CN112444973A

CN112444973A - Head-up display device

Info

Publication number: CN112444973A
Application number: CN201910822767.5A
Authority: CN
Inventors: 方涛; 徐俊峰; 吴慧军
Original assignee: Future Beijing Black Technology Co ltd
Current assignee: Future Beijing Black Technology Co ltd
Priority date: 2019-09-02
Filing date: 2019-09-02
Publication date: 2021-03-05

Abstract

The present invention provides a head-up display device, including: a light reflecting layer and a head-up display body with an image source; the light reflecting layer is arranged at a position where an imaging light path between the image source and the external reflecting device is reflected, and is used for reflecting light rays with first characteristics and absorbing or transmitting light rays with second characteristics; the second characteristic is a different characteristic from the first characteristic; the image source is used for emitting imaging light with the first characteristic, and the imaging light is reflected by the light reflecting layer and then enters the reflecting device. According to the head-up display device provided by the embodiment of the invention, the characteristic that the light reflecting layer can reflect the imaging light with the first characteristic is utilized, so that the head-up display device can normally image; meanwhile, a part of external light can be filtered, namely the light with the second characteristic can be absorbed or transmitted, so that the illumination intensity of the external light entering the image source can be reduced, and the image source can be prevented from being burnt out due to the fact that the external light is too strong.

Description

Head-up display device

Technical Field

The invention relates to the technical field of head-up displays, in particular to a head-up display device.

Background

HUD (head up display, the new line display) utilizes car windshield can image (virtual image), make the new line display can throw out the image that contains the panel board information, the driver is when watching the outside real environment of windshield, can also watch the formation of image of new line display, thereby can avoid the driver to hang down the distraction that the panel board leads to at the driving in-process, can improve and drive factor of safety, also can bring better driving experience simultaneously.

The traditional HUD is internally provided with an image source, and when strong external light enters the image source, the temperature of the image source is increased, and the normal work of the image source can be influenced. In addition, the HUD is typically also provided with a curved mirror, and the image source is close to the focal plane of the curved mirror, and the HUD can normally operate. However, when strong light (such as sunlight) exists outside the vehicle, the external light can pass through the windshield to reach the curved mirror and then be converged on the focal plane of the curved mirror, so that the converged light spot may burn out an image source, and even cause an accident due to vehicle fire. Referring to fig. 1, when the sun is at an angle or position, sunlight may be transmitted through the windshield and directly incident on the curved mirror 1 of the HUD, causing light to converge near the image source 2, potentially burning the image source 2.

Disclosure of Invention

To solve the above problems, embodiments of the present invention provide a head-up display device.

An embodiment of the present invention provides a head-up display device, including: a light reflecting layer and a head-up display body with an image source;

the light reflecting layer is arranged at a position where an imaging light path between the image source and the external reflecting device is reflected, and is used for reflecting light rays with first characteristics and absorbing or transmitting light rays with second characteristics; the second characteristic is a different characteristic than the first characteristic;

the image source is used for emitting imaging light rays with first characteristics, and the imaging light rays are reflected by the light ray reflecting layer and then enter the reflecting device.

In the scheme provided by the embodiment of the invention, the head-up display equipment can normally image by utilizing the characteristic that the light reflecting layer can reflect the imaging light with the first characteristic; meanwhile, a part of external light can be filtered, namely the light with the second characteristic can be absorbed or transmitted, so that the illumination intensity of the external light entering the image source can be reduced, and the image source can be prevented from being burnt out due to the fact that the external light is too strong.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 shows a schematic diagram of the imaging principle of a head-up display and the potential for burn-in;

fig. 2 is a schematic diagram illustrating a first structure of a head-up display device according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a screen burn-in prevention principle of a head-up display device according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating a second structure of a head-up display device according to an embodiment of the invention;

fig. 5 is a schematic diagram illustrating a third structure of a head-up display device according to an embodiment of the invention;

fig. 6 is a schematic diagram illustrating a fourth structure of a head-up display device according to an embodiment of the invention;

fig. 7 is a schematic diagram illustrating a fifth structure of a head-up display device according to an embodiment of the invention;

fig. 8 is a schematic diagram illustrating a sixth structure of a head-up display device according to an embodiment of the present invention;

fig. 9 is a schematic diagram illustrating a seventh structure of the head-up display device according to the embodiment of the present invention.

Icon:

10-head-up display body, 20-reflection device, 100-light transmission element, 110-image source, 120-curved mirror, 130-plane mirror and 200-light reflection layer.

Detailed Description

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

According to the head-up display device provided by the embodiment of the invention, the special light reflecting layer is arranged at the position where the imaging light path is reflected, so that the imaging is not influenced, and meanwhile, part of external light can be filtered. Referring to fig. 2, the head-up display apparatus includes: a light reflecting layer 200 and a head-up display body 10 having an image source 110.

The light reflecting layer 200 is disposed at a position where an imaging light path between the image source 110 and an external reflection device is reflected, and the light reflecting layer 200 is used for reflecting light with a first characteristic and absorbing or transmitting light with a second characteristic; the second characteristic is a different characteristic from the first characteristic. The image source 110 is configured to emit an image light having a first characteristic, and the image light is reflected by the light reflection layer 200 and then enters the reflection device.

In the embodiment of the present invention, a reflection element, such as a curved mirror, a plane mirror, etc., is disposed in the conventional head-up display body, and when the imaging light emitted from the image source 110 enters the reflection element, the light path is reflected, that is, the position for placing the reflection element in the head-up display body 10 is the "position where the imaging light path is reflected" in this embodiment. The light reflecting layer 200 with a reflecting function is disposed at this position, the imaging light emitted from the image source 110 can be incident to the light reflecting layer 200, and the imaging light is transmitted to the reflecting device 20 after being reflected by the light reflecting layer 200, so that the normal imaging of the image source 110 is not affected. In fig. 2, the light reflection layer 200 is disposed at a position of the curved mirror in the head-up display body 10, and meanwhile, in order to ensure normal imaging of the image source 110, the structure of the light reflection layer 200 is consistent with that of the curved mirror, that is, the light reflection layer 200 is also concave. The curved mirror may be a free-form surface mirror, a spherical mirror, a hyperboloid mirror, a parabolic mirror, or the like.

The reflection device 20 is a transparent device with a reflection function, and may be a component additionally disposed in the automobile and having a function of reflecting the imaging light, or may be a windshield of the automobile, or a transparent reflection film coated on an inner side of the windshield, which is not limited in this embodiment. In fig. 2, the reflecting device 20 is illustrated as a windshield.

In the embodiment of the present invention, the imaging light emitted from the image source 110 has the first characteristic, and the light reflection layer 200 can reflect the light having the first characteristic, so that the imaging light having the first characteristic emitted from the image source 110 can be reflected by the light reflection layer 200 and transmitted to the reflection device 20 after being incident on the light reflection layer 200, and then imaged by the external reflection device 20, that is, the light reflection layer 200 does not affect the imaging process of the head-up display device. Meanwhile, since the light reflection layer 200 can also absorb or transmit light with the second characteristic, when external light is incident into the head-up display body 10, the light reflection layer 200 can absorb or transmit a part of light with the second characteristic in the external light, and since the image source 110 is disposed on the imaging light path reflected by the light reflection layer 200 at this time, the light with the second characteristic is not incident into the image source 110, so that the intensity of the external light incident into the image source 110 can be reduced, and the image source 110 is prevented from being burnt out due to too strong external light.

Specifically, referring to fig. 3, in a normal operating state, the image source 110 emits an imaging light ray a having a first characteristic, and the imaging light ray a is reflected to the reflection device 20 by the reflection of the light reflection layer 200, so that a virtual image is formed outside the reflection device 20 for a driver to see. When the external sun is located in a specific position of the automobile, the sunlight B emitted by the sun can just pass through the light outlet of the head-up display body 10 and enter the interior of the head-up display body 10, and then the sunlight B is incident to the light reflecting layer 200; since the sunlight B is natural light mixed with light rays with various characteristics, based on the function of the light reflection layer 200, the light ray C with the first characteristic in the sunlight B can be reflected by the light reflection layer 200 and reach the image source 110, and the light ray D with the second characteristic in the sunlight B can be absorbed or transmitted by the light reflection layer 200, which is illustrated in fig. 3 as the light ray D with the second characteristic is transmitted by the light reflection layer 200. That is, after the light reflection layer 200 acts, only the light C with the first characteristic in the external sunlight B can reach the image source 110, so that the light reflection layer 200 can filter out part of the light in the external sunlight, reduce the illumination intensity incident on the image source 110, and prevent the image source 110 from being burnt out by the external sunlight.

It will be understood by those skilled in the art that since the head-up display body 10 includes the image source 110 and may further include a plurality of reflective elements capable of changing the propagation direction of the light path, such as a plurality of curved mirrors, flat mirrors, etc., the light reflection layer 200 may be disposed at any position of the reflective elements. In addition, the phrase "the imaging light is reflected by the light reflection layer 200 and then enters the reflection device 20" in this embodiment does not limit that the imaging light is reflected by the light reflection layer 200 and then directly emitted to the reflection device 20, and the imaging light may also be reflected by the light reflection layer 200 and then indirectly emitted to the reflection device 20 through one or more other reflection elements. In addition, the "light outlet" of the head-up display body refers to an opening for emitting imaging light from the image source, but external light may also enter the head-up display body through the "light outlet", that is, the "light outlet" is a light inlet for external light.

According to the head-up display device provided by the embodiment of the invention, the light reflecting layer is arranged at the position where the imaging light path in the head-up display body is reflected, and the head-up display device can normally image by utilizing the characteristic that the light reflecting layer can reflect the imaging light with the first characteristic; meanwhile, a part of external light can be filtered, namely the light with the second characteristic can be absorbed or transmitted, so that the illumination intensity of the external light entering the image source can be reduced, and the image source can be prevented from being burnt out due to the fact that the external light is too strong.

On the basis of the above embodiments, since the space for installing the head-up display device in the vehicle is limited, in order to ensure that the image source is located near the focal plane of the curved mirror, at least one of the reflective elements in the head-up display body 10 is a plane mirror, that is, the head-up display body 10 may include a curved mirror and a plane mirror, and the plane mirror is used to adjust the imaging optical path along which the imaging light propagates, thereby reducing the volume of the head-up display body. At this time, the light reflecting layer 200 may also be disposed at the position of the plane mirror; meanwhile, in order not to affect the normal imaging of the image source 110, the light reflection layer 200 needs to have a planar structure. Therefore, the light reflection layer 200 in the present embodiment has various structural forms.

Specifically, the light reflection layer 200 is a concave structure, and the light reflection layer 200 is disposed at a first position, which is a position for placing the curved mirror in the head-up display body 10. Referring to fig. 2 or fig. 3, the light reflection layer 200 is a concave structure similar to the original curved mirror structure, and the image source 110 is located near the focal plane of the light reflection layer 200. Preferably, the image source 110 may be located at the focal plane of the light reflecting layer 200 having the concave structure, or the image source 110 is located within one focal length of the light reflecting layer 200 having the concave structure, that is, the image source 110 is located at the side of the focal plane of the light reflecting layer 200 close to the light reflecting layer 200.

Alternatively, the light reflection layer 200 has a planar structure, and the light reflection layer 200 is disposed at a second position where a plane mirror is disposed in the head-up display body 10. Referring to fig. 4, the light reflecting layer 200 is a planar structure that is the same as the original planar mirror structure, and the imaging light emitted from the image source 110 passes through the light reflecting layer 200 and then enters the reflecting device 20 to be imaged; in fig. 4, the curved mirror 120 is included in the head-up display body 10, and the image light is reflected by the light reflection layer 200 and then emitted to the curved mirror 120 and then to the reflection device 20. The principle of the light reflection layer 200 that can avoid burning the image source 110 is similar to that of the light reflection layer with any structure, and reference may be made to the description related to fig. 3, which is not repeated herein.

Further, as described above, the light reflecting layer 200 is disposed at a position where the imaging optical path between the image source 110 and the external reflection device is reflected, and the light reflecting layer 200 may be particularly disposed at a position where a reflecting element (e.g., a curved mirror or a flat mirror) is disposed. Because the original reflection element has the function of reflecting the imaging light, the light reflection layer 200 can replace the original reflection element, and the light reflection layer 200 replaces the original reflection element to achieve the purpose of reflecting the imaging light. Or, the light reflection layer 200 may also be directly attached to the surface of the original reflection element, so that the conventional head-up display may be conveniently modified, and the conventional head-up display may also achieve the function of avoiding screen baking. In this embodiment, the light reflection layer 200 may be an optical film with selective transmittance and reflectance based on the existing process; specifically, the light reflection layer 200 may be an optical film made of an inorganic dielectric material or an organic polymer material, and the optical film is formed by stacking at least two film layers having different refractive indexes. The term "different refractive index" as used herein means that the refractive index of the film layer is different in at least one of the three directions xyz; the optical film having selective reflection and selective transmission characteristics, which can selectively reflect light having a first characteristic and selectively transmit or absorb light having a second characteristic, can be formed by selecting desired film layers having different refractive indexes in advance and stacking the film layers in a preset order, and can be used as the light reflection layer 200 in this embodiment.

Specifically, for the film layer of the inorganic dielectric material, the composition of the film layer is 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 the organic high molecular material, the film layer of the organic high molecular material comprises at least two thermoplastic organic polymer film layers; the two thermoplastic polymer film layers are alternately arranged to form the optical film, and the refractive indexes of the two thermoplastic polymer film layers are different. The molecules of the organic polymer material are in a chain structure, and the molecules are arranged in a certain direction after being stretched, so that the refractive indexes in different directions are different, namely, the required film can be formed through a specific stretching process. The thermoplastic polymer may be PET (polyethylene terephthalate) and its derivatives with different degrees of polymerization, PEN (polyethylene naphthalate) and its derivatives with different degrees of polymerization, PBT (polybutylene terephthalate) and its derivatives with different degrees of polymerization, and the like, which is not limited in this embodiment. The light reflection layer 200 in this embodiment is preferably an optical film made of an organic polymer material, and is conveniently attached to the surface of the original reflection element.

Specifically, when the light reflection layer 200 is a concave structure, the original curved mirror 120 may be replaced by the light reflection layer 200 with the concave structure, and the structure of the head-up display device is shown in fig. 2; alternatively, the light reflection layer 200 with a concave structure may be disposed on the surface of the original curved mirror 120, and the structure of the head-up display device is shown in fig. 5.

When the light reflection layer 200 is a planar structure, the original plane mirror 130 can be replaced by the light reflection layer 200 with the planar structure, and the structure of the head-up display device is shown in fig. 4; alternatively, the light reflection layer 200 of the planar structure may be disposed on the surface of the original plane mirror 130, and the structure of the head-up display device is shown in fig. 6.

Optionally, a plurality of light reflecting layers 200 may be further disposed in this embodiment. When the head-up display body 10 includes both the curved mirror 120 and the plane mirror 130, the light reflecting layers 200 may be disposed on both the curved mirror 120 and the plane mirror 130. Referring to fig. 7, the head-up display device is provided with a light reflecting layer 200 of a concave structure at a curved mirror 120 and another light reflecting layer 200 of a planar structure at a flat mirror 130.

In addition, when the head-up display apparatus is provided with a plurality of light reflecting layers 200, different light reflecting layers 200 may absorb or transmit light having different characteristics, that is, different light reflecting layers may absorb or transmit light having different second characteristics. As shown in fig. 7, if the imaging light emitted from the image source 110 is linearly polarized light in the first polarization direction and is RGB three color bands, that is, the first characteristic includes three bands, and the light of each band is linearly polarized light in the first polarization direction; at this time, the light reflection layer 200 of the planar structure can reflect the light of the first characteristic and absorb or transmit the linearly polarized light of the second polarization direction, that is, the second characteristic corresponding to the light reflection layer 200 of the planar structure is the linearly polarized light of the second polarization direction; meanwhile, the light reflecting layer 200 with the concave structure may also reflect the light with the first characteristic, but may absorb or transmit the light with other spectral bands except the RGB three-color spectral bands, that is, the second characteristic corresponding to the light reflecting layer 200 with the concave structure is the other spectral bands except the RGB three-color spectral bands. In this embodiment, the light rays with other characteristics than the first characteristic in the external light rays can be better filtered by combining the plurality of different light ray reflecting layers 200, so that the filtering effect on the external light rays is improved; meanwhile, the design requirement on each light reflecting layer 200 can be reduced, the processing difficulty is reduced, and the cost of each light reflecting layer 200 is reduced.

It can be understood by those skilled in the art that, when the light reflection layer 200 is disposed on the surface of the reflective element, in order to distinguish the light reflection layer 200 from the reflective element (i.e. the curved mirror 120 or the flat mirror 130), the light reflection layer 200 is spaced apart from the reflective element by a certain distance in fig. 5 to 7.

The light ray described in this embodiment has multiple characteristics, such as the first characteristic, the second characteristic, and the like, and essentially means that the light ray can be decomposed into light rays with multiple characteristics. The characteristic of the light may specifically be a polarization characteristic (i.e., a polarization state), a wavelength characteristic, a phase characteristic, a direction characteristic, or the like.

Specifically, in the embodiment of the present invention, the first characteristic and the second characteristic are two different polarization characteristics, that is, the first characteristic is a first polarization characteristic, and the second characteristic is a second polarization characteristic. The polarization characteristics specifically include linear polarization, circular polarization, elliptical polarization, and the like. In this embodiment, if the polarization directions of the two linear polarizations are different, the polarization characteristics of the two linear polarizations are also different; the included angles of the slow axes of the two elliptical polarizations are different, and the polarization characteristics can also be considered to be different; the polarization characteristics are different if the two circular polarizations have different rotation directions (left-hand or right-hand).

In this embodiment, the image source 110 can emit Light with a specific polarization characteristic, for example, an LCD (Liquid Crystal Display) image source can emit linearly polarized Light with a specific polarization direction, a DLP (Digital Light Processing) image source, a diffuser and an image source composed of a backlight module can all emit Light with a specific polarization. In the embodiment, the image source 110 is taken as an LCD as an example, and based on the imaging principle of liquid crystal, the light emitted from the image source 110 at this time is linearly polarized with a specific polarization direction, for example, the linear polarization with the polarization direction parallel to the long side of the liquid crystal display. In this embodiment, the imaging light emitted from the image source 110 is a linearly polarized light having a first polarization direction, that is, the first characteristic is: linear polarization of the first polarization direction, and accordingly, the second characteristic is: linear polarization of the second polarization direction. Preferably, the first polarization direction is perpendicular to the second polarization direction, and the light reflection layer 200 can more effectively distinguish the light having the first characteristic from the light having the second characteristic, so that the light having the second characteristic can be more effectively absorbed or transmitted. In the embodiment of the present invention, the "second characteristic is a characteristic different from the first characteristic" means that the first characteristic is not completely the same as the second characteristic. For example, the first characteristic is linear polarization and the second characteristic is circular polarization; alternatively, the first characteristic is a 500nm wavelength, the second characteristic is a 600nm wavelength, or the second characteristic is a wavelength other than 500 nm; alternatively, the first characteristic is linear polarization with a wavelength of 500nm, and the second characteristic is linear polarization with a wavelength of 600nm, or the like.

In addition, the image source 110 may also emit imaging light with circular polarization or elliptical polarization, where the first polarization characteristic is left-handed circular polarization and the second polarization characteristic is right-handed circular polarization; or

The first polarization characteristic is right-handed circular polarization, and the second polarization characteristic is left-handed circular polarization; or

The first polarization characteristic is left-handed elliptical polarization, and the second polarization characteristic is right-handed elliptical polarization; or

The first polarization characteristic is right-handed elliptical polarization and the second polarization characteristic is left-handed elliptical polarization.

In this embodiment, the first characteristic and the second characteristic are two linear polarizations in which polarization directions are perpendicular, for example. The natural light can be decomposed into two linear polarizations with perpendicular polarization directions, that is, the natural light can be decomposed into a linearly polarized light line with a first polarization direction and a linearly polarized light line with a second polarization direction, and the light reflection layer 200 in this embodiment can transmit or absorb the linearly polarized light line with the second polarization direction. As shown in fig. 3, after the natural light B reaches the light reflection layer 200, the linearly polarized light C with the first polarization direction in the natural light B may be reflected by the light reflection layer 200 and reach the image source 110, and the linearly polarized light D with the second polarization direction in the natural light B is absorbed or transmitted by the light reflection layer 200, that is, 50% of the light in the natural light B is absorbed or transmitted by the light reflection layer 200, so that the intensity of the external light can be reduced by 50%, and the image source 110 is effectively prevented from being burned out by the external light.

Further, as described above, the characteristic of the light in the present embodiment may be a wavelength characteristic. In this embodiment, the first characteristic comprises one or more spectral bands; at this time, the second characteristic may be a band including another band different from the band of the first characteristic. For example, the first characteristic may include a wavelength band of 500nm to 600nm, in which case the second characteristic may be a band of 600nm to 700nm, or a band other than 500nm to 600 nm.

Specifically, when the image source 110 needs to form a color image, the imaging light emitted from the image source 110 includes at least three spectral bands, for example, the light emitted from the image source 110 is RGB three-spectral band. In this embodiment, the first characteristic comprises at least three non-overlapping spectral bands; the central point of the first of the at least three bands is located between 410nm and 480nm, which corresponds to the blue (B) band; the central point of the second band is located between 500nm and 565nm, which corresponds to the green (G) band; the third band has a center point between 590nm and 690nm, which corresponds to the red (R) band.

In this embodiment, the central point of the spectral band may be an average value of two critical values of the spectral band, or may be a certain point in the spectral band determined in other manners, which is not limited in this embodiment. For example, if the band is 500nm to 600nm, the two critical values before and after the band are 500nm and 600nm, respectively, 550nm can be used as the center point of the band. In addition, in order to ensure the imaging effect of the image source 110, it is necessary to avoid the excessive bandwidth; the width of the spectral band in the embodiment is not more than 50nm to ensure the color saturation when the image source is imaged.

In the embodiment of the present invention, it is assumed that the natural light is visible light, and the width of the spectral band is 400nm, if the first characteristic includes three spectral bands, and the total width of the three spectral bands is 100 nm; meanwhile, the second characteristic is other than the first characteristic, that is, the total band width of the second characteristic is 300 nm. Referring to fig. 3, when the natural light B is emitted to the light reflection layer 200, the light ray with the width of 300nm (i.e. the light ray D with the second characteristic) in the natural light B is transmitted or absorbed by the light reflection layer 200, and only the light ray C with the width of 100nm (i.e. the light ray C with the first characteristic) can be incident on the image source 110. In the case of disregarding other physical quantities of the natural light B, it can be considered that only 25% of the rays of the natural light B can be incident on the image source 110, so that the illumination intensity incident on the image source 110 can also be reduced.

Optionally, in this embodiment, the first characteristic includes one or more spectral bands having a predetermined polarization state. Specifically, the image source 110 may emit Light with a specific polarization characteristic, for example, an LCD (Liquid Crystal Display) image source may emit linearly polarized Light with a specific polarization direction, a DLP (Digital Light Processing) image source, a diffuser, an image source composed of a backlight module, and the like may all emit Light with a specific polarization. In this embodiment, the image source 110 is taken as an LCD for illustration, the imaging light emitted by the image source 110 may be linearly polarized light of three colors RGB, that is, the first characteristic includes three spectral bands, and the light of each spectral band is linearly polarized light in the first polarization direction. At this time, the second characteristic may be other than the first characteristic, that is, the light reflecting layer 200 absorbs or transmits all the external light except the RGB three spectral bands of the linearly polarized light of the first polarization direction. For convenience of explanation, taking the first characteristic as an example that the first characteristic includes only one spectral band, the spectral band is 500nm to 600nm and is linearly polarized in a first polarization direction, if the spectral band of some part of the external light is 600nm to 700nm and is linearly polarized in a second polarization direction, the light is light with a second characteristic; alternatively, if a certain part of the external light has a band of 500nm to 600nm but is linearly polarized in the second polarization direction, the part of the external light may be regarded as light having the second characteristic.

Still taking the width of the natural spectral band as 400nm as an example, since the optical line width of the first characteristic is 100nm, the light reflecting layer 200 can filter 75% of external natural light, i.e. only 25% of external natural light is reflected to the image source 110; meanwhile, the light reflecting layer 200 can further filter out the linear polarization of the second polarization direction, that is, 50% of light can be further filtered out, and finally, only 12.5% of light of external natural light can be reflected by the light reflecting layer 200, so that the filtering and blocking effects of the light reflecting layer 200 on the external light can be further improved.

On the basis of the above embodiment, referring to fig. 8, the head-up display device provided by the embodiment of the invention further includes a light transmitting element 100. The light transmission element 100 is disposed on a light path from the image source 110 to the external reflection device 20, and the light transmission element 100 is configured to transmit a light ray having a first characteristic and reflect or absorb a light ray having a third characteristic; the third characteristic is a different characteristic from the first characteristic.

In the embodiment of the present invention, the light transmitting element 100 is disposed on the imaging light path from the image source 110 to the external reflection device 20. Since the light reflecting layer 200 is disposed at the position where the imaging light path is reflected, the light transmitting element 100 may be disposed between the image source 110 and the light reflecting layer 200, or between the light reflecting layer 200 and the reflecting device 20; when the head-up display body 10 further includes other reflective elements, the light transmitting element 100 may be disposed between the light reflective layer 200 and a reflective element, which only needs to ensure that the light transmitting element 100 is disposed on the light path from the image source 110 to the external reflection device 20. Referring to fig. 9, the head-up display body 10 includes a curved mirror 120 and a plane mirror 130, and the light reflection layer 200 is disposed on the surface of the plane mirror 130, in which case the light transmission element 100 may be disposed between the light reflection layer 200 and the curved mirror 120; of course, the light transmitting device 100 can be disposed between the light reflecting layer 200 and the image source 110, or between the curved mirror 120 and the external reflection device 20, which is not limited in this embodiment.

In the embodiment of the invention, the image source 110 is used for emitting imaging light with the first characteristic. Since the light transmissive element 100 is capable of transmitting light with the first characteristic, the imaging light emitted from the image source 110 can be transmitted through the light transmissive element 100 and finally imaged by the external reflection device 20, i.e. the light transmissive element 100 does not affect the imaging process of the head-up display device. Meanwhile, since the light transmission element 100 can reflect or absorb the light with the third characteristic, when the external light is incident into the head-up display device, the light transmission element 100 can absorb or reflect the light with the third characteristic in the external light, so that the intensity of the external light incident to the image source 110 can be reduced, and the image source 110 is prevented from being burnt out due to the excessively strong external light.

In this embodiment, the third characteristic and the second characteristic are different from the first characteristic, and the third characteristic may be the same as or different from the second characteristic, so that a part of the external light can be further filtered by the combined action of the light reflecting layer 200 and the light transmitting element 100. As shown in fig. 8, if the imaging light emitted from the image source 110 is linearly polarized light in the first polarization direction and is RGB three color bands, that is, the first characteristic includes three bands, and the light of each band is linearly polarized light in the first polarization direction; at this time, the light reflection layer 200 may reflect the light with the first characteristic, and absorb or transmit the linearly polarized light with the second polarization direction, that is, the second characteristic is the linear polarization with the second polarization direction; meanwhile, the light transmission element 100 may also reflect the light of the first characteristic, but may absorb or reflect light of other spectral bands than the RGB three-color spectral band, i.e., the third characteristic is other spectral bands than the RGB three-color spectral band. In this embodiment, the light reflecting layer 200 and the light reflecting element 100 can be combined to better filter out light rays with other characteristics than the first characteristic from the external light rays, so as to improve the filtering effect on the external light rays; meanwhile, the design requirements for the light reflecting layer 200 and the light transmitting element 100 can be reduced, and the cost of the light reflecting layer 200 and the light transmitting element 100 can be reduced.

On the basis of the above embodiment, the light transmitting element 100 is specifically disposed on the light path from the image source 110 to the opening of the head-up display body 10. That is, the light transmitting element 100 is not disposed between the opening of the head-up display body 10 and the reflection device 20. When the light transmission element 100 is disposed between the opening of the head-up display body 10 and the reflection device 20, although external light can be blocked from entering the head-up display body, light of a road or an environment outside the vehicle can be partially filtered by the light transmission element 100, which may affect an observer to normally view a scene outside the vehicle. In this embodiment, the light transmitting element 100 is disposed on the light path from the image source 110 to the opening of the head-up display body 10, so as to avoid the above-mentioned problem.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A head-up display device, comprising: a light reflecting layer and a head-up display body with an image source;

2. The head-up display device of claim 1,

the light reflecting layer is of an inwards concave structure and is arranged at a first position, and the first position is used for placing the curved mirror in the head-up display body; and/or

The light reflection layer is of a plane structure and is arranged at a second position, and the second position is used for placing a plane mirror in the head-up display body.

3. The head-up display device according to claim 1 or 2, wherein the first characteristic is a first polarization characteristic and the second characteristic is a second polarization characteristic.

4. The head-up display device of claim 3,

the first polarization characteristic is linear polarization with a first polarization direction, the second polarization characteristic is linear polarization with a second polarization direction, and the first polarization direction is perpendicular to the second polarization direction; or

The first polarization characteristic is left-handed circular polarization, and the second polarization characteristic is right-handed circular polarization; or

The first polarization characteristic is right-handed elliptical polarization, and the second polarization characteristic is left-handed elliptical polarization.

5. The heads-up display device of claim 1 or 2 wherein the first characteristic comprises one or more spectral bands.

6. The heads-up display device of claim 5 wherein the first characteristic includes at least three non-overlapping spectral bands;

the central point of the first band of the at least three bands is between 411nm and 480nm, the central point of the second band is between 500nm and 565nm, and the central point of the third band is between 590nm and 690 nm.

7. The heads-up display device of claim 5 wherein the first characteristic includes one or more spectral bands having a predetermined polarization state.

8. The head-up display device according to claim 1 or 2, further comprising a light transmitting element;

the light ray transmission element is arranged on a light path between the image source and the external reflection device, and is used for transmitting the light ray with the first characteristic and reflecting or absorbing the light ray with the third characteristic; the third characteristic is a different characteristic than the first characteristic.

9. The head-up display device according to claim 1, wherein the light reflecting layer is an optical film made of an inorganic dielectric material or an organic polymer material, and the optical film is formed by stacking at least two film layers having different refractive indexes.