Laser projection device and image display method

Abstract

The present disclosure belongs to the technical field of display. Provided are a laser projection device and an image display method. On the basis of a video signal, a display driving component (102) sends an enable signal and a PWM signal to a laser driving component (105), sends an enable signal to a phase light modulation component (107), and sends a display driving signal to a light modulator (103). The laser driving component (105) sends a light source driving signal to a light source component (104) on the basis of the enable signal and the PWM signal, so as to drive the light source component (104) to emit primary-colored light. A video processing component (106) sends a phase video signal to the phase light modulation component (107) on the basis of the video signal. The phase light modulation component (107) performs phase light modulation on the basis of the phase video signal and the enable signal, so as to emit modulated light to the light modulator (103). The present disclosure redistributes light energy in space, and thus improves the peak brightness and the light energy efficiency.

Description

Laser projection device and image display method

[0001] The present disclosure claims priority to Chinese patent application No. 202311056608.1 filed on August 21, 2023, entitled “Laser TV, and Local Backlight Adjustment Method for Laser TV”, and Chinese patent application No. 202311056611.3 filed on August 21, 2023, entitled “Laser TV, and Local Backlight Adjustment Method for Laser TV”, the entire contents of which are incorporated by reference into the present disclosure. Technical Field

[0002] The present disclosure relates to the field of display technology, and in particular to a laser projection device and an image display method. Background Art

[0003] Laser projection is a next-generation display technology that uses lasers as a light source and digital light processing (DLP) technology to display images. Laser projection equipment offers advantages such as energy saving, eye protection, and vibrant colors.

[0004] Summary of the Invention

[0005] The present disclosure provides a laser projection device and an image display method, and the technical solutions of the laser projection device and the image display method are described as follows.

[0006] In a first aspect, the present disclosure provides a laser projection device. The laser projection device includes a main control chip, a display driver component, a light modulation device, a light source component, and a laser driver component;

[0007] The main control chip is used to generate a video signal according to an external video source;

[0008] The display driving component is connected to the laser driving component and the light modulation device respectively, and the display driving component is used to obtain the video signal, and send an enable signal and a PWM signal to the laser driving component according to the video signal, and send a display driving signal to the light modulation device according to the video signal;

[0009] The laser driving component is connected to the light source component, and the laser driving component is used to send a light source driving signal to the light source component according to the enable signal and the PWM signal, so as to drive the light source component to light up and emit primary color light;

[0010] The laser projection device also includes a phase light modulation component and a video processing component;

[0011] The video processing component is connected to the main control chip and the phase light modulation component respectively, and the video processing component is used to send a phase video signal to the phase light modulation component according to the video signal;

[0012] The display driving component is connected to the phase light modulation component, and the display driving component is further used to send the enable signal to the phase light modulation component;

[0013] The phase light modulation component is used to perform phase light modulation according to the phase video signal and the enable signal to emit modulated light to the light modulation device;

[0014] The light modulation device is used to display an image based on the modulated light.

[0015] In a second aspect, the present disclosure provides an image display method for a laser projection device. The laser projection device includes a main control chip, a display driver component, a light modulation device, a light source component, a laser driver component, a phase light modulation component, and a video processing component; the display driver component is connected to the laser driver component, the light modulation device, and the phase light modulation component, respectively; the laser driver component is connected to the light source component, and the video processing component is connected to the main control chip and the phase light modulation component, respectively;

[0016] The method includes: obtaining a video signal through the display driving component, sending an enable signal and a PWM signal to the laser driving component according to the video signal, sending the enable signal to the phase light modulation component, and sending a display driving signal to the light modulation device; sending a light source driving signal to the light source component according to the enable signal and the PWM signal through the laser driving component to drive the light source component to light up and emit primary color light; sending a phase video signal to the phase light modulation component according to the video signal through the video processing component; performing phase light modulation through the phase light modulation component according to the phase video signal and the enable signal to emit modulated light to the light modulation device; and displaying an image based on the modulated light through the light modulation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic structural diagram of a laser projection device according to an embodiment of the present disclosure;

[0018] FIG2 is a schematic diagram of a backlight local adjustment according to an embodiment of the present disclosure;

[0019] FIG3 is a schematic diagram of a phase light modulator and a multi-chip light modulator to achieve local backlight adjustment according to an embodiment of the present disclosure;

[0020] FIG4 is a schematic diagram of another example of local backlight adjustment according to an embodiment of the present disclosure;

[0021] FIG5 is a schematic diagram of a monolithic phase light modulator and a monolithic light modulator for realizing local backlight adjustment according to an embodiment of the present disclosure;

[0022] FIG6 is an example of a monolithic phase light modulator and a light modulator to achieve local backlight adjustment according to an embodiment of the present disclosure;

[0023] FIG7 is a schematic structural diagram of a laser projection device provided by an embodiment of the present disclosure;

[0024] FIG8 is a schematic diagram of the structure of a video processing component provided by an embodiment of the present disclosure;

[0025] FIG9 is a schematic diagram of the structure of another video processing component provided by an embodiment of the present disclosure;

[0026] FIG10 is a schematic structural diagram of another laser projection device provided by the present disclosure;

[0027] FIG11 is a schematic diagram of a light source, phase modulation, and display synchronization according to an embodiment of the present disclosure;

[0028] FIG12 is a schematic structural diagram of a phase light modulation component provided by an embodiment of the present disclosure;

[0029] FIG13 is a schematic structural diagram of a bias voltage conversion circuit provided in an embodiment of the present disclosure;

[0030] FIG14 is a schematic structural diagram of another bias voltage conversion circuit provided by an embodiment of the present disclosure;

[0031] FIG15 is a schematic diagram of a waveform diagram of an enable signal and a bias voltage according to an embodiment of the present disclosure;

[0032] FIG16 is a schematic diagram of adjusting the delay of the enable signal corresponding to the subsequent primary color light in the case of delay in an example of an embodiment of the present disclosure;

[0033] FIG17 is a schematic diagram of an example of an embodiment of the present disclosure in which a bias voltage signal is not superimposed with a first voltage signal and a bias voltage signal is superimposed with a first voltage signal;

[0034] FIG18 is a schematic diagram of a waveform diagram of an enable signal and a bias voltage signal superimposed with a first voltage signal according to an embodiment of the present disclosure;

[0035] FIG19 is a schematic diagram of a first brightness correction parameter and an image area according to an embodiment of the present disclosure;

[0036] FIG20 is a schematic diagram of a target matrix according to an embodiment of the present disclosure;

[0037] FIG21 is a flow chart of an image display method of a laser projection device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] Figure 1 is a schematic diagram of the structure of a laser projection device provided by an embodiment of the present disclosure. Referring to Figure 1 , the laser projection device 1 (also known as a laser TV) includes a light source 10, a light modulation assembly 20, a lens 30, and a housing 40 (only a portion of the housing 40 is shown in Figure 1 ). The light modulation assembly 20 may include the light modulation device 103 and the phase light modulation assembly 107 described below.

[0039] The light source 10 is configured to provide an illumination beam (a laser beam). The light modulation assembly 20 is configured to modulate the illumination beam provided by the light source 10 using an image signal to produce a projection beam. The lens 30 is configured to project the projection beam onto a screen or wall to form a projection image. The light source 10, light modulation assembly 20, and lens 30 are assembled in a housing 40. The light source 10, light modulation assembly 20, and lens 30 can be connected sequentially along the direction of beam propagation.

[0040] The light source 10, the light modulation assembly 20 and the lens 30 can be respectively enclosed by corresponding housings. The housings corresponding to the light source 10, the light modulation assembly 20 and the lens 30 can support the corresponding optical components and ensure that the optical components meet certain sealing or airtight requirements.

[0041] One end of the light modulation component 20 is connected to the lens 30 , and the light modulation component 20 and the lens 30 are arranged along the emission direction (eg, parallel to the N direction) of the projection beam of the laser projection device 1 . The other end of the light modulation component 20 can be connected to the light source 10 .

[0042] In one possible implementation, the arrangement direction of the light source 10 and the light modulation component 20 is approximately perpendicular to the arrangement direction of the light modulation component 20 and the lens 30, that is, in the laser projection device 1, the emission direction of the projection light beam (for example, parallel to the N direction) is approximately perpendicular to the emission direction of the illumination light beam (for example, parallel to the M direction).

[0043] Due to the limitations of the light source, laser projectors cannot achieve local backlight adjustment and high-dynamic range (HDR) display by adjusting the brightness of the lamp beads in different areas, as is done with LCD TV backlights. To achieve local backlight adjustment, laser projectors can use the following methods.

[0044] In one possible implementation, as shown in Figure 2, an additional light modulator is added, so that the light source output is first modulated by the first light modulator before being irradiated by the second light modulator for display. This solution has poor practicality, fails to increase peak brightness, and has low light efficiency. After modulation by the first light modulator, the dark field portion of the light is discarded, and only the bright field portion of the light is reflected to the second light modulator for display. As shown in Figure 2, by significantly reducing the dark field brightness, local backlight modulation is achieved, thereby achieving a high dynamic range display effect.

[0045] In another possible implementation, as shown in Figure 3, for the three-chip three-color laser light modulator display technology, a phase light modulator is added to modulate each primary color light to the light modulator. The phase modulation of the phase light modulator is shown in Figure 4. The advantage of phase light modulation is that it can not only reduce the dark field brightness but also increase the peak brightness, thereby achieving local adjustment of the backlight over a large range, and has high light efficiency and extremely high technical advantages. In this solution, since the three primary colors are combined in space through an optical device (such as the three-chip light modulator in Figure 3) for the final display, the display timing and phase light modulation timing only need to meet the frame synchronization of the video image, and there is no need to consider additional signal synchronization requirements. Among them, as shown in Figure 3, the square with vertical cross-section lines represents the red image, the square with oblique cross-section lines represents the green image, and the square with horizontal cross-section lines represents the blue image. The blank square on the far right represents the image synthesized by the red image, the green image, and the blue image.

[0046] In another possible implementation, for the single-chip light modulator display technology (as shown in FIG5 ), an embodiment of the present disclosure provides a laser projection device. The laser projection device uses a phase light modulator to perform phase modulation on the light source output, thereby adjusting the distribution of light energy in space. Combined with the primary color display timing of the single-chip light modulator, the timing synchronization of the local adjustment and display of each primary color backlight is achieved, the peak brightness is increased and the dark field brightness is reduced, the light energy efficiency is improved, and HDR display is achieved. Among them, the lighting timing of the primary color light displayed by the single-chip light modulator is time-division multiplexed. As shown in FIG5 , the square including the vertical section line represents the red image, the square including the oblique section line represents the green image, and the square including the horizontal section line represents the blue image. The blank square on the far right represents the image synthesized by the red image, the green image and the blue image.

[0047] The following is an introduction to the basic principles of how phase light modulation devices achieve local backlight adjustment.

[0048] A phase light modulator consists of multiple micron-sized dimming mirrors. Each mirror has a flat reflective surface that can be moved vertically in a direction perpendicular to the reflective surface. This vertical displacement of the mirrors alters the phase relationship between the incident light beams, as shown in Figure 4. Because laser light is coherent, phase shifts cause diffraction, thereby adjusting the light intensity distribution within the image. In actual display effects, this can be achieved by "shifting" light from dark areas to bright areas, brightening bright areas and modifying dark areas, thereby achieving localized backlight adjustment with a high dynamic range.

[0049] A monolithic phase light modulator is used in conjunction with an optical modulator to achieve local backlight adjustment. As shown in Figure 6, the three-color laser light source is sequentially lit to emit light. When the monochromatic laser is irradiated onto the phase light modulator, the device can phase-modulate the light according to the displayed image content. The phase is changed by the up and down displacement of the pixel point (i.e., micromirror). The modulated light is input to the surface of the optical modulator. The diffracted light is strong in the area corresponding to the bright image and weak in the area corresponding to the dark image, thereby achieving local adjustment of the backlight. The diffracted light is further pulse-width modulated (PWM) by the optical modulator and then imaged on the screen through the lens, thus achieving HDR display.

[0050] In other words, after being dimmed by the phase light modulator, at least two of the illumination beams have different intensities. This can increase the brightness difference between at least two image subregions in the projected image, thereby improving the dynamic contrast of the projected image without changing the brightness of the light source or processing the projected image, thereby enhancing the display quality of the image subsequently projected through the lens.

[0051] Specifically, controlling the phase light modulator requires phase information in the spatial light field. Since the phase information cannot be measured, it needs to be obtained using a phase recovery algorithm. Using the light field amplitude (intensity) information of the known input surface (image plane) and output surface (far-field diffraction plane, i.e., the light modulator), the transformation relationship between the two light fields is known, and the light field phase information can be iteratively solved by diffraction calculation (i.e., multiple constraint replacements and transformations in both the spatial and spectral domains). Here, taking the Gerchberg-Saxtong (hereinafter referred to as GS) algorithm as an example, the input surface light wave function f(x,y) of the illumination beam output by the light source at the phase light modulator can be expressed as: f(x,y)=A(x,y)exp(iΦ(x,y)) (1)

[0052] Where A(x,y) and Φ(x,y) represent the amplitude distribution and phase distribution of the light field at the phase light modulator. A(x,y) is a known quantity, Φ(x,y) can be estimated during the initial calculation, and (x,y) represents the coordinates of the input surface (image plane).

[0053] After phase modulation, the amplitude distribution and phase distribution at the output surface can be expressed by the optical wave function g(u,v): g(u,v)=B(u,v)exp(iθ(u,v)) (2)

[0054] Where B(u,v), θ(u,v), and (u,v) represent the amplitude distribution, phase distribution, and coordinates of the point on the output surface of the illumination beam after phase modulation, respectively. Since the intensity information after modulation depends on the video signal, the amplitude distribution is known.

[0055] Based on the light wave functions f and g, the following transformation conditions are satisfied: g = F(f), f = F-1(g) (3)

[0056] Where F represents Fourier transform, and F-1 represents inverse Fourier transform. Therefore, the input light wave function can be transformed into the output light wave function through Fourier transform, and the output light wave function can be transformed into the input light wave function through inverse Fourier transform.

[0057] In summary, the GS algorithm process is as follows:

[0058] Step 1: Estimate the initial input phase information Φ0(x,y), where n is the number of cycles.

[0059] Step 2: Perform Fourier transform on the input function f(x,y)=A(x,y)exp(iΦ0(x,y)) to obtain the light wave function g'(u,v), where g'(u,v)=B'(u,v)exp(iθn(u,v)), and obtain the phase relationship θn(u,v).

[0060] Step 3: Replace the phase information in the output function with θn(u,v) to obtain g(u,v)=B(u,v)exp(iθn(u,v)).

[0061] Step 4. Perform inverse Fourier transform on g(u,v)=B(u,v)exp(iθn(u,v)) to obtain f'(x,y)=A'(x,y)exp(iΦn(x,y)).

[0062] Step 5: Determine whether the mean square error of the output amplitudes B'(u,v) and B(u,v) is less than the specified index ε or reaches a certain number of iterative loop operations K. If not, execute step 6; if yes, execute step 7.

[0063] Step 6: Replace the phase information in the input function with Φn(x,y) and repeat step 2.

[0064] Step 7: Complete the phase recovery operation. Φk(x, y) is the phase distribution function required by the phase optical modulation device to represent the phase information.

[0065] The following detailed description of the technical solution of the present disclosure is provided in conjunction with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0066] FIG7 is a schematic diagram of the structure of a laser projection device provided by an embodiment of the present disclosure. As shown in FIG7 , the laser projection device 1 includes: a main control chip 101 , a display driver component 102 , a light modulation device 103 , a light source component 104 and a laser driver component 105 .

[0067] The main control chip 101 is configured to generate a video signal based on an external video source. For example, the external video source may be a network video source, a High Definition Multimedia Interface (HDMI) video signal, or a video source stored in a storage medium such as a USB flash drive. The decoded video signal may be a V-By-One signal developed for image transmission, or a Low Voltage Differential Signaling (LVDS) interface.

[0068] The display driver component 102 is connected to the laser driver component 105 and the light modulator 103, respectively. The display driver component 102 is used to obtain a video signal, send a synchronization signal to the laser driver component 105 based on the video signal, and send a display driver signal to the light modulator 103 based on the video signal. The display driver signal is transmitted according to a first timing sequence. For example, if the first timing sequence is an RGB cycle (i.e., a red light-green light-blue light cycle, hereinafter using R to represent red light, G to represent green light, and B to represent blue light), the light modulator 103 displays an image in the order of red light-green light-blue light.

[0069] In one possible implementation, the synchronization signals sent by the display driver component 102 to the laser driver component 105 include an enable signal and a PWM signal. The enable signal can be a timing control signal, typically represented as X_EN, where X represents the abbreviation for different primary colors of light. The enable signal is used to coordinate the timing of the output of different color lights. The PWM signal is a square wave signal used to provide a current signal for laser lighting. The display driver component 102 can determine the enable signal and PWM signal based on the video signal.

[0070] In one possible implementation, after receiving the video signal, the display driver component 102 determines the display quality requirement based on the video signal, then determines the first timing based on the display quality requirement, and generates a display driver signal based on the specific partitioning of the light modulator 103 and the bit range of each primary color pixel.

[0071] The laser driving component 105 is connected to the light source component 104. The laser driving component 105 is used to send a light source driving signal to the light source component 104 according to the synchronization signal to drive the light source component 104 to light up and emit primary color light. The light source driving signal is transmitted according to the second timing.

[0072] Exemplarily, the light source assembly 104 includes three-color lasers, namely red, green, and blue lasers. If the second time sequence is RGB cycle, the light source assembly 104 uses the three-color lasers to emit three-color laser light beams in the order of red light, green light, and blue light.

[0073] In a possible implementation, as shown in FIG. 7 , the laser projection device 1 further includes a video processing component 106 and a phase light modulation component 107 .

[0074] The video processing component 106 is respectively connected to the main control chip 101, the display driver component 102, and the phase light modulation component 107, wherein the video processing component 106 is used to receive the video signal sent by the main control chip 101 and send a phase video signal to the phase light modulation component 107 according to the video signal.

[0075] Specifically, the video processing component 106 may perform a phase recovery operation on the video signal to generate a phase video signal, so that the phase light modulation component 107 may perform phase modulation based on the phase video signal.

[0076] The display driver component 102 is connected to the phase light modulation component 107. The display driver component 102 is further configured to send a synchronization signal to the phase light modulation component 107. The synchronization signal sent by the display driver component 102 to the phase light modulation component 107 may include only an enable signal or may include an enable signal and a PWM signal.

[0077] The phase light modulation component 107 is configured to perform phase light modulation based on the phase video signal and the synchronization signal (e.g., the enable signal) to transmit modulated light to the light modulation device 103. The phase video signal and the synchronization signal may be transmitted according to a third timing sequence. For example, if the third timing sequence is an RGB cycle, the phase light modulation component 107 performs phase light modulation in the order of red light, green light, and blue light.

[0078] The light modulation device 103 is used to display images based on modulated light.

[0079] In one possible implementation, the light modulator 103 is configured to refresh the state of a micromirror on the light modulator 103 according to a first timing sequence, where the state is either on or off. The micromirrors of the light modulator, after the state is refreshed, display an image based on the modulated light received.

[0080] The first, second and third timings are synchronized, and the duration of each primary color is equal, so that the light source component 104 lights up, the light modulator 103 displays an image, and the phase light modulation component 107 performs phase light modulation to achieve synchronization.

[0081] In order to synchronize the first timing sequence with the third timing sequence, since there is a certain hysteresis in the on and off of the laser, the display driving component 102 can fine-tune the delay of the first timing sequence to synchronize the first timing sequence with the third timing sequence.

[0082] In one possible implementation, the main control chip 101 is a system on chip (SOC). In one possible implementation, the display driver component 102 is a digital light processing chip (DLP). In one possible implementation, the light modulation device 103 is a digital micromirror device (DMD).

[0083] In one possible implementation, the video processing component 106 includes a field programmable gate array (FPGA) chip, or the video processing component 106 is a graphics processing unit (GPU), which can be configured with memory, such as double data rate synchronous dynamic random access memory (DDR SDRAM), to cooperate with the FPGA chip or GPU to implement large-scale image processing operations.

[0084] In this embodiment, the display driver component 102 is configured to acquire a video signal and, based on the video signal, send a synchronization signal to the laser driver component 105, which in turn sends a display driver signal to the light modulator 103 based on the video signal. The laser driver component 105 is configured to send a light source driver signal to the light source component based on the synchronization signal, thereby driving the light source component 104 to illuminate and emit primary color light. The video processing component 106 is configured to send a phase video signal to the phase light modulator 107 based on the video signal. The display driver component 102 is also configured to send a synchronization signal to the phase light modulator 107. The phase light modulator 107 is configured to perform phase light modulation based on the phase video signal and the synchronization signal, thereby emitting modulated light to the light modulator 103. The light modulator 103 is configured to display an image based on the modulated light in a first timing sequence. This allows for spatial redistribution of light energy when implementing local backlight modulation, thereby increasing peak brightness and reducing dark field brightness, thereby improving light energy efficiency.

[0085] In the embodiment of the present disclosure, the display driving component 102 may obtain the video signal in the following two ways.

[0086] In a possible implementation, as shown in FIG7 , the video processing component 106 is connected to the display driving component 102 , and the display driving component 102 is specifically configured to receive a video signal sent by the video processing component.

[0087] In another possible implementation, as shown in FIG9 , the main control chip 101 is connected to the display driver component 102 , and the display driver component 102 is configured to receive a video signal sent by the main control chip 101 .

[0088] Next, the video processing component 106 generates a phase video signal according to the video signal in detail:

[0089] The video signal is usually a multi-channel serial signal, which needs to be decoded first to generate multiple sub-video signals. For example, the multiple sub-video signals may include: an R sub-video signal, a G sub-video signal, and a B sub-video signal.

[0090] In the embodiment of the present disclosure, multiple sub-video signals may be generated in the following two ways.

[0091] Decoding method 1: The video processing component 106 generates multiple sub-video signals based on the video signal, simplifying the interface link but increasing the computing power of the video processing component 106. The video signal is output from the video interface in the main control chip 101 and input to the video processing component 106. The video processing component 106 decodes the video signal to obtain the R sub-video signal, the G sub-video signal, and the B sub-video signal, and can store the sub-video signals in memory.

[0092] Decoding method 2: The main control chip 101 generates multiple sub-video signals based on the video signal, and then inputs the multiple sub-video signals to the video processing component 106. This method can reduce the computing power requirements of the video processing component 106 and transfer this part of the processing process to the main control chip 101 for completion.

[0093] The video processing component 106 is specifically configured to obtain multiple sub-video signals, each of which is obtained by decoding the video signal. For each sub-video signal, the video processing component 106 determines a phase information signal corresponding to the sub-video signal. A phase video signal is determined based on the phase information signals of the multiple sub-video signals. It is understood that the phase information signal includes multiple phase image information.

[0094] For the above decoding method 1 for generating multiple sub-video signals, as shown in FIG8 , the video processing component 106 includes a bypass video signal output circuit 1061 , a sub-frame decoding circuit 1062 , a phase recovery operation circuit 1063 and a phase video signal output circuit 1064 .

[0095] As shown in FIG8 , bypass video signal output circuit 1061 is used to split the video signal into two paths within video processing component 106. One path is used to decode the sub-video signal. The other path, without image processing, directly outputs the video signal to display driver component 102 for use by light modulator 103 for image display.

[0096] The subframe decoding circuit 1062 is configured to receive the video signal sent from the main control chip 101 and, based on the video signal, obtain the horizontal synchronization signal, the vertical synchronization signal, the enable synchronization signal, and the R, G, and B grayscale value information of all pixels. The circuit generates an R sub-video signal based on the R grayscale value information, a G sub-video signal based on the G grayscale value information, and a B sub-video signal based on the B grayscale value information. The circuit can also store the R, G, and B sub-video signals in memory for subsequent phase recovery operations.

[0097] Specifically, the relationship between the video signal, sub-video signal and image is as follows: the video signal includes multiple images. For any image in the video signal, the image includes an R sub-image, a G sub-image and a B sub-image. Multiple R sub-images generate an R sub-video signal, multiple G sub-images generate a G sub-video signal, and multiple B sub-images generate a B sub-video signal.

[0098] In one possible implementation, the subframe decoding circuit 1062 determines whether to compress the resolution of an image based on the resolution of the phase light modulation component 107 in the phase light modulation component 107. Specifically, the first resolution of the phase light modulation component 107 is obtained. Based on the first resolution, pixel compression is performed on an image in the video signal having a resolution higher than the first resolution, so that the resolution of the compressed image matches the first resolution.

[0099] Specifically, for an image in the video signal having a resolution higher than the first resolution, the sub-frame decoding circuit 1062 performs pixel compression on the image according to the first resolution, so that the resolution of the pixel-compressed image matches the first resolution.

[0100] In other words, when the number of pixels in the phase light modulation component 107 (phase light modulation device 1072) is smaller than the number of pixels in the light modulation device 103, the high-resolution image in the video signal needs to be compressed to obtain a low-resolution image that matches the required number of pixels in the phase light modulation component 107. A subsequent phase recovery operation is then performed based on the resolution-adjusted image to obtain phase video information, which can also reduce the time required for the subsequent phase recovery operation.

[0101] Phase recovery circuit 1063 is configured to read the R, G, and B sub-video signals from memory. Using the R sub-video signal as an example, multiple iterative operations are performed using a phase recovery algorithm to obtain phase information for each pixel in the R sub-video signal and generate R phase map information. The generated phase map information can be cached in memory for subsequent output. The phase recovery operation time for the R, G, and B sub-video signals can be less than the display duration of each frame.

[0102] The phase video signal output circuit 1064 is used to generate a phase video signal according to the decoded horizontal synchronization signal, field synchronization signal, enable synchronization signal, and R phase map information, G phase map information, and B phase map information.

[0103] It should be noted that in order to ensure that the video signal and phase video signal output by the video processing component 106 are synchronized, the bypass video signal output circuit 1061 can adjust the delay of outputting the video signal to the display driver component 102 so that the video signal and phase video signal are output synchronously.

[0104] For the aforementioned decoding method 2 for generating multiple sub-video signals, as shown in FIG9 , the main control chip 101 includes a sub-frame decoding circuit. Specifically, the main control chip 101 needs to add sub-video signal decoding functionality in addition to normal video signal decoding, and also add an additional video signal output port for outputting the sub-video signals. The output of the video signal requires adjustment of the delay to meet the computational time requirements. The sub-video signal must maintain a stable phase difference and frame synchronization with the video signal, ensuring that the video signal and the phase video signal are output synchronously.

[0105] Specifically, the main control chip 101 can simultaneously decode the external video source to obtain a video signal and generate a sub-video signal. It can also generate a sub-video signal by compressing the image in the video signal based on the resolution of the back-end phase optical modulation component 107. The sub-video signal can be output via a transistor-transistor logic (TTL) interface, simplifying the decoding requirements of the video processing component 106.

[0106] 9 , the video processing component 106 includes a phase recovery circuit 1063 and a phase video signal output circuit 1064. Since the video signal does not need to be decoded by the video processing component 106 to obtain the sub-video signal, the video processing component 106 only needs to receive the sub-video signal.

[0107] Phase recovery circuit 1063 is configured to receive the R sub-video signal, the G sub-video signal, and the B sub-video signal. Using the R sub-video signal as an example, multiple iterative operations are performed using a phase recovery algorithm to obtain phase information for each pixel in the R sub-video signal and generate R phase map information. The generated phase map information can be cached in memory for subsequent output. The phase recovery operation time for the R, G, and B sub-video signals can be less than the display duration of each frame.

[0108] The phase video signal output circuit 1064 is used to generate a phase video signal based on the horizontal synchronization signal, field synchronization signal, enable synchronization signal obtained by decoding the main control chip 101, combined with the R phase image information, G phase image information and B phase image information.

[0109] In one possible implementation, in decoding mode 2, the video processing component 106 receives the video signal and the sub-video signal separately, and performs delay adjustment and output of the video signal. This mode has the advantage of using a unified chip (the chip in the video processing component 106) to adjust the timing.

[0110] Next, the phase light modulation implemented by the phase light modulation component 107 will be described in detail.

[0111] As shown in FIG10 , which is a schematic structural diagram of another laser projection device provided by the present disclosure, the laser projection device 1 includes: a main control chip 101 , a display driver component 102 , a light modulation device 103 , a light source component 104 , a laser driver component 105 , and a video processing component 106 .

[0112] For the connection relationship among the main control chip 101, the display driver component 102, the light modulation device 103, the light source component 104, the laser driver component 105, and the video processing component 106, and the specific implementation, refer to the above embodiment and will not be repeated here.

[0113] The phase light modulation component 107 includes a dimming driving component 1071 and a phase light modulation device 1072 .

[0114] The dimming driver component 1071 is connected to the video processing component 106 and the phase light modulator 1072. The video processing component 106 is configured to send a phase video signal to the dimming driver component 1071. The display driver component 102 is configured to send an enable signal to the dimming driver component 1071. The dimming driver component 1071 is configured to determine the bias voltage of the phase light modulator 1072 based on the enable signal. The phase video signal and the bias voltage are then sent to the phase light modulator 1072.

[0115] Phase light modulator 1072 is configured to perform phase light modulation based on the phase video signal and the bias voltage, thereby transmitting modulated light to light modulator 103, so that light modulator 103 displays an image based on the modulated light. In one possible implementation, phase light modulator 1072 is a phase modulator (PLM).

[0116] It is known that when the geometric distance that a light wave propagates in a medium is consistent, the phase change is related to the wavelength of the light wave. For the dimming driver component 1071, its input is a phase video signal, that is, multiple phase diagram information (images after Fourier transformation). Therefore, the maximum displacement that the lens can adjust is particularly important, and the role of the bias voltage is to determine the maximum displacement of the micromirror of the PLM chip. Then, different bias voltages correspond to the three light waves of different wavelengths. In other words, it is the wavelength of light that affects phase modulation. For light waves of different wavelengths, different bias voltages can be used to displace the lens to achieve phase modulation of the light wave.

[0117] The bias voltage can determine the displacement step of the micromirror of the PLM chip (phase light modulator 1072). Since the number of displacement steps of the micromirror of the PLM chip is fixed, it can also be considered that the bias voltage determines the maximum displacement of the micromirror of the PLM chip.

[0118] In one possible implementation, the phase light modulator 1072 is specifically configured to control the displacement of micromirrors on the phase light modulator 1072 based on a bias voltage, thereby phase-modulating the primary light through the displaced micromirrors to achieve precise phase adjustment of light of different wavelengths. The bias voltage includes sub-bias voltages corresponding to primary light of different wavelengths. For example, the bias voltage may include a sub-bias voltage corresponding to red primary light, a sub-bias voltage corresponding to green primary light, and a sub-bias voltage corresponding to blue primary light. Alternatively, it can be understood that different primary lights have different bias voltages.

[0119] In one possible implementation, the phase light modulator 1072 is specifically configured to adjust the displacement step size of a micromirror on the phase light modulator 1072 according to a bias voltage. The adjusted micromirror is then used to phase modulate the primary color light to achieve precise phase adjustment of light of different wavelengths.

[0120] In one possible implementation, the phase light modulator 1072 is specifically configured to adjust the maximum displacement of a micromirror on the phase light modulator 1072 according to a bias voltage. The adjusted micromirror is then used to phase modulate the primary color light to achieve precise phase adjustment of light of different wavelengths.

[0121] It can be understood that since the second timing sequence and the third timing sequence are synchronized, for example, taking the red primary light as an example, when the light source assembly 104 emits the red primary light, the phase light modulation assembly 107 controls the up and down displacement of the micromirror according to the sub-bias voltage corresponding to the red light, so that the displaced micromirror can phase modulate the red primary light emitted by the light source assembly 104.

[0122] In one possible implementation, the phase light modulation component 107 receives the dimming drive signal at the same time as the light modulation device 103 receives the display drive signal. "Coincident" here means that the phase light modulation component 107 receives the dimming instruction synchronously with the light modulation device 103 receiving the display instruction. Specifically, for example, the delay of a faster-transmitting drive signal can be adjusted to meet the transmission time requirement of a slower-transmitting drive signal, so that the phase light modulation device 1072 and the light modulation device 103 receive the drive signals simultaneously.

[0123] In one possible implementation, the display time of the video signal corresponding to the target primary color of the target frame by the light modulator 103 at least partially overlaps with the display time of the phase video signal corresponding to the target primary color of the target frame by the phase light modulator 1072. The target frame is any frame.

[0124] In one possible implementation, the display driver component 102 may incorporate image correction functions such as projection keystone correction, screen entry correction, or obstacle avoidance, requiring additional image correction processing. For example, after buffering a frame of image information, an image correction algorithm may be used to shift the corresponding pixels and recalculate their grayscale information to implement the image correction function. Therefore, it is necessary to increase the delay between the dimming driver component 1071 sending the dimming drive signal to the phase light modulator 1072 to synchronize the display driver component 102 with the display drive signal output.

[0125] In one possible implementation, the optical modulator 103 is specifically used to: refresh the states of multiple micromirrors on the optical modulator 103 according to a first timing sequence, the states being on or off, and receive modulated light through the refreshed multiple micromirrors of the optical modulator to display an image.

[0126] For example, taking red primary light as an example, when the light source assembly 104 emits red primary light, the phase light modulator 1072 controls the up and down displacement of the micromirror based on the bias voltage corresponding to the red light, so that the displaced micromirror can phase modulate the red primary light emitted by the light source assembly 104. The light modulator determines to refresh the micromirror corresponding to the red primary light on the light modulator 103, causing the phase light modulator 1072 to send modulated light to the light modulator 103. The light modulator 103 receives the modulated light corresponding to the red primary light through the refreshed micromirror to display an image.

[0127] Specifically, as shown in FIG11 , FIG11 is a schematic diagram of light source, phase modulation, and display synchronization. Specifically, the light source assembly 104 emits red primary light, the phase light modulator 1072 performs phase modulation on the red primary light, and the light modulator 103 performs image display on the modulated light corresponding to the red primary light. The following uses red primary light as an example for illustration:

[0128] Before the laser driving component 105 and the dimming driving component 1071 receive the synchronization signal, the light modulating device 103 and the phase light modulating device 1072 complete the reception of the red image data.

[0129] When the laser driver component 105 and the dimming driver component 1071 receive the synchronization signal, they will synchronously perform the following operations:

[0130] (1) The laser driving component 105 drives the red laser in the light source component 104 to light up, so as to emit red primary color light to the phase light modulation device 1072, and the lasers of other colors are turned off.

[0131] (2) The phase light modulator 1072 receives the dimming drive signal sent by the dimming drive component 1071, which sends a sub-bias voltage corresponding to the red primary light to the phase light modulator 1072 (wherein the minimum unit of the micromirror displacement of the phase light modulator 1072 meets the red laser wavelength requirement). After receiving the dimming drive signal, the phase light modulator 1072 moves the micromirror up and down according to the sub-bias voltage to achieve phase modulation of the red primary light, that is, to achieve low-resolution backlight adjustment.

[0132] (3) The light modulator 103 receives the display drive signal sent by the display drive component 102. After receiving the display drive signal, the light modulator 103 refreshes the state of the micromirrors on the light modulator 103. By adjusting the flipping time of the micromirrors, multiple micromirrors are flipped simultaneously according to the determined states to achieve PWM modulation of the modulated light emitted by the phase light modulator 1072, that is, to achieve high display resolution, thereby realizing image display.

[0133] It should be noted that, as shown in Figure 11, the square including vertical cross-section lines represents the red image, and the denser the cross-section lines, the higher the resolution. The square including oblique cross-section lines represents the green image, and the denser the cross-section lines, the higher the resolution. The square including horizontal cross-section lines represents the blue image, and the denser the cross-section lines, the higher the resolution. The blank square represents an image composed of red, green and blue images. In addition, the synchronization corresponding to other primary colors, such as the red primary color light, is consistent. For the green primary color light and the blue primary color light, the above-mentioned red primary color light can be referred to, and no further details will be given here.

[0134] In this embodiment, the display driver component 102 is configured to acquire a video signal and, based on the video signal, send synchronization signals to the laser driver component 105 and the dimming driver component 1071. Furthermore, the display driver signal is sent to the light modulator 103 based on the video signal. The laser driver component 105 is configured to send a light source driver signal to the light source component based on the synchronization signal, thereby driving the light source component 104 to illuminate and emit primary color light. The video processing component 106 is configured to send a phase video signal to the dimming driver component 1071 based on the video signal. The dimming driver component 1071, based on the phase video signal and the synchronization signal, sends a dimming driver signal to the phase light modulator 1072, causing the phase light modulator 1072 to perform phase light modulation according to the dimming driver signal, thereby emitting modulated light to the light modulator 103. The light modulator 103 is configured to display images based on the modulated light. This allows for spatial redistribution of light energy when implementing local backlight modulation, increasing peak brightness and reducing dark field brightness, thereby improving light energy efficiency.

[0135] The following describes in detail how the phase light modulation component 107 phase-modulates each primary light color. Figure 12 is a schematic diagram of the structure of a phase light modulation component 107 provided in an embodiment of the present disclosure. As shown in Figure 12, the phase light modulation component 107 includes a dimming driver component 1071 and a phase light modulation device 1072. The dimming driver component 1071 includes a dimming driver circuit 710 and a bias voltage conversion circuit 711.

[0136] The video processing component 106 is connected to the dimming driving circuit 710. The video processing component 106 is specifically configured to send a phase video signal to the dimming driving circuit 710 according to the video signal.

[0137] The display driver component 102 is respectively connected to the dimming driver circuit 710 , the bias voltage conversion circuit 711 , and the laser driver component 105 . The display driver component 102 is specifically configured to send an enable signal to the dimming driver circuit 710 and the bias voltage conversion circuit 711 .

[0138] In one possible implementation, the display driver component 102 includes a digital-to-analog converter (DAC). The display driver component 102 is specifically configured to determine a PWM signal based on a video signal, perform digital-to-analog conversion on the PWM signal using the DAC, and obtain a converted PWM signal. The converted PWM signal and an enable signal are then transmitted to the laser driver component 105.

[0139] Accordingly, the laser driving component 105 can generate a light source driving signal according to the converted PWM signal and the enable signal.

[0140] The bias voltage conversion circuit 711 is connected to the phase optical modulator 1072. The bias voltage conversion circuit 711 is configured to send a bias voltage to the phase optical modulator 1072 according to an enable signal.

[0141] The dimming driver circuit 710 is connected to the phase light modulator 1072. The dimming driver circuit 710 is used to send the phase image information in the phase video signal to the phase light modulator 1072 according to the enable signal, drive the micromirror of the phase light modulator 1072 to move under the bias voltage, and combine the phase video signal to achieve phase modulation.

[0142] It can be understood that the phase video signal is composed of continuous phase image information (also called a hologram). Therefore, the dimming drive circuit 710 can enable the phase light modulator 1072 to achieve phase modulation based on the corresponding phase image information and the bias voltage according to the cyclic order of the primary color light of the third timing.

[0143] The following is an exemplary description of the implementation of the bias voltage conversion circuit 711 provided in the embodiment of the present disclosure. It should be noted that the bias voltage conversion circuit 711 provided in the embodiment of the present disclosure can be applied to any laser projection device that needs to generate a bias voltage, and is not limited to application in the laser projection device 1 shown in Figures 7 and 10. Furthermore, the bias voltage conversion circuit 711 provided in the embodiment of the present disclosure can be applied to any laser projection device that needs to generate multiple bias voltages.

[0144] In one possible implementation, FIG13 is a schematic diagram of the structure of a bias voltage conversion circuit 711 provided in an embodiment of the present disclosure. As shown in FIG13 , the bias voltage conversion circuit 711 includes multiple voltage regulators 7111 and an analog selection switch 7112. The analog selection switch 7112 is respectively connected to the multiple voltage regulators 7111 and the phase optical modulator 1072. The multiple voltage regulators 7111 are configured to send a plurality of target voltages to the analog selection switch 7112. The analog selection switch 7112 is configured to determine a bias voltage from the plurality of target voltages and send the bias voltage to the phase optical modulator 1072. Thus, the bias voltage conversion circuit 711 provided in an embodiment of the present disclosure is capable of generating a plurality of bias voltages.

[0145] When the bias voltage conversion circuit 711 is used in the laser projection device shown in Figures 7 and 10, as shown in Figure 13, the analog selection switch 7112 is also connected to the display driver component 102. Multiple voltage regulators 7111 are used to send target voltages corresponding to multiple primary colors to the analog selection switch 7112. For example, three voltage regulators 7111 are used in the figure as an example. The three voltage regulators 7111 send target voltages corresponding to the red primary color, the green primary color, and the blue primary color to the analog selection switch 7112, respectively.

[0146] The display driving component 102 is configured to send an enable signal to the analog selection switch 7112 .

[0147] The analog selection switch 7112 is used to determine a bias voltage from target voltages corresponding to the multiple primary color lights according to the enable signal, and send the bias voltage to the phase light modulator 1072 .

[0148] For example, if the third timing sequence determined by the enable signal is an RGB cycle, for example, when the cycle reaches R, the analog selector switch can determine the target voltage corresponding to the red primary light from the target voltages corresponding to the red primary light, the green primary light, and the blue primary light as the bias voltage. The target voltages corresponding to the three primary lights are respectively input to the analog selector switch 7112 through three voltage regulators 7111, so that the analog selector switch 7112 can output different bias voltages based on the third timing sequence, achieving the purpose of voltage switching. In other words, when light of a specific color is projected onto the phase light modulator 1072, the bias voltage is also switched to the corresponding voltage value to determine the movement of the micromirrors of the phase light modulator 1072 to achieve phase modulation.

[0149] In one possible implementation, the laser projection device 1 further includes a power supply 108. The bias voltage conversion circuit 711 further includes a direct current (DC / DC) converter 7113. The DC converter 7113 is connected to the power supply 108 and multiple voltage regulators 7111, respectively. The DC converter 7113 is configured to input a first voltage to each of the multiple voltage regulators 7111 according to the driving voltage input by the power supply 108. For any one of the voltage regulators 7111, the DC converter 7113 is configured to input a target voltage corresponding to the voltage regulator 7111 to the analog selection switch 7112 according to the first voltage. The target voltage corresponding to each voltage regulator 7111 is different.

[0150] For example, the power supply 108 can generate a 12V supply voltage to drive the bias voltage conversion circuit 711. After the 12V voltage signal passes through the DC / DC converter, a 5V voltage signal is generated, which is input into the three voltage regulators 7111. By changing the resistance values ​​of the voltage divider resistors in the three voltage regulators 7111, different target signals can be generated, so that the analog selection switch 7112 can switch the voltage to output the corresponding bias voltage.

[0151] In one possible implementation, as shown in FIG13 , a digital-to-analog converter 7115 can be added to the bias voltage conversion circuit 711, and the display driver component 102 is specifically configured to: determine a PWM signal based on a video signal, and perform digital-to-analog conversion of the PWM signal through the digital-to-analog converter 7115 on the bias voltage conversion circuit 711 to obtain a converted PWM signal. The digital-to-analog converted PWM signal is then sent to the laser driver component 105, so that the laser driver component 105 generates a light source drive signal based on the converted PWM signal and an enable signal. In this case, the synchronization signal sent to the bias voltage conversion circuit 711 (or referred to as the phase light modulation component 107) includes an enable signal and a PWM signal. It is understandable that the bias voltage conversion circuit 711 may not include the digital-to-analog converter 7115, and the synchronization signal sent to the phase light modulation component 107 may only include an enable signal.

[0152] In this embodiment, the phase light modulation component 107 includes a dimming driver component 1071 and a phase light modulation device 1072. The dimming driver component 1071 includes a dimming driver circuit 710 and a bias voltage conversion circuit 711. The bias voltage conversion circuit 711 is configured to send a bias voltage to the phase light modulation device 1072 based on an enable signal. The dimming driver circuit 710 is configured to drive the micromirrors of the phase light modulation device 1072 to move under the bias voltage based on a synchronization signal and a phase video signal to achieve phase modulation. This allows for spatial redistribution of light energy when implementing local backlight modulation, thereby increasing peak brightness and reducing dark field brightness.

[0153] In one possible implementation, FIG14 is a schematic diagram of another bias voltage conversion circuit 711 provided in an embodiment of the present disclosure. As shown in FIG14 , the bias voltage conversion circuit 711 includes a control component 7114 , a DAC 7115 , and an amplifier 7116 .

[0154] The control component 7114 is connected to the DAC 7115. For example, the control component 7114 and the DAC 7115 can be connected via an Inter-Integrated Circuit (I2C) bus or a Serial Peripheral Interface (SPI) bus. Connection via the SPI bus can improve communication efficiency, and the present disclosure does not limit the connection method between the control component 7114 and the DAC 7115.

[0155] Control component 7114 is configured to input a target voltage to DAC 7115. DAC 7115 is configured to convert the target voltage into an analog voltage signal. Amplifier 7116 is connected to DAC 7115 and phase optical modulator 1072, respectively. Amplifier 7116 is configured to transmit a bias voltage to phase optical modulator 1072 based on the analog voltage signal. Thus, by adjusting the target voltage input to DAC 7115 by control component 7114, the bias voltage transmitted by amplifier 7116 to phase optical modulator 1072 can be adjusted.

[0156] When the bias voltage conversion circuit 711 is used in the laser projection device shown in Figures 7 and 10, as shown in Figure 14, the control component 7114 is also connected to the display driver component 102. The display driver component 102 is specifically configured to send an enable signal to the control component 7114. The control component 7114 is configured to input the target voltage corresponding to the primary color light to the DAC 7115 based on the enable signal. The DAC 7115 is configured to convert the target voltage corresponding to the primary color light into a voltage analog signal. The amplifier 7116 is configured to send a bias voltage to the phase light modulator 1072 based on the voltage analog signal.

[0157] In a possible implementation, the bias voltage conversion circuit 711 further includes four resistors 7117 and one capacitor 7118 , which is a required circuit structure. For details on the connection between the amplifier 7116 and the four resistors 7117 and one capacitor 7118 , refer to FIG. 14 .

[0158] In one possible implementation, if a digital-to-analog conversion function is integrated into the control component 7114, the control component 7114 is also used to perform digital-to-analog conversion on the target voltage to obtain a voltage analog signal, and send the voltage analog signal to the amplifier 7116 through the DA interface, so that the amplifier 7116 is used to send a bias voltage to the phase optical modulator 1072 according to the voltage analog signal.

[0159] In one possible implementation, the control component 7114 may be a microcontroller unit (MCU).

[0160] For example, the control component 7114 can receive enable signals corresponding to the red primary light, the green primary light, and the blue primary light (i.e., R_EN, G_EN, and B_EN) through interrupt ports IN1, IN2, and IN3, respectively, so that the control component 7114 outputs three different target voltages to input voltage analog signals to the amplifier 7116. The amplifier 7116 can adjust the voltage range. For example, when the target voltage is low, the amplification factor of the amplifier 7116 is less than 1 to improve control accuracy and input a bias voltage to the phase optical modulator 1072.

[0161] Because the target voltage is easily distorted after conversion by DAC 7115 and amplification by amplifier 7116, voltage correction can be performed as follows: In one possible implementation, amplifier 7116 is connected to control component 7114. Amplifier 7116 is also configured to send a bias voltage to control component 7114. Control component 7114 is also configured to perform voltage correction on subsequent target voltages corresponding to the primary color lights based on the bias voltage.

[0162] Specifically, amplifier 7116 can be connected to the AD interface of control component 7114 to input a bias voltage to the AD interface. Control component 7114 can calculate a voltage deviation based on the voltage value received by the AD interface and the voltage value of the bias voltage required for the current primary color light. Then, based on this voltage deviation, it can perform voltage correction on the target voltage corresponding to the subsequent primary color light. The bias voltage required for the current primary color light can be understood as a set bias voltage or a standard bias voltage.

[0163] For example, if the bias voltage required for the current primary light is 1.15V, and the voltage value received by the control component 7114 based on the AD interface is 1.14V, there is a voltage deviation of 0.01V. The control component 7114 can increase the target voltage corresponding to the subsequent primary light by 0.01V. For example, if the bias voltage required for the subsequent primary light is 1.18V (the target voltage for this primary light is 1.18V), the target voltage corresponding to this primary light can be increased by 0.01V (i.e., 1.19V) to compensate for the 0.01V loss after DAC conversion and amplification by the amplifier 7116, so that the bias voltage input to the phase light modulator 1072 is the required 1.18V.

[0164] The voltage deviation between the voltage value output by the amplifier 7116 and the target voltage is used to determine the error introduced by the voltage value after DAC conversion and amplification by the amplifier 7116. The bias voltage of the subsequent primary color light is corrected based on the error to achieve closed-loop control and improve the accuracy of the bias voltage input to the phase light modulator 1072.

[0165] For example, Figure 15 is a schematic diagram of waveforms of an enable signal and a bias voltage. Figure 15 shows the waveforms when there is no delay. VBIAS represents the bias voltage, RED_EN represents the enable signal corresponding to the red primary light, GREEN_EN represents the enable signal corresponding to the green primary light, and BLUE_EN represents the enable signal corresponding to the blue primary light. Since it takes a certain amount of time for the voltage value to undergo DAC conversion and amplifier amplification after the control component 7114 receives the enable signal, in order to synchronize the output of the enable signal by the display driver component 102 with the output of the bias voltage by the amplifier 7116, the delay in the subsequent output of the enable signal corresponding to the primary light can be adjusted in the following manner.

[0166] In one possible implementation, as shown in FIG16 , the first moment at which the amplifier 7116 outputs the bias voltage corresponding to the current primary light, and the second moment at which the display driver component 102 outputs the enable signal corresponding to the current primary light, are determined. A first duration is determined based on the first and second moments, and the subsequent output of the enable signal corresponding to the primary light is time-adjusted based on the first duration, thereby achieving synchronization.

[0167] Specifically, the control component 7114 is configured to receive, at the INT4 pin, an input / output (IO) level signal obtained through voltage conversion and a Schmitt trigger combination (the triangle symbol in FIG14 ). The IO level signal is generated based on a voltage signal of a bias voltage output by the amplifier, and the control component can determine the first moment based on the IO level signal.

[0168] Exemplarily, for ease of understanding, taking the current primary color light as red primary color light and the subsequent primary color light as green primary color light as an example, FIG16 is a schematic diagram of adjusting the delay of the enable signal corresponding to the subsequent primary color light when there is a delay.

[0169] Furthermore, because the bias voltage controls the height of the micromirror of phase light modulator 1072, different wavelengths of the relevant light waves correspond to different bias voltages. Within a certain bias voltage range, slight changes in the voltage cause slight changes in the height of the micromirror, which in turn cause changes in the position of the coherent speckle, thereby forming speckle.

[0170] To further reduce speckle, in one possible implementation, the bias voltage is adjusted based on the first voltage signal to obtain a processed bias voltage, and the processed bias voltage is sent to the phase optical modulator 1072. The first voltage signal is used to control the bias voltage to vary within a target voltage range.

[0171] It can be understood that the bias voltage is transmitted to the phase light modulator 1072 in the form of a continuous signal. That is, the bias voltage received by the phase light modulator 1072 can be referred to as a bias voltage signal. Specifically, the control component is further configured to output a first voltage signal, and the amplifier 7116 is specifically configured to superimpose the first voltage signal with the bias voltage signal to obtain a processed bias voltage signal. For example, as shown in FIG17 , FIG17 is a schematic diagram of the bias voltage signal before and after the first voltage signal is superimposed. The processed bias voltage signal is input into the phase light modulator 1072 to drive the micromirror of the phase light modulator 1072 to produce a tiny vibration, corresponding to the rapid displacement of the diffraction image speckle. The speckle contrast is reduced through time integration to achieve speckle reduction. FIG18 is a schematic diagram of the waveform of the bias voltage after the enable signal and the speckle reduction waveform are superimposed.

[0172] In one possible implementation, the display driver component 102 may send a control signal to the control component 7114. The control signal may be used to control the operating mode of the control component, such as whether to superimpose the first voltage signal, or to specify whether the control component performs despeckle processing on one or more of the three primary colors, as well as the amplitude and frequency of the despeckle waveform.

[0173] Next, how the video processing component 106 determines the phase video signal according to the video signal is described in detail.

[0174] In a possible implementation, the video processing component 106 may generate a phase video signal according to the video signal sent by the main control chip 101 .

[0175] Specifically, the video processing component 106 can obtain multiple sub-video signals, each of which is generated based on the video signal. For a specific implementation, reference can be made to the above embodiments. For any sub-video signal, brightness information of multiple sub-images in the sub-video signal is obtained, and phase image information corresponding to the sub-video signal is generated based on the brightness information of the multiple sub-images. A phase video signal is generated based on the phase image information corresponding to the multiple sub-video signals.

[0176] In another possible implementation, the video processing component 106 may obtain a brightness correction parameter, and generate a phase video signal according to the brightness correction parameter and the video signal.

[0177] Specifically, the video processing component 106 can obtain multiple sub-video signals. For any sub-video signal, it obtains brightness information of multiple sub-images in the sub-video signal and generates phase image information corresponding to the sub-video signal based on the brightness information of the multiple sub-images and brightness correction parameters. A phase video signal is generated based on the phase image information corresponding to the multiple sub-video signals. For example, the brightness information can be a brightness value.

[0178] The brightness correction parameters include first brightness correction parameters corresponding to multiple colors, namely, the first brightness correction parameter corresponding to R, the first brightness correction parameter corresponding to G, and the first brightness correction parameter corresponding to B. For example, taking R as an example, its corresponding first brightness correction parameter is as shown in FIG19 , which illustrates dividing an image into 3×3 image regions, with each number representing a brightness compensation parameter for one image region.

[0179] For example, for any sub-image in the R sub-video signal, as shown in FIG19 , the sub-image is divided into 3×3 image regions, and then the brightness information of each image region is calculated. The numbers in the figure represent the brightness value of each image region. In one possible implementation, the brightness information of the center point of the image region is obtained, and the brightness information of the image region is represented by the brightness information of the center point.

[0180] After obtaining the brightness information of an image region, the brightness compensation parameters for that region can be obtained. For example, by multiplying the brightness information of image region 1 with the brightness compensation parameters for the corresponding image region (i.e., image region 1) in Figure 19, the brightness of low-brightness image regions is increased, while that of high-brightness image regions is decreased. This shifts some of the light from the center region to the corners, adjusting the intensity distribution of the illumination beam. This compensates for the brightness of darker areas in the image, thereby improving the brightness uniformity of the final displayed image.

[0181] The following is a detailed introduction on how to obtain the brightness correction parameters.

[0182] In a possible implementation, the video processing component 106 is further configured to obtain brightness information of the first image corresponding to the plurality of color charts, and determine brightness correction parameters according to the brightness information of the first image corresponding to the plurality of color charts.

[0183] The video processing component 106 may store the brightness correction parameters for use in generating the phase video signal.

[0184] Illustratively, the video processing component 106 may receive a first image sent by a brightness measurement device. The brightness measurement device may be a device with a specific shooting function or a brightness meter, etc., which is not limited in the present disclosure.

[0185] In one possible implementation, the video processing component 106 is specifically used to: for a first image corresponding to any color map card, divide the first image into multiple image areas, obtain first brightness information of the image area for any image area, and determine brightness compensation parameters corresponding to the multiple image areas based on the first brightness information corresponding to the multiple image areas, and determine first brightness correction parameters corresponding to the color map card based on the brightness compensation parameters corresponding to the multiple image areas.

[0186] Specifically, to determine brightness compensation parameters corresponding to the plurality of image regions based on the first brightness information corresponding to the plurality of image regions, the video processing component 106 is specifically configured to obtain a target matrix. For any value in the target matrix, the target matrix is ​​divided by the first brightness information of the corresponding image region to obtain the brightness compensation parameter corresponding to the image region.

[0187] In one possible implementation, the target matrix may be determined based on the average value of the first brightness information of multiple image regions. It is understood that the value of the target matrix may be a target parameter for uniform brightness distribution, for example, the first target matrix shown in FIG20 .

[0188] In one possible implementation, the target matrix may also include different target parameters, where the target parameters corresponding to darker image areas and the target parameters corresponding to brighter image areas may be different, to achieve local brightness adjustment, such as the second target matrix shown in FIG20 .

[0189] For example, a pure color chart can be projected onto a projection screen using the laser projection device 1, and the brightness measurement device can capture the pure color chart to obtain a first image. The video processing component 106 can then divide the first image into multiple image regions, for example, 9 image regions, 16 image regions, or more. The more image regions there are, the more refined the correction to the image's brightness uniformity.

[0190] For any image area, for example, the brightness information of the center point of the image area can be obtained, and then the brightness information of the center point can be expressed as the brightness information of the image area. The center point can be the central pixel point of the image area, and the number of central pixel points can be one or more, which is not limited in this disclosure.

[0191] It can be understood that a red pure color picture card can obtain a first brightness correction parameter, a green pure color picture card can obtain a first brightness correction parameter, and a blue pure color picture card can obtain a first brightness correction parameter. The brightness adjustment component 109 can determine that the brightness correction parameter includes first brightness correction parameters corresponding to multiple colors, namely, the first brightness correction parameter corresponding to red, the first brightness correction parameter corresponding to green, and the first brightness correction parameter corresponding to blue.

[0192] In a possible implementation, after the brightness correction parameters are obtained, the brightness correction parameters are verified, that is, the first brightness correction parameter corresponding to red, the first brightness correction parameter corresponding to green, and the first brightness correction parameter corresponding to blue are verified respectively.

[0193] Specifically, for any color chart corresponding to a first brightness correction parameter, a determination is made as to whether the first brightness correction parameter satisfies a preset condition. If not, the first brightness correction parameter corresponding to the pure color chart is modified to obtain a second brightness correction parameter, which satisfies the preset condition. If so, the first brightness correction parameter corresponding to the color chart is used as the second brightness correction parameter.

[0194] That is, for first brightness correction parameters that do not meet the preset conditions, the brightness correction needs to be corrected to obtain a corrected brightness correction parameter, i.e., the second brightness correction parameter. For first brightness correction parameters that meet the preset conditions, no correction is required, and the first brightness correction parameter corresponding to the color chart is used as the second brightness correction parameter, i.e., the first brightness correction parameter is equal to the second brightness correction parameter.

[0195] The preset condition is that the brightness of the first image after brightness correction is performed according to the first brightness correction parameter is uniformly distributed.

[0196] Taking the first brightness correction parameter corresponding to red as an example, the brightness of the first image corresponding to the red chart is corrected based on this first brightness correction parameter. The corrected first image is then divided into multiple image regions. The brightness information of each image region is determined, and then the difference between the brightness values ​​of any two image regions is calculated. If each difference is less than a preset threshold, the brightness distribution of the first image after brightness correction is determined to be uniform.

[0197] In a possible implementation, the first brightness correction parameter is modified as follows:

[0198] Exemplarily, for the first brightness correction parameter corresponding to any color card, for example, when the video processing component 106 generates the first brightness correction parameter, it divides the first image corresponding to the color card into 9 image areas.

[0199] Then, for the correction of the first brightness correction parameter, the video processing component 106 is specifically configured to:

[0200] The first image corresponding to the color chart is divided into 16 image regions. For any image region, third brightness information of the image region is obtained, and a brightness compensation parameter corresponding to the image region is determined based on the third brightness information. Based on the brightness compensation parameters corresponding to the multiple image regions, a corrected first brightness correction parameter can be determined.

[0201] In this embodiment, the video processing component 106 can determine first brightness correction parameters corresponding to different colors based on the first image corresponding to the three-color pure color chart, so that after the video signal is subsequently decomposed into the R sub-video signal, the G sub-video signal, and the B sub-video signal, for example, the first-level brightness correction parameter corresponding to R can be used to perform brightness compensation on the R sub-image in the R sub-video signal, and then the phase map information corresponding to R is generated based on the brightness-compensated R sub-image, thereby improving the brightness uniformity of the final displayed image.

[0202] FIG21 is a flow chart of an image display method of a laser projection device provided by an embodiment of the present disclosure. The structure of the laser projection device can refer to the above embodiment. As shown in FIG21, the method includes the following steps:

[0203] S101 , through the display driving component, according to the video signal, sending an enable signal and a PWM signal to the laser driving component, sending an enable signal to the phase light modulation component, and sending a display driving signal to the light modulation device.

[0204] S102 , sending a light source driving signal to the light source assembly according to the enable signal and the PWM signal via the laser driving assembly, and driving the light source assembly to light up according to the light source driving signal to emit primary color light.

[0205] S103 , sending a phase video signal to a phase light modulation component according to the video signal through the video processing component.

[0206] S104 , performing phase light modulation on the primary color light according to the enable signal and the phase video signal through the phase light modulation component, so as to emit modulated light to the light modulation device.

[0207] S105 , displaying an image based on the modulated light through a light modulation device.

[0208] In one possible implementation, step S104 includes the following steps: determining a bias voltage according to an enable signal through a phase light modulation component, and performing phase light modulation on the primary color light according to the phase video signal and the bias voltage to emit modulated light to the light modulation device.

[0209] The present disclosure also provides a computer-readable storage medium, which may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes. Specifically, the computer-readable storage medium stores program instructions, and the program instructions are used for the methods in the above embodiments.

[0210] The present disclosure also provides a program product, which includes execution instructions stored in a readable storage medium. At least one control module of a display device can read the execution instructions from the readable storage medium, and at least one control module executes the execution instructions to cause the display device to implement the methods provided in the various embodiments described above.

[0211] The above descriptions are merely optional embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A laser projection device, characterized in that: The laser projection device includes a main control chip, a display driving component, a light modulation device, a light source component and a laser driving component; The main control chip is used to generate a video signal according to an external video source; The display driving component is connected to the laser driving component and the light modulation device respectively, and the display driving component is used to obtain the video signal, and send an enable signal and a PWM signal to the laser driving component according to the video signal, and send a display driving signal to the light modulation device according to the video signal; The laser driving component is connected to the light source component, and the laser driving component is used to send a light source driving signal to the light source component according to the enable signal and the PWM signal, so as to drive the light source component to light up and emit primary color light; The laser projection device also includes a phase light modulation component and a video processing component; The video processing component is connected to the main control chip and the phase light modulation component respectively, and the video processing component is used to send a phase video signal to the phase light modulation component according to the video signal; The display driving component is connected to the phase light modulation component, and the display driving component is further used to send the enable signal to the phase light modulation component; The phase light modulation component is used to perform phase light modulation according to the phase video signal and the enable signal to emit modulated light to the light modulation device; The light modulation device is used to display an image based on the modulated light.

2. The laser projection device according to claim 1, characterized in that: The phase light modulation component includes a phase light modulation device and a dimming driving component, and the dimming driving component is respectively connected to the video processing component, the display driving component, and the phase light modulation device; The video processing component is used to send the phase video signal to the dimming driving component; The display driving component is used to send the enable signal to the dimming driving component; The dimming driving component is used to determine the bias voltage of the phase light modulation device according to the enable signal; sending the phase video signal and the bias voltage to the phase optical modulator; The phase light modulation device is used to perform phase light modulation according to the phase video signal and the bias voltage to emit modulated light to the light modulation device.

3. The laser projection device according to claim 2, characterized in that: The phase optical modulation device is used for: According to the bias voltage, the displacement of the micromirror on the phase light modulation device is controlled so as to perform phase modulation on the primary color light through the displaced micromirror.

4. The laser projection device according to claim 2, characterized in that: The phase optical modulation device is used for: According to the bias voltage, adjusting the displacement step length of the micromirror on the phase light modulation device; The primary color light is phase modulated according to the adjusted micromirror.

5. The laser projection device according to any one of claims 2 to 4, characterized in that: The time when the phase light modulation device receives the phase video signal is consistent with the time when the light modulation device receives the display driving signal.

6. The laser projection device according to any one of claims 2 to 4, characterized in that: The display time of the video signal corresponding to the target primary color of the target frame displayed by the light modulation device at least partially overlaps with the display time of the phase video signal corresponding to the target primary color of the target frame displayed by the phase light modulation device.

7. The laser projection device according to claim 2, characterized in that: The dimming driving component includes a dimming driving circuit and a bias voltage conversion circuit; The video processing component is connected to the dimming driving circuit, and the video processing component is used to send the phase video signal to the dimming driving circuit; The display driving component is connected to the dimming driving circuit and the bias voltage conversion circuit respectively, and the display driving component is used to send the enable signal to the bias voltage conversion circuit and the dimming driving circuit; The dimming driving circuit is connected to the phase light modulation device, and the dimming driving circuit is used to signal, sending the phase video signal to the phase light modulation device; The bias voltage conversion circuit is connected to the phase optical modulation device, and the bias voltage conversion circuit is used to send the bias voltage to the phase optical modulation device according to the enable signal.

8. The laser projection device according to claim 7, characterized in that: The bias voltage conversion circuit also includes a digital-to-analog converter DAC; The DAC is connected to the display driving component and the laser driving component respectively; The display driving component is used to send the PWM signal to the DAC; The DAC is used to perform digital-to-analog conversion on the PWM signal to obtain a converted PWM signal, and send the converted PWM signal to the laser driving component. The converted PWM signal is used to generate the light source driving signal with the enable signal.

9. The laser projection device according to claim 7 or 8, characterized in that: The bias voltage conversion circuit includes a plurality of voltage regulators and an analog selection switch; The analog selection switch is respectively connected to the plurality of voltage regulators, the display driving component and the phase light modulation device; The plurality of voltage regulators are used to send target voltages corresponding to a plurality of primary color lights to the analog selection switch, wherein the target voltage corresponding to each voltage regulator is different; The display driving component is used to send the enable signal to the analog selection switch; The analog selection switch is used to determine the bias voltage from the target voltages corresponding to the multiple primary color lights according to the enable signal, and send the bias voltage to the phase light modulation device.

10. The laser projection device according to claim 9, characterized in that: The laser projection device further includes a power supply, and the bias voltage conversion circuit further includes a DC converter; The DC converter is connected to the power supply and the plurality of voltage regulators respectively, and the DC converter is used to input a first voltage to the plurality of voltage regulators respectively according to a driving voltage input by the power supply; For any voltage regulator, it is used to input a target voltage corresponding to the voltage regulator to the analog selection switch according to the first voltage.

11. The laser projection device according to claim 7 or 8, characterized in that: The bias voltage conversion circuit includes a control component, a digital-to-analog converter DAC and an amplifier, and the control component is connected to the display driving component and the DAC respectively; The display driving component is used to send the enabling signal to the control component; The control component is used to input a target voltage corresponding to the primary color light indicated by the enable signal to the DAC according to the enable signal, wherein the target voltages corresponding to different primary color lights are different; The DAC is used to convert the target voltage into a voltage analog signal; The amplifier is connected to the DAC and the phase optical modulation device respectively, and the amplifier is used to send the bias voltage to the phase optical modulation device according to the voltage analog signal.

12. The laser projection device according to claim 11, characterized in that: The control component receives the enable signals corresponding to the multiple primary color lights sent by the display driving component through multiple interrupt ports respectively.

13. The laser projection device according to claim 11, characterized in that: The amplifier is also connected to the control component, and the amplifier is also used to send the bias voltage to the control component; The control component is further used to correct the target voltage sent to the DAC according to the difference between the bias voltage sent by the amplifier and the set bias voltage.

14. The laser projection device according to claim 11, characterized in that: The amplifier is also connected to the control component, and the control component is used to output a first voltage signal to the amplifier; The amplifier is also used to superimpose the first voltage signal with a bias voltage signal to obtain a processed bias voltage signal, and send the processed bias voltage signal to the phase optical modulation device, wherein the bias voltage signal includes a continuous bias voltage, and the first voltage signal is used to control the bias voltage to change within a target voltage range.

15. The laser projection device according to any one of claims 1 to 4, characterized in that: The video processing component is used to: Acquire a plurality of sub-video signals, wherein the plurality of sub-video signals are obtained after decoding the video signal, wherein the plurality of sub-video signals correspond to a plurality of primary colors respectively; For any sub-video signal, determining a phase information signal corresponding to the sub-video signal; The phase video signal is determined according to phase information signals corresponding to a plurality of sub-video signals.

16. The laser projection device according to any one of claims 1 to 4, characterized in that: The video processing component is used to: Acquire a first resolution of the phase light modulation component; According to the first resolution, pixel compression is performed on an image in the video signal having a resolution higher than the first resolution, so that the resolution of the pixel-compressed image matches the first resolution.

17. The laser projection device according to any one of claims 1 to 4, characterized in that: The video processing component is connected to the display driving component, and the display driving component is used to receive the video signal sent by the video processing component.

18. The laser projection device according to any one of claims 1 to 4, characterized in that: The main control chip is connected to the display driving component, and the display driving component is used to receive the video signal sent by the main control chip.

19. An image display method of a laser projection device, characterized in that: The laser projection device includes a main control chip, a display driving component, a light modulation device, a light source component, a laser driving component, a phase light modulation component and a video processing component; The display driving component is connected to the laser driving component, the light modulating device and the phase light modulating component respectively; the laser driving component is connected to the light source component; the video processing component is connected to the main control chip and the phase light modulating component respectively; The method comprises: Acquire a video signal through the display driving component, send an enable signal and a PWM signal to the laser driving component according to the video signal, send the enable signal to the phase light modulation component, and send a display driving signal to the light modulation device according to the video signal; Sending a light source driving signal to the light source assembly according to the enable signal and the PWM signal through the laser driving assembly to drive the light source assembly to light up and emit primary color light; Sending a phase video signal to the phase light modulation component according to the video signal through the video processing component; By means of the phase light modulation component, phase light modulation is performed according to the phase video signal and the enable signal, so as to emit modulated light to the light modulation device; An image is displayed based on the modulated light through the light modulation device.

Images