CN117130155A

CN117130155A - Display device and display method

Info

Publication number: CN117130155A
Application number: CN202210541991.9A
Authority: CN
Inventors: 赵晗; 赵晴; 陈拓; 林旗清
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2023-11-28
Also published as: CN115639673B; WO2023221578A1; CN115639673A

Abstract

The present application provides a display device and a display method, which can be applied to a display device, wherein the device comprises one or more different types of vehicles, such as automobiles, bicycles, motorcycles, trains, subways, airplanes, ships, aircrafts, robots or other types of vehicles or movable objects, etc. The display device comprises a dust cover and an imaging unit, wherein the dust cover is attached with: a first polarizing plate for transmitting a first polarized light in sunlight; a first quarter wave plate for converting the first polarized light into circular polarized light. The imaging unit is used for emitting imaging light and transmitting the circularly polarized light to the first quarter wave plate; the first quarter wave plate converts the circularly polarized light to light of the second polarization that can be blocked by the first polarizer. According to the device disclosed by the application, the plurality of wave plates are additionally arranged on the surface of the dust cover, so that sunlight cannot exit through the dust cover again after entering the imaging unit through the dust cover, glare caused by the sunlight is eliminated, and the display effect is improved.

Description

Display device and display method

Technical Field

The present application relates to the field of optical communication technology, and more particularly, to a display device and a display method.

Background

With the continuous development of automobile technology, the requirements on the convenience and safety of automobile use are increasing. For example, head Up Display (HUD) (or head up display system) has been widely used for automobiles. The head-up display is a device for projecting instrument information (such as speed), navigation information and the like to the front of the visual field of a driver, the driver can see the instrument information and the navigation information in front of the visual field, and the instrument panel or the central control display screen below the steering wheel does not need to be observed at a low head, so that the braking response time under emergency conditions can be improved, and the driving safety is improved.

There is a technology to achieve miniaturization of a display system by folding an optical path. However, in this technique, a reflecting mirror is added below the dust cover, and when sunlight is directly incident, serious glare is caused, resulting in poor display effect.

Therefore, there is a need for a display device and a display method that can eliminate glare caused by sunlight and improve display effects.

Disclosure of Invention

The application provides a display device and a display method, which can eliminate glare caused by sunlight and improve display effect.

In a first aspect, a display device is provided that is applicable to display equipment, including but not limited to one or more different types of vehicles, such as automobiles, bicycles, motorcycles, trains, subways, airplanes, boats, aircraft, robots or other types of vehicles or movable objects, etc. The display device comprises a dust cover and an imaging unit, wherein a first polaroid and a first quarter wave plate are stuck on the dust cover, the first polaroid is used for transmitting first polarized light in sunlight, and the first quarter wave plate is used for converting the first polarized light into first circular polarized light; the imaging unit is used for emitting imaging light and transmitting the first circularly polarized light to the first quarter wave plate by the imaging unit; the first quarter wave plate is further used for converting the first circularly polarized light into second polarized light, the polarization direction of the second polarized light is different from that of the first polarized light, and the second polarized light is blocked by the first polaroid, so that sunlight cannot exit from the dust cover.

According to the device disclosed by the application, the plurality of wave plates are additionally arranged on the surface of the dust cover, so that sunlight cannot exit through the dust cover again after entering the imaging unit through the dust cover, glare caused by the sunlight is eliminated, and the display effect is improved.

It will be appreciated that the first quarter wave plate is used to convert the first polarized light into circular polarized light, which may be elliptical polarized light or other possible non-circular polarized light, when the first quarter wave plate is not offset from the optical axis of the polarizer by 45 ° as a result of the conversion in an ideal state. For ease of description, circular polarization is used herein generically to represent this type of light.

It should also be understood that the blocking of the second polarized light by the first polarizer may be specifically construed as the absorption, elimination or reflection of the second polarized light by the first polarizer, and the present application is not limited thereto. In addition, in the embodiment of the application, the surface of the device is attached with a wave plate, a polaroid and the like, and the surface of the device is also coated with the wave plate, the polaroid or embedded with the wave plate and the polaroid. For example, "the first polarizer is attached to the dust cover" may also be expressed as "the first polarizer is plated to the dust cover" or "the first polarizer is embedded to the dust cover". Alternatively, the polarizing plate may be referred to as a polarizing film, and the name thereof is not limited by the present application.

With reference to the first aspect, in some implementations of the first aspect, a second polarizer is further attached to the dust cover, and the first polarizer is configured to transmit the first polarized light, reflect the second polarized light, and absorb the second polarized light. Alternatively, the first polarizer is used for transmitting the first polarized light and absorbing the second polarized light, and the second polarizer is used for transmitting the first polarized light and reflecting the second polarized light. In this way, the second polarized light is reflected and absorbed simultaneously by the additional new polaroid, so that glare caused by sunlight is further reduced, and the display effect is improved. When the polarizing plate (for example, the first polarizing plate) for treating the sunlight first is used for transmitting the first polarized light and absorbing the second polarized light, the second polarized light in the sunlight can be absorbed, so that the glare caused by the sunlight can be further reduced.

With reference to the first aspect, in some implementations of the first aspect, the imaging unit includes a first image source, a first free-form surface mirror, a second free-form surface mirror, and a glass plate, where a second quarter wave plate is attached to the first image source, the first image source is used for generating first image source light, a polarization direction of the first image source light is different from a polarization direction of the first polarized light, and the second quarter wave plate is used for converting the first image source light into second circular polarized light; the first free-form surface mirror is used for transmitting the second circularly polarized light to the glass plate; a third quarter wave plate, a third polaroid and a fourth quarter wave plate are attached to the surface of the glass plate, which is close to the first image source, wherein the third quarter wave plate is used for converting the second circular polarized light into third polarized light, the third polarized light is transmitted to the third quarter wave plate by the third polaroid, and the third quarter wave plate is also used for converting the third polarized light into third circular polarized light; the second free-form surface mirror is used for transmitting the third circularly polarized light to the third quarter-wave plate; the third quarter wave plate is further used for converting third circularly polarized light into fourth polarized light, the polarization direction of the fourth polarized light is different from that of the third polarized light, the third polarizing plate is further used for transmitting the fourth polarized light to the fourth quarter wave plate, the fourth quarter wave plate is further used for converting the fourth polarized light into fourth circularly polarized light, the first quarter wave plate is further used for converting the fourth circularly polarized light into fifth polarized light, the polarization direction of the fifth polarized light is different from that of the fourth polarized light, and the fifth polarized light forms a virtual image of the first image source light through the windshield. In this way, the miniaturization of the display device is realized by utilizing the folding of the light path, and the loss caused by polarization is avoided in the whole light path transmission process, so that the display effect is improved.

With reference to the first aspect, in some implementations of the first aspect, a fourth polarizer is further attached to the glass plate, and the fourth polarizer is located between the fourth quarter-wave plate and the third polarizer, and is configured to transmit the fourth polarized light and absorb the third polarized light. In this way, the third polarized light is reflected and absorbed simultaneously by the additional new polaroid, so that glare caused by sunlight is further reduced, and the display effect is improved.

With reference to the first aspect, in some implementations of the first aspect, a surface of the glass plate away from the first image source is attached with an anti-reflection plate or is coated with an anti-reflection film, and the anti-reflection plate (anti-reflection film) is used for reducing reflectivity of the first circular polarized light. Wherein the anti-reflection waveplate may also be referred to as an anti-reflection waveplate. In this way, the circularly polarized light reflected to the windshield is reduced by additionally adding the anti-reflection wave plate, so that glare caused by sunlight is further reduced, and the display effect is improved.

With reference to the first aspect, in some implementations of the first aspect, the display device further includes a second image source, where a polarization direction of the second image source is different from a polarization direction of the first polarized light, and an imaging distance of the second image source is smaller than an imaging distance of the first image source, or a distance of the second image source from the glass plate is greater than a distance of the first image source from the glass plate, in other words, the second image source is farther away from the glass plate than the first image source. In so doing, the free-form mirror can be reused, thereby achieving miniaturization of bifocal imaging.

With reference to the first aspect, in other implementation manners of the first aspect, the imaging unit includes a liquid crystal display and an oriented backlight image source, a fifth polarizer and a fifth quarter-wave plate are attached to a surface of a side, close to the dust cover, of the liquid crystal display, and the oriented backlight is used for generating oriented backlight image source light, and a polarization direction of the oriented backlight image source light is different from that of the first polarized light; the liquid crystal display is used for transmitting the directional backlight image source light to the fifth quarter wave plate; the fifth quarter wave plate is used for converting the directional backlight image source light into second circularly polarized light; the first quarter wave plate is further used for converting the second circularly polarized light into third polarized light, the polarization direction of the third polarized light is different from that of the second polarized light, and the third polarized light passes through the windshield to form a virtual image of the directional backlight image source light. In this way, the whole light path does not need to adopt a curved mirror, the device is small in size, and the problem of sunlight backflow caused by condensation of the curved mirror does not exist, so that the display effect is improved.

With reference to the first aspect, in other implementation manners of the first aspect, a sixth polarizer is further attached to the liquid crystal display, the fifth polarizer is used for transmitting the third polarized light, reflecting the second polarized light, and the sixth polarizer is used for transmitting the third polarized light and absorbing the second polarized light; alternatively, the fifth polarizer is used for transmitting the third polarized light, absorbing the second polarized light, and the sixth polarizer is used for transmitting the third polarized light and reflecting the second polarized light. In this way, the second polarized light is reflected and absorbed simultaneously by the additional new polaroid, so that glare caused by sunlight is further reduced, and the display effect is improved.

With reference to the first aspect, in other implementation manners of the first aspect, a surface of a side, close to the dust cover, of the liquid crystal display is further adhered with an anti-reflection wave plate or is coated with an anti-reflection film, and the anti-reflection wave plate (anti-reflection film) is used for reducing reflectivity of the first circular polarized light. Wherein the anti-reflection waveplate may also be referred to as an anti-reflection waveplate. In this way, the circularly polarized light reflected to the windshield is reduced by additionally adding the anti-reflection wave plate, so that glare caused by sunlight is further reduced, and the display effect is improved.

With reference to the first aspect, in further implementations of the first aspect, the imaging unit includes a third image source, a third freeform mirror, a mirror, and a glass plate, the third image source configured to generate third image source light, the third image source light being the first polarized light; a seventh quarter wave plate and a sixth polaroid are attached to the surface of the glass plate, which is close to the third image source, and the sixth polaroid is used for transmitting the light of the third image source to the reflecting mirror; the eighth quarter wave plate is attached to the reflector and is used for converting the third image source light into second circular polarized light, the reflector is used for transmitting the second circular polarized light to the eighth quarter wave plate, and the eighth quarter wave plate is also used for converting the second circular polarized light into sixth polarized light. The third curved mirror is used for transmitting the sixth polarized light to a seventh quarter wave plate, the seventh quarter wave plate is used for converting the sixth polarized light into third circularly polarized light, the first quarter wave plate is also used for converting the third circularly polarized light into seventh polarized light, the polarization direction of the seventh polarized light is different from that of the sixth polarized light, and the seventh polarized light forms a virtual image of the third image source light through the windshield. In this way, the miniaturization of the display device is realized by utilizing the folding of the light path, and the loss caused by polarization is avoided in the whole light path transmission process, so that the display effect is improved.

With reference to the first aspect, in still other implementation manners of the first aspect, a seventh polarizer is attached to the third curved mirror, and the seventh polarizer is used for transmitting the seventh polarized light and reflecting the sixth polarized light.

In a second aspect, a display method is provided. The method is performed by a display device comprising a dust cover on which a first polarizer for transmitting a first polarized light in sunlight and blocking a second polarized light of the sunlight and an imaging unit for emitting the imaged light are attached, the first quarter wave plate for converting the first polarized light into a first circular polarized light, the method comprising: the first polarized light of the sunlight is transmitted to the first quarter wave plate through the first polaroid; converting the first polarized light into first circularly polarized light through a first quarter wave plate; the first circularly polarized light is transmitted to a first quarter wave plate through an imaging unit; the first circularly polarized light is converted into second polarized light through the first quarter wave plate, the polarization direction of the second polarized light is different from that of the first polarized light, and the second polarized light is blocked by the first polarizing plate, so that sunlight cannot exit from the dust cover.

According to the method disclosed by the application, the plurality of wave plates are additionally arranged on the surface of the dust cover, so that sunlight cannot exit through the dust cover again after entering the imaging unit through the dust cover, glare caused by the sunlight can be eliminated, and the display effect is improved.

With reference to the second aspect, in certain implementations of the second aspect, the second polarized light is blocked by the first polarizer, including: the second polarized light is reflected by the first polarizer; alternatively, the second polarized light is absorbed by the first polarizer.

With reference to the second aspect, in some implementations of the second aspect, the imaging unit includes a first image source, a first free-form surface mirror, a second free-form surface mirror, and a glass plate, the first image source has a second quarter-wave plate attached thereto, and the glass plate has a third quarter-wave plate, a third polarizer, and a fourth quarter-wave plate attached to a surface of the glass plate adjacent to the first image source, and the method further includes: the first image source generates first image source light, and the polarization direction of the first image source light is different from that of the first polarized light; the first image source light is converted into second circularly polarized light through a second quarter wave plate; the second circular polarized light is transmitted to the glass plate through the first free-form surface mirror, and the second circular polarized light is converted into third polarized light through the third quarter wave plate; the third polarized light is transmitted to a third quarter wave plate through a third polaroid and is converted into third circularly polarized light through the third quarter wave plate; the third circularly polarized light is transmitted to a third quarter wave plate through a second freeform mirror, and is converted into fourth polarized light through the third quarter wave plate, wherein the polarization direction of the fourth polarized light is different from that of the third polarized light; the fourth polarized light is transmitted to a fourth quarter wave plate through a third polarizing plate, the fourth polarized light is converted into fourth circular polarized light through the fourth quarter wave plate, the fourth circular polarized light is converted into fifth polarized light through the first quarter wave plate, the polarization direction of the fifth polarized light is different from that of the fourth polarized light, and the fifth polarized light passes through a windshield to form a virtual image of the first image source light.

With reference to the second aspect, in other implementation manners of the second aspect, the imaging unit includes a liquid crystal display and an oriented backlight image source, a surface of a side, close to the dust cover, of the liquid crystal display is attached with a fifth polarizer and a fifth quarter-wave plate, and the method further includes: the directional backlight image source generates directional backlight image source light, and the polarization direction of the directional backlight image source light is different from that of the first polarized light; the directional backlight image source light is transmitted to a fifth quarter wave plate through the liquid crystal display, and is converted into second circular polarized light through the fifth quarter wave plate; the second circularly polarized light is converted into third polarized light through the first quarter wave plate, and the third polarized light passes through the windshield to form a virtual image of the first image source light.

With reference to the second aspect, in still other implementations of the second aspect, the imaging unit includes a third image source, a third free-form surface mirror, a mirror, and a glass plate, a seventh quarter-wave plate and a sixth polarizer are attached to a surface of the glass plate near the third image source, and an eighth quarter-wave plate is attached to the mirror, and the method further includes: the third image source generates third image source light, and the polarization direction of the third image source light is the same as that of the first polarized light; the third image source light is reflected to a reflector through a sixth polarizer, converted into second circular polarized light through an eighth quarter-wave plate, reflected to the eighth quarter-wave plate through the reflector, converted into sixth polarized light through the eighth quarter-wave plate and transmitted to a third free-form surface mirror; the sixth polarized light is transmitted to the glass plate through a third free-form surface mirror and is converted into third circular polarized light through a seventh quarter wave plate; the third circularly polarized light is converted into seventh polarized light through the first quarter wave plate, the polarization direction of the seventh polarized light is different from that of the sixth polarized light, and the third polarized light passes through the windshield to form a virtual image of third image source light.

In a third aspect, a vehicle is provided. The vehicle comprises a display device as described in the first aspect and any one of the possible implementations of the first aspect.

With reference to the third aspect, in certain implementations of the third aspect, the display device is mounted in an instrument panel of the vehicle.

With reference to the third aspect, in certain implementations of the third aspect, the vehicle further includes a windshield, and the image light emitted by the display device is incident on the windshield, and the windshield reflects the image light to a human eye.

The foregoing second aspect and the third aspect may refer to the description of the beneficial effects in the first aspect, and are not repeated herein.

Drawings

Fig. 1 is a schematic diagram of the imaging principle of a heads-up display.

FIG. 2 is a schematic diagram of an example of an imaging system for a head-up device

Fig. 3 is a schematic structural diagram of a head-up display device of the present application.

Fig. 4 is a schematic structural diagram of a first display device according to an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a second display device according to an embodiment of the present application.

Fig. 6 is a schematic structural diagram of a third display device according to an embodiment of the present application.

Fig. 7 is a schematic structural diagram of a fourth display device according to an embodiment of the present application.

Fig. 8 is a schematic structural diagram of a fifth display device according to an embodiment of the present application.

Fig. 9 is a flowchart of a first display method according to an embodiment of the present application.

Fig. 10 is a flowchart of a second display method according to an embodiment of the present application.

Fig. 11 is a flowchart of a third display method according to an embodiment of the present application.

Fig. 12 is a flowchart of a fourth display method according to an embodiment of the present application.

Fig. 13 is a schematic circuit diagram of a display device according to an embodiment of the application.

Fig. 14 is a schematic view of a functional framework of a vehicle according to an embodiment of the present application.

Detailed Description

The technical scheme of the application will be described below with reference to the accompanying drawings.

With the continuous development of automobile technology, the requirements on the convenience and safety of automobile use are increasing.

Fig. 1 shows a schematic diagram of an imaging principle of a Head Up Display (HUD) (or referred to as a head-up display system). As shown in fig. 1, the head-up display device 100 includes an image source 110 and a free-form surface mirror 120. The head-up display is a device for projecting instrument information (such as speed), navigation information and the like to the front of the visual field of a driver, the driver can see the instrument information and the navigation information in front of the visual field, and the instrument panel or the central control display screen below the steering wheel does not need to be observed at a low head, so that the braking response time under emergency conditions can be improved, and the driving safety is improved. The HUD device is provided on a vehicle, such as an automobile, a bicycle, a motorcycle, a train, a subway, an airplane, a ship, an aircraft, a robot or other type of vehicle or movable object, etc.

As shown in fig. 2, in an example of application of the HUD device to a vehicle, the HUD device is used to project status information of the vehicle, indication information of external objects, navigation information, and the like, through a windshield of the vehicle, within a field of view of a driver. Status information includes, but is not limited to, travel speed, mileage, fuel amount, water temperature, and lamp status, etc. The indication information of the external object includes, but is not limited to, safe car distance, surrounding obstacle, reversing image and the like. The navigation information includes, but is not limited to, directional arrow, distance, travel time, and the like. The virtual images corresponding to the navigation information and the indication information of the external object can be superimposed on the real environment outside the vehicle, so that the driver can obtain the visual effect of augmented reality, and the virtual images can be used for augmented reality (augmented reality, AR) navigation, adaptive cruising, lane departure early warning and the like. Since the virtual image corresponding to the navigation information can be combined with the real image, the HUD device is generally matched with an advanced driving assistance system (advanced driving assistant system, ADAS) of the automobile. In order not to disturb road conditions, the virtual image corresponding to the instrument information is usually about 2 meters to 3 meters from the human eye. In order to better integrate the virtual image corresponding to the navigation information with the real road surface, the distance between the virtual image corresponding to the navigation information and the human eye is generally about 7 meters to 15 meters. The position of the virtual image of the navigation information is called a far focal plane, and the plane of the virtual image of the instrument information is called a near focal plane.

Fig. 3 is a schematic structural diagram of a head-up display device of the present application. As shown in fig. 3, head-up display device 300 includes image source 210, quarter-wave plate 220, mirror 230, quarter-wave plate 240, reflective polarizer 250, freeform mirror 260, and glass plate 241, wherein quarter-wave plate 240 and reflective polarizer 250 are attached (plated) to glass plate 241. The optical signal emitted from the image source 210 is P light, which is converted into circular polarized light by the quarter wave plate 220, the circular polarized light is reflected by the reflecting mirror 230 and then converted into S light by the quarter wave plate 240, the S light is reflected by the reflecting polarizer 250 to the quarter wave plate 240 and converted into circular polarized light, the circular polarized light is reflected by the free-form surface mirror 260 to the quarter wave plate 220 and converted into P light, and the P light is transmitted to the windshield 270 through the reflecting polarizer 250 to form a virtual image 280, and is transmitted to the human eye 290.

The technology can realize miniaturization of a display system through folding of an optical path. However, in this technique, a glass plate is added below the dust cover, and when sunlight is directly incident, specular reflection light enters eyes, which causes serious glare and causes poor display effect.

Based on the above, the application provides a display device and a display method, which are beneficial to eliminating glare caused by sunlight and improving display effect.

Fig. 4 is a schematic structural diagram of a display device according to an embodiment of the present application. As shown in fig. 4, the apparatus 400 includes a dust cover 310 and an imaging unit 350. The dust cover 310 is attached with a first polarizer 320 and a first quarter wave plate 330, the first polarizer 320 is used for transmitting the first polarized light in the sunlight, and the first quarter wave plate 330 is used for converting the first polarized light into the first circular polarized light. The imaging unit 350 is configured to emit imaging light, and the first circularly polarized light is transmitted to the first quarter wave plate 330 by the imaging unit 350; the first quarter wave plate 330 also serves to convert the first circularly polarized light into second polarized light, which is blocked by the first polarizer 320 so that sunlight cannot exit from the dust cap 310.

In the embodiment of the present application, the first quarter-wave plate is used to convert the first polarized light into circular polarized light, which may be elliptical polarized light or other possible non-circular polarized light when the deviation of the optical axis of the first quarter-wave plate from the first polarizer is not equal to 45 °. Where there is no energy loss from the circular polarization passing through the polarizer, elliptical polarization or other possible non-circular polarization may cause energy loss from the polarizer, for ease of description, circular polarization is used herein to represent this type of light.

In the embodiment of the present application, the second polarized light is blocked by the first polarizer, which may be specifically explained as that the second polarized light is absorbed, eliminated or reflected by the first polarizer, which is not limited by the present application.

As a possible implementation, the dust cover 310 is further attached with a second polarizer, where the first polarizer 320 is used to transmit the first polarized light, reflect the second polarized light, and the second polarizer is used to transmit the first polarized light and absorb the second polarized light. Alternatively, the first polarizer 320 is used to transmit light of a first polarization, absorb light of a second polarization, and the second polarizer is used to transmit light of the first polarization and reflect light of the second polarization. In this way, the second polarized light is reflected and absorbed simultaneously by the additional new polaroid, so that glare caused by sunlight is further reduced, and the display effect is improved. Wherein the polarization direction of the first polarized light is different from the polarization direction of the second polarized light, for example, the first polarized light may be parallel polarized light S light, and the second polarized light may be perpendicular polarized light P light; alternatively, the first polarized light may be vertically polarized light P light and the second polarized light may be parallel polarized light S light.

Fig. 5 is a schematic structural diagram of a second display device according to an embodiment of the present application. As shown in fig. 5, the apparatus 500 illustrates a specific structure of the imaging unit 350 in the apparatus 400, wherein the dust cover 450, the first quarter wave plate 451, and the first polarizer 452 are the same as the dust cover 310, the first quarter wave plate 330, and the first polarizer 320 in the apparatus 300, and will not be described herein. The imaging unit 350 may include a first image source 410, a first free-form surface mirror 420, a second free-form surface mirror 440, and a glass plate 430, where the first image source 410 is attached with a second quarter wave plate 411, the first image source 410 is used to generate first image source light, and the second quarter wave plate 411 is used to convert the first image source light into second circular polarized light; the first freeform mirror 420 is used to transmit the second circularly polarized light to the glass plate 430; the surface of the glass plate 430 near the first image source 410 is attached with a third quarter wave plate 431, a third polarizer 432 and a fourth quarter wave plate 433. The third quarter wave plate 431 is used for converting the second circularly polarized light into third polarized light, the third polarized light is transmitted to the third quarter wave plate 431 by the third polarizer 432, and the third quarter wave plate 431 is also used for converting the third polarized light into third circularly polarized light; the second freeform mirror 440 is used for transmitting the third circularly polarized light to the third quarter wave plate 431; the third quarter waveplate 431 is further configured to convert the third circularly polarized light into fourth polarized light, the third polarizer 432 is further configured to transmit the fourth polarized light to the fourth quarter waveplate 433, the fourth quarter waveplate 433 is further configured to convert the fourth polarized light into fourth circularly polarized light, the first quarter waveplate 451 is further configured to convert the fourth circularly polarized light into fifth polarized light, and the fifth polarized light forms a virtual image of the first image source light through the windshield 460. In this way, the miniaturization of the display device is realized by utilizing the folding of the light path, and the loss caused by polarization is avoided in the whole light path transmission process, so that the display effect is improved.

It should be understood that in this embodiment, the polarization directions of the first polarized light, the third polarized light and the fifth polarized light are the same (e.g., the same as the parallel polarized light S light or the perpendicular polarized light P light), and the polarization directions of the first image source light, the second polarized light and the fourth polarized light are the same (e.g., the same as the perpendicular polarized light P light or the parallel polarized light S light).

In an embodiment of the present application, although not shown, a fourth polarizer may be attached to the glass plate, the fourth polarizer being located between the fourth quarter wave plate 433 and the third polarizer 432. The fourth polarizer is used for transmitting the fourth polarized light and absorbing the third polarized light. In this way, the first polarized light is reflected and absorbed simultaneously by the additional new polaroid, so that glare caused by sunlight is further reduced, and the display effect is improved.

In an embodiment of the present application, although not shown, the surface of the glass plate 430 away from the first image source 410 may be further attached with an anti-reflection plate or a plated anti-reflection film, which is used to reduce the reflectivity of the first circular polarized light generated after the sunlight passes through the dust cover and the first quarter wave plate and the first polarizer. Wherein the anti-reflection waveplate may also be referred to as an anti-reflection waveplate. In this way, the circularly polarized light reflected to the windshield is reduced by additionally adding the anti-reflection wave plate, so that glare caused by sunlight is further reduced, and the display effect is improved.

In an embodiment of the present application, the display device further includes a second image source (such as the image source 412 shown in fig. 6), where the second image source is configured to generate a second image source optical signal, and an imaging distance of the second image source is smaller than an imaging distance of the first image source, or a distance between the second image source and the glass plate is greater than a distance between the first image source and the glass plate. Correspondingly, a sixth quarter wave plate (such as the wave plate 413 shown in fig. 6) may be attached to the second image source. By so doing, the free-form surface mirror can be multiplexed while realizing the bifocal surface imaging, thereby realizing miniaturization of the bifocal surface imaging device.

Fig. 7 is a schematic structural diagram of a fourth display device according to an embodiment of the present application. As shown in fig. 7, the apparatus 700 shows a specific structure of the imaging unit 350 in the apparatus 400, wherein the dust cover 650, the first quarter-wave plate 651, and the first polarizing plate 652 are the same as the dust cover 310, the first quarter-wave plate 330, and the first polarizing plate 320 in the apparatus 300, and will not be described herein.

The imaging unit 350 includes a liquid crystal display 620 and an orientation backlight image source 610, wherein a fifth polarizer 621 and a fifth quarter wave plate 622 are attached to an upper surface of the liquid crystal display 620, i.e. a surface of a side near the dust cover 650, and the orientation backlight image source 610 is used for generating orientation backlight image source light; the liquid crystal display 620 is configured to transmit the directional backlight image source light to the fifth quarter waveplate 622; the fifth quarter waveplate 622 is used to convert the directional backlight image source light into a second circularly polarized light; the first quarter waveplate 651 also serves to convert the second circularly polarized light to third polarized light, which passes through the windshield 660 to form a virtual image of the directional backlight source light. In this way, the whole light path does not need to adopt a curved mirror, the device is small in size, and the problem of sunlight backflow caused by condensation of the curved mirror does not exist, so that the display effect is improved.

It should be understood that in the embodiment of the present application, the polarization directions of the directional backlight image source light and the second polarized light are the same (for example, the same vertical polarized light P light or the same parallel polarized light S light), and the polarization directions of the first polarized light and the third polarized light are the same (for example, the same parallel polarized light S light or the same vertical polarized light P light).

In an embodiment of the present application, although not shown, a sixth polarizer may be attached to the liquid crystal display 620, the fifth polarizer 621 is used to transmit the third polarized light, reflect the second polarized light, and the sixth polarizer is used to transmit the third polarized light and absorb the second polarized light; alternatively, the fifth polarizing plate 621 is configured to transmit light of the third polarization, absorb light of the second polarization, and the sixth polarizing plate is configured to transmit light of the third polarization and reflect light of the second polarization. In this way, the second polarized light is reflected and absorbed simultaneously by the additional new polaroid, so that glare caused by sunlight is further reduced, and the display effect is improved.

Optionally, an anti-reflection plate or an anti-reflection film is attached to a surface of the side of the liquid crystal display 620, which is close to the dust cover 650, and the anti-reflection plate (anti-reflection film) is used for reducing the reflectivity of the first circular polarized light generated after the sunlight passes through the dust cover, the first quarter wave plate and the first polarizer. Wherein the anti-reflection waveplate may also be referred to as an anti-reflection waveplate. In this way, the circularly polarized light reflected to the windshield is reduced by additionally adding the anti-reflection wave plate, so that glare caused by sunlight is further reduced, and the display effect is improved.

Fig. 8 is a schematic structural diagram of a fifth display device according to an embodiment of the present application. As shown in fig. 8, the apparatus 800 illustrates a specific structure of the imaging unit 350 in the apparatus 400, wherein the dust cover 450, the first quarter wave plate 451, and the first polarizer 452 are the same as the dust cover 310, the first quarter wave plate 330, and the first polarizer 320 in the apparatus 300, and will not be described herein. The imaging unit 350 may include a third image source 414, a third free-form surface mirror 441, a mirror 421, and a glass plate 430. The third image source 414 is configured to generate third image source light, which may be the same type of light as the first polarized light; a seventh quarter wave plate 434 and a sixth polarizer 435 are attached to the surface of the glass plate 430 near the third image source 414, the sixth polarizer 435 is used for transmitting the third image source light to an eighth quarter wave plate 422 attached to the mirror 421, and the eighth quarter wave plate 422 is used for converting the third image source light into a second circular polarized light; the mirror 421 emits the second circularly polarized light to the eighth quarter wave plate 422, and the eighth quarter wave plate 422 also serves to convert the second circularly polarized light into sixth polarized light. The third curved mirror 441 is configured to transmit the sixth polarized light to the seventh quarter wave plate 434, the seventh quarter wave plate 434 is configured to convert the sixth polarized light into the second circular polarized light, and the first quarter wave plate 451 is further configured to convert the second circular polarized light into the seventh polarized light, and the seventh polarized light forms a virtual image of the third image source light through the windshield 460. In this way, the miniaturization of the display device is realized by utilizing the folding of the light path, and the loss caused by polarization is avoided in the whole light path transmission process, so that the display effect is improved.

The third freeform surface is attached with a seventh polarizer 442, and the seventh polarizer 442 is used for transmitting the seventh polarized light and reflecting the sixth polarized light.

In the embodiment of the present application, the third image source light may be transmitted to the sixth polarizer 435 through the third freeform mirror 441 and the seventh polarizer 442, for example, the third freeform mirror 441 may be a lens, and may transmit the third image source light, or the third freeform mirror 441 may have an opening that allows the third image source light to pass through, which is not limited by the present application.

In the present embodiment, the polarization directions of the third image source light, the first polarized light, and the seventh polarized light are the same (for example, the same as the perpendicular polarized light P light or the parallel polarized light S light), and the polarization directions of the second polarized light and the sixth polarized light are the same (for example, the same as the parallel polarized light S light or the parallel polarized light S light).

In an embodiment of the present application, although not shown, the surface of the glass plate 430 away from the third image source 414 may be further attached or coated with an anti-reflection plate (anti-reflection film) for reducing the reflectivity of the first circular polarized light generated after the sunlight passes through the dust cover and the first quarter wave plate and the first polarizer. Among them, the antireflection plate (antireflection film) may also be referred to as an antireflection plate. In this way, the circularly polarized light reflected to the windshield is reduced by additionally adding the anti-reflection wave plate, so that glare caused by sunlight is further reduced, and the display effect is improved.

Fig. 9 is a schematic flow chart of a first display method according to an embodiment of the present application. The method is performed by any of the apparatus 400 to the apparatus 800 described above.

S910, the first polarized light of the sunlight is transmitted to the first quarter wave plate through the first polarizer.

S920, the first polarized light is converted into first circular polarized light through the first quarter wave plate.

S930, the first circularly polarized light is transmitted to the first quarter wave plate through the imaging unit.

S940, the first circularly polarized light is converted into second polarized light through the first quarter wave plate, and the second polarized light is blocked by the first polaroid, so that sunlight cannot exit from the dust cover.

Wherein the polarization direction of the second polarized light is different from the polarization direction of the first polarized light, the second polarized light is blocked by the first polarizer, comprising: the second polarized light is reflected by the first polarizer; alternatively, the second polarized light is absorbed by the first polarizer.

According to the method disclosed by the application, the plurality of wave plates are additionally arranged on the surface of the dust cover, so that sunlight cannot exit through the dust cover again after entering the imaging unit through the dust cover, glare caused by the sunlight is eliminated, and the display effect is improved.

Fig. 10 is a schematic flow chart of a second display method according to an embodiment of the present application. The method is performed by either of the apparatus 500 or the apparatus 600 described above.

S1010, the first image source generates first image source light.

Wherein the polarization direction of the first image source light is different from the polarization direction of the first polarized light shown in the above method 900.

S1020, the first image source light is converted into second circularly polarized light through the second quarter wave plate.

S1030, the second circular polarized light is transmitted to the glass plate through the first free-form surface mirror, and the second circular polarized light is converted into third polarized light through the third quarter wave plate.

S1040, the third polarized light is transmitted to the third quarter wave plate through the third polaroid, and is converted into third circular polarized light through the third quarter wave plate.

S1050, the third circular polarized light is transmitted to the third quarter wave plate through the second free-form surface mirror, and is converted into fourth polarized light through the third quarter wave plate.

S1060, the fourth polarized light is transmitted to the fourth quarter wave plate through the third polaroid, the fourth polarized light is converted into fourth circular polarized light through the fourth quarter wave plate, the fourth circular polarized light is converted into fifth polarized light through the first quarter wave plate, and the fifth polarized light forms a virtual image of the first image source light through the windshield.

According to the display method disclosed by the application, the plurality of wave plates are newly added on the surface of the dust cover, so that sunlight cannot exit through the dust cover again after entering the imaging unit through the dust cover, glare caused by the sunlight is eliminated, miniaturization of the display device is realized by utilizing light path folding, loss caused by polarization is avoided in the whole light path transmission process, and the display effect is improved.

Fig. 11 is a schematic flow chart of a third display method according to an embodiment of the present application. The method is performed by the apparatus 700 described above.

S1110, the directional backlight image source generates directional backlight image source light.

Wherein the polarization direction of the directional backlight image source light is different from the polarization direction of the first polarized light shown in the above-described method 900.

S1120, the directional backlight image source light is transmitted to a fifth quarter wave plate through the liquid crystal display, and is converted into second circular polarized light through the fifth quarter wave plate.

S1130, the second circularly polarized light is converted into third polarized light by the first quarter wave plate, and the third polarized light forms a virtual image of the first image source light through the windshield.

According to the display method disclosed by the application, the plurality of wave plates are newly added on the surface of the dust cover, so that sunlight cannot exit through the dust cover again after entering the imaging unit through the dust cover, glare caused by the sunlight can be eliminated, a curved mirror is not required to be adopted in the whole light path, the device is small in size, the problem of sunlight backflow caused by condensation of the curved mirror is solved, and the display effect can be improved.

Fig. 12 is a flowchart illustrating a fourth display method according to an embodiment of the present application. The method is performed by the apparatus 800 described above.

S1210, the third image source generates third image source light.

Wherein the polarization direction of the third image source light is the same as the polarization direction of the first polarized light shown in the above method 900.

S1220, the third image source light is reflected by the sixth polarizer to the eighth quarter wave plate attached to the surface of the reflector to be converted into second circular polarized light, and the second circular polarized light is reflected by the reflector to the eighth quarter wave plate to be converted into sixth polarized light and transmitted to the third curved mirror.

And S1230, transmitting the sixth polarized light to the glass plate through the third curved mirror, and converting the sixth polarized light into third circular polarized light through a seventh quarter wave plate on the surface of the glass plate.

S1240, the third circularly polarized light is converted into seventh polarized light by the first quarter wave plate, and the seventh polarized light forms a virtual image of the first image source light through the windshield.

Fig. 13 is a schematic circuit diagram of a display device according to an embodiment of the present application. As shown in fig. 13, the circuits in the display device mainly include a main processor (host CPU) 3101, an external memory interface 3102, an internal memory 3103, an audio module 3104, a video module 3105, a power module 3106, a wireless communication module 3107, an i/O interface 3108, a video interface 3109, a display circuit 3110, a modulator 3111, and the like. The main processor 3101 and its peripheral components such as an external memory interface 3102, an internal memory 3103, an audio module 3104, a video module 3105, a power module 3106, a wireless communication module 3107, an i/O interface 3108, a video interface 3109, and a display circuit 3110 may be connected via a bus. The main processor 3101 may be referred to as a front-end processor.

In addition, the circuit diagram illustrated in the embodiment of the present application does not constitute a specific limitation of the display device. In other embodiments of the application, the display device may include more or less components than shown, or certain components may be combined, or certain components may be split, or different arrangements of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

The main processor 3101 includes one or more processing units, for example: the main processor 3101 may include an application processor (Application Processor, AP), a modem processor, a graphics processor (Graphics Processing Unit, GPU), an image signal processor (Image Signal Processor, ISP), a controller, a video codec, a digital signal processor (Digital Signal Processor, DSP), a baseband processor, and/or a Neural network processor (Neural-Network Processing Unit, NPU), etc. Wherein the different processing units may be separate devices or may be integrated in one or more processors.

A memory may also be provided in the main processor 3101 for storing instructions and data. In some embodiments, the memory in the main processor 3101 is a cache memory. The memory may hold instructions or data that the main processor 3101 has just used or recycled. If the main processor 3101 needs to reuse the instruction or data, it may be called directly from the memory. Repeated accesses are avoided, reducing the latency of the main processor 3101, and thus improving the efficiency of the system.

In some embodiments, the display device may also include a plurality of Input/Output (I/O) interfaces 3108 connected to the main processor 3101. The interface 3108 may include an integrated circuit (Inter-Integrated Circuit, I2C) interface, an integrated circuit built-in audio (Inter-Integrated Circuit Sound, I2S) interface, a pulse code modulation (Pulse Code Modulation, PCM) interface, a universal asynchronous receiver Transmitter (Universal Asynchronous Receiver/Transmitter, UART) interface, a mobile industry processor interface (Mobile Industry Processor Interface, MIPI), a General-Purpose Input/Output (GPIO) interface, a subscriber identity module (Subscriber Identity Module, SIM) interface, and/or a universal serial bus (Universal Serial Bus, USB) interface, a controller area network (Controller Area Network, CAN) interface, and the like. The I/O interface 3108 may be connected to a device such as a mouse, a touch pad, a keyboard, a camera, a speaker/horn, or a microphone, or may be connected to a physical key (e.g., a volume key, a brightness adjustment key, or an on/off key) on the display device.

The external memory interface 3102 may be used to connect an external memory card, such as a Micro SD card, to realize expansion of the memory capability of the display device. The external memory card communicates with the main processor 3101 through an external memory interface 3102, implementing a data storage function.

The internal memory 3103 may be used to store computer executable program code comprising instructions. The internal memory 3103 may include a storage program area and a storage data area. The storage program area may store an operating system, an application program (such as a call function, a time setting function, etc.) required for at least one function, and the like. The storage data area may store data created during use of the display device (e.g., phone book, universal time, etc.), etc. In addition, the internal memory 3103 may include a high-speed random access memory, and may also include a nonvolatile memory such as at least one magnetic disk storage device, a flash memory device, a universal flash memory (Universal Flash Storage, UFS), or the like. The main processor 3101 executes various functional applications of the display device and data processing by executing instructions stored in the internal memory 3103, and/or instructions stored in a memory provided in the main processor 3101.

The display device can implement audio functions through an audio module 3104, an application processor, and the like. Such as music playing, talking, etc.

The audio module 3104 is used to convert digital audio information into an analog audio signal output, and also to convert an analog audio input into a digital audio signal. The audio module 3104 may also be used to encode and decode audio signals, such as for playback or recording. In some embodiments, the audio module 3104 may be provided in the main processor 3101, or some functional modules of the audio module 3104 may be provided in the main processor 3101.

The video interface 3109 may receive externally input audio and video signals, which may specifically be a high-definition multimedia interface (High Definition Multimedia Interface, HDMI), a digital video interface (Digital Visual Interface, DVI), a video graphics array (Video Graphics Array, VGA), a Display Port (DP), etc., and the video interface 3109 may also output video. When the display device is used as a head-up display, the video interface 3109 may receive a speed signal and an electric quantity signal input by a peripheral device, and may also receive an AR video signal input from the outside. When the display device is used as a projector, the video interface 3109 can receive a video signal input from an external computer or a terminal device.

The video module 3105 may decode video input by the video interface 3109, for example, h.264 decoding. The video module can also encode the video collected by the display device, for example, H.264 encoding is carried out on the video collected by the external camera. The main processor 3101 may decode the video input from the video interface 3109, and output the decoded image signal to the display circuit 3110.

The display circuit 3110 and the modulator 3111 are for displaying corresponding images. In this embodiment, the video interface 3109 receives an externally input video source signal, the video module 3105 decodes and/or digitizes the video source signal, and outputs one or more image signals to the display circuit 3110, and the display circuit 3110 drives the modulator 3111 to image the incident polarized light according to the input image signal, so as to output at least two imaging lights. Further, the main processor 3101 may output one or more image signals to the display circuit 3110.

In this embodiment, the display circuit 3110 and the modulator 3111 may be electronic components in a modulation unit, and the display circuit 3110 may be referred to as a driving circuit.

The power module 3106 is configured to provide power to the main processor 3101 and the light source 3100 according to input power (e.g., direct current), and a rechargeable battery may be included in the power module 3106, and the rechargeable battery may provide power to the main processor 3101 and the light source 3100. Light from light source 3100 may be transmitted to modulator 3111 for imaging to form an image light signal.

The wireless communication module 3107 may enable the display device to communicate wirelessly with the outside world, which may provide solutions for wireless communication such as wireless local area network (Wireless Local Area Networks, WLAN) (e.g., wireless fidelity (Wireless Fidelity, wi-Fi) network), bluetooth (BT), global navigation satellite system (Global Navigation Satellite System, GNSS), frequency modulation (Frequency Modulation, FM), near field wireless communication technology (Near Field Communication, NFC), infrared technology (IR), etc. The wireless communication module 3107 may be one or more devices integrating at least one communication processing module. The wireless communication module 3107 receives electromagnetic waves via an antenna, modulates the electromagnetic wave signals, filters the electromagnetic wave signals, and transmits the processed signals to the main processor 3101. The wireless communication module 3107 may also receive a signal to be transmitted from the main processor 3101, frequency-modulate it, amplify it, and convert it into electromagnetic waves to radiate.

In addition, the video data decoded by the video module 3105 may be received wirelessly by the wireless communication module 3107 or read from an external memory, for example, the display device may receive video data from a terminal device or an in-vehicle entertainment system via a wireless lan in the vehicle, and the display device may read audio/video data stored in the external memory, in addition to the video data input via the video interface 3109.

The display device may be mounted on a vehicle, and referring to fig. 14, fig. 14 is a schematic view of a possible functional frame of a vehicle according to an embodiment of the present application.

As shown in FIG. 14, various subsystems may be included in the functional framework of the vehicle, such as a sensor system 12, a control system 14, one or more peripheral devices 16 (one shown in the illustration), a power supply 18, a computer system 20, and a display system 22, as shown. Alternatively, the vehicle may include other functional systems, such as an engine system to power the vehicle, etc., as the application is not limited herein.

The sensor system 12 may include a plurality of sensing devices that sense the measured information and convert the sensed information to an electrical signal or other desired form of information output according to a certain rule. As shown, these detection devices may include, but are not limited to, a global positioning system (global positioning system, GPS), a vehicle speed sensor, an inertial measurement unit (inertial measurement unit, IMU), a radar unit, a laser rangefinder, an imaging device, a wheel speed sensor, a steering sensor, a gear sensor, or other elements for automatic detection, and so forth.

The control system 14 may include several elements such as a steering unit, a braking unit, a lighting system, an autopilot system, a map navigation system, a network timing system, and an obstacle avoidance system as shown. Optionally, control system 14 may also include elements such as throttle controls and engine controls for controlling the speed of travel of the vehicle, as the application is not limited.

Peripheral device 16 may include several elements such as the communication system in the illustration, a touch screen, a user interface, a microphone, and a speaker, among others. Wherein the communication system is used for realizing network communication between the vehicle and other devices except the vehicle. In practical applications, the communication system may employ wireless communication technology or wired communication technology to enable network communication between the vehicle and other devices. The wired communication technology may refer to communication between the vehicle and other devices through a network cable or an optical fiber, etc.

The power source 18 represents a system that provides power or energy to the vehicle, which may include, but is not limited to, a rechargeable lithium battery or lead acid battery, or the like. In practical applications, one or more battery packs in the power supply are used to provide electrical energy or power for vehicle start-up, the type and materials of the power supply are not limiting of the application.

Several functions of the vehicle are performed by the control of the computer system 20. The computer system 20 may include one or more processors 2001 (shown as one processor) and memory 2002 (which may also be referred to as storage devices). In practical applications, the memory 2002 is also internal to the computer system 20, or external to the computer system 20, for example, as a cache in a vehicle, and the application is not limited thereto. Wherein,

the processor 2001 may include one or more general-purpose processors, such as a graphics processor (graphic processing unit, GPU). The processor 2001 may be used to execute related programs or instructions corresponding to the programs stored in the memory 2002 to implement the corresponding functions of the vehicle.

Memory 2002 may include volatile memory (RAM), such as RAM; the memory may also include a non-volatile memory (non-volatile memory), such as ROM, flash memory (flash memory), HDD, or solid state disk SSD; memory 2002 may also include combinations of the above types of memory. Memory 2002 may be used to store a set of program codes or instructions corresponding to the program codes so that processor 2001 invokes the program codes or instructions stored in memory 2002 to implement the corresponding functions of the vehicle. In the present application, the memory 2002 may store a set of program codes for vehicle control, and the processor 2001 may call the program codes to control the safe running of the vehicle, and how the safe running of the vehicle is achieved will be described in detail below.

Alternatively, the memory 2002 may store information such as road maps, driving routes, sensor data, and the like, in addition to program codes or instructions. The computer system 20 may implement the relevant functions of the vehicle in combination with other elements in the functional framework schematic of the vehicle, such as sensors in the sensor system, GPS, etc. For example, the computer system 20 may control the direction of travel or speed of travel of the vehicle, etc., based on data input from the sensor system 12, and the application is not limited.

The display system 22 may display image information, such as navigation information, play video, and the like. The specific structure of the display system 22 refers to the embodiment of the display device described above, and will not be described herein.

Wherein FIG. 14 illustrates the present application as including four subsystems, sensor system 12, control system 14, computer system 20, and display system 22 are exemplary only, and not limiting. In practical applications, the vehicle may combine several elements in the vehicle according to different functions, thereby obtaining subsystems with corresponding different functions. In practice, the vehicle may include more or fewer systems or elements, and the application is not limited.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A display device comprising a dust cover and an imaging unit, wherein:

the dustproof cover is stuck with a first polaroid and a first quarter wave plate, the first polaroid is used for transmitting first polarized light in sunlight, and the first quarter wave plate is used for converting the first polarized light into first circular polarized light;

the imaging unit is used for emitting imaging light, and the first circularly polarized light is transmitted to the first quarter wave plate by the imaging unit;

the first quarter wave plate is further used for converting the first circularly polarized light into second polarized light, the polarization direction of the second polarized light is different from that of the first polarized light, and the second polarized light is blocked by the first polarizing plate, so that sunlight cannot exit from the dust cover.

2. The display device of claim 1, wherein the dust cap is further attached with a second polarizer,

the first polaroid is used for transmitting the first polarized light and reflecting the second polarized light, and the second polaroid is used for transmitting the first polarized light and absorbing the second polarized light; or,

the first polaroid is used for transmitting the first polarized light and absorbing the second polarized light, and the second polaroid is used for transmitting the first polarized light and reflecting the second polarized light.

3. The display device according to claim 1 or 2, wherein the imaging unit comprises a first image source, a first free-form surface mirror, a second free-form surface mirror, and a glass plate,

a second quarter wave plate is attached to the first image source, the first image source is used for generating first image source light, the polarization direction of the first image source light is different from that of the first polarized light, and the second quarter wave plate is used for converting the first image source light into second circular polarized light;

the first freeform mirror is used for transmitting the second circularly polarized light to the glass plate;

a third quarter wave plate, a third polaroid and a fourth quarter wave plate are attached to the surface, close to the first image source, of the glass plate, the third quarter wave plate is used for converting the second circular polarized light into third polarized light, the third polarized light is transmitted to the third quarter wave plate by the third polaroid, and the third quarter wave plate is also used for converting the third polarized light into third circular polarized light;

the second freeform mirror is used for transmitting the third circularly polarized light to the third quarter-wave plate;

The third quarter wave plate is further used for converting the third circularly polarized light into fourth polarized light, the polarization direction of the fourth polarized light is different from that of the third polarized light, the third polarizing plate is further used for transmitting the fourth polarized light to the fourth quarter wave plate, the fourth quarter wave plate is further used for converting the fourth polarized light into fourth circularly polarized light, the first quarter wave plate is further used for converting the fourth circularly polarized light into fifth polarized light, the polarization direction of the fifth polarized light is different from that of the fourth polarized light, and the fifth polarized light forms a virtual image of the first image source light through a windshield.

4. A display device according to claim 3, wherein a fourth polarizer is further attached to the glass plate, the fourth polarizer being located between the fourth quarter wave plate and the third polarizer, the fourth polarizer being configured to transmit the fourth polarized light and absorb the third polarized light.

5. The display device according to claim 3 or 4, wherein a surface of the glass plate away from the first image source is attached with an anti-reflection wave plate, and the anti-reflection wave plate is used for reducing the reflectivity of the first circular polarized light.

6. The display device according to any one of claims 3 to 5, further comprising a second image source for generating second image source light having a polarization direction different from a polarization direction of the first polarized light, an imaging distance of the second image source being smaller than an imaging distance of the first image source.

7. The display device of any one of claims 3 to 5, further comprising a second image source for generating a second image source light signal, the second image source being a greater distance from the glass sheet than the first image source.

8. The display device according to claim 1 or 2, wherein the imaging unit comprises a liquid crystal display and a directional backlight, a fifth polarizer and a fifth quarter-wave plate are attached to a surface of one side of the liquid crystal display, which is close to the dust cover,

the directional backlight image source is used for generating directional backlight image source light, and the polarization direction of the directional backlight image source light is different from that of the first polarized light;

the liquid crystal display is used for transmitting the directional backlight image source light to the fifth quarter wave plate;

The fifth quarter wave plate is used for converting the directional backlight image source light into second circularly polarized light;

the first quarter wave plate is further used for converting the second circularly polarized light into third polarized light, the polarization direction of the third polarized light is different from that of the second polarized light, and the third polarized light forms a virtual image of the directional backlight image source light through a windshield.

9. The display device of claim 8, wherein a sixth polarizer is further attached to the liquid crystal display,

the fifth polaroid is used for transmitting the third polarized light and reflecting the second polarized light, and the sixth polaroid is used for transmitting the third polarized light and absorbing the second polarized light; or,

the fifth polaroid is used for transmitting the first polarized light and absorbing the second polarized light, and the sixth polaroid is used for transmitting the third polarized light and reflecting the second polarized light.

10. The display device according to claim 8 or 9, wherein an anti-reflection wave plate is attached to a surface of the side, close to the dust cover, of the liquid crystal display, and the anti-reflection wave plate is used for reducing reflectivity of the first circular polarized light.

11. The display device according to claim 1 or 2, wherein the imaging unit comprises a third image source, a third free-form surface mirror, a reflecting mirror, and a glass plate,

the third image source is used for generating third image source light, and the polarization direction of the third image source light is the same as that of the first polarized light;

a seventh quarter wave plate and a sixth polaroid are attached to the surface of the glass plate, which is close to the third image source, and the sixth polaroid is used for transmitting the third image source light to the reflecting mirror;

the reflection mirror is stuck with an eighth quarter wave plate, the eighth quarter wave plate is used for converting the third image source light into second circular polarized light, the reflection mirror is used for transmitting the second circular polarized light to the eighth quarter wave plate, and the eighth quarter wave plate is also used for converting the second circular polarized light into sixth polarized light;

the third curved mirror is configured to transmit the sixth polarized light to the seventh quarter wave plate, the seventh quarter wave plate is configured to convert the sixth polarized light into a third circularly polarized light,

the first quarter wave plate is further configured to convert the third circularly polarized light into seventh polarized light, where a polarization direction of the seventh polarized light is different from a polarization direction of the sixth polarized light, and the seventh polarized light forms a virtual image of the third image source light through a windshield.

12. The display device according to claim 11, wherein a seventh polarizing plate is attached to the third curved mirror, and the seventh polarizing plate is configured to transmit the seventh polarized light and reflect the sixth polarized light.

13. A display method performed by a display device including a dust cover on which a first polarizing plate for transmitting first polarized light in sunlight and blocking second polarized light of the sunlight is attached, and an imaging unit for emitting imaging light, the method comprising:

the first polarized light of the sunlight is transmitted to a first quarter wave plate through the first polaroid;

the first polarized light is converted into first circularly polarized light through the first quarter wave plate;

the first circularly polarized light is transmitted to the first quarter wave plate through the imaging unit;

the first circularly polarized light is converted into second polarized light through the first quarter wave plate, the polarization direction of the second polarized light is different from that of the first polarized light, and the second polarized light is blocked by the first polaroid, so that sunlight cannot exit from the dust cover.

14. The method of claim 13, wherein the second polarized light is blocked by the first polarizer, comprising:

the second polarized light is reflected by the first polarizer; or,

the second polarized light is absorbed by the first polarizer.

15. The method of claim 13 or 14, wherein the imaging unit comprises a first image source, a first free-form surface mirror, a second free-form surface mirror, and a glass plate, the first image source having a second quarter-wave plate affixed thereto, and the glass plate having a third quarter-wave plate, a third polarizer, and a fourth quarter-wave plate affixed to a surface of the glass plate proximate the first image source, the method further comprising:

the first image source generates first image source light, and the polarization direction of the first image source light is different from that of the first polarized light;

the first image source light is converted into second circularly polarized light through the second quarter wave plate;

the second circular polarized light is transmitted to the glass plate through the first free-form surface mirror, and the second circular polarized light is converted into third polarized light through the third quarter wave plate;

the third polarized light is transmitted to the third quarter wave plate through the third polaroid and is converted into third circularly polarized light through the third quarter wave plate;

The third circularly polarized light is transmitted to the third quarter wave plate through the second freeform mirror, and is converted into fourth polarized light through the third quarter wave plate, wherein the polarization direction of the fourth polarized light is different from that of the third polarized light;

the fourth polarized light is transmitted to the fourth quarter wave plate through the third polarizing plate, the fourth polarized light is converted into fourth circular polarized light through the fourth quarter wave plate, the fourth circular polarized light is converted into fifth polarized light through the first quarter wave plate, the polarization direction of the fifth polarized light is different from that of the fourth polarized light, and the fifth polarized light forms a virtual image of the first image source light through a windshield.

16. The method of claim 13 or 14, wherein the imaging unit comprises a liquid crystal display and a directional backlight, a fifth polarizer and a fifth quarter-wave plate are attached to a side surface of the liquid crystal display adjacent to the dust cap, the method further comprising:

the directional backlight image source generates directional backlight image source light, and the polarization direction of the directional backlight image source light is different from that of the first polarized light;

The directional backlight image source light is transmitted to the fifth quarter wave plate through the liquid crystal display and is converted into second circular polarized light through the fifth quarter wave plate;

the second circularly polarized light is converted into third polarized light through the first quarter wave plate, the polarization direction of the third polarized light is different from that of the second polarized light, and the third polarized light forms a virtual image of the directional backlight image source light through a windshield.

17. The method of claim 13 or 14, wherein the imaging unit comprises a third image source, a third free-form surface mirror, a mirror, and a glass plate, the glass plate having a seventh quarter-wave plate and a sixth polarizer attached to a surface proximate the third image source, and an eighth quarter-wave plate attached to the mirror, the method further comprising:

the third image source generates third image source light, and the polarization direction of the third image source light is the same as that of the first polarized light;

the third image source light is reflected to the eighth quarter wave plate through the sixth polaroid, converted to second circular polarized light through the eighth quarter wave plate, reflected to the eighth quarter wave plate through the reflector, converted to sixth polarized light through the eighth quarter wave plate and transmitted to the third free-form surface mirror;

The sixth polarized light is transmitted to the glass plate through the third free-form surface mirror and is converted into third circularly polarized light through the seventh quarter wave plate;

the sixth circularly polarized light is converted into seventh polarized light through the first quarter wave plate, the polarization direction of the seventh polarized light is different from that of the sixth polarized light, and the third polarized light forms a virtual image of the third image source light through a windshield.

18. A vehicle, characterized in that the vehicle comprises a display device according to any one of claims 1 to 12.

19. The vehicle of claim 18, wherein the display device is mounted in an instrument panel of the vehicle.

20. The vehicle according to claim 18 or 19, further comprising a windshield, the image light emitted by the display device being incident on the windshield, the windshield reflecting the image light to a human eye.