JP4332514B2 - Encoder code plate, encoder, mold manufacturing method for encoder code plate, mold for encoder code plate, and manufacturing method of encoder code plate - Google Patents

Description

  The present invention relates to a high-resolution optical encoder that performs position detection in a servo system.

  Conventionally, an encoder is used as a displacement sensor in a servo system such as an NC machine tool. The encoder detects displacement information such as the position and angle of an object that performs rotation, linear motion, rotational motion, and the like of a motor. The encoder is roughly classified to detect displacement information by one of a magnetic method and an optical method.

  The optical encoder includes a light source, a housing that houses a light receiving unit that receives light from the light source, and an optical scale (code plate) as a moving object. For example, in an optical rotary encoder that detects rotation information of a rotating body, a slit-like light transmitting portion and a light shielding portion are periodically arranged on a rotating disk (code plate) connected to the rotating body. FIG. 12 is a cross-sectional view of a detection unit of an optical encoder that includes a code plate 120, a light source 122, and a light receiving unit 123. The code plate 120 is provided between the light source 122 and the light receiving unit 123. The code plate 120 has a pattern 121 obtained by vapor-depositing Cr on a glass plate, and selectively receives the light beam 124 in order to detect the position using the pattern 121. Such a code plate 120 has problems such as being easily broken, heavy, and expensive.

  On the other hand, conventionally, a code plate formed of plastic or the like has been used (see Patent Document 1). FIG. 13A shows a cross-sectional view of a code plate 130 made of plastic. The substrate 132 of the code plate 130 is provided with a recess, and a predetermined pattern for modulating the incident light in a predetermined direction is formed in the recess. FIG. 13B shows an enlarged cross-sectional view of the substrate 132. A pattern 136 is formed on the bottom surface of the recess 134 of the substrate 132. The code plate 130 rotates on the rotation axis P, and detects rotation information based on light from the light source detected through the pattern 136 of the recess 134.

Japanese Patent Laid-Open No. 11-23321

  The code plate 130 shown in FIG. 13 detects only the relative movement amount because the single pattern 136 is provided on the entire planar bottom surface of the recess 134, that is, only a so-called single track exists. I can't. In this case, the absolute position cannot be determined when the servo system is turned off or reset.

  An object of the present invention is to provide a high resolution encoder code plate capable of detecting an absolute position.

  An encoder code plate according to the present invention is an encoder code plate formed using a transparent substrate, and is provided on the transparent substrate, and a plurality of tracks each having a different pattern between the plurality of tracks. And each of the plurality of tracks is provided with each of the surfaces and an inter-track region having a different height, thereby achieving the above object.

  Each of the surfaces of the plurality of tracks includes a transmissive portion that transmits light and a reflective portion that reflects light, and different patterns may be formed depending on the arrangement of the transmissive portion and the reflective portion.

  The transmission part may be a flat surface, and the reflection part may be a groove formed in a V shape with respect to the transmission part.

  The transmission part may be a flat surface, and the reflection part may be a protrusion formed in a V shape with respect to the transmission part.

  Each surface of the plurality of tracks may have a different height.

  A flat surface may be further provided on the transparent substrate at a position different from the positions of the plurality of tracks, and the flat surface may be provided at a position higher than each of the surfaces of the plurality of tracks.

  An encoder according to the present invention includes a light source that irradiates light, a housing that houses a light receiving unit that receives light from the light source, and an encoder code plate in which the plurality of tracks are provided between the light source and the light receiving unit. The encoder code plate described above detects the position information of the object by transmitting or reflecting the light emitted from the light source, thereby achieving the above object.

  A mold manufacturing method for an encoder code plate according to the present invention includes a step of processing a plurality of tracks each having a flat surface in a first material, and the flat surface between the plurality of tracks. Machining the inter-track areas of different heights, forming different patterns on each of the flat surfaces, plating the pattern of the first material, and plating from the first material And obtaining the mold, thereby achieving the above object.

  The step of forming different patterns may be a step of forming V-shaped grooves having different arrangements on each of the flat surfaces.

  The step of processing the plurality of tracks may be a step of processing a plurality of tracks each having a different height.

  The plating may be Ni plating.

  A mold manufacturing method for an encoder code plate according to the present invention includes a step of plating a base material, a step of processing a plurality of tracks each having a flat surface on a plating portion, and a plurality of tracks. In addition, the step of processing the inter-track region having a height different from that of the flat surface and the step of obtaining a mold by forming a different pattern on each of the flat surfaces, the above object is achieved. The

  The step of forming different patterns may be a step of forming V-shaped grooves having different arrangements on each of the flat surfaces.

  The step of processing the plurality of tracks may be a step of processing a plurality of tracks each having a different height.

  The plating may be NiP plating.

  The plating may be Cu plating, and may further include a step of performing NiP plating on the plurality of tracks and the inter-track region.

  The method of manufacturing an encoder code plate according to the present invention includes a step of injecting a transparent resin material into a mold obtained by the above-described method, and peeling the resin material from the mold to obtain an encoder code plate. And the above-mentioned purpose is achieved.

  The encoder code plate of the present invention and its mold have a plurality of tracks each having a different pattern. Thereby, it is possible to reduce the size by narrowing the track interval. Such an encoder code plate can detect the absolute position of a moving object with high resolution.

  Since different patterns are formed depending on the arrangement of the transmission part and the reflection part, the optical characteristics of each track are different. As a result, the absolute position of the moving object can be detected with high resolution.

  Since the reflection portion is a V-shaped groove or protrusion with respect to the transmission portion, a burr is not generated when the V-groove is processed, and a highly accurate code plate can be obtained and stable position information can be obtained.

  Since the surfaces of the plurality of tracks have different heights, the tracks can be made small with a small spacing between the tracks.

  A flat surface was provided at a position higher than the respective surfaces of the plurality of tracks. As a result, the truck can be protected during assembly. That is, stable position information can be obtained without damaging the track pattern.

  By forming the encoder using the encoder code plate described above, the absolute position of the moving object can be detected with high resolution.

  Since plating is Ni plating, Cu plating, or NiP plating, it is technically easy. By performing NiP plating on the track and the area between the tracks, it is possible to prevent oxidation and prolong the life during molding.

  Since the encoder code plate is manufactured by resin injection molding, cost reduction can be realized.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In this embodiment, a code plate mainly used for an optical encoder will be described. Here, the optical encoder is a sensor that detects displacement information such as the position and angle of an object that performs rotation, linear motion, rotational motion, and the like of a motor and the like by an optical method. As the optical encoder, a rotary encoder used for a subject that performs a rotational motion, a linear encoder used for a subject that performs a linear motion, and the like are known. The optical encoder includes a light source, a housing that houses a light receiving unit that receives light from the light source, and a code plate connected to a rotating body as a moving object. For example, FIG. 12 shows a code plate 120 of an optical encoder, a light source 122, and a light receiving unit 123. The code plate 120 is provided between the light source 122 and the light receiving unit 123.

(Embodiment 1)
Hereinafter, the code plate of the optical encoder according to the first embodiment will be described. First, in order to detect the absolute position of the detection target with high resolution, a plurality of tracks having different patterns are required. A “track” refers to a segmented region through which a light beam from the light source 122 passes. Therefore, in this embodiment, two tracks are provided on the code plate. (A)-(d) of FIG. 1 is a figure which shows the structure of the code board (henceforth a "code board") 10 for rotary encoders which has two tracks by this Embodiment. The optical rotary encoder periodically arranges slit-like light transmitting portions and light shielding portions on a rotating disk (code plate) connected to a rotating body, and detects rotation information of the rotating body. The code plate 10 is used when detecting the absolute position of the rotation angle, and is formed of a transparent resin material such as polycarbonate. (A) is a top view, (b) is a sectional view, and (c) and (d) are partial sectional views.

  Referring to FIG. 1A, the code plate 10 is a circular plate-like body having two types of tracks 1 and 2 and a flat portion 4. Each of the tracks 1, 2 and the flat portion 4 is formed concentrically and is divided by a concentric recess 3. Different patterns are formed on the tracks 1 and 2 by grooves formed in a V shape (hereinafter referred to as “V grooves”). (D) and (c) show the shapes of the A-A ′ cross section of the track 1 and the B-B ′ cross section of the track 2. The V-groove of each cross section is a reflection part that reflects light according to the principle described later. The flat surface between the V grooves is a transmission part that transmits light. The V-groove pattern of each track is formed radially (in the radial direction).

  FIG. 1B is a cross-sectional view taken along line C-C ′ shown in FIG. As can be understood from (b), it can be said that the tracks 1 and 2 and the flat portion 4 are provided to protrude from the code plate 10. The upper surface of the track 2 is higher than the upper surface of the track 1. Further, the flat portion 4 where no pattern is formed is located at a higher position (the thickest part of the disc). A light receiving portion is provided on the side where the tracks 1 and 2 are provided, and a light source is provided on the opposite side. The code plate 10 rotates about the rotation axis P, and passes or reflects the light flux from the light source.

  Hereinafter, the principle of transmitting or reflecting the light beam will be described in more detail. FIG. 2 is a cross-sectional view of the V-groove portion of the track. Light from a light source (not shown) that reaches the V-groove portion is totally internally reflected and is not transmitted to the light receiving portion side of the code plate 10. On the other hand, the light from the light source that reaches the plane portion between the V-grooves is transmitted and enters a light receiving unit (not shown). By forming the V-groove pattern in this way, transmitted light can be selectively received by a light receiving portion (not shown).

  FIG. 3A is a graph showing the relationship between the displacement of the code plate and the signal intensity, which changes according to the V-groove shape of the track 2. As shown in the figure, in the track 2, the pitch of the V-groove changes, and a change in the amount of transmitted light can be detected correspondingly. The absolute position can be detected by forming a pattern in which the V-groove pitch changes on the entire circumference of the code plate. On the other hand, FIG. 3B is a graph showing the relationship between the displacement of the code plate and the signal intensity, which changes according to the V-groove shape of the track 1. In the track 1, V grooves having a constant pitch are formed on the entire circumference of the code plate. By inserting light-shielding slits having the same pitch in the light-receiving portion of the transmitted light from the track 1, as shown in FIG. 3B, a change in the transmitted light amount corresponding to this pitch can be detected. That is, the absolute position can be detected with high resolution by processing the two types of detection signals in combination.

  Hereinafter, the principle of detecting the position will be described. The pattern carved in the track 2 generates a signal whose level changes in accordance with each position where the code plate rotates once. By detecting this signal, a rough absolute position can be detected. Then, with the pattern carved on the track 1, a signal whose level is repeated a predetermined number of times (for example, 16 times) is generated. By arranging the light receiving elements having the same pitch as the pattern pitch of the track 1 in the light receiving portion, for example, a signal shown in FIG. 3B is obtained according to the movement of the code plate. The approximate absolute position can be detected by the signal based on the track 2 pattern, and the position can be detected with higher accuracy by the signal based on the track 1 pattern. For example, if the repetition is 16 times, the position can be detected with an accuracy of about 16 times.

  By providing the flat portion 4 (FIG. 1) at the uppermost portion of the code plate 10, that is, the thickest portion, the pattern portions of the track 1 and the track 2 can be protected at the time of assembly and the like, without damaging the pattern portion. Stable position information can be obtained.

  Next, a method for manufacturing the code plate 10 (FIG. 1) will be described. The code plate 10 (FIG. 1) is manufactured by injection molding a resin. A mold material is required for injection molding. FIGS. 4A to 4C are diagrams showing a manufacturing process of the mold material 45. FIG. The manufacturing process of the mold material 45 includes (a) a process of processing the shape of the code plate 10 on the base material, (b) a process of plating the processed base material, and (c) a process of peeling the plating from the base material. It is divided roughly into. The peeled plating becomes a mold material.

  FIG. 4A shows a base material 40 obtained by processing the shape of the code plate 10. As the base material, brass or the like is used. The processing steps will be described. First, the ring portions 41 and 42 corresponding to the track 1 and the track 2 are processed flat. A height difference is provided in the ring. In other words, the upper surface of the ring portion 42 is positioned higher than the upper surface of the ring portion 41. Each upper surface is a mirror surface having a small surface roughness. A concentric recess 43 is processed adjacent to each ring 41, 42. Next, V-grooves are processed on the upper surfaces of the ring portions 41 and 42. Since the patterns of the track 1 and the track 2 are different, the patterns of the V grooves on the upper surfaces of the ring portions 41 and 42 are also different. Here, the reason why the height difference is provided in the ring portions 41 and 42 is to prevent the tool from interfering with the other ring portion when processing the V-groove pattern on the upper surface of one ring portion. FIG. 5 is a diagram illustrating the position of the tool 50 during machining. As understood from the drawing, the tool 50 can process the ring portion 41 without interfering with the ring portion 42 due to the difference in height between the ring portions 41 and 42. Moreover, by providing the recessed part 43 between ring parts, the chip | tip at the time of V-groove processing is escaped, and generation | occurrence | production of a burr | flash can be suppressed.

  Next, (b) of FIG. 4 shows the base material 40 after processing and the plated portion 45 provided thereon. The plating part 45 performs Ni plating called electroforming plating. The plating is performed until a sufficient thickness is obtained with respect to the height difference of the ring portion, the concentric recess amount, and the depth of the V groove of each ring portion.

  FIG. 4C shows the plated portion 45 peeled from the base material. This plated portion is used as the mold material 45 when the code plate 10 is manufactured. Needless to say, the mold material 45 is an inverted product of the base material 40. By injecting a transparent resin material to the mold material 45, the code plate 10 (FIG. 1) is obtained.

  As described above, a small and highly accurate code plate can be obtained by the presence of the recesses between the tracks, the height of the plurality of tracks being not the same, and the above-described manufacturing method. Further, since the code plate 10 can be manufactured by resin injection molding after the mold is manufactured, the manufacturing cost can be reduced.

(Embodiment 2)
In the second embodiment, as in the first embodiment, a rotary encoder code plate (hereinafter referred to as a “code plate”) that performs absolute position detection of the rotation angle will be described. The code plate has a plurality of tracks having different patterns and is made of a transparent resin material such as polycarbonate. FIGS. 6A to 6D are diagrams showing a configuration of a code plate 60 having two tracks according to the present embodiment. The code plate 60 is used when detecting the absolute position of the rotation angle, and is formed of a transparent resin material such as polycarbonate. (A) is a top view, (b) is a sectional view, and (c) and (d) are partial sectional views.

  The code plate 60 shown in FIG. 6 is different from the code plate 10 (FIG. 1) in that the concave and convex portions of the code plate 10 (FIG. 1) are inverted. This will be specifically described below.

  Referring to FIG. 6A, the code plate 60 is a circular plate-like body having two types of tracks 61 and 62 and a flat portion 64. Each of the tracks 61 and 62 and the flat portion 64 is formed concentrically, and is divided by a concentric convex portion 63. That is, the protrusion 63 protrudes with respect to the tracks 61 and 62. Each of the tracks 61 and 62 has a different pattern formed by a V-shaped protrusion (hereinafter, “V protrusion”). (D) and (c) show the A-A ′ cross section of the track 61 and the B-B ′ cross section of the track 62. The V protrusions in each cross section are reflecting portions that reflect light according to the principle described later. The flat surface between the V protrusions is a transmission part that transmits light. The V protrusion pattern of each track is formed radially (in the radial direction).

FIG. 6B is a cross-sectional view taken along line CC ′ shown in FIG. As can be understood from (b), it can be said that the tracks 61 and 62 are provided as concave portions of the code plate 60. The upper surface of the track 62 is higher than the upper surface of the track 61. The flat portion 64 where no pattern is formed is located at the highest position (the thickest part of the disk). A light receiving portion is provided on the side where the tracks 61 and 62 are provided, and a light source is provided on the opposite side. The code plate 60 rotates about the rotation axis P, and passes or reflects the light flux from the light source.

  Hereinafter, the principle of transmitting or reflecting the light beam will be described in more detail. FIG. 7 is a cross-sectional view of the V protrusion portion of the track. Light from a light source (not shown) that reaches the V-projection part is totally internally reflected and is not transmitted to the light receiving part side of the code plate 60. On the other hand, the light from the light source that reaches the plane portion between the V protrusions is transmitted and enters a light receiving unit (not shown). By forming the pattern of the V protrusions in this way, it is possible to selectively receive transmitted light at a light receiving portion (not shown).

  FIG. 8A is a graph showing the relationship between the signal plate intensity and the code plate position displacement, which changes in accordance with the pitch of the V protrusions of the track 62. On the other hand, FIG. 8B is a graph showing the relationship between the signal plate intensity and the signal plate position displacement, which changes in accordance with the V-projection shape of the track 61. The difference between (a) and (b) in FIG. 8 and (a) and (b) in FIG. 3 is generally only a difference between a V protrusion and a V groove. Therefore, since the description of (a) and (b) of FIG. 3 should just be read, the description is abbreviate | omitted. Further, the provision of the flat portion 64 at the uppermost portion (thickest portion) of the code plate 60 can protect the track and obtain stable position information, as in the first embodiment.

  Next, a method for manufacturing the code plate 60 (FIG. 6) will be described. The code plate 60 (FIG. 6) is manufactured by injection molding a resin. FIG. 9 is a diagram showing a mold base material 95 and a mold 90 that are necessary for injection molding. First, Cu plating is performed on the mold base material 95. A steel material is often used as a mold base material. Thereafter, ring portions 91 and 92 corresponding to the tracks 61 and 62 (FIG. 6) are processed flat on the surface of the Cu plating portion 90 opposite to the mold base material 95. A height difference is provided in the ring. That is, the distance from the mold base material 95 is such that the surface of the ring portion 92 is closer than the surface of the ring portion 91. Each surface is a mirror surface with a small surface roughness. A concentric recess 93 is processed adjacent to each of the rings 91 and 92. The recessed part 93 is a part which should become the protrusion part 63 (FIG. 6) in the molded product. Next, a V groove is processed on the Cu plating surface. The processed V-groove becomes a V projection in the molded product. Since the patterns of the track 61 and the track 62 are different, the patterns of the V grooves on the ring portions 91 and 92 are also different.

  Here, the reason why the ring portions 91 and 92 (FIG. 9) are provided with a height difference is to prevent the tool from interfering with the other ring portion when processing the V-groove pattern on the surface of the one ring portion. Because. FIG. 10 is a diagram illustrating the position of the tool 100 during machining. As understood from the figure, the tool 100 can process the ring portion 91 without interfering with the ring portion 92 due to the difference in height between the ring portions 91 and 92. Moreover, by providing the recessed part 93 between ring parts, the chip | tip at the time of V-groove processing is escaped, and generation | occurrence | production of a burr | flash can be suppressed.

  After the V-groove processing, NiP is plated on the entire surface with a thickness of about 0.5 μm in order to prevent oxidation and prolong the life during molding.

  The mold 90 can also be constituted by NiP plating instead of Cu. In this case, the latter plating, that is, the entire NiP plating is not necessary.

  As described above, it is possible to obtain a small and highly accurate code plate by the presence of protrusions between tracks, the height of a plurality of tracks being not the same, and the above-described manufacturing method. Further, since the code plate 60 can be manufactured by resin injection molding after the mold is manufactured, the manufacturing cost can be reduced.

(Embodiment 3)
In the first and second embodiments, the optical rotary encoder including a plurality of tracks having different patterns has been described. In the third embodiment, an optical linear encoder including a plurality of tracks having different patterns will be described. An optical linear encoder is a sensor that detects displacement information such as the position and velocity of an object that performs linear motion by an optical method.

  11A to 11D are diagrams showing the configuration of a linear encoder code plate (hereinafter referred to as “code plate”) 110 having two tracks according to the present embodiment. The code plate 10 is used when detecting the absolute position of an object that moves linearly, and is formed of a transparent resin material such as polycarbonate. (A) is a top view, (b) is a sectional view, and (c) and (d) are partial sectional views.

  Referring to (a) of FIG. 11, the code plate 110 is a rectangular plate-like body including two linear tracks 111 and 112 and a flat portion 114. Each of the tracks 111 and 112 and the flat portion 114 is divided by a recess 113. Each of the tracks 111 and 112 has a different pattern formed by a V-shaped groove (hereinafter referred to as “V groove”). (D) and (c) show the shapes of the A-A ′ section of the track 1 and the B-B ′ section of the track 2. As in the first embodiment, the V-groove of each cross section is a reflecting portion that reflects light according to the principle described later. The flat surface between the V grooves is a transmission part that transmits light. The V-groove pattern of each track is provided in parallel with the C-C ′ direction.

  FIG. 11B is a cross-sectional view taken along line C-C ′ shown in FIG. As can be understood from (b), it can be said that the tracks 111 and 112 and the flat portion 114 are provided protruding from the code plate 110. The upper surface of the track 112 is higher than the upper surface of the track 111. Further, the flat portion 114 where no pattern is formed is located at a higher position (the thickest part of the disc). A light receiving portion is provided on the side where the tracks 111 and 112 are provided, and a light source is provided on the opposite side.

  The principle that light is transmitted / reflected through the code plate 110 and the relationship between the position displacement of the code plate and the signal intensity are substantially the same as those described with reference to FIGS. . The code plate 110 having such a configuration can be easily manufactured by manufacturing a mold in the same manner as in the first embodiment. However, the manufacturing process of the mold is substantially the same as the process described with reference to FIGS. As a result, the same effect as in the first embodiment can be obtained.

  Further, a code plate in which the code plate 110 is deformed by reversing the tracks 111, 112, the flat portion 114, and the concave portion 113 by using the V groove pattern provided in the tracks 111, 112 as V protrusions. (Not shown) can be obtained. The principle that light is transmitted / reflected through the code plate and the relationship between the displacement of the code plate and the signal intensity are substantially the same as those described with reference to FIGS. . Such a code plate can be easily manufactured by manufacturing a metal mold in the same manner as in the second embodiment. However, the manufacturing process of the mold is substantially the same as the process described with reference to FIG. 9 and FIG. As a result, an effect equivalent to that of the second embodiment can be obtained.

It is a figure which shows the structure of the code board for rotary encoders which has two tracks by Embodiment 1. FIG. (A) is a top view. (B) is sectional drawing. (C) And (d) is a fragmentary sectional view. It is sectional drawing of the V-groove part of a track | truck. (A) And (b) is a graph which shows the relationship between the displacement of a code | cord | chord board and signal intensity which change according to each V-groove shape of two tracks. (A) is a figure which shows the base material which processed the shape of the code | cord board. (B) is a figure which shows the base material after a process, and the plating part provided on it. (C) is a figure which shows the plating part peeled from the base material. It is a figure which shows the position of the tool at the time of a process. FIG. 6 is a diagram illustrating a configuration of a code plate having two tracks according to a second embodiment. (A) is a top view. (B) is sectional drawing. (C) And (d) is a fragmentary sectional view. It is sectional drawing of the V protrusion part of a track | truck. (A) And (b) is a graph which shows the relationship between the displacement of a code | cord | chord board and signal intensity which change according to each V protrusion shape of two tracks. It is a figure which shows the metal mold | die base material and metal mold | die required in the case of injection molding. It is a figure which shows the position of the tool at the time of a process. FIG. 10 is a diagram illustrating a configuration of a linear encoder code plate having two tracks according to a third embodiment. (A) is a top view. (B) is sectional drawing. (C) And (d) is a fragmentary sectional view. It is sectional drawing of the detection part of the optical encoder provided with the code | cord board, the light source, and the light-receiving part. (A) is sectional drawing of the code board formed with the plastic. (B) is an expanded sectional view of a board | substrate.

Explanation of symbols

1, 2 tracks, 3 recesses, 4 flat parts, 10 code plate for encoder.

Claims (3)

A transparent substrate;
The cross-sectional shape provided on the surface of the transparent substrate is V-shaped and includes a V-shaped part that reflects light and a flat part that transmits light, and the vertical direction is perpendicular to the V-shaped part. A first track having a first pattern in which the pitch between the V-shaped portions changes;
The cross-sectional shape provided on the surface of the transparent substrate is V-shaped and includes a V-shaped part that reflects light and a flat part that transmits light, and the vertical direction is perpendicular to the V-shaped part. A second track having a second pattern in which the pitch between the V-shaped portions is constant ;
An inter-track region between the first track and the second track;
A central part not forming a pattern;
With
The first track and the second track are respectively provided on surfaces having different heights from the surface of the transparent substrate,
The inter-track region between the first track and the second track protrudes in the thickness direction from the surface on which each track is provided , and
The encoder code plate , wherein the central portion is thickest in a thickness direction from the surface of the transparent substrate . The encoder code plate according to claim 1 ,
A light source for irradiating light to the encoder code plate;
A light receiving unit that receives light transmitted through the encoder code plate among the light emitted from the light source;
A housing for housing the encoder code plate, the light source, and the light receiving unit ;
An encoder comprising: Producing a mold for the encoder code plate;
Injecting a transparent resin material onto the manufactured mold;
The resin in which the resin material is peeled from the mold, and the first pattern, the second pattern, the inter-track area, and the central portion on the surface of the mold are reversely transferred to the surface. Obtaining an encoder code plate made of a material;
A method of manufacturing an encoder code plate including:
The step of manufacturing the mold includes:
A sub-step of plating on the first material;
The plating surface has a V-shaped section having a V-shaped cross section and a flat section, and a pitch between the V-shaped sections changes along a direction perpendicular to the V-shaped section. A sub-step of processing a first track having a pattern;
On the surface of the plating, a second pattern having a V-shaped cross-sectional shape and a flat portion, and a constant pitch between the V-shaped portions along a direction perpendicular to the V-shaped portion. Processing a second track having a surface with a height different from a height at which the first track is provided when viewed from the surface of the transparent substrate;
Each track has a height difference that allows a chip generated during processing of the V-shaped portion to escape in the inter-track region between the first track and the second track on the surface of the plating. A sub-step that is lower than the surface provided with
A sub-step for processing the center of the surface of the plating deepest in the thickness direction;
A method for manufacturing an encoder code plate.

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