Splice display device for floating images and multi-layer display device including the same

Abstract

The present invention relates to a splice display device for floating images and a multi-layer display device including the splice display device, which comprises a display module arranged to emit display light constituting a target image on a display surface, a plurality of optical imaging modules arranged to receive the display light and form a floating image in the air, and a one-dimensional scattering screen for dispersing the light in the y-direction, each of the plurality of optical imaging modules includes a first one-dimensional conjugate imaging element for converging a point light beam from the display surface on the one-dimensional scattering screen in the y-direction, and a second one-dimensional conjugate imaging element for converging a point light beam from the display surface on a floating image plane different from the plane where the one-dimensional scattering screen is located in the x-direction, and the x-direction and the y-direction are respectively perpendicular to the main optical axis of the optical imaging module.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The embodiments described herein relate generally to light field 3D display technology, and more particularly to a splice display device for floating images and a multi-layer display device including the splice display device. [Background technology]

[0002] Among many display technologies, the floating display technology has attracted the attention of many researchers because it can present images in the air, giving viewers a strong visual impact and a sensory experience that is both real and fake.

[0003] Conventional floating display technologies fall into three main categories. The first category is traditional optical lens imaging, such as a concave reflector plus a splitter mirror structure. This optical structure was the first proposed solution for such display systems. An illuminated real object or content displayed on an LCD is reflected by the splitter mirror and enters the concave reflector. The light then passes through the converging function of the concave reflector and passes through the splitter mirror again, forming an image on the other side. The viewer then sees a floating image. The floating image size of this solution is small, but suffers from significant aberrations such as distortion. The second category utilizes the integrated imaging principle. This solution consists of a microlens array and several image cell arrays. Light rays emitted from points displaying the same image information in the image cells pass through corresponding microlenses and converge in space to form a floating image point. The advantage of this solution is that the display device is ultra-thin, essentially the same thickness as the display. The disadvantages are low resolution and high cost.

[0004] The third category uses a "negative refractive index screen" composed of a special microstructure to form a floating image, and mainly includes the following types: a. Retro-reflection structure plus beam splitter. This structure is mainly composed of glass microbeads or microprism arrays. This structure allows the reflected light and the incident light to be parallel and opposite in direction. Light emitted from the display source enters the retro-reflection structure via the beam splitter. The reflected light passes through the retro-reflection structure and passes through the beam splitter again in the opposite direction to the incident light, converging on the other side to form an image. b. Double-layer plane mirror array. This solution consists of two plane mirror arrays, one above the other, with the plane mirror units between the two layers perpendicular to each other. Light emitted from the display source is reflected by the plane mirror array and then converges on the other side to form an image. c. Micro-convex structure array. This solution consists of a micro-convex structure array. Light emitted from the display source is reflected twice by the micro-convex structure and then converges on the other side to form an image. The advantage of this technology is that there is no aberration, but the disadvantage is that ghost images exist, and the "negative refractive index screen" is expensive to fabricate and the system is large in volume.

[0005] The required size of the floating image varies depending on the needs of the scene. In the prior art, although there are various floating display technologies as mentioned above, the size of the floating image displayed on the floating display device is generally limited at the manufacturer's design stage and cannot be adjusted during use.

[0006] Thus, if users want to display floating images of different sizes according to different application scenes, they usually need to purchase floating display devices of different sizes. For manufacturers of floating display devices, it is necessary to design different floating display devices (especially design different optical systems to fit image display units of different sizes) according to different user needs and adapt them one by one, which consumes a lot of manpower and material resources. Summary of the Invention [Problem to be solved by the invention]

[0007] Exemplary embodiments of the present invention are made to overcome the above and / or other problems in the prior art, and in particular to provide a splice display device for floating images that can utilize a single modular design to achieve seamless splicing of floating images of various sizes, while at the same time having lower manufacturing costs and a more compact optical layout. [Means for solving the problem]

[0008] Specifically, an exemplary embodiment of the present invention provides a splice display device for floating images, comprising: a display module arranged to emit display light constituting a target image on a display surface; a plurality of optical imaging modules arranged to receive the display light and form a floating image in the air; and a one-dimensional scattering screen for diverging light in the y direction, wherein each of the plurality of optical imaging modules includes a first one-dimensional conjugate imaging element for converging a point light beam from the display surface onto the one-dimensional scattering screen in the y direction, and a second one-dimensional conjugate imaging element for converging the point light beam from the display surface onto a floating image plane different from the plane in which the one-dimensional scattering screen is located in the x direction, wherein the x direction and the y direction are each perpendicular to the main optical axis of the optical imaging module.

[0009] In the splice display device according to the above exemplary embodiment, a floating image is formed in the air by a display module and a plurality of imaging modules, and a large viewing angle range can be formed in the second direction by using a scattering screen, thereby realizing a large-sized floating display. Such a splice display device does not need to design a different optical imaging system for a specific size of floating image, but only requires selecting a display module, an appropriate number of imaging modules, and a scattering screen according to the size of the required floating image. In addition, small-sized optical elements are easier to process than large-sized optical elements, which significantly reduces the cost of realizing floating displays of different sizes. In addition, such a splice display device is significantly thinner and more compact than large-sized floating display devices in the prior art.

[0010] According to another exemplary embodiment of the present invention, there is provided a multi-layer display device comprising: a splice display device according to the above exemplary embodiment; and a transparent display device arranged optically downstream of the splice display device, the transparent display device having a display surface at a different position from the floating image surface.

[0011] Other features and aspects will become apparent from the following detailed description, drawings, and claims. [Brief explanation of the drawings]

[0012] The present invention will be better understood by describing exemplary embodiments thereof with reference to the accompanying drawings, in which:

[0013] [Figure 1] FIG. 1 is a schematic block diagram illustrating a Splice Display for floating images according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a splice display including a one-dimensional scattering screen according to an embodiment of the present invention; [Figure 3]1A and 1B are principle schematic diagrams illustrating the propagation of light rays in a first direction and a second direction in an optical imaging module and a one-dimensional scattering screen according to an embodiment of the present invention; [Figure 4] 1 is a schematic diagram showing that a pixel point on a display module is imaged to the same point on a first image plane through multiple optical imaging modules. [Figure 5] 1 shows an exemplary structure of a one-dimensional retroreflective screen. [Figure 6] FIG. 2 is a schematic block diagram of an optical imaging module according to an alternative embodiment of the present invention. [Figure 7] FIG. 2 is a schematic diagram showing secondary reflected light rays and primary reflected light rays of a retroreflective screen. [Figure 8] FIG. 2 is a schematic block diagram illustrating an optical imaging module according to an alternative embodiment of the present invention. [Figure 9] 1 is a structural example showing an ultra-micro louver structure. [Figure 10] FIG. 10 is a schematic block diagram illustrating an optical imaging module according to another alternative embodiment of the present invention. [Figure 11] FIG. 2 is a schematic diagram showing a primary reflected light beam from a retroreflective screen. [Figure 12] FIG. 10 is a schematic block diagram illustrating an optical imaging module according to another alternative embodiment of the present invention. [Figure 13] 1 is a structural example showing a cylindrical sawtooth diffraction grating. [Figure 14] 1 is a schematic structural diagram showing a splice display device according to a preferred embodiment of the present invention; [Figure 15] 1 is a schematic diagram illustrating a multi-layer display device according to an embodiment of the present invention; [Figure 16] FIG. 1 is a schematic diagram showing a transparent display device realized by micro-projection. [Figure 17] FIG. 1 is a schematic diagram showing that a multi-layer display device realizes naked-eye 3D display. [Figure 18A] FIG. 1 is an explanatory schematic diagram showing a display module using a three-dimensional display. [Figure 18B]FIG. 1 is an explanatory schematic diagram showing a display module using a three-dimensional display. [Figure 18C] FIG. 1 is an explanatory schematic diagram showing a display module using a three-dimensional display. [Figure 19] 1 is a schematic diagram showing a splice display device including a selectable light deflection unit; FIG. [Figure 20] FIG. 1 is a schematic diagram illustrating a splice display device including a selectable lens array. [Figure 21] FIG. 1 is a schematic diagram illustrating a portion of a splice display device including a selectable microlens array. [Figure 22] 1 is a schematic diagram illustrating a splice display device including selectable mirrored optical imaging modules; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Specific embodiments of the present invention will be described below. However, for the sake of brevity, it is not possible to fully describe all features of actual embodiments in this specification. It should be understood that in the actual implementation of any embodiment, various specific decisions are often made in the course of any engineering or design project to achieve the specific goals of the developer and to satisfy system-related or commercial constraints, and these decisions may vary from one embodiment to another. It should also be understood that such development may require complex and lengthy efforts, but for those skilled in the art related to the content disclosed in this invention, some changes in design, manufacturing, production, etc. made based on the technical content disclosed in this disclosure are merely existing technical means, and should not be understood as deficient in the content of this disclosure.

[0015] Unless otherwise defined, technical or scientific terms used in the claims and the specification shall have the ordinary meaning understood by a person of ordinary skill in the art to which the invention pertains. The terms "first," "second," and similar terms used in the specification and claims of this invention patent application do not denote any order, quantity, or importance, but are used merely to distinguish different components. Similar terms such as "one" or "1" do not denote a quantitative limitation, but rather indicate the presence of at least one. Similar terms such as "comprise" or "include" mean that the element or object preceding "comprise" or "include" encompasses the elements or objects listed after "comprise" or "include" and their equivalents, but do not exclude other elements or objects. Similar terms such as "connect" or "couple" do not limit the connection to physical or mechanical connections, nor do they limit the connection to direct or indirect connections. The phrase "A is approximately equal to B" means that the tolerances in manufacturing processes, i.e., the numerical values ​​of A and B, are within ±10% of each other, are taken into consideration.

[0016] For ease of explanation, light is considered to propagate along an optical path from an optically "upstream" position to an optically "downstream" position in a light beam. Accordingly, the relative positions of optical elements in an optical path can also be described in these two terms.

[0017] A floating display device typically includes an image display unit and an optical system, where the image display unit displays an original image on the object plane of the optical system using direct display or indirect projection, and then the image light is formed into a floating image in the air by the optical system. To achieve a large-sized floating display, larger optical elements must be fabricated, which can rapidly increase processing costs and reduce the precision of the optical elements. Therefore, a floating image splicing display device has been proposed, which includes an image display unit and multiple optical systems, forms multiple floating element images in the air, and splices the multiple floating element images to form a complete floating image. This technical solution realizes seamless splicing of floating images, while also having low manufacturing costs and making the floating display device more compact.

[0018] 1 is a schematic block diagram showing a splice display device 100 for floating images according to an embodiment of the present invention. Referring to FIG. 1, the splice display device 100 according to an embodiment of the present invention includes a display module 110 and a plurality of optical imaging modules 120. 1~n The display module 110 may be arranged to emit display light that constitutes a target image. 1~n Each optical imaging module 120 can be positioned to receive the display light emitted from the display module 110 to form a floating image in the air. i defines an object plane 10, a first image plane 15, and a second image plane 20. A display module 110 (particularly its display surface) is disposed in the object plane 10 of the plurality of optical imaging modules. Light rays emitted from pixel points on the display module 110 are incident on the plurality of optical imaging modules 120. 1~n , can be focused in the y-direction onto a first image plane 15 and in the x-direction onto a second image plane 20 by at least one of the optical imaging modules.

[0019] In an embodiment of the present invention, the display module 110 may be configured by splicing together multiple display units, or may be a single display device, which may have a single complete display area or multiple separate display areas. In this way, the display module 110 may have multiple display sections arranged along the y direction. Each display section may be arranged to display a corresponding portion of the target image. The target image displayed on the display module 110 and the multiple optical imaging modules 120 may be connected to each other. 1~n The floating image displayed on the floating image plane (that is, the second image plane 20) can have an erect image formation relationship in the y direction.

[0020] The splice display device 100 according to an embodiment of the present invention may further include a one-dimensional scattering screen 130 disposed on the first image plane 15 to diffuse light in the y direction, as shown in Fig. 2. In an embodiment of the present invention, the one-dimensional scattering screen 130 may be an entire scattering screen or may be composed of multiple individual scattering screens. In some embodiments of the present invention, the display surface of the display module 110 may be arranged parallel to the one-dimensional scattering screen 130.

[0021] 3 is a principle schematic diagram illustrating ray propagation in a first direction and a second direction in an optical imaging module 120 and a one-dimensional scattering screen 130 according to an embodiment of the present invention. The optical imaging module 120 includes a first one-dimensional conjugate imaging element 121 and a second one-dimensional conjugate imaging element 122, and can define an object plane 10, a first image plane 15, and a second image plane 20. The first one-dimensional conjugate imaging element 121 can have a microstructure unit for imaging in the first direction (y direction), such that a light beam from a point (b1, o, b2) on the object plane 10 is converged in the y direction onto the first image plane 15. The one-dimensional scattering screen 130 can be disposed on the first image plane 15 to diverge the light beam in the y direction. The second one-dimensional conjugate imaging element 122 may have microstructure units for imaging in a second direction (x-direction) such that a light beam from a point (a1, o, a2) on the object plane 10 is converged in the x-direction onto the second image plane 20. The microstructure units of the first one-dimensional conjugate imaging element 121 and the microstructure units of the second one-dimensional conjugate imaging element 122 may be arranged orthogonal to each other. The first direction and the second direction are respectively orthogonal to a main optical axis of the optical imaging module 120. The first one-dimensional conjugate imaging element 121 may be arranged between the object plane 10 and the second one-dimensional conjugate imaging element 122 along the main optical axis. The first one-dimensional conjugate imaging element 121 and / or the second one-dimensional conjugate imaging element 122 may be transmissive or reflective. For example, the first one-dimensional conjugate imaging element 121 and / or the second one-dimensional conjugate imaging element 122 may be a one-dimensional retro-reflection screen, a one-dimensional grating transmission array, a one-dimensional holographic diffraction grating, etc. The advantage of employing such conjugate imaging elements is that the positional relationship (object and image) is conjugate, the image does not magnify, and there is no aberration.

[0022] In some embodiments of the present invention, the optical path between the one-dimensional scattering screen 130 and the first one-dimensional conjugate imaging element 121 is approximately equal to the optical path between the object plane 10 and the first one-dimensional conjugate imaging element 121, and the one-dimensional scattering screen 130 can diverge light in the y direction. Alternatively, the optical path (distance) from the object plane 10 to the first one-dimensional conjugate imaging element 121 can be a, and the optical path (distance) from the object plane 10 to the second one-dimensional conjugate imaging element 122 can satisfy b≦2a. The height of the floating image (the distance to the one-dimensional scattering screen 130) is 2*(ba). Alternatively, the object plane 10 and the second image plane 20 of the optical imaging module 120 can be arranged approximately symmetrically with respect to the second one-dimensional conjugate imaging element 122. Alternatively, the first one-dimensional conjugate imaging element 121 and the second one-dimensional conjugate imaging element 122 can be arranged relatively parallel to each other. Alternatively, the optical imaging module 120 may have a one-dimensional aperture stop for limiting the height of the light rays passing through the optical imaging module 120 in the y direction, rather than limiting the passage of light in the x direction. Preferably, the first one-dimensional conjugate imaging element 121 can be provided as such a one-dimensional aperture stop.

[0023] As shown in the figure, in the x direction, light rays emitted from object points a1, o, and a2 on the object plane 10 are imaged at a1", o", and a2" on the second image plane 20 by the second one-dimensional conjugate imaging element 122. In the y direction, light rays emitted from object points b1, o, and b1 are imaged on the one-dimensional scattering screen 130 by the first one-dimensional conjugate imaging element 121 to form image points b1', o', and b2'. The light rays at the image points b1', o', and b2' are imaged on the scattering screen 130 by the first one-dimensional conjugate imaging element 121. 0 in the y direction, forming a large viewing angle range in the y direction. The optical imaging module 120 may have an image height in the x direction (on the second image plane 20) equal to the object height in the x direction (on the object plane 10), and an image height in the y direction (on the first image plane 15) equal to the object height in the y direction (on the object plane 10) or larger than the object height in the y direction (if a y-direction magnification optical system is present). In an embodiment of the present invention, multiple optical imaging modules 120 1~nmay have the same structure.

[0024] The foregoing describes a splice display device 100 for floating images according to an exemplary embodiment of the present invention. In this device, a floating image is formed in the air using a display module and multiple imaging modules, while a scattering screen is used to form a wide viewing angle range in the second direction, thereby realizing a large-sized floating display. This splice display device 100 does not require the design of a different optical imaging system for a specific size of floating image. Instead, the user simply selects a display module, an appropriate number of imaging modules, and a scattering screen according to the size of the floating image required. Furthermore, small-sized optical elements are easier to process than large-sized optical elements, significantly reducing the cost of realizing floating displays of different sizes. Furthermore, this splice display device 100 is significantly thinner and more compact than large-sized floating display devices in the prior art.

[0025] It is understood that in the x direction, the physical structure and optical properties of the optical imaging module may be approximately the same, so that it can be further spliced ​​in the x direction by several sets of the above splice display devices in order to further reduce the size of the optical elements and facilitate processing.

[0026] The central field of view has a large acceptance taper angle, while the edge field of view has a small acceptance taper angle, so the individual optical imaging modules 120 i In order to effectively improve the brightness unevenness problem, the light beams emitted from the pixel points on the display module 110 are projected onto multiple optical imaging modules 120. 1~n This allows the image to be focused at the same point.

[0027] Referring to FIG. 4, pixel points (e.g., a, b, c, d, e, f) on the display surface of the display module 110 are imaged by a plurality of optical imaging modules 120. 1~n(Although Fig. 4b and Fig. 4c show only the first optical imaging module 1201 and the second optical imaging module 1202, those skilled in the art will understand that the light emitted from the pixel point is transmitted through all the multiple optical imaging modules 120 1~n , b1, c1, d1, e1, f1) in the first image plane 15 (where the scattering screen 130 is placed).

[0028] In an alternative embodiment of the present invention, multiple optical imaging modules 120 1~n At least one of the optical imaging modules 120 further includes a spectral flat plate for reflecting light rays emitted from the object surface. The use of a spectral flat plate has the advantages of preventing light emitted from the display module from directly entering the human eye and reducing the thickness of the optical module by folding the optical path (e.g., converting the optical length from the z direction to the y direction). In an alternative embodiment of the present invention, the first one-dimensional conjugate imaging element 121 and the second one-dimensional conjugate imaging element 122 may be a retroreflective screen (RMA). An example of a one-dimensional retroreflective screen is shown in FIG. 5, where a light ray arbitrarily incident on the surface of the one-dimensional retroreflective screen is partially reflected according to the original angle.

[0029] 6 is a schematic block diagram of an optical imaging module according to an alternative embodiment of the present invention. As shown in the figure, display light at the display surface / object surface 10 is reflected by a spectral flat panel 123, enters a first one-dimensional conjugate imaging element (one-dimensional retroreflection screen) 121, is reflected by the first one-dimensional conjugate imaging element 121, is transmitted again by the spectral flat panel 123, enters a second one-dimensional conjugate imaging element retroreflection screen 122, is reflected by the second one-dimensional conjugate imaging element 122, and is reflected again by the spectral flat panel 123, so as to be formed as a floating image on a second image plane 20.

[0030] In an alternative embodiment of the present invention, the image height in the y direction at the first image plane 15 of the optical imaging module 120 is equal to or greater than the spacing between the first one-dimensional conjugate imaging element 121 and the second one-dimensional conjugate imaging element 122. By way of example, the image height in the y direction at the first image plane 15 of the optical imaging module 120 may be less than 200 mm, and the spacing between the first one-dimensional conjugate imaging element 121 and the second one-dimensional conjugate imaging element 122 may be less than 200 mm.

[0031] 6, in this embodiment, the spectral flat panel 123 may be disposed at an angle between the first one-dimensional conjugate imaging element 121 and the second one-dimensional conjugate imaging element 122 and between the object plane 10 and the first image plane 15 of the optical imaging module 120, and the first one-dimensional conjugate imaging element 121 and the second one-dimensional conjugate imaging element 122 may be disposed relatively parallel to each other. The display module 110 (particularly its display surface) and the first and second one-dimensional conjugate imaging elements 121 and 122 disposed on the object plane 10 of the optical imaging module 120 may be disposed perpendicular to each other, and the spectral flat panel 123 may be disposed at an angle, preferably at a 45° angle, to the display surface, the first one-dimensional conjugate imaging element 121, and the second one-dimensional conjugate imaging element 122, respectively.

[0032] In an alternative embodiment, the optical path between the one-dimensional scattering screen 130 and the first one-dimensional conjugate imaging element 121 can be approximately equal to the optical path between the display module 110 and the first one-dimensional conjugate imaging element 121. The display module 110 and the floating image at the second image plane 20 can be arranged approximately symmetrically with respect to the second one-dimensional conjugate imaging element 122. Preferably, the first one-dimensional conjugate imaging element 121 can be arranged as an aperture stop of the optical imaging module 120 to limit the height of the light beam passing through the optical imaging module 120 in the y direction, for example, by setting the y-direction light-transmitting aperture to 100 mm or less.

[0033] Referring to FIG. 7, for a retroreflective screen, the light rays secondarily reflected by the microstructures of the retroreflective screen are the imaging light rays, while the primarily reflected light rays are stray light that may form ghost images. Therefore, as shown in FIG. 8, in a preferred embodiment, the optical imaging module 820 can include a filter element 824 disposed between the first one-dimensional conjugate imaging element 821 and the spectral plate 823. The filter element 824 can be used as a light angle selector, absorbing large-angle light rays at small-angle light rays. The filter element 824 can be a microlouver structure or can be realized using a plating film. An example of a microlouver structure, as shown in FIG. 9, can be used to absorb large-angle light rays at small-angle light rays (usually within ±25 degrees). In this way, normal display light rays can pass through, while the primarily reflected light rays are absorbed due to their large angle, thereby eliminating ghost images. It may be understood that a filter element 824 may further be provided between the second one-dimensional conjugate imaging element 822 and the spectroscopic plate 823 to remove ghost images due to primary reflections of the second one-dimensional conjugate imaging element 822.

[0034] In another alternative embodiment of the present invention, ghost images can be eliminated by polarized light absorption. Referring to Fig. 10, an optical imaging module 1020 includes a polarizing and splitting plate 1023 disposed between a first retroreflective screen 1021 and a second retroreflective screen 1022, as well as a first 1 / 2λ wave plate 1025, a second 1 / 2λ wave plate 1026, and a polarizing plate 1027. The polarizing and splitting plate may be realized by plating a polarizing and splitting film on a plate, or the polarizing and splitting plate 1023 may be formed by attaching a polarizing and splitting film (APF) 1024 to the surface of the plate. The first ½λ wave plate 1025 may be provided on the light incident side of the first retroreflective screen 1021 (for example, between the first retroreflective screen 1021 and the spectral plate 1023), and the second ½λ wave plate 1026 may be provided on the light incident side of the second retroreflective screen 1022 (for example, between the second reflector 1022 and the spectral plate 1023). The included angle between the optical axis directions of the ½λ wave plates 1025 and 1026 and the one-dimensional retroreflective screen microstructure direction may be 22.5° or 67.5°. The polarizer 1027 may be provided between the spectral plate 1023 and the second image plane 20.

[0035] As shown in FIG. 10, when light emitted from the display surface (i.e., object surface 10) is s-polarized (0 degree direction) (this application is not limited to this, and the light emitted from the display surface may be natural light), it is irradiated onto the polarizing spectroscopic plate 1023, reflected, and irradiated onto the ½ wavelength plate 1025, becoming 45-degree linearly polarized light. It is then irradiated onto the first retroreflective screen 1021, and after being reflected twice by the right-angle microstructure, it remains 45-degree linearly polarized light. It then passes through the first ½ wavelength plate 1025 again to become p-polarized light (90 the s-polarized light is converted into s-polarized light (0 degree direction), passes through the polarizing spectroscopic plate 1023, is irradiated onto the ½ wavelength plate 1026, and becomes 45-degree linearly polarized light, then is irradiated onto the second retroreflective screen 1022, is reflected twice by the right-angle microstructures, and is still 45-degree linearly polarized light, passes through the second ½ wavelength plate 1026 again, becomes s-polarized light (0 degree direction), is reflected again by the polarizing spectroscopic plate 1023, is irradiated onto the polarizing plate 1027, and the s-polarized light passes through the polarizing plate 1027 and is irradiated onto the scattering screen 1030 arranged at the first image plane 15.

[0036] The light beams (ghost image beams, as shown in FIG. 11 ) primarily reflected by the first retroreflective screen 1021 remain s-polarized (0-degree direction) even after passing through the first ½λ waveplate 1025 twice, and are retroreflected by the spectral flat plate 1023 so that they cannot travel the original path. In this example, the polarizer 1027 is configured to transmit s-polarized light and absorb p-polarized light. Alternatively, the polarizer 1027 may be a circular polarizer, which can prevent light beams incident on the optical imaging module from being reflected back out, thereby achieving a light extinction effect.

[0037] Alternatively, a second 1 / 2λ waveplate 1026 can be placed on the surface of the polarizing spectroscopy plate 1023 facing the scattering screen 1030, and a polarizer 1027 passes p-polarized light and absorbs s-polarized light. If the light emitted from the display surface (i.e., the object surface 10) is s-polarized light, it is irradiated onto the polarizing spectroscopic plate 1023 and then reflected, irradiated onto the first retroreflective screen 1021 and reflected, passes through the first 1 / 2λ wavelength plate 1025 twice to be converted into p-polarized light, passes through the polarizing spectroscopic plate 1023, then passes through the second 1 / 2λ wavelength plate 1026 to be converted into 45-degree polarized light, is irradiated onto the second retroreflective screen 1022 and reflected, passes again through the second 1 / 2λ wavelength plate 1026 to become s-polarized light, is reflected again by the polarizing spectroscopic plate, passes through the second 1 / 2λ wavelength plate 1026 a third time to become p-polarized light, passes through the polarizing plate 1027 and is irradiated onto the scattering screen 1030 arranged at the first image plane 15.

[0038] Alternatively, the optical imaging module 1020 may include a one-dimensional aperture stop 1028 to limit the height of the light rays passing through the optical imaging module 1020 in the y direction, rather than limiting the passage of the light rays in the x direction. As previously mentioned, the aperture stop 1028 may be provided separately (as shown) or may be integrated into the first retro-reflective screen 1021.

[0039] Alternatively, the optical imaging module 1220 may include one or more lenses (or a group of lenses). Referring to FIG. 12, the optical imaging module 1220 may further include a first lens 1224 and a second lens 1225 in addition to the first retroreflective screen 1221, the second retroreflective screen 1222, and the spectral flat panel 1223. The first lens 1224 and the second lens 1225 may be cylindrical mirrors having refractive index only in the y direction. By increasing the number of lenses, the optical imaging module 1220 has a magnification role in the y direction, i.e., the image height at the first image plane 15 is larger than the object height at the object plane. The first lens 1024 may be disposed between the object plane 10 and the spectral flat panel 1223, and the second lens 1225 may be disposed between the second retroreflective screen 1222 and the spectral flat panel 1223. Preferably, the second lens 1225 may be integrally formed with the second retroreflective screen 1222. For example, a cylindrical mirror and a one-dimensional retroreflective screen can be integrally formed into a cylindrical sawtooth diffraction grating, as used in the second lens 1225 and the second retroreflective screen 1222. As shown in Fig. 13, the cylindrical sawtooth diffraction grating has a curved surface in the y direction and a one-dimensional sawtooth structure in the x direction, and the sawtooth structure is an isosceles triangle structure with an apex angle of 90 degrees.

[0040] 19, the splice display apparatus 100 further includes one or more beam deflection units 140 for collimating the light beams emitted from the optical imaging module 120, and the collimated light beams can further pass through a scattering screen 130 to obtain a more uniform viewing distribution. Preferably, the beam deflection units 140 may be equally spaced Fresnel lenses to prevent the seams between the lenses from appearing in the floating image. For example, the beam deflection units 140 may be TIR Fresnel lenses.

[0041] As shown in Figure 14, the display module 110 is preferably a single flat panel display, where the display module is a single complete display area, and the multiple optical imaging modules 120 adopt a reflective structure including two orthogonal one-dimensional retroreflective screens and a spectral flat panel. A portion of the light emitted from a pixel point a on the display is imaged by the optical imaging module 1201, and another portion is imaged by the optical imaging module 1202, and finally imaged to the same image point a' on the scattering screen 130. The light beam passing through the optical imaging module 1201 has only a downward field of view, and the light beam passing through the optical imaging module 1202 has only an upward field of view. Due to the splicing requirements of this reflective structure, a portion of the light emitted from the pixel point a is blocked by the retroreflective screen, resulting in a partial loss of field of view. Therefore, the role of the one-dimensional scattering screen 130 is to diffuse the light from the image point a' in the y direction, thereby achieving a large and continuous viewing angle in the y direction. On the other hand, the x-direction splice provides a large, continuous viewing angle because there are no physical structural obstructions, such as a retroreflective screen, making it easier to achieve a wide viewing angle and eliminating the need for a scattering screen to diffuse the light beam. The advantages of adopting this structure are that the optical system is aberration-free, eliminating the need to correct aberrations such as field curvature, simplifying the structure, and providing images with equal size in both the x and y directions, eliminating the need for additional scaling transformations on the image. Furthermore, because the display module is a complete single image, no additional splicing processing is required on the image, and one-to-one splice alignment is not required for each optical imaging module and display module, simplifying manufacturing and reducing costs. At the same time, the beam taper angles passing through the center and edge pixels of the optical imaging module are balanced, approximating the beam energies formed by different pixel points illuminated on the scattering screen 130 and achieving uniform brightness.

[0042] Alternatively, referring to Figure 20, the splice display device 100 may further include a lens array 150 arranged in front of the scattering screen 130, where the image of the display module 110 is projected onto the scattering screen 130 by the optical imaging module 120 in the y direction, and each sub-lens of the lens array 150 corresponds to an image area and is used to display a part of the floating image, and the light-emitting points representing the same image information on the scattering screen 130 are converged to a single point in space through different sub-lenses, thereby realizing the formation of a floating image plane in the y direction that is superimposed on the floating image plane 20 formed in the x direction. This can facilitate the solution of the spatial positioning problem of the floating image in the y direction.

[0043] Alternatively, the splice display device 100 may further include a microlens array 160 disposed in front of the scattering screen 130, and the image of the display module 110 is projected onto the scattering screen 130 by the optical imaging module 120 in the y direction. Using the principle of multi-viewpoint 3D display, the human eye sees different regions on the scattering screen through the microlens array at different viewing area positions. As shown in FIG. 21 , the image seen at the observation position from viewpoint 1 is a3b3, the image seen at the observation position from viewpoint 2 is a2b2, and the image seen at the observation position from viewpoint 3 is a1b1. Thus, although the observation positions of the human eye in the y direction in space vary, the positions of the floating image planes seen are all fixed at ab, and the image plane perceived by the human eye is superimposed on the floating image plane 20 formed on a horizontal plane by the optical imaging module. This solves the spatial positioning problem of the floating image in the y direction.

[0044] Also, referring to Figure 22, the multiple optical imaging modules 120 in the splice display device 100 may be arranged mirrored in the y direction, so that the conjugate imaging element 121 or 122 can be used redundantly. In this way, the size of the splice portion of the multiple optical imaging modules 120 can be reduced, which also plays a role in reducing costs.

[0045] According to another exemplary embodiment of the present invention, a multi-layer display device is also provided.

[0046] FIG. 15 is a schematic diagram illustrating a multi-layer display device 1500 according to an embodiment of the present invention. The multi-layer display device 1500 may include the splice display device 100 and a transparent display device 200. The transparent display device 200 may be located on the light-emitting side (optical downstream side) of the splice display device 100. The display surface of the transparent display device 200 is located at a different position from the floating image surface 20 of the splice display device 100, specifically between the floating image surface 20 and the splice display device 100. The transparent display device 200 may have high transmittance, such as a transparent OLED / LED / LCD display or film (slide). As shown in FIG. 16, the transparent display device 200 can also be obtained by placing a transparent film (film haze less than 5%) in front of the splice display device 100 and projecting an image from a microprojector. Alternatively, the transparent film may have angle selectivity for light rays, scattering large-angle light rays (projected image) and directly transmitting small-angle light rays (floating image).

[0047] The above describes a multi-layer display device 1500 according to an exemplary embodiment of the present invention. The multi-layer display device 1500 has a display surface 1 and a display surface 2. The splice display device 100 can form a floating image on the display surface 1 (image surface 20), and the transparent display device 200 can display different information on the display surface 2. In this way, secondary information can be displayed on the display surface 2, and important information can be displayed on the display surface 1, thereby improving the efficiency and experience of people's information acquisition. Alternatively, as shown in FIG. 17, it is also possible to realize a naked-eye 3D display by displaying images of the same size on the display surface 1 and the display surface 2, taking advantage of the differences in darkness and color caused by objects being farther and farther from the viewer, and further superimposing images of the objects in front and behind the viewer to give the viewer a three-dimensional effect.

[0048] Alternatively, the display module 110 may be a naked-eye 3D display, which may be a multi-viewpoint free-standing stereoscopic display or a light field display. As shown in FIG. 18A, a typical naked-eye 3D display is composed of a flat panel display and a micro-optical unit, which may be a microlens or a slit diffraction grating. The flat panel display generates parallax images, which are then sent separately to the observer's left and right eyes via the micro-optical unit, utilizing the binocular parallax effect of the human eye to create a three-dimensional effect. As shown in FIG. 18B, point a1 on the display module 110 enters the right eye, and point a2 enters the left eye. According to the principle of binocular parallax, the point seen by the human eye is point a, which is located in front of the screen. Point b1 on the screen enters the right eye, and point b2 enters the left eye. According to the principle of binocular parallax, the point seen by the human eye is point b, which is located behind the screen. Because both eyes view point c on the screen, the viewer perceives point c as being located on the screen. Therefore, the 3D images displayed by conventional naked-eye 3D displays are 3D images within a certain depth range in front and behind the screen, with the screen as the depth center. When viewing, the human eye focuses on the physical screen of the 3D display, so the user cannot perceive the 3D image floating in space, which affects the viewing experience.

[0049] To solve this problem, the display module 110 of the present invention may adopt a multi-viewpoint / light field display, in which the screen surface of the multi-viewpoint / light field display is projected into space by the optical imaging module 120 of the present invention to form a floating image plane, and by displaying a parallax image on the multi-viewpoint / light field display, a 3D image with a certain range in front and behind the floating image plane as the depth center can be formed in space. As shown in Figure 17C, on the floating image plane, point a is on the front depth of field plane, point b is on the rear depth of field plane, and point c is on the floating image plane of the display device, so that the formed 3D image is completely floating in the air, providing a better 3D experience.

[0050] The above has described in detail the splice display device, the optical imaging module used, and the multi-layer display device according to the exemplary embodiments of the present invention. The advantages of the present invention are: 1) the structure of a single optical imaging module in the splice display device is simple, and the required optical element size is small, which makes it easy to process and effectively reduces costs; 2) display modules (or display units) with a certain number of display areas and a certain number of optical imaging modules and scattering screens can be used to realize floating displays of different sizes as needed, that is, splicing is particularly advantageous for realizing floating displays of large sizes; 3) the optical imaging module is designed once, and the corresponding number of identical optical imaging modules are used according to the required floating image size to seamlessly splice the floating images, rather than having to design different optical imaging modules for different floating image sizes; 4) the thickness of the splice display device is small, which makes it thin and lightweight; 5) the splice display device can be an aberration-free method, which does not require optical aberration correction and has a simple optical structure. Using this splice display device, the light field reconstruction of the display module in mid-air is realized, which is a light field 3D display technology. The image side opening angle of the light beam in the display module formed by the optical imaging module along the x-direction is relatively large to satisfy the binocular parallax condition, thereby realizing a floating image display.

[0051] It should be understood that the above description is general and not limiting. For example, the above-described examples (and / or various aspects thereof) may be used in conjunction with each other. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the various embodiments of the invention without departing from the scope of the invention. While the sizes and types of materials described herein are used to define the parameters of the various embodiments of the invention, the various examples are not meant to be limiting, but are illustrative examples. Many other examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the various embodiments of the invention should be determined with reference to the appended claims, along with the full scope of equivalents claimed therein.

Claims

1. a display module arranged to emit display light constituting a target image on a display surface; a plurality of optical imaging modules arranged in a y direction and disposed to receive the display light and form a floating image in the air; a one-dimensional scattering screen for diverging light in the y-direction, wherein each of the plurality of optical imaging modules comprises: a first one-dimensional conjugate imaging element for focusing a point light beam from the display surface onto the one-dimensional scattering screen in the y direction; and a second one-dimensional conjugate imaging element for converging the point light beam from the display surface onto a floating image plane different from the plane on which the one-dimensional scattering screen is located in the x-direction, wherein the x-direction and the y-direction are respectively perpendicular to the main optical axis of the optical imaging module.

2. the first one-dimensional conjugate imaging element is disposed along a principal optical axis between the display surface and the second one-dimensional conjugate imaging element; the first one-dimensional conjugate imaging element and the second one-dimensional conjugate imaging element are provided relatively parallel to each other, the microstructure units of the first one-dimensional conjugate imaging element and the microstructure units of the second one-dimensional conjugate imaging element are arranged perpendicular to each other; and / or 2. The splice display device according to claim 1, wherein the display surface of the display module and the one-dimensional scattering screen are arranged parallel to each other.

3. The splice display device of claim 1, characterized in that the optical path from the display surface to the first one-dimensional conjugate imaging element is a, and the optical path from the display surface to the second one-dimensional conjugate imaging element is b, where b≦2a.

4. 2. The splice display device according to claim 1, wherein the display module is configured by splicing a plurality of display units together, or the display module has a plurality of individual display areas.

5. 2. The splice display device of claim 1, wherein the image heights of the plurality of optical imaging modules in the x-direction are equal to the object height of the target image on the display surface in the x-direction.

6. 2. The splice display device according to claim 1, wherein the target image displayed on the display surface and the floating image appearing on the floating image surface are in an erect image formation relationship.

7. The splice display device of claim 1 , wherein the plurality of optical imaging modules have the same structure.

8. 2. The splice display device of claim 1, wherein the optical path between the one-dimensional scattering screen and the first one-dimensional conjugate imaging element is approximately equal to the optical path between the display surface and the first one-dimensional conjugate imaging element.

9. 2. The splice display device of claim 1, wherein the display surface and the floating image surface are disposed substantially symmetrically with respect to the second one-dimensional conjugate imaging element.

10. 2. The splice display device of claim 1, wherein at least one of the plurality of optical imaging modules has a one-dimensional aperture stop for limiting the height of light rays passing through the at least one optical imaging module in the y direction, rather than limiting light rays in the x direction.

11. 2. The splice display device of claim 1, wherein at least one optical imaging module among the plurality of optical imaging modules further comprises a spectral flat plate, and the first one-dimensional conjugate imaging element and the second one-dimensional conjugate imaging element are retroreflective screens, and the display light is reflected by the spectral flat plate before entering the first one-dimensional conjugate imaging element, and then reflected by the first one-dimensional conjugate imaging element and then transmitted by the spectral flat plate before entering the second one-dimensional conjugate imaging element, and then reflected by the second one-dimensional conjugate imaging element and then reflected by the spectral flat plate, and then formed as the floating image on the floating image surface.

12. 2. The splice display device of claim 1, wherein the distance between the first one-dimensional conjugate imaging element and the second one-dimensional conjugate imaging element is less than 200 mm.

13. the spectroscopic plate is disposed obliquely between the first one-dimensional conjugate imaging element and the second one-dimensional conjugate imaging element and between the display surface and the floating image surface, the spectroscopic plate is a polarized spectroscopic plate, and the at least one optical imaging module: a first phase delay plate provided between the first one-dimensional conjugate imaging element and the spectroscopic plate; 12. The splice display device of claim 11, further comprising a second phase retardation plate disposed between the second one-dimensional conjugate imaging element and the spectroscopic plate.

14. 14. The splice display device of claim 13, wherein at least one of the first phase retardation plate and the second phase retardation plate is a 1 / 2λ wave plate, and the angle between the optical axis direction and the extension direction of the micro-structure units of the retroreflective screen is 22.5° or 67.5°.

15. 10. The splice display device of claim 1, wherein at least one of the plurality of optical imaging modules further comprises a filter element applied to light rays passing through a predetermined angular range.

16. The splice display device of claim 1, further comprising at least one light deflection unit arranged along the main optical axis between the plurality of optical imaging modules and the one-dimensional scattering screen.

17. 10. The splice display device of claim 1, further comprising a lens array disposed along the main optical axis between the one-dimensional scattering screen and the floating image surface.

18. 18. The splice display device of any one of claims 1 to 17, wherein the display module is a three-dimensional display.

19. The splice display device of claim 1; a transparent display device optically downstream of said spliced ​​display device, said transparent display device having a display surface at a different location than said floating image surface.

20. 20. The multi-layer display device of claim 19, wherein the transparent display device comprises a transparent display or is realized by projecting an image onto a transparent / semi-transparent film.

Images