Display module and head-up display system

Abstract

The invention discloses a display module and a head-up display system. The display module comprises a transparent substrate; the light-emitting element is arranged on one side of the transparent substrate; the plurality of light-emitting elements are arranged in an array; the first color changing layer is arranged on one side, far away from the light emitting element, of the transparent substrate; wherein the light transmittance of the first color changing layer is adjustable. According to the technical scheme provided by the invention, the view field is not blocked while the head-up display effect is improved.

Description

Technical Field

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

[0002] Head Up Display (HUD) technology has gradually been widely used in the automotive field. Head Up Display projects important information (such as vehicle speed, navigation, etc.) displayed on the instrument panel during driving onto the front windshield, so that the driver can see the information on the instrument panel without lowering his head. This can not only help novices who lack experience in speed judgment to control their speed and avoid speeding violations in speed-limited sections, but more importantly, it can enable the driver to read the information instantly without shifting the large field of vision, and always maintain the best observation state.

[0003] There are two main display modes of existing head-up displays: one is the traditional display screen type, which is directly hung on the edge of the windshield for display, but it will cause a blind spot in the driver's field of vision; the other is a projection display screen, which projects the image onto the front windshield through reflection through an image generation module, but the imaging effect is poor. Summary of the invention

[0004] Embodiments of the present invention provide a display module and a head-up display system to improve the head-up display effect while not blocking the field of view.

[0005] In a first aspect, an embodiment of the present invention provides a display module, comprising: a transparent substrate;

[0006] A light emitting element is disposed on one side of the transparent substrate; a plurality of the light emitting elements are arranged in an array;

[0007] A first color-changing layer is disposed on a side of the transparent substrate away from the light-emitting element;

[0008] Wherein, the light transmittance of the first color-changing layer is adjustable.

[0009] In the second aspect, an embodiment of the present invention further provides a head-up display system, comprising a display module provided by any embodiment of the present invention; the head-up display system is integrated in the front windshield of the vehicle or on the central control platform in front of the steering wheel; the first color-changing layer of the display module is arranged on the side away from the steering wheel.

[0010] In the present invention, the display module includes a first color-changing layer, a transparent substrate and a light-emitting element arranged in sequence. The light-emitting element is bound, attached or welded on the transparent substrate and can emit light of corresponding colors. Then the display module forms a transparent display effect and can be used as a head-up display screen of the vehicle to achieve assisted driving. And a first color-changing layer is formed on the back of the transparent substrate, and the light transmittance of the first color-changing layer can be adjusted. When the driver needs to obtain clear road information, the first color-changing layer can be adjusted to a transparent state or a high-transparency state; when the driver needs a high-ratio display screen, the first color-changing layer can be adjusted to a non-transparent state or a low-transparency state. The display module provided in this embodiment can be applied to a head-up display screen, and the display module in a transparent state will not form a blind spot in the driver's field of vision, providing the driver with assisted driving information while improving driving safety performance. In addition, the display module of this embodiment is not a projection imaging, but the screen is directly displayed by the display module, and the imaging quality is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic diagram of the structure of a display module provided by an embodiment of the present invention;

[0012] Figure 2 A schematic diagram of the structure of another display module provided by an embodiment of the present invention;

[0013] Figure 3 A schematic diagram of the structure of a printed circuit board provided by an embodiment of the present invention;

[0014] Figure 4 A schematic structural diagram of a first color-changing layer provided in an embodiment of the present invention;

[0015] Figure 5 A schematic diagram of the structure of another display module provided by an embodiment of the present invention;

[0016] Figure 6 A schematic diagram of the structure of a head-up display system provided by an embodiment of the present invention;

[0017] Figure 7 A schematic diagram of the structure of another head-up display system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0019] From the above, it can be seen that in the prior art, due to the existence of an opaque panel structure, the rear of the traditional display screen is opaque, and the HUD technology will block part of the windshield and cause a blind spot in the field of vision; and the disadvantage of the projection solution is that the image quality is reduced after the image is projected, and the light has a greater impact on the imaging effect.

[0020] To solve the above problems, an embodiment of the present invention provides a display module, such as Figure 1 As shown, Figure 1 A schematic diagram of the structure of a display module provided by an embodiment of the present invention, the display module comprises: a transparent substrate 11;

[0021] The light emitting element 12 is disposed on one side of the transparent substrate 11; a plurality of light emitting elements 12 are arranged in an array;

[0022] The first color-changing layer 13 is disposed on a side of the transparent substrate 11 away from the light-emitting element 12;

[0023] The light transmittance of the first color-changing layer 13 is adjustable.

[0024] Specifically, the display module includes a first color-changing layer 13, a transparent substrate 11 and a light-emitting element 12 which are arranged in sequence. The transparent substrate 11 is a transparent material, and illustratively, other materials may be PI, PET or transparent glass. And the first color-changing layer 13 is a film layer that can adjust the light transmittance under the action of voltage or electric field. illustratively, the first color-changing layer 13 can be converted between a transparent state or a non-transparent state, and can also be converted between a high transparent state and a low transparent state, wherein the light transmittance of the first color-changing layer 13 in the transparent state is greater than the light transmittance of the first color-changing layer 13 in the non-transparent state, and the light transmittance of the first color-changing layer 13 in the high transparent state is greater than the light transmittance of the first color-changing layer 13 in the low transparent state. Optionally, in this embodiment, the first color-changing layer 13 may only include two states with different light transmittances, and there may be multiple states between the transparent state and the non-transparent state, and the light transmittance of each state is different, thereby realizing multi-level adjustment of the light transmittance of the first color-changing layer 13.

[0025] The transparent substrate 11 may also be provided with an electrode pad electrically connected to the electrode driving the light-emitting element 12 to provide the light-emitting element 12 with a working current. The light-emitting elements 12 arranged in an array can display the corresponding display screen, and because the first color-changing layer 13 is light-transmissive, the display module can allow ambient light to pass through the display module while displaying videos or pictures normally, thereby achieving a transparent display. When the user needs to view the surrounding environment through the display module, the first color-changing layer 13 can be controlled to be in a transparent state to achieve a transparent display of the display module; and when the user needs to obtain a clearer display screen, the light transmittance of the first color-changing layer 13 can be controlled to be reduced to achieve a high-contrast display of the display module. Optionally, such as Figure 1 As shown, the light-emitting element 12 may include a red light-emitting element 121, a green light-emitting element 122 and a blue light-emitting element 123, or the light-emitting element may also include a red light-emitting element, a green light-emitting element, a blue light-emitting element and a white light-emitting element. This embodiment does not specifically limit the type of the light-emitting element.

[0026] In the prior art, transparent LED display screens often use strip light strips to achieve light transmission. However, since there are large gaps between adjacent light strips, the spacing between adjacent LED lights is large, and high-resolution screen display cannot be achieved. In this embodiment, a transparent substrate 11 is directly used. The circuit layer driving the light-emitting element 12 on the transparent substrate 11 can be made of transparent material or metal grid material, so that the light-emitting element 12 is evenly arranged on the plane of the entire display module, which can achieve a smaller spacing between light-emitting points, better flatness, and improve the screen display resolution, and can display more complex images or videos. In this embodiment, the display module can be used in the field of head-up display of vehicles, the design of advertising walls in shopping malls, and other fields that require transparent display. This embodiment does not specifically limit its application field.

[0027] In an embodiment of the present invention, the display module includes a first color-changing layer, a transparent substrate and a light-emitting element arranged in sequence. The light-emitting element is bound, attached or welded on the transparent substrate and can emit light of corresponding colors. Then the display module forms a transparent display effect and can be used as a head-up display screen of the vehicle to achieve assisted driving. And a first color-changing layer is formed on the back of the transparent substrate, and the light transmittance of the first color-changing layer can be adjusted. When the driver needs to obtain clear road information, the first color-changing layer can be adjusted to a transparent state or a high-transparency state; when the driver needs a high-ratio display screen, the first color-changing layer can be adjusted to a non-transparent state or a low-transparency state. The display module provided in this embodiment can be applied to a head-up display screen, and the display module in a transparent state will not form a blind spot in the driver's field of vision, providing the driver with assisted driving information while improving driving safety performance. In addition, the display module of this embodiment is not a projection imaging, but is directly displayed by the display module, and the imaging quality is high.

[0028] The above is the core idea of ​​the present invention. The technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Figure 2A schematic diagram of the structure of another display module provided in an embodiment of the present invention, optionally, the transparent substrate 11 can be a printed circuit board made of glass as a base material; a first pad 111 and a second pad 112 are provided on one side of the printed circuit board close to the light-emitting element 12; the first pole of the light-emitting element 12 is electrically connected to the first pad 111; the second pole of the light-emitting element 12 is electrically connected to the second pad 112.

[0030] Traditional printed circuit boards PCB usually use plastic substrates, while the printed circuit board in this embodiment uses glass as the substrate material. Glass Substrate PCB is a printed circuit board that uses glass material as a substrate. Glass-based circuit boards have excellent thermal stability and mechanical strength, and can maintain stability under high temperature and high humidity environments. And the glass substrate has a lower coefficient of thermal expansion, which can provide better dimensional stability and high-precision circuit layout. In addition, the glass substrate also has excellent insulation properties, chemical corrosion resistance and wear resistance. Because the display module of this embodiment needs to display high-precision images, the printed circuit board using glass material as a substrate can provide higher circuit density, better signal transmission performance and a more stable working environment, and also has a longer service life and a lower failure rate, while ensuring that the printed circuit board is light-transmitting, while improving the performance of the display module. The light-emitting element 12 includes a first electrode (e.g., a positive electrode) and a second electrode (e.g., a negative electrode), and the circuit layer of the transparent substrate 11 can provide driving voltages for the first electrode and the second electrode, respectively. Specifically, the circuit layer on the transparent substrate 11 is provided with a first pad 111 and a second pad 112, and the first pad 111 provides voltage for the first electrode, and the second pad 112 provides voltage for the second electrode.

[0031] Figure 3 A structural schematic diagram of a printed circuit board provided for an embodiment of the present invention, optionally, the printed circuit board may include a glass substrate 113, a circuit group layer 114 and a transparent solder resist ink layer 116 which are sequentially away from the first color change layer 13; the circuit group layer 114 includes a plurality of conductive material layers 118; a conductive material layer 118 which is closest to the light emitting element 12 among the plurality of conductive material layers 118 is provided with the first solder pad 111 and the second solder pad 112; in a plane parallel to the transparent substrate, there is no overlapping area between the transparent solder resist ink layer 116 and the first solder pad 111 and the second solder pad 112.

[0032] The circuit group layer 114 is used to form a circuit for driving the corresponding light-emitting element 12. Optionally, each light-emitting element 12 can be individually controlled to emit light through the circuit. The circuit group layer 114 may include a plurality of conductive material layers 118, and the conductive material layers 118 are used to form connecting terminals or connecting circuits. The two adjacent conductive material layers 118 are electrically insulated by an insulating layer 117. The layer closest to the light-emitting element 12 in the plurality of conductive material layers 118 forms a first pad 111 and a second pad 112, etc. In addition, a layer of transparent solder resist ink 116 is coated on the circuit group layer 114, and the transparent solder resist ink 116 can expose the first pad 111 and the second pad 112, and cover other metal traces to avoid welding short circuits, thereby playing a protective role and extending the service life of the PCB. The main components of the transparent solder resist ink layer 116 include pigments, high temperature resistant polymer resins, cross-linked resins, photoinitiators, additives, etc. High temperature resistant polymer resins and cross-linked resins are the materials that constitute its basic skeleton, with good insulation performance, fire resistance, oil resistance, water resistance, acid and alkali resistance, wear resistance, and good corrosion resistance. After receiving or absorbing external energy, the photoinitiator undergoes chemical changes, and can initiate polymerization under the action of ultraviolet light. It is a key component in the photocuring process. The pigment is responsible for providing the color and hiding power of the ink, and the additive is used to adjust the viscosity, drying speed and other properties of the ink to meet different application requirements. The transparent solder resist ink layer 116 is mainly used as a protective layer, coated on the circuits and substrates that do not need to be soldered on the printed circuit board, or used as a solder resist to protect the formed circuit graphics for a long time. The solder resist ink layer has a variety of colors, such as green, black, red, blue, yellow, white, etc. This embodiment realizes the design of the transparent solder resist ink layer 116 by adjusting the pigment, so that the printed circuit board is transparent. Optionally, the conductive material layer 118 can be a metal nanofilm, an oxide film layer, a polymer film layer, a composite film layer, silver nanowires, MXene, graphene or carbon nanotubes. Among them, the metal nanofilm can be a nanofilm of metals such as gold, silver, and copper; the oxide film layer can be a material such as ITO, AZO, GZO, etc.; the polymer film layer can be a material such as polythiophene, polyaniline, polypyrrole, etc. and their derivatives, conductive fillers (such as carbon nanotubes, metal nanowires, etc.) and polymer matrix composites. The material of the above-mentioned conductive material layer 118 can form a transparent film layer that will not block ambient light, so as to further realize the transparent design of the printed circuit board. In addition, the conductive material layer 118 can also be a grid-shaped metal material, so that the gaps between the grids can realize the design of the transparent substrate 11.

[0033] Continue to refer Figure 3, Optionally, the display module may also include: an encapsulation layer 14; the encapsulation layer 14 is arranged on the side of the light-emitting element 12 away from the transparent substrate 11; the light-emitting element 12 is an LED, Mini-LED or Micro-LED. With the rapid development of gallium nitride LED display technology, especially the miniaturization of LED, 100 micron (Mini-LED) or even micron-level LED (Micro-LED) can be manufactured, making it possible to manufacture high-resolution LED displays. Since LED, Mini-LED and Micro-LED are active luminescent, they do not rely on organic compounds to emit light. Theoretically, their display quality is like OLED, but it is brighter and has a longer life. In addition, LED, Mini-LED and Micro-LED can be directly welded on a printed circuit board, and the manufacturing process is very simple. An encapsulation layer 14 is formed on the light-emitting element 12, and the encapsulation layer 14 can protect the light-emitting element 12, effectively prevent water and oxygen from invading, and improve the reliability of the display module. In this embodiment, the display module can be integrated into the automotive glass of the vehicle and the glass wall of the advertising wall to form an electrically controlled smart glass. Optionally, the light emitting element 12 can be bonded to the first pad 111 and the second pad 112 using materials such as anisotropic conductive adhesive ACF and prefabricated tin. When the light emitting element 12 and the conductive material layer 118 are bonded together using ACF or prefabricated tin, a strong electrical connection between the light emitting element 12 and the corresponding connection end can be achieved, and the problem of solder overflow at the bonding point can be avoided, thereby reducing the reflective area of ​​the solder and improving the display effect of the display module.

[0034] Figure 4 A structural schematic diagram of a first color-changing layer provided in an embodiment of the present invention, optionally, the first color-changing layer 13 may include a first substrate 131, a first conductive electrode layer 132, a dimming layer 133, a second conductive electrode layer 134 and a second substrate 135 which are sequentially away from the transparent substrate 11; the first conductive electrode layer 132 is electrically connected to the first voltage output terminal; the second conductive electrode layer 134 is electrically connected to the second voltage output terminal; the first difference between the first voltage outputted from the first voltage output terminal and the second voltage outputted from the second voltage output terminal is adjustable; the dimming layer 133 is used to adjust the light transmittance under the control of the first difference, so that the first color-changing layer 13 can be switched between a transparent state and a non-transparent state, or between a high transparency state and a low transparency state.

[0035] The first color-changing layer 13 is a film layer that can change the light transmittance through voltage or electric field, and includes a first substrate 131 and a second substrate 135 that are arranged opposite to each other. The first substrate 131 and the second substrate 135 are transparent materials such as PI or PET. A first conductive electrode layer 132 and a second conductive electrode layer 134 are also arranged between the first substrate 131 and the second substrate 135. The first conductive electrode layer 132 and the second conductive electrode layer 134 can also be transparent conductive materials such as IRO. The first conductive electrode layer 132 outputs a first voltage, and the second conductive electrode layer 134 outputs a second voltage. A first difference is formed between the first voltage and the second voltage. A dimming layer 133 is formed between the first conductive electrode layer 132 and the second conductive electrode layer 134. The light transmittance of the dimming layer 133 changes with the change of the first difference. For example, in the field of head-up display, when the driver needs to observe the road conditions while obtaining the display information of the display module, the dimming layer 133 can be controlled to be in a transparent state; when the driver has sun protection needs or privacy protection needs, the dimming layer 133 can be controlled to be in a non-transparent state to prevent external light from penetrating the display module. When the dimming layer 133 is in a transparent state, if the ambient light is bright, the dimming layer 133 can be controlled to be in a low-transparency state to increase the contrast between the first color-changing layer 13 and the light-emitting element 12, thereby improving the display clarity of the display module; if the ambient light is dark, the dimming layer 133 can be controlled to be in a high-transparency state to prevent the display module from blocking the ambient light.

[0036] Optionally, the light transmittance ranges from 30% to 90%; the display module also includes: a light sensor; the light sensor is used to measure ambient light; the light transmittance of the dimming layer is adjusted according to the ambient light. In this embodiment, the display module may include a light sensor, which may be arranged on the side wall of the display module, or may be arranged on the central control platform. The vehicle controller may automatically adjust the first difference between the first voltage and the second voltage according to the ambient light measured by the light sensor, thereby adjusting the light transmittance of the dimming layer, ensuring that the display module displays the picture clearly while avoiding the display module from blocking the ambient light, thereby improving the driving safety performance of the driver.

[0037] Optionally, the above transparent state can be divided into a high transparent state and a low transparent state. When the display module is applied to a head-up display system, when the brightness of the external environment is high and the image displayed by the display module is not clear, the dimming layer 133 can be controlled to a low transparent state to enhance the contrast of the display module; when the brightness of the external environment is low and the driver cannot see the road conditions clearly, the dimming layer 133 can be controlled to a high transparent state to increase the amount of light entering from the external environment.

[0038] Optionally, the dimming layer 133 may be one of a polymer dispersed liquid crystal layer (PDLC), a liquid crystal layer (LC), an electrochromic layer (EC), and a suspended particle device (SPD).

[0039] Exemplarily, if the dimming layer 133 includes a polymer dispersed liquid crystal layer, which contains dispersed liquid crystal particles, the light transmittance can be controlled by voltage regulation, so that the dimming layer 133 can be infinitely adjusted between a transparent state and a fogged state, and the polymer dispersed liquid crystal layer has a low cost and is conducive to large-area settings, then this embodiment can form a larger display module on the windshield.

[0040] If the dimming layer 133 includes a liquid crystal layer and liquid crystal molecules are arranged between the two PS supporting layers, the orientation of the liquid crystal is changed by the electric field, thereby infinitely adjusting the light transmittance, and the liquid crystal layer has better heat insulation performance. When there is a need for sun protection, the dimming layer 133 preferably uses a liquid crystal layer.

[0041] If the dimming layer 133 includes an electrochromic layer, specifically, the dimming layer 133 may include an electrochromic layer, a dielectric and an ion storage layer arranged in sequence. When an electric field is applied from the ion storage layer to the electrochromic layer, the electrochromic layer is colored to reduce the light transmittance. When an electric field is applied from the electrochromic layer to the ion storage layer, the electrochromic layer fades to increase the light transmittance. When the driver has privacy requirements, the dimming layer 133 is preferably an electrochromic layer.

[0042] If the dimming layer 133 includes a suspended particle layer, the dimming layer 133 can control the light transmittance by changing the arrangement of the suspended particles in the electric field. When the dimming layer 133 is in the electric field, it is in a transparent state, and when the dimming layer 133 is not in the electric field, it is in a non-transparent state, and the dimming speed of the suspended particle layer is faster.

[0043] Figure 5 A structural schematic diagram of another display module provided for an embodiment of the present invention, optionally, the display module may further include: a second color-changing layer 15; the second color-changing layer 15 is arranged on the side of the light-emitting element 12 away from the transparent substrate 11; the light transmittance of the second color-changing layer 15 is adjustable; the light transmittance of the first color-changing layer 13 is greater than the light transmittance of the second color-changing layer 15, so as to display setting information on the side of the display module close to the first color-changing layer 13; the setting information is contact information, emergency information or advertising information.

[0044] When the display module is used in the field of head-up display, the first color-changing layer 13 can be on the side away from the driver, and the second color-changing layer 15 can be on the side close to the driver. The light transmittance of the first color-changing layer 13 and the second color-changing layer 15 is adjustable. For example, when the driver needs to advertise or has key information to be displayed to the outside world, it is necessary to control the light transmittance of the first color-changing layer 13 to be greater than the light transmittance of the second color-changing layer 15, so that people outside the vehicle can clearly obtain the set information, and the set information is contact information, emergency information or advertising information, etc. Of course, when the driver needs to display navigation information, vehicle speed information and other data that he needs to observe, the light transmittance of the second color-changing layer 15 can be adjusted to be greater than the first color-changing layer 13.

[0045] An embodiment of the present invention also provides a head-up display system. Figure 6 A schematic diagram of the structure of a head-up display system provided by an embodiment of the present invention is shown in FIG. Figure 7 FIG. 1 is a schematic diagram of another head-up display system provided by an embodiment of the present invention. Figure 6 and Figure 7 As shown, the head-up display system provided in the embodiment of the present invention includes the display module 200 described in any embodiment of the present invention. Figure 7 As shown, the head-up display system can be integrated into the front windshield 300 of the vehicle 100, or integrated into the front windshield 300 of the vehicle 100. Figure 6 In this embodiment, the first color-changing layer of the display module 200 is arranged on the side away from the steering wheel, and the light-emitting element is close to the driver's side, so that the driver can obtain a clearer display image, and at the same time, the display effect of the head-up display screen is improved while realizing transparent display. Figure 7 As shown, the area occupied by the display module 200 on the windshield 300 can be set according to user needs.

[0046] The head-up display system provided by the embodiment of the present invention includes the technical features of the display module provided by any embodiment of the present invention, and has the beneficial effects of the corresponding technical features, which will not be repeated here.

[0047] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A display module, characterized in that: include: Transparent substrate; A light emitting element is disposed on one side of the transparent substrate; A plurality of said light emitting elements are arranged in an array; A first color-changing layer is disposed on a side of the transparent substrate away from the light-emitting element; Wherein, the light transmittance of the first color-changing layer is adjustable.

2. The display module according to claim 1, characterized in that: The transparent substrate is a printed circuit board made of glass as a base material; A first pad and a second pad are provided on one side of the printed circuit board close to the light emitting element; the first electrode of the light emitting element is electrically connected to the first pad; and the second electrode of the light emitting element is electrically connected to the second pad.

3. The display module according to claim 2, characterized in that: The printed circuit board comprises a glass substrate, a circuit assembly layer and a transparent solder resist ink layer which are sequentially away from the first color-changing layer; The circuit assembly layer comprises multiple conductive material layers; an insulating layer is formed between adjacent conductive material layers; a conductive material layer closest to the light emitting element among the multiple conductive material layers is provided with the first pad and the second pad; In a plane parallel to the transparent substrate, there is no overlapping area between the transparent solder resist ink layer and the first pad and the second pad.

4. The display module according to claim 3, characterized in that: The conductive material layer is a metal nanofilm, an oxide film layer, a polymer film layer, a composite film layer, a silver nanowire, MXene, graphene or a carbon nanotube.

5. The display module according to claim 1, characterized in that: The first color-changing layer comprises a first substrate, a first conductive electrode layer, a dimming layer, a second conductive electrode layer and a second substrate which are sequentially away from the transparent substrate; The first conductive electrode layer is electrically connected to the first voltage output terminal; the second conductive electrode layer is electrically connected to the second voltage output terminal; a first difference between a first voltage output from the first voltage output terminal and a second voltage output from the second voltage output terminal is adjustable; The dimming layer is used to adjust light transmittance under the control of the first difference.

6. The display module according to claim 5, characterized in that: The display module further includes: a light sensor; the light sensor is used to measure ambient light; The light transmittance of the dimming layer is adjusted according to the ambient light.

7. The display module according to claim 5, characterized in that: The dimming layer is one of a polymer dispersed liquid crystal layer, an electrochromic layer and a suspended particle layer.

8. The display module according to claim 1, characterized in that: Also includes: Encapsulation layer; The encapsulation layer is arranged on a side of the light emitting element away from the transparent substrate; The light emitting element is LED, Mini-LED or Micro-LED.

9. The display module according to claim 1, characterized in that: Also includes: The second color changing layer; The second color-changing layer is arranged on a side of the light-emitting element away from the transparent substrate; the light transmittance of the second color-changing layer is adjustable; The light transmittance of the first color-changing layer is greater than the light transmittance of the second color-changing layer, so that setting information is displayed on the side of the display module close to the first color-changing layer; the setting information is contact information, emergency information or advertising information.

10. A head-up display system, characterized in that: The display module comprises any one of claims 1 to 9 above; the head-up display system is integrated in the front windshield of the vehicle or on the central control platform in front of the steering wheel; The first color-changing layer of the display module is arranged on a side away from the steering wheel.

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