A head-up display system and a control method thereof

Abstract

The application provides a head-up display system and a control method thereof, wherein the head-up display system comprises a head-up display device, the head-up display device comprises: a first image source, emitting a P-polarized light beam; a second image source, emitting an S-polarized light beam; and a beam combining element, located on the propagation path of the P-polarized light beam and the S-polarized light beam, and combining the P-polarized light beam and the S-polarized light beam into a coaxial light beam which propagates coaxially. The head-up display system provided by the embodiment of the application can realize accurate polarization brightness compensation, low heat dissipation and over-temperature prevention.

Description

Technical Field

[0001] This invention relates to the field of head-up display technology, and more particularly to a head-up display system and its control method. Background Technology

[0002] In-vehicle head-up display (HUD) technology projects driving information such as vehicle speed, navigation, and vehicle condition warnings onto the driver's field of vision, blending it with the external road scene to effectively improve driving safety and the intelligent driving experience. However, existing conventional in-vehicle HUD imaging solutions have the following significant technical defects: the Brewster angle of the windshield causes a decrease in the brightness of P-polarized light. The fixed installation angle of the windshield means that the incident angle of the imaging beam from the HUD system easily approaches the Brewster angle, resulting in a significant decrease in the reflectivity of P-polarized light in the optical path. This ultimately leads to a darker and less bright image displayed by the HUD system. Existing single-polarization imaging structures cannot adapt to this optical characteristic and cannot specifically compensate for P-polarized light loss, resulting in poor imaging consistency and display quality. Summary of the Invention

[0003] This invention provides a head-up display system and its control method to achieve precise polarization brightness compensation, low heat dissipation, and overheat protection.

[0004] In a first aspect, embodiments of the present invention provide a head-up display system, including a head-up display device, the head-up display device comprising: First image source, emitting a P-polarized beam; The second image source emits an S-polarized beam; A beam combiner is located on the propagation paths of the P-polarized beam and the S-polarized beam, merging the P-polarized beam and the S-polarized beam into a coaxial beam that propagates coaxially.

[0005] Optionally, the beam combining element includes a polarizing beam splitter, with the first image source and the second image source located on adjacent sides of the polarizing beam splitter.

[0006] Optionally, the head-up display device further includes a tilting mirror and a freeform surface reflector; The deflector is located on one side of the beam combining element and on the propagation path of the coaxial beam. It reflects the coaxial beam to the freeform mirror, which in turn reflects the coaxial beam to the light-emitting window of the head-up display device.

[0007] Optionally, the brightness of the P-polarized beam emitted from the first image source is greater than the brightness of the S-polarized beam emitted from the second image source.

[0008] Optionally, it also includes a control module, which is electrically connected to the first image source and the second image source, and is used to allocate the drive signal value of the first image source and the drive signal value of the second image source.

[0009] Secondly, embodiments of the present invention provide a control method based on the head-up display system described in the first aspect, comprising: Determine the total brightness of the target; The drive signal values ​​of the first image source and the second image source are allocated according to the total target brightness.

[0010] Optionally, before determining the target total brightness, the method further includes: Obtain the ambient light level; The steps for determining the total brightness of the target include: The total target brightness is calculated based on the ambient light level.

[0011] Optionally, allocating the drive signal values ​​of the first image source and the second image source according to the target total brightness includes: Based on the total target brightness, the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source are obtained. The driving signal value of the first image source is obtained based on the brightness of the P-polarized beam emitted from the first image source; and the driving signal value of the second image source is obtained based on the brightness of the S-polarized beam emitted from the second image source.

[0012] Optionally, based on the total target brightness, the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source are obtained, including: Determine the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light; Based on the total target brightness, the total loss coefficient of S-polarized light, and the total loss coefficient of P-polarized light, the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source are obtained.

[0013] Optionally, determining the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light includes: Obtain the installation tilt angle of the windshield; Based on the installation tilt angle, determine the P-polarized light reflectivity and S-polarized light reflectivity of the windshield; Based on the P-polarized light reflectivity and S-polarized light reflectivity of the windshield, as well as the parameters of the beam combining element, the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light are determined.

[0014] The head-up display system provided in this invention independently adjusts the brightness of the P-polarized beam emitted from the first image source and the S-polarized beam emitted from the second image source, precisely matching the reflection loss of the two polarized beams as needed. This invention eliminates the need for the image sources to operate at full load for extended periods, effectively reducing heat dissipation pressure and the risk of overheating. Furthermore, relying on the coaxial beam combining design of the dual image sources, the structure is compact and can adapt to the differences in polarization loss due to the installation tilt angle of windshields in different vehicle models, effectively stabilizing the imaging quality of the head-up display system and improving the operational stability and lifespan of the in-vehicle display device. The dual image source (including the first and second image sources) independent dimming architecture allows each image source to match its own loss as needed, eliminating the need for full-power supplementary lighting on a single path. This results in lower overall power consumption and heat dissipation load, effectively avoiding the risk of device overheating caused by the combined heat generated by sunlight backflow. Attached Figure Description

[0015] Figure 1 A schematic diagram of a head-up display system provided in an embodiment of the present invention; Figure 2 A schematic diagram of a beam combining element provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another head-up display system provided in an embodiment of the present invention; Figure 4 A flowchart of a control method for a head-up display system provided in an embodiment of the present invention; Figure 5 A flowchart of another control method for a head-up display system provided in an embodiment of the present invention; Figure 6 A flowchart of another control method for a head-up display system provided in an embodiment of the present invention; Figure 7 This is a graph showing the reflectivity of S-rays and P-rays as a function of the incident angle. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0017] Research has revealed that individual image sources suffer from heat dissipation and overheating defects due to overall current boosting for illumination. Currently, the industry commonly compensates for the brightness deficiency of P-polarized light by increasing the overall operating current of a single image source. This compensation method requires the light source to be under high load for extended periods, drastically increasing the heat dissipation load on the equipment. Furthermore, automotive applications often experience sunlight backflow, where the heat generated by the light source itself, combined with the high temperatures from external strong light radiation, easily leads to overheating, aging, and damage to the light source components, significantly reducing the stability and lifespan of the HUD.

[0018] Individual image sources suffer from limitations in adaptability and energy consumption for uniform dimming. A single image source only supports uniform brightness adjustment across the entire device, and cannot perform independent dimming for P-polarized and S-polarized light in different zones. S-polarized light is minimally affected by the Brewster angle and has sufficient brightness; full-area current boosting would result in significant wasted power consumption. Furthermore, it cannot adapt to the differences in polarization loss caused by the tilt angle of windshields in different vehicle models. This results in poor device versatility and makes it difficult to simultaneously meet the automotive application requirements of high-definition imaging, low-power operation, and high-temperature safety protection.

[0019] Figure 1 This is a schematic diagram of a head-up display system provided in an embodiment of the present invention, with reference to... Figure 1 The head-up display system includes a head-up display device 3, which includes a first image source 31, a second image source 32, and a beam combiner 33. The first image source 31 emits a P-polarized beam, and the second image source 32 emits an S-polarized beam. The beam combiner 33 is located on the propagation path of the P-polarized and S-polarized beams, merging them into a coaxial beam that propagates coaxially. The coaxial beam is the combined beam of the P-polarized and S-polarized beams. The P-polarized and S-polarized beams share a rear-end optical path and achieve imaging through the windshield.

[0020] The head-up display system provided in this embodiment of the invention independently adjusts the brightness of the P-polarized beam emitted from the first image source 31 and the S-polarized beam emitted from the second image source 32, precisely matching the reflection loss of the two polarized beams as needed. This embodiment of the invention eliminates the need for the image sources to operate at full load for extended periods, effectively reducing heat dissipation pressure and the risk of overheating. Furthermore, relying on the coaxial beam combining design of the dual image sources, the structure is compact and can adapt to the differences in polarization loss due to the installation tilt angle of windshields in different vehicle models, effectively stabilizing the imaging quality of the head-up display system and improving the operational stability and lifespan of the in-vehicle display device. The dual image source (including the first image source 31 and the second image source 32) features a separate independent dimming architecture, with each image source matching its own loss as needed. This eliminates the need for full-power supplementary lighting on a single path, resulting in lower overall power consumption and heat dissipation load, effectively avoiding the risk of device overheating caused by the combined heat generated by sunlight backflow.

[0021] Figure 2 This is a schematic diagram of a beam combining element provided in an embodiment of the present invention, with reference to... Figure 1 and Figure 2The beam combining element 33 includes a polarizing beam splitter prism, with a first image source 31 and a second image source 32 located on adjacent sides of the polarizing beam splitter prism. The first image source 31 and the second image source 32 are respectively arranged on the two incident sides of the polarizing beam splitter prism. The P-polarized beam emitted from the first image source 31 passes through the polarizing beam splitter prism, and the S-polarized beam emitted from the second image source 32 is reflected by the polarizing beam splitter prism and then combined with the P-polarized beam. The output axis of the first image source 31 coincides with the transmission axis of the polarizing beam splitter prism, and the output axis of the second image source 32 coincides with the reflection axis of the polarizing beam splitter prism. The P-polarized beam and the S-polarized beam are combined into a coaxial beam by the polarizing beam splitter prism. In other words, two orthogonally polarized beams are coaxially combined by the PBS polarizing beam splitter prism through transmission and reflection, respectively.

[0022] Optionally, refer to Figure 1 The head-up display device 3 also includes a deflector 34 and a freeform surface reflector 35. The deflector 34 is located on one side of the beam combiner element 33, specifically, on the side of the beam combiner element 33 away from the first image source 31. The deflector 34 is located on the propagation path of the coaxial beam, reflecting the coaxial beam to the freeform surface reflector 35, which in turn reflects the coaxial beam to the light-emitting window of the head-up display device 3. After exiting through the light-emitting window of the head-up display device 3, the coaxial beam is projected onto the windshield 2, and after being reflected by the windshield 2, it enters the driver's eye box area 1, forming a virtual image 4. In this embodiment of the invention, the deflector 34 can bend the light path, reduce the overall space occupied by the device, and adapt to the narrow installation environment of the dashboard.

[0023] In other embodiments, the head-up display device 3 may also include a freeform mirror 35 instead of a deflector 34. The freeform mirror 35 is located on the propagation path of the coaxial beam and reflects the coaxial beam to the light-emitting window of the head-up display device 3.

[0024] Optionally, the brightness of the P-polarized beam emitted from the first image source 31 is greater than the brightness of the S-polarized beam emitted from the second image source 32. Compared to the brightness of the S-polarized beam emitted from the second image source 32, the brightness of the P-polarized beam emitted from the first image source 31 is greater, thereby compensating for the reflection loss of P-polarized light caused by the Brewster angle, that is, compensating for the greater reflection loss of P-polarized light compared to S-polarized light, making the brightness of P-polarized light and S-polarized light projected onto the eye box region 1 more balanced, and improving the imaging brightness.

[0025] Figure 3 This is a schematic diagram of another head-up display system provided in an embodiment of the present invention; see reference. Figure 3The head-up display system also includes a polarizing lens 5. P-polarized light projected onto the eye box area 1 can pass through the polarizing lens 5, while S-polarized light projected onto the eye box area 1 is completely blocked by the polarizing lens 5 and cannot pass through. The light beam projected onto the eye box area 1 is only P-polarized light. This can reduce the brightness of the S-polarized beam emitted from the second image source 32, for example, reducing the brightness of the S-polarized beam emitted from the second image source 32 to a preset brightness in standby mode, or reducing the brightness of the S-polarized beam emitted from the second image source 32 to 0. This reduces unnecessary power consumption and heat generation. In this scenario, it also satisfies that: the brightness of the P-polarized beam emitted from the first image source 31 is greater than the brightness of the S-polarized beam emitted from the second image source 32.

[0026] Optionally, refer to Figure 3 The head-up display system also includes a control module (not shown in the figure). The control module is electrically connected to the first image source 31 and the second image source 32. The control module is used to allocate the drive signal values ​​of the first image source 31 and the second image source 32. The drive signal values ​​may include current values ​​and / or voltage values. Thus, through the adaptive dimming mechanism of the control module, the brightness of the first image source 31 and the second image source 32 is controlled to accurately compensate for the P-polarization light loss caused by the Brewster angle. Furthermore, it can adjust the brightness of the first image source 31 and the second image source 32 to suit specific scenarios (e.g., when the user is wearing polarized sunglasses 5).

[0027] For example, refer to Figure 3 The head-up display system also includes a light sensor 36, which is communicatively connected to the control module. The light sensor 36 is used to collect ambient light; the control module obtains the ambient light from the light sensor 36 and calculates the target total brightness based on the ambient light. The light sensor 36 is fixedly installed on the housing of the head-up display device 3, specifically on the inner edge of the light-emitting window of the head-up display device 3. The light sensor 36 is located in the non-imaging area outside the main imaging optical path, with its photosensitive surface facing the ambient environment. For example, the photosensitive surface of the light sensor 36 can face the ambient environment in front of the vehicle, allowing it to directly collect the ambient light intensity through the windshield 2. In this embodiment, the control module adaptively adjusts the brightness based on the ambient light detected by the light sensor 36, adapting to changes in ambient light and accurately compensating for P-polarized light loss caused by the Brewster angle.

[0028] Figure 4 A flowchart of a control method for a head-up display system provided in an embodiment of the present invention is shown below. Figures 1-4 The control method for the head-up display system includes the following steps: S101. Determine the total brightness of the target.

[0029] The target total brightness is the brightness of the beam projected onto eye box region 1, which is the sum of the brightness of the P-polarized beam and the S-polarized beam projected onto eye box region 1. In one example, if the beam projected onto eye box region 1 consists only of a P-polarized beam and no S-polarized beam, then the brightness of the S-polarized beam projected onto eye box region 1 is 0, and the target total brightness is equal to the brightness of the P-polarized beam projected onto eye box region 1.

[0030] S102. Allocate the driving signal values ​​of the first image source and the second image source according to the total target brightness.

[0031] The control method provided in this embodiment of the invention is based on the head-up display system described in the above embodiments. The control method can be executed by the control module within the head-up display system. The target total brightness is determined. Drive signal values ​​for the first image source and the second image source are allocated according to the target total brightness. A dual-image source architecture (including the first image source 31 and the second image source 32) with independent dimming allows each image source to match its own losses as needed, eliminating the need for full-power single-channel supplemental lighting. This results in lower overall power consumption and heat dissipation load, effectively avoiding the risk of device overheating caused by sunlight backflow and combined heat generation. Through the adaptive dimming mechanism of the control module, the luminous brightness of the first image source 31 and the second image source 32 is controlled to accurately compensate for the P-polarized light loss caused by the Brewster angle. Furthermore, the luminous brightness of the first image source 31 and the second image source 32 is adjusted to suit specific scenarios (e.g., when the user is wearing polarized sunglasses 5).

[0032] Figure 5 A flowchart of another control method for a head-up display system provided in an embodiment of the present invention is shown below. Figures 1-3 ,as well as Figure 5 The control method for the head-up display system includes the following steps: S201, Obtain ambient brightness.

[0033] The light sensor 36 collects the ambient brightness and transmits it to the control module, which in turn obtains the ambient brightness from the light sensor 36.

[0034] S202. Calculate the total brightness of the target based on the ambient brightness.

[0035] The control module calculates the total target brightness used for imaging from the human eye side based on the ambient brightness. The greater the ambient brightness, the greater the total brightness of the target. The larger the value, the smaller the ambient brightness, and the greater the total brightness of the target. The smaller the value, the more automatically the overall brightness of the target will decrease at night. To avoid glare.

[0036] S203. Based on the total target brightness, obtain the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source.

[0037] In this step, the brightness of the P-polarized beam projected onto eyelid region 1 and the brightness of the S-polarized beam projected onto eyelid region 1 are allocated according to the target total brightness. For example, A% of the target total brightness is allocated to the brightness of the P-polarized beam projected onto eyelid region 1, and B% of the target total brightness is allocated to the brightness of the S-polarized beam projected onto eyelid region 1. A% + B% = 100%. In one example, 50% of the target total brightness is allocated to the brightness of the P-polarized beam projected onto eyelid region 1, and 50% of the target total brightness is allocated to the brightness of the S-polarized beam projected onto eyelid region 1. In another example, 100% of the target total brightness is allocated to the brightness of the P-polarized beam projected onto eyelid region 1.

[0038] Furthermore, the brightness of the P-polarized beam emitted from the first image source 31 is obtained based on the brightness of the P-polarized beam projected onto the eye box region 1. And the brightness of the S-polarized beam emitted from the second image source 32 is obtained based on the brightness of the S-polarized beam projected onto the eye box region 1.

[0039] S204. Obtain the driving signal value of the first image source based on the brightness of the P-polarized beam emitted from the first image source; and obtain the driving signal value of the second image source based on the brightness of the S-polarized beam emitted from the second image source.

[0040] The driving signal value may include current value and / or voltage value. Taking the driving signal value including current value as an example, the current value of the first image source 31 and the current value of the second image source 32 are the total driving current, which belongs to the global brightness adjustment dimension and is unrelated to the grayscale driving current of the sub-pixels in the image source (including the first image source 31 or the second image source 32). The adjustment process does not change the image content.

[0041] For example, the brightness of the P-polarized beam emitted from the first image source 31 is The brightness of the S-polarized beam emitted from the second image source 32 is The current value of the first image source 31 is The current value of the second image source 32 is ,satisfy: , ;in, Let be the photoelectric conversion coefficient of the S-polarized beam. denoted as the photoelectric conversion coefficient of the P-polarized beam.

[0042] In this embodiment of the invention, the control module independently calculates and outputs two driving signal values ​​based on the target total brightness. In view of the greater P light loss at Brewster angle, the driving signal value of the first image source 31 can be increased accordingly to accurately compensate for reflection loss. Both driving signal values ​​are limited to the rated safe range to avoid device overload.

[0043] Figure 6 A flowchart of another control method for a head-up display system provided in an embodiment of the present invention is shown below. Figures 1-3 ,as well as Figure 6 The control method for the head-up display system includes the following steps: S301, Obtain ambient brightness.

[0044] S302. Calculate the total brightness of the target based on the ambient brightness.

[0045] S303. Obtain the installation tilt angle of the windshield.

[0046] In this step, the installation tilt angle of the windshield 2 can be obtained based on external input.

[0047] S304. Determine the P-polarized light reflectivity and S-polarized light reflectivity of the windshield 2 based on the installation tilt angle.

[0048] In this step, the P-polarized light reflectivity and S-polarized light reflectivity of windshield 2 are determined based on the installation tilt angle. Specifically, based on the installation tilt angle, a pre-stored parameter table is retrieved, and the P-polarized light reflectivity and S-polarized light reflectivity corresponding to the installation tilt angle are matched in the pre-stored parameter table.

[0049] Figure 7 The graphs show the reflectance of S-rays and P-rays as a function of the incident angle; see reference. Figure 7 The corresponding variation law of S-polarized beam (i.e., S-polarized beam) and P-polarized beam (i.e., P-polarized beam) is that as the incident angle increases, the reflectivity Rs of the S-polarized beam increases monotonically, while the reflectivity Rp of the P-polarized beam first decreases and then increases, reaching its lowest point near Brewster's angle.

[0050] S305. Based on the P-polarized light reflectivity and S-polarized light reflectivity of the windshield, as well as the parameters of the beam combining element, determine the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light.

[0051] For example, the head-up display device 3 may also include a freeform surface reflector 35 and a deflector 34. This step may specifically include: determining the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light based on the P-polarized light reflectivity and S-polarized light reflectivity of the windshield 2, the parameters of the beam combining element 33, the P-polarized light reflectivity and S-polarized light reflectivity of the deflector 34, and the P-polarized light reflectivity and S-polarized light reflectivity of the freeform surface reflector 35.

[0052] For example, the S-polarized light reflectance of the beam combiner 33 is... The S-polarized light reflectance of the folding mirror 34 is The S-polarized light reflectance of the freeform surface mirror 35 is... The S-polarized light reflectance of windshield 2 is The total loss coefficient of S-polarized light is ,satisfy: The transmittance of p-polarized light from beam combiner 33 is... The P-polarized light reflectance of the 34-fold deflector is... The reflectivity of P-polarized light from the freeform surface mirror 35 is... The P-polarized light reflectance of windshield 2 is The total loss coefficient of P-polarized light is ,satisfy: .

[0053] S306. Based on the total target brightness, the total loss coefficient of S-polarized light, and the total loss coefficient of P-polarized light, obtain the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source.

[0054] Specifically, based on the total target brightness, the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light, as well as the distribution ratio of S-polarized beams and P-polarized beams, the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source are obtained.

[0055] For example, ,in, This represents the brightness of the S-polarized beam projected onto eyebox region 1. This represents the brightness of the P-polarized beam projected onto eyebox region 1. A% of the total target brightness is allocated to the brightness of the P-polarized beam projected onto eyebox region 1, and B% of the total target brightness is allocated to the brightness of the S-polarized beam projected onto eyebox region 1. A% + B% = 100%. The values ​​of A and B can be chosen based on specific application scenarios and / or setting requirements. For example, both A and B can be 50. However, this is not a limitation. A can also be 55, and B can be 45.

[0056] For example, after switching to sunglasses mode, S-beams are completely blocked by polarized sunglasses 5, and the total brightness is solely provided by P-beams. The control module updates the calculation logic as follows: That is to say, A is 100 and B is 0.

[0057] S307. Obtain the driving signal value of the first image source based on the brightness of the P-polarized beam emitted from the first image source; and obtain the driving signal value of the second image source based on the brightness of the S-polarized beam emitted from the second image source.

[0058] In this embodiment of the invention, the control module independently calculates and outputs the values ​​of two driving signals based on the target total brightness and the two loss coefficients (including the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light). Furthermore, it adapts to different vehicle windshield tilt angles and sets polarization loss to suit the imaging. In other embodiments, the steps of obtaining the loss system involved in S303 to S305 can be performed simultaneously with the steps of obtaining the target total brightness involved in S301 to S302, or the steps of obtaining the loss system involved in S303 to S305 can be performed before the steps of obtaining the target total brightness involved in S301 to S302. In summary, this embodiment of the invention has the following beneficial effects: accurate compensation for polarization loss and stable imaging effect. By detecting the ambient brightness in real time with a light sensor and combining it with fixed optical path parameters, the power of the first image source 31 corresponding to the P-polarized beam is independently adjusted to accurately compensate for the P-polarized light reflection loss caused by the Brewster angle, solving the problem of dark imaging in traditional HUDs. Leveraging a dual-polarization independent dimming design, it can adapt to changes in ambient brightness between day and night, while also being compatible with special driving scenarios where only P-polarized light passes through when users wear polarized sunglasses, significantly improving the driving experience and display versatility. The device boasts a longer lifespan, employing a separate independent dimming mode that eliminates the need for full-load supplementation of the entire light source, greatly reducing the continuous heat dissipation pressure on the light source. This effectively avoids overheating and component aging damage caused by sunlight backflow combined with the heat generated during light source operation, improving stability under automotive conditions. It also reduces overall power consumption, achieving energy efficiency. Abandoning the traditional single-light source overall current boosting compensation method, it only compensates for the power of the first image source 31 corresponding to the higher-loss P-polarized light as needed, avoiding ineffective power output from the second image source 32 corresponding to S-polarized light, reducing energy waste and improving light energy utilization efficiency. With a compact structure and strong vehicle adaptability, it adopts a beam combiner element 33 to achieve coaxial imaging of dual light sources. The dual optical paths share optical structures such as the rear-end convection mirror 34 and the freeform surface reflector 35, eliminating the need for additional optical components. The overall structure is simple and easy to integrate and install in the narrow space of a vehicle. It supports parametric input adaptation of windshield tilt angle, can quickly match the differences in windshield tilt angle of multiple vehicle models, has strong mass production versatility, and low adaptation cost.

[0059] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A head-up display system, characterized in that, Includes a head-up display device, the head-up display device comprising: First image source, emitting a P-polarized beam; The second image source emits an S-polarized beam; A beam combiner is located on the propagation paths of the P-polarized beam and the S-polarized beam, merging the P-polarized beam and the S-polarized beam into a coaxial beam that propagates coaxially.

2. The head-up display system according to claim 1, characterized in that, The beam combining element includes a polarizing beam splitter, with the first image source and the second image source located on adjacent sides of the polarizing beam splitter.

3. The head-up display system according to claim 1, characterized in that, The head-up display device also includes a tilting mirror and a freeform surface reflector; The deflector is located on one side of the beam combining element and on the propagation path of the coaxial beam. It reflects the coaxial beam to the freeform mirror, which in turn reflects the coaxial beam to the light-emitting window of the head-up display device.

4. The head-up display system according to claim 1, characterized in that, The brightness of the P-polarized beam emitted from the first image source is greater than the brightness of the S-polarized beam emitted from the second image source.

5. The head-up display system according to claim 1, characterized in that, It also includes a control module, which is electrically connected to the first image source and the second image source, and is used to allocate the drive signal value of the first image source and the drive signal value of the second image source.

6. A control method based on the head-up display system of claim 1, characterized in that, include: Determine the total brightness of the target; The drive signal values ​​of the first image source and the second image source are allocated according to the total target brightness.

7. The control method according to claim 6, characterized in that, Before determining the target total brightness, the following is also included: Obtain the ambient light level; The steps for determining the total brightness of the target include: The total target brightness is calculated based on the ambient light level.

8. The control method according to claim 6, characterized in that, The driving signal values ​​of the first image source and the second image source are allocated according to the target total brightness, including: Based on the total target brightness, the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source are obtained. The driving signal value of the first image source is obtained based on the brightness of the P-polarized beam emitted from the first image source; and the driving signal value of the second image source is obtained based on the brightness of the S-polarized beam emitted from the second image source.

9. The control method according to claim 8, characterized in that, Based on the total target brightness, the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source are obtained, including: Determine the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light; Based on the total target brightness, the total loss coefficient of S-polarized light, and the total loss coefficient of P-polarized light, the brightness of the P-polarized beam emitted from the first image source and the brightness of the S-polarized beam emitted from the second image source are obtained.

10. The control method according to claim 9, characterized in that, Determine the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light, including: Obtain the installation tilt angle of the windshield; Based on the installation tilt angle, determine the P-polarized light reflectivity and S-polarized light reflectivity of the windshield; Based on the P-polarized light reflectivity and S-polarized light reflectivity of the windshield, as well as the parameters of the beam combining element, the total loss coefficient of S-polarized light and the total loss coefficient of P-polarized light are determined.

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