Filter film, amplification reflection element, head-up display and vehicle

Abstract

The embodiment of the invention provides a filter film, an amplification reflection element, a head-up display and a vehicle, the filter film is arranged on the surface of a curved mirror, the filter film can selectively reflect first light with a first wavelength characteristic and can transmit or absorb second light with a second wavelength characteristic, the reflectivity of the filter film to the first light is larger than or equal to 50%. According to the head-up display, the image light emitted by the image source on the light path of the head-up display can be imaged after being reflected by the filter film, and meanwhile, the light of other wavebands in the sunlight is cut off, so that the light of other wavebands in the sunlight is prevented from being reflected by the filter film and then irradiated to the image source to focus, and the temperature of the image source is prevented from being too high. The image source is effectively prevented from being burnt out, the working reliability and stability of the head-up display are improved, and the service life of the head-up display is prolonged.

Description

Technical Field

[0001] The present disclosure relates to the field of light filtering technology, and in particular to a light filtering film, an amplifying reflective element, a head-up display and a vehicle. Background Art

[0002] HUD (head up display) is also called a head-up display. By projecting the light emitted by the image source of the HUD onto an imaging window (such as a rear-mounted imaging board or a vehicle windshield, etc.), the user can directly see the image without lowering his head, thereby improving the user experience. In the prior art, when sunlight shines on the HUD, it may cause the image source temperature to rise. Excessive temperature may cause the image source to burn in, affecting the normal operation and service life of the image source. Summary of the invention

[0003] The purpose of the embodiments of the present disclosure is to provide a filter film, an amplifying reflective element, a head-up display and a vehicle to solve the technical problem in the prior art that when sunlight shines on the HUD, it may cause the image source temperature to rise, resulting in screen burn-in, affecting the normal operation and service life of the image source.

[0004] In order to solve the above technical problems, the embodiments of the present disclosure adopt the following technical solutions:

[0005] A filter film is provided on the surface of a curved mirror. The filter film can selectively reflect a first light with a first wavelength characteristic and can transmit or absorb a second light with a second wavelength characteristic, wherein the reflectivity of the filter film to the first light is greater than or equal to 50%.

[0006] In some embodiments, the first wavelength characteristic is a first preset band, the reflectivity of the filter film to light in the first preset band is ≥80%, and the second wavelength characteristic is a second preset band, the reflectivity of the filter film to light in the second preset band is ≤20%.

[0007] In some embodiments, the wavelength range of the first preset band is 410-480nm and 510-650nm, or the wavelength range of the first preset band is 420-460nm and 520-620nm; the wavelength range of the second preset band is other wavelength ranges within 0-1900nm except the wavelength range of the first preset band.

[0008] In some embodiments, the filter film is a three-pass filter film with three passbands corresponding to the three primary colors of red, green and blue respectively, and the first light with the first wavelength characteristic is light within the three spectral ranges of red, green and blue.

[0009] In some embodiments, the filter film is a selective wavelength reflective transmission film or a selective wavelength reflective absorption film.

[0010] In some embodiments, the first light having the first wavelength characteristic is a light having an S polarization characteristic or a P polarization characteristic.

[0011] In some embodiments, the wavelength range of the first light having the first wavelength characteristic is determined according to the wavelength range of the image light emitted by the image source corresponding to the curved mirror.

[0012] In some embodiments, the filter film is a coating film, and the filter film includes a first refractive index film layer and a second refractive index film layer alternately stacked, and the refractive index of the first refractive index film layer is greater than the refractive index of the second refractive index film layer.

[0013] In some embodiments, the refractive index of the first refractive index film layer is in the range of 1.8 to 2.6, and the refractive index of the second refractive index film layer is in the range of 1.3 to 1.8; and / or,

[0014] The first refractive index film layer is a metal compound film layer, and the second refractive index film layer is an inorganic compound film layer; and / or,

[0015] The thickness of the first refractive index film layer is in the range of 1 to 200 nm, and the thickness of the second refractive index film layer is in the range of 1 to 200 nm; and / or,

[0016] The number of the first refractive index film layers is 10 to 30, and the number of the second refractive index film layers is 10 to 30.

[0017] In some embodiments, the filter film further includes a smoothing layer, and the smoothing layer is disposed on at least one side of a film layer group formed by the first refractive index film layer and the second refractive index film layer.

[0018] In some embodiments, the curved mirror is made of glass or plastic.

[0019] In some embodiments, the filter film is coated on a surface of the curved mirror close to the image source.

[0020] The disclosed embodiment also provides a magnifying reflective element, comprising a curved mirror and any one of the filter films described above.

[0021] The present disclosure also provides a head-up display, including:

[0022] A head-up display body, the head-up display body comprising an image source, the image source being used to emit image light;

[0023] A reflective device mounted on or near the windshield of a vehicle;

[0024] The amplifying reflective element is installed on the optical path between the image source and the reflective device, and the amplifying reflective element is the amplifying reflective element mentioned above.

[0025] In some embodiments, the image light emitted by the image source is a first light having a first polarization characteristic and a first wavelength characteristic, and the amplifying reflective element can selectively reflect the first light and can transmit or absorb a second light, wherein the second light is other light except the light having the first polarization characteristic and the first wavelength characteristic.

[0026] The disclosed embodiment also provides a means of transportation, comprising the above-mentioned head-up display.

[0027] The filter film, amplifying reflective element, head-up display and vehicle provided by the embodiments of the present disclosure can ensure that the image light emitted by the image source in the optical path of the head-up display is highly imaged after being reflected by the filter film by setting the filter film to be able to selectively reflect the first light with a first wavelength characteristic and to be able to transmit or absorb the second light with a second wavelength characteristic. At the same time, the light of other wavelength bands in the sunlight is cut off to prevent the light of other wavelength bands in the sunlight from being reflected by the filter film and then irradiating and focusing at the image source, thereby causing the temperature of the image source to be too high, effectively avoiding burning of the image source, facilitating improving the working reliability and stability of the head-up display, and extending the service life of the head-up display. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 This is a schematic diagram of the imaging principle of the head-up display according to an embodiment of the present disclosure;

[0030] Figure 2 is a schematic structural diagram of an amplifying reflective element according to an embodiment of the present disclosure;

[0031] Figure 3 is a schematic structural diagram of a filter film according to an embodiment of the present disclosure;

[0032] Figure 4 is a schematic diagram of the working state of the filter film according to an embodiment of the present disclosure;

[0033] Figure 5 is a graph showing the relationship between the wavelength and reflectivity of the first light according to an embodiment of the present disclosure;

[0034] Figure 6 FIG. 4 is another relationship curve diagram between the wavelength and reflectivity of the first light according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] Various aspects and features of the present disclosure are described herein with reference to the drawings.

[0036] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present disclosure will occur to those skilled in the art.

[0037] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the general description of the present disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0038] These and other characteristics of the present disclosure will become apparent from the following description of a preferred form of embodiment given as a non-limiting example, with reference to the attached drawings.

[0039] It should also be understood that, although the present disclosure has been described with reference to some specific examples, those skilled in the art will be able to realize many other equivalent forms of the present disclosure that have the features described in the claims and are therefore within the scope of protection defined thereby.

[0040] The above and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0041] Specific embodiments of the present disclosure are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present disclosure, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of ways with substantially any suitable detailed structure.

[0042] This specification may use the phrases "in one embodiment," "in another embodiment," "in a further embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present disclosure.

[0043] Figure 1 The imaging principle diagram of the head-up display is shown in FIG. Figure 1As shown, the head-up display 10 uses the optical reflection principle to reflect, for example, automobile driving assistance information, navigation information, check control information, and ADAS information through the windshield 20 to the human eye to form a virtual image. For example, the head-up display 10 includes an image source 110 and an amplifying reflective element 120. The image light emitted by the image source 110 can be incident on the amplifying reflective element 120, and is incident on the windshield 20 under the reflection effect of the amplifying reflective element 120. The image light is reflected to the human eye by the windshield 20 as an external reflection device to form a virtual image. The virtual image can be projected near the windshield 20 or in front of the windshield 20 for viewing by the user.

[0044] For example, the magnifying reflective element 120 may be a curved reflector.

[0045] For example, the image source 110 may be a display screen, and the display screen may be an LCD screen or an LED screen; the image source 110 may also be a DLP (Digital Light Processing) image source, an LBS (Laser Beam Scanning) image source, an image source composed of a diffuser and a backlight module, etc. The image source composed of a diffuser and a backlight module may be an LCOS (Liquid Crystal on Silicon) image source, and a red, green, and blue laser or LED with a relatively high power is used as a light source to illuminate the LCOS through a light combining system, and finally an image is formed on the diffuser. In this embodiment, the image source 110 takes a display screen as an example, and the coordinated imaging of the image source 110 and the amplifying reflective element 120 is described.

[0046] like Figure 1 As shown, when sunlight flows back, external sunlight will be incident on the windshield 20, and will be incident on the image source 110 under the transmission of the windshield 20 and the reflection of the amplifying reflective element 120. The sunlight irradiates the image source 110 and is focused on the image source 110, causing the temperature of the image source 110 to rise too much. The image source 110 may be burned by the focused sunlight and cannot be used. For example, when the image source 110 is a display screen, screen burn-in may occur.

[0047] In view of this, embodiments of the present disclosure provide a filter film, an amplifying reflective element, a head-up display, and a vehicle.

[0048] Example 1

[0049] Figure 2 FIG. 1 is a schematic diagram showing the structure of the amplifying reflective element of an embodiment of the present disclosure, Figure 3 The structure diagram of the filter film of the embodiment of the present disclosure is shown. Figure 4FIG. 2 shows a schematic diagram of the working state of the filter film according to an embodiment of the present disclosure. Figures 2 to 4 As shown, the first embodiment of the present disclosure provides a filter film 1, which is arranged on the surface of the curved mirror 2. The filter film 1 can selectively reflect a first light with a first wavelength characteristic and can transmit or absorb a second light with a second wavelength characteristic, wherein the reflectivity of the filter film 1 to the first light is greater than or equal to 50%.

[0050] For example, the first light with the first wavelength characteristic refers to the image light (light A) emitted by the image source 110 that can be incident on the filter film 1 and can form a virtual image after being reflected by the filter film 1. The image light is reflected by the filter film 1 with a reflectivity of at least 50%, so as to improve the display brightness and display effect of the virtual image formed by the image light, that is, as much useful image light related to imaging emitted by the image source 110 as possible is reflected to the windshield 20 to ensure the formation of a complete and high-quality virtual image, that is, the filter film 1 that can selectively reflect the first light with the first wavelength characteristic is provided, and does not affect the imaging process of the head-up display. For example, the reflectivity of the filter film 1 to the first light is greater than or equal to 60%, or the reflectivity of the filter film 1 to the first light is greater than or equal to 70%, or the reflectivity of the filter film 1 to the first light is greater than or equal to 80%, or the reflectivity of the filter film 1 to the first light is greater than or equal to 90%.

[0051] For example, the second light with the second wavelength characteristic refers to the light with the second wavelength characteristic in the external light B represented by the external sunlight. In other words, the second light refers to the light with the second wavelength characteristic in the natural light. After the second light is incident on the filter film 1, it can be transmitted or absorbed by the filter film 1 (for example, forming the above-mentioned transmitted light C), so as to prevent the second light from being reflected by the filter film 1 and irradiating the image source 110, thereby reducing the intensity of the external light B incident on the image source 110, and preventing the external light B from being too strong and focusing on the image source 110, causing the image source 110 to rise too much in temperature, thereby burning the image source 110.

[0052] Optionally, the first wavelength characteristic is different from the second wavelength characteristic to prevent the absorption or transmission of the second light by the filter film 1 from affecting the imaging of the first light. In other words, the first light (reflected light D) with the first wavelength characteristic in the external light B can be reflected to the image source 110 by the filter film 1, so as to prevent the first light from being transmitted or absorbed by the filter film 1 and affecting the imaging effect of the head-up display 10. Only the first light with the first wavelength characteristic can be reflected to the image source 110, which greatly reduces the number of external light B incident on the image source 110 and reduces the intensity of the external light B incident on the image source 110. In this embodiment, the second light can be any light in the solar spectrum except the wavelength band of the first light.

[0053] The filter film 1 provided in the embodiment of the present disclosure can ensure that the image light emitted by the image source 110 in the optical path of the head-up display 10 is clearly imaged after being reflected by the filter film 1, by setting the filter film 1 to be able to selectively reflect the first light with the first wavelength characteristic, and to be able to transmit or absorb the second light with the second wavelength characteristic. At the same time, the light of other wavelength bands in the sunlight is cut off to prevent the light of other wavelength bands in the sunlight from being reflected by the filter film 1 and then irradiated and focused on the image source 110, thereby causing the temperature of the image source 110 to be too high, thereby effectively avoiding burning of the image source 110, facilitating improving the working reliability and stability of the head-up display 10, and extending the service life of the head-up display 10.

[0054] In some embodiments, the first wavelength characteristic is a first preset band, and the reflectivity of the filter film 1 to the light in the first preset band is ≥80%, for example, the reflectivity of the filter film 1 to the light in the first preset band is ≥85%, or the reflectivity of the filter film 1 to the light in the first preset band is ≥90%, or for example, the reflectivity of the filter film 1 to the light in the first preset band is ≥95%; the second wavelength characteristic is a second preset band, and the reflectivity of the filter film 1 to the light in the second preset band is ≤20%, for example, the reflectivity of the filter film 1 to the light in the second preset band is ≤15%, or the reflectivity of the filter film 1 to the light in the second preset band is ≤10%, or the reflectivity of the filter film 1 to the light in the second preset band is ≤5%.

[0055] For example, the first preset wavelength band includes a wavelength range of image light for imaging through the windshield 20, for example, the first preset wavelength band is a wavelength range of visible light emitted by the image source 110. The filter film 1 can reflect the image light in the wavelength range to the windshield 20 with a high reflectivity, so as to achieve high-quality imaging of the head-up display; the second preset wavelength band can be any wavelength range except the first preset wavelength band, and the reflectivity of the filter film 1 to the light in the second preset wavelength band is ≤20%, so that no or only a small amount of light in the second preset wavelength band can be reflected by the filter film 1 and irradiated to the image source 110, which can effectively prevent excessive external light from irradiating to the image source 110 and prevent the image source 110 from burning.

[0056] In some embodiments, Figure 5 As shown, the wavelength range of the first preset band is 410-480nm (it should be understood that the numerical ranges shown in the embodiments of the present disclosure include endpoints) and 510-650nm, or as Figure 6 As shown, the wavelength range of the first preset band is 420-460nm and 520-620nm;

[0057] The wavelength range of the second preset wavelength band is other wavelength ranges within 0 to 1900 nm except the wavelength range of the first preset wavelength band.

[0058] The image light emitted by the image source 110 is mainly visible light (visible light wavelength range is 390nm~780nm), among which the light in the wavelength range of 410~480nm is blue light, and the light in the wavelength range of 510~650nm includes green light (520nm~532nm), yellow light (577nm~589nm) and red light (635nm~650nm).

[0059] In this embodiment, the first light is a light with a wavelength range of 410-480nm and / or 510-650nm, and can use the three primary colors of red, green and blue to form a rich color complete imaging, while using yellow light to correct the virtual image formed, so as to achieve high-quality imaging. In addition, the filter film 1 is set to have a higher reflectivity for a selected part of the wavelength range within the visible light range, and has a lower reflectivity for other wavelength ranges within the visible light range, so as to avoid excessive external sunlight being reflected to the image source 110 through the filter film 1.

[0060] It can be understood that the wavelength range of the first preset band removes the light in the range of 480 to 510 nm (cyan light or light blue light), reducing the color information (color gamut), thereby improving the saturation of the virtual image after imaging and achieving high-quality imaging.

[0061] To further ensure high-quality imaging of the head-up display 10, the wavelength range of blue light can be narrowed, and high-energy short-wave blue light with higher energy in the wavelength range of 420nm to 460nm can be used; and / or, based on the wavelength critical values ​​of green light and red light, visible light in the wavelength range of 520 to 620nm can be used.

[0062] Exemplarily, the wavelength ranges of 410-480nm and 510-650nm are relatively wide, and the reflectivity of the filter film 1 to the light (first light) within the wavelength ranges of 410-480nm and 510-650nm can be set to be greater than 50%; the wavelength ranges of 420-460nm and / or 520-620nm are relatively narrow, and the reflectivity of the filter film 1 to the light within the wavelength ranges of 420-460nm and / or 520-620nm can be set to be greater than 80%, so as to achieve high reflection of the light within this wavelength range and improve the imaging quality.

[0063] The wavelength range of the second preset wavelength band is a wavelength range other than the wavelength range of the first preset wavelength band within 0 to 1900 nm, so that the filter film 1 can cut off (such as transmitting or absorbing) as much external light as possible to prevent the image source 110 from burning in, for example, blocking light except for the range of 0 to 410 nm and 480 to 1900 nm. It can be understood that the light within the second preset wavelength band may include any type of light within the second preset wavelength band, such as visible light, infrared light, and ultraviolet light.

[0064] In some embodiments, the filter film 1 is a three-pass filter film with three passbands corresponding to the three primary colors of red, green and blue (R, G, B), and the first light with the first wavelength characteristic is light within the three spectral ranges of red, green and blue.

[0065] For example, the filter film 1 can be a three-way filter film with RGB three primary colors, which corresponds to the backlight spectrum of the head-up display 10 and the spectrum of the image light of the image source 110, so that the three primary color light that is beneficial to imaging is reflected by the filter film 1 with a higher reflectivity, and the light in other wavelength ranges has high transmittance or high absorption rate and cannot be reflected by the filter film 1, which does not affect the imaging of the head-up display 10 and the display brightness and clarity of the virtual image screen 30 after imaging, and can reduce the external sunlight incident on the image source 110 after being reflected by the filter film 1, so as to achieve the purpose of preventing screen burn-in. In addition, the three-way filter film is easy to process and has a low cost.

[0066] In some embodiments, the wavelength range of the first light having the first wavelength characteristic is determined according to the wavelength range of the image light emitted by the image source 110 corresponding to the curved mirror 2 .

[0067] That is, the first preset wavelength band is selected and determined according to the needs of the image source 110. For example, the image light emitted by the image source 110 can be RGB three-color light. With the three-way filter film, the RGB three-color light can be reflected to the windshield 20 with a higher reflectivity, so that the red, green and blue primary colors can be used to form a colorful virtual image. At the same time, the wavelength range of the first light is determined according to the wavelength range of the image light emitted by the image source, so that specific optical effects can be achieved, such as reducing reflections, improving contrast, etc., and improving imaging quality. For example, the first preset wavelength band is the same as the wavelength range of the image light emitted by the image source 110.

[0068] The reflectivity of the filter film 1 can also be determined according to the image source 110. For example, when the intensity of the image light emitted by the image source 110 is relatively large, the reflectivity can be set to be relatively small (at least 50%); and when the intensity of the image light is relatively small, the reflectivity can be set to be relatively large so as to allow as much of the image light as possible to be reflected by the filter film 1.

[0069] In some embodiments, the filter film 1 is a selective wavelength reflective transmissive film or a selective wavelength reflective absorbing film.

[0070] It should be understood here that the selective wavelength reflective transmissive film can reflect the first light and transmit the second light, and the selective wavelength reflective absorptive film can reflect the first light and absorb the second light.

[0071] When the filter film 1 is a selective wavelength reflective and transmissive film, the first light with the first wavelength characteristic can be reflected at the filter film 1 with a high reflectivity (at least 50%), and the second light with the second wavelength characteristic can be transmitted through the filter film 1 with a high transmittance, so that the second light cannot be reflected to the image source 110 through the filter film 1. While the first light is used for imaging, the intensity of the external light incident to the image source 110 is greatly reduced. For example, only the light with the same wavelength as the first light in the external light can be incident to the image source 110 after being reflected by the filter film 1.

[0072] When the filter film 1 is a selective wavelength reflection and absorption film, the first light with a first wavelength characteristic can be reflected at the filter film 1 with a higher reflectivity (at least 50%), and the second light with a second wavelength characteristic can be absorbed at a higher absorption rate. While using the first light to form an image, the intensity of external light incident on the image source 110 is greatly reduced.

[0073] In some embodiments, the first light having the first wavelength characteristic is a light having an S polarization characteristic or a P polarization characteristic, or the first light having the first wavelength characteristic is a linearly polarized light or a circularly polarized light.

[0074] When light is incident on the surface of the filter film 1 at a non-perpendicular angle, both the reflection and transmission characteristics depend on the polarization phenomenon. Therefore, in order to ensure the light transmission performance of the filter film 1, the first light can be set to a light with polarization characteristics. Among them, the polarization direction of the light with S polarization characteristics (S polarized light) is perpendicular to the plane composed of the incident, reflected, refracted light and the normal line; and the polarization direction of the light with P polarization characteristics (P polarized light) is in the plane composed of the incident, reflected, refracted light and the normal line. Linearly polarized light refers to light whose vibration direction is in the same plane; circularly polarized light refers to light whose light vector does not change in size, but whose vibration direction changes with the phase. For example, LCD image sources can emit linearly polarized light with a specific polarization direction, and DLP image sources, diffusers, and image sources composed of backlight modules can all emit specific polarized light.

[0075] In a specific implementation, the image source 110 can be controlled to emit light with specific polarization characteristics, so that the first light with specific polarization characteristics can be reflected by the filter film 1 with a higher reflectivity. For example, if the image source 110 emits P-polarized light, the filter film 1 reflects the P-polarized light with a higher reflectivity; if the image source 110 emits S-polarized light, the filter film 1 reflects the S-polarized light with a higher reflectivity.

[0076] Preferably, the image source 110 emits P polarized light or S polarized light of a specific wavelength band, for example, P polarized light of a specific wavelength band, and the first light can be P polarized light of the specific wavelength band. The filter film 1 can reflect the P polarized light of the specific wavelength band with a higher reflectivity, and transmit or absorb P polarized light of other wavelength bands and S polarized light of all wavelength bands with a higher transmittance or absorptivity. That is, the second light can include light in the same wavelength band as the first light but with different polarization characteristics. Thus, the range of the first light is further limited, so that more of the external sunlight is transmitted or absorbed by the filter film 1, thereby further reducing the intensity of the external sunlight irradiated to the image source 110.

[0077] Exemplarily, the image light emitted by the image source 110 can be linearly polarized light of RGB three colors, that is, at this time, the first wavelength characteristic of the first light includes three spectral bands, and the light of each spectral band is linearly polarized light in the first polarization direction; the second light with the second wavelength characteristic can be all light with other characteristics except the light with the first wavelength characteristic in the linear polarized light in the first polarization direction, that is, the filter film 1 absorbs or transmits all other light in the external light except the three spectral bands of RGB of the linear polarized light in the first polarization direction.

[0078] The image source 110 may also emit any light of a specific wavelength band, and the filter film 1 may also be a selective polarized reflective transmissive film or a polarized reflective absorptive film. For example, when the image source 100 emits any light of a specific wavelength band, the first light is a P-polarized light of a specific wavelength band, and the filter film 1 may reflect the P-polarized light of the specific wavelength band with a higher reflectivity, and transmit or absorb the P-polarized light of other wavelength bands and the S-polarized light of all wavelength bands with a higher transmittance or absorptivity, so as to prevent the P-polarized light of other wavelength bands and the S-polarized light of all wavelength ranges from being incident on the image source 110 after being reflected by the filter film 1.

[0079] In some embodiments, the filter film 1 is a coating. Coating is a technology that coats one or more layers of dielectric or metal films on an optical element or substrate to change the transmission behavior of light waves in the material. This technology can adjust various properties of light, including light transmission, reflection, absorption, scattering, polarization and phase. Through the reasonable design and arrangement of different film layers, optical coatings can change the way light of a specific wavelength propagates on an optical element. The refractive index is a measure of the degree to which light bends when propagating in different media. For example, Figure 3As shown, the filter film 1 includes a first refractive index film layer 11 and a second refractive index film layer 12 which are alternately stacked, and the refractive index of the first refractive index film layer 11 is greater than the refractive index of the second refractive index film layer 12. Such different refractive indices will cause reflection, refraction and interference of light inside the filter film, so that the filter film 1 can selectively reflect, transmit or absorb light within a specific wavelength range. For example, the filter film 1 can be a dielectric film or a metal film coated on the curved mirror 2, or a combination of the two films. The filter film 1 is coated to facilitate the assembly and fixation of the filter film 1, and can effectively change the transmission characteristics of light such as transmission, reflection, absorption, scattering, polarization and phase change.

[0080] The filter film 1 may be a single-layer or multi-layer structure. In the present embodiment, the filter film 1 is a multi-layer structure, including a first refractive index film layer 11 and a second refractive index film layer 12 which are stacked, wherein the refractive index of the first refractive index film layer 11 is greater than the refractive index of the second refractive index film layer 12, that is, the first refractive index film layer 11 is a high refractive index film layer, and the second refractive index film layer 12 is a low refractive index film layer. By alternately stacking different types of refractive index film layers, higher quality requirements of the filter film 1 can be met on the basis of achieving functions such as reflection enhancement, transmission enhancement, and beam splitting. For example, different types of refractive index film layers can be used to meet the equivalent refractive index while allowing the first light in the formed part of the filter film 1 to be focused to improve the imaging quality, while another part of the filter film 1 has a brightening effect to improve the brightness of the virtual image after imaging.

[0081] The first refractive index film layer 11 and the second refractive index film layer 12 can be alternately stacked or grouped. For example, a plurality of first refractive index film layers 11 are stacked to form a first film layer group, a plurality of second refractive index film layers 12 are stacked to form a second film layer group, and the first film layer group and the second film layer group are stacked to form the filter film 1. Of course, a plurality of first film layer groups and second film layer groups can also be alternately stacked.

[0082] It is understandable that the first refractive index film layer 11 and the second refractive index film layer 12 have different refractive indexes in at least one direction in the three directions XYZ. When manufacturing the optical filter film 1, the required film layers with different refractive indices are pre-selected and the film layers are stacked in a pre-set order to form the optical filter film 1 that can selectively reflect the first light with the first wavelength characteristic and can transmit or absorb the second light with the second wavelength characteristic.

[0083] In some embodiments, the refractive index range of the first refractive index film layer 11 is 1.8 to 2.6, and the refractive index range of the second refractive index film layer 12 is 1.3 to 1.8. The refractive index range of the first refractive index film layer 11 is matched with the refractive index range of the second refractive index film layer 12, so that the first light can be reflected with a higher light reflectivity and the second light can be transmitted with a higher transmittance, so that the filter film 1 can better match the air medium, thereby reducing dispersion vibration to achieve better optical performance.

[0084] In some embodiments, the first refractive index film 11 is a metal compound film, and the second refractive index film 12 is an inorganic compound film. The filter film 1 can be an optical film made of an inorganic dielectric material or an organic polymer material.

[0085] For the film layer of inorganic dielectric material, the composition of the film layer can be selected from one or more of tantalum pentoxide, titanium dioxide, magnesium oxide, zinc oxide, zirconium oxide, silicon dioxide, magnesium fluoride, silicon nitride, silicon oxynitride, and aluminum fluoride. For the film layer of organic polymer material, the film layer of organic polymer material includes at least two thermoplastic organic polymer film layers; the two thermoplastic polymer film layers are alternately arranged to form an optical film, and the refractive index of the two thermoplastic polymer film layers is different. Among them, the molecules of organic polymer material are chain structures, and after stretching, the molecules are arranged in a certain direction, resulting in different refractive indices in different directions, that is, the desired film can be formed by a specific stretching process. The thermoplastic polymer can specifically be PET (polyethylene terephthalate) and its derivatives with different polymerization degrees, PEN (polyethylene naphthalate) and its derivatives with different polymerization degrees, PBT (polybutylene terephthalate) and its derivatives with different polymerization degrees, etc., which are not specifically limited in the present disclosure.

[0086] For example, the first refractive index film layer 11 is a titanium pentoxide (TI3O5) film layer, and the second refractive index film layer 12 is a silicon dioxide (SiO2) film layer. This combination can utilize the optical properties of different materials to make the filter film 1 more precise and effective in selectively reflecting, transmitting and absorbing light.

[0087] In some embodiments, the thickness of the first refractive index film layer 11 is in the range of 1 to 200 nm, and the thickness of the second refractive index film layer 12 is in the range of 1 to 200 nm.

[0088] Specifically, the thickness of the film layer will affect the interference effect of light between the film layers. For example, the thickness of the first refractive index film layer ranges from 10 to 120 nm, and the thickness of the second refractive index film layer ranges from 10 to 190 nm. The above thickness can be used to change the phase difference and amplitude of light, thereby achieving interference enhancement or cancellation of light of a specific wavelength, and further controlling the transmission characteristics of light.

[0089] In some embodiments, the number of the first refractive index film layers is 10 to 30, and the number of the second refractive index film layers is 10 to 30.

[0090] The number of layers of the first refractive index film layer and the second refractive index film layer is preferably the same, for example, both are 20 layers, so as to achieve a better filtering effect while avoiding an increase in the cost and thickness of the filter film 1 due to too many film layers, and avoiding an influence on the optical properties (such as interference) of the filter film 1 due to too few film layers.

[0091] The number of layers of the first refractive index film layer 11 and the second refractive index film layer 12 may also be different. For example, the film layers located on the outermost sides may both be set to be the first refractive index film layer 11. In this case, the number of layers of the first refractive index film layer 11 is greater than the number of layers of the second refractive index film layer 12, so that when the image light from the image source 110 and the external light emitted by the sunlight are incident on the filter film 1, they are first incident on the first refractive index film layer 11.

[0092] In some embodiments, the filter film 1 further includes a smoothing layer, and the smoothing layer is disposed on at least one side of the film layer group formed by the first refractive index film layer 11 and the second refractive index film layer 12 .

[0093] Specifically, the smoothing layer is disposed on the outermost side of the filter film 1, which can make the spectrum passing through the filter film 1 smoother. This helps to improve the stability of the reflectivity and transmittance of the filter film 1, so that the filter film can more accurately control the required spectral characteristics. At the same time, the smoothing layer can also prevent the existence of unfavorable factors such as bubbles and impurities that affect the propagation of light, thereby maintaining the clarity and accuracy of the optical device.

[0094] In some embodiments, the curved mirror 2 is made of glass or plastic. The curved mirror 2 is a curved reflector.

[0095] Specifically, the curved mirror 2 made of glass has excellent optical properties and stability, as well as good corrosion resistance, and can work stably for a long time in various environments. The curved mirror 2 made of plastic can play a role in applications that require weight reduction, such as in some mobile devices. Secondly, plastic can be more easily processed into complex curved shapes, which is very useful in some customized designs. Plastic materials include polycarbonate (PC) and polymethyl methacrylate (PMMA).

[0096] In some embodiments, the filter film 1 is plated on a surface of the curved mirror 2 that is close to the image source 110 .

[0097] Specifically, Figure 4As shown, the filter film 1 is placed on the side surface of the curved mirror 2 close to the image source 110. After the light is emitted from the image source 110, the filter film 1 can selectively reflect the light through the filter film 1 on the curved mirror 2, thereby achieving a filtering effect and ensuring an imaging effect; at the same time, before the external light passes through the windshield 20 and is incident on the curved mirror 2, the second light with a second wavelength characteristic is transmitted or absorbed by the filter film 1, so as to prevent the second light from being incident on the image source 110 after being reflected by the curved mirror 2, thereby effectively reducing the external light incident on the image source 110 and preventing screen burn-in.

[0098] Example 2

[0099] like Figures 1 to 4 As shown, the second embodiment of the present disclosure provides a magnifying reflective element 120, including a curved mirror 2 and the filter film 1 described in the above-mentioned embodiment 1 of the present disclosure.

[0100] The magnifying reflective element 120 is preferably a curved mirror 2, and the curved mirror 2 is a free-form mirror, a spherical mirror, a hyperbolic mirror or a parabolic mirror.

[0101] Example 3

[0102] like Figures 1 to 4 As shown, the third embodiment of the present disclosure provides a head-up display 10, including:

[0103] A head-up display body, the head-up display body includes an image source 110, and the image source 110 is used to emit image light;

[0104] A reflective device, mounted on the windshield 20 of the vehicle or mounted near the windshield 20;

[0105] The magnifying reflective element 120 is installed on the optical path between the image source 110 and the reflective device. The magnifying reflective element 120 is the magnifying reflective element 120 described in the second embodiment.

[0106] Specifically, the head-up display body is equipped with an image source 110, which includes a liquid crystal screen or other device that can generate light. The image light emitted by the image source 110 is reflected by the amplifying reflective element 120 and then incident on the reflective device. The reflective device enables the image light emitted from the image source 110 to be projected within the driver's line of sight at a specific angle, so that the driver can see the information in front of his line of sight without moving his line of sight away from the road.

[0107] The amplifying and reflecting element 120 is installed in the optical path between the image source 110 and the reflecting device, and can effectively amplify and reflect the image light to facilitate subsequent imaging. At the same time, the filter film 1 installed on the amplifying and reflecting element 120 can improve the imaging quality while avoiding the image source 110 from being burned due to excessive external light, thereby ensuring the normal operation of the image source 110 and increasing the service life of the image source 110.

[0108] In some embodiments, the image light emitted by the image source 110 is a first light having a first polarization characteristic and a first wavelength characteristic, and the amplifying reflective element 120 can selectively reflect the first light and can transmit or absorb a second light, wherein the second light is other light except the light having the first polarization characteristic and the first wavelength characteristic.

[0109] For example, the first light with the first polarization characteristic and the first wavelength characteristic refers to linearly polarized light of three colors: red, green and blue. After the image source 110 emits the first light, the filter film 1 in the amplifying and reflecting element 120 can reflect the first light with a higher reflectivity, so that the first light is incident on the windshield installed on the vehicle or on a reflecting device installed near the windshield, thereby achieving high-quality imaging. At this time, external light passes through the windshield 20 and is incident on the amplifying and reflecting element 120. The filter film 1 in the amplifying and reflecting element 120 can transmit or absorb the second light to reduce the external light incident on the image source 110 after being reflected by the filter film 1, thereby avoiding burning of the image source 110 due to excessive external light.

[0110] Example 4

[0111] A fourth embodiment of the present disclosure provides a means of transport, including the above-mentioned head-up display. The means of transport may be any one of a car, a truck, a pickup truck, a train, an airplane, and the like.

[0112] It should be noted that the vehicle corresponds to the head-up display of the above-mentioned embodiment, the head-up display 10 corresponds to the magnifying reflective element 120 of the above-mentioned embodiment, the magnifying reflective element 120 corresponds to the filter film 1 of the above-mentioned embodiment, and any optional items in the embodiment of the filter film 1 are also applicable to the embodiments of the magnifying reflective element 120, the head-up display 10 and the vehicle, which will not be repeated here.

[0113] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) by each other to form a technical solution.

[0114] In addition, although each operation is described in a specific order, this should not be understood as requiring these operations to be performed in the specific order shown or in a sequential order. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination mode.

Claims

1. A filter film, characterized in that: The filter film is arranged on the surface of the curved mirror, and the filter film can selectively reflect the first light with the first wavelength characteristic and can transmit or absorb the second light with the second wavelength characteristic, wherein the reflectivity of the filter film to the first light is greater than or equal to 50%.

2. The filter film according to claim 1, characterized in that: The first wavelength characteristic is a first preset wavelength band, and the reflectivity of the filter film to the light in the first preset wavelength band is ≥80%. The second wavelength characteristic is a second preset wavelength band, and the reflectivity of the filter film to the light in the second preset wavelength band is ≤20%.

3. The filter film according to claim 2, characterized in that: The wavelength range of the first preset band is 410-480nm and 510-650nm, or the wavelength range of the first preset band is 420-460nm and 520-620nm; the wavelength range of the second preset band is other wavelength ranges within 0-1900nm except the wavelength range of the first preset band.

4. The filter film according to claim 1, characterized in that: The filter film is a three-pass filter film with three passbands corresponding to the three primary colors of red, green and blue respectively, and the first light with the first wavelength characteristic is the light within the three spectral ranges of red, green and blue.

5. The filter film according to claim 1, characterized in that: The filter film is a selective wavelength reflection transmission film or a selective wavelength reflection absorption film.

6. The optical filter film according to any one of claims 1 to 4, characterized in that: The first light with the first wavelength characteristic is a light with an S polarization characteristic or a P polarization characteristic.

7. The optical filter film according to any one of claims 1 to 4, characterized in that: The wavelength range of the first light having the first wavelength characteristic is determined according to the wavelength range of the image light emitted by the image source corresponding to the curved mirror.

8. The optical filter film according to any one of claims 1 to 4, characterized in that: The filter film is a coating film, and includes a first refractive index film layer and a second refractive index film layer alternately stacked, wherein the refractive index of the first refractive index film layer is greater than the refractive index of the second refractive index film layer.

9. The filter film according to claim 8, characterized in that: The refractive index of the first refractive index film layer is in the range of 1.8 to 2.6, and the refractive index of the second refractive index film layer is in the range of 1.3 to 1.8; and / or, The first refractive index film layer is a metal compound film layer, and the second refractive index film layer is an inorganic compound film layer; and / or, The thickness of the first refractive index film layer is in the range of 1 to 200 nm, and the thickness of the second refractive index film layer is in the range of 1 to 200 nm; and / or, The number of the first refractive index film layers is 10 to 30, and the number of the second refractive index film layers is 10 to 30.

10. The filter film according to claim 8, characterized in that: The filter film further includes a smoothing layer, and the smoothing layer is disposed on at least one side of a film layer group formed by the first refractive index film layer and the second refractive index film layer.

11. The optical filter film according to any one of claims 1 to 4, characterized in that: The curved mirror is made of glass or plastic.

12. The filter film according to claim 7, characterized in that: The filter film is plated on a surface of the curved mirror on one side close to the image source.

13. An amplifying reflective element, characterized in that: The invention comprises a curved mirror and a filter film according to any one of claims 1 to 12.

14. A head-up display, characterized in that: include: A head-up display body, the head-up display body comprising an image source, the image source being used to emit image light; A reflective device mounted on or near the windshield of a vehicle; An amplifying reflective element is installed on the optical path between the image source and the reflecting device, and the amplifying reflective element is the amplifying reflective element according to claim 13.

15. The head-up display according to claim 14, characterized in that: The image light emitted by the image source is a first light with a first polarization characteristic and a first wavelength characteristic, and the amplifying reflective element can selectively reflect the first light and can transmit or absorb a second light, wherein the second light is other light except the light with the first polarization characteristic and the first wavelength characteristic.

16. A means of transport, characterized in that: Includes the head-up display according to claim 14 or 15.

Images