Head-up display device, vehicle, and method for controlling head-up display device

Abstract

The embodiment of the invention provides a head-up display device, a vehicle and a control method of the head-up display device.The head-up display device comprises an image source and a reflection imaging part, the image source is used for emitting image light, and the reflection imaging part is used for reflecting the image light into an eye box area corresponding to the head-up display device. The image source comprises a liquid crystal display screen and a plurality of backlight lamps, the backlight lamps are installed on the back side of the liquid crystal display screen and used for providing backlight for the liquid crystal display screen so that the liquid crystal display screen can emit the image light rays, the brightness of at least one backlight lamp in the backlight lamps can be independently adjusted, and the brightness of the backlight lamps can be independently adjusted. And the heat received by the liquid crystal display screen from the backlight lamp is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of head-up display, and in particular to a head-up display device, a vehicle, and a control method for the head-up display device. Background Art

[0002] HUD (head up display) is also called a head-up display. By projecting the light emitted by the HUD image source onto an imaging window (such as a rear-mounted imaging board or a vehicle's windshield, etc.), users can directly see the image without lowering their heads, avoiding distractions caused by drivers looking down at the dashboard while driving, thereby improving driving safety and user driving experience.

[0003] HUD can be divided into LCD type HUD, projector type HUD and other types of HUD according to the type of image source. Among them, LCD type HUD uses LCD as the main body to form image light, while projector type HUD uses projector (such as DLP projector or LCOS projector) as the main body to form image light.

[0004] The projector-type HUD is limited by the structure of the projector, which has the problems of large size, high cost, and poor reliability. In addition, the imaging principle of the projector requires a screen to form an image, that is, the image formed by the light emitted by the projector shining on the screen is used as the source image. Since a screen is needed for imaging, the fineness of the image is limited by the fineness of the screen. Compared with the LCD-type HUD, the clarity, contrast, cost and volume of the virtual image of the projector-type HUD are disadvantageous. The LCD-type HUD has great advantages in terms of clarity, contrast and brightness of the virtual image, but it faces the problem of screen burn-in. For example, when sunlight flows back into the HUD and shines on the LCD screen for a period of time, it may damage the LCD screen or reduce the life of the LCD screen. Summary of the invention

[0005] The purpose of the embodiments of the present disclosure is to provide a head-up display device, a vehicle, and a control method for the head-up display device to solve the technical problems in the prior art that the image source of the head-up display is prone to screen burn-in due to sunlight and has high power consumption.

[0006] In order to solve the above technical problems, the embodiments of the present disclosure adopt the following technical solutions:

[0007] The embodiment of the present disclosure provides a head-up display device, including an image source and a reflective imaging unit, wherein the image source is used to emit image light, and the reflective imaging unit is used to reflect the image light into an eye box area corresponding to the head-up display device, wherein the image source includes:

[0008] LCD display;

[0009] A plurality of backlights are installed on the back side of the liquid crystal display screen, and are used to provide backlight for the liquid crystal display screen so that the liquid crystal display screen emits the image light. The brightness of at least one of the plurality of backlights can be independently adjusted to reduce the heat received by the liquid crystal display screen from the backlight.

[0010] In some embodiments, a plurality of the backlights are arranged in zones on the back side of the liquid crystal display screen, each zone includes at least one backlight, and each backlight corresponds to one or more pixels of the liquid crystal display screen.

[0011] In some embodiments, the image source further includes a backlight circuit board, a plurality of the backlight lamps are mounted on the backlight circuit board, and at least one heat dissipation hole is provided on the backlight circuit board.

[0012] In some embodiments, the heat dissipation holes are filled with a heat-conducting medium, and the thermal resistance of the heat-conducting medium is smaller than the thermal resistance of the backlight circuit board.

[0013] In some embodiments, a controller is further included, the controller is connected to the image source, and the controller is configured to adjust the brightness of the backlight according to the ambient visual brightness of the ambient space corresponding to the virtual image formed by the head-up display device.

[0014] In some embodiments, the controller is further configured to determine the maximum brightness of the LCD screen in a current state according to the maximum heat load allowed by the LCD screen and the sunlight heat load currently received by the LCD screen.

[0015] The disclosed embodiment also provides a vehicle, comprising the above-mentioned head-up display device.

[0016] The present disclosure also provides a control method for a head-up display device, wherein the head-up display device includes an image source and a reflective imaging unit, wherein the image source is used to emit image light, and the reflective imaging unit is used to reflect the image light into an eye box area corresponding to the head-up display device, wherein the image source includes a liquid crystal display screen and a plurality of backlights, wherein the plurality of backlights are installed on the back side of the liquid crystal display screen, and the control method includes:

[0017] Determining a backlight corresponding to a display position of a virtual image content in a virtual image formed by the head-up display device;

[0018] The brightness of the backlight corresponding to the display position is determined according to the ambient visual brightness of the ambient space corresponding to the virtual image, and the backlight that does not correspond to the display position is turned off.

[0019] In some embodiments, determining the brightness of a backlight corresponding to the display position according to the ambient visual brightness of an ambient space corresponding to the virtual image includes:

[0020] Determining the theoretical brightness of the backlight corresponding to the display position according to the ambient visual brightness;

[0021] Determine whether the theoretical brightness of the backlight is less than or equal to the maximum brightness of the LCD screen in the current state, wherein the maximum brightness is determined according to the maximum heat load allowed by the LCD screen and the sunlight heat load currently received by the LCD screen;

[0022] If so, the brightness of the backlight corresponding to the display position is adjusted to the theoretical brightness.

[0023] In some embodiments, the method further comprises:

[0024] Collecting an image of the environment in front of the vehicle by an image acquisition device;

[0025] Analyze the environment image to obtain a first environment light brightness of the environment space, wherein the first environment light brightness is the brightness of the environment light perceived by the eye box area;

[0026] Collecting the second ambient light brightness of the environment where the vehicle is located by means of a sensor;

[0027] The ambient visual brightness of the ambient space is determined according to the first ambient brightness and the second ambient light brightness.

[0028] The head-up display device, vehicle and control method of the head-up display device provided in the embodiments of the present disclosure, by setting at least one backlight among the multiple backlights installed on the back side of the liquid crystal display screen to a structure with independently adjustable brightness, so as to reduce the heat received by the liquid crystal display screen from the backlight, the liquid crystal display screen can be protected, and the burn-in phenomenon of the liquid crystal display screen due to sunlight backflow etc. can be effectively avoided, the service life of the liquid crystal display screen can be increased, and the power consumption of the head-up display can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 It is a structural schematic diagram of an image source of a head-up display device according to an embodiment of the present disclosure;

[0031] Figure 2 It is a schematic diagram of imaging of a head-up display device according to an embodiment of the present disclosure;

[0032] Figure 3 is another imaging schematic diagram of the head-up display device according to an embodiment of the present disclosure;

[0033] Figure 4 The present invention is a flowchart of a control method of a device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] Various aspects and features of the present disclosure are described herein with reference to the drawings.

[0035] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present disclosure will occur to those skilled in the art.

[0036] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the general description of the present disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0037] These and other characteristics of the present disclosure will become apparent from the following description of a preferred form of embodiment given as a non-limiting example, with reference to the attached drawings.

[0038] It should also be understood that, although the present disclosure has been described with reference to some specific examples, those skilled in the art will be able to realize many other equivalent forms of the present disclosure that have the features described in the claims and are therefore within the scope of protection defined thereby.

[0039] The above and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0040] Specific embodiments of the present disclosure are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present disclosure, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of ways with substantially any suitable detailed structure.

[0041] This specification may use the phrases "in one embodiment," "in another embodiment," "in a further embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present disclosure.

[0042] Figure 1 A schematic diagram showing the structure of an image source of a head-up display device according to an embodiment of the present disclosure is shown. Figure 2 FIG. 2 shows an imaging schematic diagram of a head-up display device according to an embodiment of the present disclosure. Figure 1 and Figure 2 As shown, the embodiment of the present disclosure provides a head-up display device 100, including an image source 10 and a reflective imaging unit, wherein the image source 10 is used to emit image light, and the reflective imaging unit is, for example, a windshield 200, which is used to reflect the image light into an eye box area 300 corresponding to the head-up display device 100, and the image source 10 includes a liquid crystal display screen 1 and a plurality of backlight lamps 2, wherein the plurality of backlight lamps 2 are installed on the back side of the liquid crystal display screen 1, and are used to provide backlight for the liquid crystal display screen 1, so that the liquid crystal display screen 1 emits image light, and the brightness of at least one backlight lamp 2 among the plurality of backlight lamps 2 can be independently adjusted to reduce the heat received by the liquid crystal display screen 1 from the backlight lamps 2.

[0043] like Figure 2 As shown, the image light emitted by the image source 10 of the head-up display device 100 is reflected by the reflective imaging unit to the eye box area 300, so that the user's eyes can see the virtual image 400 when they are in the eye box area 300. In this embodiment, in order to enable the user to see a larger virtual image 400, an amplification component 20 is provided between the image source 10 and the reflective imaging unit to amplify the image output by the image source 10.

[0044] In some examples, the amplifying assembly 20 may include a plane mirror 201 and a curved mirror 202. In other examples, the amplifying assembly 20 may include an HOE amplifying element disposed on the reflective imaging portion, which is not limited thereto.

[0045] The eye box area 300 refers to the area where the eyes of the observer (such as the driver, passenger and / or other user) are located and the image formed by the head-up display device 100 can be observed. The observer can see the formed image at different positions of the eyes in the eye box area 300.

[0046] After studying the working process of the head-up display (HUD), the inventors found that the heat sources on the LCD screen 1 are mainly three parts. The first is the heat transferred to the LCD screen 1 from the environment (determined by the environment such as the temperature of the cabin inside the car), the second is the heat generated and transferred to the LCD screen 1 when the backlight 2 is turned on, and the third is the heat from the sunlight irradiating to the LCD screen 1 when sunlight backflow occurs.

[0047] In this embodiment, by setting at least one backlight 2 among the multiple backlights 2 to have an independently adjustable brightness structure (local control of the backlight 2), the brightness of at least some of the backlights 2 among the multiple backlights 2 can be independently adjusted and controlled, for example, the brightness of the backlight 2 corresponding to the portion without virtual image content in the virtual image 400 is reduced or the backlight 2 corresponding to the portion without virtual image content in the virtual image 400 is turned off. In this way, while ensuring that the virtual image content is displayed with the original brightness, the overall power consumption of the backlight 2 can be reduced. Compared with the prior art, each backlight 2 in the head-up display device is not independently controlled and needs to be simultaneously controlled when working. When the backlight 2 is turned on, the heat generated by the backlight 2 can be reduced, thereby reducing the heat transferred from the backlight 2 to the LCD screen 1. When the maximum amount of heat that the LCD screen 1 can withstand is limited, a larger heat margin is reserved for the backflow of sunlight, thereby reducing the risk of damage to the LCD screen 1 due to the backflow of sunlight, effectively avoiding the burn-in phenomenon of the LCD screen 1, and increasing the service life of the LCD screen 1. At the same time, there is no need to turn on all the backlights 2 or adjust all the backlights 2 to the same brightness, which can reduce the power consumption of the head-up display device 100, achieve energy-saving effects, and increase the service life of the head-up display device 100.

[0048] It is understandable that the brightness of at least one backlight 2 among the above-mentioned multiple backlights 2 can be independently adjusted, including at least one backlight 2 can be independently turned on or off (the brightness is 0 when turned off), and / or the brightness value of the turned-on backlight 2 can be arbitrarily adjusted.

[0049] The head-up display device provided by the embodiment of the present disclosure is configured such that at least one of the multiple backlights 2 installed on the back side of the liquid crystal display screen 1 is configured to have independently adjustable brightness, that is, the head-up display device is a device with a locally controllable backlight 2, so as to reduce the heat received by the liquid crystal display screen 1 from the backlight 2, thereby protecting the liquid crystal display screen 1, effectively preventing the liquid crystal display screen 1 from being burned in due to sunlight backflow, etc., thereby increasing the service life of the liquid crystal display screen 1 and reducing the power consumption of the head-up display device 100.

[0050] In addition, since the amount of heat that the liquid crystal display screen 1 can withstand has an upper limit, the maximum brightness of the existing head-up display device 100 is limited by the amount of heat that the liquid crystal display screen 1 can withstand, which results in the virtual image content of the head-up display device 100 being unclear in some scenes with high ambient brightness. In this embodiment, the brightness of at least one backlight 2 of the head-up display device 100 can be adjusted independently (the backlight 2 of the head-up display device 100 can be locally controlled), and because the entire frame of the virtual image in the field of the head-up display device 100 is usually not filled with the virtual image content, that is, when displaying the virtual image content, there are blank areas on the liquid crystal display screen 1 where no content needs to be displayed (this is different from the liquid crystal screen of an ordinary display), and the backlights 2 corresponding to these blank areas can reduce the brightness to an extremely low level, or even turn off, which reduces the number of backlights 2 that are turned on in the head-up display device 100 of this embodiment during operation compared to the head-up display device 100 with all lights always on, thereby enabling the liquid crystal display screen 1 to support the backlight 2 that is turned on (lit) under the same power consumption or the same external temperature. The light 2 reaches a higher brightness, which can improve the maximum brightness of the backlight 2 in the turned-on state, thereby improving the adaptability and use effect of the head-up display device 100, so that the head-up display device 100 can adapt to a wider range of environmental brightness, ensuring that the virtual image content is also clearly visible in scenes with high environmental brightness, thereby solving the problem in the prior art that the virtual image 400 of the head-up display device 100 is insufficient in brightness when the sunlight is strong or the reflection is strong, and the virtual image content may not be seen clearly; or, at night, the brightness of the backlight 2 corresponding to the virtual image content part can be reduced to the lowest possible, and the backlight 2 corresponding to the part without virtual image content can be directly turned off, thereby solving the problem in the prior art that the head-up display device 100 is easy to see a gray frame when observed at night (the brightness of the virtual image is too large relative to the brightness of the external environment).

[0051] In the above embodiment, the brightness of the backlight 2 is adjusted directly according to the ambient brightness in the driving environment of the vehicle to ensure that the user can see the virtual image content clearly or avoid seeing irrelevant content.

[0052] In addition, the liquid crystal display screen 1 in the existing liquid crystal display type HUD mainly controls the display of different colors at different positions of the screen by controlling the angle of rotation of the liquid crystal, etc., and the backlight is always in the on state during the operation of the liquid crystal display. Specifically, in the head-up display device 100, in order not to affect the user's observation of the environment and road conditions, although the virtual image 400 of the head-up display device 100 can cover a large space, a large part of the virtual image 400 does not display the virtual image content (also referred to as UI). For the user, the part that does not display the virtual image content is transparent, that is, it is best not to have the image light from the head-up display device 100 incident on the user's eyes. However, it is difficult for the existing liquid crystal display screen 1 to completely filter out the backlight corresponding to this part, which results in a part of the light leakage always reaching the user's eye box area 300. In this case, in scenes with low ambient brightness such as at night, this part of the light leakage will also be more conspicuous, interfering with the user's observation of the environment and road conditions. Therefore, in this embodiment, by performing zone control on the backlight, the backlight 2 corresponding to the part without virtual image content can be directly turned off, which fundamentally solves the problem of light leakage, so that the user will not see unnecessary light leakage at night, thereby improving the user's visual experience.

[0053] Each backlight 2 corresponds to one or more pixels of the liquid crystal display screen 1 to provide backlight for a single pixel or multiple pixels to meet different display effects of the liquid crystal display screen 1 .

[0054] In some embodiments, a plurality of backlights 2 are arranged in zones on the back side of the liquid crystal display screen 1 , each zone includes at least one backlight 2 , and each backlight 2 corresponds to one or more pixels of the liquid crystal display screen 1 .

[0055] This can meet the requirements of display fineness, brightness uniformity and contrast of different partitions. The brightness of the backlights 2 in the partition area can be controlled together or independently, and there is no limitation on this.

[0056] When there is only one backlight 2 in a partition area, the control of a single backlight can be implemented; when a partition area contains multiple backlights 2, linkage control or independent control of the multiple backlights can be implemented.

[0057] In some embodiments, Figure 1 As shown, the image source 10 further includes a backlight circuit board 3 , a plurality of backlight lamps 2 are mounted on the backlight circuit board 3 , and at least one heat dissipation hole is provided on the backlight circuit board 3 .

[0058] The backlight 2 is fixedly mounted on the backlight circuit board 3, and then the backlight circuit board 3 is mounted on the back side of the liquid crystal display screen 1, which is convenient for the installation of the backlight 2, and different conductive contacts on the backlight circuit board 3 can be used to achieve independent control of at least one backlight 2; when part of the backlight 2 is damaged, the backlight circuit board 3 can be disassembled and the required backlight can be replaced, which is convenient for disassembly, assembly and maintenance.

[0059] Optionally, the plurality of backlight lamps 2 are distributed on the backlight circuit board 3 in an array (eg, a 9×16 rectangular array).

[0060] In order to improve the contrast of the virtual image content part (the part with virtual image content in the virtual image screen) and the part without virtual image content (the part without virtual image content in the virtual image screen) in the virtual image 400, as well as the fineness of the virtual image content, the density of the backlight 2 in the head-up display device is relatively high. For example, in this embodiment, a 9×16 backlight array is arranged on a 4.1-inch screen, so that the area covered by the backlight spot provided by the backlight 2 is adapted to the size of the virtual image content (also referred to as UI) part, avoiding the waste of light at the edge of the virtual image content part and reducing the contrast of the above display. However, due to the high density of the backlight, the heat dissipation of the backlight in this backlight array is more difficult. If the heat dissipation effect is not good, it will cause heat accumulation inside the head-up display device, affecting the service life of the liquid crystal display screen 1. Therefore, in this embodiment, at least one heat dissipation hole is opened on the backlight circuit board 3, so that the backlight 2 that is lit and working can dissipate heat in time. In a preferred embodiment, at least one heat dissipation hole is located below the backlight 2 to ensure the heat dissipation effect.

[0061] In some embodiments, the heat dissipation holes are filled with a heat-conducting medium, and the thermal resistance of the heat-conducting medium is smaller than the thermal resistance of the backlight circuit board 3, so that the heat dissipation medium in the heat dissipation holes can be used to dissipate heat in time, and the heat transfer on the backlight circuit board 3 can be reduced to improve the heat dissipation effect. The heat-conducting medium is, for example, air or a heat-conducting non-metallic material or a heat-conducting metal material.

[0062] In some embodiments, Figure 1 As shown, the image source 10 also includes a collimating structure 4, which is arranged between the liquid crystal display screen 1 and the backlight 2, and is used to collimate the backlight emitted by the backlight 2 to avoid or reduce the diffusion of light emitted by one or some backlights 2 into the areas corresponding to other backlights 2. On the one hand, it can reduce the waste of light, thereby reducing power consumption while ensuring the brightness of the backlight 2, and on the other hand, it can effectively improve the contrast of the virtual image content.

[0063] In some embodiments, the head-up display device 100 further includes a controller connected to the image source 10 , and the controller is configured to adjust the brightness of the backlight 2 according to the ambient visual brightness of the ambient space corresponding to the virtual image 400 formed by the head-up display device 100 .

[0064] like Figure 3 As shown, in the AR-HUD (enhanced display head-up display device), the reflective imaging unit reflects the image light emitted by different image sources (the first image source 101 and the second image source 102) into the eye box area 300. In some cases, in order to ensure that the virtual images corresponding to different image sources have a certain overlap in the height direction of the eye box area, the reflective imaging unit adds a semi-transparent and semi-reflective structure (for example, the plane reflector 201 is a semi-transparent and semi-reflective mirror) in the optical path of the head-up display device, so that part of the image light emitted by the first image source 101 is reflected by the semi-transparent and semi-reflective structure, and then forms a first virtual image 401, and the other part is transmitted by the semi-transparent and semi-reflective structure (the semi-transparent and semi-reflective structure of this embodiment is not limited to a transmittance of 50%, and the transmittance and reflectance of the semi-transparent and semi-reflective structure can be appropriately adjusted according to different structures, materials, etc.), and part of the image light emitted by the second image source 102 is transmitted by the semi-transparent and semi-reflective structure, and then forms a second virtual image 402, and the other part is reflected.

[0065] It is not difficult to see in this working process that at least part of the energy of the image light emitted by the image source is wasted, that is, compared with Figure 2 The head-up display device shown in the figure has a relatively bright AR-HUD under the same conditions. Figure 2 The brightness of the HUD shown will decrease. To ensure the same virtual image brightness, the backlight needs to provide a higher brightness, which means that the LCD screen 1 receives more heat. However, since the amount of heat that the LCD screen 1 can withstand is fixed, the brightness of the AR-HUD cannot adapt to higher ambient brightness, resulting in insufficient brightness. Similarly, the naked eye 3D HUD also has similar problems.

[0066] In order to solve this problem, in this embodiment, the controller detects the ambient visual brightness of the ambient space corresponding to the display position of the virtual image content through a sensor, and then determines the theoretical brightness of the backlight 2 corresponding to the virtual image content based on the ambient visual brightness, and then compares the theoretical brightness with the maximum brightness of the backlight 2 allowed by the LCD screen 1 in the current state. If the theoretical brightness is less than or equal to the maximum brightness allowed by the backlight 2, the brightness of the backlight 2 is adjusted to the theoretical brightness. If the theoretical brightness is greater than the maximum brightness allowed by the backlight 2, the brightness of the backlight 2 can be adjusted within the range of [0, maximum brightness] according to the ambient brightness at the display position of the ambient space where the virtual image content is located, for example, the brightness of the backlight 2 is adjusted to the maximum brightness. In this way, the LCD screen 1 can be protected and the upper limit brightness that the backlight 2 can reach can be increased, thereby solving the problem of insufficient brightness of the LCD screen 1.

[0067] It should be noted that the ambient visual brightness of the ambient space corresponding to the virtual image 400 formed by the head-up display device 100 refers to the brightness of the ambient space perceived by the user's eyes when observing the virtual image content.

[0068] It can be understood that since the backlight 2 of the part without virtual image content is directly turned off, the ambient visual brightness of the ambient space corresponding to the virtual image 400 formed by the above-mentioned head-up display device 100 mainly refers to the ambient visual brightness of the ambient space corresponding to the display position of the virtual image content, so as to improve the display contrast between the virtual image content part and the part without virtual image content, and ensure the clear display of the virtual image content.

[0069] Optionally, the ambient visual brightness of the ambient space corresponding to the display position of the virtual image content may include the ambient visual brightness at a position near the display position of the virtual image content.

[0070] Preferably, in this embodiment, the environment image in front of the vehicle can be collected by a camera installed on the vehicle, and then the environment image is analyzed and processed to obtain a first ambient light brightness equivalent to the ambient light perceived by the user's eye box area 300; in addition, the second ambient light brightness of the environment in which the vehicle is located can be collected by a sensor installed on the vehicle, and then the ambient visual brightness of the environment space corresponding to the virtual image content can be determined according to the first ambient light and the second ambient light brightness, so as to improve the accuracy of the determination of the ambient visual brightness. In this embodiment, when determining the ambient visual brightness, not only the second ambient light brightness detected by the sensor is used, but also the visual brightness changes caused by the colors of other environmental objects such as vehicles, obstacles, pedestrians, buildings, trees on the road, and the different reflective abilities of objects of different materials are taken into account.

[0071] In some implementations, when determining the ambient visual brightness, the target object in the image is identified based on the captured ambient image, and based on the identification result, it can be determined whether there is strong reflection in the user's line of sight (light reflected from the external environment to the eye box area 300). In the case of reflection, the determined ambient visual brightness will be brighter, thereby improving the accuracy of the ambient visual brightness determination.

[0072] Optionally, the controller is further configured to determine the maximum brightness of the backlight 2 allowed in the current state of the LCD screen 1 according to the maximum heat load allowed by the LCD screen 1 and the sunlight heat load currently received by the LCD screen 1 .

[0073] Among them, the maximum heat load allowed by the LCD screen 1 can be determined based on the structure of the LCD screen 1, the material of the material, etc., and the sunlight heat load currently received by the LCD screen 1 can be determined based on the vehicle position, the direction of the front of the vehicle, the position of the sun relative to the earth, the opening position of the head-up display device 100, etc. The sunlight heat that flows back into the LCD screen 1 of the HUD. Of course, in other embodiments, the heat load currently received by the LCD screen 1 can also be determined by other appropriate methods, such as detecting the temperature of the LCD screen 1 by a sensor, which is not limited. In addition, it should be noted that the sunlight heat load currently received by the LCD screen 1 may include heat transferred to the LCD screen 1 other than sunlight backflow.

[0074] After determining the maximum heat load allowed by the LCD screen 1 and the sunlight heat load currently received by the LCD screen 1, the remaining heat that the LCD screen 1 can still withstand (which can also be understood as the remaining temperature rise margin of the LCD screen 1) can be determined. According to the number of backlights 2 that need to be lit and the remaining heat, the maximum brightness of each backlight 2 that is lit can be determined, that is, the maximum brightness of the backlight 2 allowed in the current state of the LCD screen 1 can be obtained. This is because there is a relationship between the brightness of the backlight 2 and the temperature rise of the LCD screen 1 caused by the backlight 2 irradiating the LCD screen 1.

[0075] Because the ambient visual brightness has been determined before, in order to make the user watch the virtual image content more comfortable and avoid the problem of the virtual image content being too dark or glaring, a brightness of a virtual image content that matches the ambient visual brightness can be determined, and based on the brightness of the matching virtual image content, the theoretical brightness of the corresponding backlight 2 can be determined. The theoretical brightness of the backlight 2 can make the brightness of the virtual image content corresponding to the backlight 2 match the ambient visual brightness.

[0076] Based on the determined theoretical brightness and the maximum brightness of the backlight 2 that is lit, the brightness of the backlight 2 can be determined to ensure that the final brightness of the backlight 2 is more closely matched to the theoretical brightness without damaging the liquid crystal display 1.

[0077] In the present embodiment, the determination of the maximum brightness of the backlight 2 takes into account the current heat load of the liquid crystal display 1 and the real-time number of backlights 2 that are lit. Therefore, compared with a conventional head-up display device 100 in which all backlights 2 are always on, the maximum brightness of the backlight 2 of the head-up display device 100 of the present embodiment can be higher. In other words, the HUD of the present embodiment can achieve a higher upper limit on the brightness of the virtual image content.

[0078] The embodiment of the present disclosure further provides a vehicle, comprising the above-mentioned head-up display device 100. The vehicle may be any one of a car, a truck, a pickup truck, a train, and the like.

[0079] Figure 4 FIG. 1 is a flow chart showing a method for controlling a head-up display device according to an embodiment of the present disclosure. Figures 1 to 4 As shown, the embodiment of the present disclosure also provides a control method of a head-up display device 100, the head-up display device 100 includes an image source 10 and a reflective imaging unit, the image source 10 is used to emit image light, the reflective imaging unit is used to reflect the image light into an eye box area 300 corresponding to the head-up display device 100, the image source 10 includes a liquid crystal display screen 1 and a plurality of backlight lamps 2, the plurality of backlight lamps 2 are installed on the back side of the liquid crystal display screen 1, and the control method includes:

[0080] S101: determining a backlight 2 corresponding to a display position of a virtual image content in a virtual image 400 formed by the head-up display device 100;

[0081] S102: Determine the brightness of the backlight 2 corresponding to the display position according to the ambient visual brightness of the ambient space corresponding to the virtual image 400, and turn off the backlight 2 that does not correspond to the display position.

[0082] The reflective imaging portion is, for example, a windshield 200. Since the brightness of some head-up display devices 100 (such as AR-HUD) cannot adapt to higher ambient brightness, there is a problem of insufficient brightness (for example, the virtual image content cannot be seen clearly). In order to solve this problem, in this embodiment, according to the display position of the virtual image content in the virtual image 400 formed by the head-up display device 100, the position of the pixel of the liquid crystal display screen 1 that can effectively image the virtual image content at the display position is determined, and then the backlight 2 corresponding to the position of the pixel of the liquid crystal display screen 1 is determined, and the backlight 2 is turned on, so that the liquid crystal display screen 1 emits corresponding image light, and then the user can see the virtual image content of the virtual image 400. After the backlight 2 corresponding to the display position of the virtual image content is turned on, the brightness of the backlight 2 can be determined according to the ambient visual brightness of the ambient space corresponding to the display position of the virtual image content, and the backlight 2 that does not correspond to the display position of the virtual image content is turned off to ensure that the user can see the virtual image content clearly.

[0083] It can be understood that since the backlight 2 of the part without virtual image content is directly turned off, the ambient visual brightness of the ambient space corresponding to the virtual image 400 formed by the above-mentioned head-up display device 100 mainly refers to the ambient visual brightness of the ambient space corresponding to the display position of the virtual image content, so as to improve the display contrast between the virtual image content part and the part without virtual image content, and ensure the clear display of the virtual image content.

[0084] In some embodiments, in step S102, determining the brightness of the backlight 2 corresponding to the display position according to the ambient visual brightness of the ambient space corresponding to the virtual image 400 includes:

[0085] S1021: Determine the theoretical brightness of the backlight 2 corresponding to the display position according to the ambient visual brightness;

[0086] S1022: Determine whether the theoretical brightness of the backlight 2 is less than or equal to the maximum brightness of the liquid crystal display screen 1 in the current state, wherein the maximum brightness is determined according to the maximum heat load allowed by the liquid crystal display screen 1 and the sunlight heat load currently received by the liquid crystal display screen 1;

[0087] S1023: If yes, adjust the brightness of the backlight 2 corresponding to the display position to the theoretical brightness.

[0088] In this embodiment, the ambient visual brightness of the environment space corresponding to the display position of the virtual image content can be detected by a camera, a light sensor, etc., and then the theoretical brightness of the backlight 2 corresponding to the virtual image content can be determined according to the ambient visual brightness. The theoretical brightness of the backlight 2 can make the brightness of the virtual image content corresponding to the backlight 2 match the ambient visual brightness. Then the theoretical brightness is compared with the maximum brightness of the backlight 2 allowed by the liquid crystal display screen 1 in the current state. If the theoretical brightness is less than or equal to the maximum brightness allowed by the backlight 2, the brightness of the backlight 2 is adjusted to the theoretical brightness. If the theoretical brightness is greater than the maximum brightness allowed by the backlight 2, the brightness of the backlight 2 can be adjusted within the range of [0, maximum brightness] according to the ambient brightness at the display position of the environment space where the virtual image content is located, for example, the brightness of the backlight 2 is adjusted to the maximum brightness. In this way, the liquid crystal display screen 1 can be protected, and the upper limit brightness that the backlight 2 can reach can be increased, so that the final brightness of the backlight 2 is more matched with the theoretical brightness, and the problem of insufficient brightness of the liquid crystal display screen 1 is solved.

[0089] In some embodiments, the method further comprises:

[0090] S201: Capturing an image of the environment in front of the vehicle by an image acquisition device;

[0091] S202: Analyze the environment image to obtain a first environment light brightness of the environment space, wherein the first environment light brightness is the brightness of the environment light perceived by the eye box area 300;

[0092] S203: collecting the second ambient light brightness of the environment where the vehicle is located through a sensor;

[0093] S204: Determine the ambient visual brightness of the ambient space according to the first ambient brightness and the second ambient light brightness.

[0094] In this embodiment, the environmental image in front of the vehicle can be collected by a camera installed on the vehicle, and then the environmental image is analyzed and processed to obtain a first ambient light brightness equivalent to the ambient light perceived by the user's eye box area 300; in addition, the second ambient light brightness of the environment can be collected by a sensor installed on the vehicle, and then the ambient visual brightness of the environmental space corresponding to the virtual image content is determined based on the first ambient light and the second ambient light brightness, so as to improve the accuracy of the determination of the ambient visual brightness. In this embodiment, when determining the ambient visual brightness, not only the second ambient light brightness detected by the sensor is used, but also the visual brightness changes caused by the colors of other environmental objects such as vehicles, obstacles, pedestrians, buildings, trees on the road, and the different reflective abilities of objects of different materials are taken into account.

[0095] In some implementations, when determining the ambient visual brightness, the target object in the image is identified based on the captured ambient image, and based on the identification result, it can be determined whether there is strong reflection in the user's line of sight (light reflected from the external environment to the eye box area 300). In the case of reflection, the determined ambient visual brightness will be brighter, which can improve the accuracy of the ambient visual brightness determination.

[0096] The control method of the vehicle and the head-up display device corresponds to the head-up display device in the above-mentioned embodiment. Any optional items in the head-up display device embodiment are also applicable to the embodiment of the control method of the vehicle and the head-up display device, which will not be repeated here.

[0097] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) by each other to form a technical solution.

Claims

1. A head-up display device, characterized in that: It includes an image source and a reflective imaging unit, wherein the image source is used to emit image light, and the reflective imaging unit is used to reflect the image light into the eye box area corresponding to the head-up display device, and the image source includes: LCD display; A plurality of backlights are installed on the back side of the liquid crystal display screen, and are used to provide backlight for the liquid crystal display screen so that the liquid crystal display screen emits the image light. The brightness of at least one of the plurality of backlights can be independently adjusted to reduce the heat received by the liquid crystal display screen from the backlight.

2. The head-up display device according to claim 1, characterized in that: The plurality of backlights are arranged in zones on the back side of the liquid crystal display screen, each zone includes at least one backlight, and each backlight corresponds to one or more pixels of the liquid crystal display screen.

3. The head-up display device according to claim 1, characterized in that: The image source further comprises a backlight circuit board, a plurality of the backlight lamps are mounted on the backlight circuit board, and at least one heat dissipation hole is provided on the backlight circuit board.

4. The head-up display device according to claim 3, characterized in that: The heat dissipation holes are filled with a heat-conducting medium, and the thermal resistance of the heat-conducting medium is smaller than the thermal resistance of the backlight circuit board.

5. The head-up display device according to claim 1, characterized in that: It also includes a controller connected to the image source, and the controller is configured to adjust the brightness of the backlight according to the ambient visual brightness of the ambient space corresponding to the virtual image formed by the head-up display device.

6. The head-up display device according to claim 5, characterized in that: The controller is also configured to determine the maximum brightness of the LCD screen in a current state according to the maximum heat load allowed by the LCD screen and the sunlight heat load currently received by the LCD screen.

7. A vehicle, characterized in that: A head-up display device comprising any one of claims 1 to 6.

8. A method for controlling a head-up display device, characterized in that: The head-up display device includes an image source and a reflective imaging unit, wherein the image source is used to emit image light, and the reflective imaging unit is used to reflect the image light into an eye box area corresponding to the head-up display device, wherein the image source includes a liquid crystal display screen and a plurality of backlights, wherein the plurality of backlights are installed on the back side of the liquid crystal display screen, and the control method includes: Determining a backlight corresponding to a display position of a virtual image content in a virtual image formed by the head-up display device; The brightness of the backlight corresponding to the display position is determined according to the ambient visual brightness of the ambient space corresponding to the virtual image, and the backlight that does not correspond to the display position is turned off.

9. The method according to claim 8, characterized in that Determining the brightness of a backlight corresponding to the display position according to the ambient visual brightness of the ambient space corresponding to the virtual image includes: Determining the theoretical brightness of the backlight corresponding to the display position according to the ambient visual brightness; Determine whether the theoretical brightness of the backlight is less than or equal to the maximum brightness of the LCD screen in the current state, wherein the maximum brightness is determined according to the maximum heat load allowed by the LCD screen and the sunlight heat load currently received by the LCD screen; If so, the brightness of the backlight corresponding to the display position is adjusted to the theoretical brightness.

10. The method according to claim 9, characterized in that The method further comprises: Collecting an image of the environment in front of the vehicle by an image acquisition device; Analyze the environment image to obtain a first environment light brightness of the environment space, wherein the first environment light brightness is the brightness of the environment light perceived by the eye box area; Collecting the second ambient light brightness of the environment where the vehicle is located by means of a sensor; The ambient visual brightness of the ambient space is determined according to the first ambient brightness and the second ambient light brightness.

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