Head-up display device, backlight adjusting method and medium

Abstract

The invention provides a head-up display device, a backlight adjusting method and a medium, and the head-up display device comprises a backlight plate which is arranged in the head-up display device and comprises a plurality of backlight areas; the control unit is coupled with the backlight plate through a multi-channel driving circuit so as to divide the to-be-displayed image into a plurality of image areas based on the plurality of backlight areas, determine brightness information corresponding to each image area in the plurality of image areas and generate a brightness control signal corresponding to each image area according to the brightness information; and the multi-channel driving circuit comprises a plurality of signal receiving channels, and the signal receiving channels receive the brightness control signal corresponding to one of the plurality of image areas and control the brightness of one backlight area corresponding to one image area based on the brightness control signal corresponding to one image area. The brightness of different backlight areas can be independently controlled, the brightness uniformity and contrast of a picture are improved, and better driving experience is brought.

Description

Technical Field

[0001] This disclosure relates to the field of display control technology, and in particular to head-up display devices, backlight adjustment methods and media. Background Technology

[0002] Head-up display (HUD) technology projects vehicle driving or navigation information onto the windshield, allowing drivers to obtain key information without looking down, thereby improving driving comfort and safety.

[0003] Current head-up display (HUD) devices typically adjust the backlight by controlling the brightness of the entire backlight panel using a single control signal or a small number of grouped control signals. However, due to the individual optical characteristics of the light-emitting elements in the backlight panel, the displayed image is prone to problems such as uneven brightness and low contrast. In complex driving environments, this can affect the clarity of information recognition, thereby impacting driving comfort and safety. Summary of the Invention

[0004] This disclosure provides a head-up display device, a backlight adjustment method, and a medium; it enables independent control of the brightness of different backlight areas, improves the brightness uniformity and contrast of the screen, and brings a better driving experience.

[0005] The technical solution disclosed herein is implemented as follows: In a first aspect, this disclosure provides a head-up display device, comprising: a backlight panel disposed inside the head-up display device, the backlight panel including multiple backlight areas; a control unit coupled to the backlight panel via a multi-channel driving circuit to divide an image to be displayed into multiple image areas based on the multiple backlight areas, determine the brightness information corresponding to each image area in the multiple image areas, and generate a brightness control signal corresponding to each image area based on the brightness information; and a multi-channel driving circuit including multiple signal receiving channels, the signal receiving channels receiving a brightness control signal corresponding to one image area in the multiple image areas, and controlling the brightness of a backlight area corresponding to one image area based on the brightness control signal corresponding to one image area.

[0006] Secondly, this disclosure provides a backlight adjustment method, comprising: dividing an image to be displayed into multiple image regions based on multiple backlight regions; determining the brightness information corresponding to each image region in the multiple image regions, and generating a brightness control signal corresponding to each image region based on the brightness information; receiving a brightness control signal corresponding to one image region in the multiple image regions, and controlling the brightness of a backlight region corresponding to the one image region based on the brightness control signal corresponding to the one image region.

[0007] Thirdly, this disclosure provides a computer storage medium storing at least one instruction, which is executed by a processor to implement the backlight adjustment method as described in the second aspect.

[0008] By applying the embodiments of this disclosure, the control unit inside the head-up display device divides the image to be displayed into multiple image regions according to the multiple backlight areas included in the backlight panel. The brightness information corresponding to each image region is calculated, and a brightness control signal capable of individually controlling each image region is generated based on the brightness information of each image region. Then, through a multi-channel driving circuit, each signal receiving channel is responsible for transmitting the brightness control signal of one image region to the corresponding backlight region, thereby realizing independent control of the brightness of different backlight regions. This can eliminate the brightness deviation caused by individual differences in the light-emitting elements and accurately display the bright and dark parts in the same image, thereby improving the brightness uniformity and contrast of the image and bringing a better driving experience. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of a vehicle head-up display system provided in an embodiment of the present disclosure.

[0010] Figure 2 This is a schematic diagram illustrating the composition of a backlight panel provided in an embodiment of this disclosure.

[0011] Figure 3 An exemplary perspective view from a vehicle driver's seat is provided for this disclosure.

[0012] Figure 4 This is a schematic diagram of the composition of a head-up display device provided in an embodiment of this disclosure.

[0013] Figure 5 This is a schematic diagram illustrating the composition of another head-up display device provided in an embodiment of this disclosure.

[0014] Figure 6 This is a flowchart of a backlight adjustment method provided in an embodiment of the present disclosure.

[0015] Figure 7 This is a schematic diagram of the composition of a head-up display device provided in an embodiment of this disclosure. Detailed Implementation

[0016] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.

[0017] To enable those skilled in the art to better understand the technical solutions in the embodiments of this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art should fall within the protection scope of this disclosure.

[0018] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0019] Furthermore, in the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0020] To facilitate understanding of the technical solutions of the embodiments of this disclosure, the related technologies of the embodiments of this disclosure are described below. The following related technologies are optional solutions and can be combined with the technical solutions of the embodiments of this disclosure in any way, and they all fall within the protection scope of the embodiments of this disclosure.

[0021] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.

[0022] Most related technologies use a single control signal or a small number of grouped control signals to regulate the brightness of the entire backlight panel. However, during the manufacturing process, there are inherent differences in the forward voltage and luminous efficiency of the light-emitting elements in the same batch of backlight panels. This results in high-efficiency light-emitting elements appearing brighter and low-efficiency light-emitting elements appearing darker. Furthermore, the light transmission loss of the HUD optical system varies regionally, with edge areas typically experiencing higher losses than the center areas. This leads to an overly bright center and dark edges in the displayed image, creating a noticeable "vignetting." In addition, when the displayed image contains a mixture of bright areas (such as navigation arrows) and dark areas (such as a black background), the backlight panel still emits light according to the global brightness target. This causes the dark areas of the image to continue emitting light, failing to achieve a pure black effect, resulting in low image contrast and affecting image clarity.

[0023] In view of this, the present disclosure provides a head-up display device. Through a control unit within the head-up display device, the image to be displayed is divided into multiple image regions according to the multiple backlight areas included in the backlight panel. Brightness information is calculated for each image region, and a brightness control signal capable of individually controlling each image region is generated based on the brightness information of that image region. Then, through a multi-channel driving circuit, each signal receiving channel is responsible for transmitting the brightness control signal of one image region to the corresponding backlight region, thereby achieving independent control of the brightness of different backlight regions. This eliminates brightness deviations caused by individual differences in the light-emitting elements and accurately displays bright and dark areas in the same image, thereby improving the brightness uniformity and contrast of the image and bringing a better driving experience.

[0024] Due to the individual optical characteristics of the light-emitting elements in the backlight panel, images displayed based on a single brightness value are prone to problems such as uneven brightness display and low image contrast. In complex driving environments, this may affect the clarity of information recognition, thereby affecting driving comfort and safety.

[0025] Figure 1 This is a schematic diagram of the structure of an in-vehicle head-up display system provided in an embodiment of this disclosure. The in-vehicle head-up display system 10 includes a head-up display device 100, a windshield 200, a virtual projection surface 300, and a virtual image 301.

[0026] The head-up display device 100 includes a control unit 110, a multi-channel drive circuit 120, and an optical system 130.

[0027] Specifically, the optical system 130 includes a backlight panel 131, a display panel 132, and an optical path assembly 133. The backlight panel 131 provides a light source, which can be a monochrome LED, a multi-color LED, a halogen lamp, a laser, etc. The display panel 132 receives the light source provided by the backlight panel 131 and, based on the display control signal from the control unit 110, converts the display control signal into a corresponding visual display image (such as a navigation path, instrument panel data, etc.), providing an image carrier for subsequent optical projection. The optical path assembly 133 performs optical processing on the visual display image output by the display panel 132, including reflection, optical path shaping, and magnification, projecting the processed image as light onto the windshield 200. The windshield 200 reflects the incident light, allowing the driver's visual system 40 to perceive a virtual image 301 located on the virtual projection surface 300. This virtual image 301 can be superimposed on the actual road conditions in front of the vehicle, thus achieving the effect of clearly obtaining information without looking down.

[0028] See Figure 2 , Figure 2 This is a schematic diagram illustrating the composition of a backlight panel according to an embodiment of this disclosure. Figure 2As shown, a backlight panel 131 is disposed inside the head-up display device 100. The backlight panel 131 includes multiple backlight areas 1310, each backlight area 1310 consisting of a set of light sources. For example, the backlight panel 131 includes M×N backlight areas 1310, and each set of light sources is an independent LED light group, where M and N are both positive integers greater than 1, M represents the number of rows, and N represents the number of columns.

[0029] Specifically, the control unit 110 is coupled to the backlight panel 131 via a multi-channel drive circuit 120 to divide the image 50 to be displayed into multiple image regions 500 based on multiple backlight regions 1310, determine the brightness information corresponding to each image region 500, and generate a brightness control signal corresponding to each image region 500 based on the brightness information. In some examples, the control unit 110 can divide the image 50 to be displayed into multiple image regions 500 based on partition configuration parameters. These partition configuration parameters can be fixed in the hardware logic or received through a parameter configuration interface. The partition configuration parameters are determined based on the number and size of the backlight regions 1310, and the image regions 500 divided by the partition configuration parameters correspond one-to-one with the backlight regions 1310 in spatial distribution. For example, the backlight panel includes 12×8 backlight areas 1310. For a frame of 1080p image 50 to be displayed, the image 50 to be displayed can be divided into 12×8 image areas 500, and the backlight areas 1310 correspond one-to-one with the image areas 500.

[0030] It should be noted that the multiple backlight areas 1310 included in the backlight panel 131 are physical partitions, while the control unit 110 divides the image 50 to be displayed according to these physical partitions, resulting in multiple image areas 500 that are virtual logical partitions. Each virtual logical partition has a one-to-one mapping relationship with a physical partition.

[0031] The multi-channel driving circuit 120 includes multiple signal receiving channels. Each signal receiving channel receives a brightness control signal corresponding to an image region 500 in the image to be displayed 50, and controls the brightness of a backlight region 1310 corresponding to that image region 500 based on the brightness control signal. In some examples, the number of signal receiving channels included in the multi-channel driving circuit 120 is the same as or greater than the number of backlight regions 1310. When the number is the same, there is a one-to-one correspondence between the signal receiving channels and the backlight regions 1310.

[0032] In this embodiment, the control unit inside the head-up display device divides the image to be displayed into multiple image regions according to the multiple backlight areas included in the backlight panel. The brightness information corresponding to each image region is calculated, and a brightness control signal capable of individually controlling each image region is generated based on the brightness information of each image region. Then, through a multi-channel driving circuit, each signal receiving channel is responsible for transmitting the brightness control signal of one image region to the corresponding backlight region, thereby realizing independent control of the brightness of different backlight regions. This can eliminate the brightness deviation caused by individual differences in the light-emitting elements and accurately display the bright and dark parts in the same image, thereby improving the brightness uniformity and contrast of the image and bringing a better driving experience.

[0033] See Figure 3 , Figure 3 This is an exemplary perspective view from a vehicle driver's seat provided in this disclosure. Figure 3 As shown, the optical path component 133 reflects the image 50 to be displayed onto the windshield 200 through the aperture 201. A viewer can view the image 50 within the display area of ​​the windshield 200. In some examples, the optical path component 133 may include one or more reflective mirrors (plane mirrors) and concave mirrors (magnifying glasses). The image 50 to be displayed is reflected back by the reflective mirror and magnified by the concave mirror before being reflected back onto the windshield 200 to form a virtual image 301 that can be observed by the user. The visual effect of this virtual image 301 is that it is projected onto a virtual projection surface 300 at a predetermined distance in front of the windshield 200. In some examples, the optical path component 133 may be omitted, and the image 50 to be displayed may be directly projected onto the windshield 200 to form a virtual image 301 on the virtual projection surface 300. Depending on the perception distance of the driver's vision system 40, the virtual projection surface 300 may include a near-focal surface (e.g., a perception distance of 1-2 meters) and / or a far-focal surface (e.g., a perception distance of 10-50 meters).

[0034] exist Figure 3 In this configuration, the windshield 200 is visually positioned above the vehicle's dashboard 202. The driver can turn the steering wheel 203 within the passenger cabin to steer the vehicle, for example, to change lanes, merge, and park. In some embodiments, the steering wheel 203 may be retracted or omitted.

[0035] Figure 4 This is a schematic diagram illustrating the composition of a head-up display device according to an embodiment of this disclosure. The head-up display device 100 includes a control unit 110, a multi-channel drive circuit 120, and an optical system 130.

[0036] Specifically, the control unit 110 is communicatively coupled to the light sensor 600. The control unit 110 includes an image input interface 111, a brightness input interface 112, a memory 113, and multiple parallel hardware processing units 114.

[0037] The image input interface 111 is used to receive image data from an image source, which includes one or more frames of images to be displayed. For example, the image source may include an in-vehicle infotainment system, an intelligent driving assistance system, an in-vehicle navigation system, a mobile phone interconnection system, etc., and these image sources can provide diverse visual information. For instance, an in-vehicle infotainment system can provide images such as a multimedia interactive interface and song playback status; an intelligent driving assistance system can provide dynamic interactive images such as following distance markings and the speed of the vehicle ahead; an in-vehicle navigation system can provide route planning images including turn arrows, lane guidance, and road names; and a mobile phone interconnection system can synchronize mirrored images such as the mobile phone navigation interface and caller ID.

[0038] The brightness input interface 112 is used to receive the vehicle ambient light intensity transmitted by the light sensor 600, or to receive a brightness reference value from the microprocessor unit (MCU). The brightness reference value is used to provide a global reference constraint for the control unit 110 to generate a brightness control signal. For example, the light sensor 600 may be a sensor with ambient light detection capabilities, such as an automotive ambient light sensor (ALS). In some examples, the control unit 110 may directly receive the brightness reference value from the microprocessor unit (MCU) through the brightness input interface 112, or it may receive the vehicle ambient light intensity collected by the light sensor 600 through the brightness input interface 112 to generate a brightness reference value.

[0039] Memory 113 is coupled to image input interface 111 and luminance input interface 112 to store image data received from image input interface 111 and vehicle ambient light intensity or luminance reference values ​​received from luminance input interface 112. Furthermore, memory 113 is also coupled to multiple parallel hardware processing units 114. Memory 113 also stores program instructions for execution by the multiple parallel hardware processing units 114. Specifically, memory 113 can be implemented as random access memory (RAM), read-only memory (ROM), or non-transitory computer-readable storage medium.

[0040] Multiple parallel hardware processing units 114 execute programs or instructions in memory 113 to perform the steps of determining the brightness information corresponding to each image region in multiple image regions and generating a brightness control signal corresponding to each image region based on the brightness information.

[0041] For example, multiple parallel hardware processing units 114 can be physically implemented as dedicated parallel computing units of field programmable gate arrays (FPGAs), complex programmable logic devices (CPLDs), application specific integrated circuits (ASICs), heterogeneous system-on-chips (HSoCs), graphics processing units (GPUs), or parallel computing arrays of neural processing units (NPUs), etc., and need to be selected according to the specific requirements of the head-up display device 100, such as performance requirements, cost budget, and mass production scenarios.

[0042] Specifically, multiple parallel hardware processing units 114 determine the brightness information corresponding to each image region in multiple image regions through parallel processing operations, and generate brightness control signals corresponding to each image region based on the brightness information through parallel processing operations.

[0043] In some embodiments, when the image input interface 111 receives the image 50 to be displayed (such as RGB format data with 1080p resolution) from the image source, it first caches the image 50 to be displayed in the memory 113; then, multiple parallel hardware processing units 114 synchronously read the preset partition configuration parameters and the image 50 to be displayed from the memory 113 and perform parallel processing operations.

[0044] In some examples, parallel processing includes the following steps: First, hardware processing unit 114 reads the partition configuration parameters (e.g., M=12, N=8, corresponding to 12×8 image regions) stored in memory 113, and logically divides the image 50 to be displayed into a virtual grid of 12 rows × 8 columns according to these parameters. Each hardware processing unit 114 corresponds to one image region 500, forming a one-to-one task allocation relationship. For example, the image region 500 in the first row and first column is handled by the first hardware processing unit 114, the image region in the first row and second column is handled by the second hardware processing unit 114, and so on, ensuring that all image regions 500 enter the processing flow simultaneously without any serial waiting. Second, each hardware processing unit 114 synchronously traverses all pixels contained in its corresponding image region 500 to determine the brightness information of its corresponding image region 500. Then, each hardware processing unit 114 synchronously performs signal mapping conversion on the brightness information of its corresponding image region 500, converting the brightness information into a brightness control signal.

[0045] Specifically, the signal mapping conversion can be implemented as a PWM signal mapping conversion, and the brightness control signal is a 16-bit precision Pulse Width Modulation (PWM) control signal.

[0046] In this embodiment, multiple parallel hardware processing units of the control unit synchronously complete the determination of brightness information and the generation of brightness control signals for each image area through parallel operation. On the one hand, it can compress the entire process delay from image analysis to signal output to the microsecond level, which can adapt to dynamic images with frame rates of 60fps and above (such as navigation route switching and real-time vehicle speed updates), avoiding display lag from affecting the acquisition of driving information. On the other hand, it can ensure that multiple brightness control signals are output to the multi-channel drive circuit synchronously without time difference, preventing brightness deviation in each backlight area due to signal delay, thereby ensuring the brightness uniformity of the HUD display and eliminating the visual discontinuity during dynamic display.

[0047] In some embodiments, each hardware processing unit 114 synchronously performs signal mapping conversion on the brightness information of its corresponding image region 500. After converting the brightness information into a brightness control signal, it can further perform brightness calibration processing on the brightness control signal based on the brightness reference value received by the brightness input interface 112.

[0048] Specifically, each hardware processing unit 114 receives a brightness reference value and, through the brightness reference value and the brightness calibration algorithm stored in the memory 113, synchronously adjusts the brightness control signal to the target brightness control signal.

[0049] The target brightness control signal is a brightness control signal calibrated using a brightness reference value. The brightness reference value comes from the vehicle MCU, which issues corresponding brightness reference values ​​based on different driving scenarios. For example, the brightness reference value is 100 in a sunny scenario and 50 in a nighttime scenario. The specific calculation formula for the brightness calibration algorithm is shown in equation (1) below.

[0050] Target brightness control signal = brightness control signal × (brightness reference value / 255) (1) Here, 255 represents the maximum brightness (peak value) in 8-bit binary data format.

[0051] In some examples, the brightness reference value may include a global brightness reference value that constrains the overall brightness and / or a target brightness reference value that adjusts the brightness of a specific image region. When the brightness reference value is a global brightness reference value, each hardware processing unit 114 performs parallel processing operations to synchronously calibrate the brightness control signal corresponding to each image region based on the same global brightness reference value. When the brightness reference value is a target brightness reference value that adjusts the brightness of a specific image region, each hardware processing unit 114 performs parallel processing operations to synchronously calibrate the brightness control signal corresponding to each image region based on differentiated brightness reference values.

[0052] By applying this embodiment, the vehicle MCU can issue appropriate brightness reference values ​​based on different driving scenarios such as sunny days and nighttime, ensuring that the HUD brightness accurately matches the ambient light requirements and avoiding the problems of being too dark to see in bright light or too bright to see at night. Furthermore, relying on the parallel processing characteristics of the hardware processing unit, it can simultaneously complete global unified brightness calibration or local differentiated brightness calibration, taking into account the consistency and specificity of brightness control in various image areas, effectively improving the clarity and visual safety of HUD display in different driving scenarios.

[0053] In some embodiments, the control unit 110 specifically employs a field-programmable gate array (FPGA) with hardware-level parallel processing capabilities. See also Figure 5 , Figure 5 This is a schematic diagram illustrating the composition of another head-up display device provided in an embodiment of this disclosure. The head-up display device 100 includes a control unit 110, a multi-channel drive circuit 120, and an optical system 130.

[0054] Specifically, when the control unit 110 is an FPGA, the control unit 110 includes an image input interface 111, a brightness input interface 112, and an FPGA main control unit 115.

[0055] The FPGA main control unit 115 includes an image analysis module 1152 and a PWM generation module 1154. The image analysis module 1152 and the PWM generation module 1154 are communicatively coupled.

[0056] Specifically, the image analysis module 1152 receives the image 50 to be displayed from the image input interface 111, divides the image 50 to be displayed into multiple image regions 500, and calculates the brightness information of each image region 500 in parallel; the PWM generation module 1154 receives the brightness information from the image analysis module 1152 and generates the brightness control signal corresponding to each image region 500 in parallel.

[0057] In this embodiment, through the hardware-level parallel collaboration between the image analysis module 1152 and the PWM generation module 1154 within the FPGA main control unit 115, on the one hand, parallel calculation of brightness information of multiple image regions and parallel generation of brightness control signals can be completed synchronously, compressing the entire process delay from image reception to control signal output to the microsecond level, meeting the low-latency display requirements of HUD for real-time navigation paths, dynamic vehicle speeds, and other information; on the other hand, it can ensure that multiple brightness control signals are output to the multi-channel drive circuit without time difference, avoiding brightness deviation in each backlight area due to poor signal synchronization, effectively ensuring the brightness uniformity of the display screen, and eliminating the "dim corner" problem from the hardware level.

[0058] In some embodiments, brightness information may include brightness feature values, specifically determined by the brightness values ​​of all pixels within an image region. In some examples, the brightness feature value can be determined by calculating the arithmetic mean of the brightness values ​​of all pixels, or the maximum value (peak value) of the brightness values ​​among all pixels can be used as the brightness feature value corresponding to the image region.

[0059] For example, if the image to be displayed 50 is an RGB format image, firstly, the RGB values ​​of the pixels are converted into grayscale brightness values, and then the brightness characteristic values ​​are determined by calculating the arithmetic mean or the maximum value.

[0060] In some examples, brightness information may also include brightness levels, such as high brightness level, bright level, dark level, and low darkness level. High brightness level corresponds to strong light scenes (e.g., ambient light ≥ 10000 lux) or bright areas of an image (e.g., brightness feature value ≥ 200, such as navigation arrows or vehicle speed numbers), and is labeled "HL"; bright level corresponds to normal daytime scenes (e.g., 100 lux ≤ ambient light < 10000 lux), and is labeled "L"; dark level corresponds to dusk / dawn scenes (e.g., 10 lux ≤ ambient light < 100 lux) or dark areas of an image (e.g., 50 ≤ brightness feature value < 120, such as a light-colored background), and is labeled "D"; low darkness level corresponds to nighttime scenes (e.g., ambient light < 10 lux) or completely black areas of an image (brightness feature value < 50, such as a black background at night), and is labeled "LD".

[0061] In practical applications, brightness feature values ​​can be converted into corresponding brightness control signals, or brightness control signals can be generated based on brightness feature values ​​and corresponding brightness levels.

[0062] By applying this embodiment, the overall brightness distribution of the image area can be accurately reflected by calculating the arithmetic mean of the image area, avoiding image imbalance caused by local highlights or low brightness; by calculating the maximum brightness of the image area, key highlight information such as navigation arrows and vehicle speed numbers can be focused, ensuring the recognizability of core content in complex environments.

[0063] In some embodiments, the backlight panel 131 is implemented as a partitioned LED light panel, and the multiple backlight areas are M×N light groups physically divided on the partitioned LED light panel, where M and N are both positive integers greater than 1.

[0064] Specifically, the values ​​of M and N need to match the resolution of the image to be displayed and the imaging accuracy of the HUD optical system. For example, for a 1080p (1920×1080 pixels) resolution image, M=12 and N=8 can be set, corresponding to 12 rows × 8 columns, a total of 96 light groups; for a 720p (1280×720 pixels) resolution, M=8 and N=6 can be set, corresponding to 48 light groups. The physical size of each light group matches the pixel range of the corresponding image area. For example, a single light group for a 1080p image corresponds to an image area of ​​1920 / 12=160 pixels and 1080 / 8=135 pixels, ensuring that the light emission range of the light group can completely cover the corresponding image area and avoid crosstalk between different backlight areas.

[0065] In some examples, each light assembly consists of 4-8 automotive-grade light-emitting diodes (LEDs). The LEDs can be selected as high-brightness devices compliant with AEC-Q102 certification, with a wide operating temperature range of -40℃ to +125℃, capable of withstanding the extreme high and low temperature conditions of the automotive environment. The LEDs adopt a "2 series 2 parallel" or "2 series 4 parallel" topology. The series design ensures that the current of each LED in the light assembly is consistent, avoiding uneven brightness caused by individual differences; the parallel design reduces the impact of a single LED failure on the entire light assembly, improving reliability.

[0066] In some examples, each LED group on the zoned LED board has two independent pins (positive and negative) with a standard 2.54mm pin pitch to accommodate the output of multi-channel driver circuits. The board uses an FR4 fiberglass substrate with an anti-oxidation coating and pre-drilled heat dissipation holes at the edges. These holes, in contact with the metal heat-conducting pillars of the HUD device housing, conduct the heat generated by the LEDs during operation to the outside, preventing localized overheating and brightness degradation.

[0067] In this embodiment, by designing the backlight panel 131 as a partitioned structure with M×N independent lamp groups, the brightness of each lamp group can be independently adjusted. The driving current of the edge lamp group can be increased separately to compensate for the brightness deviation caused by the light loss in the edge area of ​​the optical system, thereby eliminating "dark corners" and avoiding uneven brightness of the screen. The physical partitions of the lamp groups correspond strictly one-to-one with the virtual partitions of the image, providing hardware support for one control signal per area. This ensures that the lamp groups in dark areas can reduce brightness separately and the lamp groups in bright areas can increase brightness separately, thereby improving the contrast of the screen and avoiding unclear image display.

[0068] In some embodiments, the multi-channel driving circuit is a multi-channel LED driving circuit, and the multiple signal receiving channels are multiple constant current driving channels.

[0069] Specifically, one group of lights in a partitioned LED light panel is coupled to the output of one of the multiple constant current drive channels, forming a one-to-one correspondence between the light group and the constant current drive channel.

[0070] In some examples, the number of constant current driving channels in a multi-channel LED driver circuit is exactly the same as the number of lamp groups in a partitioned LED light board (e.g., 96 lamp groups correspond to 96 constant current channels), and each channel includes a receiver, a signal conversion module, and an output.

[0071] The receiving end employs a Low-Voltage Differential Signaling (LVDS) interface to receive a 16-bit precision Pulse Width Modulation (PWM) control signal (frequency 1.2kHz) from the FPGA main control unit 115. This provides electromagnetic interference (EMI) immunity, protecting against signal noise from motors, air conditioners, and other equipment in the automotive environment. The signal conversion module integrates a high-precision digital-to-analog converter (DAC) and a constant current control chip (such as the TI TPS92691) to convert the PWM signal into an adjustable constant current signal ranging from 0 to 300mA, with a current adjustment accuracy of ±1%, ensuring consistent output current across different channels. The output end connects to the positive and negative pins of the zoned LED light group via high-temperature resistant silicone wires. The wires have a cross-sectional area of ​​0.5mm² and can withstand a maximum instantaneous current of 3A, preventing wire burnout due to overload.

[0072] In some examples, the pin definitions of the constant current drive channel output terminals are strictly matched with the lamp group pins (positive to positive, negative to negative), and the channel number (e.g., "CH1~CH96") and lamp group number (e.g., "G1-1~G12-8") are marked at the interface to avoid wiring errors during installation. At the same time, the wire length is uniformly 15cm to reduce impedance differences between different channels (impedance deviation <0.1Ω), avoiding brightness differences in the lamp group under the same current due to impedance differences.

[0073] By applying this embodiment, a precise execution link is provided for zone dimming through the one-to-one coupling of the lamp group and the constant current channel. Each lamp group is driven by a dedicated constant current channel, and there is no current sharing between channels, which can reduce the brightness adjustment error of a single lamp group and improve the brightness uniformity of the screen.

[0074] In some embodiments, the constant current driving channel receives the target brightness control signal corresponding to the target image area, converts the target brightness control signal into a target driving current, and controls the brightness of the target backlight area based on the target driving current.

[0075] Specifically, the target image area is any one of multiple image areas, and the target brightness control signal is the brightness control signal corresponding to the target image area. The constant current drive channel receives the target brightness control signal, converts it into a target drive current, and thereby drives the target backlight area to display brightness, thus realizing the conversion of the control signal into physical light emission.

[0076] In some examples, the receiver of the constant current drive channel first receives the target brightness control signal from the FPGA, and then converts the target brightness control signal into a target drive current through a signal-to-current mapping algorithm. Specifically, the target brightness control signal can be the duty cycle of a PWM signal, and the signal-to-current mapping algorithm can specifically include: maximum drive current × PWM signal duty cycle = target drive current.

[0077] For example, the maximum drive current is the peak current supported by the lamp hardware (e.g., 200mA, determined by the LED's rated current). When the target image area is dark (e.g., black background, brightness characteristic value ≤30), and the PWM signal duty cycle is 5%, the target drive current = 200mA × 5% = 10mA, and the lamp brightness drops to near-off, presenting a pure black effect. When the target image area is bright (e.g., navigation arrow, brightness characteristic value ≥200), and the PWM signal duty cycle is 90%, the target drive current = 200mA × 90% = 180mA, and the lamp emits light in a high-brightness state, ensuring that the information is clearly visible.

[0078] By applying this embodiment, the brightness control signal can be accurately converted into driving current through the constant current driving channel of the multi-channel LED driving circuit. Thus, through multiple independent constant current driving channels, precise driving of each backlight area can be achieved, which can effectively reduce dark field current, thereby reducing dark field power consumption, improving screen contrast, avoiding visual interference caused by night driving, and improving driving safety.

[0079] It should be noted that those skilled in the art will understand that the structure of the head-up display device 100 shown in the above figures does not constitute a limitation on the head-up display device 100. The head-up display device 100 may include more or fewer components than shown, or combine certain components, or have different component arrangements. For example, the head-up display device 100 may also include a display screen, camera assembly, microphone, speaker, radio frequency circuit, input unit, sensors (such as accelerometer, angular velocity sensor, IMU sensor, etc.), audio circuit, WiFi module, power supply, Bluetooth module, etc., which will not be described in detail here.

[0080] See Figure 6 , Figure 6 This is a flowchart of a backlight adjustment method provided in an embodiment of the present disclosure. Specifically, it includes steps S602-S606.

[0081] Step S602: Based on multiple backlight areas, divide the image to be displayed into multiple image regions.

[0082] Specifically, step S602 can be executed by the control unit of the head-up display device (e.g., a field-programmable gate array, FPGA). For example, firstly, the control unit reads preset partition configuration parameters from memory. These parameters are consistent with the physical partitions of the backlight panel; that is, when the backlight panel contains M×N independent backlight areas (M and N are both positive integers greater than 1), the configuration parameters synchronously set the number of image partitions to M×N. Subsequently, the control unit receives image data (supporting RGB color mode or grayscale image format) from an image source (such as an in-vehicle infotainment system) through an image input interface and caches a complete frame of the image to be displayed in the FPGA's built-in block random access memory (BRAM). Finally, based on the partition configuration parameters, the control unit logically divides the cached entire frame of image into M×N virtual image areas. Each virtual image area establishes a strict one-to-one spatial correspondence with a physical backlight area of ​​the backlight panel. This mapping relationship can be embedded in the FPGA's hardware logic during system design to ensure that subsequent dimming actions accurately match the image content.

[0083] Step S604: Determine the brightness information corresponding to each image region in multiple image regions, and generate a brightness control signal corresponding to each image region based on the brightness information.

[0084] Specifically, the FPGA leverages its built-in multiple parallel hardware processing units to efficiently process each image region. For example, firstly, the FPGA's image analysis module initiates parallel computation: multiple hardware processing units synchronously traverse each image region at a frequency of 52MHz, extracting brightness data from all pixels within each region, and then calculating the brightness information of that region (range 0-255) using an arithmetic mean or maximum value algorithm. Next, the FPGA obtains a brightness reference value through the brightness input interface and calibrates the brightness information of each region against this reference value. Finally, based on the calibrated brightness values, the FPGA synchronously generates M×N channels of 16-bit high-precision PWM control signals (frequency 1.2kHz) in hardware parallel mode, with each signal corresponding to the brightness adjustment requirements of one image region.

[0085] Step S606: Receive a brightness control signal corresponding to one of the multiple image regions, and control the brightness of a backlight region corresponding to the image region based on the brightness control signal corresponding to the image region.

[0086] Specifically, step S606 is executed by a multi-channel driving circuit (e.g., a multi-channel LED driving circuit), which includes multiple constant current driving channels corresponding to the number of image regions. For example, firstly, each constant current driving channel receives a brightness control signal (e.g., a PWM signal) for one of the corresponding output image regions from multiple parallel hardware processing units within the FPGA via a dedicated receiver. Subsequently, the signal conversion module within the constant current driving channel filters and shapes the PWM signal to remove electromagnetic noise from the vehicle environment. Then, the built-in constant current control chip converts the PWM signal into a precise target control current (the current magnitude is linearly related to the PWM signal duty cycle; the larger the duty cycle, the larger the current). Finally, the output of the constant current driving channel transmits the target control current to the corresponding physical backlight area on the backlight board (i.e., a group of LEDs in a zoned LED light panel). The LED chips in the group emit light under current drive, and their brightness is determined by the magnitude of the target control current, achieving independent dimming of one area per channel.

[0087] For specific implementation methods of steps S602-S606, please refer to the embodiments corresponding to the head-up display device 100, which will not be repeated here.

[0088] By applying this embodiment, the image to be displayed is divided into multiple image regions according to the multiple backlight areas included in the backlight panel. The brightness information corresponding to each image region is calculated separately, and a brightness control signal that can be individually controlled for each image region is generated based on the brightness information of each image region. This enables the independent generation of brightness control signals for each image region, avoiding problems such as dark corners and low contrast caused by a single driving signal. Then, through an independent signal receiving channel, the brightness control signal of one image region is transmitted to the corresponding backlight region. This enables independent control of the brightness of different backlight regions, thereby eliminating brightness deviations caused by individual differences in light-emitting elements and accurately displaying bright and dark areas in the same image, improving the brightness uniformity and contrast of the image, and bringing a better driving experience.

[0089] and Figure 6 Corresponding to the method embodiments shown, this disclosure also provides embodiments of a head-up display device. Figure 7 This is a schematic diagram illustrating the composition of a head-up display device provided in this disclosure. Figure 7 As shown, the head-up display device 700 includes: Region division module 702: is configured to divide the image to be displayed into multiple image regions based on multiple backlight regions.

[0090] Determining module 704: is configured to determine the brightness information corresponding to each image region in multiple image regions, and generate a brightness control signal corresponding to each image region based on the brightness information.

[0091] The receiving module 706 is configured to receive a brightness control signal corresponding to one of the multiple image regions, and control the brightness of a backlight region corresponding to the image region based on the brightness control signal corresponding to the image region.

[0092] The above is a schematic scheme of a head-up display device provided in this disclosure. The technical solution of this head-up display device and the technical solution of the backlight adjustment method described above belong to the same concept. For details not described in detail in the technical solution of the head-up display device, please refer to the description of the technical solution of the backlight adjustment method described above.

[0093] This disclosure also provides a computer-readable storage medium storing at least one instruction that is executed by a processor to implement the backlight adjustment method as described in the above embodiments.

[0094] This disclosure also provides a computer program product including computer instructions stored in a computer-readable storage medium; a processor of a head-up display device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the head-up display device to perform the backlight adjustment method described in the above embodiments.

[0095] Those skilled in the art will recognize that the functions described in this disclosure in one or more of the examples above can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0096] It should be noted that the technical solutions described in this disclosure can be combined arbitrarily as long as they do not conflict.

[0097] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A head-up display device, characterized in that, include: A backlight panel is disposed inside the head-up display device, and the backlight panel includes multiple backlight areas; The control unit is coupled to the backlight panel through a multi-channel driving circuit to divide the image to be displayed into multiple image regions based on the multiple backlight areas, determine the brightness information corresponding to each of the multiple image regions, and generate a brightness control signal corresponding to each of the image regions based on the brightness information. as well as The multi-channel driving circuit includes multiple signal receiving channels. Each signal receiving channel receives a brightness control signal corresponding to one of the multiple image regions and controls the brightness of a backlight region corresponding to that image region based on the brightness control signal.

2. The head-up display device according to claim 1, characterized in that, The control unit includes multiple parallel hardware processing units. These multiple parallel hardware processing units determine the brightness information corresponding to each of the multiple image regions through parallel processing operations. Furthermore, these multiple parallel hardware processing units generate brightness control signals corresponding to each of the image regions based on the brightness information through parallel processing operations.

3. The head-up display device according to claim 2, characterized in that, The control unit includes a brightness input interface; The multiple parallel hardware processing units receive a brightness reference value input through the brightness input interface, adjust the brightness information based on the brightness reference value, and generate a brightness control signal corresponding to each image region through parallel processing operations based on the adjusted brightness information.

4. The head-up display device according to any one of claims 1-3, characterized in that, The control unit is a field-programmable gate array.

5. The head-up display device according to claim 1, characterized in that, The brightness information is determined based on the brightness values ​​of pixels within the image area.

6. The head-up display device according to claim 1, characterized in that, The backlight panel is a zoned LED light panel, and the multiple backlight areas are M×N light groups physically divided on the zoned LED light panel, where M and N are both positive integers greater than 1.

7. The head-up display device according to claim 6, characterized in that, The multi-channel driving circuit is a multi-channel LED driving circuit, and the multiple signal receiving channels are multiple constant current driving channels. One of the LED groups in the partitioned LED light panel is coupled to the output terminal of one of the multiple constant current drive channels.

8. The head-up display device according to claim 7, characterized in that, The constant current driving channel receives the target brightness control signal corresponding to the target image area, converts the target brightness control signal into a target driving current, and controls the brightness of the target backlight area based on the target driving current.

9. A backlight adjustment method, characterized in that, include: Based on multiple backlight areas, the image to be displayed is divided into multiple image regions; Determine the brightness information corresponding to each of the plurality of image regions, and generate a brightness control signal corresponding to each of the image regions based on the brightness information; The system receives a brightness control signal corresponding to one of the multiple image regions and controls the brightness of a backlight region corresponding to that image region based on the brightness control signal.

10. A computer storage medium, characterized in that, The computer storage medium stores at least one instruction, which can be executed by a processor to implement the backlight adjustment method as described in claim 9.

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