Vehicle window projection display system, liquid crystal film manufacturing method, and vehicle

Abstract

The application discloses a vehicle window projection display system, a liquid crystal film manufacturing method and a vehicle, and relates to the technical field of vehicle window display. The disclosed vehicle window projection display system comprises a first liquid crystal film arranged on a vehicle window glass. The first liquid crystal film is used for scattering polarized light emitted by a projection device to display a projection image carried by the polarized light on the vehicle window glass. A photo-thermal material and dye molecules are arranged in liquid crystal micro-zones of the first liquid crystal film. Heat is generated by the photo-thermal material absorbing near-infrared light in natural light to induce long axes of each liquid crystal molecule to be oriented in various directions, and long axes of each dye molecule are also driven to be oriented in various directions. The light absorption capacity of the dye molecules is enhanced, the absorption of external strong light is realized, the background brightness during projection image display is reduced, the visual contrast is improved, and the visual experience of the driver and the passenger is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle window display technology, and in particular to a vehicle window projection display system, a liquid crystal film manufacturing method, and a vehicle. Background Technology

[0002] With the development of automotive intelligent cockpit technology, transparent window display, as an augmented reality display technology that can directly present vehicle status, road condition information and entertainment content on the window while maintaining high transmittance of the environmental background, can provide drivers and passengers with an immersive visual experience.

[0003] Currently, a common method for transparent displays in car windows is projection technology, which involves projecting an image emitted by a projector directly onto the car window glass, using the reflection from the glass surface to project the image into the viewer's eyes. However, with this display method, when external sunlight is strong, a large amount of natural light enters the car through the window, superimposing on the projected image. This results in excessively high background brightness and severely reduced contrast of the projected image, leading to a poor overall visual effect and negatively impacting the viewing experience of drivers and passengers. Summary of the Invention

[0004] The main purpose of this application is to provide a vehicle window projection display system, a liquid crystal film manufacturing method, and a vehicle, aiming to solve the technical problem that the overall visual effect of the prior art is not good, which affects the viewing experience of drivers and passengers.

[0005] To achieve the above objectives, this application proposes a vehicle window projection display system, the vehicle window projection display system comprising: A first liquid crystal film disposed on the vehicle window glass is used to scatter polarized light emitted by the projection device in order to display the projected image carried by the polarized light on the vehicle window glass. The first liquid crystal film contains at least one liquid crystal microregion, which includes: a photothermal material, multiple liquid crystal molecules, and multiple dye molecules; The long axis of the dye molecules is aligned with the long axis of the liquid crystal molecules. When the illumination intensity of the natural light is less than or equal to a preset intensity threshold, each liquid crystal molecule in the first liquid crystal film is in a vertical orientation state, wherein the long axis of each liquid crystal molecule is oriented in a direction perpendicular to the car window glass. The photothermal material is used to generate heat by absorbing near-infrared light in natural light when the intensity of natural light is greater than the preset intensity threshold. The heat induces the long axis of each liquid crystal molecule to align in various directions, thereby driving the long axis of each dye molecule to align in various directions, so that the natural light with the polarization direction parallel to the long axis of the dye molecule is absorbed by the dye molecule.

[0006] In one embodiment, the vehicle window projection display system further includes: a polymer matrix; The polymer matrix contains the liquid crystal microregions; The first liquid crystal film is also used to scatter the polarized light emitted by the projection device based on the refractive index of the liquid crystal micro-region to the polarized light and the refractive index of the polymer matrix to the polarized light, so as to display the projected image carried by the polarized light on the car window glass.

[0007] In one embodiment, the liquid crystal microregion has a first refractive index for P-polarized light, and the polymer matrix has a second refractive index for the P-polarized light; The first refractive index and the second refractive index are inconsistent when the vertical orientation is in the stated state; The first liquid crystal film is also used to scatter the P-polarized light emitted by the projection device when each of the liquid crystal molecules is in the vertical orientation state and the first refractive index is inconsistent with the second refractive index, so as to display the projected image carried by the P-polarized light on the car window glass.

[0008] In one embodiment, the vehicle window projection display system further includes: a second liquid crystal film having a preset rotation direction; The second liquid crystal film is disposed between the first liquid crystal film and the outer glass of the vehicle window; The second liquid crystal film is used to reflect circularly polarized light in the natural light with the same preset rotation direction within a preset visible light band, and to transmit circularly polarized light in the natural light with the opposite preset rotation direction.

[0009] In one embodiment, the preset rotation direction of the second liquid crystal film is left-handed or right-handed.

[0010] In one embodiment, the second liquid crystal film is a broadband reflective cholesteric liquid crystal film.

[0011] In one embodiment, when the illumination intensity of the natural light exceeds the preset intensity threshold, each of the liquid crystal molecules in the first liquid crystal film is in a random orientation state, wherein the long axis of each liquid crystal molecule is oriented in various directions. The first liquid crystal film is also used to transmit P-polarized light emitted by the projection device when each of the liquid crystal molecules is in the random orientation state; The second liquid crystal film is used to reflect the portion of the transmitted P-polarized light that has the same rotation direction as the preset direction, so as to display the projected image carried by the P-polarized light on the car window glass.

[0012] In one embodiment, the method for fabricating the first liquid crystal thin film is as follows: The photocurable material, liquid crystal material, and photoinitiator are mixed evenly to form a mixture; The mixture is placed between the first transparent conductive film and the second transparent conductive film; The mixture is cured under the condition of applying voltage to the first transparent conductive film and the second transparent conductive film to obtain the first liquid crystal film.

[0013] In one embodiment, the step of curing the mixture to obtain a first liquid crystal film under the condition of applying a voltage to the first transparent conductive film and the second transparent conductive film includes: Pressure is applied to make the mixture evenly distributed between the first transparent conductive film and the second transparent conductive film; A voltage is applied to the first transparent conductive film and the second transparent conductive film to make the liquid crystal molecules in the liquid crystal material vertically oriented; While maintaining the voltage, the mixture is irradiated with a light source to cure the photocurable material into a polymer matrix, resulting in a cured mixture. During the curing process of the photocurable material, the liquid crystal molecules in the liquid crystal material undergo phase separation and aggregate to form multiple liquid crystal microregions composed of the liquid crystal molecules, and the liquid crystal microregions are distributed within the polymer matrix. The first transparent conductive film and the second transparent conductive film are peeled off from the cured mixture to obtain the first liquid crystal film.

[0014] This application also provides a vehicle that includes the window projection display system described above.

[0015] One or more technical solutions proposed in this application have at least the following technical effects: The vehicle window projection display system provided in this application includes: a first liquid crystal film disposed on the vehicle window glass, the first liquid crystal film being used to scatter polarized light emitted by a projection device to display a projected image carried by polarized light on the vehicle window glass; the first liquid crystal film having at least one liquid crystal micro-region, the liquid crystal micro-region including a photothermal material, liquid crystal molecules, and multiple dye molecules; the long axis direction of the dye molecules being consistent with the long axis direction of the liquid crystal molecules; each liquid crystal molecule in the first liquid crystal film being in a vertically oriented state when the illumination intensity of natural light is less than or equal to a preset intensity threshold, the vertical orientation state being that the long axis of each liquid crystal molecule is oriented in a direction perpendicular to the vehicle window glass; the photothermal material being used to generate heat by absorbing near-infrared light in natural light when the illumination intensity of natural light is greater than the preset intensity threshold, and to induce the long axis of each liquid crystal molecule to align in various directions through the heat, thereby driving the long axis of each dye molecule to align in various directions; so that natural light with a polarization direction parallel to the long axis of the dye molecules is absorbed by the dye molecules. This application provides photothermal materials and dye molecules within the liquid crystal micro-regions of the first liquid crystal film. The photothermal materials absorb natural light to generate heat, which induces the long axes of each liquid crystal molecule to align in various directions. This drives the long axes of each dye molecule to also align in various directions, thereby enhancing the light absorption capacity of the dye molecules. This allows the dye molecules to absorb natural light parallel to their long axes, achieving absorption of strong external light, reducing the background brightness when projecting images, improving visual contrast, and ultimately enhancing the viewing experience for drivers and passengers. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the first embodiment of the vehicle window projection display system of this application; Figure 2 This is a simplified schematic diagram of the scattering process in the first embodiment of this application; Figure 3 This is a schematic diagram of liquid crystal molecules in a vertically oriented state in the second embodiment of this application; Figure 4 This is a schematic diagram of liquid crystal molecules in a randomly oriented state in the second embodiment of this application; Figure 5 This is a schematic diagram of the structure of the third embodiment of the vehicle window projection display system of this application; Figure 6 This is a schematic flowchart of the liquid crystal thin film fabrication method of this application; Figure 7 This is a schematic diagram of the manufacturing process of the liquid crystal thin film in this application.

[0019] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0021] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0022] The main solution of this application embodiment is: a vehicle window projection display system includes a first liquid crystal film disposed on the vehicle window glass. The first liquid crystal film is used to scatter polarized light emitted by the projection device to display the projected image carried by the polarized light on the vehicle window glass. The first liquid crystal film is provided with at least one liquid crystal micro-region, which includes a photothermal material, multiple liquid crystal molecules, and multiple dye molecules. The long axis direction of the dye molecules is consistent with the long axis direction of the liquid crystal molecules. When the illumination intensity of natural light is less than or equal to a preset intensity threshold, each liquid crystal molecule in the first liquid crystal film is in a vertical orientation state, which means that the long axis of each liquid crystal molecule is oriented in a direction perpendicular to the vehicle window glass. The photothermal material is used to generate heat by absorbing near-infrared light in natural light when the illumination intensity of natural light is greater than the preset intensity threshold, and induces the long axis of each liquid crystal molecule to align in various directions through heat, thereby driving the long axis of each dye molecule to align in various directions, so that natural light with a polarization direction parallel to the long axis of the dye molecules is absorbed by the dye molecules.

[0023] Under the existing display method, when the external sunlight is strong, a large amount of natural light enters the car through the windows and overlaps with the projected image, resulting in excessively high background brightness and severely reduced contrast of the projected image. This leads to poor overall visual effect and affects the viewing experience of drivers and passengers.

[0024] This application provides a solution in which photothermal materials and dye molecules are disposed in the liquid crystal micro-regions of the first liquid crystal film. The photothermal materials absorb natural light to generate heat, thereby inducing the long axes of each liquid crystal molecule to align in various directions. This drives the long axes of each dye molecule to also align in various directions, thereby enhancing the light absorption capacity of the dye molecules. The dye molecules can absorb natural light parallel to the long axes of the dye molecules, thereby achieving the absorption of strong external light, reducing the background brightness when projecting images, improving visual contrast, and thus improving the viewing experience of drivers and passengers.

[0025] Based on this, embodiments of this application provide a vehicle window projection display system, referring to... Figure 1 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the vehicle window projection display system of this application.

[0026] In this embodiment, the vehicle window projection display system includes: A first liquid crystal film 20 is disposed on the window glass 10. The first liquid crystal film 20 is used to scatter polarized light emitted by the projection device 30 so as to display the projected image carried by the polarized light on the window glass 10.

[0027] It should be noted that the vehicle window glass 10 includes an outer glass layer 11 and an inner glass layer 12. The outer glass layer 11 may be a layer of glass facing the external environment of the vehicle. The inner glass layer 12 may be a layer of glass facing the interior of the vehicle's passenger compartment. The outer glass layer 11 and the inner glass layer 12 may be bonded together by one or more intermediate functional layers (such as PVB film) to form a solid whole.

[0028] Understandably, the first liquid crystal film 20 can be a composite film composed of a polymer matrix 24 and a plurality of liquid crystal microregions 21 dispersed therein. The first liquid crystal film 20 is embedded as a sandwich layer between the outer glass layer 11 and the inner glass layer 12, and is firmly bonded to the two glass layers through a sandwich glass process to form an integrated vehicle window glass assembly.

[0029] Furthermore, the first liquid crystal film 20 contains a plurality of liquid crystal microregions 21, and each liquid crystal microregion 21 contains a large number of liquid crystal molecules 22.

[0030] The liquid crystal microregion 21 can be a tiny spatial region formed inside the first liquid crystal film 20, which is formed by the aggregation of liquid crystal material and is distributed in a dispersed manner. Each liquid crystal microregion 21 is an independent liquid crystal phase unit, filled with liquid crystal molecules 22, and its size is typically on the order of micrometers. The boundary of the liquid crystal microregion 21 separates the internal liquid crystal molecules 22 from other external materials.

[0031] Liquid crystal molecules 22, as the basic units constituting the liquid crystal micro-region 21, are elongated and have fluidity. The liquid crystal molecules 22 can be arranged in a certain direction (e.g., vertical orientation or random orientation) within the liquid crystal micro-region 21, and their orientation affects the propagation path of incident light.

[0032] It should be noted that the projection device 30 can be an optical device capable of generating and emitting polarized light carrying a projected image. The projection device 30 can be concealed and installed inside or below the vehicle's dashboard, located below the driver's line of sight to avoid obstructing the driver's view. For example, it can be installed inside the driver's side dashboard (for windshield display), inside the passenger side dashboard (for passenger side window display), or in the central area of ​​the dashboard.

[0033] Reference Figure 2 , Figure 2 This is a simplified schematic diagram of the scattering process in the first embodiment of this application. After the user starts the projection device 30, the projection device 30 can modulate the projected image to be displayed onto polarized light and project the polarized light onto the inner glass 12 at a large angle. The inner surface of the inner glass 12 can be coated with an anti-reflection film to reduce reflection loss and allow most of the polarized light to pass through the inner glass 12 efficiently. The polarized light transmitted through the inner glass reaches the first liquid crystal film 20. When the polarized light enters the liquid crystal micro-region 21 of the first liquid crystal film 20, due to the angular relationship between the alignment direction of the liquid crystal molecules 22 and the vibration direction of the polarized light, the polarized light undergoes multiple changes in propagation direction inside the liquid crystal micro-region 21 and at the boundary of the liquid crystal micro-region 21, resulting in scattering. The scattered polarized light propagates in multiple directions, with a portion heading towards the inside of the vehicle, passing through the inner glass 12 again, and entering the eyes of the observer (driver or passenger). Because the projected image carried by the polarized light during scattering is preserved, the observer can receive this scattered light through the inner glass 12, thus seeing a clear projected image on the inner glass 12. At this time, natural light can pass through the outer glass 11, the first liquid crystal film 20, and the inner glass 12.

[0034] The first liquid crystal film 20 has at least one liquid crystal micro-region 21, and the liquid crystal micro-region 21 includes: photothermal material, multiple liquid crystal molecules 22 and multiple dye molecules 23.

[0035] The long axis of the dye molecule 23 is aligned with the long axis of the liquid crystal molecule 22.

[0036] Understandably, photothermal materials can be substances that absorb light energy and convert it into heat energy, such as organic photothermal dyes, carbon nanotubes, and gold nanoparticles. When these photothermal materials are exposed to natural light, they absorb energy from the light, causing their own temperature to rise, and then transfer the heat to other surrounding materials.

[0037] Figure 1 Although the photothermal material is not shown, it should be noted that the photothermal material is located in the liquid crystal micro-region 21 inside the first liquid crystal film 20, and is filled in the liquid crystal micro-region together with the liquid crystal molecules 22 and the dye molecules 23, and the photothermal material is uniformly mixed with the liquid crystal molecules 22 and the dye molecules 23.

[0038] Understandably, natural light can be sunlight from the external environment.

[0039] It should be noted that dye molecule 23 can be a dichroic organic molecule, whose absorption capacity depends on the angle between the polarization direction of the incident light and the long axis of the dye molecule. When the polarization direction of the light is parallel to the long axis of the dye molecule, the dye molecule absorbs the light most strongly; when the polarization direction of the light is perpendicular to the long axis of the dye molecule, the dye molecule absorbs the light least strongly.

[0040] In this process, dye molecules 23 dissolve in the liquid crystal medium composed of liquid crystal molecules 22 and are uniformly mixed with the liquid crystal molecules 22. Due to the ordered orientation of the liquid crystal molecules 22, the long axis of the dye molecules 23 spontaneously aligns along the long axis of the liquid crystal molecules 22 under the anchoring effect of the liquid crystal molecules 22. In the liquid crystal micro-region 21, the dye molecules 23 and the liquid crystal molecules 22 are filled together in the same liquid crystal micro-region 21 without any physical barriers between them, and are uniformly mixed. Therefore, the orientation of the dye molecules 23 is determined by the orientation of the liquid crystal molecules 22.

[0041] It should be understood that, Figure 1 The number of liquid crystal micro-regions 21, liquid crystal molecules 22, and dye molecules 23 shown is for illustrative purposes only and is not intended to limit the scope of this embodiment. The specific number of liquid crystal micro-regions 21, liquid crystal molecules 22, and dye molecules 23 can be adjusted according to the actual scenario.

[0042] When the illumination intensity of the natural light is less than or equal to the preset intensity threshold, each of the liquid crystal molecules 22 in the first liquid crystal film 20 is in a vertical orientation state, wherein the long axis of each liquid crystal molecule is oriented in a direction perpendicular to the window glass 10.

[0043] Understandably, the liquid crystal molecules 22 can maintain a vertically oriented state without an external electric field because a vertically oriented rigid polymer network is formed inside the first liquid crystal film 20. This vertically oriented rigid polymer network acts on the liquid crystal molecules 22 through surface anchoring forces, inducing the long axis of the liquid crystal molecules 22 to align perpendicular to the window glass 10. Specifically, during the preparation of the first liquid crystal film 20, a voltage is applied to pre-orient the liquid crystal molecules 22 vertically, and a photocurable material is cured to form a polymer matrix 24 while maintaining the voltage. The cured polymer matrix 24 contains a rigid network with a vertically oriented structure. This rigid network, through its surface anchoring forces, allows the liquid crystal molecules 22 to maintain a vertically oriented state even without an external voltage. Therefore, when the intensity of natural light is less than or equal to a preset intensity threshold, the liquid crystal molecules 22 can maintain their long axis perpendicular to the window glass 10 without relying on a continuous electric field.

[0044] The photothermal material is used to absorb near-infrared heat generated by natural light when the intensity of natural light is greater than a preset intensity threshold, and to induce the long axis of each liquid crystal molecule to align in various directions through the heat, so that the long axis of each dye molecule aligns in various directions.

[0045] It should be noted that the preset intensity threshold can be a pre-defined light intensity value, used to determine whether the current natural light is strong enough to require a change in the orientation of liquid crystal molecules. For example, the preset intensity threshold can be set to 50,000 lux; when the natural light intensity exceeds this value, it is considered a strong light environment.

[0046] In its implementation, the aforementioned photothermal material continuously monitors the intensity of natural light under illumination. When the photothermal material detects that the intensity of natural light exceeds a preset intensity threshold, it absorbs the near-infrared light energy from the natural light and converts it into heat. Subsequently, the photothermal material releases the generated heat into the interior of the liquid crystal micro-region 21, causing the temperature within the liquid crystal micro-region 21 to rise. The increased heat induces the liquid crystal molecules 22 within the liquid crystal micro-region 21 to transition from an ordered arrangement to a disordered state, causing the long axes of each liquid crystal molecule to align in various directions. Since the long axis of the dye molecule 23 is aligned with the long axis of the liquid crystal molecule 22, when the long axes of the liquid crystal molecules align in various directions, the long axes of the dye molecules also align accordingly.

[0047] The dye molecule 23 is used to absorb the natural light whose polarization direction is parallel to the long axis of the dye molecule.

[0048] In a specific implementation, with the long axis of the dye molecules 23 oriented in various directions, the dye molecules 23 can absorb natural light whose polarization direction is parallel to the long axis of the dye molecules. Since natural light contains light with various polarization directions, and the long axes of the dye molecules are distributed in various directions, light with different polarization directions in natural light can be absorbed by the corresponding dye molecules 23. Through the above absorption, the transmittance of the first liquid crystal film 20 decreases, that is, the blackness of the first liquid crystal film 20 increases, but the haze of the first liquid crystal film 20 remains at a low level. Therefore, in a strong light environment, the first liquid crystal film 20 can improve the contrast of the projected image by changing its own optical properties, thus ensuring the readability of the projected image.

[0049] This embodiment of the vehicle window projection display system includes: a first liquid crystal film disposed on the vehicle window glass, the first liquid crystal film being used to scatter polarized light emitted by the projection device to display a projected image carried by the polarized light on the vehicle window glass; the first liquid crystal film having at least one liquid crystal micro-region, the liquid crystal micro-region including a photothermal material, multiple liquid crystal molecules, and multiple dye molecules; the long axis direction of the dye molecules being consistent with the long axis direction of the liquid crystal molecules; each liquid crystal molecule in the first liquid crystal film being in a vertically oriented state when the illumination intensity of natural light is less than or equal to a preset intensity threshold, the vertical orientation state being that the long axis of each liquid crystal molecule is oriented in a direction perpendicular to the vehicle window glass; the photothermal material being used to generate heat by absorbing near-infrared light in natural light when the illumination intensity of natural light is greater than the preset intensity threshold, and to induce the long axis of each liquid crystal molecule to align in various directions through the heat, thereby driving the long axis of each dye molecule to align in various directions, so that natural light with a polarization direction parallel to the long axis of the dye molecules is absorbed by the dye molecules. In this embodiment, photothermal materials and dye molecules are disposed within the liquid crystal micro-regions of the first liquid crystal film. The photothermal materials absorb natural light to generate heat, which induces the long axes of each liquid crystal molecule to align in various directions. This drives the long axes of each dye molecule to also align in various directions, thereby enhancing the light absorption capacity of the dye molecules. The dye molecules can absorb natural light parallel to the long axes of the dye molecules, thus achieving the absorption of strong external light, reducing the background brightness when projecting images, improving visual contrast, and thereby improving the viewing experience of drivers and passengers.

[0050] Based on the first embodiment of this application, a second embodiment of this application is proposed. In the second embodiment of this application, content that is the same as or similar to that in the first embodiment described above can be referred to the above description and will not be repeated hereafter.

[0051] In this embodiment, we continue to refer to... Figure 1 The vehicle window projection display system also includes a polymer matrix 24.

[0052] The polymer matrix 24 contains the liquid crystal microregions 21.

[0053] The first liquid crystal film 20 is also used to scatter the polarized light emitted by the projection device 30 based on the refractive index of the liquid crystal micro-region 21 to the polarized light and the refractive index of the polymer matrix 24 to the polarized light, so as to display the projected image carried by the polarized light on the car window glass 10.

[0054] It should be noted that the polymer matrix 24 can be a solid framework material formed by polymerizing a photocurable material, such as an acrylate polymer. The polymer matrix 24 has a fixed refractive index, which can provide support and separation for the liquid crystal microregions 21. The polymer matrix 24 is a continuous phase, in which multiple liquid crystal microregions 21 are disposed, that is, the liquid crystal microregions 21 are dispersed inside the polymer matrix 24 and surrounded by the polymer matrix 24.

[0055] Understandably, the refractive index of the liquid crystal micro-region 21 for polarized light can be the equivalent refractive index value exhibited by the liquid crystal molecules 22 in the liquid crystal micro-region 21 for light with a specific polarization direction due to different orientation states. The refractive index of the polymer matrix 24 for polarized light can be the fixed refractive index value exhibited by the polymer matrix 24 as an isotropic material for light with different polarization directions.

[0056] In its implementation, polarized light enters the first liquid crystal film 20, passes through the polymer matrix 24, and encounters liquid crystal micro-regions 21 dispersed within the polymer matrix 24. Since the refractive index of the liquid crystal micro-regions 21 for polarized light differs from that of the polymer matrix 24, the polarized light undergoes a change in propagation direction at the interface between the liquid crystal micro-regions 21 and the polymer matrix 24, i.e., scattering occurs. The scattered polarized light propagates in multiple directions, with a portion pointing towards the interior of the vehicle, passing through the window glass 10, and entering the observer's eyes. Through this scattering effect based on refractive index differences, the first liquid crystal film 20 converts the polarized light emitted by the projection device 30 into scattered light carrying the projected image, thereby displaying the projected image carried by the polarized light on the window glass 10.

[0057] In this embodiment, the liquid crystal micro-region 21 has a first refractive index for P-polarized light, and the polymer matrix 24 has a second refractive index for the P-polarized light.

[0058] The first refractive index and the second refractive index are inconsistent when the vertical orientation is in the stated state.

[0059] It should be noted that P-polarized light can refer to polarized light whose electric field vibration direction is parallel to the plane of incidence.

[0060] Understandably, the first refractive index can refer to the equivalent refractive index value exhibited by the liquid crystal micro-region 21 in the first liquid crystal film 20 for P-polarized light in a vertically aligned state. The second refractive index can refer to the refractive index value of the polymer matrix 24 for P-polarized light.

[0061] The reason why the first and second refractive indices are inconsistent in the vertically oriented state is that, in the vertically oriented state, the long axis of the liquid crystal molecules 22 in the liquid crystal micro-region 21 is perpendicular to the direction of the window glass 10. The vibration direction of the P-polarized light is parallel to the incident plane. When the P-polarized light enters the liquid crystal micro-region 21 at a non-perpendicular incident angle, the effective refractive index exhibited by the liquid crystal micro-region 21 for the P-polarized light is the first refractive index, which is between the ordinary and extraordinary refractive indices of the liquid crystal micro-region 21. The polymer matrix 24 is an isotropic material, and its second refractive index for the P-polarized light is designed to be equal to or close to the ordinary refractive index of the liquid crystal micro-region 21. Since the first refractive index is greater than the ordinary refractive index of the liquid crystal micro-region 21, the first and second refractive indices are inconsistent.

[0062] Reference Figure 3 , Figure 3 This is a schematic diagram of liquid crystal molecules in a vertically aligned state according to the second embodiment of this application. The vertical alignment state refers to the arrangement of liquid crystal molecules 22 with their long axes perpendicular to the surface of the window glass 10. In this state, the long axes of all liquid crystal molecules 22 face the same direction, that is, perpendicular to the direction of the window glass 10. At this time, the dye molecules 23 maintain a vertically aligned state along with the liquid crystal molecules 22.

[0063] The first liquid crystal film 20 is also used to scatter the P-polarized light emitted by the projection device 30 when each of the liquid crystal molecules 22 is in the vertical orientation state and the first refractive index is inconsistent with the second refractive index, so as to display the projected image carried by the P-polarized light on the window glass 10.

[0064] In a specific implementation, when the intensity of natural light is less than or equal to a preset intensity threshold, the liquid crystal molecules 22 in the first liquid crystal film 20 are in a vertically aligned state. In this vertically aligned state, the long axis of each liquid crystal molecule 22 is perpendicular to the direction of the car window glass 10. At this time, the liquid crystal micro-region 21 has a first refractive index for P-polarized light, and the polymer matrix 24 has a second refractive index for P-polarized light, and the first and second refractive indices are not equal. When the projection device 30 emits P-polarized light that illuminates the first liquid crystal film 20, the first liquid crystal film 20 utilizes the inconsistency between the first and second refractive indices to scatter the P-polarized light emitted by the projection device 30. The scattered P-polarized light propagates in multiple directions, with a portion pointing towards the interior of the vehicle, passing through the car window glass 10, and entering the observer's eyes. Through this scattering effect, the first liquid crystal film 20 displays the projected image carried by the P-polarized light on the car window glass 10.

[0065] It should be understood that in a strong light environment where the intensity of natural light is less than or equal to a preset intensity threshold, the liquid crystal molecules 22 in the first liquid crystal film 20 are vertically aligned, causing the first liquid crystal film 20 to strongly scatter the P-polarized light emitted by the projection device 30 while maintaining high transparency. This scattering effect significantly increases the energy of the P-polarized light incident on the observer's eye, thereby improving the brightness of the projected image. Simultaneously, since the liquid crystal molecules 22 can maintain their alignment without an external electric field, the first liquid crystal film 20 does not require a transparent conductive film and a corresponding power supply circuit, simplifying the film structure and reducing material costs and process complexity. Therefore, the above solution achieves high-brightness projection display while ensuring high transmittance of the vehicle window glass 10, and has the advantages of simple structure and low cost.

[0066] Based on the first and second embodiments of this application, a third embodiment of this application is proposed. In this third embodiment, content that is the same as or similar to the first and second embodiments described above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 4 , Figure 4 This is a schematic diagram of the structure of the third embodiment of the vehicle window projection display system of this application.

[0067] In this embodiment, the vehicle window projection display system further includes a second liquid crystal film 40 having a preset rotation direction.

[0068] The second liquid crystal film 40 is disposed between the first liquid crystal film 20 and the outer glass 11 of the window glass 10.

[0069] It should be noted that the second liquid crystal film 40 can be a liquid crystal film with a helical molecular arrangement structure, such as a broadband reflective cholesteric liquid crystal film. The second liquid crystal film 40 is disposed between the first liquid crystal film 20 and the outer glass 11, that is, the second liquid crystal film 40 is located on the side of the outer glass 11 facing the inside of the vehicle, and the first liquid crystal film 20 is located on the side of the second liquid crystal film 40 facing the inside of the vehicle.

[0070] Understandably, the preset rotation direction can refer to the rotation direction of the circularly polarized light that can be reflected by the second liquid crystal film 40, which can be left-handed or right-handed.

[0071] Left-handed rotation refers to the direction in which the electric field vector rotates counterclockwise when viewed against the direction of light propagation. Right-handed rotation refers to the direction in which the electric field vector rotates clockwise when viewed against the direction of light propagation.

[0072] It should be noted that the preset visible light band can refer to the visible light band with a wavelength range within a pre-specified range, such as the visible light band from 400 nanometers to 800 nanometers.

[0073] The second liquid crystal film 40 is used to reflect circularly polarized light in the natural light with the same preset rotation direction within a preset visible light band, and to transmit circularly polarized light in the natural light with the opposite preset rotation direction.

[0074] It should be noted that circularly polarized light can refer to light whose electric field vector rotates around the direction of propagation during propagation, and the direction of rotation is divided into left-handed and right-handed.

[0075] In a specific implementation, the second liquid crystal film 40 is disposed between the first liquid crystal film 20 and the outer glass layer 11. When external natural light shines on the vehicle window glass 10, the natural light first passes through the outer glass layer 11 and then reaches the second liquid crystal film 40. The second liquid crystal film 40 has a preset rotation direction, such as left-hand or right-hand rotation. Within a preset visible light band, the second liquid crystal film 40 reflects the circularly polarized light in the natural light with the same preset rotation direction back, preventing it from entering the vehicle interior; at the same time, the second liquid crystal film 40 allows the circularly polarized light in the natural light with the opposite preset rotation direction to pass through, allowing this portion of the circularly polarized light to continue propagating inward, passing through the first liquid crystal film 20 and the inner glass layer 12 in sequence before entering the vehicle interior.

[0076] It should be understood that, through the selective reflection and transmission of the second liquid crystal film 40, the total amount of natural light entering the vehicle can be reduced, thereby reducing the background brightness and helping to improve the contrast of the projected image.

[0077] In this embodiment, when the illumination intensity of the natural light exceeds the preset intensity threshold, each of the liquid crystal molecules 22 in the first liquid crystal film 20 is in a random orientation state, wherein the long axis of each liquid crystal molecule is oriented in various directions.

[0078] Reference Figure 5 , Figure 5 This is a schematic diagram of liquid crystal molecules in a randomly oriented state according to the second embodiment of this application. The random orientation state refers to the arrangement of liquid crystal molecules 22 with their long axes pointing in different directions. In this state, the long axes of the liquid crystal molecules 22 no longer point in the same direction but are randomly distributed. At this time, the dye molecules 23 maintain a random orientation state along with the liquid crystal molecules 22.

[0079] The first liquid crystal film 20 is also used to transmit P-polarized light emitted by the projection device 30 when each of the liquid crystal molecules 22 is in the random orientation state.

[0080] In its implementation, when the intensity of natural light exceeds a preset intensity threshold, the liquid crystal molecules 22 in the first liquid crystal film 20 are in a randomly oriented state. In this random orientation state, the long axes of the liquid crystal molecules 22 are oriented in different directions, resulting in spatial non-uniformity of the refractive index of P-polarized light within the liquid crystal micro-region 21. Simultaneously, the refractive index of the polymer matrix 24 for P-polarized light is designed to be equal to or very close to the average refractive index of the liquid crystal micro-region 21 for P-polarized light, and there is no significant difference in refractive index between the liquid crystal micro-region 21 and the polymer matrix 24. Therefore, when P-polarized light emitted from the projection device 30 enters the first liquid crystal film 20, the propagation direction of the P-polarized light does not change at the interface between the liquid crystal micro-region 21 and the polymer matrix 24; that is, the P-polarized light does not scatter but propagates in a straight line through the first liquid crystal film 20, achieving transmission.

[0081] The second liquid crystal film 40 is used to reflect the portion of the transmitted P-polarized light that has the same rotation direction as the preset direction, so as to display the projected image carried by the P-polarized light on the window glass 10.

[0082] The P-polarized light passing through the first liquid crystal film 20 continues to propagate towards the outer glass 11, reaching the second liquid crystal film 40 located between the first liquid crystal film 20 and the outer glass 11. The second liquid crystal film 40 has a preset rotation direction, such as left-handed or right-handed. The P-polarized light emitted from the projection device 30 can be optically decomposed into two beams of circularly polarized light with equal energy and opposite rotation directions. One beam of circularly polarized light rotates in the same direction as the preset rotation direction of the second liquid crystal film 40, while the other beam rotates in the opposite direction. When these two beams of circularly polarized light are transmitted into the second liquid crystal film 40, the second liquid crystal film 40 reflects the beam of circularly polarized light with the same preset rotation direction, causing it to change its propagation direction and return towards the interior of the vehicle. At the same time, the second liquid crystal film 40 allows the circularly polarized light with the opposite preset rotation direction to pass through, allowing it to continue propagating towards the outer glass 11 and eventually exit the window. The circularly polarized light (carrying projected image information) reflected by the second liquid crystal film 40 passes back through the first liquid crystal film 20 and the inner glass 12 and enters the eyes of the observer inside the vehicle. Because the reflected light retains the projected image information carried by the P-polarized light, the observer can see the projected image on the window glass 10.

[0083] It should be understood that in the above process, the first liquid crystal film 20 ensures that the light signal emitted by the projection device 30 can be smoothly transmitted to the second liquid crystal film 40 and reflected for imaging by transmitting P-polarized light; the second liquid crystal film 40, on the other hand, uses a polarization-selective reflection mechanism to redirect some of the energy in the P-polarized light transmitted through the first liquid crystal film 20 back towards the human eye, thus achieving imaging in strong light environments. Through the synergistic effect of the first liquid crystal film 20 and the second liquid crystal film 40, the background brightness is darkened while retaining sufficient intensity of projected reflected light under strong light conditions, significantly improving the contrast and readability of the projected image, effectively suppressing glare, and thus enhancing the viewing experience of drivers and passengers in strong light environments.

[0084] In this embodiment, refer to Figure 6 , Figure 6 This is a schematic diagram of the fabrication method of the first liquid crystal film of this application. The fabrication method of the first liquid crystal film 20 includes steps S10 to S30: Step S10: Mix the photocurable material, liquid crystal material and photoinitiator evenly to form mixture 50.

[0085] It should be noted that the aforementioned photocurable materials can refer to liquid materials that can undergo polymerization reactions under light irradiation to form a polymer matrix, such as acrylate monomers or prepolymers.

[0086] Understandably, liquid crystal materials can refer to organic compounds that have a liquid crystal phase, such as nematic liquid crystals, used to form liquid crystal microregions and provide liquid crystal molecules.

[0087] It should be noted that photoinitiators can refer to substances that can absorb light energy and generate free radicals or cations, thereby initiating the polymerization of photocurable materials, such as benzoyl compounds.

[0088] Understandably, a mixture can refer to a liquid mixture formed by uniformly mixing photocurable materials, liquid crystal materials, and photoinitiators.

[0089] For ease of understanding, please refer to Figure 7 This embodiment will be illustrated by example. Figure 7 This is a schematic diagram illustrating the manufacturing process of the liquid crystal thin film in this application. Figure 7 In this process, a mixture 50 is formed by uniformly mixing a photocurable material, a liquid crystal material, and a photoinitiator in a predetermined ratio.

[0090] Step S20: Place the mixture 50 between the first transparent conductive film 61 and the second transparent conductive film 62.

[0091] It should be noted that both the first transparent conductive film 61 and the second transparent conductive film 62 can be flexible films or rigid substrates with a transparent conductive layer (e.g., indium tin oxide) deposited on their surfaces, used to apply voltage during the curing process to control the orientation of liquid crystal molecules.

[0092] In a specific implementation, the mixture 50 can be added to the first transparent conductive film 61 first, and then the second transparent conductive film 62 can be covered, so that the mixture is sandwiched between the first transparent conductive film 61 and the second transparent conductive film 62 by the mixture 50.

[0093] In step S30, the mixture 50 is cured under the condition of applying voltage to the first transparent conductive film 61 and the second transparent conductive film 62 to obtain the first liquid crystal film 20.

[0094] In a specific implementation, the first transparent conductive film 61 and the second transparent conductive film 62 are connected to an electrical device V. A voltage is applied to the first and second transparent conductive films 61 and 62 through the electrical device V, causing the liquid crystal molecules 22 in the liquid crystal material of the mixture to align along the electric field direction. While maintaining the voltage, the manufacturing equipment cures the mixture 50, for example, by irradiating the mixture with ultraviolet light, causing the photocurable material to undergo a polymerization reaction and solidify into a polymer matrix 24. Simultaneously, the liquid crystal material separates from the mixture to form liquid crystal microregions 21, and the liquid crystal molecules 22 are locked in a vertically oriented state after curing. After the curing process is completed, the manufacturing equipment obtains a first liquid crystal film 20.

[0095] In one feasible implementation, step S30 includes steps S301 to S304: Step S301: Apply pressure to make the mixture 50 evenly distributed between the first transparent conductive film 61 and the second transparent conductive film 62.

[0096] In practice, pressure can be applied (e.g., using a roller press to press the two transparent conductive films together) to make the mixture 50 evenly distributed between the first transparent conductive film 61 and the second transparent conductive film 62, thereby eliminating air bubbles and controlling the film thickness.

[0097] Step S302: Apply voltage to the first transparent conductive film 61 and the second transparent conductive film 62 to make the liquid crystal molecules in the liquid crystal material vertically oriented.

[0098] In a specific implementation, the first transparent conductive film 61 and the second transparent conductive film 62 can be connected to an electrical device V, and a voltage can be applied to the first transparent conductive film 61 and the second transparent conductive film 62 to generate an electric field between the first transparent conductive film 61 and the second transparent conductive film 62, so that the liquid crystal molecules 22 in the liquid crystal material are aligned along the direction of the electric field, that is, the liquid crystal molecules 22 are in a vertical orientation state.

[0099] In step S303, while maintaining the voltage, the mixture 50 is irradiated by a light source to cure the photocurable material into a polymer matrix 24, thereby obtaining the cured mixture.

[0100] During the curing process of the photocurable material, the liquid crystal molecules 22 in the liquid crystal material undergo phase separation and aggregate to form a plurality of liquid crystal microregions 21 composed of the liquid crystal molecules 22, and the liquid crystal microregions 21 are distributed within the polymer matrix 24.

[0101] In a practical implementation, the mixture 50 can be irradiated with a light source while maintaining the aforementioned voltage. Under light irradiation, the photocurable material undergoes a polymerization reaction and solidifies into a polymer matrix 24. During the curing process of the photocurable material, the liquid crystal molecules 22 in the liquid crystal material undergo phase separation due to decreased solubility, precipitating out of the mixture 50 and aggregating to form multiple liquid crystal microregions 21. These liquid crystal microregions 21 are composed of liquid crystal molecules 22 and are dispersed within the polymer matrix 24. After curing is complete, the cured mixture is obtained.

[0102] Step S304: Peel off the first transparent conductive film 61 and the second transparent conductive film 62 from the cured mixture to obtain the first liquid crystal film 20.

[0103] In a specific implementation, the first transparent conductive film 61 and the second transparent conductive film 62 can be peeled off from the cured mixture, so that the cured mixture can independently become the first liquid crystal film 20.

[0104] It should be understood that by applying a voltage 62 to the first transparent conductive film 61 and the second transparent conductive film, the liquid crystal molecules 22 in the liquid crystal material are pre-oriented vertically before curing. Photocuring is then performed while maintaining the voltage, resulting in the formation of a rigid polymer network with a vertically oriented structure within the polymer matrix 24 formed by the polymerization of the photocurable material. This rigid polymer network acts on the liquid crystal molecules through surface anchoring forces, enabling the liquid crystal molecules 22 to maintain their vertical orientation even without an external voltage. Therefore, the first liquid crystal film obtained using the above manufacturing process can maintain the vertical orientation of the liquid crystal molecules without relying on a transparent conductive film and continuous electrical drive, thus simplifying the film structure, eliminating the need for a transparent conductive film and its associated power supply circuit, and reducing material costs and process complexity.

[0105] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the vehicle window projection display system of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0106] This application also provides a vehicle that includes the window projection display system described above.

[0107] The vehicle provided in this application solves the technical problem of poor overall visual effect in existing technologies, which affects the viewing experience of drivers and passengers. Compared with the prior art, the beneficial effects of the vehicle provided in this application are the same as those of the window projection display system provided in the above embodiments, and will not be repeated here.

[0108] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A vehicle window projection display system, characterized in that, The vehicle window projection display system includes: A first liquid crystal film disposed on the vehicle window glass is used to scatter polarized light emitted by the projection device in order to display the projected image carried by the polarized light on the vehicle window glass. The first liquid crystal film contains at least one liquid crystal microregion, which includes: a photothermal material, liquid crystal molecules, and multiple dye molecules; The long axis of the dye molecules is aligned with the long axis of the liquid crystal molecules. When the illumination intensity of the natural light is less than or equal to a preset intensity threshold, each liquid crystal molecule in the first liquid crystal film is in a vertical orientation state, wherein the long axis of each liquid crystal molecule is oriented in a direction perpendicular to the car window glass. The photothermal material is used to generate heat by absorbing near-infrared light in natural light when the intensity of natural light is greater than the preset intensity threshold. The heat induces the long axis of each liquid crystal molecule to align in various directions, thereby driving the long axis of each dye molecule to align in various directions, so that the natural light with the polarization direction parallel to the long axis of the dye molecule is absorbed by the dye molecule.

2. The vehicle window projection display system as described in claim 1, characterized in that, The vehicle window projection display system also includes: a polymer matrix; The polymer matrix contains the liquid crystal microregions; The first liquid crystal film is also used to scatter the polarized light emitted by the projection device based on the refractive index of the liquid crystal micro-region to the polarized light and the refractive index of the polymer matrix to the polarized light, so as to display the projected image carried by the polarized light on the car window glass.

3. The vehicle window projection display system as described in claim 2, characterized in that, The liquid crystal micro-region has a first refractive index for P-polarized light, and the polymer matrix has a second refractive index for P-polarized light. The first refractive index and the second refractive index are inconsistent when the vertical orientation is in the stated state; The first liquid crystal film is also used to scatter the P-polarized light emitted by the projection device when each of the liquid crystal molecules is in the vertical orientation state and the first refractive index is inconsistent with the second refractive index, so as to display the projected image carried by the P-polarized light on the car window glass.

4. The vehicle window projection display system as described in claim 1, characterized in that, The vehicle window projection display system further includes: a second liquid crystal film having a preset rotation direction; The second liquid crystal film is disposed between the first liquid crystal film and the outer glass of the vehicle window; The second liquid crystal film is used to reflect circularly polarized light in the natural light with the same preset rotation direction within a preset visible light band, and to transmit circularly polarized light in the natural light with the opposite preset rotation direction.

5. The vehicle window projection display system as described in claim 4, characterized in that, The preset rotation direction of the second liquid crystal film is left-handed or right-handed.

6. The vehicle window projection display system as described in claim 5, characterized in that, The second liquid crystal film is a broadband reflective cholesteric phase liquid crystal film.

7. The vehicle window projection display system as described in claim 3, characterized in that, When the intensity of natural light exceeds the preset intensity threshold, each liquid crystal molecule in the first liquid crystal film is in a random orientation state, wherein the long axis of each liquid crystal molecule is oriented in various directions. The first liquid crystal film is also used to transmit P-polarized light emitted by the projection device when each of the liquid crystal molecules is in the random orientation state; The second liquid crystal film is used to reflect the portion of the transmitted P-polarized light that has the same rotation direction as the preset direction, so as to display the projected image carried by the P-polarized light on the car window glass.

8. The vehicle window projection display system as described in claim 1, characterized in that, The method for manufacturing the first liquid crystal thin film is as follows: The photocurable material, liquid crystal material, and photoinitiator are mixed evenly to form a mixture; The mixture is placed between the first transparent conductive film and the second transparent conductive film; The mixture is cured under the condition of applying voltage to the first transparent conductive film and the second transparent conductive film to obtain the first liquid crystal film.

9. The vehicle window projection display system as described in claim 8, characterized in that, The step of curing the mixture to obtain the first liquid crystal film under the condition of applying a voltage to the first transparent conductive film and the second transparent conductive film includes: Pressure is applied to make the mixture evenly distributed between the first transparent conductive film and the second transparent conductive film; A voltage is applied to the first transparent conductive film and the second transparent conductive film to make the liquid crystal molecules in the liquid crystal material vertically oriented; While maintaining the voltage, the mixture is irradiated with a light source to cure the photocurable material into a polymer matrix, resulting in a cured mixture. During the curing process of the photocurable material, the liquid crystal molecules in the liquid crystal material undergo phase separation and aggregate to form multiple liquid crystal microregions composed of the liquid crystal molecules, and the liquid crystal microregions are distributed within the polymer matrix. The first transparent conductive film and the second transparent conductive film are peeled off from the cured mixture to obtain the first liquid crystal film.

10. A vehicle, characterized in that, The vehicle includes the window projection display system as described in any one of claims 1 to 9.

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