Head-up display structure for preventing sunlight from flowing backwards and control method thereof

Abstract

The invention discloses a head-up display sunlight backflow prevention structure, which comprises an image generation unit, an optical element group, a windshield, an optical regulation and control module, an optical detection module and a control module which are arranged on a vehicle body, and is characterized in that the image generation unit is used for generating image information for projection, and the optical element group is used for projecting the image information for projection; the windshield is used for reflecting image information from the optical element group to form an observable virtual image, and the optical detection module is used for detecting direction information of external natural light entering the vehicle body from the outer side of the windshield; the optical regulation and control module is located in a light path between the optical element set and the windshield to regulate the propagation path of external natural light, and the control module is electrically connected with the optical detection module and the optical regulation and control module. The system can dynamically adapt to the incident direction of strong light, can accurately block backward sunlight through a total reflection principle, prevents the image generation unit from being damaged, and guarantees the stable operation of the system.

Description

Technical Field

[0001] This invention relates to the field of vehicle-mounted optical display technology, and in particular to a head-up display structure and control method for preventing backlighting. Background Technology

[0002] Head-up display (HUD) systems project driving information onto the windshield to create a virtual image, allowing drivers to access information without looking down, thus improving driving safety. However, strong external light can easily enter the system through the windshield, causing excessive heat generation in the image generation unit, affecting operational stability and even damaging components.

[0003] Existing technologies use infrared filters to block backlighting, but this results in a loss of image brightness and cannot balance protection effectiveness with display quality. Summary of the Invention

[0004] In order to solve the technical problems existing in the background art, the present invention proposes a head-up display anti-sunlight backflow structure and its control method.

[0005] This invention proposes a head-up display (HUD) structure and control method to prevent backlighting, comprising: an image generation unit, an optical element group, a windshield, an optical control module, a light detection module, and a control module mounted on the vehicle body. The image generation unit generates projectable image information, the optical element group projects the projectable image information, the windshield reflects the image information from the optical element group to form an observable virtual image, the light detection module detects the direction of external natural light entering the vehicle body from the outside of the windshield, the optical control module is located in the optical path between the optical element group and the windshield to adjust the propagation path of external natural light, and the control module is electrically connected to the light detection module and the optical control module respectively. The control module can control the optical control module to dynamically adjust its spatial angle based on the direction information of the natural light detected by the light detection module, so that at least part of the natural light is blocked by the optical control module, while the image information projected by the optical element group can pass through the optical control module.

[0006] Preferably, the vehicle body also includes an eye box, and the optical element group includes a primary reflector and a secondary curved reflector. After receiving the image information that can be projected generated by the image generation unit, the primary reflector reflects it to the secondary curved reflector, the secondary curved reflector then reflects the image information to the windshield, and the windshield then reflects the image information to the eye box.

[0007] Preferably, the optical control module includes a transparent baffle and an adjuster capable of driving the transparent baffle to move.

[0008] Preferably, the transparent baffle has a layered structure and includes at least a first material layer and a second material layer, wherein the refractive index of the first material layer is greater than that of the second material layer.

[0009] Preferably, the side of the transparent baffle facing the optical element assembly is coated with an anti-reflective film.

[0010] Preferably, the regulator includes a stepper motor and a two-dimensional rotary table connected to the output end of the stepper motor, and the transparent baffle is connected to the two-dimensional rotary table via a universal joint.

[0011] Preferably, the light detection module includes a CMOS image sensor installed inside the vehicle body, located below the windshield.

[0012] A control method for a head-up display anti-sunlight backflow structure, the control module's control method includes the following steps: S1: Obtain the strongest incident direction of external natural light through the light detection module; S2: Based on the incident direction, calculate the target angle of the optical control module required to make the natural light undergo total internal reflection at the optical control module, and ensure that the principal ray of the imaging light can be incident under transmission conditions. S3: Control the optical adjustment module to rotate to the target angle.

[0013] Preferably, in step S2, the control module can also access the vehicle bus to obtain vehicle position, attitude and time information, and integrate the solar azimuth angle predicted based on this information to calculate the target angle.

[0014] The present invention proposes a head-up display anti-sunlight backflow structure and its control method, the advantages of which are: 1. Dynamic active protection against backlighting: It can sense the direction of strong light in real time and dynamically adjust the angle of the optical control module. Through the principle of total internal reflection, it can accurately block backlighting, effectively avoid excessive temperature rise of the image generation unit, and ensure long-term stable operation of the system.

[0015] 2. Without relying on filters or low-reflection coatings, selective separation of backflow light blocking and imaging light transmission is achieved through optical path optimization, ensuring efficient transmission of imaging light without sacrificing display brightness and clarity.

[0016] 3. By integrating real-time detection and solar azimuth prediction data, the protection effect can be maintained even if the light detection module fails temporarily, adapting to complex driving lighting scenarios and improving the continuity of protection in extreme environments.

[0017] 4. The optical control module has a compact structure and can be directly integrated into the existing head-up display optical path without requiring significant changes to the original system architecture, thus reducing the cost of modification and application. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall optical path of a head-up display structure for preventing backflow of sunlight, as proposed in this invention. Figure 2 This is a schematic diagram illustrating the working principle of a transparent baffle for a head-up display anti-sunlight backflow structure proposed in this invention; Figure 3 This is a flowchart of a control method for a head-up display anti-sunlight backflow structure proposed in this invention. Detailed Implementation

[0019] refer to Figure 1-3 This invention proposes a head-up display (HUD) structure to prevent backlighting, comprising: an image generation unit 1 mounted on the vehicle body, an optical element group, a windshield 4, an optical control module, a light detection module, and a control module. The image generation unit 1 generates projectable image information, which is driving-related information required by the HUD system. The optical element group receives the image information output by the image generation unit 1 and reflects and transmits it for projection. The windshield 4 reflects the image information from the optical element group, forming a virtual image for the driver to observe. The light detection module continuously detects ambient natural light entering the vehicle body from outside the windshield 4, focusing on the incident direction of the ambient natural light. The optical control module is located in the optical path between the optical element group and the windshield 4 to adjust the propagation path of ambient natural light, selectively blocking backlighting. The control module is electrically connected to both the light detection module and the optical control module, serving as the core control unit for signal reception, data processing, and command execution.

[0020] The control module can generate corresponding control signals based on the direction information of natural light detected by the light detection module and transmit them to the optical control module to control the optical control module to dynamically adjust its spatial angle. Through this angle adjustment, at least part of the external natural light that may enter the image generation unit 1 in reverse is blocked by the optical control module and cannot continue to propagate along the light path to the image generation unit 1; at the same time, it ensures that the image information projected by the optical element group can pass smoothly through the optical control module, ensuring the smoothness of the image projection path.

[0021] The vehicle body also includes an "eyebox 5," which provides the head movement space within which the driver can observe a complete and clear virtual image. The optical element assembly includes a primary reflector 2 and a secondary curved reflector 3, which together form the optical path for reflecting and transmitting image information: after receiving the projectable image information generated by the image generation unit 1, the primary reflector 2 reflects it to the secondary curved reflector 3; the secondary curved reflector 3 reflects the received image information while simultaneously performing image magnification processing, and then reflects the processed image information to the windshield 4; the windshield 4 receives the image information and reflects it to the area of ​​the eyebox 5, allowing the driver to observe a clear virtual image within the eyebox 5 area.

[0022] The optical control module includes a transparent baffle 6 and an adjuster 7. The adjuster 7 is connected to the transparent baffle 6 and can drive the transparent baffle 6 to adjust the spatial angle.

[0023] The transparent baffle 6 has a layered structure and includes at least a first material layer M1 and a second material layer M2. The refractive index of the first material layer M1 is greater than that of the second material layer M2. Based on this difference in refractive index, when external natural light is incident on the interface between the two materials at a specific angle, the condition for total internal reflection can be met, causing the natural light to undergo total internal reflection at the interface, thereby blocking its continued propagation along the light path.

[0024] The transparent baffle 6 has an anti-reflective film 9 coated on the side facing the optical element group. The anti-reflective film 9 is used to reduce the reflection loss on the surface of the transparent baffle 6 during the transmission of image information and ensure the efficient transmission of imaging light.

[0025] The regulator 7 includes a stepper motor and a two-dimensional rotary table connected to the output of the stepper motor. The transparent baffle 6 is connected to the two-dimensional rotary table via a universal joint. The stepper motor receives control signals output from the control module and drives the two-dimensional rotary table to move. The two-dimensional rotary table can drive the transparent baffle 6 to rotate independently around mutually perpendicular X-axis and Y-axis, realizing multi-dimensional adjustment of the spatial angle of the transparent baffle 6 to adapt to natural light incident scenes from different directions.

[0026] The light detection module includes a CMOS image sensor 8 installed inside the vehicle body. The CMOS image sensor 8 is located below the windshield 4. Its detection field of view covers the natural light incident area that enters from the windshield 4 and may propagate to the optical element group. It can collect the light intensity distribution and incident direction information of natural light in the area in real time and transmit the collected information to the control module.

[0027] A control method for a head-up display anti-sunlight backflow structure, the control module's control method includes the following steps: S1: Obtain the strongest incident direction of external natural light through the light detection module; specifically, the light detection module continuously collects natural light signals within its detection field of view, identifies the natural light beam with the strongest light intensity through signal analysis and processing, determines the incident direction information of the strongest natural light, and then transmits the direction information to the control module.

[0028] S2: Based on the incident direction, calculate the target angle of the optical control module required for total internal reflection of natural light at the optical control module, and ensure that the principal ray of the imaging light can be incident under transmission conditions; the control module has a built-in optical path analysis algorithm, which, based on the incident direction of the strongest natural light, the material properties of the optical control module, and the current optical path parameters, solves the target angle for total internal reflection of the strongest natural light on the surface of the optical control module; at the same time, the algorithm verifies the incident angle of the principal ray of the imaging light projected by the optical element group when it is incident on the optical control module under this target angle, ensuring that the incident angle meets the transmission conditions and ensuring that the imaging light can pass through normally.

[0029] S3: Control the optical adjustment module to rotate to the target angle; the control module converts the calculated target angle into a corresponding control command and transmits it to the adjuster 7 of the optical adjustment module. The adjuster 7 drives the optical adjustment module to move according to the control command until it is adjusted to the target angle, completing the preparation to block the backflow of natural light; then, the light detection module continuously monitors the incident direction of natural light, and the control module executes steps S1 to S3 in a loop to realize the dynamic adaptation and adjustment of the angle of the optical adjustment module.

[0030] In step S2, the control module can also access the vehicle bus to obtain vehicle position, attitude, and time information, and integrate the solar azimuth angle predicted based on this information to calculate the target angle. Specifically, the control module reads the vehicle's GPS position, heading angle, real-time time, and vehicle attitude sensor information from the vehicle bus; based on the solar position calculation model, combined with the read vehicle position and time information, it calculates the theoretical solar azimuth angle and altitude angle; then, combined with the vehicle attitude information, it calculates the theoretical natural light incident direction; subsequently, the control module integrates the strongest natural light incident direction collected in real time by the light detection module with the above-mentioned theoretical incident direction for data complementarity verification; when the two information are consistent, the target angle is calculated based on the real-time detected incident direction; when the light detection module fails to detect due to obstruction or other reasons, it automatically switches to calculating the target angle based on the theoretical incident direction to ensure the continuity and reliability of the target angle calculation.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A head-up display anti-sunward backflow structure, characterized by, The application relates to an image generation unit (1), an optical element group, a windshield (4), an optical control module, a light detection module and a control module which are installed on a vehicle body, the image generation unit (1) is used for generating image information which can be projected, the optical element group is used for projecting the image information which can be projected, the windshield (4) is used for reflecting the image information from the optical element group to form a visible image, the light detection module is used for detecting the direction information of external natural light which enters the vehicle body from the outside of the windshield (4), the optical control module is located in the light path between the optical element group and the windshield (4) to adjust the propagation path of the external natural light, and the control module is electrically connected with the light detection module and the optical control module. The control module can control the optical control module to dynamically adjust the spatial angle of the optical control module based on the direction information of the natural light detected by the light detection module, so that at least part of the natural light is blocked by the optical control module, and meanwhile the image information projected by the optical element group can penetrate the optical control module. The vehicle body also has an eye box (5), the optical element group comprises a first mirror (2) and a second curved mirror (3), the first mirror (2) reflects the image information which can be projected generated by the image generation unit (1) to the second curved mirror (3), the second curved mirror (3) reflects the image information to the windshield (4), and the windshield (4) reflects the image information to the eye box (5). 2.The head-up display anti-sunlight backflow structure and control method thereof according to claim 1, wherein, The optical control module comprises a transparent shield (6) and an adjuster (7) which can drive the transparent shield (6) to move. 3.The head-up display anti-sunlight backflow structure and control method thereof according to claim 1, wherein, The transparent shield (6) has a laminated structure and comprises at least a first material layer and a second material layer, the refractive index of the first material layer is greater than that of the second material layer.

4. The head-up display anti-sunlight backflow structure according to claim 3, characterized in that, The side of the transparent shield (6) facing the optical element group is coated with an anti-reflection film (9).

5. The head-up display anti-sunlight backflow structure according to claim 4, characterized in that, The adjuster (7) comprises a stepping motor and a two-dimensional rotating table connected with the output end of the stepping motor, and the transparent shield (6) is connected with the two-dimensional rotating table through a universal joint. 6.The head-up display anti-sunlight backflow structure and control method thereof according to claim 3, wherein, The light detection module comprises a CMOS image sensor (8) installed in the interior of the vehicle body, and the CMOS image sensor (8) is located below the windshield (4).

7. The head-up display anti-sunlight backflow structure according to claim 1, characterized in that, The control method of the control module comprises the following steps:

8. A control method for the head-up display anti-sunlight backflow structure according to any one of claims 1 to 7, characterized in that, S1: acquiring the incident direction of the external natural light with the strongest intensity through the light detection module; S2: calculating the target angle of the optical control module required for making the natural light totally reflect at the optical control module according to the incident direction, and ensuring that the chief ray of the imaging light can be incident in the transmission condition; S3: controlling the optical control module to rotate to the target angle. In the step S2, the control module can also access the vehicle bus to acquire the vehicle position, posture and time information, and fuse the solar azimuth angle predicted based on the information to calculate the target angle.

9. The control method of the head-up display anti-sunlight backflow structure according to claim 8, characterized by, ​

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