Galvanometer driving circuit, projection equipment and galvanometer driving method

Abstract

The embodiment of the invention provides a galvanometer driving circuit, projection equipment and a galvanometer driving method, and relates to the technical field of laser projection. The galvanometer driving circuit comprises a digital waveform generation module, a digital-to-analog conversion module and an operational amplification module, the digital waveform generation module is used for generating a digital waveform signal and transmitting the digital waveform signal to the digital-to-analog conversion module, and the digital waveform signal comprises a digital driving waveform signal; the digital-to-analog conversion module is used for carrying out digital-to-analog conversion on the digital driving waveform signal and transmitting an analog driving waveform signal obtained through digital-to-analog conversion to the operational amplification module; the operational amplification module is used for generating a first driving voltage and a second driving voltage which are opposite in phase according to the analog driving waveform signal, transmitting the first driving voltage to the coil positive electrode and transmitting the second driving voltage to the coil negative electrode. The embodiment of the invention is used for solving the problem of high cost of a galvanometer driving circuit.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser projection technology, and more specifically, to a galvanometer drive circuit, a projection device, and a galvanometer drive method. Background Art

[0002] In the application of digital light processing (DLP) projection technology, a deflectable galvanometer is used to improve the resolution. The deflection of the galvanometer produces an offset of the display pixels, thereby improving the resolution of the final projected image.

[0003] The galvanometer needs a galvanometer drive circuit to drive the galvanometer for deflection. At present, current driving is usually used to drive the galvanometer deflection. However, the current driving method requires both a positive voltage generation circuit and a negative voltage generation circuit. The circuit requires more components, which increases the cost of the galvanometer drive circuit. Summary of the invention

[0004] The exemplary embodiments of the present application provide a galvanometer drive circuit, a projection device, and a galvanometer drive method, which are used to solve the problem of high cost of the galvanometer drive circuit.

[0005] The technical solutions provided by the embodiments of this application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a galvanometer drive circuit, comprising: a digital waveform generation module, a digital-to-analog conversion module, and an operational amplifier module;

[0007] The digital waveform generation module is connected to the digital-to-analog conversion module, and is used to generate a digital waveform signal and transmit the digital waveform signal to the digital-to-analog conversion module, wherein the digital waveform signal includes a digital driving waveform signal;

[0008] The digital-to-analog conversion module is also connected to the operational amplifier module, and the digital-to-analog conversion module is used to perform digital-to-analog conversion on the digital driving waveform signal, and transmit the analog driving waveform signal converted from the digital-to-analog conversion to the operational amplifier module;

[0009] The operational amplifier module is also connected to the positive pole and the negative pole of the coil of the galvanometer. The operational amplifier module is used to generate a first drive voltage and a second drive voltage with opposite phases according to the analog drive waveform signal, and transmit the first drive voltage to the positive pole of the coil, and transmit the second drive voltage to the negative pole of the coil, wherein the difference between the first drive voltage and the second drive voltage is the drive signal of the galvanometer, and the drive signal is used to drive the galvanometer to deflect.

[0010] In a second aspect, an embodiment of the present application provides a projection device, including: a display control component, a light source driving component, a light source, a light valve, a galvanometer driving component, a galvanometer, and a lens, wherein the galvanometer driving component includes the galvanometer driving circuit described in any embodiment of the first aspect;

[0011] The display control component is respectively connected to the light source driving component, the light valve and the galvanometer driving component. The light source driving component is also connected to the light source. The galvanometer driving component is also connected to the galvanometer. The galvanometer is located between the light valve and the lens.

[0012] In a third aspect, an embodiment of the present application provides a galvanometer driving method, including:

[0013] generating a digital waveform signal, wherein the digital waveform signal comprises a digital driving waveform signal;

[0014] Performing digital-to-analog conversion on the digital driving waveform signal to obtain an analog driving waveform signal;

[0015] A first driving voltage and a second driving voltage with opposite phases are generated according to the analog driving waveform signal, and the first driving voltage is applied to the positive pole of the coil of the galvanometer, and the second driving voltage is applied to the negative pole of the coil of the galvanometer, so that the difference between the first driving voltage and the second driving voltage serves as the driving signal of the galvanometer to drive the galvanometer to deflect.

[0016] It can be seen from the above technical solutions that the galvanometer drive circuit, projection device and galvanometer drive method provided in the embodiment of the present application use an operational amplifier module to divide the analog drive waveform signal into two, obtain a first drive voltage and a second drive voltage with opposite phases, and apply the first drive voltage to the positive pole of the coil of the galvanometer, and apply the second drive voltage to the negative pole of the coil of the galvanometer, and use the difference between the first drive voltage and the second drive voltage to achieve voltage drive on the galvanometer. In this way, the galvanometer drive circuit provided in the embodiment of the present application only needs to use one voltage generation circuit (corresponding to the digital waveform generation module of the present application), and the analog drive waveform signal generated by the digital waveform generation module and converted by the digital-to-analog conversion module is processed into two drive voltages with opposite phases through the operational amplifier module, and the voltage drive of the galvanometer is achieved by using the difference between the two drive voltages to drive the galvanometer to deflect, thereby saving a voltage generation circuit and reducing the cost of the galvanometer drive circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the implementation methods in the embodiments of the present application or the related technologies, the following is a brief introduction to the drawings required for use in the embodiments or the related technology descriptions. Obviously, the drawings described below are some embodiments of the present application, and a person skilled in the art can also obtain other drawings based on these drawings.

[0018] Figure 1 A schematic diagram of the structure of a projection device in some embodiments is shown;

[0019] Figure 2 A schematic diagram showing display resolution expansion in some embodiments;

[0020] Figure 3 A schematic diagram showing the structure of another projection device in some embodiments is shown;

[0021] Figure 4 A schematic structural diagram of a single-axis galvanometer in some embodiments is shown;

[0022] Figure 5 A structural block diagram of a galvanometer drive circuit in some embodiments is shown;

[0023] Figure 6 A structural block diagram of another galvanometer drive circuit in some embodiments is shown;

[0024] Figure 7 A circuit diagram of an operational amplifier module in some embodiments is shown;

[0025] Figure 8 A structural block diagram of another galvanometer drive circuit in some embodiments is shown;

[0026] Fig. 9 A circuit diagram of a galvanometer drive circuit in some embodiments is shown;

[0027] Fig.10 shows a waveform diagram of a first driving voltage in some embodiments;

[0028] Fig.11 shows a waveform diagram of a second driving voltage in some embodiments;

[0029] Fig.12 shows a waveform diagram of a driving signal in some embodiments;

[0030] Fig.13 A flow chart of a galvanometer driving method in some embodiments is shown. DETAILED DESCRIPTION

[0031] In order to make the purpose and implementation method of the present application clearer, the exemplary implementation method of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0032] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0033] The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0034] Figure 1 FIG. 4 shows a schematic diagram of the structure of a projection device in some embodiments. Figure 1 As shown, the projection device may include: a display control component 10, a light source driving component 20, a light source 30, a light valve 40, a galvanometer driving component 50, a galvanometer 60 and a lens 70, wherein the galvanometer driving component 50 includes a galvanometer driving circuit provided in an embodiment of the present application (see the detailed description below); the display control component 10 is respectively connected to the light source driving component 20, the light valve 40 and the galvanometer driving component 50, the light source driving component 20 is also connected to the light source 30, the galvanometer driving component 50 is also connected to the galvanometer 60, and the galvanometer 60 is located between the light valve 40 and the lens 70.

[0035] The light source driving assembly 20 is one or more (including two), and the light source 30 includes a laser corresponding to the light source driving assembly 20. The display control assembly 10 may include a digital light processing chip (DLPC). For example, the digital light processing chip may be DLPC 3437. The light source 30 may be a laser light source, for example, Figure 1 , the laser light source may include a blue laser, a red laser and a green laser. The light valve 40 may be a digital micro-mirror device (DMD). The galvanometer 60 may be used to shift sub-images of different frames to different positions of the projection screen, thereby realizing the superposition display of the multiple frames of sub-images, thereby achieving the effect of expanding the resolution of the projection device. Optionally, the galvanometer 60 may have two deflection positions, that is, the galvanometer 60 may shift the sub-image to two different positions of the projection screen, thereby increasing the resolution of the projection device by 1 times, for example, increasing the 720p resolution to 2K resolution, increasing the 3K resolution to 4K resolution, etc.

[0036] Specifically, a frame of target image to be projected and displayed (which may be an image with a lower resolution, such as an image with a 720p resolution) is processed into two frames of sub-images via the display control component 10. In the process of projecting and displaying each frame of sub-images, the display control component 10 may control the galvanometer drive component 50 to generate a digital drive waveform signal corresponding to a frame of sub-images. The galvanometer drive component 50 converts the digital drive waveform signal into an analog drive waveform signal, and generates a first drive voltage and a second drive voltage with opposite phases according to the analog drive waveform signal. The first drive voltage is applied to the positive pole of the coil of the galvanometer, and the second drive voltage is applied to the negative pole of the coil of the galvanometer. The voltage difference between the first drive voltage and the second drive voltage (i.e., the drive signal) is used to drive the galvanometer 60 to deflect. Among them, the digital drive waveform signals corresponding to different frames of sub-images are different, thereby realizing the projection of two frames of sub-images to different positions on the projection screen, and then realizing the superposition display of the two frames of sub-images to display a frame of target image, that is, realizing the display of a lower resolution image at a higher resolution. Among them, the voltage direction of the drive signal may remain unchanged, so the deflection direction of the galvanometer 60 is a fixed direction, and the changing waveform of the drive signal may be a sine wave. Exemplarily, reference Figure 2 , the galvanometer 60 can deflect back and forth between position A and position B under the drive of the above drive signal. In this way, when projecting and displaying a sub-image a of a frame of the target image, the display control component 10 controls the galvanometer drive component 50 to generate a digital drive waveform signal corresponding to the sub-image a, and the galvanometer drive component 50 applies a drive signal to the galvanometer 60 according to the digital drive waveform signal, so that the galvanometer 60 deflects to position A, and then the galvanometer 60 remains unchanged, thereby completing the display of sub-image a. When projecting and displaying a sub-image b of the frame of the target image, the display control component 10 controls the galvanometer drive component 50 to generate a digital drive waveform signal corresponding to the sub-image b, and the galvanometer drive component 50 applies a drive signal to the galvanometer 60 according to the digital drive waveform signal, so that the galvanometer 60 deflects to position B, and then the galvanometer 60 remains unchanged, thereby completing the display of sub-image b. Therefore, for each frame of the target image, two frames of sub-images are projected at different deflection positions of the galvanometer 60, thereby realizing the projection and display of different frames of sub-images to different positions of the projection screen.

[0037] In some embodiments, reference Figure 3 If the projection device is a projection TV, the projection device may further include a main control chip 80, a power supply 90, a start control component 100 and a program storage component 200. The main control chip 80 is connected to the start control component 100 and the display control component 10 respectively, the power supply 90 is connected to the laser drive component 20, and the program storage component 200 is connected to the display control component 10.

[0038] The main control chip 80 sends a start command to the start control component 100. The start control component 100 starts working after receiving the start command, and outputs 1.1 volts (V), 1.8V, 3.3V, 2.5V and 5V to the display control component 10 in sequence according to the power-on timing of the start control component 100 to power the display control component 10. After that, when the power supply voltage and timing are correct, the start control component 100 sends a reset signal to the display control component 10. After the display control component 10 receives the reset signal sent by the power management chip, the start control component 100 starts to supply power to the light valve 40. After that, the start control component 100 outputs three voltages to the light valve 40, namely, voltage bias (voltage bias, VBIAS) 18V, voltage reset (voltage reset, VRST) -14V, and voltage offset (voltage offset, VOFS) 10V. After the voltage of the light valve 40 is normal, the light valve 40 starts working. The display control component 10 sends the primary color scale value of the sub-image to the light valve 40 through LVDS communication to realize the display of the sub-image.

[0039] In some embodiments, the display control component includes a field programmable gate array (FPGA), and the digital waveform generation module in the galvanometer drive circuit provided in the embodiment of the present application can be integrated into the field programmable gate array. In this way, the digital drive waveform signal for driving the galvanometer can be generated by the FPGA, which saves the space occupied by the device and is conducive to further miniaturization of the projection device.

[0040] In some embodiments, reference Figure 4The galvanometer includes a base 61, a fixed plate 62, a spring (not shown in the figure, covered by a swinging member 63), a swinging member 63 and an optical lens 64; the base 61 has a first hollow area, and a pillar 611 is provided on each of the opposite sides of a diagonal of the first hollow area. A magnetic component is provided at the edge of one side of the first hollow area, and the magnetic component includes a coil 612 and a magnet 613. A connector 614 is provided at the end of the base 61, and the connector 614 is respectively connected to the coil 612 and the output end of the galvanometer drive circuit; the fixed plate 62 is located on the side of the base 61 opposite to the magnetic component, and the fixed plate 62 has a second hollow area, and the fixed plate 62 is used to fix the base 61; the spring is fixed on the pillar 611, and the swinging member 63 is covered on the spring with the pillar 611 as a fulcrum. The swinging member 63 has a third hollow area, and the third hollow area is used to carry the optical lens 64, and the orthographic projection of the optical lens 64 on the base 61 and the orthographic projection of the second hollow area on the base 61 overlap with the first hollow area. Optionally, a support sheet 621 and an insert sheet 622 extending through the base 61 are provided on one side of the second light-transmitting area of ​​the fixed plate 62, and the support sheet 621 abuts against the side of the base, and the support sheet 621 and the insert sheet 622 are used to fix the coil 612 and the magnet 613. The galvanometer provided in this embodiment is a two-dimensional galvanometer, or a single-axis galvanometer. When the galvanometer drive circuit inputs a drive signal to the coil 612 through the connector 614, the magnetic component generates an adsorption or repulsion effect, and the side end of the swing member 63 swings around the virtual axis L (i.e., a diagonal line of the swing member 63) due to the adsorption or repulsion effect, thereby projecting two sub-images to different positions, thereby increasing the resolution of the projection device by 1 times.

[0041] In the related art, the galvanometer deflection is driven by directly applying a driving current to the coil, while the above embodiment of the present application drives the galvanometer deflection by applying a driving voltage at both ends of the coil, thereby reducing the negative voltage generation circuit and reducing the cost. Based on this, in order to reduce the driving cost, the difference between the first driving voltage and the second driving voltage is used to drive (i.e., voltage drive) the galvanometer deflection, and the embodiment of the present application proposes a galvanometer drive circuit.

[0042] Figure 5 FIG. 4 shows a structural block diagram of a galvanometer drive circuit in some embodiments. Figure 5As shown, the galvanometer drive circuit may include: a digital waveform generation module 1, a digital-to-analog conversion module 2 and an operational amplifier module 3; the digital waveform generation module 1 is connected to the digital-to-analog conversion module 2, the digital waveform generation module 1 is used to generate a digital waveform signal, and transmit the digital waveform signal to the digital-to-analog conversion module 2, wherein the digital waveform signal includes a digital drive waveform signal; the digital-to-analog conversion module 2 is also connected to the operational amplifier module 3, the digital-to-analog conversion module 2 is used to perform digital-to-analog conversion on the digital drive waveform signal, and transmit the analog drive waveform signal converted from the digital-to-analog conversion to the operational amplifier module 3; the operational amplifier module 3 is also connected to the positive pole and the negative pole of the coil of the galvanometer, the operational amplifier module 3 is used to generate a first drive voltage and a second drive voltage with opposite phases according to the analog drive waveform signal, and transmit the first drive voltage to the positive pole of the coil, and transmit the second drive voltage to the negative pole of the coil, wherein the difference between the first drive voltage and the second drive voltage is the drive signal of the galvanometer, and the drive signal is used to drive the galvanometer to deflect.

[0043] In this embodiment, the digital waveform generation module 1 may include a positive voltage generation circuit, which may be a waveform generator, and the digital waveform generation module 1 may be built into the FPGA. Each amplitude of the waveform corresponding to the digital drive waveform signal may be stored in a lookup table. By setting the number of amplitudes for generating the digital drive waveform signal and the number of clock cycles (clock cycles of the digital-to-analog conversion module 2) required to output each amplitude, the digital waveform generation module 1 may output the amplitude of the digital quantity in sequence in combination with the lookup table, thereby obtaining a digital drive waveform signal. The digital-to-analog conversion module 2 may include a DAC converter, and when the digital-to-analog conversion module 2 receives the digital drive waveform signal transmitted by the digital waveform generation module 1, it can convert the digital drive waveform signal into an analog drive waveform signal. Since the operational amplifier module 3 cannot directly amplify the digital signal, after the digital-to-analog conversion module 2 converts the digital drive waveform signal into an analog drive waveform signal, the operational amplifier module 3 may amplify the analog drive waveform signal. In addition, the operational amplifier module 3 may include at least one operational amplifier group, and one operational amplifier group may include two operational amplifiers, and the two operational amplifiers respectively amplify the analog drive waveform signal to obtain a first drive voltage and a second drive voltage with opposite phases. Optionally, the two operational amplifiers can be implemented by a dual operational amplifier chip. In this embodiment, since the first driving voltage and the second driving voltage are in opposite phases, the amplitude of the driving signal obtained by using the difference between the first driving voltage and the second driving voltage is at least twice the amplitude of the analog driving waveform signal, so that a voltage signal with a smaller amplitude can be used to generate a voltage driving signal with a larger amplitude, which can not only avoid burning the operational amplifier module 3 due to the excessive amplitude of the analog driving waveform signal, but also improve the stability of the voltage drive.

[0044] Based on the above technical solution, the digital waveform generation module 1 can generate a corresponding digital driving waveform signal according to the actual sub-image, thereby generating driving signals with different phases to drive the galvanometer to deflect to different positions, thereby achieving the offset of two frames of sub-images, thereby improving the image display resolution.

[0045] The galvanometer drive circuit provided in the embodiment of the present application adopts an operational amplifier module to divide the analog drive waveform signal into two, obtain a first drive voltage and a second drive voltage with opposite phases, and apply the first drive voltage to the positive pole of the coil of the galvanometer, and apply the second drive voltage to the negative pole of the coil of the galvanometer, and use the difference between the first drive voltage and the second drive voltage to realize voltage drive of the galvanometer. In this way, the galvanometer drive circuit provided in the embodiment of the present application only needs to use one voltage generation circuit (corresponding to the digital waveform generation module of the present application), and the analog drive waveform signal generated by the digital waveform generation module and converted by the digital-to-analog conversion module is processed into two drive voltages with opposite phases through the operational amplifier module, and the difference between the two drive voltages is used to realize voltage drive of the galvanometer to drive the galvanometer to deflect, thereby saving one voltage generation circuit and reducing the cost of the galvanometer drive circuit.

[0046] In addition, in the related art, when the galvanometer is driven by current driving, since the galvanometer is connected in series in the galvanometer driving circuit, when the galvanometer works abnormally, it is impossible to determine whether it is the galvanometer driving circuit fault or the galvanometer fault by detecting the driving current. However, the present application uses voltage driving to drive the galvanometer. When the galvanometer works abnormally, the galvanometer driving circuit or the galvanometer fault can be determined by detecting the first driving voltage and the second driving voltage. For example, when the first driving voltage and the second driving voltage are normal, it means that the galvanometer driving circuit works normally, and the galvanometer is faulty at this time; when the first driving voltage and the second driving voltage are abnormal, it means that the galvanometer driving circuit is faulty. Therefore, the driving method of the present application is more conducive to troubleshooting the cause of the fault.

[0047] Based on the above embodiments, in some embodiments, reference Figure 6, the operational amplifier module 3 includes a first operational amplifier A1 and a second operational amplifier A2, the output end of the digital-to-analog conversion module 2 for outputting the analog driving waveform signal is connected to the first input end of the first operational amplifier A1 and the second input end of the second operational amplifier A2, the output end of the first operational amplifier A1 is connected to the positive pole of the coil, and the output end of the second operational amplifier A2 is connected to the negative pole of the coil, wherein one of the first operational amplifier A1 and the second operational amplifier A2 realizes in-phase amplification, and the other realizes inverting amplification. For example, the output end of the digital-to-analog conversion module 2 is connected to the inverting input end of the first operational amplifier A1 and the in-phase input end of the second operational amplifier A2, the output end of the first operational amplifier A1 is connected to the positive pole of the coil, and the output end of the second operational amplifier A2 is connected to the negative pole of the coil, wherein the first operational amplifier A1 realizes inverting amplification, at this time, the analog driving waveform signal is input from the inverting input end of the first operational amplifier A1, and the output is inverted with the input. The second operational amplifier A2 realizes in-phase amplification, at this time, the analog driving waveform signal is input from the in-phase input end of the second operational amplifier A2, and the output is in-phase with the input. The operational amplifier includes two input terminals, namely a non-inverting input terminal and an inverting input terminal. By designing the connection between the output terminal of the digital-to-analog conversion module 2 and the non-inverting input terminal and the inverting input terminal of the operational amplifier, in-phase amplification or inverting amplification can be achieved. The present application can generate a first driving voltage and a second driving voltage with opposite phases by implementing an operational amplifier for in-phase amplification and an operational amplifier for inverting amplification.

[0048] Specifically, in some embodiments, Figure 7 As shown, the first input terminal of the first operational amplifier A1 is an inverting input terminal, and the operational amplifier module also includes a first resistor R2, a second resistor R3, a third resistor R4 and a fourth resistor R5; the first resistor R2 is respectively connected to the output terminal of the digital-to-analog conversion module and the inverting input terminal of the first operational amplifier A1, the second resistor R3 is respectively connected to the inverting input terminal of the first operational amplifier A1 and the output terminal of the first operational amplifier A1, the third resistor R4 and the fourth resistor R5 are connected in series between the power supply voltage V_DAC and the ground, and the non-inverting input terminal of the first operational amplifier A1 is connected between the third resistor R4 and the fourth resistor R5.

[0049] At this time, according to the virtual short and virtual open principle of the operational amplifier, we can get:

[0050]

[0051]

[0052] From formula (2), we can get:

[0053] Substituting formula (1) into formula (3), we can obtain:

[0054] Therefore, the analog driving waveform signal V i The first driving voltage V_p can be obtained through the first operational amplifier A1.

[0055] In some embodiments, continue to refer to Figure 7 , the second input terminal of the second operational amplifier A2 is the in-phase input terminal, and the operational amplifier module also includes a fifth resistor R6, a sixth resistor R7, a seventh resistor R8 and an eighth resistor R9; the fifth resistor R6 is respectively connected to the output terminal of the digital-to-analog conversion module and the in-phase input terminal of the second operational amplifier A2, the sixth resistor R7 is respectively connected to the power supply voltage V_DAC and the in-phase input terminal of the second operational amplifier A2, the seventh resistor R8 and the eighth resistor R9 are connected in series between the output terminal of the second operational amplifier A2 and the ground, and the inverting input terminal of the second operational amplifier A2 is connected between the seventh resistor R8 and the eighth resistor R9.

[0056] At this time, according to the virtual short and virtual open principle of the operational amplifier, we can get:

[0057] V A2+ =V A2- (5)

[0058]

[0059]

[0060] Substituting formula (7) into formula (6) yields:

[0061]

[0062] Therefore, the analog driving waveform signal V i The second driving voltage V_n can be obtained through the second operational amplifier A2.

[0063] According to formula (4) and formula (8), the formula of the driving signal can be obtained:

[0064]

[0065] Therefore, based on the above formula (9), various parameters such as resistance can be configured according to actual galvanometer requirements, and the digital driving waveform signal output by the digital waveform generation module can be converted into an amplified driving signal that can drive the galvanometer to achieve galvanometer deflection.

[0066] The first operational amplifier A1 and the second operational amplifier A2 can be implemented by a dual operational amplifier chip N4.

[0067] In some embodiments, the digital waveform signal also includes a waveform output clock signal and a waveform output enable signal, wherein the waveform output clock signal is used to synchronize the analog drive waveform signal output by the digital-to-analog conversion module with the digital drive waveform signal, and the waveform output enable signal is used to instruct the digital-to-analog conversion module to perform digital-to-analog conversion on the digital drive waveform signal and output the analog drive waveform signal.

[0068] In some embodiments, reference Figure 8 and Fig. 9 The galvanometer drive circuit also includes a level conversion module 4; the level conversion module 4 can convert the logic level from VCCA to VCCB, the level conversion module 4 is connected to the digital waveform generation module 1 and the digital-to-analog conversion module 2 respectively, and the level conversion module 4 is used to convert the logic level of the digital waveform signal to a logic level that matches the operation of the digital-to-analog conversion module 2, so that the digital-to-analog conversion module 2 can work normally and realize the conversion of the digital drive waveform signal by the digital-to-analog conversion module 2. For example, the waveform output clock signal WG_CLK and the waveform output enable signal WG_SYNCz are 1.8V level, the amplitude level of the digital drive waveform signal WG_DATA is 1.8V, and the working level of the digital-to-analog conversion module 2 is 3.3V. At this time, the logic level of the above digital waveform signal needs to be converted to 3.3V through the level conversion module 4, and then the converted digital waveform signal is transmitted to the digital-to-analog conversion module 2.

[0069] Based on the above embodiments, the present application discloses a first driving voltage, a second driving voltage and a driving signal by configuring the parameters of the circuit elements. Fig.10 , Fig.11 and Fig.12 , C1, C2, C3, C4 are all 100nF, R1 = 100K, R2 = 40.2K, R3 = 121K, R4 = 10K, R5 = 47.5K, R6 = 5.6K, R7 = 56K, R8 = 5.1K, R9 = 12K. Substituting the above parameters into the above formula (4) and formula (7), we can get:

[0070] V_p=10.9-3Vi

[0071] V_n=1+3.05Vi.

[0072] refer to Fig.10, Vi is a waveform with a maximum amplitude level of 3.3V, which is input to the inverting input terminal A1- of the first operational amplifier A1, and the output waveform is amplified and output. The amplification relationship between the output waveform of the first operational amplifier A1 and the input waveform is the corresponding relationship of the formula V_p=10.9-3Vi. The output V_p voltage waveform of the first operational amplifier A1 is the input waveform inverted and amplified and output. The actual output waveform Vi_L voltage is about 1.3V, and the corresponding output waveform V_p_H voltage is about 7V, and the Vi_H voltage is about 1.96V, and the corresponding output waveform V_p_L voltage is about 5V. The waveform after the peak-to-valley difference is amplified is about 3 times the input waveform. The actual input and output waveforms correspond to the formula relationship one by one and are consistent.

[0073] Vi is also input to the in-phase input terminal A2+ of the second operational amplifier A2. The input waveform Vi is the same as the input waveform input to the first operational amplifier A1. The output waveform is amplified in-phase, and the waveforms are in-phase. The amplification relationship between the output waveform of the second operational amplifier A2 and the input waveform is the corresponding relationship of the formula V_n=1+3.05Vi. The actual waveform output Vi_L voltage is about 1.3V, and the corresponding output waveform V_n_L voltage is about 4.965V. The Vi_H voltage is about 1.96V, and the corresponding output waveform V_n_H voltage is about 6.978V. The actual input and output waveforms correspond to the formula relationship one by one. This verifies that the maximum and minimum amplitudes of the V_p and V_n waveforms are approximately the same, the parameter configuration is correct, and it is the required driving waveform. The voltage applied to both ends of the galvanometer is the difference between the output waveform V_p of the first operational amplifier A1 and the output waveform V_n of the second operational amplifier A2, such as Fig.12 As shown in the figure, the waveform with the largest amplitude is the waveform of the final voltage signal of the galvanometer, and the amplitude V is twice the input amplitude Vid. The galvanometer moves under the drive of this voltage drive waveform, and the voltage level driving the galvanometer is relatively high (such as the peak high level part reaches 8V), which improves the stability of the drive.

[0074] The present application also provides a galvanometer driving method, such as Fig.13 As shown, the galvanometer driving method includes:

[0075] S110, generating a digital waveform signal.

[0076] The digital waveform signal includes a digital driving waveform signal.

[0077] S120 , performing digital-to-analog conversion on the digital driving waveform signal to obtain an analog driving waveform signal.

[0078] S130, generating a first driving voltage and a second driving voltage with opposite phases according to the analog driving waveform signal, and applying the first driving voltage to the positive pole of the coil of the galvanometer, and applying the second driving voltage to the negative pole of the coil of the galvanometer, so that the difference between the first driving voltage and the second driving voltage is used as the driving signal of the galvanometer to drive the galvanometer to deflect.

[0079] The galvanometer driving method provided in the embodiment of the present application can be implemented using the galvanometer driving circuit provided in the embodiment of the present application. The specific steps can refer to the functions of the relevant modules in the galvanometer driving circuit, which will not be repeated here.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0081] For the convenience of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A galvanometer drive circuit, characterized in that: include: Digital waveform generation module, digital-to-analog conversion module and operational amplifier module; The digital waveform generation module is connected to the digital-to-analog conversion module, and is used to generate a digital waveform signal and transmit the digital waveform signal to the digital-to-analog conversion module, wherein the digital waveform signal includes a digital driving waveform signal; The digital-to-analog conversion module is also connected to the operational amplifier module, and the digital-to-analog conversion module is used to perform digital-to-analog conversion on the digital driving waveform signal, and transmit the analog driving waveform signal converted from the digital-to-analog conversion to the operational amplifier module; The operational amplifier module is also connected to the positive pole and the negative pole of the coil of the galvanometer. The operational amplifier module is used to generate a first drive voltage and a second drive voltage with opposite phases according to the analog drive waveform signal, and transmit the first drive voltage to the positive pole of the coil, and transmit the second drive voltage to the negative pole of the coil, wherein the difference between the first drive voltage and the second drive voltage is the drive signal of the galvanometer, and the drive signal is used to drive the galvanometer to deflect.

2. The galvanometer drive circuit according to claim 1, characterized in that: The operational amplifier module includes a first operational amplifier and a second operational amplifier. The output end of the digital-to-analog conversion module for outputting the analog drive waveform signal is connected to the first input end of the first operational amplifier and the second input end of the second operational amplifier. The output end of the first operational amplifier is connected to the positive pole of the coil, and the output end of the second operational amplifier is connected to the negative pole of the coil. One of the first operational amplifier and the second operational amplifier realizes in-phase amplification, and the other realizes inverting amplification.

3. The galvanometer drive circuit according to claim 2, characterized in that: The first input terminal of the first operational amplifier is an inverting input terminal, and the operational amplifier module further includes a first resistor, a second resistor, a third resistor and a fourth resistor; The first resistor is connected to the output end of the digital-to-analog conversion module and the inverting input end of the first operational amplifier, respectively; the second resistor is connected to the inverting input end of the first operational amplifier and the output end of the first operational amplifier, respectively; the third resistor and the fourth resistor are connected in series between the power supply voltage and the ground; and the non-inverting input end of the first operational amplifier is connected between the third resistor and the fourth resistor.

4. The galvanometer drive circuit according to claim 3, characterized in that: The second input terminal of the second operational amplifier is a non-inverting input terminal, and the operational amplifier module further includes a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; The fifth resistor is respectively connected to the output end of the digital-to-analog conversion module and the non-inverting input end of the second operational amplifier, the sixth resistor is respectively connected to the power supply voltage and the non-inverting input end of the second operational amplifier, the seventh resistor and the eighth resistor are connected in series between the output end of the second operational amplifier and ground, and the inverting input end of the second operational amplifier is connected between the seventh resistor and the eighth resistor.

5. The galvanometer drive circuit according to claim 1, characterized in that: The digital waveform signal also includes a waveform output clock signal and a waveform output enable signal, wherein the waveform output clock signal is used to synchronize the analog drive waveform signal output by the digital-to-analog conversion module with the digital drive waveform signal, and the waveform output enable signal is used to instruct the digital-to-analog conversion module to perform digital-to-analog conversion on the digital drive waveform signal and output the analog drive waveform signal.

6. The galvanometer drive circuit according to any one of claims 1 to 5, characterized in that: The galvanometer drive circuit also includes a level conversion module; The level conversion module is connected to the digital waveform generation module and the digital-to-analog conversion module respectively, and is used to convert the logic level of the digital waveform signal into a logic level matching the operation of the digital-to-analog conversion module.

7. A projection device, characterized in that: include: A display control component, a light source driving component, a light source, a light valve, a galvanometer driving component, a galvanometer and a lens, wherein the galvanometer driving component comprises a galvanometer driving circuit according to any one of claims 1 to 6; The display control component is respectively connected to the light source driving component, the light valve and the galvanometer driving component. The light source driving component is also connected to the light source. The galvanometer driving component is also connected to the galvanometer. The galvanometer is located between the light valve and the lens.

8. The projection device according to claim 7, characterized in that: The display control component includes a field programmable gate array, and the digital waveform generation module in the galvanometer drive circuit is integrated into the field programmable gate array.

9. The projection device according to claim 7, characterized in that: The galvanometer comprises a base, a fixing plate, a spring, a swinging member and an optical lens; The base has a first hollow area, and a pillar is provided on each of the opposite sides of a diagonal line of the first hollow area. A magnetic component is provided at the edge of one side of the first hollow area, and the magnetic component includes a coil and a magnet. A connector is provided at the end of the base, and the connector is respectively connected to the coil and the output end of the galvanometer drive circuit; The fixing plate is located on a side of the base opposite to the magnetic component, the fixing plate has a second hollow area, and the fixing plate is used to fix the base; The spring sheet is fixed on the pillar, and the swinging member is covered on the spring sheet with the pillar as a fulcrum. The swinging member has a third hollow area, and the third hollow area is used to support the optical lens. The orthographic projection of the optical lens on the base and the orthographic projection of the second hollow area on the base both overlap with the first hollow area.

10. A galvanometer driving method, characterized in that: include: generating a digital waveform signal, wherein the digital waveform signal comprises a digital driving waveform signal; Performing digital-to-analog conversion on the digital driving waveform signal to obtain an analog driving waveform signal; A first driving voltage and a second driving voltage with opposite phases are generated according to the analog driving waveform signal, and the first driving voltage is applied to the positive pole of the coil of the galvanometer, and the second driving voltage is applied to the negative pole of the coil of the galvanometer, so that the difference between the first driving voltage and the second driving voltage serves as the driving signal of the galvanometer to drive the galvanometer to deflect.

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