Brightness adjusting method of head-up display and head-up display system

Abstract

The invention provides a brightness adjusting method of a head-up display and a head-up display system, which can adjust the angle of an illuminance sensor when the virtual image height of the head-up display (imaging unit) changes, ensure that the target area (detection area) of the illuminance sensor is aligned with the virtual image background area of the head-up display (imaging unit), and improve the brightness of the head-up display (imaging unit). And the illuminance sensor can accurately obtain the illuminance of the virtual image background area. The brightness of the head-up display (imaging unit) is adjusted according to the illuminance of the virtual image background area, so that the brightness of the head-up display (imaging unit) and the brightness of the virtual image background area can be basically kept consistent, a driver can be ensured to enjoy comfortable visual experience, and visual fatigue caused by uncomfortable brightness is reduced.

Description

Technical Field

[0001] The present invention generally relates to the field of brightness adjustment of a head-up display, and in particular to a brightness adjustment method of a head-up display and a head-up display system. Background Art

[0002] Head-up display (HUD), also known as head-up display, was originally designed as a display system for military fighter jets to help pilots view key information at any time during flight. In recent years, automotive head-up display technology has gradually matured, and can project important driving information such as speed and navigation directly onto the windshield in front of the driver. This design allows drivers to obtain the required information without lowering their heads, effectively reducing cognitive load and significantly improving driving safety.

[0003] The virtual image brightness adjustment of the head-up display is crucial to ensure the driver's visual experience. To ensure that the driver can enjoy a comfortable visual experience, the head-up display must be able to sense changes in the external ambient light and automatically adjust the virtual image brightness to ensure that the display content (virtual image) of the head-up display matches the background (environment) brightness to avoid the virtual image being too bright or too dark. In addition, considering the height differences between different drivers, the head-up display generally provides multiple virtual image height gears to meet the observation needs of drivers of different heights. When adjusting the virtual image height gear, the background area of ​​the real world corresponding to the virtual image will also change accordingly, which may cause the brightness of the virtual image to differ from the brightness of the virtual image background area, thereby affecting the driver's visual experience.

[0004] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the prior art in the field. Summary of the invention

[0005] In view of one or more defects in the prior art, the present invention provides a brightness adjustment method for a head-up display, the brightness adjustment method comprising:

[0006] Obtaining a virtual image height of the head-up display;

[0007] According to the virtual image height, adjusting the angle of the light illumination sensor so that the target area of ​​the light illumination sensor is aligned with the virtual image background area of ​​the head-up display;

[0008] Acquiring the illuminance of the virtual image background area by means of the illuminance sensor; and

[0009] The brightness of the head-up display is adjusted according to the illumination of the virtual image background area.

[0010] According to one aspect of the present invention, the step of obtaining the virtual image height of the head-up display comprises:

[0011] Receiving height adjustment instructions input from outside;

[0012] determining a virtual image height of a head-up display according to the height adjustment instruction and the first relationship; and

[0013] The first relationship is a corresponding relationship between the height adjustment instruction and the virtual image height.

[0014] According to one aspect of the present invention, the step of obtaining the virtual image height of the head-up display comprises:

[0015] Get the user's image;

[0016] Performing eye detection on the image to determine the eye position of the user; and

[0017] The height of the virtual image of the head-up display is determined based on the user's eye position.

[0018] According to one aspect of the present invention, the step of adjusting the angle of the light intensity sensor according to the virtual image height comprises:

[0019] determining an angle of a light intensity sensor according to the virtual image height and the second relationship;

[0020] The second relationship is a corresponding relationship between the virtual image height and the angle of the light intensity sensor.

[0021] According to one aspect of the present invention, the step of adjusting the angle of the light intensity sensor according to the virtual image height comprises:

[0022] Determining imaging parameters of the head-up display according to the virtual image height and a third relationship, wherein the third relationship is a corresponding relationship between the virtual image height and the imaging parameters;

[0023] The angle of the light intensity sensor is determined according to the imaging parameters of the head-up display.

[0024] According to one aspect of the present invention, the imaging parameters include a projection distance, coordinates of an observation point, and a lower viewing angle and a left viewing angle based on the observation point.

[0025] According to one aspect of the present invention, the step of determining the angle of the light intensity sensor according to the imaging parameters of the head-up display comprises:

[0026] Determining the position of the reference point of the virtual image background area according to the imaging parameters of the head-up display;

[0027] The angle of the light intensity sensor is determined according to the position of the reference point of the virtual image background area and the position of the light intensity sensor.

[0028] According to one aspect of the present invention, the position P of the reference point of the virtual image background area is determined according to the following formula: center :

[0029]

[0030] Among them, x center is the x-axis coordinate of the reference point of the virtual image background area, y center is the y-axis coordinate of the reference point of the virtual image background area, z center is the z-axis coordinate of the reference point of the virtual image background area, x eye is the x-axis coordinate of the observation point, y eye is the y-axis coordinate of the observation point, z eye is the z-axis coordinate of the observation point, VID is the projection distance of the head-up display, θ LDA is the downward viewing angle based on the observation point, θ LOA is the left perspective based on the observation point.

[0031] According to one aspect of the present invention, the rotation angle θ of the light intensity sensor relative to the y-axis is determined according to the following formula: y :

[0032]

[0033] The rotation angle θ of the light sensor relative to the z-axis is determined according to the following formula: z :

[0034]

[0035] Among them, x center is the x-axis coordinate of the reference point of the virtual image background area, y center is the x-axis coordinate of the reference point of the virtual image background area, y center is the z-axis coordinate of the reference point of the virtual image background area, x sensor is the x-axis coordinate of the light sensor, y sensor is the y-axis coordinate of the light sensor, z sensor is the z-axis coordinate of the light sensor.

[0036] An embodiment of the present invention further provides a head-up display system, comprising:

[0037] Imaging unit;

[0038] an adjustable light level sensor configured to detect a light level in a target area; and

[0039] A control unit is coupled to the imaging unit and the light illumination sensor respectively, and the control unit is configured to: obtain the virtual image height of the imaging unit; adjust the angle of the light illumination sensor according to the virtual image height so that the target area of ​​the light illumination sensor is aligned with the virtual image background area of ​​the imaging unit; and adjust the brightness of the imaging unit according to the illumination of the virtual image background area.

[0040] According to one aspect of the present invention, the head-up display system further comprises a human-machine interaction interface, wherein the human-machine interaction interface is configured to output a height adjustment instruction in response to an external operation;

[0041] The control unit is coupled to the human-computer interaction interface, and the control unit is configured to: receive a height adjustment instruction input from the outside, and determine the virtual image height of the imaging unit according to the height adjustment instruction and a first relationship, wherein the first relationship is the corresponding relationship between the height adjustment instruction and the virtual image height.

[0042] According to one aspect of the present invention, the head-up display system further includes:

[0043] a camera configured to capture an image of a user; and

[0044] A human eye recognition module, coupled to the camera and the control unit respectively, and configured to perform human eye detection on the image to determine the eye position of the user;

[0045] Wherein, the control unit is configured to determine the virtual image height of the imaging unit according to the user's eye position.

[0046] According to one aspect of the present invention, the control unit is configured to determine the angle of the light intensity sensor according to the virtual image height and the second relationship;

[0047] The second relationship is a corresponding relationship between the virtual image height and the angle of the light intensity sensor.

[0048] According to one aspect of the present invention, the control unit is configured as:

[0049] Determining imaging parameters of the imaging unit according to the virtual image height and a third relationship, wherein the third relationship is a corresponding relationship between the virtual image height and the imaging parameter;

[0050] The angle of the light illumination sensor is determined according to the imaging parameters of the imaging unit.

[0051] Compared with the prior art, the embodiments of the present invention provide a head-up display brightness adjustment method and head-up display system, which can adjust the angle of the light illuminance sensor when the height of the virtual image of the head-up display (imaging unit) changes, ensure that the target area (detection area) of the light illuminance sensor is aligned with the virtual image background area of ​​the head-up display (imaging unit), and enable the light illuminance sensor to accurately obtain the illuminance of the virtual image background area. According to the illuminance of the virtual image background area, the brightness of the head-up display (imaging unit) is adjusted, so that the brightness of the head-up display (imaging unit) and the brightness of the virtual image background area are basically consistent, which is conducive to ensuring that the driver enjoys a comfortable visual experience and reducing visual fatigue caused by brightness discomfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0053] Figure 1 A flow chart showing a method for adjusting brightness of a head-up display according to an embodiment of the present invention is shown;

[0054] Figure 2 A schematic diagram of an application scenario of a head-up display according to an embodiment of the present invention is shown;

[0055] Figure 3 A schematic diagram showing a virtual image background area according to an embodiment of the present invention is shown;

[0056] Figure 4 A schematic diagram showing a light intensity sensor sensing the light intensity of a target area according to an embodiment of the present invention is shown;

[0057] Figure 5 A schematic diagram of a head-up display system according to an embodiment of the present invention is shown;

[0058] Figure 6 A schematic diagram of a head-up display system according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0059] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0060] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0061] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.

[0063] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0064] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0065] Figure 1 FIG. 1 is a flow chart showing a method 100 for adjusting brightness of a head-up display according to an embodiment of the present invention. Figure 1 As shown, the brightness adjustment method 100 includes the following steps, and each step is described in detail below.

[0066] In step S110: the virtual image height of the head-up display is obtained.

[0067] Figure 2 FIG. 4 shows a schematic diagram of an application scenario of a head-up display according to an embodiment of the present invention. Figure 2 As shown, in the vehicle scene, a head-up display is provided below the front windshield to project a virtual image to a specific area in front of the driver, such as vehicle speed, navigation information, etc. The head-up display has multiple virtual image height levels ( Figure 2 The virtual image height of the head-up display can be characterized by the virtual image height gear, and different virtual image height gears correspond to different virtual image heights. The user can change the virtual image height by adjusting the virtual image height gear, so that the virtual image of the head-up display matches the driver's eye position, ensuring that the driver can see a clear and complete image. A light intensity sensor is also provided in the vehicle for sensing the light intensity outside the vehicle, such as sensing the light intensity of a target area. The light intensity sensor can be provided independently of the head-up display, or it can be integrated in the head-up display.

[0068] In some embodiments, the virtual image height gear of the head-up display is currently stored in a storage module of the head-up display, and the virtual image height gear (virtual image height) of the head-up display can be obtained by reading the storage module. It should be noted that the virtual image height and the virtual image height gear are in a one-to-one correspondence. In some embodiments, the virtual image height can be adjusted by adjusting the virtual image height gear of the head-up display. Therefore, obtaining the virtual image height gear is to obtain the virtual image height.

[0069] In other embodiments, the head-up display adjusts the virtual image height level according to the height adjustment instruction input by the user, and there is a one-to-one correspondence relationship (first relationship) between the height adjustment instruction and the virtual image height level, and the first relationship can be specifically expressed as a mapping table, which lists all height adjustment instructions and specifies the corresponding virtual image height level for each height adjustment instruction. Therefore, the height adjustment instruction input from the outside can be received, and the virtual image height level (virtual image height) currently in the head-up display can be determined according to the height adjustment instruction and the first relationship.

[0070] In some other embodiments, a camera is provided in the vehicle, and the camera can be provided independently of the head-up display or integrated in the head-up display. The image of the user (driver) can be acquired through the camera, and the image can be analyzed using human eye detection technology to determine the user's eye position (including eye height). There is a preset correspondence between the virtual image height level of the head-up display and the user's eye position, for example: each virtual image height level corresponds to a specific eye position range, the eye position range is also called an eyebox, and the eye position range can cover one or more eye positions. After the user's eye position is determined, the virtual image height level (virtual image height) corresponding to the user's eye position can be determined by querying the correspondence.

[0071] In step S120 : according to the height of the virtual image, the angle of the light intensity sensor is adjusted so that the target area of ​​the light intensity sensor is aligned with the virtual image background area of ​​the head-up display.

[0072] Figure 3 FIG. 4 is a schematic diagram showing a virtual image background area according to an embodiment of the present invention. Figure 3 As shown, the virtual image background area of ​​the head-up display can be understood as a perspective projection quadrangular pyramid area formed by the observation point and the far plane. Among them, the observation point refers to the spatial position of the user (driver)'s eyes when observing the virtual image projected by the head-up display. The far plane refers to the area corresponding to the virtual image projected by the head-up display at the farthest display distance.

[0073] Figure 4A schematic diagram showing a light intensity sensor sensing the light intensity of a target area according to an embodiment of the present invention is shown. Figure 2 and Figure 4 As shown in the figure, the angle of the sensor can be understood as the installation angle of the sensor in space. Figure 2 and Figure 4 , y, z are shown in the figure. In the vehicle scene, the three-dimensional rectangular coordinate system can be a vehicle coordinate system, where the origin is the center of mass of the vehicle or the midpoint of the rear axle, the x-axis is the front-to-back direction of the vehicle, the y-axis is the left-to-right direction of the vehicle, and the z-axis is the vertical direction of the vehicle. In the three-dimensional rectangular coordinate system, the angle of the light sensor can be expressed by three Euler angles, which are the rotation angle θ of the light sensor relative to the x-axis. x , the rotation angle θ of the light sensor relative to the y-axis y and the rotation angle θ of the light sensor relative to the z-axis z . Rotation angle θ x ,θ y ,θ z Together they define the orientation of the light sensor in space, thereby determining its detection direction. In a specific implementation, the rotation angle θ of the light sensor can be adjusted y ,θ z , the detection direction of the light intensity sensor is adjusted so that the target area of ​​the light intensity sensor is aligned with the virtual image background area of ​​the head-up display.

[0074] In some embodiments, the angle of the light sensor can be determined according to the virtual image height level (virtual image height) and the second relationship. The second relationship refers to the correspondence between the virtual image height level (virtual image height) and the angle of the light sensor. The correspondence can be a mapping table that maps different virtual image height levels (virtual image heights) to the angle of the light sensor (for example, the rotation angle θ y ,θ z After determining the virtual image height gear (virtual image height) of the head-up display, the corresponding angle of the illumination sensor can be determined by querying the mapping table (second relationship).

[0075] In other embodiments, the imaging parameters of the head-up display may be determined according to the virtual image height level (virtual image height) and the third relationship; the angle θ of the light intensity sensor may be determined according to the imaging parameters of the head-up display. y ,θ z .

[0076] The imaging parameters may include the coordinates of the observation point, the projection distance, and the downward and left viewing angles based on the observation point. The imaging parameters may also include the field of view, etc. The projection distance refers to the distance between the center of the virtual image (the center point of the virtual image projected by the head-up display) and the observation point. The downward viewing angle based on the observation point refers to the distance between the line connecting the observation point and the center of the virtual image and the horizontal plane (e.g. Figure 4 The left viewing angle based on the observation point refers to the angle between the line connecting the observation point and the center of the virtual image and the vertical plane (e.g. Figure 4 The third relationship refers to the correspondence between the virtual image height level (virtual image height) and the imaging parameters. The correspondence may be a mapping table that corresponds different virtual image height levels (virtual image heights) to various imaging parameters. After determining the virtual image height level (virtual image height) of the head-up display, the various imaging parameters corresponding thereto may be determined by querying the mapping table (third relationship).

[0077] The position of the reference point of the virtual image background area can be calculated according to the imaging parameters of the head-up display. The reference point of the virtual image background area can be the center point of the virtual image projected by the head-up display, or it can be other points in the virtual image background area. The following description takes the reference point as the center point of the virtual image projected by the head-up display as an example. In a specific embodiment, the position P of the reference point of the virtual image background area can be calculated by the following formula: center :

[0078]

[0079] In the formula, x center is the x-axis coordinate of the reference point of the virtual image background area, y center is the y-axis coordinate of the reference point of the virtual image background area, z center is the z-axis coordinate of the reference point of the virtual image background area, x eye is the x-axis coordinate of the observation point, y eye is the y-axis coordinate of the observation point, z eye is the z-axis coordinate of the observation point, VID is the projection distance of the head-up display, θ LDA is the downward viewing angle based on the observation point, θ LOA is the left perspective based on the observation point.

[0080] The angle θ of the light sensor can be calculated based on the position of the reference point in the virtual image background area and the position of the light sensor. y ,θ z In a specific implementation, the coordinates of the light intensity sensor are known, for example: the x-axis coordinate of the light intensity sensor is x sensor , the y-axis coordinate is y sensor , the z-axis coordinate is z sensorThe angle θ of the light sensor can be calculated by the following formula y ,θ z :

[0081]

[0082] After determining the angle of the light sensor corresponding to the virtual image height gear (virtual image height) of the head-up display, the light sensor can be adjusted using a mechanical device such as a turntable to adjust the light sensor to the angle so that the target area of ​​the light sensor is aligned with the virtual image background area of ​​the head-up display. This enables the light sensor to accurately obtain the light intensity of the virtual image background area to optimize the display effect.

[0083] In step S130: the illuminance of the virtual image background area is acquired by a illuminance sensor.

[0084] In step S140: the brightness of the head-up display is adjusted according to the illumination of the virtual image background area.

[0085] In a specific implementation, the illuminance sensor can sense the illuminance of the virtual image background area at a fixed time interval Δt1. Correspondingly, the brightness of the head-up display can be adjusted at the time interval Δt1, and the time interval Δt1 is, for example, 0.1 second, 0.2 second, 0.5 second, 1 second, 2 seconds or a longer time interval.

[0086] In some embodiments, there is a preset corresponding relationship (fourth relationship) between the illuminance of the virtual image background area and the brightness of the head-up display. For example, the brightness of the head-up display can be represented by a brightness level, and each brightness level of the head-up display corresponds to a specific illuminance range, which can be a point value or an interval range. Whenever the illuminance sensor senses the illuminance of the virtual image background area, the brightness (brightness level) of the head-up display corresponding to the illuminance of the virtual image background area can be determined by querying the corresponding relationship (fourth relationship).

[0087] In other embodiments, the effective ambient light illumination at the current moment can be calculated based on the illumination of the virtual image background area sensed by the illumination sensor at the current moment t0 and one or more previous moments (for example, t0-△t1 moment, t0-2△t1 moment, ..., t0-n△t1 moment). For example, the mean or median of the illumination of the virtual image background area sensed at these moments (t0 moment, t0-△t1 moment, ..., t0-n△t1 moment) can be used as the effective ambient light illumination at the current moment. There is a preset corresponding relationship (fifth relationship) between the effective ambient light illumination and the brightness of the head-up display. For example, each brightness level of the head-up display corresponds to a specific effective ambient light illumination range, which can be a point value or an interval range. After determining the effective ambient light illumination at the current moment, the brightness (brightness level) of the head-up display corresponding to the effective ambient light illumination at the current moment can be determined by querying the corresponding relationship (fifth relationship).

[0088] In a specific embodiment, after determining the brightness (brightness level) of the head-up display corresponding to the illuminance (effective illuminance) of the virtual image background area, the head-up display can be adjusted to the brightness (brightness level) by adjusting the luminous power of the backlight module of the head-up display. This brightness adjustment can be done instantly to quickly respond to changes in ambient light, or it can be gradual to provide a smooth visual transition and avoid interference to the user due to sudden changes in brightness. Whether it is instantaneous or gradual adjustment, the purpose is to ensure that users can enjoy a comfortable and clear display effect under different lighting conditions.

[0089] Compared with the prior art, the embodiment of the present invention provides a method 100 for adjusting the brightness of a head-up display, which can adjust the angle of the light illuminance sensor when the height of the virtual image of the head-up display changes, so as to ensure that the target area (detection area) of the light illuminance sensor is aligned with the virtual image background area of ​​the head-up display (imaging unit), so that the light illuminance sensor can accurately obtain the illuminance of the virtual image background area. According to the illuminance of the virtual image background area, the brightness of the head-up display is adjusted, so that the brightness of the head-up display (virtual image brightness) and the brightness of the virtual image background area are basically consistent, which is conducive to ensuring that the driver enjoys a comfortable visual experience and reducing visual fatigue caused by brightness discomfort.

[0090] Figure 5 A schematic diagram of a head-up display system 200 according to an embodiment of the present invention is shown below. Figure 5 Describe in detail.

[0091] like Figure 5As shown, the head-up display system 200 includes an imaging unit 210, an illuminance sensor 220 and a control unit 230. Among them, the imaging unit 210 is configured to project a virtual image to a specific area, for example, including vehicle speed, navigation information, etc. The imaging unit 210 has a plurality of virtual image height gears, and the virtual image height of the imaging unit 210 can be characterized by the virtual image height gear, and different virtual image height gears correspond to different virtual image heights. The user can change the virtual image height by adjusting the virtual image height gear, so that the virtual image of the imaging unit 210 matches the driver's eye position, ensuring that the driver can see a clear and complete image. The illuminance sensor 220 is configured to detect the illuminance of the target area, and the angle of the illuminance sensor 220 is adjustable. By adjusting the angle of the illuminance sensor 220, the detection direction and detection area of ​​the illuminance sensor 220 can be changed. The control unit 230 is coupled to the imaging unit 210 and the light illuminance sensor 220 respectively, and the control unit 230 is configured to obtain the virtual image height of the imaging unit 210; the angle of the light illuminance sensor 220 can be adjusted according to the virtual image height of the imaging unit 210 so that the target area of ​​the light illuminance sensor 220 is aligned with the virtual image background area of ​​the imaging unit 210; the brightness of the imaging unit 210 can be adjusted according to the illumination of the virtual image background area.

[0092] According to one embodiment of the present invention, Figure 5 As shown, the head-up display system 200 may also include a human-machine interaction interface 240, which may be a graphical user interface, a voice user interface, a physical button, a physical knob, etc. The human-machine interaction interface 240 is configured to recognize and output a height adjustment instruction in response to an external operation (e.g., a voice instruction, a pressing action, a rotating action, etc.). There is a one-to-one correspondence relationship (a first relationship) between the height adjustment instruction and the virtual image height gear, and the first relationship may be specifically expressed as a mapping table, which lists all height adjustment instructions and specifies the corresponding virtual image height gear for each height adjustment instruction. The control unit 230 is coupled to the human-machine interaction interface 240, and the control unit 230 is configured to receive the height adjustment instruction and determine the virtual image height of the imaging unit 210 according to the height adjustment instruction and the first relationship. In some embodiments, the current virtual image height (virtual image height gear) of the imaging unit 210 is stored in a storage module of the imaging unit 210, and the control unit 230 may obtain the current virtual image height (virtual image height gear) of the imaging unit 210 by reading the storage module.

[0093] According to one embodiment of the present invention, Figure 5As shown, the control unit 230 can be configured to determine the angle of the light illumination sensor 220 according to the virtual image height gear (virtual image height) of the imaging unit 210 and the second relationship, wherein the second relationship refers to the correspondence between the virtual image height gear (virtual image height) and the angle of the light illumination sensor 220, and the correspondence can be a mapping table, which corresponds different virtual image height gears (virtual image heights) to the angle of the light illumination sensor 220. After determining the virtual image height gear (virtual image height) currently located by the imaging unit 210, the corresponding angle of the light illumination sensor 220 can be determined by querying this mapping table (second relationship). In other embodiments, the control unit 230 can also be configured to determine the imaging parameters of the imaging unit 210 according to the virtual image height gear (virtual image height) and the third relationship; the angle of the light illumination sensor 220 can be determined according to the imaging parameters of the imaging unit 210. The third relationship refers to the correspondence between the virtual image height level (virtual image height) and the imaging parameters, and the correspondence may be a mapping table, which corresponds different virtual image height levels (virtual image heights) to various imaging parameters. After determining the virtual image height level (virtual image height) currently in which the imaging unit 210 is located, the various imaging parameters corresponding thereto may be determined by querying the mapping table (third relationship).

[0094] According to one embodiment of the present invention, the light intensity sensor 220 can be arranged on a mechanical device such as a turntable. The control unit 230 is configured to control the mechanical device such as a turntable to adjust the posture (angle) of the light intensity sensor 220 so that the target area of ​​the light intensity sensor 220 is aligned with the virtual image background area of ​​the imaging unit 210.

[0095] According to one embodiment of the present invention, Figure 5As shown, the illuminance sensor 220 is configured to sense the illuminance of the virtual image background area at a fixed time interval △t1. The control unit 230 is configured to adjust the brightness of the imaging unit 210 at the time interval △t1. Specifically, there is a preset corresponding relationship (fourth relationship) between the illuminance of the virtual image background area and the brightness of the imaging unit 210. For example, the brightness of the imaging unit 210 can be represented by a brightness level, and each brightness level of the imaging unit 210 corresponds to a specific illuminance range, which can be a point value or an interval range. The control unit 230 is configured to determine the brightness (brightness level) of the imaging unit 210 corresponding to the illuminance of the virtual image background area according to the illuminance of the virtual image background area at the current moment and the fourth relationship, and output a brightness adjustment signal to the imaging unit 210 to control the imaging unit 210 to adjust to the brightness (brightness level). In other embodiments, the control unit 230 is configured to calculate the effective ambient light illumination at the current moment according to the illumination of the virtual image background area sensed by the illumination sensor 220 at the current moment t0 and one or more previous moments (for example, moment t0-△t1, moment t0-2△t1, ..., moment t0-n△t1). The control unit 230 is also configured to determine the brightness (brightness level) of the imaging unit 210 corresponding to the effective ambient light illumination at the current moment according to the effective ambient light illumination at the current moment and the fifth relationship, and output a brightness adjustment signal to the imaging unit 210 to control the imaging unit 210 to adjust to the brightness (brightness level). Among them, the fifth relationship is the corresponding relationship between the effective ambient light illumination and the brightness of the imaging unit 210, for example: each brightness level of the imaging unit 210 corresponds to a specific effective ambient light illumination range, and the effective ambient light illumination range can be a point value or an interval range.

[0096] Figure 6 A schematic diagram of a head-up display system 300 according to another embodiment of the present invention is shown. Figure 6As shown, the head-up display system 300 also includes an imaging unit 310, an illuminance sensor 320 and a control unit 330, wherein the imaging unit 310, the illuminance sensor 320 and the control unit 330 can adopt the same or similar structure and function as the corresponding structure (device) in the head-up display system 200, which will not be repeated here. The head-up display system 300 also includes a camera 340 and a human eye recognition module 350, wherein the camera 340 is configured to capture an image of a user (driver). The human eye recognition module 350 is coupled to the camera 340, and the human eye recognition module 350 is configured to perform human eye detection on the image to determine the user's eye position. The control unit 330 is coupled to the human eye recognition module 350, and the control unit 330 is configured to determine the virtual image height of the imaging unit 310 according to the user's eye position. Specifically, there is a preset correspondence between the virtual image height (virtual image height level) of the imaging unit 310 and the eye position of the user, for example, each virtual image height level corresponds to a specific eye position range, the eye position range is also called an eyebox, and the eye position range may cover one or more eye positions. After the eye position of the user is determined, the virtual image height level (virtual image height) corresponding to the eye position of the user may be determined by querying the correspondence.

[0097] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for adjusting brightness of a head-up display, the method comprising: Obtaining a virtual image height of the head-up display; According to the virtual image height, adjusting the angle of the light illumination sensor so that the target area of ​​the light illumination sensor is aligned with the virtual image background area of ​​the head-up display; Acquiring the illuminance of the virtual image background area by means of the illuminance sensor; and The brightness of the head-up display is adjusted according to the illumination of the virtual image background area.

2. The brightness adjustment method according to claim 1, wherein: The step of obtaining the virtual image height of the head-up display comprises: Receiving height adjustment instructions input from outside; determining a virtual image height of a head-up display according to the height adjustment instruction and the first relationship; and The first relationship is a corresponding relationship between the height adjustment instruction and the virtual image height.

3. The brightness adjustment method according to claim 1, wherein: The step of obtaining the virtual image height of the head-up display comprises: Get the user's image; Performing eye detection on the image to determine the eye position of the user; and The height of the virtual image of the head-up display is determined based on the user's eye position.

4. The brightness adjustment method according to claim 1, wherein: The step of adjusting the angle of the light intensity sensor according to the virtual image height comprises: determining an angle of a light intensity sensor according to the virtual image height and the second relationship; The second relationship is a corresponding relationship between the virtual image height and the angle of the light intensity sensor.

5. The brightness adjustment method according to claim 4, wherein: The step of adjusting the angle of the light intensity sensor according to the virtual image height comprises: Determining imaging parameters of the head-up display according to the virtual image height and a third relationship, wherein the third relationship is a corresponding relationship between the virtual image height and the imaging parameters; The angle of the light intensity sensor is determined according to the imaging parameters of the head-up display.

6. The brightness adjustment method according to claim 5, wherein: The imaging parameters include a projection distance, coordinates of an observation point, and a lower viewing angle and a left viewing angle based on the observation point.

7. The brightness adjustment method according to claim 5, wherein: The step of determining the angle of the light intensity sensor according to the imaging parameters of the head-up display comprises: Determining the position of the reference point of the virtual image background area according to the imaging parameters of the head-up display; The angle of the light intensity sensor is determined according to the position of the reference point of the virtual image background area and the position of the light intensity sensor.

8. The brightness adjustment method according to claim 7, wherein: The position P of the reference point of the virtual image background area is determined according to the following formula center : Among them, x center is the x-axis coordinate of the reference point of the virtual image background area, y center is the y-axis coordinate of the reference point of the virtual image background area, z center is the z-axis coordinate of the reference point of the virtual image background area, x eye is the x-axis coordinate of the observation point, y eye is the y-axis coordinate of the observation point, z eye is the z-axis coordinate of the observation point, VID is the projection distance of the head-up display, θ LDA is the downward viewing angle based on the observation point, θ LOA is the left perspective based on the observation point.

9. The brightness adjustment method according to claim 7, wherein: The rotation angle θ of the light sensor relative to the y-axis is determined according to the following formula: y : The rotation angle θ of the light sensor relative to the z-axis is determined according to the following formula: z : Among them, x center is the x-axis coordinate of the reference point of the virtual image background area, y center is the x-axis coordinate of the reference point of the virtual image background area, y center is the z-axis coordinate of the reference point of the virtual image background area, x sensor is the x-axis coordinate of the light sensor, y sensor is the y-axis coordinate of the light sensor, z sensor is the z-axis coordinate of the light sensor.

10. A head-up display system, comprising: Imaging unit; an adjustable light level sensor configured to detect a light level in a target area; and A control unit is coupled to the imaging unit and the light illumination sensor respectively, and the control unit is configured to: obtain the virtual image height of the imaging unit; adjust the angle of the light illumination sensor according to the virtual image height so that the target area of ​​the light illumination sensor is aligned with the virtual image background area of ​​the imaging unit; and adjust the brightness of the imaging unit according to the illumination of the virtual image background area.

11. The head-up display system according to claim 10, wherein: The head-up display system further includes a human-machine interaction interface configured to output a height adjustment instruction in response to an external operation; The control unit is coupled to the human-computer interaction interface, and the control unit is configured to: receive a height adjustment instruction input from the outside, and determine the virtual image height of the imaging unit according to the height adjustment instruction and a first relationship, wherein the first relationship is the corresponding relationship between the height adjustment instruction and the virtual image height.

12. The head-up display system according to claim 10, wherein: The head-up display system further includes: a camera configured to capture an image of a user; and A human eye recognition module, coupled to the camera and the control unit respectively, and configured to perform human eye detection on the image to determine the eye position of the user; Wherein, the control unit is configured to determine the virtual image height of the imaging unit according to the user's eye position.

13. The head-up display system according to claim 10, wherein: The control unit is configured to determine an angle of the light intensity sensor according to the virtual image height and a second relationship; The second relationship is a corresponding relationship between the virtual image height and the angle of the light intensity sensor.

14. The head-up display system according to claim 10, wherein: The control unit is configured as follows: Determining imaging parameters of the imaging unit according to the virtual image height and a third relationship, wherein the third relationship is a corresponding relationship between the virtual image height and the imaging parameter; The angle of the light illumination sensor is determined according to the imaging parameters of the imaging unit.

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