Optical sensing assembly and encoder
By using specific design and signal processing methods of scales and sensors in optical encoders, the encoder's sensitivity to position deviation and environmental pollution are solved, and high-fine absolute position sensing and stability improvement are achieved.
Patent Information
- Application Number
- CN202410188326.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2025-08-22
AI Technical Summary
Existing optical encoders are sensitive to position deviations and are susceptible to environmental pollution under high accuracy requirements, resulting in poor signal stability.
The design is adopted that includes two pattern areas and the sensor includes four sensing areas. The phase array arrangement is used to combine four sets of incremental position signals and verb effect for signal processing to achieve high-fine absolute position sensing.
It improves the stability and environmental pollution resistance of the encoder, enhances the assembly positioning margin, and achieves high-fine absolute position sensing.
Smart Images
Figure CN120521484A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to an optical sensing component and an encoder. Background Art
[0002] With the advancement of technology, encoder technology is widely used in precision instrument control fields such as motor speed measurement and position detection. For example, absolute encoders can be used to detect the number of motor revolutions, rotation direction, and rotation position.
[0003] In the prior art, optical encoders often use Gray code or M-sequence encoding (Mcode) to obtain absolute position information. Their main architecture includes a light transmitter, a light receiver, a code disk, and processing circuitry. In reflective optical encoders, the light transmitter and light receiver are positioned on the same side of the code disk, and the desired signal output is achieved by appropriately designing the pattern on the code disk.
[0004] However, because existing encoder architectures and encoding methods are extremely sensitive to positional deviations, encoder assembly alignment requires extreme precision. Furthermore, as encoder accuracy requirements increase, the corresponding optical receiver sensing area also shrinks significantly. This results in external environmental contamination such as oil, dirt, and particulate matter seriously affecting the absolute position signal sensed.
[0005] Therefore, developing an optical sensing component and an encoder using it that is different from previous ones to improve the problems and shortcomings of the existing technology, achieve high-precision absolute position sensing, have higher tolerance to environmental pollution, and enhance the stability of the encoder, is a key issue in the current technical field. Summary of the Invention
[0006] In view of this, an object of the present disclosure is to provide an optical sensing component and an encoder using the same that can solve the above-mentioned problems.
[0007] To achieve the above objectives, according to one embodiment of the present disclosure, an optical sensing component includes a scale, a sensor, and a light source. The scale includes a first pattern area and a second pattern area. The first pattern area includes a plurality of first patterns periodically arranged in a first direction and a second direction. The second pattern area includes a plurality of second patterns periodically arranged in the first direction and the second direction. The sensor is configured to move relative to the scale in a first direction and includes a first sensing area, a second sensing area, a third sensing area, and a fourth sensing area. The first sensing area is configured to sense changes in the first pattern area in the first direction. The second sensing area is configured to sense changes in the second pattern area in the first direction. The third sensing area is configured to sense changes in the first pattern area in the second direction. The fourth sensing area is configured to sense changes in the second pattern area in the second direction. The light source is configured to emit light toward the scale.
[0008] In one or more embodiments of the present disclosure, the first patterns arranged along the first direction are gradually shifted in the second direction.
[0009] In one or more embodiments of the present disclosure, the first pattern is arranged in multiple rows. These rows have a pitch in the first direction. The first patterns in each row have another pitch in the second direction. These rows, which are spaced M times the pitch along the first direction, are progressively offset in the second direction by a distance of the other pitch. M is an integer greater than 2.
[0010] In one or more embodiments of the present disclosure, when the sensor moves a distance M times the pitch in the first direction relative to the scale, the first sensing region generates M periodic signals, and the third sensing region generates one periodic signal.
[0011] In one or more embodiments of the present disclosure, the second patterns arranged along the first direction are gradually shifted in the second direction.
[0012] In one or more embodiments of the present disclosure, the second pattern is arranged in multiple rows. These rows have a pitch in the first direction. The second patterns in each row have another pitch in the second direction. These rows, which are spaced N times the pitch along the first direction, are progressively offset in the second direction by a distance of the other pitch. N is an integer greater than 2.
[0013] In one or more embodiments of the present disclosure, when the sensor moves N times the pitch in the first direction relative to the scale, the second sensing region generates N periodic signals, and the fourth sensing region generates one periodic signal.
[0014] In one or more embodiments of the present disclosure, the sensing units of each of the first sensing region, the second sensing region, the third sensing region, and the fourth sensing region are arranged in a phased array.
[0015] To achieve the above-mentioned objectives, according to one embodiment of the present disclosure, an encoder includes an optical sensing component and a signal processing unit. The optical sensing component includes a scale and a sensor. The scale includes a first pattern area and a second pattern area. The first pattern area includes a plurality of first patterns periodically arranged in a first direction and a second direction. The second pattern area includes a plurality of second patterns periodically arranged in the first direction and the second direction. The sensor is configured to move relative to the scale in a first direction and includes a first sensing area, a second sensing area, a third sensing area, and a fourth sensing area. The first sensing area is configured to sense changes in the first pattern area in the first direction and generate a first sensing position signal accordingly. The second sensing area is configured to sense changes in the second pattern area in the first direction and generate a second sensing position signal accordingly. The third sensing area is configured to sense changes in the first pattern area in the second direction and generate a third sensing position signal accordingly. The fourth sensing area is configured to sense changes in the second pattern area in the second direction and generate a fourth sensing position signal accordingly. The signal processing unit is connected to the sensor and is configured to: calculate first sensing position information, second sensing position information, third sensing position information and fourth sensing position information from the first sensing position signal, the second sensing position signal, the third sensing position signal and the fourth sensing position signal, respectively; generate first composite position information based on the first sensing position information and the second sensing position information; generate second composite position information based on the third sensing position information and the first composite position information; generate third composite position information based on the fourth sensing position information and the first composite position information; and generate fourth composite position information based on the second composite position information and the third composite position information.
[0016] In one or more embodiments of the present disclosure, the first patterns arranged along the first direction are gradually shifted in the second direction.
[0017] In one or more embodiments of the present disclosure, the first pattern is arranged in multiple rows. These rows have a pitch in the first direction. The first patterns in each row have another pitch in the second direction. These rows, which are spaced M times the pitch along the first direction, are progressively offset in the second direction by a distance of the other pitch. M is an integer greater than 2.
[0018] In one or more embodiments of the present disclosure, when the sensor moves a distance M times the pitch in the first direction relative to the scale, the first sensing region generates M periodic signals, and the third sensing region generates one periodic signal.
[0019] In one or more embodiments of the present disclosure, the second patterns arranged along the first direction are gradually shifted in the second direction.
[0020] In one or more embodiments of the present disclosure, the second pattern is arranged in multiple rows. These rows have a pitch in the first direction. The second patterns in each row have another pitch in the second direction. These rows, which are spaced N times the pitch along the first direction, are progressively offset in the second direction by a distance of the other pitch. N is an integer greater than 2.
[0021] In one or more embodiments of the present disclosure, when the sensor moves N times the pitch in the first direction relative to the scale, the second sensing region generates N periodic signals, and the fourth sensing region generates one periodic signal.
[0022] In one or more embodiments of the present disclosure, the sensing units of each of the first sensing region, the second sensing region, the third sensing region, and the fourth sensing region are arranged in a phased array.
[0023] In one or more embodiments of the present disclosure, the signal processing unit is configured to calculate first composite position information based on a vernier effect using the first sensed position information and the second sensed position information.
[0024] In one or more embodiments of the present disclosure, the signal processing unit is configured to calculate the second composite position information based on the vernier effect using the third sensed position information and the first composite position information.
[0025] In one or more embodiments of the present disclosure, the signal processing unit is configured to calculate third composite position information based on a vernier effect using the fourth sensed position information and the first composite position information.
[0026] In one or more embodiments of the present disclosure, the signal processing unit is configured to calculate fourth synthetic position information based on the vernier effect using the second synthetic position information and the third synthetic position information.
[0027] In summary, in the optical sensing component of the present disclosure, the scale includes two pattern areas, and the sensor includes four sensing areas. Two of the sensing areas are configured to sense one of the pattern areas, while the other two sensing areas are configured to sense the other pattern area. Since the scale only includes two pattern areas, the optical sensing component only requires a smaller sensing area, thereby increasing the assembly margin of the mechanism. Moreover, the sensing units in each sensing area are arranged in a phased array, thus having higher resistance to environmental pollution and better assembly positioning margin, thereby improving the stability of the encoder. In addition, the encoding and decoding of the encoder using this optical sensing component uses four sets of incremental position signals and a vernier effect, thereby achieving high-precision absolute position sensing.
[0028] The above description is only used to illustrate the problems to be solved by the present disclosure, the technical means for solving the problems, and the effects produced, etc. The specific details of the present disclosure will be introduced in detail in the following embodiments and related drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] To make the above and other objects, features, advantages and embodiments of the present disclosure more apparent and understandable, the accompanying drawings are described as follows:
[0030] Figure 1 FIG1 is a partial perspective view of an encoder according to an embodiment of the present disclosure.
[0031] Figure 2 To illustrate Figure 1 A partial schematic diagram of the scale in .
[0032] Figure 3 To illustrate Figure 1 Schematic diagram of the sensor, light source and signal processing unit in the .
[0033] Figure 4 FIG1 is a partial schematic diagram illustrating a first pattern area of a scale according to an embodiment of the present disclosure.
[0034] Figure 5 FIG1 is a partial schematic diagram illustrating a second pattern area of a scale according to an embodiment of the present disclosure.
[0035] Figure 6 FIG1 is a partial schematic diagram illustrating a first sensing area of a sensor according to one embodiment of the present disclosure.
[0036] Figure 7 FIG1 is a partial schematic diagram illustrating a second sensing area of a sensor according to one embodiment of the present disclosure.
[0037] Figure 8 FIG1 is a partial schematic diagram illustrating a third sensing region of a sensor according to an embodiment of the present disclosure.
[0038] Figure 9 FIG. 1 is a partial schematic diagram illustrating a fourth sensing region of a sensor according to an embodiment of the present disclosure.
[0039] Figure 10 FIG1 is a schematic diagram illustrating first sensing position signals obtained by sensing the first pattern area using the first sensing area and the third sensing area respectively.
[0040] Figure 11 FIG2 is a schematic diagram illustrating first sensing position information and third sensing position information calculated from the first sensing position signal and the third sensing position signal respectively.
[0041] Figure 12Schematic diagram illustrating a second sensing position signal and a fourth sensing position signal obtained by sensing the second pattern area using the second sensing area and the fourth sensing area respectively.
[0042] Figure 13 FIG2 is a schematic diagram illustrating second sensing position information and fourth sensing position information calculated from the second sensing position signal and the fourth sensing position signal respectively.
[0043] Figure 14A is a schematic diagram illustrating a 16-cycle signal.
[0044] Figure 14B is a schematic diagram showing a 15-cycle signal.
[0045] Figure 14C FIG. 4 is a schematic diagram illustrating a difference signal between a 16-cycle signal and a 15-cycle signal. FIG.
[0046] Figure 14D To display the data in unsigned 10-bit format Figure 14C Schematic diagram of the difference signal in .
[0047] Figure 15 FIG2 is a schematic diagram illustrating a method for detecting a position of an encoder according to an embodiment of the present disclosure for obtaining position information.
[0048] The description of the accompanying drawings is as follows:
[0049] 100: Encoder
[0050] 110: Optical sensing components
[0051] 111: Ruler
[0052] 111a: First pattern area
[0053] 111b: Second pattern area
[0054] 112: Sensor
[0055] 112a: First sensing area
[0056] A1+, A1-, B1+, B1-, A2+, A2-, B2+, B2-, A3+, A3-, B3+, B3-, A4+, A4-, B4+, B4-: Sensing unit
[0057] 112b: Second sensing area
[0058] 112c: Third sensing area
[0059] 112d: Fourth sensing zone
[0060] 113: Light Source
[0061] 120: Signal processing unit
[0062] a: first position
[0063] b: Second position
[0064] c: third position
[0065] d: fourth position
[0066] C1, C2: Row
[0067] D1: First direction
[0068] D2: Second direction
[0069] G1: First pattern
[0070] G2: Second pattern
[0071] P1: First pitch
[0072] P1', P2': Pitch
[0073] P2: Second pitch
[0074] P3: third pitch
[0075] P4: fourth pitch
[0076] SA1+, SA1-, SB1+, SB1-: First sensing position signal
[0077] SA2+, SA2-, SB2+, SB2-: Second sensing position signal
[0078] SA3+, SA3-, SB3+, SB3-: Third sensing position signal
[0079] SA4+, SA4-, SB4+, SB4-: Fourth sensing position signal DETAILED DESCRIPTION
[0080] The following diagrams illustrate various embodiments of the present disclosure. For clarity, many practical details will be included in the following description. However, it should be understood that these practical details are not intended to limit the present disclosure. In other words, these practical details are not essential to some embodiments of the present disclosure. Furthermore, to simplify the diagrams, some conventional structures and components are depicted in a simplified schematic manner.
[0081] Please refer to Figure 1 , which is a partial stereoscopic diagram illustrating an encoder 100 according to an embodiment of the present disclosure. Figure 1As shown, in this embodiment, the encoder 100 includes an optical sensing assembly 110. The optical sensing assembly 110 includes a scale 111, a sensor 112, and a light source 113. The scale 111 and the sensor 112 are disposed opposite each other and are capable of relative displacement. For example, the scale 111 can move linearly or rotate relative to the sensor 112. The light source 113 is disposed on the side of the sensor 112 facing the scale 111 and is configured to emit light toward the scale 111. The sensor 112 is configured to receive and sense light reflected from the scale 111.
[0082] Please refer to Figure 2 as well as Figure 3 . Figure 2 To illustrate Figure 1 A partial schematic diagram of the scale 111 in FIG. Figure 3 To illustrate Figure 1 Schematic diagram of the sensor 112, light source 113 and signal processing unit 120. Figure 2 and Figure 3 As shown, in this embodiment, the scale 111 includes a first pattern area 111a and a second pattern area 111b. The first pattern area 111a and the second pattern area 111b extend in a first direction D1 and are aligned in a second direction D2. The first direction D1 and the second direction D2 are perpendicular to each other. The sensor 112 is configured to move relative to the scale 111 in the first direction D1 and includes a first sensing area 112a, a second sensing area 112b, a third sensing area 112c, and a fourth sensing area 112d. The first sensing area 112a is configured to sense changes in the first pattern area 111a in the first direction D1. The second sensing area 112b is configured to sense changes in the second pattern area 111b in the first direction D1. The third sensing area 112c is configured to sense changes in the first pattern area 111a in the second direction D2. The fourth sensing area 112d is configured to sense changes in the second pattern area 111b in the second direction D2.
[0083] In some embodiments where the encoder 100 is linear, the first direction D1 is the X direction, and the second direction D2 is the Y direction. In some embodiments where the encoder 100 is rotary, the first direction D1 is the circumferential (θ) direction, and the second direction D2 is the radial (R) direction.
[0084] Please refer to Figure 4 , which is a partial schematic diagram illustrating the first pattern area 111a of the scale 111 according to one embodiment of the present disclosure. Figure 4As shown, in this embodiment, the first pattern region 111a of the scale 111 includes a plurality of first patterns G1 periodically arranged in the first direction D1 and the second direction D2. Specifically, the first patterns G1 are arranged in a plurality of rows C1. These rows C1 have a first pitch P1 in the first direction D1. The first patterns G1 in each row C1 have a different pitch P1' in the second direction D2. In other words, the first patterns G1 in the first pattern region 111a form a two-dimensional pattern.
[0085] In this embodiment, each first pattern G1 is square in shape, but the present disclosure is not limited thereto. In some embodiments, the scale 111 employs a reflective structure, in which case the first pattern G1 is a highly reflective region, while the region outside the first pattern G1 is a low-reflective region. In some embodiments, the scale 111 employs a transmissive structure, in which case the first pattern G1 is a highly transparent region, while the region outside the first pattern G1 is a low-transmittance region.
[0086] Specifically, the first patterns G1 arranged along the first direction D1 are gradually offset in the second direction D2. Figure 4 As shown, these rows C1, which travel a distance M times the first pitch P1 along the first direction D1, are progressively offset by a pitch P1' in the second direction D2. M is an integer greater than 2. In other words, each first pattern G1 has a third pitch P3 in the first direction D1, and the third pitch P3 is M times the first pitch P1. Correspondingly, when the sensor 112 moves a distance M times the first pitch P1 in the first direction D1 relative to the scale 111, the first sensing region 112a generates M periodic signals, and the third sensing region 112c generates one periodic signal.
[0087] In some embodiments, M is an integer greater than 2. For example, Figure 4 As shown, M is 12 (ie, the rows C1 that pass a distance 12 times the first pitch P1 along the first direction D1 are gradually shifted by a distance of one pitch P1 ′ in the second direction D2 ), but the present disclosure is not limited thereto.
[0088] Please refer to Figure 5 , which is a partial schematic diagram illustrating the second pattern area 111b of the scale 111 according to one embodiment of the present disclosure. Figure 5 As shown, in this embodiment, the second pattern region 111b of the scale 111 includes a plurality of second patterns G2 periodically arranged in the first direction D1 and the second direction D2. Specifically, the second patterns G2 are arranged in a plurality of rows C2. These rows C2 have a second pitch P2 in the first direction D1. The second patterns G2 in each row C2 have another pitch P2' in the second direction D2. In other words, the second patterns G2 in the second pattern region 111b form a two-dimensional pattern.
[0089] In this embodiment, each second pattern G2 is square in shape, but the present disclosure is not limited thereto. In some embodiments, if the scale 111 employs a reflective structure, the second pattern G2 is a highly reflective region, while the area outside the second pattern G2 is a low-reflective region. In some embodiments, if the scale 111 employs a transmissive structure, the second pattern G2 is a highly transparent region, while the area outside the second pattern G2 is a low-transmittance region.
[0090] Specifically, the second patterns G2 arranged along the first direction D1 are gradually offset in the second direction D2. Figure 5 As shown, these rows C2, which travel N times the second pitch P2 along the first direction D1, are progressively offset by a pitch P2' in the second direction D2. N is an integer greater than 2. In other words, each second pattern G2 has a fourth pitch P4 in the first direction D1, and the fourth pitch P4 is N times the second pitch P2. Correspondingly, when the sensor 112 moves a distance N times the second pitch P2 in the first direction D1 relative to the scale 111, the second sensing region 112b generates N periodic signals, and the fourth sensing region 112d generates one periodic signal.
[0091] With the aforementioned structural configuration, while the sensor 112 and scale 111 are moving relative to each other in the first direction D1, the sensor 112 can simultaneously sense the first pattern region 111a using the first sensing region 112a and the third sensing region 112c, and simultaneously sense the second pattern region 111b using the second sensing region 112b and the fourth sensing region 112d. Because the scale 111 only includes two pattern regions, the optical sensor assembly 110 requires a smaller sensing area, thereby increasing the assembly margin of the mechanism.
[0092] In some embodiments, N is an integer greater than 2. For example, Figure 5 As shown, N is 12 (ie, the rows C2 that pass a distance 12 times the second pitch P2 along the first direction D1 are gradually shifted by a distance of one pitch P2 ′ in the second direction D2 ), but the disclosure is not limited thereto.
[0093] Please refer to Figure 6 、 Figure 7 、 Figure 8 as well as Figure 9 . Figure 6 FIG. 1 is a partial schematic diagram illustrating a first sensing region 112 a of a sensor 112 according to one embodiment of the present disclosure. Figure 7 FIG. 1 is a partial schematic diagram illustrating the second sensing region 112 b of the sensor 112 according to one embodiment of the present disclosure. Figure 8FIG. 1 is a partial schematic diagram illustrating the third sensing region 112 c of the sensor 112 according to one embodiment of the present disclosure. Figure 9 FIG. 1 is a partial schematic diagram illustrating the fourth sensing area 112d of the sensor 112 according to one embodiment of the present disclosure. Figures 6 to 9 As shown, the first sensing region 112a includes a plurality of sensing units A1+, B1+, A1-, and B1- arranged in a phased array. The second sensing region 112b includes a plurality of sensing units A2+, B2+, A2-, and B2- arranged in a phased array. The third sensing region 112c includes a plurality of sensing units A3+, B3+, A3-, and B3- arranged in a phased array. The fourth sensing region 112d includes a plurality of sensing units A4+, B4+, A4-, and B4- arranged in a phased array. Specifically, the sensing units A1+, B1+, A1-, and B1- of the first sensing region 112a are arranged in a periodic phased array in a first direction D1, i.e., the arrangement of sensing units A1+, B1+, A1-, and B1- is repeated in an alternating manner for multiple periods. The sensing cells A2+, B2+, A2-, and B2- in the second sensing region 112b are arranged in a periodic phased array along the first direction D1, i.e., the arrangement of sensing cells A2+, B2+, A2-, and B2- is repeated in an alternating pattern. The sensing cells A3+, B3+, A3-, and B3- in the third sensing region 112c are arranged in a periodic phased array along the second direction D2, i.e., the arrangement of sensing cells A3+, B3+, A3-, and B3- is repeated in an alternating pattern. The sensing cells A4+, B4+, A4-, and B4- in the fourth sensing region 112d are arranged in a periodic phased array along the second direction D2, i.e., the arrangement of sensing cells A4+, B4+, A4-, and B4- is repeated in an alternating pattern. By adopting a phased array arrangement, the first sensing area 112 a , the second sensing area 112 b , the third sensing area 112 c and the fourth sensing area 112 d can have higher environmental pollution resistance and better assembly positioning margin, thereby improving the stability of the encoder 100 .
[0094] Please refer to Figure 10 , which is a schematic diagram illustrating the first sensing position signal and the third sensing position signal obtained by sensing the first pattern area 111a using the first sensing area 112a and the third sensing area 112c respectively. Figure 10As shown, in this embodiment, after sensing changes in the first pattern region 111a in the first direction D1, the first sensing region 112a generates a first sensing position signal. Specifically, the sensing units A1+, B1+, A1-, and B1- in the first sensing region 112a generate first sensing position signals SA1+, SB1+, SA1-, and SB1-, respectively. After sensing changes in the first pattern region 111a in the second direction D2, the third sensing region 112c generates a third sensing position signal. Specifically, the sensing units A3+, B3+, A3-, and B3- in the third sensing region 112c generate third sensing position signals SA3+, SB3+, SA3-, and SB3-, respectively.
[0095] like Figure 3 As shown, in this embodiment, the encoder 100 further includes a signal processing unit 120 (indicated by a dotted line). The signal processing unit 120 is connected to the sensor 112 and is configured to process the first sensing position signals SA1+, SB1+, SA1-, and SB1- generated by the first sensing area 112a and the third sensing position signals SA3+, SB3+, SA3-, and SB3- generated by the third sensing area 112c. In this embodiment, the signal processing unit 120 is integrated with the sensor 112, but the present disclosure is not limited to this. In actual applications, the signal processing unit 120 and the sensor 112 may be non-integrated and connected via additional components.
[0096] Please refer to Figure 11 , which is a schematic diagram illustrating the first sensing position information and the third sensing position information calculated from the first sensing position signal and the third sensing position signal respectively. In this embodiment, the signal processing unit 120 is configured to calculate the first sensing position signal SA1+, SB1+, SA1-, SB1- (such as Figure 10 As shown) calculate the first sensing position information (as shown Figure 11 As shown). For example, the first sensing position information can be calculated by an inverse tangent function (ie, ATAN function). The first sensing position information also has a first pitch P1. In addition, the signal processing unit 120 is further configured to receive the third sensing position signals SA3+, SB3+, SA3-, SB3- (as shown). Figure 10 ) calculate the third sensing position information (as shown) Figure 11 For example, the third sensing position information can be calculated using an inverse tangent function. The third sensing position information also has a third pitch P3.
[0097] Please refer to Figure 12 , is a schematic diagram illustrating a second sensing position signal and a fourth sensing position signal obtained by sensing the second pattern area 111b using the second sensing area 112b and the fourth sensing area 112d respectively. Figure 12 As shown, in this embodiment, after sensing the change of the second pattern region 111b in the first direction D1, the second sensing region 112b generates second sensing position signals SA2+, SB2+, SA2-, and SB2-, respectively. After sensing the change of the second pattern region 111b in the second direction D2, the fourth sensing region 112d generates fourth sensing position signals SA4+, SB4+, SA4-, and SB4-, respectively.
[0098] Please refer to Figure 13 , which is a schematic diagram illustrating the second sensing position information and the fourth sensing position information calculated from the second sensing position signal and the fourth sensing position signal, respectively. In this embodiment, the signal processing unit 120 is further configured to calculate the second sensing position signals SA2+, SB2+, SA2-, SB2- (such as Figure 12 As shown) calculate the second sensing position information (as shown Figure 13 As shown). For example, the second sensing position information can be calculated by an inverse tangent function. The second sensing position information also has a second pitch P2. In addition, the signal processing unit 120 is further configured to receive the fourth sensing position signals SA4+, SB4+, SA4-, SB4- (as shown). Figure 12 ) calculate the fourth sensing position information (as shown) Figure 13 For example, the fourth sensing position information can be calculated using an inverse tangent function. The fourth sensing position information also has a fourth pitch P4.
[0099] In this embodiment, the signal processing unit 120 is further configured to generate first composite position information based on the first sensing position information and the second sensing position information, generate second composite position information based on the third sensing position information and the first composite position information, generate third composite position information based on the fourth sensing position information and the first composite position information, and generate fourth composite position information based on the second composite position information and the third composite position information. Specifically, the signal processing unit 120 is configured to calculate the first composite position information based on the Vernier effect using the first sensing position information and the second sensing position information. The signal processing unit 120 is further configured to calculate the second composite position information based on the Vernier effect using the third sensing position information and the first composite position information. The signal processing unit 120 is further configured to calculate the third composite position information based on the Vernier effect using the fourth sensing position information and the first composite position information. The signal processing unit 120 is further configured to calculate the fourth composite position information based on the Vernier effect using the second composite position information and the third composite position information. The principle of the Vernier effect is briefly described as follows.
[0100] Please refer to Figure 14A 、 Figure 14B 、 Figure 14C as well as Figure 14D . Figure 14A is a schematic diagram illustrating a 16-cycle signal. Figure 14B is a schematic diagram showing a 15-cycle signal. Figure 14C FIG. 4 is a schematic diagram illustrating a difference signal between a 16-cycle signal and a 15-cycle signal. FIG. Figure 14D To display the data in unsigned 10-bit format Figure 14C Schematic diagram of the difference signal in . 14A to 14D As shown, Figure 14A The 16-cycle signal in Figure 14B After subtracting the 15-cycle signal in, we can get Figure 14C Further, Figure 14C The difference signal in is converted into unsigned 10-bit data form to obtain Figure 14D A single cycle signal is shown.
[0101] In some embodiments where the encoder 100 is linear, N is equal to M+1. The first composite position information has a first composite pitch PS1. The second pitch P2 of the second sensed position information is (M-1) / M times the first pitch P1 of the first sensed position information, such that the first composite pitch PS1 is (M-1) times the first pitch P1 or M times the second pitch P2. M is an integer greater than 2.
[0102] In some embodiments where the encoder 100 is linear, the second composite position information has a second composite pitch PS2. The first composite pitch PS1 is (M-1) / M times the third pitch P3, such that the second composite pitch PS2 is (M-1) times the third pitch P3 or M times the first composite pitch PS1. N is an integer greater than 2.
[0103] In some embodiments where the encoder 100 is linear, the third composite position information has a third composite pitch PS3. The first composite pitch PS1 is M / (M+1) times the fourth pitch P4, such that the third composite pitch PS3 is M times the fourth pitch P4 or (M+1) times the first composite pitch PS1. M is an integer greater than 2.
[0104] In some embodiments where the encoder 100 is linear, the fourth composite position information has a fourth composite pitch PS4. The third composite pitch PS3 is (M+1) / M times the second composite pitch PS2, such that the fourth composite pitch PS4 is (M+1) times the second composite pitch PS2 or M times the third composite pitch PS3. M is an integer greater than 2.
[0105] For example, under the conditions that M is 32, the first pitch P1 is 64 μm, the second pitch P2 is 62 μm, the third pitch P3 is 2,048 μm and the fourth pitch P4 is 2,046 μm, the signal processing unit 120 can generate first synthetic position information of the first synthetic pitch PS1 being 1,984 μm, second synthetic position information of the second synthetic pitch PS2 being 63,488 μm, third synthetic position information of the third synthetic pitch PS3 being 65,472 μm and fourth synthetic position information of the fourth synthetic pitch PS4 being 2,095,104 μm.
[0106] For example, under the conditions that M is 64, the first pitch P1 is 64μm, the second pitch P2 is 63μm, the third pitch P3 is 4,096μm and the fourth pitch P4 is 4,095μm, the signal processing unit 120 can generate first synthetic position information that the first synthetic pitch PS1 is 4,032μm, second synthetic position information that the second synthetic pitch PS2 is 258,048μm, third synthetic position information that the third synthetic pitch PS3 is 262,080μm and fourth synthetic position information that the fourth synthetic pitch PS4 is 16,773,120μm.
[0107] It should be noted that the fourth synthesized position information parsed by the signal processing unit 120 can be used as preliminary absolute position information. The second or third synthesized position information parsed by the signal processing unit 120 can be used as low-precision position information. The third sensed position information, the fourth sensed position information, or the first synthesized position information parsed by the signal processing unit 120 can be used as medium-precision position information. The first or second sensed position information can be used as high-precision position information.
[0108] Please refer to Figure 5 , which is a schematic diagram illustrating a method for obtaining position information using a position detection method of an encoder 100 according to an embodiment of the present disclosure. Figure 5As shown, in this embodiment, the signal processing unit 120 is further configured to parse the first position a from the fourth synthetic position information (i.e., preliminary absolute position information). The signal processing unit 120 is further configured to map the first position a to the second synthetic position information or the third synthetic position information (i.e., low-precision position information) and parse out the second position b, which is shown as the second cycle number position. The signal processing unit 120 is further configured to map the second position b to the third sensed position information, the fourth sensed position information, or the first synthetic position information (i.e., medium-precision position information) and parse out the third position c, which is shown as the fifth cycle number position. The signal processing unit 120 is further configured to map the third position c to the first sensed position information or the second sensed position information (i.e., high-precision position information) and parse out the fourth position d, where the fourth position d is a high-precision absolute position. This progressive position resolution process maps a low-precision incremental position from a preliminary absolute position, then maps a medium-precision incremental position from the low-precision incremental position, and finally maps a high-precision incremental position from the medium-precision incremental position. The resulting position information is the high-precision absolute position. Thus, the encoder 100 of this embodiment can achieve high-precision absolute position sensing.
[0109] From the above detailed description of the specific embodiments of the present disclosure, it can be clearly seen that in the optical sensing component of the present disclosure, the scale includes two pattern areas, and the sensor includes four sensing areas. Two of the sensing areas are configured to sense one of the pattern areas, and the other two sensing areas are configured to sense the other pattern area. Since the scale only includes two pattern areas, the optical sensing component only requires a smaller sensing area, thereby increasing the assembly margin of the mechanism. In addition, the sensing units of each sensing area are arranged in a phase array, so they have higher resistance to environmental pollution and better assembly positioning margin, thereby improving the stability of the encoder. In addition, the encoding and decoding of the encoder using this optical sensing component use four sets of incremental position signals and a vernier effect, so that high-precision absolute position sensing can be achieved.
[0110] Although the present disclosure has been disclosed in the form of an embodiment as described above, it is not intended to limit the present disclosure. Anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.
Claims
1. An optical sensing component, comprising: A scale, including: a first pattern region comprising a plurality of first patterns periodically arranged in a first direction and a second direction; and a second pattern region comprising a plurality of second patterns periodically arranged in the first direction and the second direction; a sensor configured to move relative to the scale in the first direction, and comprising: a first sensing region configured to sense changes of the first pattern region in the first direction; a second sensing area configured to sense changes of the second pattern area in the first direction; a third sensing region configured to sense changes of the first pattern region in the second direction; as well as a fourth sensing region configured to sense changes of the second pattern region in the second direction; and A light source is configured to emit light toward the scale. 2 . The optical sensing component as claimed in claim 1 , wherein the plurality of first patterns arranged along the first direction are gradually offset in the second direction.
3. The optical sensing component as described in claim 2, wherein the plurality of first patterns are arranged into a plurality of rows, the plurality of rows having a pitch in the first direction, the plurality of first patterns in each row having another pitch in the second direction, and the plurality of rows passing a distance M times the pitch along the first direction are progressively offset in the second direction by a distance of the another pitch, wherein M is an integer greater than 2. 4 . The optical sensing component as claimed in claim 3 , wherein when the sensor moves a distance M times the pitch in the first direction relative to the scale, the first sensing region generates M periodic signals, and the third sensing region generates one periodic signal. 5 . The optical sensing component as claimed in claim 1 , wherein the plurality of second patterns arranged along the first direction are gradually offset in the second direction.
6. The optical sensing component as described in claim 5, wherein the plurality of second patterns are arranged into a plurality of rows, the plurality of rows having a pitch in the first direction, the plurality of second patterns in each row having another pitch in the second direction, and the plurality of rows passing a distance N times the pitch along the first direction are progressively offset in the second direction by a distance of the another pitch, wherein N is an integer greater than 2. 7 . The optical sensing component of claim 6 , wherein when the sensor moves a distance N times the pitch in the first direction relative to the scale, the second sensing region generates N periodic signals, and the fourth sensing region generates one periodic signal. 8 . The optical sensing component as claimed in claim 1 , wherein the sensing units of each of the first sensing region, the second sensing region, the third sensing region, and the fourth sensing region are arranged in a phase array.
9. An encoder comprising: An optical sensing component, comprising: A ruler, including: a first pattern region comprising a plurality of first patterns periodically arranged in a first direction and a second direction; and a second pattern region comprising a plurality of second patterns periodically arranged in the first direction and the second direction; as well as a sensor configured to move relative to the scale in the first direction, and comprising: a first sensing region configured to sense a change of the first pattern region in the first direction and generate a first sensing position signal accordingly; a second sensing region configured to sense a change of the second pattern region in the first direction and generate a second sensing position signal accordingly; a third sensing region configured to sense a change of the first pattern region in the second direction and generate a third sensing position signal accordingly; as well as a fourth sensing region configured to sense a change of the second pattern region in the second direction and generate a fourth sensing position signal accordingly; as well as a signal processing unit connected to the sensor and configured to: Calculating first sensing position information, second sensing position information, third sensing position information, and fourth sensing position information from the first sensing position signal, the second sensing position signal, the third sensing position signal, and the fourth sensing position signal, respectively; generating first composite position information according to the first sensed position information and the second sensed position information; generating second composite position information according to the third sensed position information and the first composite position information; generating third composite position information according to the fourth sensed position information and the first composite position information; as well as A fourth composite position information is generated according to the second composite position information and the third composite position information. 10 . The encoder of claim 9 , wherein the plurality of first patterns arranged along the first direction are gradually shifted in the second direction.
11. An encoder as described in claim 10, wherein the multiple first patterns are arranged into multiple rows, the multiple rows have a pitch in the first direction, the multiple first patterns in each row have another pitch in the second direction, and the multiple rows that pass a distance M times the pitch along the first direction are progressively offset by a distance of the other pitch in the second direction, wherein M is an integer greater than 2. 12 . The encoder of claim 11 , wherein when the sensor moves a distance M times the pitch in the first direction relative to the scale, the first sensing region generates M periodic signals, and the third sensing region generates one periodic signal.
13. The encoder of claim 9, wherein the plurality of second patterns arranged along the first direction are gradually shifted in the second direction.
14. An encoder as described in claim 13, wherein the multiple second patterns are arranged into multiple rows, the multiple rows have a pitch in the first direction, the multiple second patterns in each row have another pitch in the second direction, and the multiple rows that pass a distance N times the pitch along the first direction are progressively offset by a distance of the other pitch in the second direction, wherein N is an integer greater than 2. 15 . The encoder of claim 14 , wherein when the sensor moves a distance N times the pitch in the first direction relative to the scale, the second sensing region generates N periodic signals, and the fourth sensing region generates one periodic signal. 16 . The encoder as claimed in claim 9 , wherein the sensing units of each of the first sensing area, the second sensing area, the third sensing area, and the fourth sensing area are arranged in a phase array. 17 . The encoder of claim 9 , wherein the signal processing unit is configured to calculate the first synthesized position information based on a vernier effect using the first sensed position information and the second sensed position information. 18 . The encoder of claim 9 , wherein the signal processing unit is configured to calculate the second synthetic position information based on a vernier effect using the third sensed position information and the first synthetic position information. 19 . The encoder of claim 9 , wherein the signal processing unit is configured to calculate the third synthetic position information based on a vernier effect using the fourth sensed position information and the first synthetic position information. 20 . The encoder of claim 9 , wherein the signal processing unit is configured to calculate the fourth synthesized position information based on a vernier effect using the second synthesized position information and the third synthesized position information.