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

Abstract

The utility model 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, a tiled body of optical scales for an encoder, and an optical encoder. Background Art

[0002] Conventionally, an optical encoder has been used in a servo motor or the like having a control mechanism. The optical encoder includes an optical scale, a light source such as an LED that irradiates light onto the optical scale, and a light detector that detects transmitted light or reflected light from the optical scale. High precision is required for the optical encoder. Therefore, traceability that can track the manufacturing history of the optical encoder is important in the event of a problem.

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

[0004] The optical scale used in the optical encoder also requires traceability. Conventionally, as a method for identifying an optical scale, there are known methods: a method in which identification information is letters, numbers, or labels and is discriminated by the human eye; and a method in which character recognition is performed by OCR (Optical Character Recognition). However, in the case of discrimination by the human eye, there are problems in terms of misreading and input errors, or efficiency and cost. In addition, in the case of OCR, since characters are read by a machine, it is advantageous in terms of efficiency and cost, but there is a concern about misreading. SUMMARY OF THE UTILITY MODEL

[0005] The present utility model has been completed in view of the above circumstances, 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 having two regions with different reflectivities or transmittances, and the optical scale for an encoder has a two-dimensional code.

[0007] Another embodiment of the present disclosure provides a tiled body of optical scales for an encoder, in which a plurality of optical scales for an encoder are mounted on a plate. The optical scale for an encoder has an optical pattern having two regions with different reflectivities or transmittances, and the optical scale for an encoder has a two-dimensional code. The tiled body of optical scales for an encoder has one or more unit regions, and in the unit region, the two-dimensional code is different for each optical scale for an encoder.

[0008] Another embodiment of the present disclosure provides an optical encoder, which includes: the above-described optical scale for an encoder; 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.

[0009] In the optical scale for an encoder of the present disclosure, the effect of ensuring traceability is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0012] Figure 3 is a schematic top view illustrating a mosaic body of the optical scale for an encoder of the present disclosure.

[0013] Figure 4 is a schematic top view illustrating a mosaic body of the optical scale for an encoder of the present disclosure, and is Figure 3 or Figure 9 a partial enlarged view.

[0014] Figures 5(a) - 5(c) is a schematic cross-sectional view illustrating the optical scale for an encoder of the present disclosure.

[0015] FIG. 6(a) and FIG. 6(b) are schematic cross-sectional views illustrating the optical scale for an encoder of the present disclosure.

[0016] FIG. 7(a) and FIG. 7(b) are schematic cross-sectional views illustrating the optical scale for an encoder of the present disclosure.

[0017] FIG. 8(a) and FIG. 8(b) are schematic views of a blanking device used in a singulation process in a manufacturing method of the optical scale for an encoder of the present disclosure.

[0018] Figure 9 is a schematic top view illustrating a mosaic body of the optical scale for an encoder of the present disclosure.

[0019] Figure 10 is a schematic top view showing a state in which the optical scale for an encoder of the present disclosure is housed in a housing member.

[0020] Figure 11 is a schematic perspective view illustrating the optical encoder of the present disclosure.

[0021] Figure 12 is a schematic perspective view illustrating the optical encoder of the present disclosure.

[0022] Description of Reference Numerals

[0023] 1…High-reflection substrate;

[0024] 2…Low-reflection layer;

[0025] 10…Optical reflection scale for encoder;

[0026] 11…High-reflection area;

[0027] 12…Low-reflection area;

[0028] 13…Optical pattern;

[0029] 14…Two-dimensional code;

[0030] 20…Optical transmission scale for encoder;

[0031] 21…Transmission area;

[0032] 22…Light-shielding area;

[0033] 23…Optical pattern;

[0034] 24…Two-dimensional code;

[0035] 31…Transparent substrate;

[0036] 32…Light-shielding layer;

[0037] 50…Optical scale assembly for encoder;

[0038] 100A, 100B…Optical encoders;

[0039] U1, U2…Unit areas. Detailed Embodiments

[0040] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be implemented in various different ways and is not limited to the description of the embodiments illustrated below. In addition, regarding the drawings, in order to make the description clearer, the width, thickness, shape, etc. of each part are sometimes shown schematically compared with 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 each figure, for the figures that have appeared before, the same reference numerals are assigned to the same elements as before, and sometimes the detailed description is appropriately omitted.

[0041] In this specification, when describing the form of arranging other components on a certain component, if simply expressed as "above" or "below" without special explanation, it includes both the case of arranging other components directly above or directly below in contact with a certain component and the case of arranging other components with another component in between above or below a certain component. In addition, in this specification, when describing the form of arranging other components on the surface of a certain component, if simply expressed as "on the side of... surface" or "on the... surface" without special explanation, it includes both the case of arranging other components directly above or directly below in contact with a certain component and the case of arranging other components with another component in between above or below a certain component.

[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 for encoder mosaic body, and the optical encoder of the present disclosure will be described in detail.

[0044] A. Optical scale for encoder

[0045] The optical scale for encoder of the present disclosure has an optical pattern as follows: the optical pattern has two regions with different reflectivities or transmittances, and among them, the optical scale for encoder has a two-dimensional code. The optical scale for encoder of the present disclosure can be a reflective optical scale for encoder having an optical pattern as follows: the optical pattern has two regions with different reflectivities, namely a reflection region (high reflection region) and a non-reflection region (low reflection region). The optical scale for encoder of the present disclosure can also be a transmissive optical scale for encoder having an optical pattern as follows: the optical pattern has two regions with different transmittances, namely a transmission region and a non-transmission region (light-shielding region).

[0046] Figure 1 is a schematic top view showing an example of the reflective optical scale for encoder of the present disclosure. As Figure 1 illustrated, the reflective optical scale for encoder 10 has an optical pattern 13, and this optical pattern 13 has two regions with different reflectivities, namely a high reflection region 11 and a low reflection region 12. The reflective optical scale for encoder 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 is a schematic top view showing an example of the transmissive optical scale for encoder of the present disclosure. As Figure 2As illustrated, the transmissive optical scale 20 for an encoder has an optical pattern 23, and the optical pattern 23 has two regions with different transmittances, namely a transmissive region 21 and a light-shielding region 22. The transmissive optical scale 20 for an encoder has a two-dimensional code 24 in a region other than the optical pattern region where the optical pattern 23 is disposed.

[0048] In the present disclosure, by associating the manufacturing history of the optical scale for an encoder with the two-dimensional code, traceability can be ensured. The two-dimensional code can improve the reading accuracy. Therefore, traceability can be improved. In addition, the two-dimensional code can record a lot of information in a space-saving manner. The size of characters recognizable by the human eye is about 2 mm to 3 mm, but in the case of a two-dimensional code, the overall size of the two-dimensional code can be made smaller than this. Therefore, in the optical scale for an encoder, it is possible to easily dispose the two-dimensional code in a region other than the optical pattern region. In addition, since the two-dimensional code is read by a machine, high efficiency can be achieved and labor costs can be reduced.

[0049] When manufacturing an optical scale, a panel body on which a plurality of optical scales are panel-mounted is sometimes used.

[0050] Figure 3 is a schematic top view showing an example of an optical scale panel body for an encoder on which a plurality of optical scales for an encoder are panel-mounted. Figure 4 is Figure 3 a partial enlarged view of. In the present disclosure, the optical scale for an encoder (the reflective optical scale 10 for an encoder or the transmissive optical scale 20 for an encoder) is manufactured by separating a single piece from the optical scale panel body 50 for an encoder as shown in Figure 3 and Figure 4 .

[0051] In the present disclosure, the two-dimensional code may include information for identifying the position of the optical scale for an encoder in the optical scale panel body for an encoder. In Figure 3 , since 100 optical scales for an encoder (the reflective optical scale 10 for an encoder or the transmissive optical scale 20 for an encoder) are panel-mounted on the optical scale panel body 50 for an encoder, it is possible to determine which position among the 100 positions the optical scale for an encoder (the reflective optical scale 10 for an encoder or the transmissive optical scale 20 for an encoder) is by means of the two-dimensional code. The two-dimensional code includes information indicating the row number and the column number in, for example, 10 rows × 10 columns. By providing the optical scale for an encoder with a two-dimensional code, even the optical scale for an encoder separated from the optical scale panel body for an encoder can easily determine at which position in the optical scale panel body for an encoder it was manufactured.

[0052] Regarding the substrate in the optical scale tile body for an encoder, there may sometimes be undulations or warping in the substrate itself. In addition, in the optical scale tile body for an encoder, in two regions with different reflectivities or transmittances, there may sometimes be errors in the pattern size, or reflectivity or transmittance, compared with the design values. In such cases, the characteristics of the optical scale for the encoder vary according to the position in the optical scale tile body for the encoder. In such cases, by using a two-dimensional code to determine the position of the optical scale for the encoder in the optical scale tile body for the encoder, even after the optical scale for the encoder is separated from the optical scale tile body for the encoder into individual pieces, different characteristics can be grasped according to the position in the optical scale tile body for the encoder. For example, the optical scale for the encoder can be used based on grasping different characteristics according to the position in the optical scale tile body for the encoder. In addition, for example, in cases 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 tile body for the encoder. Therefore, by associating the characteristics that vary according to the position in the optical scale tile body for the encoder with the two-dimensional code, quality management can be efficiently carried out.

[0053] Here, for example, in the case of forming two regions with different transmittances or reflectivities using photolithography, the photomask is reused. Therefore, even when manufacturing an optical scale using the same photomask, the state of the optical scale may sometimes change according to 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, in the case of forming two regions with different transmittances or reflectivities using photolithography, the size of the tile body in a plan view was, for example, 5 inches square. In this case, the number of optical scales provided on the tile body was in the range of several tens to around twenty-something, which was relatively small. Therefore, in this case, in order to mass-produce, the number of times the photomask was reused increased. Therefore, from the perspective of traceability, it became important to determine the manufacturing time point such as the number of times the photomask was used, and almost no consideration was given to the position of the optical scale in the tile body. In addition, even if information for identifying the position of the optical scale in the tile body was given, since the amount of information for identifying the position of the optical scale in the tile body was small, it was sufficient to use characters discriminated by the human eye or recognized by OCR as the identification information, and there was no need to use a two-dimensional code with a large amount of information.

[0055] On the other hand, when more than a hundred or around several hundred optical scales for encoders are assembled on the optical scale assembly for encoders, the optical scales for encoders are manufactured in large quantities at one time, so it is desirable to ensure traceability. In addition, if the number of optical scales for encoders in the optical scale assembly for encoders is large, the base material in the optical scale assembly for encoders becomes large, so sometimes the base material itself is prone to undulation or warping. Furthermore, the photomask used in manufacturing also becomes large, so sometimes the pattern size is prone to deviation. Therefore, from the perspective of traceability, it is important to determine the position of the optical scale for encoders in the optical scale assembly for encoders. In the present disclosure, as described above, the position of the optical scale for encoders in the optical scale assembly for encoders can be determined by a QR code. Therefore, the present disclosure is useful when the number of optical scales for encoders in the optical scale assembly for encoders is large and the optical scale assembly for encoders is large.

[0056] In addition, in the present disclosure, when a pattern-like low-reflection layer is disposed on the first surface of a high-reflection base material as described later, and the region where the low-reflection layer is disposed is a low-reflection region, and the region where the low-reflection layer is not disposed is a high-reflection region, an optical pattern and a QR code can be formed simultaneously. In addition, in the present disclosure, when a pattern-like high-reflection layer is disposed on the first surface of a low-reflection base material as described later, and the region where the high-reflection layer is disposed is a high-reflection region, and the region where the high-reflection layer is not disposed is a low-reflection region, an optical pattern and a QR code can be formed simultaneously. In addition, in the present disclosure, when a pattern-like light-shielding layer is disposed on the first surface of a transparent base material as described later, and the region where the light-shielding layer is disposed is a light-shielding region, and the region where the light-shielding layer is not disposed is a transmission region, an optical pattern and a QR code can be formed simultaneously. Therefore, an optical scale for encoders with a QR code can be manufactured without increasing the manufacturing process.

[0057] Hereinafter, the optical scale for encoders of the present disclosure will be described for each structure.

[0058] 1. QR code

[0059] In the present disclosure, the manufacturing history of the optical scale for encoders is associated with the QR code.

[0060] The optical scale for encoders of the present disclosure is preferably manufactured by singling out the optical scale assembly for encoders. Therefore, the QR code preferably includes information for identifying the position of the optical scale for encoders in the optical scale assembly for encoders.

[0061] In addition, when manufacturing an optical scale for an encoder using photolithography, the two-dimensional code may also include information for identifying a photomask. The information for identifying a photomask is information inherent to the photomask. In the optical scale assembly for an encoder, the information for identifying a photomask is the same.

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

[0063] As the two-dimensional code, for example, it may be a matrix two-dimensional code or a stacked two-dimensional code. Among them, a matrix two-dimensional code is preferred. A matrix two-dimensional code can increase the amount of information and is easy to read. In addition, generally speaking, a stacked two-dimensional code is rectangular, while a matrix two-dimensional code is square. Therefore, compared with a stacked two-dimensional code, a matrix two-dimensional code is easier to be arranged in an area outside the optical pattern area. Specifically, QR Code (registered trademark), micro QR Code, rMQR Code, Data Matrix, Veri Code, Aztec Code, and Maxi Code can be cited. Among them, QR Code (registered trademark), micro QR Code, rMQR Code, and Data Matrix are preferred, micro QR Code, rMQR Code, and Data Matrix are more preferred, and Data Matrix is further preferred. QR Code (registered trademark) has high versatility. In addition, since the micro QR Code, rMQR Code, and Data Matrix can reduce the size of the two-dimensional code, in the optical scale for an encoder, the two-dimensional code can be easily arranged in an area outside the optical pattern area.

[0064] In the optical scale for an encoder of the present disclosure, 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 reflectivities or transmittances. The optical pattern is a pattern used to detect the displacement of the optical scale for an encoder in an optical encoder.

[0065] In addition, regarding the position of the two-dimensional code, for example, as Figure 2 shown, preferably, the end of the two-dimensional code 24 is separated from the end of the optical scale 20 for an encoder by a distance d1. The above distance d1 is preferably 0.2 mm or more, and more preferably 0.5 mm or more. In this case, as Figure 4 shown, in the optical scale assembly 50 for an encoder, the end of the two-dimensional code 14 or 24 is separated from the cutting line L by a distance d1. If the above distance d1 is within the above range, the influence of cutting on the two-dimensional code can be suppressed. Specifically, the influence of cutting on the reading of the two-dimensional code can be suppressed. On the other hand, regarding the upper limit of the above distance d1, as long as the two-dimensional code is arranged in an area outside the optical pattern area, there is no particular limitation.

[0066] In addition, regarding the position of the two-dimensional code, for example, asFigure 2 As shown, preferably, the end of the two-dimensional code 24 is separated from the end of the optical pattern region where the optical pattern 23 is disposed by a distance d2. The above distance d2 is preferably 3 mm or more, more preferably 10 mm or more. On the other hand, regarding the upper limit of the above distance d2, there is no particular limitation as long as the two-dimensional code is disposed in a region other than the optical pattern region and the above distance d1 is within a specified range.

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

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

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

[0070] For example, as shown in FIG. 5(a), when a pattern-shaped low-reflection layer 2 is disposed on the first surface 1a of the high-reflection substrate 1, and the region where the low-reflection layer 2 is disposed is the low-reflection region 12 and the region where the low-reflection layer 2 is not disposed is the high-reflection region 11, it is preferable that the two-dimensional code 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, as shown in FIG. 5(b), in the two-dimensional code 14, it may be that the code portion 15 is the portion where the low-reflection layer 2 is disposed, and the background portion 16 is the portion where the low-reflection layer 2 is not disposed. In addition, although not shown, in the two-dimensional code, it may also be that the code portion is the portion where the low-reflection layer is not disposed, and the background portion is the portion where the low-reflection layer is disposed.

[0071] In addition, although not shown, when a pattern-shaped high-reflection layer is disposed on the first surface of the low-reflection substrate, and the region where the high-reflection layer is disposed is the high-reflection region and the region where the high-reflection layer is not disposed is the low-reflection region, it is preferable 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 may be that the code portion is the portion where the high-reflection layer is disposed, and the background portion is the portion where the high-reflection layer is not disposed. In addition, in the two-dimensional code, it may also be that the code portion is the portion where the high-reflection layer is not disposed, and the background portion is the portion where the high-reflection layer is disposed.

[0072] In addition, for example, as shown in FIG. 6(a), when a pattern-shaped light-shielding layer 32 is disposed on the first surface 31a of the transparent substrate 31, and the region where the light-shielding layer 32 is disposed is the light-shielding region 22 and the region where the light-shielding layer 32 is not disposed is the transmission region 21, it is preferable 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, as shown in FIG. 6(b), in the two-dimensional code 24, it may be that the code portion 25 is the portion where the light-shielding layer 32 is disposed, and the background portion 26 is the portion where the light-shielding layer 32 is not disposed. In addition, although not shown, in the two-dimensional code, it may also be that the code portion is the portion where the light-shielding layer is not disposed, and the background portion is the portion where the light-shielding layer is disposed.

[0073] 2. Other identification information

[0074] The reflective optical scale for an encoder of the present disclosure may also have identification information other than the two-dimensional code. As other identification information, for example, a manufacturer, a manufacturing date, and a lot number can be cited. Other identification information is, for example, characters, numbers, and labels. Other identification information can be discriminated by the human eye or can be subjected to character recognition by OCR.

[0075] In the optical scale for an encoder of the present disclosure, the position of other identification information is not particularly limited, but it is preferable that other identification information is disposed in a region other than the optical pattern region.

[0076] Other identification information can be formed simultaneously with the optical pattern in the same manner as the above-described two-dimensional code.

[0077] 3. Reflective optical scale for encoder

[0078] The reflective optical scale for encoder of the present disclosure has an optical pattern as follows: the optical pattern has two regions with different reflectivities, that is, a high-reflection region and a low-reflection region. As long as the reflective optical scale for encoder of the present disclosure has an optical pattern having a high-reflection region and a low-reflection region, its structure is not particularly limited. The reflective optical scale for encoder may also have: a high-reflection substrate having a first surface and a second surface facing the first surface; and a pattern-shaped low-reflection layer disposed 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 facing the first surface; and a pattern-shaped high-reflection layer disposed on the first surface side of the low-reflection substrate. Hereinafter, each mode will be described.

[0079] (1) First mode of reflective optical scale for encoder

[0080] The first mode of the reflective optical scale for encoder of the present disclosure has: a high-reflection substrate having a first surface and a second surface facing the first surface; and a pattern-shaped low-reflection layer disposed on the first surface side of the high-reflection substrate.

[0081] FIG. 5(a) is a Figure 1 magnified cross-sectional view taken along line A-A of the dashed box a portion of. As Figure 1 illustrated in and FIG. 5(a), the reflective optical scale for encoder 10 has: a disk-shaped high-reflection substrate 1 having a first surface 1a and a second surface 1b facing the first surface 1a; and a low-reflection layer 2 disposed 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 for encoder 10 has a perforated disk shape, and a low-reflection region 12 where the low-reflection layer 2 is disposed and a high-reflection region 11 where the low-reflection layer 2 is not disposed are alternately arranged in the circumferential direction. The low-reflection region 12 has the high-reflection substrate 1 and the low-reflection layer 2 in the thickness direction of the reflective optical scale for encoder 10. The high-reflection region 11 has the high-reflection substrate 1. The reflectivity in the high-reflection region 11 is higher than the reflectivity in the low-reflection region 12. In addition, the reflectivity in the high-reflection region 11 and the reflectivity in the low-reflection region 12 represent the reflectivity at the same wavelength and the same incident angle.

[0082] Hereinafter, the reflective optical scale for encoder of this mode will be described for each structure.

[0083] (a) High-reflection substrate

[0084] The highly reflective substrate in this method has a high reflectivity. The reflectivity of the first surface of the highly reflective substrate is, for example, 50% or more, may be 55% or more, or may be 60% or more. The above reflectivity is, for example, 100% or less. Specifically, the reflectivity of the first surface of the highly reflective substrate is 50% or more and 100% or less, may be 55% or more and 100% or less, or may be 60% or more and 100% or less. If the above reflectivity is within the above range, the difference in reflectivity between the highly reflective region and the low reflective region is large, so that false detection of the optical detector can be prevented and the detection accuracy of the signal can be improved.

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

[0086] In the measurement of reflectivity, SolidSpec 3700DUV manufactured by Shimadzu Corporation is used. The irradiated beam size is about 6 mm × 15 mm. Measurement is also performed on P-polarized light and S-polarized light, and the average of the sum is obtained, thereby calculating 45° linearly polarized light and calculating the reflectivity.

[0087] The highly reflective substrate may be a metal substrate or may have a support substrate and a metal layer disposed on one surface of the support substrate.

[0088] As the material of the metal substrate, those preferably satisfying the above reflectivity include, for example, stainless steel (SUS), copper, aluminum, etc.

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

[0090] As the material of the support substrate, for example, glass and resin can be cited. 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] In addition, as the material of the metal layer, those preferably satisfying the above reflectivity include, for example, chromium, silver, aluminum, rhodium, gold, copper, and alloys mainly composed of these metals. Among them, a metal chromium film is preferred.

[0092] The thickness of the metal layer is, for example, 0.05 μm or more, and may also be 0.1 μm or more. Additionally, the thickness of the metal layer is, for example, 0.3 μm or less, and may also be 0.2 μm or less. Specifically, the thickness of the metal layer is, for example, 0.05 μm or more and 0.3 μm or less, and may also be 0.1 μm or more and 0.2 μm or less.

[0093] Herein, the "thickness" of each component refers to the thickness obtained by general measurement methods. As measurement methods for thickness, for example, a stylus method of calculating the thickness by tracing the surface with a stylus and detecting unevenness, an optical method of calculating the thickness based on spectroscopic reflectance spectra, etc. can be cited. Specifically, the thickness is measured using the stylus type film thickness gauge "P-15" manufactured by KLA-Tencor Corporation. Additionally, the thickness is the average of the measured values of the thickness 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 of the measured values of the thickness at two locations symmetric about the center of the disk-shaped metal substrate.

[0094] In the case of a rotary encoder, the highly reflective substrate is disk-shaped. The highly reflective substrate can, for example, be a perforated disk shape having a central hole, or may not have a central hole. On the other hand, in the case of a linear encoder, the highly reflective substrate is rectangular.

[0095] In the case where the highly reflective substrate is a perforated disk shape, in a top view, the outer diameter of the highly reflective substrate is, for example, 15 mm or more, and may also be 20 mm or more. On the other hand, the outer diameter of the highly reflective substrate is, for example, 70 mm or less, and may also be 60 mm or less. Specifically, the outer diameter of the highly reflective substrate is, for example, 15 mm or more and 70 mm or less, and may also be 20 mm or more and 60 mm or less.

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

[0097] Additionally, in the above case, the difference between the above outer diameter and the above inner diameter, that is, the outer-inner diameter difference, is, for example, 8 mm or more and 13 mm or less.

[0098] In the case where the highly reflective substrate is a metal substrate or a resin substrate with a substrate, the highly reflective substrate may have a chamfer at the outer peripheral edge on the first surface side. Fig. 5(c) is Figure 1Enlarged cross-sectional view taken along line B-B of the dashed box b. In Fig. 5(c), the high-reflection substrate 1 has a chamfer P at the outer peripheral edge on the first surface 1a side. An encoder-reflective optical scale having a chamfer at the outer peripheral edge on the first surface side of the high-reflection substrate is usually manufactured by blanking a panel body. In the case of blanking the panel body, unlike the etching process of the panel body, there is no need to provide a bridge connecting the encoder optical scale and the frame, so no bridge marks are generated. Therefore, the occurrence of local deformation can be suppressed. In addition, there is no need to reduce the thickness of the metal substrate to cut costs and improve accuracy. Therefore, the metal substrate can be thickened, and undulations or warping can be suppressed. In addition, it is advantageous in terms of cost compared to the etching process of the panel body.

[0099] In addition, in the case where the high-reflection substrate is a metal substrate or a substrate having a resin substrate, and in the case where the high-reflection substrate is a perforated disk shape, a chamfer may also be provided at the inner peripheral edge on the first surface side.

[0100] (b) Low-reflection layer

[0101] In this embodiment, the low-reflection layer is disposed in a pattern on the first surface side of the high-reflection substrate.

[0102] It is only necessary that the reflectance in the low-reflection region is lower than the reflectance in the high-reflection region. Specifically, it is only necessary that the reflectance of the low-reflection region is lower than the reflectance of the first surface of the above-mentioned high-reflection substrate. In the low-reflection region, the reflectance at any wavelength in the range of 500 nm or more and 1000 nm or less is, for example, 10% or less, may be 5% or less, or may be 1% or less. On the other hand, the above-mentioned reflectance of the low-reflection region is, for example, 0% or more. Specifically, the above-mentioned reflectance of the low-reflection region is 0% or more and 10% or less, may be 0% or more and 5% or less, or may be 0% or more and 1% or less. If the above-mentioned reflectance is within the above range, the difference between the reflectance in the high-reflection region and the reflectance in the low-reflection region can be increased.

[0103] In the low-reflection region, when the wavelength of the incident light is any wavelength in the range of 500 nm or more and 1000 nm or less, more preferably, the reflectance at any incident angle in the range of 5° or more and 70° or less 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 chromium metal film starting from the high-reflection substrate side, and a chromium oxide film and a chromium nitride film arranged in a different order on the surface of the chromium metal film opposite to the high-reflection substrate. If the low-reflection layer has such a three-layer structure, the reflectivity of the low-reflection region can be reduced to the above range. In addition, if only chromium metal is prepared, the chromium oxide film and the chromium nitride film can be easily formed by using reactive sputtering or the like. Furthermore, if the low-reflection layer is as described above, high-precision patterning can be more easily performed compared with the silicon oxide film.

[0105] In this specification, regarding "the chromium oxide film and the chromium nitride film arranged in a different order on the surface of the chromium metal film opposite to the high-reflection substrate", they can be arranged in the order of the chromium metal film, the chromium oxide film, and the chromium nitride film, or in the order of the chromium metal film, the chromium nitride film, and the chromium oxide film.

[0106] For example, in FIG. 7(a), the low-reflection layer 2 has a chromium metal film 2c, a chromium nitride film 2b, and a chromium oxide film 2a starting from the high-reflection substrate 1 side. On the other hand, in FIG. 7(b), the low-reflection layer 2 has a chromium metal film 2c, a chromium oxide film 2a, and a chromium nitride film 2b starting from the high-reflection substrate 1 side.

[0107] In the low-reflection layer, the film located 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. This is because the reflectivity of the low-reflection region can be reduced more effectively.

[0108] Hereinafter, the "low-reflection layer in which a chromium metal film, a chromium nitride film, and a chromium oxide film are sequentially arranged" is referred to as a low-reflection layer of the first specification, and the "low-reflection layer in which a chromium metal film, a chromium oxide film, and a chromium nitride film are sequentially arranged" 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 chromium metal film, a chromium nitride film, and a chromium oxide film are sequentially arranged starting from the high-reflection substrate side. In the low-reflection region having the low-reflection layer of this specification, the reflectivity at any wavelength in the range of 500 nm or more and 1000 nm or less can be reduced to 5% or less, and particularly can be reduced to 0.5% or less. In addition, the change in reflectivity with respect to the wavelength change is relatively slow, and the control of the reflectivity becomes easy.

[0111] (i-1) Chromium metal film

[0112] In this specification, the chromium metal film is disposed on the first surface of the high-reflection substrate. The chromium metal film is a layer composed of chromium metal. The chromium metal film is a layer that substantially does not 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 chromium metal film is preferably 40 nm or more, more preferably 70 nm or more, for example.

[0113] As a method for forming the chromium metal film, for example, physical vapor deposition (PVD) methods such as sputtering, ion plating, and vacuum evaporation are used.

[0114] (i-2) Chromium nitride film

[0115] The chromium nitride film in this specification is disposed between the chromium metal film and the chromium oxide film. Different from chromium oxynitride, chromium oxynitride carbide, etc., the main components of the chromium nitride film are chromium and nitrogen, and it substantially 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 proportion of all elements contained in the chromium nitride film is set to 100 atomic%, the proportion of chromium and nitrogen is preferably 80 atomic% or more and 100 atomic% or less, more preferably 90 atomic% or more and 100 atomic% or less. In the chromium nitride film, as impurities, for example, hydrogen, oxygen, carbon, etc. may be contained.

[0118] The thickness (T N ) of the chromium nitride film is preferably 5 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, for example. In addition, in relation to the thickness (T O ) of the chromium oxide film described later, when the wavelength is 850 nm, the sum of T N and T O is preferably 40 nm or more. In addition, when the wavelength is 550 nm, the sum of T N and T O is preferably 20 nm or more. If the thickness is such, compared with the case where the thickness is outside the above range, it is possible to easily reduce the reflectance of the low-reflection region to a desired 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 reflectance in the entire region from the green region to the infrared region, that is, at wavelengths of about 500 nm or more and 1000 nm or less.

[0119] As a method for forming chromium nitride, for example, physical vapor deposition (PVD) methods such as reactive sputtering, ion plating, and vacuum evaporation are 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 the 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] In this specification, the chromium oxide film is disposed on the surface of the chromium nitride film opposite to the metallic chromium film. The main components of the chromium oxide film are chromium and oxygen, and unlike chromium oxynitride, chromium oxynitride carbide, etc., it substantially does not contain impurities other than chromium and oxygen.

[0122] In the chromium oxide (CrOy) film, y representing 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 set to 100 atomic%, the ratio of chromium and oxygen is preferably 80 atomic% or more and 100 atomic% or less, more preferably 90 atomic% or more and 100 atomic% or less. In the chromium oxide film, as impurities, for example, hydrogen, nitrogen, carbon, etc. may be contained.

[0124] The thickness of the chromium oxide film is not particularly limited. For example, it is preferably 5 nm or more and 100 nm or less, 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. Furthermore, the thickness of the chromium oxide film is preferably 10 nm or more and 65 nm or less. It is easy to reduce the reflectance in the entire region from the green region to the infrared region, that is, the reflectance at wavelengths of about 500 nm or more and 1000 nm or less.

[0125] As a method for forming chromium oxide, for example, physical vapor deposition (PVD) methods such as reactive sputtering, ion plating, and vacuum evaporation are used. When using the reactive sputtering method, oxygen gas can be introduced into argon (Ar) gas, and a chromium oxide film can be formed by the 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 gas.

[0126] (ii) Low-reflection layer of the second specification

[0127] In the low-reflection layer of this specification, a metallic chromium film, a chromium oxide film, and a chromium nitride film are sequentially disposed from the high-reflection substrate side. In the low-reflection region having the low-reflection layer of this specification, the reflectance at any wavelength in the range of 500 nm or more and 1000 nm or less can be reduced to 5% or less, and particularly can be reduced to 1% or less.

[0128] (ii-1) Chromium metal film

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

[0130] (ii-2) Chromium oxide film

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

[0132] The thickness of the chromium oxide film is not particularly limited. For example, it is preferably 5 nm or more and 60 nm or less, 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 chromium nitride film is preferably within a specified range. Furthermore, regarding the thickness of the chromium oxide film, in order to easily reduce the reflectance in the entire region from the green region to the infrared region, that is, the reflectance at wavelengths around 500 nm or more and 1000 nm or less, it is preferably 5 nm or more and 35 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 above first specification, so the description here is omitted.

[0134] (ii-3) Chromium nitride film

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

[0136] The thickness of the chromium nitride film (T N ) is not particularly limited. For example, it is preferably 5 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less. Furthermore, in relation to the thickness of the chromium oxide film (T O ), when the wavelength is 850 nm, the total of T N and T O is preferably 30 nm or more, and when the wavelength is 550 nm, the total of T N and T O 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 reflectance in the entire region from the green region to the infrared region, that is, the reflectance at wavelengths around 500 nm or more and 1000 nm or less.

[0137] The formation method of the chromium nitride film is the same as that of the chromium nitride film in the low-reflection layer of the above first specification, so the description here is omitted.

[0138] (iii) Formation method of the 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, first, a chromium metal film is formed on the first surface of the high-reflection substrate by a sputtering method or the like, and then, a chromium nitride film and a chromium oxide film are formed. Subsequently, the chromium metal film, the chromium nitride film, and the chromium oxide film are patterned by photolithography and etching.

[0141] In addition, in the case of the lift-off method, for example, first, a resist pattern is formed on the first surface of the high-reflection substrate, and a chromium metal 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, by removing the resist pattern, the chromium metal film, the chromium nitride film, and the chromium oxide film formed directly above the resist pattern are lifted off, and a pattern of the chromium metal film, the chromium nitride film, and the chromium oxide film is obtained.

[0142] (c) Other structures

[0143] In addition to the above-described high-reflection substrate and low-reflection layer, the reflective optical scale for an encoder according to this embodiment may further include other layers. For example, the reflective optical scale for an encoder according to this embodiment may also have a protective layer between the high-reflection substrate and the low-reflection layer.

[0144] Regarding the protective layer, preferably, it has transparency and a function of protecting the high-reflection substrate. By providing the protective layer, there is no concern that the surface of the high-reflection substrate becomes rough and the surface roughness increases during etching when forming the low-reflection layer in a pattern shape. Therefore, diffuse reflection of light can be suppressed. The protective layer may be provided over the entire area of the high-reflection substrate in a plan view or may 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 high-reflection substrate, and it may be either an organic material or an inorganic material.

[0146] The organic material preferably contains a resin. The resin used as the protective layer is not particularly limited as long as it can obtain a protective layer with transparency. For example, radiation-curable resins cured by irradiation with ionizing radiation such as ultraviolet rays and electron beams, and thermosetting resins cured by heating can be mentioned. Specifically, novolak resins, polyolefin resins, polyester resins, urethane resins, polyimide resins, acrylic resins, and epoxy resins are preferred. Regarding novolak resins, phenol novolak resins are preferred among them. This is because their electrical properties are excellent and they can suppress defects caused by charging. Regarding acrylic resins, acrylic esters with three or more functional groups such as pentaerythritol tetraacrylate and dipentaerythritol tetraacrylate are preferred. This is because they can improve photocurability. Regarding epoxy resins, epoxy acrylate resins having a fluorene structure are preferred. This is because they can improve heat resistance, close adhesion, and chemical resistance. Regarding epoxy resins, cardo epoxy resins are also preferred. This is because they can impart excellent transparency, heat resistance, surface hardness, and flatness. In the organic material, in addition to the resin, a polymerization initiator or various additives may also be contained.

[0147] As the inorganic material, inorganic compounds can be mentioned. As the inorganic compounds, for example, oxides, nitrides, carbonitrides, and oxynitride carbides 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 mentioned. Silicon dioxide (SiO2) is particularly preferred. The inorganic compounds can be used alone or the above materials can be mixed in any proportion.

[0148] (2) Second mode of the reflective optical scale for an encoder

[0149] The second mode of the reflective optical scale for an encoder of the present disclosure has: a low-reflection substrate having a first surface and a second surface opposed to the first surface; and a pattern-shaped high-reflection layer disposed on the first surface side of the low-reflection substrate.

[0150] Hereinafter, the reflective optical scale for an encoder of this mode will be described for each structure.

[0151] (a) Low-reflection substrate

[0152] The low-reflection substrate in this mode 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 mode of the reflective optical scale for an encoder.

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

[0154] Regarding the material of the low-reflection substrate, as long as it has low reflectivity, there is no particular limitation, and it can be either an organic material or an inorganic material.

[0155] Similarly, regarding the material of the low-reflection layer, as long as it has low reflectivity, there is no particular limitation, and it can be either an organic material or an inorganic material. The organic material preferably contains a resin. As the resin used for the low-reflection layer, as long as it is a resin capable of obtaining a low-reflection layer, there is no particular limitation. For example, radiation-curable resins that are cured by irradiation with ionizing radiation such as ultraviolet rays and electron beams, and thermosetting resins that are cured by heating can be cited. Specifically, novolak-based resins, polyolefin-based resins, polyester-based resins, urethane-based resins, polyimide-based resins, acrylic-based resins, and epoxy-based resins are preferred. Regarding novolak-based resins, phenol novolak resin is preferably used. This is because its electrical properties are excellent and it can suppress defects caused by electrification. Regarding acrylic-based resins, acrylate esters having three or more functional groups such as pentaerythritol tetraacrylate and dipentaerythritol tetraacrylate are preferably used. This is because it can improve the photocurability. Regarding epoxy-based resins, epoxy acrylate resins having a fluorene structure are preferred. This is because it can improve heat resistance, close adhesion, and chemical resistance. Regarding epoxy-based resins, cardo epoxy resins are also preferably used. This is because it can impart heat resistance, surface hardness, and flatness. In the organic material, in addition to the resin, a polymerization initiator or various additives may also be contained.

[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 mode of the above-described reflective optical scale for an encoder. Among them, the low-reflection layer is preferably the low-reflection layer of the above-described first specification or the second specification.

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

[0158] In the case of a rotary encoder, the low-reflection substrate is disk-shaped. The low-reflection substrate can be, for example, a perforated disk shape having a central hole, or may not have a central hole. On the other hand, in the case of a linear encoder, the low-reflection substrate is rectangular.

[0159] When the low-reflection substrate is a perforated disk shape, the outer diameter and inner diameter of the low-reflection substrate in a top view are the same as the outer diameter and inner diameter of the high-reflection substrate in the first mode of the above-described reflective optical scale for an encoder.

[0160] In the case where the low-reflection substrate has a resin substrate, the low-reflection substrate may have a bead at the outer peripheral edge on the first surface side. Further, in the case where the low-reflection substrate has a resin substrate and the low-reflection substrate is a perforated disk shape, a bead may also be provided at the inner peripheral edge on the first surface side.

[0161] (b) High-reflection layer

[0162] In this embodiment, the high-reflection layer is disposed in a pattern on the first surface side of the low-reflection substrate.

[0163] It is sufficient that the reflectance in the high-reflection region is higher than the reflectance in the low-reflection region. Specifically, it is sufficient that the reflectance of the high-reflection region is higher than the reflectance of the above-mentioned low-reflection substrate. The reflectance of the high-reflection region is the same as the reflectance of the first surface of the high-reflection substrate in the first embodiment of the above-mentioned reflection type optical scale for an encoder.

[0164] The high-reflection layer only needs to satisfy the above-mentioned reflectance, and its structure is not particularly limited. For example, a metal film can be cited. The metal film is preferably composed of a metal having a high reflectance. As the metal, for example, chromium, silver, aluminum, rhodium, gold, copper, and alloys mainly composed of these metals can be cited. 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, 0.05 μm or more and 0.3 μm or less, and can also be 0.1 μm or more and 0.2 μm or less.

[0165] 4. Transmission type optical scale for an encoder

[0166] The transmission type optical scale for an encoder of the present disclosure has an optical pattern having two regions with different transmittances, namely, a transmission region and a light-shielding region. The transmission type optical scale for an encoder of the present disclosure only needs to have an optical pattern having a transmission region and a light-shielding region, and its structure is not particularly limited. However, it preferably has: a transparent substrate having a first surface and a second surface opposed to the first surface; and a patterned light-shielding layer disposed on the first surface side of the transparent substrate.

[0167] FIG. 6(a) is Figure 2 an enlarged cross-sectional view taken along line A-A of the dashed box a part of Figure 2As illustrated in FIG. 6(a), the transmissive optical scale 20 for an encoder includes: a disk-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 disposed in a pattern along the circumferential direction of the transparent substrate 31 on the first surface 31a side of the transparent substrate 31. The transmissive optical scale 20 for an encoder has a perforated disk shape, and the light-shielding regions 22 where the light-shielding layer 32 is disposed and the transmissive regions 21 where the light-shielding layer 32 is not disposed are alternately arranged in the circumferential direction. The light-shielding region 22 has the transparent substrate 31 and the light-shielding layer 32 in the thickness direction of the transmissive optical scale 20 for an encoder. The transmissive region 21 has the transparent substrate 31. The transmittance at the transmissive region 21 is higher than the transmittance at the light-shielding region 22. In addition, the transmittance at the transmissive region 21 and the transmittance at the light-shielding region 22 represent the transmittance at the same wavelength.

[0168] Hereinafter, the reflective optical scale for an encoder of the present disclosure will be described for each structure.

[0169] (1) Transparent Substrate

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

[0171] Examples of the material of the transparent substrate include glass and resin. Glass has high strength and a small coefficient of linear expansion, so that dimensional changes associated with temperature changes in the use environment can be suppressed. As the resin, those satisfying the above transmittance are preferred, and examples thereof include 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, and phenolic resin.

[0172] Regarding the thickness of the transparent substrate, there is no particular limitation as long as it is a thickness that satisfies the above transmittance, and for example, it is 0.1 mm or more and 2 mm or less.

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

[0174] (2) Light-Shielding Layer

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

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

[0177] In this specification, the optical density is the transmittance density. For the optical density, it is measured using an optical densitometer. The optical densitometer is a measuring instrument having the following structure: irradiating light onto a specimen (the object to be measured) and measuring the intensity of the transmitted light. Specifically, using the TAKANO OD reflectometer manufactured by TAKANO Co., Ltd., the measurement is performed by irradiating light in a direction perpendicular to the specimen.

[0178] As long as the light-shielding layer satisfies the above optical density, its constitution is not particularly limited. For example, the structure of the light-shielding layer may be the same as the structure of the above low-reflection layer.

[0179] 5. Manufacturing method of an optical scale for an encoder

[0180] The manufacturing method of the optical scale for an encoder of the present disclosure preferably includes: a step of manufacturing a ganged body, manufacturing an encoder optical scale ganged body in which a plurality of encoder optical scales are mounted on a ganged body; and a singulation step of singulating the encoder optical scale ganged body.

[0181] Regarding the encoder optical scale ganged body, it will be described later, so the description here is omitted.

[0182] As a method of singulating the encoder optical scale ganged body, it varies depending on the substrate of the encoder optical scale ganged body. When the substrate of the encoder optical scale ganged body is a high-reflection substrate and the high-reflection substrate is a metal substrate, blanking and etching processes can be cited. In addition, when the substrate of the encoder optical scale ganged body is a high-reflection substrate and the high-reflection substrate has a glass substrate, when the substrate of the encoder optical scale ganged body is a low-reflection substrate and the low-reflection substrate has a glass substrate, and when the substrate of the encoder optical scale ganged body is a transparent substrate and the transparent substrate is a glass substrate, machine cutting can be cited. In addition, when the substrate of the encoder optical scale ganged body is a high-reflection substrate and the high-reflection substrate has a resin substrate, when the substrate of the encoder optical scale ganged body is a low-reflection substrate and the low-reflection substrate has a resin substrate, and when the substrate of the encoder optical scale ganged body is a transparent substrate and the transparent substrate is a resin substrate, blanking can be cited.

[0183] As described above, in the case of blanking the panel body, unlike the etching process of the panel body, there is no need to provide a bridge connecting the optical scale for the encoder and the frame, so no bridge marks will be generated. 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 cut costs and improve accuracy. Therefore, the thickness of the metal substrate can be increased, and undulations or warping can be suppressed. In addition, it is more advantageous in terms of cost compared to the etching process of the panel body.

[0184] In addition, when the size of the optical scale panel body for the encoder is large, when singulating the optical scale panel body for the encoder, instead of singulating the optical scale panel body for the encoder as a whole, it may be possible to first divide the optical scale panel body for the encoder into multiple pieces and then singulate them.

[0185] Figures 8(a) - 8(b) It is a schematic diagram showing an example of a blanking device used in the singulation process. First, as shown in Fig. 8(a), the optical scale panel body 50 for the encoder is placed on the lower stage 62 having the lower blade 61. Next, as shown in Fig. 8(b), the lower stage 62 is moved upward and the upper stage 63 having the upper blade 64 is moved downward to press the optical scale panel body 50 for the encoder, thereby blanking the optical scale panel body 50 for the encoder. In addition, it is preferable to arrange a pressing member 65 at a position opposed to the upper blade 64. During the blanking process, the metal substrate can be sandwiched by the upper blade 64 and the pressing member 65 to perform blanking with less burr and collapse. In this way, individual reflective optical scales 10 for the encoder are obtained.

[0186] 6. Use of the optical scale for the encoder

[0187] The optical scale for the encoder of the present disclosure can be used for a rotary encoder or a linear encoder.

[0188] B. Optical scale panel body for the encoder

[0189] The optical scale panel body for the encoder of the present disclosure is an optical scale panel body for the encoder in which a plurality of optical scales for the encoder are mounted on a panel. The optical scale for the encoder has such an optical pattern: the optical pattern has two regions with different reflectivities or transmittances. Among them, the above-mentioned optical scale for the encoder has a two-dimensional code, and the above-mentioned optical scale panel body for the encoder has one or more unit regions. In the above-mentioned unit region, the above-mentioned two-dimensional code is different for each of the above-mentioned optical scales for the encoder.

[0190] Figure 3 and Figure 9 is a schematic top view showing an example of the optical scale panel body for the encoder of the present disclosure, Figure 4 isFigure 3 and Figure 9 partial enlarged views. As Figure 3 and Figure 9 shown, in the encoder optical scale mosaic body 50, multiple encoder optical scales (encoder reflective optical scale 10 or encoder transmissive optical scale 20) having optical patterns as follows are mounted on the mosaic plates: the optical patterns have two regions with different reflectivities or transmittivities. As Figure 4 shown, the encoder optical scale (encoder reflective optical scale 10 or encoder transmissive optical scale 20) has a two-dimensional code 14 or 24.

[0191] In Figure 3 the encoder optical scale mosaic body 50 has a unit area U1, and in the unit area U1, the two-dimensional code 14 or 24 is different for each encoder optical scale (encoder reflective optical scale 10 or encoder transmissive optical scale 20). Specifically, in Figure 3 a total of 100 encoder optical scales (encoder reflective optical scale 10 or encoder transmissive optical scale 20) are arranged in 10 rows × 10 columns. In the unit area U1, the two-dimensional codes 14 or 24 of the 100 encoder optical scales (encoder reflective optical scale 10 or encoder transmissive optical scale 20) are different from each other.

[0192] On the other hand, in Figure 9 the encoder optical scale mosaic body 50 has two unit areas U1, U2, and in the unit area U1, the two-dimensional code 14 or 24 is different for each encoder optical scale (encoder reflective optical scale 10 or encoder transmissive optical scale 20), and similarly, in the unit area U2, the two-dimensional code 14 or 24 is different for each encoder optical scale (encoder reflective optical scale 10 or encoder transmissive optical scale 20). Specifically, in Figure 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 Figure 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 assembly for encoders 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 plate body for an encoder disclosed in the present invention will be described. Figure 10 Schematic diagram showing the state where the optical scale of the encoder is stored in the storage component. Figure 10 As shown, the optical scale for encoder (the reflective optical scale 10 for encoder or the transmissive optical scale 20 for encoder) is housed in the housing part 70 for each unit area. Figure 10 It will Figure 3 The example shown is a case where the encoder optical scale assembly is singulated. The storage component 70 includes 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 case], since the optical scale mosaic body 50 for the encoder has a unit area U1, 100 optical scales for the encoder are accommodated in one accommodating member. On the other hand, in Figure 9 In [the case], since the optical scale mosaic body 50 for the encoder has two unit areas U1 and U2, the optical scales are accommodated in the accommodating member for each unit area U1 and U2, that is, 160 optical scales for the encoder are divided and accommodated in two accommodating members for each unit area.

[0197] In the case where the optical scale mosaic body for the encoder of the present disclosure has a plurality of unit areas, there are optical scales for the encoder with the same two-dimensional code in one unit area and other unit areas. In contrast, in the unit area, the two-dimensional code is different for each optical scale for the encoder. Therefore, by accommodating the optical scales for the encoder in the accommodating member for each unit area, traceability can be ensured.

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

[0199] In the optical scale mosaic body for the encoder of the present disclosure, the number of optical scales for the encoder is preferably 50 or more, may be 200 or more, and may be 400 or more. Thus, the present disclosure is useful when the number of optical scales for the encoder in the optical scale mosaic body is large. On the other hand, the upper limit of the number of optical scales for the encoder in the optical scale mosaic body is not particularly limited, but due to the limitations of the manufacturing apparatus, it is, for example, 3000 or less.

[0200] The size of the optical scale mosaic body for the encoder of the present disclosure when viewed from above is not particularly limited, but the length of one side of the optical scale mosaic body is preferably 150 mm or more, more preferably 300 mm or more, and still more preferably 350 mm or more. As described above, the present disclosure is useful when the size of the optical scale mosaic body when viewed from above is large. The upper limit of the size of the optical scale mosaic body for the encoder of the present disclosure when viewed from above is not particularly limited, but due to the limitations of the manufacturing apparatus, the length of one side of the optical scale mosaic body is, for example, 920 mm or less.

[0201] The optical scale mosaic body for the encoder of the present disclosure may also have identification information other than the two-dimensional code. As other identification information, for example, manufacturer, manufacturing date, and lot number can be cited. Other identification information is, for example, characters, numbers, and marks. Other identification information can be discriminated by the human eye or can be subjected to character recognition by OCR.

[0202] In the optical scale laminate for an encoder of the present disclosure, the positions of other identification information are not particularly limited. The other identification information may be arranged on each optical scale for an encoder, or may be arranged in an area other than the optical scale for an encoder.

[0203] In the case of an optical scale laminate for an encoder in which a plurality of reflective optical scales for an encoder are laminated on a laminate, as a method of laminating a plurality of patterned low-reflective layers on the first surface of a highly reflective substrate, it is the same as the method for forming the above-described low-reflective layer. Further, in the case of an optical scale laminate for an encoder in which a plurality of transmissive optical scales for an encoder are laminated on a laminate, as a method of laminating a plurality of patterned light-shielding layers on the first surface of a transparent substrate, it is the same as the method for forming the above-described light-shielding layer.

[0204] C. Optical encoder

[0205] The optical encoder of the present disclosure includes: the above-described optical scale for an encoder; 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.

[0206] The optical encoder of the present disclosure may be a reflective encoder or a transmissive encoder.

[0207] Figure 11 FIG. is a schematic perspective view showing an example of the 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 an encoder; and a light source 81 and a light detector 82 arranged on the same plane with respect to the reflective optical scale 10 for an encoder. In Figure 11 a fixed slit 83 is arranged between the light detector 82 and the reflective optical scale 10 for an encoder.

[0208] Figure 12 FIG. 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 an encoder; a light source 91 arranged on one surface side of the transmissive optical scale 20 for an encoder; and a light detector 92 arranged on the other surface side of the transmissive optical scale 20 for an encoder. In Figure 12 a lens 93 is arranged between the light source 91 and the transmissive optical scale 20 for an encoder.

[0209] According to the present disclosure, since the above-described optical scale for an encoder is provided, the same effects as those of the above-described optical scale for an encoder are 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-mentioned "A. Optical scale for encoder", so the description here is omitted.

[0213] 2. Light source

[0214] As the light source, for example, an LED (light-emitting diode), a 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 with respect to the optical reflective scale is, for example, 5° or more and 70° or less.

[0215] 3. Light detector

[0216] The light detector detects the light reflected or transmitted by the optical scale. The light detector includes, for example, a light-receiving element such as a photodiode, an imaging element. As the light-receiving element, for example, a photoelectric conversion element can be cited.

[0217] 4. Others

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

[0219] In the case where the optical encoder in the present disclosure is a transmissive encoder, a lens may be provided between the light source and the optical transmissive scale for encoder. By providing the lens, the light from the light source can be changed from diffused light to parallel light.

[0220] In addition, the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are illustrative, and any solution having a structure substantially the same as the technical idea described in the claims of the present disclosure and achieving the same effects is included in the technical scope of the present disclosure.

[0221] That is, in the present disclosure, the following solutions are provided.

[0222] [1] An optical scale for encoder, having an optical pattern as follows: the optical pattern has two regions with different reflectivities or transmittivities, and the optical scale for encoder has a two-dimensional code.

[0223] [2] The optical scale for encoder according to [1], wherein the two-dimensional code is arranged in a region other than the optical pattern region where the optical pattern is arranged.

[0224] [3]The optical scale for an encoder according to [1] or [2], wherein the optical scale for an encoder includes: a disk-shaped highly reflective substrate having a first surface and a second surface opposed to the first surface; and a pattern-shaped low-reflective layer disposed on the first surface side of the highly reflective substrate.

[0225] [4]The optical scale for an encoder according to [1] or [2], wherein the optical scale for an encoder includes: a disk-shaped transparent substrate having a first surface and a second surface opposed to the first surface; and a pattern-shaped light-shielding layer disposed on the first surface side of the transparent substrate.

[0226] [5]The 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 assembly for an encoder, in which a plurality of optical scales for an encoder are mounted on a panel, and the optical scale for an encoder has an optical pattern having two regions with different reflectivities or transmittivities, wherein the optical scale for an encoder has a two-dimensional code, the optical scale assembly for an encoder has one or more unit regions, and in the unit region, the two-dimensional code is different for each optical scale for an encoder.

[0228] [7]An optical encoder, comprising: the optical scale for an encoder according to 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, which has an optical pattern as follows: the optical pattern has two regions with different reflectivities or transmittivities, and is characterized in that, the optical scale for the encoder has a two-dimensional code.

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

3. The optical scale for the encoder according to claim 1, characterized in that, the optical scale for the encoder has: a highly reflective substrate having a first surface and a second surface opposed to the first surface; and a pattern-shaped low-reflective layer arranged on the first surface side of the highly reflective substrate.

4. The optical scale for the encoder according to claim 1, characterized in that, the optical scale for the encoder has: a transparent substrate having a first surface and a second surface opposed to the first surface; and a pattern-shaped light-shielding layer arranged on the first surface side of the transparent substrate.

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

6. An optical scale assembly for an encoder, in which a plurality of optical scales for the encoder are mounted on the panels. The optical scale for the encoder has an optical pattern as follows: the optical pattern has two regions with different reflectivities or transmittivities, and is characterized in that, the optical scale for the encoder has a two-dimensional code, the optical scale assembly for the encoder has one or more unit regions, in the unit region, the two-dimensional code is different for each optical scale for the encoder.

7. An optical encoder, characterized in that, the optical encoder includes: the optical scale for the encoder according to any one of claims 1 to 5; a light source that irradiates measurement light onto the surface of the optical scale for the encoder; and a light detector that detects the reflected light or transmitted light from the optical scale for the encoder.

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