Device and method for floating display

Abstract

Disclosed are an apparatus and method for a suspended display. The apparatus includes: an optical imaging system configured to receive light constituting an object plane image on its object plane to present a suspended image at its output image plane, wherein the optical imaging system includes a primary scattering screen for scattering light in a specific direction; an image display unit configured to form an object plane image on the object plane of the optical imaging system, wherein the light constituting the object plane image propagates through the optical imaging system and reaches the primary scattering screen to form an illuminated area on the primary scattering screen; a detection unit configured to detect user feature information; and a control unit configured to acquire the feature information from the detection unit and, based on changes in the feature information, change the size and / or position of the illuminated area on the primary scattering screen according to information from the optical imaging system, thereby maintaining at least one attribute of the suspended image substantially unchanged.

Description

Technical Field

[0001] The embodiments described herein generally relate to the field of optical display technology, and more particularly to an apparatus and method for floating display, which can be used for naked-eye 3D display. Background Art

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

[0003] A suspended display device typically includes a scattering screen that diverges a light beam in a specific direction, so that the light beam forms a larger viewing angle range in the specific direction. At the same time, the suspended display device enables the light beam to have a larger image-side aperture angle in another direction orthogonal to the specific direction and the optical axis, thereby satisfying the binocular parallax condition, thereby presenting a suspended image at its output image plane. Such a suspended image has parallax in the other direction but not in the specific direction.

[0004] The size of the floating image will change as the human eye moves in a specific direction, but the image size in the other direction will not change as the position of the human eye changes, resulting in a change in the display ratio of the image and causing viewing discomfort. Summary of the Invention

[0005] The purpose of the exemplary embodiments of the present invention is to overcome the above-mentioned and / or other problems in the prior art, and in particular to enable real-time change of the display position and size of a floating image based on changes in the position of the user's facial features, thereby ensuring that the floating image observed by the user remains substantially unchanged, thereby improving the user's comfort when viewing the floating image.

[0006] Specifically, exemplary embodiments of the present invention provide a device for floating display, the device comprising: an optical imaging system configured to receive light constituting an object plane image on an object plane thereof to present a floating image at an output image plane thereof, wherein the optical imaging system comprises a primary scattering screen for emitting light in a specific direction, the specific direction being orthogonal to an optical axis of the optical imaging system; an image display unit configured to form the object plane image on the object plane of the optical imaging system, wherein the light constituting the object plane image propagates through the optical imaging system and reaches the primary scattering screen to form an illuminated area on the primary scattering screen; a detection unit configured to detect feature information of the user; and a control unit configured to acquire the feature information from the detection unit and, based on a change in the feature information, change a size and / or position of the illuminated area on the primary scattering screen according to information of the optical imaging system, thereby substantially maintaining at least one attribute of the floating image.

[0007] According to another exemplary embodiment of the present invention, a method for suspended display is provided, the method comprising: forming an object plane image on an object plane of an optical imaging system, wherein the optical imaging system is configured to receive light constituting the object plane image on its object plane to present a suspended image at its output image plane, the optical imaging system comprising a primary scattering screen for emitting light in a specific direction, the specific direction being orthogonal to an optical axis of the optical imaging system, and the light constituting the object plane image propagates through the optical imaging system and reaches the primary scattering screen to form an illuminated area on the primary scattering screen; detecting feature information of the user; and changing the size and / or position of the illuminated area on the primary scattering screen according to information of the optical imaging system based on changes in the feature information, thereby keeping at least one attribute of the suspended image substantially unchanged.

[0008] Preferably, in the apparatus or method of the above exemplary embodiments, the at least one attribute of the suspended image includes a position and a size of the suspended image.

[0009] Preferably, in the device of the above exemplary embodiment, the control unit changes the size and / or position of the illumination area on the primary scattering screen by causing the image display unit to adjust the size and / or position of the object plane image formed on the object plane.

[0010] Preferably, in the apparatus of the aforementioned exemplary embodiment, the optical imaging system further comprises at least one imaging unit, located between the object plane and the primary diffuser screen on the optical axis, wherein the at least one imaging unit has a focal length in the specific direction; and the control unit changes the size and / or position of the illuminated area on the primary diffuser screen by adjusting the focal length of the at least one imaging unit to thereby change the magnification of the illuminated area relative to the object plane image. Preferably, the at least one imaging unit comprises a zoom lens, and the focal length of the zoom lens can be changed by powering on.

[0011] Preferably, in the apparatus of the above exemplary embodiment, the optical imaging system further comprises an optical reflective element, located between the object plane and the primary scattering screen on the optical axis, and reflecting light from the object plane at an angle relative to the specific direction; and the control unit changes the size and / or position of the illuminated area on the primary scattering screen by adjusting the angle to thereby change the position of the illuminated area in the specific direction.

[0012] Preferably, in the apparatus of the above exemplary embodiment, the detection unit is further configured to determine eye coordinates of the user, and the feature information includes the eye coordinates.

[0013] Preferably, in the apparatus or method of the above exemplary embodiment, the information of the optical imaging system includes: a mapping relationship between an object plane image of the optical imaging system and an illuminated area on the primary scattering screen, and / or a variable parameter range of an adjustable optical element within the optical imaging system.

[0014] Preferably, in the method of the above exemplary embodiment, the size and / or position of the illumination area on the primary scattering screen is changed by adjusting the size and / or position of the object plane image formed on the object plane.

[0015] Preferably, in the method of the above exemplary embodiment, the optical imaging system further includes at least one imaging unit, located between the object plane and the primary diffuser screen on the optical axis, wherein the at least one imaging unit has a focal length in the specific direction, and the size and / or position of the illuminated area on the primary diffuser screen is changed by adjusting the focal length of the at least one imaging unit to thereby change the magnification of the illuminated area relative to the object plane image. Preferably, the at least one imaging unit includes a zoom lens, and the focal length of the zoom lens can be changed by powering on.

[0016] Preferably, in the method of the above exemplary embodiment, the optical imaging system further includes an optical reflective element, which is located between the object plane and the primary scattering screen on the optical axis. The optical reflective element reflects light from the object plane at an angle relative to the specific direction. The size and / or position of the illuminated area on the primary scattering screen is changed by adjusting the angle to thereby change the position of the illuminated area in the specific direction.

[0017] Preferably, the method of the above exemplary embodiment further comprises determining eye coordinates of the user, and the feature information includes the eye coordinates.

[0018] Preferably, the method of the above exemplary embodiment further comprises the following steps: before forming an object plane image on the object plane of the optical imaging system, detecting characteristic information of the user and setting the position and size of the object plane image based on the characteristic information.

[0019] Preferably, the method of the above exemplary embodiment further comprises the following steps: before forming an object plane image on the object plane of the optical imaging system, detecting characteristic information of the user and setting the focal length of the at least one imaging unit based on the characteristic information.

[0020] Other features and aspects will become apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention may be better understood by describing exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0022] Figure 1A A schematic diagram showing the principle of the imaging process of the optical imaging system 100 for floating display;

[0023] Figure 1B Schematic diagram showing the principle of light propagation in the horizontal direction and the vertical direction of an exemplary optical imaging system 100 for floating display;

[0024] Figure 2 A schematic diagram showing the imaging of light rays at a point on the object plane within an exemplary optical imaging system 100;

[0025] Figure 3 Schematic diagram showing the principle of light propagation in a first direction and a second direction of an exemplary optical imaging system 200 for floating display;

[0026] Figure 4A A schematic diagram showing the principle of the imaging process of an exemplary optical imaging system 300 for floating display;

[0027] Figure 4B Schematic diagram showing the principle of light propagation in a first direction and a second direction of an exemplary optical imaging system 300 for floating display;

[0028] Figure 5 Schematic diagram showing the principle of light propagation in a first direction and a second direction of an exemplary optical imaging system 400 for floating display;

[0029] Figure 6 Schematic diagram showing the principle of light propagation in a first direction and a second direction of an exemplary optical imaging system 500 for floating display;

[0030] Figure 7 Schematic diagram showing the principle of light propagation in a first direction and a second direction of an exemplary optical imaging system 600 for floating display;

[0031] Figure 8 shows example elements of an imaging unit;

[0032] Figure 9 An example of a one-dimensional retroreflective screen is shown;

[0033] Figure 10A shows an example of a diffuser screen;

[0034] Figure 10B An example of a louver shading structure is shown;

[0035] Figure 11A A schematic diagram showing the addition of a relay imaging unit;

[0036] Figure 11B A schematic diagram showing an optional afocal system;

[0037] Figures 12A-12C A schematic diagram showing a first example of a floating display device;

[0038] Figure 13 A schematic side view and a top view showing a second example of a suspended display device;

[0039] Figure 14 A schematic diagram showing a third example of a floating display device;

[0040] Figures 15A-15C A schematic perspective view, a side view and a top view respectively show a fourth example of a floating display device;

[0041] Figure 16 A schematic diagram showing a fifth example of a floating display device;

[0042] Figure 17 A schematic diagram showing a sixth example of a floating display device;

[0043] Figure 18 A schematic diagram showing a seventh example of a floating display device;

[0044] Figure 19 A schematic diagram showing a floating display device according to an eighth example;

[0045] Figures 20A-20C A schematic diagram of a surround view display device 2000 is shown;

[0046] Figure 21A-21B Examples of how the suspended image changes as the position of the human eye changes are shown respectively;

[0047] Figure 22 A schematic block diagram of a device for floating display according to an embodiment of the present invention is shown;

[0048] Figure 23 and Figure 24 Schematic diagrams respectively showing a control unit according to an exemplary embodiment of the present invention making at least one attribute of a hovering image substantially unchanged based on the position of the eyes;

[0049] Figure 25 、 Figure 26 and Figure 27 illustrative diagrams respectively showing changes in the size and position of the illumination area on the primary diffuser screen; and

[0050] Figure 28is a flowchart of a method for floating display according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The specific embodiments of the present invention will be described below. It should be noted that in the specific description of these embodiments, in order to provide a concise description, this specification cannot provide a detailed description of all the features of the actual embodiments. It should be understood that in the actual implementation of any embodiment, just as in the process of any engineering project or design project, in order to achieve the specific goals of the developer and to meet system-related or business-related restrictions, various specific decisions are often made, and this will also change from one embodiment to another. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the content disclosed by the present invention, some design, manufacturing or production changes based on the technical content disclosed in this disclosure are just conventional technical means and should not be understood as the content of this disclosure being insufficient.

[0052] Unless otherwise defined, the technical or scientific terms used in the claims and description shall have the usual meaning understood by persons of ordinary skill in the technical field to which the invention belongs. The words "first", "second" and similar terms used in the description and claims of the patent application of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "one" or "a" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprising" mean that the elements or objects appearing before "include" or "comprising" cover the elements or objects listed after "include" or "comprising" and their equivalent elements, and do not exclude other elements or objects. Words such as "connected" or "connected" and similar terms are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0053] Figure 1A A schematic diagram showing the principle of the imaging process of an exemplary optical imaging system 100 for floating display. Figure 1B Schematic diagrams showing the principle of light propagation in the horizontal and vertical directions of an exemplary optical imaging system 100 for floating display.

[0054] See also Figure 1AIn a stereoscopic diagram of light transmission, an exemplary optical imaging system 100 for suspended display can define an object plane 10, a first image plane 101, and a second image plane 102 along its optical axis. The optical imaging system can include at least one imaging unit 110 and a primary scattering screen 120. The at least one imaging unit 110 is located between the object plane and the first image plane on the optical axis and has different capabilities for converging light in a first direction and a second direction. The first direction and the second direction are respectively orthogonal to the optical axis. The primary scattering screen 120 can diverge light in a second direction. The optical imaging system 100 is configured such that a light beam from a point on the object plane 10 forms a line image in a first direction on the first image plane 101, and a light beam from a point on the object plane 10 forms a line image in a second direction on the second image plane 102. The second image plane 102 is a suspended image plane. Optionally, the primary scattering screen 120 can be placed within the focal depth (generally referred to as the depth of field) of the first image plane 101.

[0055] The beam propagation of the optical imaging system 100 is profiled in a first direction and a second direction. The first direction and the second direction may be substantially orthogonal. For example, the first direction may be a horizontal direction and the second direction may be a vertical direction, or vice versa. Figure 1B In the first direction, the light emitted by the object points a1, o, a2 on the object plane 10 has a large divergence angle and is imaged as a1', o', a2' on the second image plane 102 by at least one imaging unit 110 (such as a lens, a retroreflective screen, a cylindrical mirror, etc.). In the second direction, the light emitted by the object points b1, o, b2 is imaged on the first image plane 101 by at least one imaging unit 110 to form image points b1', o', b2'; the main scattering screen 120 is placed within the focal depth of the first image plane 101 (as an example). , shown as being placed at first image plane 101), light from image points b1', o', and b2' is scattered in the second direction by scattering screen 120, thereby forming a larger viewing angle in the second direction. In this manner, the image-side aperture angle of a point on object plane 10 imaged along the first direction by primary imaging unit 110 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying binocular parallax conditions. Consequently, a suspended image can be formed at second image plane 102, exhibiting parallax in the first direction but lacking parallax in the second direction.

[0056] Figure 2 Schematic diagram showing the imaging of light rays at a point on the object plane within the exemplary optical imaging system 100. Figure 2 It can be seen that a point p on the object plane 10 forms a line image ab and a line image cd on the first image plane 101 and the second image plane 102 respectively through the imaging unit 110 .

[0057] The object plane 10 can be the display surface of a self-luminous display, or the projection surface generated by a projection display, and the light emitted by the display (i.e., the image source) can be set according to the light divergence angle requirements. In particular, the light emitted by the object point on the object plane needs to have a certain object-side aperture angle in the first direction (for example, 30 degrees to 180 degrees, specifically determined by the image-side aperture angle combined with the Laplace invariant formula as needed), which can be achieved through the inherent characteristics of the light source (i.e., the image source), or can be achieved by modulating the light from the light source (i.e., the image source). For example, a self-luminous display such as an OLED can emit light with a large divergence angle, so when its display surface is set at the object plane of the above-mentioned optical imaging system 100, the effect of a suspended display can be achieved.

[0058] Optionally, when the light emitted from the object point on the object plane 10 does not have a large divergence angle in the first direction, an additional scattering screen can be provided at the object plane 10 for diverging the light in the first direction, so that the light emitted by the additional scattering screen has a large divergence angle in the first direction.

[0059] As described above, at least one imaging unit 110 is configured to have different abilities to converge light in the first direction and the second direction. For a lens, this means having different focal lengths f in the first direction and the second direction, where f can be ∞. For example, for a cylindrical mirror, f is ∞ in the second direction. A one-dimensional retroreflective screen can also be used to achieve such an effect. The imaging unit 110 may include a main imaging unit for imaging, and one or more auxiliary imaging units or optical elements for propagating or modulating light. Note that each of the at least one imaging unit 110 may be an optical element or a combination of multiple optical elements.

[0060] Optionally, in some embodiments, at least one imaging unit 110 may include a main imaging unit and an auxiliary imaging unit. The main imaging unit is configured to converge light in a first direction. The auxiliary imaging unit may be disposed at any position between the object plane 10 and the first image plane 101. The auxiliary imaging unit may include a one-dimensional aperture stop for constraining light from the object plane 10 in a second direction. For example, the one-dimensional aperture stop may be a slit grating. The one-dimensional aperture stop may be configured to be small enough to obtain a relatively large depth of focus in the second direction. The auxiliary imaging unit may also include an optical element disposed between the object plane 10 and the one-dimensional aperture stop for converging light in the second direction, thereby allowing more light from the object plane 10 to pass through the one-dimensional aperture stop to increase the imaging light intensity. Optionally, the optical element may convert a light beam from a point on the object plane into approximately parallel light in the second direction, so that the divergence angle of the light beam after passing through the aperture stop is close to 0. For example, the optical element may be a lens or a lens group.

[0061] Optionally, at least one imaging unit may include a plurality of optical elements constituting an afocal system in the second direction, so that parallel light beams in the second direction with different incident angles entering the afocal system from an entrance pupil of the afocal system are still parallel light beams in the second direction with different angles after passing through the afocal system at its exit pupil, such as Figure 11B shown.

[0062] Figure 3 Schematic diagram showing the principle of light propagation in the first direction and the second direction of an exemplary optical imaging system 200 for floating display. Figures 1A-1B The optical imaging system 100 described is the same and will not be described in detail here. The following mainly describes the differences of the optical imaging system 200.

[0063] The beam propagation of the optical imaging system 200 is analyzed in a cross-section in the first direction and the second direction. Figure 2 In the first direction, the light emitted by the object points a1, o, a2 on the object plane 10 has a large divergence angle and is imaged as a1', o", a2' on the second image plane 102 through the main imaging unit 211. In the second direction, the light emitted by the object points b1, o, b2 passes through the auxiliary imaging unit 212 (at Figure 2 The primary scattering screen 220 (illustrated in the figure as an optical element 2122 and a slit aperture 2121) is imaged on the first image plane 101, forming image points b1', o', and b2'. The primary scattering screen 220 is positioned within the focal depth of the first image plane 101 (illustrated as being positioned at the first image plane 101). Light rays from the image points b1', o', and b2' are scattered by the primary scattering screen 220 in the second direction, thereby forming a wide viewing angle in the second direction. In this manner, the image-side aperture angle of a point on the object plane 10 imaged along the first direction by the primary imaging unit 211 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition. Consequently, a suspended image is formed on the second image plane 102. This suspended image has parallax in the first direction (e.g., horizontal direction) but no parallax in the second direction (e.g., vertical direction).

[0064] In the above optional embodiment, the auxiliary imaging unit 212 may only include a one-dimensional aperture stop 2121 for pinhole imaging, thereby achieving the floating display effect of the optical imaging system 200 without including the one-dimensional aperture stop 2121. Figure 2 However, considering the optical efficiency and imaging clarity, the optical imaging system preferably includes an optical element 2122 (e.g., a lens or a lens group) to improve the imaging effect. For example, the optical element 2122 can transform the light beam from a point on the object plane 10 into approximately parallel light in the second direction, so that the light beam divergence angle after passing through the aperture stop is close to 0. Note that although in Figure 3 , the auxiliary imaging unit 212 is shown to be between the object plane 10 and the main imaging unit 211, but those skilled in the art will appreciate that the auxiliary imaging unit 212 may also be disposed between the main imaging unit 211 and the first image plane 101; or, some optical elements in the auxiliary imaging unit 212 may be disposed between the object plane 10 and the main imaging unit 211, while other optical elements may be disposed between the main imaging unit 211 and the first image plane 101.

[0065] In particular, if the one-dimensional aperture stop 2121 is set to be small enough, a large depth of field can be obtained in the second direction. In this way, the main scattering screen 220 can be placed at any position between the one-dimensional aperture stop 2121 and the second image plane 102. Alternatively, the object plane 10 can be placed on the focal plane of the optical element 2122, so that an approximately parallel light beam in the second direction can be obtained. During the light transmission process, the main imaging unit does not change the divergence angle of the light in the second direction, so the light beam emitted by the object point is irradiated on the main scattering screen and is approximately parallel light in the second direction. In this embodiment, the object plane 10 can be the display surface of a self-luminous display, or the projection surface generated by a projection display, and the light emitted by the display (i.e., the image source) can be set according to the light divergence angle requirements.

[0066] Optionally, in some embodiments, at least one imaging unit 110 may include a main imaging unit and an auxiliary imaging unit. The main imaging unit may be configured to converge light in a first direction. The auxiliary imaging unit may be configured so that the optical imaging system 100 further defines one or more relay image planes, which are located between the object plane and the main scattering screen on the optical axis. The optical imaging system 100 may also include an additional scattering screen disposed within the focal depth of a specific relay image plane in the one or more relay image planes for diverging light in the first direction. The auxiliary imaging unit may be configured to form a light beam from a point on the object plane 10 into a line image in a second direction at the specific relay image plane.

[0067] Figure 4A A schematic diagram showing the principle of the imaging process of an exemplary optical imaging system 300 for floating display. Figure 4B Schematic diagram showing the principle of light propagation in the first direction and the second direction of an exemplary optical imaging system 300 for floating display. Figure 1A-3 The optical imaging systems 100 and 200 described above are the same and will not be described in detail herein. The following mainly describes the differences of the optical imaging system 300 .

[0068] like Figure 4AAs shown, in the optical imaging system 300, the imaging process of a light beam emitted from an object point on the object plane 10 on each image plane is as follows: the light beam passes through the auxiliary imaging unit 312 and is imaged as a line beam ef on the relay image plane 103 (i.e., a specific relay image plane). The additional diffuser screen 330 can be positioned within the focal depth of the relay image plane 103 and diverges the light beam only in a first direction without changing the propagation direction of the light beam in a second direction. That is, the line beam ef on the relay image plane is diverged in the first direction. The light beam diverged by the additional diffuser screen is converged in the first direction by the main imaging unit 311. The light beam emitted from the object point on the object plane 10 passes through the auxiliary imaging unit 312 and converges into a line beam ab on the first image plane 101. ab is substantially orthogonal to ef and is also orthogonal to the optical axis of the optical imaging system 300. The line beam ab is scattered in the second direction by the main diffuser screen 320 and finally converges into a line beam cd on the second image plane 102. The relay image plane 103 is associated with the arrangement of the additional diffuser screen 330 and is therefore referred to herein as a specific relay image plane. A characteristic of exemplary optical imaging system 300 is that a light beam from an object point on the object plane is imaged not as a point on the first, second, and relay image planes, but as a line. Specifically, line ef is the image of object point o on relay image plane 103, line ab is the image of object point o on first image plane 101, and line cd is the image of object point o on second image plane 102.

[0069] The beam propagation of the optical imaging system 300 is analyzed in a cross-section in the first direction and the second direction. Figure 4BIn the first direction, the light emitted by the object points a1, o, a2 on the object plane 10 is imaged as a1', o', a2' on the relay image plane 303 through the auxiliary imaging unit 312 (as an example, the figure shows the optical element 3122 and the aperture stop 3121); the additional scattering screen 330 is placed in the focal depth of the relay image plane 303 (as an example, the figure shows it is placed at the relay image plane 303), and the light of the image points a1', o', a2' is scattered by the additional scattering screen 330 in the first direction and is imaged on the second image plane 102 through the main imaging unit 311 to form image points a1", o"', a2". In the second direction, the light emitted by the object points b1, o, b2 is imaged by the auxiliary imaging unit 312 (as an example, the figure shows it is placed at the relay image plane 303). The primary imaging element 312 is imaged on the first image plane 101, forming image points b1', o", and b2'. The primary scattering screen 320 is placed within the focal depth of the first image plane 101 (as an example, shown in the figure as being placed at the first image plane 101). Light rays from the image points b1', o", and b2' are scattered in the second direction by the primary scattering screen 320, thereby forming a larger viewing angle range in the second direction. In this way, the image-side aperture angle of the point on the object plane 10 imaged along the first direction by the primary imaging unit 311 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), so as to meet the binocular parallax condition. Thus, a suspended image can be formed on the second image plane 102, and the suspended image has parallax in the first direction but no parallax in the second direction.

[0070] An object point on the object plane 10 corresponds to a line segment on the relay image plane 303, the first image plane 101, and the second image plane 102, respectively. Because the optical path is reversible, a line segment on the relay image plane 303, the first image plane 101, and the second image plane 102 is also imaged on a point on the object plane, forming a mapping relationship with a certain regularity. Such a mapping relationship is referred to as "optical conjugation" in this specification.

[0071] Note that although the auxiliary imaging unit 312 is shown in FIG4 as being between the object plane 10 and the main imaging unit 311, those skilled in the art will appreciate that the auxiliary imaging unit 312 may also be disposed between the main imaging unit 311 and the first image plane 101; or, some optical elements in the auxiliary imaging unit 312 may be disposed between the object plane 10 and the main imaging unit 311, while other optical elements may be disposed between the main imaging unit 311 and the first image plane 101.

[0072] In some embodiments of the present invention, the auxiliary imaging unit 312 is not required, but depends on the nature of the display source (i.e., light source) used with the optical imaging system 300. For example, if the display source is a laser scanning or parallel light source, the auxiliary imaging unit 312 can be omitted. Alternatively, in other embodiments of the present invention, the auxiliary imaging unit 312 can be integrated into the display source and thus not included in the optical imaging system 300.

[0073] Figure 5 Schematic diagram showing the principle of light propagation in the first direction and the second direction of an exemplary optical imaging system 400 for floating display. Figures 4A-4B The optical imaging system 300 described is the same and will not be described in detail here. The following mainly describes the differences of the optical imaging system 400.

[0074] The optical imaging system 400 can be used in a projection manner. For example, the projection plane of the projection display source can be set as the object plane of the optical imaging system 400.

[0075] The optical imaging system 400 may include an auxiliary imaging unit 412, an additional scattering screen 430, a main imaging unit 411, and a main scattering screen 420. The auxiliary imaging unit 412 may include an aperture stop 4121 and an optical element 4122 (e.g., a lens or a lens group). Light emitted from an object point on the object plane 10 is collimated into approximately parallel light by the optical element 4122 and then passes through the aperture stop 4121. The aperture stop is set to be sufficiently small (e.g., less than 200 μm). In the first direction, light rays emitted from object points a1, o, and a2 on the object plane are imaged as a1', o', and a2' on the relay image plane 403 through the optical element 4122 and the aperture stop 4121. The additional scattering screen 430 is placed at the relay image plane 403. Light rays from the image points a1', o', and a2' are scattered by the additional scattering screen 430 in the first direction. The scattered light rays have a certain divergence angle (for example, 30 degrees to 180 degrees) and are imaged on the second image plane 102 through the main imaging unit 411 to form image points a1", a1'', a2''. o”', a2”. In the second direction, the light emitted by the object points b1, o, b2 is imaged on the first image plane 101 through the optical element 4122 and the aperture stop 4121 to form image points b1', o”, b2'; because in this case, the auxiliary imaging unit 412 makes the light beam emitted by the object point parallel light in the second direction, and the divergence angle is close to 0. During the light transmission process, the main imaging unit does not change the divergence angle of the light in the second direction. Therefore, when the light beam emitted by the object point is irradiated on the main scattering screen, it is approximately parallel light in the second direction. The optical imaging system has infinite depth of focus in the second direction, and the first image plane 101 can be any position between the main imaging unit 411 and the second image plane 102. The primary scattering screen 420 is placed at the first image plane 101. Light from image points b1', o", and b2' is scattered in the second direction by the primary scattering screen 420, thereby forming a larger viewing angle in the second direction. In this manner, the image-side aperture angle of a point on the object plane 10 imaged along the first direction by the primary imaging unit 411 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition. As a result, a suspended image can be formed at the second image plane 102. This suspended image has parallax in the first direction but no parallax in the second direction.

[0076] Alternatively, in the optical imaging system 400, the object plane 10 is positioned at the focal plane of an optical element 4122. Light emitted from object points at different positions on the object plane 10 is collimated into parallel light at different angles by the optical element 4122. An aperture stop 4121 is positioned at the focal position on the other side of the optical element 4122. The parallel light at different angles converges at the focal position, passes through the aperture stop 4121, and is projected onto the diffuser screen. In this manner, the size of the aperture stop 4121 can be reduced to a very small size, allowing the object point light beams to form pixels on the diffuser screen. In this case, the relay image plane and the first image plane have infinite depth of focus, so the primary diffuser screen and the additional diffuser screen can be placed anywhere within the focal depth of the corresponding image planes. Furthermore, the primary diffuser screen and the additional diffuser screen can be placed at a certain angle (e.g., not 90 degrees) to the optical axis, thereby creating the technical effect of a suspended image being imaged at a certain angle relative to the primary diffuser screen.

[0077] Note that the auxiliary imaging unit 412 may only include the aperture stop 4121 for pinhole imaging, and thus the floating display effect of the optical imaging system 400 may be achieved without including the aperture stop 4121. Figure 5 However, considering the optical efficiency and imaging clarity, the optical imaging system preferably includes a lens to further improve the imaging effect.

[0078] Figure 6 Schematic diagram showing the principle of light propagation in the first direction and the second direction of an exemplary optical imaging system 500 for floating display. Figures 4A-4B The optical imaging system 300 described is the same and will not be described in detail here. The following mainly describes the differences of the optical imaging system 400.

[0079] The optical imaging system 500 can be used using a laser scanning method. The optical imaging system 500 can further define a relay image plane 503 and include an additional diffuser screen 530, a main imaging unit 511, and a main diffuser screen 520. The additional diffuser screen 530 can be positioned at the relay image plane 503. A light beam from a laser light source can be scanned onto the relay image plane 503 of the optical imaging system 500 via a two-dimensional scanning galvanometer.

[0080] See also Figure 6The parallel laser beam emitted by the RGB laser light source passes through the two-dimensional scanning galvanometer to form image points a1', o', a2' on the additional scattering screen 530. The image points a1', o', a2' are diverged in the first direction by the additional scattering screen 530, and then converged by the main imaging unit 511 to form images a1", o"', a2" on the second image plane 102. In the second direction, the laser beam passes through the two-dimensional scanning galvanometer to form image points b1', o", b2' on the main scattering screen 520, and then is scattered by the main scattering screen 520, so that it has a larger viewing angle in the second direction. During the light transmission process, the main imaging unit does not change the divergence angle of the light in the second direction. Therefore, the light beam emitted by the object point is irradiated on the main scattering screen and is approximately parallel light in the second direction. In particular, the reverse extension line of the scanning laser beam can be considered to form a virtual object plane 10, which is a1, o, a2 in the first direction and b1, o, b2 in the second direction. In this way, the image side aperture angle of the point on the object plane 10 imaged along the first direction through the main imaging unit 511 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition, thereby forming a suspended image at the second image plane 102, which has a first direction parallax but no second direction parallax.

[0081] Figure 7 Schematic diagram showing the principle of light propagation in the first direction and the second direction of an exemplary optical imaging system 600 for floating display. Figures 4A-4B The optical imaging system 300 described above is the same and will not be described in detail here. The following mainly describes the differences of the optical imaging system 600.

[0082] The optical imaging system 600 can be used in conjunction with a parallel light source. Figure 7 , the parallel light source illuminates the spatial light modulator (which can be regarded as the object plane 10), forming the pixel a1, o, a2 (which can be regarded as the object point a1, o, a2 on the object plane 10). Similar to the reference Figure 4A-6According to the imaging principle, the parallel projections of pixels a1, o, and a2 onto relay image plane 603 form image points a1', o', and a2'. These image points a1', o', and a2' are scattered in the first direction by the additional scattering screen 630 and imaged onto the second image plane 102 by the main imaging unit 611, forming corresponding image points a1", o'", and a2". The image points of pixels b1, o, and b2 on the spatial light modulator on the first image plane 101 are b1', o", and b2', which are then scattered in the second direction by the main scattering screen 620, resulting in a larger viewing angle in the second direction. During light transmission, the main imaging unit does not change the divergence angle of the light in the second direction. Therefore, the light beam emitted by the object point, which is illuminated by the main scattering screen, is approximately parallel light in the second direction. In this way, the image aperture angle of the point on the object plane 10 imaged along the first direction through the main imaging unit 611 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition, thereby also forming a suspended image at the second image plane 102, which has a first direction parallax but no second direction parallax.

[0083] A spatial light modulator (SLM) is a device that modulates the spatial distribution of light waves. Generally speaking, a SLM consists of many independent units arranged in a one- or two-dimensional array. Each unit can independently receive control from an optical or electrical signal and change its optical properties accordingly, thereby modulating the light waves that illuminate it.

[0084] See also Figure 8 In the above optical imaging system, at least one imaging unit (particularly the primary imaging unit) between the primary diffuser and the additional diffuser can include a lens, a mirror, and / or a one-dimensional retroreflective screen (with a 90-degree V-groove angle) to adjust the light in the first direction. Using a lens / mirror allows the optical imaging system to magnify the image, whereas using only a one-dimensional retroreflective screen does not.

[0085] See also Figure 9 In some embodiments of the present invention, a one-dimensional retroreflective screen may be a microprism array structure, with the microprism surface coated with a reflective layer, and the angle between the V-shaped grooves of the microprisms is 90 degrees. The principle of a one-dimensional retroreflective screen is that any light incident on the surface of the one-dimensional retroreflective screen is reflected at the original angle in one direction and as a mirror in the other direction. Alternatively, in other embodiments of the present invention, the one-dimensional retroreflective screen may have other structures, such as a holographic structure.

[0086] Alternatively, as Figure 10A As shown, the scattering screen can be a directional scattering screen composed of a prism array and a cylindrical mirror array, which is used to better control the angle of the light emitted from the scattering screen and improve the display quality.

[0087] Optionally, a shutter shading structure can be arranged on the light-emitting side of the diffuser screen to control the angle of the light emitted from the diffuser screen. Figure 10B A viewing angle control film with a shutter structure can be superimposed on the scattering screen to control the angle of light emitted from the scattering screen and improve the display quality.

[0088] Optionally, in order to further improve the light and thin design of the system, the size of the optical imaging system 300 or 400 can be compressed in the second direction. For example, a relay imaging unit can be added in the second direction. Figure 11A For example, for the above-mentioned optical imaging system 300, by adding optical elements 3123 and 3124 (such as a cylindrical lens pair) and an aperture stop 3121 between the object plane 10 and the first image plane 101, the optical elements 3123 and 3124 form an afocal system (telephoto system) in the second direction. The aperture stop 3121 is the entrance pupil position of the afocal system, and the position 3125 is the exit pupil position of the system. The function of the afocal system is to ensure that parallel light beams with different incident angles in the second direction passing through the aperture stop are still parallel light beams with different angles in the second direction after passing through the afocal system at the exit pupil position, as shown in FIG. Figure 11B As shown in Figure 1 , the light beam emitted by the object point impinges on the primary diffuser screen and is approximately parallel in the second direction. This design allows light in the second direction to be transmitted within a very narrow space. Thus, in addition to the specific relay image planes described above for positioning additional diffusers within their focal depths, the optical imaging system 300 or 400 can further define additional relay image planes.

[0089] Similar to the above optical imaging system, the present invention also provides a corresponding floating display device, which includes the optical imaging system described above and an image display unit, wherein the image display unit is configured to emit light constituting an image toward the object plane of the optical imaging system.

[0090] Optionally, the suspension display device further includes a spatial light modulator disposed at the object plane, for modulating the parallel light from the image display unit.

[0091] The image display unit may be a direct-view display source, in which case the display surface of the image display unit may be disposed at the object plane. Alternatively, the image display unit may be a projection display source, in which case the projection surface of the image display unit may be disposed at the object plane.

[0092] Hereinafter, several examples of the floating display device will be described.

[0093] First example

[0094] Figures 12A-12C A schematic diagram of a first example of a suspended display device is shown, wherein an optical imaging system 1200 for suspended display is used in conjunction with a laser MEMS scanning projection. Several details of the optical imaging system in the suspended display device according to the first example are similar to those described above. Figure 5 The optical imaging system 400 or 500 described in Example 6 is the same and will not be described in detail here. The following mainly describes the differences of the optical imaging system 1200 of the first example.

[0095] In this example, the optical imaging system 1200 may include an auxiliary imaging unit, an additional diffusion screen 1230, a main imaging unit 1211, and a main diffusion screen 1220. The auxiliary imaging unit 1212 may include a first lens 12121, a second lens 12122, and a plane mirror 12123.

[0096] like Figure 12A and 12B As shown, the imaging process of the light beam emitted from the object point on the virtual object plane 10 through the optical imaging system 1200 is as follows: after the laser beam passes through the lens 12121, the propagation in the horizontal direction x and the vertical direction y is parallel; the parallel laser beam is diverged in the horizontal direction x by the additional scattering screen 1230 (i.e., at the relay image plane 1203); the optical elements 12121 and 12122 constitute an afocal system (telescopic system) in the second direction, position 12124 is the entrance pupil position of the afocal system (the galvanometer position of the MEMS scanning projection), and position 12125 is the exit pupil position of the system. The function of the afocal system is to make the parallel light beams in the second direction with different incident angles through the aperture stop be parallel light beams in the second direction with different angles after passing through the afocal system at the exit pupil position. Therefore, the light emitted by the object point The light beam is irradiated on the main scattering screen and is approximately parallel in the second direction. The main scattering screen 1220 (i.e., at the first image plane 101) scatters the light only in the z direction (corresponding to the vertical direction relative to the optical axis of the optical system 1200) without changing the transmission of the light in the x direction (corresponding to the horizontal direction relative to the optical axis of the optical system 1200). The horizontally diverging light is reflected by the one-dimensional retroreflective screen 1211 and then passes through the main scattering screen 1220, converging on the suspended image surface (i.e., the second image plane 102). The vertically transmitted light is converged in the vertical direction y by the second lens (i.e., the cylindrical lens), then reflected by the plane reflector 12123 and the one-dimensional retroreflective screen 1211 to propagate toward the main scattering screen 1220, where it is then scattered by the main scattering screen 1220, forming a larger field of view angle in the vertical direction y. Figure 12CAs shown, light emitted by a virtual object point is scattered in the horizontal direction x by additional scattering screen 1230, reflected by plane mirror 12123 and one-dimensional retroreflective screen 1211, and imaged as a horizontal line ab on first image plane 101. It is then scattered vertically by primary scattering screen 1220, resulting in an image formed as a vertical line cd on second image plane 102. In this way, the image-side aperture angle of a point on object plane 10 imaged along the first direction by primary imaging unit 1211 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition. Consequently, a suspended image can be formed on the suspended image plane (i.e., second image plane 102), exhibiting horizontal parallax but no vertical parallax. In this example, relay image plane 1203 can serve as the object plane of the present invention.

[0097] Second example

[0098] Figure 13 A schematic side view and a top view of a second example of a suspended display device are shown, wherein an optical imaging system 1300 for suspended display is used in conjunction with parallel light projection. Several details of the optical imaging system 1300 in the suspended display device according to the second example are similar to those described above with respect to Figure 7 The optical imaging system 600 described is the same and will not be described in detail here. The following mainly describes the differences of the second example.

[0099] like Figure 13 As shown, the suspended display device includes a parallel light source, a spatial light modulator, and an optical imaging system 1300. In this example, the spatial light modulator can be a transmissive display screen, such as an LCD. The surface on which the spatial light modulator is located can be considered as object plane 10. Optical imaging system 1300 can include an additional diffuser screen 1330, an imaging unit 110, and a primary diffuser screen 1320 along its optical axis. Imaging unit 110 can include a one-dimensional retroreflective screen disposed between additional diffuser screen 1330 and primary diffuser screen 1320 on the optical axis.

[0100] A parallel light source illuminates the spatial light modulator, forming image elements a, o, and b (which can be considered object points a, o, and b on the object plane). The parallel light is scattered by the additional scattering screen 1330 in a horizontal direction perpendicular to the optical axis on the relay image plane 1303 and redirected by the one-dimensional retroreflective screen to illuminate the first image plane 101. The main scattering screen 1320 scatters the light in a vertical direction perpendicular to the optical axis, resulting in a larger viewing angle in the vertical direction. In this way, the image-side aperture angle of the point on the object plane 10 imaged along the first direction by the main imaging unit 110 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition. Thus, a suspended image (a', o', b') can be formed on the second image plane 102. This suspended image has horizontal parallax but no vertical parallax.

[0101] Third example

[0102] Figure 14 A schematic diagram of a third example of a suspended display device is shown, wherein a waveguide is used to transmit light between the additional diffuser screen and the main diffuser screen. Several details of the imaging process of the optical imaging system 1400 of the suspended display device according to the third example are similar to those described above. Figure 4A-5 The imaging process described is the same and will not be described in detail here. The following mainly describes the differences of the third example.

[0103] In this example, the levitation display device includes an optical imaging system 1400 for levitation display, an RGB laser light source, and a scanning galvanometer, wherein the scanning galvanometer is configured to guide light constituting an image from the RGB laser light source to the optical imaging system 1400.

[0104] Optical imaging system 1400 may define, along its optical axis, an object plane 10, a relay image plane 1403, a first image plane 101, and a second image plane 102. Optical imaging system 1400 includes: an auxiliary imaging unit disposed on an optical path between object plane 10 and first image plane 101; an additional diffuser screen 1430 disposed at relay image plane 1403; a main imaging unit disposed on an optical path between object plane 10 and first image plane 101; and a main diffuser screen 2 disposed at first image plane 101.

[0105] The auxiliary imaging unit may include lens 1 (lens 1), lens 2 (lens 2), a reflector MR, and an optical waveguide WG. The optical waveguide WG is a flat plate structure made of glass or PMMA, within which light is continuously transmitted by total internal reflection. Lens 2 is a toric mirror with different focal lengths in the x and y directions, and the s1 and s2 surfaces of the optical waveguide are freeform surfaces. The main imaging unit 1411 may include lens 3 (lens 3), which is a cylindrical Fresnel lens. The additional diffuser 1430 disperses light only in the horizontal direction orthogonal to the optical axis and does not change the propagation direction of light in the vertical direction orthogonal to the optical axis. The main diffuser 1420 is a reflective diffuser that disperses light in the vertical direction.

[0106] Specifically, the light beam transmission direction in the optical system 1400 is the optical axis direction, the first direction and the second direction are two directions orthogonal to the optical axis, and the first direction and the second direction are orthogonal to each other.

[0107] The RGB laser light source vibrates in the first and second directions via a scanning galvanometer SG, projecting the laser beam at various angles. The beam first passes through lens 1 (lens 1), modulating the beams at various angles in the second direction into parallel beams propagating along the optical axis. The beams then pass through lens 2 (lens 2), a toric lens with a focal length of f1 in the first direction and f2 in the second direction. This modulates the beams at various angles in the first direction into parallel beams propagating along the optical axis. The beams in the second direction are then reconverged and redirected by a reflector MR, redirecting the beams at different propagation angles into the optical waveguide WG. Lens 2 (lens 2) is a plano-convex lens. An optional additional diffuser screen 1430, a cylindrical lens array, is attached to the plane of lens 2 (lens 2). The scanning beam impinges on diffuser screen 1430, diverging the light in the first direction without altering the light propagation in the second direction. The surface of diffuser screen 1430 serves as the relay image plane 1403. Light entering the optical waveguide is modulated by the free-form surface S1 within the waveguide WG, collimating the light beam in the second direction to a parallel beam. The beam then undergoes total internal reflection within the waveguide, without altering the propagation of the diverging light beam in the first direction. It is then modulated again by the free-form surface S2, transforming the light beam in the second direction into a converging beam, without altering the propagation of the diverging light beam in the first direction. The main imaging unit 1411 (lens 3) is a reflective cylindrical Fresnel lens that reconverges the diverging light emitted from the waveguide in the first direction. The main scattering screen 1420 is a reflective cylindrical concave mirror array. The converging light reflected by the reflective cylindrical Fresnel mirrors strikes the main scattering screen 1420, where it is scattered. The light converges in space in the first direction, forming an image, thereby forming a suspended image at the second image plane 102. Specifically, the light diverges in the second direction, thereby expanding the field of view in the second direction.

[0108] Optical elements Lens 1, Lens 2, S1, and S2 form an afocal system (telephoto system) in the second direction. Position k1 is the entrance pupil position of the afocal system (the galvanometer position of the MEMS scanning projection), and position k2 is the exit pupil position of the system. The function of the afocal system is to ensure that parallel light beams in the second direction with different incident angles passing through the aperture stop are still parallel light beams in the second direction at different angles after passing through the afocal system at the exit pupil position. Therefore, the light beam emitted by the object point passes through Lens 1, Lens 2, S1, and S2 and illuminates the primary scattering screen, and is approximately parallel light in the second direction.

[0109] In this manner, the image-side aperture angle of a point on the object plane 10 imaged in the first direction by the primary imaging unit 1411 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition. Consequently, a suspended image can be formed on the second image plane (i.e., the suspended image plane) 102. This suspended image has horizontal parallax but no vertical parallax. Furthermore, the use of optical waveguides for light transmission enables a lighter, thinner off-axis system design, resulting in higher optical efficiency and greater ease of modular production.

[0110] Fourth Example

[0111] Figures 15A-15C A schematic perspective view, side view, and top view of a fourth example of a suspended display device are shown, respectively, employing a concave mirror for imaging. Several details of the imaging process of the optical imaging system 1500 of the fourth example are identical to those of the optical imaging system 1300 of the second example and are not further described here. The following primarily describes the differences of the fourth example.

[0112] As shown, the suspended display device includes a parallel light source, a spatial light modulator (i.e., a display screen), and an optical imaging system 1500. In this example, the optical imaging system may include a first diffuser screen 1530, at least one imaging unit 1510, and a second diffuser screen 1520. The at least one imaging unit 1510 may include a semi-reflective mirror (i.e., an auxiliary imaging unit) 1512 and a cylindrical reflector (i.e., a primary imaging unit) 1511 disposed on the optical path between the second diffuser screen 1520 and the first diffuser screen 1530.

[0113] In the optical system 1500 , the light beam transmission direction is the optical axis direction. The first direction and the second direction are two directions orthogonal to the optical axis, and the first direction and the second direction are orthogonal to each other.

[0114] Light emitted by a parallel light source illuminates the display screen, forming a display image. The surface where the display image is located can be considered object plane 10. The light emitted from the surface where the display image is located is parallel light, resulting in a parallel projection image. Any location behind the display screen can serve as the image plane. The display image is incident on a first diffuser screen 1530, which disperses the light in a first direction without altering the propagation of light in a second direction. The location of first diffuser screen 1530 can be considered the relay image plane. Light passing through first diffuser screen 1530 partially passes through half-mirror 1512 and illuminates cylindrical reflector 1511. Cylindrical reflector 1511 converges the light in the first direction without altering the propagation of light in the second direction. Light reflected by cylindrical reflector 1511 is partially reflected by half-mirror 1512 and then illuminates second diffuser screen 1520. Second diffuser screen 1520 can be a cylindrical microlens array or a one-dimensional holographic diffuser. Second diffuser screen 1520 diffuses light in the second direction, expanding the field of view in the second direction. Light traveling in the first direction converges in space to form suspended image 102 (i.e., at second image plane 102). During light transmission, the primary imaging unit does not change the divergence angle of the light in the second direction. Therefore, the light beam emitted by the object point that impinges on the primary diffuser screen appears approximately parallel in the second direction.

[0115] In this manner, the image-side aperture angle of a point on the object plane 10 formed along the first direction by the primary imaging unit 1511 is relatively large (i.e., 20 degrees or greater, preferably greater than 30 degrees), satisfying the binocular parallax condition. Consequently, a suspended image can be formed on the suspended image plane (second image plane 102), exhibiting horizontal parallax but no vertical parallax. Furthermore, due to the use of a cylindrical reflector, the image can be magnified horizontally without being magnified vertically.

[0116] Fifth Example

[0117] Figure 16 A schematic diagram of a fifth example of a levitated display device is shown, in which an optical imaging system 1600 for levitated display is used in conjunction with laser MEMS scanning projection. Several details of the optical imaging system 1600 in the levitated display device according to the fifth example are identical to those of the optical imaging system 1200 described above with reference to Figures 12A-12C and are not further described here. The following primarily describes the differences of the fifth example.

[0118] In this example, the x- and y-direction scanning galvanometers can be separately configured; the x-galvanometer controls the laser beam to scan an image in the x-direction, while the y-galvanometer controls the laser beam to scan an image in the y-direction. The V-groove microstructure can be integrated into the y-galvanometer. In this example, parallel light scanning imaging is employed. The primary imaging unit does not alter the light divergence angle in the second direction. Therefore, the light beam emitted by the object point, which impinges on the primary scattering screen, is approximately parallel in the second direction. This structure offers the advantage of a very thin optical system.

[0119] Sixth Example

[0120] Figure 17 A schematic diagram of a sixth example of a levitated display device is shown, in which an optical imaging system 1700 for levitated display is used in conjunction with laser MEMS scanning projection. Several details of the imaging process of the levitated display device according to the third example are identical to those of the optical imaging system 1200 described above with reference to Figures 12A-12C and will not be repeated here. The following primarily describes the differences of the sixth example.

[0121] In this example, the optical imaging system 1700 includes: an auxiliary imaging unit, which is arranged between the object plane 10 and the first image plane 101 on the optical path; an additional scattering screen 1730, which is arranged at the relay image plane 1703; a main imaging unit, which is arranged between the object plane 10 and the first image plane 101 on the optical path; and a main scattering screen 1720, which is arranged at the first image plane 101. Figure 17 , shows the arrangement of the auxiliary imaging unit and the main imaging unit in the optical imaging system 1700 according to the sixth example. Specifically, the auxiliary imaging unit may include a first polarization beam splitter prism pbs1, a first lens lens1, a plurality of reflectors MR1 ​​and MR2, a first polarization beam splitter prism pbs2, a second lens lens2, a third polarization beam splitter prism pbs3, a third lens lens3 and other optical elements. Lens lens2 is a complex curved mirror, which has different radii of curvature in the x and y directions and can simultaneously modulate light in the x and y directions. The main imaging unit may include a retroreflective screen 1711. In this example, the first lens lens1, the second lens lens2 and the third lens lens3 are all plano-convex lenses, and a metal reflective layer is coated on the plano-convex surface.

[0122] In the optical system 1700 , the light beam transmission direction is the optical axis direction. The first direction and the second direction are two directions orthogonal to the optical axis, and the first direction and the second direction are orthogonal to each other.

[0123] The RGB laser light source vibrates in the first and second directions via a scanning galvanometer, projecting the laser beam at different angles. A linear polarizer is provided on the front surface of the first polarization beam splitter prism PBS1 to obtain a highly polarized P-state laser beam (referred to as P-light). A quarter-wave plate is provided between the first polarization beam splitter prism PBS1 and the first lens LENS1. The P-light passes through the first polarization beam splitter prism PBS1 and is converted into circularly polarized light after the quarter-wave plate. It is then reflected by the first lens LENS1 and passes through the quarter-wave plate again. At this point, the laser beam is S-state polarized light (referred to as S-light). The first lens LENS1 is a cylindrical reflector used to converge the laser beam in the second direction and limit the height of the optical system in the second direction. The S-light is reflected by the beam splitting interface of the first polarization beam splitter prism PBS1 and then reflected by the first reflector MR1, changing the transmission path and irradiating the second polarization beam splitter prism PBS2. A quarter-wave plate is placed between the second polarization beam splitter prism pbs2 and the second lens 2. S-light is reflected by the beam splitting interface of the second polarization beam splitter prism pbs2 and then by the second lens 2. After passing through the quarter-wave plate twice, it is converted into p-light. After passing through the beam splitting interface of the second polarization beam splitter prism pbs2, it is irradiated onto the reflector MR2. The second lens MR2 is a toric lens with different focal lengths in the first and second directions. The function of the second lens MR2 is to collimate the laser beams at different angles in the first and second directions into beams that propagate parallel to the optical axis in the first and second directions. A quarter-wave plate is placed between the reflector MR2 and the second polarization beam splitter prism pbs2. The light reflected by the reflector MR2 passes through the quarter-wave plate and is converted into s-light. It is reflected by the beam splitting interface of the second polarization beam splitter prism pbs2 and then exits the second polarization beam splitter prism pbs2. An additional scattering screen 1730 is provided on the light-emitting surface of the second polarization beam splitter prism pbs2. This surface serves as the relay image plane 1703. Light emitted from a point on the virtual object plane forms a line segment image in the second direction on the relay image plane 1703. The additional scattering screen diverges the light beams impinging on the scattering screen in the first direction without changing the transmission of light in the second direction. A 1 / 2 wave plate is arranged between the polarization beam splitter prism pbs3 and the additional scattering screen. The s light emitted from the additional scattering screen is converted into p light after passing through the 1 / 2 wave plate and then enters the third polarization beam splitter prism pbs3. It is irradiated onto the cylindrical reflector lens3 through the beam splitting plane of the third polarization beam splitter prism pbs3. A 1 / 4 wave plate is arranged between the polarization beam splitter prism pbs3 and the cylindrical reflector lens3. The p light reflected from the cylindrical reflector lens3 passes through the 1 / 4 wave plate twice and is converted into s light. It is reflected by the beam splitting interface, and the optical axis is rotated 90 degrees and irradiated onto the one-dimensional retroreflective screen. In this example, the one-dimensional retroreflective screen is the main imaging unit 1711, which is a V-groove array structure with a V-groove angle of 90 degrees and a metal reflective layer coated on the surface.A one-dimensional retroreflective screen is positioned at a 30-degree angle to the XZ plane. The diverging light beam emitted by the additional scattering screen in the first direction is reflected by the one-dimensional retroreflective screen and converges spatially in the first direction, forming a suspended image at the second image plane (i.e., the suspended image plane) 102. The angle between the suspended image and the XZ plane is 60 degrees. A primary scattering screen 1720 is positioned along the XZ direction between the suspended image plane 102 and the one-dimensional retroreflective screen. This position can be considered the position of the first image plane 101. Because the light beam is parallel in the second direction and has infinite depth of field, the first image plane 101 and the primary scattering screen 1720 can be positioned anywhere between the main imaging unit 1711 and the suspended image plane 102 according to design requirements. The primary scattering screen diverges light in the second direction, expanding the field of view in the second direction. In this example, the optical elements between the scanning galvanometer and the main imaging unit 1711 form an afocal imaging system, which ensures that the light beam emitted by the object point is illuminated by the primary scattering screen and is approximately parallel in the second direction.

[0124] In this way, a suspended image can be formed at the second image plane (i.e., the suspended image plane) 102, with horizontal parallax but no vertical parallax. Furthermore, because the entire system is a reflective optical system, it exhibits no chromatic aberration and is spatially foldable, facilitating the realization of a large-scale, lightweight suspended display device.

[0125] Optionally, the polarization beam splitter prism PBs in this example can be replaced by a polarization reflection plate.

[0126] Example 7

[0127] Figure 18 A schematic diagram of a seventh example of a suspended display device is shown, wherein an optical imaging system 1800 for suspended display is used in conjunction with parallel light projection and a lens group is used to form an image in a first direction. Several details of the optical imaging system 1800 in the suspended display device according to the seventh example are similar to those described above with respect to Figure 7 The optical imaging system 600 described is the same and will not be described in detail here. The following mainly describes the differences of the seventh example.

[0128] As shown in the figure, the floating display device includes a parallel light image source and an optical imaging system 1800. In this example, the optical imaging system may include an additional diffuser screen 1830, an imaging unit 1811, and a main diffuser screen 1820. The imaging unit may include a first lens 1, a second lens 2, a third lens 3, a first reflector, and a second reflector, disposed on the optical path between the additional diffuser screen 1830 and the main diffuser screen 1820. Figure 18The arrangement is as shown, where lens 1, lens 2, and lens 3 are the primary imaging units. The first lens 1, the second lens 2, and the third lens 3 can be cylindrical lenses. The lens group functions to amplify the image in the first direction and correct image aberrations. The second diffuser screen 2 is arranged at a certain angle.

[0129] In this example, the parallel image source consists of a parallel backlight source and an LCD display. The LCD display surface is object plane 10. Parallel light emitted by the LCD is projected onto an additional diffuser screen 1830, which disperses the light horizontally without altering vertical light transmission. The surface on which the additional diffuser screen resides is the relay image plane 1803. Light emitted by the additional diffuser screen passes through the first lens 1, the second lens 2, and the third lens 3, forming a real image in space, forming a suspended image plane 102. The first and second reflectors are used to alter the light transmission path. Light reflected by reflector 2 strikes the tilted primary diffuser screen 1820, which disperses the light in the second direction, expanding the vertical field of view.

[0130] In this way, the imaging plane of the image on the object plane 10 along the first direction has a relatively large image aperture angle at the second image plane 102 (i.e., 20 degrees or greater, preferably greater than 30 degrees), thereby forming a suspended image magnified in the second direction at the suspended image plane, and the suspended image has horizontal parallax but no vertical parallax.

[0131] In this example, the image in the first direction is magnified by the lens group, and the image in the second direction is magnified by parallel light irradiating the tilted main scattering screen. The two directions can have different magnifications. In order to obtain suspended images with normal proportions in the first and second directions, the pixel size of the spatial light modulator (LCD display) is preferably set to be different in the two directions, that is, the display pixels are not square but rectangular.

[0132] Example 8

[0133] Figure 19 A schematic diagram of an eighth example of a levitated display device is shown, in which an optical imaging system 1900 for levitated display is used in conjunction with laser MEMS scanning projection. Several details of the imaging process of the optical imaging system 1900 of the levitated display device according to the eighth example are identical to those of the optical imaging system 1700 according to the sixth example and are not further described here. The following primarily describes the differences of the eighth example.

[0134] In this example, the fourth lens lens 4 and the reflector are used to replace the retroreflective screen, as shown in FIG. Figure 19 The fourth lens 4 can be quickly moved mechanically along the y direction. According to the object-image formula, the image distance v satisfies u is the object distance. In this example, f remains unchanged, so if u increases, v decreases. The suspended image surface can be moved back and forth along the optical axis. When the fourth lens lens4 moves fast enough along the y direction so that the time of a movement cycle is less than 0.1s, and the current required image is displayed at each moving position, the dynamic effect of the suspended image can be achieved. When a cross-sectional image of the 3D image is displayed at each moving position, the 3D image effect can be seen using the multi-layer 3D display principle. Optionally, if the imaging lens adopts a fast zoom lens such as liquid / liquid crystal, the position of the suspended image can also be changed by changing the focal length f of the imaging lens, thereby achieving a dynamic or 3D effect.

[0135] Similar to the above-mentioned floating display device, the present invention also provides a corresponding surround-view display device.

[0136] Figure 20A A schematic diagram of a surround-view display device 2000 is shown, in which a splicing solution is adopted to realize a 360-degree viewable surround-view display device.

[0137] In this example, the surround display device 2000 is composed of 8 of any of the aforementioned floating display devices (as an example, Figure 20B A possible configuration of the suspension display device is shown. Figure 20A Reference numerals 2001-2008 represent eight suspended display devices respectively. Figure 20C Show Figure 20B The top view of the example suspension display device is shown in the figure. As shown in the figure, the suspension display device is a trapezoidal structure. Figure 20A Preferably, the suspended image 102 is at an angle of 45-90 degrees to the horizontal. It can be further precisely set so that the center point O of the suspended image 102 formed by the 8 suspended display device units coincides with each other. For example, if the horizontal field of view of each group of suspended images is 45 degrees, then 8 groups of suspended display devices can be spliced ​​into a 360-degree full field of view. When 8 groups of suspended display devices are used to display images corresponding to 8 positions of a three-dimensional object, the surround-view display device has a 3D display effect. Note that the use of a splicing scheme to apply 8 suspended display devices is only an example and not a limitation. Those skilled in the art will understand that the number of spliced ​​suspended display devices can be any integer greater than 2, which can achieve a surround-view / 3D display effect.

[0138] The above describes in detail an optical imaging system for floating display, a floating display device incorporating the same, and a surround-view display device. With this optical imaging system, a point light beam on an object plane is imaged along a first direction by an imaging unit, resulting in a relatively large image-side aperture angle, satisfying binocular parallax conditions. This enables floating image display, and the suspended image exhibits only unidirectional parallax, further enabling naked-eye 3D display.

[0139] The above implementation plan can be described according to the following terms:

[0140] 1. An optical imaging system for suspended display, wherein the optical imaging system defines an object plane, a first image plane, and a second image plane in sequence along its optical axis, and comprises:

[0141] at least one imaging unit located between the object plane and the first image plane on the optical axis, wherein the at least one imaging unit has different light converging capabilities in a first direction and a second direction, the first direction and the second direction being orthogonal to the optical axis, respectively; and

[0142] a main scattering screen, wherein the main scattering screen scatters light along the second direction,

[0143] The optical imaging system is configured such that a light beam from a point on the object plane forms a line image in the first direction on the first image plane, and such that a light beam from a point on the object plane forms a line image in the second direction on the second image plane, wherein the second image plane is a suspended image plane.

[0144] 2. The optical imaging system according to clause 1, further comprising an additional scattering screen, disposed at the object plane, for scattering light along the first direction.

[0145] 3. The optical imaging system of clause 1, wherein the at least one imaging unit comprises:

[0146] A main imaging unit is configured to converge light in the first direction.

[0147] 4. The optical imaging system according to clause 3, wherein the primary imaging unit is a one-dimensional retroreflective screen.

[0148] 5. The optical imaging system according to clause 3, wherein the at least one imaging unit further comprises an auxiliary imaging unit arranged between the object plane and the primary scattering screen, and the auxiliary imaging unit comprises a one-dimensional aperture stop for constraining light from the object plane in the second direction.

[0149] 6. An optical imaging system according to clause 5, wherein the auxiliary imaging unit further comprises an optical element arranged between the object plane and the one-dimensional aperture stop for converting the light beam from a point on the object plane into approximately parallel light in the second direction.

[0150] 7. The optical imaging system of clause 3, wherein:

[0151] The at least one imaging unit further includes an auxiliary imaging unit so that the optical imaging system further defines one or more relay image planes, wherein the one or more relay image planes are located between the object plane and the primary scattering screen on the optical axis, and the optical imaging system further includes an additional scattering screen arranged within a focal depth of a specific relay image plane among the one or more relay image planes for diverging light along the first direction.

[0152] 8. The optical imaging system according to clause 7, wherein the auxiliary imaging unit is configured to form a light beam from a point on the object plane into a line image in the second direction at the specific relay image plane.

[0153] 9. The optical imaging system according to clause 7, wherein the auxiliary imaging unit comprises an aperture stop and an optical element arranged between the object plane and the aperture stop, wherein the optical element causes the light beam from a point on the object plane to be collimated into approximately parallel light.

[0154] 10. The optical imaging system according to clause 9, wherein the aperture stop is reduced so that a light beam from a point on the object plane is projected onto the additional scattering screen to form a pixel point.

[0155] 11. The optical imaging system of clause 7, wherein the additional diffuser screen is positioned at an angle to the optical axis.

[0156] 12. The optical imaging system of clause 1, wherein the primary diffuser screen is positioned at an angle to the optical axis.

[0157] 13. The optical imaging system according to clause 1, wherein a shutter light-shielding structure is arranged on the light-emitting side of the main diffuser screen to control the angle of the light emitted from the main diffuser screen.

[0158] 14. The optical imaging system of clause 1, wherein the at least one imaging unit comprises one or more of:

[0159] a one-dimensional retroreflective screen for converging light in the first direction;

[0160] a toric mirror for modulating light in the first direction and the second direction simultaneously;

[0161] an optical waveguide for propagating light therethrough;

[0162] Cylindrical lenses, which focus light in one direction without changing the propagation of light in another direction orthogonal to that direction; and

[0163] The lens group is located between the object plane and the first image plane on the optical axis and is used to propagate light therebetween.

[0164] 15. An optical imaging system according to claim 1, wherein the at least one imaging unit includes a plurality of optical elements constituting an afocal system in the second direction, so that a parallel light beam in the second direction with different incident angles entering the afocal system from an entrance pupil of the afocal system remains a parallel light beam in the second direction with different angles after passing through the afocal system at its exit pupil.

[0165] 16. The optical imaging system of clause 1, wherein the optical imaging system has an infinite depth of focus in the second direction for the first image plane, the first image plane being located at any position between the at least one imaging unit and the second image plane.

[0166] 17. The optical imaging system according to clause 3, wherein the main imaging unit is capable of reciprocating along the optical axis or has a fast zoom function.

[0167] 18. A suspension display device, comprising:

[0168] An optical imaging system according to clauses 1-17; and

[0169] An image display unit is configured to emit light constituting an image toward an object plane of the optical imaging system.

[0170] 19. The levitation display device according to clause 18, further comprising a spatial light modulator disposed at the object plane, for modulating the parallel light from the image display unit.

[0171] 20. The levitation display device according to clause 18, wherein the image display unit is a laser light source, and the levitation display device further comprises one or more scanning galvanometers for modulating the laser beam from the image display unit to scan out the image.

[0172] 21. A suspended display device according to clause 20, wherein the one or more scanning galvanometers include a first scanning galvanometer and a second scanning galvanometer, the first scanning galvanometer is used to scan the image in a first direction, the second scanning galvanometer is used to scan the image in a second direction, and the first scanning galvanometer is separately arranged from the second scanning galvanometer.

[0173] 22. The levitation display device according to clause 18, wherein:

[0174] The image display unit is a direct-view display source, and the display surface of the image display unit is arranged at the object plane; or

[0175] The image display unit is a projection display source, and a projection surface of the image display unit is arranged at the object plane.

[0176] 23. A surround view display device comprising:

[0177] A plurality of the suspended display devices according to clauses 18-22 are arranged in a spliced ​​manner.

[0178] Adaptive adjustment of floating images

[0179] In an optical imaging system that includes a scattering screen that radiates light in a specific direction (e.g., the y-direction), the position and / or size of the suspended image will change as the human eye moves in that specific direction, while the position and / or size of the image in another direction (e.g., the x-direction) will not change with changes in the position of the human eye, resulting in a change in the image display ratio and causing viewing discomfort.

[0180] See also Figure 21A When the main scattering screen and the main optical axis are tilted at a certain angle, the size of the illuminated area on the main scattering screen is ab; when the human eye is at position O1, the size of the suspended image is a1b1, and when the human eye is at position O2, the size of the suspended image is a2b2.

[0181] See also Figure 21B When the main scattering screen and the main optical axis are set vertically, the size of the illuminated area on the main scattering surface is ab; when the human eye is at position O1, the position of the suspended image is a1b1, and when the human eye is at position O2, the position of the suspended image is a2b2.

[0182] To overcome the above-mentioned technical problems, the present invention provides a device for suspended display, comprising: an optical imaging system configured to receive light constituting an object plane image on its object plane to present a suspended image at its output image plane, wherein the optical imaging system includes a primary scattering screen for emitting light in a specific direction, wherein the specific direction is orthogonal to the optical axis of the optical imaging system; an image display unit configured to form the object plane image on the object plane of the optical imaging system, wherein the light constituting the object plane image propagates through the optical imaging system and reaches the primary scattering screen to form an illuminated area on the primary scattering screen; a detection unit configured to detect feature information of the user; and a control unit configured to acquire the feature information from the detection unit and, based on changes in the feature information, change the size and / or position of the illuminated area on the primary scattering screen according to information of the optical imaging system, thereby keeping at least one attribute of the suspended image substantially unchanged. In this device, the size and / or position of the illuminated area on the main diffuser screen is adjusted based on the position of the user's facial features, thereby ensuring that the observed floating image has substantially the same size and / or position when the position of the user's eyes changes, thereby improving the user's comfort when viewing the floating image while ensuring the accuracy of the interaction.

[0183] A schematic block diagram of a device for floating display provided by an embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0184] Figure 22 A schematic block diagram of an apparatus 2200 for floating display according to an embodiment of the present invention is shown. The apparatus 2200 for floating display includes: an optical imaging system 2201 , an image display unit 2202 , a detection unit 2203 , and a control unit 2204 .

[0185] The optical imaging system 2201 can be configured to receive light constituting an object surface image on its object surface to present a suspended image at its output image plane. The optical imaging system 2201 can include a primary scattering screen for scattering light in a specific direction, the specific direction being orthogonal to the optical axis of the optical imaging system 2201. The optical imaging system 2201 can be any of those described above, or can have other structures and configurations and have known or detectable optical information (e.g., the relative relationship between the source image on the object surface and the illuminated area on the primary scattering screen).

[0186] The image display unit 2202 can be configured to form an object plane image on the object plane of the optical imaging system 2201. Light constituting the object plane image propagates within the optical imaging system 2201 and reaches the primary diffuser screen, forming an illuminated area on the primary diffuser screen. The image display unit 2202 can be a direct-view display source, in which case the display surface of the image display unit 2202 can be positioned at the object plane. Alternatively, the image display unit 2202 can be a projection display source, in which case the projection surface of the image display unit 2202 can be positioned at the object plane.

[0187] The detection unit 2203 can be configured to obtain user feature information in real time or at predetermined time intervals. The control unit 2204 can be configured to obtain the feature information from the detection unit 2203 in real time or at predetermined time intervals, and based on changes in the feature information, change the size and / or position of the illuminated area on the primary diffuser screen according to information from the optical imaging system 2201, thereby maintaining at least one attribute of the suspended image (as observed by the user's eyes) substantially unchanged. The feature information can be the location of facial features, such as the location (i.e., coordinates) of the eyes, nose, ears, and the like. The information from the optical imaging system 2201 can include a mapping relationship between the object plane image of the optical imaging system and the illuminated area on the primary diffuser screen, and / or the variable parameter range of adjustable optical elements within the optical imaging system (e.g., the variable focal length range of a zoom lens or the variable angle range of a reflector). The mapping relationship can represent the relationship between the position and size of the object plane image and the position and size of the illuminated area on the primary diffuser screen. For example, based on changes in the feature information (e.g., the coordinates of the eye position), the control unit 2204 can determine the desired position and size of the illuminated area on the primary diffuser screen required to maintain at least one attribute of the suspended image substantially unchanged. The at least one attribute of the hovering image may include a position and a size of the hovering image.

[0188] Figure 23 and Figure 24 Schematic diagrams respectively illustrate how the control unit 2204 keeps at least one attribute of the hovering image substantially unchanged based on eye positions according to an exemplary embodiment of the present invention.

[0189] When the main scattering screen is tilted at a certain angle relative to the optical axis, the control unit 2204 can adjust the image size on the main scattering screen according to the detected changes in the human eye position, so that the floating images seen at different positions of the human eye are close in position. Figure 23 As shown, when the human eye is at position O1, the size of the illuminated area on the main scattering screen is ab, and the position of the suspended image is a1b1. When the human eye is at position O2, the size of the illuminated area on the main scattering screen is adjusted to a'b', and the position of the suspended image remains a1b1.

[0190] When the main scattering screen is perpendicularly arranged with respect to the optical axis, the control unit 2203 can adjust the image position on the main scattering screen according to the detected change in the human eye position, so that the positions of the floating images seen at different positions of the human eye are close. As Figure 24 shown, when the human eye is at the O1 position, the size of the illuminated area on the main scattering screen is ab, and the position of the floating image is a1b1. When the human eye is at the O2 position, the position of the illuminated area on the main scattering screen is adjusted to a'b', and the position of the floating image remains a1b1.

[0191] In some embodiments of the present invention, the control unit 2204 can change the size and / or position of the illuminated area on the main scattering screen in the following manner: making the image display unit 2202 adjust the size and / or position of the object plane image formed on the object plane. The object plane and the image plane (for example, the illuminated area on the main scattering screen) are in a mapping relationship, and by changing the size and position of the actual display area of the object plane, the size and position of the illuminated area on the main scattering screen are changed.

[0192] Figure 25 An exemplary illustration of changing the size and position of the illuminated area on the main scattering screen is shown, in which the size and position of the actual display area on the object plane are changed.

[0193] In some embodiments of the present invention, the optical imaging system 2201 can include at least one imaging unit, and the at least one imaging unit is located between the object plane and the main scattering screen on the optical axis. The at least one imaging unit has a focal length in a specific direction. Thus, the control unit 2204 can change the size and / or position of the illuminated area on the main scattering screen in the following manner: adjusting the focal length of the at least one imaging unit to change the magnification of the illuminated area relative to the object plane image. For example, the at least one imaging unit can include a zoom lens and can change the focal length of the zoom lens by applying power.

[0194] Figure 26 An exemplary illustration of changing the size of the illuminated area on the main scattering screen is shown, in which the focal length of the imaging lens / lens group of the optical imaging system is changed to change the magnification of the object plane in a specific direction.

[0195] As shown in the figure, the object plane light beam a0b0 forms an illuminated area on the main scattering screen through the imaging lens group lens1, lens2, lens3, where lens3 is a liquid / liquid crystal lens and its focal length can be changed by applying power. When the human eye position is O1, the focal length of lens3 in the upper figure is f1, the image on the main scattering screen is ab, and the floating image observed by the human eye is a1b1; when the human eye position is O2, the focal length of lens3 in the lower figure is f2, f1 < f2, at this time the image on the main scattering screen is a'b', and the floating image observed by the human eye is a2b2. a1b1 and a2b2 are basically of equal size.

[0196] In some embodiments of the present invention, the optical imaging system 2201 may include an optical reflective element positioned between the object plane and the primary diffuser screen along the optical axis. The optical reflective element reflects light from the object plane at an angle relative to a specific direction. In this manner, the control unit can change the size and / or position of the illuminated area on the primary diffuser screen by adjusting the angle to thereby change the position of the illuminated area in the specific direction.

[0197] Figure 27 An exemplary diagram showing changing the position of the illumination area on the primary diffusion screen, wherein the angle of the reflector in the optical imaging system is adjusted, is shown.

[0198] As shown in the figure, when the human eye is at position O1, the mirror rotates to position P1, and the image formed by the object beam a0b0 on the main scattering screen is a'b', and the suspended image observed by the human eye is a1b1; when the human eye is at position O2, the mirror rotates to position P2, and the image formed by the object beam on the main scattering screen is ab, and the suspended image observed by the human eye is still a1b1.

[0199] The three aforementioned methods for adjusting the image (i.e., the illuminated area) formed on the primary diffuser screen can be used individually or in combination. Furthermore, those skilled in the art will recognize that the size and / or position of the image formed on the primary diffuser screen can be adjusted by other methods (such as adjusting other types of optical elements capable of adjusting the light beam). These other methods may depend on the specific configuration and structure of the optical imaging system used for the suspended display. Alternatively, in Figure 27 In the example shown, the position of the illuminated area can also be changed by rotating the one-dimensional retroreflective screen.

[0200] The above describes in detail an improved device for floating display according to an exemplary embodiment of the present invention. This device can modify the size and / or position of the illuminated area on the main diffuser screen based on changes in the position of a user's facial features, thereby ensuring that the position and / or size of the floating image observed by the user remains substantially unchanged, thereby improving the user's viewing comfort when viewing the floating image.

[0201] According to an embodiment of the present invention, a method for floating display is also provided. Figure 28 , Figure 28 2800 is a flow chart of a method 2800 for floating display according to an embodiment of the present invention. Figure 22 The device 2200 shown is used as an example. Figure 28As shown, the method 2800 for floating display according to an embodiment of the present invention may include the following steps S2810 to S2850.

[0202] In step S2810, an object plane image is formed on the object plane of the optical imaging system.

[0203] The optical imaging system can be configured to receive light constituting an object plane image on its object plane, thereby presenting a suspended image at its output image plane. The optical imaging system can include a primary scattering screen for scattering light in a specific direction, the specific direction being orthogonal to the optical axis of the optical imaging system. The light constituting the object plane image propagates through the optical imaging system and reaches the primary scattering screen, forming an illuminated area on the primary scattering screen. Step S2810 can be implemented, for example, using the image display unit described above.

[0204] In step S2830, the characteristic information of the user is detected. Step S2830 can be implemented, for example, by the detection unit described above.

[0205] In step S2850, based on the change in the characteristic information, the size and / or position of the illuminated area on the primary scattering screen is changed according to information from the optical imaging system, thereby maintaining at least one attribute of the suspended image substantially unchanged. Step S2850 can be implemented, for example, by the control unit described above.

[0206] By adopting this method, the size and / or position of the illuminated area on the main diffuser screen is adjusted based on the position of the user's facial features, thereby ensuring that the observed floating image has substantially the same size and / or position when the position of the user's eyes changes, thereby improving the user's comfort when viewing the floating image.

[0207] In some embodiments of the present invention, the at least one attribute of the hovering image may include the position and size of the hovering image.

[0208] In some embodiments of the present invention, the size and / or position of the illumination area on the primary scattering screen may be changed by adjusting the size and / or position of the object plane image formed on the object plane.

[0209] In some embodiments of the present invention, the optical imaging system may further include at least one imaging unit, located between the object plane and the primary diffuser screen along the optical axis. The at least one imaging unit has a focal length in a specific direction, and the size and / or position of the illuminated area on the primary diffuser screen can be changed by adjusting the focal length of the at least one imaging unit to thereby change the magnification of the illuminated area relative to the object plane image. For example, the at least one imaging unit may include a zoom lens, and the focal length of the zoom lens can be changed by applying power.

[0210] In some embodiments of the present invention, the optical imaging system may further include an optical reflective element, which is located between the object plane and the primary scattering screen on the optical axis. The optical reflective element reflects light from the object plane at an angle relative to a specific direction. The size and / or position of the illuminated area on the primary scattering screen may be changed by adjusting the angle to change the position of the illuminated area in the specific direction.

[0211] In some embodiments of the present invention, eye coordinates may be calculated based on the acquired facial image, and the feature information includes the eye coordinates.

[0212] In some embodiments of the present invention, the information of the optical imaging system may include: a mapping relationship between an object plane image of the optical imaging system and an illuminated area on the primary scattering screen, and / or a variable parameter range of an adjustable optical element in the optical imaging system.

[0213] Optionally, method 2800 may further include the following steps: before forming an object plane image on the object plane of the optical imaging system, detecting characteristic information of the user and setting the position and size of the object plane image and / or the focal length of at least one imaging unit based on the characteristic information.

[0214] So far, the apparatus and method for floating display according to the present invention have been described.

[0215] The present invention can change the display position and size of the floating image based on the position change of the user's facial features, thereby ensuring that the floating image observed by the user does not change substantially, and improving the user's comfort when viewing the floating image.

[0216] It should be understood that the above description is illustrative and not restrictive. For example, the above embodiments (and / or their aspects) can be used in combination with each other. In addition, without departing from the scope of the present invention, many modifications can be made to adapt specific conditions or materials to the teachings of the various embodiments of the present invention. Although the size and type of materials described herein are used to define the parameters of the various embodiments of the present invention, the various embodiments are not meant to be restrictive, but rather exemplary embodiments. Upon reading the above description, many other embodiments will be apparent to those skilled in the art. Therefore, the scope of the various embodiments of the present invention should be determined with reference to the appended claims, and the full range of equivalent forms claimed for protection by these claims.

Claims

1. A device for floating display, comprising: an optical imaging system configured to receive light constituting an object plane image on its object plane to present a suspended image at its output image plane, wherein the optical imaging system comprises a primary scattering screen for scattering light in a specific direction, the specific direction being orthogonal to an optical axis of the optical imaging system; an image display unit configured to form the object plane image on the object plane of the optical imaging system, wherein light constituting the object plane image propagates through the optical imaging system and reaches the primary scattering screen to form an illuminated area on the primary scattering screen; a detection unit configured to detect feature information of a user, wherein the detection unit is further configured to determine eye coordinates of the user, and the feature information includes the eye coordinates; as well as a control unit configured to obtain the characteristic information from the detection unit and, based on a change in the characteristic information, change the size and / or position of the illuminated area on the primary scattering screen according to information from the optical imaging system, thereby maintaining at least one attribute of the suspended image observed by a human eye at different positions, wherein the at least one attribute of the suspended image includes the position and size of the suspended image.

2. A method for floating display, the method comprising: forming an object plane image on an object plane of an optical imaging system, wherein the optical imaging system is configured to receive light constituting the object plane image on its object plane to present a suspended image at its output image plane, the optical imaging system comprising a primary scattering screen for emitting light in a specific direction, the specific direction being orthogonal to an optical axis of the optical imaging system, and the light constituting the object plane image propagates through the optical imaging system and reaches the primary scattering screen to form an illuminated area on the primary scattering screen; Detecting user's characteristic information; Determining eye coordinates of the user, wherein the feature information includes the eye coordinates; Based on the change in the characteristic information, the size and / or position of the illuminated area on the primary scattering screen is changed according to information from the optical imaging system, so that at least one attribute of the suspended image observed by the human eye at different positions remains unchanged, wherein the at least one attribute of the suspended image includes the position and size of the suspended image.

3. The device according to claim 1 or the method according to claim 2, wherein the size and / or position of the illumination area on the primary scattering screen is changed by adjusting the size and / or position of the object plane image formed on the object plane.

4. The apparatus of claim 1 or the method of claim 2, wherein: The optical imaging system further comprises at least one imaging unit, wherein the at least one imaging unit is located between the object plane and the primary scattering screen on the optical axis, wherein the at least one imaging unit has a focal length in the specific direction; and The size and / or position of the illumination area on the primary scattering screen is changed by adjusting the focal length of the at least one imaging unit to thereby change the magnification of the illumination area relative to the object plane image. 5 . The apparatus or method of claim 4 , wherein the at least one imaging unit comprises a zoom lens, and the focal length of the zoom lens can be changed by powering on.

6. The apparatus of claim 1 or the method of claim 2, wherein: The optical imaging system further includes an optical reflective element, the optical reflective element being located between the object plane and the primary scattering screen on the optical axis, and the optical reflective element reflecting light from the object plane at an angle relative to the specific direction; and The size and / or position of the illumination area on the primary scattering screen is changed by adjusting the angle to thereby change the position of the illumination area in the specific direction.

7. The apparatus of claim 1 or the method of claim 2, wherein the information of the optical imaging system comprises: The mapping relationship between the object plane image of the optical imaging system and the illuminated area on the primary scattering screen, and / or the variable parameter range of the adjustable optical element in the optical imaging system.

8. The method of claim 2, further comprising the steps of: Before an object plane image is formed on an object plane of the optical imaging system, characteristic information of a user is detected and a position and a size of the object plane image are set based on the characteristic information.

9. The method of claim 4, further comprising the steps of: Before forming an object plane image on the object plane of the optical imaging system, characteristic information of the user is detected and the focal length of the at least one imaging unit is set based on the characteristic information.

Images