WO2021052104A1 - 一种全息显示*** - Google Patents

一种全息显示*** Download PDF

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Publication number
WO2021052104A1
WO2021052104A1 PCT/CN2020/110405 CN2020110405W WO2021052104A1 WO 2021052104 A1 WO2021052104 A1 WO 2021052104A1 CN 2020110405 W CN2020110405 W CN 2020110405W WO 2021052104 A1 WO2021052104 A1 WO 2021052104A1
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WIPO (PCT)
Prior art keywords
screen
projector
holographic
display system
geometric
Prior art date
Application number
PCT/CN2020/110405
Other languages
English (en)
French (fr)
Inventor
王广军
余为伟
Original Assignee
荆门市探梦科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201910875975.1A external-priority patent/CN110471249B/zh
Priority claimed from CN202010303406.2A external-priority patent/CN111338177A/zh
Priority claimed from CN202010303403.9A external-priority patent/CN111338176A/zh
Priority claimed from CN202010303254.6A external-priority patent/CN111338175A/zh
Application filed by 荆门市探梦科技有限公司 filed Critical 荆门市探梦科技有限公司
Priority to US17/753,804 priority Critical patent/US20220365363A1/en
Publication of WO2021052104A1 publication Critical patent/WO2021052104A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B30/00—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images
    • G02B30/50—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images the image being built up from image elements distributed over a 3D volume, e.g. voxels
    • G02B30/56—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images the image being built up from image elements distributed over a 3D volume, e.g. voxels by projecting aerial or floating images
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G02B17/02—Catoptric systems, e.g. image erecting and reversing system
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B30/00—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images
    • G02B30/40—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images giving the observer of a single two-dimensional [2D] image a perception of depth
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B35/00—Stereoscopic photography
    • G03B35/18—Stereoscopic photography by simultaneous viewing
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/04—Processes or apparatus for producing holograms
    • G03H1/10—Processes or apparatus for producing holograms using modulated reference beam
    • G03H1/12—Spatial modulation, e.g. ghost imaging
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/10—Processing, recording or transmission of stereoscopic or multi-view image signals
    • H04N13/106—Processing image signals
    • H04N13/128—Adjusting depth or disparity
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/30—Image reproducers
    • H04N13/363—Image reproducers using image projection screens
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/30—Image reproducers
    • H04N13/366—Image reproducers using viewer tracking
    • H04N13/383—Image reproducers using viewer tracking for tracking with gaze detection, i.e. detecting the lines of sight of the viewer's eyes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/12—Picture reproducers
    • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B30/00—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images
    • G02B30/50—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images the image being built up from image elements distributed over a 3D volume, e.g. voxels
    • G02B30/54—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images the image being built up from image elements distributed over a 3D volume, e.g. voxels the 3D volume being generated by moving a 2D surface, e.g. by vibrating or rotating the 2D surface

Definitions

  • the present invention relates to the field of 3D display, in particular to a holographic display system.
  • 3D display technology can provide depth information to show a more realistic display scene.
  • mainstream 3D display solutions such as 3D movies in theaters
  • 3D display solutions are pseudo 3D display images based on parallax image pairs, and cannot display real 3D images.
  • 3D display technologies have been proposed, there is no technology that can truly and stably display large-scale, high-quality 3D images.
  • Holographic display is considered to be the ultimate solution in the display field, but due to its extremely demanding requirements for equipment and environment, it is difficult to realize commercial applications in the short term.
  • the authorized announcement number CN106773469B provides a new on-site reproduction holographic scheme.
  • the optical path layout needs to use the same projection area as the projection screen area.
  • Large parallel light, as a reference light source (the 3D image observed by the human eye is distorted when the reference light source is a non-parallel light), its optical path layout requirements are relatively strict, and it is difficult to implement.
  • the patent application number CN107831558A provides an equivalent negative refractive index flat lens and designs an air projection.
  • a large-area flat display device is required, and it can only be displayed in front of the screen.
  • the device is very heavy and has a display space. Limited, the display position is fixed, which makes the viewing angle limited, and it is impossible to observe at a certain angle.
  • it is very difficult to achieve a true 3D display. It can only achieve an effect similar to the Pepar’s phantom.
  • the present invention provides a holographic display system that can be displayed in front of or behind the screen, with infinite display space, flexible viewing angles, and can display super-large images in a very small device space, super-deep depth of field, and realize low cost , The purpose of high-quality 3D image display.
  • On-site holographic display system including holographic projector (1), projection screen (2), interactive response unit (3) and processor (4);
  • the positions of the holographic projector (1) and the projection screen (2) correspond to each other, and the holographic projector (1) is used to project a 3D image with depth information in space;
  • the projection screen (2) is a screen that converges the image points on one side of the projection screen (2) to the other side of the projection screen (2) to form a conjugate image point, which is used to project the holographic projector (1) Convert the 3D image with depth information to its conjugate position;
  • the holographic projector (1) and/or the projection screen (2) is provided with a motion actuator (5) connected to the processor (4), and the motion actuator (5) is used to control the holographic projector (1). ) And the relative movement and/or overall movement between the projection screen (2);
  • the lens diameter of the holographic projector (1) is D
  • the maximum horizontal length of the projection screen (2) is L
  • the weight of the holographic projector (1) is W, which satisfies:
  • the interactive response unit (3) includes a human eye tracking unit (31) and an interactive motion capture unit (32) or only includes an interactive motion capture unit (32), and the human eye tracking unit (31) is used to track human eyes ( E) position and send the positioning information of the human eye (E) to the processor (4), and the interactive motion capture unit (32) is used to identify the user’s interactive action and send the user’s interactive action information to the processor (4) ), the processor (4) controls the system to make a corresponding response according to the positioning information of the human eye (E) and/or the user interaction action information;
  • the processor (4) is electrically connected to the holographic projector (1), the interactive response unit (3) and the motion actuator (5), and the processor (4) sends projection data information to the holographic projector (1). ) To control the projection picture and picture depth of the holographic projector (1).
  • Transmissive geometric holographic display system including:
  • the display element (6) is used to project picture information in space
  • the transmissive geometric holographic screen (7) is a screen that converges the image points on one side of the transmissive geometric holographic screen (7) to the other side to form a conjugate image point, and its position corresponds to the display element (6), Used for converting the image projected by the display element (6) to the optical conjugate position relative to the transmissive geometric holographic screen (7);
  • the supporting structure (8) is matched with the display element (6) and the transmissive geometric holographic screen (7) respectively, and provides physical structural support for both;
  • the controller (9) is electrically connected to the display element (6), and the display element (6) adopts at least one ordinary projection device capable of projecting a two-dimensional picture, wherein the viewpoint of the transmissive geometric holographic display system
  • the number is n, the average value of the diameter of the transparent part of the outermost lens of the ordinary projection equipment included in the display element (6) is D decimeter, and the average value of the projection light source power of the ordinary projection equipment included in the display element (6) is P Watt, meet:
  • Folding optical path geometric holographic display system including:
  • the transmissive geometric holographic screen (7) is a screen that converges the image points on one side of the transmissive geometric holographic screen (7) to the other side to form a conjugate image point;
  • the supporting structure (8) is matched with the projector (6) and the transmissive geometric holographic screen (7) respectively, and provides physical structural support for both;
  • the controller (9) is electrically connected to the projector (6),
  • the folding optical path geometric holographic display system further includes at least one optical path folding mirror group (10) arranged on one or both sides of the transmissive geometric holographic screen (7) and respectively connected to the supporting structure (8).
  • the optical path The folding mirror group (10) includes at least one plane mirror with reflection function, which is used to change the propagation path of the light projected by the projector (6);
  • the number of viewpoints of the folded optical path geometric holographic display system is n
  • the average value of the diameter of the transparent part of the outermost lens of the projector (6) is D decimeter
  • the average value of the projection light source power of the projector (6) For P watts, satisfy:
  • the reflective geometric holographic display system includes:
  • the supporting structure (8) is matched with the projector (6), the auxiliary imaging screen (7) and the reflective geometric holographic screen (11) respectively, and provides physical structural support for the three;
  • the controller (9) is electrically connected to the projector (6);
  • the number of viewpoints of the reflective geometric holographic display system is n
  • the average value of the diameter of the light-transmitting part of the outermost lens of the projector (6) is D decimeter
  • the average value of the power of the projection light source of the projector (6) For P watts, satisfy:
  • the 3D image that can be observed reduces the cost.
  • the 3D image can be displayed in front of or behind the projection screen.
  • the display space is infinite, and in a very small device space, it can also display a super large picture and super deep depth of field. ;
  • the screen display area is less than 80% due to the viewing angle.
  • the entire screen of the system of the present invention can be used to display the picture, so that it is truly borderless and perfectly integrated with the environment;
  • the processor controls the projection picture and the depth of field of the display element with the depth of field information. Since the depth of focus is adjustable, it can effectively avoid the visual fatigue caused by the user watching the fixed focus depth for a long time, thereby reducing the occurrence of myopia , Can improve the user's eyesight;
  • the eye tracking unit can identify the position of the human eye, and then adjust the relative position of the holographic projector and the screen in real time by controlling the motion actuator, so that the human eye and the holographic projector are always symmetrical with respect to the projection screen (optical conjugate to each other) ), to ensure that the 3D image can be accurately observed by the user, and to achieve the purpose of freedom of observation angle.
  • FIG. 1 is a system diagram provided by Embodiment 1 of the present invention.
  • FIG. 2 is a schematic diagram provided by Embodiment 1 of the present invention.
  • FIG. 3 is a schematic diagram of a transmissive geometric holographic display system provided by Embodiment 2 of the present invention.
  • FIG. 4 is a schematic diagram of several viewpoint configurations for off-screen display provided in Embodiment 2 of the present invention.
  • FIG. 5 is a schematic diagram of a system configuration of multiple viewpoints according to Embodiment 2 of the present invention.
  • FIG. 6 is a schematic diagram of a space 0.1m and beyond the outermost lens of the projection lens provided by the second embodiment of the present invention.
  • FIG. 7 is a schematic diagram of the ellipsoidal visible space, that is, the window provided in the second embodiment
  • FIG. 8 is a schematic diagram of the coordinate system (X′, Y′, Z′) where the ellipsoid visible space provided in the second embodiment of the present invention is located;
  • FIG. 9 is a schematic diagram of a system including one projector and one optical path folding mirror group according to the third embodiment of the present invention.
  • FIG. 10 is a schematic diagram of a system in which an optical path folding mirror group is added to the same side on the basis of FIG. 9 provided in the third embodiment of the present invention.
  • FIG. 11 is a system diagram of optical path folding mirror groups provided on both sides of a transmissive geometric holographic screen and an optical path diagram of optical conversion provided by the third embodiment of the present invention
  • FIG. 12 is a schematic diagram of a system configuration of multiple viewpoints of the present invention provided by the third embodiment of the present invention.
  • FIG. 13 is a schematic diagram of the coordinate system (X′, Y′, Z′) where the ellipsoid visible space provided in the third embodiment of the present invention is located;
  • FIG. 14 is a schematic diagram and optical path diagram of the system of the present invention in which the projector provided by the fourth embodiment of the present invention and a reflective geometric holographic screen are located on the same side of the auxiliary imaging screen;
  • FIG. 15 is a schematic diagram and optical path diagram of a system of the present invention in which the projector and a reflective geometric holographic screen provided by the fourth embodiment of the present invention are respectively located on both sides of the auxiliary imaging screen;
  • FIG. 16 is a schematic diagram and optical path diagram of the system of the present invention with two reflective geometric holographic screens respectively located on both sides of the auxiliary imaging screen according to Embodiment 4 of the present invention;
  • FIG. 17 is a schematic diagram of the system of the present invention in which an optical path folding mirror group is added to the same side of the projector on the basis of FIG. 14 provided in the fourth embodiment of the present invention;
  • FIG. 18 is a schematic diagram of the system of the present invention in which another optical path folding lens group is added to the other side of the auxiliary imaging screen on the basis of FIG. 17 provided in the fourth embodiment of the present invention;
  • FIG. 19 is a schematic structural diagram of a reflective geometric holographic screen with a right-angled triangle in cross section after a part of the reflective film is hidden according to the fourth embodiment of the present invention.
  • 20 is a diagram of the retroreflected light path of the columnar elementary prism provided by the fourth embodiment of the present invention to light that is not parallel to the cross section;
  • 21 is a schematic structural diagram of a reflective geometric holographic screen with a pentagonal cross-section of a combination of a rectangle and a right-angled triangle after a part of the reflective film is hidden according to the fourth embodiment of the present invention
  • FIG. 22 is a diagram of the retroreflected light path of the columnar elementary prism included in FIG. 23 provided by the fourth embodiment of the present invention to light that is not parallel to the cross section;
  • FIG. 23 is a schematic diagram of the reflected light path of the light provided by the fourth embodiment of the present invention on mutually perpendicular surfaces, that is, a right-angle reflecting wall;
  • 24 is a schematic diagram of the coordinate system (X′, Y′, Z′) where the ellipsoid visible space provided by the fourth embodiment of the present invention is located.
  • horizontal does not mean that the component is required to be absolutely horizontal or overhanging, but may be slightly inclined.
  • horizontal only means that its direction is more horizontal than “vertical”, and it does not mean that the structure must be completely horizontal, but can be slightly inclined.
  • An on-site holographic display system including a holographic projector 1, a projection screen 2, an interactive response unit 3, and a processor 4;
  • the holographic projector 1 is located on one side of the projection screen 2.
  • the holographic projector 1 is used to project a 3D image with depth information in space. It is preferable to use two holographic projectors 1 to realize the binocular display mode.
  • the lens only needs to cover the user's single eye, so the lens diameter (transmitting part) of a single holographic projector 1 suitable for binocular display mode does not need to be too large, and only one holographic projector with a larger lens diameter (transmitting part) D can be used. 1 to realize a holographic projector 1 covering both eyes of the user at the same time.
  • the projection screen 2 is a screen that converges the image points on one side of the projection screen to the other side of the projection screen to form a conjugate image point, preferably an equivalent negative refractive index plane lens, and has the image points on one side of the projection screen converge to the projection
  • the other side of the screen 2 forms a conjugate image point, which is used to convert the 3D image with depth information projected by the holographic projector 1 to its conjugate position for the user to observe;
  • the holographic projector 1 is provided with a motion actuator 5 connected to the processor 4.
  • the motion actuator 5 is used to control the relative motion and/or overall motion between the holographic projector 1 and the projection screen 2 to adjust the holographic projector 1
  • the spatial position of the projection screen 2 the specific implementation of the motion actuator 5 is various, and ordinary people in the industry can design the mechanical structure by themselves according to the working principle of the present invention to achieve;
  • the interactive response unit 3 is arranged above the projection screen 2.
  • the interactive response unit 3 includes a human eye tracking unit 31 and an interactive motion capture unit 32.
  • the human eye tracking unit 31 is used to track the position of the human eye E and send the location information of the human eye E
  • the eye tracking unit 3 includes a camera and an infrared distance detector.
  • the camera uses image recognition technology to recognize the face and locate the position of the eye E.
  • the infrared distance detector detects the distance between the eye E and the projection screen 2. distance;
  • the interactive motion capture unit 32 is used to identify the user’s interactive motion and send the user’s interactive motion information to the processor 4.
  • An infrared camera can be used as the interactive motion capture unit 32 to capture the user’s interactive motion.
  • the processor 4 is based on the positioning of the human eye E Information or user interaction action information to control the system to respond accordingly, for example, according to the pan gesture signal, the processor 4 controls the screen to pan, or according to the corresponding other interactive actions to control the zoom, zoom in, zoom out, touch, etc. .
  • the processor 4 is electrically connected to the holographic projector 1, the interactive response unit 3, and the motion actuator 5, and is used to control the work of each part. Specifically, the processor 4 sends projection data information to the holographic projector 1 to control the holography. The projection picture and picture depth of the projector 1, and according to the received human eye E positioning information and user interactive action information obtained by the interactive response unit 3, the motion actuator 5 is controlled to adjust the spatial position of the holographic projector 1 and the projection screen 2 To enable users to view 3D pictures normally, it should be noted that the control program of the processor 4 used in the present invention is a common prior art.
  • the processor 4 controls the projection image and the depth of field of the holographic projector 1. Since the depth of focus is adjustable, visual fatigue caused by the user watching a fixed focus depth image for a long time can be avoided, thereby reducing the occurrence of myopia and improving vision.
  • the invention can be used for fixed display, such as office, home office video and audio, vehicle display, etc., and can also realize the fields of compact mobile display and head-mounted display.
  • the diameter of the lens (transmissive part) of the holographic projector 1 is D (in mm)
  • the weight (not including the mass of auxiliary parts such as the wire harness)
  • W in g
  • the maximum horizontal length of the projection screen 2 is L ( The unit is cm), which should be met in actual application:
  • the weight W of the holographic projector 1 has a more prominent influence on the stability of the system display. If the weight W is too small, the natural vibration frequency of the system will be relatively high. Environmental vibration (such as construction, etc.), user body movement or air convection (such as fans, Air-conditioning airflow) will cause vibration and resonance, which will easily produce noise or be interfered by external noise, resulting in picture jitter, which affects picture quality and makes users unable to receive stable pictures; for only the holographic projector 1
  • the motion actuator 5 connected to the processor 4 when the weight W of the holographic projector 1 is too large, when adjusting the relative position of the holographic projector 1 and the projection screen 2, difficulty in image tracking is likely to occur, and it is also used for adjustment.
  • the motion actuator 5 at the position of the holographic projector 1 has higher requirements in terms of load-bearing, strength and other aspects, and the cost will increase accordingly.
  • the impact of the lens diameter (transmissive part) D of the holographic projector 1 and the maximum horizontal length L of the projection screen 2 on the system is mainly reflected in the quality and visual effects of the displayed picture:
  • the corresponding viewing angle will also increase. If the maximum horizontal length L of the projection screen 2 is too large, it will be difficult to track and easily lose the picture, and the motion sweep range is too large to easily affect user activities and even cause certain danger; the horizontal maximum length L of the projection screen 2 is too small, the display The screen is too small to create an immersive experience.
  • the weight W of the holographic projector 1 ranges from 200g to 3000g. Because W is too large or too small, there are disadvantages as described above.
  • the weight of the holographic projector 1 W( The quality of auxiliary parts such as wire harnesses is not included) is the preferred value 500g
  • the lens diameter (transmissive part) D of the holographic projector 1 is 5mm ⁇ 80mm
  • the maximum horizontal length L of the projection screen 2 is 15cm ⁇ 150cm, as shown in the following table:
  • Embodiment 5 is the best embodiment for fixed display applications.
  • the weight W of the holographic projector 1 is used as a variable:
  • Embodiment 10 and Embodiment 11 further illustrate that the weight W of the holographic projector 1 affects the system only in stability when it is used for fixed display.
  • the relative position of the user's eye E and the system is fixed, and the eye tracking unit 31 can be eliminated.
  • the mass W of the holographic projector 1 is large, it will cause inconvenience to wear, and the holographic projector 1 adopts a miniature model, and the mass W is relatively small.
  • W is 5g-15g.
  • the weight W of the holographic projector 1 is preferably 10g
  • the lens diameter (transmissive part) D of the holographic projector 1 is 1mm-15mm
  • the horizontal maximum length L of the projection screen 2 is 0.8cm ⁇ 5cm
  • Embodiment 16 is the best embodiment of wearable display.
  • the lens diameter (transmissive part) D of the holographic projector 1 takes the maximum value of 80mm for fixed display applications, and the weight (not including the quality of auxiliary components such as wiring harness) W takes the minimum value of 5g for wearable display applications.
  • the horizontal maximum length L of the projection screen 2 is taken as the minimum 0.8cm of the wearable display application, and it can be obtained So in the limit The range of
  • the system of the present invention can achieve the effect of holographic display, but only when the lens diameter (transmissive part) D, weight W of the holographic projector 1 and the maximum horizontal length L of the projection screen 2 are all When it is optimal, a good display effect can be achieved to meet the needs of users.
  • the projection light of the holographic projector 1 may include red, blue and green light sources.
  • the projection screen 2 can also be a screen with an equivalent negative refractive index flat lens;
  • the interactive response unit 3 is used to locate the position of the human eye E and capture user interaction, so its position can also be located in the projection Below the screen 2, or other positions, as long as it can accurately locate the position of the human eye E and the user's interactive action information;
  • the motion actuator 5 is used to adjust the spatial position between the holographic projector 1 and the projection screen 2, Therefore, it is not only set on the holographic projector 1, but also on the projection screen 2.
  • both the holographic projector 1 and the projection screen 2 are equipped with a motion actuator 5 for realizing the holographic projector 1 and the projection screen 2.
  • the optical conjugate area can always cover the human eye, which can track the position of the user's eyes in real time, so that the user can always watch the picture normally.
  • the projection screen 2 used in the present invention is a negative refractive index plane lens that can converge the image points on one side of the projection screen 2 to the other side of the projection screen 2 and form a conjugate image point. Therefore, if a diverging 3D image can be projected in the air, without the aid of a reference light source, after being converted by the projection screen 2 of a negative refractive index flat lens, a 3D image that can be observed suspended in the air can be obtained.
  • the projection screen 2 of the negative refractive index flat lens can only convert the projected 3D image to its optical conjugate position (relative to the negative refractive index flat lens) (also a symmetrical position), once the user moves, such as moving left and right back and forth, The 3D image cannot be accurately observed by the user.
  • the human eye tracking unit 31 can identify the position of the human eye E, and then adjust the position of the holographic projector 1 or the projection screen 2 in real time to make the human eye E and the holographic projector 1 symmetrical with respect to the projection screen 2 (optically sharing each other). Yoke), you can ensure that the user can always observe the screen.
  • the projection screen 2 only images the image on one side at its symmetrical position on the other side, which is similar to the Pepper imaging principle. Therefore, other auxiliary technologies are needed to achieve 3D imaging. Therefore, the present invention uses a holographic projector 1 to project 3D. The image is then transformed to its symmetrical position through the projection screen 2 for observation.
  • the holographic projector 1 projects a diverging 3D image in the air without the aid of an additional reference light source. After conversion by the projection screen 2 of the equivalent negative refractive index flat lens, one can be obtained. The 3D image suspended in the air that can be observed reduces the cost. Compared with the Pepper-like phantom method, the screen display area is less than 80% due to the viewing angle. The entire screen of the system of the present invention can be used The display picture is truly borderless and perfectly integrated with the environment. At the same time, the 3D image can be displayed in front or behind the projection screen. The display space is infinite, and in a very small device space, it can also display super-large pictures and super Deep depth of field.
  • the present invention provides a transmissive geometric holographic display system, which includes a display element 6, a transmissive geometric holographic screen 7, a supporting structure 8 and a controller 9;
  • the 3D film sources in the theater are in the form of stereo image pairs, and the 3D effect is expressed through binocular parallax, but the actual image depth of focus is fixed at one position, so it will cause visual fatigue.
  • the system display element 6 of the present invention is used to project picture information in space, and a holographic projector can be directly used as the display element 6 to project a 3D picture or a series of two-bit picture groups distributed in the space with different depths of field;
  • a projection device capable of displaying three-dimensional images can be used to replace the above-mentioned holographic projector.
  • an ordinary projection device can be further optically designed so that it can realize 3D display based on a single projector.
  • You can refer to the application number as 202010029144.5 is an all-solid-state holographic projector that realizes the technical solution of three-dimensional image display by adding some optical elements to the inside of the projector for optical design, which is not specifically limited here.
  • an ordinary projection device capable of projecting a two-dimensional image can also be used as the display element 6, which can project a two-dimensional image on a certain focal plane in the space, and then adjust the image by the controller 9.
  • the depth of field and content of the two-dimensional picture can show the real distance between the picture and the user while presenting the picture content, so as to achieve the effect of projecting a picture with depth information in the space; in actual operation, the depth of focus
  • the adjustment can be real-time adjustment, or it can be done at a certain interval of time to adjust the depth of focus.
  • the equivalent focal depth of the picture can be moved to a reasonable position, thereby avoiding the problem that the 3D focal depth (the focal depth effect caused by binocular parallax) is different from the actual focal depth and presents a more realistic 3D effect.
  • this method can effectively reduce the cost.
  • the above-mentioned ordinary projection equipment can use a common ordinary projector or simply modify it.
  • the transmissive geometric holographic screen 7 is a screen that converges the image points on one side of the transmissive geometric holographic screen 7 to the other side to form a conjugate image point. Its position corresponds to the display element 6 and is used to project the display element 6
  • the output image is converted to the optical conjugate position relative to the transmissive geometric holographic screen 7, preferably a flexible holographic screen, which can be made into a scroll screen or a folding screen, so that the overall system is more compact and portable. Of course, it can also be used for suitable occasions. Use a hard screen;
  • the transmissive geometric holographic screen 7 can be replaced by an ordinary projection screen, such as an ordinary rear projection screen;
  • the supporting structure 8 is matched with the display element 6 and the transmissive geometric holographic screen 7 respectively, and provides physical structural support for both. Specifically, the supporting structure 8 can be made into a structurally fixed support frame. At this time, the display system of the present invention The whole is fixed, and the user needs to be in a fixed position to observe the screen;
  • the controller 9 is electrically connected to the display element 6, and the display element 6 can adjust the depth of field and display content of the projection screen according to the control signal of the controller 9;
  • the support structure 8 is a structure that can move or deform, and electrically connect the support structure 8 with the controller 9.
  • the support structure 8 makes a corresponding response based on the control information of the controller 9
  • the relative movement and/or overall movement of the display element 6 and the transmissive geometric holographic screen 7 are realized, so that the visual window of the system always covers the user's eyes, so that the user can watch the picture normally in different directions.
  • the support structure 8 is a general prior art, and those skilled in the art can design by themselves according to the actual application space conditions. For example, it is very easy to design a deformable structure by using some hinge structures and structures similar to umbrella shafts. Here No specific restrictions;
  • the holographic display system of the present invention further includes an interactive motion capture unit 101 electrically connected to the controller 9.
  • the interactive motion capture unit 101 is used to identify the user's interactive motion and The information is sent to the controller 9, and the controller 9 adjusts the display screen content according to the received user interaction action information obtained by the interactive action capture unit 101 to realize the interaction between the user and the screen.
  • the camera can be combined with machine vision technology to identify the user.
  • the user’s interactive information can be acquired by the gesture action of the user, so as to control the screen display content or control the movement of the support structure 8 to adjust the spatial position and posture of the projection device and/or the transmissive geometric holographic screen 7.
  • the controller 9 can also be based on the received interactive action
  • the user interaction action information acquired by the capture unit 101 is used to adjust the content of the display screen in real time, and realize the interaction between the user and the screen, such as controlling the screen to pan according to the pan gesture signal, or controlling the zooming, zooming in, and zooming of the screen according to the corresponding other interactive actions. Push far, touch and other operations;
  • the setting of the interactive motion capture unit 101 has positive significance for application scenarios similar to wearable applications where the user's spatial position relative to the display system is fixed;
  • an eye tracking unit 102 electrically connected to the controller 9.
  • the eye tracking unit 102 is used to track the position of the human eye and locate the human eye.
  • the information is sent to the controller 9, and the controller 9 controls the support structure 8 to make corresponding action responses according to the received eye positioning information obtained by the eye tracking unit 102 to adjust the display element 6 and the transmissive geometric holographic screen 7
  • the relative position and/or the overall spatial position of the so that the user's eyes are always in the visual space of the system, so that the user's eyes can always receive the projection information even in the state of motion, and watch the picture normally.
  • the human eye tracking unit 102 and the interactive motion capture unit 101 can be integrated in the same device, such as using a machine vision camera device.
  • the controller 9 sends the image and the average focal depth information of the image to the projector, and the projector adjusts the projection focal depth by itself, and the projector can project the image to a specific focal depth position for people Watch.
  • the transmissive geometric holographic display system of the present invention has a very special point. It cannot be viewed by a large number of users at the same time like a traditional 2D display device.
  • the concept of viewpoint is introduced here:
  • the display system can provide a viewing window for one eye, then the system has a viewpoint.
  • the binocular display system two eyes can watch at the same time, so the number of viewpoints is 2.
  • the display system can be viewed by n eyes at the same time, the number of viewpoints is n.
  • the structure of the system needs to be set reasonably in consideration of practicability.
  • the outermost lens of the projector is relative to the optical conjugate area of the transmissive geometric holographic screen 7 (also the mirror symmetry area, which can be called the window ) Can cover the user's two eyes.
  • the transmissive geometric holographic screen 7 also the mirror symmetry area, which can be called the window
  • the window can cover the user's two eyes.
  • the area between the two eyes can also be used to view images in principle, it is impossible to use it under actual conditions. It can only be viewed by both eyes at the same time, so this situation is quite Yu has two viewpoints;
  • the projection lenses of the two projectors form two separate sub-areas relative to the optical conjugate area of the transmissive geometric holographic screen 7.
  • the distance between the two sub-regions exactly matches the distance between human eyes, it can be viewed by both eyes at the same time (case b), so there are two viewpoints;
  • the number of viewpoints of the system will increase accordingly.
  • the specific number depends on the specific conditions of a to d.
  • the number of viewpoints of the display system is n and the number of viewpoints used
  • the size and quantity of the lens of the projector are related.
  • An effective design strategy is to properly design the support structure 8 to make it have structural adjustment functions, such as adjusting the distance or spatial position between the two projectors, so that it can be flexibly adjusted according to the user’s interpupillary distance and the application site during use.
  • the geometry of support structure 8 is adapted to actual needs.
  • the projection system is backward compatible and switched to the 2D projection mode (such as adjusting the projection focal plane of the projector to directly project the 2D image on the transmissive geometric holographic screen 7, or use an ordinary projection screen to replace or place
  • the 2D projection screen is displayed on the front or back surface of the transmissive geometric holographic screen 7
  • the image focal plane coincides with the screen, and the number of viewpoints will be greatly increased, but these viewpoints have great viewing limitations, only the screen can be seen
  • the upper screen and the off-screen screen output by the display system cannot be viewed, so it cannot be counted into the number of real viewpoints.
  • the actual effective viewpoint should be the viewpoint from which the screen in all modes of the system can be viewed, including on-screen and in front of the screen. , The point of view where the off-screen display content behind the screen can be observed.
  • the number of viewpoints of the transmissive geometric holographic display system of the present invention is n
  • the average value of the diameter of the light-transmitting part of the outermost lens of the projection device included in the display element 6 is D decimetres (dm)
  • the projection device included in the display element 6 The average displayed luminous flux is L lumens (lm)
  • the displayed luminous flux viewpoint product is n 1.27 ⁇ L.
  • the displayed luminous flux viewpoint product satisfies: n 1.27 ⁇ L ⁇ 24000 can ensure a better display effect and system Reliability.
  • the measurement method of the display luminous flux L(lm) of a single projection device can refer to the ANSI lumens test method:
  • the average illuminance multiplied by the projected screen area is ANSI lumens, which is the display luminous flux described in the present invention.
  • test value of L may be quite different.
  • the illuminance test is carried out according to the actual illumination area to take a point test, preferably in the illumination area and the outer boundary of the illumination area about 10cm to 30cm in the light band that is more uniformly selected 8 points and 1 point in the illumination area not more than 20cm from the center of the screen, a total of 9 points are tested for illuminance, and then the average value of the 9 illuminance values is multiplied by the actual area of the illuminated area to obtain the displayed luminous flux value.
  • the display luminous flux of a single projector is the same as the average displayed luminous flux.
  • the luminous flux of each projection unit can be tested separately Then take the average value as the value of the displayed luminous flux.
  • the number of eyes of the user is an even number
  • the number of viewpoints n is set to an even number
  • Examples 1-27 show that when the display luminous flux viewpoint product n 1.27 ⁇ L ⁇ 24000, the display effect is good, and the user scores are all above 80 points.
  • the display luminous flux viewpoint product n 1.27 ⁇ L in Comparative Example 1 is 31351 , User ratings are low, the screen is dazzling, and the actual display effect is not good.
  • the measurement of the power P of the light source of the projection equipment can directly test the voltage at both ends of the light source and the current passing through the light source under the normal working state, and then multiply and calculate the power value.
  • the data shows: power viewpoint product
  • the user scores are all above 80 points, while the power viewpoint product in Comparative Example 1 It is 679, the user score is low, the screen is dazzling, and the actual display effect is not good.
  • the power of the light source is less than 400W, it can basically meet the design life of 5 years, thereby ensuring reliability.
  • the ordinary projectors used in the above embodiments can also be replaced by holographic projectors or other projection devices capable of realizing three-dimensional image display.
  • the above design formulas related to the number of viewpoints, light source power and display luminous flux are also used for holographic projectors.
  • the data of the foregoing embodiment can also show that the display effect and reliability of the holographic display system can be effectively improved through reasonable optical parameter settings.
  • the principle of the display system of the present invention can be referred to the patent application number 201910875975.1.
  • the projector can project images at different depths in space, that is, it can provide additional depth of field information for the projection image, but the projector
  • the projected images are all divergent light and cannot be directly viewed by human eyes. This is why a conventional projection system must use a receiving screen.
  • the light path conversion effect of the transmissive geometric holographic screen 7 can make the divergent light projected by the projector re-converge to the optical conjugate position of the projector relative to the transmissive geometric holographic screen 7, that is, its mirror image position, thereby forming convergent light. It can be viewed directly by the human eye. Therefore, although the transmissive geometric holographic screen 7 is used in the holographic display system of the present invention, its function is completely different from the receiving screen of the traditional projection display system.
  • the receiving screen of the traditional projection system is used to randomly scatter light for users to watch.
  • the transmissive geometric holographic screen 7 is more like a special optical element, which can perform specific optical conversion of light, and reconverge the light emitted by the light spot on one side of the screen to the mirror position of the light spot relative to the screen. A very small area nearby, thus forming a convergent real image point suspended in the air.
  • This unique imaging feature makes it possible to perform imaging at different depths in space (off-screen imaging) to achieve true 3D display.
  • the picture seen by the user during use is completely consistent with the picture projected by the projector.
  • the image projected by the projector is from the outermost lens, the user sees the image as far as the eye.
  • the photopic distance of the human eye is generally 25cm, and the closest object is generally also 10cm away. Therefore, when selecting the projector, the projection focal depth can be optimized in a space greater than 0.1m from the outer surface of the outermost lens of the projection lens. Projector (ordinary projector or holographic projector) adjusted inside (as shown in Figure 6).
  • the relative position between the projector and the transmissive geometric holographic screen and the overall spatial position are adjusted to drive the window to accurately track the user's eye movement trajectory is the most ideal solution.
  • the human eye can view the picture as long as the user is inside the window, so the user does not need to track the movement of the user's eye accurately when moving, as long as the user's eye can be roughly tracked to ensure that the user's eyes are within the window. Yes, even slightly shifted out of the window, but the pupils and the window have intersections, and the screen can be viewed normally.
  • the above discussion mainly focuses on the user moving up and down relative to the screen.
  • the screen can be viewed normally.
  • the user's eye tracking does not need to be particularly accurate, as long as the accuracy is ensured to meet the use requirements.
  • the light above and below the screen will have an intersecting diamond-shaped area.
  • the screen can be observed, but when the diamond is close
  • the angular position is easier to cause tracking loss. Therefore, a relatively small ellipsoidal visible area is further defined inside the prismatic area to reduce the probability of tracking loss.
  • the ellipsoid area is described below, as shown in Figure 8.
  • the ellipsoid visible space is based on the center of the outermost lens of each projector of the display element 6 as the origin, and the normal line outside the lens center as the Y-axis direction, passing the origin and perpendicular to the
  • the straight line in the horizontal plane is the X axis
  • the straight line passing through the origin and perpendicular to the X and Y axes is the coordinate system of the Z axis (X, Y, Z), which is relative to the optical conjugate coordinate system of the transmissive geometric holographic screen 7 (X' ,Y',Z'), the space that satisfies the following relationship:
  • K is an extended constant, the unit is dm, and the range of K is 0 ⁇ K ⁇ 0.08;
  • n is the conjugate deviation constant, and the range of m is 0 ⁇ m ⁇ 5.
  • K and D determine the cross-section of the visible space in the plane perpendicular to the Y′ axis.
  • the screen can be viewed within the diameter of the projection lens.
  • an expansion constant K is introduced, the value of which depends on the diameter of the human eye, usually the maximum diameter of the human eye pupil is 0.08dm, so take it here 0.08dm is used as the expansion constant.
  • the display system of the present invention due to the adjustable depth of focus, can avoid visual fatigue caused by users watching fixed-focus images for a long time, thereby avoiding the occurrence of myopia, and can improve the level of vision.
  • the present invention can be used for fixed display, such as office, home hall video and audio, vehicle display, etc., and can also realize small and intricate mobile display and head-mounted display.
  • the quality of projection equipment in different application scenarios can be selected:
  • Desktop application preferably projection equipment with a mass of less than 5kg;
  • Mobile terminal preferably a projection device with a mass less than 300g;
  • optical elements such as anti-reflection films, light-absorbing films, and filters can be appropriately added to further enhance the effect of the system.
  • the second embodiment of the present invention has the following advantages:
  • the present invention provides a folding optical path geometric holographic display system, including at least one projector 6, a transmissive geometric holographic screen 7, a supporting structure 8, a controller 9 and at least one optical path folding mirror group 10;
  • the supporting structure 8 in this embodiment is matched with the projector 6, the transmissive geometric holographic screen 7 and the optical path folding mirror group 10, respectively, to provide physical structural support for the three, which can be specifically
  • the supporting structure 8 can be made into a fixed structure.
  • the display system of the present invention is fixed as a whole, and the user needs to be in a fixed position to observe the screen;
  • the optical path folding mirror group 10 is supported by a supporting structure 8, which includes at least one plane mirror with reflection function, which is used to change the propagation path of the light projected by the projector 6, and is specifically arranged on one side of the transmissive geometric holographic screen 7, or as an optical path
  • a supporting structure 8 which includes at least one plane mirror with reflection function, which is used to change the propagation path of the light projected by the projector 6, and is specifically arranged on one side of the transmissive geometric holographic screen 7, or as an optical path
  • folding mirror groups 10 they are arranged on one side of the transmissive geometric holographic screen 7 or on both sides of the transmissive geometric holographic screen 7, depending on the spatial form of the applied scene;
  • the controller 9 is electrically connected to the projector 6, and the projector 6 can adjust the depth of field and screen content of the projected image according to the control signal of the controller 9;
  • the support structure 8 is a structure that can move or deform, electrically connect the support structure 8 and the controller 9, and the support structure 8 will respond accordingly according to the control information of the controller 9.
  • the transmissive geometric holographic screen 7 and the optical path folding mirror group 10 so that the visual window of the system always covers the user's eyes, so that the user can move in different directions.
  • the picture can be viewed normally.
  • the supporting structure 8 is a general prior art, and those skilled in the art can design by themselves according to the actual application space conditions. For example, it is very easy to use some hinge structures and structures similar to umbrella shafts. Design a deformable structure, there is no specific limitation here;
  • the holographic display system of the present invention further includes an interactive motion capture unit and a human eye tracking unit electrically connected to the controller 9.
  • the corresponding interactive motion capture unit and human eye tracking unit can be referred to in the second embodiment.
  • the specific content of the interactive motion capture unit 101 and the eye tracking unit 102 will not be described in detail in this embodiment.
  • the specific focusing process can also refer to the related content in the second embodiment, which will not be described in detail in this embodiment.
  • the system is equipped with a light path folding mirror group 10 on the same side as the projector 6.
  • the projection image of the projector 6 is optically transformed by the light path folding mirror group 10 and the transmissive geometric holographic screen 7.
  • An off-screen display screen is formed on the other side of the screen 7, which can be viewed by the human eye through the window as shown in the figure;
  • the system is configured with two optical path folding mirror groups 10, both of which are located on the same side of the projector 6 relative to the transmissive geometric holographic screen 7.
  • the projection image of the projector 6 passes through the two optical path folding mirror groups 10 and the transmissive geometric holographic screen.
  • an off-screen display image is formed on the other side of the transmissive geometric holographic screen 7, which can be viewed by human eyes through the window as shown in the figure;
  • the system is also equipped with two optical path folding mirror groups 10, but they are respectively arranged on both sides of the transmissive geometric holographic screen 7, and the projection image of the projector 6 passes through the two optical path folding mirror groups 10 and the transmissive geometric holographic screen 7 After optical conversion, an off-screen display is formed on the other side of the transmissive geometric holographic screen 7, which can be viewed by the human eye through the window as shown in the figure;
  • optical conversion principle of the projection image of the projector 6 by the optical path folding mirror group 10 and the transmissive geometric holographic screen 7 can refer to the optical path conversion principle of FIG. 11.
  • the number of optical path folding mirror groups 10 is greater, no matter what the arrangement and combination, as long as the projection image of the projector 6 can be optically transformed and an off-screen display image is formed at the optical conjugate, it belongs to the protection of the present invention. range.
  • the folding optical path geometric holographic display system of the present invention has a very special place. It cannot be viewed by a large number of users at the same time as the traditional 2D display device.
  • the concept of viewpoint is also introduced here. For details, refer to the description of the viewpoint in the second embodiment, which is not described in detail in this embodiment.
  • the projector 6 in the display system is a common projector, the number of the optical path folding mirror group 10 is one, and the projector 6 is set on the same side of the transmissive geometric holographic screen 7 as an example.
  • the effect of the display system it should be noted that, in the case of using the same parameters, the data parameters of Examples 1 to 27 can be referred to the table in Example 2. This example will not be described in detail, and obtained The effect and conclusion of the are the same, therefore, it will not be repeated in this embodiment.
  • the difference from the second embodiment is that the ellipsoid area in this embodiment is specifically shown in Figure 13.
  • the ellipsoid visible space is the visible space with the center of the outermost lens of each projector 6 lens as the origin. Taking the normal line outside the lens center as the Y-axis direction, the line passing the origin and perpendicular to the horizontal plane as the X axis, and the line passing the origin perpendicular to the X and Y axes as the Z-axis coordinate system (X, Y, Z) passing through the optics In the converted optical conjugate coordinate system (X′, Y′, Z′), the space that satisfies the following relationship:
  • K is an extended constant, the unit is dm, and the range of K is 0 ⁇ K ⁇ 0.08;
  • n is the conjugate deviation constant, and the range of m is 0 ⁇ m ⁇ 5.
  • the third embodiment of the present invention has the following advantages:
  • the optical path folding mirror group that can change the propagation path of the light projected by the projector, the optical path can be flexibly transformed and folded, and the space can be reasonably used to reduce the space occupancy rate of the entire display system and improve the display system layout very effectively Flexibility
  • the projector adopts ordinary projection equipment that can project two-dimensional images, which can greatly reduce costs and improve practicability.
  • Ordinary projection equipment can project two-dimensional images on a certain focal plane in the space, and the controller can adjust the projection image Depth of focus, to realize the image display with depth of field information, present a more realistic 3D effect, overcome the limitation of the shortage of 3D film sources, and reduce costs;
  • the present invention provides a reflective geometric holographic display system, including at least one projector 6, an auxiliary imaging screen 7, a reflective geometric holographic screen 11, a supporting structure 8 and a controller 9;
  • the auxiliary imaging screen 7 in this embodiment is used for light splitting, preferably a semi-transmissive and semi-reflective film.
  • the auxiliary imaging screen 7 After the projection light of the projector 6 is irradiated on the auxiliary imaging screen 7, part of the light is reflected to the reflective geometry On the holographic screen 11, the reflective geometric holographic screen 11 modulates the light, so that any light irradiated on the reflective geometric holographic screen 11 is retroreflected and returned to the original direction. The retroreflected light part passes through the auxiliary imaging screen 7 and then returns to the original direction.
  • An off-screen projection picture is formed in the air;
  • the reflective geometric holographic screen 11 is used to retro-reflect incident light rays at other angles that are not parallel to the cross-section. These rays can be retroreflected back after being offset by a distance of dmm.
  • d is the outgoing light and reflective geometric holography.
  • the distance between the intersection of the incident surface of the film and the incident light, d ⁇ 2mm usually for giant screen movies like movie theaters, because the user is far from the screen, the image point deviation 2mm is not easy for the human eye to distinguish, and it can still display a clearer picture. However, if the deviation is too large, the image quality will be affected), a flexible holographic screen is preferred.
  • the number of reflective geometric holographic screens 11 is one or two: when the number of reflective geometric holographic screens 11 is one, set it in the auxiliary Either side of the imaging screen 7; when the number of reflective geometric holographic screens 11 is two, they are set on both sides of the auxiliary imaging screen 7.
  • the system includes two reflective geometric holographic screens 11, the light energy of the system Both the utilization rate and the image quality are high.
  • the reflective geometric holographic screen 11 is provided with a series of cylindrical primitive prisms 111 with a cross-section of a right-angled triangle or a pentagonal combination of a rectangle and a right-angled triangle, wherein the above-mentioned right-angled triangle is preferably Isosceles right triangle;
  • the columnar elementary prism 111 is provided with a number of alternately arranged transparent layers 112 and reflective layers 113 along the length direction. This structure can be obtained by a top-down two-dimensional processing method.
  • the processing technology is extremely simple and the processing accuracy is high. Very high, excellent image quality;
  • the bottom surface of the columnar elementary prism 111 is the light incident surface, the reflective layer 113, the end face of the columnar elementary prism 111, and the oblique surface where the right-angled side of the cross-section is located are the reflective surfaces.
  • a layer of reflective film 114 is provided on the inclined surface for specular reflection of light;
  • the end surface of the columnar element prism 111 as a reflecting surface may also be provided with a reflective film 114 that reflects light. It should be noted that if the end surface of the columnar element prism 111 is in the process of processing, the end surface of the columnar element prism 111 is The reflective layer 113 does not need to be coated with the reflective film 114 on the end surface of the reflective layer 113, and the reflective layer 113 itself has the function of specularly reflecting light.
  • the reflection layer 113 may not be included in the prism of the right triangle part. This structure can also realize the retroreflection of light.
  • the angle error range involved in the cross-section of the columnar elementary prism is within ⁇ 5°, including the right-angled triangle and the right angle of the pentagon of the cross-section, as well as the length direction of the transparent layer 112, the reflective layer 113 and the columnar elementary prism 111.
  • Angle although the above principles are based on ideal geometric shapes, but in actual situations, the machining process may not be able to produce a completely ideal geometric shape, there will be certain errors in the angle, and the vertex cannot be an ideal geometric point. It is a rounded corner with a very small radius.
  • the manufacturing error is relatively small, there will be a slight deviation between the direction of the reflected light and the ideal situation of retroreflection. These deviations cannot be distinguished by the human eye, and the aberrations caused by these errors are also very small, so very good imaging effects can also be achieved.
  • the right angle error included in the cross-section of the columnar element prism 111 is within ⁇ 5°, the user experience is relatively satisfactory, and when it exceeds this range, the user begins to feel that the imaging effect is unacceptable.
  • the geometric vertex is allowed to be a relatively small fillet (for example, the radius is less than 0.1mm), and then a better imaging function can also be achieved.
  • the smaller the error the higher the user evaluation, so the error should be minimized during production.
  • the supporting structure 8 is matched with the projector 6, the auxiliary imaging screen 7 and the reflective geometric holographic screen 11 respectively, and provides physical structural support for the three. Specifically, the supporting structure 8 can be made into a structurally fixed support frame. At this time, The display system of the present invention is fixed as a whole, and the user needs to be in a fixed position to observe the picture;
  • the controller 9 is electrically connected to the projector 6, and the projector 6 can adjust the depth of field and screen content of the projected image according to the control signal of the controller 9;
  • the cross-section is a right-angled triangle or a pentagonal combination of a rectangle and a right-angled triangle
  • there are multiple right-angled reflecting walls including the right-angled reflecting walls formed by the two inclined surfaces of the columnar elementary prism 111, and the inclined surfaces are respectively connected to the reflecting layer 113 or the columnar base.
  • the right-angle reflection wall formed by the end face of the element prism 111, so this kind of microstructure unit has the function of reflecting the light in the space, so if many such microstructures are densely arranged on a plane, it can be used for large-area incident light. Perform the same reflection.
  • the incident light parallel to the cross section of the columnar elementary prism 111 according to the optical path principle of FIG. 11, it can realize the 3D imaging of the light retroreflected by two reflections of two inclined planes.
  • the holographic display system of the present invention further includes an interactive motion capture unit and a human eye tracking unit that are electrically connected to the controller 9.
  • an interactive motion capture unit and a human eye tracking unit that are electrically connected to the controller 9.
  • the support structure 8 is a structure that can move or deform, electrically connect the support structure 8 and the controller 9, and the support structure 8 will respond accordingly according to the control information of the controller 9.
  • the supporting structure 8 is a general prior art, and those skilled in the art can design it according to the actual application space conditions. For example, it can be designed very easily by using some hinge structures and structures similar to umbrella shafts. Structures that can be deformed are not specifically limited here;
  • a light path folding mirror group 12 can be arranged on one or both sides of the auxiliary imaging screen 7.
  • the light path folding mirror group 12 includes at least one mirror, so that it can Adjust the imaging light path to adapt it to various application space scenarios.
  • the support structure 9 can also control the projector 6, the auxiliary imaging screen 7, the reflective geometric holographic screen 11 and the optical path folding mirror group 12 at the same time for relative or overall control. The movement can be adjusted in real time to ensure that the user can watch it normally.
  • the specific focusing process can also refer to the related content in the second embodiment, which will not be described in detail in this embodiment.
  • the projector 6 and a reflective geometric holographic screen 11 are located on the same side of the auxiliary imaging screen 7.
  • the projection light part of the projector 6 is irradiated on the reflective geometric holographic screen 11 through the beam splitting of the auxiliary imaging screen 7.
  • the retro-reflected light of the geometric holographic screen 11 After the retro-reflected light of the geometric holographic screen 11, the original direction is reflected back and after passing through the auxiliary imaging screen 7, an off-screen display image is formed on the other side of the auxiliary imaging screen 7, and the human eye passes through as shown in the figure. You can watch it in the window;
  • the projector 6 and a reflective geometric holographic screen 11 are respectively located on both sides of the auxiliary imaging screen 7.
  • the projection light of the projector 6 passes through the auxiliary imaging screen 7 and then irradiates the reflective geometric holographic screen 11, passing After the reflective geometric holographic screen 11 retroreflects the light, it reflects in the original direction and passes through the light splitting of the auxiliary imaging screen 7, forming an off-screen display picture in the space, which can be viewed by the human eye through the window as shown in the figure. ;
  • the reflective geometric holographic display system of the present invention has a very special place. It cannot be viewed by a large number of users at the same time like a traditional 2D display device.
  • the concept of viewpoint is also introduced here. For details, refer to the description of the viewpoint in the second embodiment, which is not described in detail in this embodiment.
  • the projectors 6 in the system are all common projectors, and the reflective geometric holographic screen 11 and the projector 6 are located on the same side of the auxiliary imaging screen 7 as an example to illustrate the effect of the corresponding display system;
  • the data parameters of Embodiment 1 to Embodiment 27 can be referred to the table in Embodiment 2. This embodiment will not be described in detail, and the effect conclusions obtained are the same. Therefore, this embodiment I won't repeat it in
  • the display principle of the embodiment of the present invention the projector 6 can project images at different depths in space, that is, it can provide additional depth of field information for the projected images, but the images projected by the projector 6 are all divergent light and cannot be seen by human eyes. Direct viewing is also the reason why a conventional projection system must use a receiving screen.
  • the reflective geometric holographic screen 11 of the present invention has the function of retroreflecting the original path of the light irradiated thereon.
  • the auxiliary imaging screen 7 is a semi-transparent and semi-reflective film with a light splitting function. In this way, after the light emitted by the projector 6 irradiates the auxiliary imaging screen 7, part of the light is reflected on the reflective geometric holographic screen 11.
  • the light will return to the original path (or close to the original). Way back), the returned light passes through the auxiliary imaging screen 7 again, and part of the light passes through the auxiliary imaging screen 7 to form a convergent off-screen projection picture in the air.
  • the human eye is at the position of the projector 6 relative to the auxiliary imaging screen In the mirror position (human eyes can normally see the complete projection picture only in a small area of the projector relative to the mirror position of the auxiliary imaging screen), the image can be observed.
  • the picture that the user sees when in use is completely consistent with the picture projected by the projector 6.
  • the image projected by the projector 6 is from its outermost lens, the user sees the image as far as the eye.
  • the photopic distance of the human eye is generally 25cm, and the closest object is generally 10cm away. Therefore, when selecting the projector 6, the projection focal depth can be preferably greater than 0.1m from the outer surface of the outermost lens of the projection lens.
  • Adjustable projector ordinary projector or holographic projector in the space (as shown in Figure 6).
  • the difference from the second embodiment is that the ellipsoidal area in this embodiment is specifically shown in Figure 24.
  • the ellipsoidal visible space is the visible space with the center of the outermost lens of each projector 6 as the origin. Taking the normal line outside the lens center as the Y-axis direction, the line passing the origin and perpendicular to the horizontal plane as the X axis, and the line passing the origin perpendicular to the X and Y axes as the Z-axis coordinate system (X, Y, Z) passing through the optics In the converted optical conjugate coordinate system (X′, Y′, Z′), the space that satisfies the following relationship:
  • K is an extended constant, the unit is dm, and the range of K is 0 ⁇ K ⁇ 0.08;
  • n is the conjugate deviation constant, and the range of m is 0 ⁇ m ⁇ 5.
  • the fourth embodiment of the present invention has the following advantages:
  • the display system of the present invention adopts two reflective geometric holographic screens, which are respectively arranged on both sides of the auxiliary imaging screen. There is no interference of non-imaging beams during the imaging process, thereby greatly improving imaging quality and high light source utilization;
  • the supporting structure as a deformable or movable structure, the relative movement and/or overall movement among the projector, the auxiliary imaging screen and the reflective geometric holographic screen can be realized to realize dynamic display;
  • the embodiments of the present invention can also undergo various simple evolutions. For example, it is also possible to add/use polarizing films and 1/4 glass plates, antireflection films, light-absorbing films and other optical elements to further improve light utilization and display effects, all covering within the protection scope of the present invention.

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Abstract

本申请提供一种全息显示***，包括现场全息显示***、透射式几何全息显示***、折叠光路几何全息显示***和反射式几何全息显示***，采用能够直接显示带有景深信息画面的显示元件，在空中投影出发散的3D图像，无需另外的参考光源辅助，经过等效负折射率平面透镜的投影屏转换后，得到一个悬浮在空中的、可以被观察的3D图像，降低了成本，同时该3D图像可以在投影屏的前方或者后方显示，显示空间无限大，而且在极小的设备空间内，也可以显示超大画面和超深景深。

Description

一种全息显示***
本申请要求于2019年09月17日提交中国专利局、申请号为201910875975.1、发明名称为“现场全息显示***”的国内申请的优先权，其全部内容通过引用结合在本申请中。
本申请要求于2020年04月17日提交中国专利局、申请号为202010303254.6、发明名称为“透射式几何全息显示***”的国内申请的优先权，其全部内容通过引用结合在本申请中。
本申请要求于2020年04月17日提交中国专利局、申请号为202010303403.9、发明名称为“折叠光路几何全息显示***”的国内申请的优先权，其全部内容通过引用结合在本申请中。
本申请要求于2020年04月17日提交中国专利局、申请号为202010303406.2、发明名称为“反射式几何全息显示***”的国内申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及3D显示领域，尤其是涉及一种全息显示***。
背景技术
3D显示技术可以提供深度信息，从而展示出更加逼真的显示场景。目前主流的3D显示解决方案(比如影院的3D电影)都是基于视差图像对的伪3D显示图，并不能够显示真实的3D图像。虽然，现在已经提出很多3D的显示技术，但是还没有一种技术可以能够真正稳定地显示大尺度、高品质3D图像。全息显示被认为是显示领域的终极解决方案，但是由于其对设备、环境等的要求极为苛刻，所以短期内很难实现商业化应用。
授权公告号为CN106773469B的专利提供了一种全新的现场再现全息方案，为了人眼能够观察到显示大尺度、稳定、高品质的3D图像，其光路布置时，需要采用投射面积与投影屏面积一样大的平行光，作为参考光源(参考光源为非平行光时人眼观察到的3D图像带有畸变)，其光路布置要求比较苛刻，实现难度较大。
申请号为CN107831558A的专利提供了一种等效负折射率平面透镜，并设计了一种空气投影，但是需要使用大面积的平面显示设备，而且只能在屏幕前方显示，设备非常笨重，显示空间有限，显示位置固定，使得观察角度受限，偏移一定角度就无法观察，而且要想实现真实的3D显示，还非常困难，只能实现类似佩帕尔幻象的效果。
发明内容
有鉴于此，本发明提供一种全息显示***，可以实现在屏幕前方或者后方显示，显示空间无限大，观察角度灵活，而且可以在极小的设备空间显示超大画面，超深景深，实现低成本、高质量3D图像显示的目的。
为实现上述目的，本发明提供如下技术方案：
现场全息显示***：包括全息投影器(1)、投影屏(2)、交互响应单元(3)和处理器(4)；
所述全息投影器(1)与投影屏(2)位置相互对应，所述全息投影器(1)用于在空间投影出具有深度信息的3D图像；
所述投影屏(2)是具有把投影屏(2)一侧的像点汇聚到投影屏(2)另一侧形成共轭像点的屏幕，其用于把全息投影器(1)投影出的具有深度信息的3D图像转化到其共轭位置；
所述全息投影器(1)和/或投影屏(2)上设有与处理器(4)连接的运动执行机构(5)，所述运动执行机构(5)用于控制全息投影器(1)和投影屏(2)之间的相对运动和/或整体运动；
全息投影器(1)的镜头直径为D，投影屏(2)的水平方向最大长度为L，全息投影器(1)的重量为W，满足：
Figure PCTCN2020110405-appb-000001
所述交互响应单元(3)包括人眼跟踪单元(31)和交互动作捕捉单元(32)或只包括交互动作捕捉单元(32)，所述人眼跟踪单元(31)用于跟 踪人眼(E)的位置并将人眼(E)的定位信息发送给处理器(4)，所述交互动作捕捉单元(32)用于识别用户的交互动作并将用户交互动作信息发送给处理器(4)，所述处理器(4)根据人眼(E)的定位信息和/或用户交互动作信息来控制***做出相应的响应；
所述处理器(4)分别与全息投影器(1)、交互响应单元(3)和运动执行机构(5)电连接，所述处理器(4)发送投影数据信息给到全息投影器(1)，来控制全息投影器(1)的投影画面和画面深度。
透射式几何全息显示***，包括：
显示元件(6)，用于在空间投影画面信息；
透射式几何全息屏(7)，是具有把透射式几何全息屏(7)一侧的像点汇聚到其另一侧形成共轭像点的屏幕，其位置与显示元件(6)相对应，用于把显示元件(6)投影出的图像转化到相对透射式几何全息屏(7)的光学共轭位置；
支持结构(8)，分别与显示元件(6)和透射式几何全息屏(7)相匹配，为二者提供物理结构支撑；
控制器(9)，与显示元件(6)电连接，：所述显示元件(6)采用至少一个、能够投影出二维画面的普通投影设备，其中，所述透射式几何全息显示***的视点数为n，所述显示元件(6)包含的普通投影设备最外侧镜片的透光部分直径的均值为D分米，所述显示元件(6)包含的普通投影设备投影光源功率的均值为P瓦，满足：
Figure PCTCN2020110405-appb-000002
折叠光路几何全息显示***，包括：
至少一个投影器(6)，用于在空间投影画面信息；
透射式几何全息屏(7)，是具有把透射式几何全息屏(7)一侧的像点会聚到其另一侧形成共轭像点的屏幕；
支持结构(8)，分别与投影器(6)和透射式几何全息屏(7)相匹配，为二者提供物理结构支撑；
控制器(9)，与投影器(6)电连接，
其中折叠光路几何全息显示***：还包括至少一个、设置于透射式几何全息屏(7)的一侧或者两侧且分别与支持结构(8)连接的光路折叠镜组(10)，所述光路折叠镜组(10)至少包含一面具有反射功能的平面镜，其用于改变投影器(6)投射光线的传播路径；
其中，所述折叠光路几何全息显示***的视点数为n，所述投影器(6)最外侧镜片的透光部分直径的均值为D分米，所述投影器(6)投影光源功率的均值为P瓦，满足：
Figure PCTCN2020110405-appb-000003
反射式几何全息显示***，包括：
至少一个投影器(6)，用于在空间投影出画面信息；
辅助成像屏(7)，用于分光；
一个位于辅助成像屏(7)一侧或者是两个分别位于辅助成像屏(7)两侧的反射式几何全息屏(11)；
支持结构(8)，分别与投影器(6)、辅助成像屏(7)和反射式几何全息屏(11)相匹配，为三者提供物理结构支撑；
控制器(9)，与投影器(6)电连接；
其中，所述反射式几何全息显示***的视点数为n，所述投影器(6)最外侧镜片的透光部分直径的均值为D分米，所述投影器(6)投影光源功率的均值为P瓦，满足：
Figure PCTCN2020110405-appb-000004
与现有技术相比，本发明的优点在于：
1、采用能够直接显示带有景深信息画面的显示元件，在空中投影出发散的3D图像，无需另外的参考光源辅助，经过等效负折射率平面透镜的投影屏转换后，得到一个悬浮在空中的、可以被观察的3D图像，降低了成本，同时该3D图像可以在投影屏的前方或者后方显示，显示空间无限大，而且在极小的设备空间内，也可以显示超大画面和超深景深；
2、相对于佩帕尔幻象方式由于受到可视角的影响，屏幕显示面积小于80％，本发明所述的***整个屏幕都可以用来显示画面，做到真正的无边框，与环境完美融合；
3、通过处理器来控制显示带有景深信息画面的显示元件的投影画面和景深，由于焦深深度可调，可以有效避免用户长时间观看固定焦深画面造成的视觉疲劳，从而减少近视的发生，可以改善用户视力；
4、通过人眼跟踪单元可以识别人眼位置，然后通过控制运动执行机构来实时调整全息投影器与屏幕的相对位置，使人眼和全息投影器始终相对于投影屏对称(互为光学共轭)，保证了3D图像可以准确地被用户观察到，实现了观察角度自由的目的。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据提供的附图获得其他的附图。
图1为本发明实施例一提供的***图；
图2为本发明实施例一提供的原理图；
图3为本发明实施例二提供的透射式几何全息显示***的示意图；
图4为本发明实施例二提供的离屏显示的几种视点配置示意图；
图5为本发明实施例二提供的多个视点的***配置示意图；
图6为本发明实施例二提供的距离投影镜头最外侧镜片0.1m及以外的空间示意图；
图7为实施例二中提供的椭球可视空间即视窗的示意图；
图8为本发明实施例二提供的椭球可视空间所在坐标系(X′,Y′,Z′)的示意图；
图9为本发明实施例三提供的一种包含1个投影器和1个光路折叠镜组的***示意图；
图10为在本发明实施例三提供的图9的基础上，于同一侧增加了1个光路折叠镜组的***示意图；
图11为本发明实施例三提供的于透射式几何全息屏两侧分别设置有光路折叠镜组的***图及光学转化的光路图；
图12为本发明实施例三提供的本发明多个视点的***配置示意图；
图13为本发明实施例三提供的椭球可视空间所在坐标系(X′,Y′,Z′)的示意图；
图14为本发明实施例四提供的投影器与一个反射式几何全息屏位于辅助成像屏同一侧的本发明***示意图及光路图；
图15为本发明实施例四提供的投影器与一个反射式几何全息屏分别 位于辅助成像屏两侧的本发明一种***示意图及光路图；
图16为本发明实施例四提供的两个反射式几何全息屏分别位于辅助成像屏两侧的本发明***示意图及光路图；
图17为在本发明实施例四提供的图14的基础上，于投影器的同一侧增加了光路折叠镜组的本发明***示意图；
图18为在本发明实施例四提供的图17的基础上，于辅助成像屏的另一侧又增加了一个光路折叠镜组的本发明***示意图；
图19为本发明实施例四提供的隐藏了部分的反射膜后，横截面为直角三角形的反射式几何全息屏的结构示意图；
图20为本发明实施例四提供的柱状基元棱镜对与横截面不平行的光线的逆反射光路图；
图21为本发明实施例四提供的隐藏了部分的反射膜后，横截面为矩形和直角三角形组合的五边形的一种反射式几何全息屏的结构示意图；
图22为本发明实施例四提供的图23中包括的柱状基元棱镜对与横截面不平行的光线的逆反射光路图；
图23为本发明实施例四提供的光线在相互垂直的表面即直角反射壁的反射光路示意图；
图24为本发明实施例四提供的椭球可视空间所在坐标系(X′,Y′,Z′)的示意图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
为了使本领域技术人员更好地理解本发明的技术方案，下面结合附图 对本发明进行详细描述，本部分的描述仅是示范性和解释性，不应对本发明的保护范围有任何的限制作用。
应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。
需要说明的是，术语“中心”、“上”、“下”、“左”、“右”、“竖直”、“水平”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，或者是该发明产品使用时惯常摆放的方位或位置关系，仅是为了便于描述本发明和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。此外，术语“第一”、“第二”、“第三”等仅用于区分描述，而不能理解为指示或暗示相对重要性。
此外，术语“水平”、“竖直”、“悬垂”等术语并不表示要求部件绝对水平或悬垂，而是可以稍微倾斜。如“水平”仅仅是指其方向相对“竖直”而言更加水平，并不是表示该结构一定要完全水平，而是可以稍微倾斜。
在本发明的描述中，还需要说明的是，除非另有明确的规定和限定，术语“设置”、“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本发明中的具体含义。
实施例一
请参照图1至图2，本发明提供一种技术方案：
现场全息显示***，包括全息投影器1、投影屏2、交互响应单元3和处理器4；
全息投影器1位于投影屏2的一侧，全息投影器1用于在空间投影出 具有深度信息的3D图像，优选使用两个全息投影器1实现双眼显示模式，此时单个全息投影器1的镜头只需要覆盖用户的单眼，所以适用双眼显示模式的单个全息投影器1的镜头直径(透光部分)无需太大，也可以只选用一个镜头直径(透光部分)D较大的全息投影器1来实现一个全息投影器1同时覆盖用户双眼。
投影屏2为具有把投影屏一侧的像点汇聚到投影屏另一侧形成共轭像点的屏幕，优选等效负折射率平面透镜，具有把投影屏2一侧的像点汇聚到投影屏2的另一侧形成共轭像点的作用，其用于将全息投影器1投影出的具有深度信息的3D图像转化到其共轭位置，供用户观察；
全息投影器1上设有与处理器4连接的运动执行机构5，运动执行机构5用于控制全息投影器1和投影屏2之间的相对运动和/或整体运动，来调节全息投影器1和投影屏2的空间位置，运动执行机构5具体实施方式多种多样，业内一般人员都可以根据本发明的工作原理自行设计机械结构来实现；
交互响应单元3设置在投影屏2上方，交互响应单元3包括人眼跟踪单元31和交互动作捕捉单元32，人眼跟踪单元31用于跟踪人眼E的位置并将人眼E的定位信息发送给处理器4，人眼跟踪单元3包括摄像机和红外距离探测器，摄像机利用图像识别技术识别人脸并且定位出人眼E的位置，红外距离探测器探测人眼E和投影屏2之间的距离；
交互动作捕捉单元32用于识别用户的交互动作并将用户交互动作信息发送给处理器4，可以采用红外摄像头作为交互动作捕捉单元32来捕捉用户的交互动作，处理器4根据人眼E的定位信息或用户交互动作信息来控制***做出相应的响应，比如根据平移手势信号，处理器4控制画面进行平移，或者根据对应的其他交互动作控制画面的放大、拉近、推远、触碰等。
处理器4分别与全息投影器1、交互响应单元3和运动执行机构5电连接，用于控制各部分的工作，具体为：处理器4发送投影数据信息给到 全息投影器1，来控制全息投影器1的投影画面和画面深度，并根据接收到的交互响应单元3获取的人眼E定位信息和用户交互动作信息，来控制运动执行机构5调整全息投影器1和投影屏2的空间位置，使用户可以正常观看3D画面，需要说明的是本发明所采用的处理器4的控制程序是常见的现有技术。
通过处理器4来控制全息投影器1的投影画面和景深，由于焦深深度可调，可以避免用户长时间观看固定焦深画面造成的视觉疲劳，从而减少了近视的发生，可以改善视力。
本发明可以用于固定显示，如办公、家厅影音、车载显示等，也可以实现小巧的移动显示和头戴显示等领域。
全息投影器1的镜头直径(透光部分)为D(单位为mm)、重量(不包含线束等辅助部件的质量)为W(单位为g)，投影屏2的水平方向最大长度为L(单位为cm)，实际应用时应满足：
Figure PCTCN2020110405-appb-000005
其中全息投影器1的重量W对***显示稳定性的影响较为突出，重量W过小，***固有振动频率就会比较高，环境振动(如施工等)、用户身体运动或者空气对流(如风扇、空调气流)等都会使其产生振动，发生共振，从而容易产生噪音或者受外界噪音干扰，出现画面抖动情况，影响画质，使用户无法接收到稳定的画面；对于只在全息投影器1上设有与处理器4连接的运动执行机构5的情形，全息投影器1的重量W过大时，在调整全息投影器1和投影屏2的相对位置时，容易出现画面跟踪困难，同时用来调整全息投影器1位置的运动执行机构5本身的承重性、强度等各个方面要求较高，成本会相应增加。
全息投影器1的镜头直径(透光部分)D和投影屏2的水平方向最大长度L对***的影响主要体现在显示画面的质量和视觉效果方面：
当D过小时，用户稍微运动一下就会脱离可见视窗，容易出现投影画 面难以跟踪；D越大，其输出图像的立体角覆盖度越大，但D过大时，一方面光源功耗增加，容易造成器件产热增多，降低寿命和可靠性，另一方面又会造成光通量过大，有损伤视力的风险；
投影屏2的水平方向最大长度L增加时相应的可视角度也会增加。投影屏2的水平方向最大长度L过大会造成跟踪困难，容易丢失画面，而且运动扫掠范围过大容易影响到用户活动，甚至造成一定危险；投影屏2的水平方向最大长度L过小时，显示的画面太小，无法营造沉浸式体验。
综上，为了保证不同的应用场景下(如桌面应用、商场展示应用、影院应用以及头戴式应用)，能够显示高质量的画面，同时又不会对用户活动范围造成影响，需要满足：
Figure PCTCN2020110405-appb-000006
下面结合以下实施例对本发明作进一步说明：
1)固定显示
在固定显示应用时，全息投影器1的重量W取值范围200g～3000g，由于W过大和过小都存在如上述的弊端，在采用以下实施例进行说明时，全息投影器1的重量W(不包含线束等辅助部件的质量)取优选值500g，全息投影器1的镜头直径(透光部分)D为5mm～80mm，投影屏2的水平方向最大长度L为15cm～150cm，具体如下表：
Figure PCTCN2020110405-appb-000007
Figure PCTCN2020110405-appb-000008
实施例5为固定显示应用的最佳实施例，为了进一步说明全息投影器1的重量W对***的影响，在实施例5基础上，以全息投影器1的重量W作为变量：
Figure PCTCN2020110405-appb-000009
实施例10和实施例11进一步说明了固定显示应用时，全息投影器1的重量W对***的影响仅限于稳定性的影响。
2)穿戴式显示
对于头戴式显示应用时，用户眼睛E与***的相对位置是固定不变的，那么人眼跟踪单元31就可以取消掉。
实际应用时，如果全息投影器1质量W较大会造成穿戴不便，而且全息投影器1采用的是微型型号，质量W都相对较小，常规情况W为5g～15g。在采用以下实施例进行说明时，全息投影器1的重量W优选10g，全息投影器1的镜头直径(透光部分)D为1mm～15mm，投影屏2的水平方向最大长度L为0.8cm～5cm，具体如下表：
Figure PCTCN2020110405-appb-000010
实施例16为穿戴式显示的最佳实施例。
基于以上实施例的数据，全息投影器1的镜头直径(透光部分)D取固定显示应用的最大值80mm、重量(不包含线束等辅助部件的质量)W取穿戴式显示应用的最小值5g，投影屏2的水平方向最大长度L取穿戴式显示应用的最小值0.8cm，可以得出
Figure PCTCN2020110405-appb-000011
所以在限定
Figure PCTCN2020110405-appb-000012
的范围时取
Figure PCTCN2020110405-appb-000013
而通过上述实施例也表明，
Figure PCTCN2020110405-appb-000014
的范围内，都可以使本发明所述的***实现全息显示的效果，但是只有当全息投影器1的镜头直径(透光部分)D、重量W和投影屏2的水平方向最大长度L均为最优时，才会达到好的显示效果，从而满足用户的需求。
为了显示彩色画面，全息投影器1的投射光可以包含红色、蓝色和绿色三元色光源。
本发明在实际应用时，投影屏2也可以采用等效负折射率平面透镜的 屏幕；交互响应单元3是用来定位人眼E的位置和捕捉用户交互动作的，所以其位置也可以位于投影屏2的下方，或者其他位置，只要是能够实现准确定位人眼E位置和用户交互动作信息即可；运动执行机构5用于调节全息投影器1和投影屏2两者之间的空间位置，所以不单单是设置在全息投影器1上，也可以设置在投影屏2上或者是全息投影器1和投影屏2上都设有运动执行机构5，用于实现全息投影器1和投影屏2相对位置的调整，以使得人眼E与投影器处于光学共轭位置；或者用于调整全息投影器1和投影屏2整体运动，使得在用户观看过程中存在运动时，能够整体移动全息投影器1和投影屏2；或者，运动执行机构5可以同时在将全息投影器1和投影屏2作为整体调整位置时，还微调全息投影器1和投影屏2之间的相对位置，以保持投影器的光学共轭区域始终能够覆盖人眼，从而能够实时跟踪用户眼睛的位置，使用户始终能够正常观看画面。
原理：本发明采用的投影屏2是一种可以将投影屏2一侧的像点汇聚到投影屏2的另一侧并形成共轭像点的负折射率平面透镜。因此，如果可以在空中投影出发散的3D图像，无需参考光源的辅助，经过负折射率平面透镜的投影屏2转换后，就可以得到一个悬浮在空中的、可以被观察的3D图像。
但是由于负折射率平面透镜的投影屏2只能把投影的3D图像转化到其(相对于负折射率平面透镜)光学共轭位置(也是对称位置)，一旦用户运动起来，比如左右前后移动，3D图像就无法准确被用户观察到。通过人眼跟踪单元31可以识别人眼E的位置，然后通过实时调整全息投影器1或者投影屏2的位置，使人眼E和全息投影器1相对于投影屏2互相对称 (互为光学共轭)，就可以保证用户始终可以观察到画面。投影屏2只是把一侧的图像在其另一侧对称位置成像类似于佩珀耳成像原理，因此还需要使用其他辅助技术才可以实现3D成像，所以本发明使用了全息投影器1投影出3D图像，然后通过投影屏2转化到其对称位置供观察。
本发明实施例一所述的显示***，全息投影器1在空中投影出发散的3D图像，无需另外的参考光源辅助，经过等效负折射率平面透镜的投影屏2转换后，就可以得到一个悬浮在空中的、可以被观察的3D图像，降低了成本，相对于似佩帕尔幻象方式由于受到可视角的影响，屏幕显示面积小于80％，本发明所述的***整个屏幕都可以用来显示画面，做到真正的无边框，与环境完美融合，同时该3D图像可以在投影屏的前方或者后方显示，显示空间无限大，而且在极小的设备空间内，也可以显示超大画面和超深景深。
实施例二
如图3，本发明提供一种透射式几何全息显示***，包括显示元件6、透射式几何全息屏7、支持结构8和控制器9；
通常影院的3D片源都是立体图像对的形式，通过双目视差来表现出3D效果，但是实际画面焦深是固定在一个位置的，所以会引起视觉疲劳。本发明的***显示元件6是用于在空间投影画面信息，可以直接采用全息投影仪作为显示元件6，在空间内投影出3D画面或者一系列分布在在空间不同景深的二位画面组；也可以使用能够实现三维画面显示的投影设备来 替代上述的全息投影仪，例如，可以进一步对普通投影设备进行光学设计，使之能够在采用单个投影仪的基础上实现3D显示，可以参考申请号为202010029144.5的一种全固态全息投影器，通过在投影仪内部通过增加一些光学元件进行光学设计实现三维画面显示的技术方案，这里不做具体限定。
在本发明的其他实施例中，还可以采用能够投影二维画面的普通投影设备作为显示元件6，可以实现在空间内的某个焦平面上投影出二维画面，然后通过控制器9来调节二维画面的景深和画面内容，呈现出画面内容的同时还可以表现出画面与用户之间的真实的距离感，从而实现在空间投影出具有深度信息的画面的效果；实际操作中，焦深调节可以是实时调节，也可以是间隔一定时间做一次焦深调整。
由于投影及焦深可调，所以可以把画面等效焦深移动到合理的位置，从而避免了3D焦深(双眼视差带来的焦深效果)与实际焦深不同的问题，呈现出更加逼真的3D效果。这种方式相对于全息投影仪作为显示元件6来说，可以有效降低成本，具体的，上述普通投影设备可以使用常见的普通投影仪或者其简单修改即可。
透射式几何全息屏7是具有把透射式几何全息屏7一侧的像点汇聚到其另一侧形成共轭像点的屏幕，其位置与显示元件6相对应，用于把显示元件6投影出的图像转化到相对透射式几何全息屏7的光学共轭位置，优选使用柔性全息屏，这样可以做成卷轴屏或者折叠屏，从而使***整体更加紧凑、便携，当然对于合适的场合也可以使用硬质的屏幕；
当需要兼容显示2D画面时，透射式几何全息屏7可以用普通投影屏替代，如普通背投屏；
支持结构8分别与显示元件6和透射式几何全息屏7相匹配，为二者提供物理结构支撑，具体可以是将支持结构8可以做成结构固定的支撑架，此时，本发明的显示***整体是固定不动的，用户需要在一个固定的方位才可以观察到画面；
控制器9与显示元件6电连接，显示元件6可以根据控制器9的控制信号来调节投影画面的景深和显示内容；
为了增加显示***的灵活性，我们还可以将支持结构8设置为可以运动或者变形的结构，将支持结构8和控制器9电连接，支持结构8根据并控制器9的控制信息，做出相应响应动作，实现显示元件6和透射式几何全息屏7的相对运动和/或整体运动，使得***的可视视窗始终覆盖用户的眼睛，使得用户在不同的方位都可以正常观看画面，需要说明的是支持结构8为一般现有技术，本领域的技术人员可以根据实际应用的空间条件自行设计，比如：使用一些铰链结构和类似于伞轴的结构可以非常容易的设计出可以变形的结构，这里不做具体限定；
作为优选方案，如图4所示，本发明所述的全息显示***还包括与控制器9电连接的交互动作捕捉单元101，交互动作捕捉单元101用于识别用户的交互动作并将用户交互动作信息发送给控制器9，控制器9根据接收到的交互动作捕捉单元101获取的用户交互动作信息调整显示画面内容，实现用户与画面的交互动作，具体可以是采用摄像头结合机器视觉技 术来识别用户的手势动作来获取用户的交互信息，从而控制画面显示内容或者控制支持结构8运动来调整投影设备和/或透射式几何全息屏7的空间位置和姿态，控制器9还可以根据接收的交互动作捕捉单元101获取的用户交互动作信息来实时调整显示画面内容，实现用户与画面的交互动作，比如根据平移手势信号，控制画面进行平移，或者根据对应的其他交互动作控制画面的放大、拉近、推远、触碰等操作；
交互动作捕捉单元101的设置对于类似于穿戴式应用这种用户相对显示***的空间位置固定不变的应用情景具有积极的意义；
另外，对于用户相对显示***的空间位置实时变动的应用情景，需要设置一个与控制器9电连接的人眼跟踪单元102，人眼跟踪单元102用于跟踪人眼的位置并将人眼的定位信息发送给控制器9，控制器9根据接收到的人眼跟踪单元102获取的人眼定位信息，来控制支持结构8做出相应的动作响应，来调整显示元件6和透射式几何全息屏7的相对位置和/或整体空间位置，使用户眼睛始终处于***的可视空间内，这样用户即使在运动状态下眼睛也可以始终接收到投影信息，正常观看画面。
实际应用中，人眼跟踪单元102和交互动作捕捉单元101可以集成在同一个设备内完成，比如使用一个机器视觉摄像设备等。
以普通投影仪作为显示元件6时，控制器9把画面以及画面的平均焦深信息发送给投影仪，投影仪自己调整投影焦深，投影仪就可以把画面投射到特定焦深位置，供人眼观看。
需要说明的是普通投影仪一般有自动对焦功能，开机时投影仪会根据 内置的距离传感器测量屏幕距离投影仪的距离，然后驱动镜头调整到合适的位置，使投影焦深与屏幕重合；在本发明的***中也可以去除掉其自带的距离传感器，使控制器9直接发送焦深数据到投影仪从而实现对投影焦深的控制，具体实现方式为现有成熟硬件通信技术，这里不做赘述。
本发明所述的透射式几何全息显示***跟传统显示***相比有一个非常特殊的地方，它无法像传统2D显示器件一样可以供大量用户同时观看，为了方便表述，这里引入视点的概念：
如果显示***可以为一只眼睛提供一个观窗，那么这个***就拥有一个视点。而对于双眼显示***，可以供两只眼睛同时观看，所以视点数量为2。当显示***可以供n只眼睛同时观看，视点数量就为n。实际设计时，还需要考虑实用性的情况下合理设置***的结构。
如图5所示，a情况下，对应于使用一个大口径的投影仪，投影仪的最外侧镜片相对于透射式几何全息屏7的光学共轭区(也是镜像对称区，可以称之为视窗)可以覆盖用户的两只眼睛，此时虽然两只眼睛之间的区域原理上也能够观看图像，但是实际条件下却不可能使用到，只能同时供两只眼睛观看，所以这种情形相当于有两个视点；
b到d的情况下，对应于使用两个小口径的投影仪，两个投影仪的投影镜片相对于透射式几何全息屏7的光学共轭区形成两个分立的子区。当两个子区之间的间距与人眼的间距刚好匹配时就可以供两只眼睛同时观看(b情形)，因此有两个视点；
当两个子区之间的间距比人眼之间的间距小(c情形)或者比人眼间 距大(d情形)时，两只眼睛只有一个能观看到图像，因此只有一个视点。
如图5，同理，当投影仪的数量更多时，那么***的视点数就会相应的增多，具体数量根据符合a～d的具体情形而定，显示***的视点数为n与所采用的投影仪的镜头大小以及数量相关。
类似地，对于多用户***设计时更是需要考虑使用情境下用户之间的空间位置关系，合理设计每个视窗之间的空间分布情况，避免出现***实际可用视点小于设计视点的情况。一个有效的设计策略是，通过合理设计支持结构8使其具备结构调整功能，比如可以调整两个投影仪之间的距离或者空间位置，这样在使用时就可以根据用户瞳距和应用场地灵活调整支持结构8的几何形态来适应实际需求。
需要说明的是，当投影***向下兼容切换到2D投影模式时(如调整投影仪的投影焦平面直接在透射式几何全息屏7上投影2D画面，或者用一个普通的投影承接屏替代或者放置在透射式几何全息屏7前表面或者后表面进行2D投影画面的承接显示)，图像焦平面与屏幕重合，视点数量会大大增加，但是这些视点具有很大的观看局限性，只能看到屏幕上的画面，显示***输出的离屏画面都无法观看到，所以不能计入到真正的视点数量里面，实际有效的视点应该是可以观看***所有模式下的画面的视点，包括屏幕上以及屏幕前、屏幕后的离屏显示内容都可以观察到的视点。
传统2D显示器件，如电视、投影仪、电脑等，视点数量非常多，可以同时被众多用户观看，这是因为其光源发出的光线，发散度较高，无指向性，因此也对亮度要求比较高。但是对于本发明的全息显示***，视点 数都比较少，其显示器件(如全息投影仪或者普通投影仪)发出的光会非常高效的汇集到视窗位置被人眼接收，因此如果光强太强容易造成眩晕，图像不清晰，甚至对人眼造成伤害，同时过高的光通量往往需要光源(如投影仪内部的灯泡、LED灯等)在高功率下运行，而光源长期运行在高功率模式下使用寿命就会大幅缩减，所以光通量不能设计的过高。但是，随着视点数量增加，显示***的总光通量也需要提高，来保证每个视点都能够提供清晰的画面，由于本发明显示***光路的复杂性，视点与光通量之间并不是简单的线性关系。
本发明所述的透射式几何全息显示***的视点数为n，显示元件6包含的投影设备最外侧镜片的透光部分直径的均值为D分米(dm)，显示元件6包含的投影设备的平均显示光通量L流明(lm)，显示光通量视点积为n 1.27·L，综上，结合实际测试效果，显示光通量视点积满足：n 1.27·L≤24000时可以够保证比较好的显示效果和***的可靠性。
其中，单个投影设备的显示光通量L(lm)的测定方法可以参考ANSI流明的测试方法：
1)将显示***中的投影仪与幕之间距离设置为：2.4米；
2)屏幕为60英寸；
3)用照度计测量屏幕“田”字形九个交叉点上的各点照度，并求得9个点的平均照度；
4)平均照度乘以投影画面面积就是ANSI流明，也就是本发明所述的显示光通量。
对于显示不同的画面，L的测试值可能会有较大差异，实际测试中，优选显示全白画面进行测试，即每一个像素都显示为白色的情况；
当投影仪的光照区域无法很好的跟屏幕匹配时，照度测试按照实际光照区域进行取点测试，优选在光照区域内与光照区域的外边界相距约10cm～30cm的光带内较均匀的选取8个点和距离屏幕中心不超过20cm的光照区内1个点，共9个点进行照度测试，然后将9个照度值的平均值与光照区域的实际面积相乘得到显示光通量值。
对于只包含一个投影设备的应用，可以按照上述方式进行测试显示光通量(单个投影仪的显示光通量和平均显示光通量数值一样)，当使用到多个投影仪时，可以分别测试每个投影单元的光通量然后取平均值作为显示光通量的值。
另外，在实际测试中，不同的设计结构(如密封和散热性的差异)也会对***的寿命产生比明显的影响，所以实际在测试过程不同的设计结构可能对实测数据带来一定波动，但是整体的趋势不会改变，显示配置参数的最优值不会变化。
下面以普通投影仪作为显示元件6为例，对本发明作进一步说明：
实施例1：采用一个镜头直径0.5dm的投影仪作为显示元件6，视点数n＝1，可以供单户使用单个眼睛进行观看；
通常用户眼睛数量为偶数，视点数n设置为偶数，
实施例2～24：采用1个镜头直径大于6.5dm的投影仪或者是2个镜 头直径小于6.5dm的投影仪作为显示元件6，视点数n＝2，可以供单用户双眼观看；
实施例25：采用4个镜头直径为0.4dm的投影仪作为显示元件6，***视点数n＝4，可以供双用户同时观看；
实施例26：采用6个镜头直径为0.3dm的投影仪作为显示元件6，视点数n＝6，三口之家可以同时观看；
实施例27：采用8个镜头直径为0.2dm的投影仪作为显示元件6，视点数n＝8，四口之家同时观看，具体如下表：
Figure PCTCN2020110405-appb-000015
实施例1～27的数据表明：显示光通量视点积n 1.27·L≤24000时，显示效果均较好，用户评分均在80分以上，对比例1中的显示光通量视点积 n 1.27·L为31351，用户评分低，画面刺眼，实际显示效果欠佳。
实际使用时，除了需要考虑视点数量n与光通量L之间的设计关系外，还需要单个投影仪孔径大小与光通量之间的匹配。当单个投影仪孔径较大时，显示光的视觉利用率就会偏低，很多光线只能到达人眼之外的区域，所以此时需要适当增加光通量，根据上述实施例1～27的应用，实际应用中可以参考如下表达式进行设计：
Figure PCTCN2020110405-appb-000016
基于光源功率对于***显示效果以及可靠性的影响。投影仪内部光源工作在高功率模式下时寿命往往会大幅下降，因此尽可能使其工作在小功率的模式。但是，视点数量较多或者当单个投影仪孔径较大时，显示光的视觉利用率就会偏低，很多光线只能到达人眼之外的区域，所以此时需要适当增加光源的功率来提高光通量，显示元件6包含的投影设备投影光源功率的均值为P瓦(W),测试发现当满足如下关系式的时候，***可以在一个较优的条件下运行：
Figure PCTCN2020110405-appb-000017
投影设备光源功率P的测量可以直接测试其正常工作状态下的光源两端的电压和通过光源的电流然后进行相乘计算得到功率值。
在实施例1～27的基础上，再引入光源功率P(W)进行说明，具体见下表：
Figure PCTCN2020110405-appb-000018
数据表明：功率视点积
Figure PCTCN2020110405-appb-000019
时，显示效果均较好，用户评分均在80分以上，而对比例1中的功率视点积
Figure PCTCN2020110405-appb-000020
为679，用户评分低，画面刺眼，实际显示效果欠佳。此外，当光源功率小于400W时，基本可以满足5年的设计寿命，进而可以保证可靠性。
上述实施方式中采用的普通投影仪还可以用全息投影仪或者其它能够实现三维画面显示的投影设备替代。同时上述涉及到视点数量、光源功率和显示光通量的设计公式对于全息投影仪同样使用。
另外在实际测试中还发现，实施例1～27的高温高湿环境(85℃、相对湿度85％)加速测试中3000h依然可以正常工作，而对比例1在3000h时光源已经损坏，无法发光，说明不合理的设计参数会大大降低使用寿命，上述的测试俗称双85老化测试，3000h加速老化测试相当于实际工况条件 下5年的最低使用寿命标准。
上述实施例的数据也可以说明：通过合理的光学参数设置能够有效提高全息显示***的显示效果和可靠性。
本发明所述的显示***的原理可以参考申请号为201910875975.1的专利，这里简单介绍一下：投影仪可以在空间不同深度处投射出画面，也就是可以为投影画面提供额外的景深信息，但是投影仪投出去的画面都是发散光，无法被人眼直接观看，这也是常规投影***必须要使用一个承接屏幕的原因。
而透射式几何全息屏7的光路转化作用可以使投影仪投射出去的发散光重新汇聚到投影仪相对于透射式几何全息屏7的光学共轭位置，也就是其镜像位置，从而形成汇聚光，就可以被人眼直接观看了。所以虽然本发明的全息显示***里面使用了透射式几何全息屏7，但是其作用与传统投影显示***的承接屏却完全不同。传统投影***的承接屏用于把光线随机散射开供用户观看。而透射式几何全息屏7的作用更像是一种特殊的光学元件，它能够对光线进行特定的光学转换，把屏幕一侧的光点发出的光线重新汇聚到光点相对于屏幕的镜像位置附近极小的区域，从而形成一个汇聚的悬浮在空中的实像点。这种独特的成像特点使得它可以在空间不同深度进行成像(离屏成像)，实现真正的3D显示。
从本发明的显示原理分析可以发现，用户在使用时看到的画面完全跟投影仪投射出去的画面一致。投影仪投射出去的画面距离其最外侧镜片多远，用户看到的画面距离眼睛就多远。生活中，人眼的明视距离一般在 25cm，观看最近的物体一般也在10cm之外，所以投影仪选择的时候可以优选投影焦深可以在距离投影镜头最外侧镜片外表面大于0.1m的空间内(如图6)调节的投影仪(普通投影仪或者全息投影仪)。
用户处于静态时只要调整好***结构使用户眼睛被视窗覆盖就可以使用户正常观看到画面，但是如果用户处于运动状态就会很容易使眼睛脱离视窗从而无法正常观看画面。因此，针对用户无法完全处于静止状态下的应用场景，增加用户眼睛定位跟踪然后实时调节视窗的空间位置使其始终覆盖用户的眼睛是非常重要的。但是实际场景下，显示***的元器件参数各不相同，很难找出一套适用于所有***的跟踪方式。原理上，如果能够非常精准的定位用户眼睛运动轨迹，然后通过调整投影仪和透射式几何全息屏之间的相对位置和整体空间位置来驱动视窗精准跟踪用户眼睛运动轨迹是最理想的方案。但是，完全精准的跟踪用户眼睛和精准的控制视窗位置是非常困难的，即使能实现也需要付出比较大的成本代价，实用性不强。
事实上，由于视窗本身有一定大小，人眼只要在视窗之内就可以观看到画面，所以用户运动时并不需要完全精确跟踪用户眼睛的运动轨迹只要能大致跟踪保证用户眼睛在视窗之内即可，甚至稍微偏移出视窗一点，但是瞳孔跟之窗有交集也可以正常观看画面。
以上主要针对用户相对屏幕左右上下移动情况进行的讨论，另外，用户前后移动时，如果不偏离视窗中心太多也完全可以正常观看到画面。综上，对于用户眼睛的跟踪并不需要特别精确，只要保证在一定精度内即可满足使用要求。具体如图7，屏幕上方和下方的光线会有一个相交的菱形 区域，原理上只要实时调整支持结构使用户眼睛始终处于上述的菱形可视空间内，即可观察到画面，但是在菱形的靠近角位的地方，比较容易出跟踪丢失的问题，所以在棱形区域的内部进一步限定一个相对较小的椭球可视区域，减小跟踪丢失的概率。
以下对椭球区域进行说明，如图8，椭球可视空间是以显示元件6的每个投影仪最外侧镜片中心为原点，以镜片中心外法线为Y轴方向，以过原点垂直于水平面的直线为X轴，以过原点垂直于X轴和Y轴的直线为Z轴的坐标系(X,Y,Z)，相对于透射式几何全息屏7的光学共轭坐标系(X＇,Y＇,Z＇)下，满足以下关系式的空间：
Figure PCTCN2020110405-appb-000021
其中K为一个扩展常数，单位为dm，K范围0<K<0.08；
m为共轭偏差常数，m范围为0≤m≤5。
以上表达式是一个椭球形围成的空间，其中m的取值影响y轴方向椭球的长度。从图7可以看到，可视空间在Y′轴方向有一定延伸，实际测试发现，可视空间在Y′轴方向有一定延伸长度大概在透镜直径D的6倍左右，在这个范围内都可以看到清晰的画面，但是实际考虑到跟踪效果，在Y′轴方向延伸长度小于透镜直径的5倍范围内都可以比较容易实现较好的显示效果。此外，实际测试发现：
当m取5时，画面的全部显示区域都可以清晰的看到，只在局部边界区域，画面清晰度稍微差一些但依然可以分辨清楚显示细节；
当m取3时，画面的全部显示区域都可以清晰的看到，即使在边界区域，画面也比较清晰，跟踪稳定性也非常好；
当m取2时，画面的全部显示范围完整，显示细节非常清楚，跟踪稳定性比较好，只是偶尔有跟丢情况，适合桌面办公场景；
当m取1时，画面的全部显示范围完整，显示细节非常清楚，跟踪稳定性稍差，跟丢频率有所增加，适合观影娱乐应用场景；
K和D决定了垂直与Y′轴平面内可视空间的截面，原理上投影镜片的直径范围内都可以观看到画面，实际上只要人眼与投影镜片的光学共轭区有相交，即使人员不完全在投影镜片的光学共轭区域之内也可以看到画面，所以引入一个扩展常数K，其数值取决于人眼的直径大小，通常人眼瞳孔的直径最大值是0.08dm，所以这里取0.08dm作为扩展常数。
虽然，数学上m不可以取0，但是这里取0有物理上的意义，即Y′都等于0的平面上的点。
本发明在使用多个投影仪(普通投影仪或者全息投影仪)时可以选择完全一样的型号，也可以根据实际应用场景需求选用不同的型号。
本发明显示***，由于焦深深度可调，可以避免用户长时间观看固定焦深画面造成的视觉疲劳，从而避免了近视的发生，可以改善视力水平。
本发明可以用于固定显示，如办公、家厅影音、车载显示等，也可以实现小巧的移动显示和头戴显示等领域，不同应用场景下投影设备的质量选用：
桌面应用：优选质量小于5kg的投影设备；
移动终端：优选质量小于300g的投影设备；
穿戴应用：优选质量小于100g的投影设备。
本发明实施时可以适当增加一些增透膜，吸光膜、滤光片等光学元件来进一步提升***的效果。
与现有技术相比，本发明实施例二的优点在于：
1、采用普通投影设备在空间内的某个焦平面上投影出二维画面，通过控制器调节投影画面的焦深，来实现带有景深信息的画面显示，呈现出更加逼真的3D效果，克服了3D片源短缺的限制，同时使用普通投影设备作为显示元件，能够大大降低成本，提高实用性；
2、合理的光学参数设置能够有效提高全息显示***的显示效果和可靠性。
实施例三
如图9至图12，本发明提供一种折叠光路几何全息显示***，包括至少一个投影器6、透射式几何全息屏7、支持结构8、控制器9和至少一个光路折叠镜组10；
本实施例中投影器6的相关内容可以参考实施例二中的显示元件。本实施例中对此不作赘述。
与实施例二中不同的是，本实施例中支持结构8分别与投影器6、透射式几何全息屏7和光路折叠镜组10相匹配，分别为三者提供物理结构支 撑，具体可以是将支持结构8可以做成结构固定的支撑架，此时，本发明的显示***整体是固定不动的，用户需要在一个固定的方位才可以观察到画面；
光路折叠镜组10通过支持结构8支撑，其至少包含一面具有反射功能的平面镜，用于改变投影器6投射光线的传播路径，具体设置于透射式几何全息屏7的一侧，或者是当光路折叠镜组10数量为多个时，则将其设置于透射式几何全息屏7的一侧或者分别设置于透射式几何全息屏7的两侧，具体根据所应用的场景的空间形式而定；
控制器9与投影器6电连接，投影器6可以根据控制器9的控制信号来调节投影画面的景深和画面内容；
为了增加显示***的灵活性，我们还可以将支持结构8设置为可以运动或者变形的结构，将支持结构8和控制器9电连接，支持结构8根据控制器9的控制信息做出相应响应动作，从而实现投影器6、透射式几何全息屏7和光路折叠镜组10三者之间相对运动和/或整体运动，使得***的可视视窗始终覆盖用户的眼睛，使得用户在不同的方位都可以正常观看画面，需要说明的是支持结构8为一般现有技术，本领域的技术人员可以根据实际应用的空间条件自行设计，比如：使用一些铰链结构和类似于伞轴的结构可以非常容易的设计出可以变形的结构，这里不做具体限定；
同样作为优选方案，本发明所述的全息显示***还包括与控制器9电连接的交互动作捕捉单元和人眼跟踪单元，对应的交互动作捕捉单元和人眼跟踪单元可以参见实施例二中的交互动作捕捉单元101和人眼跟踪单元 102的具体内容，本实施例中对此不作详细赘述。关于支持结构的相关内容，也可以参见实施例二中的相关内容，本实施例中对此也不作详细赘述。
同样的，普通投影仪作为投影器时，具体对焦过程，也可以参见实施例二中相关的内容，本实施例中对此不作赘述。
以本发明采用一个投影器6为例进行说明：
如图9，***配置有一个与投影器6位于同一侧的光路折叠镜组10，投影器6的投影画面经过光路折叠镜组10和透射式几何全息屏7光学转化后，在透射式几何全息屏7的另一侧形成有离屏的显示画面，人眼通过如图所示的视窗即可观看到；
如图10，***配置有两个光路折叠镜组10，均与投影器6相对于透射式几何全息屏7位于同一侧，投影器6的投影画面经过两个光路折叠镜组10以及透射式几何全息屏7光学转化后，在透射式几何全息屏7的另一侧形成有离屏的显示画面，人眼通过如图所示的视窗即可观看到；
如图11，***同样***配置有两个光路折叠镜组10，但是分别设置于透射式几何全息屏7两侧，投影器6的投影画面经过两个光路折叠镜组10以及透射式几何全息屏7光学转化后，在透射式几何全息屏7的另一侧形成有离屏的显示画面，人眼通过如图所示的视窗即可观看到；
需要说明的，光路折叠镜组10和透射式几何全息屏7对投影器6的投影画面光学转化原理，可以参考图11的光路转化原理。当光路折叠镜组10的数量更多时，不论是怎样的排列组合，只要能够使投影器6的投影画面经过光学转化后在光学共轭处形成有离屏的显示画面都属于本发明的保 护范围。
以上只是对本发明进行的举例说明，并不是对本发明的限定，对于投影器6为多个时，同样适用。
本发明所述的折叠光路几何全息显示***跟传统显示***相比有一个非常特殊的地方，它无法像传统2D显示器件一样可以供大量用户同时观看，为了方便表述，这里同样引入视点的概念，具体可以参见实施例二中关于视点的说明，本实施例中对此不作详细说明。
本实施例中，以显示***中投影器6均采用普通投影仪，光路折叠镜组10的数量均为1个，且与投影器6设置于透射式几何全息屏7的同一侧为例说明对应的显示***的效果；需要说明的是，在采用相同参数情况下，实施例1～实施例27的数据参数均可以参见实施例二中的表格，本实施例中对此不作详细说明，且得到的效果结论相同，因此，本实施例中不再赘述。
与实施例二中不同的是，本实施例中的椭球区域具体如图13所示，椭球可视空间为所述可视空间是以每个投影器6镜头最外侧镜片中心为原点，以镜片中心外法线为Y轴方向，以过原点垂直于水平面的直线为X轴，以过原点垂直于X轴和Y轴的直线为Z轴的坐标系(X,Y,Z)经过光学转化后光学共轭坐标系(X′,Y′,Z′)下，满足以下关系式的空间：
Figure PCTCN2020110405-appb-000022
其中K为一个扩展常数，单位为dm，K范围为0<K<0.08；
m为共轭偏差常数，m范围为0≤m≤5。
其他内容，请参见实施例二所述。
与现有技术相比，本发明实施例三的优点在于：
1、通过引入能够改变投影器投射光线的传播路径的光路折叠镜组，对光路进行灵活的转化折叠，能够合理地利用空间，来降低整个显示***的空间占有率，非常有效的提高显示***布局的灵活性；
2、投影器采用能够投影二维画面的普通投影设备，能够大大降低成本，提高实用性，普通投影设备可以在空间内的某个焦平面上投影出二维画面，通过控制器调节投影画面的焦深，来实现带有景深信息的画面显示，呈现出更加逼真的3D效果，克服了3D片源短缺的限制，降低成本；
3、合理的光学参数设置能够有效提高全息显示***的显示效果和可靠性。
实施例四
如图14至图18，本发明提供一种反射式几何全息显示***，包括至少一个投影器6、辅助成像屏7、反射式几何全息屏11、支持结构8和控制器9；
本实施例中投影器6的相关内容可以参考实施例二中的显示元件。本实施例中对此不作赘述。
与实施例二中不同的是，本实施例中辅助成像屏7用于分光，优选半 透半反膜，投影器6的投射光线照射到辅助成像屏7之后，部分光线被反射到反射式几何全息屏11上，通过反射式几何全息屏11对光线的调制，使任意照射在反射式几何全息屏11上的光线逆反射后原方向返回，逆反射的光线部分透过辅助成像屏7后在空中形成离屏的投影画面；
反射式几何全息屏11用于对照射到其上的、与截面不平行的其他角度的入射光线进行逆反射，可以这些光线偏移距离dmm之后逆反射回去，d为出射光线与反射式几何全息膜入射面的交点到入射光线的距离，d≤2mm(通常对于类似电影院的巨幕电影，由于用户距离屏幕较远所以像点偏差2mm人眼也不容易分辨，依然可以显示比较清晰的画面，但是偏差过大的话，画质就会受到影响)，优选柔性的全息屏，反射式几何全息屏11的数量为一个或者两个：反射式几何全息屏11数量为一个时，将其设置于辅助成像屏7的任意一侧；反射式几何全息屏11数量为两个个时，则分别设置于辅助成像屏7的两侧，当***包含2个反射式几何全息屏11时，***的光能利用率和成像质量均较高。
优选的是，如图19至图22，反射式几何全息屏11的内部设有一系列横截面为直角三角形或者矩形和直角三角形组合的五边形的柱状基元棱镜111，其中上述的直角三角形优选等腰直角三角形；
柱状基元棱镜111内部、沿长度方向上设有若干相间排列的透明层112和反射层113，这种结构可以通过自上而下的二维加工方式获得，加工工艺及其简单，加工精度有非常高，成像质量优异；
柱状基元棱镜111的底面为光线入射面，反射层113、柱状基元棱镜 111的端面以及横截面的直角边所在的斜面为反射面，柱状基元棱镜111横截面包含的直角三角形的直角边所在的斜面上设置有一层反射膜114，用于对光线进行镜面反射；
作为另一种方案，作为反射面的柱状基元棱镜111的端面上也可以设置有一层对光线进行反射的反射膜114，需要说明的，如果在加工过程中，柱状基元棱镜111的端面为反射层113，则无需在该反射层113的端面上镀反射膜114，反射层113本身具有对光线进行镜面反射的功能。
另外，横截面为矩形和直角三角形组合的五边形的柱状基元棱镜111内，直角三角形部分的棱镜内部可以不含反射层113，这种结构同样可以实现光线的逆反射。
上述柱状基元棱镜横截面所涉及的角度误差范围在±5°以内，包括横截面的直角三角形和五边形的直角以及透明层112和反射层113与柱状基元棱镜111的长度方向所成角度，虽然以上原理是基于理想几何形状来实现的，但是实际情况下，加工过程可能无法制造出完全理想的几何形状，角度也会存在一定的误差，顶点也不可能是一个理想的几何点而是一个半径非常小的圆角。当生产制造误差比较小时，反射光的方向跟逆反射理想的情况发生微小偏差，这些偏差人眼无法分辨，由这些误差带来的像差也非常小，因此同样可以实现非常好的成像效果。
比如柱状基元棱镜111横截面的包括的直角误差在±5°之内时，用户体验相对比较满意，当超出这个范围后，用户开始觉得成像效果无法接受。同样几何顶点允许是一个比较小的圆角(比如半径小于0.1mm)，那么同样 可以实现比较好的成像功能。当然误差越小用户评价越高，所以生产时要尽量降低误差。
当然误差越小用户评价越高，所以生产时要尽量降低误差。类似的加工误差对于切削方向和粘接方向同样适用。
具体应用时，客厅应用的角度误差在±2.5°以内时，用户体验相对比较满意；
桌面应用的角度误差在±1°以内时，用户体验相对比较满意；
移动终端应用的角度误差在±0.5°以内时，用户体验相对比较满意。
支持结构8分别与投影器6、辅助成像屏7和反射式几何全息屏11相匹配，为三者提供物理结构支撑，具体可以是将支持结构8可以做成结构固定的支撑架，此时，本发明的显示***整体是固定不动的，用户需要在一个固定的方位才可以观察到画面；
控制器9与投影器6电连接，投影器6可以根据控制器9的控制信号来调节投影画面的景深和画面内容；
逆反射原理说明：如图23，一条光线照射在形成直角的两个反射壁上时，经过两次反射后,出射光线会沿着平行于入射光线的方向传播。当直角反射壁足够小时，出射光线和入射光线之间的距离也会非常小，小到人眼无法分辨，视觉上就像光线原路返回一样。当然，二维平面内直角反射壁只能使平面内的光线进行原路反射，如果能够在空间中形成一个直角三棱锥结构的反射壁，就可以对空间中的光线进行原路反射。
无论是横截面为直角三角形或者矩形和直角三角形组合的五边形都具有多个直角反射壁，包括柱状基元棱镜111的两个斜面形成的直角反射壁以及斜面分别与反射层113或者柱状基元棱镜111的端面形成的直角反射壁，因此这种微结构单元具有对空间的光线进行原路反射的功能，所以如果一个平面上密集布置很多这种微结构，就可以对大面积的入射光进行原路反射。
如图20所示，任意与柱状基元棱镜111的横截面不平行的光线从入射面射到反射层113或者是柱状基元棱镜111的端面反射膜114上时，经过一次反射至相邻的一个斜面上，经过该斜面镀的反射膜114的二次反射，将光线反射到另一个斜面上，再经过该斜面上镀的反射膜114的三次反射，即可实现将光线偏移dmm后平行于入射光的方向反射回去，这些逆反射回去的光线可以进行3D成像；
同理，如图22所示，任意与柱状基元棱镜111的横截面不平行的光线从入射面射到反射层113或者柱状基元棱镜111的端面的反射膜114上时，也可以经过多次反射后逆反射回去进行3D成像；
而对于平行于柱状基元棱镜111横截面的入射光，按照图11的光路原理经过两斜面的两次反射即可实现光想逆反射3D成像。
作为优选方案，本发明所述的全息显示***还包括与控制器9电连接的交互动作捕捉单元和人眼跟踪单元，对应的交互动作捕捉单元和人眼跟踪单元可以参见实施例二中的交互动作捕捉单元和人眼跟踪单元的具体内容，本实施例中对此不作详细赘述。
为了增加显示***的灵活性，我们还可以将支持结构8设置为可以运动或者变形的结构，将支持结构8和控制器9电连接，支持结构8根据控制器9的控制信息做出相应响应动作，从而实现投影器6、辅助成像屏7和反射式几何全息屏11三者之间相对运动和/或整体运动，使得***的可视视窗始终覆盖用户的眼睛，使得用户在不同的方位都可以正常观看画面，需要说明的是支持结构8为一般现有技术，本领域的技术人员可以根据实际应用的空间条件自行设计，比如：使用一些铰链结构和类似于伞轴的结构可以非常容易的设计出可以变形的结构，这里不做具体限定；
如图17和图18，为了进一步提升***的灵活性，还可以在辅助成像屏7的一侧或者两侧设置光路折叠镜组12，光路折叠镜组12中至少包含一面反射镜，这样就可以对成像光路进行调整，使其能够适应各种应用空间场景。对于包含光路折叠镜组12的全息显示***，还可以通过支持结构9同时控制投影器6、辅助成像屏7、反射式几何全息屏11和光路折叠镜组12四者之间的进行相对或者整体运动从而实时调整，保证用户可以正常观看。
同样的，普通投影仪作为投影器时，具体对焦过程，也可以参见实施例二中相关的内容，本实施例中对此不作赘述。
以本发明采用一个投影器6为例进行说明：
如图14，投影器6与一个反射式几何全息屏11位于辅助成像屏7的同一侧，投影器6的投影光线部分经过辅助成像屏7的分光照射到反射式几何全息屏11上，经过反射式几何全息屏11的对光线的逆反射后，原方 向反射回并透过辅助成像屏7后，于辅助成像屏7的另一侧形成离屏的显示画面，人眼通过如图所示的视窗即可观看到；
如图15，投影器6与一个反射式几何全息屏11分别位于辅助成像屏7的两侧，投影器6的投影光线部分透过辅助成像屏7后照射到反射式几何全息屏11上，经过反射式几何全息屏11的对光线的逆反射后，原方向反射并经过辅助成像屏7的分光后，于空间内形成离屏的显示画面，人眼通过如图所示的视窗即可观看到；
从图14和图15的光路原理容易发现，当辅助成像屏7为半透半反膜时，光线的能量利用率只有1/4，为了提升光能利用率可以使用一些特殊的光学设计比如偏振+波片的方案，可以大幅度提升光能利用率，具体设计方案为本领域内一般的通识，这里不做赘述。此外，如图16所示，还可以采用两个反射式几何全息屏11的方案，即在辅助成像屏7两侧分别设置两个反射式几何全息屏11，这样可以有效提升***的光能利用率(提升一倍)和成像质量。
需要说明的，以上只是对本发明进行的举例说明，并不是对本发明的限定，对于投影器6为多个时，同样适用。
本发明所述的反射式几何全息显示***跟传统显示***相比有一个非常特殊的地方，它无法像传统2D显示器件一样可以供大量用户同时观看，为了方便表述，这里也引入视点的概念，具体可以参见实施例二中关于视点的说明，本实施例中对此不作详细说明。
本实施例中，以***中投影器6均采用普通投影仪，反射式几何全息 屏11均与投影器6位于辅助成像屏7的同一侧为例说明对应的显示***的效果；需要说明的是，在采用相同参数情况下，实施例1～实施例27的数据参数均可以参见实施例二中的表格，本实施例中对此不作详细说明，且得到的效果结论相同，因此，本实施例中不再赘述。
本发明实施例的显示原理：投影器6可以在空间不同深度处投射出画面，也就是可以为投影画面提供额外的景深信息，但是投影器6投出去的画面都是发散光，无法被人眼直接观看，这也是常规投影***必须要使用一个承接屏幕的原因。而本发明的反射式几何全息屏11具有使照射到其上的光线原路逆反射的功能。辅助成像屏7是一个具有分光功能的半透半反膜。这样，投影器6发出的光线照射到辅助成像屏7之后，部分光线被反射到反射式几何全息屏11上，由于反射式几何全息屏11的逆反射功能，光线会原路返回(或者近似原路返回)，返回的光线再次经过辅助成像屏7，并有部分光线透过辅助成像屏7在空中形成汇聚的离屏投影画面，此时，如果人眼处于投影器6相对于辅助成像屏的镜像位置时(人眼只有在投影器相对于辅助成像屏的镜像位置的一个很小的区域内才可以正常看到完整投影画面)，就可以观察到图像。
从本发明的显示原理分析可以发现，用户在使用时看到的画面完全跟投影器6投射出去的画面一致。投影器6投射出去的画面距离其最外侧镜片多远，用户看到的画面距离眼睛就多远。生活中，人眼的明视距离一般在25cm，观看最近的物体一般也在10cm之外，所以投影器6选择的时候可以优选投影焦深可以在距离投影镜头最外侧镜片外表面大于0.1m的空间内(如图6)调节的投影器(普通投影仪或者全息投影仪)。
与实施例二中不同的是，本实施例中的椭球区域具体如图24所示，椭球可视空间为所述可视空间是以每个投影器6镜头最外侧镜片中心为原点，以镜片中心外法线为Y轴方向，以过原点垂直于水平面的直线为X轴，以过原点垂直于X轴和Y轴的直线为Z轴的坐标系(X,Y,Z)经过光学转化后光学共轭坐标系(X′,Y′,Z′)下，满足以下关系式的空间：
Figure PCTCN2020110405-appb-000023
其中K为一个扩展常数，单位为dm，K范围为0<K<0.08；
m为共轭偏差常数，m范围为0≤m≤5。
其他内容，请参见实施例二所述。
与现有技术相比，本发明实施例四的优点在于：
1、通过引入具备调制任意角度的光线实现逆反射的反射式几何全息屏，对入射光线进行调制，省去了其他的光学模组，一定程度上节约了成本，缩小了***的占用空间；
2、本发明的显示***采用两个反射式几何全息屏，并分别设置于辅助成像屏的两侧，成像过程中没有非成像光束的干扰，从而大大提高成像质量，光源利用率高；
3、通过将支持支持结构设置为可变形或者运动的结构，从而实现投影器、辅助成像屏和反射式几何全息屏三者之间相对运动和/或整体运动，来实现动态显示；
4、合理的光学参数设置能够有效提高全息显示***的显示效果和可靠性。
本发明的实施例还可以进行各种简单演变，比如，还可以增加/使用偏 振膜和1/4玻片、增透膜、吸光膜等光学元件进一步提高光的利用率和显示效果，都涵盖在本发明的保护范围内。
需要说明的是，本说明书中的各个实施例均采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似的部分互相参见即可。
对所公开的实施例的上述说明，使本领域专业技术人员能够实现或使用本发明。对这些实施例的多种修改对本领域的专业技术人员来说将是显而易见的，本文中所定义的一般原理可以在不脱离本发明的精神或范围的情况下，在其它实施例中实现。因此，本发明将不会被限制于本文所示的这些实施例，而是要符合与本文所公开的原理和新颖特点相一致的最宽的范围。

Claims (36)

  1. 现场全息显示***，其特征在于：包括全息投影器(1)、投影屏(2)、交互响应单元(3)和处理器(4)；
    所述全息投影器(1)与投影屏(2)位置相互对应，所述全息投影器(1)用于在空间投影出具有深度信息的3D图像；
    所述投影屏(2)是具有把投影屏(2)一侧的像点汇聚到投影屏(2)另一侧形成共轭像点的屏幕，其用于把全息投影器(1)投影出的具有深度信息的3D图像转化到其共轭位置；
    所述全息投影器(1)和/或投影屏(2)上设有与处理器(4)连接的运动执行机构(5)，所述运动执行机构(5)用于控制全息投影器(1)和投影屏(2)之间的相对运动和/或整体运动；
    全息投影器(1)的镜头直径为D，投影屏(2)的水平方向最大长度为L，全息投影器(1)的重量为W，满足：
    Figure PCTCN2020110405-appb-100001
    所述交互响应单元(3)包括人眼跟踪单元(31)和交互动作捕捉单元(32)或只包括交互动作捕捉单元(32)，所述人眼跟踪单元(31)用于跟踪人眼(E)的位置并将人眼(E)的定位信息发送给处理器(4)，所述交互动作捕捉单元(32)用于识别用户的交互动作并将用户交互动作信息发送给处理器(4)，所述处理器(4)根据人眼(E)的定位信息和/或用户交互动作信息来控制***做出相应的响应；
    所述处理器(4)分别与全息投影器(1)、交互响应单元(3)和运动执行机构(5)电连接，所述处理器(4)发送投影数据信息给到全息投影器(1)，来控制全息投影器(1)的投影画面和画面深度。
  2. 根据权利要求1所述的一种现场全息显示***，其特征在于：所述投影屏(2)为负折射率平面透镜或等效负折射率平面透镜。
  3. 根据权利要求1所述的一种现场全息显示***，其特征在于：所述人眼跟踪单元(31)包括摄像机和红外距离探测器，所述摄像机利用图像识别技术识别人脸并且定位出人眼(E)的位置，所述红外距离探测器探测人眼(E)和投影屏(2)之间的距离。
  4. 根据权利要求1所述的一种现场全息显示***，其特征在于：所述全息投影器(1)的投射光包含红色、蓝色和绿色三元色光源。
  5. 透射式几何全息显示***，包括：
    显示元件(6)，用于在空间投影画面信息；
    透射式几何全息屏(7)，是具有把透射式几何全息屏(7)一侧的像点汇聚到其另一侧形成共轭像点的屏幕，其位置与显示元件(6)相对应，用于把显示元件(6)投影出的图像转化到相对透射式几何全息屏(7)的光学共轭位置；
    支持结构(8)，分别与显示元件(6)和透射式几何全息屏(7)相匹配，为二者提供物理结构支撑；
    控制器(9)，与显示元件(6)电连接，其特征在于：所述显示元件(6)采用至少一个、能够投影出二维画面的普通投影设备，其中，所述透射式几何全息显示***的视点数为n，所述显示元件(6)包含的普通投影设备最外侧镜片的透光部分直径的均值为D分米，所述显示元件(6)包含的普通投影设备投影光源功率的均值为P瓦，满足：
    Figure PCTCN2020110405-appb-100002
  6. 根据权利要求5所述的透射式几何全息显示***，其特征在于：所 述显示元件(6)包含的普通投影设备的显示光通量均值为L流明，其与所述透射式几何全息显示***的视点数n之间满足：
    n 1.27·L≤24000。
  7. 根据权利要求6所述的透射式几何全息显示***，其特征在于：所述透射式几何全息显示***的视点数n，所述显示元件(6)包含的普通投影设备最外侧镜片的透光部分直径的均值D分米以及所述显示元件(6)包含的普通投影设备的平均显示光通量L流明之间满足：
    Figure PCTCN2020110405-appb-100003
  8. 根据权利要求5～7任意一项所述的透射式几何全息显示***，其特征在于：所述显示元件(6)所采用的多个普通投影设备，可以使用能够实现三维画面或者分布在空间不同景深的二维画面组显示的投影设备替代。
  9. 根据权利要求1所述的透射式几何全息显示***，其特征在于：所述显示元件(6)的投影焦深在距离镜头的最外侧镜片0.1m以及0.1m以外的空间内可调。
  10. 根据权利要求1所述的透射式几何全息显示***，其特征在于：所述透射式几何全息屏(7)采用柔性全息屏。
  11. 根据权利要求1所述的透射式几何全息显示***，其特征在于：所述支持结构(8)为可以运动或者变形的结构，与控制器(9)电连接，所述控制器(9)能够控制支持结构(8)来实现显示元件(6)和透射式几 何全息屏(7)的相对运动和/或整体运动。
  12. 根据权利要求11所述的透射式几何全息显示***，其特征在于：还包括与控制器(9)电连接的交互动作捕捉单元(101)，所述交互动作捕捉单元(101)用于识别用户的交互动作并将用户交互动作信息发送给控制器(9)，所述控制器(9)根据接收到的交互动作捕捉单元(101)获取的用户交互动作信息调整显示画面内容。
  13. 根据权利要求12所述的透射式几何全息显示***，其特征在于：还包括与控制器(9)电连接的人眼跟踪单元(102)，所述人眼跟踪单元(102)用于跟踪人眼的位置并将人眼的定位信息发送给控制器(9)，所述控制器(9)根据接收到的人眼跟踪单元(102)获取的人眼定位信息，来控制支持结构(8)做出相应的动作响应，来调整显示元件(6)和透射式几何全息屏(7)的相对位置和/或整体空间位置，使用户眼睛始终处于***的可视空间内。
  14. 根据权利要求13所述的透射式几何全息显示***，其特征在于：所述可视空间是以显示元件(6)的每个投影设备最外侧镜片中心为原点，以镜片中心外法线为Y轴方向，以过原点垂直于水平面的直线为X轴，以过原点垂直于X轴和Y轴的直线为Z轴的坐标系(X,Y,Z)相对于透射式几何全息屏(7)的光学共轭坐标系(X′,Y′,Z′)下满足以下关系式的空间：
    Figure PCTCN2020110405-appb-100004
    其中K为一个扩展常数，单位为分米，K范围为0<K<0.08；
    m为共轭偏差常数，m范围为0≤m≤5。
  15. 折叠光路几何全息显示***，包括：
    至少一个投影器(6)，用于在空间投影画面信息；
    透射式几何全息屏(7)，是具有把透射式几何全息屏(7)一侧的像点会聚到其另一侧形成共轭像点的屏幕；
    支持结构(8)，分别与投影器(6)和透射式几何全息屏(7)相匹配，为二者提供物理结构支撑；
    控制器(9)，与投影器(6)电连接，其特征在于：还包括至少一个、设置于透射式几何全息屏(7)的一侧或者两侧且分别与支持结构(8)连接的光路折叠镜组(10)，所述光路折叠镜组(10)至少包含一面具有反射功能的平面镜，其用于改变投影器(6)投射光线的传播路径；
    其中，所述折叠光路几何全息显示***的视点数为n，所述投影器(6)最外侧镜片的透光部分直径的均值为D分米，所述投影器(6)投影光源功率的均值为P瓦，满足：
    Figure PCTCN2020110405-appb-100005
  16. 根据权利要求15所述的折叠光路几何全息显示***，其特征在于：所述投影器(6)的显示光通量的均值为L流明，与所述折叠光路几何全息显示***的视点数n之间满足：
    n 1.27·L≤24000。
  17. 根据权利要求16所述的折叠光路几何全息显示***，其特征在于：所述折叠光路几何全息显示***的视点数n与投影器(6)的显示光通量的均值L流明和投影器(6)最外侧镜片的透光部分直径的均值D分米之间满足：
    Figure PCTCN2020110405-appb-100006
  18. 根据权利要求15～17任意一项所述的折叠光路几何全息显示***，其特征在于：所述投影器(6)采用能够投影出二维画面的普通投影设备或者是能够投影出三维画面或者分布在空间不同深度的二维画面组的全息投影设备。
  19. 根据权利要求18所述的折叠光路几何全息显示***，其特征在于：所述投影器(6)的投影焦深在距离投影器(6)镜头的最外侧镜片0.1m以及0.1m以外的空间内可调。
  20. 根据权利要求15所述的折叠光路几何全息显示***，其特征在于：所述透射式几何全息屏(7)采用柔性全息屏。
  21. 根据权利要求15所述的折叠光路几何全息显示***，其特征在于：所述支持结构(8)为可以变形或者运动的结构，与控制器(9)电连接，所述控制器(9)能够控制支持结构(8)变形或者运动，从而实现投影器(6)、透射式几何全息屏(7)和光路折叠镜组(10)三者之间相对运动和/或整体运动。
  22. 根据权利要求21所述的折叠光路几何全息显示***，其特征在于： 还包括与控制器(9)电连接的交互动作捕捉单元(101)，所述交互动作捕捉单元(31)用于识别用户的交互动作并将用户交互动作信息发送给控制器(9)，所述控制器(9)根据接收到的交互动作捕捉单元(101)获取的用户交互动作信息调整显示画面内容。
  23. 根据权利要求22所述的折叠光路几何全息显示***，其特征在于：还包括与控制器(9)电连接的人眼跟踪单元(102)，所述人眼跟踪单元(102)用于跟踪人眼的位置并将人眼的定位信息发送给控制器(9)，所述控制器(9)根据接收到的人眼跟踪单元(102)获取的人眼定位信息，来控制支持结构(8)做出相应的动作响应，来调整投影器(6)和透射式几何全息屏(7)的相对位置和/或整体空间位置，使用户眼睛始终处于***的可视空间内。
  24. 根据权利要求23所述的折叠光路几何全息显示***，其特征在于：所述可视空间是以每个投影器(6)镜头最外侧镜片中心为原点，以镜片中心外法线为Y轴方向，以过原点垂直于水平面的直线为X轴，以过原点垂直于X轴和Y轴的直线为Z轴的坐标系(X,Y,Z)经过光学转化后光学共轭坐标系(X′,Y′,Z′)下，满足以下关系式的空间：
    Figure PCTCN2020110405-appb-100007
    其中K为一个扩展常数，单位为分米，K范围为0<K<0.08；
    m为共轭偏差常数，m范围为0≤m≤5。
  25. 反射式几何全息显示***，其特征在于,包括：
    至少一个投影器(6)，用于在空间投影出画面信息；
    辅助成像屏(7)，用于分光；
    一个位于辅助成像屏(7)一侧或者是两个分别位于辅助成像屏(7)两侧的反射式几何全息屏(11)；
    支持结构(8)，分别与投影器(6)、辅助成像屏(7)和反射式几何全息屏(11)相匹配，为三者提供物理结构支撑；
    控制器(9)，与投影器(6)电连接；
    其中，所述反射式几何全息显示***的视点数为n，所述投影器(6)最外侧镜片的透光部分直径的均值为D分米，所述投影器(6)投影光源功率的均值为P瓦，满足：
    Figure PCTCN2020110405-appb-100008
  26. 根据权利要求25所述的反射式几何全息显示***，其特征在于：所述投影器(6)的显示光通量的均值为L流明，与所述反射式几何全息显示***的视点数n之间满足：
    n 1.27·L≤24000。
  27. 根据权利要求26所述的反射式几何全息显示***，其特征在于：所述反射式几何全息显示***的视点数n与投影器(6)的显示光通量的均值L流明和投影器(6)最外侧镜片的透光部分直径的均值D分米之间满足：
    Figure PCTCN2020110405-appb-100009
  28. 根据权利要求25～27任意一项所述的反射式几何全息显示***，其特征在于：所述反射式几何全息屏(11)为柔性全息屏，其内部设有一系列横截面为直角三角形或者矩形和直角三角形组合的五边形的柱状基元棱镜(111)，所述柱状基元棱镜(111)内部、沿长度方向上设有若干相间排列的透明层(112)和反射层(113)，所述柱状基元棱镜(111)横截面包含的直角三角形的直角边所在的斜面上设置有一层反射膜(114)，用于对光线进行镜面反射；
    所述柱状基元棱镜(111)横截面为直角三角形或者矩形和直角三角形组合的五边形所包含的直角以及透明层(112)和反射层(113)与柱状基元棱镜(111)的长度方向所成角度的误差范围在±5°以内
  29. 根据权利要求28所述的反射式几何全息显示***，其特征在于：所述横截面为矩形和直角三角形组合的五边形的柱状基元棱镜(111)内，所述直角三角形部分的棱镜内部不含反射层(113)。
  30. 根据权利要求25所述的反射式几何全息显示***，其特征在于：还包含至少一个设置于辅助成像屏(7)的一侧或者两侧的光路折叠镜组(12)，用于调整光路。
  31. 根据权利要求25所述的反射式几何全息显示***，其特征在于：所述投影器(6)采用能够投影出二维画面的普通投影设备或者是能够投影出三维画面或者分布在空间不同景深处的二维画面组的全息投影设备。
  32. 根据权利要求31所述的反射式几何全息显示***，其特征在于：所述投影器(6)的投影焦深在距离投影器(6)镜头的最外侧镜片0.1m以及0.1m以外的空间内可调。
  33. 根据权利要求25所述的反射式几何全息显示***，其特征在于：所述支持结构(8)为可以变形或者运动的结构，与控制器(9)电连接，所述控制器(9)能够控制支持结构(8)变形或者运动，从而实现投影器(6)、辅助成像屏(7)和反射式几何全息屏(11)三者之间相对运动和/或整体运动。
  34. 根据权利要求33所述的反射式几何全息显示***，其特征在于：还包括与控制器(9)电连接的交互动作捕捉单元(101)，所述交互动作捕捉单元(101)用于识别用户的交互动作并将用户交互动作信息发送给控制器(9)，所述控制器(9)根据接收到的交互动作捕捉单元(101)获取的用户交互动作信息调整显示画面内容。
  35. 根据权利要求34所述的反射式几何全息显示***，其特征在于：还包括与控制器(9)电连接的人眼跟踪单元(102)，所述人眼跟踪单元(102)用于跟踪人眼的位置并将人眼的定位信息发送给控制器(9)，所述控制器(9)根据接收到的人眼跟踪单元(102)获取的人眼定位信息，来控制支持结构(8)做出相应的动作响应，来调整投影器(6)、辅助成像屏(7)和反射式几何全息屏(11)的相对位置和/或整体空间位置，使用户眼睛始终处于***的可视空间内。
  36. 根据权利要求35所述的反射式几何全息显示***，其特征在于： 所述可视空间是以投影器(6)镜头最外侧镜片中心为原点，以镜片中心外法线为Y轴方向，以过原点垂直于水平面的直线为X轴，以过原点垂直于X轴和Y轴的直线为Z轴的坐标系(X,Y,Z)经过一系列光学转化后光学共轭坐标系(X′,Y′,Z′)下，满足以下关系式的空间：
    Figure PCTCN2020110405-appb-100010
    其中K为一个扩展常数，单位为分米，K范围为0<K<0.08；
    m为共轭偏差常数，m范围为0≤m≤5。
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