Vehicle window glass, head-up display device, vehicle and exposure light path system thereof

Abstract

The invention provides vehicle window glass, a head-up display device, a vehicle and an exposure light path system.The vehicle window glass comprises a glass substrate, a holographic film material and a first protective film, the glass substrate comprises an outer glass plate, an inner glass plate and a middle layer, and the outer glass plate and the inner glass plate are stacked; and the middle layer is connected between the outer glass plate and the inner glass plate. The holographic film material is located between the outer glass plate and the middle layer, or the holographic film material is located between the middle layer and the inner glass plate, the holographic film material comprises a first area and a second area, the first area is provided with a first grating, the second area is provided with a second grating, and the first grating and the second grating are arranged on the outer glass plate. The included angle between the first grating and the surface of the holographic film material is different from the included angle between the second grating and the surface of the holographic film material. According to the technical scheme, the projection information of different vehicles can be displayed on different focal planes, and the driving safety of a driver is improved.

Description

Technical Field

[0001] The present application relates to the field of glass technology, and in particular to a vehicle window glass, a head-up display device, a vehicle, and an exposure light path system. Background Art

[0002] At present, the vehicle's on-board head-up display system will display the vehicle's own instrument panel information and navigation direction information on the same focal plane. This will cause the instrument panel information to overlap with the foreground when the vehicle is driving on urban roads, thereby interfering with the driver's vision. Summary of the invention

[0003] The embodiments of the present application provide a vehicle window glass, a head-up display device, a vehicle and an exposure light path system, which can display different vehicle projection information on different focal planes to improve the driving safety of the driver.

[0004] In a first aspect, the present application provides a vehicle window glass, comprising a glass substrate and a holographic film material, wherein the glass substrate comprises an outer glass plate, an inner glass plate and an intermediate layer, wherein the outer glass plate is stacked with the inner glass plate, and the intermediate layer is connected between the outer glass plate and the inner glass plate;

[0005] The holographic film is located between the outer glass plate and the middle layer, or the holographic film is located between the middle layer and the inner glass plate, the holographic film includes a first area and a second area, the first area has a first grating, the second area has a second grating, and the angle between the first grating and the surface of the holographic film is different from the angle between the second grating and the surface of the holographic film.

[0006] In this embodiment, the driver does not need to lower his head to check the dashboard or the central control screen, and his sight can always remain on the road ahead, thereby reducing the dangerous situations that may be caused by the diversion of sight. This function is particularly important when driving at high speeds or at night, because it helps the driver to react faster and avoid potential accidents. The driver does not need to frequently adjust the focus of his eyes to view the projected information and road conditions respectively, thereby reducing eye fatigue. In long-term use, this helps to maintain the driver's attention and alertness, and improve driving safety.

[0007] In a possible implementation manner, the vehicle window glass further includes a first protective film, and the first protective film is located between the intermediate layer and the holographic film material.

[0008] In a possible implementation manner, the vehicle window glass further includes a second protective film, and the second protective film is connected to a surface of the holographic film material facing away from the first protective film.

[0009] In a possible implementation manner, there are two intermediate layers, one intermediate layer is connected to the surface of the first protective film facing away from the holographic film material, and the other intermediate layer is connected to the surface of the second protective film facing away from the holographic film material.

[0010] In one possible embodiment, both the first grating and the second grating include periodic stripes, and the angle between the periodic stripes of the first grating and the surface of the holographic film is in one of the ranges of 0 to 35°, 42 to 55°, and 60 to 85°, and the angle between the periodic stripes of the second grating and the surface of the holographic film is in another of the ranges of 0 to 35°, 42 to 55°, and 60 to 85°.

[0011] In a possible implementation manner, a stripe interval of the periodic stripes of the first grating is in the range of 200 nm to 400 nm.

[0012] In a possible implementation manner, the thickness of the holographic film is in the range of 15 μm-120 μm.

[0013] In a second aspect, the present application also provides a head-up display device, comprising an image generating unit and a vehicle window glass as described above, wherein the image generating unit is used to project light onto a first area and a second area of ​​the holographic film material, and the first area and the second area reflect the projected light so that the corresponding images of the first area and the second area are focused at different depths of the holographic film material.

[0014] In a third aspect, the present application also provides a vehicle, comprising a vehicle body and the head-up display device as described above, wherein the head-up display device is connected to the vehicle body.

[0015] In a fourth aspect, the present application provides an exposure optical path system for a holographic film material, which is used for preparing the holographic film material. The exposure optical path system includes a first laser, a first light splitting unit, a first light intensity control unit, a second light intensity control unit, a first angle control unit, a second angle control unit and a moving unit.

[0016] The first laser is used to emit a first laser.

[0017] The first beam splitting unit is used to receive the first laser and split the first laser into a first sub-beam and a second sub-beam.

[0018] The first light intensity control unit is used to receive the first sub-beam and adjust the light intensity of the first sub-beam to form a first recording light.

[0019] The first angle control unit is used to receive the first recording light and adjust the angle of the first recording light so that the first recording light irradiates the first area of ​​the substrate.

[0020] The second light intensity control unit is used to receive the second sub-beam and adjust the light intensity of the second sub-beam to form a second recording light.

[0021] The second angle control unit is used to receive the second recording light and adjust the angle of the second recording light so that the second recording light irradiates the first area of ​​the substrate.

[0022] The second recording light and the first recording light are respectively used to irradiate opposite sides of the substrate in the thickness direction, so that the first area forms a first grating of the holographic film material.

[0023] The moving unit is used to connect with the substrate and move the substrate so that the first recording light and the second recording light are irradiated to the second area of ​​the substrate, so that the second area forms a second grating of the holographic film material.

[0024] In this embodiment, the exposure optical path system avoids using a large refractor, and uses a light intensity control unit and an angle control unit to adjust the light intensity and angle of the first recording light and the second recording light, so that the first recording light and the second recording light can directly irradiate the opposite sides of the thickness direction of the substrate. The first recording light and the second recording light meet and interfere inside the substrate. In the area where the interference is enhanced, the light intensity is enhanced, and the film material is exposed to a greater light intensity. In the area where the interference is weakened, the light intensity is weakened, and the film material is exposed to a smaller light intensity. Since the properties of the substrate such as absorption, reflection or refraction of light may change due to different light intensities, the areas where the interference is enhanced and weakened will form specific patterns or structures on the substrate. These patterns or structures are the basic units of the grating: slits or grooves.

[0025] It is known that currently, a convex lens or other transmission mirror is generally used to form coherent light of a substrate, thereby forming a grating on the substrate. However, due to the shape limitation of the convex lens, if multiple gratings are to be prepared on the same substrate, multiple lenses need to be used in the processing of the substrate. This results in a longer production process, an increased possibility of production defects in holographic film materials, and thus affects the production yield of holographic film materials and increases the production cost of head-up display devices.

[0026] Since the exposure optical path system has a light intensity control unit, an angle control unit and a moving unit, the exposure optical path system can theoretically irradiate light of any light intensity within an adjustable range at any angle within the adjustable range to any area within the adjustable range on the substrate. The exposure optical path system of the present application can directly change the angle, intensity and incident position of the coherent light without replacing the lens. The substrate can form the first grating and the second grating in the same process technology, thereby simplifying the preparation process of the holographic film material, reducing the possibility of production defects in the holographic film material, thereby improving the production yield of the holographic film material, and saving the production cost of the head-up display device and the vehicle.

[0027] In a possible implementation manner, the exposure optical path system further includes a second laser, which is used to emit a second laser, and the first laser and the second laser have different colors.

[0028] The exposure optical path system further includes a second beam splitting unit, which is used to receive the second laser and split the second laser into a third sub-beam and a fourth sub-beam;

[0029] The first light intensity control unit is used to receive the first sub-beam and the third sub-beam, and adjust the light intensity of the first sub-beam and the third sub-beam to form a third recording light, and the second light intensity control unit is used to receive the second sub-beam and the fourth sub-beam, and adjust the light intensity of the second sub-beam and the fourth sub-beam to form a fourth recording light.

[0030] In a possible implementation manner, the exposure optical path system further includes a third laser, which is used to emit a third laser, and the first laser, the second laser, and the third laser have different colors.

[0031] The exposure optical path system further includes a third beam splitting unit, which is used to receive the third laser and split the third laser into a fifth sub-beam and a sixth sub-beam;

[0032] The first light intensity control unit is used to receive the first sub-beam, the third sub-beam and the fifth sub-beam, and adjust the light intensity of the first sub-beam, the third sub-beam and the fifth sub-beam to form a third recording light, and the second light intensity control unit is used to receive the second sub-beam, the fourth sub-beam and the sixth sub-beam, and adjust the light intensity of the second sub-beam, the fourth sub-beam and the sixth sub-beam to form a fourth recording light.

[0033] In this embodiment, by adjusting the light intensity ratio and angle parameters of the incident light beam in the exposure system, grating fringes with different periods and inclination angles are formed inside the holographic material, and holographic film materials with different focal planes are obtained, which can reflect and image light of multiple wavelengths, can reflect and image off-axis or on the same optical axis, and can almost fully transmit light beams of other wavelengths, and has the characteristics of almost fully reflecting selected wavelength light beams and fully transmitting non-selected wavelength light beams. Therefore, the holographic film material can reflect and image the projection light, and directly transmit other sunlight light without affecting the image clarity.

[0034] In a possible implementation, the first laser is red light, the second laser is green light, the third laser is blue light, the intensity ratio of the red light to the green light is in the range of 1-1.5, and the intensity ratio of the blue light to the green light is in the range of 1.5-2.

[0035] In this embodiment, by adjusting the light intensity ratio of red light, green light and blue light, the spectral bandwidth of the grating formed by the interference of the third recording light and the fourth recording light is increased, so that the first grating and the second grating can reflect light with wavelengths within the visible light range, so that the colors of the images in the first area and the second area are richer.

[0036] In a possible implementation manner, the exposure optical path system further includes a first reflector, and the first reflector is used to reflect the first recording light emitted by the first light intensity control unit toward the first angle control unit.

[0037] In this embodiment, the first reflective element can flexibly adjust the propagation direction of the light path from the first light intensity control unit to the first angle control unit, so that the relative positions of the first light intensity control unit and the first angle control unit can be flexibly set.

[0038] In a possible implementation manner, the exposure optical path system further includes a first reflector, a second reflector, and a third reflector;

[0039] The third recording light includes red light, green light and blue light. The first reflector is used to reflect the red light, the second reflector is used to reflect the green light, and the third reflector is used to reflect the blue light, so that the red light, the green light and the blue light are mixed to form white light and reflected to the first angle control unit.

[0040] In a possible implementation manner, the first angle control unit and the second angle control unit are located on opposite sides of the moving unit.

[0041] In this embodiment, the moving unit can control the substrate to move between the first angle control unit and the second angle control unit, so that the first recording light and the second recording light can interfere with each other at any position of the substrate to form a grating.

[0042] In a possible implementation manner, the second light intensity control unit is located on the laser propagation path of the first laser.

[0043] In this embodiment, the first light splitting unit can reflect part of the first laser light to the first light intensity control unit, and another part of the first laser light can directly irradiate the second light intensity control unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained like these drawings without paying any creative work.

[0045] Figure 1 is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0046] Figure 2 yes Figure 1 A structural schematic diagram of a head-up display device shown;

[0047] Figure 3 yes Figure 2 A schematic cross-sectional view of a vehicle window glass shown;

[0048] Figure 4 yes Figure 2 A schematic structural diagram of the vehicle window glass from another angle shown;

[0049] Figure 5 yes Figure 1 Another structural schematic diagram of the head-up display device shown;

[0050] Figure 6 yes Figure 2 Another schematic cross-sectional view of a vehicle window glass shown;

[0051] Figure 7 yes Figure 2 Another schematic cross-sectional view of the vehicle window glass shown;

[0052] Figure 8 yes Figure 2 Another schematic cross-sectional view of a vehicle window glass shown;

[0053] Fig. 9 It is a schematic diagram of the principle of forming holographic film by exposure interference;

[0054] Fig.10 It is a structural schematic diagram of an exposure optical path system provided in an embodiment of the present application;

[0055] Fig.11 It is a structural schematic diagram of another exposure optical path system provided in an embodiment of the present application.

[0056] Reference numerals: vehicle 100, vehicle body 10, head-up display device 20, image generating unit 21, vehicle window glass 22, glass substrate 221, holographic film material 222, outer glass plate 2211, inner glass plate 2212, first intermediate layer 2213, second intermediate layer 2214, first region 2221, second region 2222, first grating 2223, second grating 2224, third region 2225, first protective film 223, second protective film 224, first recording light 301, second recording light 302, third recording light 303, fourth recording light 304, exposure optical path system 300, first laser 310, first light splitting unit 320, first light intensity control unit 330, second light intensity control unit 3 40. A first angle control unit 350. A second angle control unit 360. A moving unit 370. A first laser 311. A first sub-beam 3111. A second sub-beam 3112. A substrate 2220. A first reflector 380. A second reflector 381. A third reflector 382. A fourth reflector 383. A fifth reflector 384. A second laser 390. A third laser 400. A second spectroscopic unit 410. A third spectroscopic unit 420. A second laser 391. A third laser 401. A third sub-beam 3911. A fourth sub-beam 3912. A fifth sub-beam 4011. A sixth sub-beam 4012. A sixth reflector 385. A seventh reflector 386. An eighth reflector 387. A ninth reflector 388. DETAILED DESCRIPTION

[0057] For ease of understanding, the terms involved in the embodiments of the present application are first explained.

[0058] And / or: It is just a way to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0059] Multiple: refers to two or more than two.

[0060] Connection: should be understood in a broad sense. For example, A and B are connected, which can be either direct or indirect through an intermediary.

[0061] The specific implementation of the present application will be clearly described below in conjunction with the accompanying drawings.

[0062] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of a vehicle 100 provided in an embodiment of the present application. The vehicle 100 includes a vehicle body 10 and a head-up display device 20. The head-up display device 20 is connected to the vehicle body 10.

[0063] It should be noted that Figure 1 The purpose is only to schematically describe the connection relationship between the vehicle body 10 and the head-up display device 20, and it does not specifically limit the connection position, specific structure and quantity of each device. The structure shown in the embodiment of the present application does not constitute a specific limitation on the vehicle 100. In other embodiments of the present application, the vehicle 100 includes Figure 1 More or fewer components may be shown, or some components may be combined or separated, or the components may be arranged differently.

[0064] See also Figure 2 , Figure 2 yes Figure 1 A structural schematic diagram of a head-up display device 20 shown. The head-up display device 20 includes a picture generation unit 21 (picture generation unit, PGU) and a window glass 22. The image generation unit 21 is used to project light onto the window glass 22. The image generation unit 21 presents an image based on the projected light. Among them, the wavelength of the projected light can be in the range of 380nm to 780nm, which is close to the spectral range of visible light that can be perceived by the human eye. The wavelength range of the projected light also covers the wavelengths RGB: 469nm (blue), 529nm (green), 629nm (red). Therefore, the window glass 22 described in the present application can cooperate with the image generation unit 21 to achieve full-color display of the head-up display image.

[0065] The image generating unit 21 can be used to emit projection light including relevant text and image information such as speed, engine speed, fuel consumption, tire pressure, dynamic navigation, night vision, real-view map, etc. onto the vehicle window glass 22, so that the observer in the vehicle can observe the head-up display image located in front of the vehicle window glass 22, so that the vehicle 100 can realize a head-up display (HUD) or even an augmented reality head-up display (AR-HUD). The image generating unit 21 is an element known to those skilled in the art, including but not limited to laser, light emitting diode (LED), liquid crystal display (LCD), digital light processing (DLP), electroluminescence (EL), cathode ray tube (CRT), vacuum fluorescent tube (VFD), etc. At the same time, the position and incident angle of the image generating unit 21 are adjustable to suit observers at different positions or heights in the vehicle.

[0066] See also Figure 3 , Figure 3 yes Figure 2A schematic cross-sectional view of a vehicle window glass 22 is shown. The vehicle window glass 22 includes a glass substrate 221 and a holographic film material 222 .

[0067] The glass substrate 221 may be a laminated glass. The glass substrate 221 may include an outer glass plate 2211, an inner glass plate 2212, and an intermediate layer (not shown) disposed between the outer glass plate 2211 and the inner glass plate 2212. The transmittance of the outer glass plate 2211 and / or the inner glass plate 2212 to near-infrared rays with a wavelength of 850nm to 1650nm may be greater than or equal to 91%, and the visible light transmittance of the glass substrate 221 may be greater than or equal to 70%, meeting the regulatory requirements for the front windshield of the vehicle 100.

[0068] It should be noted that the laminated glass used as the front windshield is usually curved, but the shape of the laminated glass is not limited to the shape described above. It can be any shape that meets the requirements for the use of vehicle window glass. For example, the glass substrate 221 can also be a flat plate. The embodiments of the present application do not have strict requirements on the shape of the glass substrate 221.

[0069] The outer glass plate 2211 and the inner glass plate 2212 may be ultra-transparent glass (ultra-white glass). The content of iron oxide (FeO) in ultra-transparent glass is relatively low. Calculated by weight percentage, the outer glass plate 2211 and the inner glass plate 2212 may contain 0 to 0.1% of iron oxide (Fe2O3), for example, the content of iron oxide (Fe2O3) in the outer glass plate 2211 and the inner glass plate 2212 is less than or equal to 0.09%, less than or equal to 0.08%, less than or equal to 0.07%, less than or equal to 0.05%, less than or equal to 0.04%, less than or equal to 0.03%, less than or equal to 0.02%, less than or equal to 0.015%, or less than or equal to 0.01%, and even the outer glass plate 2211 and the inner glass plate 2212 may contain substantially no iron oxide (FeO). Exemplarily, the outer glass plate 2211 and the inner glass plate 2212 may be soda-lime-silicon ultra-transparent glass, borosilicate glass, or high-aluminum glass, etc. The outer glass plate 2211 may be single-layer glass, double-layer laminated glass, or hollow glass, etc. The inner glass plate 2212 may be single-layer glass, double-layer laminated glass, or hollow glass, etc. The thickness of the inner glass plate 2212 may be 2.1 mm, 2.0 mm, or 1.8 mm, etc., or the thickness of the inner glass plate 2212 may be less than or equal to 1.6 mm.

[0070] The middle layer is used to connect the outer glass plate 2211 and the inner glass plate 2212, so that the vehicle window glass presents a sandwich structure as a whole, so as to improve the safety of the vehicle window glass and meet the safety standards and regulatory requirements of the vehicle window glass 100. The material of the middle layer can be polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), thermoplastic polyurethane elastomer (TPU) or ionomeric polymer film (SGP), etc. Exemplarily, the middle layer can be a single-layer structure or a multi-layer structure, and the multi-layer structure can be exemplified by a double-layer structure, a three-layer structure, a four-layer structure, a five-layer structure, etc.

[0071] For ease of description, the following is a schematic illustration of an intermediate layer having two film layers. The two intermediate layers are the first intermediate layer 2213 and the second intermediate layer 2214. The outer glass plate 2211, the first intermediate layer 2213, the second intermediate layer 2214 and the inner glass plate 2212 are stacked in sequence. The material of the first intermediate layer 2213 and the second intermediate layer 2214 can be PVB or EVA. The thickness of the first intermediate layer 2213 and the thickness of the second intermediate layer 2214 can be 0.76mm±0.02mm, or 0.38mm±0.02mm, or 200um~380um, or 100um~200um, or 50um~100um, or 50um. The bonding force of the first intermediate layer 2213 and the second intermediate layer 2214 is greater than or equal to 10MPa.

[0072] Please refer to Figure 2 and Figure 4 , Figure 4 yes Figure 2 A schematic diagram of the structure of the vehicle window glass 22 shown in another angle. The holographic film material 222 has a first area 2221 and a second area 2222. The first area 2221 and the second area 2222 can be arranged at intervals, or the first area 2221 and the second area 2222 can be arranged adjacent to each other. The first area 2221 has a first grating 2223. The first grating 2223 is located inside the holographic film material 222. The second area 2222 has a second grating 2224. The angle α1 between the first grating 2223 and the surface of the holographic film material 222 is different from the angle α2 between the second grating 2224 and the surface of the holographic film material 222. The first grating 2223 and the second grating 2224 are formed by partial structures of the holographic film material 222 through exposure interference. Among them, the imaging focal lengths of the first grating 2223 and the second grating 2224 are different.

[0073] In some other embodiments, see Figure 5 , Figure 5 yes Figure 1Another structural schematic diagram of the head-up display device 20 shown. The holographic film material 222 may also be provided with a third area 2225. The third area 2225 may be spaced apart from the first area 2221 and the second area 2222. Alternatively, the third area 2225 may be located on the side of the second area 2222 away from the first area 2221. The third area 2225 has a third grating (not shown). The third grating is formed by a partial structure of the holographic film material 222 through exposure interference. The third grating has a different focal length from the first grating 2223 and the second grating 2224.

[0074] In some other embodiments, the holographic film 222 may include more than four regions, each of which is provided with a grating structure, and the imaging focal length of the grating structure in each region is different. The present application hereinafter takes the holographic film 222 having two regions as an example.

[0075] For a first possible implementation, see Figure 6 , Figure 6 yes Figure 2 Another cross-sectional schematic diagram of the vehicle window glass 22 shown. The holographic film material 222 is connected between the first intermediate layer 2213 and the second intermediate layer 2214. A first protective film 223 may be provided between the holographic film material 222 and the first intermediate layer 2213. A second protective film 224 may be provided between the holographic film material 222 and the second intermediate layer 2214. Exemplarily, the first protective film 223 and the second protective film 224 may be transparent film layers, and the materials of the first protective film 223 and the second protective film 224 may be PET, PC, TAC, PMMA, etc., and the light transmittance of the first protective film 223 and the second protective film 224 may be greater than or equal to 90%. Further, the light transmittance of the first protective film 223 and the second protective film 224 may be greater than or equal to 95%. The haze of the first protective film 223 and the second protective film 224 may be less than or equal to 1%. Further, the haze of the first protective film 223 and the second protective film 224 may be less than or equal to 0.5%.

[0076] In this embodiment, the first protective film 223 and the second protective film 224 can prevent the holographic film 222 from being contaminated by the first intermediate layer 2213 and / or the second intermediate layer 2214, thereby preventing the grating structure on the holographic film 222 from being deformed due to the influence of the composition.

[0077] In a second possible embodiment, see Figure 7 , Figure 7 yes Figure 2Another cross-sectional schematic diagram of the vehicle window glass 22 is shown. The glass substrate 221 may have an intermediate layer (first intermediate layer 2213). The holographic film 222 may be disposed between the first intermediate layer 2213 and the inner glass plate 2212, or the holographic film 222 may be disposed between the first intermediate layer 2213 and the outer glass plate 2211. A first protective film 223 may be disposed between the holographic film 222 and the first intermediate layer 2213. For example, see Figure 8 , Figure 8 yes Figure 2 Another cross-sectional schematic diagram of the vehicle window glass 22 is shown. A second protective film 224 may be provided between the holographic film 222 and the inner glass plate 2212 .

[0078] In this embodiment, the holographic film 222 can be set on a glass plate (inner glass plate 2212 or outer glass plate 2211), and then superimposed with the first protective film 223, the first intermediate layer 2213 and another glass plate (outer glass plate 2211 or inner glass plate 2212) to form a vehicle window glass 22.

[0079] In a third possible embodiment, the holographic film 222 may be attached to the side of the inner glass plate 2212 facing away from the intermediate layer.

[0080] In this embodiment, the glass substrate 221 can be formed in an existing process, and the holographic film 222 can be added to the side of the glass substrate 221 facing the interior of the vehicle.

[0081] Please refer to Figure 2 The image generating unit 21 is used to project light onto the first area 2221 and the second area 2222 of the holographic film 222 . The first area 2221 and the second area 2222 reflect the projected light, so that the corresponding images of the first area 2221 and the second area 2222 are focused at different depths of the holographic film 222 .

[0082] It is understandable that at present, some head-up display systems generally use geometric optical curved surface reflection imaging systems, and in order to ensure the area of ​​the imaging frame, the system requires large free-form surface reflectors and other optical devices to be combined in a certain way, and the final head-up display system is relatively large. This requires a major transformation of the vehicle's center console, and the cost and safety issues are more prominent, which greatly hinders the market popularization of vehicle-mounted head-up display systems.

[0083] The head-up display system is mainly realized by projection, and the most common method is to directly use the reflection of the windshield. For the image of the head-up display system, the higher the reflectivity of the windshield, the better, but for safety reasons, the reflectivity cannot be too high. In order to achieve the ideal imaging effect, a high-power image source is required to increase the brightness of the image.

[0084] In addition, current vehicle-mounted head-up display systems are basically single-focal-plane systems, in which the vehicle's instrument panel information (such as speed, gear position) and navigation direction information are displayed on the same focal plane at the same time. This situation will cause the instrument panel information to overlap with the foreground when driving on urban roads, thereby interfering with the driver's vision.

[0085] See also Fig. 9 . Fig. 9 2 is a schematic diagram of the principle of forming a holographic film material 222 by exposure interference. In the embodiment of the present application, the holographic film material 222 can be formed by exposure interference, and the holographic film material 222 can be formed into a periodic grating structure by double-beam interference.

[0086] The coherent light irradiated on the two side surfaces of the holographic film material 222 is defined as the first recording light 301 and the second recording light 302. The angle between the first recording light 301 and the normal of the surface of the holographic film material 222 is θ1, and the angle between the second recording light 302 and the normal of the surface of the holographic film material 222 is θ2. The angle between the first recording light 301 and the second recording light 302 is 2θ. The period of the grating of the holographic film material 222 is Λ, and the wavelength of the first recording light 301 and the second recording light 302 is λ. The refractive index of the holographic film material 222 is n. The above parameters satisfy the following relationship: Λ=λ / (2n·sinθ).

[0087] In the present application, the grating period of the volume holographic film 222 and the inclination angle between the grating and the surface of the holographic film 222 are changed by adjusting the parameters of the first recording light 301 and the second recording light 302 in the exposure optical path system, so as to produce a holographic film 222 with a volume holographic grating having different focal planes. Among them, the focal plane is not an actual plane, and the focal plane refers to the projection position of the information seen by the driver. The focal plane can be the position where the virtual image of the projected image seen by the driver is located.

[0088] For a possible embodiment, see Fig.10 , Fig.10 The exposure optical system 300 includes a first laser 310, a first light splitting unit 320, a first light intensity control unit 330, a second light intensity control unit 340, a first angle control unit 350, a second angle control unit 360 and a moving unit 370.

[0089] The first laser 310 is used to emit a first laser 311. The first laser 310 may be a laser light source with a coherence length greater than or equal to 50 m. The first laser 310 may be a helium-cadmium laser, a single longitudinal mode laser, an argon ion laser, etc. The color of the first laser 311 may be white light or a single color light, etc. The color of the first laser 311 may be adjusted according to the preparation requirements of the holographic film material 222. The present application does not limit the laser color and type of the first laser 311.

[0090] The first beam splitting unit 320 is used to receive the first laser 311 and split the first laser 311 into a first sub-beam 3111 and a second sub-beam 3112 .

[0091] The first light intensity control unit 330 is used to receive the first sub-beam 3111 and adjust the light intensity of the first sub-beam 3111 to form the first recording light 301. The spectral bandwidth of the grating of the volume holographic film 222 is increased by adjusting the light intensity ratio of different wavelengths of the first recording light 301. Exemplarily, the first light intensity control unit 330 is usually composed of a wave plate, a polarizer, and an adjustable attenuator to achieve the purpose of light intensity ratio.

[0092] The first angle control unit 350 is used to receive the first recording light 301 and adjust the angle of the first recording light 301 so that the first recording light 301 irradiates the first area 2221 of the substrate 2220. Exemplarily, the first angle control unit 350 may include a rotating motion platform (not shown), a coated reflector (not shown) and a drive control device (not shown). The rotating motion platform may be connected to the coated reflector. The drive control device may drive the rotating motion platform to move, thereby controlling the angle of the coated reflector to adjust the angle of the first recording light 301.

[0093] The second light intensity control unit 340 is used to receive the second sub-beam 3112 and adjust the light intensity of the second sub-beam 3112 to form the second recording light 302. The specific structure of the second light intensity control unit 340 can refer to the above description of the first light intensity control unit 330, and the specific structure of the second light intensity control unit 340 is not described in detail in this application.

[0094] The second light intensity control unit 340 may be located on a laser propagation path of the first laser 310 .

[0095] In this embodiment, the first light splitting unit 320 can reflect part of the first laser 311 to the first light intensity control unit 330 , and another part of the first laser 311 can be directly irradiated to the second light intensity control unit 340 .

[0096] The second angle control unit 360 is used to receive the second recording light 302 and adjust the angle of the second recording light 302 so that the second recording light 302 irradiates the first area 2221 of the substrate 2220. The specific structure of the second angle control unit 360 can refer to the description of the first angle control unit 350 above, and the specific structure of the second angle control unit 360 is not described in detail in this application.

[0097] The second recording light 302 and the first recording light 301 are used to irradiate opposite sides of the substrate 2220 in the thickness direction, so that the first region 2221 forms the first grating 2223 of the holographic film 222. The holographic film 222 is the structure formed after the substrate 2220 is prepared with gratings.

[0098] The moving unit 370 is used to connect with the substrate 2220 and move the substrate 2220 so that the first recording light 301 and the second recording light 302 are irradiated to the second area 2222 of the substrate 2220, so that the second area 2222 forms the second grating 2224 of the holographic film material 222. Exemplarily, the moving unit 370 may include a fixing clamp (not shown) and a displacement platform (not shown). The displacement platform may be fixedly connected to the holographic film material 222 by the fixing clamp. The displacement platform may drive the holographic film material 222 to move. The first angle control unit 350 and the second angle control unit 360 are located on opposite sides of the moving unit 370.

[0099] In this embodiment, the moving unit 370 can control the substrate 2220 to move between the first angle control unit 350 and the second angle control unit 360 so that the first recording light 301 and the second recording light 302 can interfere with each other at any position of the substrate 2220 to form a grating.

[0100] Exemplarily, the exposure optical path system 300 may further include a laser shutter unit (not shown), a first reflector 380, a second reflector 381, a third reflector 382, ​​a fourth reflector 383, and a fifth reflector 384. The laser shutter unit may be located between the first laser 310 and the first light splitting unit 320. The laser shutter unit may control the opening and closing of the first laser 310, thereby controlling the exposure time of the exposure optical path system 300.

[0101] The first reflector 380 is used to reflect the first recording light 301 emitted by the first light intensity control unit 330 toward the second reflector 381 , and the second reflector 381 reflects the first recording light 301 toward the first angle control unit 350 .

[0102] The third reflector 382 is used to reflect the second recording light 302 emitted by the second light intensity control unit 340 toward the fourth reflector 383 , and the fourth reflector 383 reflects the second recording light 302 toward the fifth reflector 384 . The fifth reflector 384 reflects the second recording light 302 toward the second angle control unit 360 .

[0103] In this embodiment, the first reflector 380 and the second reflector 381 can flexibly adjust the propagation direction of the light path from the first light intensity control unit 330 to the first angle control unit 350, so that the relative positions of the first light intensity control unit 330 and the first angle control unit 350 can be flexibly set. The third reflector 382, ​​the fourth reflector 383 and the fifth reflector 384 can flexibly adjust the propagation direction of the light path from the second light intensity control unit 340 to the second angle control unit 360, so that the relative positions of the second light intensity control unit 340 and the second angle control unit 360 can be flexibly set.

[0104] In this embodiment, the exposure optical path system 300 avoids using a large optical lens, and uses a light intensity control unit and an angle control unit to adjust the light intensity and angle of the first recording light 301 and the second recording light 302, so that the first recording light 301 and the second recording light 302 can directly irradiate the opposite sides of the thickness direction of the substrate 2220. The first recording light 301 and the second recording light 302 meet and interfere inside the substrate 2220. In the area where the interference is enhanced, the light intensity is enhanced, and the film material is subjected to a greater light intensity. In the area where the interference is weakened, the light intensity is weakened, and the film material is subjected to a smaller light intensity. Since the properties of the substrate 2220 such as absorption, reflection or refraction of light may change due to different light intensities, the areas where the interference is enhanced and weakened will form specific patterns or structures on the substrate 2220. These patterns or structures are the basic units of the grating: slits or grooves.

[0105] It is known that currently, a convex lens or other transmission mirror is generally used to form coherent light of a substrate, thereby forming a grating on the substrate. However, due to the shape limitation of the convex lens, if multiple gratings are to be prepared on the same substrate, multiple lenses need to be used in the processing of the substrate. This results in a longer production process, an increased possibility of production defects in holographic film materials, and thus affects the production yield of holographic film materials and increases the production cost of head-up display devices.

[0106] Since the exposure optical path system 300 has a light intensity control unit, an angle control unit and a moving unit 370, the exposure optical path system 300 can theoretically irradiate light of any light intensity within an adjustable range at any angle within the adjustable range to any area within the adjustable range on the substrate 2220. The exposure optical path system 300 of the present application can directly change the angle, intensity and incident position of the coherent light without replacing the lens. The substrate 2220 can form the first grating 2223 and the second grating 2224 in the same process technology, thereby simplifying the preparation process of the holographic film material 222, reducing the possibility of production defects of the holographic film material 222, thereby improving the production yield of the holographic film material 222, and saving the production cost of the head-up display device 20 and the vehicle 100.

[0107] In the embodiment of the present application, the volume holographic head-up display device 20 has less light energy loss than the current mainstream traditional liquid crystal lens head-up display system, and because it uses a high-power light source, the image brightness it outputs can reach 10,000 nit. And the multi-focal plane system can be designed by modulating the beam parameters of the exposure optical path system 300 to achieve the purpose of clear imaging at different distances in front of the driver. And the head-up display device 20 has a large field of view, which can reach more than 35°.

[0108] For another possible implementation, see Fig.11 , Fig.11 : is a schematic diagram of the structure of another exposure optical path system 300 provided in an embodiment of the present application. The exposure optical path system 300 also includes a second laser 390, a third laser 400, a second splitter unit 410 and a third splitter unit 420. The second laser 390 is used to emit a second laser 391, and the third laser 400 is used to emit a third laser 401. The colors of the first laser 311, the second laser 391 and the third laser 401 are different. Exemplarily, the first laser 311 is red light, the second laser 391 is green light, and the third laser 401 is blue light. The light intensity ratio of red light to green light is between 1-1.5, and the light intensity ratio of blue light to green light is between 1.5-2.

[0109] The second beam splitter 410 is used to receive the second laser 391 and split the second laser 391 into a third sub-beam 3911 and a fourth sub-beam 3912 . The third beam splitter 420 is used to receive the third laser 401 and split the third laser 401 into a fifth sub-beam 4011 and a sixth sub-beam 4012 .

[0110] The first light intensity control unit 330 is used to receive the first sub-beam 3111, the third sub-beam 3911 and the fifth sub-beam 4011, and adjust the light intensity of the first sub-beam 3111, the third sub-beam 3911 and the fifth sub-beam 4011 to form the third recording light 303. The second light intensity control unit 340 is used to receive the second sub-beam 3112, the fourth sub-beam 3912 and the sixth sub-beam 4012, and adjust the light intensity of the second sub-beam 3112, the fourth sub-beam 3912 and the sixth sub-beam 4012 to form the fourth recording light 304.

[0111] In this embodiment, by adjusting the intensity ratio and angle parameters of the recording light in the exposure optical path system 300, grating stripes with different periods and inclination angles are formed inside the base material 2220, and holographic film materials 222 with different focal planes are obtained, which can reflect and image light of multiple wavelengths, can reflect and image light off-axis or on the same optical axis, and can almost fully transmit light beams of other wavelengths, and has the characteristics of almost fully reflecting light beams of selected wavelengths and fully transmitting light beams of non-selected wavelengths. Therefore, the holographic film material 222 can reflect and image the projection light, and directly transmit other light beams of sunlight without affecting the image clarity.

[0112] In other possible embodiments, unlike the exposure optical path system including one laser (first laser 310) and the exposure optical path system including three lasers (first laser 310, second laser 390, third laser 400), the exposure optical path system may also include only two lasers. The two lasers may be the first laser 310 and the second laser 390 mentioned above. In this embodiment, the setting mode of the first laser 310 may refer to the specific description of the first laser 310 above. In this embodiment, the setting mode of the second laser 390 may refer to the specific description of the second laser 390 above. This embodiment does not repeat the first laser 310 and the second laser 390 here. In this embodiment, the first laser 310 and the second laser 390 may emit monochromatic light or mixed color light.

[0113] The exposure optical path system 300 provided in the embodiment of the present application forms a periodic grating inside the holographic film material 222. The angle β between the first grating 2223 and / or the second grating 2224 and the surface of the holographic film material 222 is in the range of 0-35°, 42-55° and 60-85° (including the end values ​​of the range). The stripe spacing distance between the first grating 2223 and the second grating 2224 can be between 200nm and 400nm (including the end values ​​of 200nm and 400nm).

[0114] Generally, the stripe interval between the first grating 2223 and the second grating 2224 is about half of the wavelength of the recording light, so the photosensitivity range of the holographic film material 222 can be between 400nm-650nm (including the endpoint value 400nm-650nm). The thickness range of the holographic film material 222 can be between 15μm-120μm. In some specific embodiments, the thickness range of the holographic film material 222 can be between 15μm-55μm, 60μm-80μm and 90-120μm (all including the range endpoint value). The material of the holographic film material 222 can include a combination of one or more of a photopolymer material, a silver halide material, a polymer liquid crystal and dichromated gelatin. The holographic film material 222 has a beam expansion function. When the light from the image generating unit 21 is irradiated to the holographic film material 222, the holographic film material 222 can enlarge the imaging area, thereby replacing the function of the free-form surface mirror of the traditional head-up display system. Thus, the volume of the entire head-up display device 20 is reduced.

[0115] When the projection light of the image generating unit 21 is irradiated to the holographic film material 222 of the vehicle window glass 22, the first area 2221 and the second area 2222 can reflect the projection light and form a virtual image at the driver's eye box position. At the same time, the scene outside the glass substrate 221 is fully transmitted. At this time, the distance from the imaging plane of the holographic film material 222 to the eye box depends on the maximum angle of the exposure light path. The reflected image of the first area 2221 can display dashboard information such as speed. The distance between the projected virtual image of the first area 2221 and the human eye can range from 0.2m-0.5m, or 0.5m-1.5m, or 1.5m to 3m (all including the range end values). The reflected image of the second area 2222 can display navigation, road assistance and other information. The distance range between the projected virtual image of the second area 2222 and the human eye can be 3m-4.5m, or 4.5m-7.5m, or 7.5m-9.5m, or 9.5m~11m, or greater than 11m (all including the range endpoint values).

[0116] In this embodiment, by adjusting the light intensity ratio of red light, green light, and blue light, the spectral bandwidth of the grating formed by the interference of the third recording light 303 and the fourth recording light 304 is increased, so that the first grating 2223 and the second grating 2224 can reflect light with wavelengths within the visible light range, so that the colors of the images in the first area 2221 and the second area 2222 are richer.

[0117] The exposure optical path system 300 may further include a first reflector 380 , a second reflector 381 , a third reflector 382 , a fourth reflector 383 , a fifth reflector 384 , a sixth reflector 385 , a seventh reflector 386 , an eighth reflector 387 and a ninth reflector 388 .

[0118] The third recording light 303 includes red light, green light and blue light. The first reflector 380 is used to reflect red light, the second reflector 381 is used to reflect green light, and the third reflector 382 is used to reflect blue light, so that the red light, green light and blue light are mixed to form white light and reflected to the fourth reflector 383, and the fourth reflector 383 reflects the white light to the first angle control unit 350.

[0119] The fourth recording light 304 includes red light, green light and blue light. The fifth reflector 384 is used to reflect red light, the sixth reflector 385 is used to reflect green light, and the seventh reflector 386 is used to reflect blue light, so that the red light, green light and blue light are mixed to form white light and reflected to the eighth reflector 387. The eighth reflector 387 reflects the white light to the ninth reflector 388, and the ninth reflector 388 reflects the white light to the first angle control unit 350.

[0120] The present application also adjusts the intensity ratio of the three wavelengths of the first laser 311, the second laser 391 and the third laser 401, so as to improve the diffraction efficiency of the holographic film material 222. Please refer to Table 1.

[0121] Table 1. Test results of diffraction efficiency of different RGB light intensity ratios

[0122]

[0123] As can be seen from Table 1, by adjusting the ratio of red, green and blue light intensities, the diffraction efficiency of the holographic film 222 can be improved, so that the images of the first area 2221 and the second area 2222 of the holographic film 222 are clearer, which further promotes the application of the volume holographic film 222 in the head-up display direction.

[0124] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A vehicle window glass, characterized in that: It comprises a glass substrate and a holographic film material, wherein the glass substrate comprises an outer glass plate, an inner glass plate and an intermediate layer, the outer glass plate is stacked with the inner glass plate, and the intermediate layer is connected between the outer glass plate and the inner glass plate; The holographic film is located between the outer glass plate and the middle layer, or the holographic film is located between the middle layer and the inner glass plate, the holographic film includes a first area and a second area, the first area has a first grating, the second area has a second grating, and the angle between the first grating and the surface of the holographic film is different from the angle between the second grating and the surface of the holographic film.

2. The vehicle window glass according to claim 1, characterized in that: The vehicle window glass further includes a first protective film, which is located between the intermediate layer and the holographic film material.

3. The vehicle window glass according to claim 2, characterized in that: The vehicle window glass further includes a second protective film, which is connected to a surface of the holographic film material facing away from the first protective film.

4. The vehicle window glass according to claim 3, characterized in that: There are two intermediate layers, one of which is connected to the surface of the first protective film facing away from the holographic film material, and the other intermediate layer is connected to the surface of the second protective film facing away from the holographic film material.

5. The vehicle window glass according to any one of claims 1 to 4, characterized in that: The first grating and the second grating both include periodic stripes, and the angle between the periodic stripes of the first grating and the surface of the holographic film is within one of the ranges of 0 to 35°, 42 to 55°, and 60 to 85°, and the angle between the periodic stripes of the second grating and the surface of the holographic film is within another range of 0 to 35°, 42 to 55°, and 60 to 85°.

6. The vehicle window glass according to claim 5, characterized in that: The stripe interval of the periodic stripes of the first grating is in the range of 200nm to 400nm.

7. The vehicle window glass according to any one of claims 1 to 4, characterized in that: The thickness of the holographic film is in the range of 15 μm-120 μm.

8. A head-up display device, characterized in that: It comprises an image generating unit and a vehicle window glass as described in any one of claims 1 to 6, wherein the image generating unit is used to project light onto a first area and a second area of ​​the holographic film material, and the first area and the second area reflect the projected light so that the corresponding images of the first area and the second area are focused at different depths of the holographic film material.

9. A vehicle, characterized in that: It comprises a vehicle body and the head-up display device as claimed in claim 8, wherein the head-up display device is connected to the vehicle body.

10. An exposure optical path system for a holographic film, characterized in that: Used for preparing holographic film materials, the exposure optical path system includes a first laser, a first light splitting unit, a first light intensity control unit, a second light intensity control unit, a first angle control unit, a second angle control unit and a moving unit; The first laser is used to emit a first laser; The first beam splitting unit is used to receive the first laser and split the first laser into a first sub-beam and a second sub-beam; The first light intensity control unit is used to receive the first sub-beam and adjust the light intensity of the first sub-beam to form a first recording light; The first angle control unit is used to receive the first recording light and adjust the angle of the first recording light so that the first recording light irradiates the first area of ​​the substrate; The second light intensity control unit is used for receiving the second sub-beam and adjusting the light intensity of the second sub-beam to form a second recording light; The second angle control unit is used to receive the second recording light and adjust the angle of the second recording light so that the second recording light irradiates the first area of ​​the substrate; The second recording light and the first recording light are used to irradiate opposite sides of the substrate in the thickness direction, so that the first area forms a first grating of the holographic film material; The moving unit is used to connect with the substrate and move the substrate so that the first recording light and the second recording light are irradiated to the second area of ​​the substrate, so that the second area forms a second grating of the holographic film material.

11. The exposure optical path system according to claim 10, characterized in that: The exposure optical path system further includes a second laser, the second laser is used to emit a second laser, and the first laser and the second laser have different colors; The exposure optical path system further includes a second beam splitting unit, which is used to receive the second laser and split the second laser into a third sub-beam and a fourth sub-beam; The first light intensity control unit is used to receive the first sub-beam and the third sub-beam, and adjust the light intensity of the first sub-beam and the third sub-beam to form a third recording light, and the second light intensity control unit is used to receive the second sub-beam and the fourth sub-beam, and adjust the light intensity of the second sub-beam and the fourth sub-beam to form a fourth recording light.

12. The exposure optical path system according to claim 11, characterized in that: The exposure optical path system further includes a third laser, which is used to emit a third laser, and the colors of the first laser, the second laser and the third laser are different; The exposure optical path system further includes a third beam splitting unit, which is used to receive the third laser and split the third laser into a fifth sub-beam and a sixth sub-beam; The first light intensity control unit is used to receive the first sub-beam, the third sub-beam and the fifth sub-beam, and adjust the light intensity of the first sub-beam, the third sub-beam and the fifth sub-beam to form a third recording light, and the second light intensity control unit is used to receive the second sub-beam, the fourth sub-beam and the sixth sub-beam, and adjust the light intensity of the second sub-beam, the fourth sub-beam and the sixth sub-beam to form a fourth recording light.

13. The exposure optical path system according to claim 12, characterized in that: The first laser is red light, the second laser is green light, the third laser is blue light, the light intensity ratio of the red light to the green light is in a range of 1-1.5, and the light intensity ratio of the blue light to the green light is in a range of 1.5-2.

14. The exposure optical path system according to claim 10, characterized in that: The exposure optical path system further includes a first reflector, and the first reflector is used to reflect the first recording light emitted by the first light intensity control unit toward the first angle control unit.

15. The exposure optical path system according to claim 13, characterized in that: The exposure optical path system further includes a first reflector, a second reflector and a third reflector; The third recording light includes red light, green light and blue light. The first reflector is used to reflect the red light, the second reflector is used to reflect the green light, and the third reflector is used to reflect the blue light, so that the red light, the green light and the blue light are mixed to form white light and reflected to the first angle control unit.

16. The exposure optical path system according to claim 10, characterized in that: The first angle control unit and the second angle control unit are located on opposite sides of the moving unit.

17. The exposure optical path system according to any one of claims 10 to 16, characterized in that: The second light intensity control unit is located on the laser propagation path of the first laser.

Images