Fresnel lens and head-up display system
By combining the design of a refractive lens and a total internal reflection lens in a Fresnel lens, the problem of low luminous efficiency of the Fresnel lens for light with a large incident angle is solved, thereby achieving improved luminous efficiency and reduced system power consumption.
Patent Information
- Application Number
- CN202422892071.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-26
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-11-26
AI Technical Summary
When existing Fresnel lenses collimate light with a large incident angle, the reflected light intensity is large, resulting in low light efficiency.
It adopts a combination design of internal refractive lens and external total internal reflection lens. The refractive lens is used to process light with a smaller incident angle, and the total internal reflection lens is used to process light with a larger incident angle. The light is converted into parallel light through reflection and refraction, thereby improving the lighting efficiency.
The light efficiency of the Fresnel lens is improved, the power consumption of the backlight source is reduced, and the overall power consumption and heat dissipation pressure of the head-up display system are reduced.
Smart Images
Figure CN223347067U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical devices, and in particular to a Fresnel lens and a head-up display system. Background Art
[0002] The Fresnel lens is designed based on the principle of light refraction. The Fresnel lens can collimate the light emitted by a point light source into parallel light.
[0003] In the related art, when a Fresnel lens collimates light with a large incident angle, the light with a large incident angle is reflected on the surface of the Fresnel lens, and the reflected light intensity is large, resulting in low light efficiency of the Fresnel lens. Utility Model Content
[0004] The embodiments of the present application provide a Fresnel lens and a head-up display system to achieve the effect of improving the light effect of the Fresnel lens.
[0005] In a first aspect, an embodiment of the present application provides a Fresnel lens, comprising:
[0006] a refractive lens in the inner region; the refractive lens is used to diverge a first light ray emitted by a point light source into parallel light, and an incident angle of the first light ray falls within a first angle range;
[0007] A total internal reflection lens is located in the external area; the total internal reflection lens is used to diverge the second light emitted by the point light source into parallel light, the incident angle of the second light belongs to the second angle interval, and the incident angle of the light belonging to the first angle interval is smaller than the incident angle of the light belonging to the second angle interval.
[0008] In some embodiments, the refractive lens includes a first incident surface; the first incident surface includes a central refractive surface and a plurality of refractive annular surfaces; the refractive annular surfaces include a first prism and a second prism; the first prism and the second prism form a refractive annular surface with a serrated cross-section; the first prism is used to refract the first light to diverge the first light into parallel light.
[0009] In some embodiments, the relative position between the first prism and the second prism is the same in multiple refractive annular surfaces.
[0010] In some embodiments, the heights of the multiple refractive annular zones are the same.
[0011] In some embodiments, the refractive lens further includes a first exit surface; the first exit surface is a plane; and the central refractive surface is a smooth convex surface.
[0012] In some embodiments, the total internal reflection lens includes a second incident surface; the second incident surface includes multiple total internal reflection annular surfaces; the total internal reflection annular surfaces include a third prism and a fourth prism; the third prism and the fourth prism form a total internal reflection annular surface with a serrated cross-section; the third prism is used to refract the second light, and the fourth prism is used to perform total internal reflection on the refracted second light, so as to diverge the second light into parallel light.
[0013] In some embodiments, the relative position between the third prism and the fourth prism is the same in multiple total internal reflection annular surface.
[0014] In some embodiments, the heights of the plurality of total internal reflection zone surfaces are consistent.
[0015] In some embodiments, the total internal reflection lens further includes a second exit surface; the second exit surface is a plane.
[0016] In a second aspect, an embodiment of the present application provides a head-up display system, comprising:
[0017] A backlight source, a Fresnel lens, a light homogenizing component, a display component, and a reflective component; the Fresnel lens is the Fresnel lens of the first aspect;
[0018] The backlight source is used to provide a point light source;
[0019] Fresnel lens is used to diverge the light from a point light source into parallel light;
[0020] The light homogenization component is used to uniformly process the parallel light to obtain uniform parallel light;
[0021] The display component is used to display multimedia information under the illumination of uniform parallel light;
[0022] The reflection component is used for reflecting the multimedia information so as to project the multimedia information onto the windshield of the vehicle.
[0023] The Fresnel lens and head-up display system provided by the embodiments of the present application include a refractive lens in an inner region, configured to diverge a first light ray emitted by a point light source into parallel light, the incident angle of the first light ray falling within a first angle range; and a total internal reflection lens in an outer region, configured to diverge a second light ray emitted by the point light source into parallel light, the incident angle of the second light ray falling within a second angle range, wherein the incident angle of the light ray falling within the first angle range is smaller than the incident angle of the light ray falling within the second angle range. For the second light ray with a larger incident angle, the second light ray is reflected and refracted on a surface of the total internal reflection lens, the refracted light intensity being greater than the reflected light intensity. The refracted second light ray is then totally internally reflected on another lens surface of the total internal reflection lens, thereby changing the direction of the refracted second light ray and completely reflecting the refracted second light ray out of the total internal reflection lens to produce parallel light. This results in a higher intensity of the parallel light, thereby improving the light efficiency of the Fresnel lens. Using this Fresnel lens in a head-up display system can reduce the power consumption of the backlight source while meeting the same luminous flux conditions, thereby reducing the overall power consumption and heat dissipation pressure of the head-up display system. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0025] Figure 1 A schematic diagram of the structure of the Fresnel lens provided in this application;
[0026] Figure 2 The structure of the Fresnel lens in the related art;
[0027] Figure 3 for Figure 2 Schematic diagram of the optical path when the Fresnel lens processes light with a large incident angle;
[0028] Figure 4 for Figure 2 Schematic diagram of the light intensity of the Fresnel lens;
[0029] Figure 5 Schematic diagram of the light intensity of the Fresnel lens provided in this application;
[0030] Figure 6 A schematic diagram of the structure of the refractive lens provided in this application;
[0031] Figure 7 A schematic structural diagram of the total internal reflection lens provided in this application;
[0032] Figure 8 This is a schematic diagram of the structure of the head-up display system provided in this application.
[0033] Description of reference numerals:
[0034] 110: refractive lens; 120: total internal reflection lens; 610: central refractive surface; 620: refractive annular surface; 6201: first prism; 6202: second prism; 630: first exit surface; 710: total internal reflection annular surface; 7101: third prism; 7102: fourth prism; 720: second exit surface; 80: head-up display system; 810: backlight source; 820: Fresnel lens; 830: light homogenization component; 840: display component; 850: reflection component.
[0035] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION
[0036] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
[0037] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.
[0038] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.
[0039] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.
[0040] Figure 1 The structural diagram of the Fresnel lens provided in this application is as follows: Figure 1 As shown, the Fresnel lens includes:
[0041] The refractive lens 110 is located in the inner area; the refractive lens 110 is used to diverge the first light emitted by the point light source into parallel light, and the incident angle of the first light belongs to the first angle range;
[0042] The total internal reflection lens 120 is located in the external area; the total internal reflection lens 120 is used to diverge the second light emitted by the point light source into parallel light, the incident angle of the second light belongs to the second angle range, and the incident angle of the light belonging to the first angle range is smaller than the incident angle of the light belonging to the second angle range.
[0043] The inner area is the area close to the optical axis of the Fresnel lens and surrounding the optical axis, and the outer area is the area away from the optical axis of the Fresnel lens and surrounding the inner area; that is, the optical axis passes through the refractive lens 110, and the total internal reflection lens 120 surrounds the periphery of the refractive lens 110.
[0044] The incident angle of the light is the angle between the light and the optical axis of the Fresnel lens; the refractive lens 110 is used to diverge the first light whose incident angle belongs to the first angle range, and the total internal reflection lens 120 is used to diverge the second light whose incident angle belongs to the second angle range; it is easy to understand that the refractive lens 110 is used to diverge the first light whose incident angle is smaller (belonging to the first angle range), and the total internal reflection lens 120 is used to diverge the second light whose incident angle is larger (belonging to the second angle range).
[0045] For example, the first angle interval may be [0°, 30°], and the second angle interval may be (30°, 85°]; in actual applications, the values of the first angle interval and the second angle interval may be set according to actual needs, for example, the first angle interval is [0°, 35°], and the second angle interval is (35°, 85°].
[0046] It should be noted that if Figure 2 As shown in FIG, the conventional Fresnel lens is a refractive Fresnel lens; as shown in FIG. Figure 3 As shown, for light with a large incident angle, since the incident angle of the light is larger than that of the incident surface (of the refractive Fresnel lens) when the light strikes the refractive Fresnel lens, the light is reflected and refracted on the surface of the refractive Fresnel lens, and the reflected light is stronger than the refracted light. That is, the intensity of the parallel light collimated by refraction is smaller, and the efficiency of the refractive Fresnel lens is lower. The light intensity distribution of the refractive Fresnel lens is shown in FIG. Figure 4As shown in the figure, simulation calculations show that the light efficiency of the refractive Fresnel lens is 43.94%, which means that the traditional Fresnel lens has a lower light efficiency when processing light with a larger incident angle.
[0047] In the embodiment of the present application, the Fresnel lens includes a refractive lens 110 in an inner area and a total internal reflection lens 120 in an outer area. The refractive lens 110 is used to diverge the first light with a smaller incident angle, and the total internal reflection lens 120 is used to diverge the second light with a larger incident angle.
[0048] Among them, total internal reflection refers to the phenomenon that when light is emitted from a denser medium (i.e., the refractive index of light in this medium is large, such as a lens) to the interface of a less dense medium (i.e., the refractive index of light in this medium is small, such as air), all of it is reflected back into the original medium.
[0049] Specifically, for light with a larger incident angle, the incident angle of the light with one lens surface of the total internal reflection lens 120 is smaller, and the light is reflected and refracted on the surface of the total internal reflection lens 120. The refracted light is stronger than the reflected light, and the refracted light is totally internally reflected on the other lens surface of the total internal reflection lens 120 to change the direction of the refracted light and reflect all the refracted light out of the total internal reflection lens 120 to obtain parallel light, so that the intensity of the parallel light is greater, thereby improving the light effect of the Fresnel lens.
[0050] The light intensity distribution of the Fresnel lens in the embodiment of the present application is as follows Figure 5 As shown; through simulation calculation, it can be concluded that the light efficiency of the Fresnel lens in the embodiment of the present application reaches 78%, which is about 77.3% higher than that of the traditional refractive Fresnel lens.
[0051] The above-mentioned Fresnel lens includes a refractive lens in an internal area; the refractive lens is used to diverge the first light emitted by a point light source into parallel light, and the incident angle of the first light belongs to a first angle range; a total internal reflection lens is located in an external area; the total internal reflection lens is used to diverge the second light emitted by the point light source into parallel light, and the incident angle of the second light belongs to a second angle range, and the incident angle of the light belonging to the first angle range is smaller than the incident angle of the light belonging to the second angle range; for the second light with a larger incident angle, the second light is reflected and refracted on the surface of the total internal reflection lens, the refracted light is stronger than the reflected light, and the refracted second light is totally internally reflected on the other lens surface of the total internal reflection lens to change the direction of the refracted second light, and all the refracted second light is reflected out of the total internal reflection lens to obtain parallel light, so that the intensity of the parallel light is larger, thereby improving the light effect of the Fresnel lens.
[0052] In some embodiments, the refractive lens includes a first incident surface; the first incident surface includes a central refractive surface and a plurality of refractive annular surfaces; the refractive annular surfaces include a first prism and a second prism; the first prism and the second prism form a refractive annular surface with a serrated cross-section; the first prism is used to refract the first light to diverge the first light into parallel light.
[0053] Figure 6 is a schematic diagram of a partial cross section of a refractive lens (on the optical axis side); the first incident surface of the refractive lens includes a central refractive surface 610 and a plurality of refractive annular surfaces 620; Figure 6 It can be seen that the first prism 6201 and the second prism 6202 form a refractive annular surface 620 with a sawtooth cross-section; for the first light ray with a smaller incident angle among the first light rays (such as L1), it enters the refractive lens through the central refractive surface and is refracted, and the first light ray is collimated by refraction; for the first light ray with a larger incident angle among the first light rays (such as L2-L4), it enters the refractive lens through the first prism 6201 and is refracted, and the first light ray is collimated by refraction, so as to realize the divergence of the first light ray into parallel light.
[0054] In some embodiments, the relative position between the first prism 6201 and the second prism 6202 is the same in multiple refractive annular surfaces 620.
[0055] Specifically, through Figure 6 It can be seen that the relative position between the first prism 6201 and the second prism 6202 is the same in multiple refractive annular surfaces 620 , including: the relative angle and relative distance between the first prism 6201 and the second prism 6202 are the same in multiple refractive annular surfaces 620 .
[0056] In some embodiments, the heights of the multiple refractive annular zones are the same.
[0057] The height of the multiple refractive annular surfaces refers to the sawtooth height of the cross-section of the multiple refractive annular surfaces, that is, the distance between the connection point of the first prism and the second prism and the first exit surface of the refractive lens.
[0058] In an optional manner, the sawtooth thickness of the cross-sections of the multiple refractive annular zones is uniform; wherein the sawtooth thickness of the cross-section of the refractive annular zone refers to the farthest distance between the first prism and the second prism.
[0059] That is to say, the structure of each first prism in the multiple refractive annular surfaces is the same, the structure of each second prism in the multiple refractive annular surfaces is the same, and the relative position between the first prism and the second prism is the same in the multiple refractive annular surfaces, that is, the multiple refractive annular surfaces are completely identical refractive annular surfaces; the sawtooth height and sawtooth thickness of the cross-sections of the multiple refractive annular surfaces are uniform.
[0060] In some embodiments, the refractive lens further includes a first exit surface; the first exit surface is a plane; and the central refractive surface is a smooth convex surface.
[0061] like Figure 6 As shown, the first exit surface 630 is a plane; the central refractive surface can be a partially spherical surface. The height of the central refractive surface (the distance between the highest point of the central refractive surface and the first exit surface) can be set to be the same as the sawtooth height of the multiple refractive annular surfaces. In this way, the overall height of the refractive lens is uniform, making it easier to manufacture and process.
[0062] In practical applications, the sawtooth heights of the multiple refractive annular surfaces and the height of the central refractive surface can be 2-3 mm.
[0063] In some embodiments, the total internal reflection lens includes a second incident surface; the second incident surface includes multiple total internal reflection annular surfaces; the total internal reflection annular surfaces include a third prism and a fourth prism; the third prism and the fourth prism form a total internal reflection annular surface with a serrated cross-section; the third prism is used to refract the second light, and the fourth prism is used to perform total internal reflection on the refracted second light, so as to diverge the second light into parallel light.
[0064] Figure 7 is a schematic diagram of a partial cross section of a total internal reflection lens (on the optical axis side); the second incident surface of the total internal reflection lens includes a plurality of total internal reflection annular surfaces 710; Figure 7 It can be seen that the third prism 7101 and the fourth prism 7102 form a total internal reflection annular surface 710 with a sawtooth cross-section; the second light (such as L5-L8) enters the total internal reflection lens through the third prism 7101 and is refracted, so that the second light is refracted to the fourth prism 7102, and the refracted second light is completely reflected out of the total internal reflection lens by the fourth prism 7102, so as to realize the divergence of the second light into parallel light.
[0065] In some embodiments, the relative position between the third prism and the fourth prism is the same in multiple total internal reflection annular surface.
[0066] Specifically, through Figure 7 It can be seen that the relative position between the third prism and the fourth prism is the same in multiple total internal reflection annular surfaces, including: the relative angle and relative distance between the third prism and the fourth prism are the same in multiple total internal reflection annular surfaces.
[0067] In some embodiments, the heights of the plurality of total internal reflection zone surfaces are consistent.
[0068] The height of the multiple total internal reflection annular surfaces refers to the sawtooth height of the cross-section of the multiple total internal reflection annular surfaces, that is, the distance between the connection point of the third prism and the fourth prism and the second exit surface of the total internal reflection lens.
[0069] In an optional manner, the sawtooth thickness of the cross sections of the plurality of total internal reflection annular zones is uniform; wherein the sawtooth thickness of the cross sections of the total internal reflection annular zones refers to the farthest distance between the third prism and the fourth prism.
[0070] That is to say, the structure of each third prism in the multiple total internal reflection annular surfaces is the same, the structure of each fourth prism in the multiple total internal reflection annular surfaces is the same, and the relative position between the third prism and the fourth prism is the same in the multiple total internal reflection annular surfaces, that is, the multiple total internal reflection annular surfaces are completely identical total internal reflection annular surfaces; the serration height and serration thickness of the cross-sections of the multiple total internal reflection annular surfaces are uniform.
[0071] In practical applications, the height of the multiple total internal reflection annular surfaces can be 2-3 mm, so that the overall height of the total internal reflection lens is uniform and easy to process.
[0072] In some embodiments, the total internal reflection lens further includes a second exit surface; the second exit surface is a plane.
[0073] like Figure 7 As shown, the second exit surface 720 is a plane; it can be understood that, in the Fresnel lens of the embodiment of the present application, the first exit surface of the refractive lens and the second exit surface of the total internal reflection lens are parts of the exit surface of the Fresnel lens.
[0074] The above-mentioned Fresnel lens includes a refractive lens in an internal area; the refractive lens is used to diverge the first light emitted by a point light source into parallel light, and the incident angle of the first light belongs to a first angle range; a total internal reflection lens is located in an external area; the total internal reflection lens is used to diverge the second light emitted by the point light source into parallel light, and the incident angle of the second light belongs to a second angle range, and the incident angle of the light belonging to the first angle range is smaller than the incident angle of the light belonging to the second angle range; for the second light with a larger incident angle, the second light is reflected and refracted on the surface of the total internal reflection lens, the refracted light is stronger than the reflected light, and the refracted second light is totally internally reflected on the other lens surface of the total internal reflection lens to change the direction of the refracted second light, and all the refracted second light is reflected out of the total internal reflection lens to obtain parallel light, so that the intensity of the parallel light is larger, thereby improving the light effect of the Fresnel lens.
[0075] Figure 8 The schematic diagram of the head-up display system provided in this application is as follows: Figure 8 As shown, the head-up display system 80 includes: a backlight source 810, a Fresnel lens 820, a light homogenization component 830, a display component 840 and a reflection component 850; the Fresnel lens 820 is the Fresnel lens mentioned above;
[0076] The backlight source 810 is used to provide a point light source;
[0077] The Fresnel lens 820 is used to diverge the light emitted by the point light source into parallel light;
[0078] The light homogenization component 830 is used to uniformly process the parallel light to obtain uniform parallel light;
[0079] The display component 840 is used to display multimedia information under the illumination of uniform parallel light;
[0080] The reflection component 850 is used to reflect the multimedia information so as to project the multimedia information onto the windshield of the vehicle.
[0081] The light homogenizing component 830 may be a light homogenizing film; the multimedia information may be graphics, text, or video, and specifically may be driving information, map information, etc. involved in the vehicle's driving process.
[0082] Among them, the backlight light source 810 can be an LED light source, and the distance between the LED light source and the Fresnel lens 820 can be determined according to the size of the refractive lens and the total internal reflection lens in the Fresnel lens 820. The distance between the LED light source and the Fresnel lens 820 ensures that, among the light emitted by the LED light source, the first light with a smaller incident angle (belonging to the first angle range) is collimated by the refractive lens, and the second light with a larger incident angle (belonging to the second angle range) is collimated by the total internal reflection lens, thereby improving the intensity of the parallel light diverged by the Fresnel lens.
[0083] The above-mentioned head-up display system uses a Fresnel lens to diverge the light emitted by a point light source into parallel light. Since the Fresnel lens includes a refractive lens and a total internal reflection lens, the refractive lens diverges the light with a smaller incident angle, and the total internal reflection lens diverges the light with a larger incident angle. This improves the light intensity of the parallel light diverged by the Fresnel lens. While meeting the same luminous flux conditions, it can reduce the power consumption of the backlight light source, thereby reducing the overall power consumption and heat dissipation pressure of the head-up display system.
[0084] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.
[0085] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.
Claims
1. A Fresnel lens, characterized in that: include: a refractive lens in the inner area; the refractive lens is used to diverge a first light ray emitted by a point light source into parallel light, wherein the incident angle of the first light ray belongs to a first angle range; A total internal reflection lens is located in the external area; the total internal reflection lens is used to diverge the second light emitted by the point light source into parallel light, the incident angle of the second light belongs to the second angle interval, and the incident angle of the light belonging to the first angle interval is smaller than the incident angle of the light belonging to the second angle interval.
2. The Fresnel lens according to claim 1, wherein: The refractive lens includes a first incident surface; The first incident surface includes a central refractive surface and a plurality of refractive annular surfaces; The refractive annular surface includes a first prism and a second prism; the first prism and the second prism form the refractive annular surface with a sawtooth cross section; The first prism is used to refract the first light to diverge the first light into parallel light.
3. The Fresnel lens according to claim 2, wherein: The relative positions of the first prism and the second prism are the same in the multiple refractive annular surfaces.
4. The Fresnel lens according to claim 2, wherein: The heights of the multiple refractive ring-shaped surfaces are the same.
5. The Fresnel lens according to any one of claims 2 to 4, characterized in that: The refractive lens further includes a first exit surface; the first exit surface is a plane; and the central refractive surface is a smooth convex surface.
6. The Fresnel lens according to claim 1, wherein: The total internal reflection lens includes a second incident surface; The second incident surface includes a plurality of total internal reflection annular surfaces; The total internal reflection annular surface includes a third prism and a fourth prism; the third prism and the fourth prism form the total internal reflection annular surface with a sawtooth cross section; The third prism is used to refract the second light, and the fourth prism is used to perform total internal reflection on the refracted second light, so as to diverge the second light into parallel light.
7. The Fresnel lens according to claim 6, wherein: The relative positions of the third prism and the fourth prism are the same in the plurality of total internal reflection annular zone surfaces.
8. The Fresnel lens according to claim 7, wherein: The heights of the multiple total internal reflection annular zones are consistent.
9. The Fresnel lens according to any one of claims 6 to 8, characterized in that The total internal reflection lens further includes a second emitting surface; the second emitting surface is a plane.
10. A head-up display system, characterized in that: include: A backlight source, a Fresnel lens, a light homogenizing component, a display component, and a reflective component; the Fresnel lens is the Fresnel lens according to any one of claims 1 to 9; The backlight source is used to provide a point light source; The Fresnel lens is used to diverge the light emitted by the point light source into parallel light; The light homogenizing component is used to uniformly process the parallel light to obtain uniform parallel light; The display component is used to display multimedia information under the illumination of the uniform parallel light; The reflection component is used to reflect the multimedia information so as to project the multimedia information onto the windshield of the vehicle.