WO2023225907A1 - 悬浮光学器件、光学模组及光学系统 - Google Patents

悬浮光学器件、光学模组及光学系统 Download PDF

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Publication number
WO2023225907A1
WO2023225907A1 PCT/CN2022/095000 CN2022095000W WO2023225907A1 WO 2023225907 A1 WO2023225907 A1 WO 2023225907A1 CN 2022095000 W CN2022095000 W CN 2022095000W WO 2023225907 A1 WO2023225907 A1 WO 2023225907A1
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Prior art keywords
convergence
layer
optical
light
focusing
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PCT/CN2022/095000
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English (en)
French (fr)
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任慧
张友明
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华为技术有限公司
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Priority to PCT/CN2022/095000 priority Critical patent/WO2023225907A1/zh
Publication of WO2023225907A1 publication Critical patent/WO2023225907A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays

Definitions

  • the present application relates to the field of display technology, and in particular to a suspended optical device, an optical module and an optical system.
  • Suspended display is a new type of display method that can show the shocking floating display effect in science fiction movies.
  • a common structure for realizing suspended display uses a set of optical elements as the suspended optical device 01 to image the light source image K in the air without a medium.
  • the resulting image is called a suspended image K’.
  • the suspended image is K’, there is no obstacle between it and the viewer, and the viewer can interact with the suspended image K’.
  • the viewer's physical location can overlap with the physical location of the suspended image. Taking the plane L0 where the floating optical device 01 is located as the axis of symmetry, the floating image K’ and the light source image K are symmetrically distributed.
  • the floating display device in the existing display technology has a large amount of light loss during the floating imaging process, which affects the imaging effect of the floating display.
  • This application provides a suspension optical device, an optical module and an optical system, which have less light loss during suspension imaging and can optimize the imaging effect of the suspension display.
  • the present application provides a suspension optical device that can be used for suspension display.
  • the suspended optical device includes a focusing layer, a transmission layer and a convergence layer sequentially stacked along the direction of the optical axis. This optical axis is the optical axis of the suspended optical device.
  • the transmission layer has an incident surface and an exit surface.
  • the focusing layer is disposed on one side of the incident surface of the transmissive layer, and is used to converge incident light onto the incident surface of the transmissive layer. After light enters the transmission layer from the incident surface, the transmission layer needs to modulate the light and guide it to the exit surface.
  • the convergence layer is disposed on one side of the exit surface of the transmission layer, and is used to guide the light emitted from the exit surface of the transmission layer into exit light.
  • the focusing layer, the transmission layer and the convergence layer cooperate to make the incident light and the outgoing light symmetrical about the transmission layer.
  • the focusing layer includes a plurality of focusing units that are periodically arrayed along a direction perpendicular to the optical axis.
  • the convergence layer includes a plurality of convergence units, and the plurality of convergence units are periodically arrayed along a direction perpendicular to the optical axis. Multiple focusing units and multiple convergence units correspond one to one.
  • the focusing unit can focus the incident light rays originating from the same pixel to the same incident convergence point on the incident surface of the transmission layer.
  • Light from the same pixel incident on the focusing unit corresponds to an incident convergence point.
  • the transmission layer can modulate the light from the incident convergence point on the incident surface to the exit convergence point on the exit surface in a one-to-one correspondence, and each incident convergence point corresponds to an exit convergence point.
  • the light rays from the exit convergence point on the exit surface enter the convergence unit, and the convergence unit can converge the light rays from the same exit convergence point into exit rays.
  • Each outgoing convergence point corresponds to a set of outgoing rays.
  • a first included angle is formed between the incident light ray and the incident surface of the transmission layer, and the first included angle is an acute angle.
  • a second included angle is formed between the emitted light ray and the emission surface of the transmission layer, and the second included angle is also an acute angle.
  • the opening at the first included angle and the opening at the second included angle face the same side of the optical axis, and the first included angle and the second included angle are equal in size.
  • the focusing layer can converge the incident light onto the incident surface of the transmissive layer, while the convergence layer can converge the light on the exit surface of the transmissive layer and emit it.
  • the light source image is imaged as a suspension in a symmetrical manner about the transmissive layer. image.
  • the light source image is composed of multiple pixels, and the light emitted by any pixel on the light source image can be incident on multiple focusing units as incident light.
  • the incident light rays and outgoing light rays corresponding to the corresponding focusing units and convergence units can be symmetrical about the transmission layer, so that the light rays emitted from multiple convergence units can form a pixel on the suspended image.
  • multiple pixels can form a suspended image, ensuring that the suspended image is the same as the light source image.
  • the loss of light can be controlled and the light efficiency of suspended imaging can be improved, thereby optimizing and improving the effect of suspended image display.
  • multiple focus units and multiple convergence units can be arranged symmetrically with respect to the transmission layer, that is, along the optical axis direction of the suspension optical device, multiple focus units and multiple convergence units correspond one to one. Therefore, between each group of corresponding focusing units and converging units, the optical center of the focusing unit and the optical center of the converging unit are aligned along the optical axis direction.
  • the incident light passes through the light processing of the focusing unit, the transmission layer and the convergence unit, and the resulting outgoing light will be symmetrical to the incident light with respect to the transmission layer.
  • the distance between the transmission layer and the focusing unit is equal to the distance between the transmission layer and the convergence unit, that is to say, the focusing unit and the convergence unit are symmetrical about the transmission layer.
  • Such a symmetrical structure is conducive to the realization of suspended display.
  • the transmission layer is located at 1-2 times the focal length of the focusing unit, and the transmission layer is located at 1-2 times the focal length of the convergence unit.
  • the limited position of the transmissive layer relative to the focusing unit can ensure that the focusing unit can converge the incident light rays originating from the same pixel to the same incident convergence point on the incident surface of the transmissive layer.
  • the limited position of the transmission layer relative to the convergence unit can ensure that the convergence unit can converge and export the light rays from the same exit convergence point on the exit surface of the transmission layer into a set of exit rays that are symmetrical to the above-mentioned incident light rays with respect to the transmission layer.
  • the focusing unit and the convergence unit can choose the same structure, the same material, or both the structure and the material.
  • the array period of the multiple focusing units is the same as the array period of the multiple convergence units. Possibly, the array period of the plurality of focusing units and the array period of the plurality of convergence units are both 0.3-1 mm. Wherein, the distance between the optical axes of any two adjacent focusing units is the array period of the focusing unit, and the distance between the optical axes of any two adjacent convergence units is the array period of the convergence unit.
  • the transmission layer includes a plurality of transmission units, the plurality of transmission units are periodically arrayed along the direction perpendicular to the optical axis, and the plurality of transmission units correspond to the plurality of focusing units one-to-one, then the plurality of transmission units are also There will be a one-to-one correspondence with multiple convergence units; among the corresponding focusing units, transmission units and convergence units, the focusing unit is used to modulate the incident light so that the incident light emitted by the same pixel converges on the incident surface of the transmission unit the same incident convergence point; the transmission unit can modulate the light from the incident convergence point to the exit convergence point on the exit surface of the transmission unit in a one-to-one correspondence; the convergence unit is used to modulate the light from the exit convergence point so that the same The light rays from the exit convergence point converge to the exit ray; the incident ray and the exit ray are symmetrical about the transmission unit.
  • Such a structural design can further accurately modulate the incident light, making the imaging of
  • the transmission unit may be a first optical structure with a beam deflection function.
  • the first optical structure may include any one or a combination of aspherical optical elements, metasurface optical elements, and diffractive optical elements.
  • the first optical structure is a metasurface optical element or a diffractive optical element
  • the first optical structure includes a first substrate and a first micro-nano structure disposed on the first substrate.
  • the focusing unit and the convergence unit may both be second optical structures with focusing imaging functions.
  • the second optical structure may specifically include any one or a combination of at least two of spherical optical elements, aspherical optical elements, metasurface optical elements, and diffractive optical elements.
  • the second optical structure is a metasurface optical element or a diffractive optical element
  • the second optical structure includes a second substrate and a second micro-nano structure disposed on the second substrate.
  • the above-mentioned first micro-nano structure and the second micro-nano structure are both micro-nano structures.
  • the micro-nano structure here is composed of at least two transparent media with different refractive indexes, which can modulate light to achieve the effect of light deflection.
  • the suspended optical device may also include an aperture.
  • the diaphragm can be specifically provided between the focusing layer and the transmission layer, between the transmission layer and the convergence layer, on the side of the focusing layer facing away from the transmission layer, or on the side of the convergence layer facing away from the transmission layer. The diaphragm is used to control the incident light amount and aberration of the suspended optical device imaging.
  • this application also provides an optical module, which includes a support member and any of the above-mentioned suspended optical devices.
  • the support member can provide support for the suspended optical device, so that the focusing layer, the transmissive layer and the convergent layer in the suspended optical device are sequentially stacked along the optical axis direction of the device.
  • the support will not affect the incidence and emission of light from the suspended optical device.
  • the present application also provides an optical system, which can be a light source image generator and any of the above-mentioned suspended optical devices.
  • the light source image generator is specifically arranged on the side of the focusing layer away from the transmission layer.
  • the light source image generator can generate a light source image.
  • the focusing layer, transmission layer, and convergence layer of the suspended optical device can process the light emitted by the light source image, and finally converge
  • the side of the layer away from the transmission layer is imaged as a suspended image, and the suspended image and the light source image are symmetrical about the transmission layer.
  • the light source image generator is a 2D image display or a 3D image display.
  • Figure 1 is a schematic diagram of the principle of a floating display in the prior art
  • Figure 2a is a schematic structural diagram of a suspension optical system in the prior art
  • Figure 2b is a schematic diagram of the principle of a beam splitter in a suspended optical system in the prior art
  • Figure 2c is a schematic diagram of the structure and principle of a retroreflector in a suspended optical system in the prior art
  • Figure 3a is a schematic structural diagram of a suspension optical system in the prior art
  • Figure 3b is a schematic diagram of the dihedral reflection structure of a suspended optical system in the prior art
  • Figure 3c is a schematic diagram of the dihedral reflection array principle of a suspended optical system in the prior art
  • Figures 4a and 4b are schematic structural diagrams of a suspended optical device provided by embodiments of the present application.
  • Figure 5a is a schematic structural diagram of a suspended optical device provided by an embodiment of the present application.
  • Figure 5b is a schematic structural diagram of a second optical structure in a suspended optical device provided by an embodiment of the present application.
  • Figures 6a and 6b are optical path diagrams of a group of unit structures in a suspended optical device provided by embodiments of the present application;
  • Figure 7 is an optical path diagram of a suspended optical device provided by an embodiment of the present application.
  • Figures 8a and 8b are optical path diagrams of a suspended optical device provided by embodiments of the present application.
  • Figures 9a to 9c are optical path diagrams of a suspended optical device provided by embodiments of the present application.
  • Figure 10 is a schematic structural diagram of a suspended optical device provided by an embodiment of the present application.
  • Figure 11 is an optical path diagram of a suspended optical device provided by an embodiment of the present application.
  • Figure 12 is a schematic structural diagram of a first optical structure in a suspended optical device provided by an embodiment of the present application.
  • Figure 13a is a schematic structural diagram of a suspended optical device provided by an embodiment of the present application.
  • Figure 13b is an optical path diagram of a suspended optical device provided by an embodiment of the present application.
  • Figures 14a to 14d are schematic structural diagrams of a suspended optical device provided by embodiments of the present application.
  • Figure 15a is a schematic structural diagram of an optical module provided by an embodiment of the present application.
  • Figure 15b is a schematic cross-sectional structural diagram of an optical module provided by an embodiment of the present application.
  • Figures 16a and 16b are schematic structural diagrams of an optical system provided by embodiments of the present application.
  • Suspension display technology can image in the air, allowing viewers to see images floating in the air.
  • the light emitted by the light source image K is processed by the levitation optical device to form a levitation image K'.
  • the ratio of the light energy of the finally formed levitation image K' to the light energy of the light source image K is the light efficiency of the levitation optical device.
  • a floating optical system is used.
  • the floating optical device used to realize floating display consists of a retroreflector 011 and a beam splitter 012.
  • the plane where the beam splitter 012 is located is L0, and the light source image K and the retroreflector 011 are arranged on the same side of the beam splitter 012. Among them, as shown in FIG.
  • the beam splitter 012 is a semi-transparent and half-reflecting mirror, which can half transmit and half reflect the incident light.
  • the microstructure array 0111 can be a micro-angled reflector (as shown in Figure 2c) or a micro-spherical reflector (not shown here).
  • the microstructure array 0111 can perform secondary reflection on part of the incident light (such as light b1 and light b2), so that the outgoing light and the incident light are parallel to each other and in opposite directions; the other part of the incident light (such as light b3) is micro-reflected Structure array 0111 is lost in one reflection.
  • the light source image generator 013 generates a light source image K within a certain viewing angle range.
  • the light ray a1 forming the light source image K is first incident on the spectroscope 012.
  • Half of the light ray a2 is transmitted and lost, and the other half of the light ray a2 is lost.
  • a3 is reflected by the beam splitter onto retroreflector 011.
  • the microstructure array 0111 on the retroreflector 011 modulates each incident light beam so that the exit direction of the modulated light beam is the same as the incident direction.
  • the light a4 that passes through the retroreflector 011 passes through the spectroscope 012 again.
  • the virtual image K' and the light source image K are symmetrical about the plane L0 where the beam splitter 012 is located. It can be seen from the optical path principle shown in Figure 2a that the light needs to pass through the beam splitter 012 twice, and half of the energy is lost each time.
  • the retroreflector 011 will also cause energy loss when modulating the light beam. Assume that the light energy of the light source image K is 100%, and the light energy after passing through the beam splitter 012 is 50%.
  • FIG. 3c illustrates another suspended optical system.
  • the suspended optical device used to realize suspended display consists of a dihedral corner reflector array (DCRA).
  • DCRA dihedral corner reflector array
  • the dihedral reflective array specifically includes a first mirror array 014 and a second mirror array 015 arranged orthogonally.
  • the first mirror array 014 and the second mirror array 015 can form countless square micro-reflector units (square micro-reflector, SMR) B.
  • the inner wall of each micro-reflective unit B is coated with reflective material.
  • the inner wall of the micro-reflective unit B can reflect the light c1 twice to make the direction of the outgoing light and the incident light symmetrical.
  • the light source image generator 013 generates a light source image K within a certain viewing angle range.
  • the light b1 emitted by the light source image K is incident on the dihedral reflector array, and a part of the light d1 occurs in the dihedral reflector array.
  • the outgoing light d2 is exactly symmetrical to the direction of the incident light b1; part of the incident light d3 directly penetrates the hollow micro-reflective unit B and is lost here (refer to Figure 3c Light c3), the remaining light is reflected once (refer to light c2 in Figure 3c) or multiple times in the dihedral reflection array, forming a ghost image or stray light.
  • the ghost image and stray light will interfere with the suspended image K' .
  • the manufacturing process of this kind of suspended optical device is complicated and has more light loss. Assume that the light energy of the light source image K is 100%, and the light passes through the dihedral reflector array.
  • embodiments of the present application provide a suspension optical device for improving the light efficiency of the suspension display.
  • an embodiment of the present application provides a floating optical device 10, which can be used for floating display.
  • the floating optical device 10 has an optical axis P, and the direction of the optical axis of the floating optical device 10 is the direction of the optical axis P.
  • the suspension optical device 10 includes a focusing layer 1, a transmission layer 2 and a convergence layer 3 stacked in sequence.
  • the transmission layer 2 has an incident surface e1 and an exit surface e2. That is, for the transmissive layer 2, the light will enter the transmissive layer 2 from the incident surface e1, and exit the transmissive layer 2 from the exit surface e2.
  • the plane where the transmission layer 2 is located is the first plane L1.
  • the focusing layer 1 is located on the light incident surface e1 side of the transmission layer 2, and the plane where the focusing layer 1 is located is the second plane L2.
  • the convergence layer 3 is located on the light exit surface e2 side of the transmission layer 2, and the plane where the convergence layer 3 is located is the third plane L3.
  • the first plane L1, the second plane L2, and the third plane L3 are all perpendicular to the optical axis P.
  • the focusing layer 1 can converge the incident light onto the incident surface e1 of the transmissive layer 2, while the converging layer 3 can converge and emit the light emitted from the exit surface e2 of the transmissive layer 2, and finally the light source image is reflected on the converging layer 3
  • the side away from the transmission layer 2 is imaged as a suspended image.
  • the focusing layer 1 includes a plurality of focusing units 11 .
  • the plurality of focusing units 11 are periodically arrayed along a direction perpendicular to the optical axis.
  • the plane where each focusing unit 11 is located is the second plane L2 .
  • the convergence layer 3 includes a plurality of convergence units 31.
  • the plurality of convergence units 31 are periodically arrayed along the direction perpendicular to the optical axis.
  • the plane where each convergence unit 31 is located is the third plane L3.
  • multiple focus units 11 and multiple convergence units 31 correspond one to one.
  • each focusing unit 11 has an optical axis
  • each convergence unit 31 also has an optical axis.
  • the optical axis of any focusing unit 11 is parallel to the optical axis P of the above-mentioned floating optical device 10, and the optical axis of any one convergence unit It is also parallel to the optical axis P of the above-mentioned floating optical device 10. Furthermore, in the focus unit 11 and the convergence unit 31 that correspond to each other, the optical axis of the focus unit 11 and the optical axis of the convergence unit 31 overlap.
  • the focusing unit 11 can focus the incident light onto the incident surface e1 of the transmissive layer 2 , and the converging unit 31 can converge the light on the exit surface e2 of the transmissive layer 2 and then emit it as an outgoing ray.
  • the outgoing light ray and the incident light ray are related to the transmissive layer 2 symmetry.
  • the focusing layer 1 and the convergence layer 3 are arranged symmetrically with respect to the transmission layer 2 . It is assumed that the distance between the plane L1 where the transmission layer 2 is located and the plane L2 where the focusing layer 1 is located is h1, the distance between the plane L1 where the transmission layer 2 is located and the plane L3 where the convergence layer 3 is located is h2, h1 and h2 are equal.
  • the transmissive layer 2 is disposed at 1-2 times the focal length of the focusing unit 11
  • the transmissive layer 2 is disposed at 1-2 times the focal length of the convergence unit 31 .
  • the transmissive layer 2 is located at 1 times the focal length of the focusing unit 11
  • the transmissive layer 2 is disposed at 1 times the focal length of the convergence unit 31 .
  • the array periods of the focusing unit 11 and the convergence unit 31 can be set to be the same, and their range can be 0.3-1 mm.
  • the distance between the optical axes of any two adjacent focusing units 11 is the array period of the focusing unit 11 . It can be inferred that the distance between the optical axes of any two adjacent convergence units 31 is the array period of the convergence units 31 .
  • two groups of focusing units 11 and convergence units 31 corresponding to each other are taken as an example for explanation.
  • the optical axis of the focusing unit 11 and the optical axis of the converging unit 31 are collinear and are set as the optical axis S1.
  • the optical axis of the focusing unit 11 and the optical axis of the converging unit 31 are collinear and are set as the optical axis S2.
  • the optical axis S1 and the optical axis S2 are respectively parallel to the optical axis P of the floating optical device 10, and the distance between the optical axis S1 and the optical axis S2 is the array period H, that is to say, the array period of the focusing unit 11 and the convergence unit 31 All are H, and the value range of H is 0.3-1mm.
  • the array period can be 0.4mm, 0.6mm, 0.9mm.
  • the focusing unit 11 and the convergence unit 31 are both first optical structures with focusing imaging functions.
  • the first optical structure is a microlens
  • the focusing layer 1 is equivalent to a microlens array
  • the convergence layer 3 is also a microlens array.
  • the first optical structure may be any one of a spherical optical element, an aspherical optical element, a metasurface optical element, a diffractive optical element, or a combination of at least two of these optical elements.
  • both the focusing unit 11 and the converging unit 31 are spherical optical elements.
  • the production technology of spherical optical elements is relatively mature and has been used in various technical fields of industry and scientific research. Optical components with other surface types can also be mass-produced using semiconductor processes or nanoimprint processes. Therefore, the processing achievability of the focusing unit 11 and the convergence unit 31 is relatively high, which is beneficial to cost reduction.
  • the focusing unit 11 and the convergence unit 31 try to select materials with higher light transmittance, such as photoresist.
  • the focusing unit 11 and the converging unit 31 may have the same structure or the same material, or may have the same structure and material.
  • the second optical structure when the second optical structure is a metasurface optical element or a diffractive optical element, as shown in FIG. 5b , the second optical structure includes a second substrate 41 and a second substrate 41 disposed on the second substrate.
  • the second substrate 41 may specifically be an inorganic transparent material (such as silicon dioxide, silicon carbide), or an organic material (such as polymethylmethacrylate, photoresist).
  • the second micro-nano structure 42 here is composed of at least two transparent media with different refractive indexes, examples here are the first medium 421 and the second medium 422 .
  • the first medium 421 is polymethyl methacrylate (PMMA), and the second medium 422 is air.
  • the first micro-nano structures 42 have micron or nanoscale feature sizes and are arranged in an array in a specific manner.
  • the second micro-nano structure 42 is a sub-wavelength unit.
  • the distance between any two points on the cross section of each second micro-nano structure 42 is smaller than the wavelength of the incident light.
  • the distance between any two adjacent second micro-nano structures 42 is smaller than the wavelength of the incident light, so that the second micro-nano structure 42 can phase modulate the incident light, thereby achieving the effect of deflecting the light path.
  • the focusing units 11 , convergence units 31 , and transmission layer 2 that correspond to each other are set as a set of unit structures. Since the focusing unit 11 is small enough and the pixel is far enough away from the focusing unit 11, the incident light M1 among the light emitted by the pixel that can be incident on the focusing unit 11 is approximately parallel. As shown in Figure 6a. A beam of light originating from the same pixel (for convenience of illustration, here the examples of light rays originating from the same pixel are parallel to each other) are used as incident light M1, incident from one side of the focusing unit 11.
  • the focusing unit 11 modulates the incident light M1 so that the incident light M1 converges to the same incident convergence point O1 on the incident surface e1 of the transmission layer 2 and enters the transmission layer 2 from the incident convergence point O1.
  • the transmission layer 2 modulates the light incident on the convergence point O1, and modulates this part of the light to the exit convergence point O2 on the exit surface e2 of the transmission layer 2.
  • the light rays emit from the exit convergence point O2 and then diverge into the convergence unit 31.
  • the convergence unit 31 modulates the light rays emitted from the exit convergence point O2 so that the light rays can exit from the convergence unit 31 in an approximately parallel state.
  • the light emitted from the self-converging unit 31 is the outgoing light M2, and the outgoing light M2 and the incident light M1 are symmetrical with respect to the transmission layer 2 .
  • the incident light M1 includes the light m11, the light m12, and the light m13.
  • the light m11 After passing through the focusing unit 11, the transmission layer 2, and the convergence unit 31, the light m11 emerges as the light m21.
  • the transmission layer 2, and the convergence unit 31 After passing through the focusing unit 11, the transmission layer 2, and the convergence unit 31, the light m12 emerges as the light m22.
  • the transmission layer 2, and the convergence unit 31 the light m13 emerges as the light m23.
  • the light m21, the light m22, and the light m23 form the outgoing light M2, and the light m23, the light m22, and the light m21 are arranged in sequence.
  • a set of parallel incident rays form an outgoing ray after passing through the focusing unit 11 , the transmission layer 2 , and the convergence unit 31 .
  • the direction of the outgoing light ray is symmetrical to the direction of the incident light ray with respect to the transmission layer 2 .
  • along the The sequence of rays represents the information the rays carry. Since the focusing unit 11 is small enough, when the pixel size on the light source image is larger than the focusing unit 11, the information carried by the incident light M1 is the information of the same pixel.
  • Preliminary pixel inversion processing can avoid inversion of the outgoing information content. All in all, in the embodiment of the present application, the focusing unit 11 of the periodic array and the convergence unit 31 of the periodic array, combined with the transmission layer 2, can image the information of the same pixel into the suspended image at the same time in a symmetrical manner with respect to the transmission layer 2. One pixel achieves the effect of floating imaging.
  • the incident light M1 from one pixel is an example of a set of parallel lights
  • the incident light M1' from another pixel is another set of parallel lights.
  • the incident light The directions of M1 and incident light M1' are different.
  • the incident light M1 and the incident light M1' are incident from one side of the focusing unit 11, and the focusing unit 11 modulates the incident light M1 so that the incident light M1 originating from a pixel converges to the same incident convergence on the incident surface e of the transmission layer 2 point O1, and enters the transmission layer 2 from the incident convergence point O1.
  • the focusing unit 11 modulates the incident light M1', so that the incident light M1' originating from another pixel converges to the same incident convergence point O1' on the incident surface e of the transmission layer 2, and enters transmission from the incident convergence point O1 Layer 2.
  • the transmission layer 2 modulates the light incident on the convergence point O1, and modulates this part of the light to the exit convergence point O2 on the exit surface e2 of the transmission layer 2.
  • the transmission layer 2 modulates the light incident on the convergence point O1', so that this part of the light converges to the exit convergence point O2' on the exit surface e2 of the transmission layer 2.
  • the light rays emit from the exit convergence point O2 and then diverge into the convergence unit 31.
  • the convergence unit 31 modulates the light rays emitted from the exit convergence point O2 so that the light rays can be emitted from the convergence unit 31 in an approximately parallel state (i.e., the exit light ray M2).
  • the outgoing light ray M2 and the incident light ray M1 are symmetrical with respect to the transmission layer 2 .
  • the light rays emit from the exit convergence point O2' and then diverge into the convergence unit 31.
  • the convergence unit 31 modulates the light rays emitted from the exit convergence point O2' so that the light rays can self-converge in a state of being approximately parallel to each other (i.e., the exit light ray M2'). 31 shot.
  • the direction of the outgoing light ray M2’ is symmetrical to the direction of the incident light ray M1’ with respect to the transmission layer 2.
  • the focusing layer 1 is composed of a plurality of focusing units 11 in a periodic array
  • the convergence layer 3 is also composed of a plurality of convergence units 31 in a periodic array.
  • FIG. 7 for each group of corresponding focusing units 11 and convergence units 31 , it can be considered that each group of corresponding groups of focusing units 11 and convergence units 31 can combine with the transmission layer 2 to process a certain part of the incident light into outgoing light.
  • the direction of the outgoing light ray and the direction of the incident light ray are symmetrical with respect to the transmission layer 2 .
  • the corresponding focusing unit 11 and the converging unit 31 can levitate and display sufficiently small light, for example, the light of a point can be levitated and displayed as a levitating point. , it can be considered that the outgoing light ray and the incident light ray are symmetrical with respect to the transmission layer 2 .
  • the levitation optical device 10 is applied to the levitation display.
  • the light source image A is a 2D image.
  • the light source image A is composed of countless pixels, and each pixel emits a wide beam at a certain angle.
  • a pixel Q on the light source image A emits a wide beam F at the illustrated angle.
  • the wide beam F can be viewed as consisting of numerous thin beams f in various directions.
  • Each thin beam f is incident on the floating optical device 10, and is processed by the focusing layer 1, the transmission layer 2 and the convergence layer 3 in sequence, and then emerges as a wide beam F' composed of multiple thin beams f'.
  • the wide beam F' is concentrated into the floating optical device 10.
  • pixel Q' and pixel Q are symmetrical with respect to the transmission layer 2 .
  • one thin beam f in the incident light corresponds to a group of corresponding focusing units 11 and convergence units 31 .
  • the light of the thin beam f is first converged by the focusing unit 11.
  • the transmission layer 2 performs specific deflection modulation on the light, and modulates the light to the same exit convergence point on the exit surface e2 of the transmission layer 2 (not shown here).
  • the light emitted from the same exit convergence point is modulated again by the convergence unit 31, and finally the light emitted from the convergence unit 31 returns to approximately parallel beams, and these beams can be regarded as thin beams f'.
  • the thin beam f’ and the thin beam f are symmetrical with respect to the transmission layer 2.
  • All the thin beams f’ form the wide beam F shown in Figure 8a, which corresponds to converging to a point in the air, which is the suspended pixel Q’ in the suspended image A’.
  • Countless pixels such as pixel Q’ form the suspended image A’.
  • the light source image A is a 2D image
  • the suspended image A' formed through the floating optical device 10 is also a 2D image.
  • the levitation optical device 10 provided by the embodiment of the present application can levitate any point on the light source image A in a symmetrical manner (symmetrical with respect to the transmission layer 2) into a levitation image A'.
  • the light source image B is a 3D image.
  • the light source image B is composed of countless light source pixels.
  • Each pixel on the light source image B emits a wide beam at a certain angle.
  • the pixel R on the light source image B emits a wide beam G at the illustrated angle.
  • the wide beam G can be viewed as consisting of numerous thin beams g in various directions.
  • Each thin beam g is incident on the floating optical device 10, and is processed by the focusing layer 1, the transmission layer 2 and the convergence layer 3 in sequence, and then emerges as a wide beam G' composed of multiple thin beams g'.
  • the wide beam G' is concentrated into the floating optical device 10.
  • pixel R' of image B' pixel R' and pixel R are symmetrical with respect to the transmission layer 2 .
  • Countless pixels such as pixel R’ form a suspended image B’.
  • the optical path principle of the thin beam g being processed by the focusing layer 1, the transmission layer 2 and the convergence layer 3 can be referred to as shown in Figure 8b, and will not be described again here.
  • a thin beam g in the example incident light corresponds to a group of corresponding focusing units 11 and convergence units 31 .
  • the light of the thin beam f is first converged by the focusing unit 11.
  • the transmission layer 2 performs specific deflection modulation on the light, and modulates the light to the same exit convergence point on the exit surface e2 of the transmission layer 2 (not shown here).
  • the light emitted from the same exit convergence point is modulated again by the convergence unit 31, and finally the light emitted from the convergence unit 31 returns to approximately parallel beams, and these beams can be regarded as thin beams g'.
  • the thin beam g' and the thin beam g are symmetrical with respect to the transmission layer 2. All the thin beams g’ form the wide beam F shown in Figure 9b, which corresponds to converge to a point in the air, which is the suspended pixel R’ in the suspended image B’. Countless pixels such as pixel R’ form a suspended image B’.
  • the transmission layer 2 includes a plurality of transmission units 21.
  • the plurality of transmission units 21 are periodically arrayed along the direction perpendicular to the optical axis.
  • the plane of each transmission unit 21 is the first plane L1.
  • the first plane L1 can be shown in Figure 4a.
  • multiple transmission units 21 , multiple focus units 11 , and multiple convergence units 31 correspond one to one.
  • the focusing layer 1 shows five focusing units 11
  • the convergence layer 3 shows five convergence units 31
  • the transmission layer 2 shows five transmission units 21 .
  • one focusing unit 11 corresponds to one convergence unit 31
  • one focusing unit 11 also corresponds to one transmission unit 21 .
  • each focusing unit 11 has an optical axis
  • each converging unit 31 also has an optical axis
  • each transmission unit 21 also has an optical axis.
  • the optical axis of any focusing unit 11 is parallel to the optical axis P of the above-mentioned floating optical device 10
  • the optical axis of any one converging unit 31 is also parallel to the optical axis P of the above-mentioned floating optical device 10
  • the optical axis of any one transmission unit 21 is also parallel to the optical axis P of the above-mentioned floating optical device 10. Parallel to the optical axis P of the above-mentioned floating optical device 10.
  • the optical axis of the focus unit 11 the optical axis of the transmission unit 21 , and the optical axis of the convergence unit 31 overlap.
  • Such a structural design can further refine the incident light, making the imaging of suspended images more accurate and reducing the occurrence of stray light and interference light.
  • the array periods of the focusing unit 11 , the transmission unit 21 , and the convergence unit 31 can be set to be the same, and the range of the array period can be 0.3-1 mm.
  • the distance between the optical axes of any two adjacent focusing units 11 is the array period of the focusing unit 11 .
  • two groups of corresponding focusing units 11 , transmission units 21 , and convergence units 31 are used as an example for explanation.
  • the optical axis of the focus unit 11, the transmission unit 21, and the convergence unit 31 are collinear and are set as the optical axis S1.
  • the optical axis of the focus unit 11, the transmission unit 21, and the convergence unit 31 are collinear and are set as the optical axis S2.
  • the distance between the optical axis S1 and the optical axis S2 is the array period H. That is to say, the array periods of the focusing unit 11, the transmission unit 21, and the convergence unit 31 are all H, and the value range of H is 0.3-1 mm. For example, H is selected as 0.4mm, 0.6mm or 0.9mm.
  • the focusing unit 11 can focus the incident light onto the incident surface e1 of the transmissive layer 2, and the convergence unit 31 can converge the light on the exit surface e2 of the transmissive layer 2 and then emit it as an outgoing light.
  • the optical path principle can be referred to As shown in Figure 11.
  • transmission unit 21, and convergence unit 31 it can be considered that each group of corresponding focusing unit 11, transmission unit 21, and convergence unit 31 processes a certain part of the incident light into an exit light, and the exit light
  • the direction is symmetrical to the direction of incident light with respect to the transmissive layer 2 .
  • the corresponding focusing unit 11, the transmitting unit 21, and the converging unit 31 can levitate and display sufficiently small light, for example, levitate and display the light of a point. is a suspended point. From a macro perspective, the opposite display between the image of the outgoing ray and the image of the incident ray is negligible. Therefore, it can be considered that the outgoing ray and the incident ray are symmetrical about the transmission layer 2 .
  • the transmission unit 21 is a first optical structure with a beam deflection function. Therefore, the transmissive layer 2 corresponds to the first optical structure array.
  • the first optical structure may be any one of an aspherical optical element, a metasurface optical element, a diffractive optical element, or a combination of at least two of these optical elements.
  • the first optical structure is a metasurface optical element or a diffractive optical element, its structure may be as shown in FIG. Nanostructure52.
  • the first substrate 51 may be an inorganic transparent material (such as silicon dioxide, silicon carbide), or an organic material (such as polymethylmethacrylate, photoresist).
  • the first micro-nano structure 52 here is composed of at least two transparent media with different refractive indexes, and examples here are the third medium 521 and the fourth medium 522 .
  • the third medium 521 is polymethyl methacrylate (PMMA), and the fourth medium 522 is air.
  • the first micro-nano structure 52 has micron or nanoscale feature sizes and is arranged in an array in a specific manner. Taking the metasurface type as an example, the first micro-nano structure 52 is a sub-wavelength unit. Along the horizontal plane where the first substrate 51 is located, the distance between any two points on the cross section of each first micro-nano structure 52 is smaller than the wavelength of the incident light. Moreover, the distance between any two adjacent first micro-nano structures 52 is smaller than the wavelength of the incident light, so that the first micro-nano structure 52 can phase modulate the incident light, thereby achieving the effect of deflecting the light path.
  • the plurality of focusing units 11 and the plurality of convergence units 31 correspond one to one along the optical axis direction.
  • the suspended image formed after the incident light is processed by the floating optical device 10 and the light source image are symmetrical with respect to the transmission layer 2 .
  • the optical axis T1 of the focus unit 11 and the optical axis T3 of the convergence unit 31 are along a vertical direction.
  • the optical path diagram of the incident light ray and the outgoing light ray can be shown in Figure 13b.
  • the optical axis T3 of the converging unit 31 has an offset of z relative to the optical axis T1 of the focusing unit 11 .
  • a beam of light originating from the same pixel for convenience of illustration, here the examples of light originating from the same pixel are parallel to each other
  • the included angle ⁇ 1 is an acute angle, and the opening of the first included angle ⁇ 1 faces the left side of the device structure in the figure.
  • the incident light M1 is incident from one side of the focusing unit 11, and the focusing unit 11 modulates the incident light M1 so that the incident light M1 converges to the same incident convergence point O1 on the incident surface e1 of the transmission layer 2, and exits from the incident convergence point O1 enters the transmission layer 2.
  • the transmission layer 2 modulates the light incident on the convergence point O1, and modulates this part of the light to the exit convergence point O2 on the exit surface e2 of the transmission layer 2.
  • the light rays emit from the exit convergence point O2 and then diverge into the convergence unit 31.
  • the convergence unit 31 modulates the light rays emitted from the exit convergence point O2 so that the light rays can exit from the convergence unit 31 in an approximately parallel state.
  • the light emitted from the convergence unit 31 is the exit light M2, and a second included angle ⁇ 2 is formed between the exit light M2 and the surface of the convergence unit 31 away from the transmission layer 2.
  • the second included angle ⁇ 2 is also an acute angle.
  • the second included angle ⁇ 2 is also an acute angle, and the opening of the second included angle ⁇ 2 is also facing the left side of the device structure in the figure. Taking the optical axis P as a reference, it can be considered that the opening at the first included angle ⁇ 1 and the opening at the second included angle ⁇ 2 face the same side of the optical axis P.
  • the second included angle ⁇ 2 is equal to the first included angle ⁇ 1.
  • the incident light M1 and the outgoing light M2 may have a certain positional offset in the direction of the optical axis, from the perspective of light waves and carrying the same information, the information of the incident light M1 and the outgoing light M2 is exactly the same, and the same pixel can be The information is imaged to the same pixel of the suspended image to achieve the effect of suspended imaging.
  • embodiments of the present application also provide a suspended optical device 10 with an aperture 6.
  • the diaphragm 6 can be arranged on the side of the convergence layer 3 facing away from the transmission layer 2 as shown in Figure 14a; the diaphragm 6 can also be arranged on the side of the focusing layer 1 facing away from the transmission layer 2 as shown in Figure 14b; Diaphragm 6 can also be provided between the convergence layer 3 and the transmission layer 2 as shown in Figure 14c; the diaphragm 6 can also be provided between the transmission layer 2 and the focusing layer 1 as shown in Figure 14d.
  • the existence of the diaphragm 6 can control the light passing through the floating optical device 10 , that is to say, the diaphragm 6 is used to control the incident light amount and aberration of the imaging of the floating optical device 10 .
  • the setting position of the diaphragm 6 does not affect its functional realization.
  • the suspension optical device 10 when the suspension optical device 10 provided by the embodiment of the present application is applied to a suspension display, the light emitted by each pixel on the light source image can be incident on different focusing units 11 of the focusing layer 1 , and each focusing unit 11
  • the incident light can be modulated so that the incident light coming from the same pixel can converge to the same incident convergence point on the incident surface e1 of the transmission layer 2, and the incident light coming from the same pixel corresponds to an incident convergence point.
  • the transmission layer 2 can modulate the light from the same incident convergence point on the incident surface e1 to the exit convergence point on the exit surface e2.
  • Each convergence unit 31 can modulate the light rays from the outgoing convergence point, so that the light rays from the same outgoing convergence point can converge into approximately mutually parallel outgoing rays, and each group of approximately mutually parallel outgoing rays corresponds to one exit convergence point.
  • the periodic array structure of the focusing unit 11 and the periodic array structure of the convergence unit 31 can process the light of each pixel on the light emitted by the light source image, so that the outgoing light can exit symmetrically with the incident light about the transmission layer 2 Light can form a suspended image, ensuring that the suspended image has the same information as the light source image.
  • the outgoing light rays and the incident light rays can be symmetrical with respect to the transmission layer 2 .
  • the loss of light can be controlled and the light efficiency of suspension imaging can be improved, thereby optimizing and improving the clarity and contrast of the suspension image display.
  • the optical module 100 includes a support 20 and any of the suspended optical devices 10 provided in the above embodiments.
  • the floating optical device 10 here is exemplified as a circular shape.
  • the support member 20 is annular and has a hollow in the middle.
  • the floating optical device 10 is disposed at the hollow position in the middle of the supporting member 20 . That is, the supporting member 20 provides support for the floating optical device 10 from the circumferential edge of the floating optical device 10 , and the middle part of the supporting member 20 The hollowing out will not affect the entrance and exit of light.
  • Figure 15b shows a schematic cross-sectional structural diagram of the optical module 100.
  • the circumferential edges of the focusing layer 1, the transmission layer 2 and the convergence layer 3 in the suspension optical device 10 are all fixed to the support 20.
  • the focusing layer 1, the transmission layer 2 and The convergence layers 3 are sequentially stacked along the direction of the optical axis P.
  • the optical system includes a light source image generator 200 and any one of the above optical modules 100.
  • the light source image generator 200 is disposed on the side of the focusing layer 1 of the floating optical device 10 away from the transmission layer 2.
  • the light source image A generated by the light source image generator can be formed by passing through the focusing layer 1, the transmission layer 2, and the convergence layer 3 in sequence. Hover image.
  • This optical system has many application scenarios, including but not limited to public places such as elevators, restaurants, and banks, as well as private places such as private cars and home desktops.
  • the optical system is applied to button suspension displays in public places, which can achieve contactless interaction and has the advantages of safer, more hygienic and more privacy.
  • this optical system is applied to virtual decorations of private cars or on-board elf suspension displays, it will bring a more shocking, cooler and more personalized experience.
  • this optical system is applied to a home desktop suspension display, the three-dimensional suspension display and zero-distance interactive operation can increase the gaming experience and fun, and realize the naked-eye virtual and real fusion function.
  • the light source image generator 200 is a 2D image display, such as a liquid crystal display (LCD), an organic light-emitting diode (OLED) screen, or a projection screen.
  • the light source image generator generates Light source image A is a 2D image.
  • the light source image A is composed of countless pixels, and each pixel emits a wide beam of light at a certain angle.
  • a pixel Q on the light source image A emits a wide beam F at the illustrated angle.
  • the wide beam F can be viewed as consisting of numerous thin beams f in various directions.
  • Each thin beam f is incident on the suspension optical device 10, and is processed by the focusing layer 1, the transmission layer 2 and the convergence layer 3 in sequence, and then emerges as a wide beam F' composed of multiple thin beams f'.
  • the wide beam F' is concentrated into the suspension.
  • pixel Q' of image A' pixel Q' and pixel Q are symmetrical with respect to the transmission layer 2 .
  • Countless pixels such as pixel Q’ form the suspended image A’.
  • the processing of countless thin beams f by the focusing layer 1, the transmission layer 2 and the convergence layer 3 can be referred to FIG. 8b, and will not be described again here.
  • the light source image generator 200 is a 3D image display, and the light source image B generated by the light source image generator 20 is a 3D image.
  • the light source image B is composed of countless pixels, and each pixel on the light source image B emits a wide beam of light at a certain angle.
  • the pixel R on the light source image B emits a wide beam G at the illustrated angle.
  • the wide beam G can be viewed as consisting of numerous thin beams g in various directions. Each thin beam g is incident on the floating optical device 10, and is processed by the focusing layer 1, the transmission layer 2 and the convergence layer 3 in sequence, and then emerges as a wide beam G' composed of multiple thin beams g'.
  • the wide beam G' is concentrated into the floating optical device 10.
  • pixel R' of image B' pixel R' and pixel R are symmetrical with respect to the transmission layer 2 .
  • Countless pixels such as pixel R’ form a suspended image B’.
  • the optical path principle of the thin beam g being processed by the focusing layer 1, the transmission layer 2 and the convergence layer 3 can be referred to as shown in Figure 8b, and will not be described again here.
  • the optical system provided by the embodiment of the present application can image the image (including 2D image and 3D image) produced by the light source image generator into a levitation image through the transmission of the levitation optical device 10 , and the brightness, clarity, and contrast of the floating image are relatively high, which can achieve a better floating display effect.

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Abstract

本申请提供了一种悬浮光学器件、光学模组及光学系统，用于悬浮显示。该悬浮光学器件包括沿光轴的方向依次叠置的聚焦层、透射层和收敛层；聚焦层包括多个周期性阵列聚焦单元，收敛层包括多个周期性阵列的收敛单元，多个聚焦单元和多个收敛单元沿光轴的方向一一对应；在相互对应的聚焦单元和收敛单元中，聚焦单元用于对入射光线进行调制，以使相互平行的入射光线汇聚到透射层的入射面上的同一个入射汇聚点；透射层将入射汇聚点的光线一一对应地调制到透射层的出射面上的出射汇聚点；收敛单元用于对出射汇聚点的光线进行调制，以使同一个出射汇聚点的光线收敛为相互平行的出射光线。该悬浮光学器件在悬浮成像时光损耗较小。

Description

悬浮光学器件、光学模组及光学系统 技术领域
本申请涉及显示技术领域，尤其涉及到一种悬浮光学器件、光学模组及光学系统。
背景技术
悬浮显示是一种新型的显示方式，可以展现出科幻电影中震撼的浮空式显示效果。如图1所示的一种实现悬浮显示的常见结构，利用一组光学元件作为悬浮光学器件01，对光源图像K在空气中无介质成像，所成图像称为悬浮图像K’。其中，悬浮图像为K’，与观看者之间没有任何障碍物，观看者可以与悬浮图像K’进行交互。此处，观看者的物理位置可以与悬浮图像的物理位置重叠。以悬浮光学器件01所在平面L0为对称轴，悬浮图像K’和光源图像K呈对称分布。
现有显示技术中的悬浮显示器件的悬浮成像过程中光损耗较多，影响悬浮显示的成像效果。
发明内容
本申请提供了一种悬浮光学器件、光学模组及光学系统，在悬浮成像时光损耗较小，能够优化悬浮显示的成像效果。
第一方面，本申请提供一种可以用于悬浮显示的悬浮光学器件。该悬浮光学器件包括沿光轴的方向依次叠置的聚焦层、透射层和收敛层。该光轴为悬浮光学器件的光轴。参照光线的走向，透射层具有入射面和出射面。聚焦层设置于透射层的入射面一侧，用于将入射光线汇聚到透射层的入射面上。光线自入射面进入透射层后，透射层需要对光线进行调制，并导向出射面。收敛层设置于透射层的出射面一侧，用于将透射层出射面射出的光线导出为出射光线。在光线的传递过程中，聚焦层、透射层以及收敛层配合使得入射光线和出射光线关于透射层对称。为了达到这一效果，聚焦层包括多个聚焦单元，多个聚焦单元沿垂直于光轴方向周期性阵列。对应地，收敛层包括多个收敛单元，多个收敛单元沿垂直于光轴方向周期性阵列。多个聚焦单元和多个收敛单元一一对应。在一组相互对应的聚焦单元和收敛单元中，聚焦单元可以将入射光线中源自同一个像素的光线聚焦到透射层的入射面上的同一个入射汇聚点。源自同一个像素的光线入射到该聚焦单元上对应一个入射汇聚点，当光源图像的光线具有多个方向的光线时，入射面上的入射汇聚点将会有多个。透射层可以将入射面上的入射汇聚点的光线一一对应地调制到出射面上的出射汇聚点，每个入射汇聚点对应一个出射汇聚点。出射面上的出射汇聚点的光线进入收敛单元，收敛单元可以将同一个出射汇聚点的光线收敛为出射光线。每个出射汇聚点对应一组出射光线。入射光线与透射层的入射面之间形成第一夹角，该第一夹角为锐角。出射光线与透射层的处射面之间形成第二夹角，该第二夹角也为锐角。其中，第一夹角的开口与第二夹角的开口朝向光轴的同一侧，且第一夹角和第二夹角大小相等。
在应用中，聚焦层可以将入射光线汇聚到透射层的入射面上，而收敛层则可以将透射层的出射面上的光线收敛出射，最终将光源图像以关于透射层对称的方式成像为悬浮图像。光源图像由多个像素组成，光源图像上任意一个像素发出的光线可以作为入射光线入射到 多个聚焦单元上。相互对应的聚焦单元、收敛单元所对应的入射光线和出射光线可以关于透射层对称，从而，自多个收敛单元出射的光线能够形成悬浮图像上的一个像素。最终，多个像素可以组成悬浮图像，保证悬浮图像与光源图像相同。在整个光线传输过程中，除了器件材料的透过率对光的损耗之外，基本无其他损耗。因此，只要保证器件的高透过率，即可控制光的损耗，提高悬浮成像的光效率，从而优化提高悬浮图像显示的效果。
其中，可以将多个聚焦单元和多个收敛单元设置为关于透射层对称，即沿悬浮光学器件的光轴方向，多个聚焦单元和多个收敛单元一一对应。使得每一组相互对应的聚焦单元和收敛单元之间，聚焦单元的光学中心与收敛单元的光学中心沿光轴方向对齐。入射光线经过聚焦单元、透射层以及收敛单元的光线处理，形成的出射光线将会与入射光线关于透射层对称。
可能地，在相互对应的聚焦单元和收敛单元中，透射层与聚焦单元之间的距离等于透射层与收敛单元之间的距离，也就是说聚焦单元和收敛单元关于透射层对称。这样的对称结构，有利于悬浮显示的实现。
其中，透射层位于聚焦单元的1-2倍焦距处，且透射层位于收敛单元的1-2倍焦距处。透射层相对聚焦单元的位置限定，可以确保聚焦单元可以将入射光线中源自同一个像素的光线汇聚到透射层的入射面上同一入射汇聚点。透射层相对收敛单元的位置限定，可以确保收敛单元可以将透射层的出射面上同一出射汇聚点的光线收敛导出为一组出射光线，该出射光线与上述入射光线关于透射层对称。此处，聚焦单元和收敛单元可以选择同样的结构，也可以选择同样的材质，也可以结构和材料均相同。
在一些可能实现的方式中，多个聚焦单元的阵列周期与多个收敛单元的阵列周期相同。可能地，多个聚焦单元的阵列周期和多个收敛单元的阵列周期均为0.3-1mm。其中，任意两个相邻的聚焦单元的光轴之间的间距即为聚焦单元的阵列周期，任意两个相邻的收敛单元的光轴之间的间距即为收敛单元的阵列周期。
在一些可能实现的方式中，透射层包括多个透射单元，多个透射单元沿垂直于光轴方向周期性阵列，且多个透射单元与多个聚焦单元一一对应，则多个透射单元也会与多个收敛单元一一对应；在相互对应的聚焦单元、透射单元和收敛单元中，聚焦单元用于对入射光线进行调制，以使同一像素发出的入射光线汇聚到透射单元的入射面上的同一个入射汇聚点；透射单元可以将入射汇聚点的光线一一对应地调制到透射单元的出射面上的出射汇聚点；收敛单元用于对出射汇聚点的光线进行调制，以使同一个出射汇聚点的光线收敛为出射光线；入射光线和出射光线关于透射单元对称。这样的结构设计，能够进一步对入射光线进行精准调制，使得悬浮图像的成像更精准，减少杂光、干扰光的出现。
其中，透射单元可以为具有光束偏转功能的第一光学结构。第一光学结构体可以包括非球面型光学元件、超表面型光学元件、衍射光学元件中的任意一种或多种的组合。当第一光学结构为超表面型光学元件或衍射光学元件，第一光学结构包括第一衬底以及设置于第一衬底上的第一微纳结构。
而聚焦单元和收敛单元可以均为具有聚焦成像功能的第二光学结构。第二光学结构具体可以包括球面型光学元件、非球面型光学元件、超表面型光学元件、衍射光学元件中的任意一种或至少两种的组合。当第二光学结构为超表面型光学元件或衍射光学元件，第二光学结构包括第二衬底以及设置于第二衬底上的第二微纳结构。
上述第一微纳结构和第二微纳结构均为微纳结构，此处的微纳结构由至少两种不同折 射率的透明介质构成，可以对光线进行调制，达到光线偏折的效果。
在一些可能实现的方式中，该悬浮光学器件还可以包括光阑。光阑具体可以设置于聚焦层与透射层之间、透射层与收敛层之间、聚焦层背离透射层的一侧或收敛层背离透射层的一侧。光阑用于对悬浮光学器件成像的光入射量和像差进行控制。
第二方面，本申请还提供一种光学模组，该光学模组包括支撑件以及上述任意一种悬浮光学器件。支撑件能够为悬浮光学器件提供支撑，使得悬浮光学器件中的聚焦层、透射层以及收敛层沿器件的光轴方向依次叠置。当然，支撑件不会影响悬浮光学器件的光线入射和出射。
第三方面，本申请还提供一种光学系统，该光学系统可以光源图像生成器以及上述任意一种悬浮光学器件。光源图像生成器具体设置于聚焦层背离透射层的一侧，光源图像生成器可以生成光源图像，悬浮光学器件的聚焦层、透射层、收敛层可以对光源图像发出的光线进行处理，最终在收敛层背离透射层的一侧成像为悬浮图像，悬浮图像与光源图像关于透射层对称。其中，光源图像生成器为2D图像显示器或3D图像显示器。
附图说明
图1为现有技术中的一种悬浮显示的原理示意图；
图2a为现有技术中的一种悬浮光学系统的结构示意图；
图2b为现有技术中的一种悬浮光学系统中分光器的原理示意图；
图2c为现有技术中的一种悬浮光学系统中逆反射器的结构及原理示意图；
图3a为现有技术中的一种悬浮光学系统的结构示意图；
图3b为现有技术中的一种悬浮光学系统的二面角反射结构示意图；
图3c为现有技术中的一种悬浮光学系统的二面角反射阵列原理示意图；
图4a和图4b为本申请实施例提供的一种悬浮光学器件的结构示意图；
图5a为本申请实施例提供的一种悬浮光学器件的结构示意图；
图5b为本申请实施例提供的一种悬浮光学器件中第二光学结构的结构示意图；
图6a和图6b为本申请实施例提供的一种悬浮光学器件中一组单元结构的光路图；
图7为本申请实施例提供的一种悬浮光学器件的光路图；
图8a和图8b为本申请实施例提供的一种悬浮光学器件的光路图；
图9a至图9c为本申请实施例提供的一种悬浮光学器件的光路图；
图10为本申请实施例提供的一种悬浮光学器件的结构示意图；
图11为本申请实施例提供的一种悬浮光学器件的光路图；
图12为本申请实施例提供的一种悬浮光学器件中第一光学结构的结构示意图；
图13a为本申请实施例提供的一种悬浮光学器件的结构示意图；
图13b为本申请实施例提供的一种悬浮光学器件的光路图；
图14a至图14d为本申请实施例提供的一种悬浮光学器件的结构示意图；
图15a为本申请实施例提供的一种光学模组的结构示意图；
图15b为本申请实施例提供的一种光学模组的剖面结构示意图；
图16a和图16b为本申请实施例提供的一种光学系统的结构示意图。
具体实施方式
悬浮显示技术可以在空气中成像，使观看者看到漂浮在空气中的影像。结合图1，光源图像K发出的光线经过悬浮光学器件的处理后形成悬浮图像K’，最终形成的悬浮图像K’的光能量与光源图像K的光能量之比为悬浮光学器件的光效率。如图2a所示的一种悬浮光学系统，用于实现悬浮显示的悬浮光学器件由逆反射器011和分光器012组成。分光器012所在平面为L0，光源图像K和逆反射器011设置于分光器012的同一侧。其中，结合图2b所示，分光器012为一种半透半反镜，可以对入射光进行一半透射一半反射。逆反射器011上具有微结构阵列0111，该微结构阵列0111具体可以为微角状反射镜(如图2c所示例)或微球状反射镜(此处未示例)。在图2c中，微结构阵列0111能够对一部分入射光(如光线b1和光线b2)进行二次反射，使得出射光与入射光相互平行且方向相反；另一部分入射光(如光线b3)被微结构阵列0111一次反射损失掉。结合图2a和图2b、图2c，光源图像生成器013产生一定视角范围的光源图像K，形成光源图像K的光线a1首先入射到分光器012上，一半光线a2透射出去损失掉，另一半光线a3被分光器反射到逆反射器011上。逆反射器011上的微结构阵列0111对入射的每一束光线进行调制，使得调制后的光束出射方向与入射方向相同。经过逆反射器011的光线a4再次经过分光器012，一半光线a5被反射损失掉，另一半光线a6透射后形成悬浮图像K’，被观看者看到。其中，虚拟图像K’与光源图像K关于分光器012所在平面L0对称。通过图2a所示的光路原理可知，光线需要两次经过分光器012，每次都有一半的能量损失，逆反射器011在对光束进行调制时也会产生能量损失。假设光源图像K的光能量为100％，经过分光器012后的光能量为50％。假设逆反射器011的反射率高达97％，经过逆反射器011反射后的光能量剩余50％×97％×97％≈47％。再次经过分光器012后得到悬浮图像K’的光能量仅剩余47％×50％＝23.5％。可见，图2a中的悬浮光学器件在进行悬浮显示时，光能量几乎有80％的损失，总光效率仅约为20％。
图3c所示例的另一种悬浮光学系统，用于实现悬浮显示的悬浮光学器件由二面角反射阵列(dihedral corner reflector array，DCRA)构成。参照图3b所示，该二面角反射阵列具体包括正交排布的第一反射镜阵列014和第二反射镜阵列015。第一反射镜阵列014和第二反射镜阵列015可以构成无数个正方形的微反射单元(square micro-reflector，SMR)B。每个微反射单元B的内壁涂有反射材料。如图3c所示，微反射单元B的内壁可以对光线c1进行二次反射使得出射光线与入射光线方向对称，光线c2经过一次反射或多次反射形成杂散光，光线c3则穿过微反射单元B的空隙被损失掉。结合图3a和图3c，光源图像发生器013产生一定视角范围的光源图像K，光源图像K发出的光线b1入射到二面角反射镜阵列上，其中一部分光线d1在二面角反射阵列内发生两次发射(可以参照图3c中的光线c1)，出射的光线d2正好与入射光线b1方向对称；一部分入射光线d3直接穿透过中空的微反射单元B在此损失(可以参照图3c中的光线c3)，其余的光线在二面角反射阵列里发生一次反射(可以参照图3c中的光线c2)或多次反射，形成鬼像或杂散光，鬼像和杂散光会干扰悬浮图像K’。这种悬浮光学器件制作工艺复杂，且具有较多的光损失。假设光源图像K的光能量为100％，光线经过二面角反射镜阵列，由于SMR是中空，假设有至少40％的光线直接穿透过SMR损失，剩余60％。假设再有20％的光只能发生一次反射和多次反射形成鬼像和杂散光，剩余60％-20％＝40％，假设二面角反射镜阵列每次反射率高达97％，最后得到悬浮图像K’的光能量仅剩余40％×97％×97％≈37％。可见，图3a 中的悬浮光学器件在进行悬浮显示时，光能量超过60％的损失，总光效率不到40％。
可见，现有技术中的悬浮光学器件成像过程中光损失严重，光效率非常低，不利于悬浮成像，导致悬浮图像的亮度、清晰度和对比度比较低，这些缺陷也使得悬浮显示技术难以扩大应用。为此，本申请实施例提供一种悬浮光学器件，用于提高悬浮显示的光效率。
为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述。
以下实施例中所使用的术语只是为了描述特定实施例的目的，而并非旨在作为对本申请的限制。如在本申请的说明书和所附权利要求书中所使用的那样，单数表达形式“一个”、“一种”、“所述”、“上述”、“该”和“这一”旨在也包括例如“一个或多个”这种表达形式，除非其上下文中明确地有相反指示。
在本说明书中描述的参考“一个实施例”或“一些实施例”等意味着在本申请的一个或多个实施例中包括结合该实施例描述的特定特征、结构或特点。由此，在本说明书中的不同之处出现的语句“在一个实施例中”、“在一些实施例中”、“在其他一些实施例中”、“在另外一些实施例中”等不是必然都参考相同的实施例，而是意味着“一个或多个但不是所有的实施例”，除非是以其他方式另外特别强调。术语“包括”、“包含”、“具有”及它们的变形都意味着“包括但不限于”，除非是以其他方式另外特别强调。
请参照图4a，本申请实施例提供一种悬浮光学器件10，该悬浮光学器件10可以用于悬浮显示。该悬浮光学器件10具有光轴P，悬浮光学器件10的光轴方向即光轴P的方向。沿光轴P的方向，悬浮光学器件10包括依次叠置的聚焦层1、透射层2以及收敛层3。按照应用时的光线入射与光线出射方向，透射层2具有入射面e1和出射面e2。即对于透射层2，光线将从入射面e1进入透射层2，并从出射面e2射出透射层2。设定，透射层2所在平面为第一平面L1。聚焦层1位于透射层2的入光面e1一侧，聚焦层1所在平面为第二平面L2。收敛层3则位于透射层2的出光面e2一侧，收敛层3所在平面为第三平面L3。第一平面L1、第二平面L2、第三平面L3均垂直于光轴P。在应用中，聚焦层1可以将入射光线汇聚到透射层2的入射面e1上，而收敛层3则可以将透射层2的出射面e2射出的光线收敛出射，最终将光源图像在收敛层3远离透射层2的一侧成像为悬浮图像。
结合图4b所示，聚焦层1包括有多个聚焦单元11，多个聚焦单元11沿垂直于光轴方向周期性阵列，每个聚焦单元11所在平面为第二平面L2。收敛层3包括有多个收敛单元31，多个收敛单元31，沿垂直于光轴方向周期性阵列，每个收敛单元31所在平面为第三平面L3。沿光轴方向，多个聚焦单元11和多个收敛单元31一一对应。在相互对应的聚焦单元11与收敛单元31之间，聚焦单元11的光学中心与收敛单元31的光学中心之间的连线垂直于透射层2所在平面，也即聚焦单元11的光轴与收敛单元31的光轴共线。在图4b中，聚焦层1示出了五个聚焦单元11，对应地，收敛层3示出了五个收敛单元31。应当理解，每个聚焦单元11都具有光轴，每个收敛单元31也具有光轴，任意一个聚焦单元11的光轴平行于上述悬浮光学器件10的光轴P，任意一个收敛单元的光轴也平行于上述悬浮光学器件10的光轴P。并且，在相互对应的聚焦单元11和收敛单元31中，聚焦单元11的光轴和收敛单元31的光轴重合。聚焦单元11可以将入射光线聚焦到透射层2的入射面e1上，收敛单元31则可以将透射层2的出射面e2上的光收敛后出射为出射光线，出射光线与入射光线关于透射层2对称。
其中，结合图4a和图4b所示，聚焦层1和收敛层3关于透射层2对称设置。设定， 透射层2所在平面L1与聚焦层1所在平面L2之间的距离为h1，透射层2所在平面L1与收敛层3所在平面L3之间的距离为h2，h1与h2相等。其中，透射层2设置于聚焦单元11的1-2倍焦距处，且透射层2设置于收敛单元31的1-2倍焦距处。例如，透射层2位于聚焦单元11的1倍焦距出，且透射层2设置于收敛单元31的1倍焦距处。
如图4b所示，可以将聚焦单元11和收敛单元31的阵列周期设置为相同，其范围可以取0.3-1mm。以聚焦单元11为例，任意两个相邻的聚焦单元11的光轴之间的间距即为聚焦单元11的阵列周期。可推论地，任意两个相邻的收敛单元31的光轴之间的间距即为收敛单元31的阵列周期。任意两个相邻在图4b中，以两组相互对应的聚焦单元11、收敛单元31为例进行说明。第一组相互对应的聚焦单元11、收敛单元31中，聚焦单元11的光轴、收敛单元31的光轴共线，设定为光轴S1。第二组相互对应的聚焦单元11、收敛单元31中，聚焦单元11的光轴、收敛单元31的光轴共线，设定为光轴S2。光轴S1与光轴S2分别平行于悬浮光学器件10的光轴P，且光轴S1与光轴S2之间的间距为阵列周期H，也就是说，聚焦单元11、收敛单元31的阵列周期均为H，H的取值范围为0.3-1mm。例如，阵列周期可以为0.4mm、0.6mm、0.9mm。
其中，聚焦单元11和收敛单元31均为具有聚焦成像功能的第一光学结构。例如，第一光学结构为微透镜，则聚焦层1相当于微透镜阵列，收敛层3也为微透镜阵列。具体地，第一光学结构可以为球面型光学元件、非球面型光学元件、超表面型光学元件、衍射光学元件中的任意一种，还可以是这些光学元件中至少两种的组合。如图5a所示，聚焦单元11和收敛单元31均为球面型的光学元件。球面型的光学元件生产技术比较成熟，已应用于工业和科研各技术领域。其他面型的光学元件也可以借助半导体工艺或纳米压印工艺，实现大规模批量生产。因此，聚焦单元11和收敛单元31加工可实现度比较高，有利于实现成本的降低。
为了达到较好的透光效果，聚焦单元11和收敛单元31尽量选择透光率较高的材料，例如光刻胶。聚焦单元11和收敛单元31可以结构相同，也可以材料相同，还可以结构、材料均相同。
在一种具体的实施方式中，当第二光学结构为超表面型光学元件或衍射光学元件，如图5b所示，第二光学结构包括第二衬底41以及设置于所述第二衬底41上的第二微纳结构42。第二衬底41具体可以是无机透明材料(例如二氧化硅、碳化硅)，也可以是有机材料(例如聚甲基丙烯酸甲酯、光刻胶)。此处的第二微纳结构42由至少两种不同折射率的透明介质构成，此处示例为第一介质421和第二介质422。例如，第一介质421为聚甲基丙烯酸甲酯(polymethyl methacrylate，PMMA)，第二介质422为空气。第一微纳结构42具有微米或纳米尺度特征尺寸，按照特定方式阵列排布。以超表面型为例，第二微纳结构42为亚波长单元。沿第二衬底41所在水平面，每个第二微纳结构42的横截面上，任意两点之间的距离小于入射光的波长。并且，任意两个相邻的第二微纳结构42之间的间距小于入射光线的波长，使得第二微纳结构42可以对入射光线进行相位调制，从而达到光路偏折的效果。
以一组相互对应的聚焦单元11和收敛单元31为例，设定相互对应的聚焦单元11、收敛单元31、透射层2为一组单元结构。由于聚焦单元11足够小，该像素距离聚焦单元11具有足够远的距离，该像素发出的光线中能够入射到聚焦单元11上的入射光线M1近似平行。如图6a所示。以一束源自同一像素的光线(为方便示意，此处源自同一像素的光线示 例为相互平行)作为入射光线M1，自聚焦单元11一侧入射。聚焦单元11对该入射光线M1进行调制，使得入射光线M1汇聚到透射层2的入射面e1上的同一个入射汇聚点O1，并自该入射汇聚点O1进入透射层2。透射层2对该入射汇聚点O1的光线进行调制，将该部分光线调制到透射层2的出射面e2上的出射汇聚点O2。光线自出射汇聚点O2射出后发散进入收敛单元31，收敛单元31对该出射汇聚点O2射出的光线进行调制，使得光线能够以近似相互平行的状态自收敛单元31射出。自收敛单元31射出的光线为出射光线M2，出射光线M2与入射光线M1关于透射层2对称。
具体地，请继续参照图6a，沿X方向，入射光线M1包括光线m11、光线m12、光线m13。光线m11在经过聚焦单元11、透射层2、收敛单元31之后出射为光线m21。光线m12在经过聚焦单元11、透射层2、收敛单元31之后出射为光线m22。光线m13在经过聚焦单元11、透射层2、收敛单元31之后出射为光线m23。光线m21、光线m22、光线m23组成出射光线M2，光线m23、光线m22、光线m21依次排列。也就是说，对于一个聚焦单元11，一组平行的入射光线在经过聚焦单元11、透射层2、收敛单元31之后形成出射光线，出射光线方向与入射光线方向关于透射层2对称。沿X方向，入射光线M1包括光线m11、光线m12、光线m13，这与出射光M2包括光线m23、光线m22、光线m21，入射光线M1的标记顺序与出射光线M2的标记顺序沿X方向相反。光线的顺序代表了光线携带的信息。由于聚焦单元11足够小，当光源图像上的像素尺寸大于聚焦单元11时，入射光线M1携带的信息为同一个像素的信息。此时，虽然光线m11、光线m12、光线m13以及m23、光线m22、光线m21看似在空间上不连续，且出射光线M2的顺序与入射光线M1的顺序相反，但从光波角度和携带相同信息的角度来看，入射光线M1与出射光线M2的信息完全相同，不会影响图像信息的反转。当光源图像的像素尺寸小于聚焦单元11时，出射光线M2的顺序与入射光线M1的顺序相反，但反转的像素从宏观上看不会有显著影响，或者从光源生成器端对光源图像进行预先的像素反转处理可以避免出射信息内容的反转。总而言之，本申请实施例中周期性阵列的聚焦单元11和周期性阵列的收敛单元31，结合透射层2，都能将同一个像素的信息以关于透射层2对称的方式成像到悬浮图像的同一个像素，取得悬浮成像的效果。
如果入射光线包括多个方向的光线，如图6b所示，源自一个像素的入射光线M1示例为一组平行光，源自另一个像素入射光线M1’示例为另一组平行光，入射光线M1与入射光线M1’的方向不同。入射光线M1和入射光线M1’自聚焦单元11一侧入射，聚焦单元11对入射光线M1进行调制，使得源自一个像素的入射光线M1汇聚到透射层2的入射面e上的同一个入射汇聚点O1，并自该入射汇聚点O1进入透射层2。聚焦单元11对入射光线M1’进行调制，使得源自另一个像素的入射光线M1’汇聚到透射层2的入射面e上的同一个入射汇聚点O1’，并自该入射汇聚点O1进入透射层2。透射层2对入射汇聚点O1的光线进行调制，将该部分光线调制到透射层2的出射面e2上的出射汇聚点O2。透射层2对入射汇聚点O1’的光线进行调制，使得该部分光线汇聚到透射层2的出射面e2上的出射汇聚点O2’。光线自出射汇聚点O2射出后发散进入收敛单元31，收敛单元31对该出射汇聚点O2射出的光线进行调制，使得光线能够以近似相互平行的状态(即出射光线M2)自收敛单元31射出。出射光线M2与入射光线M1关于透射层2对称。光线自出射汇聚点O2’射出后发散进入收敛单元31，收敛单元31对该出射汇聚点O2’射出的光线进行调制，使得光线能够以近似相互平行的状态(即出射光线M2’)自收敛单元31射出。出射光线 M2’的方向与入射光线M1’的方向关于透射层2对称。
结合图6a和图6b可知，入射光线到出射光线的光传递过程中，除了悬浮光学器件10各个器件自身的透过率对光的损耗，基本没有其他的损耗。也就是说，本申请实施例所提供的悬浮光学器件10对光线的损耗比较小，将聚焦层1、透射层2、收敛层3均设定为高透过率的材料，即可提高整个器件的光效率。例如，设定聚焦层1、透射层2、收敛层3的光透过率均为92％，则悬浮光学器件10的总光效率为92％×92％×92％≈78％。这个光效率数据，与现有技术相比，具有明显的提升。
对于整个悬浮光学器件10，聚焦层1由多个聚焦单元11周期性阵列而成，收敛层3也是由多个收敛单元31周期性阵列而成。如图7所示，对于每一组相互对应的聚焦单元11和收敛单元31，可以认为每一组相互对应的聚焦单元11和收敛单元31可以结合透射层2将某一部分入射光线处理为出射光线，出射光线方向与入射光线方向关于透射层2对称。只要将聚焦单元11和收敛单元31设置的足够小，使得相互对应的聚焦单元11和收敛单元31可以将足够细小的光线悬浮显示，例如将一个点的光线悬浮显示为一个悬浮的点，在宏观上，可以认为出射光线与入射光线关于透射层2对称。
将该悬浮光学器件10应用到悬浮显示中，如图8a所示，光源图像A为2D图像，光源图像A由无数个像素组成，每个像素发射出一定角度的宽光束。示例性地，光源图像A上的像素Q发出图示角度的宽光束F。该宽光束F可以看成由无数个方向的细光束f组成。每个细光束f入射到悬浮光学器件10上，依次经过聚焦层1、透射层2和收敛层3处理后出射为多个细光束f’组成的宽光束F’，宽光束F’集中到悬浮图像A’的像素Q’处，像素Q’与像素Q关于透射层2对称。具体可以结合图8b所示，示例入射光线中一个细光束f对应组相互对应的聚焦单元11、收敛单元31。以一个细光束f所对应的一组近似相互平行的光线为例，在每一组相互对应的细光束f、聚焦单元11、收敛单元31中，细光束f的光线首先被聚焦单元11汇聚到透射层2的入射面e1上同一个入射汇聚点(此处未示出)，透射层2对该光线进行特定偏转调制，将光线调制至透射层2的出射面e2上同一个出射汇聚点(此处未示出)。由同一个出射汇聚点射出的光线被收敛单元31再次调制，最终自收敛单元31射出的光线恢复近似相互平行的光束，这些光束即可以看作细光束f’。细光束f’与细光束f关于透射层2对称。所有的细光束f’组成图8a所示的宽光束F，对应汇聚到空中一点，该点即悬浮图像A’中的悬浮像素Q’。无数个如像素Q’的像素组成悬浮图像A’。
在图8a和图8b中，光源图像A为2D图像，经过悬浮光学器件10悬浮成像的悬浮图像A’也为2D图像。基于上述实施例介绍，本申请实施例所提供的悬浮光学器件10可以将光源图像A上的任意一个点以对称的方式(关于透射层2对称)悬浮成像为悬浮图像A’。
在一些实施例中，如图9a所示，光源图像B为3D图像，光源图像B由无数个光源像素组成，光源图像B上每个像素发射出一定角度的宽光束。示例性地，光源图像B上的像素R发出图示角度的宽光束G。该宽光束G可以看成由无数个方向的细光束g组成。每个细光束g入射到悬浮光学器件10上，依次经过聚焦层1、透射层2和收敛层3处理后出射为多个细光束g’组成的宽光束G’，宽光束G’集中到悬浮图像B’的像素R’处，像素R’与像素R关于透射层2对称。无数个如像素R’的像素组成悬浮图像B’。细光束g被聚焦层1、透射层2和收敛层3处理的光路原理可以参照图8b所示，此处不再赘述。
请继续参照图9b所示的悬浮光学器件10，与图9a所示的悬浮光学器件10相比，该悬浮光学器件10相对水平面45°倾斜设置。悬浮光学器件10中的聚焦层1、透射层2、 收敛层3的结构可以参照图9a，此处不再赘述。如图9c所示，示例入射光线中一个细光束g对应组相互对应的聚焦单元11、收敛单元31。以一个细光束g所对应的一组近似相互平行的光线为例，在每一组相互对应的细光束g、聚焦单元11、收敛单元31中，细光束f的光线首先被聚焦单元11汇聚到透射层2的入射面e1上同一个入射汇聚点(此处未示出)，透射层2对该光线进行特定偏转调制，将光线调制至透射层2的出射面e2上同一个出射汇聚点(此处未示出)。由同一个出射汇聚点射出的光线被收敛单元31再次调制，最终自收敛单元31射出的光线恢复近似相互平行的光束，这些光束即可以看作细光束g’。细光束g’与细光束g关于透射层2对称。所有的细光束g’组成图9b所示的宽光束F，对应汇聚到空中一点，该点即悬浮图像B’中的悬浮像素R’。无数个如像素R’的像素组成悬浮图像B’。
在一些实施例中，如图10所示，透射层2包括多个透射单元21，沿垂直于光轴方向，多个透射单元21周期性阵列，每个透射单元21所在平面为第一平面L1(第一平面L1可以参考图4a所示)。沿光轴方向，多个透射单元21、多个聚焦单元11、多个收敛单元31一一对应。在图10中，聚焦层1示出了五个聚焦单元11，收敛层3示出了五个收敛单元31，透射层2示出了五个透射单元21。沿光轴方向，一个聚焦单元11对应一个收敛单元31，一个聚焦单元11也对应一个透射单元21。应当理解，每个聚焦单元11都具有光轴，每个收敛单元31也具有光轴，每个透射单元21也具有光轴。任意一个聚焦单元11的光轴平行于上述悬浮光学器件10的光轴P，任意一个收敛单元31的光轴也平行于上述悬浮光学器件10的光轴P，任意一个透射单元21的光轴也平行于上述悬浮光学器件10的光轴P。并且，在相互对应的聚焦单元11、透射单元21、收敛单元31中，聚焦单元11的光轴、透射单元21的光轴、收敛单元31的光轴重合。这样的结构设计，能够进一步对入射光线进行精细化处理，使得悬浮图像的成像更精准，减少杂光、干扰光的出现。
其中，如图10所示，可以将聚焦单元11、透射单元21、收敛单元31的阵列周期设置为相同，阵列周期的范围可以取0.3-1mm。以聚焦单元11为例，任意两个相邻的聚焦单元11的光轴之间的间距即为聚焦单元11的阵列周期。如图10所示，以两组相互对应的聚焦单元11、透射单元21、收敛单元31为例进行说明。第一组相互对应的聚焦单元11、透射单元21、收敛单元31中，聚焦单元11的光轴、透射单元21的光轴、收敛单元31的光轴共线，设定为光轴S1。第二组相互对应的聚焦单元11、透射单元21、收敛单元31中，聚焦单元11的光轴、透射单元21的光轴、收敛单元31的光轴共线，设定为光轴S2。光轴S1与光轴S2之间的间距为阵列周期H，也就是说，聚焦单元11、透射单元21、收敛单元31的阵列周期均为H，该H的取值范围为0.3-1mm。例如，H选择为0.4mm、0.6mm或0.9mm。
结合图10，聚焦单元11可以将入射光线聚焦到透射层2的入射面e1上，收敛单元31则可以将透射层2的出射面e2上的光收敛后出射为出射光线，其光路原理可以参照图11所示。对于每一组相互对应的聚焦单元11、透射单元21、收敛单元31，可以认为每一组相互对应的聚焦单元11、透射单元21、收敛单元31将某一部分入射光线处理为出射光线，出射光线方向与入射光线方向关于透射层2对称。只要将聚焦单元11、透射单元21、收敛单元31设置的足够小，使得相互对应的聚焦单元11、透射单元21、收敛单元31可以将足够细小的光线悬浮显示，例如将一个点的光线悬浮显示为一个悬浮的点，在宏观上，出射光线图像与入射光线图像的相反显示可以忽略不计，因此可以认为出射光线与入射光线关 于透射层2对称。
其中，透射单元21为具有光束偏转功能的第一光学结构。因此，透射层2相当于第一光学结构阵列。具体地，第一光学结构可以为非球面型光学元件、超表面型光学元件、衍射光学元件中的任意一种，还可以是这些光学元件中至少两种的组合。当第一光学结构为超表面型光学元件或衍射光学元件，其结构可以参照图12所示，第一光学结构包括第一衬底51以及设置于所述第一衬底51上的第一微纳结构52。第一衬底51具体可以是无机透明材料(例如二氧化硅、碳化硅)，也可以是有机材料(例如聚甲基丙烯酸甲酯、光刻胶)。此处的第一微纳结构52由至少两种不同折射率的透明介质构成，此处示例为第三介质521和第四介质522。例如，第三介质521为聚甲基丙烯酸甲酯(polymethyl methacrylate，PMMA)，第四介质522为空气。第一微纳结构52具有微米或纳米尺度特征尺寸，按照特定方式阵列排布。以超表面型为例，第一微纳结构52为亚波长单元。沿第一衬底51所在水平面，每个第一微纳结构52的横截面上，任意两点之间的距离小于入射光的波长。并且，任意两个相邻的第一微纳结构52之间的间距小于入射光线的波长，使得第一微纳结构52可以对入射光线进行相位调制，从而达到光路偏折的效果。
在上述实施例中，多个聚焦单元11和多个收敛单元31沿光轴方向一一对应，入射光线经过悬浮光学器件10处理后形成的悬浮图像与光源图像关于透射层2对称。在另一些实施例中，如图13a所示，在相互对应的聚焦单元11与收敛单元31之间，垂直于光轴方向，聚焦单元11的光轴T1与收敛单元31的光轴T3沿垂直于光轴方向可以有z的偏移量。对应地，入射光线与出射光线的光路图可以参照图13b所示。以一组相互对应的聚焦单元11和收敛单元31为例，沿垂直于光轴的X方向，收敛单元31的光轴T3相对聚焦单元11的光轴T1存在z的偏移量。以一束源自同一像素的光线(为方便示意，此处源自同一像素的光线示例为相互平行)作为入射光线M1，入射光线M1与聚焦单元11背离透射层2的表面之间形成第一夹角β1，该第一夹角β1为锐角，且第一夹角β1的开口朝向图示器件结构的左侧。入射光线M1自聚焦单元11一侧入射，聚焦单元11对该入射光线M1进行调制，使得入射光线M1汇聚到透射层2的入射面e1上的同一个入射汇聚点O1，并自该入射汇聚点O1进入透射层2。透射层2对该入射汇聚点O1的光线进行调制，将该部分光线调制到透射层2的出射面e2上的出射汇聚点O2。光线自出射汇聚点O2射出后发散进入收敛单元31，收敛单元31对该出射汇聚点O2射出的光线进行调制，使得光线能够以近似相互平行的状态自收敛单元31射出。自收敛单元31射出的光线为出射光线M2，出射光线M2与收敛单元31背离透射层2的表面之间形成第二夹角β2，该第二夹角β2也为锐角。第二夹角β2也为锐角，且第二夹角β2的开口也朝向图示器件结构的左侧。以光轴P为参考，可以认为，第一夹角β1的开口和第二夹角β2的开口朝向光轴P的同一侧。并且，第二夹角β2与第一夹角β1大小相等。出射光线M2与入射光线M1沿X方向可能存在w的偏移量。虽然入射光线M1和出射光线M2在光轴方向上有一定的位置偏移，但是从光波角度和携带相同信息的角度来看，入射光线M1与出射光线M2的信息完全相同，能将同一个像素的信息成像到悬浮图像的同一个像素，取得悬浮成像的效果。
基于图4a所示的悬浮光学器件10，如图14a至图14d所示，本申请实施例还提供一种具有光阑6的悬浮光学器件10。光阑6具体可以如图14a所示，设置于收敛层3背离透射层2的一侧；光阑6还可以如图14b所示，设置于聚焦层1背离透射层2的一侧；光阑6还可以如图14c所示，设置于收敛层3与透射层2之间；光阑6还可以如图14d所示， 设置于透射层2与聚焦层1之间。光阑6的存在，可以对经过悬浮光学器件10的光线控制，也就是说，光阑6用于对悬浮光学器件10成像的光入射量和像差进行控制。光阑6的设置位置不影响其功能实现。
综上所述，本申请实施例所提供的悬浮光学器件10在应用到悬浮显示时，光源图像上的每个像素发出的光线可以入射到聚焦层1不同的聚焦单元11，每个聚焦单元11都可以对入射的光线进行调制，使得源自同一个像素的入射光线能够汇聚到透射层2的入射面e1上的同一个入射汇聚点，源自同一个像素的入射光线对应一个入射汇聚点。透射层2则可以将入射面e1上同一个入射汇聚点的光线调制至出射面e2上的出射汇聚点。每个收敛单元31可以对出射汇聚点的光线进行调制，使得同一个出射汇聚点的光线可以收敛为近似相互平行的出射光线，每组近似相互平行的出射光线对应一个出射汇聚点。其中，聚焦单元11的周期性阵列结构以及收敛单元31的周期性阵列结构，可以对光源图像发出的光线上的每个像素的光线进行处理，使得出射光线可以与入射光线关于透射层2对称出射光线可以组成悬浮图像，保证悬浮图像与光源图像信息相同。在选择多个收敛单元31和多个聚焦单元11沿光轴一一对应时，还可以使出射光线可以与入射光线关于透射层2对称。在整个光线传输过程中，除了器件材料的透过率对光的损耗之外，基本无其他损耗。因此，只要保证器件的高透过率，即可控制光的损耗，提高悬浮成像的光效率，从而优化提高悬浮图像显示的清晰度、对比度。
基于上述悬浮光学器件10，本申请实施例还提供一种光学模组100。如图15a所示，该光学模组100包括支撑件20以及上述实施例所提供的任意一种悬浮光学器件10。此处悬浮光学器件10示例为圆形。支撑件20呈环形，中间具有镂空，悬浮光学器件10设置于支撑件20的中间镂空位置，即支撑件20自悬浮光学器件10的周向边缘为悬浮光学器件10提供支撑，且支撑件20中部的镂空不会影响光线的入射与出射。图15b示出了光学模组100的剖面结构示意图，悬浮光学器件10中的聚焦层1、透射层2以及收敛层3的周向边缘均固定于支撑件20，聚焦层1、透射层2以及收敛层3沿光轴P的方向依次叠置。
此外，本申请实施例还提供一种光学系统。如图16a和图16b所示，该光学系统包括光源图像生成器200以及上述任意一种光学模组100。光源图像生成器200设置于悬浮光学器件10的聚焦层1远离透射层2的一侧，光源图像生成器生成的光源图像A发出的光线可以依次经过聚焦层1、透射层2、收敛层3形成悬浮图像。该光学系统具有较多的应用场景，包括但不限于电梯、餐厅、银行等公共场所，以及私家车、家用桌面等私人场所。例如，该光学系统应用到公共场所的按钮悬浮显示中，能够实现非接触式交互，具有更安全、更卫生、更隐私的优点。该光学系统应用到私人汽车的虚拟装饰物或车载精灵悬浮显示时，会带来更震撼、更炫酷、更个性化的使用体验。该光学系统应用到家用桌面悬浮显示时，立体悬浮显示和零距离的交互操作可以增加游戏体验与乐趣，实现裸眼的虚实融合功能。
如图16a所示，光源图像生成器200为2D图像显示器，例如液晶显示器(liquid crystal display，LCD)、有机发光二极管(organic light-emitting diode，OLED)屏幕、投影屏，光源图像生成器生成的光源图像A为2D图像。光源图像A由无数个像素组成，每个像素发射出一定角度的宽光束。示例性地，光源图像A上的像素Q发出图示角度的宽光束F。该宽光束F可以看成由无数个方向的细光束f组成。每个细光束f入射到悬浮光学器件10上，依次经过聚焦层1、透射层2和收敛层3处理后出射为多个细光束f’组成的宽光束F’， 宽光束F’集中到悬浮图像A’的像素Q’处，像素Q’与像素Q关于透射层2对称。无数个如像素Q’的像素组成悬浮图像A’。其中，聚焦层1、透射层2和收敛层3对无数个细光束f光线处理可以参照图8b所示，此处不再赘述。
如图16a所示，光源图像生成器200为3D图像显示器，光源图像生成器20生成的光源图像B为3D图像。光源图像B由无数个像素组成，光源图像B上每个像素发射出一定角度的宽光束。示例性地，光源图像B上的像素R发出图示角度的宽光束G。该宽光束G可以看成由无数个方向的细光束g组成。每个细光束g入射到悬浮光学器件10上，依次经过聚焦层1、透射层2和收敛层3处理后出射为多个细光束g’组成的宽光束G’，宽光束G’集中到悬浮图像B’的像素R’处，像素R’与像素R关于透射层2对称。无数个如像素R’的像素组成悬浮图像B’。细光束g被聚焦层1、透射层2和收敛层3处理的光路原理可以参照图8b所示，此处不再赘述。
由于悬浮光学器件10具有较高的光效率，因此，本申请实施例提供的光学系统能够通过悬浮光学器件10的透射将光源图像生成器生产的图像(包括2D图像和3D图像)成像为悬浮图像，且悬浮图像的亮度、清晰度、对比度都比较高，能够取得较好的悬浮显示效果。
以上，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以权利要求的保护范围为准。

Claims (17)

  1. 一种悬浮光学器件，其特征在于，包括：沿光轴方向依次叠置的聚焦层、透射层和收敛层；所述透射层具有朝向所述聚焦层的入射面和朝向所述收敛层的出射面；
    所述聚焦层包括多个聚焦单元，所述多个聚焦单元沿垂直于所述光轴方向周期性阵列；所述收敛层包括多个收敛单元，所述多个收敛单元沿垂直于所述光轴方向周期性阵列；且所述多个聚焦单元和所述多个收敛单元一一对应；
    在相互对应的所述聚焦单元和所述收敛单元中，所述聚焦单元用于对入射光线进行调制，以使同一个像素发出的入射光线汇聚到所述透射层的入射面上的同一个入射汇聚点；所述透射层用于将所述入射汇聚点的光线一一对应地调制所述透射层的出射面上的出射汇聚点；所述收敛单元用于对所述出射汇聚点的光线进行调制，以使同一个所述出射汇聚点的光线收敛为出射光线；
    所述入射光线与所述透射层的入射面之间形成第一夹角，所述出射光线与所述透射层的出射面之间形成第二夹角；所述第一夹角的开口与所述第二夹角的开口朝向所述光轴的同一侧；所述第一夹角和所述第二夹角均为锐角，且所述第一夹角与所述第二夹角大小相等。
  2. 如权利要求1所述的悬浮光学器件，其特征在于，所述多个聚焦单元和所述多个收敛单元关于所述透射层对称，以使所述入射光线和所述出射光线关于所述透射层对称。
  3. 如权利要求1或2所述的悬浮光学器件，其特征在于，所述透射层包括多个透射单元，所述多个透射单元沿垂直于所述光轴方向周期性阵列，且所述多个透射单元与所述多个聚焦单元一一对应；
    所述透射单元将所述入射汇聚点的光线一一对应地调制到所述透射单元的出射面上的出射汇聚点。
  4. 如权利要求3所述的悬浮光学器件，其特征在于，所述透射单元为具有光束偏转功能的第一光学结构。
  5. 如权利要求4所述的悬浮光学器件，其特征在于，所述第一光学结构包括非球面型光学元件、超表面型光学元件、衍射光学元件中的任意一种或多种的组合。
  6. 如权利要求5所述的悬浮光学器件，其特征在于，当所述第一光学结构为超表面型光学元件或衍射光学元件，所述第一光学结构包括第一衬底以及设置于所述第一衬底上的第一微纳结构。
  7. 如权利要求1-6中任一项所述的悬浮光学器件，其特征在于，所述聚焦单元和所述收敛单元均为具有聚焦成像功能的第二光学结构。
  8. 如权利要求7所述的悬浮光学器件，其特征在于，所述第二光学结构包括球面型光学元件、非球面型光学元件、超表面型光学元件、衍射光学元件中的任意一种或至少两种的组合。
  9. 如权利要求8所述的悬浮光学器件，其特征在于，当所述第二光学结构为超表面型光学元件或衍射光学元件，所述第二光学结构包括第二衬底以及设置于所述第二衬底上的第二微纳结构。
  10. 如权利要求1-9中任一项所述的悬浮光学器件，其特征在于，所述透射层与所述聚焦层之间的距离等于所述透射层与所述收敛单元之间的距离。
  11. 如权利要求10所述的悬浮光学器件，其特征在于，所述透射层位于所述聚焦单元的1-2倍焦距处，且所述透射层位于所述收敛单元的1-2倍焦距处。
  12. 如权利要求1-11中任一项所述的悬浮光学器件，其特征在于，多个所述聚焦单元的阵列周期与多个所述收敛单元的阵列周期相同。
  13. 如权利要求12所述的悬浮光学器件，其特征在于，多个所述聚焦单元的阵列周期与多个所述收敛单元的阵列周期均为0.3-1mm。
  14. 如权利要求1-13中任一项所述的悬浮光学器件，其特征在于，还包括光阑；
    沿所述光轴方向，所述光阑位于所述聚焦层与所述透射层之间；或，所述光阑位于所述透射层与所述收敛层之间；或，所述光阑位于所述聚焦层背离所述透射层的一侧；或，所述光阑位于所述收敛层背离所述透射层的一侧。
  15. 一种光学模组，其特征在于，包括支撑件以及如权利要求1-14中任一项所述的悬浮光学器件；
    所述聚焦层、所述透射层和所述收敛层沿光轴方向依次固定于所述支撑件。
  16. 一种光学系统，其特征在于，包括光源图像生成器以及如权利要求15所述的光学模组；所述光源图像生成器设置于所述聚焦层背离所述透射层的一侧以用于生成光源图像。
  17. 如权利要求16所述的光学系统，其特征在于，所述光源图像生成器为2D图像显示器或3D图像显示器。
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106773090A (zh) * 2017-01-23 2017-05-31 清华大学 一种新型三维悬浮显示系统及实时光场渲染方法
CN206804900U (zh) * 2016-10-14 2017-12-26 昇印光电（昆山）股份有限公司 一种图像结构成像装置
CN115113403A (zh) * 2022-06-30 2022-09-27 上海天马微电子有限公司 成像装置及其控制方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN206804900U (zh) * 2016-10-14 2017-12-26 昇印光电（昆山）股份有限公司 一种图像结构成像装置
CN106773090A (zh) * 2017-01-23 2017-05-31 清华大学 一种新型三维悬浮显示系统及实时光场渲染方法
CN115113403A (zh) * 2022-06-30 2022-09-27 上海天马微电子有限公司 成像装置及其控制方法

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