A driving control circuit and control method of an electromagnetically driven Fabry-Perot filter chip

Abstract

The present invention relates to a driving control circuit of an electromagnetically driven Fabry-Perot filter chip, comprising a printed circuit board, a light-through hole provided in the center of the printed circuit board, a microprocessor and an excitation circuit connected to the microprocessor, wherein the excitation circuit comprises a current driving chip connected to the microprocessor and a hollow electromagnetic coil connected to the current driving chip and coaxially arranged with the light-through hole, the microprocessor is used for respectively outputting two-way PWM signals with different duty cycle sizes and directions, the current driving chip receives the PWM signals and outputs corresponding currents with different sizes and opposite directions, the hollow electromagnetic coil is used for receiving the current and performing excitation, thereby driving a movable mirror of the Fabry-Perot filter chip to move up and down to change the length of the cavity of the Fabry-Perot filter chip; the structure can realize bidirectional wide-band linear tuning of the electromagnetically driven Fabry-Perot filter chip, and improve the spectral modulation fineness, response speed and response frequency of the electromagnetically driven Fabry-Perot filter chip.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent optomechanical system control, and in particular to a driving control circuit and a control method of an electromagnetically driven Fabry-Perot filter chip. Background Art

[0002] As early as 1897, French physicists C. Fabry and A. Perot proposed the parallel plane cavity interferometer, namely the Fabry-Perot filter, based on the principle of multi-beam interference. Since the interference fringes are very fine and sharp, the Fabry-Perot filter has always been an important tool in the fields of precision measurement and ultra-fine spectroscopy research. However, the spectral output characteristics of the traditional Fabry-Perot filter are single, and it is difficult to achieve tunable filtering. Since the 1980s, with the rise and development of micro-electro-mechanical systems (MEMS) technology, in order to meet the practical application needs of Fabry-Perot filters in optical communications, optical sensing, and laser systems, researchers have further proposed MEMS tunable Fabry-Perot filter chips based on traditional Fabry-Perot filters. The MEMS tunable Fabry-Perot filter chip is an optical filter chip based on the Fabry-Perot filter as a prototype and manufactured by MEMS technology. Its basic structure consists of two parallel mirrors and an intermediate cavity. The two mirrors are coated with a semi-transmissive and semi-reflective film on one side of the inner wall of the cavity. When the length of the Fabry-Perot cavity is an integer multiple of half the wavelength of the incident light, incident light of a specific wavelength forms a stable resonance in the cavity, thereby passing through the cavity with higher energy, while light of other wavelengths gradually attenuates and weakens in the cavity. From a macroscopic perspective, this is the spectral selective transmittance of the MEMS tunable Fabry-Perot filter chip.

[0003] The formula for the resonant wavelength of the incident light in the Fabry-Perot cavity is:

[0004]

[0005] where λ m is the resonance wavelength, n is the refractive index of the medium in the cavity, d is the cavity length of the Fabry-Perot cavity, θ is the incident angle, and m is the interference order.

[0006] In the MEMS tunable Fabry-Perot filter chip structure, one mirror is fixed and the other is a movable mirror. According to formula (1), the movable mirror is driven to move and the cavity length d of the Fabry-Perot cavity is changed, so the resonant wavelength λ of the incident light can be adjusted. m , thereby adjusting the spectral output characteristics of the MEMS tunable Fabry-Perot filter chip.

[0007] At present, the driving technologies used for MEMS tunable Fabry-Perot filter chips mainly include thermal driving, electrostatic driving and piezoelectric driving. As early as 1997, J. Peerlings et al. proposed a tunable Fabry-Perot filter chip based on thermal driving technology (IEEE Photon. Technol. Lett, vol. 9, pp. 1235-1237, 1997). Figure 3 As shown, the movable mirror support beam is heated by the electrothermal effect of the heating element, and the support beam is deformed by the heat to adjust the position of the movable mirror, control the change of the cavity length of the Fabry-Perot cavity, and realize the change of the spectral output characteristics of the Fabry-Perot filter chip. Since the movable mirror support beam requires a long heating process, the structure of the adjustable Fabry-Perot filter chip based on thermal drive responds slowly and consumes a lot of power, which is difficult to meet the requirements of practical applications. MEMS adjustable Fabry-Perot filter chip based on electrostatic drive (Proc. SPIE, vol. 4841, pp. 578-585, 2003), such as Figure 4 As shown, the movable mirror is driven to move through the interaction between the charges on the two mirror electrodes, thus changing the cavity length of the Fabry-Perot cavity and adjusting the spectral output characteristics of the Fabry-Perot filter chip. The MEMS adjustable Fabry-Perot filter chip based on electrostatic drive has a fast response speed, but the electric field between the charges on the two mirror plates can easily break through the chip and cause device failure; the Fabry-Perot filter chip based on electrostatic drive also has a "pull-down" problem in its structure, and the movable mirror's moving range is only about one-third of the length of the Fabry-Perot cavity, and the adjustable spectral range is relatively small. Figure 5 As shown, when voltage is applied to piezoelectric materials, they will deform due to the inverse piezoelectric effect. Therefore, they can also be used to drive the change of the cavity length of the Fabry-Perot cavity to achieve spectral control. In 2013, the Finnish National Technology Research Center successfully developed a MEMS adjustable Fabry-Perot filter chip based on piezoelectric drive (Proc. SPIE, vol. 8870, 887002, 2013). However, piezoelectric materials have poor compatibility with MEMS processes. Therefore, the MEMS adjustable Fabry-Perot filter chip based on piezoelectric drive still has many problems in terms of mass production and high-efficiency production. In 2004, HK Lee and others from South Korea proposed an electromagnetically driven MEMS adjustable Fabry-Perot filter chip (IEEE Photon. Technol. Lett, vol. 16, pp. 2087-2089, 2004), which can use electromagnetic force for drive control, thereby adjusting its spectral output characteristics. As Figure 6 As shown in the figure, the interaction force between the excitation coil and the magnetic field is used to drive the movable mirror in the Fabry-Perot filter chip structure to move and change its spectral output characteristics. Compared with thermal drive, electrostatic drive, and piezoelectric drive, electromagnetic drive has the advantages of low power consumption, fast structural response, strong robustness, and bidirectional wide-band linear modulation, which can further meet the practical application needs of related systems.

[0008] Although the MEMS adjustable Perot filter chip has shown broad application prospects in the fields of optical imaging, detection and identification, etc., current research is still mainly focused on the structural design and manufacturing process of the MEMS adjustable Perot filter chip. With the increasingly urgent demand for integration and systematization, higher requirements are placed on the performance of the MEMS adjustable Perot filter chip, such as spectral modulation fineness, response speed, response frequency and modularity, which requires a high-performance drive control circuit. The drive control circuit proposed by the present invention is based on the electromagnetic drive principle of the MEMS adjustable Perot filter chip. Through the comprehensive application of embedded and circuit design technologies, it can realize the bidirectional wide-band linear tuning of the electromagnetically driven MEMS adjustable Perot filter chip, improve the spectral modulation fineness, response speed and response frequency of the electromagnetically driven MEMS adjustable Perot filter chip, and meet the practical application needs of rapid integration with other systems. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a driving control circuit and a control method for an electromagnetically driven MEMS tunable Fabry-Perot filter chip, which can realize bidirectional wide-range linear tuning of the electromagnetically driven MEMS tunable Fabry-Perot filter chip and improve the spectral modulation fineness, response speed and response frequency of the electromagnetically driven MEMS tunable Fabry-Perot filter chip during actual operation.

[0010] In the first aspect, the technical solution adopted by the present invention is a driving control circuit of an electromagnetically driven Fabry-Perot filter chip, wherein the Fabry-Perot filter chip includes a substrate, a fixed mirror located on the substrate, a movable mirror located above the fixed mirror, a permanent magnet installed on the upper surface or the lower surface of the movable mirror, and a cavity formed between the fixed mirror and the movable mirror; the driving control circuit includes a printed circuit board, a light-through hole opened in the center of the printed circuit board, a microprocessor installed on the printed circuit board, and an excitation circuit installed on the printed circuit board and connected to the microprocessor, wherein the excitation circuit includes a current driving chip connected to the microprocessor and a hollow electromagnetic wire connected to the current driving chip and coaxially arranged with the light-through hole. circle, the light-through hole is used for allowing incident light emitted by an external light source to pass through, and the incident light is filtered by the Fabry filter chip after passing through the light-through hole, the microprocessor is used to respectively output two-way PWM signals with different duty cycle sizes and directions, the current driving chip is used to receive the two-way PWM signals with different duty cycle sizes and opposite directions, and output corresponding currents of different sizes and opposite directions according to the PWM signals, the hollow electromagnetic coil is used to receive the corresponding currents of different sizes and opposite directions output by the current driving chip and excite, thereby driving the movable mirror of the Fabry filter chip to move up and down to change the length of the cavity of the Fabry filter chip.

[0011] The beneficial effects of the present invention are as follows: a driving control circuit of the electromagnetically driven Fabry-Perot filter chip is adopted, a hollow electromagnetic coil is installed on a printed circuit board, the hollow electromagnetic coil is coaxially arranged with a light-through hole opened in the center of the printed circuit board, two-way PWM signals with different duty cycles and directions are respectively outputted by a microprocessor, a current driving chip outputs corresponding currents with different magnitudes and opposite directions after receiving the PWM signals, the hollow electromagnetic coil receives the current outputted by the current driving chip and performs excitation, thereby driving the Fabry-Perot filter chip to change the length of the cavity of the Fabry-Perot filter chip, once the length of the cavity of the Fabry-Perot filter chip changes, the spectral characteristics of the output light of the Fabry-Perot filter chip will change; the present invention outputs two-way PWM signals with different duty cycles and directions by a microprocessor to perform current excitation, thereby regulating the spectral characteristics of the output light of the Fabry-Perot filter chip, compared with the electrostatic driving method in the original technology, the spectral linear tuning amplitude is larger; and compared with the thermal driving method, the electromagnetically driven control method makes the modulation accuracy of the spectrum higher, the response speed faster, and the corresponding response frequency higher.

[0012] Preferably, the drive control circuit also includes a communication protocol conversion circuit connected to the microprocessor and a communication and power interface circuit connected to the communication protocol conversion circuit. The communication and power interface circuit is connected to a host computer. With this structure, the host computer sends control instructions to the microprocessor through the communication and power interface and the communication protocol conversion circuit. After receiving the instructions, the microprocessor sends a PWM signal of corresponding duty cycle size and direction to the current drive chip, thereby regulating the spectral characteristics of the output light of the Fabry-Perot filter chip. The structure is simple, the modulation accuracy is higher, the response speed is faster, and the corresponding response frequency is also higher.

[0013] Preferably, the excitation circuit also includes a current detection chip connected between the microprocessor and the hollow electromagnetic coil, and the current detection chip is used to detect the actual current value in the hollow electromagnetic coil and feed the actual current value back to the microprocessor. With this structure, the actual current value in the hollow electromagnetic coil is collected in real time by the current detection chip, and the actual current value is fed back to the microprocessor. The microprocessor compares the received actual current value with the calculated theoretical current value, and then corrects the output PWM signal to improve the spectral modulation accuracy.

[0014] In a second aspect, the technical solution adopted by the present invention is a control method for a driving control circuit of an electromagnetically driven Fabry-Perot filter chip, the method comprising the following steps:

[0015] S1. The host computer calculates the coil current value that needs to flow through the hollow electromagnetic coil corresponding to the target wavelength through the electromagnetic drive model of the Fabry filter chip, and then sends the coil current value to the microprocessor through the communication protocol conversion circuit and the communication and power interface circuit in turn;

[0016] S2, after receiving the coil current value, the microprocessor generates a PWM signal of corresponding magnitude and direction, and transmits the generated PWM signal to the current driving chip;

[0017] S3, after receiving the PWM signal, the current driving chip generates a current of corresponding magnitude and direction and transmits it to the hollow electromagnetic coil;

[0018] S4, a clockwise current or a counterclockwise current of corresponding magnitude is generated in the hollow electromagnetic coil and excited, thereby driving the movable mirror of the Fabry-Perot filter chip to reach a desired position, and regulating the spectral output characteristics of the Fabry-Perot filter chip;

[0019] S5. The current detection chip detects the magnitude and direction of the current in the hollow electromagnetic coil and feeds back to the microprocessor for closed-loop feedback control of the current in the hollow electromagnetic coil, thereby improving the fineness and stability of the spectral modulation of the Fabry-Perot filter chip by the driving control circuit of the electromagnetic-driven Fabry-Perot filter chip.

[0020] The control method of the driving control circuit of the electromagnetically driven Fabry-Perot filter chip mentioned above is adopted, and two-way PWM signals with different duty cycle sizes and directions are outputted respectively by a microprocessor, and the current driving chip outputs corresponding currents with different sizes and opposite directions after receiving the PWM signals, and the hollow electromagnetic coil receives the current outputted by the current driving chip and is excited, thereby driving the movable mirror of the Fabry-Perot filter chip to reach the expected position, so that the spectral characteristics of the output light of the Fabry-Perot filter chip are changed; the present invention controls the hollow electromagnetic coil to be excited by the microprocessor to output two-way PWM signals with different duty cycle sizes and directions respectively, thereby regulating the spectral characteristics of the output light of the Fabry-Perot filter chip, and compared with the electrostatic driving method in the original technology, its linear tuning amplitude is larger; and compared with the thermal driving method, the electromagnetic driving control method makes the modulation accuracy of the spectrum higher, the response speed faster, and the corresponding response frequency is also higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a front view of a driving control circuit of an electromagnetic driven Fabry-Perot filter chip of the present invention;

[0022] Figure 2 A top view of a driving control circuit of an electromagnetically driven Fabry-Perot filter chip of the present invention;

[0023] Figure 3This is a schematic diagram of the spectrum control principle of the heat-driven Fabry-Perot filter chip in the prior art;

[0024] Figure 4 This is a schematic diagram of the spectrum control principle of the electrostatically driven Fabry-Perot filter chip in the prior art;

[0025] Figure 5 This is a schematic diagram of the spectrum control principle of the piezoelectric driven Fabry-Perot filter chip in the prior art;

[0026] Figure 6 This is a schematic diagram of the spectrum control principle of the electromagnetic driven Fabry-Perot filter chip in the present invention;

[0027] Figure 7 A schematic diagram of the wavelength range of light output by the electromagnetically driven Fabry-Perot filter chip of the present invention after spectrum regulation;

[0028] Figure 8 This is a system block diagram of a driving control circuit of an electromagnetically driven Fabry-Perot filter chip of the present invention;

[0029] Fig. 9 is a circuit schematic diagram of the excitation circuit in the present invention;

[0030] Fig.10 It is the working circuit principle diagram of the microprocessor in the present invention;

[0031] Fig.11 is a circuit schematic diagram of the crystal oscillator circuit in the present invention;

[0032] Fig.12 is a circuit schematic diagram of the reset circuit in the present invention;

[0033] Fig.13 is a circuit schematic diagram of the communication protocol conversion circuit in the present invention;

[0034] Fig.14 is a circuit schematic diagram of the voltage stabilizing circuit in the present invention;

[0035] Fig.15 It is a circuit schematic diagram of the communication and power interface circuit in the present invention;

[0036] Fig.16 The flowchart is a control method of a driving control circuit of an electromagnetically driven Fabry-Perot filter chip in the present invention;

[0037] As shown in the figure: 1. Printed circuit board; 2. Positioning hole; 3. Hollow electromagnetic coil; 4. Current detection chip; 5. Microprocessor; 6. Crystal oscillator; 7. Capacitor and resistor; 8. Reset button; 9. Communication protocol conversion chip; 10. Voltage regulator chip; 11. Communication and power interface; 12. Current drive chip; 13. Light hole. DETAILED DESCRIPTION

[0038] The invention will be further described below with reference to the accompanying drawings and in combination with specific implementations, so that those skilled in the art can implement the invention with reference to the description. The protection scope of the invention is not limited to the specific implementations.

[0039] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or positional relationship indicated by terms such as "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the accompanying drawings, which 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 orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0040] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0041] In the description of the embodiments of the present application, 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 components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] The present invention relates to a driving control circuit of an electromagnetically driven Fabry-Perot filter chip. Figure 6 As shown, the Fabry filter chip includes a substrate, a fixed mirror located on the substrate, a movable mirror located above the fixed mirror, a permanent magnet disposed on the movable mirror, and a cavity located between the fixed mirror and the movable mirror; Figure 1As shown, the driving control circuit includes a printed circuit board 1, a light hole 13 opened in the center of the printed circuit board 1, a microprocessor 5 installed on the printed circuit board 1, and an excitation circuit installed on the printed circuit board 1 and connected to the microprocessor 5. The excitation circuit includes a current driving chip 12 connected to the microprocessor 5 and a hollow electromagnetic coil 3 connected to the current driving chip 12 and coaxially arranged with the light hole 13. The light hole 13 is used for allowing incident light emitted by an external light source to pass through. After passing through the light hole 13, the incident light is filtered by the Fabry filter chip. The microprocessor 5 is used to output two-way PWM signals with different duty cycle sizes and directions respectively. The current driving chip 12 is used to receive the two-way PWM signals with different duty cycle sizes and opposite directions, and output corresponding currents with different sizes and opposite directions according to the PWM signals. The hollow electromagnetic coil 3 is used to receive the corresponding currents with different sizes and opposite directions output by the current driving chip 12 and excite, thereby driving the movable mirror of the Fabry filter chip to move up and down to change the length of the cavity of the Fabry filter chip.

[0043] The spectrum control principle of the driving control circuit of the electromagnetic driven Fabry-Perot filter chip provided by the present invention is shown in Figure 6 ,exist Figure 6 In (a), a permanent magnet sheet is arranged on the lower surface of the movable mirror, and a clockwise current is generated in the electromagnetic coil for excitation. The coil current excitation repels the permanent magnet sheet, thereby driving the movable mirror of the Fabry-Perot filter chip to move toward the fixed mirror, so that the length d+Δd of the cavity of the Fabry-Perot filter chip decreases. As the current value gradually increases, the cavity length of the Fabry-Perot cavity gradually decreases. The incident light emitted by the external light source sequentially passes through the hollow electromagnetic coil 3 and the light hole 13 to reach the Fabry-Perot filter chip. The incident light is filtered by the Fabry-Perot filter chip and then transmitted out. The length of the cavity of the Fabry-Perot filter chip decreases, and the resonant wavelength becomes shorter, so that light of a specific wavelength can be transmitted out from the Fabry-Perot filter chip. Figure 6 In (b), a counterclockwise current is generated in the electromagnetic coil for excitation. The coil current excitation attracts the permanent magnet sheet, thereby driving the movable mirror of the Fabry-Perot filter chip to move away from the fixed mirror, so that the length d+Δd of the cavity of the Fabry-Perot filter chip increases. As the current value gradually increases, the cavity length of the Fabry-Perot cavity gradually increases. The incident light emitted by the external light source passes through the hollow electromagnetic coil 3 and the light-through hole 13 in turn to reach the Fabry-Perot filter chip. The incident light is filtered by the Fabry-Perot filter chip and then transmitted out. The length of the cavity of the Fabry-Perot filter chip increases, and the resonant wavelength becomes longer, so that light of a specific wavelength can be transmitted from the Fabry-Perot filter chip. Therefore, controlling the magnitude and direction of the current in the hollow electromagnetic coil 3 can realize the regulation of the spectral output characteristics of the electromagnetically driven Fabry-Perot filter chip.

[0044] use Figure 1A driving control circuit of an electromagnetically driven Fabry-Perot filter chip is disclosed. A hollow electromagnetic coil 3 is installed on a printed circuit board 1. The hollow electromagnetic coil 3 is coaxially arranged with a light-through hole 13 opened in the center of the printed circuit board 1. A microprocessor 5 is used to output two-way PWM signals with different duty cycles and directions. After receiving the PWM signals, a current driving chip 12 outputs corresponding currents with different sizes and opposite directions. The hollow electromagnetic coil 3 receives the current output by the current driving chip 12 and performs excitation, thereby driving the Fabry-Perot filter chip to change the length of the cavity of the Fabry-Perot filter chip. Once the length of the cavity of the Fabry-Perot filter chip changes, the spectral characteristics of the output light of the Fabry-Perot filter chip will change. The present invention uses a microprocessor 5 to output two-way PWM signals with different duty cycles and directions for current excitation, thereby regulating the spectral characteristics of the output light of the Fabry-Perot filter chip. Figure 3 Compared with the thermal drive method in the electromagnetic drive control method, the modulation accuracy of the spectrum is higher, the response speed is faster, and the corresponding response frequency is also higher; and compared with Figure 4 Compared with the electrostatic driving method in the invention, the method of the present invention can realize bidirectional modulation, and the linear tuning amplitude is larger, and only the current size needs to be changed.

[0045] like Figure 8 As shown, the drive control circuit also includes a communication protocol conversion circuit connected to the microprocessor 5 and a communication and power interface circuit connected to the communication protocol conversion circuit, and the communication and power interface circuit is connected to the host computer. Figure 8 In the embodiment, the microprocessor 5 has IIC communication, PWM signal generation and serial communication functions; the communication and power interface 11 is the hardware interface for communication between the host computer and the microprocessor 5, and is also the hardware interface for powering all circuit units on the printed circuit board 1; the current driving chip 12 has a dual-channel DC current output capability, which can generate clockwise or counterclockwise currents of different sizes in the hollow electromagnetic coil 3 for excitation, and drive and regulate the spectral output characteristics of the Fabry-Perot filter chip; the host computer sends a control instruction to the microprocessor 5 through the communication protocol conversion circuit and the communication and power interface 11, and the microprocessor 5 sends a PWM signal of corresponding duty cycle size and direction to the current driving chip 12 after receiving the instruction, so as to regulate the spectral characteristics of the output light of the Fabry-Perot filter chip. The structure is simple, the modulation accuracy is higher, the response speed is faster, and the corresponding response frequency is also higher.

[0046] like Figure 8As shown, the excitation circuit also includes a current detection chip 4 connected between the microprocessor 5 and the hollow electromagnetic coil 3. The current detection chip 4 is used to detect the actual current value in the hollow electromagnetic coil 3 and feed the actual current value back to the microprocessor 5. With this structure, the actual current value in the hollow electromagnetic coil 3 is collected in real time by the current detection chip 4, and the actual current value is fed back to the microprocessor 5. The microprocessor 5 compares the received actual current value with the calculated theoretical current value, and then corrects the output PWM signal to improve the spectral modulation accuracy.

[0047] like Figure 1 As shown, the driving control circuit of the electromagnetic driven Fabry filter chip provided by the present invention also includes a reset circuit installed on the printed circuit board 1 and connected to the microprocessor 5. The reset circuit includes a reset button 8. The reset button 8 has the function of manually resetting the driving control circuit. The reset button 8 uses a non-self-locking switch. The reset circuit is shown in FIG. Fig.12 , with power-on automatic reset and key manual reset functions, the NRST pin of the reset circuit triggers the reset of the microprocessor 5 in a low level state; the drive control circuit also includes a crystal oscillator circuit installed on the printed circuit board 1 and connected to the microprocessor 5, the crystal oscillator circuit includes a crystal oscillator 6, the crystal oscillator 6 can select active or passive crystal oscillators 6 of different frequencies according to the actual use requirements of the microprocessor 5, and the external crystal oscillator 6 can be omitted when the microprocessor has its own clock signal, see Fig.11 The crystal oscillator circuit is given; the drive control circuit also includes a voltage stabilizing circuit installed on the printed circuit board 1 and connected to the microprocessor 5, the voltage stabilizing circuit includes a voltage stabilizing chip 10, and the voltage stabilizing chip 10 has a voltage stabilizing and filtering function for the voltage from the communication and power interface 11, and can supply power to all circuit units on the printed circuit board 1; Figure 1 In the circuit, the current detection chip 4, the microprocessor 5, the crystal oscillator 6, the capacitor and the resistor 7, the reset button 8, the communication protocol conversion chip 9, the voltage stabilizing chip 10, the communication and power interface 11 and the current driving chip 12 and the circuit connection relationship between them are completed on the printed circuit board 1 through surface mounting technology (SMT).

[0048] like Figure 1 As shown, the printed circuit board 1 is also provided with a mounting positioning hole 2, which is used for integrating the drive control circuit with other systems; the mounting positioning hole 2 is a through hole with a diameter of 3 mm.

[0049] The printed circuit board 1 can be made of FR4, PI, PET, aluminum and other materials using standard PCB technology. The central light hole 13 of the printed circuit board 1 can be designed into different shapes such as circular, rectangular, triangular and polygonal according to actual use requirements. The central light hole 13 and the hollow electromagnetic coil 3 can be fixed by bonding, welding and other methods. Figure 1 As shown, the printed circuit board 1 is circular in shape, with a diameter of 50 mm, a central light hole 13 with a diameter of 16 mm, and is made of FR4 material and processed by standard PCB technology with a thickness of 2 mm. The hollow electromagnetic coil 3 is fixed to the central light hole 13 of the printed circuit board 1 by a bonding process.

[0050] like Figure 1 As shown, the hollow electromagnetic coil 3 has a light hole 13 at the lower center thereof, and the hollow electromagnetic coil 3 can be wound with a single layer or multiple layers of enameled metal wire. The cross section of the hollow electromagnetic coil 3 can be designed into a circular, rectangular, triangular or other polygonal shape according to the use requirements, and the central light hole 13 can be designed into a circular, rectangular, triangular or other polygonal shape according to the actual use requirements. Figure 1 The hollow electromagnetic coil 3 is wound with a copper enameled wire of 10 m in length and 0.25 mm in diameter, and the coil inductance is 5 H. The hollow electromagnetic coil 3 and the light-through hole 13 in the center are both circular, with an inner diameter of 10 mm and an outer diameter of 16 mm.

[0051] The current driving chip 12 can be a current driving chip 12 with dual-channel DC output capability such as TA6856 and MX1919, which is used to mount the hollow electromagnetic coil 3 to generate an electromagnetic field of corresponding size and direction to drive the change of the spectral output characteristics of the electromagnetic driven Fabry-Perot filter chip.

[0052] like Fig. 9 As shown, the current driving chip 12 uses TA6856. The two logic input terminals FI and BI of the TA6586 current driving chip 12 are used to control the two logic output terminals FO and BO to generate clockwise or counterclockwise currents of different magnitudes in the hollow electromagnetic coil 3. When FI=H, BI=L (H: high level, L: low level), FO=H, BO=L, that is, the current is output in the forward direction, and the current in the hollow electromagnetic coil 3 is clockwise; when FI=L, BI=H, FO=L, BO=H, that is, the current is output in the reverse direction, and the current in the hollow electromagnetic coil 3 is counterclockwise. The bidirectional current output capability of the TA6586 current driving chip 12 enables the present invention to have the ability to bidirectionally drive the electromagnetic driven Fabry-Perot filter chip. Fig. 9In the embodiment, the FO and BO ports of the TA6586 current driver chip 12 are respectively connected to the two ends of the hollow electromagnetic coil 3, and the FI and BI ports are respectively connected to the two PWM signal generating ports PWM_F and PWM_B of the microprocessor 5. The precision resistor R3 with a resistance of 0.1 ohms is connected in series with the hollow electromagnetic coil 3, and its two ends are respectively connected to the VIN+ and VIN- ports of the INA219 current detection chip 4. The actual current magnitude and direction of the hollow electromagnetic coil 3 are obtained by detecting the voltage across R3. The SDA and SCL of the INA219 current detection chip 4 are respectively connected to the SDA and SCL pins of the microprocessor 5, and the hardware connection for realizing IIC communication is used to feed back the actual current value in the hollow electromagnetic coil 3 to the microprocessor 5.

[0053] like Fig. 9 As shown, the current detection chip 4 can be a power monitoring chip with bidirectional current monitoring capability such as INA219; the current detection chip 4 is used to monitor the magnitude and direction of the actual current in the hollow electromagnetic coil 3 and feed back to the microprocessor 5. The current detection chip 4 detects the actual current value in the hollow electromagnetic coil 3 and then feeds back to the microprocessor 5 to improve the accuracy and stability of the current control of the hollow electromagnetic coil 3.

[0054] The microprocessor 5 can be an integrated circuit chip such as STM32, ST89C51, Arduino, etc. that supports PWM signal generation and communication functions. Fig.10 As shown, the microprocessor 5 uses STM32F103C8T6. STM32F103C8T6 is a cost-effective 32-bit microprocessor 5 chip with general input and output, PWM signal generation, IIC communication, timer and interrupt functions. The VDD pin is the power input port of the chip and needs to be connected to a 3.3V power supply; the OSC-IN pin and OSC-OUT pin are the clock signal input ports of the chip and are connected to Fig.11 The XTAL1 and XTAL2 pins of the chip are connected to the PA4 and PA5 pins respectively. Fig. 9 The SDA and SCL pins of the chip; the PA6 and PA7 pins are the PWM signal output pins of the chip, which are connected to Fig. 9 PWM_F and PWM_B are used to control the current driving chip 12 to output clockwise or counterclockwise currents of different magnitudes in the hollow electromagnetic coil 3; PA9 and PA10 are serial communication pins of the chip, which are connected to Fig.13 The RXD and TXD pins are used to receive instructions from the host computer.

[0055] like Fig.11 As shown, the crystal oscillator 6 in the crystal oscillator circuit uses an 8M active crystal oscillator 6, both ends of the crystal oscillator 6 are grounded through a 22pF capacitor and connected in series through a 1M resistor.

[0056] The capacitor and resistor 7 are peripheral devices required for the normal operation of the core chip of each functional unit of the electromagnetic driven Fabry-Perot filter chip drive control circuit, and different quantities or types can be selected according to actual needs.

[0057] like Fig.12 As shown, when the printed circuit board 1 is just powered on, the capacitor C7 is charged and turned on, and the REST terminal is grounded, triggering the reset of the drive control circuit; when the reset button 8 is pressed, REST is grounded, triggering the reset of the drive control circuit.

[0058] The communication protocol conversion chip 9 can be selected from universal serial communication bus (USB) protocol to serial port chips such as CH340, HT42B534, CP2104, etc., or other types of communication protocol conversion chips 9 can be selected according to actual use requirements. Fig.13 As shown, the communication protocol conversion chip 9 uses CH340C. The CH340C chip is a commonly used USB protocol to serial port protocol chip. Its TXD pin and RXD pin are serial port communication pins, which are connected to Fig.10 The Rx and Tx pins of the USB port are connected to the D+ and D- pins respectively. Fig.15 The connection methods of the other pins refer to the chip manual.

[0059] The 5V power supply of the printed circuit board 1 comes directly from the communication and power interface circuit, or it can be obtained from the communication and power interface circuit after voltage stabilization and filtering. The voltage stabilization circuit can use AMS1117, LM1117 and other voltage stabilization chips 10 to reduce the 5V voltage to 3.3V. The 5V and 3.3V voltages are filtered to power the remaining circuit units on the printed circuit board 1. According to actual use requirements, the driving voltage can also be adjusted to other values, and the corresponding functional chips can be selected. Fig.14 The voltage stabilizing circuit provided as shown, the voltage stabilizing chip 10 uses AMS1117-3.3V. Fig.14 The VIN pin of the AMS1117-3.3V chip is used for 5V voltage input, and the VOUT pin outputs the 3.3V voltage obtained by stepping down. C8 and C9 are filter capacitors.

[0060] The communication and power interface 11 can be a standard communication hardware interface such as USB, which is used to realize the physical connection between the printed circuit board 1 and the host computer for communication and power supply. Fig.15 The communication and power interface circuit provided in the figure, the communication and power interface 11 uses a standard USB Type-C interface, the USB Type-C interface is a standard hardware interface based on USB protocol communication and has the ability to supply 5V power. Its working principle is shown in Fig.15 .

[0061] The working process of the driving control circuit of the electromagnetic driven Perot filter chip provided by the present invention is further described as follows: After the STM32F103C8T6 microprocessor 5 receives the instruction of the required output current size and direction in the hollow electromagnetic coil 3 via the USB Type-C communication and power interface 11 and the USB to serial port CH340C communication protocol conversion chip 9, the corresponding duty cycle PWM signal is sent to the FI or BI pin of the TA6586 current driving chip 12 through the PA6 and PA7 pins. After receiving the PWM signal, the TA6586 current driving chip 12 generates a clockwise or counterclockwise current of corresponding size in the hollow electromagnetic coil 3 for excitation, thereby driving the movable mirror of the Perot filter chip to reach the expected position and adjusting its spectral output characteristics. When the STM32F103C8T6 microprocessor 5 sends a PWM signal to the FI pin of the TA6586 current driver chip 12 and BI=L, the current direction in the hollow electromagnetic coil 3 is clockwise, and the current size depends on the size of the duty cycle of the PWM signal. The hollow electromagnetic coil 3 drives the movable mirror of the Fabry-Perot filter chip to move downward, the cavity length of the Fabry-Perot cavity is reduced, and the resonant wavelength in the cavity is reduced; when the STM32F103C8T6 microprocessor 5 sends a PWM signal to the BI pin of the TA6586 current driver chip 12 and FI=L, the current direction in the hollow electromagnetic coil 3 is counterclockwise, and the current size depends on the size of the duty cycle of the PWM signal. The hollow electromagnetic coil 3 drives the movable mirror of the Fabry-Perot filter chip to move upward, the cavity length of the Fabry-Perot cavity is increased, and the resonant wavelength in the cavity is increased. The INA219 current detection chip 4 measures the actual current size and direction in the hollow electromagnetic coil 3 through the 0.1 precision voltage divider resistor R3 and feeds back to the STM32F103C8T6 microprocessor 5 through the IIC communication interface to improve the control accuracy and stability of the current in the hollow electromagnetic coil 3, achieve fast and accurate adjustment of the cavity length of the Fabry-Perot cavity, and regulate the spectral output characteristics of the electromagnetic driven Fabry-Perot filter chip.

[0062] The present invention also provides a control method for a driving control circuit of an electromagnetically driven Fabry-Perot filter chip, such as Fig.16 As shown, the method comprises the following steps:

[0063] S1, the host computer calculates the coil current value that needs to flow through the hollow electromagnetic coil 3 corresponding to the target wavelength through the electromagnetic drive model of the Fabry filter chip, and then sends the coil current value to the microprocessor 5 through the communication protocol conversion chip 9 and the communication and power interface 11 in turn;

[0064] S2, the microprocessor 5 generates a PWM signal of corresponding magnitude and direction after receiving the coil current value, and transmits the generated PWM signal to the current driving chip 12;

[0065] S3, after receiving the PWM signal, the current driving chip 12 generates a current of corresponding magnitude and direction and transmits it to the hollow electromagnetic coil 3;

[0066] S4, a clockwise current or a counterclockwise current of corresponding magnitude is generated in the hollow electromagnetic coil 3 and excited, thereby driving the movable mirror of the Fabry-Perot filter chip to reach a desired position, and regulating the spectral output characteristics of the Fabry-Perot filter chip;

[0067] S5. The current detection chip 4 detects the magnitude and direction of the current in the hollow electromagnetic coil 3 and feeds it back to the microprocessor 5 for closed-loop feedback control of the current in the hollow electromagnetic coil 3, thereby improving the spectral modulation fineness and stability of the electromagnetic driven Fabry-Perot filter chip by the driving control circuit of the Fabry-Perot filter chip.

[0068] The control method of the driving control circuit of the electromagnetically driven Fabry-Perot filter chip mentioned above is adopted, and two-way PWM signals with different duty cycle sizes and directions are respectively outputted by the microprocessor 5, and the current driving chip 12 outputs corresponding currents of different sizes and opposite directions after receiving the PWM signals, and the hollow electromagnetic coil 3 receives the current outputted by the current driving chip 12 and performs excitation, thereby driving the movable mirror of the Fabry-Perot filter chip to reach the expected position, so that the spectral characteristics of the output light of the Fabry-Perot filter chip are changed; the present invention performs current excitation by respectively outputting two-way PWM signals with different duty cycle sizes and directions by the microprocessor 5, thereby regulating the spectral characteristics of the output light of the Fabry-Perot filter chip, and compared with the electrostatic driving method in the original technology, its linear tuning amplitude is larger; and compared with the thermal driving method, the electromagnetic driving control method makes the modulation accuracy of the spectrum higher, the response speed faster, and the corresponding response frequency is also higher.

Claims

1. A driving control circuit of an electromagnetically driven Fabry-Perot filter chip, the Fabry-Perot filter chip comprising a substrate, a fixed mirror located on the substrate, a movable mirror located above the fixed mirror, a permanent magnet installed on the upper surface or the lower surface of the movable mirror, and a cavity formed between the fixed mirror and the movable mirror; characterized in that: The drive control circuit comprises a printed circuit board (1), a light-through hole (13) provided at the center of the printed circuit board (1), a microprocessor (5) mounted on the printed circuit board (1), and an excitation circuit mounted on the printed circuit board (1) and connected to the microprocessor (5); the excitation circuit comprises a current drive chip (12) connected to the microprocessor (5) and a hollow electromagnetic coil (3) connected to the current drive chip (12) and coaxially arranged with the light-through hole (13); the light-through hole (13) is used for incident light emitted by an external light source to pass through; the incident light passes through the light-through hole (13) and then passes through the electromagnetic coil (3). The filter is filtered through the Fabry filter chip, the microprocessor (5) is used to output two-way PWM signals with different duty cycles and directions respectively, the current driving chip (12) is used to receive the two-way PWM signals with different duty cycles and opposite directions, and output corresponding currents of different sizes and opposite directions according to the PWM signals, and the hollow electromagnetic coil (3) is used to receive the corresponding currents of different sizes and opposite directions output by the current driving chip (12) and excite, thereby driving the movable mirror of the Fabry filter chip to move up and down to change the length of the cavity of the Fabry filter chip.

2. The driving control circuit of the electromagnetic driven Fabry-Perot filter chip according to claim 1, characterized in that: The drive control circuit also includes a communication protocol conversion circuit connected to the microprocessor (5) and a communication and power interface circuit connected to the communication protocol conversion circuit, and the communication and power interface circuit is connected to a host computer.

3. The driving control circuit of the electromagnetic driven Fabry-Perot filter chip according to claim 1, characterized in that: The excitation circuit also includes a current detection chip (4) connected between the microprocessor (5) and the hollow electromagnetic coil (3), wherein the current detection chip (4) is used to detect an actual current value and a current direction in the hollow electromagnetic coil (3), and to feed back the actual current value and the current direction to the microprocessor (5).

4. A control method for the driving control circuit of the electromagnetic driven Fabry-Perot filter chip according to claim 2, the method comprising the following steps: S1, the host computer calculates the coil current value required to flow through the hollow electromagnetic coil (3) corresponding to the target wavelength through the electromagnetic drive model of the Fabry filter chip, and then sends the coil current value to the microprocessor (5) through the communication and power interface circuit and the communication protocol conversion circuit in sequence; S2, the microprocessor (5) generates a PWM signal of corresponding magnitude and direction after receiving the coil current value, and transmits the generated PWM signal to the current driving chip (12); S3, after receiving the PWM signal, the current driving chip (12) generates a current of corresponding magnitude and direction and transmits it to the hollow electromagnetic coil (3); S4, generating a clockwise current or a counterclockwise current of corresponding magnitude in the hollow electromagnetic coil (3) and performing excitation, thereby driving the movable mirror of the Fabry-Perot filter chip to reach a desired position, and regulating the spectral output characteristics of the Fabry-Perot filter chip; S5. The current detection chip (4) detects the magnitude and direction of the current in the hollow electromagnetic coil (3) and feeds back to the microprocessor (5) for closed-loop feedback control of the current in the hollow electromagnetic coil (3), thereby improving the fineness and stability of the spectral modulation of the Fabry-Perot filter chip by the drive control circuit of the electromagnetic driven Fabry-Perot filter chip.

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