A head-up display system

Abstract

The application discloses a head-up display system, comprising a light source, a separate light diffusion element, a liquid crystal panel and a transreflective device, the separate light diffusion element diffuses light emitted by the light source into at least two light beams in different directions, each of the light beams comprises a preset shape of a cross section, the liquid crystal panel converts light incident on the liquid crystal panel into image light and emits the image light, the image light is reflected on the transreflective device, and the reflected light is directed to at least two different observation areas; the at least two light beams in different directions correspond to the observation areas one by one, and the cross sections of the at least two light beams in the observation areas are separated from each other. Through the head-up display system provided by the embodiment of the application, different observers in a vehicle can observe images in at least two areas, and applications such as multi-person multi-angle viewing can be expanded, the use experience and convenience of the HUD are improved, and the application scenarios of the HUD are expanded.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical display technology, and particularly relates to a head-up display system. BACKGROUND

[0002] HUD (head up display) is a kind of optical design through reflection, which projects the light emitted by the image source onto the imaging window (imaging plate, windshield, etc.), so that the driver can directly see the picture without lowering his head, thereby avoiding the distraction caused by the driver's lowering his head to look at the instrument panel during driving, improving the driving safety factor, and bringing better driving experience.

[0003] Specifically, the light emitted by the HUD image source is reflected on the transparent imaging window and remains on one side of the cockpit, entering the driver's eyes. These light rays entering the driver's eyes make the driver see the virtual image of the picture displayed on the HUD image source in the space on the other side of the imaging window. At the same time, since the imaging window itself is transparent, the ambient light on the other side of the imaging window can still transmit through it to the driver's eyes, so that the driver can see the HUD image while still observing the road conditions outside the vehicle during driving. However, the existing HUD design is basically only for the driver to watch, which brings many inconveniences in actual use and limits the application scenarios and further promotion of the HUD. SUMMARY

[0004] In order to overcome the problem that the head-up display system in the prior art can only be watched by the driver, the present application provides a head-up display system, which comprises: a light source, the light source emits light rays;

[0005] a separate light diffusion element, the separate light diffusion element diffuses the light rays emitted by the light source into at least two different direction light beams, each of the light beams comprises a preset shape cross section;

[0006] a liquid crystal panel, the liquid crystal panel converts the light rays incident to the liquid crystal panel into image light rays and emits the image light rays;

[0007] a transflector device, the image light rays are reflected on the transflector device, and the reflected light rays are directed to at least two different observation areas;

[0008] The at least two different direction light beams correspond one-to-one to the observation areas, and the cross sections of the at least two light beams in the observation areas are separated from each other;

[0009] The external ambient light rays are transmitted to the at least two different observation areas through the transflector device, and the external ambient and the observation areas are respectively located on one side of the two sides of the space separated by the transflector device.

[0010] Optionally, in another embodiment, the at least two observation regions include an observation region corresponding to a driver of the vehicle and an observation region corresponding to a passenger of the vehicle.

[0011] Optionally, in another embodiment, the at least two observation regions correspond to observation regions of any at least two passengers in the vehicle.

[0012] Optionally, in another embodiment, the liquid crystal panel includes a first polarization control element, a liquid crystal layer, and a second polarization control element; the first polarization control element transmits light of a first polarization characteristic, and the second polarization control element transmits light of a second polarization characteristic; the light of the first polarization characteristic and the light of the second polarization characteristic are orthogonal in polarization direction.

[0013] Optionally, in another embodiment, the light source includes one or more electroluminescent elements.

[0014] Optionally, in another embodiment, the split light diffusion element includes a light direction layer and a light diffusion layer; the light direction layer emits light emitted by the light source in at least two different directions; the light diffusion layer diffuses the light emitted in the at least two different directions into at least two light beams; the light diffusion layer is disposed on a side of the light direction layer away from the light source.

[0015] Optionally, in another embodiment, the light direction layer includes a plurality of micro-prism structures.

[0016] Optionally, in another embodiment, the head-up display system further includes a reflective light guide element; the reflective light guide element is disposed in a light emission direction of the light source; an inner reflective surface of the reflective light guide element faces the light source and forms a transmission channel allowing light to pass through; light emitted by the light source is transmitted to the liquid crystal panel through the transmission channel of the reflective light guide element.

[0017] Optionally, in another embodiment, the reflective light guide element includes a hollow shell provided with an inner reflective surface; the hollow shell includes a light emission opening and an end opening away from the light emission opening; a size of the end opening is smaller than a size of the light emission opening.

[0018] Optionally, in another embodiment, the light emission opening of the hollow shell faces the liquid crystal panel; the end opening of the hollow shell is disposed with the light source; light emitted by the light source is transmitted through the transmission channel of the hollow shell and reflected on the inner reflective surface, and is transmitted to the liquid crystal panel.

[0019] Optionally, in another embodiment, the inner reflective surface of the hollow shell includes at least one of a parabolic shape, a quadrangular prism shape, or a free-form surface shape.

[0020] Optionally, in another embodiment, the inner reflective surface of the hollow shell is in the shape of a quadrangular frustum; the shape of the end opening comprises at least one of a rectangle, a trapezoid, a parallelogram or a square; the shape of the light exit opening comprises at least one of a rectangle, a trapezoid, a parallelogram or a square.

[0021] Optionally, in another embodiment, the reflective light guide element comprises a solid transparent body; the solid transparent body comprises a light exit surface and an end portion away from the light exit surface; the solid transparent body has a refractive index greater than 1.

[0022] Optionally, in another embodiment, the light exit surface of the solid transparent body faces the liquid crystal panel; the light source is disposed at the end portion of the solid transparent body away from the light exit opening; the light emitted by the light source is transmitted through the transmission channel of the solid transparent body and totally reflected on the inner reflective surface to be transmitted to the liquid crystal panel.

[0023] Optionally, in another embodiment, the head-up display system further comprises a collimating element; the collimating element is disposed between the light source and the liquid crystal panel; the collimating element adjusts the light emitted by the light source to be parallel light.

[0024] Optionally, in another embodiment, the collimating element comprises at least one of a collimating lens or a collimating film.

[0025] Optionally, in another embodiment, the collimating element is disposed inside the hollow shell, and the size of the collimating element is smaller than the size of the light exit opening of the hollow shell; the collimating element adjusts and collimates the light transmitted in the hollow shell to be emitted to the liquid crystal panel.

[0026] Optionally, in another embodiment, the collimating element is disposed on the light exit surface of the solid transparent body.

[0027] Optionally, in another embodiment, the end portion of the solid transparent body where the light source is disposed is provided with a cavity, and the collimating element is disposed on one side of the cavity close to the light exit surface; the collimating element adjusts and collimates the light transmitted in the solid transparent body to be emitted to the liquid crystal panel.

[0028] Optionally, in another embodiment, the end portion of the solid transparent body where the light source is disposed is provided with a cavity, and the light exit surface of the solid transparent body is provided with a slot; the collimating element is disposed on the bottom surface of the slot; the collimating element adjusts and collimates the light transmitted in the solid transparent body to be emitted to the liquid crystal panel.

[0029] Optionally, in another embodiment, the head-up display system further comprises a diffusing element; the diffusing element diffuses the light emitted by the light source; the diffusing element is arranged in a stacked manner with the separate light diffusion element, and the diffusing element and the separate light diffusion element are spaced apart by a preset distance.

[0030] Optionally, in another embodiment, the diffusing element is a diffractive optical element or a scattering optical element.

[0031] In the above scheme provided by the embodiment of the application, the light source and the separate light diffusion element are arranged, the separate light diffusion element diffuses the light emitted by the light source into at least two light beams in different directions, each light beam includes a preset shaped cross section; the liquid crystal panel converts and emits image light from the incident light, the image light is reflected on the transflector, and the reflected light is directed to at least two different observation areas, the observation areas correspond to the diffused light beams one by one, the HUD can observe the image in at least two areas, and the application of the HUD can be expanded to multi-person multi-angle viewing and the like, thereby improving the use experience and convenience of the HUD and expanding the application scenarios of the HUD.

[0032] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the following preferred embodiments are specifically described below, and the accompanying drawings are referred to for detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The structure of the head-up display system of an embodiment of the application is shown Figure 1 ;

[0034] Figure 2 The structure of the head-up display system of an embodiment of the application is shown Figure 1 ;

[0035] Figure 3 The structure of the head-up display system of an embodiment of the application is shown Figure 3 ;

[0036] Figure 4 The structure of the liquid crystal panel of an embodiment of the application is shown

[0037] Figure 5 The effect of the separate light diffusion element on the light of an embodiment of the application is shown Figure 1 ;

[0038] Figure 6a The structure of the separate light diffusion element of an embodiment of the application is shown Figure 1 ;

[0039] Figure 6b The structure of the separate light diffusion element of an embodiment of the application is shown Figure 2 ;

[0040] Figure 7a A schematic diagram showing the effect of a split light diffusion element on light rays according to an embodiment of the application Figure 2 ;

[0041] Figure 7b A schematic diagram showing the effect of a split light diffusion element on light rays according to an embodiment of the application Figure 3 ;

[0042] Figure 8 A schematic diagram showing the structure of a split light diffusion element according to an embodiment of the application Figure 3 ;

[0043] Figure 9 A schematic diagram showing the structure of a split light diffusion element according to an embodiment of the application Figure 4 ;

[0044] Figure 10 A schematic diagram showing the structure of a head-up display system according to an embodiment of the application Figure 1 ;

[0045] Figure 11a A schematic diagram showing the structure of a hollow housing according to an embodiment of the application Figure 1 ;

[0046] Figure 11b A schematic diagram showing the structure of a hollow housing according to an embodiment of the application Figure 2 ;

[0047] Figure 12 A schematic diagram showing the structure of a hollow housing according to an embodiment of the application Figure 3 ;

[0048] Figure 13 A schematic diagram showing the structure of a head-up display system according to an embodiment of the application Figure 2 ;

[0049] Figure 14 A schematic diagram showing the structure of a head-up display system according to an embodiment of the application Figure 3 ;

[0050] Figure 15 A schematic diagram showing the structure of a head-up display system according to an embodiment of the application Figure 4 ;

[0051] Figure 16 A schematic diagram showing the structure of a head-up display system according to an embodiment of the application Figure 5 ;

[0052] Figure 17a A schematic diagram showing the structure of a head-up display system according to an embodiment of the application

[0053] Figure 17b Fig. 7 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application;

[0054] Figure 18 Fig. 8 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 8

[0055] Figure 19 Fig. 9 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 9

[0056] Figure 20a Fig. 10 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 9

[0057] Figure 20b Fig. 11 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 10

[0058] Figure 21a Fig. 12 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 10

[0059] Figure 21b Fig. 13 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 10

[0060] Figure 21c Fig. 14 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 10

[0061] Figure 21d Fig. 15 shows a partial structural schematic diagram of a head-up display system according to an embodiment of the present application; Figure 10

[0062] Reference signs: 101 - light source; 102 - split light diffusion element; 103 - liquid crystal panel; 104 - reflective light guide element; 105 - collimating element; 106 - diffusing element; 100 - image source; 200 - transflective device; 300 - first observation area; 301 - second observation area; 400 - first virtual image; 401 - second virtual image; 1031 - liquid crystal layer; 1032 - first polarization control element; 1033 - second polarization control element; 1021 - light ray orientation layer; 1022 - light ray diffusion layer; 1041 - hollow shell; 1042 - hollow shell light exit opening; 1043 - hollow shell end opening; 1044 - solid transparent body; 1045 - solid transparent body light exit surface; 1046 - solid transparent body end. DETAILED DESCRIPTION

[0063] ​​​​​​​​The embodiments of the present application will be described below in further detail with reference to the drawings.

[0064] The present application also can be embodied in a different specific form, without departing from the spirit or essential characteristics of the application. To clearly illustrate the implementation of the present application, the following will describe the embodiments with reference to the accompanying drawings, in which:

[0065] It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and thus the drawings only show the components related to the present application, rather than the number, shape and size of the components in actual implementation. The actual implementation of the components can be randomly changed in shape, number and proportion, and the layout of the components can be more complex.

[0066] It should be noted that, for the sake of brevity and clarity, the scheme of the present application will be described below by describing several representative embodiments. Numerous details of the embodiments are only used to help understand the scheme of the present application. However, it is obvious that the technical scheme of the present application can not be limited to these details. In order to avoid unnecessary confusion of the scheme of the present application, some embodiments are not described in detail, but only the framework is given. In the following, "comprising" means "including but not limited to", "according to" means "at least according to, but not limited to only according to". "First", "second", etc. are only used to refer to the characteristics, and are not intended to limit the characteristics, such as the order. Due to the language habit of Chinese, when the quantity of a component is not specially pointed out, it means that the component can be one or more, or can be understood as at least one.

[0067] The present embodiment provides a display system, referring to Figure 1As shown, it includes: a light source 101 that emits light; a split light diffusion element 102 that diffuses the light emitted by the light source 101 into at least two beams in different directions, each beam having a cross-section of a preset shape; a liquid crystal panel 103 that converts the light incident on the liquid crystal panel 103 into image light and emits image light; a transflector 200 that reflects the image light, the reflected light being directed toward at least two different observation areas; at least two beams in different directions corresponding one-to-one with the observation areas, and the cross-sections of the at least two beams in the observation areas being separated from each other; and ambient light being transmitted through the transflector 200 to at least two different observation areas, the ambient light and the observation areas being located on one side of the space separated by the transflector 200.

[0068] In this embodiment, the light source 101 can be a point light source, a line light source, or a surface light source, and the number of light sources 101 can be one or more, without limitation. A separate light diffusion element 102 is provided to diffuse the light emitted by the light source 101 into at least two beams in different directions, and each beam includes a cross-section of a preset shape, thereby changing both the propagation direction and the diffusion state of the light. Specifically, the cross-section refers to the cross-section along the principal optical axis of the beam propagation, and the preset shape includes, but is not limited to, a line, triangle, rectangle, square, circle, ellipse, trapezoid, or parallelogram. In this embodiment, the light emitted by the light source 101 diffused by the separate light diffusion element 102 includes light emitted directly from the light source 101 or light emitted indirectly from the light source 101, wherein light emitted directly from the light source 101 specifically refers to light emitted by the light source 101 without passing through other elements; light emitted indirectly from the light source 101 specifically refers to light emitted by the light source 101 that has passed through other elements before exiting the separate light diffusion element 102. Figure 1 As shown, for the split light diffusion element 102, the light emitted from the light source 101 directly reaches the split light diffusion element 102, therefore... Figure 1 In a corresponding embodiment, the split light diffusion element 102 diffuses the light emitted directly from the light source 101 and forms light beams in at least two different directions. Figure 1Take the light emitted by the light source 101 as an example, which is diffused into two light beams after passing through the split light diffusion element 102. In the figure, CRA and CRB represent the chief rays of the two light beams formed after diffusion. The chief ray specifically refers to the center of the light beam energy distribution, pointing to the direction of maximum light intensity of the light beam. The direction of the chief ray can also be the direction of the symmetry axis of the light intensity distribution of the light beam, which is generally the central axis direction of the light beam. The direction of the chief ray represents the main direction of the light propagation of the light beam. The light intensity of the light rays in the direction of the chief ray and the direction close to the chief ray is greater than that of the light rays in other directions. That is, the chief ray of the light beam can represent the overall propagation and direction change of the light rays of the light beam.

[0069] As Figure 1As shown, the two light beams diffused by the split light diffusion element 102 then pass through the liquid crystal panel 103, where the liquid crystal panel 103 converts the light beams into image light and emits image light. Those skilled in the art will understand that the light, after passing through the liquid crystal panel, forms an image on the surface of the liquid crystal panel; that is, the light emitted from the liquid crystal panel is image light that includes image information. Because the liquid crystal panel hardly changes the direction of the principal optical axis of the light beam, the image light formed by the two light beams passing through the liquid crystal panel 103 also includes image light beams oriented in two directions, and the principal optical axes of the two image light beams are still CRA and CRB; the two image light beams are then reflected on the transflection device 200, and the reflected light is directed towards the first observation area 300 and the second observation area 301, two different observation areas. That is, the two beams in different directions correspond one-to-one with the observation areas, and the cross sections of the two beams in the observation areas are separated from each other, so that the observers whose eyes are located in the first observation area 300 and the second observation area 301 can see their respective first virtual images 400 and second virtual images 401. The first virtual images 400 and the second virtual images 401 are virtual images formed by the reflection imaging of the two different image light beams after passing through the transflection device 200; at the same time, the light from the external environment is transmitted through the transflection device 200 to the first observation area 300 and the second observation area 301, and the external environment and the observation areas are respectively located on one side of the two sides of the space divided by the transflection device 200. Specifically, the reflective device 200 can be the windshield of a vehicle, the external environment can be the environment outside the windshield, and the observation area can be the observation area of ​​an observer inside the windshield, such as a passenger or driver. Both the driver and passenger can see the HUD image, enabling multi-angle viewing and observation of the external environment without affecting normal driving. Specifically, the first observation area 300 and the second observation area 301 can be respectively set as the eyebox areas of the passenger and driver; the eyebox area refers to the area where the observer's eyes are located and where the HUD image can be seen. In this case, it is sufficient for the two light beams to cover the eyebox areas of the driver and passenger respectively. The driver and passenger eyebox areas do not overlap, and the cross-sections of the two light beams in the eyebox areas are also separate and non-overlapping. Preferably, the shape of the cross-sections of the two light beams at the first observation area 300 and the second observation area 301 is the same as the shape of the eyebox area, and the cross-sectional size of the light beams is close to that of the driver and passenger eyebox areas, precisely covering the eyebox range, which can further improve light efficiency. In this embodiment, both the first observation area 300 and the second observation area 301 have a certain size. Even if the observer's eyes are deviated from the center of the observation area by a certain distance, such as moving a certain distance up or down or left or right, as long as the observer's eyes are still within the observation area, the observer can still see the HUD image.

[0070] Or, such as Figure 2As shown, the light emitted by the light source 101 first passes through the liquid crystal panel 103 to form image light, and the image light then passes through the split light diffusion element 102 and is diffused into two different light beams. For the split light diffusion element 102, the light emitted by the light source 101 first passes through the liquid crystal panel 103 and then reaches the light diffusion element 102, so Figure 2 In a corresponding embodiment, the split light diffusion element 102 diffuses the light emitted indirectly by the light source 101 and forms at least two different light beams, and the image light can be considered as the light emitted indirectly by the light source 101. The two different light beams are reflected by the transflector 200 to the different first observation area 300 and second observation area 301 in a similar manner as described above, and thus will not be described again.

[0071] Those skilled in the art should understand that Figure 1 and Figure 2 The figure shows a schematic diagram of the head-up display system of the present embodiment applied to a vehicle, in which the x direction represents the direction of travel of the vehicle. It can be understood that the two different observation areas, the first observation area 300 and the second observation area 301, can be distributed in the vertical direction (i.e. the z direction perpendicular to the xy plane of the vehicle) or in the horizontal direction (i.e. the y direction of the xy plane of the vehicle). Preferably, the first observation area 300 and the second observation area 301 are distributed in the horizontal direction and correspond to the eye box regions of the driver and the passenger, respectively. Figure 1 and Figure 2 In a corresponding embodiment, the split light diffusion element 102 can also diffuse more light beams to correspond to more observation areas, and the implementation process is similar to the above process, which will not be listed and described again in the present embodiment.

[0072] Figure 3 The figure shows a schematic diagram of another perspective of the head-up display system of the present embodiment. For the convenience of explanation and description, the head-up display system of the present embodiment removes other components except the transflector 200 to form an image source 100. The image source 100 emits image light, and the image source 100 is used instead of the light source 101, the split light diffusion element 102 and the liquid crystal panel 103 for explanation and description. Figure 3The smaller display area 1001 of the image source 100 is taken as an example for illustration, and the solid arrows in the figure represent the principal axes CRA and CRB of the two light beams emitted by different pixel points of the display area 1001. The two light beams emitted by different pixel points are reflected along the principal axes CRA and CRB, respectively, to the transflective device 200, and then reflected to the first observation area 300 and the second observation area 301, respectively. Different observers can see the first virtual image 400 and the second virtual image 401 corresponding to the first observation area 300 and the second observation area 301, respectively. The first virtual image 400 and the second virtual image 401 are formed outside the transflective device 200. For convenience of illustration, the transflective device is taken as a plane in the embodiments of the present application and the accompanying drawings, but in actual application, the transflective device 200 can be a curved surface with an arc, such as a windshield, and the imaging principle is similar to the above process, which is not described herein. It should be understood by those skilled in the art that the position of the virtual image is not fixed when the transflective device 200 is a curved surface, and therefore, when the transflective device 200 is a windshield or an imaging window with an arc, the virtual image in the embodiments refers to the virtual image observed from each observation area, i.e., the position of the virtual image is the position of the virtual image observed from each observation area by different observers.

[0073] When the head-up display system described in the embodiments is installed on a vehicle or other transportation tool, the transflective device 200 in the embodiments can be a windshield of the vehicle, or a transflective film attached to the windshield, or an imaging window formed of a transparent material, including a transparent resin, a high-molecular transparent material or glass, such as an imaging window of a combiner-HUD (C-HUD). Different observation areas correspond to eye-box regions of different observers in the transportation tool, such as the eye-box regions of the driver and the passenger. The driver or the passenger can not only observe the virtual image formed by reflection, but also can normally view the scene outside the vehicle through the transflective device 200 and reach the observation area of the driver or the passenger. The image source 100 in the embodiments can be arranged below the windshield or on the surface of the console of the vehicle, and further, the image source 100 can be arranged in a large area, so that the light emitted therefrom can form a large-size image after being reflected by the transflective device 200, further improving the use experience of the head-up display system.

[0074] In the embodiments, the light emitted by the light source 101 is diffused into at least two light beams in different directions by the separated light diffusion element 102, and the light is converted into image light by the liquid crystal panel. The image light is reflected on the transflective device 200 to form an image, and the reflected light is directed to at least two different observation areas, so that different observers such as the driver and the passenger can see the image of the HUD, multi-angle observation is realized, the convenience of using the HUD is improved, and the use experience of the HUD is improved.

[0075] On the basis of the above-mentioned embodiments of the present application, the at least two observation regions include an observation region corresponding to the driver of the vehicle and an observation region corresponding to the passenger, such as Figures 1-3 As shown, the at least two observation regions include a second observation region 301 corresponding to the eye box region of the driver and a first observation region 300 corresponding to the eye box region of the front passenger; or, the at least two observation regions include observation regions corresponding to any at least two eye box regions of the passengers in the vehicle, such as observation regions corresponding to the eye box region of the front passenger and the eye box region of the rear passenger, respectively, or observation regions corresponding to the eye box regions of the multiple passengers in the rear seat, respectively, which can be set for different passengers in the vehicle, respectively, to further improve the use experience and convenience of the HUD.

[0076] On the basis of the above-mentioned embodiments of the present application, the light source 101 specifically includes one or more electroluminescent elements, which generate light through electric field excitation, including but not limited to a light emitting diode (LED), an organic light emitting diode (OLED), a mini light emitting diode (Mini LED), a micro light emitting diode (Micro LED), a cold cathode fluorescent lamp (CCFL), a cold LED light (CLL), an electro luminescent (EL), a field emission display (FED), or a quantum dot light source (QD), etc.

[0077] On the basis of the above-mentioned embodiments of the present application, the liquid crystal panel 103 includes a first polarization control element 1032, a liquid crystal layer 1031, and a second polarization control element 1033; the first polarization control element 1032 transmits light of a first polarization characteristic, and the second polarization control element 1033 transmits light of a second polarization characteristic; the polarization directions of the light of the first polarization characteristic and the light of the second polarization characteristic are orthogonal. Specifically, the liquid crystal layer includes a twisted nematic (TN) liquid crystal, a high twisted nematic (HTN) liquid crystal, a super twisted nematic (STN) liquid crystal, a formated super twisted nematic (FSTN) liquid crystal, or a blue phase liquid crystal, etc. Figure 4As a structural schematic diagram of the liquid crystal panel 103, the second polarization control element 1033 faces the light source 101. The light rays of the first polarization characteristic are orthogonal to the polarization direction of the light rays of the second polarization state, and the polarization state can specifically include linear polarization, elliptical polarization, circular polarization, etc. Specifically, the light rays of the first polarization characteristic are horizontally linearly polarized light, and the light rays of the second polarization characteristic are vertically linearly polarized light; or the light rays of the first polarization characteristic are vertically linearly polarized light, and the light rays of the second polarization characteristic are horizontally linearly polarized light; or the light rays of the first polarization characteristic are left-handed circularly polarized light, and the light rays of the second polarization characteristic are right-handed circularly polarized light; or the light rays of the first polarization characteristic are right-handed circularly polarized light, and the light rays of the second polarization characteristic are left-handed circularly polarized light; or the light rays of the first polarization characteristic are left-handed elliptical polarized light, and the light rays of the second polarization characteristic are right-handed elliptical polarized light; or the light rays of the first polarization characteristic are right-handed elliptical polarized light, and the light rays of the second polarization characteristic are left-handed elliptical polarized light. The light rays are converted into image light rays by the first polarization control element 1032, the liquid crystal layer 1031, and the second polarization control element 1033, and observers in different regions can see images.

[0078] On the basis of the above-mentioned embodiments of the present application, the split light diffusion element 102 includes a light ray orientation layer 1021 and a light ray diffusion layer 1022. The light ray orientation layer 1021 emits light rays emitted by the light source 101 in at least two different directions. The light ray diffusion layer 1022 diffuses the light rays emitted in at least two different directions into at least two light beams. The light ray diffusion layer 1022 is arranged on the side of the light ray orientation layer 1021 away from the light source. The light rays emitted directly or indirectly by the light source 101 first pass through the light ray orientation layer 1021, and then pass through the light ray diffusion layer 1022 to be diffused into light beams in at least two different directions, as shown in Figure 5 .

[0079] Specifically, the light ray orientation layer 1021 includes a plurality of micro-prism structures. The material of the micro-prism is a transparent material with a refractive index greater than 1, including but not limited to Polymethyl Methacrylate (PMMA), Polycarbonate (PC), or glass, etc. As shown in Figure 6a , 6bAs shown, the micro-prism structure includes triangular cross-sectioned triangular prism structure, and the light is refracted by the micro-prism to at least two different directions; the light diffusion layer includes an element capable of diffusing the light into a light beam with a preset shape cross-section, such as a diffractive optical element (DOE), which can diffuse the light into a light beam with a preset shape cross-section by controlling the microstructure of the diffractive optical element, and the preset shape includes but is not limited to linear, triangular, rectangular, square, circular, elliptical, trapezoidal or parallelogram; the dispersion angle of each light beam in the horizontal and vertical directions after diffusion can also be accurately controlled, and the dispersion angle can be specifically 5°-30°, the larger the dispersion angle, the higher the light dispersion degree, and the lower the final imaging brightness, and vice versa; the dispersion angle specifically refers to the included angle between the two light rays deviating from the principal axis with the largest angle. Specifically, the diffractive optical element includes a beam shaper.

[0080] Optionally, the cross-sectional preset shapes of the at least two light beams can be the same or different, such as Figure 5 The split light diffusion element in the middle diffuses the light into two light beams with rectangular cross-sectional shapes, or can diffuse the light into a light beam with a preset rectangular cross-sectional shape and a light beam with a preset circular cross-sectional shape; the dispersion angles of the at least two light beams can also be the same or different, the light intensities in the final observation area can be the same or different, and the brightness of the final image can be the same or different.

[0081] Figure 7a The light path diagram of the light emitted directly or indirectly by the light source 101 incident on the light directional layer 1021 is shown, and the light is taken as an example of being split into two light beams for explanation and description. The light first enters the micro-prism structure of the light directional layer 1021, and due to the refractive effect of the micro-prism structure, the principal axes CRA and CRB of the two outgoing light beams are refracted to two different directions, which is achieved by adjusting the refractive index of the micro-prism structure and the angle of the micro-prism structure. Smaller micro-prism angle (prism angle refers to the internal angle of the prism) or larger refractive index will result in larger light refraction angle, and when the light refraction angle is greater than a certain critical value, the principal axes CRA and CRB of the outgoing light beams point to different directions; specifically, the refractive index of the micro-prism structure is in the range of 1.45 to 1.6. Figure 6bThe light path schematic diagram when the light emitted by the light source 101 directly or indirectly is incident by the light diffusion layer 1022 is shown, it can be seen that the light with small incident angle close to the vertical direction reaches the light directional layer 1021 and is totally reflected when the light is emitted, and the light is shot back to the side of light incidence after twice total reflection, and the light cannot be emitted; the light with large incident angle is refracted out of the light directional layer, the refraction angle of the main optical axis CRA of the emitted light beam is small, and the main optical axis is emitted to one direction and cannot be emitted to at least two directions, when the light emitted by the light source 101 directly or indirectly is incident by the light diffusion layer 1022, only the light with large angle can be emitted and form a single light beam. That is, the light diffusion layer 1022 is arranged on the side of the light directional layer 1021 away from the light source, one side of the split light diffusion element 102 with the micro-prism structure faces the light source 101, and the light emitted by the light source 101 directly or indirectly is diffused into at least two different directions, including the light beam with a preset shape section, after passing through the split light diffusion element.

[0082] Optionally, as shown in Figure 8 , Figure 9 , the micro-prism structure further includes the prism structure with a cross section of a right-angled triangle and the prism structure with a cross section of a right-angled trapezoid arranged in pairs, and the principle of light directional emission is similar to the three-prism structure, which is not described herein again. Preferably, the height of the micro-prism structure is 50 μm-200 μm, the length of the bottom side of the micro-prism structure is 50 μm-300 μm, and the included angle between adjacent micro-prism structures is 60-120°.

[0083] On the basis of the above-mentioned embodiments of the present application, because the light emitted by the light source 101 has a certain dispersion angle, the light with large dispersion angle is difficult to be used for imaging, and the head-up display system further includes: a reflective light guide element 104, which is arranged on the light emitting direction of the light source 101, the inner reflective surface of the reflective light guide element 104 faces the light source 101 and forms a transmission channel allowing light to pass through, and the light emitted by the light source 101 is transmitted to the liquid crystal panel 103 through the transmission channel of the reflective light guide element 104. Specifically, the reflective light guide element 104 includes a hollow shell with an inner reflective surface or a solid transparent body with an inner reflective surface; as shown in Figure 10 , the reflective light guide element 104 is arranged on the light emitting direction of the light source 101, the inner reflective surface faces the light source 101, part of the light emitted by the light source 101 is transmitted and emitted in the transmission channel of the reflective light guide element 104, and another part of the light with large emission angle is reflected on the inner reflective surface of the reflective light guide element 104 and emitted; the light transmitted through the reflective light guide element is transmitted to the liquid crystal panel 103, and specifically, the light is directly transmitted to the liquid crystal panel 103, as shown in Figure 10As shown in the figure, the light emitted by the light source 101 can be directly transmitted to the liquid crystal panel 103, or can be indirectly transmitted to the liquid crystal panel 103, that is, the light can be transmitted to the liquid crystal panel 103 after passing through the separate light diffusion element 102, and both can be regarded as the transmission of the light emitted by the light source 101 through the transmission channel of the reflective light guide element 104 to the liquid crystal panel. By arranging the reflective light guide element 104, the light emitted by the light source 101 and difficult to transmit to the liquid crystal panel 103 is reflected on the inner reflection surface of the reflective light guide element 104, and the angle of the reflected light changes and converges to the center, which can improve the utilization rate of the light emitted by the light source 101 and improve the light efficiency of the head-up display system.

[0084] Specifically, the reflective light guide element 104 includes a hollow shell 1041 provided with an inner reflection surface, the hollow shell 1041 includes a light outlet opening 1042 and an end opening 1043 away from the light outlet opening, the size of the end opening 1043 is smaller than the size of the light outlet opening 1042; the inner reflection surface of the hollow shell 1041 includes an inner reflection surface formed by aluminizing, silver plating, plating other metals or plating dielectric film, and the light can be specularly reflected on the inner reflection surface. The inner reflection surface of the hollow shell 1041 can specifically include at least one of a parabolic shape, a quadrangular prism shape or a free-form surface shape, the shape of the end opening 1043 includes at least one of a rectangle, a trapezoid, a parallelogram or a square, and the shape of the light outlet opening 1042 includes at least one of a rectangle, a trapezoid, a parallelogram or a square. Referring to Figure 11a As shown in the figure, the hollow shell 1041 includes a rectangular light outlet opening 1042 and a trapezoidal end opening 1043, and the size of the light outlet opening 1042 is smaller than that of the end opening; Figure 11b Another hollow shell 1041 with a quadrangular prism-shaped inner reflection surface is shown, which includes a rectangular light outlet opening 1042 and a rectangular end opening 1043. It can be understood that the shape of the hollow shell 1041 can be different from the shape of the inner reflection surface, as long as the inner reflection surface is the shape that can reflect the light as described above; in the embodiment of the present application, the shape of the hollow shell 1041 is consistent with the shape of the inner reflection surface for convenience of description.

[0085] Further, the light outlet opening 1042 of the hollow shell 1041 faces the liquid crystal panel 103, and the end opening 1043 of the hollow shell 1041 is provided with the light source 101, and optionally, the end opening 1043 of the hollow shell 1041 can be provided with one or more light sources 101, as shown in Figure 11a 、 Figure 11b and Figure 12 As shown in the figure, the light emitted by the light source 101 is transmitted through the transmission channel of the hollow shell 1041 and reflected on the inner reflection surface, and is transmitted to the liquid crystal panel 103, Figure 13A schematic diagram illustrates the transmission of light emitted from light source 101 through a truncated pyramid-shaped hollow housing 1041. The light-emitting opening 1042 of the hollow housing 1041 faces the liquid crystal panel 103. Part of the light emitted from light source 101 is transmitted and emitted through the transmission channel of the hollow housing 1041, while another part is reflected and emitted from the inner reflective surface of the hollow housing 1041. The light transmitted through the hollow housing 1041 is then transmitted to the liquid crystal panel 103; specifically, the light can be directly transmitted to the liquid crystal panel 103, such as... Figure 13 As shown; alternatively, the light can be indirectly transmitted to the LCD panel 103. The light can first pass through the split light diffusion element 102 before being transmitted to the LCD panel 103. Both can be considered as the light emitted by the light source 101 being transmitted to the LCD panel 103 through the transmission channel of the hollow housing 1041. By setting the hollow housing 1041, the large-angle light emitted by the light source 101, which is difficult to reach the LCD panel 103, is reflected on the inner reflective surface of the hollow housing 1041. After reflection, the angle of the light changes and converges towards the center, which can improve the utilization rate of the light emitted by the light source 101, thereby improving the light efficiency of the head-up display system.

[0086] Alternatively, in this embodiment of the invention, the reflective light guide element 104 may further include a solid transparent body 1044, which includes a light-emitting surface 1045 and an end portion 1046 away from the light-emitting surface; the refractive index of the solid transparent body is greater than 1. See also Figure 14 As shown, the solid transparent body 1044 includes a light-emitting surface 1045 and an end 1046; the inner reflective surface of the solid transparent body 1044 includes curved surface shape, free-form surface shape or conical surface shape, etc.

[0087] Furthermore, the light-emitting surface 1045 of the solid transparent body 1044 faces the liquid crystal panel 103, and the light source 101 is disposed at the end 1046 of the solid transparent body 1044 away from the light-emitting opening. The light emitted by the light source is transmitted through the transmission channel of the solid transparent body 1044 and is totally reflected on the inner reflective surface, and the light is transmitted to the liquid crystal panel 103. Specifically, the light source 101 is disposed on the outer side near the end 1046, that is, the light source 101 is disposed in the air. Figure 14A schematic diagram illustrates the transmission of light emitted from light source 101 through solid transparent body 1044. Since the refractive index of solid transparent body 1044 is greater than 1, and the surrounding medium of solid transparent body 1044 is generally air (refractive index 1), when large-angle light emitted from light source 101 reaches the inner surface of solid transparent body 1044, total internal reflection occurs when the light travels from the optically denser medium (i.e., solid transparent body) to the optically less dense medium (i.e., air) at a preset angle of incidence. In other words, the solid transparent body... The inner reflective surface of the solid transparent body 1044 specifically refers to the inner surface of the solid transparent body 1044; the light-emitting surface 1045 of the solid transparent body 1044 faces the liquid crystal panel 103. Part of the light emitted from the light source 101 is transmitted and emitted through the transmission channel of the solid transparent body 1044, while the other part of the light undergoes total internal reflection on the inner reflective surface of the solid transparent body 1044 and is then transmitted and emitted. The light transmitted through the solid transparent body 1044 is transmitted to the liquid crystal panel 103, specifically, the light can be directly transmitted to the liquid crystal panel 103, such as... Figure 14 As shown; alternatively, the light can be indirectly transmitted to the LCD panel 103. The light can first pass through the split light diffusion element 102 before being transmitted to the LCD panel 103. Both can be considered as the light emitted by the light source 101 being transmitted to the LCD panel 103 through the transmission channel of the solid transparent body 1044. By setting the solid transparent body 1044, the large-angle light emitted by the light source 101, which is difficult to reach the LCD panel 103, is reflected on the inner surface of the solid transparent body 1044. After reflection, the angle of the light changes and converges towards the center, which can improve the utilization rate of the light emitted by the light source 101, thereby improving the light efficiency of the head-up display system.

[0088] Furthermore, a high-reflectivity coating can be applied to the exterior of the solid transparent body 1044. Specifically, some of the large-angle light emitted by the light source 101 meets the conditions for total internal reflection and is transmitted to the liquid crystal panel 103. The remaining light that does not meet the conditions for total internal reflection undergoes specular reflection on the high-reflectivity coating and is transmitted to the liquid crystal panel 103, thereby further improving the efficiency of the light emitted by the light source 101.

[0089] In this embodiment of the invention, by setting a reflective light guide element 104, the light emitted by the light source 101 at a large angle that is difficult to reach the liquid crystal panel 103 is reflected on the inner reflective surface of the reflective light guide element 104. After reflection, the angle of the light changes and converges towards the center, which can improve the utilization rate of the light emitted by the light source 101 in the head-up display system, thereby improving the light efficiency of the head-up display system.

[0090] Based on the above embodiments of the present invention, the head-up display system further includes a collimation element 105. Specifically, the collimation element 105 is disposed between the light source 101 and the liquid crystal panel 103, and the collimation element 105 adjusts the light emitted by the light source 101 into parallel light. See also Figure 15As shown, the collimating element 105 is arranged between the light source 101 and the liquid crystal panel 103, and the light emitted by the light source 101 is adjusted to be parallel or nearly parallel light after passing through the collimating element 105. Optionally, the collimating element 105 can be a collimating lens or a collimating film. Figure 15 The collimating element 105 is illustrated by a collimating lens in this embodiment. The collimating lens includes one or more of a convex lens, a Fresnel lens, and a lens combination (for example, a combination of a convex lens and a concave lens, a combination of a Fresnel lens and a concave lens, etc.). Specifically, the collimating element 105 can be a convex lens, and the light source 101 can be arranged at the focal length of the convex lens, that is, the distance between the convex lens and the light source is the focal length of the convex lens, so that the light emitted by the light source 101 in different directions can be parallel after passing through the collimating element 105. Alternatively, the collimating element 105 can be a collimating film, such as a BEF film (Brightness Enhancement Film), which is used to adjust the emission direction of the light to a preset angle range, for example, to collect the light within an angle range of ±35° from the normal line of the collimating film. The collimating element 105 can cover all the light emitted by the light source 101, or can cover part of the light emitted by the light source 101, which is not limited in this embodiment.

[0091] In this embodiment, the collimating element 105 is arranged to collimate the light emitted by the light source 101, and the parallel light after collimation is transmitted to the liquid crystal panel 103, the light divergence angle is small, the light consistency is good, and the light is efficiently incident on the liquid crystal panel 103, thereby improving the conversion efficiency of the liquid crystal panel 103 to the image light, and further improving the light efficiency of the head-up display system.

[0092] On the basis of the above-mentioned embodiments of the present application, the collimating element 105 can be a collimating lens, the collimating element 105 is arranged inside the hollow shell 1041, and the size of the collimating element 105 is smaller than the size of the light-emitting opening of the hollow shell 1041; the collimating element 105 adjusts and collimates the light transmitted in the hollow shell 1041 and emits the light to the liquid crystal panel 103. Specifically, as shown in Figure 16 The collimating element 105 is arranged inside the hollow shell 1041, and the size of the collimating element is smaller than the size of the opening of the hollow shell 1041, the collimating element 105 collimates part of the light transmitted in the hollow shell 1041 and emits the light to the liquid crystal panel 103, and the part of the light is the central light emitted by the light source 101 with a small angle, which is converted to parallel or nearly parallel light after passing through the collimating element 105. The collimating element 105 collimates part of the light emitted by the light source 101, and the emission angle of the part of the light is small; and the light emitted by the light source 101 with a large emission angle is reflected and collected by the inner reflecting surface of the hollow shell 1041, so that the collimating element 101 and the hollow shell 1041 can more effectively collect and collimate the light emitted by the light source 101, and further improve the light utilization.

[0093] Alternatively, the collimating element 105 can also be arranged on the light exit surface of the solid transparent body 1044, as shown in Figure 17a and Figure 17b The large-angle light emitted by the light source 101 is incident on the inner surface of the solid transparent body 1044, and the light satisfying the total reflection angle condition is totally reflected on the inner surface. The collimating element 105 adjusts the light transmitted in the solid transparent body 1044 and the light totally reflected on the inner surface into parallel light or nearly parallel light. Optionally, a certain distance can be kept between the solid transparent body 1044 and the collimating element 105, or they can be fully attached, as shown in Figure 17a , or they can be integrally formed, as shown in Figure 17b . The combination of the collimating element 105 and the solid transparent body 1044 can more effectively converge and collimate the light emitted by the light source 101, further improving the light utilization rate.

[0094] Meanwhile, in a preferred embodiment of the present embodiment, the solid transparent body 1044 is arranged with a cavity at the end 1046 of the light source 101, and the collimating element 105 is arranged on one side of the cavity close to the light exit surface 1045. The collimating element 105 adjusts and collimates the light transmitted in the solid transparent body 1044 and then emits it to the liquid crystal panel 103. Specifically, as shown in Figure 18 , the light source 101 is arranged in the cavity, and the collimating element 105 is arranged at the middle position of the solid transparent body. The size of the collimating element 105 is smaller than the size of the light exit surface of the solid transparent body 1044. The collimating element 105 collimates part of the light emitted by the light source 101 in the solid transparent body 1044 and then emits it to the liquid crystal panel 103. Other light with a larger exit angle is totally reflected in the solid transparent body 1044 and then collimated and emitted. Optionally, the collimating element 105 is a collimating lens, and the light source 101 is arranged at the focal point of the collimating lens. The collimating lens can be made of the same material as the solid transparent body, facilitating integrated integration.

[0095] Alternatively, as shown in Figure 19 , the collimating element 105 is arranged on the light exit surface of the solid transparent body 1044.As shown, the end 1046 of the solid transparent body 1044 provided with the cavity, the light exit surface of the solid transparent body 1044 is provided with a groove, the collimating element 105 is arranged on the bottom surface of the groove, and the collimating element 105 emits the light transmitted in the solid transparent body 1044 to the liquid crystal panel 103 after adjusting and collimating the light. Specifically, the light source 101 is arranged in the cavity, the solid transparent body 1044 is provided with a groove at the middle position of the end close to the light exit surface, and the collimating element 105 is arranged on the bottom surface of the groove; the collimating element 105 emits part of the light emitted by the light source 101 in the solid transparent body 1044 to the liquid crystal panel 103 after collimating the light; other light with a larger exit angle is emitted after total reflection in the solid transparent body 1044 and then collimated; optionally, the collimating element 105 is a collimating lens, the light source 101 is arranged at the focal point of the collimating lens, and the collimating lens can be made of the same material as the solid transparent body, facilitating integrated.

[0096] In the embodiment, by combining the collimating element 101 and the reflective light guide element 104, the light emitted by the light source 101 can be more effectively gathered and collimated, the light utilization rate is further improved, and the picture brightness of the head-up system is improved and the power consumption is reduced.

[0097] On the basis of the above-mentioned embodiments of the application, the head-up display system further comprises a diffusing element 106, which diffuses the light emitted by the light source 101; the diffusing element 106 and the separate light diffusion element 102 are stacked, and the diffusing element 106 and the separate light diffusion element 102 are spaced apart by a preset distance. Specifically, the diffusing element 106 can diffuse the light emitted directly or indirectly by the light source 101, which can further uniformize the light, so that the imaging brightness of the liquid crystal panel 103 is relatively uniform. The diffusing element 106 specifically diffuses the light into a single light beam, and the diffusing element 106 can be a diffractive optical element (DOE), such as a beam shaper, etc. The specific structure of the diffractive optical element can be referred to the above-mentioned description of the separate light diffusion element, which will not be described here. Alternatively, the diffusing element 106 can be a scattering optical element, such as a homogenizing sheet, a diffusion sheet, etc., which mainly diffuses the light through scattering.

[0098] At the same time, in order to ensure that the diffusing element 106 can play a corresponding role, the diffusing element 106 and the separate light diffusion element 102 are spaced apart by a preset distance, which can be 40-50 mm. In addition, the diffusing element 106 and the separate light diffusion element 102 in the embodiment can be arranged on both sides of the liquid crystal panel 103, as shown in Figure 20a 、 Figure 20b shown; the diffusing element 106 and the separate light diffusion element 102 can also be arranged on the same side of the liquid crystal panel 103, as shown inFigure 21a 、 Figure 21b 、 Figure 21c and Figure 21d as shown.

[0099] In this embodiment, through the interval arrangement of the diffusion element and the separate light diffusion element, the light rays are directionally diffused, and the light brightness is further uniform, thereby ensuring the imaging brightness uniformity of the head-up display system.

[0100] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A head-up display system, characterized in that, include: A light source that emits light; A split-type light diffusion element, wherein the split-type light diffusion element diffuses the light emitted by the light source into at least two beams in different directions, each beam including a cross-section of a predetermined shape; A liquid crystal panel that converts incident light into image light and emits the image light. A reflective device, wherein the image light is reflected on the reflective device and the reflected light is directed toward at least two different observation areas; wherein the reflective device is the windshield of a vehicle; The at least two beams of light in different directions correspond one-to-one with the observation area, and the cross sections of the at least two beams of light in different directions in the observation area are separated from each other; wherein, the different observation areas correspond to the eye box areas of different observers inside the vehicle, and the eye box areas of different observers inside the vehicle do not overlap; External ambient light is transmitted through the transflector to the at least two different observation areas, wherein the external environment and the observation areas are located on one side of the space separated by the transflector. The discrete light diffusion element is located between the light source and the liquid crystal panel; the discrete light diffusion element includes a light orientation layer and a light diffusion layer; the light orientation layer directs the light emitted by the light source to emit light in at least two different directions; the light diffusion layer diffuses the light emitted in the at least two different directions into light beams in the at least two different directions; the light diffusion layer is disposed on the side of the light orientation layer away from the light source.

2. The head-up display system according to claim 1, characterized in that, The at least two different observation areas include the observation area for the driver of the corresponding vehicle and the observation area for the corresponding passenger.

3. The head-up display system according to claim 1, characterized in that, The at least two distinct observation areas correspond to the observation areas of any at least two passengers within the vehicle.

4. The head-up display system according to claim 1, characterized in that, The liquid crystal panel includes a first polarization control element, a liquid crystal layer, and a second polarization control element; The first polarization control element transmits light with a first polarization characteristic, and the second polarization control element transmits light with a second polarization characteristic; the polarization directions of the light with the first polarization characteristic and the light with the second polarization characteristic are orthogonal.

5. The head-up display system according to claim 1, characterized in that, The light source includes one or more electroluminescent elements.

6. The head-up display system according to claim 1, characterized in that, The light-directing layer comprises multiple microprism structures.

7. The head-up display system according to claim 1, characterized in that, The head-up display system further includes: a reflective light guide element; The reflective light guide element is disposed in the light emission direction of the light source; the inner reflective surface of the reflective light guide element faces the light source and forms a transmission channel that allows light to pass through; The light emitted by the light source is transmitted to the liquid crystal panel through the transmission channel of the reflective light guide element.

8. The head-up display system according to claim 7, characterized in that, The reflective light guide element includes a hollow housing with an inner reflective surface; The hollow shell includes a light-emitting opening and an end opening away from the light-emitting opening; The size of the end opening is smaller than the size of the light-emitting opening.

9. The head-up display system according to claim 8, characterized in that, The light-emitting opening of the hollow shell faces the liquid crystal panel; The light source is disposed at the end opening of the hollow shell; The light emitted by the light source is transmitted through the transmission channel of the hollow shell and reflected on the inner reflective surface, and then transmitted to the liquid crystal panel.

10. The head-up display system according to claim 9, characterized in that, The inner reflective surface of the hollow shell includes at least one shape selected from parabolic, frustum, or freeform surfaces.

11. The head-up display system according to claim 10, characterized in that, The inner reflective surface of the hollow shell is in the shape of a truncated pyramid; The shape of the end opening includes at least one of trapezoidal and parallelogram shapes; The shape of the light-emitting opening includes at least one of trapezoidal and parallelogram shapes.

12. The head-up display system according to claim 7, characterized in that, The reflective light guide element includes a solid transparent body; The solid transparent body includes a light-emitting surface and an end away from the light-emitting surface; The refractive index of the solid transparent body is greater than 1.

13. The head-up display system according to claim 12, characterized in that, The light-emitting surface of the solid transparent body faces the liquid crystal panel; The light source is located at the end of the solid transparent body away from the light-emitting opening; The light emitted by the light source is transmitted through the transmission channel of the solid transparent body and is totally reflected on the inner reflective surface before being transmitted to the liquid crystal panel.

14. The head-up display system according to any one of claims 8-11, characterized in that, The head-up display system further includes: a collimation element; The collimation element is disposed between the light source and the liquid crystal panel; The collimating element adjusts the light emitted by the light source into parallel light.

15. The head-up display system according to claim 14, characterized in that, The collimating element includes at least one of a collimating lens or a collimating film.

16. The head-up display system according to claim 15, characterized in that, The collimating element is disposed inside the hollow housing, and the size of the collimating element is smaller than the size of the light-emitting opening of the hollow housing; The collimating element adjusts and collimates the light transmitted inside the hollow housing before emitting it onto the liquid crystal panel.

17. The head-up display system according to claim 12 or 13, characterized in that, The head-up display system further includes: a collimation element; The collimation element is disposed between the light source and the liquid crystal panel; The collimating element adjusts the light emitted by the light source into parallel light.

18. The head-up display system according to claim 17, characterized in that, The collimating element includes at least one of a collimating lens or a collimating film.

19. The head-up display system according to claim 18, characterized in that, The collimating element is disposed on the light-emitting surface of the solid transparent body.

20. The head-up display system according to claim 18, characterized in that, The solid transparent body has a cavity at the end where the light source is located, and the collimating element is located on the side of the cavity near the light-emitting surface; The collimating element adjusts and collimates the light transmitted within the solid transparent body before emitting it onto the liquid crystal panel.

21. The head-up display system according to claim 18, characterized in that, The solid transparent body has a cavity at the end where the light source is located, and the light-emitting surface of the solid transparent body has a slot. The collimating element is located on the bottom surface of the slot. The collimating element adjusts and collimates the light transmitted within the solid transparent body before emitting it onto the liquid crystal panel.

22. The head-up display system according to claim 1, characterized in that, The head-up display system further includes: a diffusion element; The diffusion element diffuses the light emitted by the light source; The diffusion element and the separate light diffusion element are stacked together, and the diffusion element and the separate light diffusion element are spaced apart by a preset distance.

23. The head-up display system according to claim 22, characterized in that, The diffusion element is a diffractive optical element or a scattering optical element.

Images