Head-up display, protection method thereof, and vehicle

Abstract

The present invention provides a head-up display (HUD), a protection method therefor, and a vehicle, comprising an image generation unit, a polarization splitter film, a first reflective unit, and a dustproof film, arranged in sequence. The image generation unit generates a first light beam carrying image information, the first light beam being first polarized light; the polarization splitter film transmits the first light beam to the first reflective unit; the first reflective unit includes at least one cold mirror, which reflects the first light beam to the dustproof film; the dustproof film transmits the first light beam; the cold mirror further transmits infrared light in a second light beam transmitted through the dustproof film and reflects non-infrared light in the second light beam to the polarization splitter film; the polarization splitter film reflects the second polarized light in the second light beam. In this HUD, the second polarized light in the second light beam is reflected by the polarization splitter film, reducing the second polarized light in the second light beam entering the image generation unit, thereby reducing the light energy entering the image generation unit and protecting the image generation unit.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of head-up display, and in particular to a head-up display, a protection method thereof, and a vehicle. Background Art

[0002] A Head Up Display (HUD) is a driving assistance system that projects important information such as speed and navigation onto the windshield in front of the driver, allowing the driver to see important driving information such as speed and navigation without lowering or turning his head.

[0003] As the image area displayed by heads-up displays increases and the magnification of heads-up displays increases, the risk of sunlight backflow increases. This leads to a greater concentration of sunlight energy on the image generation unit, potentially damaging the unit. However, currently, no heads-up display (HUD) can process the light entering the HUD to minimize damage to the image generation unit when sunlight backflow occurs. Summary of the Invention

[0004] The main technical problem solved by the embodiments of the present invention is to provide a head-up display and its protection method and vehicle, which can process the light entering the head-up display and reduce the energy of the light entering the image generation unit, thereby reducing damage to the image generation unit and protecting the image generation unit.

[0005] A technical solution adopted in an embodiment of the present invention is: providing a head-up display, which includes: an image generation unit, a polarization splitting film, a first reflection unit and a dust-proof film arranged in sequence along a first optical path; wherein the image generation unit is used to generate a first light with image information, and the first light is a first polarized light; the polarization splitting film is used to transmit the first light to the first reflection unit; the first reflection unit includes at least one cold light mirror, and the cold light mirror is used to reflect the first light to the dust-proof film; the dust-proof film is used to transmit the first light; the cold light mirror is also used to transmit infrared light in a second light transmitted through the dust-proof film, and reflect non-infrared light in the second light to the polarization splitting film; the polarization splitting film is used to reflect the second polarized light in the second light.

[0006] In some embodiments, the polarization splitting film is curved.

[0007] In some embodiments, the first reflecting unit further includes a first reflecting mirror, and the at least one cold light mirror includes a first cold light mirror; the first cold light mirror and the first reflecting mirror are sequentially arranged between the polarization splitting film and the dust-proof film along the first optical path.

[0008] In a second aspect, an embodiment of the present invention provides a vehicle comprising a windshield and a head-up display as described in any one of the first aspects; the dust-proof film and the windshield are sequentially arranged along the first optical path.

[0009] In a third aspect, an embodiment of the present invention provides a method for protecting a head-up display, which is applied to a head-up display as described in any one of the first aspects, and the method includes: transmitting infrared light in a second light transmitted through the dust-proof film through the cold light mirror, and reflecting non-infrared light in the second light to the polarization splitting film; and reflecting the second polarized light in the second light through the polarization splitting film.

[0010] In a fourth aspect, an embodiment of the present invention provides a head-up display, which includes: an image generation unit, a polarization splitter film, an infrared reflector, a second reflective unit and a dust-proof film arranged in sequence; wherein the image generation unit is used to generate a first light with image information, and the first light is a first polarized light; the polarization splitter film is used to transmit the first light to the infrared reflector; the infrared reflector is used to transmit the first light to the second reflective unit; the second reflective unit is used to reflect the first light to the dust-proof film; the dust-proof film is used to transmit the first light; the second reflective unit is also used to reflect the second light transmitted through the dust-proof film to the infrared reflector; the infrared reflector is used to reflect the infrared light in the second light, and transmit the non-infrared light in the second light to the polarization splitter film; the polarization splitter film is used to reflect the second polarized light in the second light.

[0011] In some embodiments, the polarization splitting film and the infrared reflector are both curved.

[0012] In some embodiments, the polarization splitting film is attached to the infrared reflector.

[0013] In some embodiments, the second reflecting unit includes at least one reflecting mirror.

[0014] In a fifth aspect, an embodiment of the present invention provides a vehicle comprising a windshield and a head-up display as described in any one of the fourth aspects; the windshield is arranged in the light emitting direction of the dustproof film.

[0015] In a sixth aspect, an embodiment of the present invention provides a method for protecting a head-up display, which is applied to a head-up display as described in any one of the fourth aspects, and the method includes: reflecting the infrared light in the second light transmitted through the dust-proof film through the infrared reflector, and transmitting the non-infrared light in the second light to the polarization splitting film; reflecting the second polarized light in the second light through the polarization splitting film.

[0016] The beneficial effects of the embodiments of the present invention are as follows: Unlike the prior art, the embodiments of the present invention provide a head-up display, a protection method thereof, and a vehicle, comprising an image generation unit, a polarization splitter film, a first reflective unit, and a dustproof film, arranged sequentially along a first optical path. The image generation unit is configured to generate a first light beam carrying image information, the first light beam being first polarized light; the polarization splitter film is configured to transmit the first light beam to the first reflective unit; the first reflective unit includes at least one cold mirror configured to reflect the first light beam to the dustproof film; the dustproof film is configured to transmit the first light beam; the cold mirror is further configured to transmit infrared light in a second light beam transmitted through the dustproof film, and to reflect non-infrared light in the second light beam to the polarization splitter film; and the polarization splitter film is configured to reflect the second polarized light beam in the second light beam. In this head-up display, the second polarized light in the second light is reflected out by a polarizing beam splitter film, thereby reducing the second polarized light in the second light entering the image generation unit, thereby reducing the light energy entering the image generation unit and protecting the image generation unit; in addition, a cold light mirror is used to transmit the infrared light in the second light, thereby reducing the infrared light in the second light entering the image generation unit, further reducing the light energy entering the image generation unit, and further protecting the image generation unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily described by pictures in the corresponding drawings. These exemplified descriptions do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise stated, the figures in the drawings do not constitute a scale limitation.

[0018] Figure 1 1 is a schematic structural diagram of a head-up display provided by an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 Schematic diagram of the optical path of the second light in ;

[0020] Figure 3 1 is a flow chart of a method for protecting a head-up display provided by an embodiment of the present invention;

[0021] Figure 4 is a schematic structural diagram of another head-up display provided by an embodiment of the present invention;

[0022] Figure 5 yes Figure 4 Schematic diagram of the optical path of the second light in ;

[0023] Figure 6 The figure is a flow chart of another head-up display protection method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0025] For ease of understanding of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those generally understood by those skilled in the art in the field of the present application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0026] It should be noted that, unless they conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of this application. Furthermore, although the functional modules are divided in the device schematic, in some cases, the module division may be different from that in the device. Furthermore, the terms "first," "second," and the like used herein do not limit the order of data or execution; they are merely used to distinguish between identical or similar items with substantially the same functions and effects.

[0027] An embodiment of the present invention provides a head-up display (HUD) that uses a liquid crystal display (LCD) as an image generation unit. This HUD can prevent the LCD from overheating and failing when strong sunlight flows back. In this HUD, a cold light mirror is used to eliminate infrared light, or a polarized dust-proof film is used to eliminate P-polarized light. However, in the above-mentioned manner, although the light entering the HUD is processed, the area of ​​the dust-proof film and the cold light mirror is often large, resulting in an increased size and cost of the HUD.

[0028] In order to solve the above technical problems, an embodiment of the present invention also provides a head-up display, which can process the light entering the head-up display, reduce damage to the image generation unit, thereby protecting the image generation unit, and reducing the size and cost of the head-up display.

[0029] In the first aspect, an embodiment of the present invention further provides a head-up display, see Figure 1 The head-up display includes: an image generating unit 10, a polarization splitting film 20, a first reflecting unit 30 and a dustproof film 40 arranged in sequence along a first optical path.

[0030] The image generation unit 10 is configured to generate a first light beam L1 carrying image information. The first light beam L1 is first polarized light. The polarizing beam splitting film 20 is configured to transmit the first light beam L1 to the first reflecting unit 30. The first reflecting unit 30 includes at least one cold mirror (which may include 31), which is configured to reflect the first light beam L1 to the dustproof film 40. The dustproof film 40 is configured to transmit the first light beam L1. The cold mirror is also configured to transmit infrared light within the second light beam L2 transmitted through the dustproof film 40, and to reflect non-infrared light within the second light beam L2 to the polarizing beam splitting film 20. The polarizing beam splitting film 20 is configured to reflect the second polarized light within the second light beam L2.

[0031] Specifically, the image generating unit 10 includes an LCD, which can be used to emit a first light ray L1 carrying image information, and the first light ray L1 has a first polarization state, such as S-polarized light. The polarization splitting film 20 has polarization splitting properties, which can be used to transmit the first polarized light and reflect the second polarized light, such as transmitting S-polarized light and reflecting P-polarized light. The surface of the cold light mirror (which may include 31) is coated with an infrared transmitting film, which enables the cold light mirror to transmit infrared light and reflect non-infrared light. The surface type of the cold light mirror (which may include 31) can be a plane or a curved surface. In this way, the surface of the cold light mirror can be designed to shape the second light ray L2 and correct the aberration. The dustproof film 40 can be made of polymethylmethacrylate (PMMA), polycarbonate (PC) or other transparent materials, which can be used to transmit light and prevent dust, so as to prevent dust in the environment from entering the head-up display.

[0032] In this head-up display, the S-polarized light generated by the image generation unit 10 can be transmitted to the first reflection unit 30 after passing through the polarization splitting film 20. The first reflection unit 30 will reflect the S-polarized light to the dust-proof film 40. Finally, the S-polarized light is transmitted through the dust-proof film 40 and subsequently applied to a vehicle. The S-polarized light can be reflected by the windshield 50 and enter the human eye 60, and the human eye 60 can observe the image content.

[0033] When sun flooding occurs, refer to Figure 2 The second light L2 from the outside is transmitted through the dust-proof film 40 to the first reflecting unit 30. When it is reflected by the cold light mirror (which may include 31) in the first reflecting unit 30, the infrared light in the second light L2 will be transmitted through the cold light mirror (which may include 31) and cannot continue to propagate to the polarizing beam splitting film 20. At the same time, the non-infrared light in the second light L2 is reflected by the cold light mirror (which may include 31) to the polarizing beam splitting film 20. Then, the P-polarized light in the second light L2 will be reflected by the polarizing beam splitting film 20 and cannot enter the image generating unit 10.

[0034] If the infrared-transmitting film in the cold mirror transmits 100% infrared light, and the polarizing beam splitter film 20 reflects 100% P-polarized light, theoretically, only the S-polarized light in the non-infrared portion of the second light L2 will ultimately enter the image generation unit 10. Compared to direct backflow of the second light L2 into the image generation unit 10, the head-up display provided by the embodiments of the present invention can process the second light L2 when sunlight backflow occurs, reducing the infrared and P-polarized light in the second light entering the image generation unit 10, significantly reducing the light energy entering the image generation unit 10, thereby minimizing damage to the image generation unit 10 and protecting the image generation unit 10. Furthermore, the polarizing beam splitter film 20 is disposed between the image generation unit 10 and the first reflective unit 30, allowing the use of a smaller polarizing beam splitter film 20, thereby reducing the size and cost of the head-up display.

[0035] In order to prevent the P-polarized light reflected by the polarizing beam splitter film from being focused on a certain position of the head-up display, such as being reflected on a certain position of the head-up display housing, in some embodiments, the polarizing beam splitter film is curved. Figure 2 The polarizing beam splitting film 20 may be cylindrical in shape, with its concave side facing the image generating unit 10. In this way, when reflecting the P-polarized light in the second light L2, the divergence angle of the P-polarized light can be increased, thereby spreading the light and preventing the P-polarized light reflected by the polarizing beam splitting film 20 from focusing on a certain position, causing excessive local temperature, thereby ensuring the normal operation of the head-up display.

[0036] In some embodiments, the first reflective unit further includes at least one reflector. The reflector is coated with a high-reflectivity film, which can be used to reflect light. For example, the reflector can be an aluminum reflector, comprising a glass substrate and an aluminum film coated on the surface of the glass substrate. Thus, the aluminum reflector can be used to reflect light. Furthermore, the reflector can have a flat or curved surface, and the curved surface can be a free-form surface, for example. This allows the reflector surface to be designed to shape the second light and correct aberrations.

[0037] Specifically, in some of the embodiments, please refer to Figure 1 At least one reflector includes a first reflector 32 , and at least one cold light mirror includes a first cold light mirror 31 . The first cold light mirror 31 and the first reflector 32 are sequentially arranged between the polarization splitting film 20 and the dustproof film 40 along the first optical path.

[0038] In this head-up display, the S-polarized light generated by the image generation unit 10 passes through the polarization splitting film 20 and is transmitted to the first cold light mirror 31. The S-polarized light is reflected by the first cold light mirror 31 and the first reflecting mirror 32 to the dust-proof film 40. The S-polarized light is transmitted through the dust-proof film 40 to the windshield 50, and then reflected by the windshield 50 and enters the human eye 60. In this way, the human eye 60 can observe the image content, thereby realizing a head-up display.

[0039] When sun flooding occurs, refer to Figure 2 The second light L2 from the outside is transmitted through the windshield 50 to the dust-proof film 40, and then transmitted through the dust-proof film 40 to the first reflector 32, and then reflected by the first reflector 32 to the first cold light mirror 31. The first cold light mirror 31 will reflect the non-infrared light in the second light L2 to the polarization splitting film 20, and transmit the infrared light in the second light L2. Then, the P-polarized light in the second light L2 will be reflected by the polarization splitting film 20.

[0040] As can be seen, in this head-up display, when sunlight backflow occurs, on the one hand, the infrared light in the external second light beam L2 will be transmitted by the first cold mirror 31, and this portion of light will not be able to continue to propagate to the polarizing beam splitter film 20. On the other hand, the P-polarized light in the second light beam L2 that propagates to the polarizing beam splitter film 20 will be reflected by the polarizing beam splitter film 20. Therefore, the first cold mirror 31 and the polarizing beam splitter film 20 can reduce the infrared and P-polarized light in the second light beam that enters the image generation unit, significantly reducing the energy of the second light beam L2 that propagates to the image generation unit 10. This reduces the heating effect of the second light beam L2 on the image generation unit 10, reduces damage to the image generation unit 10, and thus protects the image generation unit 10. Furthermore, placing the polarizing beam splitter film 20 close to the image generation unit 10 can reduce the area of ​​the polarizing beam splitter film 20, thereby reducing the cost and volume of the head-up display.

[0041] In a second aspect, an embodiment of the present invention further provides a vehicle, comprising a windshield and a heads-up display according to any one of the first aspects; the dustproof film and the windshield are sequentially arranged along a first optical path. In this embodiment, the heads-up display has the same structure and functions as the heads-up display according to any one of the first aspects, and a detailed description thereof will not be repeated here. The vehicle can be a car, train, or other such vehicle.

[0042] In a third aspect, an embodiment of the present invention provides a method for protecting a head-up display, which is applied to a head-up display as described in any one of the first aspects. Figure 3 , the protection method includes:

[0043] Step S100: transmitting infrared light in the second light transmitted through the dust-proof film through the cold mirror, and reflecting non-infrared light in the second light to the polarization splitting film;

[0044] Step S200: reflecting the second polarized light in the second light through the polarization splitting film.

[0045] Specifically, in Figure 1 In the HUD shown, when sunlight intrusion occurs, refer to Figure 2 The second light L2 from the outside is transmitted through the dust-proof film 40 to the first reflecting unit 30. When it is reflected by the cold light mirror (which may include 31) in the first reflecting unit 30, the infrared light in the second light L2 will be transmitted through the cold light mirror (which may include 31) and cannot continue to propagate to the polarizing beam splitting film 20. At the same time, the non-infrared light in the second light L2 is reflected by the cold light mirror (which may include 31) to the polarizing beam splitting film 20. Then, the P-polarized light in the second light L2 will be reflected by the polarizing beam splitting film 20 and cannot enter the image generating unit 10.

[0046] If the infrared transmitting film in the cold light mirror transmits 100% of infrared light and the reflectivity of the polarization splitting film 20 for reflecting P-polarized light is 100%, theoretically, only the S-polarized light in the non-infrared light in the second light L2 will eventually enter the image generation unit 10. Compared with the second light L2 directly flowing back into the image generation unit 10, the protection method provided by the embodiment of the present invention can process the second light L2 when sunlight backflow occurs, reduce the infrared light and P-polarized light in the second light entering the image generation unit 10, greatly reduce the light energy entering the image generation unit 10, thereby reducing damage to the image generation unit 10 and protecting the image generation unit 10.

[0047] In a fourth aspect, an embodiment of the present invention further provides a head-up display, see Figure 4 The head-up display includes: an image generating unit 10, a polarization splitting film 20, an infrared reflective mirror 80, a second reflective unit 70 and a dustproof film 40 which are arranged in sequence.

[0048] The image generation unit 10 is configured to generate a first light beam L1 carrying image information. The first light beam L1 is first polarized light. The polarizing beam splitting film 20 is configured to transmit the first light beam L1 to an infrared reflector 80. The infrared reflector 80 is configured to transmit the first light beam L1 to a second reflective unit 70. The second reflective unit 70 is configured to reflect the first light beam L1 to a dustproof film 40. The dustproof film 40 is configured to transmit the first light beam L1. The second reflective unit 70 is further configured to reflect a second light beam L2 transmitted through the dustproof film 40 to the infrared reflective mirror 80. The infrared reflective mirror 80 is configured to reflect the infrared light in the second light beam L2 and transmit the non-infrared light in the second light beam L2 to the polarizing beam splitting film 20. The polarizing beam splitting film 20 is configured to reflect the second polarized light in the second light beam L2.

[0049] Specifically, the image generation unit 10 includes an LCD, which can be used to emit a first light beam L1 carrying image information, and the first light beam L1 has a first polarization state, such as S-polarized light. The polarization splitting film 20 has polarization splitting properties, which can be used to transmit the first polarized light and reflect the second polarized light, such as transmitting S-polarized light and reflecting P-polarized light. The infrared reflector 80 includes an infrared reflective film, which can reflect infrared light and transmit non-infrared light. The dustproof film 40 can be made of polymethyl methacrylate (PMMA), polycarbonate (PC) or other transparent materials, and can be used to transmit light and prevent dust, so as to prevent dust in the environment from entering the head-up display.

[0050] In this HUD, see Figure 4 The S-polarized light generated by the image generation unit 10 is transmitted through the polarization splitting film 20 to the infrared reflector 80, and then transmitted through the infrared reflector 80 to the second reflective unit 70. The second reflective unit 70 reflects the S-polarized light to the dust-proof film 40. Finally, the S-polarized light is transmitted out through the dust-proof film 40 and subsequently applied to a vehicle. The S-polarized light can be reflected by the windshield 50 and then enter the human eye 60. The human eye 60 can observe the image content, thereby realizing a head-up display.

[0051] When sun flooding occurs, refer to Figure 5 The second light L2 from the outside is transmitted through the dust-proof film 40 to the second reflecting unit 70, and is reflected by the second reflecting unit 70 to the infrared reflecting mirror 80. The infrared reflecting mirror 80 reflects the infrared light in the second light L2 and transmits the non-infrared light in the second light L2 to the polarizing beam splitting film 20. Then, the polarizing beam splitting film 20 reflects the P polarized light in the second light L2.

[0052] In this head-up display, if the infrared reflector 80 reflects 100% infrared light and the polarization splitting film 20 reflects 100% P-polarized light, theoretically, the infrared and P-polarized light in the second light beam L2 cannot enter the image generation unit 10. Ultimately, only the S-polarized light in the non-infrared portion of the second light beam L2 enters the image generation unit 10. Compared to direct backflow of the second light beam L2 into the image generation unit 10, the head-up display provided by the present embodiment processes the second light beam L2 when sunlight backflow occurs, reducing the infrared and P-polarized light in the second light beam that enters the image generation unit 10. This significantly reduces the light energy entering the image generation unit 10, thereby minimizing damage to the image generation unit 10 and protecting the image generation unit 10. Furthermore, the infrared reflector 80 and the polarization splitting film 20 are disposed between the image generation unit 10 and the second reflective unit 70, allowing the use of smaller polarization splitting films 20 and infrared reflector 80, thereby reducing the size and cost of the head-up display.

[0053] In order to prevent the infrared light reflected by the infrared reflector from being focused on a certain position of the head-up display, such as being reflected on a certain position of the head-up display housing, in some embodiments, the infrared reflector is curved. Figure 5 The infrared reflector 80 may be cylindrical in shape, with its concave side facing the image generating unit 10. In this way, when reflecting the infrared light in the second light L2, the divergence angle of the infrared light can be increased, thereby causing the light to disperse. This can prevent the infrared light reflected by the infrared reflector 80 from focusing on a certain position, causing the local temperature to be too high, thereby ensuring that the head-up display can work normally.

[0054] In order to prevent the P-polarized light reflected by the polarizing beam splitter film from being focused on a certain position of the head-up display, such as being reflected on a certain position of the head-up display housing, in some embodiments, the polarizing beam splitter film is curved. Figure 5 The polarizing beam splitting film 20 may be cylindrical in shape, with its concave side facing the image generating unit 10. In this way, when reflecting the P-polarized light in the second light L2, the divergence angle of the P-polarized light can be increased, thereby spreading the light. This can prevent the P-polarized light reflected by the polarizing beam splitting film 20 from focusing on a certain position, causing excessive local temperature, thereby ensuring the normal operation of the head-up display.

[0055] To further reduce the volume inside the heads-up display, in some embodiments, see Figure 4 The polarizing beam splitting film 20 is attached to the infrared reflector 80. By attaching the polarizing beam splitting film 20 to the infrared reflector 80, the distance between the infrared reflector 80 and the polarizing beam splitting film 20 can be reduced, thereby reducing the volume inside the head-up display and improving the overall compactness.

[0056] In some embodiments, the second reflective unit includes at least one reflector. The reflector is coated with a high-reflectivity film, which can be used to reflect light. For example, the reflector can be an aluminum reflector, comprising a glass substrate and an aluminum film coated on the surface of the glass substrate. Thus, the aluminum reflector can be used to reflect light. Furthermore, the reflector can have a flat or curved surface, including freeform surfaces. This allows the reflector surface to be designed to shape the second light and correct aberrations.

[0057] Specifically, in some of the embodiments, please refer to Figure 4 The second reflecting unit 70 includes a second reflecting mirror 71 and a third reflecting mirror 72 ; the second reflecting mirror 71 and the third reflecting mirror 72 are sequentially arranged between the infrared reflecting mirror 80 and the dust-proof film 40 along the first optical path.

[0058] In this HUD, see Figure 4 The S-polarized light generated by the image generation unit 10 is transmitted through the polarization splitting film 20 to the infrared reflector 80, and then through the infrared reflector 80 to the second reflector 71. The second reflector 71 reflects the S-polarized light to the third reflector 72. The third reflector 72 reflects the S-polarized light to the dust-proof film 40. Finally, the S-polarized light is transmitted through the dust-proof film 40 to the windshield 50. Finally, the S-polarized light can be reflected by the windshield 50 and then enter the human eye 60. The human eye 60 can observe the image content, thereby realizing the head-up display.

[0059] When sun backflow occurs, refer to Figure 5 The external second light L2 is transmitted through the dust-proof film 40 to the third reflector 72, reflected by the third reflector 72 to the second reflector 71, and then reflected by the second reflector 71 to the infrared reflector 80. The infrared reflector 80 in the second light L2 will transmit the non-infrared light in the second light L2 to the polarization splitting film 20, and reflect the infrared light in the second light L2. Then, the P-polarized light in this part of the second light L2 will be reflected by the polarization splitting film 20.

[0060] As can be seen, in this head-up display, when sunlight backflow occurs, on the one hand, the infrared light in the external second light beam L2 will be reflected by the infrared reflector 80, preventing this portion of light from further propagating to the image generation unit 10. On the other hand, the P-polarized light in the second light beam L2 that propagates onto the polarizing beam splitting film 20 will also be reflected by the polarizing beam splitting film 20, preventing this portion of light from further propagating to the image generation unit 10. Thus, the infrared reflector 80 and the polarizing beam splitting film 20 can reduce the amount of infrared light and P-polarized light in the second light beam L2 that enters the image generation unit, significantly reducing the energy of the second light beam L2 that propagates to the image generation unit 10. This reduces the temperature rise caused by the second light beam L2 on the image generation unit 10, minimizing damage to the image generation unit 10 and thus protecting the image generation unit 10. Furthermore, placing the infrared reflector 80 and the polarizing beam splitting film 20 close to the image generation unit 10 can reduce their area, thereby reducing the cost and size of the head-up display.

[0061] In a fifth aspect, an embodiment of the present invention further provides a vehicle comprising a windshield and a heads-up display as described in any one of the third aspects; the windshield is positioned in the light-emitting direction of the dustproof film. In this embodiment, the heads-up display has the same structure and functions as the heads-up display described in any one of the third aspects, and a detailed description thereof will not be repeated here. The vehicle may be a car, train, or other such vehicle.

[0062] In a sixth aspect, an embodiment of the present invention provides a method for protecting a head-up display, which is applied to a head-up display as described in any one of the fourth aspects. Figure 6 , the method comprising:

[0063] Step S300: reflecting the infrared light in the second light transmitted through the dust-proof film by the infrared reflector, and transmitting the non-infrared light in the second light to the polarization splitting film;

[0064] Step S400: reflecting the second polarized light in the second light through the polarization splitting film.

[0065] Specifically, in Figure 4 In the HUD shown, when sunlight intrusion occurs, refer to Figure 5 The second light L2 from the outside is transmitted through the dust-proof film 40 to the second reflecting unit 70, and is reflected by the second reflecting unit 70 to the infrared reflecting mirror 80. The infrared reflecting mirror 80 reflects the infrared light in the second light L2 and transmits the non-infrared light in the second light L2 to the polarizing beam splitting film 20. Then, the polarizing beam splitting film 20 reflects the P polarized light in the second light L2.

[0066] In this head-up display, if the infrared reflector 80 reflects infrared light at a ratio of 100% and the polarization splitter film 20 reflects P-polarized light at a reflectivity of 100%, theoretically, the infrared light and P-polarized light in the second light L2 cannot enter the image generation unit 10, and ultimately only the S-polarized light in the non-infrared light in the second light L2 enters the image generation unit 10. Compared with the second light L2 directly flowing back into the image generation unit 10, the protection method provided by the embodiment of the present invention can process the second light L2 when sunlight backflow occurs, reduce the infrared light and P-polarized light in the second light entering the image generation unit 10, greatly reduce the light energy entering the image generation unit 10, thereby reducing damage to the image generation unit 10 and protecting the image generation unit 10.

[0067] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A head-up display, characterized in that: include: An image generating unit, a polarization splitting film, a first reflecting unit and a dust-proof film are sequentially arranged along a first optical path; Wherein, the image generating unit is used to generate a first light with image information, and the first light is a first polarized light; The polarizing beam splitting film is used to transmit the first light to the first reflecting unit; The first reflecting unit includes at least one cold light mirror, and the cold light mirror is used to reflect the first light to the dust-proof film; The dustproof film is used to transmit the first light; The cold light mirror is further configured to transmit infrared light in the second light transmitted through the dust-proof film, and reflect non-infrared light in the second light to the polarization splitting film; The polarization splitting film is used to reflect the second polarized light in the second light; The polarization splitting film is cylindrical in shape, and the concave side of the polarization splitting film faces the image generating unit.

2. The head-up display according to claim 1, wherein: The first reflecting unit includes a first reflecting mirror, and the at least one cold light mirror includes a first cold light mirror; The first cold mirror and the first reflecting mirror are sequentially arranged between the polarization splitting film and the dust-proof film along the first optical path.

3. A method for protecting a head-up display, characterized in that: Applied to the head-up display according to any one of claims 1-2, the protection method comprises: transmitting infrared light in the second light transmitted through the dust-proof film through the cold mirror, and reflecting non-infrared light in the second light to the polarization splitting film; The second polarized light in the second light is reflected by the polarization splitting film.

4. A head-up display, characterized in that: include: An image generating unit, a polarization splitting film, an infrared reflector, a second reflecting unit and a dustproof film are sequentially arranged; Wherein, the image generating unit is used to generate a first light with image information, and the first light is a first polarized light; The polarization splitting film is used to transmit the first light to the infrared reflector; The infrared reflector is used to transmit the first light to the second reflective unit; The second reflecting unit is used to reflect the first light to the dust-proof film; The dustproof film is used to transmit the first light; The second reflecting unit is further used to reflect the second light transmitted through the dust-proof film to the infrared reflecting mirror; The infrared reflector is used to reflect the infrared light in the second light and transmit the non-infrared light in the second light to the polarization splitting film; The polarization splitting film is used to reflect the second polarized light in the second light; The polarization splitting film is cylindrical in shape, and the concave side of the polarization splitting film faces the image generating unit.

5. The head-up display according to claim 4, characterized in that The infrared reflector is in a curved shape.

6. The head-up display according to claim 5, characterized in that The polarization splitting film is attached to the infrared reflector.

7. The head-up display according to any one of claims 4 to 6, characterized in that: The second reflecting unit includes at least one reflecting mirror.

8. A means of transport, characterized in that: comprising a windshield, and the head-up display according to any one of claims 1 to 2, wherein the dustproof film and the windshield are sequentially arranged along the first optical path; or, The vehicle includes a windshield and a head-up display according to any one of claims 4 to 7, wherein the windshield is arranged in the light emitting direction of the dustproof film.

9. A method for protecting a head-up display, characterized in that: Applied to the head-up display according to any one of claims 4 to 7, the method comprising: reflecting infrared light in the second light transmitted through the dust-proof film by the infrared reflecting mirror, and transmitting non-infrared light in the second light to the polarization splitting film; The second polarized light in the second light is reflected by the polarization splitting film.

Images