Optical encoder

Abstract

The utility model discloses an optical encoder. The optical encoder comprises a first code disc and an image sensor. The first code disc is provided with a first spiral pattern, the center of the first code disc is located on a first rotating shaft, and the first spiral pattern starts from the first rotating shaft to one side edge of the first code disc. The image sensor is used for sensing the change of brightness information reflected by an image in a first part range of the first code disc and determining the rotation position of the first code disc. The rotational position is an absolute position. The optical encoder can easily realize the function of an absolute encoder, supports large off-axis installation and long-distance installation, and is high in installation elasticity.

Description

Technical Field

[0001] This utility model relates to an optical encoding mechanism, and more particularly to an optical encoder. Background Technology

[0002] Generally, the installation location of traditional optically enhanced and optically absolute encoders is limited by their architecture. For example, during installation, the sensing circuit of the optical encoder needs to be aligned very precisely with the rotating shaft, and a single sensing circuit of a traditional optical encoder requires a separate rotating shaft. Multiple sensing circuits of different traditional optical encoders require multiple different rotating shafts. Utility Model Content

[0003] Therefore, one of the objectives of this utility model is to disclose a novel optical encoder to solve the problems of the aforementioned conventional technology.

[0004] According to an embodiment of this utility model, an optical encoder is disclosed. The optical encoder includes a first code disk and an image sensor. The first code disk has a first spiral pattern. The center of the first code disk is located on a first rotation axis. The first spiral pattern starts from the first rotation axis and ends at one side of the first code disk. The image sensor is used to sense changes in brightness information reflected by an image within a first portion of the first code disk, and to determine the rotational position of the first code disk. This rotational position is an absolute position.

[0005] According to an embodiment of this utility model, an optical encoder is disclosed. The optical encoder includes a code disk and an image sensor. The code disk has a spiral pattern, the center of which is located on a rotation axis, and the spiral pattern starts from the rotation axis and ends at the side of the code disk. The image sensor is used to sense changes in brightness information reflected by an image over a portion of the code disk to determine the rotational position of the code disk, wherein the rotational position is an absolute position.

[0006] According to an embodiment of the present invention, an optical encoder is disclosed. The optical encoder includes a code disk and an image sensor. The code disk has a spiral pattern that rotates from the center of the code disk to the side of the code disk. The image sensor is used to sense changes in brightness information reflected by an image over a portion of the code disk to determine the rotational position of the code disk, wherein the rotational position is an absolute position.

[0007] According to an embodiment of this utility model, an optical encoder is disclosed. The optical encoder includes a code disk and an image sensor. The code disk has a spiral pattern and is located on a rotating axis, with the spiral pattern starting from the rotating axis and ending at the side of the code disk. The image sensor is used to sense changes in brightness information reflected by an image over a portion of the code disk to determine the rotational position of the code disk, wherein the rotational position is an absolute position.

[0008] According to embodiments of this invention, the disclosed novel optical encoder expands the application areas of image sensors in gesture and / or encoder applications. By using a simply designed spiral code disk, it can accurately reflect the brightness information of the spiral pattern. By capturing changes in the shape, center of gravity, and / or area of ​​the two-dimensional bright surface region, the function of an absolute encoder can be easily achieved, while also supporting large off-axis mounting. As long as the code disk surface of the rotating axis falls within the field of view of the optical encoder, it can support large off-axis and long-distance mounting, offering high installation flexibility. Furthermore, a single optical encoder can be used to detect multiple rotating axes; multiple rotating axes can be detected within the field of view of the novel optical encoder. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a novel optical encoder according to an embodiment of the present invention.

[0010] Figure 2 yes Figure 1 The diagram shows an example of the first code disk rotating counterclockwise.

[0011] Figure 3 yes Figure 1 The diagram shows an example of the first code disk rotating clockwise.

[0012] Figure 4 yes Figure 1 The diagram shows an embodiment where the image sensor is positioned on different planes.

[0013] Figure 5 This is an example schematic diagram of a first code disk with an Archimedean spiral pattern according to an embodiment of the present invention.

[0014] Figure 6 This is a schematic diagram of a novel optical encoder according to another embodiment of the present invention.

[0015] The reference numerals in the attached figures are explained as follows:

[0016] 100, 600 optical encoders

[0017] 105, 605A First Code Disc

[0018] 105A Top Cover

[0019] 105B base

[0020] 110 Image Sensor

[0021] 115 Light-emitting circuit

[0022] 120 Optical Sensing Circuit

[0023] 201, 202, 203, 301, 302, 303 Two-dimensional bright surface areas

[0024] 601 Three-dimensional mechanical system

[0025] 602A First Tool Head Device

[0026] 603 work surface

[0027] 605B Second Code Disk Detailed Implementation

[0028] Please refer to Figure 1 . Figure 1 This is a schematic diagram of a novel optical encoder 100 according to an embodiment of the present invention. The optical encoder 100 is, for example, an optical rotary encoder and includes at least a first code wheel 105 and an optical sensor, for example, an image sensor 110.

[0029] The first code disk 105 has a first spiral pattern. The center of the first code disk is located on a first rotation axis (or the center of the code disk 105 is located on the rotation axis, or the code disk 105 is located on the rotation axis). The first spiral pattern starts from the first rotation axis and ends at one side of the first code disk, or the spiral pattern starts from the center of the code disk or the rotation axis and rotates to the side of the code disk. The image sensor 110 includes a light-emitting circuit 115 and an optical sensing circuit 120. The light-emitting circuit 115 is used to emit light to one or more code disks (such as the first code disk 105), and the optical sensing circuit 120 is used to receive and sense changes in brightness information reflected from a first portion of the image of the first code disk 105 through a specific viewing angle to determine the rotational position of the first code disk 105, wherein the rotational position can be an absolute position.

[0030] Specifically, for example, the first code disk 105 consists of a top cover 105A and a base 105B. The top cover 105A is formed, for example, by a simple geometric shape. Specifically, it is, for example, a non-reflective circle, such as a dark circle. The dark circle has, for example, a fan-shaped notch at its bottom. The fan-shaped notch corresponds to a first portion of the first code disk 105. For example, the proportion of the fan-shaped notch is approximately one-eighth to one-sixth of the circumference of the first code disk 105; however, this is not a limitation of the present invention. The first rotating axis is capable of rotating clockwise or counterclockwise. The fan-shaped notch of the top cover 105A does not rotate with the first rotating axis; its position is fixed.

[0031] The upper surface of the base 105B has, for example, a first spiral pattern, making the first code disk 105 a spiral barcode disk. The first spiral pattern on the upper surface of the base 105B is a simple and distinctive curved graphic, presenting a dark shape (e.g., a dark black shape) resembling a curved crescent or vortex. The first spiral pattern gradually curls inward from one end, forming a dynamic spiral structure. In other words, the first spiral pattern can be a dark, non-reflective pattern, while other areas of the upper surface of the base 105B are bright areas, such as those capable of reflecting light, or vice versa. In this embodiment, the first code disk 105 includes the spiral pattern and other bright areas. In practice, the upper surface of the base 105B can be made of a glossy material, and then the dark, non-reflective first spiral pattern is drawn or coated on the upper surface. The first spiral pattern on the upper surface of the base rotates with the first rotation axis, and its position is not fixed. When the spiral pattern rotates with the first rotation axis, the other bright areas also rotate and reflect the change in brightness information to the image sensor 110, so that the image sensor 100 can determine the rotation position of the first code disk 105 accordingly.

[0032] For example, in one embodiment, the image sensor 110 is used to determine the rotation position, rotation angle, and rotation direction of the first code disk 105 based on the change in the shape of a two-dimensional bright area corresponding to the change in brightness information. Alternatively, in one embodiment, the image sensor 110 is used to determine the rotation position, rotation angle, and rotation direction of the first code disk 105 based on the change in the center of gravity of a two-dimensional bright area corresponding to the change in brightness information. Alternatively, in one embodiment, the image sensor 110 is used to determine the rotation position, rotation angle, and rotation direction of the first code disk 105 based on the change in the area of ​​a two-dimensional bright area corresponding to the change in brightness information.

[0033] Figure 2 yes Figure 1 The diagram shows an example of the first code disk 105 rotating counterclockwise. (See attached diagram.) Figure 2 As shown, from left to right, when the first code disk 105 rotates counterclockwise, for example, the two-dimensional bright surface area 201 transforms into the two-dimensional bright surface area 202, and then the two-dimensional bright surface area 202 transforms into the two-dimensional bright surface area 203. The two-dimensional bright surface area undergoes unique changes in shape, center of gravity, and / or area size depending on the rotation position of the first rotation axis. This allows the image sensor 110 to determine the absolute rotation position, rotation angle, and rotation direction of the first code disk 105 based on the unique changes in shape, center of gravity, and / or area size of the sensed image (i.e., the two-dimensional bright surface area).

[0034] Similarly, Figure 3 yes Figure 1 The diagram shows an example of the first code disk 105 rotating clockwise. (See attached diagram.) Figure 3 As shown, from left to right, when the first code disk 105 rotates clockwise, for example, the two-dimensional bright surface area 301 transforms into the two-dimensional bright surface area 302, and then the two-dimensional bright surface area 302 transforms into the two-dimensional bright surface area 303. That is to say, the two-dimensional bright surface area will produce different unique changes in shape, different unique changes in center of gravity position, and / or different unique changes in area size as the first rotation axis rotates. This allows the image sensor 110 to determine the absolute rotation position, rotation angle, and rotation direction of the first code disk 105 based on the different unique changes in shape, different unique changes in center of gravity position, and / or different unique changes in area size of the sensed image (i.e., the two-dimensional bright surface area).

[0035] Furthermore, the image sensor 110 can be mounted on different planes. Figure 4 yes Figure 1 The illustrated diagram shows an embodiment where the image sensor 110 is disposed on different planes. For example... Figure 1 As shown, the image sensor 110 is disposed at a first spatial position on a first plane. The image sensor 110 is positioned on one side of the first code disk 105, and this side is not located directly above, below, in front of, or behind the first code disk 105. In comparison, as... Figure 4As shown, the image sensor 110 can also be disposed at different second spatial positions on different second planes, or at different third spatial positions on different third planes. The second spatial position is located on the other side of the first code disk 105 and is not directly above, below, in front of, or behind the first code disk 105. The third spatial position is directly above or in front of the first code disk 105. It should be noted that as long as the image sensor 110 can determine the rotation position of the first code disk 105 by capturing changes in brightness information reflected from the image within the first portion of the image from its viewing angle at any spatial position, the image sensor 110 can be disposed at any of these spatial positions.

[0036] In addition, spiral patterns can be of different types, such as the Archimedes spiral pattern. Figure 5 This is an example schematic diagram of a first code disk 105 with an Archimedean spiral pattern according to an embodiment of the present invention. Figure 5 As shown in the left half, the upper surface of the first code disk 105 has an Archimedean spiral pattern and other areas. The Archimedean spiral pattern is a bright or light-colored (e.g., white) pattern, while the other areas are dark or dark-colored (e.g., black) patterns. The Archimedean spiral (or helix) is a curve formed by a point moving along a straight line at a constant speed, while that straight line rotates around a fixed point at a constant angular velocity. A characteristic of this spiral is that the distance from any point to the origin is proportional to the polar angle corresponding to that point. The Archimedean spiral can be represented mathematically as:

[0037] r = a + bθ;

[0038] Where r is the distance from any point to the origin, θ is the polar angle, a is the initial distance, and b is the step size of the helix (i.e., the radius that is increased when controlling the rotation of the helix).

[0039] like Figure 5 As shown in the right half, the horizontal axis represents the range of polar angle θ (i.e., different rotation angles of the first code disk 105), and the vertical axis, represented by r, refers to the distance from any point to the origin (the center origin of the first code disk 105), that is, the distance of the image sensor 110 within this first part of the range when the first code disk 105 rotates (e.g., ...). Figure 1The image sensor 110 measures the changes in brightness information sensed within the area (e.g., the change in distance between the center of gravity of the corresponding sensed two-dimensional bright area and the central origin), and this distance change has a linear relationship with the rotation angle of the first code disk 105. Therefore, based on this linear relationship, the image sensor 110 can accurately determine the rotation angle (i.e., the absolute rotation position) of the first code disk 105 by measuring the change in distance between the center of gravity of the corresponding sensed two-dimensional bright area and the central origin of the first code disk 105.

[0040] Similarly, in one embodiment, the Archimedean spiral pattern on the upper surface of the first code disk 105 can be a dark area or a dark-colored pattern, while other areas are light areas or light-colored patterns. In this case, the image sensor 110 determines the absolute rotational position, rotation angle, and rotation direction of the first code disk 105 by sensing the changes in shape, weight, and / or area of ​​the two-dimensional dark area as the first rotation axis rotates.

[0041] Furthermore, Figure 6 This is a schematic diagram of a novel optical encoder 600 according to another embodiment of the present invention. Figure 6As shown, the novel optical encoder 600 includes a three-dimensional mechanical system 601, a first code disk 605A, a second code disk 605B, and an image sensor 110. The three-dimensional mechanical system 601 adopts a standard three-dimensional Cartesian coordinate system, including three axes: X, Y, and Z. On the vertical Z-axis, the three-dimensional mechanical system 601 includes a column-type support structure, and a first tool head device 602A is disposed above the side of this column-type support structure. The first tool head device 602A has the first code disk 605A, the center point of which corresponds to a first rotation axis, which rotates, for example, parallel to the Y-axis, on a horizontal plane. On the horizontal plane formed by the X and Y axes, the three-dimensional mechanical system 601 includes and forms a worktable surface 603. The second encoder disk 605B is disposed above the worktable 603. The center point of the second encoder disk 605B corresponds to a second rotation axis, which rotates, for example, parallel to the Z-axis in a vertical plane. That is, the first rotation axis and the second rotation axis are located in two different three-dimensional planes. Furthermore, the first tool head device (i.e., a top tool head) can move up and down along the support structure in response to the rotation of the first encoder disk 605A, enabling the entire three-dimensional mechanical system 601 to achieve relatively precise positioning and motion control of the top tool head. An object to be processed can also be placed on the upper surface of the worktable 603 (i.e., above the second encoder disk 605B), and its relatively precise positioning and motion control can be achieved in response to the rotation of the second encoder disk 605B. For example, the three-dimensional mechanical system 601 can be a CNC machine tool or a 3D printer (but is not limited to this), and complex machining trajectories can be achieved through three-axis linkage. Figure 6 The arrows in the diagram indicate the motion characteristics of the entire system in various directions of motion.

[0042] Furthermore, to achieve accurate detection of the rotational positions of the first code disk 605A and the second code disk 605B, the novel optical encoder 600 can determine and decide the absolute rotational positions of the first code disk 605A and the second code disk 605B using a single image sensor 110. Specifically, the first code disk 605A has a first spiral pattern (e.g., Figure 1 or Figure 5 The spiral pattern is not shown in Figure 6 (Middle). The center of the first code disk 605A is located on the first rotation axis. The first spiral pattern, for example, starts from the first rotation axis and ends at one side of the first code disk 605A. The second code disk 605B also has a spiral pattern, for example (for example, the second spiral pattern is...). Figure 1 or Figure 5 The spiral pattern is not shown in Figure 6 (In the middle). The center of the second code disk 605B is located on the second rotation axis. The second spiral pattern starts from the second rotation axis and ends at one side of the second code disk 605B. The second spiral pattern may be the same as or different from the first spiral pattern. Figure 6 The single image sensor 110 shown can sense changes in brightness information reflected from the image within a first portion of the first code disk 605A, such as ROI_B, using the same viewing angle to determine the rotational position of the first code disk 605A. Simultaneously, it can also sense changes in brightness information reflected from the image within a second portion of the second code disk 605B, such as ROI_C, to determine the rotational position of the second code disk 605B. Both rotational positions can be absolute. Since a single image sensor 110 can sense the rotational positions of multiple code disks, device costs can be reduced. Furthermore, since the absolute rotational positions of multiple code disks can be sensed and determined as long as rotational changes of multiple code disks can be sensed within the same viewing angle, the image sensor 110 offers high flexibility in installation and supports large off-axis and long-distance installations.

[0043] In another embodiment, Figure 6 The first and second rotation axes can also be located at different positions on the same three-dimensional plane. That is, for example, the first code disk 605A and the second code disk 605B can be simultaneously placed on adjacent positions on the worktable of the three-dimensional mechanical system 601. The single image sensor 110 can also use the same viewpoint to sense the rotational positions of the two different code disks, and both rotational positions can be absolute positions. For the sake of brevity, further details are omitted.

[0044] It is worth mentioning that, in addition to the aforementioned embodiment of the code disk 105 using the top cover 105A and the base 105B with a spiral pattern, in other embodiments, the base 105B with a spiral pattern can also be used alone for absolute addressing encoding. Figure 2 Although it lacks the structure of the top cover 105A, the detection range of the image sensor 110 is only... Figure 2 Within the dashed frame, even without the top cover 105A, when the base 105B rotates counterclockwise, the pattern of the two-dimensional bright surface area 201 detected by the image sensor 110 will also have different shapes, areas, and / or center of gravity positions depending on the rotation angle. This part is similar to the concept described above and will not be elaborated further here. In other words, Figure 1 The illustrated encoder structure is only one embodiment, and this utility model is not intended to limit it.

[0045] Furthermore, the above-mentioned encoder 100 architecture is achieved by rotating the code disk 105. In other embodiments, the image sensor 110 may rotate while the code disk 105 itself remains stationary. The technical concept of this part is similar to that described above, and will not be repeated here.

[0046] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An optical encoder, characterized in that, The optical encoder includes: A first code disk having a first spiral pattern, the center of the first code disk being located on a first rotation axis, the first spiral pattern starting from the first rotation axis and ending at the side of the first code disk; and An image sensor is used to sense changes in brightness information reflected by an image in a first portion of the first code disk to determine the rotational position of the first code disk, which is an absolute position.

2. The optical encoder as described in claim 1, characterized in that, The first spiral pattern is a glossy pattern used to reflect changes in brightness information to the image sensor, so that the image sensor can determine the rotational position of the first code disk.

3. The optical encoder as described in claim 2, characterized in that, The image sensor is used to determine the rotation position, rotation angle, and rotation direction of the first code disk based on the change in the shape of the corresponding two-dimensional bright area according to the change in brightness information.

4. The optical encoder as described in claim 2, characterized in that, The image sensor is used to determine the rotation position, rotation angle, and rotation direction of the first code disk based on the change in the center of gravity of the corresponding two-dimensional bright area according to the change in the brightness information.

5. The optical encoder as described in claim 2, characterized in that, The image sensor is used to determine the rotation position, rotation angle, and rotation direction of the first code disk based on the change in the area of ​​the corresponding two-dimensional bright surface region according to the change in the brightness information.

6. The optical encoder as claimed in claim 1, characterized in that, The spiral pattern is a dark pattern. The first code disk includes the spiral pattern and other bright areas. The other bright areas are used to reflect the changes in brightness information to the image sensor, so that the image sensor can determine the rotation position of the first code disk.

7. The optical encoder as described in claim 6, characterized in that, The image sensor is used to determine the rotation position, rotation angle, and rotation direction of the first code disk based on the change in the shape of the corresponding two-dimensional bright area according to the change in brightness information.

8. The optical encoder as described in claim 6, characterized in that, The image sensor is used to determine the rotation position, rotation angle, and rotation direction of the first code disk based on the change in the center of gravity of the corresponding two-dimensional bright area according to the change in the brightness information.

9. The optical encoder as described in claim 6, characterized in that, The image sensor is used to determine the rotation position, rotation angle, and rotation direction of the first code disk based on the change in the area of ​​the corresponding two-dimensional bright surface region according to the change in the brightness information.

10. The optical encoder as claimed in claim 1, characterized in that, The image sensor is located on the side of the first code disk, and the side is not located directly above, below, in front of, or behind the first code disk.

11. The optical encoder as claimed in claim 1, characterized in that, The optical encoder further includes: a second code disk having a second spiral pattern, the center of the second code disk being located on a second rotating shaft, the second spiral pattern starting from the second rotating shaft and ending at the side of the second code disk; The image sensor is used to sense changes in the brightness information reflected by the image in the second portion of the second code disk to determine the rotation position of the second code disk, which is an absolute position.

12. The optical encoder as claimed in claim 11, characterized in that, The first axis of rotation and the second axis of rotation are located in two different three-dimensional planes.

13. The optical encoder as claimed in claim 11, characterized in that, The first rotation axis and the second rotation axis are located at different positions on the same three-dimensional plane.

14. An optical encoder, characterized in that, The optical encoder includes: A code disk having a spiral pattern, the center of which is located on a rotation axis, the spiral pattern starting from the rotation axis and ending at the side of the code disk; and An image sensor is used to sense changes in brightness information reflected from an image over a portion of the code disk to determine the rotational position of the code disk, wherein the rotational position is an absolute position.

15. An optical encoder, characterized in that, The optical encoder includes: A code disk having a spiral pattern that begins at the center of the code disk and rotates to the side of the code disk; and An image sensor is used to sense changes in brightness information reflected from an image over a portion of the code disk to determine the rotational position of the code disk, wherein the rotational position is an absolute position.

16. An optical encoder, characterized in that, The optical encoder includes: A code disk having a spiral pattern, the code disk being located on a rotating axis, the spiral pattern starting from the rotating axis and ending at the side of the code disk; and An image sensor is used to sense changes in brightness information reflected from an image over a portion of the code disk to determine the rotational position of the code disk, wherein the rotational position is an absolute position.

Images