Backlight module, control method thereof, and head-up display device

Abstract

This application provides a backlight module and its control method, as well as a head-up display (HUD) device, relating to the field of HUD technology. It includes an array light source and a focusing component, a homogenizing component, and a TFT screen sequentially located on the light-emitting side of the array light source. The light emitted from the array light source is focused by the focusing component and then homogenized by the homogenizing component to uniformly illuminate the TFT screen. The array light source includes multiple point light sources arranged in an array. By illuminating different point light sources, the TFT screen can be adjusted for zoned display. When sunlight backflow causes the TFT screen temperature to rise, triggering power saving, illuminating some point light sources can achieve localized power saving, reducing the backlight temperature rise and effectively mitigating the temperature increase of the TFT screen. This ensures the screen temperature remains within the normal operating range, preventing any impact on the user's viewing experience.

Description

Technical Field

[0001] This application relates to the field of head-up display technology, specifically to a backlight module and its control method, and a head-up display device. Background Technology

[0002] In current head-up displays (HUDs), sunlight is focused onto the screen via mirrors in the HUD system, causing backlighting and temperature rise. Additionally, the light source in the Picture Generation Unit (PGU) also generates heat, leading to backlight temperature increases. To address this screen temperature rise, a feasible solution is to reduce power consumption, specifically by decreasing backlight power consumption to lower the backlight-induced screen temperature increase.

[0003] In conventional HUD backlight module design, regardless of whether it's a long or short backlight scheme or a mixed-light system's PGU module, when sunlight backflow causes the screen temperature to rise, the backlight module in the PGU reduces power consumption by lowering the LED brightness. In a mixed-light system, on the one hand, the series-parallel design makes it difficult to control individual LEDs; on the other hand, the mixed-light system cannot perform zoned control of screen brightness and darkness, leading to the need to reduce the overall brightness of the LED array to achieve power consumption reduction. The overall reduction in backlight brightness inevitably leads to a reduction in the overall brightness of the HUD projected image, a decrease in image-environment contrast, and difficulty for the driver to see the information projected on the head-up display, resulting in driver fatigue. Summary of the Invention

[0004] The purpose of this application is to provide a backlight module and its control method, and a head-up display device, which can ensure that the user's viewing effect is not affected when the screen temperature rises under backlight to trigger power reduction.

[0005] One aspect of this application provides a backlight module, including: an array light source, and a light-concentrating component, a light-uniforming component, and a TFT screen sequentially located on the light-emitting side of the array light source. The light emitted by the array light source is converged by the light-concentrating component and then uniformly processed by the light-uniforming component to make the light illuminating the TFT screen uniform. The array light source includes multiple point light sources arranged in an array. By lighting different point light sources, the TFT screen can be adjusted for zoned display.

[0006] Optionally, the TFT screen is further surrounded by multiple temperature detectors. The temperature detectors and the point light source are both connected to a controller. The controller controls the switching and brightness of the point light source based on the temperature detected by the temperature detectors.

[0007] Optionally, the TFT screen is divided into multiple array sub-regions, each sub-region corresponding to a multiple point light source, and each temperature detector corresponding to the outermost sub-region of the array.

[0008] Optionally, the light-concentrating assembly includes multiple light-concentrating elements, and each of the multiple light-concentrating elements corresponds to one of the multiple point light sources.

[0009] Optionally, the light-concentrating element includes a light-concentrating lens or a reflector. When the light-concentrating element is the reflector, the opening of the reflector faces the light-uniforming component. In the light emitted from the array light source, a portion of the light is reflected by the inner wall of the reflector and then directed toward the light-uniforming component.

[0010] In another aspect of this application, a head-up display device is provided, including the aforementioned backlight module.

[0011] Another aspect of this application provides a control method for a backlight module, applied to the aforementioned backlight module, wherein the backlight module includes a TFT screen, a controller, multiple point light sources, and multiple temperature detectors, the multiple temperature detectors being distributed around the TFT screen; the method includes: The temperature of different areas of the TFT screen was obtained separately. When the detected temperature in the current area exceeds the preset temperature, the brightness of the point light source corresponding to the current area is adjusted.

[0012] Optionally, when the detected temperature exceeds a preset temperature, the brightness of the corresponding point light source is reduced, and then the method includes: Obtain the detection temperature of the corresponding area of ​​the TFT screen; When the detected temperature exceeds the preset temperature, the corresponding point light source is turned off.

[0013] Optionally, when the detected temperature exceeds a preset temperature, the brightness of the corresponding point light source is reduced. Afterwards, the method further includes: Adjust the virtual image positions in different areas of the TFT screen.

[0014] Optionally, adjusting the virtual image position in different areas of the TFT screen includes: The virtual image positions in different areas of the TFT screen are rearranged by using animation translation.

[0015] The backlight module and its control method, as well as the head-up display device provided in this application embodiment, through a matrix-based backlight design, can achieve localized power reduction when backlight power saving is triggered by sunlight backflow. This weakens the backlight illumination of the TFT screen in the sunlight-spotted area while maintaining normal backlight illumination in the non-spotted areas, thus maintaining the brightness and contrast of the image viewed by the user. When sunlight backflow causes the TFT screen temperature to rise, triggering power saving, localized power saving can be achieved by illuminating some point light sources, reducing the backlight temperature rise and effectively mitigating the increase in TFT screen temperature. This ensures that the screen temperature remains within the normal operating range, so that the user's viewing experience is not affected. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is one of the schematic diagrams of the backlight module structure provided in this embodiment; Figure 2 This is a diagram showing the illuminated state of the backlight module provided in this embodiment; Figure 3 This is a diagram showing the effect of the backlight module being lit up according to this embodiment; Figure 4 This is one of the backlight module structure temperature detector distribution diagrams provided in this embodiment; Figure 5 This is the second distribution diagram of the temperature detector in the backlight module structure provided in this embodiment; Figure 6 This is one of the temperature distribution curves of the backlight module structure provided in this embodiment; Figure 7 This is the second temperature distribution curve of the backlight module structure provided in this embodiment; Figure 8 This is the third backlight module structure temperature distribution curve provided in this embodiment; Figure 9 This is the fourth temperature distribution curve of the backlight module structure provided in this embodiment; Figure 10a This is one of the UI switching change diagrams of the backlight module structure provided in this embodiment; Figure 10b This is the second UI switching change diagram of the backlight module structure provided in this embodiment; Figure 11 This is the second schematic diagram of the backlight module structure provided in this embodiment; Figure 12 This is the third schematic diagram of the backlight module structure provided in this embodiment.

[0018] Icons: 1-1-Point light source; 2-1-Light-focusing component; 3-1-Light-diffusing component; 4-1-Screen; 5-1-Thermal imaging camera. Detailed Implementation

[0019] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0020] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] It should also be noted that, unless otherwise explicitly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] Please refer to Figure 1 As shown, this application embodiment provides a backlight module, including: an array light source, and a light-concentrating component 2-1, a light-uniforming component 3-1, and a TFT screen 4-1 located sequentially on the light-emitting side of the array light source. The light emitted by the array light source passes through the light-concentrating component 2-1, which converges the divergence angle of the light to make the light converge. After the light converges, it passes through the light-uniforming component 3-1 for light-uniformation processing, so that the light illuminating the TFT screen 4-1 is uniform. The array light source includes multiple point light sources 1-1 arranged in an array. By lighting up different point light sources 1-1, the TFT screen 4-1 can be adjusted for zoned display.

[0023] Multiple point light sources 1-1 are arranged in an array to form an array light source. The multiple point light sources 1-1 can be arrayed along a one-dimensional or two-dimensional direction. This application takes the formation of a matrix-type array light source by a two-dimensional array of multiple point light sources 1-1 as an example. The point light sources 1-1 can be LEDs.

[0024] like Figure 2As shown, an array of light sources formed by multiple point light sources 1-1 can achieve single-LED illumination. After passing through the focusing component 2-1 and the light-diffusing component 3-1, it can only illuminate a local area of ​​the TFT screen 4-1. In this embodiment, taking a 5*3 LED array as an example, by lighting the array LEDs at intervals and passing through the focusing component 2-1 and the light-diffusing component 3-1, the following can be achieved: Figure 3 The chessboard grid lighting effect.

[0025] The lit point light source 1-1 corresponds to the area on the TFT screen 4-1 that emits light and displays, while the unlit point light source 1-1 corresponds to the area on the TFT screen 4-1 that does not emit light or display, thereby realizing the zoned display control and adjustment of the TFT screen 4-1.

[0026] Furthermore, the light-concentrating component 2-1 includes multiple light-concentrating elements, which correspond one-to-one with multiple point light sources 1-1 to concentrate the light emitted from each point light source 1-1.

[0027] Therefore, the backlight module provided in this application embodiment, through a matrix-based backlight design, can achieve localized power reduction when backlight power saving is triggered by sunlight backflow. This weakens the backlight illumination of the TFT screen 4-1 in the sunlight spot area, while maintaining normal backlight illumination in the non-spot area, thus maintaining the brightness and contrast of the image viewed by the user. When sunlight backflow causes the temperature of the TFT screen 4-1 to rise, triggering power saving, localized power saving can be achieved by illuminating some point light sources 1-1, reducing the backlight temperature rise and effectively mitigating the temperature increase of the TFT screen 4-1. This ensures that the temperature of the screen 4-1 remains within the normal operating range, so that the user's viewing experience is not affected.

[0028] Furthermore, multiple temperature detectors are arranged around the TFT screen 4-1. The temperature detectors and the point light source 1-1 are both connected to the controller. The controller controls the switching and brightness of the point light source 1-1 based on the temperature detected by the temperature detectors.

[0029] By setting a temperature detector, temperature monitoring measures can be implemented to control the switching on and off of point light source 1-1, as well as its brightness. Specifically, the brightness of point light source 1-1 can be adjusted by controlling the array current of point light source 1-1. Reducing the brightness of the array of point light source 1-1 can also achieve local power consumption reduction and alleviate the temperature rise of TFT screen 4-1.

[0030] In this embodiment, the temperature monitoring measure is to sense the temperature of the display area surrounding the TFT screen 4-1. Figure 4As shown, when the hot spot temperature position on the TFT screen 4-1 is different, the temperature distribution detected by the temperature sensor around the display area of ​​the TFT screen 4-1 is also different. Through simulation and actual measurement, the mapping relationship between the hot spot position of the TFT screen 4-1 and the temperature distribution of the temperature detector can be obtained.

[0031] For example, Figure 4 The TFT screen 4-1 is divided into multiple array sub-regions, and each sub-region corresponds to a point light source 1-1. The multiple temperature detectors correspond to the outermost sub-region of the array.

[0032] Each sub-area corresponds to a point light source 1-1. When different point light sources 1-1 are lit, the corresponding sub-area will be lit; or by adjusting the brightness of different point light sources 1-1, the brightness of the corresponding sub-area can be controlled.

[0033] Temperature detectors are placed on the outermost sub-area side of the array area. The temperature of the corresponding sub-area is detected by the temperature detectors and fed back to the controller. The controller then controls the brightness of the corresponding point light source 1-1 based on the detected temperature, or even turns off the point light source 1-1, in order to achieve local power consumption reduction.

[0034] Assumption: data consists of temperature data detected by each temperature sensor; Data(A1)>Data(A2)>Data(A3)>Data(A4)>Data(A5),Data(D1)>Data(D2)>Data(D3); AVE(Data(A1),Data(A2),Data(A3),Data(A4),Data(A5))>AVE(Data(C1),Data(C2),Data(C3),Data(C4),Data(C5); AVE(Data(D1),Data(D2),Data(D3))>AVE(Data(B1),Data(B2),Data(B3)); Then the temperature hotspot is Figure 5 Sub-area 1; Data(A1)<Data(A2)> Data(A3)>Data(A4)>Data(A5),Data(D1)>Data(D20>Data(D3); AVE(Data(A1),Data(A2),Data(A3),Data(A4),Data(A5))>AVE(Data(C1),Data(C2),Data(C3),Data(C4),Data(C5)); AVE(Data(D1),Data(D2),Data(D3))>AVE(Data(B1),Data(B2),Data(B3)); Then the temperature hotspot is Figure 5 Sub-area 2; Data(A1) <Data(A2)<Data(A3)> Data(A4)>Data(A5),Data(D1)>Data(D2)>Data(D3); AVE(Data(A1),Data(A2),Data(A3),Data(A4),Data(A5))>AVE(Data(C1),Data(C2),Data(C3),Data(C4),Data(C5)); AVE(Data(A1),Data(A2))=AVE(Data(A4),Data(A5)); Then the temperature hotspot is Figure 5 Sub-area 3; ... Similarly, the location of hotspots can be inferred from the numerical distribution pattern of temperature detectors.

[0035] It should be noted that this mapping relationship is not a simple comparison of relative numerical values, but rather based on the temperature curve distribution of simulation or actual measurement. This mapping relationship can be corrected through computer simulation and measured data, and can also be improved and supplemented by artificial intelligence and other means.

[0036] Figure 6 It is a temperature distribution curve of a temperature hotspot in sub-region 1. Figure 7 It is a temperature distribution curve of a temperature hotspot in sub-region 2.

[0037] Reference Figure 8 When the system determines that the hotspot area is in area 1 based on the temperature distribution pattern, and the temperature in area 1 exceeds the screen's warning temperature 4-1, the system executes a power-saving strategy, reducing the brightness of the point light source 1-1 corresponding to area 1. Figure 9 As shown, the temperature of the hotspot in area 1 begins to drop. If the measures to reduce brightness cannot reduce the temperature of area 1 below the warning temperature, then the point light source 1-1 corresponding to area 1 will be turned off.

[0038] When the brightness of area 1 decreases, the TFT screen 4-1 at the corresponding position of area 1 will consider displaying low-contrast UI (virtual image position) elements. When the brightness of area 1 reaches zero, the corresponding area on screen 4-1 will not display any UI elements, and the necessary UI elements will be displayed again in other areas of screen 4-1. Figure 10a , Figure 10b To avoid abrupt changes in UI position, transitions can be made using methods including, but not limited to, animated translations.

[0039] With the above settings, when the HUD device is exposed to backlighting during use, causing the screen temperature to rise and triggering power saving, the brightness of the HUD projected image will not decrease, and it can still maintain a high contrast presentation, so the user's viewing experience will not be significantly reduced.

[0040] On the other hand, the aforementioned light-concentrating component 2-1 includes a plurality of light-concentrating elements. In some embodiments, the light-concentrating element includes a light-concentrating lens to achieve the convergence of light.

[0041] In other embodiments, such as Figure 11 As shown, the focusing element includes a reflector cup. When the focusing element is a reflector cup, the opening of the reflector cup faces the light homogenizing component 3-1. Among the light emitted from the array light source, part of the light is reflected by the inner wall of the reflector cup and then shines on the light homogenizing component 3-1, while the other part of the light is incident perpendicularly on the light homogenizing component 3-1.

[0042] The light emitted by the array light source is converged by the reflector array. The converged light passes through the light homogenizing component 3-1, which makes the light illuminating the TFT screen 4-1 uniform.

[0043] The aforementioned temperature detector can be a temperature sensor, or it can be... Figure 12 The thermal imaging camera 5-1 directly monitors the temperature distribution on the TFT screen 4-1 in real time, providing the most direct way to identify temperature hotspots on the TFT screen 4-1. By mapping the temperature distribution map to the control area of ​​the matrixed backlight, areas requiring local adjustment on the matrixed backlight can be quickly identified, offering advantages such as simple control algorithms, fast response time, and high accuracy.

[0044] On the other hand, this application embodiment also provides a control method for a backlight module, which is applied to the aforementioned backlight module. The backlight module includes a TFT screen 4-1, a controller, multiple point light sources 1-1, and multiple temperature detectors, which are distributed around the TFT screen 4-1.

[0045] The method includes: Step 100: Obtain the detection temperature of different areas of the TFT screen 4-1.

[0046] The TFT screen 4-1 is divided into multiple sub-regions, and each sub-region corresponds to a point light source 1-1. Multiple temperature detectors surround the TFT screen 4-1, and the multiple temperature detectors are located on the outermost side of the multiple sub-regions of the array.

[0047] The temperature of the corresponding sub-area is obtained by the temperature detector and fed back to the controller, so that the controller can obtain the temperature of different areas of the TFT screen 4-1.

[0048] Step 101: When the detected temperature of the current area exceeds the preset temperature, drive the brightness adjustment of the corresponding point light source 1-1 in the current area.

[0049] When the detected temperature of the sub-area (current area) exceeds the preset temperature (screen 4-1 warning temperature), the system executes a power saving strategy, and the system will reduce the brightness of the corresponding point light source 1-1. At this time, the hot spot temperature of the corresponding sub-area begins to decrease.

[0050] Step 102: Obtain the detection temperature of the corresponding area of ​​the TFT screen 4-1 again. When the detection temperature exceeds the preset temperature, turn off the corresponding point light source 1-1.

[0051] In other words, if the measures to reduce brightness cannot reduce the temperature of the sub-area to below the warning temperature, then the point light source 1-1 corresponding to the sub-area will be turned off.

[0052] When the brightness of a sub-area decreases, low-contrast UI elements will be displayed on the TFT screen 4-1 at the corresponding position in the sub-area. When the brightness of a sub-area reaches zero, the corresponding position on the TFT screen 4-1 will not display the UI, and the necessary UI elements will be re-displayed in other sub-areas of the TFT screen 4-1, such as... Figure 10a , Figure 10b As shown.

[0053] In other words, when the brightness of a sub-area decreases or returns to zero, the local brightness of the TFT screen 4-1 decreases. It is necessary to adjust the virtual image positions of different areas of the TFT screen 4-1 to redistribute the UI, ensure that the brightness of the projected image is maintained, and not affect the user's viewing experience.

[0054] In addition, to avoid abrupt changes in UI position, the UI position can be changed using methods including but not limited to animated translation, so as to rearrange the virtual image positions in different areas of the TFT screen 4-1.

[0055] Taking animation translation as an example, such as Figure 10aThe first cell in the top left corner is the screen's hotspot. When the hotspot temperature exceeds a preset temperature, the UI elements at that location will glow red and tremble slightly. At this time, an animated sprite (such as a panda) can appear in the image. This panda pushes the UI elements by pushing the reddened UI elements in an animated way. Figure 10b As shown, as the element is moved away from the hot spot, the previously reddish UI element gradually returns to its normal color, and the sprite disappears, completing the animation translation. Other methods can also be used, such as a firefighter dragging a reddish UI element to a safe area.

[0056] In summary, the matrix backlight design enables illumination segmentation, which allows for localized adjustment of the brightness of the image on the TFT screen 4-1. By monitoring the temperature, hot spots on the TFT screen 4-1 can be identified, indicating the location of the area to be adjusted for localized brightness of the matrix backlight. Localized adjustment of the backlight brightness at the hot spots will reduce the temperature of the TFT screen 4-1 in that area, ensuring that the temperature of the TFT screen 4-1 does not exceed the operating range.

[0057] By employing matrix-based backlight control and temperature control strategies to achieve localized power consumption reduction, and combined with UI layout design, the brightness of the HUD projected image does not decrease when power consumption is reduced due to backlighting, maintaining a high contrast presentation and ensuring that the user's viewing experience is not significantly diminished.

[0058] Based on this, embodiments of this application also disclose a head-up display device, including a backlight module as described above.

[0059] The head-up display device includes the same structure and beneficial effects as the backlight module in the foregoing embodiments. The structure and beneficial effects of the backlight module have been described in detail in the foregoing embodiments and will not be repeated here.

[0060] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A backlight module, characterized in that, include: The array light source includes a light-concentrating component, a light-uniforming component, and a TFT screen located sequentially on the light-emitting side of the array light source. The light emitted by the array light source is focused by the light-concentrating component and then uniformly processed by the light-uniforming component to make the light illuminating the TFT screen uniform. The array light source includes multiple point light sources arranged in an array. By lighting different point light sources, the TFT screen can be adjusted to display different zones.

2. The backlight module according to claim 1, characterized in that, The TFT screen is surrounded by multiple temperature detectors. The temperature detectors and the point light source are both connected to a controller. The controller controls the switching and brightness of the point light source based on the temperature detected by the temperature detectors.

3. The backlight module according to claim 2, characterized in that, The TFT screen is divided into multiple array sub-regions, each sub-region corresponding to a point light source, and each temperature detector corresponding to the outermost sub-region of the array.

4. The backlight module according to any one of claims 1 to 3, characterized in that, The light-concentrating component includes multiple light-concentrating elements, and each of the multiple light-concentrating elements corresponds to one of the multiple point light sources.

5. The backlight module according to claim 4, characterized in that, The light-concentrating element includes a light-concentrating lens or a reflector. When the light-concentrating element is the reflector, the opening of the reflector faces the light-uniforming component. In the light emitted from the array light source, a portion of the light is reflected by the inner wall of the reflector and then directed toward the light-uniforming component.

6. A head-up display device, characterized in that, Includes the backlight module as described in any one of claims 1 to 5.

7. A control method for a backlight module, applied to the backlight module according to any one of claims 1 to 5, characterized in that, The backlight module includes a TFT screen, a controller, multiple point light sources, and multiple temperature detectors, with the multiple temperature detectors distributed around the TFT screen; the method includes: The temperature of different areas of the TFT screen was obtained separately. When the detected temperature in the current area exceeds the preset temperature, the brightness of the point light source corresponding to the current area is adjusted.

8. The control method for the backlight module according to claim 7, characterized in that, When the detected temperature exceeds a preset temperature, the brightness of the corresponding point light source is reduced. Then, the method includes: Obtain the detection temperature of the corresponding area of ​​the TFT screen; When the detected temperature exceeds the preset temperature, the corresponding point light source is turned off.

9. The control method for the backlight module according to claim 8, characterized in that, When the detected temperature exceeds a preset temperature, the brightness of the corresponding point light source is reduced. The method then further includes: Adjust the virtual image positions in different areas of the TFT screen.

10. The control method for the backlight module according to claim 9, characterized in that, Adjusting the virtual image position in different areas of the TFT screen includes: The virtual image positions in different areas of the TFT screen are rearranged by using animation translation.

Images