Zero-searching phase switchable photoelectric encoder chip design

Abstract

The invention provides a zero-seeking phase-switchable photoelectric encoder chip design. The zero-seeking phase-switchable photoelectric encoder chip design is characterized in that the zero-seeking phase-switchable photoelectric encoder chip design is mainly composed of an incremental code channel photodiode PD array (1), a zero signal detection photodiode PD array (2), a trans-impedance amplifier TIA array (3), a switch unit array (4), a control switching circuit (5) and a photoelectric encoder chip (6). According to the invention, the problem of precision loss caused by the phase error of the increment signal and the zero signal in the practical application process of the photoelectric encoder chip can be effectively solved, the fault tolerance and reliability of the photoelectric encoder system can be effectively improved, and the photoelectric encoder chip 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 a photoelectric encoder chip design with switchable zero-seeking phase, which belongs to the field of precision position and motion detection technology. The chip has important applications in a wide range of fields such as industrial automation, CNC machine tools, medical equipment, printing and packaging equipment, aerospace, scientific experiments, robotics, automotive industry, and shipbuilding and marine engineering. Its core function is to provide high-precision zero-position detection and phase adjustment capabilities for these fields, thereby meeting the needs of precise positioning and efficient zero-seeking in complex environments, and is an important technical means to realize equipment intelligence and automation. Background Art

[0002] Traditional photoelectric encoder chip design plays an important role in positioning and motion measurement, and is widely used in industrial automation, robotics, automotive industry and other fields. Its working principle is based on optical sensing, and the absolute position of an object is determined by receiving changes in optical signals through a photodiode (PD) array. However, photoelectric encoders often face the phase matching requirements of zero position signals and incremental signals in practical applications to achieve precise positioning and motion control. This phase matching helps the system accurately identify and calibrate the position during initialization and zero position detection.

[0003] With the application of industrial automation and precision instruments, photoelectric encoders, as core components for displacement, position, and speed measurement, have higher and higher requirements for accuracy and reliability. Especially in the design and application of high-precision photoelectric encoders, due to the mechanical alignment error and installation error between the chip and the code disc, the phase of the zero-position signal and the incremental signal often cannot meet the standard requirements, which in turn affects the measurement accuracy and stability of the system. In addition, external factors such as ambient light interference, light source power fluctuations, and temperature changes can also cause errors in the encoder during operation, and even bit errors, affecting the overall performance. These bit error problems not only reduce the reliability of the encoder, but may also cause inaccurate measurements and affect the normal operation of the system. Therefore, how to achieve the adjustability of the phase of the zero-position signal and the incremental signal has become the key to improving the performance of the encoder.

[0004] At present, traditional solutions include error compensation through hardware calibration or complex adjustment circuits, but these methods are often costly and cannot deal with dynamic error problems in real time. Therefore, in order to improve the accuracy and adaptability of photoelectric encoders in harsh environments, it is necessary to design a new encoder chip structure that can not only meet the requirements of accurate position measurement, but also adjust the phase between the zero position signal and the incremental signal to adapt to different application requirements and ensure high accuracy and stability.

[0005] To this end, the present invention proposes a photoelectric encoder chip design with switchable zero-seeking phase. By adopting a combination design of a zero-position signal detection array composed of 8 photodiodes (PDs), a transimpedance amplifier (TIA) array, a switch unit array, and a control switching circuit, the design uses multiple photodiodes for signal acquisition and comparison, which improves the fault tolerance and reliability of the system and reduces failures caused by failure of a single sensor; at the same time, it can realize phase adjustment and switching of multiple zero-position signals and incremental signals to meet the requirements of different application scenarios. By controlling the selective output of the zero-position signal by the switching circuit, the output of the zero-position phase can be accurately controlled in different modes, effectively reducing the bit errors caused by mechanical errors and environmental influences, and realizing high-precision position and motion detection. Summary of the invention

[0006] The purpose of the present invention is to provide a photoelectric encoder chip design with adjustable zero-seeking phase. The design is characterized in that the design is composed of 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), and a photoelectric encoder chip (6).

[0007] The object of the present invention is achieved in that:

[0008] The incremental code channel photodiode PD array (1) generates two groups of sine-cosine changing photocurrent signals with a period of T when detecting a light signal. When the zero-position signal detection photodiode PD array (2) detects a zero-position light signal, the peaks of the zero-position photocurrent signals detected and output by PD1, PD2, PD3, PD4, PD5, PD6, PD7, and PD8 have a fixed phase difference of 9 / 8*T. The photocurrent signal generated by the zero-position signal detection photodiode PD array (2) is synchronously output to the transimpedance amplifier TIA array (3). The PD in the zero-position signal detection photodiode PD array (2) is connected to a single transimpedance amplifier TIA in the transimpedance amplifier TIA array (3). The transimpedance amplifier TIA array (3) processes and amplifies the photocurrent signal generated by the zero-position signal detection photodiode PD array (2) and outputs a voltage signal. The voltage signal is then output to the control switching circuit ( 5), the control switching circuit (5) decodes the received control signal according to the control signal of the external control device or system, generates a corresponding control signal to drive the control switch unit array (4), selects and outputs the corresponding mode signal (such as the zero position signal PD1 to PD8), and the selected zero position signal is transmitted to the subsequent processing module of the chip or the external device through the output interface for subsequent signal processing and other operations; the design of the photoelectric encoder chip with switchable zero-seeking phase can effectively improve the zero-seeking efficiency of the photoelectric encoder chip in the application process, and can effectively avoid the phase mismatch problem between the zero point signal and the incremental signal caused by the installation error and alignment error of the photoelectric encoder chip and the code disk, as well as the failure problem caused by the failure of a single photodiode. At the same time, the phase relationship switching function between the zero position signal and the incremental signal can effectively improve the fault tolerance and reliability of the system, and improve the overall accuracy of the entire photoelectric encoder system.

[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 encoding 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 encoding disk.

[0010] The photodiode structure in the zero-position signal detection photodiode PD array (2) in the design can be any one of a PN-type photodiode, a PIN-type photodiode, etc., and is mainly composed of 8 photodiodes, namely PD1, PD2, PD3, PD4, PD5, PD6, PD7, and PD8, and the distance difference between each two adjacent PDs is 9 / 8*T; that is, the zero-position signal output by the 8 PD detections can cover the entire period intersecting with the A and B signals. For example, with the A signal Taking the intersection of the falling edge of signal A and the rising edge of signal B as an example, ideally, the peak of the zero-position signal detected by PD1 is exactly at this intersection, and the peaks of the zero-position signals detected by PD2, PD3, PD4, PD5, PD6, PD7, and PD8 are respectively located at 1 / 8*T+T, 2 / 8*T+2T, 3 / 8*T+3T, 4 / 8*T+4T, 5 / 8*T+5T, 6 / 8*T+6T, and 7 / 8*T+7T of the intersection of the falling edge of signal A and the rising edge of signal B.

[0011] The transimpedance amplifier TIA in the transimpedance amplifier TIA array (3) in the design may 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), and its function is to convert the photocurrent signal generated by the zero-position signal detection photodiode PD array (2) into a voltage signal and output it; each TIA in the transimpedance amplifier TIA array (3) is connected to a PD in the zero-position signal detection photodiode PD array (2) in a single connection.

[0012] The switch unit array (4) 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 complete the selective output of zero-position signals PD of different phases in the zero-position signal detection photodiode PD array (2) under the control of the control switching circuit (5).

[0013] The control switching circuit module (5) in the design is composed of a selection input interface, a selection logic circuit, a drive and buffer circuit, an output interface, etc. Its main function is to decode the received control signal according to the control signal of the external control device or system, generate a corresponding control signal to drive the control switch unit array (4), select and output the corresponding mode signal (such as zero position signals PD1 to PD8), and transmit the selected zero position signal to the subsequent processing module of the chip or the external device through the output interface for subsequent signal processing and other operations.

[0014] The photoelectric encoder chip (6) in the design may be any one of a transmission type photoelectric encoder chip and a reflection type photoelectric encoder chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The invention discloses a schematic diagram of a photoelectric encoder chip design with a zero-seeking phase switchable, which 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), and a photoelectric encoder chip (6).

[0016] Figure 2 The invention discloses a schematic diagram of an embodiment of a photoelectric encoder chip design with a zero-seeking phase switchable structure. 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 It is a schematic diagram of the chip's external control signal module to control the coding signal of the switching circuit and the corresponding output mode.

[0018] Figure 4 1 is a schematic diagram of the phase relationship and output of the standard zero position signal and incremental A and B signals of the photoelectric encoder chip in the embodiment application.

[0019] Figure 5 This is a schematic diagram of the phase relationship and output of the zero-position signal and the incremental A and B signals when the phase deviation between the zero-position signal and the incremental A and B signals is caused by factors such as mechanical errors in the embodiment. DETAILED DESCRIPTION The present invention will be further described below in conjunction with specific embodiments. Embodiment 1:

[0020] Figure 2A schematic diagram of an embodiment of a design of a zero-seeking phase-switchable photoelectric encoder chip is provided. The embodiment 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). When the incremental code channel photodiode PD array (1) receives an optical signal during application, it will generate two groups of sine-cosine photocurrent signals A and B with a period of T and a phase difference of 90°; the zero-position signal detection photodiode PD array (2) is composed of a group of 8 photodiodes PD1, PD2, PD3, PD4, PD5, PD6, PD7, and PD8 with a distance difference of 9 / 8*T between each other. When the zero-position signal detection photodiode PD array (2) detects a zero-position optical signal, the peaks of the zero-position photocurrent signals detected and output by PD1, PD2, PD3, PD4, PD5, PD6, PD7, and PD8 will have a fixed phase difference of 9 / 8*T. The photocurrent signal generated by the zero-position signal detection photodiode PD array (2) will be synchronously output to the transimpedance amplifier TIA array (3). The zero-position signal detection photodiode PD array (2) in The PD is connected to a single transimpedance amplifier TIA in a transimpedance amplifier TIA array (3), and the transimpedance amplifier TIA array (3) processes and amplifies the photocurrent signal generated by the zero-position signal detection photodiode PD array (2), and outputs a voltage signal; when the photoelectric encoder chip (6) does not have mechanical errors, installation errors with the code disk, alignment errors, and other problems during the application process, the control signal module (7) will output a coded signal control signal of 000 to the control switching circuit (5), and the control switching circuit (5) decodes the received control signal according to the control signal of the control signal module (7), and generates a corresponding control signal to drive the control switch unit array (4), and selects the zero-position PD1 signal in the zero-position signal detection photodiode PD array (2) for output. At this time, the phase relationship between the zero-position signal and the incremental A and B signals in the output signal meets the signal processing requirements such as Figure 4 As shown, it can be used for subsequent signal processing operations.

[0021] When the photoelectric encoder chip (6) has corresponding mechanical errors during the application process, as well as installation errors and alignment errors with the code disc, problems such as Figure 5The problem of phase deviation between the zero position signal and the incremental A and B signals in the zero position signal detection photodiode PD array (2) is solved. If the zero position PD1 signal is still output at this time, the output signal processing requirement cannot be met. The control signal module (7) can output the coded signal of 001 to the control switching circuit (5). The control switching circuit (5) decodes the received control signal according to the control signal of the control signal module (7) and generates a corresponding control signal to drive the control switch unit array (4) to select the zero position PD2 signal in the zero position signal detection photodiode PD array (2) for output. At this time, the phase relationship between the zero position signal and the incremental A and B signals can meet the signal processing requirement and can be used for subsequent signal processing operations. This design of the photoelectric encoder chip with switchable zero position signal can effectively avoid the phase deviation problem between the zero position signal and the incremental A and B signals caused by many mechanical errors in the application process of the photoelectric encoder chip (6) through the switchable output of the zero position signal. Through 8 zero position PDs with uniform phase difference, the zero-seeking efficiency of the entire system and the failure problem caused by the failure of a single photodiode can be effectively improved, and the fault tolerance and reliability of the photoelectric encoder chip in the application process are effectively improved, and the overall accuracy of the entire photoelectric encoder system is improved.

Claims

1. A design of a photoelectric encoder chip with switchable zero-seeking phase, characterized by: The design is composed of an incremental code channel photodiode PD array (1), a zero signal detection photodiode PD array (2), a transimpedance amplifier TIA array (3), a switch unit array (4), a control switching circuit (5), and a photoelectric encoder chip (6); The incremental code channel photodiode PD array (1) generates two sets of sine-cosine varying photocurrent signals with a period of T when detecting a light signal. When the zero-position signal detection photodiode PD array (2) detects a zero-position light signal, the peaks of the zero-position photocurrent signals output by the detection outputs of PD1, PD2, PD3, PD4, PD5, PD6, PD7, and PD8 have a fixed phase difference of 9 / 8*T. The photocurrent signals generated by the zero-position signal detection photodiode PD array (2) are synchronously output to the transimpedance amplifier TIA array (3). The PD in the zero-position signal detection photodiode PD array (2) and the single PD in the transimpedance amplifier TIA array (3) are synchronously output to the transimpedance amplifier TIA array (3). The transimpedance amplifiers TIA are connected, and the transimpedance amplifier TIA array (3) processes and amplifies the photocurrent signal generated by the zero-position signal detection photodiode PD array (2) to output a voltage signal; and then outputs the signal to the control switching circuit (5) through the switch unit array (4); the control switching circuit (5) decodes the received control signal according to the control signal of the external control device or system, generates a corresponding control signal to drive the control switch unit array (4), selects and outputs a corresponding mode signal (such as zero-position signals PD1 to PD8); the selected zero-position signal is transmitted to the subsequent processing module of the chip or the external device through the output interface for subsequent signal processing and other operations; This design of a photoelectric encoder chip with switchable zero-seeking phase can effectively improve the zero-seeking efficiency of the photoelectric encoder chip during application, and can effectively avoid the phase mismatch between the zero-point signal and the incremental signal caused by factors such as installation errors and alignment errors of the photoelectric encoder chip and the code disk, as well as failure problems caused by the failure of a single photodiode. At the same time, the phase relationship switching function between the zero-position signal and the incremental signal can effectively improve the fault tolerance and reliability of the system, and improve the overall accuracy of the entire photoelectric encoder system.

2. A design of a photoelectric encoder chip with switchable zero-seeking phase, characterized by: The photodiode structure in the incremental code channel photodiode (PD) array (1) 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 encoding 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. 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 encoding disk.

3. A design of a photoelectric encoder chip with switchable zero-seeking phase, characterized by: The photodiode structure in the zero-position signal detection photodiode PD array (2) can be any one of a PN-type photodiode, a PIN-type photodiode, etc. It is mainly composed of 8 photodiodes, namely PD1, PD2, PD3, PD4, PD5, PD6, PD7, and PD8, and the distance difference between each two adjacent PDs is 9 / 8*T; that is, the zero-position signal output by the 8 PD detections can cover the entire period of intersection with the A and B signals. For example, taking the intersection of the falling edge of the A signal and the rising edge of the B signal as an example, ideally, the peak of the zero-position signal detected by PD1 is exactly located at this intersection, and the peak of the zero-position signal detected by PD2, PD3, PD4, PD5, PD6, PD7, and PD8 is respectively located at 1 / 8*T+T, 2 / 8*T+2T, 3 / 8*T+3T, 4 / 8*T+4T, 5 / 8*T+5T, 6 / 8*T+6T, and 7 / 8*T+7T of the intersection of the falling edge of the A signal and the rising edge of the B signal.

4. A design of a photoelectric encoder chip with switchable zero-seeking phase, characterized by: The transimpedance amplifier TIA in the transimpedance amplifier TIA array (3) in the design may 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), and its function is to convert the photocurrent signal generated by the zero-position signal detection photodiode PD array (2) into a voltage signal and output it; each TIA in the transimpedance amplifier TIA array (3) is connected to a PD in the zero-position signal detection photodiode PD array (2) in a single connection.

5. A design of a photoelectric encoder chip with switchable zero-seeking phase, characterized by: The switch unit array (4) 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 complete the selective output of zero-position signals PD of different phases in the zero-position signal detection photodiode PD array (2) under the control of the control switching circuit (5).

6. A design of a photoelectric encoder chip with switchable zero-seeking phase, characterized by: The control switching circuit module (5) is composed of a selection input interface, a selection logic circuit, a driving and buffering circuit, an output interface, etc. Its main function is to decode the received control signal according to the control signal of the external control device or system, generate a corresponding control signal to drive the control switch unit array (4), select and output the corresponding mode signal (such as zero position signals PD1 to PD8), and transmit the selected zero position signal to the subsequent processing module of the chip or the external device through the output interface for subsequent signal processing and other operations.

7. A design of a photoelectric encoder chip with switchable zero-seeking phase, characterized by: The photoelectric encoder chip (6) may be any one of a transmission type photoelectric encoder chip and a reflection type photoelectric encoder chip.

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