is separated from the end of the optical scale 20 for the encoder by a distance d1. The above distance d1 is preferably greater than 0.2 mm, and more preferably greater than 0.5 mm. In this case, Figure 4 As shown, in the optical scale plateform 50 for the encoder, the end of the two-dimensional code 14 or 24 is separated from the predetermined cutting line L by a distance d1. If the above 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 the reading of the two-dimensional code can be suppressed. On the other hand, there is no particular limitation on the upper limit of the above distance d1 as long as the two-dimensional code is configured in an area outside the optical pattern area.

[0066] In addition, regarding the location of the QR code, for example Figure 2 As shown, it is preferred that the end of the two-dimensional code 24 is separated from the end of the optical pattern area where the optical pattern 23 is arranged by a distance d2. The above distance d2 is preferably greater than 3 mm, and more preferably greater than 10 mm. On the other hand, there is no particular limitation on the upper limit of the above distance d2 as long as the two-dimensional code is arranged in an area outside the optical pattern area and the above distance d1 is within a specified range.

[0067] In the two-dimensional code, the size of the unit is, for example, preferably less than 300 μm, may be less than 200 μm, or may be less than 100 μm. If the size of the unit is within the above range, the size of the two-dimensional code can be relatively small, although it also depends on the type of the two-dimensional code. Therefore, the two-dimensional code can be easily configured in an area outside the optical pattern area. On the other hand, the size of the unit is, for example, preferably more than 10 μm, may be more than 20 μm, or may be more than 30 μm. If the size of the unit is within the above range, the two-dimensional code can be read without enlarging it, thereby improving efficiency. In addition, if the size of the unit is too small, the formation of the two-dimensional code may become difficult. Specifically, the size of the unit is preferably more than 10 μm and less than 300 μm, may be more than 20 μm and less than 200 μm, or may be more than 30 μm and less than 100 μm.

[0068] In addition, in the two-dimensional code, the width of the bar is the same as the size of the above-mentioned cell.

[0069] The size of the two-dimensional code is, for example, preferably less than 3000 μm, or less than 2000 μm, or less than 1500 μm. If the size of the two-dimensional code is within the above range, the two-dimensional code can be easily configured in an area outside the optical pattern area. On the other hand, the size of the two-dimensional code is, for example, preferably more than 100 μm, or more than 300 μm, or more than 500 μm. If the size of the two-dimensional code is within the above range, although it also depends on the type of the two-dimensional code, the two-dimensional code can be read without enlarging it, thereby improving efficiency. In addition, if the size of the two-dimensional code is too small, the formation of the two-dimensional code may become difficult. Specifically, the size of the two-dimensional code is preferably more than 100 μm and less than 3000 μm, or more than 300 μm and less than 2000 μm, or more than 500 μm and less than 1500 μm.

[0070] For example, Figure 5 As shown in (a), when a patterned low-reflection layer 2 is disposed on the first surface 1a of the high-reflection substrate 1, and the area where the low-reflection layer 2 is disposed is the low-reflection area 12, and the area where the low-reflection layer 2 is not disposed is the high-reflection area 11, it is preferred that the two-dimensional code and the optical pattern 13 are formed simultaneously. That is, the material of the two-dimensional code is preferably the same as the material of the optical pattern. In the above case, for example, Figure 5 As shown in (b), in the two-dimensional code 14, the code portion 15 may be a portion provided with the low-reflection layer 2, and the background portion 16 may be a portion not provided with the low-reflection layer 2. In addition, although not shown in the figure, in the two-dimensional code, the code portion may be a portion not provided with the low-reflection layer, and the background portion may be a portion provided with the low-reflection layer.

[0071] In addition, although not shown in the figure, when a patterned high-reflection layer is configured on the first surface of the low-reflection substrate, and the area where the high-reflection layer is configured is a high-reflection area, and the area where the high-reflection layer is not configured is a low-reflection area, it is preferred that the two-dimensional code and the optical pattern are formed simultaneously. That is, the material of the two-dimensional code is preferably the same as the material of the optical pattern. In the above case, in the two-dimensional code, it can be that the code part is the part where the high-reflection layer is configured, and the background part is the part where the high-reflection layer is not configured. In addition, in the two-dimensional code, it can also be that the code part is the part where the high-reflection layer is not configured, and the background part is the part where the high-reflection layer is configured.

[0072] In addition, for example Figure 6 As shown in (a), when a patterned light shielding layer 32 is disposed on the first surface 31a of the transparent substrate 31, and the area where the light shielding layer 32 is disposed is the light shielding area 22, and the area where the light shielding layer 32 is not disposed is the transmission area 21, it is preferred that the two-dimensional code and the optical pattern 23 are formed simultaneously. That is, the material of the two-dimensional code is preferably the same as the material of the optical pattern. In the above case, for example, Figure 6 As shown in (b), in the two-dimensional code 24, the code portion 25 may be a portion provided with the light shielding layer 32, and the background portion 26 may be a portion not provided with the light shielding layer 32. In addition, although not shown in the figure, in the two-dimensional code, the code portion may be a portion not provided with the light shielding layer, and the background portion may be a portion provided with the light shielding layer.

[0073] 2. Other identification information

[0074] The reflective optical scale for the encoder disclosed in the present invention may also have identification information other than the QR code. As other identification information, for example, the manufacturer, the date of manufacture, and the batch number can be listed. Other identification information is, for example, text, numbers, and labels. Other identification information can be judged by the human eye, or can be recognized by text through OCR.

[0075] In the optical scale for the encoder disclosed in the present invention, the position of other identification information is not particularly limited, but it is preferred that other identification information is arranged in an area other than the optical pattern area.

[0076] Other identification information can be formed simultaneously with the optical pattern, similarly to the above-mentioned two-dimensional code.

[0077] 3. Reflective optical scale for encoder

[0078] The reflective optical scale for encoder disclosed in the present invention has an optical pattern as follows: the optical pattern has two areas with different reflectivities, namely, a high-reflection area and a low-reflection area. The structure of the reflective optical scale for encoder disclosed in the present invention is not particularly limited as long as it has an optical pattern having a high-reflection area and a low-reflection area. The reflective optical scale for encoder may also 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. In addition, the reflective optical scale for 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 method is described below.

[0079] (1) The first method of reflective optical scale for encoder

[0080] The first embodiment of the reflective optical scale for encoder disclosed in the present invention comprises: a highly reflective substrate having a first surface and a second surface opposite to the first surface; and a patterned low-reflective layer arranged on the first surface side of the highly reflective substrate.

[0081] Figure 5 (a) is Figure 1 The enlarged cross-sectional view of the dashed line frame a of the AA line. Figure 1 and Figure 5 As illustrated in (a), the reflective optical scale 10 for encoder has: a disc-shaped high-reflection substrate 1 having a first surface 1a and a second surface 1b opposite to the first surface 1a; and a low-reflection layer 2, which is arranged in a pattern along the circumferential direction of the high-reflection substrate 1 on the first surface 1a side of the high-reflection substrate 1. The reflective optical scale 10 for encoder has a perforated disc shape, and low-reflection areas 12 provided with the low-reflection layer 2 and high-reflection areas 11 not provided with the low-reflection layer 2 are alternately arranged in the circumferential direction. The low-reflection area 12 has a high-reflection substrate 1 and a low-reflection layer 2 in the thickness direction of the reflective optical scale 10 for encoder. The high-reflection area 11 has a high-reflection substrate 1. The reflectivity in the high-reflection area 11 is higher than the reflectivity in the low-reflection area 12. In addition, the reflectivity in the high-reflection area 11 and the reflectivity in the low-reflection area 12 represent the reflectivity at the same wavelength and the same incident angle.

[0082] The reflective optical scale for the encoder of this method is described below according to each structure.

[0083] (a) Highly reflective substrate

[0084] The high reflective substrate in this embodiment has a high reflectivity. The reflectivity of the first surface of the high reflective substrate is, for example, 50% or more, 55% or more, or 60% or more. The above reflectivity is, for example, 100% or less. Specifically, the reflectivity of the first surface of the high reflective substrate is 50% or more and 100% or less, 55% or more and 100% or more, or 60% or more and 100% or less. If the above reflectivity is within the above range, the difference between the reflectivity in the high reflective area and the reflectivity in the low reflective area is large, so it is possible to prevent erroneous detection of the light detector and improve the detection accuracy of the signal.

[0085] In addition, in this specification, reflectivity refers to the reflectivity of the detection light used in the optical encoder. In the case of a highly reflective substrate, when the wavelength of the incident light is any wavelength in the range of 500 nm to 1000 nm, it is more preferred that the reflectivity in the range of the incident angle is 5° to 70° within the above range.

[0086] The reflectivity was measured using SolidSpec 3700DUV manufactured by Shimadzu Corporation. The irradiation beam size was about 6 mm × 15 mm. P-polarized light and S-polarized light were also measured, and the average of the sum was calculated to calculate the 45° linear polarized light and the reflectivity.

[0087] The high reflective substrate may be a metal substrate, or may include a supporting substrate and a metal layer disposed on one surface of the supporting substrate.

[0088] The material of the metal substrate preferably satisfies the above-mentioned reflectivity, and examples thereof include stainless steel (SUS), copper, and aluminum.

[0089] The thickness of the metal substrate is, for example, 0.1 mm or more, 0.3 mm or more, or 0.35 mm or more. In addition, the thickness of the metal substrate is, for example, 1.1 mm or less, 0.5 mm or less, or 0.45 mm or less. Specifically, the thickness of the metal substrate is 0.1 mm or more and 1.1 mm or less, 0.3 mm or more and 0.5 mm or less, or 0.35 mm or more and 0.45 mm or less.

[0090] Examples of the material of the support substrate include glass and resin. In the case of glass, the linear expansion coefficient is small, and dimensional changes associated with temperature changes in the use environment can be suppressed.

[0091] The material of the metal layer preferably satisfies the above-mentioned reflectivity, and examples thereof include chromium, silver, aluminum, rhodium, gold, copper, and alloys containing these metals as main components. Among them, a metal chromium film is preferred.

[0092] The thickness of the metal layer is, for example, 0.05 μm or more, or 0.1 μm or more. In addition, the thickness of the metal layer is, for example, 0.3 μm or less, or 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, or 0.1 μm or more and 0.2 μm or less.

[0093] 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 for calculating thickness by tracing the surface with a stylus and detecting concave and convex, an optical method for calculating thickness based on a spectral reflection spectrum, etc. can be cited. Specifically, the thickness is measured using a stylus film thickness meter "P-15" manufactured by KLA-Tencor. In addition, the thickness adopts the average value of the thickness measurement values ​​at multiple locations of the component as the object. For example, in the case of a metal substrate, it is sufficient to adopt the average value of the thickness measurement values ​​at two locations symmetrical about the center of the disc-shaped metal substrate.

[0094] In the case of a rotary encoder, the highly reflective substrate is in the shape of a disk. The highly reflective substrate may be, for example, a perforated disk with 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 in the shape of a rectangle.

[0095] When the high-reflection substrate is a perforated disc, the outer diameter of the high-reflection substrate is, for example, 15 mm or more, or 20 mm or more, when viewed from above. On the other hand, the outer diameter of the high-reflection substrate is, for example, 70 mm or less, or 60 mm or less. Specifically, the outer diameter of the high-reflection substrate is, for example, 15 mm or more and 70 mm or less, or 20 mm or more and 60 mm or less.

[0096] In the above case, the inner diameter of the high reflective substrate is, for example, 5 mm or more and 20 mm or less in a plan view.

[0097] In the above case, the difference between the outer diameter and the inner diameter, that is, the outer-inner diameter difference is, for example, not less than 8 mm and not more than 13 mm.

[0098] When the high-reflection substrate is a metal substrate or a resin substrate, the high-reflection substrate may have a collapsed edge at the outer peripheral edge on the first surface side. Figure 5 (c) is Figure 1 The enlarged cross-sectional view of the BB line of the dotted frame b. Figure 5In (c), the high-reflective substrate 1 has a collapsed edge P on the outer periphery on the first surface 1a side. The reflective optical scale for encoders having a collapsed edge on the outer periphery on the first surface side of the high-reflective substrate is usually manufactured by punching out a plateform. In the case of the punching process of the plateform, unlike the etching process of the plateform, there is no need to provide a bridge connecting the optical scale for encoders to the frame, so no bridge marks are produced. Therefore, the occurrence of local deformation can be suppressed. In addition, there is no need to reduce the thickness of the metal substrate in order to reduce costs and improve accuracy. Therefore, the metal substrate can be thickened, and undulation or warping can be suppressed. In addition, compared with the etching process of the plateform, it is advantageous in terms of cost.

[0099] Furthermore, when the high-reflection substrate is a metal substrate or a resin substrate and when the high-reflection substrate is in the shape of a perforated disk, the inner peripheral edge on the first surface side may have a collapsed edge.

[0100] (b) Low reflection layer

[0101] The low reflection layer in this embodiment is arranged in a pattern on the first surface side of the high reflection substrate.

[0102] As long as the reflectivity in the low-reflection area is lower than the reflectivity in the high-reflection area, it will suffice. Specifically, as long as the reflectivity in the low-reflection area is lower than the reflectivity of the first surface of the above-mentioned high-reflection substrate, it will suffice. In the low-reflection area, the reflectivity at any wavelength within the range of 500nm to 1000nm is, for example, less than 10%, less than 5%, or less than 1%. On the other hand, the above-mentioned reflectivity in the low-reflection area is, for example, more than 0%. Specifically, the above-mentioned reflectivity in the low-reflection area is more than 0% and less than 10%, more than 0% and less than 5%, or more than 0% and less than 1%. If the above-mentioned reflectivity is within the above-mentioned range, the difference between the reflectivity in the high-reflection area and the reflectivity in the low-reflection area can be increased.

[0103] In the low reflection region, when the wavelength of incident light is any wavelength within the range of 500 nm to 1000 nm, it is more preferable that the reflectance at any incident angle within the range of 5° to 70° is within the above range.

[0104] As long as the low reflection layer satisfies the above reflectivity, its structure is not particularly limited. Among them, the low reflection layer preferably has a metal chromium film from the high reflection substrate side, and a chromium oxide film and a chromium nitride film arranged in different order on the surface of the metal chromium film opposite to the high reflection substrate. If it is a low reflection layer with such a three-layer structure, the reflectivity of the low reflection area can be reduced to the above range. In addition, if only metal chromium is prepared, the chromium oxide film and the chromium nitride film can be easily formed by utilizing reactive sputtering or the like. Furthermore, if it is a low reflection layer as described above, it can also be easier to perform high-precision composition compared to a silicon oxide film.

[0105] In this specification, regarding "the chromium oxide film and the chromium nitride film arranged in different orders on the surface of the metal chromium film opposite to the high-reflective substrate", 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.

[0106] For example, in Figure 7 In (a), the low reflection layer 2 has a metal chromium film 2c, a chromium nitride film 2b, and a chromium oxide film 2a from the side of the high reflection substrate 1. Figure 7 In (b), the low reflection layer 2 has a metal chromium film 2c, a chromium oxide film 2a, and a chromium nitride film 2b from the side of the high reflection substrate 1.

[0107] In the low-reflection layer, the film on the outermost surface opposite to the high-reflection substrate is preferably a chromium oxide film or a chromium nitride film, and more preferably a chromium oxide film, because the reflectivity of the low-reflection region can be more effectively reduced.

[0108] 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.

[0109] (i) Low reflection layer of the first specification

[0110] In the low-reflection layer of this specification, a metal chromium film, a chromium nitride film, and a chromium oxide film are arranged in order from the high-reflection substrate side. In the low-reflection area of ​​the low-reflection layer of this specification, the reflectivity at any wavelength in the range of 500nm to 1000nm can be reduced to 5% or less, especially to 0.5% or less. In addition, the reflectivity changes slowly with respect to the wavelength change, and the control of the reflectivity becomes easy.

[0111] (i-1) Metal chromium film

[0112] In this specification, the metal chromium film is arranged on the first surface of the high reflective 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 is measured using a spectrophotometer "MPC-3100" manufactured by Shimadzu Corporation. The thickness of the metal chromium film is preferably 40 nm or more, and more preferably 70 nm or more, for example.

[0113] 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.

[0114] (i-2) Chromium nitride film

[0115] The chromium nitride film in this specification is arranged between the metal chromium film and the chromium oxide film. Unlike chromium oxide nitride, chromium oxide nitride 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.

[0116] In the chromium nitride (CrNx) film, x representing the atomic ratio of Cr to N is preferably 0.4 or more and 1.1 or less.

[0117] In addition, when the ratio of all elements contained in the chromium nitride film is set to 100 atomic %, the ratio of chromium to 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, for example, hydrogen, oxygen, carbon, etc. as impurities.

[0118] The thickness of the chromium nitride film (T N ) is preferably 5 nm or more and 100 nm or less, and more preferably 10 nm or more and 80 nm or less. O ), when the wavelength is 850nm, T N With T O The total of is preferably 40 nm or more. In addition, when the wavelength is 550 nm, T N With T O The total of is preferably 20 nm or more. With such a thickness, the reflectivity of the low-reflection region can be easily reduced to a desired range compared to the case where the thickness is outside the above range. Moreover, the thickness of the chromium nitride film is preferably 10 nm or more and 80 nm or less. It is easy to reduce the reflectivity in the entire region from the green region to the infrared region, that is, the reflectivity at a wavelength of about 500 nm or more and 1000 nm or less.

[0119] 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 gas 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 to nitrogen gas.

[0120] (i-3) Chromium oxide film

[0121] The chromium oxide film in this specification is arranged on the surface of the chromium nitride film opposite to the metal chromium film. The main components of the chromium oxide film are chromium and oxygen, and unlike chromium oxide nitride, chromium oxide nitride carbide, etc., it does not contain impurities other than chromium and oxygen.

[0122] In the chromium oxide (CrOy) film, y indicating the atomic ratio of Cr to O is preferably 1.4 or more and 2.1 or less.

[0123] Specifically, when the ratio of all elements contained in the chromium oxide film is 100 atomic %, the ratio of chromium to 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, for example, hydrogen, nitrogen, carbon, etc. as impurities.

[0124] The thickness of the chromium oxide film is not particularly limited, and is preferably 5 nm or more and 100 nm or less, and more preferably 10 nm or more and 80 nm or less. In addition, the sum of the thickness of the chromium oxide and the thickness of the chromium nitride film is as described above. In addition, the thickness of the chromium oxide film is preferably 10 nm or more and 65 nm or less. It is easy to reduce the reflectivity in the entire region from the green region to the infrared region, that is, the reflectivity at a wavelength of about 500 nm or more and 1000 nm or less.

[0125] 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.

[0126] (ii) Second specification low reflection layer

[0127] In the low-reflection layer of this specification, a metal chromium film, a chromium oxide film, and a chromium nitride film are arranged in order from the high-reflection substrate side. In the low-reflection region of the low-reflection layer of this specification, the reflectivity at any wavelength within the range of 500nm to 1000nm can be reduced to less than 5%, and in particular, can be reduced to less than 1%.

[0128] (ii-1) Metal chromium film

[0129] The metal chromium film in this specification is the same as the metal chromium film in the low-reflection layer of the first specification mentioned above, so the description here is omitted.

[0130] (ii-2) Chromium oxide film

[0131] The chromium oxide film in this specification is arranged between the metal chromium film and the chromium nitride film.

[0132] The thickness of the chromium oxide film is not particularly limited, and is preferably 5 nm or more and 60 nm or less, and more preferably 10 nm or more and 50 nm or less. In addition, as described later, the total 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 or more and 35 nm or less in order to easily reduce the reflectivity in the entire region from the green region to the infrared region, that is, the reflectivity at a wavelength of about 500 nm or more and 1000 nm or less.

[0133] The physical properties, composition and formation method of the chromium oxide film are the same as those of the chromium oxide film in the low reflection layer of the first specification described above, and therefore the description thereof is omitted here.

[0134] (ii-3) Chromium nitride film

[0135] The chromium nitride film in this specification is arranged on the surface of the chromium oxide film opposite to the metal chromium film.

[0136] Chromium nitride film (T N ) is not particularly limited, and is preferably 5 nm or more and 100 nm or less, and more preferably 10 nm or more and 80 nm or less. 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. Moreover, the thickness of the chromium nitride film is preferably 10 nm or more and 60 nm or less. It is easy to reduce the reflectivity in the entire region from the green region to the infrared region, that is, the reflectivity at a wavelength of about 500 nm or more and 1000 nm or less.

[0137] 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, and therefore the description thereof is omitted here.

[0138] (iii) Method for forming low reflection layer

[0139] The method for forming the low reflection layer is not particularly limited, and the low reflection layer can be formed by selective etching or lift-off.

[0140] In the case of selective etching, for example, a metal chromium film is first formed on the first surface of the highly reflective substrate by sputtering, and then a chromium nitride film and a chromium oxide film are formed. Subsequently, the metal chromium film, the chromium nitride film, and the chromium oxide film are patterned by photolithography and etching.

[0141] In the case of the lift-off method, for example, first, a resist pattern is formed on the first surface of the highly reflective 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, thereby lifting off the metal chromium film, the chromium nitride film, and the chromium oxide film formed just above the resist pattern, thereby obtaining patterns of the metal chromium film, the chromium nitride film, and the chromium oxide film.

[0142] (c) Other structures

[0143] The reflective optical scale for encoder of this mode may have other layers in addition to the above-mentioned high reflective substrate and low reflective layer. For example, the reflective optical scale for encoder of this mode may also have a protective layer between the high reflective substrate and the low reflective layer.

[0144] The protective layer is preferably transparent and has the function of protecting the high-reflection substrate. By providing the protective layer, when etching is performed to form the low-reflection layer in a pattern, there is no worry that the surface of the high-reflection substrate becomes rough, thereby increasing the surface roughness. Therefore, diffuse reflection of light can be suppressed. The protective layer can be provided in the entire area of ​​the high-reflection substrate when viewed from above, or it can be provided in a partial area.

[0145] The material of the protective layer is not particularly limited as long as it has transparency and can protect the highly reflective substrate, and may be any organic material or inorganic material.

[0146] 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, and thermosetting resins cured by heating can be listed. Specifically, preferably novolac resins, polyolefin resins, polyester resins, urethane resins, polyimide resins, acrylic resins, and epoxy resins. Regarding 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. Regarding acrylic resins, trifunctional or higher acrylates such as pentaerythritol tetraacrylate and dipentaerythritol tetraacrylate are preferred. This is because it can improve photocurability. Regarding epoxy resins, epoxy acrylate resins with fluorene structures are preferred. This is because it can improve heat resistance, close adhesion, and chemical resistance. Regarding 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.

[0147] As the inorganic material, inorganic compounds can be cited. As the inorganic compound, for example, 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 can be cited. Silicon dioxide (SiO2) is particularly preferred. The inorganic compound can be used alone or in any proportion.

[0148] (2) Second method of reflective optical scale for encoder

[0149] The second embodiment of the reflective optical scale for encoder disclosed in the present invention comprises: 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.

[0150] The reflective optical scale for the encoder of this method is described below according to each structure.

[0151] (a) Low reflective substrate

[0152] The low-reflection substrate in this embodiment has a low reflectivity. The reflectivity of the low-reflection substrate is the same as the reflectivity of the low-reflection region in the first embodiment of the reflective optical scale for encoder.

[0153] The low-reflection substrate may be a single-layer low-reflection substrate, or may include a transparent substrate and a low-reflection layer disposed on the surface of the transparent substrate opposite to the high-reflection layer.

[0154] The material of the low-reflection substrate is not particularly limited as long as it has low reflectivity, and may be any of an organic material and an inorganic material.

[0155] Similarly, the material of the low reflection layer is not particularly limited as long as it has low reflectivity, and can be any of organic materials and inorganic materials. The organic material preferably includes a resin. As the resin used for the low reflection layer, as long as it is a resin that can obtain a low reflection layer, it is not particularly limited, for example, ionizing radiation curing resins cured by irradiation of ionizing radiation such as ultraviolet rays and electron beams, and thermosetting resins cured by heating. Specifically, preferably phenolic varnish resins, polyolefin resins, polyester resins, urethane resins, polyimide resins, acrylic resins, and epoxy resins. Regarding phenolic varnish resins, phenolic varnish resins are preferred. This is because: its electrical properties are excellent and can suppress the adverse conditions caused by charging. Regarding acrylic resins, trifunctional or higher acrylates such as pentaerythritol tetraacrylate and dipentaerythritol tetraacrylate are preferred. This is because it can improve photocurability. Regarding epoxy resins, epoxy acrylate resins with fluorene structures are preferred. This is because it can improve heat resistance, close adhesion, and chemical resistance. As for the epoxy resin, phenolphthalein epoxy resin is also preferred because it can impart heat resistance, surface hardness, and flatness. In addition to the resin, the organic material may also contain a polymerization initiator or various additives.

[0156] 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 encoder, wherein the low reflection layer is preferably the low reflection layer of the first specification or the low reflection layer of the second specification.

[0157] The transparent substrate is the same as the transparent substrate in the reflective optical scale for encoder described later.

[0158] In the case of a rotary encoder, the low-reflection substrate is in the shape of a disk. The low-reflection substrate may be, for example, a perforated disk with 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 in the shape of a rectangle.

[0159] When the low-reflection substrate is in the shape of a perforated disc, the outer diameter and inner diameter of the low-reflection substrate when viewed from above are the same as the outer diameter and inner diameter of the high-reflection substrate in the first embodiment of the reflective optical scale for the encoder.

[0160] When the low-reflection substrate has a resin substrate, the low-reflection substrate may have a collapsed edge at the outer periphery of the first surface side. In addition, when the low-reflection substrate has a resin substrate and is in the shape of a perforated disk, the low-reflection substrate may have a collapsed edge at the inner periphery of the first surface side.

[0161] (b) High reflective layer

[0162] The high reflection layer in this embodiment is arranged in a pattern on the first surface side of the low reflection substrate.

[0163] As long as the reflectivity in the high-reflection area is higher than the reflectivity in the low-reflection area, it will suffice. Specifically, as long as the reflectivity in the high-reflection area is higher than the reflectivity of the low-reflection substrate, it will suffice. The reflectivity in the high-reflection area is the same as the reflectivity of the first surface of the high-reflection substrate in the first mode of the reflective optical scale for the encoder.

[0164] The structure of the high reflective layer is not particularly limited as long as it satisfies the above-mentioned reflectivity, and examples thereof include metal films. The metal film is preferably composed of a metal having a high reflectivity. Examples of the metal include chromium, silver, aluminum, rhodium, gold, copper, and alloys containing these metals as main components. Among them, a metal chromium film is preferred. The metal chromium film is a layer composed of metal chromium. The thickness of the metal film is, for example, greater than 0.05 μm and less than 0.3 μm, and may also be greater than 0.1 μm and less than 0.2 μm.

[0165] 4. Transmissive optical scale for encoder

[0166] The transmission type optical scale for encoder disclosed in the present invention has an optical pattern as follows: the optical pattern has two areas with different transmittances, namely, a transmission area and a shading area. The structure of the transmission type optical scale for encoder disclosed in the present invention is not particularly limited as long as it has an optical pattern having a transmission area and a shading area, but preferably has: a transparent substrate having a first surface and a second surface opposite to the first surface; and a patterned shading layer, which is arranged on the first surface side of the transparent substrate.

[0167] Figure 6 (a) is Figure 2 The enlarged cross-sectional view of the dashed line frame a of the AA line. Figure 2 and Figure 6As illustrated in (a), the transmission type optical scale 20 for encoder has: a disc-shaped transparent substrate 31 having a first surface 31a and a second surface 31b opposite to the first surface 31a; and a light shielding layer 32, which is arranged in a pattern along the circumferential direction of the transparent substrate 31 on the first surface 31a side of the transparent substrate 31. The transmission type optical scale 20 for encoder has a perforated disc shape, and the light shielding area 22 provided with the light shielding layer 32 and the transmission area 21 without the light shielding layer 32 are alternately arranged in the circumferential direction. The light shielding area 22 has a transparent substrate 31 and a light shielding layer 32 in the thickness direction of the transmission type optical scale 20 for encoder. The transmission area 21 has a transparent substrate 31. The transmittance at the transmission area 21 is higher than the transmittance at the light shielding area 22. In addition, the transmittance at the transmission area 21 and the transmittance at the light shielding area 22 represent the transmittance at the same wavelength.

[0168] Hereinafter, the reflective optical scale for the encoder disclosed in the present invention will be described according to each structure.

[0169] (1) Transparent substrate

[0170] The transparent substrate disclosed in the present invention has a high transmittance. The total light transmittance of the transparent substrate is, for example, 80% or more, 85% or more, or 90% or more. The total light transmittance is measured in accordance with JIS K7361-1:1997.

[0171] As the material of the transparent substrate, for example, glass and resin can be listed. Glass is high-strength and has a small linear expansion coefficient, so it can suppress the dimensional change associated with the temperature change of the use environment. As the resin, it is preferred to meet the above-mentioned transmittance, and for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), polyethylene (PE), polycarbonate (PC), acrylic resin, polyvinyl chloride, polyvinyl alcohol, polyimide, polyetherimide, polyetheretherketone, epoxy resin, silicone resin, phenolic resin can be listed.

[0172] 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 to 2 mm.

[0173] In the case of a rotary encoder, the transparent substrate is in the shape of a disk. The transparent substrate may be, for example, a perforated disk with a central hole or may not have a central hole. On the other hand, in the case of a linear encoder, the transparent substrate is in the shape of a rectangle.

[0174] (2) Light-shielding layer

[0175] The light shielding layer of the present disclosure is arranged in a pattern on the first surface side of the transparent substrate.

[0176] The transmittance in the light-shielding region may be lower than the transmittance in the transmission region. The optical density of the light-shielding region may be, for example, 2.5 or more, 3.0 or more, 3.5 or more, or 4.0 or more.

[0177] In this specification, optical density is transmission density. Optical density is measured using an optical densitometer. An optical densitometer is a measuring instrument having the following structure: light is irradiated to a sample (object to be measured) and the intensity of the transmitted light is measured. Specifically, the TAKANO OD reflectivity meter manufactured by TAKANO Corporation is used to irradiate light in a direction perpendicular to the sample for measurement.

[0178] The structure of the light shielding layer is not particularly limited as long as it satisfies the above optical density. The structure of the light shielding layer may be the same as that of the above low reflection layer, for example.

[0179] 5. Method for manufacturing optical scale for encoder

[0180] The manufacturing method of the optical scale for encoder disclosed in the present invention preferably comprises: a platemaking body manufacturing step of manufacturing an optical scale platemaking body for encoder in which a plurality of optical scales for encoder are mounted; and a singulation step of singulating the optical scale platemaking body for encoder.

[0181] The optical scale type plateform for the encoder will be described later, so the description here is omitted.

[0182] As a method of monolithicizing the optical scale plateform for encoder, it is different according to the substrate of the optical scale plateform for encoder. In the case where the substrate of the optical scale plateform for encoder is a high-reflection substrate, and the high-reflection substrate is a metal substrate, punching and etching can be listed. In addition, in the case where the substrate of the optical scale plateform for encoder is a high-reflection substrate and the high-reflection substrate has a glass substrate, the substrate of the optical scale plateform for encoder is a low-reflection substrate and the low-reflection substrate has a glass substrate, and the substrate of the optical scale plateform for encoder is a transparent substrate and the transparent substrate is a glass substrate, machine cutting can be listed. In addition, in the case where the substrate of the optical scale plateform for encoder is a high-reflection substrate and the high-reflection substrate has a resin substrate, the substrate of the optical scale plateform for encoder is a low-reflection substrate and the low-reflection substrate has a resin substrate, and the substrate of the optical scale plateform for encoder is a transparent substrate and the transparent substrate is a resin substrate, punching can be listed.

[0183] As described above, in the case of the punching process of the plate-forming body, unlike the etching process of the plate-forming body, there is no need to set a bridge connecting the optical scale for the encoder and the frame, so no bridge mark will be produced. Therefore, the generation of local deformation can be suppressed. In addition, there is no need to reduce the thickness of the metal substrate in order to reduce costs and improve accuracy. Therefore, the metal substrate can be thickened, and undulation or warping can be suppressed. In addition, compared with the etching process of the plate-forming body, it is more advantageous in terms of cost.

[0184] In addition, when the size of the optical scale plateform for the encoder is large, when the optical scale plateform for the encoder is monolithicized, it is not necessary to monolithicize the optical scale plateform for the encoder at once, but it is possible to divide the optical scale plateform for the encoder into multiple pieces in advance and then monolithicize them.

[0185] Figure 8 (a)~ Figure 8 (b) is a schematic diagram showing an example of a punching processing device used in the singulation process. Figure 8 As shown in (a), an optical scale plate-making body 50 for an encoder is placed on a lower stage 62 having a lower blade 61. Figure 8 As shown in (b), the lower stage 62 is moved upward, and the upper stage 63 having the upper blade 64 is moved downward to press the encoder optical scale plateform 50, thereby punching the encoder optical scale plateform 50. In addition, it is preferred that a pressing component 65 is arranged at a position opposite to the upper blade 64. During the punching process, the upper blade 64 and the pressing component 65 can be used to clamp the metal substrate to perform a punching process with less burrs and collapsed edges. In this way, individual reflective optical scales 10 for encoders are obtained.

[0186] 6. Application of optical scale for encoder

[0187] The optical scale for encoder disclosed in the present invention can be used for a rotary encoder or a linear encoder.

[0188] B. Optical scale for encoder

[0189] The optical scale plateform for encoder disclosed in the present invention is an optical scale plateform for encoder on which a plurality of optical scales for encoder are installed, and the optical scale for encoder has an optical pattern: the optical pattern has two areas with different reflectivity or transmittance, wherein the optical scale for encoder has a two-dimensional code, and the optical scale plateform for encoder has more than one unit area, and in the unit area, the two-dimensional code is different for each optical scale for encoder.

[0190] Figure 3 and Fig. 91 is a schematic top view showing an example of an optical scale imposition body for an encoder disclosed in the present invention, Figure 4 yes Figure 3 and Fig. 9 A partial enlarged view of the Figure 3 and Fig. 9 As shown, in the optical scale plate 50 for encoder, a plurality of optical scales for encoder (reflective optical scale 10 for encoder or transmissive optical scale 20 for encoder) having the following optical pattern are installed on the plate: the optical pattern has two areas with different reflectivity or transmittance. Figure 4 As shown, the optical scale for encoder (the reflective optical scale 10 for encoder or the transmissive optical scale 20 for encoder) has a two-dimensional code 14 or 24.

[0191] exist Figure 3 In the optical scale assembly 50 for encoder, there is a unit area U1, in which the two-dimensional code 14 or 24 is different for each optical scale for encoder (reflective optical scale 10 for encoder or transmissive optical scale 20 for encoder). Figure 3 There are 100 optical scales for encoders (reflective optical scale 10 for encoders or transmissive optical scale 20 for encoders) arranged in 10 rows x 10 columns. In the unit area U1, the two-dimensional codes 14 or 24 of the 100 optical scales for encoders (reflective optical scale 10 for encoders or transmissive optical scale 20 for encoders) are different from each other.

[0192] On the other hand, Fig. 9 In the optical scale plate 50 for encoder, there are two unit areas U1 and U2. In the unit area U1, the two-dimensional code 14 or 24 is different for each optical scale for encoder (reflective optical scale 10 for encoder or transmissive optical scale 20 for encoder). Similarly, in the unit area U2, the two-dimensional code 14 or 24 is different for each optical scale for encoder (reflective optical scale 10 for encoder or transmissive optical scale 20 for encoder). Specifically, in Fig. 9In the unit area U1, a total of 320 optical scales for encoders (reflective optical scales 10 for encoders or transmissive optical scales 20 for encoders) are arranged in 20 rows and 16 columns. In the unit area U1, 160 optical scales for encoders (reflective optical scales 10 for encoders or transmissive optical scales 20 for encoders) are arranged in 10 rows and 16 columns. Similarly, in the unit area U2, 160 optical scales for encoders (reflective optical scales 10 for encoders or transmissive optical scales 20 for encoders) 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 10 for encoders or transmissive optical scales 20 for encoders) 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 (the reflective optical scale 10 for encoders or the transmissive optical scale 20 for encoders) are different from each other.

[0193] In addition, Figure 3 as well as Fig. 9 In the figure, for the sake of illustration and easy understanding, a state in which 100 optical scales for encoders are arranged in 10 rows × 10 columns or 320 optical scales for encoders are arranged in 20 rows × 16 columns, is shown, but the number of optical scales for encoders in the optical scale plateset is not limited to this.

[0194] In the present disclosure, in a unit area, the two-dimensional code is different for each optical scale for encoder, thereby being able to determine the position of the optical scale for encoder in the optical scale for encoder imposition body. Therefore, the same effect as the above-mentioned optical scale for encoder is achieved.

[0195] An optical scale for an encoder produced by singulating the optical scale plateform for an encoder disclosed in the present invention will be described. Fig.10 Schematic diagram showing the state where the encoder optical scale is stored in the storage component. Fig.10 As shown, the optical scale for encoder (the reflective optical scale 10 for encoder or the transmissive optical scale 20 for encoder) is stored in the storage part 70 for each unit area. Fig.10 Yes Figure 3 The example of the case where the encoder optical scale plate body is singulated is shown. The storage member 70 has 100 storage sections 71, and the encoder optical scale (encoder reflective optical scale 10 or encoder transmissive optical scale 20) is stored in the storage section 71.

[0196] exist Figure 3In the embodiment, since the optical scale plate 50 for encoder has one unit area U1, 100 optical scales for encoder are accommodated in one accommodating part. Fig. 9 In the embodiment, since the optical scale plateform 50 for encoder has two unit areas U1 and U2, the optical scale is stored in the storage component according to each unit area U1 and U2, that is, the optical scale for encoder is divided into 160 units according to each unit area and stored in two storage components.

[0197] In the case where the optical scale plateform for encoder disclosed in the present invention has a plurality of unit areas, there are optical scales for encoder with the same two-dimensional code in one unit area and in other unit areas. In contrast, in the unit area, the two-dimensional code is different for each optical scale for encoder, and therefore, by storing the optical scale for encoder in the storage component for each unit area, traceability can be ensured.

[0198] The storage unit preferably displays information indicating the unit area.

[0199] In the optical scale plateform for encoder disclosed in the present invention, the number of optical scales for encoder is, for example, preferably more than 50, may be more than 200, or may be more than 400. Thus, the present invention is useful when the number of optical scales for encoder in the optical scale plateform for encoder is large. On the other hand, the upper limit of the number of optical scales for encoder in the optical scale plateform for encoder is not particularly limited, but due to the constraints of the manufacturing device, it is, for example, less than 3,000.

[0200] The size of the optical scale typesetting body for encoder disclosed in the present invention when viewed from above is not particularly limited, but the length of one side of the optical scale typesetting body for encoder is preferably greater than 150 mm, more preferably greater than 300 mm, and further preferably greater than 350 mm. As described above, the present invention is useful in cases where the size of the optical scale typesetting body for encoder when viewed from above is relatively large. The upper limit of the size of the optical scale typesetting body for encoder disclosed in the present invention when viewed from above is not particularly limited, but due to the constraints of the manufacturing device, for example, the length of one side of the optical scale typesetting body for encoder is less than 920 mm.

[0201] The optical scale plateform for encoder disclosed in the present invention may also have identification information other than the QR code. As other identification information, for example, the manufacturer, the date of manufacture, and the batch number can be listed. Other identification information is, for example, text, numbers, and symbols. Other identification information can be judged by the human eye, or can be recognized by text through OCR.

[0202] In the optical scale imposition body for encoders disclosed in the present invention, the position of other identification information is not particularly limited. Other identification information can be arranged on each optical scale for encoders, or can be arranged in an area other than the optical scale for encoders.

[0203] In the case of an encoder optical scale plateform in which a plurality of reflective optical scales for encoders are plated, a method for plate-mounting a plurality of patterned low-reflection layers on the first surface of a highly reflective substrate is the same as the method for forming the low-reflection layer described above. In addition, in the case of an encoder optical scale plateform in which a plurality of transmissive optical scales for encoders are plated, a method for plate-mounting a plurality of patterned light-shielding layers on the first surface of a transparent substrate is the same as the method for forming the light-shielding layer described above.

[0204] C. Optical encoder

[0205] The optical encoder disclosed in the present invention comprises: the above-mentioned optical scale for encoder; a light source that irradiates measurement light onto the surface of the above-mentioned optical scale for encoder; and a light detector that detects reflected light or transmitted light from the above-mentioned optical scale for encoder.

[0206] The optical encoder disclosed in the present invention may be a reflective encoder or a transmissive encoder.

[0207] Fig.11 1 is a schematic three-dimensional diagram showing an example of an optical encoder of the present disclosure, and is an example of a reflective encoder. The optical encoder 100A includes: a reflective optical scale 10 for encoder; and a light source 81 and a light detector 82 arranged on the same plane as the reflective optical scale 10 for encoder. Fig.11 In the figure, a fixed gap 83 is arranged between the light detector 82 and the reflective optical scale 10 for the encoder.

[0208] Fig.12 100B is a schematic perspective view showing another example of the optical encoder of the present disclosure, and is an example of a transmissive encoder. The optical encoder 100B includes: a transmissive optical scale 20 for encoder; a light source 91 disposed on one side of the transmissive optical scale 20 for encoder; and a light detector 92 disposed on the other side of the transmissive optical scale 20 for encoder. Fig.12 In the figure, the lens 93 is arranged between the light source 91 and the transmission type optical scale 20 for the encoder.

[0209] According to the present disclosure, since the optical scale for the encoder is provided, the same effect as the optical scale for the encoder is achieved.

[0210] Hereinafter, the optical encoder of the present disclosure will be described for each structure.

[0211] 1. Optical scale for encoder

[0212] Regarding the optical scale for encoder, it is described in the above "A. Optical scale for encoder", so the description here is omitted.

[0213] 2. Light source

[0214] As the light source, for example, LED (light emitting diode) and laser can be cited. The wavelength λ of the light irradiated from the light source is, for example, from the blue region to the infrared region, that is, about 400 nm or more and 1000 nm or less. In the case of a reflective encoder, the incident angle of the light relative to the optical reflective scale is, for example, 5° or more and 70° or less.

[0215] 3. Light detector

[0216] The photodetector detects light reflected or transmitted by the optical scale. The photodetector includes, for example, a light receiving element such as a photodiode or an imaging element. Examples of the light receiving element include a photoelectric conversion element.

[0217] 4. Others

[0218] In the case where the optical encoder disclosed in the present invention is a reflective encoder, a fixed gap may be provided between the light detector and the optical reflective scale for the encoder. By providing a fixed gap, the change in the amount of light received by the light detector becomes larger, thereby improving the detection sensitivity. The fixed gap may also be provided between the light source and the optical scale for the encoder.

[0219] When the optical encoder of the present disclosure is a transmission type encoder, a lens may be provided between the light source and the optical transmission type scale for the encoder. By providing the lens, the light from the light source can be changed from diffuse light to parallel light.

[0220] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are illustrative, and any configuration having substantially the same structure 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.

[0221] That is, in this disclosure, the following inventions are provided.

[0222] [1] An optical scale for an encoder, comprising an optical pattern having two regions with different reflectance or transmittance, wherein the optical scale for an encoder has a two-dimensional code.

[0223] [2] An optical scale for an encoder according to [1], wherein the two-dimensional code is arranged in an area outside an optical pattern area where the optical pattern is arranged.

[0224] [3] An optical scale for an encoder according to [1] or [2], wherein the optical scale for an encoder comprises: a disc-shaped 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.

[0225] [4] An optical scale for an encoder according to [1] or [2], wherein the optical scale for an encoder comprises: a disc-shaped transparent substrate having a first surface and a second surface opposite to the first surface; and a patterned light-shielding layer arranged on the first surface side of the transparent substrate.

[0226] [5] An optical scale for an encoder according to any one of [1] to [4], wherein the material of the two-dimensional code is the same as the material of the optical pattern.

[0227] [6] An optical scale plateform for encoder, wherein a plurality of optical scales for encoder are installed on the plateform, wherein the optical scale for encoder has an optical pattern as follows: the optical pattern has two areas with different reflectance or transmittance, wherein the optical scale for encoder has a two-dimensional code, and the optical scale plateform for encoder has one or more unit areas, and in the unit areas, the two-dimensional code is different for each optical scale for encoder.

[0228] [7] An optical encoder comprising: an optical scale for an encoder as described in any one of [1] to [5]; a light source that irradiates measurement light onto the surface of the optical scale for an encoder; and a light detector that detects reflected light or transmitted light from the optical scale for an encoder.

Claims

1. An optical scale for an encoder, comprising an optical pattern having two regions with different reflectivity or transmittance, wherein: The optical scale used for the encoder has a two-dimensional code.

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

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

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

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

6. An optical scale plate for an encoder, wherein a plurality of optical scales for an encoder are mounted on the plate, and the optical scale for an encoder has an optical pattern as follows: the optical pattern has two regions with different reflectivity or transmittance, wherein: The optical scale for the encoder has a two-dimensional code, The optical scale plate-making body for the encoder has more than one unit area. In the unit area, the two-dimensional code is different according to the optical scale used for each encoder.

7. An optical encoder, wherein: The optical encoder comprises: An optical scale for an encoder according to any one of claims 1 to 5; a light source for irradiating measurement light onto the surface of the optical scale for the encoder; and A light detector detects reflected light or transmitted light from the optical scale used for the encoder.

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