Digital driving waveform generation device and method of galvanometer and projection equipment

Abstract

The embodiment of the invention provides a digital driving waveform generation device and method of a galvanometer and projection equipment, and relates to the technical field of laser projection. The device comprises a subframe delay module, a clock control module, an address control module and an amplitude storage module, the sub-frame delay module is used for delaying the sub-frame signal and transmitting the delayed sub-frame signal to the address control module; the clock control module is used for providing a control clock for generating a digital driving waveform for the address control module; the amplitude storage module is used for storing a plurality of amplitudes of the digital driving waveform according to a preset storage sequence; and the address control module is used for reading the amplitudes of a preset segment number from the amplitude storage module according to a preset galvanometer type when the rising edge or the falling edge of the delay subframe signal arrives, and outputting the amplitudes in sequence according to a reading sequence to generate a digital driving waveform. The embodiment of the invention is used for generating the digital driving waveform, so that the galvanometer moves to an accurate position required by image display.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser projection technology, and more specifically, to a device and method for generating a digital drive waveform of a galvanometer, and a projection device. 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] At present, in order to drive the galvanometer deflection, a digital driving waveform corresponding to the analog driving waveform is first generated, and then the digital driving waveform is processed by a digital-to-analog converter and an operational amplifier to obtain the analog driving waveform required to drive the galvanometer. Among them, the driving effect of the galvanometer is related to the digital driving waveform, and how to generate a digital driving waveform that can move the galvanometer to the accurate position required for image display has always been a research issue in the industry. Summary of the invention

[0004] The exemplary embodiments of the present application provide a device, method and projection equipment for generating a digital driving waveform for a galvanometer, which are used to generate a digital driving waveform to move the galvanometer to an accurate position required for image display.

[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 digital drive waveform generating device for a galvanometer, comprising: a subframe delay module, a clock control module, an address control module and an amplitude storage module;

[0007] The subframe delay module is connected to the address control module, and is used to delay the subframe signal and transmit the delayed subframe signal to the address control module, wherein the subframe signal is a subframe signal of two subframes of a frame image decomposed into, and the delayed subframe signal is used to synchronize the subimage display with the start of the galvanometer movement;

[0008] The clock control module is connected to the address control module, and the clock control module is used to provide the address control module with a control clock for generating a digital drive waveform;

[0009] The amplitude storage module is connected to the address control module, and the amplitude storage module is used to store multiple amplitudes of the digital driving waveform according to a preset storage order;

[0010] The address control module is used to respond to the delayed sub-frame signal. When the rising edge or falling edge of the delayed sub-frame signal arrives, the amplitude of the preset number of segments is read from the amplitude storage module according to the preset galvanometer type, and the amplitude is output in sequence according to the reading order to generate the digital drive waveform, wherein the first to the second to last amplitudes are output at a preset segment length, and the last amplitude is output until the rising edge or falling edge of the next delayed sub-frame signal arrives, the preset galvanometer type represents the reading method of the amplitude, the preset segment number represents the number of the amplitudes stored in the amplitude storage module, and the preset segment length represents the clock length of multiple control clocks.

[0011] 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 display control component includes a digital driving waveform generating device for the galvanometer as described in any embodiment of the first aspect;

[0012] 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.

[0013] In a third aspect, an embodiment of the present application provides a method for generating a digital driving waveform of a galvanometer, comprising:

[0014] Delaying the subframe signal to obtain a delayed subframe signal, wherein the subframe signal is a subframe signal of two sub-images decomposed from a frame image, and the delayed subframe signal is used to synchronize the sub-image display with the start of the galvanometer movement;

[0015] Obtain a control clock for generating a digital drive waveform;

[0016] In response to the delayed sub-frame signal, when the rising edge or falling edge of the delayed sub-frame signal arrives, the amplitude of the preset number of segments is read from the amplitude storage module according to the preset galvanometer type, and the amplitude is output in sequence according to the reading order to generate the digital drive waveform, wherein the first to the second to last amplitudes are output at a preset segment length, and the last amplitude is output until the rising edge or falling edge of the next delayed sub-frame signal arrives, the preset galvanometer type represents the way the amplitude is read, the preset number of segments represents the number of the amplitudes stored in the amplitude storage module, and the preset segment length represents the clock length of multiple control clocks.

[0017] It can be seen from the above technical scheme that the digital drive waveform generation device, method and projection device of the galvanometer provided in the embodiment of the present application first delays the subframe signal through the subframe delay module to ensure that when the generated digital drive waveform drives the galvanometer through the galvanometer drive component, the sub-image display is aligned and synchronized with the start of the galvanometer movement; combined with the multiple amplitudes of the digital drive waveform corresponding to the analog drive waveform required to drive the galvanometer stored in the amplitude storage module according to the preset storage order, and then read the amplitude of the preset number of segments from the amplitude storage module according to the preset galvanometer type through the address control module, and use the control clock provided by the clock control module and the preset segment length to limit the duration of the amplitude output, so that the amplitudes of multiple digital quantities form a digital drive waveform that approximates the analog drive waveform. Therefore, based on the rising edge or falling edge of the delayed subframe signal, the embodiment of the present application triggers the address control module to read and output multiple amplitudes of the digital drive waveform from the amplitude storage module, forming a digital drive waveform containing multiple digital amplitudes, which can move the galvanometer to the accurate position required for image display. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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.

[0019] Figure 1 A schematic diagram of the structure of a projection device in some embodiments is shown;

[0020] Figure 2 A schematic diagram showing display resolution expansion in some embodiments;

[0021] Figure 3 A schematic diagram showing the structure of another projection device in some embodiments is shown;

[0022] Figure 4 A schematic structural diagram of a single-axis galvanometer in some embodiments is shown;

[0023] Figure 5 A structural block diagram of a digital driving waveform generating device for a galvanometer in some embodiments is shown;

[0024] Figure 6 Schematic diagrams showing analog driving waveforms and digital driving waveforms in some embodiments;

[0025] Figure 7 A timing diagram showing subframe synchronization in some embodiments;

[0026] Figure 8A schematic diagram showing the generation of digital drive waveforms in some embodiments;

[0027] Fig. 9 A schematic diagram showing the waveform output working principle in some embodiments is shown;

[0028] Fig.10 A structural block diagram of a digital driving waveform generating device for a galvanometer in some other embodiments is shown;

[0029] Fig.11 A structural block diagram of a digital driving waveform generating device for a galvanometer in some other embodiments is shown;

[0030] Fig.12 A structural block diagram of a digital driving waveform generating device for a galvanometer in some other embodiments is shown;

[0031] Fig.13 A structural block diagram of a digital driving waveform generating device for a galvanometer in some other embodiments is shown;

[0032] Fig.14 A flow chart showing a method for generating a digital driving waveform for a galvanometer in some embodiments. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Figure 1 FIG. 4 shows a schematic diagram of the structure of a projection device in some embodiments. Figure 1As 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. The display control component 10 includes a digital driving waveform generating device for the galvanometer 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.

[0037] 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 DLPC3437. 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.

[0038] 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 by the display control component 10. In the process of projecting and displaying each frame of sub-images, the display control component 10 generates a digital driving waveform corresponding to a frame of sub-images, and transmits the digital driving waveform to the galvanometer driving component 50. The galvanometer driving component 50 converts the digital driving waveform into an analog driving waveform, and generates a first driving voltage and a second driving voltage with opposite phases according to the analog driving waveform. 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. The voltage difference between the first driving voltage and the second driving voltage (i.e., the driving signal) is used to drive the galvanometer 60 to deflect. Among them, the digital driving waveforms corresponding to different frames of sub-images are different (opposite in phase), so that the two frames of sub-images can be projected to different positions on the projection screen, and then the superposition display of the two frames of sub-images is realized to display a frame of target image, that is, the image with lower resolution can be displayed with higher resolution. Among them, the voltage direction of the driving signal can remain unchanged, so the deflection direction of the galvanometer 60 is a fixed direction, and the changing waveform of the driving signal can be a sine wave. Exemplary, reference Figure 2 , the galvanometer 60 can deflect back and forth between position A and position B under the drive of the above-mentioned 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 generates a digital drive waveform 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, 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 generates a digital drive waveform 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, 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.

[0039] 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.

[0040] 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, after the power supply voltage and timing are correct, the start control component 100 sends a reset signal to the display control component 10, reads the program from the external program storage component 200 and initializes it, and then the entire projection device starts working. The display control component 10 configures the start control component 100 through the serial peripheral interface (SPI) communication, and instructs the start control component 100 to start powering 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 to work. The display control component 10 sends the primary color scale value of the sub-image to the light valve 40 through the LVDS communication interface to realize the display of the sub-image.

[0041] In some embodiments, the display control component includes a field programmable gate array (FPGA), and the field programmable gate array includes a digital drive waveform generating device for the galvanometer provided in the embodiments of the present application. In this way, the digital drive waveform for driving the galvanometer can be produced by the FPGA, which saves the space occupied by the device and is conducive to further miniaturization of the projection device.

[0042] 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.

[0043] In order to drive the galvanometer to deflect, it is necessary to generate a digital driving waveform first. The following embodiments describe the relevant device and method for generating the digital driving waveform.

[0044] Figure 5 FIG. 4 is a block diagram showing a structure of a digital drive waveform generating device for a galvanometer in some embodiments. Figure 5As shown, the digital drive waveform generating device of the galvanometer may include: a subframe delay module 1, a clock control module 2, an address control module 3 and an amplitude storage module 4; the subframe delay module 1 is connected to the address control module 3, the subframe delay module 1 is used to delay the subframe signal, and transmit the delayed delayed subframe signal to the address control module 3, wherein the subframe signal is a subframe signal of two frames of sub-images decomposed from a frame of image, and the delayed subframe signal is used to synchronize the sub-image display with the start of the galvanometer movement; the clock control module 2 is connected to the address control module 3, the clock control module 2 is used to provide the address control module 3 with a control clock for generating a digital drive waveform; the amplitude storage module 4 is connected to the address control module 3, The value storage module 4 is used to store multiple amplitudes of the digital drive waveform in a preset storage order; the address control module 3 is used to respond to the delayed sub-frame signal, and when the rising edge or falling edge of the delayed sub-frame signal arrives, read the amplitude of a preset number of segments from the amplitude storage module 4 according to the preset galvanometer type, and output the amplitudes in sequence according to the reading order to generate a digital drive waveform, wherein the first to the second to last amplitudes are output at a preset segment length, and the last amplitude is output until the rising edge or falling edge of the next delayed sub-frame signal arrives, the preset galvanometer type represents the amplitude reading method, the preset segment number represents the number of amplitudes stored in the amplitude storage module 4, and the preset segment length represents the clock length of multiple control clocks.

[0045] In the present application examples, reference Figure 6 , according to the desired waveform required to drive the galvanometer, that is, the analog driving waveform, in the digital circuit, it is necessary to convert the analog driving waveform into a digital driving waveform, and use the digital driving waveform to approximate the analog driving waveform, that is, the analog driving waveform can be estimated and realized by many segments of equal length to form an editable digital driving waveform (including the amplitude and the number of amplitudes can be edited). To this end, each amplitude of the digital driving waveform to be generated can be first stored in the amplitude storage module 4 according to a preset storage order, wherein the preset storage order can be the order of the amplitudes of the digital driving waveform. Exemplarily, each amplitude can be an 8-bit unsigned number, and the amplitude storage module 4 can include a 256×8 memory, and each amplitude can be stored in the form of a lookup table. In order to adapt to the two positions of the galvanometer movement, a frame of image is divided into two sub-frame images (i.e., two sub-frames of images in the present application), and accordingly, each sub-frame signal corresponds to a position of the galvanometer movement. Reference Figure 7The display control component decomposes a frame of image into two sub-frame images, and triggers the sub-frame signal output through the sub-frame synchronization bit timing signal. In order to ensure that the generated digital drive waveform is synchronized with the start of the galvanometer movement when the galvanometer drive component drives the galvanometer, the sub-image display is synchronized with the start of the galvanometer movement, and the sub-frame signal is delayed by the sub-frame delay module 1 to generate a delayed sub-frame signal, and transmitted to the address control module 3. When the rising edge or falling edge of the delayed sub-frame signal arrives, the address control module 3 outputs the amplitude in the amplitude storage module 4 in sequence according to the preset segment length, thereby generating a digital drive waveform.

[0046] Specifically, the subframe delay module 1 can delay the subframe signal according to the set subframe delay value. Exemplarily, the subframe delay value is a programmable value, which is a certain number of system clocks. After the subframe signal is input into the digital drive waveform generating device of the galvanometer, the time for the subframe signal to be input into the address control module 3 is first delayed from the timer. If the system clock uses a 24Mhz crystal oscillator, the system clock period is 41.667ns, and the clock used for the subframe delay is the system clock, such as 24MHz, and is not a programmable DAC clock used to drive the waveform to generate various functions. The clock control module 2 provides the address control module 3 with a control clock for generating a digital drive waveform, which is called a DAC clock. At the same time, the clock control module 2 is also connected to the galvanometer drive component of the projection device. The clock control module 2 is also used to transmit the control clock to the galvanometer drive component to provide a clock for data input to the galvanometer drive component. If the system clock is 24MHz, the range of the DAC clock is 2 to 16 system clocks. The relationship with the system clock is that the DAC clock is a system clock with a step size of 2, that is, the DAC clock is 83.33ns~666.67ns. The DAC clock is used to drive various functions of waveform generation and is input into the back-end galvanometer drive component as the data input clock of the galvanometer drive component, that is, the digital waveform output clock WG_CLK.

[0047] The preset galvanometer type characterizes the reading method of the amplitude, and the present application provides two reading methods. The first reading method is positive sequence → reverse sequence, that is, after the rising edge of the delayed subframe signal arrives, the first amplitude of the amplitude storage module 4 will be output, and this amplitude will always maintain the number of DAC clocks specified by the preset segment length, and then the second amplitude will maintain the number of DAC clocks specified by the preset segment length until the number of output amplitudes reaches the number specified by the preset segment number. Among them, the last amplitude will remain output until the falling edge of the delayed subframe signal arrives. After the falling edge of the delayed subframe signal arrives, the last amplitude of the amplitude storage module 4 will be output, and the output method is the same as the rising edge, except that the amplitude is read from the amplitude storage module 4 in reverse order, that is, the amplitude is read and output in reverse order. The second reading method is positive sequence → positive sequence inversion (inverse code or complement), that is, this amplitude will always maintain the number of DAC clocks specified by the preset segment length, and then the second amplitude will maintain the number of DAC clocks specified by the preset segment length until the number of output amplitudes reaches the number specified by the preset segment number. Among them, the last amplitude will be kept output until the falling edge of the delayed sub-frame signal arrives. After the falling edge of the delayed sub-frame signal arrives, the last amplitude of the amplitude storage module 4 will be output, and the output method is the same as the rising edge, except that the amplitude is read from the amplitude storage module 4 in the positive order after inversion, and the inversion is to take out the amplitude in the amplitude storage module 4 in the form of the inverse code (complement), and the reading order of these inverted amplitudes is the same as the rising edge, still starting from the first amplitude in the amplitude storage module 4.

[0048] The preset number of segments is the number of amplitudes for generating the digital drive waveform, and is also the number of amplitudes stored in the amplitude storage module 4. The preset number of segments can be set in a range from 2 to 255. The preset segment length is the clock length of each amplitude, that is, one amplitude maintains multiple DAC clock outputs, and the preset segment length can be set in a range of 2 to 65535 DAC clocks. It can be understood that the preset number of segments and the preset segment length jointly determine the similarity between the digital drive signal and the analog drive signal. For example, the more the preset number of segments and the shorter the preset segment length, the higher the similarity between the digital drive signal and the analog drive signal.

[0049] The address control module 3 has multiple address bits, which respectively store the numerical values ​​representing the address of the preset galvanometer type, the preset number of segments, the preset segment length, and the amplitude stored in the amplitude storage module 4. In this way, by setting the preset galvanometer type, the preset number of segments, and the preset segment length, the address control of the digital drive waveform is formed under the triggering of the control clock.

[0050] Based on the above technical solution, in a specific embodiment of data driven waveform generation, as shown in FIG. Figure 8As shown, after the rising edge or falling edge of the subframe signal arrives, the amplitude in the lookup table (amplitude storage module 4) starts to be output under the triggering of the DAC clock (control clock), and the amplitude of the first data output is 0. After 2 DAC clock cycles, the amplitude of the second data starts to be output as 2, and after another 2 DAC clock cycles, the amplitude of the third data is output as 7, and so on. After every 2 clock cycles, the 4th and 5th amplitudes 12 and 17 are output in turn. After 2 clock cycles, the last amplitude 20 in the lookup table is output, and this amplitude will be output until the falling edge or rising edge of the next subframe signal arrives, and then the amplitude in the lookup table will be output in a certain regular order (such as reverse order or inverse order).

[0051] From the above example, it can be seen that there are 6 data in the lookup table, and the amplitudes are 0, 2, 7, 12, 17, and 20 respectively, which means that the generated waveform has 6 amplitudes, that is, the preset number of segments = 6, and the length of each of the 6 amplitudes is 2 DAC clock lengths, that is, the same amplitude is output in 2 DAC clock cycles, that is, the preset segment length = 2. Therefore, by setting the preset number of segments required for the digital drive waveform, the waveform amplitudes of each segment generated by the preset number of segments of the digital drive waveform are included in the lookup table, and the number of DAC clocks required for the waveform output is determined according to the preset segment length. The preset number of segments in the lookup table are output in sequence with the preset segment length as the time period, and when the last amplitude is output, it is kept output until the next sub-frame signal rising edge or falling edge arrives, and then the amplitudes in the lookup table are output in a certain manner, so as to generate a digital drive waveform.

[0052] in addition, Fig. 9 FIG. 2 shows a schematic diagram of the waveform output working principle in some embodiments. Fig. 9As shown, after the rising edge of the delayed subframe signal arrives, the amplitude is read from the lookup table in positive order, and the amplitudes of the number specified by the preset number of segments in the lookup table are output in sequence. The last amplitude in the lookup table is kept output until the falling edge of the delayed subframe signal arrives, and the amplitude of the lookup table is read in reverse order or inverse code in positive order, and the amplitudes of the number specified by the preset number of segments in the lookup table are output in sequence. The waveform output data WG_DATA[7:0] outputted finally undergoes digital-to-analog conversion through a digital-to-analog converter, and is amplified through an operational amplifier, and finally outputs a galvanometer drive waveform, which is an analog signal waveform with driving capability. Under the triggering of the rising edge of the delayed subframe signal, the digital drive waveform begins to be output, thereby outputting the galvanometer drive waveform to drive the galvanometer to start moving, so that the galvanometer moves to position A or position B, and outputs subframe A synchronously at this position. When the falling edge of the delayed subframe signal arrives, the galvanometer drive waveform starts to output the inverse code, driving the galvanometer to move to position B or position A, and outputting subframe B at this position. Therefore, in the display of a frame of image, the galvanometer will move two positions, and output subframe A or subframe B at different positions. Therefore, the number of pixels of the final displayed frame of image increases by 1 times, and the resolution is increased to 2 times the original resolution. It should be noted that when the position of the galvanometer movement does not correspond to the subframe, the position of the galvanometer movement can be made to correspond to the subframe by editing the preset galvanometer type.

[0053] The digital drive waveform generating device for the galvanometer provided in the embodiment of the present application first delays the subframe signal through the subframe delay module to ensure that when the generated digital drive waveform drives the galvanometer through the galvanometer drive component, the sub-image display is aligned and synchronized with the start of the galvanometer movement; the multiple amplitudes of the digital drive waveform corresponding to the analog drive waveform required to drive the galvanometer stored in the amplitude storage module according to the preset storage order, and then the address control module reads the amplitude of the preset number of segments from the amplitude storage module according to the preset galvanometer type, and uses the control clock provided by the clock control module and the preset segment length to limit the duration of the amplitude output, so that the amplitudes of multiple digital quantities form a digital drive waveform that approximates the analog drive waveform. Therefore, based on the rising edge or falling edge of the delayed subframe signal, the embodiment of the present application triggers the address control module to read and output multiple amplitudes of the digital drive waveform from the amplitude storage module, forming a digital drive waveform containing multiple digital amplitudes, which can move the galvanometer to the accurate position required for image display, with low noise and optimal image quality.

[0054] In some embodiments, Fig.10 As shown, the digital drive waveform generating device of the galvanometer also includes a multiplication module 5; the multiplication module 5 is connected to the address control module 3, and the multiplication module 5 is used to multiply the digital drive waveform with a preset gain value so that the amplitude of the digital drive waveform reaches the expected amplitude of the corresponding analog drive waveform.

[0055] Specifically, the multiplication module 5 may include a multiplier. Since the amplitude read and output from the lookup table cannot reach the expected amplitude of the analog drive waveform, the preset gain value may be edited according to the multiple relationship between the expected amplitude of the analog drive waveform and the amplitude in the lookup table, and the digital drive waveform, specifically each amplitude of the digital drive waveform, is multiplied by the preset gain value through the multiplication module 5, so that the amplitude of the digital drive waveform output by the multiplication module 5 can reach the expected amplitude of the analog drive waveform, thereby improving the accuracy of the galvanometer moving position. Exemplarily, the preset gain value may be an 8-bit unsigned number, with a value range of 0 to 1.9921875.

[0056] In some embodiments, Fig.11 As shown, the digital drive waveform generating device of the galvanometer further includes an adding module 6; the adding module 6 is connected to the address control module 3, and the adding module 6 is used to apply a preset bias voltage to the digital drive waveform to adjust the central deflection angle of the galvanometer during the deflection process.

[0057] Usually, the central deflection angle of the galvanometer is 0, that is, the galvanometer deflects between the symmetrical positive deflection angle and the negative deflection angle with the 0-degree deflection angle as the axis. However, according to actual applications, the galvanometer can be deflected only at the positive deflection angle. In this case, it is necessary to apply a preset bias voltage to the digital drive waveform through the adding module 6 (such as an adder) so that the deflection of the galvanometer meets the needs of actual applications. In one embodiment, reference Fig.11 , the adding module 6 can be directly connected to the address control module 3. In another embodiment, refer to Fig.12 The addition module 6 can be connected to the address control module 3 through the multiplication module 5. Exemplarily, the preset bias voltage can be a 5-bit unsigned number with a value range of 0 to 32.

[0058] In some embodiments, Fig.13 As shown, the digital drive waveform generating device for the galvanometer further includes a selection module 7; the selection module 7 includes a first input terminal, a second input terminal and a fixed output enable terminal, and the first input terminal is connected to the address control module 3 (in the case of Fig.13 In the example shown, the first input terminal is connected to the address control module 3 via the addition module 6 and the multiplication module 5, and the second input terminal is connected to the preset fixed amplitude; the selection module 7 is used to output the digital drive waveform when the enable signal of the fixed output enable terminal is invalid (i.e., the fixed output enable is invalid); when the enable signal of the fixed output enable terminal is valid (i.e., the fixed output enable is valid), the preset fixed amplitude is output to turn off the galvanometer. The preset fixed amplitude can be an 8-bit unsigned number with a value range of 0 to 255.

[0059] For example, according to the actual needs of the user, when the user wants to display the image at a higher resolution, the user can turn on the galvanometer. At this time, the fixed output enable is invalid, the digital drive waveform is output normally, the galvanometer is driven to deflect back and forth between two different positions, and the display resolution is improved; when the user wants to display the image at the original resolution (the resolution of the projection device), the user can turn off the galvanometer. At this time, the fixed output enable is valid, the preset fixed amplitude is output, the galvanometer no longer deflects, and the resolution remains unchanged.

[0060] In addition, the present application also provides a method for generating a digital drive waveform for a galvanometer. Fig.14 As shown, the method for generating a digital driving waveform of a galvanometer includes:

[0061] S110 , delaying the subframe signal to obtain a delayed subframe signal.

[0062] The subframe signal is a subframe signal of two subframes of a frame image, and the delayed subframe signal is used to synchronize the subimage display with the start of the galvanometer movement;

[0063] S120 , obtaining a control clock for generating a digital driving waveform.

[0064] S130. In response to the delayed subframe signal, when the rising edge or falling edge of the delayed subframe signal arrives, read the amplitude of a preset number of segments from the amplitude storage module according to the preset galvanometer type, and output the amplitude in sequence according to the reading order to generate a digital driving waveform.

[0065] Among them, the first to the second to last amplitudes are output at a preset segment length, and the last amplitude is output until the rising edge or falling edge of the next delayed subframe signal arrives. The preset galvanometer type represents the amplitude reading method, the preset segment number represents the number of amplitudes stored in the amplitude storage module, and the preset segment length represents the clock length of multiple control clocks.

[0066] In some embodiments, reading the amplitude of a preset number of segments from the amplitude storage module according to the preset galvanometer type includes:

[0067] Based on the first galvanometer type of the first sub-image, read the amplitudes of a preset number of segments in positive order from the amplitude storage module;

[0068] Based on the second galvanometer type of the second sub-image, the amplitude of a preset number of segments is read in reverse sequence from the amplitude storage module, or the amplitude in the amplitude storage module is inverted and the inverted amplitude of the preset number of segments is read in positive sequence from the amplitude storage module, wherein the first sub-image and the second sub-image are two frames of sub-images decomposed from the same frame image.

[0069] In some embodiments, the method for generating a digital driving waveform of a galvanometer further includes:

[0070] multiplying the digital drive waveform by a preset gain value so that the amplitude of the digital drive waveform reaches the expected amplitude of the corresponding analog drive waveform; and / or,

[0071] A preset bias voltage is applied to the digital driving waveform to adjust the central deflection angle of the galvanometer during the deflection process.

[0072] In some embodiments, the method for generating a digital driving waveform of a galvanometer further includes:

[0073] In response to the galvanometer start-up operation, selecting a digital drive waveform output;

[0074] In response to the galvanometer closing operation, a preset fixed amplitude output is selected.

[0075] The digital driving waveform generating method for the galvanometer provided in the embodiment of the present application can be implemented by using the digital driving waveform generating device for the galvanometer provided in the embodiment of the present application. For the specific steps, please refer to the functions of the relevant modules in the digital driving waveform generating device for the galvanometer, which will not be described in detail here.

[0076] 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.

[0077] 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 digital drive waveform generating device for a galvanometer, characterized in that: include: Subframe delay module, clock control module, address control module and amplitude storage module; The subframe delay module is connected to the address control module, and is used to delay the subframe signal and transmit the delayed subframe signal to the address control module, wherein the subframe signal is a subframe signal of two subframes of a frame image decomposed into, and the delayed subframe signal is used to synchronize the subimage display with the start of the galvanometer movement; The clock control module is connected to the address control module, and the clock control module is used to provide the address control module with a control clock for generating a digital drive waveform; The amplitude storage module is connected to the address control module, and the amplitude storage module is used to store multiple amplitudes of the digital driving waveform according to a preset storage order; The address control module is used to respond to the delayed sub-frame signal. When the rising edge or falling edge of the delayed sub-frame signal arrives, the amplitude of the preset number of segments is read from the amplitude storage module according to the preset galvanometer type, and the amplitude is output in sequence according to the reading order to generate the digital drive waveform, wherein the first to the second to last amplitudes are output at a preset segment length, and the last amplitude is output until the rising edge or falling edge of the next delayed sub-frame signal arrives, the preset galvanometer type represents the reading method of the amplitude, the preset segment number represents the number of the amplitudes stored in the amplitude storage module, and the preset segment length represents the clock length of multiple control clocks.

2. The digital drive waveform generating device for a galvanometer according to claim 1, characterized in that: The digital drive waveform generating device of the galvanometer further comprises a multiplication module; The multiplication module is connected to the address control module, and is used for multiplying the digital driving waveform by a preset gain value so that the amplitude of the digital driving waveform reaches the expected amplitude of the corresponding analog driving waveform.

3. The digital drive waveform generating device for a galvanometer according to claim 1 or 2, characterized in that: The digital drive waveform generating device of the galvanometer further comprises an adding module; The adding module is connected to the address control module, and is used for applying a preset bias voltage to the digital driving waveform to adjust the central deflection angle of the galvanometer during the deflection process.

4. The digital drive waveform generating device for a galvanometer according to claim 1, characterized in that: The digital drive waveform generating device of the galvanometer further comprises a selection module; The selection module comprises a first input terminal, a second input terminal and a fixed output enable terminal, the first input terminal is connected to the address control module, and the second input terminal is connected to a preset fixed amplitude; The selection module is used to output the digital driving waveform when the enable signal of the fixed output enable end is invalid; and to output the preset fixed amplitude to turn off the galvanometer when the enable signal of the fixed output enable end is valid.

5. The digital drive waveform generating device for a galvanometer according to claim 1, characterized in that: The clock control module is also connected to the galvanometer drive component of the projection device, and the clock control module is also used to transmit the control clock to the galvanometer drive component to provide a clock for data input to the galvanometer drive component.

6. 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 display control component comprises a digital driving waveform generating device for the galvanometer according to any one of claims 1 to 5; 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.

7. A method for generating a digital drive waveform of a galvanometer, characterized in that: include: Delaying the subframe signal to obtain a delayed subframe signal, wherein the subframe signal is a subframe signal of two sub-images decomposed from a frame image, and the delayed subframe signal is used to synchronize the sub-image display with the start of the galvanometer movement; Obtain a control clock for generating a digital drive waveform; In response to the delayed sub-frame signal, when the rising edge or falling edge of the delayed sub-frame signal arrives, the amplitude of the preset number of segments is read from the amplitude storage module according to the preset galvanometer type, and the amplitude is output in sequence according to the reading order to generate the digital drive waveform, wherein the first to the second to last amplitudes are output at a preset segment length, and the last amplitude is output until the rising edge or falling edge of the next delayed sub-frame signal arrives, the preset galvanometer type represents the way the amplitude is read, the preset number of segments represents the number of the amplitudes stored in the amplitude storage module, and the preset segment length represents the clock length of multiple control clocks.

8. The method for generating a digital driving waveform of a galvanometer according to claim 7, characterized in that: The step of reading the amplitude of a preset number of segments from the amplitude storage module according to the preset galvanometer type includes: Based on the first galvanometer type of the first sub-image, read the amplitudes of a preset number of segments in positive order from the amplitude storage module; Based on the second galvanometer type of the second sub-image, the amplitude of a preset number of segments is read from the amplitude storage module in reverse sequence, or the amplitude in the amplitude storage module is inverted, and the inverted amplitude of the preset number of segments is read from the amplitude storage module in positive sequence, wherein the first sub-image and the second sub-image are two frames of sub-images decomposed from the same frame image.

9. The method for generating a digital driving waveform of a galvanometer according to claim 7, characterized in that: The method for generating a digital driving waveform of the galvanometer further comprises: multiplying the digital drive waveform by a preset gain value so that the amplitude of the digital drive waveform reaches the expected amplitude of the corresponding analog drive waveform; and / or, A preset bias voltage is applied to the digital driving waveform to adjust the central deflection angle of the galvanometer during the deflection process.

10. The method for generating a digital driving waveform of a galvanometer according to claim 7, characterized in that: The method for generating a digital driving waveform of the galvanometer further comprises: In response to the galvanometer start-up operation, selecting the digital drive waveform output; In response to the galvanometer closing operation, a preset fixed amplitude output is selected.

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