JP2024071200A - Optical Encoders - Google Patents

Abstract

[Problem] To provide an optical encoder that is easy to manufacture and can obtain an accurate signal. [Solution] The encoder includes a rotating body 60 provided with a light reflecting surface 62, light emitting elements 33Aa, 33Ba that emit light toward the light reflecting surface 62, and light receiving elements 33Ab, 33Bb that receive the light reflected by the light reflecting surface 62. High reflecting portions 615a and low reflecting portions 615b that reflect the light received from the light emitting elements 33Aa, 33Ba are formed on the light reflecting surface 62. The rotation state of the rotating body 60 is detected according to the amount of light reflected by the high reflecting portion 615a and the low reflecting portion 615b and received by the light receiving elements 33Ab, 33Bb. Both the high reflecting portion 615a and the low reflecting portion 615b are formed by printing. The low reflecting portion 615b is printed and laminated on the high reflecting portion 615a. [Selected Figure] Figure 9

Description

The present invention relates to an optical encoder that uses light to change an electrical output signal.

Conventionally, a rotating body used in an optical encoder, such as the rotating body (11) shown in FIG. 1 of Patent Document 1, is formed on the underside of a disk (13) with a scale portion (14) on its underside (reflective surface) in which reflective portions (15a) and non-reflective portions (15b) are arranged alternately in a circumferential pattern, and the reflection state of light irradiated to the scale portion (14) is detected by an optical sensor (16), thereby detecting the rotation state of the rotating body (11).

The reflective portion (15a) and the non-reflective portion (15b) of the rotating body (11) were formed by forming a scale portion (14) on the underside of the disk (13) by vapor deposition of a metal material such as aluminum, and then photo-etching the underside of this scale portion (14).

In addition, conventionally, the method of forming the reflective and non-reflective parts is not limited to the above method, and there have also been methods in which a metal plate is attached to the underside of the rotating body that serves as the reflective surface, or a metal layer is formed by plating, and then these are etched.

Japanese Patent Application Laid-Open No. 07-209023

However, as mentioned above, the process of forming a metal layer or metal plate on the reflective surface and etching it is complicated, and the manufacturing equipment is large-scale, which leads to increased manufacturing costs.

The present invention has been made in consideration of the above points, and its purpose is to provide an optical encoder that is easy to manufacture, reduces manufacturing costs, and can obtain accurate signals.

The present invention is an optical encoder comprising a rotor supported for free rotation around a rotation axis and provided with a light-reflecting surface, a light-emitting element that emits light toward the light-reflecting surface of the rotor, and a light-receiving element that receives the light reflected by the light-reflecting surface of the rotor, wherein high-reflection portions and low-reflection portions that reflect light received from the light-emitting element are formed on the light-reflecting surface of the rotor, and the rotational state of the rotor is detected according to the amount of light reflected by the high-reflection portions and low-reflection portions received by the light-receiving element, and wherein the high-reflection portions and low-reflection portions on the light-reflecting surface are both formed by printing.
According to the present invention, since both the high reflection portion and the low reflection portion are formed by printing, the high reflection portion and the low reflection portion can be easily formed. Furthermore, the equipment used for printing can be less expensive than the equipment used for deposition, etching, etc. As a result, the manufacturing cost can be reduced.

In addition to the above-mentioned features, the present invention is characterized in that the low reflectivity portion is printed and laminated on the surface of the high reflectivity portion which is printed on the light reflecting surface.
According to the present invention, since a high reflection portion and a low reflection portion can be formed by laminating two printed layers on the same surface (light reflecting surface), the manufacturing can be easily performed.
Furthermore, because the low-reflection portion is laminated on the high-reflection portion, even if the high-reflection portion is printed using a metallic-colored ink mixed with metal powder, which tends to bleed around the periphery and is difficult to print into a fine shape, the high-reflection portion can be printed on the lower layer where no fine shape is required, and then a low-reflection portion with a fine-shaped opening is printed on top of it, exposing the high-reflection portion at the opening, thereby allowing the outer periphery of the high-reflection portion to be formed finely, and resulting in a more accurate output signal.

In addition to the above features, the present invention is characterized in that a recess is formed in the light reflecting surface of the rotating body to serve as a bearing portion for supporting the rotating body.
According to the present invention, since a recess is provided as a bearing portion instead of a shaft for supporting the rotating body, there is no part protruding from the light reflecting surface, which makes it easier to perform printing work on the light reflecting surface.

In addition to the above features, the present invention is characterized in that the high reflectivity portion and the low reflectivity portion are both formed by pad printing.
According to the present invention, the high reflectivity portion and the low reflectivity portion can be formed on the surface of the reflecting surface more smoothly (smoothly) than when they are formed by other printing methods, and the state of reflection, i.e., the state of the reflected light received by the light receiving element, can be improved. In other words, if the high reflectivity portion and the low reflectivity portion are formed by screen printing, the state of the mesh of the screen is reflected on the surface of the reflecting surface, and there is a risk that the surface may become slightly wavy, but this risk can be eliminated by using the present invention.

The present invention allows for easy manufacturing, reduced manufacturing costs, and accurate signals.

1 is a schematic cross-sectional view of an optical encoder (encoder) 1. FIG. FIG. 2 is an exploded perspective view of the encoder 1. FIG. 2 is a perspective view of the encoder 1. FIG. 1 is a perspective view of a rotating body 60 as seen from below. FIG. 13 is an explanatory diagram of a method for forming a reflecting portion 615. FIG. 2 is a side cross-sectional view of a rotating body 60. FIG. 10 is a schematic explanatory diagram showing the relationship between the photosensor 33A (or 33B) and the high-reflection portion 615a and low-reflection portion 615b. FIG.

Below, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic cross-sectional view (schematic cross-sectional view taken along line A-A in Fig. 3) of an optical encoder (hereinafter simply referred to as "encoder") 1 according to one embodiment of the present invention, Fig. 2 is an exploded perspective view of the encoder 1, and Fig. 3 is a perspective view of the encoder 1. As shown in these figures, the encoder 1 is configured to include a case 10 housing a circuit board 30, a rotating body 60, and a cover 80. In the following description, "upper" refers to the direction in which the rotating body 60 is viewed from the circuit board 30, and "lower" refers to the opposite direction, but this is not intended to limit the direction in which the encoder 1 is used.

Figure 4 is a perspective view of the circuit board 30. As shown in the figure, the circuit board 30 has a rigid, substantially rectangular insulating substrate 31, which has a penetrating positioning hole 313 formed in the center and multiple (two in this example) through holes 315 around the periphery. A photo IC 33 is installed at a predetermined position on the upper surface (hereinafter referred to as the "top surface") 311 of the insulating substrate 31, and one end of multiple (six in this example) terminal plates 39 is abutted in parallel to the top surface near one side of the insulating substrate 31.

The photo IC 33 includes two pairs of photosensors 33A and 33B, and a signal processing circuit (not shown) that processes the output signals of the two pairs of photosensors 33A and 33B. Each of the photosensors 33A and 33B has a light-emitting element 33Aa and 33Ba and a light-receiving element 33Ab and 33Bb, respectively, and an output voltage is generated when the light-receiving elements 33Ab and 33Bb receive the light emitted from the light-emitting elements 33Aa and 33Ba. The signal processing circuit converts the output signals of the two pairs of photosensors 33A and 33B into rectangular electrical signals, amplifies the current value, and outputs it.

As shown in Figures 1 and 2, the case 10 is formed by molding synthetic resin into a generally box-like shape with an open top. A rectangular recessed storage section 11 is formed on the top side of the case 10. The top surface of the circuit board 30, which is insert-molded into the case 10, is exposed on the bottom surface of the storage section 11. A circular, columnar shaft section 13 that constitutes part of the case 10 is erected in the center of the top surface of the circuit board 30. A circular hole 14 is formed in the center of the shaft section 13. A bottom section (connecting section) 15 that connects to a section that constitutes the outer periphery of the side wall section 17 of the case 10 is provided on the bottom surface side of the circuit board 30 of the shaft section 13. In other words, the case 10 is configured with a bottom 15 on the underside of the circuit board 30, a side wall 17 formed to surround the periphery of the circuit board 30, and a shaft 13 that penetrates the center of the circuit board 30 from the bottom 19 and protrudes to the upper side, and the tip portions of six terminal boards 39 protrude outward from one side wall 17 of the case 10. The portions of each terminal board 39 that abut against the circuit board 30 are fixed by the synthetic resin that constitutes the case 10, and maintain a good connection state with each connection pattern of the circuit board 30. In addition, small protruding positioning portions 19 protrude from the upper surfaces of the two corners of the side wall 17.

To manufacture the case 10, the circuit board 30 and the terminal board 39 are placed in a mold having a cavity in the shape of the case 10, with one end of each terminal board 39 abutting against each connection pattern (not shown) of the circuit board 30. Molten synthetic resin is then injected into the cavity in this state, and the mold is removed after the synthetic resin has solidified, completing the case 10 with the circuit board 30 and terminal board 39 insert molded. At this time, the shaft 13 and bottom 15 of the case 10 are connected through two through holes 315 provided in the circuit board 30.

Figure 5 is a perspective view of the rotor 60 seen from below, Figure 6 is a bottom view of the rotor 60, and Figure 8 is a side cross-sectional view of the rotor 60 (a cross-sectional view rotated 90 degrees in the rotational direction from the cross-section of Figure 1). As shown in these figures and Figures 1 to 3, the rotor 60 is made of synthetic resin and is configured by integrally molding a disk-shaped main body 61 and a circular columnar knob portion (shaft) 63 protruding from the center of the upper surface of the main body 61. The lower surface of the main body 61 is a light reflecting surface 62. The outer diameter dimension of the main body 61 is formed to a dimension that allows it to be stored in the storage portion 11 of the case 10. A bearing portion 611 consisting of a circular recess is formed in the center of the light reflecting surface 62 on the lower surface of the main body 61. A circumferential reflecting portion 615 is formed in a position surrounding the periphery of the bearing portion 611 of the light reflecting surface 62.

The reflective portion 615 is configured by forming multiple sets of high reflection portions 615a and low reflection portions 615b in an endless alternating fashion at equal intervals in a circular pattern, forming a circular reflection locus surface (reflective track surface). Both the high reflection portions 615a and the low reflection portions 615b are formed by printing. More specifically, the low reflection portions 615b are printed so as to be layered on the surface of the high reflection portions 615a printed on the light reflection surface 62.

Figure 7 is an explanatory diagram of a method for forming the reflective portion 615, with Figures 7(a-1), (b-1), and (c-1) being bottom views, and Figures 7(a-2), (b-2), and (c-2) being schematic cross-sectional views (at part B-B shown in Figure 7(a-1)). As shown in Figures 7(a-1) and (a-2), a rotating body 60 is prepared before the reflective portion 615 is printed.

Next, as shown in Figures 7(b-1) and (b-2), a highly reflective portion 615a is formed by printing a metallic colored decorative ink on substantially the entire surface of the light reflecting surface 62 (excluding the area near the outer periphery and the area around the bearing portion 611). In this embodiment, pad printing is used as the printing method. That is, the highly reflective portion 615a is formed by using pad printing to primarily transfer the ink on the plate to a silicon pad using an intaglio plate, and then secondarily transfer the ink on the silicon pad to the light reflecting surface 62, which is the printed material.

In this embodiment, the ink for the highly reflective portion 615a is a metallic color (a color with a silvery metallic luster) decorative ink made by kneading aluminum powder, resin, solvent, and hardener. As a result, the highly reflective portion 615a is formed into a mirror-like surface that effectively reflects light.

Next, as shown in Figures 7(c-1) and (c-2), low-reflection areas 615b are formed by printing dark-colored decorative ink on the light-reflecting surface 62 on which the high-reflection areas 615a have been formed. In this embodiment, pad printing is used as the printing method, as with the high-reflection areas 615a.

In this embodiment, the ink for the low-reflection portion 615b is a dark-colored (black-colored) decorative ink made by kneading carbon black powder, resin, solvent, and hardener. As a result, the low-reflection portion 615b has a surface formed in a dark color (black) that is difficult to reflect.

The low-reflection portion 615b is formed in a shape that covers the entire high-reflection portion 615a, and has fan-shaped openings A1 at equal intervals in a ring shape, exposing the high-reflection portion 615a within the openings A1. More specifically, the exposed fan-shaped high-reflection portion 615a and the fan-shaped low-reflection portion 615b sandwiched between the exposed high-reflection portion 615a are formed so that the left and right sides of the high-reflection portion 615a and the low-reflection portion 615b are located on a line extending radially from the rotation axis L (FIGS. 6 and 8) of the rotor 60. The low-reflection portion 615b has an outer ring portion (outer connection portion) 615bx that connects the outer periphery of the high-reflection portion 615a in a ring shape, and an inner ring portion (inner connection portion) 615by that connects the inner periphery of the high-reflection portion 615a in a ring shape. That is, the highly reflective portion 615a is surrounded on both the left and right sides, as well as on the outer and inner sides, by the low-reflective portion 615b.

In this embodiment, pad printing is used to form both the high reflectivity portion 615a and the low reflectivity portion 615b because it can make their surfaces smoother (evener) and improve the state of reflected light compared to when they are formed by other printing methods. In other words, if the high reflectivity portion 615a and the low reflectivity portion 615b were formed by screen printing, the state of the mesh of the screen would be reflected, and there would be a risk that the surface would become slightly wavy, but this embodiment can eliminate this risk.

The reason why the low-reflection portion 615b is printed and formed on the surface of the high-reflection portion 615a printed on the light-reflection surface 62 is as follows. That is, when the high-reflection portion 615a is formed using a metallic-colored ink mixed with metal powder as in this embodiment, the outer periphery is prone to bleeding and cannot necessarily be formed precisely. On the other hand, when the low-reflection portion 615b is printed using ink mixed with carbon powder as in this embodiment, the outer periphery is unlikely to bleed and can be formed precisely. Therefore, the high-reflection portion 615a is formed on the lower layer side where a precise outer periphery shape is not necessary, and the low-reflection portion 615b having an opening A1 with a precise shape (inner periphery) is formed on top of it, exposing the high-reflection portion 615a to the opening A1, thereby forming the exposed outer periphery of the high-reflection portion 615a precisely. As a result, a more accurate on-off signal (output signal) can be obtained.

In addition, with this rotating body 60, instead of a protruding shaft for supporting the lower side of the rotating body 60, a recess is provided that serves as a bearing portion 611, so there is no part that protrudes from the light reflecting surface 62. This makes it easier to perform the above-mentioned printing work on the light reflecting surface 62. The upper side of the rotating body 60 is supported by a knob portion 63 (bearing portion 811 described below).

The cover 80 is made of a metal plate and is configured to have a cover body 81 that is approximately rectangular and has dimensions that cover the storage section 11 of the case 10, and side sections 83, 83 that are connected to a pair of opposing sides of the cover body 81 and bent downward at approximately a right angle. A cylindrical bearing section 811 is formed in the center of the cover body 81, and the center is a through hole. In addition, near the two corners of the cover body 81, positioning sections 813 consisting of small holes into which the positioning sections 19 of the case 10 are inserted are formed. At the center of the lower edge of each side section 83, other member attachment sections 831 that protrude downward are formed, and on both sides of the other member attachment sections 831, case attachment sections 833 that protrude downward are formed.

Next, to assemble the encoder 1, the main body 61 of the rotor 60 is stored in the storage section 11 of the case 10. At this time, the shaft 13 of the case 10 is inserted into the bearing section 611 of the rotor 60, thereby supporting the rotor 60 for free rotation, and the upper surface of the shaft 13 is abutted against the bottom surface of the bearing section 611, so that the distance between the lower surface of the main body 61 and the light-emitting elements 33Aa, 33Ba and the light-receiving elements 33Ab, 33Bb of the photo IC 33 is set to a predetermined distance. In other words, the shaft 13 of the case 10 and the bearing section 611 of the rotor 60 simultaneously rotate the rotor 60 and accurately set the distance between the light-emitting elements 33Aa, 33Ba and the light-receiving elements 33Ab, 33Bb and the reflecting section 615.

Next, the cover body 81 of the cover 80 is placed on the top surface of the case 10 housing the main body 61 of the rotor 60, to close the housing section 11 of the case 10. At the same time, the knob section 63 of the rotor 60 is inserted into the bearing section 811 of the cover 80, and the rotor 60 is rotatably supported. Then, by bending each case mounting section 833 of the cover 80 toward the underside of the case 10, the cover 80 is fixed to the case 10, and the encoder 1 shown in FIG. 3 is completed. Note that the above assembly procedure is one example, and it goes without saying that various other assembly procedures may be used for assembly.

In the encoder 1 configured as above, a voltage is first applied to one of the terminal plates 39 to activate the electric circuit on the circuit board 30. Here, FIG. 9 is a schematic explanatory diagram showing the relationship between one of the two photosensors 33A (or 33B) and the high reflection portion 615a and low reflection portion 615b. For convenience of illustration, the rotation direction E of the rotating body 60 and the arrangement direction of the pair of light-emitting element 33Aa (or 33Ba) and light-receiving element 33Ab (or 33Bb) provided on the photosensor 33A (or 33B) are shown as the same, but in reality the two directions are perpendicular to each other. As shown in the figure, light is irradiated from the light emitting element 33Aa (or 33Ba) of the photosensor 33A (or 33B) to the reflecting portion 615 (615a, 615b) on the bottom surface of the rotating body 60, and if the irradiated portion is the high reflecting portion 615a, most of the light is reflected and received by the light receiving element 33Ab (or 33Bb) of the photosensor 33A (or 33B), while if the irradiated portion is the low reflecting portion 615b, most of the light is not reflected and is not received by the light receiving element 33Ab (or 33Bb) of the photosensor 33A (or 33B). Therefore, when the rotating body 60 rotates, the output signal from the photosensor 33A (or 33B) changes depending on the light receiving state of the light receiving element 33Ab (or 33Bb). Specifically, an on/off signal is obtained according to the difference in the reflecting state due to the high reflecting portion 615a and the low reflecting portion 615b.

In this embodiment, the low reflectivity portion 615b is formed to surround the entire outer circumference of the high reflectivity portion 615a, so that a more accurate on/off signal can be obtained. That is, each high reflectivity portion 615a is isolated from its outer and inner peripheries by the black low reflectivity portion 615b. Therefore, even if a part of the light emitted from the light emitting element 33Aa (or 33Ba) of the photosensor 33A (or 33B) is irradiated and reflected at a position corresponding to the outer ring portion 615bx or the inner ring portion 615by, the amount of this reflected light can be reduced, and the risk of the reflected light being reflected by another member and then entering the light receiving element 33Ab (or 33Bb) and causing a malfunction can be reliably prevented. This makes it possible to obtain a more accurate on/off signal.

Both photosensors 33A and 33B are located on the same circumference centered on the rotation axis L1 of the rotating body 60, and are arranged so that they are slightly shifted in the circumferential direction with respect to the different high reflection parts 615a (or low reflection parts 615b) that are located opposite the two photosensors 33A and 33B. Therefore, when the rotating body 60 rotates, the timing at which one photosensor 33A (or 33B) passes through the high reflection part 615a (or low reflection part 615b) located opposite the photosensor 33A (or 33B) is slightly shifted from the timing at which the other photosensor 35B (or 33A) passes through the high reflection part 615a (or low reflection part 615b) located opposite the photosensor 33A (or 33B). This output signal is then output to the terminal board 39. Using the output signal obtained in this way, the direction of rotation and the speed of rotation of the rotating body 60 can be measured by analyzing a pair of on-off waveforms with different phases.

In each of the above embodiments, an example has been described in which a photo IC (photo sensor) is used that integrates a light-emitting element and a light-receiving element, but the light-emitting element, the light-receiving element, and even the signal processing circuit may be configured as separate elements and installed separately.

As described above, the encoder 1 has a rotating body 60 that is rotatably supported around the rotation axis L and has a light-reflecting surface 62, light-emitting elements 33Aa, 33Ba that emit light toward the light-reflecting surface 62 of the rotating body 60, and light-receiving elements 33Ab, 33Bb that receive the light reflected by the light-reflecting surface 62 of the rotating body 60. High-reflecting portions 615a and low-reflecting portions 615b that reflect light received from the light-emitting elements 33Aa, 33Ba are formed on the light-reflecting surface 62 of the rotating body 60, and the rotation state of the rotating body 60 is detected according to the amount of light reflected by the high-reflecting portion 615a and low-reflecting portion 615b and received by the light-receiving elements 33Ab, 33Bb. The high-reflecting portion 615a and low-reflecting portion 615b on the light-reflecting surface 62 are both formed by printing. In this way, since both the high reflection portion 615a and the low reflection portion 615b are formed by printing, the formation of these high reflection portion 615a and low reflection portion 615b can be easily performed. Furthermore, the equipment used for printing can be less expensive than the equipment used for deposition, etching, etc. This allows for a reduction in manufacturing costs.

In addition, in the encoder 1, the low reflectivity portion 615b is printed and laminated on the surface of the high reflectivity portion 615a printed on the light reflecting surface 62. By laminating two printed layers on the same surface (light reflecting surface 62) in this way, the high reflectivity portion 615a and the low reflectivity portion 615b are formed, making it easy to manufacture.

In addition, since the low-reflection portion 615b is layered on the high-reflection portion 615a, even if the high-reflection portion 615a is printed using a metallic-colored ink mixed with metal powder, which is prone to bleeding around the periphery and difficult to print into a fine shape, the high-reflection portion 615a is printed on the lower layer side where a fine shape is not required, and the low-reflection portion 615b having an opening A1 on the inner periphery of the fine shape is printed on top of it, exposing the high-reflection portion 615a to the opening A1. This allows the outer periphery of the high-reflection portion 615a to be formed finely, and a more accurate output signal can be obtained.

In addition, in this encoder 1, the shaft 13 of the case 10, which protrudes from the center of the upper surface of the circuit board 30, is rotatably supported by a concave bearing 611 provided in the center of the lower surface of the rotating body 60, but the contact area between the two is small, resulting in a structure with little wear. At the same time, the upper surface of this shaft 13 abuts against the bottom surface of the bearing 611 to support the rotating body 60 in the vertical direction, so the gap dimension between the upper surface of the circuit board 30 and the lower surface of the rotating body 60 can be accurately set to the desired dimension. This makes it possible to precisely configure a mechanism in which light emitted from the light-emitting elements 33Aa and 33Ba of the photosensors 33A and 33B is reflected by the reflecting portion 615 and received by the light-receiving elements 33Ab and 33Bb, and a highly accurate output signal can be obtained.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the technical ideas described in the claims, specification, and drawings. Any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical ideas of the present invention as long as it achieves the action and effect of the present invention. For example, in the above embodiment, the highly reflective portion is a metallic silver color, but it may be a metallic color other than silver, or even a color other than a metallic color, as long as it is a color with a higher brightness than the low reflective portion. On the other hand, in the above embodiment, the low reflective portion is formed in black, but it may be a color other than black, as long as it is a color with a lower brightness than the highly reflective portion. In the above embodiment, the entire outer periphery of the highly reflective portion is surrounded by the low reflective portion, but in some cases, the outer periphery (outer connecting portion 615bx) and the inner periphery (inner connecting portion 615by) may be omitted. In the above embodiment, both the highly reflective portion and the low reflective portion are formed by pad printing, but in some cases, they may be formed by various other printing methods such as screen printing. In some cases, the highly reflective area may be printed on top of the low reflective area.

The above description and the embodiments shown in each figure can be combined as long as there is no contradiction in the purpose and configuration. The above description and the descriptions in each figure can each be an independent embodiment, even if only partially, and the embodiment of the present invention is not limited to a single embodiment that combines the above description and each figure.

1. Optical Encoder (Encoder)
10 Case 30 Circuit board 33 Photo IC
33A, 33B Photosensor 33Aa, 33Ba Light-emitting element 33Ab, 33Bb Light-receiving element 60 Rotating body 62 Light-reflecting surface 611 Bearing portion (recess)
615 Reflection section 615a High reflection section 615b Low reflection section L Rotation shaft 80 Cover

Claims (4)

a rotating body that is rotatably supported around a rotation axis and has a light reflecting surface;
A light emitting element that emits light toward a light reflecting surface of the rotating body;
a light receiving element that receives light reflected by a light reflecting surface of the rotating body;
having
an optical encoder in which high reflection portions and low reflection portions that reflect light received from the light emitting element are formed on a light reflecting surface of the rotating body, and a rotation state of the rotating body is detected in accordance with an amount of light reflected by the high reflection portions and low reflection portions and received by the light receiving element,
13. An optical encoder, comprising: a light reflecting surface having a high reflectivity portion and a low reflectivity portion, the high reflectivity portion and the low reflectivity portion being formed by printing. 2. The optical encoder of claim 1,
The optical encoder according to claim 1, wherein the low-reflection portion is printed and laminated on a surface of the high-reflection portion which is printed on the light-reflecting surface. 3. An optical encoder according to claim 1,
An optical encoder according to claim 1, wherein a recess is formed in the light reflecting surface of the rotating body to serve as a bearing for supporting the rotating body. 3. An optical encoder according to claim 1,
13. An optical encoder, comprising: a first region for reflecting light from a first reflecting portion of the first substrate;

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