Display device, head-up display, and traffic device

Abstract

A display device, a head-up display and a traffic device. In the display device, a first image source includes a first display area; a refractive element is configured to refract image light rays emitted by at least a partial area of the first display area; the refracted image light rays passing through the refractive element are reflected by a first reflecting element and propagate to a viewing area to form a first virtual image; in a direction from a first end of the at least partial area to a second end of the at least partial area, at least part of the image light rays emitted from the at least partial area gradually decrease in optical distance between an entrance surface of the refractive element and an exit surface of the refractive element. The display device can reduce the requirement for the installation angle of the first image source for realizing inclined imaging, has small space occupation, compact structure, increases flexibility, and expands the application range of the display device for realizing inclined imaging.

Description

Technical Field

[0001] At least one embodiment of this disclosure relates to a display device, a head-up display, and a transportation device. Background Technology

[0002] Head-up displays (HUDs) utilize reflective optical designs to project image light (including vehicle information such as speed) emitted from an image source onto an imaging window (such as a windshield, imaging panel, or other structure). This allows users (such as drivers and / or passengers) to see information directly without looking down at the instrument panel while driving, improving both driving safety and the driving experience.

[0003] Heads-up displays can be tilted, meaning the image appears tilted to the human eye. For example, the near end (closer to the user) of a tilted display is lower, and the far end (closer to the user) is higher. This tilted display provides a better ground-hugging effect compared to a vertical display, allowing the image to better integrate with external objects. For instance, when displaying static or dynamic road signs such as turn arrows, the road signs appear to be flush with the road surface, providing better guidance. Summary of the Invention

[0004] At least one embodiment of this disclosure provides a display device, comprising: a first image source, a refractive element, and a first reflective element. The first image source includes a first display area; the refractive element is configured to refract image light emitted from at least a portion of the first display area; the image light refracted by the refractive element is reflected by the first reflective element and propagates to an observation area to form a first virtual image; along a direction from a first end to a second end of the at least a portion of the area, the optical distance between at least a portion of the image light emitted from the at least a portion of the area and the light-emitting surface of the refractive element gradually decreases.

[0005] For example, in a display device provided in an embodiment of this disclosure, the first virtual image corresponding to the image light emitted from the at least part of the region has a proximal end close to the observation area and a distal end far from the observation area, the image light corresponding to the first end corresponds to the proximal end, the image light corresponding to the second end corresponds to the distal end, and the height of the distal end of the first virtual image is higher than the height of the proximal end of the first virtual image.

[0006] For example, in a display device provided in one embodiment of this disclosure, the thickness of the refractive element in the direction of the principal optical axis of the image light emitted along the at least partial region gradually decreases along the direction from a first end to a second end of the at least partial region; and / or, the refractive index of the refractive element in the direction of the principal optical axis of the image light emitted along the at least partial region gradually decreases along the direction from the first end to the second end of the at least partial region.

[0007] For example, in a display device provided in one embodiment of the present disclosure, the refractive index of the refractive element is equal when the thickness of the refractive element in the direction of the principal optical axis of the image light emitted along the at least partial region gradually decreases along the direction from the first end of the at least partial region to the second end of the at least partial region; and the thickness of the refractive element in the direction of the principal optical axis of the image light emitted along the at least partial region is equal when the refractive index gradually decreases along the direction from the first end of the at least partial region to the second end of the at least partial region.

[0008] For example, in a display device provided in one embodiment of this disclosure, the surface of the refractive element away from the first image source includes a plane and / or a curved surface.

[0009] For example, in a display device provided in one embodiment of this disclosure, when the surface of the refractive element away from the first image source is a plane, the surface of the refractive element away from the first image source has a first angle with the display surface of the first display area, and the first angle is 1° to 60°.

[0010] For example, in a display device provided in one embodiment of this disclosure, the refractive element is attached to the at least partial region; or, the refractive element is spaced apart from the at least partial region in a direction perpendicular to the display surface of the first display area; or, the refractive element includes a portion attached to the at least partial region and a portion spaced apart from the at least partial region.

[0011] For example, in a display device provided in one embodiment of this disclosure, the refractive element is configured to refract image light emitted from the entire first display area.

[0012] For example, in a display device provided in an embodiment of this disclosure, the first display area includes a first sub-display area and a second sub-display area, wherein at least a portion of the area is the first sub-display area; image light emitted from the second sub-display area is incident on the first reflective element without being refracted by the refractive element, and the first reflective element is further configured to reflect the image light emitted from the second sub-display area and incident on the first reflective element to an observation area to form a second virtual image, wherein the angle between the second virtual image and the ground is greater than the angle between the first virtual image and the ground, and the second virtual image and the first virtual image have a non-zero second angle.

[0013] For example, in a display device provided in one embodiment of this disclosure, the display content of the second virtual image is independent of or related to the display content of the first virtual image.

[0014] For example, in a display device provided in one embodiment of this disclosure, the refractive element is an integrated structure, or includes a plurality of sub-refractive elements stacked in a direction perpendicular to the display surface of the first display area.

[0015] For example, a display device provided in one embodiment of this disclosure further includes a second reflective element, which is configured to reflect image light emitted from the first display area and refracted by the refractive element back to the first reflective element.

[0016] For example, a display device provided in one embodiment of this disclosure further includes a second image source, the second image source including a second display area; image light emitted from the second display area propagates to the first reflective element, and image light emitted from the second display area and propagating to the first reflective element forms a third virtual image different from the first virtual image; and the angle between the third virtual image and the ground is greater than the angle between the first virtual image and the ground, and the display surface of the first display area is parallel to the display surface of the second display area.

[0017] For example, a display device provided in one embodiment of this disclosure further includes a third reflective element; the image light emitted from the second display area is reflected by the third reflective element and then propagates to the first reflective element.

[0018] For example, a display device provided in one embodiment of this disclosure further includes a third image source and a transflective element; the third image source includes a third display area; the display surface of the third display area has a non-zero third angle with the display surface of the first display area; the transflective element is located on the side of the refractive element away from the first image source, is configured to transmit image light emitted from the first display area to the first reflective element, and is configured to reflect image light emitted from the third display area, and the image light emitted from the third display area propagates to the first reflective element after being reflected by the transflective element; the image light emitted from the third display area and propagating to the first reflective element forms a fourth virtual image different from the first virtual image, and the first virtual image and the fourth virtual image at least partially overlap.

[0019] For example, in a display device provided in one embodiment of this disclosure, the projection of the first virtual image onto the plane where the fourth virtual image is located is within the range of the fourth virtual image, or the projection of the fourth virtual image onto the plane where the first virtual image is located is within the range of the first virtual image.

[0020] For example, in a display device provided in one embodiment of this disclosure, the center of the first virtual image, the center of the fourth virtual image, and the center of the eye box region are located on the same straight line.

[0021] At least one embodiment of this disclosure also provides a head-up display, which includes a reflective imaging unit and any of the display devices provided in the embodiments of this disclosure; the reflective imaging unit is configured to reflect image light reflected from the first reflective element to the reflective imaging unit to the observation area, and transmit ambient light.

[0022] At least one embodiment of this disclosure also provides a transportation device, which includes any of the display devices provided in the embodiments of this disclosure, or any of the head-up displays provided in the embodiments of this disclosure.

[0023] For example, in a traffic device provided in one embodiment of this disclosure, when the traffic device includes the head-up display, the reflective imaging unit is the windshield or imaging window of the traffic device. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0025] Figure 1 A schematic diagram of a display device provided in at least one embodiment of this disclosure;

[0026] Figure 2AThis is a schematic diagram comparing the refraction of image light emitted from the display area of ​​the image source by the refractive element in at least one embodiment of the present disclosure with the image light emitted from the display area of ​​the image source without refraction by the refractive element.

[0027] Figure 2B This is a schematic diagram of the equivalent object distance from the display surface of the first display area to the first reflective element in at least one embodiment of the present disclosure;

[0028] Figure 3 A schematic diagram of another display device provided in at least one embodiment of the present disclosure;

[0029] Figure 4 A schematic diagram of another display device provided in at least one embodiment of the present disclosure;

[0030] Figure 5 A schematic diagram of another display device provided in at least one embodiment of the present disclosure;

[0031] Figure 6 A schematic diagram of another display device provided in at least one embodiment of this disclosure;

[0032] Figure 7 A schematic diagram of another display device provided in at least one embodiment of the present disclosure;

[0033] Figure 8 A schematic diagram of another display device provided in at least one embodiment of the present disclosure;

[0034] Figure 9 A schematic diagram of another display device provided in at least one embodiment of the present disclosure;

[0035] Figure 10 A schematic diagram of another display device provided in at least one embodiment of the present disclosure;

[0036] Figure 11 A schematic diagram of a head-up display provided for at least one embodiment of this disclosure;

[0037] Figure 12 This is a schematic diagram of a transportation device provided for at least one embodiment of the present disclosure. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0040] The features such as "parallel," "perpendicular," and "identical" used in the embodiments of this disclosure include features in the strict sense of "parallel," "perpendicular," and "identical," as well as cases where "approximately parallel," "approximately perpendicular," and "approximately identical" include certain errors, taking into account measurement and errors associated with the measurement of a specific quantity (e.g., limitations of the measurement system), and represent the acceptable deviation range for a specific value as determined by a person skilled in the art. For example, "approximately" can mean within one or more standard deviations, or within 10% or 5% of said value. Unless otherwise specified in the embodiments of this disclosure, the quantity of a component is implied to mean that the component can be one or more, or can be understood as at least one. "At least one" means one or more, and "more" means at least two.

[0041] Head-up displays (HUDs) can generate images tilted relative to the road surface. Tilted images are more in line with human viewing habits, and for example, they perform better when integrated with augmented reality elements of the external environment. For instance, when displaying road-related content (such as lane keeping indicators), tilted images provide a better ground-hugging effect and a better user experience. However, generating tilted images with a HUD typically requires adjusting the image source of the HUD device, and even further adjusting the position of the reflector, such as tilting the image source. This results in a large HUD device size, occupying a significant amount of space, and reducing its ease of use. This disclosure proposes a compact display device capable of generating tilted images, which can be used in HUDs and reduces the size of the HUD device while generating tilted images, thus improving the user experience and convenience of HUDs.

[0042] The accompanying drawings in this disclosure are not drawn to scale, and the number of image sources and images in the display device is not limited to the numbers shown in the drawings. The specific dimensions and quantity of each structure can be determined according to actual needs. The accompanying drawings described in this disclosure are only schematic diagrams.

[0043] It should be noted that the dimensions and proportions of the components and the dimensions of the geometric paths in the accompanying drawings are only schematic and are not limited to the actual dimensions and proportions of the components or the dimensions of the geometric paths. The specific length of the geometric paths should be understood in conjunction with the textual description.

[0044] At least one embodiment of this disclosure provides a display device, comprising: a first image source, a refractive element, and a first reflective element. The first image source includes a first display area; the refractive element is configured to refract image light emitted from at least a portion of the first display area; the image light refracted by the refractive element is reflected by the first reflective element and propagates to an observation area to form a first virtual image; along a direction from a first end to a second end of the at least a portion of the area, the optical distance between at least a portion of the image light emitted from the at least a portion of the area and the light-emitting surface of the refractive element gradually decreases. The display device provided by this disclosure can achieve tilted imaging without requiring a large installation space for the first image source. The first image source and the refractive element, in conjunction, can achieve a tilted image displayed in all or part of the first display area. Compared to existing tilted imaging technologies, the display device provided by this disclosure can achieve tilted images without requiring the image source to have high installation requirements (e.g., a high installation angle and a large installation space), and the display device has a simple and compact structure while still achieving a tilted image. Therefore, this display device can reduce the installation requirements of the first image source used to achieve tilt imaging, occupy less space, have a compact structure, increase flexibility, and expand the application range of display devices that achieve tilt imaging.

[0045] At least one embodiment of this disclosure also provides a head-up display, which includes a reflective imaging unit and any of the display devices provided in the embodiments of this disclosure; the reflective imaging unit is configured to reflect image light reflected from a first reflective element to the reflective imaging unit to an observation area and transmit ambient light.

[0046] At least one embodiment of this disclosure also provides a transportation device, which includes any of the display devices provided in the embodiments of this disclosure, or any of the head-up displays provided in the embodiments of this disclosure.

[0047] The display device, head-up display, and traffic equipment provided in the embodiments of this disclosure are described below with reference to the accompanying drawings. It should be noted that the same components can be configured in the same way. All embodiments of this disclosure are applicable to multiple protection subjects such as display devices, head-up displays, and traffic equipment. The same or similar content will not be repeated in each protection subject; however, reference can be made to the descriptions in the embodiments corresponding to other protection subjects.

[0048] For example, Figure 1This is a schematic diagram of a display device provided for at least one embodiment of the present disclosure. Figure 1 As shown, the display device includes a first image source 11, a refractive element 2, and a first reflective element 31. The first image source 11 includes a first display area 110; the refractive element 2 is configured to refract image light emitted from at least a portion of the first display area 110; the first reflective element 31 is configured to reflect the refracted image light by the refractive element 2 and propagate it to the observation area 5 to form a first virtual image 100; the refractive element 2 has an incident surface 21a and an exit surface 21; along the direction from the first end e1 of the at least partial area to the second end e2 of the at least partial area, the optical distance between at least a portion of the image light emitted from the at least partial area and the incident surface 21a and the exit surface 21 of the refractive element 2 gradually decreases, that is, the optical distance between at least a portion of the image light emitted from the at least partial area and the incident refractive element 2 gradually decreases during the process from the incident refractive element 2 to the exit of the refractive element 2. For example, the refractive element 2 has a lower surface 21a and an upper surface 21. For example, the lower surface 21a is the surface of the refractive element 2 near the first image source 11 (which can also be considered the incident surface of the image light), and the upper surface 21 is the surface of the refractive element 2 away from the first image source 11 (which can also be considered the emitting surface of the image light). Image light rays emitted from at least the partial region (in the direction from the first end e1 of at least the partial region to the second end e2 of at least the partial region) are... Figure 1 The optical distance of the image light rays (in the image) gradually decreases as they travel from the lower surface 21a into the refractive element 2 and out of the upper surface 21.

[0049] For example, image rays emitted from at least a portion of the region correspond to the formation of the first virtual image 100 from the near end close to the observation area 5 to the far end far from the observation area 5; along the direction from the first end e1 of at least a portion of the region to the second end of at least a portion of the region, the optical distance of the image rays emitted from at least a portion of the region gradually decreases during the process from incident on the refractive element 2 to exiting the refractive element 2. For example, in Figure 1 In the display device shown, at least a portion of the area refers to the entire first display area 110, that is, the refractive element 2 is configured to refract image light emitted from the entire first display area 110. Because in Figure 1 In the illustrated embodiment, at least a portion of the area, namely the first display area 110, is used for displaying information. Figure 1 In the following description of the illustrated embodiment, the first display area 110 refers to at least a portion of the area.

[0050] The display device provided in this disclosure can realize tilt imaging. The display device does not require high installation requirements for the first image source used to realize tilt imaging (e.g., it must be tilted relative to the ground). Setting the first image source 11 does not require or hardly requires a large space. When the display device is applied to a head-up display, the device structure is compact, which increases the installation flexibility, improves the head-up display user experience, and expands the application range of the display device that realizes tilt imaging.

[0051] For example, the first image source 11, in conjunction with the refractive element 2, can enable the first display area 110 to display a tilted image, either entirely or partially. For example, image light emitted from the first display area 110 is refracted at least at the interface between the refractive element 2 and air (e.g., the medium-air interface of the refractive element 2). Figure 1 Taking three rays as an example, rays A1, B1 and C1 emitted from the display surface 20 of the first display area 110 are refracted at the interface between the refractive element 2 and the air (e.g., the interface between the upper surface 21 and the air) to obtain rays A2, B2 and C2 respectively. During the propagation of light emitted from the display surface 20 of the first display area 110, the equivalent object distance from the display surface 20 of the first image source 11 to the first reflective element 31 is reduced by the refractive element 2 (the equivalent object distance will be explained below). The refractive element 2 increases the optical distance of the image light emitted from the first display area 110 to the first reflective element 31. Furthermore, since the optical distance of the image light emitted from the first display area 110 gradually decreases from the lower surface 21a when it enters the refractive element 2 to the upper surface 21 along the direction from the first end e1 to the second end e2 of the first display area 110, for example, the positions of light rays A1, B1 and C1 when they enter the refractive element 2 from the lower surface 21a are distributed sequentially along the direction from the first end e1 to the second end e2 of the first display area 110, and the optical distance of light rays A1, B1 and C1 decreases sequentially from the lower surface 21a when they enter the refractive element 2 to the upper surface 21. Therefore, along the direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110, the aforementioned additional optical distance gradually decreases. Consequently, along the direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110, the equivalent object distance from the display surface 20 of the first display area 110 to the first reflective element 31 gradually increases, thereby realizing that the first virtual image 100 formed by the image light rays emitted from at least a portion of the area is a tilted image.

[0052] For example, when the first reflecting element 31 includes a curved reflector (e.g., a concave reflecting surface), if the optical distance between the image light emitted from the image source and the display surface of the image source (including the image light emitted from the display surface of the image source, such as the first image source 11 of this disclosure, or the image light obtained after the image light emitted from the display surface of the image source has been processed by some optical elements, such as the refractive element 2) and the concave reflector is less than the focal length of the concave reflector, then the concave reflector forms an upright and magnified virtual image based on the image. For example, according to the imaging properties of the concave reflector, when the distance between the image light emitted from the image source and the display surface of the image source and the concave reflector (e.g., the equivalent object distance) is less than the focal length of the concave reflector (that is, the image is within one focal length of the concave reflector), the image distance of the concave reflector increases as the distance between the image and the concave reflector (that is, which can be considered as the equivalent object distance) increases. For example, the image light reflected and emitted by the first reflective element 31 will be reflected to the user's eyes after passing through a reflective imaging part such as the windshield of a traffic device. It can be understood that the windshield is generally a planar structure or a curved surface structure with a small curvature. Therefore, the image distance of the virtual image seen by the user is mainly determined by the first reflective element 31. That is, the position of the virtual image formed by the image light reflected by the first reflective element 31 mainly determines the position of the virtual image of the head-up display viewed by the user (e.g., the imaging distance of the virtual image). As mentioned above, the position of the virtual image formed by the image light reflected by the first reflective element 31 (e.g., the image distance of the virtual image) increases with the increase of the distance between the image and the concave mirror. That is, the larger the equivalent object distance between the image and the concave mirror, the larger the distance between the user using the head-up display including the display device and the image they see. In other words, the larger the distance between the observation area and the image seen by the user's eyes from the observation area. In this embodiment of the present disclosure, by setting a small-volume refractive element 2 in the optical path of the image light emitted from the image source, such as the first image source 11, to the first reflective element 31, the equivalent object distance of the image light emitted from the image source to the first reflective element is adjusted, thereby changing the imaging distance of the first reflective element 31 (for example, the image distance when the image is formed after being reflected by the first reflective element 31), and thus adjusting the imaging position, for example, forming a tilted virtual image.

[0053] Compared to existing tilt imaging technologies, the display device provided in this disclosure has lower installation requirements when displaying tilted images. For example, it requires little or no change to the setting of the display surface 20 of the image source, such as the first image source 11, or the tilt angle (e.g., a non-zero angle with the horizontal direction or with the display surface of the second image source that can form a vertical image, which can also achieve a tilted image; the horizontal direction can refer to the direction parallel to the direction of travel of the traffic equipment using the head-up display and / or the display device). Therefore, this display device can reduce the installation requirements of the first image source 11 used to achieve tilt imaging, such as reducing the installation angle requirement, reducing the installation space, increasing flexibility, and expanding the applicability of the display device for achieving tilt imaging. Of course, in some other embodiments, the first image source can also be at other angles (theoretically any angle, which can be designed according to the position of the first reflective element 31). By adding corresponding refractive elements, the required tilt angle of the tilted image can be achieved. The display device provided in this disclosure can reduce the installation requirements of the first image source.

[0054] For example, the refractive element 2 is transparent, and its refractive index differs from that of air; for example, the refractive index of the refractive element 2 is greater than that of air (i.e., greater than 1). The material of the refractive element 2 can be at least one of inorganic materials, organic materials, and composite materials. For example, the inorganic material can include glass, quartz, etc.; the organic material can include polymeric materials such as resins; and the composite material can include metal oxide-doped polymethyl methacrylate, etc. The material of the refractive element 2 is not limited to the materials listed above, as long as it is transparent and has a different refractive index than air.

[0055] For example, the transmittance of the refractive element 2 to light is 60% to 100%. For example, the transmittance of the refractive element 2 to light is 80% to 99%. For example, the transmittance of the refractive element 2 to light is 90% to 99%.

[0056] The aforementioned "optical distance of the image light emitted from the first display area 110 to the first reflective element 31 via the refractive element 2" refers to the product of the geometric path of the image light emitted from the first display area 110 to the first reflective element 31 and the refractive index of the propagation medium. When the refractive element 2 is provided, the geometric path of the image light emitted from the first display area 110 to the first reflective element 31 includes the portion passing through the refractive element 2 and the portion passing through the air. The product of the portion of the image light's geometric path passing through the refractive element 2 and the refractive index of the refractive element 2 it passes through is the aforementioned "additional optical distance." Alternatively, the aforementioned "additional optical distance" can also be defined as the product of the portion of the geometric path of the image light emitted from the first display area 110 to the first reflective element 31 that passes through the refractive element 2 and the difference in refractive index obtained by subtracting the refractive index of the air from the refractive index of the refractive element 2 it passes through.

[0057] For example, a tilted image can refer to a displayed image having a non-zero and non-90° angle with the plane (e.g., the ground) of the device on which the user is using the display device (e.g., a head-up display and / or vehicle) is located. That is, the displayed image observed by the user in the observation area 5 has a non-zero and non-90° angle relative to the instantaneous ground. The displayed image seen by the user is tilted, rather than a vertical image perpendicular to the ground during the user's use of the display device. For example, the first virtual image 100 is tilted relative to the ground. For example, the displayed content of the tilted image can include road-related images, such as at least one of lane indicators, distance indicators, and turn indicators. Tilted images have a better ground-hugging effect (e.g., better augmented reality fusion effect), allowing the image to better integrate with external objects, thus improving the user experience of the display device.

[0058] For example, the first reflective element 31 can be a curved reflector, such as a concave reflector. In this case, the reflecting surface of the concave reflector is concave, for example, the surface near the display area is a concave reflecting surface. When the display device provided in this embodiment is applied to a head-up display, the curved reflector can enable the head-up display to have a longer imaging distance and a larger imaging size. Furthermore, the curved reflector can also cooperate with a curved reflective imaging part (mentioned later) such as a windshield to eliminate the virtual image distortion caused by the reflective imaging part.

[0059] For example, the reflecting surface of the second reflecting element 321 can be a freeform surface, that is, the reflecting surface of the first reflecting element 31 does not have rotational symmetry characteristics, so as to improve the imaging quality of the display device.

[0060] Figure 2AThis is a schematic diagram comparing the refraction of image light emitted from the display area of ​​the image source by the refractive element in at least one embodiment of the present disclosure with the image light emitted from the display area of ​​the image source without refraction by the refractive element. Figure 2B for Figure 1 A schematic diagram of the equivalent object distance from the display surface of the first display area to the first reflective element. Figure 2A The function of the refractive element in at least one embodiment of this disclosure will be explained using the reference image source 301 and the refractive element 2' as examples. Figure 2B The refractive element 2' in the middle can be with Figure 2A The refractive element 2 in 2A is the same, and the reference image source 301 is equivalent to the first image source 11 in 2A, except that the tilt angle of the first image source 11 is not shown. Figure 2B As shown in the diagram on the left, image rays L1 and L2 emitted from point A on the display surface of the reference image source 301 are directly incident on the reflector without passing through the refractive element. Figure 2B As shown in the diagram on the right, image rays L3 and L4, which originate from point A on the display surface of the reference image source 301, are incident on the refractive element 2' and exit from the surface of the refractive element 2' that is away from the reference image source 301. This surface of the refractive element 2' is the interface between the refractive element 2' and the air. Since the refractive index of the refractive element 2' (the refractive index of air) differs from the refractive index of air (for example, it is greater than the refractive index of air), the image rays are refracted at this interface. The refracted image rays exit from the surface of the refractive element 2' that is away from the reference image source 301 as image rays L5 and L6, respectively, and then enter the reflector. For example, when the refractive element 2' is in close contact with the light-emitting surface of the image source, image rays L3 and L4 have the same exit angle as image rays L1 and L2, respectively (the principle is similar when there is an air layer between the refractive element 2' and the light-emitting surface of the image source); in this case, the extensions of image rays L5 and L6 emitted from the surface of the refractive element 2' away from the reference image source 301 intersect at point O (i.e., Figure 2AThe two dashed lines in the diagram intersect at point O. The surface containing multiple points O corresponding to multiple image rays is equivalent to the equivalent display surface. The distance from point O to the reflector is the equivalent object distance from the reference image source 301 to the reflector. Therefore, this equivalent object distance can be considered as the distance between the position of the image source 301 imaged by the last optical element (e.g., refractive element 2' or second reflective element 321, etc.) before the first reflective element 31 and the reflector when there are optical elements between the image source 301 and the first reflective element 31. Obviously, the distance from point O to the reflector is less than the distance from point A to the reflector. That is, when the refractive element 2' is provided, the equivalent object distance from the image source 301 to the reflector is less than the distance from the image source 301 (taking point A as an example) to the reflector when the refractive element 2' is not provided. This is equivalent to reducing the distance from the display surface of the reference image source 301 to the reflector (e.g., reducing the equivalent object distance) by providing the refractive element 2' compared to the case where the refractive element 2' is not provided under the same conditions. In the embodiments of this disclosure, for example, combined with Figure 1 and Figure 2B The reflecting surface of the first reflecting element 31 includes a curved surface, for example, the first reflecting element 31 is a curved mirror. When there is an optical element, such as a refractive element 2, between the first image source 11 and the reflecting surface of the first reflecting element 31, the equivalent object distance from the first image source 11 to the first reflecting element 31 is the distance between the position of the image ray emitted from the first image source 11 that is imaged by the last optical element, i.e., the refractive element 2, before the first reflecting element 31, and the optical center of the curved reflecting surface of the first reflecting element 31. Therefore, similarly, in Figure 1 In the display device shown, when the refractive element 2 is provided, the equivalent object distance from the display surface 20 of the first image source 11 to the first reflective element 31 is smaller than the distance from the display surface 20 of the first image source 11 to the first reflective element 31 when the refractive element 2 is not provided. Compared with the case where the refractive element 2 is not provided, it is equivalent to reducing the distance from the display surface 20 of the first image source 11 to the first reflective element 31 by providing the refractive element 2. In the display device provided in the embodiments of this disclosure, since the additional optical distance gradually decreases along the direction from the first end e1 to the second end e2 of the first display area 110, the amount of reduction of the equivalent object distance gradually decreases along the direction from the first end e1 to the second end e2 of the first display area 110. Therefore, the equivalent object distance from the display surface 20 of the first display area 110 to the first reflective element 31 gradually increases along the direction from the first end e1 to the second end e2 of the first display area 110, thereby realizing that the first virtual image 100 formed by the image light emitted from at least a part of the area is a tilted image.

[0061] like Figure 2B As shown, with Figure 1Taking the leftmost ray A1-A2-A3 emitted from the first display area 110 as an example, ray A1 is emitted from the display surface 20 of the first display area 110 and refracted at the interface between the refractive element 2 and the air to become ray A2. The line segment O1O' is perpendicular to the reflective surface of the second reflective element 321, and point O1 is the intersection of the backward extension of ray A2 and O1O'. The equivalent object distance from the display surface 20 of the first display area 110 where ray A1 is emitted from the display surface 20 of the first display area 110 to the first reflective element 31 is (M1O1+A3). Similarly, Figure 1 The equivalent object distance of the light ray B1 from the position where it exits the display surface 20 of the first display area 110 to the first reflective element 31 is (M2O2+B3). Figure 1 The equivalent object distance from the position where the light ray C1 emitted from the first display area 110 exits the display surface of the first sub-display area 111 to the first reflective element 31 is (M3O3+C3). (M3O3+C3)>(M2O2+B3)>(M1O1+A3). Here, taking the above three positions from the display surface of the first display area 110 as examples, it is explained that without the display surface 20 of the first display area 110 being tilted relative to the horizontal direction, along the direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110, the equivalent object distance from the display surface 20 of the first display area 110 to the first reflective element 31 gradually increases, thereby making the first virtual image 100 the tilted image mentioned above.

[0062] For example, such as Figure 1 As shown, the height of the far end of the first virtual image 100 is greater than the height of the near end. This first virtual image 100 conforms to the perspective relationship of the human eye. Compared to the case where the height of the near end of a tilted image is greater than the height of the far end, the greater height of the far end of the first virtual image 100 makes it more comfortable for a user (e.g., a driver) to view the tilted image while driving. When this tilted first virtual image 100 is used to present, for example, a road sign on the ground, the road sign image observed by the user has a better ground-hugging effect, thus achieving a better viewing effect. For example, "height" here can refer to the height relative to the ground.

[0063] For example, in some implementations, the height of the far end of the first virtual image 100 is smaller than the height of the near end of the first virtual image 100, which can be designed according to the needs of presenting different images.

[0064] For example, the height of the far end of the first virtual image can be made higher than the height of the near end of the first virtual image by adjusting the positional relationship between the first image source and the first reflective element, and by adjusting the height of the first end and the second end of the display surface of at least a portion of the area. It should be noted that the first end of the first display area 110 is also the first end of the display surface 20 of the first display area 110, and the second end of the first display area 110 is also the second end of the display surface 20 of the first display area 110.

[0065] For example, in Figure 1 In the illustrated embodiment, the display surface 20 of the first display area 110 is parallel to the horizontal direction, meaning the display surface 20 of the first display area 110 is not tilted. For example, the height of the first end e1 of the display surface 20 relative to the ground during the user's use of the display device is equal to the height of the second end e2 of the display surface 20 relative to the ground during the user's use of the display device. Of course, in other embodiments, the display surface 20 of the first display area 110 may also have a non-zero angle with the ground, i.e., it is tilted relative to the ground, as long as the display surface 20 of the first display area 110 cooperates with the refractive element 2 and the first reflective element 31 to form a tilted first virtual image 100. For example, in other embodiments, the image light reflected by the first reflective element 31 is reflected by the windshield to form a tilted first virtual image 100. In this case, it is sufficient that the display surface 20 of the first display area 110 cooperates with the refractive element 2, the first reflective element 31, and the windshield to form a tilted first virtual image 100. For example, the second end e2 of the display surface 20 of the first display area 110 is farther away from the first reflective element 31 than the first end e1 of the display surface 20. That is, the distance between the first end e1 of the display surface 20 of the first display area 110 and the first reflective element 31 is smaller than the distance between the second end e2 of the display surface 20 of the first display area 110 and the first reflective element 31. Furthermore, since the optical distance of the image light emitted from the first display area 110 gradually decreases from the incident refractive element 2 to the emission from the refractive element 2 along the direction from the first end to the second end of the first display area 110, the equivalent object distance from the second end e2 of the display surface 20 to the first reflective element 31 is larger. As a result, the height of the far end of the first virtual image 100 is higher than the height of the near end of the first virtual image 100.

[0066] For example, in some embodiments, the image light emitted from the first display area 110 and refracted by the refractive element 2 directly enters the first reflective element 31 without passing through other reflective elements; that is, no optical element is disposed between the entire assembly of the first image source 11 and the refractive element 2 and the first reflective element 31. Another example is... Figure 1In the embodiment shown, the display device further includes a second reflective element 321, which is configured to reflect the image light from the first display area 110 after being refracted by the refractive element 2 to the first reflective element 31. Then, the first reflective element 31 reflects the image light incident on its reflective surface, and the image light reflected by the first reflective element 31 propagates to the observation area 5 to form a first virtual image 100.

[0067] For example, in other embodiments, the second reflecting element 321 may also be a plane mirror. For example, the second reflecting element 321 may also be a curved mirror, such as one or more of a freeform surface mirror, an aspherical mirror, and a spherical mirror. The embodiments of this disclosure schematically show the second reflecting element 321 as a plane mirror. Using a plane mirror can fold the optical path within the display device to save space, and can also avoid introducing additional distortion and / or size changes to the image displayed by the display device.

[0068] For example, such as Figure 2B As shown, the second reflective element 321 is located on the display side of the first image source 11. However, this is not a limitation; in other embodiments, the second reflective element may also be located on the non-display side of the first image source, with other reflective structures directing the light emitted from the first image source toward the first reflective element. The first reflective element 31 is configured to reflect image light rays that propagate toward the first reflective element 31 after being reflected by the second reflective element 321. For example, image light rays emitted from the first image source 11 are reflected toward the first reflective element 31 by the second reflective element 321. For example, the first reflective element 31 is located on the side of the second reflective element 321 facing the first image source 11. For example, no optical element is disposed between the first reflective element 31 and the second reflective element 321, and the light rays reflected by the second reflective element 321 can directly incident on the first reflective element 31. However, this is not a limitation; in other embodiments, other optical elements, such as reflective structures or lenses, may be disposed between the first reflective element and the second reflective element, with the light rays processed by these other optical elements incident on the first reflective element.

[0069] For example, the display side of the first image source 11 refers to the side on which the first image source 11 emits light. Figure 2B The illustration shows a display device including a second reflective element 321 and a first reflective element 31, but is not limited to this case. In some other embodiments, the display device may have only a first reflective element 31 without a second reflective element 321. In this case, the image light emitted from the first sub-display area 111 and the second sub-display area 112, after being refracted by the refractive element 2, is directly incident on the first reflective element 31 without being reflected by the second reflective element 321.

[0070] For example, in Figure 1In the illustrated embodiment, the refractive index of the refractive element 2 is equal along the direction from the first end e1 to the second end e2 of the first display area 110 (i.e., along the direction from the first end of at least a portion of the area to the second end of at least a portion of the area), and the thickness of the refractive element 2 gradually decreases in the direction of the principal optical axis of the image light emitted along the at least a portion of the area. For example, in at least one embodiment, the thickness of the refractive element 2 gradually decreases in the direction perpendicular to the display surface 20 of the first display area 110. As a result, the optical distance of the image light emitted from the first display area 110 in the direction from the first end e1 to the second end e2 of the first display area 110 (i.e., at least a portion of the area) gradually decreases in the process from the incident refractive element 2 to the emission from the refractive element 2, so as to gradually adjust the equivalent object distance of the display surface 20 in the direction from the first end e1 to the second end e2 of the first display area 110, so that the equivalent object distance of the display surface 20 in this direction gradually increases, thereby obtaining a tilted first virtual image 100.

[0071] For example, the "chief light, chief ray, or optical axis" mentioned above refers to the center line or axis of the light beam, and can also be considered as the main direction of light beam propagation.

[0072] For example, the direction from the first end of at least a partial area to the second end e2 of at least a partial display area, corresponding to the thickness of the refractive element of at least a partial area gradually decreasing in the direction perpendicular to the display surface of at least a partial area, means monotonically decreasing, such as linearly decreasing or non-linearly decreasing.

[0073] For example, in Figure 1 In the embodiment shown, the entire refractive element 2 can be made of the same material, for example, as an integral structure, so that the refractive index of the refractive element 2 is equal along the direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110.

[0074] For example, such as Figure 1 As shown, the surface 21 of the refractive element 2 away from the first image source 11 is a plane. This makes the surface 21 of the refractive element 2 away from the first image source 11 gradually more uniform in the direction from the first end e1 to the second end e2 of the first display area 110, making the tilt degree of the first virtual image 100 more consistent at various positions, preventing excessive bending in local areas of the tilted image, and providing a better viewing experience for the user. Of course, in other embodiments, the surface 21 of the refractive element 2 away from the first image source 11 can also be a curved surface, as long as the thickness of the refractive element 2 in the direction perpendicular to the display surface 20 of the first display area 110 gradually decreases.

[0075] For example, the exit surface of the refractive element 2 is curved; for example, the surface of the refractive element 2 away from the first image source 11 is a convex curved surface. For example, when image light passes through the refractive element 2 including the curved exit surface, the shape of the virtual image formed by the display device will change; for example, when the display device is applied to a head-up display, the virtual image observed by the user in the viewing area is curved, for example, the curved concave surface faces the user, the part of the virtual image close to the ground can display road-related instructions, and the curved part (the part of the virtual image away from the bottom surface) can display other content, such as POI information on both sides.

[0076] For example, when the surface 21 of the refractive element 2 away from the first image source 11 is a plane, the surface 21 of the refractive element 2 away from the first image source 11 has a first angle with the display surface of the first display area 110, the first angle being 1° to 60°, for example 5° to 15°; so that the tilted first virtual image 100 has a suitable tilt angle, for example, the angle between the first virtual image 100 and the ground is 5° to 90°, which has a better ground-hugging effect, and the user has a better experience of viewing the tilted image when driving a vehicle using the display device.

[0077] For example, such as Figure 1 As shown, the orthographic projection of the refractive element 2 onto the display surface of the first display area 110 is located within the first display area 110, that is, the orthographic projection of the refractive element 2 onto the display surface of the first display area 110 is located within at least a portion of the area. For example, as... Figure 1 As shown, the orthographic projection of the refractive element 2 in the first display area 110 covers the entire first display area 110, that is, the orthographic projection of the refractive element 2 in the first display area 110 covers the entire at least part of the area, so that the image light emitted from the first display area 110 is more directly incident into the refractive element 2, thereby improving the light efficiency.

[0078] For example, such as Figure 1 As shown, the refractive element 2 is attached to the first display area 110 (i.e., at least a part of the area); for example, the refractive element 2 is tightly attached to the first display area 110, for example, directly or by means of optical adhesive, that is, there is basically no air layer between the refractive element 2 and the first display area 110; in this way, the image light emitted from the first display area 110 does not pass through the air layer and directly enters the refractive element 2, which is beneficial to improving the light efficiency.

[0079] Alternatively, in some other embodiments, the refractive element includes a portion that is attached to the first display area 110 (i.e., at least a portion of the area) and a portion that is spaced apart from the first display area 110 (i.e., at least a portion of the area).

[0080] For example, a support member can be provided between the first display area 110 and the refractive element 2. The support member can be a light-transmitting thin plate covering the first display area 110, such as a glass plate. The support member is in close contact with the first display area 110, and the refractive element 2 is in close contact with the support member. The first display area 110 and the refractive element 2 are respectively in close contact with the two side surfaces of the support member. This can prevent the heavier refractive element 2 from damaging the first display area 110 and improve the stability of the device.

[0081] For example, the display device may also include a fixing structure (not shown) configured to fix the refractive element 2. For example, the fixing structure may be located at the edge of the first image source 11, and may include a slot or clip on the side of the fixing refractive element 2. Alternatively, the refractive element 2 may be attached to the first image source 11.

[0082] For example, in some embodiments, the refractive index of the image light emitted from at least a portion of the region (e.g., the first display area 110) gradually decreases along the direction from a first end to a second end of at least a portion of the region (e.g., the first display area 110).

[0083] For example, Figure 3 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 3 The illustrated embodiments and Figure 1 The illustrated embodiments have the following differences. For example, in Figure 3 In the illustrated embodiment, the refractive index of the refractive element 2 gradually decreases along the direction from the first end e1 of the first display area 110 (i.e., at least a partial area) to the second end e2 of the first display area 110, for example, by decreasing linearly or non-linearly. In this case, for example, the thickness of the refractive element 2 is equal in the direction perpendicular to the display surface 20 of the at least partial area. Thus, it is also possible to achieve a gradual decrease in the optical distance of the image light emitted from the first display area 110 along the direction from the first end e1 of the first display area 110 (i.e., at least a partial area) to the second end e2 of the first display area 110 during the process from the incident refractive element 2 to the exit of the refractive element 2, so as to gradually adjust the equivalent object distance of the display surface 20 in the direction from the first end e1 to the second end e2 of the first display area 110, so that the equivalent object distance of the display surface 20 gradually increases along this direction, thereby obtaining a tilted first virtual image 100.

[0084] Figure 3 Other features of the illustrated embodiments and Figure 1 The same applies to [the text], please refer to [the text]. Figure 1 The description will not be repeated here.

[0085] For example, Figure 4 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 4 The embodiments shown differ from those shown in 1 in the following ways. Figure 6 As shown, the first display area 110 includes a first sub-display area 111 and a second sub-display area 112, with at least a portion of the area being the first sub-display area 111. Specifically, image light emitted from the first sub-display area 111 enters the refractive element 2, is refracted at the cross-section between the refractive element 2 and air, and then propagates to the first reflective element 31. The first reflective element 31 is configured to reflect the image light emitted from the first sub-display area 111, after passing through the refractive element 2 and being reflected by the second reflective element 321, before propagating back to the first reflective element 31. This image light ultimately propagates to the observation area 5 to form a first virtual image 100. Simultaneously, image light emitted from the second sub-display area 112 is incident on the first reflective element 31 without being refracted by the refractive element 2. The first reflective element 31 is also configured to reflect the image light emitted from the second sub-display area 112 and incident on the first reflective element 31 to the observation area 5 to form a second virtual image 200. The image light emitted from the second sub-display area travels an equal distance from all positions on the display surface of the second sub-display area 112 to the first reflective element 31, and the second virtual image 200 and the first virtual image 100 have a non-zero second angle. That is, the first virtual image 100 is a tilted image, and the second virtual image 200 is a vertical image, so as to make a local part of the displayed image in the first display area 110 tilted. For example, the angle between the second virtual image 200 and the ground is greater than the angle between the first virtual image 100 and the ground.

[0086] For example, the second virtual image 200 being a vertical image means that the second virtual image 200 is vertical relative to the horizontal direction. For example, the second virtual image 200 is substantially perpendicular to the ground, and the angle between the second virtual image 200 and the ground is 90°±10°. It should be noted that when the angle between the second virtual image 200 and the ground is 80°~100°, it can be considered that the second virtual image 200 is substantially perpendicular to the ground. The horizontal direction can refer to the direction parallel to the ground on which the traffic equipment using the head-up display travels, or the direction in which the traffic equipment using the head-up display travels. Of course, the embodiments of this disclosure are not limited to the first virtual image being in an inclined direction and the second virtual image being in a vertical direction.

[0087] Compared to the case where the image light emitted from the first display area 110 does not pass through the refraction element 2 before incident on the first reflective element 31, in this embodiment, the object distance from the display surface 20 of the entire first display area 110 to the first reflective element 31 is equal. The refraction element 2 gradually reduces the reduction in the equivalent object distance from the display surface of the first sub-display area 111 to the first reflective element 31 along the direction from the first end e1 to the second end e2 of the first sub-display area 111. This results in a gradual increase in the equivalent object distance from the display surface of the first sub-display area 111 to the first reflective element 31 along the direction from the first end e1 to the second end e2 of the first sub-display area 111. The principle of the refraction element 2 cooperating with the first sub-display area 111 to achieve tilted imaging is the same as... Figure 1 The same as in.

[0088] For example, such as Figure 4 As shown, the orthographic projection of the refractive element 2 onto the first display area 110 is located within the first sub-display area 111, so that the image light emitted from the first sub-display area 111 is more directly incident into the refractive element 2, thereby improving the light efficiency.

[0089] For example, the display surface of the first sub-display area 111 may be coplanar with or not coplanar with the display surface of the second sub-display area 112. For example, the display content of the second virtual image 200 may be independent of or related to the display content of the first virtual image 100. For example, the second virtual image 200 and the first virtual image 100 may be different images or different parts of the same image. For example, the optical distance from the first sub-display area 111 to the reflective surface of the first reflective element 31 may be different from the optical distance from the second sub-display area 112 to the reflective surface of the first reflective element 31, so that the center of the first virtual image 100 generated by the image light rays emitted from the first sub-display area 111 does not coincide with the center of the second virtual image 200 generated by the image light rays emitted from the second sub-display area 112.

[0090] For example, the aforementioned "optical distance" refers to the product of the propagation path of the image light emitted from the corresponding display area to the first reflective element and the refractive index of the propagation medium. For example, the geometric path of the image light emitted from the first sub-display area 111 to the first reflective element 31 includes the portion that passes through the refractive element 2 and the portion that passes through the air.

[0091] For example, the second sub-display area 112 is located on the side of the first sub-display area 111 away from the first reflective element 31, and the second virtual image 200 is located on the side of the first virtual image 100 away from the observation area 5. Alternatively, in other embodiments, the second sub-display area 112 is located on the side of the first sub-display area 111 closer to the first reflective element 31, and the second virtual image 200 is located on the side of the first virtual image 100 closer to the observation area 5. The design can be customized as needed.

[0092] Figure 4 Other features of the illustrated embodiments and Figure 1 The same applies to [the text], please refer to [the text]. Figure 1 The description will not be repeated here.

[0093] For example, Figure 5 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 5 The illustrated embodiments and Figure 1 The illustrated embodiments have the following differences. For example... Figure 5 As shown, the refractive element 2 is spaced apart from the first display area 110 (i.e., at least a portion thereof) in a direction perpendicular to the display surface of the first display area 110. For example, there is an air layer between the refractive element 2 and the display surface of the first display area 110. Image rays emitted from the first display area 110, taking rays A0, B0, and C0 as examples, pass through this air layer and then enter the refractive element 2. Rays A0, B0, and C0 are refracted at the surface 21 of the refractive element 2 that is away from the display surface 20 of the first display area 110 to obtain rays A1, B1, and C1. The refracted image rays exit from the surface 21 of the refractive element 2 that is away from the display surface of the first display area 110 and then enter the first reflective element 31, as shown by rays A2, B2, and C2, and rays A3, B3, and C3.

[0094] For example, Figure 5In the illustrated embodiment, the lower surface of the refractive element 2 near the first image source 11 is parallel to the display surface 20 of the first display area 110; in other embodiments, the lower surface of the refractive element 2 near the first image source 11 may not be parallel to the display surface 20 of the first display area 110. In this case, along the direction from the first end e1 of the at least partial region to the second end e2 of the first display area 110, the optical distance of image light rays emitted from the display surface 20 of the first display area 110 at the same angle gradually decreases during the process from the lower surface of the refractive element 2 near the first image source 11, when incident on the refractive element 2, to the lower surface of the refractive element 2 away from the first image source 11, when exiting from the lower surface of the refractive element 2 away from the first image source 11; for example, it may be a continuous gradual decrease; for example, along the direction from the first end e1 to the second end e2 of the first display area 110, the refractive index of the refractive element 2 is equal, and the thickness of the refractive element 2 along the principal axis direction of the image light rays emitted from the first display area 110 gradually decreases, for example, linearly decreasing and then nonlinearly decreasing; or, in some embodiments In the first display area 110, along the direction from the first end e1 to the second end e2, the thickness of the image light emitted from the first display area 110 along the principal axis gradually decreases, for example, linearly and then nonlinearly. In this case, for example, the thickness of the image light emitted from the first display area 110 along the principal axis is equal; or, along the direction from the first end e1 to the second end e2, the thickness and refractive index of the image light emitted from the first display area 110 along the principal axis are non-monotonic. This is as long as the optical distance of the image light emitted from the display surface 20 of the first display area 110 at the same angle along the direction from the first end e1 to the second end e2 gradually decreases from the lower surface of the refractive element 2 near the first image source 11 to the lower surface of the refractive element 2 away from the first image source 11.

[0095] Figure 5 Other features of the illustrated embodiments and Figure 1 The same applies to [the text], please refer to [the text]. Figure 1 The description.

[0096] For example, Figure 6 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 6 The embodiments shown differ from those shown in 1 in the following ways. Figure 6As shown, the refractive element 2 includes a plurality of sub-refractive elements stacked in a direction perpendicular to the display surface 20 of the first display area 110. For example, the refractive element 2 includes a first sub-refractive element 2a and a second sub-refractive element 2b that are adjacent to each other. For example, the first sub-refractive element 2a and the second sub-refractive element 2b are stacked and in contact with each other in a direction perpendicular to the display surface 20 of the first display area 110. For example, along the direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110, the optical distance of the image light emitted from the first display area 110 gradually decreases as it travels from the incident on the overall structure composed of multiple stacked sub-refractive elements (i.e., the entire second refractive element 2) to exiting the overall structure. This causes the reduction in the object distance from the display surface 20 of the first display area 110 to the first reflective element 31 to gradually decrease along the direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110 (for example, in this embodiment, also along the direction from near the first reflective element 31 to away from the first reflective element 31). As a result, the equivalent object distance from the display surface 20 of the first display area 110 to the first reflective element 31 gradually increases along this direction, thereby obtaining a tilted first virtual image 100.

[0097] For example, the materials of the multiple sub-refractive elements can be different, resulting in different refractive indices; for instance, the first sub-refractive element 2a and the second sub-refractive element 2b are made of different materials and have different refractive indices. By employing the aforementioned scheme of the refractive element 2 comprising multiple stacked sub-refractive elements, the refractive index of the refractive element 2 can be flexibly adjusted, satisfying various refractive index requirements. This compensates for the limitations of the refractive index range of a single-layer refractive element made of a single material, and broadens the adjustment range for image light emitted from the first display area 110.

[0098] For example, in some embodiments, such as Figure 6 As shown, along the direction from the first end e1 to the second end e2 of the first display area 110, the refractive index of the refractive element 2, which is composed of a plurality of stacked sub-refractive elements, is equal, and the thickness of the refractive element 2, which is composed of a plurality of stacked refractive elements, gradually decreases in the direction perpendicular to the display surface of the first display area 110. In this case, for example, the surface 21 of the sub-refractive element 2 that is furthest from the display surface of the second sub-display area 112 from the display surface of the first display area 110, is either a plane or a curved surface, as can be specifically described in the previous description.

[0099] Alternatively, in other embodiments, along the direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110, the overall refractive index of the refractive element 2 composed of a plurality of stacked sub-refractive elements gradually decreases, and the overall thickness of the refractive element 2 composed of a plurality of stacked sub-refractive elements is equal in the direction perpendicular to the display surface of the second sub-display area 112. For example, the refractive indices of the stacked sub-refractive elements can be made different. For example, for the first and second sub-refractive elements included in the refractive element 2, which are stacked and adjacent to each other in the direction perpendicular to the display surface of the second sub-display area 112, the refractive index of the first sub-refractive element is less than that of the second sub-refractive element. Furthermore, along the direction from the first end e1 to the second end e2 of the first display area 110, the thickness of the first sub-refractive element gradually increases in the direction perpendicular to the display surface of the second sub-display area 112, and the thickness of the second sub-refractive element gradually decreases in the direction perpendicular to the display surface of the second sub-display area 112. The shapes of the surfaces of the first and second sub-refractive elements that contact each other are complementary, so that the refractive index of the overall structure formed by the stacked refractive elements gradually decreases in the direction from the first end e1 to the second end e2 of the first display area 110, and the thickness of the overall structure formed by the stacked refractive elements is equal in the direction perpendicular to the display surface of the second sub-display area 112. Of course, there are other ways to implement this solution; the above is just one example.

[0100] Figure 6 Other features of the illustrated embodiments and Figure 1 The same applies to [the text], please refer to [the text]. Figure 1 The description.

[0101] Figure 7 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 7 The illustrated embodiments and Figure 2A The illustrated embodiments have the following differences. For example... Figure 7As shown, the display device further includes a second image source 12; the second image source 12 includes a second display area 120, and image light emitted from the second display area 120 propagates to the first reflective element 31; for example, the image light emitted from the second display area 120 and propagating to the first reflective element 31 forms a third virtual image 300 different from the first virtual image 100. The optical distance from the display surface of the second display area 120 to the first reflective element 31 is not equal to the optical distance from the display surface of the first display area 110 to the first reflective element 31, so that the distances between the third virtual image 300 and the first virtual image 100 and the user are different, thereby realizing multi-layer display; and the display surface of the first display area 110 is parallel to the display surface of the second display area 120, for example, both the display surfaces of the first display area 110 and the second display area 120 are parallel to the aforementioned horizontal direction. For example, the angle between the third virtual image 300 and the ground is greater than the angle between the first virtual image 100 and the ground.

[0102] For example, the optical distance from the display surface to the first reflective element 31 can be the optical distance from the center of the display surface to the center (e.g., the optical center) of the first reflective element 31. Similarly, the optical distance from the display surface of the first display area 110 to the first reflective element 31 can be the optical distance from the center of the display surface of the first display area 110 to the center of the first reflective element 31. Likewise, the optical distance from the display surface of the second display area 120 to the first reflective element 31 can be the optical distance from the center of the display surface of the second display area 120 to the center of the first reflective element 31.

[0103] For example, the third virtual image 300 may be a virtual image that is not exactly the same as the first virtual image 100, for example, the two virtual images may differ in at least one of their positions, sizes, tilts, and image content.

[0104] For example, for the second image source 12, no refractive element is provided. The image light emitted from the second display area 120 of the second image source 12 propagates to the first reflective element 31 without passing through the refractive element, thus the third virtual image 300 is a vertical image; for example, the third virtual image 300 is vertical relative to the horizontal direction, that is, perpendicular to the horizontal direction. This horizontal direction can refer to the direction perpendicular to the plane where the observation area 5 is located, or the direction parallel to the ground on which the traffic equipment using the head-up display travels, or the direction in which the traffic equipment using the head-up display travels. Of course, the embodiments of this disclosure are not limited to the first virtual image being along the tilt direction and the third virtual image being along the vertical direction. For example, in some other embodiments, the second display area can be tilted, for example, with Figure 7The display surface of the first display area 11 shown has a non-zero included angle, so that the second virtual image is also a tilted virtual image; or, in some other embodiments, a refractive element similar to that corresponding to the first image source 11 can be provided for the second image source 12, so that the second virtual image is also a tilted virtual image. The angles of the various images in the multilayer display can be designed as needed, and the embodiments disclosed herein are not limited thereto.

[0105] For example, such as Figure 7 As shown, the display device also includes a third reflective element 322, which is configured such that image light emitted from the second display area 120 is reflected by the third reflective element 322 and then propagates to the first reflective element 31. In other embodiments, there may be no other optical elements between the second display area 120 and the first reflective element 31, i.e., the third reflective element 322 is not provided, and the image light emitted from the second display area 120 can directly incident on the first reflective element 31. Furthermore, Figure 7 The illustration shows that there are no other optical elements between the second display area 120 and the third reflective element 322, and the image light emitted from the second display area 120 is directly incident on the third reflective element 322; however, this disclosure is not limited to this, and other optical elements, such as lenses, may also be provided between the second display area 120 and the third reflective element 322. For example, the image light emitted from the second display area 120 may be processed by other optical elements before being incident on the third reflective element 322.

[0106] For example, in Figure 7 In the illustrated embodiment, the first display area 110 is located on the side of the second display area 120 away from the first reflective element 31, and the third reflective element 322 is located on the side of the second reflective element 321 away from the first reflective element 31; or, the first display area 110 is located on the side of the second display area 120 close to the first reflective element 31, and the third reflective element 322 is located on the side of the second reflective element 321 close to the first reflective element 31.

[0107] This embodiment of the present disclosure can achieve the following: the distance from the display surface of the second display area 120 to the first reflective element 31 is not equal to the distance from the display surface of the first display area 110 to the first reflective element 31 by adjusting the distance between the second reflective element 321 and the first display area 110 and the first reflective element 31, and the distance between the third reflective element 322 and the second display area 120 and the first reflective element 31 (or, the propagation distance of the image light emitted from the display surface of the second display area 120 to the first reflective element 31 is not equal to the propagation distance of the image light emitted from the display surface of the first display area 110 to the first reflective element 31), and the optical distance of the image light emitted from the first display area 110 and the second display area 120 and propagating to the first reflective element 31 is different.

[0108] For example, such as Figure 7 As shown, the reflecting surface of the first reflecting element 31 is curved, while the reflecting surfaces of the second reflecting element 321 and the third reflecting element 322 are planar.

[0109] For example, the first display area 110 and the second display area 120 can display different images to meet the user's need to view different images. This disclosure is not limited to this; for example, portions of at least two display areas can also display the same image.

[0110] Figure 7 Other features and technical effects of the illustrated embodiments can be found in the previous descriptions. Figure 1 The description.

[0111] Figure 8 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 8 The illustrated embodiments and Figure 7 The illustrated embodiments have the following differences. For example... Figure 8 As shown, the display device further includes a fifth image source 14 and a fifth reflective element 323; the fifth image source 14 includes a fifth display area 15, the display surface of the fifth display area 15 having a non-zero third angle with the display surface of the first display area 110. The third reflective element 322 is configured to reflect image light emitted from the second display area 120 to the first reflective element 31, and the fifth reflective element 323 is configured to reflect image light emitted from the fifth display area 15 to the first reflective element 31.

[0112] For example, such as Figure 8As shown, the distance from the display surface of the second display area 120 to the first reflective element 31 is not equal to the distance from the display surface of the fifth display area 15 to the first reflective element 31 (or, the propagation distance of the image light emitted from the display surface of the second display area 120 to the first reflective element 31 is not equal to the propagation distance of the image light emitted from the display surface of the fifth display area 15 to the first reflective element 31), so that the distances from the user to the third virtual image 300 and the fifth virtual image 500 formed by the reflection of the first reflective element 31 are different. In this case, the image light emitted from the second display area 120 and the fifth display area 15 is reflected to the first reflective element 31 by the third reflective element 322 and the fifth reflective element 323, respectively, and the optical distances of the image light emitted from the second display area 120 and the fifth display area 15 are different in this reflected light path. In some other embodiments, the propagation distance of the image light emitted from the display surface of the second display area 120 to the first reflective element 31 can also be equal to the propagation distance of the image light emitted from the display surface of the first display area 110 to the first reflective element 31, so as to achieve co-layer display, that is, the third virtual image 300 and the fifth virtual image 500 are at the same distance from the user; in this case, the optical distance of the image light emitted from the second display area 120 and the first display area 110 and propagating to the first reflective element 31 is the same.

[0113] For example, in Figure 8 In this configuration, the display surface of the fifth display area 15 is parallel to the display surface of the second display area 120. Therefore, the virtual images formed by the image light emitted from the fifth display area 15 and the second display area 120 after reflection by the second reflective element are approximately parallel. For example, the angle between the reflective surface of the fifth reflective element 323 and the reflective surface of the third reflective element 322 is no greater than 20°, so that the parallelism of the virtual images formed by the image light emitted from the fifth display area 15 and the second display area 120 after reflection by the first reflective element is good. This disclosure is not limited to this; when the display surface of the fifth display area 15 and the display surface of the second display area 120 are parallel, the angle between the reflective surface of the fifth reflective element 323 and the reflective surface of the third reflective element 322 can also be greater than 20°. In this case, the virtual images formed by the image light emitted from the fifth display area 15 and the second display area 120 after reflection by the first reflective element 31 have a non-zero angle. For example, when the reflective surface of the fifth reflective element 323 is parallel to the reflective surface of the third reflective element 322, the angle between the display surface of the fifth display area 15 and the display surface of the second display area 120 may not exceed 20°.

[0114] For example, such as Figure 8As shown, the angle between the reflecting surface of the third reflecting element 322 and the reflecting surface of the fifth reflecting element 323 is no greater than 15°. For example, the angle between the reflecting surface of the third reflecting element 322 and the reflecting surface of the fifth reflecting element 323 is no greater than 10°. For example, the angle between the reflecting surface of the third reflecting element 322 and the reflecting surface of the fifth reflecting element 323 is no greater than 5°. For example, the angle between the reflecting surface of the third reflecting element 322 and the reflecting surface of the fifth reflecting element 323 is 0°. For example, the reflecting surfaces of the third reflecting element 322 and the fifth reflecting element 323 can be arranged in parallel.

[0115] For example, if the third reflecting element 322 and the fifth reflecting element 323 can be plane mirrors, then the above statement "the angle between the reflecting surface of the third reflecting element 322 and the reflecting surface of the fifth reflecting element 323 is not greater than 15°" can refer to the angle between the two plane reflecting surfaces being not greater than 15°.

[0116] For example, the third reflecting element 322 and the fifth reflecting element 323 can also be one or more of curved reflectors, aspherical reflectors and spherical reflectors. In this case, the above "the angle between the reflecting surface of the third reflecting element 322 and the reflecting surface of the fifth reflecting element 323 is not greater than 15°" can refer to the angle between the planes enclosed by the edges of the reflecting surfaces being not greater than 15°.

[0117] For example, the third reflecting element 322 and the fifth reflecting element 323 can be the same type of reflector or different types of reflectors. In the embodiments of this disclosure, it is schematically shown that both the third reflecting element 322 and the fifth reflecting element 323 are planar reflectors. By using planar reflectors, the manufacturing of the display device can be facilitated, the optical path within the display device can be folded to save space, and additional distortions and size changes in the image displayed by the display device can be avoided.

[0118] For example, such as Figure 8 As shown, the second display area 120 and the fifth display area 15 can be located on the same plane. By adjusting the position and angle of the third reflective element 322 and the fifth reflective element 323, the optical distances of the image light emitted from the second display area 120 and the fifth display area 15 and propagating to the first reflective element 31 can be different. This embodiment is not limited to this. In other embodiments, for example, the second display area and the fifth display area can be located on different planes, and the third reflective element and the fifth reflective element can be located on the same plane (or different planes). By adjusting the position of the second display area and the fifth display area, the distance from the display surface of the second display area 120 to the first reflective element 31 can be unequal to the distance from the display surface of the fifth display area 15 to the first reflective element 31, resulting in different propagation distances and different optical distances of the image light emitted from the second display area 120 and the fifth display area 15 and propagating to the first reflective element 31.

[0119] exist Figure 8 In the display device shown, the distances from the display surface of the first display area 110 to the first reflective element 31, the distances from the display surface of the second display area 120 to the first reflective element 31, and the distances from the display surface of the fifth display area 15 to the first reflective element 31 are not equal. That is, the propagation distances of the image light emitted from the display surface of the first display area 110 to the first reflective element 31, the propagation distances of the image light emitted from the display surface of the second display area 120 to the first reflective element 31, and the propagation distances of the image light emitted from the display surface of the fifth display area 15 to the first reflective element 31 are not equal. This allows imaging at different distances from the observation area 5, which is beneficial for matching and fusing images at different distances with real-world scenes at different distances. When this display device is used in a head-up display, the user does not need to switch back and forth between images at a fixed distance and real-world scenes at different distances, avoiding visual convergence adjustment conflicts and improving the user experience of the display device. In this case, for example, the optical distances of the image rays emitted from the first display area 110, the second display area 120, and the fifth display area 15 and propagating to the first reflective element 31 are different from each other. Embodiments of this disclosure can achieve unequal distances from the display surfaces of the three display areas to the first reflective element 31 by adjusting the distances between the second reflective element 321 and the first display area 110 and the first reflective element 31, the distances between the third reflective element 322 and the second display area 120 and the first reflective element 31, and the distances between the fifth reflective element 323 and the fifth display area 15 and the first reflective element 31. This results in unequal propagation distances of the image rays emitted from the display surfaces of the three display areas from their respective display surfaces to the first reflective element 31, and thus, different optical distances of the image rays emitted from the three display areas and propagating to the first reflective element 31.

[0120] For example, Figure 8 The illustration schematically shows that the first virtual image 100 is an inclined virtual image, and the distance between the first virtual image 100 and the observation area 5 is greater than the distance between the fifth virtual image 500 and the observation area 5, but less than the distance between the third virtual image 300 and the observation area 5. That is, the first virtual image 100 is located between the fifth virtual image 500 and the third virtual image 300. However, it is not limited to this; the inclined virtual image can also be the virtual image farthest from the observation area, or the virtual image closest to the observation area. This embodiment of the disclosure does not limit this.

[0121] For example, such as Figure 8As shown, the first virtual image 110 is tilted relative to the horizontal direction, i.e., it forms a non-zero, non-right angle with the horizontal direction; the third virtual image 300 and the fifth virtual image 500 are vertical relative to the horizontal direction, i.e., they are perpendicular to the horizontal direction. This horizontal direction can refer to a direction perpendicular to the plane of the observation area 5, or a direction parallel to the ground on which the traffic equipment using the head-up display is moving in real time. Of course, the embodiments of this disclosure are not limited to the first virtual image being tilted in the direction of tilt, and the second and fifth virtual images being vertical. For example, one of the second and fifth virtual images can also be a tilted virtual image, for example, along the direction from the virtual image to the observation area, the virtual image is tilted towards the observation area. For example, in some other embodiments, at least one of the display surfaces of the second display area and the fifth display area can be tilted, for example, with... Figure 8 The display surface of the first display area 11 shown has a tilt setting at the same angle or different angles, so that the virtual image formed by the light emitted from at least one of the second display area and the fifth display area is a tilted image; or, in some other embodiments, at least one of the second image source 12 and the fifth image source 14 can be provided with a refractive element similar to that corresponding to the first image source 1, so that the virtual image formed by the light emitted from at least one of the second display area and the fifth display area is a tilted image.

[0122] For example, such as Figure 8 As shown, for example, the second display area 120 and the fifth display area 15 can be display areas located at different positions on the same image source, such as partitioning the same screen to save space and cost. This disclosure is not limited to this; in other embodiments, the second display area and the fifth display area can also be located on different image sources, for example, the screens of different image sources can be close together; for example, the display surfaces of different image sources can be parallel to each other to make the second display area and the fifth display area parallel. In this case, the distance between the different image sources can be set relatively large to prevent the image light emitted by the two display areas from affecting each other.

[0123] For example, such as Figure 8 As shown, the light-shielding structure 6 provided between the second display area 120 and the fifth display area 15 can prevent the image light emitted from different display areas from affecting each other. For example, the light-shielding structure 6 can be a light-blocking plate.

[0124] For example, the second image source 12 or the fifth image source 14 may include the aforementioned light-shielding structure 6, but is not limited thereto. The aforementioned light-shielding structure may also not be a structure of the second image source 12 or the fifth image source 14. For example, the aforementioned light-shielding structure 6 may be located on the display side of the second image source 12 or the fifth image source 14, for example, at least disposed on / installed on / attached (e.g., it may be attached, fixed, tightly adhered, bonded, or adsorbed, etc.) on the display screen of the second image source 12 or the fifth image source 14; the light-shielding structure 6 may be located, for example, at the junction of the second image source 12 and the fifth image source 14.

[0125] For example, such as Figure 8 As shown, the third reflective element 322 and the fifth reflective element 323 can be two independent reflective elements so that they can be adjusted independently.

[0126] For example, the second reflecting element 321, the third reflecting element 322, and the fifth reflecting element 323 can be the same type of reflector or different types of reflectors. The embodiments of this disclosure schematically show that the second reflecting element 321, the third reflecting element 322, and the fifth reflecting element 323 are all planar reflectors.

[0127] For example, in Figure 8 In the illustrated embodiment, the fifth display area 15 can display a close-up view, such as key driving data like vehicle instrument panel parameters, such as one or more parameters like vehicle speed, fuel level, and steering. The second display area 120 can display a distant view, such as buildings. For example, the distant view displayed in the second display area 120 can include point of interest (POI) icons. For instance, the image could include a bank logo, and the bank logo image can be matched and merged with the actual location of the bank, so that when the user can see distant buildings, such as banks, the bank logo is displayed on the screen.

[0128] For example, in Figure 8 In the illustrated embodiment, the fifth display area 15 is configured to display a close-up view, the content of which may be key driving parameters such as vehicle instruments. Therefore, the size of the displayed close-up view can be relatively small. The second display area 120 is configured to display a distant view, the content of which needs to be matched and blended with the real-world scenery outside the vehicle, such as buildings. Therefore, the size of the displayed distant view is larger than the size of the close-up view. For example, the smaller close-up view will not obscure the larger distant view.

[0129] For example, in Figure 8In the illustrated embodiment, the display surface of the fifth display area 15 is parallel to the display surface of the second display area 120, and both the display surfaces of the fifth display area 15 and the second display area 120 are parallel to the display surface of the first display area 110. For example, the display surfaces of the first display area 110, the second display area 120, and the fifth display area 15 are all parallel to the aforementioned horizontal direction. Furthermore, the angle between the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 is no greater than 20°, and the angle between the display surface of the fifth display area 15 and the display surface of the first display area 110 is 5° to 90°. Therefore, the fifth virtual image 500 formed by the reflection of the image light emitted from the fifth display area 15 and the second display area 120 by the first reflective element 31 is approximately parallel to the first virtual image 500. However, the first virtual image 100 formed by the reflection of the image light emitted from the first display area 110 by the first reflective element 31 is not parallel to the first virtual image 100 formed by the reflection of the image light emitted from the fifth display area 15 by the first reflective element 31. For example, the angle between the first virtual image 100 and the fifth virtual image 500 can be 5° to 90°.

[0130] Figure 8 Other features and technical effects of the illustrated embodiments can be found in the previous descriptions. Figure 7 The description.

[0131] Figure 9 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 9 The illustrated embodiments and Figure 1 The illustrated embodiments have the following differences. For example... Figure 9As shown, for example, the display device further includes a third image source 13 and a transflective element 8; the third image source 13 includes a third display area 130; the display surface of the third display area 130 has a non-zero third angle with the display surface of the first display area 110; the transflective element 8 is located on the side of the refractive element 2 away from the first image source 11, and is configured to transmit image light emitted from the first display area 110 to the first reflective element 31, and is configured to reflect image light emitted from the third display area 130, and the image light emitted from the third display area 130 propagates to the first reflective element after being reflected by the transflective element 8; the image light emitted from the third display area 130 and propagating to the first reflective element 31 forms a fourth virtual image 400 different from the first virtual image 100, the first virtual image 100 and the fourth virtual image 400 at least partially overlap, that is, the user's eye sees the first virtual image 100 and the fourth virtual image 400 at least partially overlap in the observation area 5, thereby making the first virtual image 100 and the fourth virtual image 400 coaxial. For example, the paths of the image rays that form the first virtual image 100 and are directly incident on the observation area 5 are substantially coincident with the paths of the image rays that form the fourth virtual image 400 and are directly incident on the observation area 5, thus making the first virtual image 100 and the fourth virtual image 400 coaxial. For example, the viewing angles (e.g., downward viewing angle, top-down viewing angle, the angle between the user's line of sight and the horizontal direction) of the user's eye when observing the first virtual image 100 and the fourth virtual image 400 in the observation area 5 are substantially the same.

[0132] For example, by adjusting the refractive index of the materials of the reflective element 8 and the refractive element 2, the size of the first angle between the surface 21 of the refractive element 2 away from the first image source 11 and the display surface 20 of the first display area 110, the angle between the reflective element 8 and the display surface of the third display area 130, the distance between the reflective element 8 and the display surface of the first display area 110, and the distance between the display surfaces of the third display area 130, the light B emitted from the first display area 110 after being transmitted through the reflective element 8 and the light A emitted from the third display area 130 after being reflected by the reflective element 8 can at least partially overlap to obtain light AB. Light AB propagates to the first reflective element 31 and is reflected by the first reflective element 31. The light B reflected by the first reflective element 31 forms the first virtual image 100, and the light A reflected by the first reflective element 31 forms the fourth virtual image 400. The first virtual image 100 and the fourth virtual image 400 at least partially overlap.

[0133] For example, the projection of the first virtual image 100 onto the plane where the fourth virtual image 400 is located is within the range of the fourth virtual image 400, that is, the user's eye sees the projection of the first virtual image 100 onto the plane where the fourth virtual image 400 is located within the range of the first virtual image 100 in the observation area 5; or, the projection of the fourth virtual image 400 onto the plane where the first virtual image 100 is located is within the range of the first virtual image 100, that is, the user's eye sees the projection of the fourth virtual image 400 onto the plane where the first virtual image 100 is located within the range of the first virtual image 100 in the observation area 5.

[0134] For example, the center of the first virtual image 100, the center of the fourth virtual image 400, and the center of the eye box area are on the same straight line, and the user's eyes can see that the center of the first virtual image 100 and the center of the fourth virtual image 400 coincide in the observation area 5.

[0135] For example, the projection of the first virtual image 100 onto the plane where the fourth virtual image 400 is located can be made within the range of the fourth virtual image 400 by adjusting the angle between the reflective element 8 and the display surface of the first display area 110, the angle between the reflective element 8 and the display surface of the third display area 130, the distance between the reflective element 8 and the display surface of the first display area 110, and the distance between the display surfaces of the third display area 130.

[0136] For example, the third image source 13 includes a third display area 130, the display surface of the third display area 130 having a non-zero third angle with the display surface of the first display area 110, and the first virtual image 100 being parallel to the fourth virtual image 400 or having a non-zero second angle. For example, the third angle and the fourth angle may be equal; in some embodiments, the third angle and the fourth angle may also be unequal.

[0137] For example, the distance from the display surface of the first display area 110 to the first reflective element 31 is not equal to the distance from the display surface of the third display area 130 to the first reflective element 31, or the propagation distance of the image light emitted from the display surface of the first display area 110 to the first reflective element 31 is not equal to the propagation distance of the image light emitted from the display surface of the third display area 130 to the first reflective element 31, so as to achieve multi-layer display, that is, the distance between the first virtual image 100 and the fourth virtual image 400 and the user (e.g., the driver of the traffic equipment using the display device) is different. In this case, the optical distances of the image rays emitted by the first display area 110 and the third display area 130 and propagating to the first reflective element 31 are not equal, and they can be imaged at different distances to form multi-layered images at different distances from the user. For example, the first virtual image 100 and the fourth virtual image 400 are located in different layers. Different images can be fused with real scenes at different distances. The user's gaze does not need to switch back and forth between images at a fixed distance and real scenes at different distances, which effectively improves the user experience of the head-up display.

[0138] For example, the reflectivity of the transflective element 8 to the image light emitted from the first display area 110 can be 70%, 60%, 50%, or other suitable values, and the transmittance of the image light emitted from the third display area 130 can be 30%, 40%, 50%, or other suitable values. For example, the transmittance of the transflective element 8 to the image light emitted from the third display area 130 can be 70%, 60%, 50%, or other suitable values.

[0139] For example, the transflective element 8 includes a polarized transflective element 8. The third display area 130 emits first polarized light (polarized light with a first polarization), and the first display area 110 emits second polarized light (polarized light with a second polarization). The polarization directions of the first polarized light and the second polarized light are perpendicular. The transflective element 8 is configured to reflect the first polarized light and transmit the second polarized light. For example, the first display area 110 emits second polarized light that passes through the transflective element 8.

[0140] For example, the polarizing reflective element 8 can be an element formed by coating or laminating a transparent substrate. For example, the polarizing reflective element 8 can be a reflective film with the characteristics of reflecting first polarized light and transmitting second polarized light, such as one or more of a dual brightness enhancement film (DBEF) or a brightness enhancement film (BEF), deposited or laminated on the substrate. The embodiments disclosed herein are not limited to this; for example, the reflective element 8 can also be an integrated element.

[0141] For example, the polarization transmission and reflection element 8 can be an optical film with polarization transmission and reflection function. For example, the polarization transmission and reflection element 8 can be composed of multiple layers of films with different refractive indices arranged in a certain stacking order, and the thickness of each film layer is about 10~1000nm. The material of the film layer can be an inorganic dielectric material, such as one or more of metal oxides and metal nitrides; or it can be a polymer material, such as one or more of polypropylene, polyvinyl chloride or polyethylene.

[0142] For example, one of the first polarized light and the second polarized light includes light in the S-polarized state, and the other of the first polarized light and the second polarized light includes light in the P-polarized state. For example, the angle between the polarization directions of the first polarized light and the second polarized light can be approximately 90°. The embodiments of this disclosure are not limited to this. For example, when the polarization directions of the first polarized light and the second polarized light are perpendicular, the first polarized light and the second polarized light can also be non-S-polarized light or non-P-polarized light. For example, the first polarized light and the second polarized light can be two types of linearly polarized light with mutually perpendicular polarization directions, or two types of circularly polarized light with mutually perpendicular polarization directions, or two types of elliptically polarized light with mutually perpendicular polarization directions, etc.

[0143] For example, the transflective element 8 is a wavelength-selective transflective element 8. The image light emitted from the third display area 130 is in the first band group, and the image light emitted from the first display area 110 is in the second band group. The transflective element 8 is configured to reflect the image light of the first band group and transmit the image light of the second band group.

[0144] For example, the aforementioned "band" may include a single wavelength or a mixed range of multiple wavelengths. For instance, in the case where the band includes a single wavelength, manufacturing errors could cause light of that wavelength to be mixed with light of nearby wavelengths.

[0145] For example, the image light rays of the first and second band groups mentioned above can both include light rays in the red, green, and blue (RGB) bands, with the full width at half maximum (FWHM) of each RGB band not exceeding 50 nm. For example, both the first and second band groups include image light rays in three bands; for example, the peak value of the first band is located in the range of 410 nm to 480 nm, the peak value of the second band is located in the range of 500 nm to 565 nm, and the peak value of the third band is located in the range of 590 nm to 690 nm.

[0146] For example, the wavelength of the image light in the first band of the first band group is different from the wavelength of the image light in the first band of the second band group; the wavelength of the image light in the second band of the first band group is different from the wavelength of the image light in the second band group; and the wavelength of the image light in the third band of the first band group is different from the wavelength of the image light in the third band of the second band group.

[0147] For example, the wavelengths of the image light in each band of the first band group are all shorter than the wavelengths of the image light in each band of the second band group. For example, in the first band group, the wavelength of red light is 620 nm, the wavelength of green light is 500 nm, and the wavelength of blue light is 450 nm. For example, in the second band group, the wavelength of red light is 650 nm, the wavelength of green light is 530 nm, and the wavelength of blue light is 470 nm. This disclosure is not limited to this; for example, the wavelengths of the image light in each band of the first band group are all longer than the wavelengths of the image light in each band of the second band group. For example, in the first band group, the wavelength of red light is 670 nm, the wavelength of green light is 550 nm, and the wavelength of blue light is 470 nm. For example, in the second band group, the wavelength of red light is 650 nm, the wavelength of green light is 530 nm, and the wavelength of blue light is 450 nm. The above band relationship setting facilitates the fabrication of wavelength-selective transflective elements.

[0148] For example, the image light rays of the first and second band groups mentioned above can include image light rays of multiple bands, such as at least the light rays of the three RGB bands mentioned above to form color image light rays, which can form a color image. For example, the image light rays of the first and second band groups mentioned above can include image light rays of one color band, such as the image light rays including one of the light rays of the three RGB bands mentioned above; as another example, when the wavelengths of the image light rays of the first band group and the image light rays of the second band group are different, the image light rays can include light rays of any color band in the visible light range to form monochromatic image light rays, which can form a monochromatic image, similar to the above implementation process.

[0149] For example, the reflectivity of the image light emitted from the third display area 130 can be 70%, 80%, 90%, 95%, or other suitable values, and the transmittance of the image light emitted from the first display area 110 can be 70%, 80%, 90%, 95%, or other suitable values. This improves the utilization rate of the image light, minimizing light energy loss in the image light emitted from both the first and third display areas.

[0150] For example, the first image source 11 and the third image source 13 are image sources capable of emitting RGB mixed light, such as a light-emitting diode (LED) display or a liquid crystal display (LCD). For example, in the previous embodiments, the type of the second image source can be the same as the type of the first image source 11 and the third image source 13.

[0151] For example, the transflective element can be a polarization-wavelength selective transflective element. For instance, the image light emitted from the first display area 110 and the image light emitted from the second display area 120 may have the same or substantially the same wavelength band, but they may have different polarization states. The transflective element is configured to reflect the first image light and transmit the second image light.

[0152] For example, the "band" has the same or similar characteristics as the above embodiments, and will not be repeated here. For example, the polarization directions of the first polarization state and the second polarization state are perpendicular. For example, one of the first polarization state and the second polarization state includes an S-polarization state, and the other of the first polarization state and the second polarization state includes a P-polarization state. The embodiments of this disclosure are not limited to this. For example, when the polarization directions of the first polarization state and the second polarization state are perpendicular, they can also be non-S-polarization states or non-P-polarization states. For example, the first polarization state and the second polarization state can be two linear polarization states with mutually perpendicular polarization directions, or two circular polarization states with mutually orthogonal polarization directions, or two elliptical polarization states with mutually orthogonal polarization directions, etc.

[0153] For example, the first image ray includes RGB rays in the S-polarization state, and the second image ray includes RGB rays in the P-polarization state; for example, the first image ray includes RGB rays in the P-polarization state, and the second image ray includes RGB rays in the S-polarization state.

[0154] For example, the reflectivity of the transflective element 8 for one of the first image light rays and the second image light rays is greater than its reflectivity for the other; or, the transmittance of the transflective element 8 for one of the first image light rays and the second image light rays is greater than its transmittance for the other. For example, the reflectivity of the transflective element 8 for the second image light rays is greater than its reflectivity for the first image light rays. For example, the transmittance of the transflective element 8 for the first image light rays is greater than its transmittance for the second image light rays.

[0155] For example, the reflectivity of the transflective element 8 to one of the first image light rays and the second image light rays is greater than its reflectivity to the other, and its transmittance to one is less than its transmittance to the other. For example, the reflectivity of the transflective element 8 to the second image light rays is greater than its reflectivity to the first image light rays, and its transmittance to the second image light rays is less than its transmittance to the first image light rays.

[0156] For example, the reflectivity of the polarization-wavelength selective reflective element 8 for image light emitted from the second display area 120 can be 70%, 80%, 90%, 95%, or other suitable values, while the transmittance for image light emitted from the first display area 110 can be 70%, 80%, 90%, 95%, or other suitable values. This improves the utilization rate of image light by the reflective element 8, minimizing light energy loss in the image light emitted from both the first and second display areas.

[0157] For example, the aforementioned wavelength-selective and / or polarization-wavelength-selective transmissive elements may include selective transmissive films formed by stacking inorganic oxide thin films or polymer thin films, wherein the transmissive film is formed by stacking at least two film layers with different refractive indices. Here, "different refractive indices" refers to the film layers having different refractive indices in at least one of the x, y, and z directions. For example, by pre-selecting film layers with desired different refractive indices and stacking them in a pre-set order, a transmissive film with selective reflection and selective transmission characteristics can be formed, which can selectively reflect light with one characteristic and transmit light with another characteristic. For example, for film layers using inorganic oxide materials, the composition of the film layer is selected from one or more of tantalum pentoxide, titanium dioxide, magnesium oxide, zinc oxide, zirconium oxide, silicon dioxide, magnesium fluoride, silicon nitride, silicon oxynitride, and aluminum fluoride. For example, for film layers using organic polymer materials, the organic polymer film layer includes at least two thermoplastic organic polymer film layers. For example, two thermoplastic polymer film layers are alternately arranged to form an optical film, and the two thermoplastic polymer film layers have different refractive indices. For example, the molecules of the aforementioned organic polymer materials have a chain structure. After stretching, the molecules align in a certain direction, resulting in different refractive indices in different directions. Thus, the desired film can be formed through a specific stretching process. For example, the aforementioned thermoplastic polymer can be one or more of polyethylene terephthalate (PET) and its derivatives with different degrees of polymerization, polyethylene naphthalate (PEN) and its derivatives with different degrees of polymerization, and polybutylene terephthalate (PBT) and its derivatives with different degrees of polymerization.

[0158] Figure 10 This is a schematic diagram of another display device provided for at least one embodiment of the present disclosure. Figure 10 The illustrated embodiments and Figure 9 The embodiments shown have the following differences. Figure 10 The display device shown includes Figure 9 The first image source 11, the third image source 13, the transflective element 8, and the image source 11 shown are shown. Figure 7 The second image source 12 shown, Figure 10 The display device shown is equivalent to Figure 7The technical solution shown uses image light rays emitted from the second image source 12 to form a third virtual image 300. Figure 10 The illustrated combination of techniques for forming a first virtual image 100 using image light rays emitted from a first image source 11 and forming a fourth virtual image 400 using image light rays emitted from a third image source 13.

[0159] For example, in Figure 10 In this configuration, the distances from the display surface of the first display area 110 to the first reflective element 31, the distances from the display surface of the second display area 120 to the first reflective element 31, and the distances from the display surface of the third display area 130 to the first reflective element 31 are not equal. That is, the propagation distances of the image light emitted from the display surface of the first display area 110, the second display area 120, and the third display area 130 are not equal, thus enabling imaging at different distances from the observation area 5. In this case, the optical distances of the image light emitted from the first display area 110, the second display area 120, and the third display area 130 and propagating to the first reflective element 31 are different from each other. The embodiments of this disclosure can achieve the following: the distances between the display surfaces of the three display areas and the first reflective element 31 can be unequal, and the optical distances of the image rays emitted from the three display areas and propagating to the first reflective element 31 can be different. This can be achieved by adjusting the distances between the second reflective element 321, the transflective element 8 and the first display area 110 and the first reflective element 31, the distance between the third reflective element 322 and the second display area 120 and the first reflective element 31, and the distance between the second reflective element 321 and the third display area 130 and the first reflective element 31.

[0160] Figure 10 The technical solution shown herein for forming a third virtual image 300 using image light emitted from the second image source 12 is similar to... Figure 10 The technical solutions shown for forming a first virtual image 100 using image light rays emitted from the first image source 11 and forming a fourth virtual image 400 using image light rays emitted from the third image source 13 can be referred to the previous description and will not be repeated here.

[0161] At least one embodiment of the present invention also provides a head-up display. Figure 11 This is a schematic diagram of a head-up display provided in at least one embodiment of the present disclosure, such as... Figure 11 As shown, the head-up display includes a reflective imaging unit 4 and any of the display devices provided in the embodiments of this disclosure. Figure 11 Including Figure 2ATaking the display device shown as an example, the reflective imaging unit 4 is configured to reflect image light reflected from the first reflective element 31 to the reflective imaging unit to the observation area 5, and transmit ambient light. A user located in the observation area 5 can view the first virtual image 100 formed by the reflective imaging unit 4 on the image light emitted by the display device, and the environmental scene located on the side of the reflective imaging unit 4 away from the observation area 5. The head-up display provided in at least one embodiment of this disclosure presents a tilted image to a user (e.g., a driver or passenger) with a uniform tilt angle, preventing the presented tilted image from having excessively curved portions, avoiding problems such as unclear information display and affecting user perception due to image distortion; for example, the tilted image is a road sign image on the ground, thus giving the tilted image a better ground-hugging effect, allowing the image to better integrate with external objects, improving the user experience of the display device.

[0162] Of course, in other embodiments of the head-up display, when the head-up display includes a display device employing a multi-layer display scheme, the user located in the observation area 5 can view multiple virtual images formed by the image light emitted by the display device from the reflective imaging unit 4.

[0163] For example, the image light emitted by the elliptical display device is incident on the reflective imaging unit 4, and the light reflected by the reflective imaging unit 4 is incident on the user, such as the observation area 5 where the driver's eyes are located. The user can observe the virtual image formed on, for example, outside the reflective imaging unit, without affecting the user's observation of the external environment.

[0164] For example, the observation area 5 mentioned above could be the eyebox area, which is the planar area where the user's eyes are located and where they can see the image displayed on the head-up display. For example, even if the user's eyes are offset from the center of the eyebox area by a certain distance, such as moving up and down or left and right, the user can still see the image displayed on the head-up display while their eyes are still within the eyebox area.

[0165] For example, the reflective imaging unit 4 can be a windshield or imaging window of a motor vehicle. For example, the windshield is a windshield glass, and the imaging window is a transparent imaging panel. For example, the windshield is used to transmit and reflect image light emitted by a windshield-HUD (W-HUD), and the imaging window is used to transmit and reflect image light emitted by a combined-HUD (C-HUD).

[0166] For example, such as Figure 11As shown, the head-up display also includes a housing 700 with an opening 710. The image source 100, the first reflective element 3100, and the first reflective element 31 are all located inside the housing 700. The reflective imaging unit 4 is located outside the housing 700. The first reflective element 31 reflects the image light emitted by the image source 100 to the position of the opening 710 of the housing 700 so that it can exit from the opening 710 of the housing 700. The image light emitted from the opening 710 of the housing 700 is reflected by the reflective imaging unit 4 to the observation area 5.

[0167] For example, such as Figure 11 As shown, the virtual image formed by the reflection of the image light emitted from the first display area 110 by the reflecting imaging unit 4 is the first virtual image 100. The first virtual image 110 is tilted relative to the horizontal direction, that is, it has an angle with the horizontal direction. This horizontal direction can refer to the direction perpendicular to the plane where the observation area 5 is located, or it can refer to the direction parallel to the ground on which the traffic equipment using the head-up display is moving in real time.

[0168] For example, in at least one embodiment of this disclosure, the image source may include a light source, a backlight assembly, and an image generation unit.

[0169] For example, a light source may include at least one electroluminescent device that generates light by being excited by an electric field, such as a light-emitting diode (LED), an organic light-emitting diode (OLED), a mini LED, a micro LED, a cold cathode fluorescent lamp (CCFL), a cold LED light (CLL), an electroluminescent lamp (EL), a field emission light (FED), or a quantum dot light source (QD), etc.

[0170] For example, the image generation unit may include a liquid crystal display panel. For example, the liquid crystal display panel may include an array substrate, a counter substrate, a liquid crystal layer located between the array substrate and the counter substrate, and an encapsulating adhesive for encapsulating the liquid crystal layer. For example, the liquid crystal display panel may also include a first polarizing layer disposed on the side of the array substrate away from the counter substrate and a second polarizing layer disposed on the side of the counter substrate away from the array substrate. For example, a light source is configured to provide backlight to the liquid crystal display panel, and the backlight is converted into image light after passing through the liquid crystal display panel.

[0171] For example, at least one embodiment of this disclosure also provides a transportation device. Figure 12This is a schematic diagram of a transportation device provided for at least one embodiment of the present disclosure. Figure 12 As shown, any of the head-up displays provided in the embodiments of this disclosure may be used. Alternatively, in at least one embodiment, the transportation equipment may include any of the display devices provided in the embodiments of this disclosure.

[0172] For example, in the case of a traffic device including a head-up display, the reflective imaging unit is the windshield or imaging window of the traffic device; that is, the front window (e.g., the windshield) of the traffic device is reused as the reflective imaging unit 4 of the head-up display. The traffic device provided in this embodiment, using the aforementioned head-up display, can present a uniform tilt angle to the user (e.g., a driver or passenger) of the tilted image, such as the first virtual image 100. This prevents the presented tilted image from having excessively curved portions, avoiding problems such as unclear information display and negative impacts on user experience due to image distortion. For example, if the tilted image is a road sign image on the ground, it provides a better ground-hugging effect, allowing the image to better integrate with external objects, thus improving the user experience of the display device.

[0173] For example, when the aforementioned head-up display is applied to traffic equipment, the third virtual image 300, the fourth virtual image 400, and the fifth virtual image 500 are perpendicular to the ground. The end of the first virtual image 100 furthest from the ground is farther from the observation area 5 than the end of the first virtual image 100 closest to the ground. This allows each virtual image to be matched and fused with the corresponding real scene, enabling the driver to view the image at different distances. This facilitates the matching and fusion of images at different distances with real scenes at different distances, eliminating the need for the driver to switch back and forth between images at a fixed distance and real scenes at different distances. This avoids visual convergence and accommodation conflicts and improves the user experience of the traffic equipment.

[0174] Of course, the multiple virtual images generated by the display device and the head-up display are not limited to the first virtual image 100, the third virtual image 300, the fourth virtual image 400 and the fifth virtual image 500. These virtual images are only examples to explain the scheme of this disclosure, and may also include other tilted virtual images or vertical virtual images.

[0175] For example, the transportation equipment can be various suitable means of transportation. For instance, if a windshield is provided in the driver's position of the transportation equipment and an image is projected onto the windshield via an in-vehicle display system, it can include various types of land transportation equipment such as automobiles, or it can be water transportation equipment such as boats.

[0176] It should be noted that, for clarity, the thickness of layers or regions in the drawings used to describe embodiments of this disclosure is enlarged or reduced, i.e., these drawings are not drawn to actual scale.

[0177] Although the present disclosure has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to the embodiments of the present disclosure, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present disclosure are within the scope of protection claimed by the present disclosure.

[0178] The following points need to be explained:

[0179] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure, and other structures can be referred to the general design.

[0180] (2) Where there is no conflict, features of the same embodiment and different embodiments of this disclosure may be combined with each other.

[0181] The above description is merely an exemplary embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure, which is determined by the appended claims.

Claims

1. A display device, comprising: The first image source includes the first display area; A refractive element is configured to refract image light emitted from at least a portion of the first display area; as well as The first reflecting element, wherein the image light rays refracted by the refractive element are reflected by the first reflecting element and propagated to the observation area to form a first virtual image; Along the direction from the first end of the at least partial region to the second end of the at least partial region, the optical distance between at least a portion of the image rays emitted from the at least partial region and the incident surface of the refractive element and the emitting surface of the refractive element gradually decreases. The first display area includes a first sub-display area and a second sub-display area, wherein at least a portion of the area is the first sub-display area; Image light emitted from the second sub-display area is incident on the first reflective element without being refracted by the refractive element. The first reflective element is further configured to reflect the image light emitted from the second sub-display area and incident on the first reflective element to the observation area to form a second virtual image. The angle between the second virtual image and the ground is greater than the angle between the first virtual image and the ground, and the second virtual image and the first virtual image have a non-zero second angle.

2. The display device according to claim 1, wherein, The first virtual image corresponding to the image rays emitted from the at least part of the region has a proximal end close to the observation area and a distal end far from the observation area. The image ray corresponding to the first end corresponds to the proximal end, and the image ray corresponding to the second end corresponds to the distal end. The height of the distal end of the first virtual image is higher than the height of the proximal end of the first virtual image.

3. The display device according to claim 1, wherein, Along the direction from the first end of the at least partial region to the second end of the at least partial region, the thickness of the refractive element in the direction of the principal optical axis of the image light emitted along the at least partial region gradually decreases; and / or, along the direction from the first end of the at least partial region to the second end of the at least partial region, the refractive index of the refractive element in the direction of the principal optical axis of the image light emitted along the at least partial region gradually decreases.

4. The display device according to claim 3, wherein, Along the direction from the first end of the at least partial region to the second end of the at least partial region, as the thickness of the refractive element gradually decreases in the direction of the principal optical axis of the image light emitted along the at least partial region, the refractive index of the refractive element is equal. Along the direction from the first end of the at least partial region to the second end of the at least partial region, as the refractive index gradually decreases, the thickness of the refractive element is equal in the direction of the principal optical axis of the image light emitted along the at least partial region.

5. The display device according to claim 3, wherein, The surface of the refractive element away from the first image source includes a plane and / or a curved surface.

6. The display device according to claim 5, wherein, When the surface of the refractive element away from the first image source is a plane, the surface of the refractive element away from the first image source has a first angle with the display surface of the first display area, and the first angle is 1° to 60°.

7. The display device according to claim 1, wherein, The refractive element is attached to the at least partial region; or... The refractive element is spaced apart from the at least part of the region in a direction perpendicular to the display surface of the first display area; or, The refractive element includes a portion that is attached to the at least partial region and a portion that is spaced apart from the at least partial region.

8. The display device according to claim 1, wherein, The refractive element is configured to refract image light emitted from the entire first display area.

9. The display device according to claim 1, wherein, The display content of the second virtual image is independent of or related to the display content of the first virtual image.

10. The display device according to claim 1, wherein, The refractive element is an integrated structure, or comprises multiple sub-refractive elements stacked in a direction perpendicular to the display surface of the first display area.

11. The display device according to claim 1, further comprising: The second reflective element is configured to reflect image light emitted from the first display area and refracted by the refractive element back to the first reflective element.

12. The display device according to any one of claims 1-11, further comprising: The second image source includes a second display area, wherein image light emitted from the second display area propagates to the first reflective element, and image light emitted from the second display area and propagating to the first reflective element forms a third virtual image different from the first virtual image; and... The angle between the third virtual image and the ground is greater than the angle between the first virtual image and the ground, and the display surface of the first display area is parallel to the display surface of the second display area.

13. The display device according to claim 12, further comprising: A third reflective element, wherein the image light emitted from the second display area is reflected by the third reflective element and then propagates to the first reflective element.

14. The display device according to claim 1, further comprising: A third image source includes a third display area, wherein the display surface of the third display area has a non-zero third angle with the display surface of the first display area; and A transflective element, located on the side of the refractive element away from the first image source, is configured to transmit image light emitted from the first display area to the first reflective element, and is also configured to reflect image light emitted from the third display area, wherein the image light emitted from the third display area, after being reflected by the transflective element, propagates to the first reflective element. Image light rays emitted from the third display area and propagating to the first reflective element form a fourth virtual image different from the first virtual image, and the first virtual image and the fourth virtual image at least partially overlap.

15. The display device according to claim 14, wherein, The projection of the first virtual image onto the plane where the fourth virtual image is located is within the range of the fourth virtual image, or the projection of the fourth virtual image onto the plane where the first virtual image is located is within the range of the first virtual image.

16. The display device according to claim 14, wherein, The center of the first virtual image, the center of the fourth virtual image, and the center of the eye box region are all on the same straight line.

17. A head-up display, comprising a reflective imaging unit and a display device according to any one of claims 1-16, in, The reflective imaging unit is configured to reflect image light that has been reflected by the first reflective element and propagated to the reflective imaging unit to the observation area, while transmitting ambient light.

18. A transportation device comprising a display device according to any one of claims 1-16, or a head-up display according to claim 17.

19. The transportation equipment according to claim 18, wherein, The transportation equipment includes a head-up display according to claim 17, wherein the reflective imaging unit is a windshield or imaging window of the transportation equipment.

Images