WO2024032059A1

WO2024032059A1 - Projection apparatus, display device, vehicle and projection method

Info

Publication number: WO2024032059A1
Application number: PCT/CN2023/093035
Authority: WO
Inventors: 徐立国; 毛磊
Original assignee: 华为技术有限公司
Priority date: 2022-08-11
Filing date: 2023-05-09
Publication date: 2024-02-15
Also published as: CN117631418A

Abstract

Provided in the embodiments of the present application are a projection apparatus, a display device, a vehicle and a projection method, which can be mainly applied to a virtual image display scenario. The projection apparatus comprises an image source, a curved reflection unit and an optical element, wherein the image source is used for outputting imaging light; the curved reflection unit is used for reflecting the imaging light from the image source to the optical element; the optical element is used for reflecting the imaging light from the curved reflection unit to the curved reflection unit; the curved reflection unit is further used for reflecting the imaging light from the optical element to the optical element; the optical element is further used for transmitting the imaging light from the curved reflection unit; and a light reflection direction of the imaging light from the image source at a first reflection position on the curved reflection unit deflects in a first direction relative to a normal at the first reflection position, a light reflection direction of the imaging light from the optical element at a second reflection position on the curved reflection unit deflects in a second direction relative to a normal at the second reflection position, and the first direction is opposite to the second direction.

Description

Projection device, display equipment, vehicle and projection method

This application claims the priority of the Chinese patent application submitted to the State Intellectual Property Office of China on August 11, 2022, with application number 202210966863.9 and the application title "A projection device, display equipment, vehicle and projection method", all of which The contents are incorporated into this application by reference.

Technical field

The present application relates to the field of light display, and in particular, to a projection device, a display device, a vehicle and a projection method.

Background technique

Since virtual image display technology can achieve a large field of view and large-format visual experience in a smaller space, it is currently being widely used in various new display terminal devices. For example, vehicle head-up display (HUD), enhanced display (Augmented Reality, AR) equipment, virtual display (Virtual Reality, VR) equipment, desktop virtual imaging systems and other similar principles or forms of equipment.

For virtual image display systems, the aberrations of the system are crucial to the viewer's experience. For example, in a car HUD system, because the human eye needs to switch back and forth between the virtual image and the environment outside the car, small aberrations are very helpful in reducing the adjustment of the human eye muscles. Another example is the desktop virtual imaging system. Small aberrations make it easier for the human eye to see text clearly, and at the same time, it is less likely to cause dizziness when watching movies. In current virtual image display systems, curved reflectors are usually used to amplify the image. However, certain aberrations will occur during the image amplification process, which affects the viewer's experience.

Contents of the invention

Embodiments of the present application provide a projection device, a display device, a vehicle, and a projection method, which achieve smaller aberration and improve the viewer's experience.

In a first aspect, embodiments of the present application provide a projection device. The projection device includes: an image source, a curved surface reflection unit and optical elements. Specifically, the image source is used to output imaging light. The curved surface reflection unit is used to reflect the imaging light from the image source to the optical element. The optical element is used to reflect the imaging light from the curved surface reflection unit to the curved surface reflection unit. The curved surface reflection unit is also used to reflect the imaging light from the optical element to the optical element. The optical element is also used to transmit imaging light from the curved reflective unit. Wherein, the imaging light from the image source is deflected in the first direction by the light reflection direction of the first reflection position on the curved surface reflection unit relative to the normal line of the first reflection position, and the imaging light from the optical element is secondly reflected on the curved surface reflection unit The light reflection direction of the position is deflected to the second direction relative to the normal line of the second reflection position, and the first direction is opposite to the second direction.

In this embodiment, the curved surface reflection unit reflects the imaging light twice, wherein the first reflection light reflection direction is deflected in the first direction relative to the normal line of the first reflection position, and the second reflection light reflection direction is opposite to the normal line of the first reflection position. The normal line at the second reflection position is deflected toward the second direction, and the first direction is opposite to the second direction. In other words, this solution can make the two reflection directions of the curved surface reflection unit compensate each other, thereby compensating for the aberration generated by the imaging light passing through the curved surface reflection unit, achieving smaller aberration and improving the viewer's experience. Moreover, the folding light path design is adopted, which helps to improve the compactness of the projection device.

In some possible implementations, the curved reflection unit includes a first curved mirror and a second curved mirror. The first curved mirror is used to reflect the imaging light from the image source to the optical element. The optical element is used to reflect the imaging light from the first curved mirror to Second curved mirror. The second curved mirror is used to reflect the imaging light from the optical element to the optical element. The optical element is also used to transmit imaging light from the second curved mirror. In this embodiment, the curved surface reflection unit can use two independent curved surface mirrors, and the two reflections of the curved surface reflection unit are respectively realized by two curved surface mirrors, making the optical path design of this solution more flexible.

In some possible implementations, the first direction is clockwise and the second direction is counterclockwise, or the first direction is counterclockwise and the second direction is clockwise. In this embodiment, different optical path designs can be realized by adjusting the relative positional relationship of each part of the projection device, which improves the scalability of the solution.

In some possible implementations, the projection device further includes a polarization conversion element. The imaging light output by the image source has a polarization state. The projection device also includes a polarization conversion element. The polarization conversion element is used to convert the polarization state of the input imaging light. The optical element Used to reflect the imaging light in one polarization state and transmit the imaging light in the other polarization state. In this embodiment, the optical element can be reflective or transmissive depending on the polarization state of the incident imaging light. Therefore, arranging the polarization conversion element at an appropriate position can make the polarization states of the imaging light incident twice on the optical element different. In this way, the imaging light incident on the optical element for the first time can be fully reflected back to the curved surface reflection unit, and the imaging light incident on the optical element for the second time can be fully transmitted to the human eye, avoiding the loss of imaging light.

In some possible implementations, the imaging light output by the image source has a first polarization state. The polarization conversion element is used to convert the imaging light with the first polarization state from the image source into the imaging light with the second polarization state. The imaging light with the second polarization state is reflected by the curved surface reflection unit to the polarization conversion element. The polarization conversion element is used to convert the imaging light with the second polarization state from the curved surface reflection unit into the imaging light with the third polarization state. The imaging light with the third polarization state is reflected by the optical element to the polarization conversion element. The polarization conversion element is used to convert the imaging light with the third polarization state from the optical element into the imaging light with the fourth polarization state. The imaging light with the fourth polarization state is reflected by the curved surface reflection unit to the polarization conversion element. The polarization conversion element is used to convert the imaging light with the fourth polarization state from the curved surface reflection unit into the imaging light with the first polarization state, and the imaging light with the first polarization state is transmitted by the optical element.

In some possible implementations, the imaging light output by the image source has a second polarization state, and the imaging light with the second polarization state is reflected by the curved surface reflection unit to the polarization conversion element. The polarization conversion element is used to convert the imaging light with the second polarization state from the curved surface reflection unit into the imaging light with the third polarization state. The imaging light with the third polarization state is reflected by the optical element to the polarization conversion element. The polarization conversion element is used to convert the imaging light with the third polarization state from the optical element into the imaging light with the fourth polarization state. The imaging light with the fourth polarization state is reflected by the curved surface reflection unit to the polarization conversion element. The polarization conversion element is used to convert the imaging light with the fourth polarization state from the curved surface reflection unit into the imaging light with the first polarization state, and the imaging light with the first polarization state is transmitted by the optical element.

In some possible implementations, the image source includes a light source and a modulator. The modulator is used to modulate the light emitted by the light source to obtain imaging light including image information.

In some possible implementations, the types of modulators include but are not limited to Liquid Crystal Display (LCD), Liquid Cristal on Silicon (LCOS), Digital Micro-mirror Device (DMD) ) and thin film transistor (Thin Film Transistor, TFT).

In a second aspect, embodiments of the present application provide a display device. The display device includes a processor and a projection device as described in any embodiment of the first aspect. The processor is configured to send image data to an image source of the projection device. The image source modulates the incident light according to the image data to obtain imaging light including image information. The application scenarios of the above display devices include but are not limited to Head-Up Display (HUD), projectors, augmented reality (Augmented Reality, AR) devices and virtual display (Virtual Reality, VR) devices, etc.

In a third aspect, embodiments of the present application provide a vehicle. The vehicle includes the display device introduced in the second aspect, and the display device is installed on the vehicle. For example, the display device can be installed on the vehicle as a HUD, a vehicle display, or a vehicle light.

In some possible implementations, the vehicle further includes a reflective element, the display device is configured to project imaging light to the reflective element, and the reflective element is configured to reflect the imaging light. For example, the display device may be installed on a vehicle as a HUD, and the reflective element may be a windshield of the vehicle.

In the fourth aspect, embodiments of the present application provide a projection method. The projection method is applied to a projection device, which includes an image source, a curved surface reflection unit and optical elements. The projection method includes: outputting imaging light through an image source. The imaging light from the image source is reflected to the optical element through the curved surface reflection unit. The imaging light from the curved surface reflection unit is reflected to the curved surface reflection unit through the optical element. The imaging light from the optical element is reflected to the optical element through the curved surface reflection unit. The imaging light from the curved reflective unit is transmitted through the optical element. Wherein, the imaging light from the image source is deflected in the first direction by the light reflection direction of the first reflection position on the curved surface reflection unit relative to the normal line of the first reflection position, and the imaging light from the optical element is secondly reflected on the curved surface reflection unit The light reflection direction of the position is deflected to the second direction relative to the normal line of the second reflection position, and the first direction is opposite to the second direction.

In some possible implementations, the curved reflection unit includes a first curved mirror and a second curved mirror. The method includes: reflecting the imaging light from the image source to the optical element through the first curved mirror. The imaging light from the first curved mirror is reflected to the second curved mirror through the optical element. The imaging light from the optical element is reflected to the optical element through the second curved mirror. The imaging light from the second curved mirror is transmitted through the optical element.

In some possible implementations, the first direction is clockwise and the second direction is counterclockwise, or the first direction is counterclockwise and the second direction is clockwise.

In some possible implementations, the projection device further includes a polarization conversion element. The imaging light output by the image source has a polarization state. The projection device also includes a polarization conversion element. The polarization conversion element is used to convert the polarization state of the input imaging light. The optical element Used to reflect the imaging light in one polarization state and transmit the imaging light in the other polarization state.

In some possible implementations, the imaging light output by the image source has a first polarization state, and the method further includes: converting the imaging light with the first polarization state from the image source into imaging with a second polarization state through a polarization conversion element. Light, imaging light with a second polarization state, is reflected by the curved surface reflection unit to the polarization conversion element. The imaging light with the second polarization state from the curved surface reflection unit is converted into imaging light with the third polarization state through the polarization conversion element, and the imaging light with the third polarization state is reflected by the optical element to the polarization conversion element. The imaging light with the third polarization state from the optical element is converted into the imaging light with the fourth polarization state through the polarization conversion element, and the imaging light with the fourth polarization state is reflected by the curved surface reflection unit to the polarization conversion element. The imaging light with the fourth polarization state from the curved surface reflection unit is converted into imaging light with the first polarization state through the polarization conversion element, and the imaging light with the first polarization state is transmitted by the optical element.

In some possible implementations, the imaging light output by the image source has a second polarization state, and the imaging light with the second polarization state is reflected by the curved surface reflection unit to the polarization conversion element. The method further includes: using the polarization conversion element to reflect the light from the curved surface. The imaging light with the second polarization state of the unit is converted into the imaging light with the third polarization state, and the imaging light with the third polarization state is reflected by the optical element to the polarization conversion element. The imaging light with the third polarization state from the optical element is converted into the imaging light with the fourth polarization state through the polarization conversion element, and the imaging light with the fourth polarization state is reflected by the curved surface reflection unit to the polarization conversion element. The imaging light with the fourth polarization state from the curved surface reflection unit is converted into imaging light with the first polarization state through the polarization conversion element, and the imaging light with the first polarization state is transmitted by the optical element.

In some possible implementations, the image source includes a light source and a modulator, and the method further includes: modulating the light emitted by the light source through the modulator to obtain imaging light including image information.

In some possible implementations, modulator types include, but are not limited to, LCD, LCOS, DMD, and TFT.

In the embodiment of the present application, the curved surface reflection unit first reflects the imaging light output from the image source to the optical element. The optical element then reflects the imaging light back to the curved reflective unit. Furthermore, the curved surface reflection unit reflects the imaging light to the optical element again. Finally, the optical element transmits the imaging light reflected for the second time by the curved surface reflection unit. It can be seen that the curved surface reflection unit reflects the imaging light twice. In the first reflection, the light reflection direction is deflected in the first direction relative to the normal of the first reflection position. In the second reflection, the light reflection direction is deflected in the first direction relative to the normal of the first reflection position. The normal line of the second reflection position is deflected toward the second direction, and the first direction is opposite to the second direction. In other words, this solution can make the directions of the two reflections of the curved surface reflection unit compensate for each other, thereby compensating for the aberration generated by the imaging light passing through the curved surface reflection unit, achieving smaller aberration and improving the viewer's experience. Moreover, the folding light path design is adopted, which helps to improve the compactness of the projection device.

Description of drawings

Figure 1 is a first structural schematic diagram of a projection device in an embodiment of the present application;

Figure 2 is a second structural schematic diagram of the projection device in the embodiment of the present application;

Figure 3 is a third structural schematic diagram of the projection device in the embodiment of the present application;

Figure 4 is a fourth structural schematic diagram of the projection device in the embodiment of the present application;

Figure 5 is a fifth structural schematic diagram of the projection device in the embodiment of the present application;

Figure 6 is a schematic structural diagram of a display device in an embodiment of the present application;

Figure 7 is a schematic diagram of a display device installed on a vehicle in an embodiment of the present application;

Figure 8 is a schematic diagram of an embodiment of a projection method provided by this application.

Detailed ways

Embodiments of the present application provide a projection device, a display device, a vehicle, and a projection method, which can be mainly used in virtual image display scenarios, such as desktop virtual image display systems and Head-Up Display (HUD) systems. Embodiments of the present application can make the directions of two reflections of the curved surface reflection unit compensate each other, thereby compensating for the aberration generated by the imaging light passing through the curved surface reflection unit, achieving smaller aberration and improving the viewer's experience.

It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects, but do not limit a specific order or sequence. It is to be understood that the above terms are interchangeable under appropriate circumstances so that the embodiments described herein can be practiced in sequences other than those described herein. Furthermore, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units need not be limited to those steps or units that are expressly listed, but may include steps or units that are not expressly listed or that are not specific to the process, method, product, or device. Other steps or units inherent to the equipment.

Figure 1 is a first structural schematic diagram of a projection device in an embodiment of the present application. As shown in FIG. 1 , the projection device includes: an image source 10 , a curved surface reflection unit 20 and an optical element 30 . The image source 10 is used to output imaging light. The curved surface reflection unit 20 reflects the imaging light from the image source 10 to the optical element 30 . The optical element 30 reflects the imaging light from the curved surface reflection unit 20 back to the curved surface reflection unit 20 , and is reflected again by the curved surface reflection unit 20 . Finally, the optical element 30 transmits the imaging light reflected for the second time by the curved surface reflection unit 20 so that the human eye can receive the imaging light. Human eyes can see the virtual image formed by projection through the optical element 30 and the curved surface reflection unit 20 .

It should be understood that the imaging light output by the image source 10 contains image information. In a possible implementation, the image source 10 includes a light source and a modulator. The modulator is used to modulate the light emitted by the light source according to the image data to obtain imaging light containing image information. Among them, the types of modulators include but are not limited to Liquid Crystal Display (LCD), Liquid Cristal on Silicon (LCOS), Digital Micro-mirror Device (DMD) and Thin Film Transistor (Thin Film Transistor, TFT), etc.

It should be noted that the curved surface reflection unit 20 can enlarge the image, but certain aberrations will also occur during the image enlargement process. Therefore, in the embodiment of the present application, the curved surface reflection unit 20 reflects the imaging light twice successively, and the directions of the two reflections compensate each other, thereby compensating for the aberration generated by the imaging light passing through the curved surface reflection unit 20 and achieving a better Small aberration. For ease of introduction, the reflection of the imaging light from the image source 10 by the curved surface reflection unit 20 is called the "first reflection", and the position of the first reflection on the curved surface reflection unit 20 is called the "first reflection position". The reflection of the imaging light from the optical element 30 by the curved surface reflection unit 20 is called the "second reflection", and the position of the second reflection on the curved surface reflection unit 20 is called the "second reflection position". Specifically, the light reflection direction in which the curved surface reflection unit 20 performs the first reflection is deflected in the first direction relative to the normal line of the first reflection position, and the light reflection direction in which the curved surface reflection unit 20 performs the second reflection is deflected in the first direction relative to the normal line of the first reflection position. The normal of is deflected in the second direction, where the first direction is opposite to the second direction, realizing mutual compensation of the directions of the two reflections.

It should be understood that the reflection angle at which the curved surface reflection unit 20 reflects incident light is the angle between the reflection direction and the normal line, and the reflection angle ranges from 0° to 90°. Depending on the incident direction, the reflection direction has two different deflection directions relative to the normal, namely clockwise deflection and counterclockwise deflection. Therefore, the above-mentioned first direction and second direction are two different deflection directions. As an example, as shown in Figure 1, the first direction is clockwise and the second direction is counterclockwise. As another example, as shown in Figure 2, the first direction is counterclockwise and the second direction is clockwise.

Figure 2 is a second structural schematic diagram of the projection device in the embodiment of the present application. As shown in FIG. 2 , on the basis of the embodiment shown in FIG. 1 , by adjusting the relative position of each part of the projection device, the first direction can be counterclockwise and the second direction can be clockwise. That is to say, this application does not limit the specific directions of the first direction and the second direction, as long as the first direction is opposite to the second direction.

It should be noted that in the above embodiments shown in FIGS. 1 and 2 , the curved reflection unit 20 can be implemented by a curved mirror, and reflections are performed twice at two different positions of the curved mirror. In addition, in another possible implementation, the curved surface reflection unit 20 can also be implemented using two independent curved surface mirrors, one of which reflects the imaging light for the first time, and the other curved surface mirror performs the third reflection of the imaging light. Secondary reflection, another implementation mode will be introduced in detail below with reference to the accompanying drawings.

Figure 3 is a third structural schematic diagram of the projection device in the embodiment of the present application. As shown in FIG. 3 , the curved surface reflection unit 20 includes a curved surface mirror 201 and a curved surface mirror 202 . The curved mirror 201 is used to reflect the imaging light from the image source 10 to the optical element 30 , and then the optical element 30 reflects the imaging light to the curved mirror 202 . The curved mirror 202 then reflects the imaging light from the optical element 30 back to the optical element 30 . Finally, the optical element 30 transmits the imaging light reflected by the curved mirror 202 so that the human eye can receive the imaging light. Human eyes can see the virtual image formed by the projection through the optical element 30 and the curved mirror 202 .

In the embodiment shown in FIG. 3 , the reflection of the imaging light from the image source 10 by the curved mirror 201 is called "first reflection", and the reflection of the imaging light from the optical element 30 by the curved mirror 202 is called "first reflection". is the "second reflection". Specifically, the light reflection direction of the curved mirror 201 for the first reflection is deflected in the first direction relative to the normal line of the first reflection position, and the light reflection direction of the curved mirror 202 for the second reflection is deflected in the first direction relative to the normal line of the second reflection position. The wire is deflected in a second direction, wherein the first direction is opposite to the second direction. Taking Figure 3 as an example, the first direction is clockwise and the second direction is counterclockwise.

It should be understood that based on the embodiment shown in FIG. 3 , the relative positional relationship of each part in the projection device can also be adjusted to realize that the first direction is counterclockwise and the second direction is clockwise. For details, reference may be made to the above-mentioned transformation method between FIG. 1 and FIG. 2 , and the drawings of this embodiment are no longer provided here.

It should be noted that, in a possible implementation, the optical element 30 may be a mirror coated with a semi-transparent and semi-reflective film, and the material of the mirror is not limited in this application. That is to say, each time the imaging light incident on the optical element 30 is partially transmitted and the other part is reflected. The transmittance and reflectivity can be determined according to actual needs. For example, the transmittance and reflectance can each be 50%. Therefore, if the optical element 30 adopts a screen coated with a semi-transparent and semi-reflective film, the curved surface reflection unit 20 will first In addition to a part of the imaging light that is secondary reflected to the optical element 30 and is reflected by the optical element 30 , a part of it is also transmitted by the optical element 30 . In the same way, in addition to a part of the imaging light reflected by the curved surface reflection unit 20 to the optical element 30 for the second time, a part of it is transmitted by the optical element 30 , and a part of it is also reflected by the optical element 30 . To sum up, the advantage of this implementation is that the imaging light output by the image source 10 is natural light rather than polarized light, and the implementation is simpler. The disadvantage is that after the imaging light passes through the optical element 30 twice and is transmitted to the human eye, part of the imaging light will be lost.

Another possible implementation is described below. The image source 10 modulates natural light to obtain imaging light with a polarization state. The optical element 30 uses a mirror coated with a polarizing film. The optical element 30 can reflect or transmit according to the polarization state of the incident imaging light. Therefore, it is also necessary to provide a polarization conversion element at an appropriate position in the above-mentioned projection device for converting the polarization state of the imaging light, so that the polarization state of the imaging light incident on the optical element 30 is different twice. In this way, the imaging light incident on the optical element 30 for the first time can be completely reflected back to the curved surface reflection unit 20 , and the imaging light incident on the optical element 30 for the second time can be completely transmitted to the human eye, thus avoiding the loss of imaging light. . This application does not limit the specific type of the polarization conversion element. For example, the polarization conversion element can use a 1/4 wave plate. It should be noted that imaging light with a polarization state includes linearly polarized light and circularly polarized light, and linearly polarized light and circularly polarized light have different polarization states. Polarized light with different polarization directions in linearly polarized light can also be considered to have different polarization states. As an example, linearly polarized light includes P-polarized light and S-polarized light. The polarization directions of P-polarized light and S-polarized light are perpendicular, and the polarization states of P-polarized light and S-polarized light are different. The polarization conversion element is used to convert the polarization state of the imaging light. For example, it can convert linearly polarized light into circularly polarized light, or convert circularly polarized light into linearly polarized light.

It should be understood that in practical applications, the position of the polarization conversion element can be placed in a variety of flexible design methods. The following mainly introduces several typical implementation methods by taking the curved surface reflection unit 20 using a curved mirror as an example. Based on these implementation methods Simple transformations performed on above are all within the protection scope of this application.

Figure 4 is a fourth structural schematic diagram of a projection device in an embodiment of the present application. As shown in FIG. 4 , the projection device also includes a polarization conversion element 40 . The imaging light output by the image source 10 has polarization state 1 . The optical element 30 is used to transmit the imaging light in polarization state 1 and reflect the imaging light in polarization state 3 . Specifically, the polarization conversion element 40 converts the imaging light in polarization state 1 into the imaging light in polarization state 2, and the imaging light in polarization state 2 is reflected by the curved surface reflection unit 20 to the polarization conversion element 40 . The polarization conversion element 40 converts the imaging light in polarization state 2 into the imaging light in polarization state 3, and the imaging light in polarization state 3 is reflected by the optical element 30 to the polarization conversion element 40 . The polarization conversion element 40 converts the imaging light in polarization state 3 into the imaging light in polarization state 4, and the imaging light in polarization state 4 is reflected by the curved surface reflection unit 20 to the polarization conversion element 40 . The polarization conversion element 40 converts the imaging light in polarization state 4 into the imaging light in polarization state 1, and the imaging light in polarization state 1 is transmitted by the optical element 30, so that the human eye can receive the imaging light. It should be understood that in practical applications, the polarization conversion element 40 can be attached to the surface of the curved surface reflection unit 20 , or the polarization conversion element 40 can also be separated from the curved surface reflection unit 20 by a certain distance.

Figure 5 is a fifth structural schematic diagram of the projection device in the embodiment of the present application. As shown in Figure 5, the projection device also includes a polarization conversion element 40. The imaging light output by the image source 10 has polarization state 2. The optical element 30 is used to transmit the imaging light of polarization state 1 and reflect the imaging light of polarization state 3. Specifically, the imaging light in polarization state 2 is reflected by the curved surface reflection unit 20 to the polarization conversion element 40. The polarization conversion element 40 converts the imaging light in polarization state 2 into the imaging light in polarization state 3. The imaging light in polarization state 3 is reflected by the optical element. 30 is reflected to the polarization conversion element 40. The polarization conversion element 40 converts the imaging light in polarization state 3 into the imaging light in polarization state 4, and the imaging light in polarization state 4 is reflected by the curved surface reflection unit 20 to the polarization conversion element 40 . The polarization conversion element 40 converts the imaging light in polarization state 4 into the imaging light in polarization state 1, and the imaging light in polarization state 1 is transmitted by the optical element 30, so that the human eye can receive the imaging light. It should be understood that in practical applications, the polarization conversion element 40 can be attached to the surface of the optical element 30 , or the polarization conversion element 40 can also be separated from the optical element 30 by a certain distance.

Based on the embodiments introduced in Figures 4 and 5 above, as an example, the imaging light in polarization state 1 is P-polarized light, the imaging light in polarization state 2 is circularly polarized light, and the imaging light in polarization state 3 is S-polarized light. The imaging light in polarization state 4 is circularly polarized light.

Preferably, in some application scenarios, the projection device provided by the present application can be used to realize that the horizontal eye box of the human eye is 20mm-160mm, and the vertical eye box of the human eye is 20mm-80mm. It can also be realized that the human eye can see virtual images in the range of horizontal field of view angles of 5°-35°, and virtual images in the range of vertical field of view angles of 2°-20°. It can also achieve a virtual image distance of 2m-10m.

Based on the introduction of the above embodiments, in the embodiment of the present application, the curved surface reflection unit first reflects the imaging light output from the image source to the optical element. The optical element then reflects the imaging light back to the curved reflective unit. Furthermore, the curved surface reflection unit reflects the imaging light to the optical element again. Finally, the optical element transmits the imaging light reflected for the second time by the curved surface reflection unit. It can be seen that the curved surface reflection unit reflects the imaging light twice. In the first reflection, the light reflection direction is deflected in the first direction relative to the normal of the first reflection position. In the second reflection, the light reflection direction is deflected in the first direction relative to the normal of the first reflection position. The normal line of the two reflection positions is deflected toward the second direction, and the first direction is opposite to the second direction. In other words, this solution can make the two reflection directions of the curved surface reflection unit compensate each other, thereby compensating for the aberration generated by the imaging light passing through the curved surface reflection unit, achieving smaller aberration and improving the viewer's experience. Moreover, the folding light path design is adopted, which helps to improve the compactness of the projection device.

An embodiment of the present application also provides a display device. Figure 6 is a schematic structural diagram of a display device in an embodiment of the present application. As shown in FIG. 6 , the display device includes: a processor 601 and a projection device 602 . The projection device 602 may be the projection device introduced in any of the above embodiments. The processor 601 is configured to send image data to an image source of the projection device 602 . The image source of the projection device 602 modulates the incident light according to the image data to obtain imaging light including image information.

It should be noted that the application scenarios of the above display devices include but are not limited to Head-Up Display (HUD), projectors, augmented reality (Augmented Reality, AR) devices and virtual display (Virtual Reality, VR) devices, etc. As an example, the display device in this application is integrated into a HUD. The HUD can project navigation information, instrument information, etc. in the driver's front field of view, preventing the driver from lowering his head to view this information, thereby affecting driving safety. The image projected by the HUD is reflected by the windshield and forms a virtual image on the outside of the vehicle. As another example, the display device in the present application is integrated with a projector, and the projector can project images onto a wall or projection screen. As another example, the display device in this application is integrated with an AR device or a VR device. The AR device may include but is not limited to AR glasses or an AR helmet. The VR device may include but is not limited to VR glasses or a VR helmet. The user may wear the AR device. or VR equipment for gaming, watching videos, participating in virtual meetings, or video shopping, etc. As another example, the display device in this application is integrated into a vehicle-mounted display screen. The vehicle-mounted display screen can be installed on the back of the seat of the vehicle or in the passenger position. This application does not limit the installation location of the vehicle-mounted display screen. As another example, the display device in this application is integrated into a car light. In addition to realizing the lighting function, the car light can also implement an adaptive driving beam system (Adaptive Driving Beam, ADB), which can project text, traffic signs, etc. Complex graphics can also be projected, such as videos, to add auxiliary driving or entertainment functions.

An embodiment of the present application also provides a vehicle equipped with the above-mentioned display device. For example, the display device can be installed on the vehicle as a HUD, a vehicle display, or a vehicle light. The following uses HUD as an example to introduce a specific implementation method of installing a display device on a vehicle.

FIG. 7 is a schematic diagram of a display device installed on a vehicle in an embodiment of the present application. As shown in Figure 7, the windshield of a vehicle can reflect the light output from the display device to human eyes. Specifically, the display device is used to output imaging light carrying image information. In it, the driver or passenger is located on one side of the windshield. The windshield is used to reflect imaging light onto the windshield A virtual image forms on the other side of the glass. The reflected imaging light is transmitted to the eyes of the driver or passenger. By way of example, vehicles may be cars, trucks, motorcycles, buses, boats, airplanes, helicopters, lawn mowers, recreational vehicles, playground vehicles, construction equipment, trolleys, golf carts, trains, and handcarts etc., the embodiments of the present application are not particularly limited.

The embodiment of the present application also provides a projection method. This projection method is applied to the projection device introduced in the above embodiment. Figure 8 is a schematic diagram of an embodiment of a projection method provided by this application. In this embodiment, the projection method includes the following steps.

801. Output imaging light through the image source.

It should be understood that imaging light contains image information. The imaging light can be natural light or polarized light. For specific application scenarios, please refer to the relevant introductions of the above embodiments and will not be described again here.

802. Reflect the imaging light from the image source to the optical element through the curved surface reflection unit.

803. Reflect the imaging light from the curved surface reflection unit to the curved surface reflection unit through the optical element.

It should be understood that the optical element can be a mirror coated with a semi-transparent and semi-reflective film, or a mirror coated with a polarizing film. For specific application scenarios, please refer to the relevant introductions of the above embodiments and will not be described again here.

804. Reflect the imaging light from the optical element to the optical element through the curved surface reflection unit.

It should be understood that the curved surface reflection unit can use one curved surface mirror or two independent curved surface mirrors. For specific application scenarios, please refer to the relevant introductions of the above embodiments and will not be described again here. It should be noted that the directions of the two reflections of the curved surface reflection unit can compensate each other. For example, the light reflection direction of the curved surface reflection unit for the first reflection is deflected in the first direction relative to the normal line of the first reflection position, and the light reflection direction of the curved surface reflection unit for the second reflection is deflected relative to the normal line of the second reflection position. Deflected in a second direction, wherein the first direction is opposite to the second direction.

805. Transmit the imaging light from the curved surface reflection unit through the optical element.

It should be understood that the human eye can see the virtual image formed by projection through optical elements and curved surface reflection units.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present application, and all of them should be covered. within the protection scope of this application.

Claims

A projection device, characterized by including: an image source, a curved surface reflection unit and an optical element;

The image source is used to output imaging light;

The curved surface reflection unit is used to reflect the imaging light from the image source to the optical element;

The optical element is used to reflect the imaging light from the curved surface reflection unit to the curved surface reflection unit;

The curved surface reflection unit is also used to reflect the imaging light from the optical element to the optical element;

The optical element is also used to transmit imaging light from the curved surface reflection unit;

Wherein, the light reflection direction of the imaging light from the image source at the first reflection position on the curved surface reflection unit is deflected in the first direction relative to the normal line of the first reflection position, and the imaging light from the optical element The light reflection direction at the second reflection position on the curved surface reflection unit is deflected to a second direction relative to the normal line of the second reflection position, and the first direction is opposite to the second direction.
The projection device according to claim 1, wherein the curved surface reflection unit includes a first curved mirror and a second curved mirror;

The first curved mirror is used to reflect imaging light from the image source to the optical element;

The optical element is used to reflect the imaging light from the first curved mirror to the second curved mirror;

The second curved mirror is used to reflect the imaging light from the optical element to the optical element;

The optical element is also used to transmit imaging light from the second curved mirror.
The projection device according to claim 1 or 2, wherein the first direction is a clockwise direction, the second direction is a counterclockwise direction, or the first direction is a counterclockwise direction, and the The second direction is clockwise.
The projection device according to any one of claims 1 to 3, characterized in that the imaging light output by the image source has a polarization state, and the projection device further includes a polarization conversion element, the polarization conversion element is used to convert According to the polarization state of the input imaging light, the optical element is used to reflect the imaging light in one polarization state and transmit the imaging light in the other polarization state.
The projection device according to claim 4, wherein the imaging light output by the image source has a first polarization state;

The polarization conversion element is used to convert the imaging light with the first polarization state from the image source into the imaging light with the second polarization state, and the imaging light with the second polarization state is reflected by the curved surface The unit reflects to the polarization conversion element;

The polarization conversion element is used to convert the imaging light with the second polarization state from the curved surface reflection unit into the imaging light with the third polarization state, and the imaging light with the third polarization state is converted by the optical The element is reflected to the polarization conversion element;

The polarization conversion element is used to convert the imaging light with the third polarization state from the optical element into the imaging light with the fourth polarization state, and the imaging light with the fourth polarization state is reflected by the curved surface The unit reflects to the polarization conversion element;

The polarization conversion element is used to convert the imaging light with the fourth polarization state from the curved surface reflection unit into the imaging light with the first polarization state, and the imaging light with the first polarization state is converted into imaging light with the first polarization state. The optical element is transparent.
The projection device according to claim 4, wherein the imaging light output by the image source has a second polarization state, and the imaging light with the second polarization state is reflected by the curved surface reflection unit to the polarization conversion element;

The polarization conversion element is used to convert the imaging light with the second polarization state from the curved surface reflection unit into the imaging light with the third polarization state, and the imaging light with the third polarization state is converted by the optical The element is reflected to the polarization conversion element;

The polarization conversion element is used to convert the imaging light with the third polarization state from the optical element into the imaging light with the fourth polarization state, and the imaging light with the fourth polarization state is reflected by the curved surface The unit reflects to the polarization conversion element;

The polarization conversion element is used to convert the imaging light with the fourth polarization state from the curved surface reflection unit into the imaging light with the first polarization state, and the imaging light with the first polarization state is converted by the optical Element transmission.
The projection device according to any one of claims 1 to 6, wherein the image source includes a light source and a modulator, and the modulator is used to modulate the light emitted by the light source to obtain imaging light including image information.
The projection device according to claim 7, wherein the modulator is any one of a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), a digital micromirror device (DMD), or a thin film transistor (TFT).
A display device, characterized by comprising: a processor and the projection device according to any one of claims 1 to 8, the processor being configured to send image data to an image source of the projection device.
A vehicle, characterized by comprising: the display device according to claim 9, the display device being installed on the vehicle.
The vehicle according to claim 10, wherein the vehicle further includes a reflective element, the display device is configured to project imaging light to the reflective element, and the reflective element is configured to reflect the imaging light.
A projection method, characterized in that the projection method is applied to a projection device, and the projection device includes an image source, a curved surface reflection unit and an optical element; the method includes:

Output imaging light through the image source;

Reflect the imaging light from the image source to the optical element through the curved surface reflection unit;

Reflect the imaging light from the curved surface reflection unit to the curved surface reflection unit through optical elements;

Reflect the imaging light from the optical element to the optical element through the curved surface reflection unit;

The imaging light from the curved surface reflection unit is transmitted through the optical element;

Wherein, the light reflection direction of the imaging light from the image source at the first reflection position on the curved surface reflection unit is deflected in the first direction relative to the normal line of the first reflection position, and the imaging light from the optical element The light reflection direction at the second reflection position on the curved surface reflection unit is deflected to a second direction relative to the normal line of the second reflection position, and the first direction is opposite to the second direction.
The method of claim 12, wherein the curved reflection unit includes a first curved mirror and a second curved mirror, and the method includes:

Reflect imaging light from the image source to the optical element through the first curved mirror;

Reflect the imaging light from the first curved mirror to the second curved mirror through the optical element;

Reflect the imaging light from the optical element to the optical element through the second curved mirror;

The imaging light from the second curved mirror is transmitted through the optical element.
The method according to claim 12 or 13, characterized in that the first direction is a clockwise direction, the second direction is a counterclockwise direction, or the first direction is a counterclockwise direction, and the second direction is a counterclockwise direction. The second direction is clockwise.
The method according to any one of claims 12 to 14, characterized in that the imaging light output by the image source has a polarization state, and the projection device further includes a polarization conversion element, the polarization conversion element is used to convert the input imaging The optical element is used to reflect the imaging light in one polarization state and transmit the imaging light in the other polarization state.
The method of claim 15, wherein the imaging light output by the image source has the first polarization state, the method further comprising:

The imaging light with the first polarization state from the image source is converted into imaging light with the second polarization state through the polarization conversion element, and the imaging light with the second polarization state is reflected by the curved surface reflection unit Reflected to the polarization conversion element;

The imaging light with the second polarization state from the curved surface reflection unit is converted into imaging light with a third polarization state by the polarization conversion element, and the imaging light with the third polarization state is passed by the optical element Reflected to the polarization conversion element;

The imaging light with the third polarization state from the optical element is converted into imaging light with the fourth polarization state through the polarization conversion element, and the imaging light with the fourth polarization state is reflected by the curved surface reflection unit Reflected to the polarization conversion element;

The imaging light with the fourth polarization state from the curved surface reflection unit is converted into imaging light with the first polarization state through the polarization conversion element, and the imaging light with the first polarization state is converted by the Optical elements transmit.
The method of claim 15, wherein the imaging light output by the image source has the second polarization state, and the imaging light with the second polarization state is reflected by the curved surface reflection unit to the polarization state. conversion element, the method further includes:

The imaging light with the second polarization state from the curved surface reflection unit is converted into imaging light with a third polarization state by the polarization conversion element, and the imaging light with the third polarization state is passed by the optical element Reflected to the polarization conversion element;

The imaging light with the third polarization state from the optical element is converted into imaging light with the fourth polarization state through the polarization conversion element, and the imaging light with the fourth polarization state is reflected by the curved surface reflection unit Reflected to the polarization conversion element;

The imaging light with the fourth polarization state from the curved surface reflection unit is converted into imaging light with the first polarization state by the polarization conversion element, and the imaging light with the first polarization state is passed by the optical element transmission.
The method according to any one of claims 12 to 17, wherein the image source includes a light source and a modulator, and the method further includes:

The light emitted by the light source is modulated by the modulator to obtain imaging light including image information.
The method of claim 18, wherein the modulator is any one of a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), a digital micromirror device (DMD), or a thin film transistor (TFT).