IN-track signal fusion photoelectric encoder chip

Abstract

The invention provides an IN-track signal fusion photoelectric encoder chip. The IN-track signal fusion photoelectric encoder chip is characterized in that the IN-track signal fusion photoelectric encoder chip is mainly composed of an incremental code channel photodiode PD array (1), an IN-track signal detection photodiode PD array (2), an IN-track signal detection module (3), a gain switching control module (4), a switch unit array (5), a trans-impedance amplifier TIA1 (6) and a trans-impedance amplifier TIA2 (7). According to the invention, the problems of signal quality and precision loss caused by the influence of the IN-track signal on the output of the incremental signal when the IN-track signal and the incremental signal code disc are fused in the same code channel can be effectively solved, and the fault tolerance and reliability of a photoelectric encoder system can be effectively improved; and the method can be widely applied to the fields of industrial automation, medical equipment, aerospace and the like.

Description

Technical Field

[0001] The present invention relates to an IN-track signal fusion photoelectric encoder chip, which is mainly used to improve the stability and accuracy of incremental signals and has broad application prospects, especially in high-precision, high-speed systems such as industrial automation, medical equipment, and aerospace. The photoelectric encoder chip of the present invention can effectively process the fusion of IN-track signals and incremental signals, avoid incremental signal distortion caused by the influence of IN-track signals, and ensure the reliability and accuracy of the photoelectric encoder system at high speed. Background Art

[0002] With the increasing demand for high-precision and high-speed sensors in automation, robotics, aerospace, and medical equipment, photoelectric encoders are becoming more and more widely used as precision position detection tools. Photoelectric encoders use photodiode arrays to detect the light spot signal reflected or transmitted by the rotating code disk and convert it into an electrical signal, thereby achieving high-precision detection of object position, speed and other information.

[0003] Most existing photoelectric encoders rely on incremental signals and zero-position signals (IN-track signals) for position encoding. The incremental signal is usually represented by a pair of sine and cosine signals, while the IN-track signal is used to calibrate the position zero point. In traditional photoelectric encoders, the incremental signal and the IN-track signal are detected and processed independently, which makes it difficult to ensure the accuracy and stability of the incremental signal near the zero-point signal in practical applications, especially in high-speed or high-precision applications, which may lead to signal distortion, noise interference and poor system fault tolerance.

[0004] In addition, especially in the code disk structure where the IN-track signal and the incremental signal are integrated, the existing photoelectric encoder chip design usually cannot effectively solve the mutual interference between the incremental signal and the IN-track signal. The IN-track signal may affect the photoelectric signal of the incremental code channel and cause errors. In order to improve the reliability and accuracy of the photoelectric encoder system, the signal must be accurately processed and gain controlled to ensure that the amplitude of the output signal is stable and the phase relationship is accurate.

[0005] In response to the above problems, the present invention proposes a new photoelectric encoder chip design that integrates the detection and processing functions of incremental signals and IN-track signals. By adopting gain switching technology, the design can stabilize the output amplitude of the incremental signal by switching the gain mode when the IN-track signal is detected, ensuring stable signal quality while reducing the interference of the IN-track signal on the incremental signal. In addition, the design also effectively improves the fault tolerance and reliability of the photoelectric encoder system through the optimized IN-track signal detection module and gain switching control module, and is suitable for high-speed, high-precision industrial application environments.

[0006] The technical advantage of the present invention is that it can process incremental signals and IN-track signals at the same time, avoiding the signal interference problem in traditional designs, and ensuring the stability and accuracy of incremental signal output through dynamic gain switching, thereby effectively improving the performance of photoelectric encoders in various complex applications. Summary of the invention

[0007] The purpose of the present invention is to provide an IN-track signal fusion photoelectric encoder chip. The chip is characterized in that the design is composed of an incremental code channel photodiode PD array (1), an IN-track signal detection photodiode PD array (2), an IN-track signal detection module (3), a gain switching control module (4), a switch unit array (5), a transimpedance amplifier TIA1 (6), and a transimpedance amplifier TIA2 (7).

[0008] The object of the present invention is achieved in that: The incremental code channel photodiode PD array (1) generates two groups of sine and cosine varying photocurrent signals with a period of T when detecting light signals, and the IN-track signal detection photodiode PD array (2) generates a group of CHZ signals when detecting light signals; the IN-track signal in the IN-track signal fusion code disk is the zero position signal, which is fused with the incremental signal in the code channel of the same radius. The light reflected by the code disk at the IN-track signal position during operation will be received by the incremental code channel photodiode PD array (1) and generate an output signal different from the normal sine and cosine signal with a low amplitude. The generation of this abnormal signal is mainly due to the integration of the IN-track signal into the incremental signal code disk; the IN-track signal in the chip When the comparator circuit (31) in the IN-track signal detection module (3) detects the first falling edge of the CHZ signal output by the IN-track signal detection photodiode PD array (2), it will compare the amplitude of the input zero-point photoelectric signal and output a high-level signal. At the same time, the hysteresis circuit (32) adds a certain amount of hysteresis (threshold window) to suppress the influence of signal fluctuations and avoid false triggering due to noise near the threshold. Then, the IN-track signal detection module (3) sends the high-level signal generated by the first detected CHZ falling edge signal to the gain switching control module (4). The control logic circuit (41) in the gain switching control module (4) receives the signal from the IN-track signal detection module (3). The trigger signal of the module (3) generates a gain switch control signal, and then provides a suitable drive voltage to the switch unit array (5) through the drive circuit (42), so as to ensure that the switch unit array (5) switches from the standard gain of the transimpedance amplifier TIA1 (6) to the high gain of the transimpedance amplifier TIA2 (7); when the comparator circuit (31) in the IN-track signal detection module (3) in the chip detects the second falling edge of the CHZ signal output by the IN-track signal detection photodiode PD array (2), it will compare the amplitude of the input zero-point photoelectric signal and output the next high-level signal. The IN-track signal detection module (3) sends the high-level signal generated by the second CHZ falling edge signal detected to the In the gain switching control module (4), the gain switching control module (4) controls the switch unit array (5) to switch from the high gain of the transimpedance amplifier TIA1 (7) to the standard gain of the transimpedance amplifier TIA2 (6); the design uses the IN-track signal to trigger the switching of the incremental signal output transimpedance amplifier gain, so that the incremental signal output ensures stable amplitude and good sine and cosine characteristics. It can be effectively applied to the design of the photoelectric encoder chip of the IN-track signal fusion code disk, and avoids the influence of the IN-track signal on the output signal of the incremental code channel photodiode PD array, effectively improving the fault tolerance and reliability of the photoelectric encoder system, and can be widely used in industrial automation, medical equipment, aerospace and other fields.

[0009] The photodiode structure in the incremental code channel photodiode (PD) array (1) in the design can be any one of a PN type photodiode, a PIN type photodiode, etc., and its function is to receive the light spot signal transmitted or reflected by the code disk and convert it into a photocurrent signal; the shape of a single photodiode (PD) is diverse, and its size and distribution follow a certain rule, and it can output two sets of differential sine and cosine photocurrent signals with a period of T through light sensing during the rotation of the code disk.

[0010] The photodiode structure in the IN-track signal detection photodiode PD array (2) in the design can be any one of a PN type photodiode, a PIN type photodiode, etc., and its function is to receive the light spot signal transmitted or reflected by the code disk and convert it into a special photocurrent signal; the shape of a single photodiode (PD) is rectangular, and the spacing between it and the incremental code channel photodiode (PD) array (1) needs to be kept fixed to ensure that the photocurrent signal output by the incremental code channel photodiode (PD) array (1) and the photocurrent signal output by the IN-track signal detection photodiode PD array (2) maintain a specific phase relationship; each time the code disk rotates one circle, a peak zero point signal can be output.

[0011] The IN-track signal detection module (3) in the design is composed of a comparator circuit (31) and a hysteresis circuit (32); the comparator circuit (31) is responsible for comparing the amplitude of the input photocurrent signal and outputting a corresponding high-level signal; the hysteresis circuit (32) suppresses the influence of signal fluctuations by adding a certain hysteresis amount (threshold window), avoids false triggering of the signal due to noise near the threshold, and improves the stability and anti-interference ability of signal detection; the IN-track signal detection module (3) is mainly used to detect the IN-track signal and generate a trigger pulse signal.

[0012] The gain switching control module (4) in the design is composed of a control logic circuit (41) and a drive circuit (42); the control logic circuit (41) receives a trigger signal from a zero-point signal detection module to generate a gain switch control signal, and the drive circuit (42) provides a suitable drive voltage for the switch unit array (5) to ensure reliable switching; the gain switching control module (4) controls the switch unit array (5) to dynamically switch, thereby realizing the switching of the transimpedance amplifier TIA between the standard gain mode and the high gain mode, ensuring that the gain switching process is fast and smooth without signal distortion, thereby meeting the high-speed operation requirements of the chip.

[0013] The switch unit array (5) in the design can be any one of a digital switch unit, an analog switch unit, a field effect transistor switch unit, a CMOS switch unit and an electronic switch unit, and its main function is to realize the switching of the transimpedance amplifier TIA between the standard gain mode and the high gain mode under the driving control of the gain switching control module (4), thereby ensuring that the gain switching process is fast and smooth without signal distortion.

[0014] The transimpedance amplifier TIA1 (6) and the transimpedance amplifier TIA2 (7) in the design can be any one of a basic feedback transimpedance amplifier (TIA), a dual-input transimpedance amplifier (TIA), a differential transimpedance amplifier (TIA) and a variable gain transimpedance amplifier (TIA); the gain of the transimpedance amplifier TIA1 (6) is a standard gain, and the gain of the transimpedance amplifier TIA1 (7) is a high gain. The main function of the transimpedance amplifier TIA1 (6) is to connect the switch unit array (5) to the transimpedance amplifier TIA1 (6) to provide a standard gain output when the output signal of the incremental code channel photodiode PD array (1) is not affected by the IN-track signal; when the output signal of the incremental code channel photodiode PD array (1) is affected by the IN-track signal, the switch unit array (5) will switch to the transimpedance amplifier TIA2 (7) under the driving control of the gain switching control module (4) to provide a high gain output. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The invention is a schematic diagram of an IN-track signal fusion photoelectric encoder chip. The design comprises an incremental code channel photodiode PD array (1), an IN-track signal detection photodiode PD array (2), an IN-track signal detection module (3), a gain switching control module (4), a switch unit array (5), a transimpedance amplifier TIA1 (6), and a transimpedance amplifier TIA2 (7).

[0016] Figure 2 The invention is a schematic diagram of an embodiment of an IN-track signal fusion photoelectric encoder chip. The design comprises an incremental code channel photodiode PD array (1), a zero position signal detection photodiode PD array (2), a transimpedance amplifier TIA array (3), a switch unit array (4), a control switching circuit (5), a photoelectric encoder chip (6), and a control signal module (7).

[0017] Figure 3 This is a schematic diagram of the encoder that integrates the IN-track signal and the incremental signal.

[0018] Figure 4 Schematic diagram of the output of CHA / CHB signals and CHZ signals of the incremental code photodiode PD array (1) affected by the IN-track signal in the embodiment.

[0019] Figure 5 The diagram is a schematic diagram of the output of CHA / CHB and CHZ signals after the incremental code channel photodiode PD array (1) is adjusted by the IN-track signal detection module (3), the gain switching control module (4), the switch unit array (5), the transimpedance amplifier TIA1 (6), and the transimpedance amplifier TIA2 (7) in the embodiment. DETAILED DESCRIPTION The present invention will be further described below in conjunction with specific embodiments. Embodiment 1:

[0020] Figure 2 A schematic diagram of an embodiment of an IN-track signal fusion photoelectric encoder chip is given.

[0021] from Figure 3 The Dpaque Surface position and the Reflective Surface position can be seen, which are significantly different from the normal incremental code channel position. Here is a typical position diagram of the IN-track signal and incremental signal fusion code disk. When the code disk rotates clockwise, the CHZ signal output by the IN-track signal detection photodiode PD array (2) reaches the first falling edge position. At this time, the CHA / CHB signal output by the incremental code channel photodiode PD array (1) will be affected by the IN-track signal. The comparator circuit (31) in the IN-track signal detection module (3) will compare the amplitude of the CHZ signal passing through the hysteresis circuit (32) and output a high-level signal to the control logic circuit (41) in the gain switching control module (4). The control logic circuit will output the control signal to the drive circuit (42). The drive circuit (42) outputs a drive voltage to control the switch unit array (5) to switch the output gain of the incremental code channel photodiode PD array (1) from the standard gain of the transimpedance amplifier TIA1 (6) to the high gain of the transimpedance amplifier TIA1 (7). At this time, the transimpedance amplifier connected to the incremental code channel photodiode PD array (1) is the high gain of the transimpedance amplifier TIA1 (7).

[0022] When the code disk continues to rotate clockwise, the CHZ signal output by the IN-track signal detection photodiode PD array (2) will reach the second falling edge position, and thereafter the CHA / CHB signal output by the incremental code channel photodiode PD array (1) will not be affected by the IN-track signal. The comparator circuit (31) in the IN-track signal detection module (3) will compare the amplitude of the CHZ signal passing through the hysteresis circuit (32) and output the next high-level signal to the control logic circuit (41) in the gain switching control module (4). The control logic circuit will output the control signal to the drive circuit (42). The drive circuit (42) outputs a drive voltage to control the switch unit array (5) to switch the output gain of the incremental code channel photodiode PD array (1) from the high gain of the transimpedance amplifier TIA1 (7) to the standard gain of the transimpedance amplifier TIA1 (6). At this time, the transimpedance amplifier connected to the incremental code channel photodiode PD array (1) is the standard gain of the transimpedance amplifier TIA1 (6).

[0023] Depend on Figure 4 It can be seen that the time axis of the CHA / CHB and CHZ signals is consistent. Between the two falling edges 401 and 402 of the CHZ signal, the CHA / CHB signal output by the incremental code channel photodiode PD array (1) is obviously affected by the IN-track signal, and the amplitude is lower than the normal incremental signal. By switching the gain mode of the transimpedance amplifier TIA connected to the incremental code channel photodiode PD array (1), the output amplitude of the incremental signal CHA / CHB can be stabilized, ensuring the stability of the signal quality. After circuit adjustment, the CHA / CHB and CHZ signal output diagram is as shown in FIG. Figure 5 shown.

[0024] This design stabilizes the output amplitude of the incremental signal by detecting the IN-track signal and switching the gain mode, ensuring stable signal quality while reducing the interference of the IN-track signal on the incremental signal. It can be effectively applied to the design of photoelectric encoder chips that integrate IN-track signals with code disks, and avoid the influence of the IN-track signal on the output signal of the incremental code channel photodiode PD array, effectively improving the fault tolerance and reliability of the photoelectric encoder system, and can be widely used in industrial automation, medical equipment, aerospace and other fields.

Claims

1. An IN-track signal fusion photoelectric encoder chip, characterized by: The design is composed of an incremental code photodiode PD array (1), an IN-track signal detection photodiode PD array (2), an IN-track signal detection module (3), a gain switching control module (4), a switch unit array (5), a transimpedance amplifier TIA1 (6), and a transimpedance amplifier TIA2 (7); The incremental code channel photodiode PD array (1) generates two groups of sine and cosine varying photocurrent signals with a period of T when detecting light signals, and the IN-track signal detection photodiode PD array (2) generates a group of CHZ signals when detecting light signals; the IN-track signal in the IN-track signal fusion code disk is the zero position signal, which is fused with the incremental signal in the code channel of the same radius. The light reflected by the code disk at the IN-track signal position during operation will be received by the incremental code channel photodiode PD array (1) and generate an output signal different from the normal sine and cosine signal with a low amplitude. The generation of this abnormal signal is mainly due to the integration of the IN-track signal into the incremental signal code disk; the IN-track signal in the chip When the comparator circuit (31) in the IN-track signal detection module (3) detects the first falling edge of the CHZ signal output by the IN-track signal detection photodiode PD array (2), it will compare the amplitude of the input zero-point photoelectric signal and output a high-level signal. At the same time, the hysteresis circuit (32) adds a certain amount of hysteresis (threshold window) to suppress the influence of signal fluctuations and avoid false triggering due to noise near the threshold. Then, the IN-track signal detection module (3) sends the high-level signal generated by the first detected CHZ falling edge signal to the gain switching control module (4). The control logic circuit (41) in the gain switching control module (4) receives the signal from the IN-track signal detection module (3). The trigger signal of the module (3) generates a gain switch control signal, and then provides a suitable drive voltage to the switch unit array (5) through the drive circuit (42), so as to ensure that the switch unit array (5) switches from the standard gain of the transimpedance amplifier TIA1 (6) to the high gain of the transimpedance amplifier TIA2 (7); when the comparator circuit (31) in the IN-track signal detection module (3) in the chip detects the second falling edge of the CHZ signal output by the IN-track signal detection photodiode PD array (2), it will compare the amplitude of the input zero-point photoelectric signal and output the next high-level signal. The IN-track signal detection module (3) sends the high-level signal generated by the second CHZ falling edge signal detected to the In the gain switching control module (4), the gain switching control module (4) controls the switch unit array (5) to switch from the high gain of the transimpedance amplifier TIA1 (7) to the standard gain of the transimpedance amplifier TIA2 (6); the design uses the IN-track signal to trigger the switching of the incremental signal output transimpedance amplifier gain, so that the incremental signal output ensures stable amplitude and good sine and cosine characteristics. It can be effectively applied to the design of the photoelectric encoder chip of the IN-track signal fusion code disk, and avoids the influence of the IN-track signal on the output signal of the incremental code channel photodiode PD array, effectively improving the fault tolerance and reliability of the photoelectric encoder system, and can be widely used in industrial automation, medical equipment, aerospace and other fields.

2. An IN-track signal fusion photoelectric encoder chip, characterized by: The photodiode structure in the incremental code channel photodiode (PD) array (1) in the design can be any one of a PN type photodiode, a PIN type photodiode, etc., and its function is to receive the light spot signal transmitted or reflected by the code disk and convert it into a photocurrent signal; the shape of a single photodiode (PD) is diverse, and its size and distribution follow a certain rule, and it can output two sets of differential sine and cosine photocurrent signals with a period of T through light sensing during the rotation of the code disk.

3. An IN-track signal fusion photoelectric encoder chip, characterized by: The photodiode structure in the IN-track signal detection photodiode PD array (2) in the design can be any one of a PN type photodiode, a PIN type photodiode, etc., and its function is to receive the light spot signal transmitted or reflected by the code disk and convert it into a special photocurrent signal; the shape of a single photodiode (PD) is rectangular, and the spacing between it and the incremental code channel photodiode (PD) array (1) needs to be kept fixed to ensure that the photocurrent signal output by the incremental code channel photodiode (PD) array (1) and the photocurrent signal output by the IN-track signal detection photodiode PD array (2) maintain a specific phase relationship; each time the code disk rotates one circle, a peak zero point CHZ signal can be output.

4. An IN-track signal fusion photoelectric encoder chip, characterized by: The IN-track signal detection module (3) in the design is composed of a comparator circuit (31) and a hysteresis circuit (32); the comparator circuit (31) is responsible for comparing the amplitude of the input photocurrent signal and outputting a corresponding high-level signal; the hysteresis circuit (32) suppresses the influence of signal fluctuations by adding a certain hysteresis amount (threshold window), avoids false triggering of the signal due to noise near the threshold, and improves the stability and anti-interference ability of signal detection; the IN-track signal detection module (3) is mainly used to detect the IN-track signal and generate a trigger pulse signal.

5. An IN-track signal fusion photoelectric encoder chip, characterized by: The gain switching control module (4) in the design is composed of a control logic circuit (41) and a drive circuit (42); the control logic circuit (41) receives a trigger signal from a zero-point signal detection module to generate a gain switch control signal, and the drive circuit (42) provides a suitable drive voltage for the switch unit array (5) to ensure reliable switching; the gain switching control module (4) controls the switch unit array (5) to dynamically switch, thereby realizing the switching of the transimpedance amplifier TIA between the standard gain mode and the high gain mode, ensuring that the gain switching process is fast and smooth without signal distortion, thereby meeting the high-speed operation requirements of the chip.

6. An IN-track signal fusion photoelectric encoder chip, characterized by: The switch unit array (5) in the design can be any one of a digital switch unit, an analog switch unit, a field effect transistor switch unit, a CMOS switch unit and an electronic switch unit, and its main function is to realize the switching of the transimpedance amplifier TIA between the standard gain mode and the high gain mode under the driving control of the gain switching control module (4), thereby ensuring that the gain switching process is fast and smooth without signal distortion.

7. An IN-track signal fusion photoelectric encoder chip, characterized by: The transimpedance amplifier TIA1 (6) and the transimpedance amplifier TIA2 (7) in the design can be any one of a basic feedback transimpedance amplifier (TIA), a dual-input transimpedance amplifier (TIA), a differential transimpedance amplifier (TIA) and a variable gain transimpedance amplifier (TIA); the gain of the transimpedance amplifier TIA1 (6) is a standard gain, and the gain of the transimpedance amplifier TIA1 (7) is a high gain. The main function of the transimpedance amplifier TIA1 (6) is to connect the switch unit array (5) to the transimpedance amplifier TIA1 (6) to provide a standard gain output when the output signal of the incremental code channel photodiode PD array (1) is not affected by the IN-track signal and the amplitude is normal; when the output signal of the incremental code channel photodiode PD array (1) is affected by the IN-track signal and the amplitude is abnormally low, the switch unit array (5) will switch to the transimpedance amplifier TIA2 (7) under the driving control of the gain switching control module (4) to provide a high gain output.

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