A multi-focus image generating device, a head-up display device, and related methods and equipment

Abstract

The present application provides a multi-focus image generating device, a head-up display device, and related methods and equipment, wherein the multi-focus image generating device includes an image generating unit, a spectrometer, and a focal length adjuster. The image generating unit is used to generate a first focal plane of the multi-focus image generating device; the spectrometer is used to split the image generating unit and irradiate the light beam obtained by the splitting onto the surface of the focal length adjuster; the focal length adjuster is used to adjust the focal length of the light beam irradiated onto the surface of the focal length adjuster to generate a second focal plane of the multi-focus image generating device. The technical solution of the present application can realize continuous adjustment of any focal length by flexibly adjusting the focal length through the focal length adjuster, and realize any number and any position of focal planes (or imaging planes).

Description

Technical Field

[0001] The present application relates to the field of image display technology, and in particular to a multi-focus image generating device, a head-up display device and related methods. Background Art

[0002] Head up display (HUD), also known as parallel display system, refers to a multifunctional instrument panel centered on the driver. Its function is to project important driving information such as speed and navigation onto the windshield in front of the driver, so that the driver can see important driving information such as speed and navigation without lowering or turning his head. Figure 1 A schematic diagram of a HUD display interface is shown in FIG. Figure 1 As shown, the image displayed by the HUD includes information such as speed "4km / h" and navigation "20m right turn arrow".

[0003] However, since the images displayed by ordinary HUDs and the objects on the actual road are not in the same focal plane, the driver's eyes need to switch back and forth between road objects and the HUD imaging plane to adjust the focus of the eyes. Although the current HUD solves the problem of lowering the head, frequent focus adjustments can also cause visual fatigue and reduce the user experience. In order to realize a truly augmented reality (AR) HUD, it is necessary to solve the technical problem of multi-focal plane imaging of the image generation device. Summary of the invention

[0004] The present application provides a multi-focus image generating device, a head-up display device and related methods, the main purpose of which is to solve the technical problem of multi-focal plane imaging of the image generating device and realize continuous adjustment of any focal length.

[0005] In a first aspect, the present application provides a multi-focus image generating device, which includes: an image generating unit, a spectrometer, and a focal length adjuster. The image generating unit is used to generate a first focal plane of the multi-focus image generating device; the spectrometer is used to split the image generating unit and irradiate the split light beam to the surface of the focal length adjuster; the focal length adjuster is used to adjust the focal length of the light beam irradiated to the surface of the focal length adjuster to generate a second focal plane of the multi-focus image generating device.

[0006] In the technical solution of the present application, the focal length position can be flexibly adjusted by the focal length adjuster, so that any focal length can be continuously adjusted, and any number of focal planes (or imaging planes) in any position can be achieved.

[0007] In a possible implementation, the focal length adjuster enables the multi-focus image generating device to generate a plurality of second focal planes by loading different phase information, wherein different phase information corresponds to different second focal planes.

[0008] In the technical solution of the present application, the focal length adjuster adjusts the focal length by loading phase information, thereby controlling the number and position of focal planes, and has high flexibility.

[0009] In a possible implementation, the focus adjuster includes a plurality of imaging areas, and different imaging areas correspond to different second focal planes. The imaging area of ​​the focus adjuster can be divided by software, supporting any boundary shape and having high flexibility.

[0010] In a possible implementation, different imaging regions are loaded with different phase information. By loading different phase information in different imaging regions, image partitioning display of different focal planes can be achieved.

[0011] In a possible implementation, the image generating unit includes a light source, and the beam splitter is used to split the light beam generated by the light source. The optical path of the image generating unit can be upgraded and modified, and the implementation is simple.

[0012] In a possible implementation, when the second focal plane includes two focal planes, the position of one of the second focal planes is fixed, and the position of the other second focal plane is adjustable. When the second focal plane includes multiple focal planes, the position of any one or more focal planes can be adjusted arbitrarily, thereby constructing an adjustable dual focal plane or multiple focal planes.

[0013] In a possible implementation, the phase information loaded by the focal length adjuster includes the phase distribution of the Fresnel lens or the phase distribution of the Zernike lens. By changing the phase distribution pattern of the Fresnel lens or the Zernike lens loaded on the focal length adjuster, the focal length of the equivalent lens can be changed, thereby controlling the multi-focal image generating device to generate a plurality of continuous focal planes.

[0014] In a possible implementation, the focus adjuster is a spatial light modulator. The spatial light modulator may be a phase-type spatial light modulator, which may be implemented based on liquid crystal or micro-electromechanical system.

[0015] In a second aspect, the present application provides a method for generating a multi-focus image, which can be applied to a multi-focus image generating device, wherein the multi-focus image generating device includes an image generating unit, a spectrometer, and a focal length adjuster. The method includes: generating a first focal plane by the image generating unit; splitting the image generating unit by the spectrometer, and irradiating the light beam obtained by the splitting to the surface of the focal length adjuster; and adjusting the focal length of the light beam irradiated to the surface of the focal length adjuster by the focal length adjuster to generate a second focal plane.

[0016] In the technical solution of the present application, the focal length position can be flexibly adjusted by the focal length adjuster, so that any focal length can be continuously adjusted, and any number of focal planes (or imaging planes) in any position can be achieved.

[0017] In a possible implementation, the step of adjusting the focus of the light beam irradiated onto the surface of the focus adjuster to generate a second focal plane includes: loading different phase information on the focus adjuster to generate multiple second focal planes, wherein different phase information corresponds to different second focal planes.

[0018] In the technical solution of the present application, the focal length adjuster adjusts the focal length by loading phase information, thereby controlling the number and position of focal planes, and has high flexibility.

[0019] In a possible implementation, the method includes: dividing the focus adjuster into a plurality of imaging areas, and different imaging areas correspond to different second focal planes. The imaging area of ​​the focus adjuster can be divided by software, supporting any boundary shape and having high flexibility.

[0020] In a possible implementation, the method further includes: loading different phase information in the different imaging regions. Loading different phase information in different imaging regions can realize image partition display of different focal planes.

[0021] In a possible implementation, the image generating unit includes a light source, and the beam splitter is used to split the light beam generated by the light source. The optical path of the image generating unit can be upgraded and modified, and the implementation is simple.

[0022] In a possible implementation, when the second focal plane includes two focal planes, the method includes: fixing the position of one of the second focal planes and adjusting the position of the other second focal plane. When the second focal plane includes multiple focal planes, the position of any one or more focal planes can be adjusted arbitrarily, thereby constructing an adjustable dual focal plane or multiple focal planes.

[0023] In a possible implementation, the phase information loaded by the focal length adjuster includes the phase distribution of the Fresnel lens or the phase distribution of the Zernike lens. By changing the phase distribution pattern of the Fresnel lens or the Zernike lens loaded on the focal length adjuster, the focal length of the equivalent lens can be changed, thereby controlling the multi-focal image generating device to generate a plurality of continuous focal planes.

[0024] In a possible implementation, the focus adjuster is a spatial light modulator. The spatial light modulator may be a phase-type spatial light modulator, which may be implemented based on liquid crystal or micro-electromechanical system.

[0025] In a third aspect, the present application provides a head-up display device, characterized in that the head-up display device includes a multi-focus image generating device and an imaging component as described in the first aspect or any possible implementation of the first aspect, the multi-focus image generating device is used to generate a plurality of first images, the multi-focus image generating device has a plurality of focal planes, wherein different focal planes correspond to different images in the plurality of first images; the imaging component is used to image the plurality of first images to generate a second image for reception by human eyes.

[0026] In addition to being used in head-up display devices, the technical solution of the present application can also be applied to display devices such as flat glass displays and projectors. By generating a continuously adjustable focal plane through a multi-focus image unit, different information can be presented on different imaging planes, thereby improving the user experience.

[0027] In a fourth aspect, the present application provides a driving device, comprising: a cab, a windshield installed on the cab, and a head-up display device as described in the third aspect, wherein the head-up display device is installed in the cab, and the windshield reflects and forms a second image generated by the head-up display device.

[0028] The technical solution of the present application can solve the multi-focal plane imaging technology problem of the vehicle-mounted head-up display. The user does not need to frequently adjust the focus during driving, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a HUD display interface;

[0030] Figure 2 A schematic diagram of the structure of a multi-focus image generating device provided in this application;

[0031] Figure 3a-3c Schematic diagram of the structures of three multi-focus image generation devices provided in this application;

[0032] Figure 4a A schematic diagram of the structure of a multi-focal plane image generating device provided in this application;

[0033] Figure 4b A schematic structural diagram of another multi-focal plane image generating device provided in the present application;

[0034] Figure 5a , 5b The phase distribution diagram of the Fresnel lens provided for this application;

[0035] Figure 6a , 6b Schematic diagram of dual focal plane imaging provided for this application;

[0036] Figures 7a-7d Schematic diagram of the division method of the imaging area of ​​four spatial light modulators provided in this application;

[0037] Figure 8 A schematic diagram of an imaging surface area division method provided in this application;

[0038] Fig. 9 A schematic diagram of the structure of a HUD provided in this application. DETAILED DESCRIPTION

[0039] The embodiments of the present application relate to a multi-focus image generating device, a head-up display device and related methods, which are described in detail below in conjunction with the accompanying drawings.

[0040] Figure 2 This is a schematic diagram of the structure of a multi-focus image generation device provided in this application. Figure 2 As shown, the multi-focus imaging device includes a light source 201, an imaging component 202, a beam splitter 203 and a focal length adjuster 204. The light source 201 is used to generate a light beam with an image signal. The imaging component 202 may include a lens, a lens group, etc., to image the light beam generated by the light source 201, and generate a focal plane 1 of the multi-focus image generating device. The beam splitter 203 separates part of the light beam from the light source 201, and the separated light beam is subjected to focal length adjustment by the focal length adjuster 203, so that the multi-focus image generating device has different focal planes (focal plane 2, focal plane 3, ..., focal plane N), and the multiple focal planes can be continuously adjustable. The focal length adjuster 203 can be a spatial light modulator (Spatiallight modulator, SLM), and the position of the focal plane can be changed by loading a holographic phase map with an arbitrary phase distribution on the SLM. In addition, the position of the focal plane can also be changed by changing the light field amplitude and polarization state of the SLM. The multi-focal image generation device of the present application can realize continuous adjustment of any focal length without changing the physical position of the imaging component in the optical path, thereby generating a continuously variable imaging surface. The "focal plane" and "imaging surface" mentioned in the present application can refer to the same spatial position, that is, the position where the light beam is imaged. When the focal length of the SLM changes, the focal plane or imaging surface will also change accordingly.

[0041] Figure 3a-3c The following are schematic diagrams of the structures of three multi-focus image generation devices provided in this application. Figure 3a As shown, based on Figure 2 In the example of FIG. 3 , the light source may be a monochromatic light source 301, the imaging component may be a lens or a lens group 302, and the focal length adjuster may be a phase-type spatial light modulator 304. The lens or the lens group 302 images the light beam generated by the monochromatic light source 301 to generate a focal plane 1. The phase-type spatial light modulator 304 adjusts the focal length of the light beam split from the light source by the beam splitter 303 to generate a plurality of continuous focal planes (focal plane 2, focal plane 3, ..., focal plane N).

[0042] like Figure 3b As shown, and Figure 3a The difference is that the light source can be a three-color light source 301 of R, G, and B. If the focus adjuster is a single phase-type spatial light modulator 304, the phase-type spatial light modulator 304 can be time-division multiplexed with the three-color light sources 301 of R, G, and B. For example, the phase-type spatial light modulator 304 adjusts the focus of the R light source at the first second, adjusts the focus of the G light source at the second second, and adjusts the focus of the B light source at the third second. The phase-type spatial light modulator 304 adjusts the focus of any monochromatic light source of R, G, and B at the same time, generating a plurality of continuous focal planes (focal plane 2, focal plane 3, ..., focal plane N).

[0043] like Figure 3c As shown, and Figure 3a The difference is that the light source can adopt a three-color light source 301 of R, G, and B. If the focus adjuster adopts three phase-type spatial light modulators 304, each phase-type spatial light modulator 304 can respectively adjust the focus of one of the light sources of R, G, and B. Phase-type spatial light modulator 1 adjusts the focus of the R light source, phase-type spatial light modulator 2 adjusts the focus of the G light source, and phase-type spatial light modulator 3 adjusts the focus of the B light source. After the light beams emitted by the R, G, and B light sources are processed by the phase-type spatial light modulator 304, they can be combined by the beam combiner 305 to form multiple continuous focal planes (focal plane 2, focal plane 3, ..., focal plane N).

[0044] The embodiments of the present application can be easily implemented based on the optical path modification and upgrading of the pattern generation unit (PGU). The spatial light modulator controls the number and position of the focal planes by adjusting the focal length, and has high flexibility.

[0045] Figure 4a This is a schematic diagram of the structure of a multi-focal plane image generation device provided in this application. Figure 4a As shown, the multi-focal plane image generating device may include a PGU module 410, a spatial light modulator 420 and a beam splitter 430. Optionally, imaging screens 440 and 450 may be provided at different focal planes of the multi-focal image generating device, for example, the imaging screen 440 is located at focal plane 1, and the imaging screen 450 is located at focal plane 2. The PGU module 410 may include an amplitude imaging unit 411 and an imaging component 412, and the amplitude imaging unit 411 may include a monochromatic or polychromatic light source, for example, Figure 4aThe three-color light sources of R, G, and B are shown in the figure. The imaging component 412 may include a lens or a lens group. The spatial light modulator 420 may be implemented based on a microelectromechanical system (MEMS) or a liquid crystal. For example, liquid crystal on silicon (LCoS) is a spatial light modulator based on liquid crystal. On one optical path, the imaging component 412 is used to image the light beam generated by the amplitude imaging unit 411 on the imaging screen 440. On another optical path, the beam splitter 430 splits any one or more of the R, G, and B light sources. Figure 4a , which shows the splitting of the G light source. In addition, the R, G, and B three-color light sources can also be split in a time-division multiplexing manner. Optionally, in order to reduce the diffusion loss of the light beam split by the beam splitter 430, the light beam split by the beam splitter 430 can be collimated by the imaging component 460 and then irradiated to the surface of the spatial light modulator 420. A polarizer (not shown in the figure) can also be arranged in front of the spatial light modulator 420 to align the polarization state of the light beam incident on the surface of the spatial light modulator with the direction of the alignment layer of the spatial light modulator. The imaging component 460 can be a lens or a lens group. The spatial light modulator 420 can be a transmission or reflection type, and a phase distribution is loaded on the surface of the spatial light modulator 420 to realize the function of an equivalent lens to converge the light beam, thereby imaging on the imaging screen 450. By adjusting the focal length of the lens equivalent to the spatial light modulator 420, the position of the imaging screen 450 can be changed, so that the position of the imaging screen 450 can be adjusted arbitrarily. The imaging screen 450 can be implemented by a diffusion screen, a curtain, white paper, etc., and is set at the position of the focal plane (or imaging plane) to receive the image on the focal plane.

[0046] Figure 4b This is a schematic diagram of the structure of another multi-focal plane image generation device provided by the present application. Figure 4b As shown, and Figure 4a The difference is that an imaging screen 470 is added behind the spatial light modulator 420. The imaging screen 450 and the imaging screen 470 can be two independent components or integrated into one, but they are located at different spatial positions. Similar to the imaging screen 450, the position of the imaging screen 470 can also be adjusted by the equivalent lens focal length of the spatial light modulator 420.

[0047] In the embodiments of the present application, the focal length position can be flexibly adjusted by a spatial light modulator, so that any focal length can be continuously adjusted, and any number of focal planes (or imaging planes) at any position can be achieved.

[0048] The principle of adjusting the position of the imaging screen by a spatial light modulator is described below with reference to specific examples. Figure 5a , 5bThe phase distribution diagram of the Fresnel lens provided in this application. When the surface of the spatial light modulator is loaded with Figure 5a , 5b When the phase distribution of two Fresnel lenses with different focal lengths is shown, two different focal planes can be formed, that is, the position of the imaging screen can be adjusted to two different focal planes. The phase distribution of the Fresnel lens is loaded on the surface of the spatial light modulator to control the light field, which is equivalent to the function of the lens. Among them, the radius r of the mth ring of the Fresnel phase m =(2mfλ) 1 / 2 , where λ is the wavelength of the incident light, and f is the equivalent focal length of the lens under the phase of the mth ring. It can be seen that the spatial light modulator can realize the function of lenses with different focal lengths by loading different phase distributions, thereby adjusting the position of the focal plane and the imaging screen.

[0049] Figure 6a , 6b This is a schematic diagram of dual focal plane imaging provided in this application. In practical applications, one of the focal planes can be fixed, and the focal length of the Fresnel lens can be adjusted arbitrarily to construct an adjustable dual focal plane. Figure 6a The images of the letters A and B at different focal planes are shown. The letter A is clearer than the letter B. At this time, if you want to clearly observe the letters A and B at the same time, you can image them separately on different imaging screens (such as imaging screens 450 and 470). Figure 6b The image of the letter A and the letter B at the same focal plane is shown. The clarity of the letter A and the letter B is substantially the same. At this time, the letter A and the letter B can be clearly observed on the same imaging screen (such as the imaging screen 450) at the same time.

[0050] The surface of the spatial light modulator can also be divided into several imaging areas, and different phase distributions are loaded on different imaging areas to form different focal planes. Figures 7a-7d Schematic diagram of the division of the imaging areas of the four spatial light modulators provided in this application. The imaging area of ​​the spatial light modulator can be divided into multiple imaging areas of any number, shape, and focal length by software configuration. The number, shape, and focal length of the imaging areas can be determined by environmental factors (such as cars, pedestrians, road conditions, etc.) during the driving process of the car, so as to achieve different information imaging at different focal planes. Figure 7a As shown in Figure 1, the surface of the spatial modulator is divided into two rectangular areas. Figure 7b As shown in Figure 1, the surface of the spatial light modulator is divided into three rectangular areas. Figure 7c As shown in Figure 1, the surface of the spatial light modulator is divided into two irregular regions. Figure 7d As shown, the surface of the spatial light modulator is divided into three irregular regions. Figures 7a-7dThe division method shown can also be divided into N imaging areas such as square, fan, triangle, circle, polygon, etc. The surface of the spatial light modulator is loaded with a pattern of grayscale 0-255 (corresponding to 0-2π phase depth), and each imaging area can be loaded with the phase distribution of lenses with different focal lengths. For example, the phase distribution of the Zernike lens or the phase distribution of the Fresnel lens is loaded in each imaging area of ​​the spatial light modulator, and these phase distributions can be realized by holographic imaging functions such as the Zernike function and the Fresnel lens function. Different areas produce different focal planes, and the imaging of each focal plane can be a 2D image. The area of ​​the spatial light modulator can be divided by software, supporting arbitrary boundary shapes and high flexibility.

[0051] Figure 8 This is a schematic diagram of a method for dividing the imaging surface area provided in this application. Figure 8 As shown, the spatial position in front of the human eye can be divided into multiple imaging surface areas, and different imaging surface areas can be located at different spatial positions. Figures 7a-7d As shown, the surface area of ​​the spatial light modulator is divided, and different phase distributions are loaded in different areas, so as to produce different imaging planes (or focal planes). For example, the instrument panels 801 and 802 are imaged 30-40 cm in front of the human eye, the navigation information 803 is imaged 2-3 meters in front of the human eye, the map 804 is imaged 3-5 meters in front of the human eye, and the prompt information (such as weather, surrounding buildings, etc.) 805 is imaged 5-10 meters in front of the human eye. By dividing the surface of the spatial light modulator into regions and loading different phase distributions in different regions, image partitioning display of different focal planes can be achieved.

[0052] In the embodiments of the present application, the spatial light modulator controls the number and position of focal planes by loading different phase information in a partitioned manner, has high flexibility, and can realize focal planes (or imaging planes) of any number and position.

[0053] The multi-focus imaging device in the embodiment of the present application can be applied to display devices such as HUD, projector, flat glass display, etc. Take HUD as an example for explanation. Fig. 9 This is a schematic diagram of the structure of a HUD provided by this application. Fig. 9As shown, the HUD may include a multi-focus image generating device 901 and an imaging screen 902 in any of the aforementioned embodiments. The multi-focus image generating device 901 has multiple focal planes for generating multiple images, and different images are imaged on different focal planes. The imaging screen 902 may include a diffusion screen, a curtain, white paper, etc. The imaging screen 902 is arranged at the position of the focal plane, and is used to receive images on different focal planes generated by the image generating device 901. Images on different focal planes may be received through one imaging screen, and images on multiple focal planes may be received respectively through multiple imaging screens (one imaging screen corresponds to one focal plane). Optionally, optical elements such as an optical path folding mirror and a reflector may be arranged behind the imaging screen 902, so as to project the light beam reflected by the imaging surface on the imaging screen onto the windshield 903, so that the virtual images (or images) 904 and 905 formed on the windshield are received by the human eye 906. The focal length of the multi-focus image generating device 901 may be continuously adjusted, so as to generate different imaging planes at different positions of the same imaging screen or multiple imaging screens at different positions, and finally the human eye observes images at different distances.

[0054] The HUD provided by the present application can be used in driving equipment such as cars, buses, and airplanes, and can also be applied to a variety of AR display scenarios. Among them, when the HUD is applied to a driving device, the HUD can be installed in the cab of the driving device, and the image generated by the HUD is reflected to the human eye through the windshield of the driving device.

[0055] Applying the multi-focus imaging device of the embodiment of the present application to the HUD can make the focal length of the HUD continuously adjustable, and different information can be presented on different imaging surfaces. The user does not need to frequently adjust the focus during driving, thereby improving the user experience.

[0056] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0057] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An image generating device, characterized in that: The device comprises an image generating unit, a beam splitter and a focus adjuster. The image generating unit is used to generate a first focal plane of the image generating device; The beam splitter is used to split the light source in the image generation unit and irradiate the light beam obtained by the splitting onto the surface of the focus adjuster; The focus adjuster is used to adjust the focus of the light beam irradiated to the surface of the focus adjuster, and the focus adjuster is used to generate a plurality of continuous second focal planes of the image generating device, wherein the first focal plane and the second focal plane are generated on different optical paths; The light source is a polychromatic light source, and the focus adjuster uses three phase-type spatial light modulators, each of which corresponds to one of the R, G, and B light sources for focus adjustment; The device also includes a beam combiner, which is used to combine the light beams processed by the phase-type spatial light modulator to form a plurality of continuous focal planes.

2. The image generating device according to claim 1, wherein: The focal length adjuster enables the image generating device to generate a plurality of second focal planes by loading different phase information, wherein different phase information corresponds to different second focal planes.

3. The image generating device according to claim 1 or 2, characterized in that: The focal length adjuster includes a plurality of imaging areas, and different imaging areas correspond to different second focal planes.

4. The image generating device according to claim 3, wherein: The different imaging regions are loaded with different phase information.

5. The image generating device according to claim 4, wherein: At least one of the number, shape, and focal length of the plurality of imaging areas may be dynamically configured.

6. The image generating device according to any one of claims 1-2, 4-5, characterized in that: The second focal plane includes two focal planes, wherein the position of one second focal plane is fixed, and the position of the other second focal plane is adjustable.

7. The image generating device according to any one of claims 1-2, 4-5, characterized in that: The phase information loaded into the focal length adjuster includes the phase distribution of the Fresnel lens or the phase distribution of the Zernike lens.

8. A method for generating an image, characterized in that: The method comprises: generating a first focal plane by an image generating unit; Splitting the light source of the image generating unit by a beam splitter, and irradiating the light beam obtained by the splitting onto the surface of the focus adjuster; The focus of the light beam irradiated onto the surface of the focus adjuster is adjusted by the focus adjuster, wherein the focus adjuster is used to generate a plurality of continuous second focal planes of the image generating device, wherein the first focal plane and the second focal plane are generated on different optical paths; The light source is a polychromatic light source, the focus adjuster uses three phase-type spatial light modulators, each of the phase-type spatial light modulators respectively corresponds to one of the R, G, and B light sources to adjust the focus, and the method further includes: The light beams processed by the phase-type spatial light modulator are combined to form a plurality of continuous focal planes.

9. The method according to claim 8, characterized in that The generating of the second focal plane of the image generating device by the focal length adjuster comprises: Different phase information is loaded on the focal length adjuster to generate a plurality of second focal planes, wherein different phase information corresponds to different second focal planes.

10. The method according to claim 8 or 9, characterized in that The method comprises: The focal length adjuster is divided into a plurality of imaging areas, and different imaging areas correspond to different second focal planes.

11. The method according to claim 10, characterized in that The method further comprises: Different phase information is loaded into the different imaging regions.

12. The method according to claim 11, characterized in that At least one of the number, shape, and focal length of the plurality of imaging areas may be dynamically configured.

13. The method according to any one of claims 8-9, 11-12, characterized in that: The second focal plane includes two focal planes, and the method includes: The position of one of the second focal planes is fixed, and the position of the other second focal plane is adjusted.

14. The method according to any one of claims 8-9, 11-12, characterized in that: The phase information loaded into the focal length adjuster includes the phase distribution of the Fresnel lens or the phase distribution of the Zernike lens.

15. A display device, characterized in that: The display device comprises an image generating device and an imaging component as described in any one of claims 1 to 7, The image generating device is used to generate a first image; The imaging component is used to image the first image to generate a second image.

16. The display device according to claim 15, characterized in that The display device further comprises an imaging screen, which is arranged at the focal plane of the image generating device.

17. A driving device comprising: A cab, a windshield installed on the cab, and a display device as claimed in claim 15 or 16, wherein the display device is installed in the cab, and the windshield reflects the second image generated by the display device into an image.

Images