Vehicle head-up display system and light emitting diode device thereof

Abstract

The invention relates to the technical field of display, and provides a vehicle head-up display system and a light-emitting diode device thereof, and the light-emitting diode device comprises a light-emitting diode module, a driving circuit, a temperature sensing circuit, a cooling device and an electronic control unit. The driving circuit drives the light emitting diode module to generate display light, and the temperature sensing circuit senses the temperature. The electronic control unit is electrically connected with the cooling device, the temperature sensing circuit and the driving circuit. The electronic control unit increases the driving current output to the light emitting diode module by the driving circuit according to the variation range that the temperature exceeds the temperature default value so as to increase the brightness of the display light, and then starts the cooling device to reduce the temperature until the temperature is equal to the temperature default value. After the cooling device reduces the temperature, the electronic control unit reduces the driving current according to the variation range so as to reduce the brightness.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a vehicle head-up display system and a light emitting diode device thereof. Background Art

[0002] With the development of science and technology, the LED technology has matured and the cost has dropped significantly, and the LED display has also been widely used. The LED display is a display device composed of LEDs installed in a matrix, which can display characters and image information.

[0003] When the temperature of light-emitting diode (LED) displays rises, white balance shifts occur. This shift causes the overall color deviation of the picture, which is manifested as the color becoming increasingly bluish. This is mainly because the brightness of the red, green and blue (RGB) primary color LEDs changes with temperature, but different color LEDs have different sensitivities to temperature. Generally, red LEDs are most affected by temperature. As the temperature rises, the brightness of red LEDs decreases faster. The brightness of blue (B) and green (G) LEDs decreases more slowly than that of red LEDs. As the brightness of RGB LEDs decreases unevenly, the contribution of red decreases, while the contributions of blue and green are relatively high, making the color of the mixed light become bluish. This color shift will significantly affect the white balance of the display, causing the picture to appear increasingly bluish.

[0004] Therefore, in view of the above-mentioned problems, the present invention proposes a vehicle head-up display system and a light emitting diode device thereof to solve the problems generated in the related art. Summary of the invention

[0005] Based on this, the present invention provides a head-up display system for a vehicle and a light emitting diode device thereof, which not only performs temperature reduction control but also performs brightness compensation.

[0006] In one embodiment of the present invention, a light-emitting diode device includes a light-emitting diode module, a driving circuit, a temperature sensing circuit, a cooling device and an electronic control unit. The driving circuit is electrically connected to the light-emitting diode module and is used to drive the light-emitting diode module to generate display light. The temperature sensing circuit is disposed on the light-emitting diode module and is used to sense the temperature. The cooling device is disposed on the light-emitting diode module. The electronic control unit is electrically connected to the cooling device, the temperature sensing circuit and the driving circuit. The electronic control unit is used to receive the temperature and perform at least one brightness adjustment action. In the brightness adjustment action, the electronic control unit increases the driving current output by the driving circuit to the light-emitting diode module according to the variation range of the temperature exceeding the temperature default value to increase the brightness of the display light, and then the electronic control unit starts the cooling device to lower the temperature until the temperature is equal to the temperature default value. After the cooling device lowers the temperature, the electronic control unit reduces the driving current according to the variation range to reduce the brightness.

[0007] In one embodiment of the present invention, a head-up display system for a vehicle is provided in a vehicle, and the head-up display system for a vehicle includes a curved image source and at least one free-form mirror. The curved image source is used to emit image light including image information. The free-form mirror is located on the optical path of the image light. The free-form mirror is used to reflect the image light to form the light to be imaged, and the windshield of the vehicle is located on the optical path of the light to be imaged. The windshield is used to reflect the light to be imaged to produce a virtual image. The curved image source includes a light-emitting diode module, a driving circuit, a temperature sensing circuit, a cooling device, an electronic control unit and a curved liquid crystal display panel. The driving circuit is electrically connected to the light-emitting diode module and is used to drive the light-emitting diode module to generate display light. The temperature sensing circuit is provided on the light-emitting diode module and is used to sense temperature. The cooling device is provided on the light-emitting diode module. The electronic control unit is electrically connected to the cooling device, the temperature sensing circuit and the driving circuit. The electronic control unit is used to receive the temperature and perform at least one brightness adjustment action. In the brightness adjustment operation, the electronic control unit increases the driving current output by the driving circuit to the light emitting diode module according to the variation range of the temperature exceeding the temperature default value, so as to increase the brightness of the display light. Then the electronic control unit starts the cooling device to reduce the temperature until the temperature is equal to the temperature default value. After the cooling device reduces the temperature, the electronic control unit reduces the driving current according to the variation range to reduce the brightness. The curved liquid crystal display panel is located on the optical path of the display light, wherein the curved liquid crystal display panel converts the display light into image light.

[0008] In one embodiment of the present invention, the display light has white light, and the electronic control unit maintains the white coordinate of the display light unchanged when increasing or decreasing the driving current.

[0009] In an embodiment of the present invention, at least one brightness adjustment action includes multiple brightness adjustment actions.

[0010] In one embodiment of the present invention, the electronic control unit is used to perform multiple brightness adjustment operations at a fixed frequency.

[0011] In one embodiment of the present invention, the cooling device is a cooling fan or a refrigeration device.

[0012] In one embodiment of the present invention, the greater the field curvature of the curved image display surface of the curved image source, the smaller the primary astigmatism of the virtual image; the greater the spherical aberration of the curved image display surface of the curved image source, the smaller the secondary astigmatism of the virtual image.

[0013] In one embodiment of the present invention, the point coordinates of the curved image display surface of the curved image source are (x, y, z), and the point coordinates are located in a three-dimensional coordinate system formed by the X-axis, the Y-axis, and the Z-axis. x, y, and z are the coordinate values ​​on the X-axis, the Y-axis, and the Z-axis, respectively, and z = c1x 2 + c2xy + c3y 2 , the coordinates of the origin of the curved image display surface are (0, 0, 0), and c1 is -1.05×10 -2 to 1.05×10 -2 , c2 is -3×10 -3 Up to 3×10 -3 , c3 is -1.05×10 -2 to 1.05×10 -2 .

[0014] Based on the above, the vehicle head-up display system and the light-emitting diode device thereof use a temperature sensing circuit to sense the temperature and transmit it to the electronic control unit, which performs temperature reduction control and brightness compensation.

[0015] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. 4 is a schematic diagram of a light emitting diode device according to an embodiment of the present invention.

[0017] Figure 2 FIG. 4 is a graph showing relative brightness and temperature of red display light according to an embodiment of the present invention.

[0018] Figure 3 FIG. 4 is a graph showing relative brightness and temperature of green display light according to an embodiment of the present invention.

[0019] Figure 4 FIG. 4 is a graph showing relative brightness and temperature of blue display light according to an embodiment of the present invention.

[0020] Figure 5 FIG. 4 is a schematic diagram of a head-up display system for a vehicle according to an embodiment of the present invention.

[0021] Figure 6 FIG. 4 is a schematic diagram of a curved image source according to an embodiment of the present invention.

[0022] Description of reference numerals:

[0023] 1. Curved image source; 10. Light-emitting diode device; 100. Light-emitting diode module; 101. Driving circuit; 102. Temperature sensing circuit; 103. Cooling device; 104. Electronic control unit; 11. Curved liquid crystal display panel; 2. Free-form mirror; 3. Vehicle; 30. Windshield; T, temperature; D, display light; C, driving current; L, image light; U, light to be imaged. DETAILED DESCRIPTION

[0024] The embodiments of the present invention will be further explained below with reference to the accompanying drawings. As much as possible, the same reference numerals represent the same or similar components in the drawings and the specification. In the drawings, shapes and thicknesses may be exaggerated for simplicity and convenience. It is understood that the components not specifically shown in the drawings or described in the specification are known to those of ordinary skill in the art. Those of ordinary skill in the art may make various changes and modifications based on the contents of the present invention.

[0025] When an element is referred to as being "on...", it can generally mean that the element is directly on other elements, or that there are other elements between the two. Conversely, when an element is referred to as being "directly on" another element, it cannot have other elements between the two. As used herein, the term "and / or" includes any combination of one or more of the listed associated items.

[0026] In the following description of "one embodiment" or "an embodiment" refers to the specific elements, structures or features associated with at least one embodiment. Therefore, multiple descriptions of "one embodiment" or "an embodiment" appearing in multiple places below do not refer to the same embodiment. Furthermore, the specific components, structures and features in one or more embodiments can be combined in appropriate ways.

[0027] The disclosure is particularly described with the following examples, which are only used for illustration, because for those of ordinary skill in the art, various changes and modifications can be made without departing from the spirit and scope of the disclosure, so the protection scope of the disclosure should be determined by the scope of the attached claims. Throughout the specification and the claims, unless the content clearly specifies, the meaning of "one" and "the" includes this type of description including "one or at least one" of the elements or components. In addition, as used in the disclosure, unless it is obvious from the specific context that multiple is excluded, the singular article also includes the description of multiple elements or components. Moreover, when applied in this description and the following claims, unless the content clearly specifies, the meaning of "in which" may include "in which" and "on it". The terms used in the specification and the claims, unless otherwise specified, usually have the ordinary meaning of each term used in this field, in the content disclosed here and in the special content. Certain terms used to describe the present disclosure will be discussed below or elsewhere in this specification to provide practitioners with additional guidance in describing the present disclosure. The use of examples anywhere throughout the specification, including examples of any term discussed herein, is intended to be illustrative only and certainly does not limit the scope and meaning of the present disclosure or any exemplified term. Likewise, the present disclosure is not limited to the various embodiments set forth in this specification.

[0028] It is understood that the terms "comprising", "including", "having", "containing", "involving", etc. used herein are open-ended, that is, they mean including but not limited to. In addition, any embodiment or claim scope of the present invention does not necessarily achieve all the objects, advantages or features disclosed in the present invention. In addition, the abstract part and the title are only used to assist in searching patent documents, and are not used to limit the scope of the claims of the invention.

[0029] In addition, if the term "electrically coupled" or "electrically connected" is used, it includes any direct and indirect electrical connection means. For example, if the text describes that a first device is electrically coupled to a second device, it means that the first device can be directly connected to the second device, or indirectly connected to the second device through other devices or connection means. In addition, if the transmission and provision of electrical signals are described, a person skilled in the art should understand that the transmission process of electrical signals may be accompanied by attenuation or other non-ideal changes, but the source and receiving end of the transmission or provision of electrical signals should be regarded as the same signal if there is no special description. For example, if an electrical signal S is transmitted (or provided) from terminal A of an electronic circuit to terminal B of the electronic circuit, a voltage drop may be generated through the source and drain of a transistor switch and / or possible stray capacitance, but if the purpose of this design is not to deliberately use the attenuation or other non-ideal changes generated during transmission (or provision) to achieve certain specific technical effects, the electrical signal S should be regarded as substantially the same signal at terminal A and terminal B of the electronic circuit.

[0030] Unless otherwise specified, some conditional sentences or words, such as "can", "could", "might", or "may", are generally intended to express that the embodiment of the case has, but can also be interpreted as features, elements, or steps that may not be required. In other embodiments, these features, elements, or steps may not be required.

[0031] The following will present a vehicle head-up display system and a light emitting diode device of the present invention, which utilizes a temperature sensing circuit to sense temperature and transmits the temperature to an electronic control unit, which performs temperature reduction control and brightness compensation.

[0032] Figure 1 is a schematic diagram of a light emitting diode device according to an embodiment of the present invention. Figure 1 , the light emitting diode device 10 is introduced as follows. The light emitting diode device 10 includes a light emitting diode module 100, a driving circuit 101, a temperature sensing circuit 102, a cooling device 103 and an electronic control unit 104. The light emitting diode module 100 may include, but is not limited to, a red light emitting diode, a green light emitting diode and a blue light emitting diode. The cooling device 103 may be a cooling fan or a cooling device, but the present invention is not limited thereto. The driving circuit 101 is electrically connected to the light emitting diode module 100, the temperature sensing circuit 102 and the cooling device 103 are arranged on the light emitting diode module 100, and the electronic control unit 104 is electrically connected to the cooling device 103, the temperature sensing circuit 102 and the driving circuit 101.

[0033] The driving circuit 101 drives the light emitting diode module 100 to generate display light D. The temperature sensing circuit 102 senses the temperature T. The electronic control unit 104 receives the temperature T and performs at least one brightness adjustment action. In some embodiments of the present invention, the electronic control unit 104 can perform multiple brightness adjustment actions at a fixed frequency. For example, a brightness adjustment action is performed every 5 seconds.

[0034] In each brightness adjustment action, the electronic control unit 104 increases the driving current C output by the driving circuit 101 to the light emitting diode module 100 according to the variation range of the temperature T exceeding the temperature default value, so as to increase the brightness of the display light D. Then, the electronic control unit 104 starts the cooling device 103 to reduce the temperature T until the temperature T is equal to the temperature default value. After the cooling device 103 reduces the temperature T, the electronic control unit 104 reduces the driving current C according to the variation range of the temperature T to reduce the brightness of the display light D. In some embodiments of the present invention, the display light D has white light. When the electronic control unit 104 increases or decreases the driving current C, the white coordinate of the display light D is maintained unchanged to fix the color temperature of the display light D. The display light D includes red display light, green display light and blue display light, wherein the relative brightness of the red display light is highly sensitive to temperature, the relative brightness of the green display light is moderately sensitive to temperature, and the relative brightness of the blue display light is low sensitive to temperature.

[0035] Figure 2 FIG. 1 is a graph showing the relative brightness and temperature of red display light according to an embodiment of the present invention. Figure 1 and Figure 2 For example, when the temperature T is 25 degrees Celsius, the relative brightness of the red display light is 1, and when the temperature T is 80 degrees Celsius, the relative brightness of the red display light is 0.57. When the temperature T rises from 25 degrees Celsius to 80 degrees Celsius, the relative brightness of the red display light decreases by 43%. The electronic control unit 104 uses the temperature sensing circuit 102 to know that the current temperature T is 80 degrees Celsius. Through the preset lookup table or preset brightness compensation formula measured previously, the drive current C corresponding to the red display light after the increase can be calculated, so that the relative brightness of the red display light is compensated. Specifically, the electronic control unit 104 can increase the drive current C output by the drive circuit 101 to the light-emitting diode module 100 to 1.75 times, so that the relative brightness of the red display light increases by 43%.

[0036] Figure 3 is a graph showing the relative brightness and temperature of green display light according to an embodiment of the present invention, Figure 4 is a graph showing the relative brightness and temperature of blue display light according to an embodiment of the present invention. Figure 1 , Figure 3 and Figure 4When the temperature T rises from 25 degrees Celsius to 80 degrees Celsius, the relative brightness of the green display light and the blue display light will also decrease, but the decrease is relatively less than that of the red display light. Therefore, similarly, the built-in lookup table or preset brightness compensation formula can be obtained through previous measurements to calculate the corresponding increased driving current C of the green display light and the blue display light. Although the variation range of the corresponding increased driving current C of the green display light and the blue display light is relatively lower than the variation range of the corresponding increased driving current C of the red display light, the relative brightness of the green display light and the blue display light can also be compensated.

[0037] Figure 5 is a schematic diagram of a vehicle head-up display system according to an embodiment of the present invention, Figure 6 is a schematic diagram of a curved image source according to an embodiment of the present invention. Figure 5 and Figure 6 , the following introduces a head-up display system for a vehicle. The head-up display system for a vehicle includes a curved image source 1 and at least one free-form mirror 2, and is arranged in a vehicle 3. For convenience and clarity, the number of the free-form mirror 2 is taken as one. The curved image source 1 emits image light L including image information. The curved image display surface of the curved image source 1 may be, but is not limited to, a cylindrical surface, a spherical surface, an aspherical surface or a free-form surface, wherein the radius of curvature of the cylindrical surface or the spherical surface is 100 mm to 1000 mm. The free-form mirror 2 is located on the optical path of the image light L. The free-form mirror 2 reflects the image light L to form a light U to be imaged, and the windshield 30 of the vehicle 3 is located on the optical path of the light U to be imaged. The windshield 30 reflects the light U to be imaged into the human eye to produce a virtual image.

[0038] The curved image source 1 includes a light emitting diode device 10 and a curved liquid crystal display panel 11. The light emitting diode device 10 includes a light emitting diode module 100, a driving circuit 101, a temperature sensing circuit 102, a cooling device 103 and an electronic control unit 104. The light emitting diode module 100 may include, but is not limited to, a red light emitting diode, a green light emitting diode and a blue light emitting diode. The cooling device 103 may be a cooling fan or a cooling device, but the present invention is not limited thereto. The driving circuit 101 is electrically connected to the light emitting diode module 100, the temperature sensing circuit 102 and the cooling device 103 are disposed on the light emitting diode module 100, and the electronic control unit 104 is electrically connected to the cooling device 103, the temperature sensing circuit 102 and the driving circuit 101.

[0039] The driving circuit 101 drives the light emitting diode module 100 to generate display light D. The temperature sensing circuit 102 senses the temperature T. The electronic control unit 104 receives the temperature T and performs at least one brightness adjustment action. In some embodiments of the present invention, the electronic control unit 104 can perform multiple brightness adjustment actions at a fixed frequency. For example, a brightness adjustment action is performed every 5 seconds.

[0040] In each brightness adjustment action, the electronic control unit 104 increases the driving current C output by the driving circuit 101 to the light emitting diode module 100 according to the variation range of the temperature T exceeding the temperature default value, so as to increase the brightness of the display light D. Then, the electronic control unit 104 starts the cooling device 103 to reduce the temperature T until the temperature T is equal to the temperature default value. After the cooling device 103 reduces the temperature T, the electronic control unit 104 reduces the driving current C according to the variation range of the temperature T to reduce the brightness of the display light D. In some embodiments of the present invention, the display light D has white light. When the electronic control unit 104 increases or decreases the driving current C, the white coordinate of the display light D is maintained unchanged to fix the color temperature of the display light D. The display light D includes red display light, green display light and blue display light, wherein the relative brightness of the red display light is highly sensitive to temperature, the relative brightness of the green display light is moderately sensitive to temperature, and the relative brightness of the blue display light is low sensitive to temperature. The curved liquid crystal display panel 11 has a curved image display surface and is located on the optical path of the display light D, wherein the curved liquid crystal display panel 11 converts the display light D into the image light L.

[0041] In the automotive head-up display system 1, the comprehensive astigmatism of the virtual image is a key control item. Through the aberration balance formula, it can be known that the primary astigmatism of the virtual image can be compensated by artificially created field curvature; artificially created spherical aberration, primary astigmatism and artificially created field curvature can compensate for the secondary astigmatism of the virtual image, so as to reduce the comprehensive astigmatism. To illustrate the reason, the following primary astigmatism, field curvature, secondary astigmatism and spherical aberration are all expressed by Zernike polynomials. Primary astigmatism is expressed by Indicates that field curvature is Indicates that the secondary astigmatism is The spherical aberration is expressed as Indicates that is the radial coordinate, is the angle coordinate. , when the field curvature becomes larger, it means In other words, when the field curvature of the curved image display surface of the curved image source 1 is larger, the primary astigmatism of the virtual image is smaller. , when the spherical aberration becomes larger, it means becomes larger, making the secondary astigmatism smaller. That is to say, when the spherical aberration of the curved image display surface of the curved image source 1 is larger, the secondary astigmatism of the virtual image is smaller. In order to reduce the comprehensive astigmatism, the point coordinates of the curved image display surface of the curved image source 1 are defined as (x, y, z). The point coordinates are located in the three-dimensional coordinate system formed by the X-axis, Y-axis and Z-axis. x, y, z are the coordinate values ​​on the X-axis, Y-axis and Z-axis respectively, and z = c1x 2 + c2xy+ c3y 2 , the coordinates of the origin of the curved image display surface are (0, 0, 0), and c1 is -1.05×10 -2 to 1.05×10 -2 , c2 is -3×10 -3 Up to 3×10 -3 , c3 is -1.05×10 -2 to 1.05×10 -2 Therefore, by utilizing the curvature of the curved image source 1, combined with precisely calculated aberration distribution and aberration compensation, the shortcomings of image spots, blur, image deformation, and discomfort after long-term viewing can be eliminated; the backlight design, due to the curved image source 1, makes the system approach the ideal limited angle and position invariant (Positioninvariant) light distribution design, thereby improving the problems of poor image quality and low contrast, while greatly reducing the backlight design and difficulty. The position invariant light distribution design means that different image positions have the same light angle.

[0042] Table 1 shows the differences in image convergence, image divergence and distortion ratio between the hyperbolic imaging system, the single-curved imaging system and the automotive head-up display system of the present invention, wherein the binocular standard specification is defined as image convergence less than 5 milliradians (mrad), image divergence less than 2.5 mrad, and distortion in the eyebox less than 5%. The hyperbolic imaging system includes two curved mirrors and a flat image source, and the single-curved imaging system includes one curved mirror and a flat image source.

[0043] Table 1

[0044]

[0045] According to the simulation results in Table 1, the automotive head-up display system has the same performance as the hyperbolic imaging system in terms of binocular vision specifications, and under the same optical performance, the automotive head-up display system has a lower cost and simpler processing method. In addition, the curved image source has a better binocular vision effect than the flat image source.

[0046] According to the above embodiments, the vehicle head-up display system and the light emitting diode device thereof utilize the temperature sensing circuit to sense the temperature and transmit the temperature to the electronic control unit, which performs temperature reduction control and brightness compensation.

[0047] The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Therefore, all equivalent changes and modifications to the shape, structure, characteristics and spirit described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A light emitting diode device, characterized in that: include: Light emitting diode module; A driving circuit, electrically connected to the light emitting diode module and used to drive the light emitting diode module to generate display light; A temperature sensing circuit is provided on the light emitting diode module and is used to sense temperature; A cooling device, arranged on the light emitting diode module; as well as An electronic control unit, electrically connected to the cooling device, the temperature sensing circuit and the driving circuit; The electronic control unit is used to receive the temperature and perform at least one brightness adjustment action. In the at least one brightness adjustment action, the electronic control unit increases the driving current output by the driving circuit to the light-emitting diode module according to the variation range of the temperature exceeding the temperature default value, so as to increase the brightness of the display light. Then the electronic control unit starts the cooling device to lower the temperature until the temperature is equal to the temperature default value. After the cooling device lowers the temperature, the electronic control unit reduces the driving current according to the variation range to reduce the brightness.

2. The light emitting diode device according to claim 1, wherein: The display light has white light, and the electronic control unit maintains the white coordinate of the display light unchanged when increasing or decreasing the driving current.

3. The light emitting diode device according to claim 1, wherein: The at least one brightness adjustment action includes multiple brightness adjustment actions.

4. The light emitting diode device according to claim 3, characterized in that: The electronic control unit is used for performing the multiple brightness adjustment actions at a fixed frequency.

5. The light emitting diode device according to claim 1, wherein: The temperature-lowering device is a heat-dissipating fan or a refrigeration device.

6. A head-up display system for a vehicle, provided in a vehicle, the head-up display system for a vehicle comprising: A curved image source for emitting image light including image information; as well as at least one free-form surface mirror is located on the optical path of the image light, and the at least one free-form surface mirror is used to reflect the image light to form the light to be imaged. The windshield of the vehicle is located on the optical path of the light to be imaged, and the windshield is used to reflect the light to be imaged to generate a virtual image. Wherein, the curved image source includes: Light emitting diode module; A driving circuit, electrically connected to the light emitting diode module and used to drive the light emitting diode module to generate display light; A temperature sensing circuit is provided on the light emitting diode module and is used to sense temperature; A cooling device, arranged on the light emitting diode module; an electronic control unit, electrically connected to the cooling device, the temperature sensing circuit and the driving circuit; the electronic control unit is used to receive the temperature and perform at least one brightness adjustment action, in which the electronic control unit increases the driving current output by the driving circuit to the light-emitting diode module according to the variation range of the temperature exceeding the temperature default value, so as to increase the brightness of the display light, and then the electronic control unit starts the cooling device again to reduce the temperature until the temperature is equal to the temperature default value, and after the cooling device reduces the temperature, the electronic control unit reduces the driving current according to the variation range to reduce the brightness; and The curved liquid crystal display panel is located on the optical path of the display light, and the curved liquid crystal display panel converts the display light into the image light.

7. The vehicle head-up display system according to claim 6, characterized in that: The display light has white light, and the electronic control unit maintains the white coordinate of the display light unchanged when increasing or decreasing the driving current.

8. The vehicle head-up display system according to claim 6, characterized in that: The at least one brightness adjustment action includes multiple brightness adjustment actions.

9. The vehicle head-up display system according to claim 8, characterized in that: The electronic control unit is used for performing the multiple brightness adjustment actions at a fixed frequency.

10. The vehicle head-up display system according to claim 6, characterized in that: The temperature-lowering device is a heat-dissipating fan or a refrigeration device.

11. The vehicle head-up display system according to claim 6, characterized in that: The greater the field curvature of the curved image display surface of the curved image source, the smaller the primary astigmatism of the virtual image; the greater the spherical aberration of the curved image display surface of the curved image source, the smaller the secondary astigmatism of the virtual image.

12. The vehicle head-up display system according to claim 6, characterized in that: The point coordinates of the curved image display surface of the curved image source are (x, y, z), and the point coordinates are located in the three-dimensional coordinate system formed by the X-axis, the Y-axis and the Z-axis. x, y, and z are the coordinate values ​​on the X-axis, the Y-axis and the Z-axis respectively, and z = c1x 2 + c2xy + c3y 2 , the point coordinates of the origin of the curved image display surface are (0, 0, 0), c1 is -1.05×10 -2 to 1.05×10 -2 , c2 is -3×10 -3 Up to 3×10 -3 , c3 is -1.05×10 -2 to 1.05×10 -2 .

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