Switchable display holographic tail lamp and vehicle

Abstract

The holographic tail lamp comprises a light source assembly, a reflection assembly, a waveguide and a holographic film, when the reflection assembly is located at different switching position angles to reflect specified light beams emitted by the light source assembly, the reflected light beams formed through reflection enter the waveguide at different incident angles, and the holographic film is used for displaying the specified light beams. The waveguide receives the reflected light beam, expands the reflected light beam into an illumination light beam and then emits the illumination light beam; a plurality of holographic patterns are recorded in the holographic film and used for receiving the reference light beams, and when the angles of the illumination light beams incident on the holographic film are different, different holographic patterns are presented. According to the scheme of the automobile tail lamp, the angle multiplexing characteristic of the holographic film and the advantage of small-size pupil expansion of the waveguide are utilized, and the vehicle-mounted tail lamp which is large in visual angle, even in brightness and compact in module size is achieved.

Description

Technical Field

[0001] This application relates to the field of vehicle image display technology, and in particular to a switchable display holographic taillight and vehicle. Background Technology

[0002] Vehicle taillights serve multiple purposes: signal transmission, improved visibility, and aesthetic enhancement of the vehicle's appearance. Currently, taillight technology has evolved from traditional bulbs to LEDs and finally to OLEDs. Early taillights used incandescent bulbs, providing only illumination. With the development of LED technology, taillights began to incorporate dynamic display capabilities. OLEDs are thinner, more flexible, and capable of displaying complex patterns and animations.

[0003] Currently, the dynamic display function of vehicle taillights is developing from two-dimensional to three-dimensional display. The three-dimensional display method is based on holographic display technology. However, the holographic display technology for vehicle taillights still has the drawbacks of a small viewing angle and high cost.

[0004] Therefore, existing technologies still need to be improved and enhanced. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a switchable display holographic taillight and vehicle, thereby achieving a vehicle taillight holographic display technology with a wide viewing angle and low cost.

[0006] In a first aspect, this application provides a switchable display holographic taillight, comprising:

[0007] A light source component used to generate a specified light beam;

[0008] A reflection component is disposed in the optical path of the specified beam and has multiple different switching position angles, so that when the specified beam is reflected at different switching position angles, the reflected beams formed by the reflection enter the waveguide at different incident angles.

[0009] A waveguide, disposed in the optical path of the reflected beam, is used to receive the reflected beam and expand it into an illumination beam; the reflected beam and the illumination beam have the same transmission direction.

[0010] The holographic film records various holographic patterns formed by exposure of reference light with different incident angles and different object light. It is used to receive the illumination beam and presents different holographic patterns when the incident angle of the illumination beam on the holographic film switches between multiple angles. The different incident angles of the reflected beam entering the waveguide correspond to the different incident angles of the reference light that exposes the holographic film to form various holographic patterns.

[0011] Optionally, the reflective component includes:

[0012] A reflector is used to receive the specified light beam and reflect the specified light beam to the waveguide;

[0013] A control unit, connected to the reflector, is used to control the reflector to switch between multiple different switching position angles;

[0014] The control unit controls the reflector to switch between multiple different positions and directions to change the angle at which the illumination beam is incident on the holographic film.

[0015] Optionally, a beam expander module is further provided between the light source assembly and the reflector; the beam expander module includes a concave lens and a convex lens;

[0016] The designated light beam emitted by the light source assembly is incident on the concave lens. After being diverged by the concave lens, the designated light beam is incident on the convex lens. After being collimated by the convex lens, it is incident on the surface of the reflector as a parallel light beam.

[0017] Optionally, the waveguide includes at least one coupling grating and at least one coupling grating; each of the coupling gratings and each coupling grating is one or more of a holographic structure, an embossed structure, a liquid crystal structure, and a transflective film layer.

[0018] Optionally, the designated beam includes multiple designated sub-beams with the same transmission direction; the waveguide includes multiple beam incident areas and a beam exit area; each designated sub-beam is reflected by a reflective component and then incident into each beam incident area in the waveguide, and is coupled out from the beam exit area to form the illumination beam; each designated sub-beam corresponds one-to-one with each beam incident area and the regional layout of each beam incident area is uniformly and symmetrically distributed.

[0019] Optionally, the designated beam includes multiple designated sub-beams with the same transmission direction; the waveguide includes multiple sub-waveguides, each sub-waveguide having a beam incident area and a beam exit area; each designated sub-beam is reflected by a reflecting component and then incident into the beam incident area of ​​each sub-waveguide, and coupled out from the beam exit area, expanding its pupil through each sub-waveguide to become each illumination sub-beam; the illumination sub-beams are spliced ​​together to form an illumination beam; each designated sub-beam corresponds one-to-one with each sub-waveguide, and the regional layout of each sub-waveguide is uniformly and symmetrically distributed.

[0020] Optionally, the light source assembly includes a light source and a beam splitter; the light source is a laser light source or an LED light source; the designated beam emitted by the laser light source is split by the beam splitter to obtain multiple designated sub-beams; or, the light source assembly includes multiple laser light sources or multiple LED light sources, each laser light source or each LED light source emits a designated sub-beam, and the multiple designated sub-beams form a designated beam.

[0021] Optionally, the different incident angles of the reflected light beam entering the waveguide correspond one-to-one with the different incident angles of the reference light that exposes the holographic film to form various holographic patterns;

[0022] Optionally, the holographic film is a HOE film, and the difference between the incident angles of different illumination beams incident on the HOE film is less than 30 degrees.

[0023] Secondly, this application also provides a vehicle, which includes: the switchable display holographic taillights.

[0024] Beneficial effects:

[0025] This utility model discloses a switchable holographic taillight and vehicle. The holographic taillight includes a light source component, a reflector component, a waveguide, and a holographic film. The light source component generates a specified light beam. When the reflector component is at different switching angles, it reflects the specified light beam emitted by the light source component, and the reflected beams enter the waveguide at different incident angles. The waveguide receives the reflected beams and expands them into an illumination beam before emitting them. The specified light beam and the illumination beam have the same transmission direction. The holographic film records multiple holographic patterns to receive the reference beam. Different holographic patterns are presented when the illumination beam is incident on the holographic film at different angles. This utility model provides a taillight solution with switchable images based on a holographic film and waveguide devices. It utilizes the angle multiplexing characteristics of the holographic film and the small-volume pupil expansion advantage of the waveguide to achieve a taillight form with a large viewing angle range, uniform brightness, and compact module size. Furthermore, the holographic taillight provided by this application is low in cost and suitable for widespread application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a structural principle block diagram of the switchable display holographic taillight provided in this application;

[0028] Figure 2 A schematic diagram of the switchable display holographic taillight provided in this application;

[0029] Figure 3 An imaging schematic diagram of the switchable display holographic taillight provided in this application;

[0030] Figure 4A schematic diagram illustrating the variation of holographic film efficiency with incident angle in the embodiments provided in this application;

[0031] Figure 5 The holographic film preparation is illustrated in the embodiments provided in this application. Figure 1 ;

[0032] Figure 6 The holographic film preparation is illustrated in the embodiments provided in this application. Figure 2 ;

[0033] Figure 7 A schematic diagram of the large viewing angle imaging holographic film recording method provided in the embodiments of this application Figure 1 ;

[0034] Figure 8 A schematic diagram of the large viewing angle imaging holographic film recording method provided in the embodiments of this application Figure 2 ;

[0035] Figure 9 This is a schematic diagram of the optical path of the reflected beam incident on the waveguide at the first incident angle in an embodiment of this application;

[0036] Figure 10 This is a schematic diagram of the optical path of the reflected beam incident on the waveguide at the second incident angle in an embodiment of this application;

[0037] Figure 11 This is a schematic diagram of the optical path of the reflected beam incident on the waveguide at the third incident angle in an embodiment of this application;

[0038] Figure 12 This is a schematic diagram of the layout of the beam incident region and beam exit region in the waveguide of an embodiment of this application. Figure 1 ;

[0039] Figure 13 This is a schematic diagram of the layout of the beam incident region and beam exit region in the waveguide of an embodiment of this application. Figure 2 . Detailed Implementation

[0040] This application provides a split-type vehicle-mounted virtual image display system and a vehicle. To make the purpose, technical solution, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.

[0041] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this application's specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or components thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0042] Automotive taillights are a core component of the vehicle safety system. They serve to convey the vehicle's status (such as braking, steering, and reversing) through visual signals, and also improve visibility and enhance the vehicle's appearance.

[0043] Automotive taillight technology has evolved from traditional bulbs to LEDs, and then to OLEDs. Traditional bulbs primarily serve lighting and signaling functions, thus their functionality is limited. LED taillights offer higher brightness, lower energy consumption, and longer lifespan, and have begun to incorporate dynamic display capabilities. However, LED taillights have lower display resolution, noticeable pixels, and larger module sizes, making it difficult to achieve smooth curved displays. OLED technology allows for thinner, more flexible taillights and can display complex patterns and animations, thus improving vehicle visibility and safety, but it is also very expensive.

[0044] Holographic display technology is a technique that uses the principles of light interference and diffraction to reproduce images of objects. It records the amplitude and phase information of specific light waves emitted by an object, storing this information as interference fringes in a recording medium to form a hologram. When an external light source illuminates the hologram, due to the principle of diffraction, the original object's light waves can be reproduced, thus forming a three-dimensional image of the original object, allowing the observer to see the recorded image. Currently, holographic display technology is applied in multiple fields, such as virtual reality and augmented reality, education and training, and medical imaging.

[0045] Currently, it has been proposed to combine holographic display technology with automotive taillights to enhance their functionality, aesthetics, and safety. Holographic display technology enables taillights to present a 3D effect and can also display different patterns, text, or animations through holographic projection. This combination can not only enhance the personalization of taillights but also display specific warning information to improve vehicle safety.

[0046] However, when holographic display technology is applied to automotive taillights, there are limitations in the viewing angle and resolution of the displayed images. The viewing angle is small, and the resolution is low. Generating high-quality holographic images requires a large amount of computation, thus placing extremely high demands on hardware performance, resulting in high costs and hindering widespread adoption.

[0047] To overcome the above problems, this application provides a switchable holographic taillight, which includes a light source component, a reflector component, a waveguide, and a holographic film. The light source component generates a specified light beam, which is reflected by the reflector component and then transmitted to the waveguide. The waveguide expands the pupil of the transmitted reflected light beam to form an illumination beam that is input to the holographic film. Since the holographic film records multiple holographic patterns, different holographic patterns are presented when the incident angle of the illumination beam on the holographic film switches between multiple angles.

[0048] Furthermore, since the reflective component can transmit a specified light beam into the waveguide at different incident angles, and the angle of the illumination beam exiting the waveguide is the same as the angle at which the reflective component reflects the specified light beam into the waveguide (i.e., the angle at which the reflected beam is incident into the waveguide), the incident angle of the illumination beam on the holographic film can be adjusted by adjusting the reflection angle of the reflective component. When the incident angle of the illumination beam on the holographic film is the same as the incident angle of the reference light when any holographic pattern is exposed, a corresponding holographic pattern will be displayed on the other side of the holographic film where the illumination beam is incident. Moreover, when the incident angle of the illumination beam switches between different angles, different holographic patterns will be displayed, thus achieving a variable image effect for the car taillights.

[0049] The holographic taillight provided in this application utilizes the angle multiplexing feature of the holographic film (different incident angles can present different holographic patterns) and the small volume pupil expansion characteristic of the waveguide (the waveguide has a small volume, the thickness of the optical waveguide lens can be controlled at the millimeter level, and through two-dimensional pupil expansion technology, vertical and horizontal bidirectional exit pupil expansion can be achieved within a limited volume, increasing the field of view), to achieve a large viewing angle, uniform brightness and compact component size in automotive taillights.

[0050] The following is a more detailed description of a switchable display holographic taillight and vehicle provided by this utility model.

[0051] The present invention proposes a switchable display holographic taillight, such as... Figure 1As shown, it includes a light source assembly 101 for generating a specified light beam. The light source assembly can use a laser light source or an LED light source. Because lasers have good directionality, good monochromaticity, and strong coherence, using a laser light source can achieve better holographic pattern display effects. LED light sources have the advantages of low energy loss and low heat generation; therefore, the light source assembly can also use LED light sources as the illumination source for automotive taillights.

[0052] In practical applications, the specified beam emitted from the light source assembly 101 can be a single beam or multiple parallel beams to adapt to waveguide structures with different optimized designs.

[0053] The reflector 102 is disposed on the optical path of the specified beam and has multiple different switching position angles. When the specified beam is reflected at different switching position angles, the reflected beams formed by the reflection enter the waveguide 103 at different incident angles.

[0054] A specified light beam is incident on a reflecting component, which reflects the specified light beam into the waveguide. Since the reflecting component in this application has multiple different switching position angles, it can switch between these angles to allow the specified light beam to enter the waveguide at different incident angles. For example, if the reflecting component has two switching position angles, when the reflecting component is at the first switching position angle, the specified light beam, reflected by the reflecting component, forms a first reflected beam. The first reflected beam is incident into the waveguide at a first incident angle. When the reflecting component switches to the second switching position angle, the specified light beam is reflected by the reflecting component at the second switching position angle to form a second reflected beam, which is incident into the waveguide at a second incident angle.

[0055] Waveguide 103 is disposed in the optical path of the reflected beam to receive the reflected beam and expand the reflected beam into an illumination beam; the reflected beam and the illumination beam have the same transmission direction.

[0056] A waveguide is a structure used to guide electromagnetic waves in a directional manner. It utilizes the reflection and refraction properties of a medium to confine electromagnetic waves to a limited space for propagation. The waveguide in this application couples a reflected light beam into the waveguide so that the beam propagates within the waveguide and then couples out of the waveguide so that the beam travels along a predetermined path.

[0057] Furthermore, the waveguide used in this application is a pupil-expanding waveguide device, which can expand a small-sized beam incident on the waveguide into a large-sized beam, and control the propagation direction of the beam before and after pupil expansion to be the same. In a specific implementation, the waveguide includes: at least one coupling grating and at least one coupling grating; each of the coupling gratings and each coupling grating is one or more of a holographic structure, an embossed structure, a liquid crystal structure, and a transflective coating layer. The reflected beam enters the waveguide through the coupling grating, propagates in the waveguide to the coupling grating, and is coupled out of the waveguide through the coupling grating. To achieve the effect of beam pupil expansion, the waveguide has a periodic grating structure (or a groove-shaped grating structure). After the beam entering the waveguide is incident on the periodic grating structure, it is split into multiple diffraction orders in different directions. By adjusting the parameters of the grating to optimize the diffraction efficiency, directional propagation of the beam is achieved.

[0058] Combination Figure 2 As shown, a designated light beam emitted from the light source assembly 101 is incident into the waveguide 103. The beam is coupled into the waveguide by the coupling grating 1031 within the waveguide. The coupled beam travels along a propagation path within the waveguide to the coupling grating 1032, and then exits from the waveguide. The illumination beam coupled from the waveguide is incident on the holographic film 201, thus serving as the illumination light for the holographic film, resulting in a holographic pattern on the other side of the holographic film.

[0059] Holographic film 201 records multiple holographic patterns formed by exposure of reference light with different incident angles and different object light, and is used to receive the illumination beam. When the incident angle of the illumination beam on the holographic film switches between multiple angles, different holographic patterns are presented. The reflective component 102 switches to obtain multiple different incident angles of the specified beam that correspond to the incident angle of the reference light of the multiple holographic patterns formed by exposure.

[0060] A holographic film is an optical element fabricated using the principle of holographic gratings. It can record the three-dimensional information of an object in the form of a hologram and reproduce the holographic image of the original object under appropriate light source illumination. Therefore, the fabrication and use of holographic films mainly include: recording the light wave information of an object using the principle of interference, that is, exposing the holographic film to form a holographic pattern, and reproducing the holographic pattern using the principle of diffraction to obtain the image of the original object.

[0061] In this application, multiple different holographic patterns are first obtained by exposing the holographic film, and then different holographic patterns are presented by outputting an illumination beam from the waveguide into the holographic film at different incident angles, thereby achieving the effect of a car taillight with switchable display patterns.

[0062] Specifically, by exposing the holographic film multiple times, different angles of the light beams incident on the holographic film are achieved, resulting in different holographic patterns. Combined with... Figure 3As shown, when the incident angle of the reflected light beam onto the waveguide changes, the incident angle of the illumination light beam onto the holographic film changes synchronously, and the image 401 displayed on the holographic film as seen by the observer 301 changes. Similarly, by setting the incident angle of the reflected light beam onto the waveguide to change, the holographic taillight can display various patterns.

[0063] like Figure 4 The figure shows the trend of holographic film diffraction efficiency as a function of the incident angle of the illumination beam. By pre-exposing multiple holographic patterns on the surface of the holographic film during its fabrication, the holographic film achieves high diffraction efficiency at multiple discrete angles. Figure 4 In this context, Δθ represents the angular interval for holographic film angle reuse. The angular reuse interval Δθ in the holographic taillight of this application is greater than the half-width at half-maximum (WHM) of the "diffraction efficiency - incident angle" curve at a single angle.

[0064] In this embodiment, holographic angle multiplexing is a technique that stores multiple holograms in the same spatial region by changing the incident angle of the reference light. The angle interval refers to the difference between the reference light angles corresponding to adjacent holograms, and its magnitude directly affects storage capacity and image quality. In holographic storage, each hologram corresponds to a specific reference light angle. The angle interval is the difference between the reference light angles corresponding to adjacent holograms. For example, if the incident angle of the reference light for the first hologram is θ1 and the incident angle of the reference light for the second hologram is θ2, then the angle interval of the reference light is Δθ = |θ2 - θ1|. The size of the angle interval for angle multiplexing is related to the material of the holographic film, image quality, and storage device, so the optimal angle interval can be determined according to the material of the holographic film and the requirements of the displayed image.

[0065] Once the angular interval for holographic film angle reuse is determined, multiple different holographic patterns are exposed based on the determined angular interval to prepare the holographic film used in the automotive taillight of this application. Figure 5 The diagram illustrates the principle of a method for preparing a holographic film containing a first pattern through exposure. The holographic film is exposed once using a first reference light 601 and a first object light 701 illuminating a first object 501. The first reference light 601 and the illumination beam are incident at the same angle into the holographic film (considering the shrinkage effect of the holographic film, there may be some deviation between the two beams. However, the incident angle of the illumination beam must satisfy the Bragg condition for the diffraction efficiency of the exposed structure by the first reference light 601 and the first object light 701). Therefore, under the illumination beam, the holographic film displays the pattern of the first object 501 recorded. Similarly, as... Figure 6As shown, the holographic film is further exposed using a second reference light 602 and a second object light 702 for recording the second object 502, so that the holographic film displays the pattern of the recorded second object 502 under the illumination beam. When recording the holographic patterns of the first and second objects, the incident angle between the reference lights for recording the two holographic patterns must satisfy the angle interval for angle reuse of the holographic film to avoid crosstalk between the two holographic patterns, which would result in a low signal-to-noise ratio between the two holographic patterns. By using the above method of exposing multiple holographic patterns on the holographic film, different images can be displayed after the holographic film is illuminated by illumination beams with different incident angles. When the incident angle of the illumination beam switches between different angles, the displayed image can switch between multiple holographic patterns. For example, if the first object is an apple and the second object is a tomato, then when the incident angle of the illumination beam corresponds to the incident angle of the reference light exposing the apple pattern, the image displayed on the other side of the holographic film corresponding to the illumination beam is the apple image. When the incident angle of the illumination beam is switched to the incident angle of the reference light corresponding to the exposed tomato pattern, the image displayed on the other side of the holographic film corresponding to the illumination beam is a tomato image.

[0066] In automotive taillight applications, to achieve both switchable display patterns and an expanded viewing angle of the displayed image, this application also provides two methods for expanding the viewing angle of the holographic film display image. Combined with... Figure 7 As shown, the first implementation method is as follows: A patterned diffusion film is used as the object to be recorded during the fabrication of the holographic film. The patterned diffusion film consists of two parts: a large-angle diffusion film region 802 and a non-transparent region 801. The object light source 703 is collimated light. The object light passing through the large-angle diffusion film region 802 becomes a large-angle distribution, and then interferes with the third reference light 603 in the holographic film 201, thereby enabling the exposed holographic film 201 to produce a large-angle visible image under the illumination beam.

[0067] The second method expands the viewing angle of holographic images. It employs at least two sets of object and reference beams interfering with the holographic film to record multi-dimensional information about the object, thereby expanding the viewing angle of the displayed image. For example... Figure 8 As shown, two sets of object beams and reference beams interfere on the holographic film, taking the recording of the holographic pattern of the first object 501 as an example. The fourth object beam 704 and the fifth object beam 705 are used to record the first object 501, so that the object beams record the large-angle information of the three-dimensional information of the first object 501, thereby making the displayed image of the first object 501 presented by the holographic film an enlarged three-dimensional view image.

[0068] This invention utilizes a holographic film as a display component for automotive taillights. Based on the angle selection characteristics of the holographic film, multiple patterns are recorded on a single holographic film to achieve different display images when illumination beams are incident from different directions. This enables the automotive taillights to display multiple patterns with a wide viewing angle. Furthermore, the automotive taillights provided in this embodiment have the advantages of small module size, low cost, and three-dimensional display capability, making them suitable for widespread application.

[0069] To enable the reflective component to switch at different switching position angles, in one implementation, the reflective component includes: a reflector and a control unit connected to the reflector. The reflector receives the reflected light beam and reflects it to a waveguide; the control unit controls the reflector to switch at multiple different switching position angles; the control unit controls the reflector to switch at multiple different positions and directions to change the angle at which the illumination beam is incident on the holographic film.

[0070] The control component is connected to the reflector, which can be a mechanical connection such as a shaft connection or a gear connection. The control component and the reflector are directly connected via a drive shaft. Power from the control component is transmitted to the reflector to control its rotation within a certain range, thereby changing the reflector's position angle relative to the specified beam transmission direction. The control component can be a small motor that directly drives the reflector to rotate via the shaft. If a gear connection is used, the control component is connected to a driving gear, and the reflector is connected to a driven gear; power is transmitted through the meshing of the driving and driven gears. Gears with different numbers of teeth can be designed to meet the rotational accuracy requirements of the reflector at various switching positions.

[0071] like Figure 9 As shown, when the control unit controls the reflector to be at the first switching position angle, the designated light beam emitted by the light source assembly 101 is reflected by the reflector located at the first switching position angle to obtain a first reflected light beam. The first reflected light beam is incident on the coupling grating 1031 on the waveguide 103 at a first incident angle. The beam is transmitted within the waveguide to the coupling grating 1032 and is coupled out from the coupling grating 1032. The beam coupled out from the waveguide becomes the illumination beam of the holographic film after being expanded by the waveguide pupil and is incident on the holographic film. Figure 10As shown, when the position of the reflector is switched from a first switching angle to a second switching angle under the control of the controller, the designated light beam emitted by the light source assembly 101 is reflected by the reflector located at the second switching angle to obtain a second reflected beam. The second reflected beam is incident on the coupling grating 1031 on the waveguide 103 at a second incident angle. The beam is transmitted within the waveguide to the coupling grating 1032 and is coupled out from the coupling grating 1032. The first incident angle and the second incident angle are different, and the incident angle of the reflected beam onto the waveguide is the same as the incident angle of the illumination beam onto the holographic film. Therefore, when the reflector is at different switching angles, the angle at which the illumination beam is incident on the holographic film is different, and thus the holographic film presents different holographic patterns after being illuminated by illumination beams at different incident angles.

[0072] like Figure 11 As shown, in order to improve the continuity of the waveguide's pupil expansion and reduce the manufacturing difficulty of the waveguide, a beam expander module 104 is also provided between the light source assembly and the reflector. The beam expander module 104 includes a concave lens and a convex lens; the designated beam emitted by the light source assembly 101 is incident on the concave lens, and after being diverged by the concave lens, the designated beam is incident on the convex lens. After being collimated by the convex lens, it is incident on the surface of the reflector as a parallel beam.

[0073] Because the diameter of the specified beam is expanded by the beam expander before it enters the waveguide, the diameter of the reflected beam after reflection by the mirror is achieved. Since the waveguide can further expand the pupil of the reflected beam, the specified beam emitted from the light source assembly increases the size of the displayed image after two pupil expansions. If only the waveguide is used, the size of the displayed image is within a preset range. However, by adding the beam expander, the required waveguide thickness (i.e., the vertical distance between the top and bottom surfaces of the waveguide medium) can be reduced, thus reducing the manufacturing difficulty of the waveguide. Furthermore, since the pupil expansion continuity of the waveguide is related to the coverage length of the incident beam, the beam expander increases the size of the reflected beam, increasing the coverage length of the incident beam and thus improving the pupil expansion continuity of the waveguide.

[0074] To meet the image uniformity requirement of the holographic taillight, this invention improves the brightness uniformity of the waveguide emitted illumination beam through waveguide layout optimization. This embodiment discloses two different waveguide-light source layout optimization methods.

[0075] The first layout optimization method is to divide the designated light beam emitted by the light source into multiple designated sub-beams, set multiple beam incident areas and a beam exit area on the waveguide, so that each designated sub-beam is reflected to the respective beam incident area entering the waveguide, and then emitted through the same beam exit area, thereby improving the brightness uniformity of the illumination beam.

[0076] Specifically, the designated light beam emitted from the light source assembly includes multiple designated sub-beams with the same transmission direction; the waveguide is configured to include multiple beam incident areas and one beam exit area; each designated sub-beam is reflected by a reflector and then incident on its respective beam incident area in the waveguide, and coupled out from the beam exit area to form the illumination beam; each designated sub-beam corresponds one-to-one with each beam incident area. The regional layout of each beam incident area is uniformly and symmetrically distributed.

[0077] Combination Figure 12 As shown, taking a waveguide with four beam incident areas and one beam exit area as an example. The waveguide has a first beam incident area 211, a second beam incident area 212, a third beam incident area 213, a fourth beam incident area 214, and a first beam exit area 202. The designated beam emitted from the light source assembly includes four designated sub-beams. The propagation directions of the four designated sub-beams are parallel, and after being reflected by a mirror, the first reflected sub-beam is incident on the first beam incident area 211, the second reflected sub-beam is incident on the second beam incident area 212, the third reflected sub-beam is incident on the third beam incident area 213, and the fourth reflected sub-beam is incident on the fourth beam incident area 214. After the first, second, third, and fourth reflected sub-beams are transmitted within the waveguide, they are all output through the first beam exit area 202, thus forming a complete illumination beam. Because the first beam incident area 211, the second beam incident area 212, the third beam incident area 213, and the fourth beam incident area 214 are uniformly distributed, it ensures that the four reflector beams propagate in a uniform and symmetrical distribution within the waveguide, enhancing the uniformity of the optical field within the waveguide. Furthermore, the multiple symmetrically and uniformly distributed optical path designs can reduce aberrations caused by beam non-uniformity, thereby improving the image clarity and color consistency after the illumination beam is incident on the holographic film.

[0078] The second layout optimization method involves dividing the designated light beam emitted by the light source into multiple designated sub-beams. Multiple sub-waveguides are then positioned on the waveguide, each with an incident beam area and an exit beam area. This ensures that each designated sub-beam is reflected into its corresponding incident beam area within its respective sub-waveguide, and then emitted through its exit beam area, thereby improving the uniformity of the illumination beam's brightness. The sub-waveguides are arranged in a uniform and symmetrical distribution.

[0079] Specifically, the designated light beam emitted by the light source component includes multiple designated sub-beams with the same transmission direction; the waveguide includes multiple sub-waveguides, each of which is provided with a beam incident area and a beam exit area; each designated sub-beam is reflected by a reflector component and then incident into the beam incident area of ​​each sub-waveguide, and coupled out from the beam exit area, and expanded into each illumination sub-beam through each sub-waveguide; the illumination sub-beams are spliced ​​together to form an illumination beam; each designated sub-beam corresponds one-to-one with each sub-waveguide.

[0080] like Figure 13 As shown, the waveguide is divided into four sub-waveguides: the first sub-waveguide 21, the second sub-waveguide 22, the third sub-waveguide 23, and the fourth sub-waveguide 24. Each sub-waveguide has a separate beam incident area and a beam exit area. The first sub-waveguide 21 corresponds to the fifth beam incident area 2011 and the second beam exit area 2021; the second sub-waveguide 22 corresponds to the sixth beam incident area 2012 and the third beam exit area 2022; the third sub-waveguide 23 corresponds to the seventh beam incident area 2013 and the fourth beam exit area 2023; and the fourth sub-waveguide 24 corresponds to the eighth beam incident area 2014 and the fifth beam exit area 2024.

[0081] Because the beams propagate independently within the four sub-waveguides, crosstalk between beams is avoided. Furthermore, the uniform distribution of each sub-waveguide ensures a uniform beam distribution in the exit pupil region, preventing localized over-brightness or under-brightness of the illumination beam and improving the uniformity of the light field distribution. Moreover, the beam exit regions of the four sub-waveguides are stitched together to form a complete holographic illumination area, effectively reducing the manufacturing difficulty of large-area waveguides.

[0082] Through the different layouts of the waveguide and light source described above, the holographic taillight provided in this embodiment can achieve a brightness uniformity of more than 60% for the waveguide emitted beam, a viewing angle of more than 90 degrees for the displayed image after being illuminated by the illumination beam, and a uniformity of the object light reaching the film surface when the holographic film is exposed to light that is more than 60%.

[0083] Furthermore, in order to achieve a specified beam emitted by the light source assembly comprising multiple specified sub-beams, the light source assembly includes a laser light source or an LED light source and a beam splitter; the specified beam emitted by the laser light source is split by the beam splitter to obtain multiple specified sub-beams; or, the light source assembly includes multiple laser light sources or multiple LED light sources, and the specified sub-beams emitted by each laser light source or multiple LED light source constitute the specified beam.

[0084] Furthermore, the different incident angles of the reflected beam entering the waveguide correspond one-to-one with the different incident angles of the reference light that exposes the holographic film to form various holographic patterns, and the difference between each incident angle is less than 30 degrees.

[0085] Since the holographic pattern recorded in the holographic film can only be displayed under specific light source illumination, when reproducing and displaying various holographic patterns recorded in the holographic film, the illumination beam projected onto the holographic film must undergo interference and diffraction again to form a holographic image of the original object. Therefore, the angle at which the illumination beam is incident on the holographic film must be the same as the incident angle of the reference light when forming the holographic pattern. Because the incident angle of the reflected beam when it is incident on the waveguide is the same as the angle at which the illumination beam exits the waveguide, the reflective component switches its angle at different switching positions. After reflecting the specified beam, the incident angle of the resulting reflected beam incident on the waveguide must correspond one-to-one with the incident angle of the reference light forming the holographic pattern. Thus, by switching the position of the reflector each time, an incident angle identical to that of the reference light forming the holographic pattern is obtained, achieving the display of the holographic pattern.

[0086] Furthermore, in one embodiment, the holographic film is a HOE film, and the difference between the incident angles of different illumination beams incident on the HOE film is less than 30 degrees.

[0087] Due to the different materials used in holographic films, the angle intervals for angle reuse vary. In this embodiment, a HOE film is selected as the element for the automotive taillight display. To achieve better image display effects, the thickness of the HOE film is set to be greater than 20 μm. The reuse angle interval of the HOE film display is less than 5 degrees, and the difference between the incident angles of different illumination beams incident on the HOE film is less than 30 degrees, meaning that the variable range of the incident angles of the reflected beams incident on the waveguide is less than 30 degrees.

[0088] In addition to providing the aforementioned switchable holographic taillight, this utility model also discloses a vehicle, which includes: the aforementioned switchable holographic taillight.

[0089] Because the holographic taillight provided in this application utilizes the angle selectivity of the holographic film to record multiple patterns on a single holographic film, and presents different patterns when illumination light is incident from different directions, vehicles equipped with the holographic taillight provided in this application have the effect of switchable taillight display images.

[0090] Since the patterns recorded in the holographic film can be set as needed, the vehicle provided in this embodiment can not only display various personalized images through the vehicle's taillights, but also set the patterns recorded in the holographic film as warning-related patterns. When the vehicle encounters an emergency or malfunction, the taillights can provide a warning by combining sound and warning patterns, thereby improving the vehicle's driving safety.

[0091] This utility model discloses a switchable holographic taillight and vehicle. Utilizing the angle selectivity of a holographic film, multiple holographic patterns are pre-recorded on a single film, displaying different patterns when illuminated by beams of light from different directions. Furthermore, a pupil-expanding waveguide device is used as the illumination device for the holographic film. Through optimized design of the waveguide device and optimized layout of the light source output beam, the brightness uniformity of the holographic film illumination is improved. A reflective component is used to change the direction of the laser beam incident on the waveguide device, thereby changing the direction of the illumination beam incident on the holographic film, thus achieving the switching display between different patterns. This utility model also utilizes multi-angle uniform illumination to record holographic patterns with a wide viewing angle, thereby increasing the viewing angle and brightness uniformity of the image light. This allows vehicles equipped with the holographic taillight disclosed in this application to not only project images with a wide viewing angle but also project images with more uniform brightness, thus achieving a better image display effect.

[0092] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0093] It should be understood that the sequence number and size of each step in this embodiment do not imply the order of execution. The execution order of each process is determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application embodiment.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A switchable display holographic taillight, characterized by, include: A light source component used to generate a specified light beam; A reflection component is disposed in the optical path of the specified beam and has multiple different switching position angles, so that when the specified beam is reflected at different switching position angles, the reflected beams formed by the reflection enter the waveguide at different incident angles. A waveguide, disposed in the optical path of the reflected beam, is used to receive the reflected beam and expand it into an illumination beam; the reflected beam and the illumination beam have the same transmission direction. The holographic film records various holographic patterns formed by exposure of reference light with different incident angles and different object light. It is used to receive the illumination beam and presents different holographic patterns when the incident angle of the illumination beam on the holographic film switches between multiple angles. The different incident angles of the reflected beam entering the waveguide correspond to the different incident angles of the reference light that exposes the holographic film to form various holographic patterns.

2. The switchable display holographic tail light of claim 1, wherein, The reflective component includes: A reflector is used to receive the specified light beam and reflect the specified light beam to the waveguide; A control unit, connected to the reflector, is used to control the reflector to switch between multiple different switching position angles; The control unit controls the reflector to switch between multiple different positions and directions to change the angle at which the illumination beam is incident on the holographic film.

3. The switchable display holographic tail light of claim 2, wherein, A beam expander module is also provided between the light source assembly and the reflector; the beam expander module includes a concave lens and a convex lens; The designated light beam emitted by the light source assembly is incident on the concave lens. After being diverged by the concave lens, the designated light beam is incident on the convex lens. After being collimated by the convex lens, it is incident on the surface of the reflector as a parallel light beam.

4. The switchable display holographic taillight of claim 1, wherein, The waveguide includes at least one coupling grating and at least one coupling grating; each of the coupling gratings and each coupling grating is one or more of the following: holographic structure, relief structure, liquid crystal structure, and transflective film layer.

5. The switchable display holographic tail light of claim 1, wherein, The designated beam includes multiple designated sub-beams with the same transmission direction; the waveguide includes multiple beam incident areas and one beam exit area; each designated sub-beam is reflected by a reflective component to form a reflective sub-beam, each reflective sub-beam is incident on a beam incident area in the waveguide and coupled out from the beam exit area to form the illumination beam; each designated sub-beam corresponds one-to-one with each beam incident area and the regional layout of each beam incident area is uniformly and symmetrically distributed.

6. The switchable display holographic tail light of claim 1, wherein, The designated beam includes multiple designated sub-beams with the same transmission direction; the waveguide includes multiple sub-waveguides, each of which is provided with a beam incident area and a beam exit area; each designated sub-beam is reflected by a reflective component to form multiple reflective sub-beams, each reflective sub-beam is incident on the beam incident area of ​​each sub-waveguide and coupled out from the beam exit area, and expanded by each sub-waveguide to become each illumination sub-beam; each illumination sub-beam is spliced ​​together to form an illumination beam; each designated sub-beam corresponds one-to-one with each sub-waveguide and the regional layout of each sub-waveguide is uniformly and symmetrically distributed.

7. The switchable display holographic tail light of claim 5 or 6, wherein, The light source assembly includes a light source and a beam splitter; the light source is a laser light source or an LED light source; the designated beam emitted by the laser light source is split by the beam splitter to obtain multiple designated sub-beams; or, the light source assembly includes multiple laser light sources or multiple LED light sources, each laser light source or each LED light source emits a designated sub-beam, and the multiple designated sub-beams form a designated beam.

8. The switchable display holographic taillight of claim 1, wherein, The different incident angles of the reflected light beam entering the waveguide correspond one-to-one with the different incident angles of the reference light that exposes the holographic film to form various holographic patterns.

9. The switchable display holographic taillight of claim 1, wherein, The holographic film is a HOE film, and the difference between the incident angles of different illumination beams incident on the HOE film is less than 30 degrees.

10. A vehicle characterized by comprising: include: The switchable display holographic taillight as described in any one of claims 1-9.

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