CN218213623U

CN218213623U - Display device, head-up display and traffic equipment

Info

Publication number: CN218213623U
Application number: CN202123406916.1U
Authority: CN
Inventors: 徐俊峰; 方涛; 吴慧军
Original assignee: Futurus Technology Co Ltd
Current assignee: Futurus Technology Co Ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2023-01-03
Anticipated expiration: 2031-12-30

Abstract

A display device, a head-up display and a traffic device are provided. In the display device, a first image source comprises a first display area; the refraction element is configured to refract image light emitted from at least a partial area of the first display area; the image light rays refracted by the refraction element are reflected by the first reflection element and spread 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 the light incident surface of the refractive element and the light emitting surface of the refractive element of at least partial image light rays emitted from the at least partial region is gradually reduced. The display device can reduce the requirement on the installation angle of the first image source for realizing oblique imaging, has small occupied space and compact structure, increases the flexibility, and expands the application range of the display device for realizing oblique imaging.

Description

Display device, head-up display and traffic equipment

Technical Field

At least one embodiment of the present disclosure relates to a display device, a head-up display, and a transportation apparatus.

Background

The Head Up Display (HUD) device can project image light (including vehicle information such as vehicle speed) emitted by an image source onto an imaging window (such as a windshield, an imaging plate and the like) by utilizing a reflection type optical design, so that a user (such as a driver and/or a passenger) can directly see the information without looking down at an instrument panel in the driving process, the driving safety factor can be improved, and better driving experience can be brought.

The display frame of the head-up display can be an inclined frame, i.e. the display frame is inclined visually by human eyes. For example, the inclined picture has a lower near end (end close to the user) and a higher far end (end close to the user), so that the inclined picture has a better ground effect compared with the vertical picture, and the image can be better combined with external objects, for example, the inclined picture displays static or dynamic turning arrows or other road signs on the ground, and the road signs in the display picture appear to be attached to the road surface, so that the inclined picture has a better indication effect.

SUMMERY OF THE UTILITY MODEL

At least one embodiment of the present disclosure provides a display device, including: a first image source, a refractive element, and a first reflective element. The first image source comprises a first display area; the refraction element is configured to refract image light emitted from at least a partial area of the first display area; the image light rays refracted by the refraction element are reflected by the first reflection element and spread to the observation area to form a first virtual image; and 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 the light incident surface of the refractive element and the light emitting surface of the refractive element of at least partial image light rays emitted from the at least partial region is gradually reduced. The display device provided by the embodiment of the disclosure can realize oblique imaging, and does not require a larger installation space for the first image source. Compared with the existing oblique imaging technology, the display device provided by the embodiment of the disclosure can realize oblique images without making the image source have higher installation requirements (such as higher installation angle and larger installation space), has a simple and compact structure, and can also realize oblique images. Therefore, the display device can reduce the installation requirement on the first image source for realizing oblique imaging, has small occupied space and compact structure, increases the flexibility and expands the application range of the display device for realizing oblique imaging.

For example, in the display device provided by an embodiment of the present disclosure, the first virtual image corresponding to the image light emitted from the at least partial region has a near end close to the observation region and a far end far from the observation region, the image light corresponding to the first end corresponds to the near end, the image light corresponding to the second end corresponds to the far end, and a height of the far end of the first virtual image is higher than a height of the near end of the first virtual image.

For example, an embodiment of the present disclosure provides a display device in which, in a direction from a first end of the at least partial region to a second end of the at least partial region, a thickness of the refractive element in a main optical axis direction of an image light ray exiting along the at least partial region gradually becomes smaller; and/or the refractive index of the refractive element in the direction of the main optical axis of the image light exiting the at least partial region tapers in the direction from the first end of the at least partial region to the second end of the at least partial region

For example, an embodiment of the present disclosure provides a display device in which, in a direction from a first end of the at least partial region to a second end of the at least partial region, refractive indices of the refractive elements are equal with a thickness of the refractive elements in a main optical axis direction of image light exiting along the at least partial region gradually decreasing; the thickness of the refractive element in the direction of the main optical axis of the image light exiting along the at least partial region is equal with the refractive index gradually decreasing in the direction from the first end of the at least partial region to the second end of the at least partial region.

For example, an embodiment of the present disclosure provides a display device, wherein a surface of the refractive element away from the first image source includes a flat surface and/or a curved surface.

For example, in the display device provided in an embodiment of the present disclosure, when a surface of the refractive element away from the first image source is a plane, a first included angle is formed between the surface of the refractive element away from the first image source and the display surface of the first display area, and the first included angle is 1 ° to 60 °.

For example, an embodiment of the present disclosure provides a display device, wherein the refractive element is attached to the at least partial region; or, the refractive element is spaced from the at least partial region in a direction perpendicular to the display surface of the first display region; alternatively, the refractive element comprises a portion conforming to the at least partial region and a portion spaced from the at least part.

For example, an embodiment of the present disclosure provides a display device, wherein the refraction element is configured to refract image light emitted from the entire first display area.

For example, in a display device provided by an embodiment of the present disclosure, the first display area includes a first sub-display area and a second sub-display area, and the at least partial area is the first sub-display area; the image light rays emitted from the second sub-display area are incident to the first reflection element without being refracted by the refraction element, the first reflection element is further configured to reflect the image light rays emitted from the second sub-display area and incident to the first reflection element to the observation area so as to form a second virtual image, an included angle between the second virtual image and the ground is larger than an included angle between the first virtual image and the ground, and the second virtual image and the first virtual image have a nonzero second included angle.

For example, an embodiment of the present disclosure provides a display device in which the display content of the second virtual image and the display content of the first virtual image are independent of each other or related to each other.

For example, an embodiment of the present disclosure provides a display device, in which the refractive element is a unitary structure or includes a plurality of sub-refractive elements stacked in a direction perpendicular to a display surface of the first display region.

For example, an embodiment of the present disclosure provides a display device, further including a second reflective element, where the second reflective element is configured to reflect the image light emitted from the first display area and refracted by the refractive element to the first reflective element.

For example, an embodiment of the present disclosure provides a display device further including a second image source, where the second image source includes a second display area; image light rays emitted by the second display area are transmitted to the first reflecting element, and image light rays emitted from the second display area and transmitted to the first reflecting element form a third virtual image different from the first virtual image; and an included angle between the third virtual image and the ground is larger than an included 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.

For example, an embodiment of the present disclosure provides a display device further including a third reflective element; the image light emitted by the second display area is transmitted to the first reflecting element after being reflected by the third reflecting element.

For example, one embodiment of the present disclosure provides a display device further comprising a third image source and a transflective element; the third image source comprises a third display area; the display surface of the third display area and the display surface of the first display area form a non-zero third included angle; the transflective element is positioned on one side of the refractive element far away from the first image source, is configured to transmit the image light emitted by the first display area to the first reflecting element, and is configured to reflect the image light emitted by the third display area, and the image light emitted by the third display area is transmitted to the first reflecting element after being reflected by the transflective element; image light rays which are emitted from the third display area and travel to the first reflecting element form a fourth virtual image different from the first virtual image, and the first virtual image and the fourth virtual image are at least partially overlapped.

For example, an embodiment of the present disclosure provides a display device in which projection of the first virtual image on a plane on which the fourth virtual image is located is within a range of the fourth virtual image, or projection of the fourth virtual image on a plane on which the first virtual image is located is within a range of the first virtual image.

For example, an embodiment of the present disclosure provides a display device, in which a center of the first virtual image, a center of the fourth virtual image, and a center of the eye box region are located on a same straight line.

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

At least one embodiment of the present disclosure further provides a transportation device, which includes any one of the display devices provided in the embodiments of the present disclosure, or any one of the heads up displays provided in the embodiments of the present disclosure.

For example, an embodiment of the present disclosure provides a traffic device, where the traffic device includes the head-up display, the reflective imaging portion is a windshield or an imaging window of the traffic device.

Drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the drawings of the embodiments will be briefly described below, and it is obvious that the drawings in the following description only relate to some embodiments of the present invention, and are not intended to limit the present invention.

Fig. 1 is a schematic diagram of a display device according to at least one embodiment of the present disclosure;

fig. 2A is a schematic diagram illustrating a situation that a refraction element refracts an image light emitted from a display area of an image source in at least one embodiment of the present disclosure and a comparison that the image light emitted from the display area of the image source is not refracted by the refraction element;

fig. 2B is a schematic view of an equivalent distance from the display surface of the first display area to the first reflective element in at least one embodiment of the present disclosure;

fig. 3 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure;

fig. 4 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure;

fig. 5 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure;

fig. 6 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure;

fig. 7 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure;

fig. 8 is a schematic view of another display device provided in at least one embodiment of the present disclosure;

fig. 9 is a schematic view of another display device provided in at least one embodiment of the present disclosure;

fig. 10 is a schematic view of another display device provided in at least one embodiment of the present disclosure;

fig. 11 is a schematic diagram of a head-up display according to at least one embodiment of the present disclosure;

fig. 12 is a schematic view of a transportation device according to at least one embodiment of the present disclosure.

Detailed Description

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention are combined below to clearly and completely describe the technical solution of the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be obtained by a person skilled in the art without any inventive work based on the described embodiments of the present invention, belong to the protection scope of the present invention.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items.

The terms "parallel," "perpendicular," and "the same" as used in the embodiments of the present disclosure include strictly "parallel," "perpendicular," "the same," and the like, and the terms "substantially parallel," "substantially perpendicular," "substantially the same," and the like, include certain errors, which are within an acceptable range of deviation for a particular value, as determined by one of ordinary skill in the art, in view of the error associated with measuring the particular value (e.g., the limitations of the measurement system). For example, "approximately" can mean within one or more standard deviations, or within 10% or 5% of the stated value. When the number of one component is not particularly specified in the following of the embodiments of the present disclosure, it means that the component may be one or more, or may be understood as at least one. "at least one" means one or more, and "a plurality" means at least two.

The Head-Up Display (HUD) can form an image inclined relative to the road surface, and the inclined image is more suitable for the viewing habit of human eyes, for example, the effect is better when the HUD is augmented reality fused with the external environment, for example, the inclined image displays the content (such as a lane keeping indicator) related to the road, the ground effect is better, and the use experience is better. However, forming a tilted image by using a HUD generally requires adjusting the image source of the HUD device and even further adjusting the position of the mirror, for example, tilting the image source, which results in a HUD device that is bulky, occupies a large space, and causes a reduction in convenience in use of the HUD device. The utility model provides a can form oblique image and compact structure's display device can be used for the HUD and reduce the volume of HUD device when forming oblique image, promotes HUD's use experience and convenience.

The drawings in this disclosure are not necessarily to scale, nor are the number of image sources and images in a display device limited to the number shown in the drawings, and the specific size and number of each structure may be determined according to actual needs. The drawings described in this disclosure are schematic only.

It should be noted that the sizes and proportions of the elements and the dimensions of the geometric paths in the drawings of the present disclosure are only schematic, and are not limited to the sizes and proportions of the actual elements and the dimensions of the geometric paths, and the lengths of the geometric paths are particularly referred to and should be understood in conjunction with the description.

At least one embodiment of the present disclosure provides a display device, including: a first image source, a refractive element, and a first reflective element. The first image source comprises a first display area; the refraction element is configured to refract image light emitted from at least a partial area of the first display area; the image light rays refracted by the refraction element are reflected by the first reflection element and spread 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 the light incident surface of the refractive element and the light emitting surface of the refractive element of at least partial image light rays emitted from the at least partial region is gradually reduced. The display device provided by the embodiment of the disclosure can realize oblique imaging, and does not require a larger installation space for the first image source. The first image source and the refraction element are matched to realize that all or part of the display picture of the first display area presents an inclined image. Compared with the existing oblique imaging technology, the display device provided by the embodiment of the disclosure can realize oblique images without making the image source have higher installation requirements (such as higher installation angle and larger installation space), has a simple and compact structure, and can also realize oblique images. Therefore, the display device can reduce the installation requirement on the first image source for realizing oblique imaging, has small occupied space and compact structure, increases the flexibility and expands the application range of the display device for realizing oblique imaging.

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

The following describes a display device, a head-up display, and a transportation apparatus provided in an embodiment of the present disclosure with reference to the drawings. It should be noted that the same components may be arranged in the same manner, all the embodiments of the present disclosure are applicable to multiple protection subject matters such as a display device, a head-up display, and a transportation device, and the same or similar contents are not repeated in each protection subject matter, and reference may be made to the description in the embodiments corresponding to other protection subject matters.

Fig. 1 is a schematic view of a display device according to at least one embodiment of the present disclosure. As shown in fig. 1, the display device comprises 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; a refractive element 2 configured to refract image light emitted from at least a partial region of the first display region 110; the first reflective element 31 is configured such that the image light rays refracted by the refractive element 2 are reflected by the first reflective element 31 and propagate to the observation region 5 to form a first virtual image 100; the refraction element 2 has a light incident surface 21a and a light emitting surface 21; in a direction from the first end e1 of the at least partial region to the second end e2 of the at least partial region, an optical distance between the light incident surface 21a of the refractive element 2 and the light emitting surface 21 of the refractive element 2 of at least a part of the image light rays emitted from the at least partial region gradually decreases, that is, an optical distance between the incident refractive element 2 and the light emitting surface 21 of the refractive element 2 of at least a part of the image light rays emitted from the at least partial region gradually decreases. For example, the refractive element 2 has a lower surface 21a and an upper surface 21. For example, the lower surface 21a is a surface of the refractive element 2 close to the first image source 11 (may be considered as a light incident surface of the image light), and the upper surface 21 is a surface of the refractive element 2 far from the first image source 11 (may be considered as a light emitting surface of the image light). In a direction from the first end e1 of the at least partial region to the second end e2 of the at least partial region, an optical distance of an image ray (in the image ray in fig. 1) exiting from the at least partial region in a process from the incidence of the refractive element 2 on the lower surface 21a to the exit from the upper surface 21 becomes gradually smaller.

For example, the image light rays exiting from at least a partial region correspond to the first virtual image 100 from a near end near the observation region 5 to a far end far from the observation region 5; the optical distance of the image light exiting from the at least partial area in the direction from the first end e1 of the at least partial area to the second end of the at least partial area in the process from the entrance of the refractive element 2 to the exit of the refractive element 2 becomes gradually smaller. For example, in the display device shown in fig. 1, at least a partial region refers to the entire first display region 110, that is, the refractive element 2 is configured to refract image light emitted from the entire first display region 110. Since in the embodiment shown in fig. 1, at least a partial region is also referred to as the first display region 110, in the following description of the embodiment shown in fig. 1, the first display region 110 is referred to as at least a partial region.

The display device provided by the embodiment of the disclosure can realize oblique imaging, the display device does not require higher installation requirements for the first image source for realizing oblique imaging (for example, the first image source is required to be inclined relative to the ground), and the first image source 11 is arranged without or almost without occupying larger space.

For example, the first image source 11 and the refractive element 2 cooperate to enable all or part of the display screen of the first display area 110 to display an oblique image. For example, the image light emitted from the first display area 110 is refracted at least at the interface between the refractive element 2 and the air (e.g., the medium-air interface of the refractive element 2), for example, in fig. 1, taking three light rays as an example, the light ray A1, the light ray B1, and the light ray 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 the light ray A2, the light ray B2, and the light ray C2. In the process of transmitting the 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 is explained below), and the optical distance from the display surface 20 of the first display area 110 to the first reflective element 31 is increased by the refractive element 2; also, since the optical distance of the image light emitted from the first display region 110 in the process from the entrance of the refractive element 2 from the lower surface 21a to the exit from the upper surface 21 becomes gradually smaller in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, for example, the positions where the light A1, the light B1, and the light C1 enter the refractive element 2 from the lower surface 21a are distributed in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110 in this order, and the optical distances of the light A1, the light B1, and the light C1 in the process from the entrance of the refractive element 2 from the lower surface 21a to the exit from the upper surface 21 are reduced in this order. Therefore, the additional optical distance is gradually decreased in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, and thus, an equivalent object distance from the display surface 20 of the first display region 110 to the first reflective element 31 is gradually increased in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, thereby implementing that the image light emitted from at least a partial region corresponds to the formed first virtual image 100 as an oblique image.

For example, in the case where the first reflecting element 31 includes a curved mirror (for example, the reflecting surface is a concave surface), if the optical distance between the image light rays emitted from the image source (including the image light rays emitted from the image source such as the display surface of the first image source 11 of the present disclosure, or the image light rays obtained by processing the image light rays emitted from the display surface of the image source by some optical elements such as the refractive element 2) and the concave mirror is smaller than the focal length of the concave mirror, the concave mirror forms an erect enlarged virtual image based on the image. For example, according to the imaging property of the concave mirror, in the case that the distance (e.g., the equivalent object distance) between the image light emitted from the image source and the concave mirror from the display surface of the image source is smaller than the focal length of the concave mirror (i.e., the image is located within one focal length of the concave mirror), the image distance of the concave mirror increases with the increase of the distance (i.e., the equivalent object distance) between the image and the concave mirror. For example, the image light reflected and emitted by the first reflecting element 31 may pass through a reflective imaging part such as a windshield of a transportation device and be reflected to the eyes of the user, and it can be understood that the windshield is generally a plane structure or a curved structure with a small curvature, so that the image distance of the virtual image seen by the user is mainly determined by the first reflecting element 31, that is, the position of the virtual image formed by the first reflecting element 31 reflecting the image light mainly determines the position of the virtual image of the head-up display viewed by the user (for example, the imaging distance of the virtual image); as described above, the position of the virtual image (e.g., virtual image distance) into which the first reflecting element 31 reflects the image light rays increases as the distance between the image and the concave reflecting mirror increases, that is, the larger the equivalent object distance between the image and the concave reflecting mirror is, the larger the distance between the user using the heads up display including the display device and the image viewed therefrom is, that is, the larger the distance between the observation region and the image viewed from the observation region by the eyes of the user is. In the embodiment of the present disclosure, by disposing the refractive element 2 with a small volume on the optical path of the image source, for example, the first image source 11, where the emitted image light propagates to the first reflective element 31, so as to adjust the equivalent object distance of the image light emitted by the image source propagating to the first reflective element, thereby changing the imaging distance (for example, the image distance when imaging after being reflected by the first reflective element 31) imaged by the first reflective element 31, the adjustment of the imaging position is achieved, for example, an oblique virtual image can be formed.

Compared with the existing oblique imaging technology, the display device provided by the embodiment of the disclosure can achieve oblique images, and the installation requirement of the display device is lower, for example, the installation requirement of the display device can be lower, for example, the installation requirement of the first image source 11 for achieving oblique imaging can be reduced, the installation space can be reduced, the flexibility can be increased, and the applicability of the display device for achieving oblique imaging can be expanded, when the display device provided by the embodiment of the disclosure can achieve oblique images, the arrangement mode of the display surface 20 of the image source such as the first image source 11 can be changed without changing or changing the arrangement mode of the image source such as the oblique angle (for example, the oblique angle is a non-zero included angle with the display surface of the second image source which can form a vertical image), and therefore, the display device can reduce the installation requirement of the oblique images by adding the corresponding refraction element and expanding the applicability of the display device for achieving oblique imaging.

For example, the refractive element 2 is light-transmissive, the refractive index of the refractive element 2 being different from the refractive index of air, e.g. the refractive index of the refractive element 2 is larger than the refractive index of air (i.e. larger than 1). For example, the material of the refractive element 2 may be at least one of an inorganic material, an organic material, and a composite material; for example, the inorganic material may include glass, quartz, or the like, the organic material may include, for example, a high molecular material such as a resin material or the like, and the composite material may include metal oxide doped-polymethylmethacrylate or the like. The material of the refractive element 2 is not limited to the above-mentioned materials, and may be a material that transmits light and has a refractive index different from that of air.

For example, the light transmittance of the refractive element 2 is 60% to 100%. For example, the refractive element 2 has a light transmittance of 80% to 99%. For example, the refractive element 2 has a light transmittance of 90% to 99%.

The above-mentioned "optical distance that the refractive element 2 gives to the image light emitted from the first display region 110 to propagate to the first reflective element 31" refers to the product of the geometric path of the image light emitted from the corresponding first display region 110 to exit to the first reflective element 31 and the refractive index of the propagation medium. In the case where the refractive elements 2 are provided, the geometric path of the image ray exiting from the first display region 110 to the first reflective element 31 includes a portion thereof passing through the refractive element 2 and a portion thereof passing through air, and the product of the portion of the geometric path of the image ray passing through the refractive element 2 and the refractive index of the refractive element 2 passing therethrough is the above-mentioned "additional optical distance". Alternatively, the "additional optical distance" may be defined as a product of a refractive index difference obtained by subtracting a refractive index of air from a refractive index of the refractive element 2 which passes through a portion of a geometric path of the image light emitted from the first display region 110 in the process of propagating to the first reflective element 31, the portion passing through the refractive element 2.

For example, a tilted image may refer to a displayed image that has a non-zero and non-90 ° angle to the surface (e.g., the ground) of the device (e.g., the heads-up display and/or the vehicle) on which the user is positioned during use of the display device, i.e., a displayed image viewed by the user in the viewing area 5 has a non-zero and non-90 ° angle to the immediate ground, and a displayed image that is visually perceived by the user as tilted rather than perpendicular to the vertical image of the ground during use of the display device by the user. For example, the first virtual image 100 is tilted with respect to the ground. For example, the display content of the oblique image may be included in the image related to the road, such as at least one of the lane indicator, the forward distance indicator and the turn indicator, the oblique image has a better ground effect (e.g. a better augmented reality fusion effect), so that the image can be better combined with the external real object, and the use experience of the display device for the user is improved.

For example, the first reflective element 31 may be a curved mirror, for example, the curved mirror may be a concave mirror; in this case, the reflecting surface of the concave reflecting mirror is an inner concave surface, for example, the surface near the display region is an inner concave reflecting surface. When the display device provided by the embodiment of the disclosure is applied to a head-up display, the setting of the curved surface reflector can enable the head-up display to have a longer imaging distance and a larger imaging size, and the curved surface reflector can be matched with a reflective imaging part (mentioned later) of the curved surface, such as a windshield, so as to eliminate virtual image distortion caused by the reflective imaging part.

For example, the reflection surface of the second reflection element 321 may be a free-form surface, that is, the reflection surface of the first reflection element 31 does not have a rotational symmetry characteristic, so as to improve the imaging quality of the display device.

FIG. 2A is a schematic diagram illustrating a comparison between a refraction of a refractive element in at least one embodiment of the present disclosure for image light emitted from a display area of an image source and an image light emitted from the display area of the image source without being refracted by the refractive element; fig. 2B is a schematic view of an equivalent distance from the display surface of the first display region to the first reflective element in fig. 1. Fig. 2A explains the function of the refractive element in at least one embodiment of the disclosure by taking a reference image source 301 and a refractive element 2 'as an example, the refractive element 2' in fig. 2B may be the same as the refractive element 2 in fig. 2A, and the reference image source 301 corresponds to the first image source 11 in fig. 2A, but does not represent the inclination angle of the first image source 11. As shown in the left diagram of fig. 2B, image rays L1 and L2 emitted from a point a on the display surface of the reference image source 301 are directly incident on the mirror without passing through the refractive element. As shown in the right diagram of fig. 2B, image light L3 and image light L4, which are also emitted from point a of the display surface of the reference image source 301, are incident on the refractive element 2', and are emitted from the surface of the refractive element 2' far from the reference image source 301, the surface of the refractive element 2' far from the reference image source 301 is an interface between the refractive element 2' and air, and the image light is refracted at the interface due to the difference (for example, greater than) between the refractive index of the refractive element 2' (i.e., the refractive index of air) and the refractive index of air; the refracted image light exits the surface of the refractive element 2' remote from the reference image source 301 as image light L5 and image light L6, respectively, and then enters the mirror. For example, in the case where the refractive element 2 'is closely attached to the image source light exit surface, the exit angles of the image light L3 and the image light L4 are the same as those of the image light L1 and the image light L2, respectively (in the case where the refractive element 2' and the image source light exit surface have an air layer, the following principle is similar); in this case, the extended lines of the image light L5 and the image light L6 emitted from the surface of the refractive element 2' far from the reference image source 301 intersect at the point O (i.e., two dotted lines in fig. 2A intersect at the point O), the surface where the plurality of points O corresponding to the plurality of image light is located corresponds to the equivalent display surface, and the distance from the point O to the mirror is the equivalent object distance from the reference image source 301 to the mirror. Therefore, the equivalent object distance can be regarded as the distance between the mirror and the position where the image source 301 is imaged by the last optical element (e.g. the refractive element 2' or the second reflective element 321) before the first reflective element 31 when the optical element exists between the image source 301 and the first reflective element 31. Obviously, the distance from point O to the mirror is smaller than the distance from point a to the mirror, that is, in the case where the refractive element 2 'is provided, the equivalent object distance from the image source 301 to the mirror is smaller than the distance from the image source 301 (for example, point a) to the mirror in the case where the refractive element 2' is not provided, which is equivalent to reducing the distance from the display surface of the reference image source 301 to the mirror (for example, 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 condition. In the embodiment of the present disclosure, for example, with reference to fig. 1 and fig. 2B, the reflection surface of the first reflection element 31 includes a curved surface, for example, the first reflection element 31 is a curved mirror, and when an optical element, for example, the refraction element 2, exists between the first image source 11 and the reflection surface of the first reflection element 31, an equivalent object distance from the first image source 11 to the first reflection element 31 is a distance between a position where an image light ray emitted from the first image source 11 is imaged by the last optical element before the first reflection element 31, that is, the refraction element 2, and an optical center of the reflection surface of the first reflection element 31, which is curved. Therefore, similarly, in the display device shown in fig. 1, the equivalent object distance from the display surface 20 of the first image source 11 to the first reflection element 31 in the case where the refraction element 2 is provided is smaller than the distance from the display surface 20 of the first image source 11 to the first reflection element 31 in the case where the refraction element 2 is not provided, compared with the case where the refraction element 2 is not provided, which is equivalent to the distance from the display surface 20 of the first image source 11 to the first reflection element 31 being reduced by providing the refraction element 2. In the display apparatus provided by the embodiment of the present disclosure, since the additional optical distance gradually decreases in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, the amount of decrease in the equivalent object distance gradually decreases in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, and thus the equivalent object distance from the display surface 20 of the first display region 110 to the first reflective element 31 gradually increases in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, thereby realizing that the image light emitted from at least a partial region corresponds to the formed first virtual image 100 as an oblique image.

As shown in fig. 2B, taking a leftmost ray A1-A2-A3 emitted from the first display area 110 in fig. 1 as an example, the ray A1 is emitted from the display surface 20 of the first display area 110, and is refracted at the interface between the refractive element 2 and the air to obtain a ray A2, a line segment O1O 'is perpendicular to the reflection surface of the second reflective element 321, and a point O1 is an intersection point of a reverse extension line of the ray A2 and the line segment O1O'. The equivalent object distance from the display surface 20 of the first display area 110 to the first reflective element 31 at the position where the light ray A1 exits from the display surface 20 of the first display area 110 is (M1O 1+ A3). Similarly, the equivalent object distance from the position of the light ray B1 exiting from the display surface 20 of the first display area 110 to the first reflective element 31 in fig. 1 is (M2O 2+ B3), and the equivalent object distance from the position of the light ray C1 exiting from the first display area 110 exiting from the display surface of the first sub-display area 111 to the first reflective element 31 in fig. 1 is (M3O 3+ C3). (M3O 3+ C3) > (M2O 2+ B3) > (M1O 1+ A3). Here, taking the above three positions of the display surface of the first display region 110 as an example to explain that the display surface 20 of the first display region 110 is not required to be inclined with respect to the horizontal direction, the equivalent object distance from the display surface 20 of the first display region 110 to the first reflective element 31 in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110 gradually increases, so that the first virtual image 100 becomes the above-described inclined image.

For example, as shown in fig. 1, the height of the far end of the first virtual image 100 is greater than the height of the near end of the first virtual image 100, the first virtual image 100 is in a perspective relationship with human eyes, and compared to a case where the height of the near end of the oblique image is greater than the height of the far end, the height of the far end of the first virtual image 100 is greater than the height of the near end of the first virtual image 100, so that when a user (e.g., a driver) observes an oblique image during driving, the oblique image looks more comfortable, and when the oblique 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 contact effect, and thus the oblique first virtual image 100 can achieve a better viewing effect. For example, the term "height" as used herein may refer to a height relative to the ground.

For example, in some embodiments, the height of the distal end of the first virtual image 100 is less than the height of the proximal end of the first virtual image 100, which may be designed according to the requirements of presenting different images.

For example, the height of the distal end of the first virtual image may be higher than the height of the proximal end of the first virtual image by adjusting the positional relationship between the first image source and the first reflective element and adjusting the heights of the first end and the second end of the display surface of at least a partial region. 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.

For example, in the embodiment shown in fig. 1, the display surface 20 of the first display area 110 is parallel to the horizontal direction, i.e., the display surface 20 of the first display area 110 is not inclined; for example, the height of the first end e1 of the display surface 20 relative to the ground immediately during use of the display device by the user is equal to the height of the second end e2 of the display surface 20 relative to the ground during use of the display device by the user. Of course, in other embodiments, the display surface 20 of the first display area 110 may have a non-zero angle with the ground surface, that is, be inclined with respect to the ground surface, as long as the display surface 20 of the first display area 110 cooperates with the refraction element 2 and the first reflection element 31 to form the inclined first virtual image 100. For example, in other embodiments, the image light reflected by the first reflecting element 31 is reflected by the windshield to form the oblique first virtual image 100, and in this case, the display surface 20 of the first display region 110 cooperates with the refractive element 2, the first reflecting element 31 and the windshield to form the oblique 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, i.e., 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; also, since the optical distance of the image light exiting from the first display region 110 in the process from the incident refractive element 2 to the exit from the refractive element 2 becomes gradually smaller in the direction from the first end of the first display region 110 to the second end of the first display region 110, the equivalent object distance from the second end e2 of the display surface 20 to the first reflective element 31 is larger, and thus the height of the distal end of the first virtual image 100 is higher than the height of the proximal end of the first virtual image 100.

For example, in some embodiments, the image light emitted from the first display region 110 and refracted by the refractive element 2 is directly incident on the first reflective element 31 without passing through other reflective elements, i.e., no optical element is disposed between the whole of the first image source 11 and the refractive element 2 and the first reflective element 31. For another example, in the embodiment shown in fig. 1, the display device further includes a second reflective element 321, the second reflective element 321 is configured to reflect the image light rays, which are refracted by the refractive element 2 in the first display region 110, to the first reflective element 31, then the first reflective element 31 reflects the image light rays incident on the reflective surface thereof, and the image light rays reflected by the first reflective element 31 propagate to the observation region 5 to form the first virtual image 100.

For example, in other embodiments, the second reflective element 321 can also be a planar mirror. For example, the second reflecting element 321 may also be a curved mirror, such as one or more of a free-form surface mirror, an aspheric mirror, and a spherical mirror. The disclosed embodiment schematically illustrates the second reflective element 321 as a planar mirror. The plane reflector can fold the light path in the display device to save space, and can avoid additional distortion and/or size change of the image displayed by the display device.

For example, as shown in fig. 2B, the second reflective element 321 is located on the display side of the first image source 11. But not limited thereto, in other embodiments, the second reflective element may be located on the non-display side of the first image source, and the light emitted from the first image source is directed to the first reflective element through other reflective structures. The first reflective element 31 is configured to reflect image light traveling toward the first reflective element 31 after being reflected by the second reflective element 321. For example, the image light emitted from the first image source 11 is reflected by the second reflecting element 321 toward the first reflecting element 31. For example, the first reflective element 31 is located on a 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 reflected by the second reflective element 321 can directly enter the first reflective element 31, but the disclosure is not limited thereto, and in other embodiments, another optical element, such as a reflective structure or a lens, may be disposed between the first reflective element and the second reflective element, and the light processed by the other optical element enters the first reflective element.

For example, the display side of the first image source 11 refers to the side of the first image source 11 emitting light. Fig. 2B shows the case where the display device includes the second reflective element 321 and the first reflective element 31, but is not limited to this case, in some other embodiments, the display device may also have only the first reflective element 31 without the second reflective element 321, in which case, the image light emitted from the first sub-display region 111 and emitted from the second sub-display region 112 and refracted by the refractive element 2 is directly incident on the first reflective element 31 without being reflected by the second reflective element 321.

For example, in the embodiment shown in fig. 1, the refractive indexes of the refractive elements 2 are equal in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110 (i.e., in a direction from the first end of the at least partial region to the second end of the at least partial region), and the thicknesses of the refractive elements 2 in the direction of the main optical axis of the image light rays exiting along the at least partial region gradually decrease, for example, in at least one embodiment, the thicknesses of the refractive elements 2 in a direction perpendicular to the display surface 20 of the first display region 110 gradually decrease, so that the optical distance of the image light rays exiting from the first display region 110 in the process from the incident refractive element 2 to the exit from the refractive elements 2 gradually decreases in the direction from the first end e1 of the first display region 110 (i.e., the at least partial region) to the second end e2 of the first display region 110, so that the equivalent object distance of the display surface 20 in the direction gradually increases, thereby obtaining a virtual image of a gradually increasing image distance 100 in the direction from the first end e1 of the first display region 110 to the second end e 2.

For example, the "main optical axis" refers to the central line or axis of the light beam, and may be considered as the main direction of the light beam propagation.

For example, in a direction from the first end of the at least partial region to the second end e2 of the at least partial display region, the thickness of the refractive element corresponding to the at least partial region in a direction perpendicular to the display surface of the at least partial region gradually becomes smaller means monotonously smaller, for example, linearly smaller or non-linearly smaller.

For example, in the embodiment shown in fig. 1, the whole refractive element 2 may be made of the same material, for example, in an integrated structure, so that the refractive index of the refractive element 2 is equal in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110.

For example, as shown in fig. 1, the surface 21 of the refractive element 2 away from the first image source 11 is a plane, so that the surface 21 of the refractive element 2 away from the first image source 11 is gradually more uniform in a direction from the first end e1 of the first display area 110 to the second end e2 of the first display area 110, the inclination degree of each position of the first virtual image 100 is relatively uniform, phenomena such as excessive bending of a local inclined picture are prevented, and the viewing experience of a user is better. Of course, in other embodiments, the surface 21 of the refractive element 2 away from the first image source 11 may 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.

For example, the exit surface of the refractive element 2 is a curved surface; for example, the surface of the refractive element 2 remote from the first image source 11 is a convex curved surface. For example, when image light passes through the refractive element 2 including a curved exit surface, the virtual image formed by the display device changes in form; for example, when the display device is applied to a head-up display, a virtual image viewed by a user in an observation area is curved, for example, a curved concave surface faces the user, a portion of the virtual image close to the ground may display instruction content related to a road, and a curved portion (a portion of the virtual image away from the bottom surface) may display other content, for example, POI information on both sides.

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 and the display surface of the first display region 110 have a first included angle, and the first included angle is 1 ° to 60 °, for example, 5 ° to 15 °; so that the inclined first virtual image 100 has a proper inclination angle, for example, the included angle between the first virtual image 100 and the ground is 5-90 degrees, so that the display device has a good ground-attaching effect, and a user has a good experience of watching an inclined picture when driving the driving equipment using the display device.

For example, as shown in fig. 1, the orthographic projection of the refractive element 2 on the display surface of the first display area 110 is located within the first display area 110, i.e., the orthographic projection of the refractive element 2 on the display surface of the first display area 110 is located within at least a partial area. For example, as shown in fig. 1, the orthographic projection of the refractive element 2 on the first display area 110 covers the whole first display area 110, that is, the orthographic projection of the refractive element 2 on the first display area 110 covers the whole at least partial area, so that the image light emitted from the first display area 110 is more directly incident into the refractive element 2 to improve the light efficiency.

For example, as shown in fig. 1, the refractive element 2 is attached to the first display region 110 (i.e., at least a partial region); for example, the refractive element 2 is in close contact with the first display area 110, for example directly or via an optical glue, i.e. there is substantially no air layer between the refractive element 2 and the first display area 110; thus, the image light emitted from the first display region 110 is directly incident to the refraction element 2 without passing through the air layer, which is beneficial to improving the light efficiency.

Alternatively, in some other embodiments, the refractive element includes a portion that conforms to the first display region 110 (i.e., at least a partial region) and a portion that is spaced apart from the first display region 110 (i.e., at least a partial region).

For example, a support may be disposed between the first display region 110 and the refractive element 2, and the support may be a light-transmissive thin plate covering the first display region 110, such as a glass thin plate; the support piece is tightly attached to the first display area 110, the refraction element 2 is tightly attached to the support piece, and the first display area 110 and the refraction element 2 are respectively tightly attached to the surfaces of the two sides of the support piece, so that the first display area 110 can be prevented from being damaged by the heavy refraction element 2, and the use stability of the device is improved.

For example, the display device further comprises a fixation structure (not shown) configured to fix the refractive element 2. For example, the fixing structure is located at the edge of the first image source 11, for example, a slot or a snap that fixes the side of the refractive element 2. Alternatively, the refractive element 2 is attached to the first image source 11.

For example, in some embodiments, the refractive index of the refractive element in the direction of the primary optical axis of the image light exiting at least part of the region (e.g., first display region 110) tapers in a direction from the first end of at least part of the region (e.g., first display region 110) to the second end of at least part of the region (e.g., first display region 110).

Exemplarily, fig. 3 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure. The embodiment shown in fig. 3 differs from the embodiment shown in fig. 1 in the following way. For example, in the embodiment shown in fig. 3, the refractive index of the refractive element 2 is gradually decreased, for example, linearly decreased or non-linearly decreased, in a direction from the first end e1 of the first display region 110 (i.e., at least a partial region) to the second end e2 of the first display region 110, in which case, for example, the thicknesses of the refractive element 2 in a direction perpendicular to the display surface 20 of at least a partial region are equal. In this way, it can also be achieved that the optical distance of the image light rays exiting from the first display region 110 in the process from the incident refractive element 2 to the exit from the refractive element 2 in the direction from the first end e1 of the first display region 110 (i.e., at least a partial region) to the second end e2 of the first display region 110 gradually becomes smaller to gradually adjust the equivalent object distance of the display surface 20 in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110 so that the equivalent object distance of the display surface 20 gradually increases in this direction, thereby obtaining the tilted first virtual image 100.

Other features of the embodiment shown in fig. 3 are the same as those in fig. 1, and reference may be made to the description of fig. 1, which is not repeated herein.

For another example, fig. 4 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure. The embodiment shown in fig. 4 has the following differences from the embodiment shown in fig. 1. As shown in fig. 6, the first display area 110 includes a first sub-display area 111 and a second sub-display area 112, and at least a partial area is the first sub-display area 111; that is, the image light emitted from the first sub-display region 111 enters the refractive element 2, is refracted at the cross section of the refractive element 2 and the air, and then propagates to the first reflective element 31, and the first reflective element 31 is configured to reflect the image light emitted from the first sub-display region 111, after passing through the refractive element 2, and after being reflected by the second reflective element 321, and then propagates to the first reflective element 31, and the image light finally propagates to the observation region 5 to form the first virtual image 100. Meanwhile, the image light emitted from the second sub display region 112 is incident to the first reflective element 31 without being refracted by the refractive element 2, and the first reflective element 31 is further configured to reflect the image light emitted from the second sub display region 112 and incident to the first reflective element 31 to the observation region 5 to form the second virtual image 200. The propagation distances of the image light rays emitted from the second sub-display region from the positions of the display surface of the second sub-display region 112 to the first reflecting element 31 are equal, and the second virtual image 200 and the first virtual image 100 have a nonzero second included angle. That is, the first virtual image 100 is an oblique image, and the second virtual image 200 is a vertical image, so that the local portion of the display image of the first display region 110 is made into an oblique image. For example, the angle between the second virtual image 200 and the ground is larger than the angle between the first virtual image 100 and the ground.

For example, the second virtual image 200 is a vertical image, which means that the second virtual image 200 is vertical with respect to the horizontal direction, for example, the second virtual image 200 is substantially vertical with respect to the ground, for example, the second virtual image 200 forms an angle of 90 ° ± 10 ° with respect to the ground. It should be noted that when the second virtual image 200 is at an angle of 80 ° to 100 ° with respect to the ground, the second virtual image 200 may be considered to be substantially perpendicular to the ground. The horizontal direction may refer to a direction parallel to the ground on which the traffic device employing the head-up display travels, or a direction in which the traffic device employing the head-up display travels. Of course, the disclosed embodiments are not limited to the first virtual image being in an oblique direction and the second virtual image being in a vertical direction.

Compared with the case that the image light emitted from the first display area 110 does not undergo refraction by the refractive element 2 before entering the first reflective element 31, in the present embodiment, the object distance from the display surface 20 of the entire first display area 110 to the first reflective element 31 is equal, and the decrease degree of the equivalent object distance from the display surface of the first sub-display area 111 to the first reflective element 31 by the refractive element 2 along the direction from the first end e1 of the first sub-display area 111 to the second end e2 of the first sub-display area 111 gradually decreases, so that 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 of the first sub-display area 111 to the second end e2 of the first sub-display area 111 gradually increases, and the principle that the refractive element 2 and the first sub-display area 111 cooperate to realize oblique imaging is the same as that in fig. 1.

For example, as shown in fig. 4, the orthographic projection of the refractive element 2 in the first display area 110 is located in 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 to improve the light efficiency.

For example, the display surface of the first sub-display section 111 may or may not be coplanar with the display surface of the second sub-display section 112. For example, the display content of the second virtual image 200 and the display content of the first virtual image 100 are independent of each other or related to each other. For example, the second virtual image 200 is a different image or a different portion of the same image than the first virtual image 100. For example, the optical distance from the first sub display region 111 to the reflection surface of the first reflection element 31 is different from the optical distance from the second sub display region 112 to the reflection surface of the first reflection element 31 so that the center of the first virtual image 100 generated by the image light rays emitted from the first sub display region 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 region 112.

For example, the "optical distance" refers to the product of the propagation path of the image light emitted from the corresponding display region to the first reflective element and the refractive index of the propagation medium. For example, the geometric path of the image ray exiting from the first sub display region 111 to the first reflective element 31 includes a portion thereof passing through the refractive element 2 and a portion thereof passing through air.

For example, the second sub display region 112 is located on a side of the first sub display region 111 away from the first reflective element 31, and the second virtual image 200 is located on a side of the first virtual image 100 away from the observation region 5. Alternatively, in other embodiments, the second sub display region 112 is located on the side of the first sub display region 111 close to the first reflective element 31, and the second virtual image 200 is located on the side of the first virtual image 100 close to the observation region 5. Can be designed according to the needs.

Other features of the embodiment shown in fig. 4 are the same as those in fig. 1, and reference may be made to the description of fig. 1, which is not repeated herein.

For example, fig. 5 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure. The embodiment shown in fig. 5 has the following differences from the embodiment shown in fig. 1. As shown in fig. 5, the refractive element 2 is spaced apart from the first display area 110 (i.e., at least a partial area) in a direction perpendicular to the display surface of the first display area 110. For example, an air layer exists between the refractive element 2 and the display surface of the first display area 110, and the image light emitted from the first display area 110, taking the light ray A0, the light ray B0, and the light ray C0 as an example, passes through the air layer and then enters the refractive element 2, and the light ray A0, the light ray B0, and the light ray C0 are refracted at the surface 21 of the refractive element 2, which is far away from the display surface 20 of the first display area 110, to obtain the light ray A1, the light ray B1, and the light ray C1; the image light rays refracted are emitted from the surface 21 of the refractive element 2 away from the display surface of the first display area 110 and then incident on the first reflective element 31, as shown by the light rays A2, B2, and C2 and the light rays A3, B3, and C3.

For example, in the embodiment shown in fig. 5, the lower surface of the refractive element 2 close to the first image source 11 is parallel to the display surface 20 of the first display region 110; in other embodiments, the lower surface of the refractive element 2 close to the first image source 11 may not be parallel to the display surface 20 of the first display region 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 region 110, the optical distance of the image light rays of the same angle exiting from the display surface 20 of the first display region 110 in the process from the incident of the refractive element 2 on the lower surface of the refractive element 2 close to the first image source 11 to the exiting from the lower surface of the refractive element 2 far from the first image source 11 is gradually reduced; for example, it may be continuously tapered; for example, in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, the refractive indexes of the refractive elements 2 are equal, and the thicknesses of the refractive elements 2 in the direction of the main optical axis of the image light emitted from the first display region 110 gradually decrease, for example, nonlinearly decrease after linear decrease; alternatively, in some embodiments, the thickness of the refractive element 2 in the direction of the main optical axis of the image light emitted from the first display region 110 is gradually reduced, for example, linearly reduced and then nonlinearly reduced, in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, in which case, for example, the thickness of the refractive element 2 in the direction of the main optical axis of the image light emitted from the first display region 110 is equal; alternatively, the thickness and the refractive index of the refractive element 2 in the direction of the main optical axis of the image light emitted from the first display region 110 in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110 may change non-monotonically, as long as it is satisfied that the optical distance of the image light of the same angle emitted from the display surface 20 of the first display region 110 in the direction from the first end e1 of the first display region 110 in the process from the incident of the refractive element 2 on the lower surface of the refractive element 2 close to the first image source 11 to the emission from the lower surface of the refractive element 2 far from the first image source 11 gradually decreases in the direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110.

Other features of the embodiment shown in fig. 5 are the same as in fig. 1, and reference may be made to the description of fig. 1.

For example, fig. 6 is a schematic diagram of another display device provided in at least one embodiment of the present disclosure. The embodiment shown in fig. 6 has the following differences from the embodiment shown in fig. 1. As shown in fig. 6, 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 region 110. For example, the refractive element 2 includes a first sub-refractive element 2a and a second sub-refractive element 2b adjacent to each other. For example, the first sub-refractive element 2a and the second sub-refractive element 2b are stacked in a direction perpendicular to the display surface 20 of the first display region 110 and are in contact with each other. For example, in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, an optical distance of image light rays exiting from the first display region 110 in a process from an integral structure (i.e., the entirety of the second refractive element 2) formed by the plurality of sub refractive elements stacked in an incident manner to an exit of the integral structure is gradually reduced, so that a degree of reduction in an object distance from the display surface 20 of the first display region 110 to the first reflective element 31 is gradually reduced in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110 (for example, in the present embodiment, that is, in a direction from the vicinity of the first reflective element 31 to the far away from the first reflective element 31), so that an equivalent object distance from the display surface 20 of the first display region 110 to the first reflective element 31 is gradually increased in the direction to obtain the tilted first virtual image 100.

For example, the materials of the plurality of sub-refractive elements may be different to have different refractive indices; for example, the first sub-refractive element 2a and the second sub-refractive element 2b are different in material and different in refractive index. The refractive index of the refractive element 2 can be flexibly adjusted by adopting the scheme that the refractive element 2 comprises a plurality of stacked sub-refractive elements, the requirements of various refractive indexes can be met, the defect of the refractive index range of a single-layer refractive element made of a single material is overcome, and the adjustment range of the image light emitted from the first display area 110 is widened.

For example, in some embodiments, for example as shown in fig. 6, in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, the refractive index of the whole refractive element 2 made of the plurality of sub refractive elements arranged in a stacked manner is equal, and the thickness of the whole refractive element 2 made of the plurality of refractive elements arranged in a stacked manner in a direction perpendicular to the display surface of the first display region 110 is gradually reduced. In this case, for example, the surface 21 of the sub-refractive element 2, which is farthest from the display surface of the second sub-display area 112, of the plurality of sub-refractive elements 2, which is farther from the display surface 20 of the first display area 110, and the surface 21 of the refractive element 2, which is farther from the display surface 20 of the first display area 110, are flat surfaces or curved surfaces, and specific reference may be made to the foregoing description.

Alternatively, in other embodiments, the refractive index of the whole refractive element 2 formed by the plurality of sub-refractive elements arranged in a stack may be gradually decreased in a direction from the first end e1 of the first display region 110 to the second end e2 of the first display region 110, and the thicknesses of the whole refractive element 2 formed by the plurality of sub-refractive elements arranged in a stack in a direction perpendicular to the display surface of the second sub-display region 112 may be equal. For example, the refractive index of the stacked plurality of sub-refractive elements may be made different; for example, for the first sub-refractive element and the second sub-refractive element included in the refractive element 2 and 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 smaller than the refractive index of the second sub-refractive element, and the thickness of the first sub-refractive element in the direction perpendicular to the display surface of the second sub-display area 112 becomes gradually larger and the thickness of the second sub-refractive element in the direction perpendicular to the display surface of the second sub-display area 112 becomes gradually smaller in 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 surface of the first sub-refractive element in contact with the second sub-refractive element and the surface of the second sub-refractive element in contact with the first sub-refractive element are complementary in shape to achieve that the refractive index of the overall structure constituted by the plurality of refractive elements stacked and the refractive index of the plurality of refractive elements stacked and arranged in the direction perpendicular to the display surface of the second sub-refractive element are equal to the thickness of the overall structure 112 in the direction perpendicular to the display surface of the second sub-display area 110. Of course, there may be other ways of implementing this scheme, and the above is just one example.

Other features of the embodiment shown in fig. 6 are the same as in fig. 1, and reference may be made to the description of fig. 1.

Fig. 7 is a schematic diagram of another display device according to at least one embodiment of the present disclosure. The embodiment shown in fig. 7 has the following differences from the embodiment shown in fig. 2A. As shown in fig. 7, the display device further includes a second image source 12; the second image source 12 includes a second display area 120, and the image light emitted from the second display area 120 propagates to the first reflective element 31; for example, image light rays exiting from the second display region 120 and propagating to the first reflective element 31 form a third virtual image 300 different from the first virtual image 100, and an optical distance from the display surface of the second display region 120 to the first reflective element 31 is not equal to an optical distance from the display surface of the first display region 110 to the first reflective element 31, so that the third virtual image 300 and the first virtual image 100 are at different distances from a user, thereby implementing multi-layer display; the display surface of the first display area 110 is parallel to the display surface of the second display area 120, for example, the display surfaces of the first display area 110 and the second display area 120 are both parallel to the horizontal direction. For example, the angle between the third virtual image 300 and the ground is larger than the angle between the first virtual image 100 and the ground.

For example, the optical distance from the display surface to the first reflective element 31 may be the optical distance from the center of the display surface to the center (e.g., optical center) of the first reflective element 31. For example, the optical distance from the display surface of the first display region 110 to the first reflective element 31 may be the optical distance from the center of the display surface of the first display region 110 to the center of the first reflective element 31. The optical distance from the display surface of the second display region 120 to the first reflecting element 31 may be an optical distance from the center of the display surface of the second display region 120 to the center of the first reflecting element 31.

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, at least one of the position, size, inclination degree, and picture content of the two virtual images is different.

For example, with the second image source 12, no refractive element is provided, and the image light exiting from the second display region 120 of the second image source 12 travels to the first reflective element 31 without passing through the refractive element, so that the third virtual image 300 is a vertical image; for example, the third virtual image 300 is vertical with respect to the horizontal direction, i.e., perpendicular to the horizontal direction. The horizontal direction may refer to a direction perpendicular to a plane in which the viewing area 5 is located, or a direction parallel to a ground on which the traffic device using the head-up display travels, or a direction in which the traffic device using the head-up display travels. Of course, the embodiments of the present disclosure are not limited to the first virtual image being in an oblique direction and the third virtual image being in a vertical direction. For example, in some other embodiments, the second display region may be tilted, for example, at a non-zero angle with respect to the display surface of the first display region 11 shown in fig. 7, so that the second virtual image is also a tilted virtual image; alternatively, in some other embodiments, a refractive element similar to that provided in correspondence with the first image source 11 may be provided for the second image source 12, so that the second virtual image is also an oblique virtual image. The angles of the respective images in the multi-layer display may be designed as desired, and the embodiments of the present disclosure are not limited.

For example, as shown in fig. 7, the display device further includes a third reflective element 322, and the third reflective element 322 is configured such that the image light emitted from the second display region 120 propagates to the first reflective element 31 after being reflected by the third reflective element 322. In other embodiments, there may be no other optical element between the second display region 120 and the first reflective element 31, that is, the third reflective element 322 is not disposed, and the image light emitted from the second display region 120 may be directly incident to the first reflective element 31. In addition, fig. 7 schematically shows that there is no other optical element between the second display region 120 and the third reflective element 322, and the image light emitted from the second display region 120 is directly incident to the third reflective element 322; however, the disclosure is not limited thereto, and other optical elements, such as lenses, may be disposed 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 and then incident on the third reflective element 322.

For example, in the embodiment shown in fig. 7, the first display area 110 is located on a side of the second display area 120 away from the first reflective element 31, and the third reflective element 322 is located on a side of the second reflective element 321 away from the first reflective element 31; alternatively, the first display region 110 is located on a side of the second display region 120 close to the first reflective element 31, and the third reflective element 322 is located on a side of the second reflective element 321 close to the first reflective element 31.

The embodiment of the present disclosure may implement that 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 (or, the propagation distance from the display surface of the second display area 120 to the first reflective element 31 for 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 from the display surface of the first display area 110 to the first reflective element 31 for the image light emitted from the display surface of the first display area 110) by adjusting the distance from the second reflective element 321 to the first display area 110 and the distance from the third reflective element 322 to the second display area 120 and the first reflective element 31), and implement that the optical distances from the display surface of the first display area 110 and the second display area 120 to the image light propagated to the first reflective element 31 are not equal to each other.

For example, as shown in fig. 7, the reflection surface of the first reflection element 31 is a curved surface, and the reflection surface of the second reflection element 321 and the reflection surface of the third reflection element 322 are flat surfaces.

For example, the first display area 110 and the second display area 120 may display different images to meet the user's desire to view the different images. The embodiments of the present disclosure are not limited thereto, and for example, a portion of the at least two display regions may also display the same image.

Other features and technical effects of the embodiment shown in fig. 7 may be found in the description of fig. 1 above.

Fig. 8 is a schematic diagram of another display device according to at least one embodiment of the disclosure. The embodiment shown in fig. 8 has the following differences from the embodiment shown in fig. 7. As shown in fig. 8, the display device further comprises a fifth image source 14 and a fifth reflecting element 323; the fifth image source 14 includes a fifth display area 15, and a display surface of the fifth display area 15 has a non-zero third included angle with the display surface of the first display area 110. The third reflective element 322 is configured to reflect the image light emitted from the second display region 120 to the first reflective element 31, and the fifth reflective element 323 is configured to reflect the image light emitted from the fifth display region 15 to the first reflective element 31.

For example, as shown in fig. 8, the distance from the display surface of the second display region 120 to the first reflective element 31 is not equal to the distance from the display surface of the fifth display region 15 to the first reflective element 31 (or the propagation distance of the image light rays emitted from the display surface of the second display region 120 to the first reflective element 31 is not equal to the propagation distance of the image light rays emitted from the display surface of the fifth display region 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 respectively formed by being reflected by 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 by the third reflecting element 322 and the fifth reflecting element 323 to the first reflecting element 31, respectively, in the reflected light path in which the optical distances of the image light emitted from the second display area 120 and the fifth display area 15 are different. In other embodiments, the propagation distance of the image light emitted from the display surface of the second display region 120 to the first reflective element 31 may be equal to the propagation distance of the image light emitted from the display surface of the first display region 110 to the first reflective element 31, so as to achieve the same-layer display, that is, the distance from the third virtual image 300 and the fifth virtual image 500 to the user is the same; in this case, the optical distances of the image light emitted from the second display region 120 and the first display region 110 and transmitted to the first reflective element 31 are the same.

For example, in fig. 8, the display surface of the fifth display region 15 and the display surface of the second display region 120 are parallel, and thus the display surface of the fifth display region 15 and a virtual image formed by the image light rays emitted from the second display region 120 after being reflected by the second reflecting element are substantially parallel. For example, an included angle between the reflection surface of the fifth reflection element 323 and the reflection surface of the third reflection element 322 is not greater than 20 °, so that the parallelism of virtual images formed by the image light rays emitted by the fifth display area 15 and the second display area 120 after being reflected by the first reflection element is good. The disclosure is not limited thereto, and when the display surface of the fifth display area 15 and the display surface of the second display area 120 are parallel, the included angle between the reflection surface of the fifth reflection element 323 and the reflection surface of the third reflection element 322 may be greater than 20 °, in this case, a non-zero included angle is formed between virtual images formed after the image light rays emitted from the fifth display area 15 and the second display area 120 are reflected by the first reflection element 31. For example, when the reflective surface of the fifth reflective element 323 and the reflective surface of the third reflective element 322 are parallel, the display surface of the fifth display area 15 and the display surface of the second display area 120 may be included at an angle of not more than 20 °.

For example, as shown in fig. 8, the angle between the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 is not more than 15 °. For example, the angle between the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 is not greater than 10 °. For example, the angle between the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 is not greater than 5 °. For example, the angle between the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 is 0 °. For example, the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 may be disposed in parallel.

For example, the third reflecting element 322 and the fifth reflecting element 323 may be plane mirrors, and the above-mentioned "the angle between the reflecting surface of the third reflecting element 322 and the reflecting surface of the fifth reflecting element 323 is not more than 15 ° may mean that the angle between the two plane reflecting surfaces is not more than 15 °.

For example, the third reflective element 322 and the fifth reflective element 323 may also be one or more of a curved mirror, an aspheric mirror, a spherical mirror, and the like, and the above-mentioned "the included angle between the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 is not greater than 15 °" may mean that the included angle between the planes enclosed by the edges of the reflective surfaces is not greater than 15 °.

For example, the third reflective element 322 and the fifth reflective element 323 can be the same type of mirror or different types of mirrors, and the embodiment of the disclosure schematically illustrates that the third reflective element 322 and the fifth reflective element 323 are both planar mirrors. The plane reflector is convenient for manufacturing the display device, plays a role in folding a light path in the display device so as to save space, and can avoid bringing additional distortion, size change and the like to an image displayed by the display device.

For example, as shown in fig. 8, the second display area 120 and the fifth display area 15 may be located on the same plane, and the optical distances of the image light rays emitted from the second display area 120 and the fifth display area 15 and transmitted to the first reflecting element 31 may be different by adjusting the positions and angles of the third reflecting element 322 and the fifth reflecting element 323. The embodiment of the present disclosure is not limited thereto, and in other embodiments, for example, the second display area and the fifth display area may also be located on different planes, the third reflective element and the fifth reflective element may be located on the same plane (or different planes), and by adjusting the positions of the second display area and the fifth display area, it may be possible to implement that 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, and implement that the propagation distances of the image light rays emitted from the second display area 120 and the fifth display area 15 and propagated to the first reflective element 31 are different, and the optical distances are different.

In the display device shown in fig. 8, the distance from the display surface of the first display area 110 to the first reflective element 31, the distance from the display surface of the second display area 120 to the first reflective element 31, and the distance from the display surface of the fifth display area 15 to the first reflective element 31 are not equal to each other, that is, 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 propagation distance of the image light emitted from the display surface of the second display area 120 to the first reflective element 31, and the propagation distance of the image light emitted from the display surface of the fifth display area 15 to the first reflective element 31 are not equal to each other, so that the images at different distances from the viewing area 5 can be imaged, which facilitates the matching of the images at different distances and the scenes at different distances, so that when the display device is applied to a head-up display, the user does not need to adjust the visual experience of the display device back-and forth between the images at the fixed distances and the scenes at different distances, thereby improving the experience of adjusting the display device. In this case, for example, the optical distances of the image light rays emitted from the first display area 110, the second display area 120, and the fifth display area 15 and respectively transmitted to the first reflective element 31 are different from each other. The embodiments of the present disclosure may implement that the distances from the display surfaces of the three display regions to the first reflective element 31 are not equal to each other, the propagation distances from the corresponding display surfaces to the first reflective element 31 for the image light rays emitted from the display surfaces of the three display regions to propagate respectively to the first reflective element 31 are not equal to each other, and the optical distances from the image light rays emitted from the three display regions to propagate respectively to the first reflective element 31 are different from each other by adjusting the distance between the second reflective element 321 and the first reflective element 110 and the first reflective element 31, the distance between the third reflective element 322 and the second display region 120 and the distance between the fifth reflective element 323 and the first reflective element 31.

For example, fig. 8 schematically shows that the first virtual image 100 is an oblique virtual image, and the distance between the first virtual image 100 and the observation region 5 is greater than the distance between the fifth virtual image 500 and the observation region 5 and less than the distance between the third virtual image 300 and the observation region 5, that is, the first virtual image 100 is located between the fifth virtual image 500 and the third virtual image 300. But not limited to this, the oblique virtual image may also be a virtual image farthest from the observation region or a virtual image closest to the observation region, which is not limited by the embodiment of the present disclosure.

For example, as shown in fig. 8, the first virtual image 110 is tilted with respect to the horizontal direction, i.e., has a non-zero non-right angle with the horizontal direction; the third and fifth

virtual images

300 and 500 are vertical with respect to the horizontal direction, i.e., perpendicular to the horizontal direction. The horizontal direction may refer to a direction perpendicular to the plane of the observation area 5 or a direction parallel to the ground on which the transportation device using the head-up display travels in real time. Of course, the embodiments of the present disclosure are not limited to the first virtual image being in an oblique direction and the second and fifth virtual images being in a vertical direction. For example, one of the second virtual image and the fifth virtual image may also be a virtual image that is tilted, for example, in the virtual image-to-observation-region direction, with the virtual image tilted toward the observation region. For example, in some other embodiments, at least one of the display surface of the second display region and the display surface of the fifth display region may be obliquely disposed, for example, obliquely disposed at the same angle or a different angle from the display surface of the first display region 11 shown in fig. 8, so that a virtual image formed by light rays emitted from at least one of the second display region and the fifth display region may be an oblique image; alternatively, in some other embodiments, a refractive element similar to that corresponding to the first image source 1 may be disposed for at least one of the second image source 12 and the fifth image source 14, so that a virtual image formed by light rays emitted from at least one of the second display region and the fifth display region is an oblique image.

For example, as shown in fig. 8, the second display area 120 and the fifth display area 15 may be display areas located at different positions on the same image source, for example, the same screen, and are displayed in a partitioned manner to save space and cost. The embodiments of the present disclosure are not limited thereto, and in other embodiments, the second display area and the fifth display area may also be respectively located on different image sources, for example, screens of different image sources may be in close proximity; for example, the display surfaces of the different image sources are parallel to each other so that the second display area and the fifth display area are parallel, and the distance between the different image sources can be set to be larger to prevent the image lights emitted from the two display areas from influencing each other.

For example, as shown in fig. 8, the light shielding structure 6 is disposed between the second display area 120 and the fifth display area 15 to prevent the image lights emitted from different display areas from affecting each other. The light shielding structure 6 may be a light barrier, for example.

For example, the second image source 12 or the fifth image source 14 may include the light shielding structure 6, but is not limited thereto, and the light shielding structure may not be the structure of the second image source 12 or the fifth image source 14. For example, the light shielding structure 6 may be located at the display side of the second image source 12 or the fifth image source 14, for example, at least disposed/attached (for example, may be disposed, fixed, attached, adhered, or adsorbed) on the display screen of the second image source 12 or the fifth image source 14; the light shielding structure 6 is for example located at the junction of the second image source 12 and the fifth image source 14.

For example, as shown in fig. 8, the third reflective element 322 and the fifth reflective element 323 may be two reflective elements independent of each other, so that both are independently adjustable.

For example, the second reflecting element 321, the third reflecting element 322, and the fifth reflecting element 323 may be the same type of mirror or different types of mirrors, and the second reflecting element 321, the third reflecting element 322, and the fifth reflecting element 323 are all shown as planar mirrors in the exemplary embodiment of the disclosure.

For example, in the embodiment shown in fig. 8, the fifth display area 15 may display a close-up view, such as displaying key driving data such as vehicle meters, for example, displaying one or more of vehicle speed, fuel quantity, and steering; the second display area 120 may display a distant view such as a building, etc. For example, the perspective view displayed in the second display area 120 may include a Point of interest (POI) icon, for example, the image may include a logo of a bank, and the logo image of the bank may match and merge with the position of the real scene of the bank, so that the user may see a building far away, for example, a bank, and the logo of the bank is identified in the display view.

For example, in the embodiment shown in fig. 8, the fifth display area 15 is configured to display a close-up view, and the display content of the close-up view may be a key driving parameter such as a vehicle instrument, so that the size of the displayed close-up view may be small; the second display area 120 is configured to display a long-range view, which needs to be displayed in a manner of matching and blending with a real scene outside the vehicle, such as a building, so that the size of the long-range view is larger than that of the short-range view. For example, a close-up view with a smaller size does not obscure a distant view with a larger size.

For example, in the embodiment shown in fig. 8, the display surface of the fifth display area 15 and the display surface of the second display area 120 are parallel, and the display surface of the fifth display area 15 and the display surface of the second display area 120 are both parallel to the display surface of the first display area 110, for example, the display surface of the first display area 110, the display surface of the second display area 120, and the display surface of the fifth display area 15 are all parallel to the horizontal direction. And the included angle between the reflective surface of the third reflective element 322 and the reflective surface of the fifth reflective element 323 is not more than 20 °, and the included angle between the display surface of the fifth display region 15 and the display surface of the first display region 110 is 5 ° to 90 °. Therefore, the fifth virtual image 500 formed by the display surface of the fifth display area 15 and the image light displayed by the second display area 120 after being reflected by the first reflective element 31 is approximately parallel to the fifth virtual image 500, and the first virtual image 100 formed by the image light displayed by the first display area 110 after being reflected by the first reflective element 31 and the first virtual image 100 formed by the image light emitted by the fifth display area 15 after being reflected by the first reflective element 31 and the fifth virtual image 500 are not parallel to each other, for example, an included angle between the first virtual image 100 and the fifth virtual image 500 ° may be 5 ° to 90 °.

Other features and technical effects of the embodiment shown in fig. 8 may be found in the description of fig. 7 above.

Fig. 9 is a schematic view of another display device according to at least one embodiment of the present disclosure. The embodiment shown in fig. 9 has the following differences from the embodiment shown in fig. 1. As shown in fig. 9, for example, the display device further comprises 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 and the display surface of the first display area 110 have a non-zero third included angle; the transflective element 8 is located on a side of the refractive element 2 away from the first image source 11, and is configured to transmit the image light emitted from the first display region 110 to the first reflective element 31, and is configured to reflect the image light emitted from the third display region 130, and the image light emitted from the third display region 130 propagates to the first reflective element after being reflected by the transflective element 8; the image light rays exiting from the third display region 130 and propagating to the first reflective element 31 form a fourth virtual image 400 different from the first virtual image 100, and the first virtual image 100 and the fourth virtual image 400 at least partially overlap, that is, the first virtual image 100 and the fourth virtual image 400 at least partially overlap as seen by the eyes of the user in the observation region 5, so that the first virtual image 100 is coaxial with the fourth virtual image 400. For example, the paths of the image light rays forming the first virtual image 100 and directly incident on the observation region 5 and the paths of the image light rays forming the fourth virtual image 400 and directly incident on the observation region 5 substantially coincide, so that the first virtual image 100 and the fourth virtual image 400 are coaxial. For example, the angles of view (e.g., downward angle of view, angle of view of the user's line of sight from the horizontal direction) at which the user's eyes observe the first virtual image 100 and the fourth virtual image 400 at the observation area 5 are substantially the same.

For example, by adjusting the refractive indexes of the materials of the transflective element 8 and the refractive element 2, the size of the first included 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 region 110, the included angle between the transflective element 8 and the display surface of the third display region 130, the distance between the transflective element 8 and the display surface of the first display region 110, and the distance between the transflective element 8 and the display surface of the third display region 130, the light ray AB obtained by the light ray B emitted from the first display region 110 transmitted by the transflective element 8 at least partially coincides with the light ray obtained by the light ray a emitted from the third display region 130 reflected by the transflective element 8, the light ray AB propagates to the first reflective element 31 and is reflected by the first reflective element 31, the first virtual image 100 formed by the light ray B reflected by the first reflective element 31, the fourth virtual image 400 formed by the light ray a reflected by the first reflective element 31, and the first virtual image 100 and the fourth virtual image 400 at least partially overlap.

For example, the projection of the first virtual image 100 on the plane on which the fourth virtual image 400 is located is within the range of the fourth virtual image 400, that is, the projection of the first virtual image 100 on the plane on which the fourth virtual image 400 is located is seen by the eyes of the user at the observation region 5 is within the range of the first virtual image 100; alternatively, the projection of the fourth virtual image 400 on the plane on which the first virtual image 100 is located is within the range of the first virtual image 100, that is, the user's eyes see the projection of the fourth virtual image 400 on the plane on which the first virtual image 100 is located in the range of the first virtual image 100 at the observation region 5.

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 region may be located on the same straight line, and the center of the first virtual image 100 and the center of the fourth virtual image 400 may overlap with each other when the user sees in the observation region 5 with the eyes of the user.

For example, the projection of the first virtual image 100 on the plane where the fourth virtual image 400 is located within the range of the fourth virtual image 400, or the projection of the fourth virtual image 400 on the plane where the first virtual image 100 is located within the range of the first virtual image 100, or the center of the first virtual image 100 and the centers of the fourth virtual image 400 and the observation region 5 may be located on the same straight line by adjusting the angle between the transflective element 8 and the display surface of the first display region 110, the angle between the transflective element 8 and the display surface of the third display region 130, the distance between the transflective element 8 and the display surface of the first display region 110, and the distance between the display surfaces of the third display region 130.

For example, the third image source 13 includes a third display region 130, a display surface of the third display region 130 has a non-zero third included angle with a display surface of the first display region 110, and the first virtual image 100 is parallel to the fourth virtual image 400 or has a non-zero second included angle. For example, the third angle and the fourth angle may be equal; in some implementations, the third included angle and the fourth included angle may also be unequal.

For example, the distance from the display surface of the first display area 110 to the first reflection element 31 is not equal to the distance from the display surface of the third display area 130 to the first reflection element 31, or the propagation distance of the image light emitted by the display surface of the first display area 110 from the display surface of the first display area 110 to the first reflection element 31 is not equal to the propagation distance of the image light emitted by the display surface of the third display area 130 from the display surface of the third display area 130 to the first reflection element 31, so as to realize a multi-layer display, that is, the distances from the first virtual image 100 and the fourth virtual image 400 to a user (for example, a driver of traffic equipment using the display device) are different. In this case, the optical distances of the image light rays emitted by the first display area 110 and the third display area 130 and transmitted to the first reflective element 31 are unequal, and the images can be formed at different distances to form a multi-layer image at different distances from the user, for example, the first virtual image 100 and the fourth virtual image 400 are respectively located in different layers, different images can be fused with real scenes at different distances, the sight line of the user does not need to be switched back and forth between the image at a fixed distance and the real scenes at different distances, and the use experience of the head-up display is effectively improved.

For example, the reflectivity of the transflective element 8 for the image light emitted from the first display region 110 may be 70%, 60%, 50%, or other suitable values, and the transmittance for the image light emitted from the third display region 130 may be 30%, 40%, 50%, or other suitable values. For example, the transmittance of the image light emitted from the third display region 130 by the transflective element 8 may be 70%, 60%, 50%, or other suitable values.

For example, the transflective element 8 includes a polarizing transflective element 8, the third display region 130 emits light of a first polarization (polarized light having a first polarization), the first display region 110 emits light of a second polarization (polarized light having a second polarization), the polarization directions of the first polarized light and the second polarized light are perpendicular, and the transflective element 8 is configured to reflect the first polarized light and transmit the second polarized light. For example, the first display region 110 emits light of the second polarization transmitted through the transflective element 8.

For example, the polarization transflective element 8 may be an element formed by coating or attaching a transparent substrate. For example, the polarization transflective element 8 may be a substrate coated or pasted with a transflective Film having a characteristic of reflecting the first polarized light and transmitting the second polarized light, such as one or more of a reflective Brightness Enhancement Film (DBEF) or a prism Film (BEF). The disclosed embodiments are not limited thereto, for example, the transflective element 8 may also be an integrated element.

For example, the polarization transflective element 8 may be an optical film having a polarization transflective function, for example, the polarization transflective element 8 may be formed by combining a plurality of film layers having different refractive indexes in a certain stacking order, and each film layer has a thickness of about 10-1000 nm; the material of the film layer can be selected from inorganic dielectric materials, such as one or more of metal oxide, metal nitride and the like; high molecular material such as one or more of polypropylene, polyvinyl chloride or polyethylene can also be selected.

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 may be substantially 90 °. The embodiments of the present disclosure are not limited thereto, for example, in the case where the polarization directions of the first polarized light and the second polarized light are perpendicular, the first polarized light and the second polarized light may also be non-S polarized light or non-P polarized light, such as the first polarized light and the second polarized light may be two kinds of linearly polarized light whose polarization directions are perpendicular to each other, or two kinds of circularly polarized light whose polarization directions are perpendicular to each other, or two kinds of elliptically polarized light whose polarization directions are perpendicular to each other, or the like.

For example, the transflective element 8 is a wavelength selective transflective element 8, the wavelength band of the image light emitted from the third display region 130 is a first wavelength band group, the wavelength band of the image light emitted from the first display region 110 is a second wavelength band group, and the transflective element 8 is configured to reflect the image light of the first wavelength band group and transmit the image light of the second wavelength band group.

For example, the "wavelength band" may include a single wavelength or a mixed range of wavelengths. For example, in the case where the wavelength band includes a single wavelength, light of the wavelength may be mixed with light of a nearby wavelength due to the influence of process errors.

For example, the image light of the first and second wavelength band groups may include light of red, green and blue (RGB) wavelength bands, and a full width at half maximum of the light of each wavelength band of RGB is not greater than 50nm. For example, the first band group and the second band group each include image light of three bands, for example, a peak of a first band among the three bands is located in an interval of 410nm to 480nm, a peak of a second band is located in an interval of 500nm to 565nm, and a peak of a third band is located in an interval of 590nm to 690 nm.

For example, the wavelength of the image light of the first wavelength band in the first wavelength band group is different from the wavelength of the image light of the first wavelength band in the second wavelength band group; the wavelength of the image light of the second waveband in the first waveband group is different from that of the image light of the second waveband in the second waveband group; the wavelength of the image light of the third wavelength band in the first wavelength band group is different from the wavelength of the image light of the third wavelength band in the second wavelength band group.

For example, the wavelengths of the image light of each wavelength band in the first wavelength band group are smaller than the wavelengths of the image light of each wavelength band in the second wavelength band group. For example, in the first band group, the wavelength of red light is 620 nm, the wavelength of green light is 500nm, 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. The embodiments of the present disclosure are not limited thereto, and for example, the wavelengths of the image light of each wavelength band in the first wavelength band group are greater than the wavelengths of the image light of each wavelength band in the second wavelength band group. For example, in the first band group, the red wavelength is 670 nm, the green wavelength is 550 nm, and the blue wavelength is 470 nm. For example, in the second band group, the red wavelength is 650 nm, the green wavelength is 530 nm, and the blue wavelength is 450 nm. The arrangement of the above-mentioned wave band relation can facilitate the fabrication of the wavelength selective transflective element.

For example, the image light of the first and second wavelength band groups may include image light of a plurality of wavelength bands, for example, light of at least three wavelength bands of RGB to form color image light, and the color image light may form a color image. For example, the image light of the first and second wavelength band groups may include image light of one color band, for example, the image light includes one of the light of the three RGB wavelength bands; for another example, in the case where the wavelengths of the image light of the first wavelength band group and the image light of the second wavelength band group are different, the image light includes the wavelength band light of any color in the visible light range to form the monochromatic image light, and the monochromatic image light may form the monochromatic image, similarly to the above implementation process.

For example, the reflectivity of the image light emitted from the third display region 130 using the wavelength selective transflective element may be 70%, 80%, 90%, 95% or other suitable values, and the transmittance of the image light emitted from the first display region 110 may be 70%, 80%, 90%, 95% or other suitable values. Therefore, the utilization rate of the image light can be improved, and the light energy loss of the image light emitted by the first display area and the third display area is reduced to the minimum.

For example, the first image source 11 and the third image source 13 are image sources capable of emitting RGB mixed light, such as Light Emitting Diode (LED) displays, or Liquid Crystal Displays (LCDs), etc. For example, the type of the second image source in the previous embodiment may be the same as the types of the first image source 11 and the third image source 13.

For example, the transflective element may be a polarization-wavelength selective transflective element, such as a first display region 110 emitting image light and a second display region 120 emitting image light in wavelength bands that are coincident or substantially coincident, but each having a different polarization state, the transflective element being configured to reflect the first image light and transmit the second image light.

For example, the "band" has the same or similar characteristics as the above embodiments, and is not described herein again. 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 comprises an S polarization state and the other of the first polarization state and the second polarization state comprises a P polarization state. The embodiments of the present disclosure are not limited thereto, for example, in the case that the polarization directions of the first polarization state and the second polarization state are perpendicular, it may also be a non-S polarization state or a non-P polarization state, for example, the first polarization state and the second polarization state may be two linear polarization states with the polarization directions perpendicular to each other, or two circular polarization states with the polarization directions orthogonal to each other, or two elliptical polarization states with the polarization directions orthogonal to each other, and the like.

For example, the first image light includes RGB light of S polarization state, and the second image light includes RGB light of P polarization state; for example, the first image light includes P-polarized RGB light, and the second image light includes S-polarized RGB light.

For example, the reflectivity of the transflective element 8 for one of the first image light and the second image light is greater than that for the other; alternatively, the transmittance of the transflective element 8 for one of the first image light and the second image light is greater than that for the other. For example, the reflectivity of the transflective element 8 for the second image light is greater than the reflectivity for the first image light. For example, the transmittance of the transflective element 8 for the first image light is greater than the transmittance for the second image light.

For example, the transflective element 8 has a reflectance to one of the first image light and the second image light greater than its reflectance to the other, and a transmittance to one less than its transmittance to the other. For example, the reflectance of the transflective element 8 for the second image light is greater than the reflectance for the first image light, and the transmittance of the transflective element 8 for the second image light is less than the transmittance for the first image light.

For example, the reflectivity of the transflective element 8 using the polarization-wavelength selective transflective element to the image light emitted from the second display region 120 may be 70%, 80%, 90%, 95%, or other suitable values, and the transmittance to the image light emitted from the first display region 110 may be 70%, 80%, 90%, 95%, or other suitable values. Therefore, the utilization rate of the image light rays by the transflective element 8 can be improved, so that the light energy loss of the image light rays emitted from the first display area and the second display area is reduced as much as possible.

For example, the above-described wavelength-selective transflective element and/or polarization-wavelength selective transflective element may include a selective transflective film in which at least two film layers having different refractive indices are stacked, the transflective film being formed by stacking inorganic oxide thin films or polymer thin films. The term "different refractive index" as used herein means that the refractive index of the film layer differs in at least one of the xyz three directions. For example, by selecting desired film layers with different refractive indexes in advance and stacking the film layers in a preset order, a transflective film having selective reflection and selective transmission characteristics can be formed, and the transflective film can selectively reflect light rays with one characteristic and transmit light rays with another characteristic. For example, for a film layer using an inorganic oxide material, the composition of the film layer is selected from one or more of tantalum pentoxide, titanium dioxide, magnesium oxide, zinc oxide, zirconium oxide, silicon dioxide, magnesium fluoride, silicon nitride, silicon oxynitride, and aluminum fluoride. For example, for a film layer using an organic polymer material, the film layer of the organic polymer material 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 refractive indices of the two thermoplastic polymer film layers are different. For example, the molecules of the organic polymer material are chain-like structures, and the molecules are arranged in a certain direction after stretching, so that the refractive indexes in different directions are different, that is, a desired film can be formed by a specific stretching process. For example, the thermoplastic polymer may be one or more of polyethylene terephthalate (PET) and derivatives thereof with different polymerization degrees, polyethylene naphthalate (PEN) and derivatives thereof with different polymerization degrees, polybutylene terephthalate (PBT) and derivatives thereof with different polymerization degrees, and the like.

Fig. 10 is a schematic view of another display device according to at least one embodiment of the present disclosure. The embodiment shown in fig. 10 has the following differences from the embodiment shown in fig. 9. The display device shown in fig. 10 includes the first image source 11, the third image source 13, the transflective element 8 shown in fig. 9, and the second image source 12 shown in fig. 7, and the display device shown in fig. 10 corresponds to a combination of the technique of forming the third virtual image 300 using the image light rays emitted from the second image source 12 shown in fig. 7 and the technique of forming the first virtual image 100 using the image light rays emitted from the first image source 11 and the technique of forming the fourth virtual image 400 using the image light rays emitted from the third image source 13 shown in fig. 10.

For example, in fig. 10, the distance from the display surface of the first display region 110 to the first reflecting element 31, the distance from the display surface of the second display region 120 to the first reflecting element 31, and the distance from the display surface of the third display region 130 to the first reflecting element 31 are not equal to each other, that is, the propagation distance of the image light emitted from the display surface of the first display region 110 to the first reflecting element 31, the propagation distance of the image light emitted from the display surface of the second display region 120 to the first reflecting element 31, and the propagation distance of the image light emitted from the display surface of the third display region 130 to the first reflecting element 31 are not equal to each other, whereby images can be formed at different distances from the unequal viewing regions 5. In this case, the optical distances of the image light rays emitted from the first display region 110, the second display region 120, and the third display region 130 and respectively transmitted to the first reflective element 31 are different from each other. The embodiments of the present disclosure may implement that the distances from the display surfaces of the three display regions to the first reflective element 31 are not equal to each other, and the optical distances of the image light rays emitted by the three display regions and respectively transmitted to the first reflective element 31 are different from each other by adjusting the distances between the second reflective element 321, the transflective element 8 and the first display region 110 and the first reflective element 31, the distances between the third reflective element 322 and the second display region 120 and the first reflective element 31, and the distances between the second reflective element 321 and the third display region 130 and the first reflective element 31.

The technical solutions shown in fig. 10 for forming the third virtual image 300 by using the image light rays emitted from the second image source 12 and the technical solutions shown in fig. 10 for forming the first virtual image 100 by using the image light rays emitted from the first image source 11 and for forming the fourth virtual image 400 by using the image light rays emitted from the third image source 13 can refer to the previous description, and are not repeated here.

Fig. 11 is a schematic view of a head-up display according to at least one embodiment of the disclosure, as shown in fig. 11, the head-up display includes a reflective imaging portion 4 and any one of the display devices according to the embodiments of the disclosure, and fig. 11 includes the display device shown in fig. 2A as an example. The reflective imaging section 4 is configured to reflect the image light reflected from the first reflective element 31 to the reflective imaging section to the observation area 5, and transmit ambient light. A user in the observation area 5 can view a first virtual image 100 formed by the image light emitted from the display device by the reflective imaging part 4 and an environmental scene on the side of the reflective imaging part 4 away from the observation area 5. The head-up display provided by at least one embodiment of the present disclosure provides a uniform and consistent inclination of an oblique image presented to a user (e.g., a driver or a passenger), can prevent the presented oblique image from having an excessively curved portion, and avoids the problems of unclear information display and influence on the user's look and feel due to curved deformation of a screen; for example, the oblique image is a road sign image on the ground, so that the oblique image has a better ground-attaching effect, the image can be better combined with an external object, and the use experience of the display device for a user is improved.

Of course, in the head-up display provided in the other embodiments, when the head-up display includes a display device adopting a multi-layer display scheme, a user located in the observation area 5 may view a plurality of virtual images formed by the image light emitted from the display device by the reflective imaging section 4.

For example, image light emitted by the elliptical display device enters the reflective imaging part 4, light reflected by the reflective imaging part 4 enters a user, for example, an observation area 5 where eyes of a driver are located, and the user can observe a virtual image formed outside the reflective imaging part, for example, without affecting observation of the external environment by the user.

For example, the observation area 5 may be an eye box (eyebox) area, which is a planar area where the eyes of the user are located and where the image displayed on the head-up display can be seen. For example, when the user's eyes are offset a distance, such as up and down, left and right, relative to the center of the eye-box region, the user may still see the image displayed by the heads-up display while the user's eyes are still within the eye-box region.

For example, the reflective imaging section 4 may be a windshield or an imaging window of a motor vehicle. For example, the windshield is a windshield and the imaging window is a transparent imaging plate. For example, the Windshield is used for image light emitted from a transmission and reflection Windshield head-up display (Windshield-HUD, W-HUD) and the imaging window is used for image light emitted from a combination-HUD (C-HUD).

For example, as shown in fig. 11, the head-up display further includes a package body 700 having an opening 710, the image source 100, the first reflecting element 3100, and the first reflecting element 31 are all located inside the package body 700, the reflective imaging part 4 is located outside the package body 700, the first reflecting element 31 reflects the image light emitted from the image source 100 to the position of the opening 710 of the package body 700 to be emitted from the opening 710 of the package body 700, and the image light emitted from the opening 710 of the package body 700 is reflected to the viewing area 5 by the reflective imaging part 4.

For example, as shown in fig. 11, a virtual image formed by the reflection of the image light emitted from the first display region 110 by the reflective imaging section 4 is a first virtual image 100, and the first virtual image 110 is inclined with respect to the horizontal direction, that is, has an angle with the horizontal direction. The horizontal direction may refer to a direction perpendicular to the plane of the observation area 5 or a direction parallel to the ground on which the transportation device using the head-up display travels in real time.

For example, an image source in at least one embodiment of the present disclosure may include a light source, a backlight assembly, and an image generating part.

For example, the Light source may include at least one electroluminescent device, which generates Light by electric Field excitation, such as a Light Emitting Diode (LED), an Organic Light Emitting Diode (OLED), a Mini LED (Mini LED), a Micro LED (Micro LED), a Cold Cathode FluoreScent LamP (CCFL), a Cold Light source (Cold LED Light, CLL), an Electroluminescence (EL), an electron EmiSSion (FED), a Quantum Dot Light source (QD), or the like.

For example, the image generating section may include a liquid crystal display panel. For example, the liquid crystal display panel may include an array substrate, an opposite substrate, a liquid crystal layer between the array substrate and the opposite substrate, and a sealant encapsulating the liquid crystal layer. For example, the liquid crystal display panel further includes a first polarizing layer disposed on a side of the array substrate away from the counter substrate and a second polarizing layer disposed on a side of the counter substrate away from the array substrate. For example, the 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.

For example, at least one embodiment of the present disclosure also provides a transportation device. Fig. 12 is a schematic view of a transportation device according to at least one embodiment of the present disclosure. As shown in fig. 12, an embodiment of the present disclosure provides any one of the head up displays. Alternatively, in at least one embodiment, the transportation device includes any one of the display devices provided in the embodiments of the present disclosure.

For example, in the case where the traffic device includes a heads-up display, the reflective imaging section is a windshield or an imaging window of the traffic device, i.e., a front window (e.g., a front windshield) of the traffic device is multiplexed as the reflective imaging section 4 of the heads-up display. By applying the head-up display, the transportation device provided by the embodiment of the disclosure can provide a tilted image presented by a user (for example, a driver or a passenger), for example, the tilt of the first virtual image 100 is uniform and consistent, can prevent the presented tilted image from having an excessively curved portion, and avoid the problems of unclear information display and influence on the user's look and feel due to the curved deformation of the screen; for example, the oblique image is a road sign image on the ground, so that the oblique image has a better ground-attaching effect, the image can be better combined with an external object, and the use experience of the display device for a user is improved.

For example, when the above-mentioned new line display is applied to traffic equipment, third virtual image 300, fourth virtual image 400 and fifth virtual image 500 perpendicular to ground, the one end that ground is close to than first virtual image 100 of one end that first virtual image 100 is kept away from ground is farther apart from observation district 5's distance, thereby make each virtual image all match the integration with corresponding live-action, so that the driver watches the image in different distance departments, be favorable to the image of different distances to match the integration with the live-action of different distances, so that the driver need not to make a round trip to switch between the image of fixed distance and the live-action of different distances, the conflict is adjusted to the vision convergence, traffic equipment's use experience has been improved.

Of course, the plurality of virtual images generated by the display apparatus and the heads-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, which are merely examples to explain the scheme of the present disclosure, and may include other oblique virtual images or vertical virtual images.

For example, the transportation device may be various suitable vehicles, such as various types of land transportation devices such as automobiles, or water transportation devices such as ships, in the case where a front window is provided at a driving position of the transportation device and an image is projected onto the front window through an on-board display system.

It is noted that in the accompanying drawings used to describe embodiments of the present disclosure, the thickness of layers or regions are exaggerated or reduced for clarity, i.e., the drawings are not necessarily to scale.

Although the present disclosure has been described in detail hereinabove with respect to general illustrations and specific embodiments, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the embodiments of the disclosure. Accordingly, such modifications and improvements do not depart from the spirit of the disclosure and are intended to be within the scope of the disclosure.

The following points need to be explained:

(1) In the drawings of the embodiments of the present disclosure, only the structures related to the embodiments of the present disclosure are referred to, and other structures may refer to general designs.

(2) Features of the same embodiment and different embodiments of the disclosure may be combined with each other without conflict.

The above description is intended to be exemplary of the present disclosure, and not to limit the scope of the present disclosure, which is defined by the claims appended hereto.

Claims

1. A display device, characterized in that the display device comprises:

a first image source comprising a first display area;

a refraction element configured to refract image light emitted from at least a partial region of the first display region; and

the first reflecting element reflects the image light rays refracted by the refracting element and transmits the image light rays to the observation area to form a first virtual image;

and 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 the light incident surface of the refractive element and the light emitting surface of the refractive element of at least partial image light rays emitted from the at least partial region is gradually reduced.

2. A display device as claimed in claim 1, wherein the first virtual image corresponding to the image light rays exiting from the at least part area has a near end close to the observation area and a far end far away from the observation area, the image light rays corresponding to the first end correspond to the near end, the image light rays corresponding to the second end correspond to the far end, and the far end of the first virtual image is higher than the near end of the first virtual image.

3. The display device according to claim 1,

the thickness of the refraction element in the direction of the main optical axis of the image light ray emitted along the at least partial region is gradually reduced along the direction from the first end of the at least partial region to the second end of the at least partial region; and/or the refractive index of the refractive element in the direction of the main optical axis of the image light exiting along the at least partial region is gradually reduced in the direction from the first end of the at least partial region to the second end of the at least partial region.

4. A display device as claimed in claim 3, characterized in that the refractive indices of the refractive elements are equal with decreasing thickness of the refractive elements in the direction of the main optical axis of the image light exiting along the at least partial region in a direction from the first end of the at least partial region to the second end of the at least partial region;

the thicknesses of the refraction elements in the direction of the main optical axis of the image light rays emitted along the at least partial region are equal under the condition that the refractive indexes are gradually reduced along the direction from the first end of the at least partial region to the second end of the at least partial region.

5. A display device as claimed in claim 3, characterised in that the face of the refractive element remote from the first image source comprises a flat and/or curved face.

6. A display device as claimed in claim 5, wherein, in the case that the face of the refractive element remote from the first image source is planar, the face of the refractive element remote from the first image source and the display face of the first display region have a first included angle, the first included angle being in the range of 1 ° to 60 °.

7. The display device according to any one of claims 1 to 6, wherein the refractive element is attached to the at least partial region; or,

the refractive element is spaced from the at least partial region in a direction perpendicular to a display surface of the first display region; or,

the refractive element includes a portion conforming to the at least partial region and a portion spaced apart from the at least portion.

8. The display device according to any one of claims 1 to 7, wherein the refractive element is configured to refract image light emitted from the entire first display region.

9. The display device according to claim 1, wherein the first display region comprises a first sub-display region and a second sub-display region, and the at least partial region is the first sub-display region;

the image light rays emitted from the second sub-display region are incident to the first reflecting element without being refracted by the refracting element, the first reflecting element is further configured to reflect the image light rays emitted from the second sub-display region and incident to the first reflecting element to the observation region to form a second virtual image,

the included angle between the second virtual image and the ground is larger than the included angle between the first virtual image and the ground, and the second virtual image and the first virtual image have a non-zero second included angle.

10. A display device as recited in claim 9, wherein display content of the second virtual image is independent of or related to display content of the first virtual image.

11. The display device according to claim 1, wherein the refractive element is a unitary structure or includes a plurality of sub-refractive elements stacked in a direction perpendicular to a display surface of the first display region.

12. The display device according to claim 1, further comprising:

and the second reflecting element is configured to reflect the image light rays which are emitted by the first display area and refracted by the refracting element to the first reflecting element.

13. The display device according to any one of claims 1 to 12, wherein the display device further comprises:

the second image source comprises a second display area, wherein image light rays emitted by the second display area are transmitted to the first reflecting element, and image light rays emitted from the second display area and transmitted to the first reflecting element form a third virtual image different from the first virtual image; and also,

the included angle between the third virtual image and the ground is larger than the included 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.

14. The display device according to claim 13, further comprising:

a third reflective element, wherein the image light emitted from the second display region propagates to the first reflective element after being reflected by the third reflective element.

15. The display device according to claim 1, further comprising:

the third image source comprises a third display area, wherein a display surface of the third display area and a display surface of the first display area have a non-zero third included angle; and

a transflective element located on a side of the refractive element away from the first image source, configured to transmit the image light emitted from the first display region to the first reflective element, and configured to reflect the image light emitted from the third display region, and the image light emitted from the third display region propagates to the first reflective element after being reflected by the transflective element,

image light rays which are emitted from the third display area and travel to the first reflecting element form a fourth virtual image different from the first virtual image, and the first virtual image and the fourth virtual image are at least partially overlapped.

16. A display device as claimed in claim 15, wherein the projection of the first virtual image onto the plane on which the fourth virtual image is located is within the range of the fourth virtual image, or wherein the projection of the fourth virtual image onto the plane on which the first virtual image is located is within the range of the first virtual image.

17. The display device according to claim 15, wherein a center of the first virtual image is located on a same straight line as a center of the fourth virtual image and a center of the observation region.

18. A head-up display, characterized in that the head-up display comprises a reflective imaging section and a display device according to any one of claims 1-17,

wherein the reflective imaging section is configured to reflect the image light propagating to the reflective imaging section after being reflected by the first reflecting element to the observation area, and transmit ambient light.

19. A transportation apparatus, characterized in that the transportation apparatus comprises a display device according to any one of claims 1-17, or a heads-up display according to claim 18.

20. The transportation apparatus of claim 19, wherein the reflective imaging portion is a windshield or an imaging window of the transportation apparatus when the transportation apparatus includes the heads-up display.