Photoelectric encoder

Abstract

A photoelectric encoder relates to the technical field of encoders. The photoelectric encoder comprises an encoding part and a code reading part, the encoding part is arranged on a to-be-tested piece, and the encoding part comprises a plurality of light-transmitting areas and a plurality of light-proof areas which are alternately arranged in sequence; the code reading part comprises a photoelectric detector and at least one pulse light source, when the to-be-detected piece moves in the preset direction to drive the coding part to move, light emitted by the pulse light source can pass through a light-transmitting area and a light-proof area on the coding part, and the light passing through the light-transmitting area is received by the photoelectric detector and converted into photoelectric charges to be stored; the photoelectric encoder further comprises a signal processing circuit which is connected with the photoelectric detector. The signal processing circuit can output the photoelectric charges stored in the photoelectric detector within the light emitting interval of the pulse light source. According to the photoelectric encoder, the measurement precision and the measurement efficiency can be ensured in each measurement period, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of encoders, and in particular to a photoelectric encoder. Background Art

[0002] An encoder is a device that converts physical quantities such as displacement and angle into digital signals or electrical signals. It is widely used in many fields such as automation control, robotics, CNC machine tools, motor control, etc., and can measure the relative displacement of objects such as displacement and rotation angle.

[0003] The encoder is mainly composed of a code disk or a yardstick, a light source and a photodetector. The light emitted by the light source can illuminate the code disk or yardstick. After the light pattern changes, the photodetector receives the changed light signal and converts it into an electrical signal. However, the light source of the existing encoder usually emits light continuously throughout the entire measuring device. If the measurement time is long, the signal of the code reader will change within the measurement time, thereby generating errors and reducing the measurement accuracy. In order to reduce the error, in high-precision encoders, many detector pixels are often used to read the signal, resulting in a long decoding time and reduced measurement efficiency. In addition, if there are too many detector pixels, multiple parallel processing channels need to be set up, which leads to complex circuit settings and high costs. Summary of the invention

[0004] The object of the present invention is to provide a photoelectric device which can ensure the measurement accuracy and measurement efficiency in each measurement cycle.

[0005] The embodiment of the present invention is achieved as follows:

[0006] In one aspect of the present invention, a photoelectric encoder is provided, comprising an encoding part and a code reading part, wherein the encoding part is arranged on a piece to be tested, and the encoding part comprises a plurality of light-transmitting areas and a plurality of light-impermeable areas which are alternately arranged in sequence; the code reading part comprises a photodetector and at least one pulse light source, and when the piece to be tested moves along a preset direction to drive the encoding part to move, the light emitted by the pulse light source can pass through the light-transmitting areas and the light-impermeable areas on the encoding part, and the light passing through the light-transmitting areas is received by the photodetector and converted into photoelectric charge storage; the photoelectric encoder also comprises a signal processing circuit, which is connected to the photodetector; the signal processing circuit can output the photoelectric charge stored in the photodetector within the light-emitting interval of the pulse light source.

[0007] Optionally, the number of pulse light sources is at least one; when the number of pulse light sources is multiple, the multiple pulse light sources are evenly spaced along the movement direction of the test piece, and the arrangement period of the multiple pulse light sources is equal to the arrangement period of the multiple light-transmitting areas and the multiple light-opaque areas of the encoding part; the multiple pulse light sources emit light to generate multiple measurement signals respectively.

[0008] Optionally, the number of pulse light sources is at least one; when the number of pulse light sources is multiple, the multiple pulse light sources are evenly spaced along the movement direction of the test piece, and the arrangement period of the multiple pulse light sources differs from the arrangement period of the multiple light-transmitting areas and the multiple light-opaque areas of the encoding part by an integer number of periods.

[0009] Optionally, the photoelectric encoder further includes a control unit, which is connected to the pulse light source and can adjust the pulse period of the pulse light source according to a preset signal.

[0010] Optionally, the encoding portion includes a code disk, and a plurality of light-transmitting areas and a plurality of light-impermeable areas are alternately arranged in sequence along a displacement direction of the code disk.

[0011] Optionally, the encoding portion includes a code scale, and a plurality of light-transmitting areas and a plurality of light-impermeable areas are alternately arranged in sequence along a displacement direction of the code scale.

[0012] Optionally, the pulse light source and the photodetector are arranged opposite to each other, the encoding part is arranged between the pulse light source and the photodetector at intervals, and the light emitted by the pulse light source is transmitted through the light-transmitting area and then received by the photodetector.

[0013] Optionally, a change in light transmittance of the light-transmitting area is less than 10%.

[0014] Optionally, the pulse light source and the photoelectric detector are arranged at intervals and are both located on a side of the encoding portion away from the device under test, and the light emitted by the pulse light source is reflected by the light-transmitting area and then received by the photoelectric detector.

[0015] Optionally, the light reflectivity of the light-transmitting area varies by less than 10%.

[0016] Optionally, the photoelectric encoder further comprises a time synchronization device, one end of which is connected to the signal processing circuit and the other end of which is connected to an external device, and the external device can synchronize time with the signal processing circuit via the time synchronization device.

[0017] The beneficial effects of the present invention include:

[0018] The present application provides a photoelectric encoder, comprising an encoding part and a code reading part, wherein the encoding part is arranged on a piece to be tested, so that the encoding part can accurately reflect the motion state of the piece to be tested; the encoding part comprises a plurality of light-transmitting areas and a plurality of light-opaque areas which are alternately arranged in sequence, so that the encoding part can convert the position or motion information of the piece to be tested into a light signal; the code reading part comprises a photodetector and at least one pulse light source, and when the piece to be tested moves along a preset direction to drive the encoding part to move, the light emitted by the pulse light source can pass through the light-transmitting areas and the light-opaque areas on the encoding part, and the light passing through the light-transmitting areas is received by the photodetector and converted into photocharge storage; the photoelectric encoder also comprises a signal processing circuit, which is connected to the photodetector; the signal processing circuit can output the photocharge stored in the photodetector within the light-emitting interval of the pulse light source. Since the pulse light source emits light at intervals, compared to the light source with continuous light emission in the prior art, the present application divides each light emission into a measurement cycle through the pulse light source, and receives and converts the photocharge of each measurement cycle through the photodetector, thereby greatly improving the measurement accuracy and reducing the measurement error; at the same time, since the pulse time is very short, the error caused by the movement between the encoding part and the code reading part during the time when the photodetector reads the signal can be ignored, so a higher measurement accuracy can be obtained, and a greater displacement speed is allowed. The above-mentioned photoelectric encoder can ensure measurement accuracy and measurement efficiency in each measurement cycle, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 One of the structural schematic diagrams of the photoelectric encoder provided by an embodiment of the present invention;

[0021] Figure 2 The second structural diagram of the photoelectric encoder provided by the embodiment of the present invention;

[0022] Figure 3 The third structural schematic diagram of the photoelectric encoder provided in an embodiment of the present invention.

[0023] Icon: 100 - photoelectric encoder; 110 - encoding part; 111 - light-transmitting area; 112 - opaque area; 120 - code reading part; 121 - pulse light source; 122 - photoelectric detector; 130 - collimating lens. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Please refer to Figure 1 and Figure 2The present embodiment provides a photoelectric encoder 100, including an encoding part 110 and a code reading part 120. The encoding part 110 is arranged on a device to be tested, and the encoding part 110 includes a plurality of light-transmitting areas 111 and a plurality of light-impermeable areas 112 that are alternately arranged in sequence; the code reading part 120 includes a photodetector 122 and at least one pulse light source 121. When the device to be tested moves along a preset direction to drive the encoding part 110 to move, the light emitted by the pulse light source 121 can pass through the light-transmitting area 111 and the light-impermeable area 112 on the encoding part 110, and the light passing through the light-transmitting area 111 is received by the photodetector 122 and converted into photoelectric charge storage.

[0031] Specifically, the photoelectric encoder 100 includes an encoding unit 110 and a code reading unit 120. The encoding unit 110 is disposed on the object to be tested, and when the object to be tested moves in a preset direction, the encoding unit 110 moves synchronously therewith. In a specific embodiment of the present application, the object to be tested is a rotating shaft of a motor, and the encoding unit 110 is mounted on the rotating shaft. Therefore, every time the motor shaft rotates, the encoding unit 110 can instantly sense and synchronously make corresponding position changes.

[0032] like Figure 1 and Figure 2 As shown, the encoding part 110 includes a plurality of light-transmitting areas 111 and a plurality of light-impermeable areas 112 arranged alternately in sequence, wherein the light-transmitting areas 111 may be in the shape of a sector, a rectangle or a trapezoid, etc. As the encoding part 110 follows the movement of the DUT, the alternating changes of the light-transmitting and light-impermeable areas 112 form a series of light signals with specific rules. These light signals can be recognized by the code reading part 120 and then converted into corresponding electrical signals, ultimately realizing the accurate encoding and measurement of the moving position, speed and other information of the DUT.

[0033] The code reading unit 120 is composed of a photodetector 122 and at least one pulse light source 121. When the piece under test moves along a preset direction and drives the encoding unit 110 to move, the pulse light source 121 emits light at a set frequency, and the light passes through the light-transmitting areas 111 and the light-impermeable areas 112 alternately arranged on the encoding unit 110 in sequence.

[0034] The light emission time of the pulse light source 121 is less than 100% duty cycle, so that the pulse light source 121 emits light at intervals, and each time the light is emitted, the light can be irradiated on the encoding unit 110 to form an optical signal, and is received by the photodetector 122, thereby forming a measurement cycle. Optionally, the pulse light emission time can be controlled to be less than 1us.

[0035] Since the pulse time is very short and the error caused by the movement between the encoding part 110 and the code reading part 120 during the time when the photodetector 122 reads the signal is negligible, a higher measurement accuracy can be obtained and a greater displacement speed is allowed.

[0036] The number of pulse light sources 121 is at least one, and when the number of pulse light sources 121 is multiple, the multiple pulse light sources 121 are evenly spaced along the moving direction of the test piece. Through such a setting, it is possible to emit light from different positions to the encoding part 110, and by comprehensively processing the signals received by the pulse light sources 121 at different positions, it is possible to more accurately obtain the position and rotation angle information of the code disk.

[0037] Among them, in a specific embodiment of the present application, when the number of pulse light sources 121 is multiple, the multiple pulse light sources 121 are evenly spaced along the movement direction of the piece to be tested, and the arrangement period of the multiple pulse light sources 121 is equal to the arrangement period of the multiple light-transmitting areas 111 and the multiple light-impermeable areas 112 of the encoding part 110; the multiple pulse light sources 121 emit light to generate multiple measurement signals, which are used for redundant backup or measuring the signals of multiple code channels, ensuring that the signals of each pulse light source 121 do not interfere with each other; in another specific embodiment of the present application, the multiple pulse light sources 121 are evenly spaced along the movement direction of the piece to be tested, and the arrangement period of the multiple pulse light sources 121 is different from the arrangement period of the multiple light-transmitting areas 111 and the multiple light-impermeable areas 112 of the encoding part 110 by an integer number of periods, thereby ensuring that phase interference will not be caused after the signals are superimposed, thereby ensuring the measurement accuracy.

[0038] The photodetector 122 includes a plurality of pixels. The light signal received by the photodetector 122 accumulates photocharges in each pixel of the detector array. The average displacement of the DUT during the light emission of the pulse light source 121 is determined based on the signal difference read out from the plurality of pixels of the photodetector 122, thereby further improving the measurement accuracy. When the pulse light source 121 is turned off, the photocharge integral value in the pixel remains unchanged until the photocharge integral value in the pixel is reset after the readout to prepare for the accumulation of photocharges in the next measurement cycle. In this way, the measurement results of each measurement cycle can be made more accurate, further reducing the measurement error.

[0039] It should be noted that in one possible implementation mode of the present application, first, the photoelectric encoder 100 also includes a signal processing circuit, which is connected to the photodetector 122; the signal processing circuit can output the photocharge stored in the photodetector 122 within the light-emitting interval of the pulse light source 121.

[0040] Specifically, the signal processing circuit is connected to the photodetector 122. This connection method enables the signal processing circuit to directly obtain the signal generated and stored by the photodetector 122. During the light-emitting interval of the pulse light source 121, the signal processing circuit can output the photocharge stored in the photodetector 122.

[0041] During the operation of the photoelectric encoder 100, the pulse light source 121 emits pulse light according to a set rule, and there is an interval between two light emissions. The signal processing circuit uses this interval to process and output the photoelectric charge stored in the photodetector 122. This is because when the pulse light source 121 emits light, the photodetector 122 mainly performs the conversion and storage of light signals to photoelectric charges. At this time, if the photoelectric charge is output, it may be interfered by the light signal in the conversion process, resulting in inaccurate output signals. During the light emission interval of the pulse light source 121, the photodetector 122 has completed the conversion and storage of the corresponding light signal. At this time, the signal processing circuit can accurately output these photoelectric charges in the form of specific electrical signals. This further improves the measurement accuracy and efficiency.

[0042] Second, the photoelectric encoder 100 further includes a control unit, which is connected to the pulse light source 121 , and the control unit can adjust the pulse period of the pulse light source 121 according to a preset signal.

[0043] Specifically, the control unit is connected to the pulse light source 121 and can send various control instructions and signals to the pulse light source 121, thereby ensuring that the pulse light source 121 operates according to the required working mode and performance requirements.

[0044] The control unit can be set to connect with an external device, and the user can drive the control unit through the external device to control the pulse light source 121. Through such a connection method, the light emission frequency and the measured position data of the pulse light source 121 can be synchronously transmitted to the user; and the user can further control the light emission frequency of the pulse light source 121 through the control unit, and can also delay the light emission for a preset time after the user gives the light emission instruction of the pulse light source 121. Through the setting of the control unit, the pulse period can be adjusted, and the performance of the photoelectric encoder 100 can be flexibly adjusted to meet different usage requirements and improve the applicability and reliability of the photoelectric encoder 100 under various working conditions.

[0045] The present application divides each light emission into a measurement cycle through the pulse light source 121, and receives and converts the photoelectric charge of each measurement cycle through the photodetector 122, thereby greatly improving the measurement accuracy and reducing the measurement error. The above-mentioned photoelectric encoder 100 can ensure the measurement accuracy and measurement efficiency in each measurement cycle, and reduce the production cost.

[0046] In a specific implementation of the present application, the encoding portion 110 includes a code disk, and a plurality of light-transmitting regions 111 and a plurality of light-impermeable regions 112 are alternately arranged in sequence along the displacement direction of the code disk.

[0047] Specifically, the encoding part 110 may be a code disk, which has a circular structure. A plurality of light-transmitting areas 111 and a plurality of light-impermeable areas 112 are arranged on a surface of the code disk facing the pulse light source 121 along the displacement direction. When the code disk moves in a circular direction relative to the pulse light source 121, the light emitted by the pulse light source 121 will generate regular light signal changes due to passing through different light-transmitting and light-impermeable areas 112.

[0048] The part to be tested transmits its circular motion to the code disk through a certain connection method, such as shaft connection, coupling, etc., so that the code disk rotates along the circumferential direction relative to the pulse light source 121, ensuring that the circular motion of the part to be tested can be accurately reflected in the position change of the code disk relative to the pulse light source 121, and then the photodetector 122 can receive the corresponding light signal change to achieve the measurement of the circular motion.

[0049] Among them, the part to be tested can be the rotating shaft of a motor, the rotating part of a mechanical transmission device, etc. The code disk and the photoelectric encoder 100 can accurately measure and monitor the motion characteristics of the part to be tested, such as the movement speed, movement angle and rotation direction, and provide an accurate data basis for subsequent applications such as automated control, position detection or speed feedback.

[0050] In another specific embodiment of the present application, the encoding portion 110 includes a code scale, and a plurality of light-transmitting regions 111 and a plurality of light-impermeable regions 112 are alternately arranged in sequence along the displacement direction of the code scale.

[0051] Specifically, the encoding part 110 may be a ruler in the shape of a long strip. The ruler may be made of a material with certain rigidity and stability, such as metal or hard plastic, to ensure that it will not deform or shift during the measurement process, thereby affecting the accuracy of the measurement.

[0052] On the surface of the code ruler facing the pulse light source 121, there are multiple light-transmitting areas 111 and multiple light-impermeable areas 112, and these areas are arranged alternately in the horizontal direction. The arrangement in the horizontal direction allows these areas to pass through the light emitted by the pulse light source 121 in sequence when the code ruler moves in a straight line relative to the pulse light source 121. Different combinations of light-transmitting and light-impermeable areas 112 can represent different position information. In this way, when the code ruler moves in the horizontal direction, the light signal received by the photodetector 122 will change according to a certain coding rule, so that the position of the code ruler can be determined according to the change of the light signal, and then the linear displacement of the test piece can be accurately measured.

[0053] When the object to be tested moves in the horizontal direction, its linear motion is transmitted to the code ruler, so that the code ruler produces a relative displacement in the horizontal direction relative to the pulse light source 121. In this way, the positions of the light-transmitting area 111 and the light-impermeable area 112 on the code ruler relative to the pulse light source 121 will change, thereby causing the light emitted by the pulse light source 121 to pass through these areas to change, and finally be sensed by the photodetector 122, thereby realizing the measurement of the linear displacement.

[0054] Alternatively, if Figure 2 As shown, the pulse light source 121 and the photodetector 122 are arranged opposite to each other, which can ensure that the light can propagate from the pulse light source 121 toward the photodetector 122; the encoding part 110 is arranged at intervals between the pulse light source 121 and the photodetector 122, so that the light emitted by the pulse light source 121 must pass through the encoding part 110 during the propagation process; the light emitted by the pulse light source 121 is transmitted through the light-transmitting area 111 and then received by the photodetector 122.

[0055] like Figure 3 As shown, a collimating lens 130 can also be provided on the light output side of the pulse light source 121 . The light emitted by the pulse light source 121 can be collimated by the collimating lens 130 and vertically incident on the encoding unit 110 , and then transmitted through the light-transmitting area 111 and received by the photodetector 122 .

[0056] It should be noted that light transmittance refers to the proportion of light that can pass through the light-transmitting area 111, and the change in light transmittance refers to the fluctuation of the ability of the light-transmitting area 111 to allow light to pass through at different times, different environmental conditions or different use stages. The light transmittance of the light-transmitting area 111 of the photoelectric encoder 100 of the present application changes by less than 10%. If the light transmittance changes too much, it may cause a large deviation in the light signal received by the photodetector 122.

[0057] By controlling the light transmittance variation of the light-transmitting area 111 within a range of less than 10%, it can be ensured that the photoelectric encoder 100 can provide relatively stable and consistent light signals in various possible usage scenarios and environments, thereby making the encoding and measurement work based on these light signals more accurate and reliable, reducing the measurement error introduced by the performance fluctuation of the light-transmitting area 111, improving the performance and measurement accuracy of the entire photoelectric encoder 100 system, and providing a more stable signal foundation for subsequent signal processing and measurement applications.

[0058] Alternatively, if Figure 1 As shown, the pulse light source 121 and the photodetector 122 are arranged at intervals and located on the same side of the encoding part 110. Such an arrangement can reduce the volume of the photoelectric encoder 100; the light emitted by the pulse light source 121 is reflected by the light-transmitting area 111 and then received by the photodetector 122.

[0059] It should be noted that the light reflectivity refers to the ratio of the reflected light flux to the incident light flux when the light irradiates the surface of the light-transmitting area 111. In order to ensure the performance and measurement accuracy of the photoelectric encoder 100, the photoelectric encoder 100 of the present application makes the light reflectivity of the light-transmitting area 111 change less than 10%. If the light reflectivity changes too much, the intensity of the reflected light signal received by the photodetector 122 will fluctuate greatly, thereby affecting the accurate reading of the coded information.

[0060] The present application controls the light reflectivity variation range of the light-transmitting area 111 within 10%, which can ensure the stability of the reflected light signal throughout the service life of the photoelectric encoder 100. By limiting the light reflectivity variation of the light-transmitting area 111 to such a small range, it can ensure that the reflected light signal received by the photodetector 122 has high consistency and reliability, reduce the measurement error introduced by the light reflectivity fluctuation, and enable the photoelectric encoder 100 to work stably under various conditions, providing good optical conditions and signal basis for accurately measuring the motion information of the test piece.

[0061] In one possible implementation of the present application, the photoelectric encoder 100 also includes a time synchronization device, one end of which is connected to the signal processing circuit and the other end is connected to an external device, and the external device can synchronize time with the signal processing circuit through the time synchronization device.

[0062] Specifically, the time synchronization device can be an independent module or a functional unit integrated in other components. Its main purpose is to manage and coordinate the time information within the system to solve problems such as information inconsistency or measurement errors that may be caused by differences in time bases among different components during the operation of the photoelectric encoder 100.

[0063] One end of the time synchronization device is connected to the signal processing circuit, and the other end is connected to the external device. In the actual working process, the external device may have its own time reference, but in order to ensure the coordination of the entire system and the accuracy of information processing, it is necessary to reach a time agreement with the signal processing circuit in the photoelectric encoder 100. Through the time synchronization device, the external device can receive time information from the signal processing circuit or other system components, and adjust its own time reference according to this information.

[0064] Optionally, the synchronization signal includes but is not limited to a hardware synchronization signal, a bit synchronization signal through a communication port, or Network Time Protocol (NTP), IEEE 1588 Precision Network Time Protocol (PTP), etc.

[0065] By setting up the time synchronization device, data processing errors and operational errors caused by time deviation are avoided, the time consistency and coordination of the entire system are ensured, and the precise operation of the entire system is guaranteed.

[0066] The above description is only an optional embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0067] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A photoelectric encoder, characterized in that: It includes an encoding part and a code reading part, wherein the encoding part is arranged on the test piece, and the encoding part includes a plurality of light-transmitting areas and a plurality of light-impermeable areas which are arranged alternately in sequence; the code reading part includes a photodetector and at least one pulse light source, and when the test piece moves along a preset direction to drive the encoding part to move, the light emitted by the pulse light source can pass through the light-transmitting areas and the light-impermeable areas on the encoding part, and the light passing through the light-transmitting areas is received by the photodetector and converted into photoelectric charge storage; the photoelectric encoder also includes a signal processing circuit, which is connected to the photodetector; the signal processing circuit can output the photoelectric charge stored in the photodetector within the light-emitting interval of the pulse light source.

2. The photoelectric encoder according to claim 1, characterized in that: The number of the pulse light sources is at least one; when the number of the pulse light sources is multiple, the multiple pulse light sources are evenly spaced along the movement direction of the test piece, and the arrangement period of the multiple pulse light sources is equal to the arrangement period of the multiple light-transmitting areas and the multiple light-impermeable areas of the encoding part; the multiple pulse light sources emit light to generate multiple measurement signals respectively.

3. The photoelectric encoder according to claim 1, characterized in that: The number of the pulse light sources is at least one; when the number of the pulse light sources is multiple, the multiple pulse light sources are evenly spaced along the movement direction of the test piece, and the arrangement period of the multiple pulse light sources differs from the arrangement period of the multiple light-transmitting areas and the multiple light-impermeable areas of the encoding part by an integer number of periods.

4. The photoelectric encoder according to claim 1, characterized in that: The photoelectric encoder further includes a control unit, which is connected to the pulse light source and can adjust the pulse period of the pulse light source according to a preset signal.

5. The photoelectric encoder according to claim 1, characterized in that: The encoding part includes a code disk, and the plurality of light-transmitting areas and the plurality of light-impermeable areas are alternately arranged in sequence along the displacement direction of the code disk.

6. The photoelectric encoder according to claim 1, characterized in that: The encoding part includes a code scale, and the plurality of light-transmitting areas and the plurality of light-impermeable areas are alternately arranged in sequence along the displacement direction of the code scale.

7. The photoelectric encoder according to claim 1, characterized in that: The pulse light source is arranged opposite to the photodetector, the encoding part is arranged between the pulse light source and the photodetector, and the light emitted by the pulse light source is transmitted through the light-transmitting area and then received by the photodetector.

8. The photoelectric encoder according to claim 7, characterized in that: The light transmittance of the light-transmitting area changes by less than 10%.

9. The photoelectric encoder according to claim 1, characterized in that: The pulse light source and the photoelectric detector are spaced apart and are both located on a side of the encoding portion away from the DUT. The light emitted by the pulse light source is reflected by the light-transmitting area and then received by the photoelectric detector.

10. The photoelectric encoder according to claim 9, characterized in that: The light reflectivity of the light-transmitting area changes by less than 10%.

11. The photoelectric encoder according to claim 2, characterized in that: The photoelectric encoder also includes a time synchronization device, one end of which is connected to the signal processing circuit and the other end is connected to an external device. The external device can synchronize time with the signal processing circuit through the time synchronization device.

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