WO2022179428A1 - 光学组件、投影模组和增强现实设备 - Google Patents

光学组件、投影模组和增强现实设备 Download PDF

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Publication number
WO2022179428A1
WO2022179428A1 PCT/CN2022/076625 CN2022076625W WO2022179428A1 WO 2022179428 A1 WO2022179428 A1 WO 2022179428A1 CN 2022076625 W CN2022076625 W CN 2022076625W WO 2022179428 A1 WO2022179428 A1 WO 2022179428A1
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Prior art keywords
light
lens
polarizing beam
optical
prism
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PCT/CN2022/076625
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English (en)
French (fr)
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丁武文
闫冠屹
朱璐璐
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华为技术有限公司
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Publication of WO2022179428A1 publication Critical patent/WO2022179428A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • 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
    • 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
    • G02B27/017—Head mounted
    • G02B27/0172—Head mounted characterised by optical features
    • 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
    • G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
    • 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
    • G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
    • G02B27/283—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising used for beam splitting or combining
    • 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
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • 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
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/005—Projectors using an electronic spatial light modulator but not peculiar thereto
    • G03B21/008—Projectors using an electronic spatial light modulator but not peculiar thereto using micromirror devices
    • 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
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • 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
    • G02B27/017—Head mounted
    • G02B2027/0178—Eyeglass type

Definitions

  • the present application relates to the technical field of augmented reality, and in particular, to an optical assembly, a projection module including the optical assembly, and an augmented reality device including the projection module.
  • Augmented Reality (AR) devices are equipped with projection systems, which are used to project images to the human eye to form vision.
  • Projection systems may include lasers, microelectromechanical systems (MEMS) galvanometers, and waveguide structures.
  • the laser can emit a laser beam, and the laser beam is reflected by the MEMS galvanometer and then transmitted into the waveguide structure, and is emitted from the waveguide structure, and finally enters the human eye to form vision.
  • the MEMS galvanometer can be rotated by a signal to change the direction of the reflected laser beam, so that the laser beam can be emitted from different areas of the waveguide structure (this process is called scanning) to realize dynamic picture display.
  • the diameter of the light beam irradiated on the MEMS galvanometer is large, so that the MEMS galvanometer needs a large area. This will increase the difficulty of designing and processing MEMS galvanometers, and will also lead to larger AR devices.
  • the present application provides an optical component, a projection module and an augmented reality device, which can reduce the area of the MEMS galvanometer and realize the miniaturization of the AR device.
  • the present application provides an optical assembly, including the optical assembly including a first optical element, a polarizing beam splitter film, a phase retarder, a MEMS galvanometer and an optical 4f system;
  • the first optical element has an element The reflective surface, the element reflective surface forms a first angle with the first direction;
  • the polarizing beam splitting film forms a 90° angle with the element reflective surface;
  • the phase retardation plate is located between the polarizing beam splitting film and the micro
  • the electromechanical system galvanometers the normal of the phase retarder is along a second direction, and the second direction is orthogonal to the first direction;
  • the microelectromechanical system galvanometer and the phase retarder are spaced apart,
  • the reflective surface of the MEMS galvanometer faces the phase retarder;
  • the optical 4f system is located on the side of the polarizing beam splitter film away from the first optical element, and the optical 4f system is connected to the polarizing beam splitter film.
  • the optical component is used for processing light; wherein, the light emitted by the light source enters the first optical element from the reflecting surface of the element, and passes through
  • the polarizing beam splitting film passes through the phase retarder and strikes the reflective surface of the MEMS galvanometer; the MEMS galvanometer is used to reflect light to different directions through vibration, and the reflection in different directions After passing through the phase retarder again, the light is reflected by the polarizing beam splitting film, and enters the optical 4f system, which is used for converging the light in different directions.
  • the first optical element may be a prism without a reflection film, a prism with a reflection film, or the first optical element may be a reflection mirror.
  • the element reflective surface of the first optical element is a reflective surface of the prism, and the element reflective surface can totally reflect light.
  • the element reflective surface of the first optical element refers to the surface of the reflective film, and the element reflective surface can reflect light.
  • the first optical element is a reflective mirror, the element reflective surface of the first optical element is the reflective surface of the reflective mirror, and the element reflective surface can reflect light.
  • the MEMS galvanometer can scan parallel beams to different directions, and the optical 4f system converges the parallel beams in different directions at the same exit pupil position on the waveguide structure coupled into the structure.
  • the solution of the present application can make the incident angle of the parallel laser beam irradiated on the MEMS galvanometer to be zero, thereby realizing zero-degree incident.
  • the zero-degree incident design is beneficial to reduce the spot diameter of the light beam on the MEMS galvanometer, thus reducing the volume of the MEMS galvanometer.
  • the solution of the present application can converge parallel light beams in different directions on the waveguide structure and couple into the same exit pupil position on the structure, so as to realize the common exit pupil of parallel light beams in different directions, which can reduce the coupling area of the structure.
  • the optical 4f system includes a first lens and a second lens, the first lens is located between the polarizing beam splitter film and the second lens, the second lens is connected to the second lens A lens is arranged at intervals; the center line of the MEMS galvanometer passes through the object-side focus of the first lens; the image-side focus of the first lens coincides with the object-side focus of the second lens; After passing through the first lens, the light rays are respectively focused on different positions on the image-side focal plane of the first lens, and enter the second lens from different positions of the second lens; the second lens The light rays entering the second lens from different positions are converged at the image-side focal point of the second lens, so that the light rays in different directions are converged.
  • the optical 4f system composed of lens groups has reliable structure, high manufacturability and good optical performance.
  • the first lens includes a doublet lens, a first aspherical lens and a second aspherical lens that are spaced in sequence, the doublet lens is close to the polarizing beam splitter film, and the aspherical lens away from the polarizing beam splitter film.
  • a doublet lens can be formed by cementing two lenses, for example, a biconvex lens and a plano-concave lens.
  • the first doublet lens can be used to correct chromatic aberration.
  • the first aspherical lens may be a convex lens, the curvature of which may vary continuously from the center to the edge.
  • the refractive surface of the second aspherical lens facing the first aspherical lens may be an external convex curved surface, and the refractive surface of the second aspherical lens facing away from the first aspherical lens may be, for example, an inwardly concave curved surface.
  • the Abbe number of the doublet lens is greater than or equal to 20.
  • the Abbe number is a physical quantity representing the chromatic aberration capability of a transparent medium, and the Abbe number of the doublet lens is greater than or equal to 20 to ensure the chromatic aberration correction capability of the first doublet lens.
  • the first lens and the second lens have the same structure.
  • the first lens and the second lens are arranged in mirror images, and have the same structure and mirror positions. This design has reliable structure, high manufacturability and good optical performance.
  • the first optical element is a prism, and the first optical element has a light-receiving surface and a first bonding surface; the normal of the light-receiving surface is along the first direction; the first The bonding surface is perpendicular to the reflecting surface of the element; the polarizing beam splitting film is arranged on the first bonding surface; the light-receiving surface is used to receive light; The light entering the first optical element is totally reflected; the range of the first included angle is Wherein n is the refractive index of the first optical element, and the unit of the first included angle is degree.
  • the first optical element is a prism without a reflective film, and can perform total reflection of light through the reflection surface of the element. This design can meet specific product requirements, and is reliable in structure, high in manufacturability, and good in optical performance.
  • the first optical element includes a connecting surface, and the connecting surface connects the light-receiving surface and the element reflecting surface.
  • the first optical element with this structure has reliable structure, high manufacturability and good optical performance.
  • the first optical element includes a prism and a reflective film, the reflective film is provided on the surface of the prism, and the reflective film has a reflective surface of the element; the range of the first included angle is (22.5°, 90°).
  • the first optical element is a prism provided with a reflective film, which can reflect light through the reflective film. This design can meet specific product requirements, and is reliable in structure, high in manufacturability, and good in optical performance.
  • the optical assembly further includes a second optical element, the second optical element has a second bonding surface, a setting surface, and a light exit surface; the second bonding surface and the polarized light splitting surface
  • the side of the film facing away from the first optical element is attached; the normal line of the setting surface is along the second direction; the light emitting surface faces away from the first optical element, and the normal line of the light emitting surface is along the the first direction; the phase retardation plate is arranged on the setting surface; the optical 4f system is located on the side of the second optical element away from the first optical element, and the optical 4f system is connected to the light output
  • the mask has spaces. Setting the second optical element can limit the propagation distance of the laser beam, which is beneficial to constrain the volume of the optical 4f system.
  • the second bonding surface extends beyond the first bonding surface, and the portion of the second bonding surface that extends beyond the first bonding surface and the element reflective surface encloses a gap area. Constructing the gap area allows for total reflection to meet specific product requirements.
  • the design structure of this implementation method is reliable, the manufacturability is high, and the optical performance is better.
  • the present application provides an optical assembly comprising a first polarizing beam splitter film, a first phase retarder, a MEMS galvanometer, a second phase retarder, a first curved mirror, a second a polarizing beam splitting film, a third phase retardation plate, a flat mirror, a fourth phase retardation plate and a second curved mirror;
  • the first polarizing beam splitting film forms a second angle with the first direction;
  • the first phase retardation plate Perpendicular to the second direction, the first phase retarder is located between the first polarizing beam splitter film and the MEMS galvanometer, and is spaced from the MEMS galvanometer, wherein the second direction orthogonal to the first direction;
  • the reflective surface of the MEMS galvanometer faces the first phase retarder;
  • the second phase retarder is parallel to the first phase retarder, and is parallel to the first phase retarder
  • a phase retarder is located on both sides of the first polarizing beam splitter film;
  • the second phase retarder is located between the first
  • the phase retarder is projected onto the reflective surface of the MEMS galvanometer; the MEMS galvanometer is used to reflect light to different directions through vibration, and the reflected light in different directions passes through the first phase delay again After passing through the first polarizing beam splitting film and the second phase retardation plate in sequence, it strikes different positions on the first curved mirror; the first curved mirror reflects the light , after the reflected light passes through the second phase retarder again, it is reflected by the first polarizing beam splitting film and converges to different positions on the second polarizing beam splitting film; the second polarizing beam splitting film Reflection, the reflected light passes through the third phase retarder and strikes different positions on the third plane mirror; the third plane mirror reflects the light, and the reflected light passes through the third phase retarder again.
  • the second curved mirror After passing through the second polarizing beam splitting film and the fourth phase retardation plate in sequence, it hits different positions on the second curved mirror; the second curved mirror reflects the light and reflects the light again through the After the four-phase retarder, it is reflected by the second polarizing beam splitter film and converged.
  • the optical assembly of the present application is a reflective optical 4f system composed of prisms and mirrors.
  • the solution of the present application can also make the incident angle of the parallel laser beam irradiated on the MEMS galvanometer to be zero, thereby realizing zero-degree incident.
  • the zero-degree incident design is beneficial to reduce the spot diameter of the light beam on the MEMS galvanometer, thus reducing the volume of the MEMS galvanometer.
  • the solution of the present application can converge parallel light beams in different directions on the waveguide structure and couple them into the same exit pupil position on the structure, so as to realize the common exit pupil of parallel light beams in different directions, which can reduce the Small coupling-in structure area.
  • the optical component includes a first prism; the first prism has a light-receiving surface, a first bonding surface and a first setting surface; the normal of the light-receiving surface is along the first direction; The first bonding surface and the light-receiving surface form the second included angle; the normal line of the first setting surface is along the second direction; the first polarizing beam splitting film is arranged on the first bonding surface the joint surface; the first phase retardation plate is arranged on the first setting surface.
  • Using the first prism can support the first polarizing beam splitting film and the first phase retardation plate, increase the structural stability of the optical assembly, and ensure the optical performance of the optical assembly.
  • the optical assembly includes a second prism; the second prism is arranged at intervals from the first prism; the second prism has a second bonding surface, a second setting surface and a light exit surface;
  • the second bonding surface is perpendicular to the first bonding surface;
  • the second setting surface is parallel to the first setting surface;
  • the light-emitting surface is parallel to the light-receiving surface and faces away from the light-receiving surface ;
  • the second polarizing beam splitter film is arranged on the second bonding surface;
  • the fourth phase retarder is arranged on the second setting surface.
  • the use of the second prism can support the second polarizing beam splitting film and the fourth phase retardation plate, increase the structural stability of the optical assembly, and ensure the optical performance of the optical assembly.
  • the optical component includes a third prism, and the third prism connects the first prism and the second prism; the first polarizing beam splitting film is located between the first bonding surface and the second prism. between the surfaces of the third prism; the second polarizing beam splitter film is located between the second bonding surface and the surface of the third prism; the second phase retardation plate and the third phase retardation plate are both located in the surface of the third prism.
  • Using the third prism can easily adjust the distance between the first prism and the second prism, and support the second phase retardation plate and the third phase retardation plate, increase the structural stability of the optical assembly, and ensure the optical performance of the optical assembly.
  • a surface of the first curved mirror facing the second phase retardation plate is attached to the second phase retardation plate, and the first curved mirror faces away from the second phase retardation
  • the surface of the film is arched in the direction away from the second phase retarder; and/or, the surface of the second curved mirror facing the fourth phase retarder is attached to the fourth phase retarder, so The surface of the first curved mirror facing away from the fourth phase retarder is arched in a direction away from the second phase retarder; and/or, the flat reflection mirror is attached to the third phase retarder .
  • the curved reflector, the plane reflector and the corresponding phase retarder are attached, which can ensure the optical performance, reduce the structure size, and increase the structural reliability.
  • the range of the second included angle is [25°, 65°]. This range is beneficial to ensure the optical performance of the optical component, and can also ensure that the structure of the optical component meets the actual needs.
  • the present application provides an optical assembly
  • the optical assembly includes a polarization beam splitter film, a first phase retardation plate, a MEMS galvanometer, a second phase retardation plate and a curved mirror; the polarization beam splitter film and The first direction forms a third angle; the first phase retardation plate is perpendicular to the second direction, and the first phase retardation plate is located between the polarizing beam splitting film and the MEMS galvanometer, and is connected to the The MEMS galvanometers are arranged at intervals, wherein the second direction is orthogonal to the first direction; the reflective surface of the MEMS galvanometer faces the first phase retarder; the second phase retarder is parallel on the first phase retardation film and on both sides of the polarizing beam splitter film respectively with the first phase retardation plate; the second phase retardation plate is located between the polarizing beam splitting film and the curved mirror , and is spaced from the curved mirror; the curved mirror has a surface that is arched in a direction away from the
  • the MEMS galvanometer is used to reflect light in different directions through vibration, and the reflected light in different directions passes through different regions of the first phase retarder again, and then passes through the polarization in turn
  • the beam splitting film and the second phase retarder converge to different positions on the curved mirror; the curved mirror reflects the light, and after the reflected light passes through the second phase retarder again, it is captured by the curved mirror.
  • the polarizing beam splitting film reflects and converges.
  • the optical component of the present application is a reflection-transmission hybrid optical 4f system composed of a prism, a mirror and a lens.
  • the solution of the present application can make the laser beam irradiated on the MEMS galvanometer to be concentrated, which is beneficial to reduce the spot diameter of the light beam on the MEMS galvanometer, and thus can reduce the volume of the MEMS galvanometer.
  • a reflection-transmission hybrid optical 4f system in the solution of the present application parallel beams in different directions can be converged on the waveguide structure and coupled into the same exit pupil position on the structure, so as to realize the common exit pupil of parallel beams in different directions.
  • the area of the coupling-in structure can be reduced.
  • the optical component includes a first plano-convex lens, the first plano-convex lens is located between the MEMS galvanometer and the first phase retardation plate, the first plano-convex lens is connected to the The MEMS galvanometers are arranged at intervals, and the center line of the first plano-convex lens is along the second direction. Using the first plano-convex lens can improve image quality.
  • the optical component includes a second plano-convex lens, the second plano-convex lens is spaced apart from the polarizing beam splitter film, and the center line of the second plano-convex lens is along the first direction; wherein, The light reflected by the polarizing beam splitting film is condensed after passing through the second plano-convex lens.
  • a second plano-convex lens can improve image quality.
  • the surface of the first plano-convex lens facing the first phase retardation plate is attached to the first phase retardation plate; and/or, the second plano-convex lens faces the second prism The surface is attached to the second prism.
  • the fit design of the plano-convex lens can make the structure compact, improve manufacturability, and ensure optical performance.
  • the optical assembly includes a convex lens and a concave lens arranged at intervals, the convex lens is located between the polarizing beam splitting film and the concave lens, and the center line of the convex lens and the concave lens is along the first One direction; the focal length of the convex lens is 5mm-15mm, and the focal length of the concave lens is -5mm to -20mm; wherein, the light emitted by the light source passes through the concave lens and the convex lens in turn, and then hits the polarizing beam splitter film superior.
  • concave lenses enables beam expansion and optimization of aberrations.
  • the use of a convex lens enables focusing of the laser beam, optimizing aberrations.
  • the optical component includes a first prism, and the first prism has a light-receiving surface, a first bonding surface, and a first setting surface; the normal line of the light-receiving surface is along the first direction; the first bonding surface and the light-receiving surface form the third angle; the normal line of the first setting surface is along the second direction; the polarizing beam splitter film is arranged on the first bonding surface above; the first phase retarder is arranged on the first setting surface.
  • the use of the first prism can support the polarizing beam splitting film and the first phase retardation plate, increase the structural stability of the optical assembly, and ensure the optical performance of the optical assembly.
  • the optical component includes a second prism, and the second prism has a second bonding surface, a second setting surface and a light emitting surface; the second bonding surface is bonded to the first The surface is parallel to the first bonding surface; the second setting surface is parallel to the first setting surface and faces away from the first setting surface; the light emitting surface is parallel to the light receiving surface, and facing away from the light receiving surface; the polarizing beam splitter film is arranged between the first bonding surface and the second bonding surface; the second phase retarder is arranged on the second setting surface.
  • the use of the second prism can support the polarizing beam splitting film and the second phase retardation plate, increase the structural stability of the optical assembly, and ensure the optical performance of the optical assembly.
  • the surface of the curved mirror facing the second phase retarder is attached to the second phase retarder.
  • the range of the third included angle is [25°, 65°]. This range is beneficial to ensure the optical performance of the optical component, and can also ensure that the structure of the optical component meets the actual needs.
  • the present application provides a projection module including a laser, a waveguide structure and the optical assembly, the laser and the waveguide structure are respectively located on opposite sides of the optical assembly in the first direction ; the laser is used for emitting a parallel laser beam propagating along the first direction to the optical assembly; the waveguide structure has an exit pupil position, and the exit pupil position is used for receiving the laser light emitted by the optical assembly.
  • the waveguide structure may include a waveguide, an out-coupling structure and an in-coupling structure, and both the out-coupling structure and the in-coupling structure may be provided on the waveguide.
  • the coupling-in structure can couple the laser beam emitted from the optical component into the waveguide.
  • the laser beam in the waveguide can be emitted from the outcoupling structure and projected to the human eye, allowing the user to see.
  • the volume of the MEMS galvanometer in the optical assembly can be reduced, the volume of the projection module can be reduced.
  • the present application provides an augmented reality device, comprising a structural member and the projection module, wherein the projection module is mounted on the structural member.
  • the structural member is used for fixing, accommodating and/or carrying the projection module.
  • the augmented reality device is, for example, an AR eye
  • the structural member may include, for example, a frame and a temple.
  • FIG. 1 is a schematic three-dimensional structure diagram of an augmented reality device according to Embodiment 1;
  • FIG. 2 is a schematic diagram showing the principle of projecting an image to the human eye by the projection module of the augmented reality device of FIG. 1;
  • Fig. 3 is a kind of optical path schematic diagram of the projection module in Fig. 2;
  • 4A is a schematic diagram of the principle that a projection module of a conventional augmented reality device projects an image to the human eye;
  • Figure 4B is a comparison of the spot diameters of laser beams in different directions on the MEMS galvanometer under the default attitude of the MEMS galvanometer;
  • Figure 4C is a comparison of the spot diameters of laser beams in different directions on the MEMS galvanometer under the deflection attitude of the MEMS galvanometer;
  • Fig. 5 is another kind of optical path schematic diagram in the projection module of Fig. 2;
  • Fig. 6 is another kind of optical path schematic diagram in the projection module of Fig. 2;
  • Fig. 7 is three kinds of optical path comparison schematic diagrams in the projection module of Fig. 2;
  • FIG. 8 shows a schematic diagram of a deformed structure of the first prism of the projection module of the first embodiment
  • FIG. 9 is a schematic diagram of a light path in the projection module of the second embodiment.
  • FIG. 10 is another schematic diagram of the light path in the projection module of the second embodiment
  • FIG 11 is another schematic diagram of the light path in the projection module of the second embodiment.
  • FIG. 12 is a schematic diagram showing the comparison of three light paths in the projection module of the second embodiment
  • FIG. 13 is a schematic diagram of a light path in the projection module of the third embodiment.
  • 15 is another schematic diagram of the optical path in the projection module of the third embodiment.
  • FIG. 16 is a schematic diagram showing the comparison of three light paths in the projection module of the third embodiment.
  • 17 is a schematic diagram of a light path in the projection module of the fourth embodiment.
  • 19 is another schematic diagram of the light path in the projection module of the fourth embodiment.
  • FIG. 20 is a schematic diagram showing the comparison of three light paths in the projection module of the fourth embodiment.
  • augmented reality Augmented Reality, AR
  • smart glasses including but not limited to smart glasses and head-mounted AR devices.
  • AR Augmented Reality
  • the following description takes the AR device being smart glasses as an example.
  • the AR device 10 of the first embodiment may include a structural member 11 and a projection module 12 .
  • the structural member 11 is used to fix, carry and accommodate the projection module 12 .
  • the structural member 11 may include, for example, a frame 111 and a temple 112 .
  • the glasses frame 111 may face the user's eyes, and the temples 112 may be placed on the user's ears.
  • the above structure of the structural member 11 is only an example, and other embodiments can be designed as required.
  • the projection module 12 may include a waveguide structure 12a, and at least most of the waveguide structure 12a may be fixed in the mirror frame 111 (for example, the waveguide 121 and the coupling-out structure 122 described below may all be fixed in the mirror frame 111).
  • the waveguide structure 12a can be used as a "lens" of the smart glasses, which can display images and transmit external light so that the human eye can see the external environment.
  • the projection module 12 may further include a portion 12b, and the portion 12b may be accommodated in the temple 112, for example.
  • the portion 12b is used to couple light into the waveguide structure 12a.
  • the above-mentioned installation position of the part 12b is only an example, and is not intended to limit the solution of this embodiment.
  • FIG. 2 is a schematic diagram showing the principle of the projection module 12 projecting an image to the human eye.
  • the waveguide structure 12 a in the projection module 12 may include a waveguide 121 , an out-coupling structure 122 and an in-coupling structure 123 , wherein the out-coupling structure 122 and the coupling-in structure 123 are both disposed on the waveguide 121 .
  • Portion 12b in projection module 12 may include optical assembly 13 and laser 124 .
  • Laser 124 may be, for example, an RGB laser.
  • the laser 124 is capable of emitting a laser beam, and the laser beam passes through the optical assembly 13 and then irradiates the coupling-in structure 123 , and the coupling-in structure 123 couples the laser beam into the waveguide 121 .
  • the laser beam propagates in the waveguide 121 in a total reflection manner, and finally exits from the coupling-out structure 122, and is projected to the human eye, so that the user can produce vision.
  • the coupling-out structure 122 , the coupling-in structure 123 and the portion 12 b are all located on the side close to the human eye, which is only an example. In fact, according to product design requirements, any of the above three can be on the side close to the human eye or the side far from the human eye.
  • any one of the coupling-out structure 122 and the coupling-in structure 123 it can also be provided inside the waveguide 121 .
  • a first direction Z and a second direction X may be defined for the optical component 13, and the first direction Z and the second direction X are orthogonal.
  • the first direction Z may include two directions on the coordinate axis Z
  • the second direction X may include two directions on the coordinate axis X.
  • the first direction Z may be approximately the length direction of the temples 112
  • the second direction X may be approximately one of the other two directions of the temples 112 (eg, the height direction, for example, in the viewing angle of FIG. 1, the height direction may be vertical). straight direction).
  • the optical assembly 13 may include a first optical element 131 , a polarizing beam splitter film 139 , a second optical element 136 , a phase retarder 138 , a MEMS galvanometer 137 and a lens group 132 . These will be explained one by one below.
  • both the first optical element 131 and the second optical element 136 may be prisms, and the two may be in contact with each other.
  • the first optical element 131 may have a light receiving surface 131a, a connecting surface 131b, an element reflecting surface 131c and a first bonding surface 131d which are connected end to end in sequence.
  • the light-receiving surface 131a may be a plane, and the normal line thereof may be substantially along the first direction Z.
  • the light-receiving surface 131a faces the laser 124 so as to receive the laser beam.
  • the connection surface 131b may be a plane, and its normal line may be substantially along the second direction X, or may be other directions.
  • the connection surface 131b connects the light-receiving surface 131a and the element reflection surface 131c.
  • the element reflection surface 131c may be a plane, which may form a first angle of 45° with the first direction Z, that is, the element reflection surface 131c may form a 135° angle with the connection surface 131b.
  • the first included angle of 45° is just an example.
  • the first included angle of other values the unit of the first included angle is degrees, and the range of the first included angle can be (without endpoint values).
  • n is the refractive index of the first optical element 131 .
  • the range of the first included angle may be (36.78°, 90°), specifically 38°, 45°, 60° or 75°.
  • the first included angle is within the above-mentioned range, which is beneficial to ensure the optical performance of the optical component 13, and can also ensure that the structure of the optical component 13 meets the actual needs.
  • the following description will mainly take the first included angle being 45° as an example for description.
  • the first bonding surface 131d connects the element reflecting surface 131c and the light receiving surface 131a.
  • the first attaching surface 131d may be a flat surface, which may be substantially perpendicular to the element reflecting surface 131c.
  • the first optical element 131 can be approximately regarded as a “triangular prism” with one corner missing, and the light-receiving surface 131a, the connecting surface 131b, the element reflecting surface 131c and the first bonding surface 131d are all part of the “triangular prism”. side.
  • the light-receiving surface 131a and the element reflecting surface can be flexibly adjusted according to product requirements
  • the connection relationship between 131c and the first bonding surface 131d may be eliminated, and the light-receiving surface 131a may intersect with the element reflecting surface 131c.
  • a surface may be added, so that the element reflection surface 131c is connected to the first bonding surface 131d through the added surface, instead of intersecting the element reflection surface 131c and the first bonding surface 131d.
  • the second optical element 136 may be a triangular prism.
  • the second optical element 136 may have a second bonding surface 136a, a setting surface 136b and a light emitting surface 136c connected end to end in sequence, and the second bonding surface 136a, the setting surface 136b and the light emitting surface 136c are all sides of a triangular prism.
  • the second bonding surface 136a may be parallel to and abut against the first bonding surface 131d.
  • One side of the second bonding surface 136a may substantially coincide with the boundary of the first bonding surface 131d, and the other side of the second bonding surface 136a may extend beyond the first bonding surface 131d. Therefore, the part of the second bonding surface 136a beyond the first bonding surface 131d and the element reflecting surface 131c can enclose a gap area 13a.
  • the gap area 13a is filled with an air medium.
  • the setting surface 136b may be a plane, and the normal line thereof may be along the second direction X. As shown in FIG.
  • the light exit surface 136c may be a plane, and its normal line may be along the first direction Z.
  • the second bonding surface 136a on the premise of ensuring the positional relationship between the second bonding surface 136a, the setting surface 136b and the light-emitting surface 136c of the second optical element 136, the second bonding surface 136a, setting The connection relationship between the surface 136b and the light-emitting surface 136c.
  • a surface may be added, so that the second bonding surface 136a is connected to the light-emitting surface 136c through the added surface, instead of intersecting the second bonding surface 136a and the light-emitting surface 136c.
  • Such a second optical element 136 is not a triangular prism.
  • the polarizing beam splitting film 139 may be a flat film layer, which may be located between the first bonding surface 131d and the second bonding surface 136a, and is not only abutted against the first bonding surface 131d, but also abuts against the first bonding surface 131d and the second bonding surface 131d. Two bonding surfaces 136a.
  • the polarizing beam splitter film 139 may cover the entire second bonding surface 136a, or may only cover a partial area of the second bonding surface 136a (the partial area includes the portion where the second bonding surface 136a and the first bonding surface 131d overlap) .
  • the polarizing beam splitting film 139 may be pasted between the first bonding surface 131d and the second bonding surface 136a through a bonding process; or the polarizing beam splitting film 139 may be a coating film formed on the first bonding surface 131d.
  • the phase retardation plate 138 may be in the shape of a flat plate, which may be disposed on the disposition surface 136 b of the second optical element 136 .
  • the phase retarder 138 is used to change the polarization state of the light transmitted through the phase retarder 138 .
  • the phase retarder 138 may be a quarter glass, and the phase of the light changes by ⁇ /4 each time the light passes through it, where ⁇ is the wavelength of the light.
  • first optical element 131 and the second optical element 136 and the connection relationship among the first optical element 131 , the second optical element 136 , the polarizing beam splitting film 139 , and the retardation plate 138 are only examples , which is not intended to limit the embodiments of the present application. In other embodiments, the above designs can be adjusted and deformed according to product requirements, and the deformed designs will be described in the following.
  • the MEMS galvanometer 137 and the phase retarder 138 are spaced apart from each other.
  • the MEMS galvanometer 137 can undergo reciprocating deflection under signal control (this reciprocating deflection may be referred to as vibration), so as to reflect the light incident on the reflective surface 137a of the MEMS galvanometer 137 at different angles to realize scanning imaging.
  • the maximum vibration angle of the MEMS galvanometer 137 is called the scan angle.
  • the normal of the reflective surface 137a of the MEMS galvanometer 137 is along the second direction X, and the posture of the MEMS galvanometer 137 at this time can be referred to as the default posture.
  • the lens group 132 may be located between the second optical element 136 and the coupling structure 123 .
  • the lens group 132 may be spaced apart from the light emitting surface 136c of the second optical element 136 , and the lens group 132 and the coupling structure 123 also have a space.
  • the centerline of the lens group 132 may be substantially along the first direction Z.
  • the lens group 132 may be composed of several lenses, and the centerlines of the respective lenses may be substantially coincident.
  • the lens group 132 may include a first doublet lens 133, a first aspherical lens 134, a second aspherical lens 135, a third aspherical lens 135', a fourth aspherical lens 134', and a second doublet, which are arranged in this order.
  • the cemented lens 133 ′ has a space between each of the above lenses.
  • the first doublet lens 133 is close to the second optical element 136
  • the second doublet lens 133 ′ is far from the second optical element 136 .
  • the first doublet lens 133 can be formed by cementing two lenses, for example, a double-convex lens and a plano-concave lens (the arc-shaped dotted line in the first doublet lens 133 in FIG. 3 indicates the plane The inner concave surface of a concave lens, or an outer convex surface of the lenticular lens).
  • the refractive indices of the two lenses in the first doublet lens 133 may be the same.
  • the Abbe number of the first doublet lens 133 (a physical quantity representing the dispersion power of a transparent medium) may be greater than or equal to 20, for example.
  • the first aspherical lens 134 can be, for example, a convex lens, the curvature of which can be continuously changed from the center to the edge.
  • the refractive index of the first aspherical lens 134 may be, for example, 1.3-2.0 (inclusive).
  • the refractive surface of the second aspherical lens 135 facing the first aspherical lens 134 may be, for example, a convex curved surface, and the refractive surface of the second aspherical lens 135 facing away from the first aspherical lens 134 may be, for example, a concave curved surface.
  • the refractive index of the second aspherical lens 135 may be, for example, 1.4-2.0 (inclusive).
  • the first doublet lens 133 , the first aspherical lens 134 and the second aspherical lens 135 may constitute the first lens group 132a.
  • the focal length of the first lens group 132a may be 3mm-10mm (inclusive).
  • the first lens group 132a is used to focus light.
  • the structures, materials and optical parameters of the third aspherical lens 135 ′ and the second aspherical lens 135 may be the same, and the two may be set in a mirror image (in this embodiment, the meaning of the mirror setting is two
  • the structure, material and optical parameters of the fourth aspheric lens 134' and the first aspheric lens 134 may be the same, and the two may be arranged as mirror images.
  • the structure, material and optical parameters of the second doublet lens 133' and the first doublet lens 133 may be the same, and the two may be arranged as mirror images.
  • the mirror surfaces of the three groups of lenses arranged in the mirror image can be the same surface, and the normal line of the mirror surface can be along the first direction Z.
  • the mirrored surface passes through the focal point of the first lens group 132a, that is, the mirrored surface is the image-side focal plane of the first lens group 132a.
  • the third aspherical lens 135', the fourth aspherical lens 134' and the second doublet lens 133' may constitute the second lens group 132b.
  • the focal length of the second lens group 132b may be 3mm-10mm (inclusive).
  • the second lens group 132b and the first lens group 132a are arranged in mirror images, and their mirror images are the image-side focal planes described above.
  • the second lens group 132b is used to convert the divergent light rays emitted from the focal plane of the first lens group 132a into parallel light rays and converge at the same exit pupil position (described below).
  • the first doublet lens 133 and the second doublet lens 133' can be used to correct chromatic aberration.
  • the first aspherical lens 134, the second aspherical lens 135, the third aspherical lens 135', and the fourth aspherical lens 134' may be used to correct aberrations.
  • Using the above-mentioned multiple lenses is beneficial to improve the image quality.
  • the lens mirror design of the first embodiment may not be used, but the positions of each lens may be set as required.
  • the structure and type of each lens can also be flexibly designed as required, and is not limited to the above.
  • the lens group 132 can constitute an optical 4f system, and the optical 4f system has the following characteristics: the center line of the MEMS galvanometer 137 can pass through the object-side focus of the first lens group 132a; the first lens group 132a The image-side focus of the second lens group 132b may coincide with the object-side focus of the second lens group 132b; the image-side focus of the second lens group 132b may be coincident with the exit pupil position on the coupling structure 123 .
  • the distance from the center line of the MEMS galvanometer 137 to the coupling structure 123 ie, the image plane
  • the lens group 132 is used to form the optical 4f system, which is only an example.
  • the optical 4f system may be composed of two lenses. These two lenses can be referred to as the first lens and the second lens respectively, the first lens and the second lens can be mirrored and arranged at intervals, the focal length of the first lens can be, for example, 3mm-10mm (including the endpoint value), the second lens can be The focal length can be, for example, 3mm-10mm (including the endpoint value).
  • the first lens is equivalent to the first lens group 132a composed of the first doublet lens 133, the first aspherical lens 134 and the second aspherical lens 135, and the second lens is equivalent to the third aspherical lens 135', the fourth lens A second lens group 132b composed of an aspherical lens 134' and a second doublet lens 133'.
  • the characteristics of the optical 4f system formed by the first lens and the second lens may be the same as those described above, and will not be repeated here.
  • optical elements can also be used to form an optical 4f system, for example, a liquid crystal lens, a metasurface, a mirror, a lens, etc. can be used to form an optical 4f system.
  • the parallel laser beam can be perpendicular to the MEMS galvanometer 137 in the default posture.
  • the incident angle of the parallel laser beam on the reflective surface 137a is made zero degrees. This characteristic may be referred to as zero-degree incidence.
  • the zero-degree incidence is beneficial to reduce the area of the reflection surface 137 a of the MEMS galvanometer 137 , thereby reducing the volume of the MEMS galvanometer 137 .
  • the use of the lens group 132 to form an optical 4f system can condense parallel laser beams in different directions into the same aperture range on the coupling structure 123 , so that the parallel laser beams in different directions can be in the same diameter range on the coupling structure 123 .
  • the exit pupil is formed within the aperture range. This characteristic may be referred to as a common exit pupil, and the position on the coupling structure 123 where the exit pupil is formed is referred to as the exit pupil position.
  • the common exit pupil is beneficial to reduce the area of the coupling structure 123 .
  • FIG. 3 can represent the transmission optical path of the laser beam under the default posture of the MEMS galvanometer 137 .
  • the laser 124 can emit a parallel laser beam propagating along the first direction Z, and the parallel laser beam is perpendicular to the first direction Z.
  • the light-receiving surface 131 a of an optical element 131 enters the first optical element 131 .
  • the second direction X propagates.
  • the laser beam along the second direction X will sequentially pass through the polarizing beam splitter film 139 , enter the second optical element 136 , pass through the phase retarder 138 , and irradiate on the reflective surface 137 a of the MEMS galvanometer 137 in parallel. Since the laser beam transmitted through the phase retarder 138 is along the second direction X, the incident angle of the parallel laser beam irradiated on the reflective surface 137a of the MEMS galvanometer 137 is zero, thereby achieving zero-degree incidence.
  • FIG. 4A is a schematic diagram showing the principle of projecting an image to a human eye by a projection module in a conventional augmented reality device.
  • the parallel laser beam emitted by the laser 124 is irradiated on the MEMS galvanometer 137 obliquely at any time, that is, the laser beam is irradiated on the MEMS galvanometer 137 at any time.
  • the angle of incidence on mirror 137 is not equal to zero. This will result in a larger spot diameter of the laser beam on the MEMS galvanometer 137 .
  • the zero-degree incidence design of the laser beam makes the spot diameter of the laser beam on the MEMS galvanometer 137 smaller. This principle will be analyzed below.
  • FIG. 4B shows the comparison of the diameters of the light spots formed by the parallel laser beam on the reflection surface 137a when the parallel laser beam irradiates the reflection surface 137a of the MEMS galvanometer 137 along the second direction X and in a direction deviating from the second direction X. As shown in FIG.
  • the outermost rays L1 and L2 of the parallel laser beams can be used to represent the parallel laser beams along the second direction X, and the parallel laser beams along the second direction X can be called parallel laser beams with zero degree incidence;
  • the outermost rays L1' and L2' of the laser beam represent parallel laser beams deviating from the second direction X, and the laser beams deviating from the second direction X may be referred to as non-zero-degree incident parallel laser beams.
  • the beam diameters of the parallel laser beams in the two directions are equal, denoted by d. It can be seen from the comparison in FIG. 4B that the spot diameter of the parallel laser beam along the second direction X on the reflection surface 137a is relatively small.
  • the spot diameter of the parallel laser beam deviated from the second direction X on the reflection surface 137a is larger.
  • the spot diameters of the laser beams in the two directions are relatively small, and it can be considered that FIG. 4B represents the minimum value of the spot diameters of the laser beams in the two directions on the reflection surface 137 a.
  • the MEMS galvanometer 137 can deflect the set scanning angle, and the deflected MEMS galvanometer 137 can be said to be in a deflection posture.
  • FIG. 4C shows that the MEMS galvanometer 137 is deflected by the set scanning angle (for example, the MEMS galvanometer 137 in FIG. 4A is deflected by a certain scanning angle in the counterclockwise direction, and the MEMS galvanometer 137 in FIG. 4A is represented by a dotted line) , the diameter of the light spot on the reflection surface 137a is compared between the parallel laser beam along the second direction X and the parallel laser beam deviated from the second direction X.
  • the spot apertures of the laser beams in the two directions in FIG. 4C are larger than those in FIG. 4A , and it can be considered that FIG. 4C represents the maximum value of the spot apertures of the laser beams in the two directions on the reflection surface 137 a.
  • the spot diameter of the laser beam on the reflective surface 137a of the MEMS galvanometer 137 also changes continuously. Therefore, from FIG. 4B to FIG. 4C, the range of the spot diameter of the laser beam on the reflective surface 137a can be represented, The two endpoints of this range are the minimum and maximum values described above, respectively.
  • the zero-degree incident laser beam is a parallel laser beam along the second direction X, it can also be considered that the design of the zero-degree incident laser beam can reduce the volume of the MEMS galvanometer 137 .
  • the conventional projection module needs to increase the field of view, it is often necessary to increase the scanning angle of the MEMS galvanometer, which will lead to an increase in the volume of the MEMS galvanometer.
  • the field of view of the projection module 12 can be equal to 2*the scanning angle of the MEMS galvanometer 137, that is, the MEMS galvanometer 137 is at the same scanning angle (same as the conventional MEMS galvanometer). A larger field of view can be obtained, but the volume of the MEMS galvanometer 137 does not need to be increased. Therefore, the solution of the first embodiment can increase the viewing angle without increasing the scanning angle and volume of the MEMS galvanometer 137 , thereby expanding the user's field of view and enhancing the user experience.
  • the laser beam incident on the reflective surface 137 a of the MEMS galvanometer 137 at zero degrees is reflected back by the MEMS galvanometer 137 and passes through the phase retarder 138 again.
  • the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2.
  • the polarizing beam splitter film 139 can transmit the laser beam from the laser 124 side and reflect the laser beam transmitted through the phase retarder 138 .
  • the laser type eg P light, S light
  • the type of the polarizing beam splitting film 139 and the type of the phase retarder 138 can be combined and matched, as long as the above-mentioned optical path can be realized.
  • the laser beam reflected by the polarizing beam splitting film 139 will exit from the light-emitting surface 136c of the second optical element 136 along the first direction Z, and enter the first doublet lens 133 along the first direction Z, and enter the lens Group 132.
  • the laser beam can be focused on the image-side focal point of the first lens group 132a, which is located in the first lens group 132a. on the focal plane of the image square.
  • the light emitted from the image-side focal plane is diverging and enters the third aspherical lens 135', the fourth aspherical lens 134' and the second doublet lens 133', and finally exits the second doublet lens 133' , thereby completing the transmission in the optical assembly 13 .
  • the laser beam emitted from the second doublet lens 133 ′ is a parallel laser beam along the first direction Z, and the parallel laser beam enters the exit pupil position on the coupling structure 123 (that is, the focus of the image side of the second lens group 132 b ) ).
  • FIGS. 5 and 6 respectively show the transmission optical paths of the laser beams of the MEMS galvanometer 137 under different deflection attitudes.
  • the propagation laws of the laser beams in FIGS. 5 and 6 are the same as those shown in FIG. However, the difference from FIG. 3 is that because the MEMS galvanometer 137 is deflected, the laser beam incident on the polarizing beam splitter film 139 is no longer in the second direction X, so the laser beam incident on the first doublet lens 133 is also deviated.
  • the first direction Z is also show the transmission optical paths of the laser beams of the MEMS galvanometer 137 under different deflection attitudes.
  • the propagation laws of the laser beams in FIGS. 5 and 6 are the same as those shown in FIG. However, the difference from FIG. 3 is that because the MEMS galvanometer 137 is deflected, the laser beam incident on the polarizing beam splitter film 139 is no longer in the second direction X, so the laser beam incident on the first doublet lens 133 is
  • the MEMS galvanometer 137 After the MEMS galvanometer 137 is deflected clockwise by a certain angle from the default posture in FIG. 3 , it reaches the first deflection posture. In the first deflection attitude, the laser beam reflected by the MEMS galvanometer 137 may deviate from the second direction X. Furthermore, the laser beam reflected by the polarization beam splitting film 139 deviates from the first direction Z, and the laser beam emitted from the light exit surface 136 c of the second optical element 136 deviates from the first direction Z.
  • the laser beam from the light-emitting surface 136c of the second optical element 136 passes through the first doublet lens 133, the first aspherical lens 134 and the second aspherical lens 135 in sequence, it is focused on the image square focus of the first lens group 132a. Another location on the plane (compare to Figure 3).
  • the light emitted from the image-side focal plane is diverging, and enters another position of the third aspherical lens 135' (compared with FIG. 3), and finally exits from another position of the second doublet lens 133' (compared with the second doublet lens 133').
  • FIG. 3 compare) out, thereby completing the transmission in the optical assembly 13 .
  • the laser beam emitted from the second doublet lens 133' is still a parallel laser beam, but the parallel beam is deviated from the first direction Z.
  • the laser beam emitted from the second doublet lens 133' can be deflected by a certain angle in the clockwise direction compared to the first direction Z.
  • the laser beam emitted from the second doublet lens 133 ′ can also be irradiated to the exit pupil position on the coupling structure 123 (that is, the focus of the image side of the second lens group 132 b ) .
  • the area of the MEMS galvanometer 137 coupled into the structure 123 irradiated by the laser beam in the first deflection attitude is substantially the same as the area irradiated by the laser beam on the MEMS galvanometer 137 in the default attitude.
  • the MEMS galvanometer 137 after the MEMS galvanometer 137 is deflected by a certain angle counterclockwise from the default posture in FIG. 3 , it reaches the second deflection posture.
  • the laser beam reflected by the MEMS galvanometer 137 may be deviated from the second direction X.
  • the laser beam reflected by the polarization beam splitting film 139 deviates from the first direction Z, and the laser beam emitted from the light exit surface 136 c of the second optical element 136 deviates from the first direction Z.
  • the laser beam from the light-emitting surface 136c of the second optical element 136 passes through the first doublet lens 133, the first aspherical lens 134 and the second aspherical lens 135 in sequence, it is focused on the image square focus of the first lens group 132a. Another location on the plane (compare to Figure 5).
  • the light emitted from the image-side focal plane is diverging, and enters another position of the third aspherical lens 135' (compared with FIG. 5), and finally exits from another position of the second doublet lens 133' (compared with the second doublet lens 133').
  • FIG. 5 compare) out, thereby completing the transmission in the optical assembly 13 .
  • the laser beam emitted from the second doublet lens 133' is still a parallel laser beam, but the parallel beam is deviated from the first direction Z.
  • the laser beam emitted from the second doublet lens 133' can be deflected by a certain angle in the counterclockwise direction compared to the first direction Z.
  • the laser beam emitted from the second doublet lens 133 ′ can also be irradiated to the exit pupil position on the coupling structure 123 (that is, the focus of the image side of the second lens group 132 b ) .
  • the area of the MEMS galvanometer 137 coupled into the structure 123 irradiated by the laser beam in the second deflection attitude is substantially the same as the area irradiated by the laser beam on the MEMS galvanometer 137 coupled into the structure 123 in the default attitude.
  • FIG. 7 shows the comparison of the transmission optical paths of the laser beams of the MEMS galvanometer 137 in the default posture, the first deflection posture and the second deflection posture.
  • the MEMS galvanometer 137 changes its posture when vibrating, the laser beams emitted from the light-emitting surface 136 c of the second optical element 136 will propagate in different directions respectively, and these laser beams are divergent.
  • the optical 4f system composed of the lens group 132 the laser beams propagating in different directions can be converged to the same exit pupil area on the coupling structure 123, and even the laser beams in different directions can be coupled in the coupling structure 123.
  • An exit pupil is formed within the same aperture range on the structure 123, thereby realizing a common exit pupil. Therefore, the first embodiment can realize a common exit pupil, which is beneficial to reduce the area of the coupling-in structure 123 .
  • the first angle formed by the element reflection surface 131c and the first direction Z can be other values, and the position and attitude of the laser 124 can be adjusted to ensure that the laser beam totally reflected by the element reflection surface 131c still follows the first direction. Propagating in two directions X, which can ensure that the optical performance of the optical component 13 is basically unchanged. For example, if the first included angle is greater than 45°, the position and attitude of the laser 124 can be adjusted so that the laser beam emitted by it propagates along the upper right (take the perspective of FIG. 7 as an example); on the contrary, if the first included angle is smaller than 45°, the position and attitude of the laser 124 can be adjusted so that the laser beam emitted by it propagates along the lower right (take the perspective of FIG. 7 as an example).
  • the optical components 13 can be arranged by making full use of the length dimension of the temples 112 of the AR device 10 , ensuring that the overall size of the AR device 10 is controllable.
  • the optical component 13 of the first embodiment can be designed.
  • the second optical element 136 , the polarizing beam splitting film 139 and the phase retarder 138 can be kept unchanged, and some structural deformations can be made to the first optical element 131 .
  • the first optical element 131' can be used to replace the first optical element 131, and the outline of the first optical element 131' can be substantially consistent with the outline of the cutout area 13a in FIG. 7 .
  • the first optical element 131' may be a triangular prism, and may have a setting surface 131'a, a connecting surface 131'b and a first bonding surface 131'c which are connected end to end in sequence.
  • the normal line of the connection surface 131'b is along the second direction X.
  • the setting surface 131'a forms a first angle of 45° with the first direction Z, that is, the setting surface 131'a can form a 45° angle with the connecting surface 131'b.
  • the first included angle of 45° is just an example. In fact, according to the needs of the product, it can also be a set angle of other values, and the range of the set angle can be (22.5°, 90°) (excluding the endpoint value).
  • the set angle may be 30°, 45°, 60°, or the like.
  • the first included angle is within the above-mentioned range, which is beneficial to ensure the optical performance of the optical component, and can also ensure that the structure of the optical component meets the actual needs.
  • the first bonding surface 131'c is parallel to the second bonding surface 136a of the second optical element 136.
  • a reflective film 140 may be provided on the setting surface 131'a, and the reflective film 140 may be formed on the setting surface 131'a by a lamination process or a coating process.
  • the reflection film 140 functions to reflect the laser beam emitted by the laser 124 , and the laser beam reflected by the reflection film 140 is along the second direction X. It can be seen that the reflecting film 140 replaces the element reflecting surface 131c capable of total reflection.
  • the surface of the reflective film 140 for reflecting the laser beam may also be referred to as the element reflective surface, and the element reflective surface of the reflective film 140 has a reflection performance equivalent to that of the element reflective surface 131c.
  • the first angle formed by the setting surface 131'a and the first direction Z can be other values, and the position and attitude of the laser 124 can be adjusted to ensure that the reflected light from the setting surface 131'a is adjusted.
  • the laser beam still propagates along the second direction X, which can ensure that the optical performance of the optical component is basically unchanged.
  • the first included angle is greater than 45°, the position and attitude of the laser 124 can be adjusted so that the laser beam emitted by it propagates along the upper right (take the perspective of FIG.
  • the position and attitude of the laser 124 can be adjusted so that the laser beam emitted by the laser 124 propagates along the lower right (take the perspective of FIG. 8 as an example).
  • the first optical element 131 may be replaced by a flat mirror.
  • the plane mirror is parallel to the first bonding surface 131c in FIG. 7 , the plane mirror reflects the laser beam emitted by the laser 124 , and the laser beam reflected by the plane mirror is along the second direction X.
  • the flat mirror is equivalent to the reflective film 140 in the embodiment shown in FIG. 8 .
  • the design of the second optical element 136 can limit the propagation distance of the laser beam, which is beneficial to constrain the volume of the lens group 132 .
  • the second optical element 136 may be eliminated if this is not required in other embodiments.
  • the polarizing beam splitting film 139 may be disposed on the first bonding surface 131 d of the first optical element 131 .
  • Corresponding support structures eg, brackets
  • the above-mentioned first optical element 131, or the above-mentioned first optical element 131' or the mirror can be used.
  • the second embodiment provides an optical assembly 23 , which can also realize zero-degree incidence of the laser beam and a common exit pupil.
  • the optical component 23 is a reflective optical 4f system composed of prisms and mirrors. The structure of the optical assembly 23 will be described in detail below.
  • the optical assembly 23 may include a first prism 232, a third prism 234, a second prism 235, a flat mirror 240, a first curved mirror 241, a MEMS galvanometer 233, a second curved mirror 237, a A polarizing beam splitter film 243 , a first phase retarder 231 , a third phase retarder 239 , a second polarizer beam splitter 238 , a fourth phase retarder 236 and a second phase retarder 242 .
  • a first prism 232 a third prism 234, a second prism 235, a flat mirror 240, a first curved mirror 241, a MEMS galvanometer 233, a second curved mirror 237, a A polarizing beam splitter film 243 , a first phase retarder 231 , a third phase retarder 239 , a second polarizer beam splitter 238 , a fourth phase retarder 236 and a second phase retarder 242 .
  • both the first prism 232 and the second prism 235 may be triangular prisms, and they are respectively connected to opposite sides of the third prism 234 .
  • the structures of the first prism 232 and the second prism 235 may be substantially the same, the two may be distributed as mirror images, and the mirror surface may be the symmetry plane of the third prism 234 .
  • the third prism 234 is used to make the laser beam travel according to the set optical path, and to define the distance between the first prism 232 and the second prism 235, so as to meet the optical path requirement of the reflective optical 4f system.
  • the first prism 232 may have a light receiving surface 232a, a first setting surface 232b and a first bonding surface 232c which are connected end to end in sequence.
  • the light-receiving surface 232a may be a plane, and the normal line thereof may be along the first direction Z.
  • the first setting surface 232b may be a plane, and the normal line thereof may be along the second direction X.
  • the first bonding surface 232c may be a flat surface, which may form an included angle of 45° with the light-receiving surface 232a , that is, the first bonding surface 232c and the first direction Z form a second included angle of 45°.
  • the second included angle of 45° is merely an example.
  • the second included angle can also be other values, and the range of the second included angle can be [25°, 65°] (including the endpoint value).
  • the second included angle may specifically be 25°, 35°, 45°, 55° or 65°.
  • the second included angle is within the above-mentioned range, which is beneficial to ensure the optical performance of the optical component 23, and can also ensure that the structure of the optical component 23 meets the actual needs.
  • the following description will mainly take the second included angle being 45° as an example for description.
  • the first abutting surface 232c abuts against one side of the third prism 234 .
  • the connection relationship between the light-receiving surface 232a, the first setting surface 232b and the first bonding surface 232c of the first prism 232 can be flexibly adjusted according to the needs of the product.
  • the first prism 232 may not be a triangular prism, and the number of its sides may be greater than three.
  • the light-receiving surface 232a and the first setting surface 232b may be connected by a surface, and the surface is not perpendicular to the light-receiving surface 232a and the first setting surface 232b.
  • the second prism 235 may have a light emitting surface 235a, a second setting surface 235b and a second bonding surface 235c which are connected end to end in sequence.
  • the light-emitting surface 235a may be a plane, which is parallel to the light-receiving surface 232a and faces away from the light-receiving surface 232a.
  • the second setting surface 235b may be a plane, which may be parallel and coplanar with the first setting surface 232b.
  • the second bonding surface 235c and the light emitting surface 235a form an included angle of 45°.
  • the second bonding surface 235c and the first bonding surface 232c are arranged in mirror images.
  • the second bonding surface 235c may be perpendicular to the first bonding surface 232c.
  • the second abutting surface 235c can abut against the other side of the third prism 234 .
  • the design of the second prism 235 can limit the propagation distance of the laser beam, which is beneficial to constrain the volumes of the first curved mirror 241 and the second curved mirror 237 .
  • the positional relationship (the absolute positional relationship with respect to the first direction Z, the second direction X, and On the premise of the relative positional relationship between them), the connection relationship between the light emitting surface 235a, the second setting surface 235b and the second bonding surface 235c can be flexibly adjusted according to the needs of the product.
  • the second prism 235 may not be a triangular prism, and the number of its sides may be greater than three.
  • the light-emitting surface 235a and the second setting surface 235b may be connected by a surface, and the surface is not perpendicular to the light-emitting surface 235a and the second setting surface 235b.
  • the second setting surface 235b may only be with the first setting surface 232b, but the two may not be coplanar (or not flush).
  • the first polarizing beam splitter film 243 is located on the first bonding surface 232c and may be disposed between the first bonding surface 232c and the surface of the third prism 234 .
  • the first polarizing beam splitter film 243 may be a flat film layer, which may cover the entire first bonding surface 232c, or may only cover a partial area of the first bonding surface 232c (the partial area includes the first bonding surface 232c and the second bonding surface 232c). the portion where the surfaces of the triangular prism 234 overlap).
  • the first polarizing beam splitting film 243 can be produced by a lamination process or a coating process.
  • the second polarizing beam splitter film 238 is located on the second bonding surface 235c and may be disposed between the second bonding surface 235c and the surface of the third prism 234 .
  • the second polarizing beam splitting film 238 may be a flat film layer, which may cover the entire second bonding surface 235c, or may only cover a partial area of the second bonding surface 235c (the partial area includes the second bonding surface 235c and the second bonding surface 235c the portion where the surfaces of the triangular prism 234 overlap).
  • the second polarizing beam splitting film 238 can be produced by a lamination process or a coating process.
  • the first phase retardation plate 231 may be in the shape of a flat plate, which may be disposed on the first setting surface 232 b of the first prism 232 .
  • the first phase retarder 231 is used to change the polarization state of the light transmitted through the first phase retarder 231 .
  • the first phase retardation plate 231 may be a quarter glass plate, and the phase of the light changes by ⁇ /4 every time the light passes through it.
  • the MEMS galvanometer 233 is located on the side of the first phase retarder 231 away from the first prism 232 , and the MEMS galvanometer 233 is opposite to the first phase retarder 231 at intervals.
  • the MEMS galvanometer 233 can undergo reciprocating deflection under signal control (this reciprocating deflection may be referred to as vibration), so as to reflect the light incident on the reflective surface 233a of the MEMS galvanometer 233 at different angles to realize scanning imaging.
  • the normal of the reflecting surface 233a of the MEMS galvanometer 233 is along the second direction X, and the posture of the MEMS galvanometer 233 at this time can be called the default posture.
  • the third phase retardation plate 239 may be in the shape of a flat plate, and may be disposed on the first setting surface 235 b of the second prism 235 .
  • the third phase retarder 239 is used to change the polarization state of the light transmitted through the third phase retarder 239 .
  • the third phase retardation plate 239 may be a quarter glass plate, and the phase of the light changes by ⁇ /4 every time the light passes through it.
  • the second curved mirror 237 may be located on the side of the fourth phase retardation plate 236 away from the second prism 235 .
  • the second curved mirror 237 may have a curved reflective surface, such as an aspherical curved reflective surface.
  • the curved reflection surface of the second curved mirror 237 (the black area in FIG. 9 represents the reflective layer in the second curved mirror 237 ) may be arched in a direction away from the fourth phase retardation plate 236 .
  • the centerline of the second curved mirror 237 may be along the second direction X.
  • the side surface of the second curved mirror 237 facing the fourth phase retardation plate 236 is attached to the fourth phase retardation plate 236, and the surface of the second curved mirror 237 connected to the fourth phase retardation plate 236 is flat.
  • the second curved mirror 237 is attached to the fourth phase retardation plate 236, which can make the structure compact and have better manufacturability.
  • the entire second curved mirror may be an arc-shaped plate-like structure, and the second curved mirror and the fourth phase retardation plate 236 are arranged at intervals. This design can meet the corresponding product requirements.
  • both the second phase retardation plate 242 and the fourth phase retardation plate 236 may be flat sheets, and both may be disposed on the surface of the third prism 234 whose normal line is along the second direction X.
  • the second phase retardation plate 242 may correspond to the first prism 232
  • the fourth phase retardation plate 236 may correspond to the second prism 235 .
  • Both the second phase retardation plate 242 and the fourth phase retardation plate 236 are used to change the polarization state of the light.
  • both the third phase retardation plate 239 and the fourth phase retardation plate 236 may be quarter glass plates, and the phase of the light changes by ⁇ /4 each time the light passes through them.
  • the second phase retardation plate 242 and the fourth phase retardation plate 236 can be connected as a whole, and the two can be combined into a phase retardation plate, that is, a phase retardation plate covers the normal on the third prism 234 along the second direction X.
  • the surface of the retarder corresponds to the first prism 232 and the second prism 235 .
  • the second phase retarder 242 and the fourth phase retarder 236 may also be separate phase retarders, and the two may not be connected.
  • the flat mirror 240 may be in the shape of a flat plate.
  • the flat mirror 240 and the second curved mirror 237 are located on opposite sides of the second prism 235 in the second direction X, respectively.
  • the flat reflection mirror 240 may be located on the side of the fourth phase retardation plate 236 away from the third prism 234 and attached to the fourth phase retardation plate 236 .
  • the flat reflection mirror 240 is attached to the fourth phase retardation plate 236, which can make the structure compact and have better manufacturability.
  • the flat mirror 240 is used to control the optical path to meet the optical path requirements of the optical assembly 23 .
  • the flat mirror 240 may also be spaced apart from the fourth phase retardation plate 236 to meet certain product requirements.
  • the first curved mirror 241 may be located on the side of the second phase retardation plate 242 away from the third prism 234 , and the first curved mirror 241 and the MEMS galvanometer 233 are respectively located on the first prism 232 in the second direction Opposite sides on the X.
  • the first curved reflection mirror 241 may have a curved reflection surface (the black area in FIG. 9 represents the reflection layer in the first curved reflection mirror 241 ), such as an aspheric curved reflection surface.
  • the curved reflection surface of the first curved mirror 241 may be arched in a direction away from the second phase retardation plate 242 .
  • the center line of the first curved mirror 241 may be along the second direction X.
  • the side surface of the first curved mirror 241 facing the second phase retardation plate 242 may be attached to the second phase retardation plate 242 , and the surface connecting the first curved mirror 241 and the second phase retardation plate 242 may be flat.
  • the first curved mirror 241 is attached to the second phase retardation plate 242, which can make the structure compact and have better manufacturability.
  • the entire first curved mirror may be an arc-shaped plate-like structure, and the first curved mirror and the second phase retardation plate 242 are arranged at intervals. This design can meet the corresponding product requirements.
  • optical assembly 23 of the second embodiment The structure of the optical assembly 23 of the second embodiment is described in detail above.
  • the working principle of the optical assembly 23 will be described below by analyzing the optical path.
  • FIG. 9 can represent the transmission optical path of the laser beam under the default posture of the MEMS galvanometer 233 .
  • the laser 124 emits a parallel laser beam propagating along the first direction Z, and the parallel laser beam is perpendicular to the
  • the light-receiving surface 232 a of the first prism 232 enters the first prism 232 and irradiates the first polarizing beam splitting film 243 . Since the first polarizing beam splitting film 243 forms an included angle of 45° with the light receiving surface 232a, the first polarizing beam splitting film 243 can reflect the parallel laser beam along the second direction X.
  • the parallel laser beam along the second direction X will pass through the first phase retarder 231 and irradiate on the reflective surface 233 a of the MEMS galvanometer 233 . Since the parallel laser beam transmitted through the first phase retardation plate 231 is along the second direction X, the incident angle of the parallel laser beam irradiated on the reflective surface 233a of the MEMS galvanometer 233 is zero, thereby achieving zero-degree incidence.
  • the solution of the second embodiment can reduce the volume of the MEMS galvanometer 233 by achieving zero-degree incidence, and can also increase the field of view angle without increasing the volume and scanning angle of the MEMS galvanometer 233. Expand user horizons and enhance user experience.
  • the parallel laser beam incident on the reflection surface 233 a of the MEMS galvanometer 233 at zero degrees is reflected back by the MEMS galvanometer 233 , and will pass through the first phase retarder 231 again along the second direction X.
  • the polarization state of the parallel laser beam changes, and the phase of the parallel laser beam changes by ⁇ /2. This enables the parallel laser beam to pass through the first polarization beam splitter film 243 instead of being reflected by the first polarization beam splitter film 243 when the parallel laser beam irradiates the first polarization beam splitter film 243 again.
  • the parallel laser beam passing through the first polarizing beam splitting film 243 will enter the third prism 234 , penetrate the second phase retardation plate 242 , and irradiate the first curved mirror 241 .
  • the first curved mirror 241 reflects the parallel laser beam.
  • the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2. This causes the laser beam to be reflected by the first polarizing beam splitting film 243 instead of passing through the first polarizing beam splitting film 243 when the laser beam is irradiated on the first polarizing beam splitting film 243 again.
  • the laser beam reflected by the first polarizing beam splitting film 243 is directed to the second polarizing beam splitting film 238 .
  • the second polarizing beam splitter film 238 reflects the laser beam toward the fourth phase retardation plate 236 .
  • the laser beam can pass through the fourth phase retarder 236 and strike the flat mirror 240 .
  • the flat mirror 240 reflects the laser beam back.
  • the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2.
  • This enables the laser beam to pass through the second polarizing beam splitting film 238 instead of being reflected by the second polarizing beam splitting film 238 when the laser beam is irradiated on the second polarizing beam splitting film 238 again.
  • the laser beam passing through the second polarizing beam splitting film 238 will enter the second prism 235 and pass through the third phase retardation plate 239 to be irradiated on the second curved mirror 237 .
  • the second curved mirror 237 reflects the laser beam back.
  • the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2.
  • the laser beam reflected by the second polarizing beam splitting film 238 is emitted from the light emitting surface 235 a of the second prism 235 , thereby completing the transmission in the optical assembly 23 .
  • the laser beam emitted from the light-emitting surface 235 a is a parallel laser beam along the first direction Z, and the parallel laser beam is irradiated on the coupling-in structure 123 .
  • FIG. 10 and FIG. 11 respectively show the transmission optical paths of the laser beams of the MEMS galvanometer 233 under different deflection attitudes.
  • the propagation laws of the laser beams in FIGS. 10 and 11 are the same as those shown in FIG. However, the difference from FIG. 9 is that since the MEMS galvanometer 233 is deflected, the parallel laser beam reflected by the MEMS galvanometer 233 is no longer along the second direction X, so the parallel laser beam emitted from the second prism 235 is no longer along the second direction X.
  • the first direction Z is that since the MEMS galvanometer 233 is deflected, the parallel laser beam reflected by the MEMS galvanometer 233 is no longer along the second direction X, so the parallel laser beam emitted from the second prism 235 is no longer along the second direction X.
  • the first direction Z is that since the MEMS galvanometer 233 is deflected, the parallel laser beam reflected by the MEMS galvanometer 233 is no longer along the second direction
  • the MEMS galvanometer 233 After the MEMS galvanometer 233 is deflected clockwise by a certain angle from the default posture in FIG. 9 , it reaches the first deflection posture. In the first deflection attitude, the parallel laser beam reflected by the MEMS galvanometer 233 may deviate from the second direction X. Finally, the parallel laser beam emitted from the second prism 235 is also deviated from the first direction Z. For example, in the viewing angle of FIG. 10 , the parallel laser beam emitted from the second prism 235 can be deflected by a certain angle in the counterclockwise direction compared to the first direction Z.
  • the laser beam emitted from the second prism 235 can also irradiate the coupling structure 123 .
  • the area of the MEMS galvanometer 233 coupled into the structure 123 irradiated by the laser beam in the first deflection posture is substantially the same as the area irradiated by the laser beam on the MEMS galvanometer 233 in the default posture of the coupled structure 123 .
  • the MEMS galvanometer 233 after the MEMS galvanometer 233 is deflected by a certain angle counterclockwise from the default posture in FIG. 3 , it reaches the second deflection posture. In the second deflection attitude, the parallel laser beam reflected by the MEMS galvanometer 233 may deviate from the second direction X. Finally, the parallel laser beam emitted from the second prism 235 is also deviated from the first direction Z. For example, in the viewing angle of FIG. 11 , the parallel laser beam emitted from the second prism 235 can be deflected by a certain angle in the clockwise direction compared to the first direction Z.
  • the laser beam emitted from the second prism 235 can also be irradiated on the coupling structure 123 .
  • the area of the MEMS galvanometer 233 coupled into the structure 123 illuminated by the laser beam in the second deflection attitude is substantially the same as the area of the MEMS galvanometer 233 coupled into the structure 123 illuminated by the laser beam in the default posture.
  • FIG. 12 shows the comparison of the transmission optical paths of the laser beams of the MEMS galvanometer 233 in the default posture, the first deflection posture and the second deflection posture.
  • the MEMS galvanometer 233 changes its posture when vibrating, the parallel laser beams reflected by the MEMS galvanometer 233 will propagate in different directions respectively, so these parallel laser beams are generally divergent.
  • the optical assembly 23 constitutes an optical 4f system as a whole, which can make parallel laser beams propagating in different directions converge on the same area on the coupling structure 123, even in different directions.
  • All of the parallel laser beams can form exit pupils within the same aperture range on the coupling structure 123, thereby realizing a common exit pupil. Therefore, the second embodiment can realize a common exit pupil, which is beneficial to reduce the area of the coupling-in structure 123 .
  • the second angle formed by the first bonding surface 232c and the first direction Z may be other values.
  • optical assembly 23 of the second embodiment has fewer elements arranged in the first direction Z, and occupies a smaller size; more elements are arranged in the second direction X, and occupies a certain size (compared to the optical assembly of the first embodiment).
  • component 13 This is a structural design according to the needs of the product.
  • optical component 23 of the second embodiment can be designed.
  • the third prism 234 may be eliminated, leaving other elements.
  • corresponding supporting structures eg, brackets
  • the optical path in this embodiment can be basically the same as that in the second embodiment.
  • the second prism 235, the third prism 234, the third phase retardation plate 239, the fourth phase retardation plate 236, the second polarizing beam splitter film 238, the flat mirror 240 and the second curved surface reflection can be eliminated Mirror 237, other elements retained.
  • a corresponding support structure eg, a bracket
  • the optical path in this embodiment can be basically the same as that in the second embodiment.
  • first prism 232, the second prism 235 and the third prism 234 can be eliminated, and other elements are retained.
  • a corresponding support structure (such as a bracket) can be designed to support the first polarizing beam splitting film 243, the first phase retardation plate 231, the third phase retardation plate 239, the second polarizing beam splitting film 238, the fourth phase retardation plate 236 and the The second phase retarder 242 .
  • the optical path in this embodiment can be basically the same as that in the second embodiment.
  • the third embodiment provides an optical component 33 , which can also reduce the volume of the MEMS galvanometer and realize a common exit pupil.
  • the optical component 33 is a reflection-transmission hybrid optical 4f system composed of prisms, mirrors and lenses. The structure of the optical assembly 33 will be described in detail below.
  • the optical assembly 33 may include a first prism 337 , a second prism 332 , a curved mirror 331 , a first plano-convex lens 335 and a second plano-convex lens 333 , a polarizing beam splitter 338 , a first phase retarder 336 and The second phase retarder 339 . These will be explained one by one below.
  • both the first prism 337 and the second prism 332 can be triangular prisms, and the two can be in contact with each other.
  • the first prism 337 may have a light receiving surface 337b, a first setting surface 337c and a first bonding surface 337a which are connected end to end in sequence.
  • the light-receiving surface 337b may be a plane, and the normal line thereof may be along the first direction Z.
  • the first setting surface 337c may be a plane, and the normal line thereof may be along the second direction X.
  • the first bonding surface 337a may be a flat surface, which may form an included angle of 45° with the light-receiving surface 337b , that is, the first bonding surface 337a and the first direction Z form a third included angle of 45°.
  • the third included angle of 45° is merely an example.
  • the third included angle can also be other values, and the range of the second included angle can be [25°, 65°] (including endpoint values).
  • the second included angle may specifically be 25°, 35°, 45°, 55° or 65°.
  • the third included angle is within the above-mentioned range, which is beneficial to ensure the optical performance of the optical component 33, and can also ensure that the structure of the optical component 33 meets the actual needs.
  • the following description will mainly take the third included angle being 45° as an example for description.
  • the second prism 332 may have a light emitting surface 332b, a second setting surface 332a and a second bonding surface 332c which are connected end to end in sequence.
  • the light-emitting surface 332b may be a flat surface, which may be parallel to the light-receiving surface 337b and face away from the light-receiving surface 337b.
  • the second setting surface 332a may be a flat surface, which may be parallel to the first setting surface 337c and face away from the first setting surface 337c.
  • the second bonding surface 332c may be a flat surface, which may be parallel to the first bonding surface 337a and face the first bonding surface 337a.
  • the first prism 337 after ensuring the positional relationship of the above-mentioned surfaces of the first prism 337 (the absolute positional relationship with respect to the first direction Z, the second direction X, and the relative positional relationship between them), and the second On the premise of the positional relationship of the above-mentioned surfaces of the prism 332 (the absolute positional relationship with respect to the first direction Z, the second direction X, and the relative positional relationship between them), the first prism 337 can be flexibly adjusted according to product needs with the structure of the second prism 332.
  • the first prism 337 and/or the second prism 332 may not be triangular prisms.
  • the polarizing beam splitter film 338 may be located between the first bonding surface 337a and the second bonding surface 332c, and it can be considered that the polarizing beam splitting film 338 is disposed on the first bonding surface 337a or the second bonding surface 332c .
  • the polarizing beam splitter film 338 can be produced by a lamination process or a coating process.
  • the first phase retardation plate 336 is provided on the first setting surface 337 a of the first prism 337 .
  • the first phase retarder 336 is used to change the polarization state of the transmitted light.
  • the first phase retardation plate 336 may be a quarter glass plate, and the phase of the light changes by ⁇ /4 every time the light passes through it.
  • the second phase retardation plate 339 is provided on the second setting surface 332 a of the second prism 332 .
  • the second phase retardation plate 339 is used to change the polarization state of the transmitted light.
  • the second phase retardation plate 339 may be a quarter glass plate, and the phase of the light changes by ⁇ /4 every time the light passes through it.
  • the curved mirror 331 may be located on the side of the second phase retardation plate 339 away from the second prism 332 .
  • the curved mirror 331 may have a curved reflective surface, such as an aspherical curved reflective surface.
  • the curved reflection surface of the curved mirror 331 may be arched in a direction away from the second phase retardation plate 339 .
  • the centerline of the curved mirror 331 may be along the second direction X.
  • the surface of the curved mirror 331 facing the second phase retardation plate 339 may be attached to the second phase retardation plate 339 , and the surface of the curved mirror 331 connected to the second phase retardation plate 339 may be flat.
  • the form-fitting design enables a compact structure for improved manufacturability.
  • the curved mirror 331 may have an arc-shaped plate structure as a whole, and the curved mirror 331 may be opposite to the second phase retardation plate 339 at intervals. This design can meet certain product requirements.
  • the first plano-convex lens 335 may be located on the side of the first phase retardation plate 336 away from the first prism 337 .
  • the surface of the first plano-convex lens 335 facing the first phase retardation plate 336 may be attached to the first phase retardation plate 336 .
  • the form-fitting design enables a compact structure for improved manufacturability.
  • the surface of the first plano-convex lens 335 facing away from the first phase retardation plate 336 may be arched in a direction away from the first phase retardation plate 336 .
  • the center line of the first plano-convex lens 335 may be along the second direction X.
  • the first plano-convex lens 335 may be spaced apart from the second phase retardation plate 339 . This design can meet certain product requirements.
  • the MEMS galvanometer 334 may be located on the side of the first plano-convex lens 335 away from the first prism 337 , and the MEMS galvanometer 334 may be spaced and opposite to the first plano-convex lens 335 .
  • the MEMS galvanometer 334 can undergo reciprocating deflection under signal control (this reciprocating deflection may be referred to as vibration), so as to reflect the light incident on the reflective surface 334a of the MEMS galvanometer 334 at different angles to realize scanning imaging.
  • the normal of the reflecting surface 334a of the MEMS galvanometer 334 is along the second direction X, and the posture of the MEMS galvanometer 334 at this time can be referred to as the default posture.
  • the second plano-convex lens 333 may be located on the side of the light-emitting surface 332 b of the second prism 332 away from the first prism 337 .
  • the surface of the second plano-convex lens 333 facing the light emitting surface 332b may be attached to the light emitting surface 332b.
  • the form-fitting design enables a compact structure for improved manufacturability.
  • a surface of the second plano-convex lens 333 facing away from the second prism 332 may be arched in a direction facing away from the second prism 332 .
  • the center line of the second plano-convex lens 333 may be along the first direction Z.
  • the second plano-convex lens 333 may be spaced apart from the light-emitting surface 332b of the second prism 332, and this design can meet certain product requirements.
  • optical component 33 of the third embodiment is described in detail above.
  • the working principle of the optical assembly 33 will be described below by analyzing the optical path.
  • FIG. 13 may represent the transmission optical path of the laser beam under the default attitude of the MEMS galvanometer 334 .
  • the laser 124 emits a parallel laser beam propagating along the first direction Z, and the parallel laser beam is perpendicular to the
  • the light-receiving surface 337 b of the first prism 337 enters the first prism 337 and irradiates the polarizing beam splitting film 338 . Since the polarizing beam splitting film 338 and the light receiving surface 337b form an included angle of 45°, the polarizing beam splitting film 338 can reflect the parallel laser beam along the second direction X.
  • the parallel laser beam along the second direction X will pass through the first phase retarder 336 and irradiate on the first plano-convex lens 335 .
  • the first plano-convex lens 335 can converge the parallel laser beam, so that the diameter of the laser beam emitted from the first plano-convex lens 335 gradually shrinks, and irradiates the reflective surface 334 a of the MEMS galvanometer 334 .
  • the MEMS galvanometer 334 by making the MEMS galvanometer 334 in the default posture, the normal of the reflective surface 334a of the MEMS galvanometer 334 is along the second direction X, and the focused laser beam is irradiated on the reflective surface 334a , the area of the reflective surface 334 a can be made smaller, thereby reducing the volume of the MEMS galvanometer 334 .
  • the reflection surface 334 a of the MEMS galvanometer 334 reflects the laser beam back, and the reflected laser beam passes through the first plano-convex lens 335 and the first phase retardation plate 336 again.
  • the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2. This enables the laser beam to pass through the polarizing beam splitting film 338 instead of being reflected by the polarizing beam splitting film 338 when the laser beam is irradiated on the polarizing beam splitting film 338 again.
  • the laser beam passing through the polarizing beam splitter film 338 will enter the second prism 332 , penetrate the second phase retardation plate 339 , and irradiate the curved mirror 331 .
  • the curved mirror 331 reflects the laser beam back.
  • the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2. This causes the laser beam to be reflected by the polarizing beam splitting film 338 instead of being transmitted through the polarizing beam splitting film 338 when the laser beam is irradiated on the polarizing beam splitting film 338 again.
  • the laser beam reflected by the polarization beam splitting film 338 is emitted from the light-emitting surface 332 b of the second prism 332 and passes through the second plano-convex lens 333 , thereby completing the transmission in the optical assembly 23 .
  • the laser beam emitted from the second plano-convex lens 333 is a parallel laser beam along the first direction Z, and the parallel laser beam strikes the coupling-in structure 123 .
  • FIGS. 14 and 15 respectively show the transmission optical paths of the laser beams of the MEMS galvanometer 334 under different deflection attitudes.
  • the propagation laws of the laser beams in FIGS. 14 and 15 are the same as those shown in FIG. However, unlike FIG. 13 , since the MEMS galvanometer 334 is deflected, the parallel laser beam emitted from the second plano-convex lens 333 is no longer along the first direction Z.
  • the MEMS galvanometer 334 is deflected clockwise by a certain angle from the default posture in FIG. 13 , it reaches the first deflection posture.
  • the parallel laser beam emitted from the second plano-convex lens 333 is also deviated from the first direction Z.
  • the parallel laser beam emitted from the second plano-convex lens 333 can be deflected by a certain angle in the counterclockwise direction compared with the first direction Z.
  • the laser beam emitted from the second plano-convex lens 333 can also be irradiated on the coupling-in structure 123 .
  • the area irradiated by the laser beam on the MEMS galvanometer 334 coupled into the structure 123 in the first deflection attitude is substantially the same as the area irradiated by the laser beam on the MEMS galvanometer 334 in the default attitude coupled into the structure 123 .
  • the MEMS galvanometer 334 is deflected by a certain angle counterclockwise from the default posture in FIG. 13 , it reaches the second deflection posture.
  • the parallel laser beam emitted from the second plano-convex lens 333 is also deviated from the first direction Z.
  • the parallel laser beam emitted from the second plano-convex lens 333 can be deflected by a certain angle in the clockwise direction compared to the first direction Z.
  • the laser beam emitted from the second plano-convex lens 333 can also be irradiated on the coupling-in structure 123 .
  • the area irradiated by the laser beam on the MEMS galvanometer 334 coupled into the structure 123 in the second deflection attitude is substantially the same as the area irradiated by the laser beam on the MEMS galvanometer 334 coupled in the structure 123 in the default attitude.
  • FIG. 16 shows the comparison of the transmission optical paths of the laser beams of the MEMS galvanometer 334 in the default posture, the first deflection posture and the second deflection posture.
  • the MEMS galvanometer 334 changes its posture when vibrating, the laser beams reflected by the MEMS galvanometer 334 will propagate in different directions respectively, so these laser beams are divergent.
  • the optical assembly 33 can form a reflection-transmission hybrid optical 4f system as a whole, which can make the laser beams propagating in different directions converge to the same area on the coupling structure 123, That is, even laser beams in different directions can form exit pupils within the same aperture range on the coupling-in structure 123, so as to realize a common exit pupil. Therefore, the third embodiment can realize a common exit pupil, which is beneficial to reduce the area of the coupling-in structure 123 .
  • the third angle formed by the first bonding surface 337a and the first direction Z may be other values.
  • the position and attitude of the laser 124, and making adaptive adjustments to the specific structures and positions of the curved mirror 331, the first plano-convex lens 335 and the second plano-convex lens 333 it is ensured that the polarized light splitting on the first bonding surface 337a is ensured.
  • the laser beam reflected by the film 338 still propagates along the second direction X, which ensures that the optical path in the optical assembly 33 is basically unchanged, so that the optical performance of the optical assembly 33 is basically unchanged.
  • the optical assembly 33 of the third embodiment has fewer elements arranged in the first direction Z, and occupies a smaller size; more elements are arranged in the second direction X, and occupies a certain size (compared to the optical assembly of the first embodiment).
  • component 13 This is a structural design according to the needs of the product.
  • the use of the first plano-convex lens 335 and the second plano-convex lens 333 can improve the imaging quality.
  • the first plano-convex lens 335 and/or the second plano-convex lens 333 may be eliminated.
  • the second prism 332 can limit the propagation distance of the laser beam, which is beneficial to constrain the volumes of the first plano-convex lens 335 and the second plano-convex lens 333 . If this point is not considered in other embodiments, the second prism 332 may be eliminated. Wherein, a corresponding support structure (eg a bracket) can be designed to support the second phase retardation plate 339 .
  • first prism 337 can also be eliminated.
  • a corresponding support structure eg, a bracket
  • a bracket can be designed to support the polarizing beam splitting film 338 and the first phase retardation plate 336 .
  • the fourth embodiment provides an optical component 43 , which can also reduce the volume of the MEMS galvanometer and realize a common exit pupil.
  • the optical component 43 is also a reflection-transmission hybrid optical 4f system composed of prisms, mirrors and lenses.
  • the difference from the third embodiment is that the position of the lens in the optical assembly 43 is different from that of the lens in the optical assembly 33 .
  • the structure of the optical assembly 43 will be described in detail below.
  • the optical component 43 may include a concave lens 431, a convex lens 432, a first prism 433, a second prism 436, a first polarizing beam splitter film 439, a first phase retardation plate 434, a second phase retardation plate 437, a MEMS vibration Mirror 435 and curved mirror 438. These will be explained one by one below.
  • the concave lens 431 and the convex lens 432 are arranged at intervals, and the center lines of both can be along the first direction Z.
  • the convex lens 432 is located between the concave lens 431 and the first prism 433 , and the convex lens 432 and the first prism 433 are spaced apart.
  • the focal length of the concave lens 431 may be, for example, -5 mm to -20 mm.
  • the focal length of the convex lens 432 may be, for example, 5 mm to 15 mm.
  • the concave lens 431 is used to expand the laser beam and optimize the aberration.
  • a convex lens 432 is used to focus the laser beam, optimizing aberrations.
  • the lens group formed by the concave lens 431 and the convex lens 432 is equivalent to the first lens group 132a formed by the first doublet lens 133 , the first aspheric lens 134 and the second aspheric lens 135 in the first embodiment.
  • the lens group is not limited to being formed by two lenses, the concave lens 431 and the convex lens 432 , and the number and type of the lenses in the lens group can be designed as required.
  • the first prism 433 has a light receiving surface 433b, a first setting surface 433c and a first bonding surface 433a which are connected end to end in sequence.
  • the light-receiving surface 433b may be a plane, and the normal line thereof may be along the first direction Z.
  • the first setting surface 433c may be a plane, and the normal line thereof may be along the second direction X.
  • the first bonding surface 433a may be a flat surface, which may form an included angle of 45° with the light-receiving surface 433b , that is, the first bonding surface 433a and the first direction Z form a third included angle of 45°.
  • the third included angle of 45° is merely an example.
  • the third included angle can also be other values, and the range of the second included angle can be [25°, 65°] (including the endpoint value).
  • the second included angle may specifically be 25°, 35°, 45°, 55° or 65°.
  • the third included angle is within the above-mentioned range, which is beneficial to ensure the optical performance of the optical component 43, and can also ensure that the structure of the optical component 43 meets the actual needs.
  • the following description will mainly take the third included angle being 45° as an example for description.
  • the second prism 436 may have a light emitting surface 436b, a second setting surface 436c and a second bonding surface 436a which are connected end to end in sequence.
  • the light-emitting surface 436b may be a flat surface, which may be parallel to the light-receiving surface 433b and face away from the light-receiving surface 433b.
  • the second setting surface 436c may be a flat surface, which may be parallel to the first setting surface 433c and face away from the first setting surface 433c.
  • the second bonding surface 436a may be a flat surface, which may be parallel to the first bonding surface 433a and face the first bonding surface 433a.
  • the first prism 436 can be flexibly adjusted according to product needs with the structure of the second prism 436 .
  • the first prism 433 and/or the second prism 436 may not be triangular prisms.
  • the first polarizing beam splitter film 439 can be located between the first bonding surface 433a and the second bonding surface 436a, and it can be considered that the first polarizing beam splitting film 439 is provided on the first bonding surface 337a or the second bonding surface 337a on the joint surface 332c.
  • the first polarizing beam splitting film 439 can be produced by a lamination process or a coating process.
  • the first phase retardation plate 434 is provided on the first setting surface 433 c of the first prism 433 .
  • the first phase retarder 434 is used to change the polarization state of the transmitted light.
  • the first phase retardation plate 434 may be a quarter glass plate, and the phase of the light changes by ⁇ /4 every time the light passes through it.
  • the second phase retardation plate 437 is provided on the second setting surface 436 c of the second prism 436 .
  • the second phase retardation plate 437 is used to change the polarization state of the transmitted light.
  • the second phase retardation plate 437 may be a quarter glass plate, and the phase of the light changes by ⁇ /4 every time the light passes through it.
  • the curved mirror 438 may be located on the side of the second phase retardation plate 437 away from the second prism 436 .
  • the surface of the curved mirror 438 facing the second phase retardation plate 437 can be attached to the second phase retardation plate 437 , and the attached design can make the structure compact and improve the manufacturability.
  • the curved mirror 438 may have a curved reflective surface, such as an aspherical curved reflective surface.
  • the curved reflection surface of the curved mirror 438 may be arched in a direction away from the second phase retardation plate 437 .
  • the centerline of the curved mirror 438 may be along the second direction X.
  • the curved mirror may have an arc-shaped plate-like structure, and the curved mirror may be opposite to the second phase retardation plate 437 at intervals.
  • the MEMS galvanometer 435 may be located on the side of the first phase retarder 434 away from the first prism 433 , and the MEMS galvanometer 435 may be spaced and opposite to the first phase retarder 434 .
  • the MEMS galvanometer 435 can undergo reciprocating deflection under signal control (this reciprocating deflection may be referred to as vibration), so as to reflect the light incident on the reflective surface 435a of the MEMS galvanometer 435 at different angles to realize scanning imaging.
  • the normal of the reflective surface 435a of the MEMS galvanometer 435 is along the second direction X, and the posture of the MEMS galvanometer 435 at this time can be referred to as the default posture.
  • optical component 43 of the fourth embodiment is described in detail above.
  • the working principle of the optical assembly 43 will be described below by analyzing the optical path.
  • FIG. 17 may represent the transmission optical path of the laser beam in the default posture of the MEMS galvanometer 435 .
  • the laser 124 emits a parallel laser beam propagating in the first direction Z, and the parallel laser beams pass through the first direction Z in turn.
  • the concave lens 431 and the convex lens 432 After passing through the concave lens 431 and the convex lens 432, it becomes a condensed laser beam.
  • the condensed laser beam enters the first prism 433 from the light receiving surface 433 b of the first prism 433 and irradiates the first polarizing beam splitter film 439 .
  • the first polarizing beam splitting film 439 and the light receiving surface 433 b form an included angle of 45°, the first polarizing beam splitting film 439 can reflect the focused laser beam toward the first retardation plate 434 . After the laser beam passes through the first phase retardation plate 434 , it can be irradiated on the reflective surface 435 a of the MEMS galvanometer 435 , and the aperture of the laser beam emitted from the first phase retardation plate 434 can gradually shrink.
  • the MEMS galvanometer 435 by making the MEMS galvanometer 435 in the default posture, the normal of the reflective surface 435a of the MEMS galvanometer 435 is along the second direction X, and the focused laser beam is irradiated on the reflective surface 435a , the area of the reflective surface 435 a can be made smaller, thereby reducing the volume of the MEMS galvanometer 435 .
  • the laser beam reflected by the MEMS galvanometer 435 will pass through the first phase retarder 434 again.
  • the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2. This enables the laser beam to pass through the first polarizing beam splitting film 439 instead of being reflected by the first polarizing beam splitting film 439 when the laser beam is irradiated on the first polarizing beam splitting film 439 again.
  • the laser beam transmitted through the first polarizing beam splitter film 439 will enter the second prism 436 , penetrate through the second phase retardation plate 437 , and irradiate on the curved mirror 438 .
  • Curved mirror 438 reflects the laser beam back. After the reflected laser beam passes through the second phase retarder 437 again, the polarization state of the laser beam changes, and the phase of the laser beam changes by ⁇ /2. This causes the laser beam to be reflected by the first polarizing beam splitting film 439 instead of passing through the first polarizing beam splitting film 439 when the laser beam is irradiated on the first polarizing beam splitting film 439 again.
  • the laser beam reflected by the polarization beam splitting film 338 is emitted from the light-emitting surface 436 b of the second prism 436 , thereby completing the transmission in the optical assembly 43 .
  • the laser beam emitted from the light exit surface 436 b is a parallel laser beam along the first direction Z, and the parallel laser beam is emitted onto the coupling-in structure 123 .
  • FIGS. 18 and 19 respectively show the transmission optical paths of the laser beams of the MEMS galvanometer 435 under different deflection attitudes.
  • the propagation laws of the laser beams in FIGS. 18 and 19 are the same as those shown in FIG. However, the difference from FIG. 17 is that because the MEMS galvanometer 435 is deflected, the parallel laser beam emitted from the light exit surface 436b is no longer along the first direction Z.
  • the MEMS galvanometer 435 is deflected clockwise by a certain angle from the default posture in FIG. 17 , it reaches the first deflection posture.
  • the parallel laser beam emitted from the second prism 436 is also deviated from the first direction Z.
  • the parallel laser beam emitted from the light exit surface 436b can be deflected by a certain angle in the counterclockwise direction compared with the first direction Z. As shown in FIG.
  • the laser beam emitted from the light-emitting surface 436b can also be irradiated on the coupling-in structure 123 .
  • the area of the MEMS galvanometer 435 coupled into the structure 123 irradiated by the laser beam in the first deflection attitude is substantially the same as the area irradiated by the laser beam on the MEMS galvanometer 435 coupled into the structure 123 in the default attitude.
  • the MEMS galvanometer 435 is deflected by a certain angle counterclockwise from the default posture in FIG. 17 , it reaches the second deflection posture.
  • the parallel laser beam emitted from the light exit surface 432b also deviates from the first direction Z.
  • the parallel laser beam emitted from the light emitting surface 436b can be deflected by a certain angle in the clockwise direction compared with the first direction Z.
  • the laser beam emitted from the light-emitting surface 436b can also be irradiated on the coupling-in structure 123 .
  • the area irradiated by the laser beam on the MEMS galvanometer 435 coupled into the structure 123 in the second deflection attitude is substantially the same as the area irradiated by the laser beam on the MEMS galvanometer 435 coupled in the structure 123 in the default attitude.
  • FIG. 20 shows the comparison of the transmission optical paths of the laser beams of the MEMS galvanometer 435 in the default posture, the first deflection posture and the second deflection posture.
  • the MEMS galvanometer 435 changes its posture when vibrating, the laser beams reflected by the MEMS galvanometer 435 will propagate in different directions respectively, so these laser beams are divergent.
  • the optical component 43 due to the structural design of the optical component 43 , the laser beams propagating in different directions can be focused on the same area on the coupling structure 123 , and even the laser beams in different directions can be within the same aperture range on the coupling structure 123 .
  • An exit pupil is formed, thereby realizing a common exit pupil. Therefore, the fourth embodiment can realize a common exit pupil, which is beneficial to reduce the area of the coupling-in structure 123 .
  • the third angle formed by the first bonding surface 433a and the first direction Z may be other values.
  • the position and attitude of the laser 124 and making adaptive adjustments to the specific structures and positions of the convex lens 432 and the curved mirror 438, it is possible to ensure that the laser beam reflected by the first polarizing beam splitting film 439 on the first bonding surface 433a is still there. Propagating approximately along the second direction X, it is ensured that the optical path in the optical component 43 is basically unchanged, which can ensure that the optical performance of the optical component 43 is basically unchanged.
  • a lens may also be provided between the light-emitting surface 436b of the second prism 436 and the coupling-in structure 123 , and the laser beam emitted from the light-emitting surface 436b passes through the lens and irradiates the coupling-in structure 123 .
  • the lens in any or any of the four places.
  • no lens may be provided at all of the above positions.

Abstract

一种光学组件、包括光学组件的投影模组，以及包括投影模组的增强现实设备。光学组件（13）包括MEMS振镜（137），光学组件（13）通过零度入射设计或者使光线以聚拢状照射到MEMS振镜（137）上，能够使得MEMS振镜（137）的反射面的面积减小，从而减小MEMS振镜（137）的体积。另外，光学组件（13）包括光学4f系统或者本身构成光学4f系统，能够使不同方向的光线能均能在投影模组（12）中的波导结构的耦入结构上的同一口径范围内形成出瞳，这样能够实现共同出瞳，有利于减小耦入结构的面积。

Description

光学组件、投影模组和增强现实设备
本申请要求于2021年02月26日提交中国专利局、申请号为202110217173.9、申请名称为“光学组件、投影模组和增强现实设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及增强现实技术领域，尤其涉及一种光学组件、包括该光学组件的投影模组，以及包括该投影模组的增强现实设备。
背景技术
增强现实(Augmented Reality，AR)设备内设有投影系统，投影系统用于将图像投影到人眼以形成视觉。投影系统可以包括激光器、微机电系统(micro electro mechanical systems，MEMS)振镜和波导结构。激光器能发射激光束，激光束被MEMS振镜反射后进入波导结构内传输，并从波导结构中射出，最终进入人眼以形成视觉。MEMS振镜能够在信号驱动下转动，以改变所反射的激光束的方向，进而使激光束能从波导结构的不同区域射出(该过程称为扫描)，实现动态画面显示。
传统AR设备的投影系统中，照射到MEMS振镜上的光束的口径较大，使得MEMS振镜需要较大的面积。这会加大MEMS振镜的设计及加工难度，也会导致AR设备的体积变大。
发明内容
本申请提供了一种光学组件、投影模组和增强现实设备，能够减小MEMS振镜的面积，实现AR设备的小型化。
第一方面，本申请提供了一种光学组件，包括所述光学组件包括第一光学元件、偏振分光膜、相位延迟片、微机电系统振镜和光学4f系统；所述第一光学元件具有元件反射面，所述元件反射面与第一方向形成第一夹角；所述偏振分光膜与所述元件反射面形成90°夹角；所述相位延迟片位于所述偏振分光膜与所述微机电系统振镜之间，所述相位延迟片的法线沿第二方向，所述第二方向与所述第一方向正交；所述微机电系统振镜与所述相位延迟片具有间隔，所述微机电系统振镜的反射面朝向所述相位延迟片；所述光学4f系统位于所述偏振分光膜远离所述第一光学元件的一侧，所述光学4f系统与所述偏振分光膜具有间隔，所述光学4f系统的中心线沿所述第一方向；所述光学组件用于处理光线；其中，光源发出的光线从所述元件反射面进入所述第一光学元件，并透过所述偏振分光膜，穿过所述相位延迟片，射到所述微机电系统振镜的反射面上；所述微机电系统振镜用于通过振动将光线反射到不同方向，不同方向的反射光线再次穿过所述相位延迟片后被所述偏振分光膜反射，并进入所述光学4f系统，所述光学4f系统用于将不同方向的光线进行汇聚。
本申请的方案中，第一光学元件可以是不设反射膜的棱镜、设有反射膜的棱镜，或者第一光学元件可以是反射镜。当第一光学元件是不设反射膜的棱镜时，第一光学元件的元件反射面即为该棱镜的一个反射面，该元件反射面能对光线进行全反射。当第一光学元件是设有反射膜的棱镜时，第一光学元件的元件反射面指的是反射膜的表面，该元件反射面能对光线进行反射。当第一光学元件是反射镜时，第一光学元件的元件反射面即为该反射镜的反射面，该元件反射面能对光线进行反射。MEMS振镜能够将平行光束扫描到不同方向，光学4f系统将不同方向的平行光束汇聚在波导结构上耦入结构上的同一出瞳位置。
本申请的方案能够使照射到MEMS振镜上的平行激光束的入射角为零，由此实现零度入射。零度入射设计有利于减小光束在MEMS振镜上的光斑口径，因而能够使得MEMS振镜的体积减小。另外，本申请的方案通过光学4f系统，能够将不同方向的平行光束汇聚在波导结构上耦入结构上的同一出瞳位置，实现不同方向的平行光束的共同出瞳，这能够减小耦入结构的面积。
在一种实现方式中，所述光学4f系统包括第一透镜和第二透镜，所述第一透镜位于所述偏振分光膜与所述第二透镜之间，所述第二透镜与所述第一透镜间隔设置；所述微机电系统振镜的中心线经过所述第一透镜的物方焦点；所述第一透镜的像方焦点与所述第二透镜的物方焦点重合；不同方向的光线穿过所述第一透镜后，分别聚焦在所述第一透镜的像方焦平面上的不同位置，并从所述第二透镜的不同位置进入所述第二透镜；所述第二透镜用于将从不同位置进入所述第二透镜的光线汇聚在所述第二透镜的像方焦点处，以使得不同方向的光线进行汇聚。使用透镜组构成的光学4f系统，结构可靠，可制造性高，光学性能较好。
在一种实现方式中，所述第一透镜包括依次间隔排列的双胶合透镜、第一非球面透镜和第二非球面透镜，所述双胶合透镜靠近所述偏振分光膜，所述非球面透镜远离所述偏振分光膜。双胶合透镜可由两个透镜胶合而成，例如可由一个双凸透镜与一个平凹透镜胶合而成。第一双胶合透镜可用于校正色差。第一非球面透镜可以是凸透镜，其曲率从中心到边缘可以连续变化。第二非球面透镜朝向第一非球面透镜的折射面可以是外凸曲面，第二非球面透镜背向第一非球面透镜的折射面例如可以是内凹曲面。此种设计结构可靠，可制造性高，光学性能较好。
在一种实现方式中，所述双胶合透镜的阿贝数大于或等于20。阿贝数是表示透明介质色散能力的物理量，双胶合透镜的阿贝数大于或等于20能够保证第一双胶合透镜的色差校正能力。
在一种实现方式中，所述第一透镜与所述第二透镜的结构相同。第一透镜与所述第二透镜是镜像设置的，二者的结构相同，且位置镜像。此种设计结构可靠，可制造性高，光学性能较好。
在一种实现方式中，所述第一光学元件为棱镜，所述第一光学元件具有受光面和第一贴合面；所述受光面的法线沿所述第一方向；所述第一贴合面与所述元件反射面垂直；所述偏振分光膜设在所述第一贴合面上；所述受光面用于接收光线；所述元件反射面用于对从所述受光面射入所述第一光学元件的光线进行全反射；所述第一夹角的范围为
Figure PCTCN2022076625-appb-000001
其中n为所述第一光学元件的折射率，所述第一夹角的单位为度。本实现方式中，第一光学元件是不设反射膜的棱镜，能够通过其元件反射面对光线进行全反射。此种设计能够满足特定的产品需求，并且结构可靠，可制造性高，光学性能较好。
在一种实现方式中，所述第一光学元件包括连接面，所述连接面连接所述受光面与所述元件反射面。此种结构的第一光学元件结构可靠，可制造性高，光学性能较好。
在一种实现方式中，所述第一光学元件包括棱镜和反射膜，所述反射膜设于所述棱镜的表面，所述反射膜具有所述元件反射面；所述第一夹角的范围为(22.5°，90°)。本实现方式中，第一光学元件是设有反射膜的棱镜，能够通过反射膜对光线进行反射。此种设计能够满足特定的产品需求，并且结构可靠，可制造性高，光学性能较好。
在一种实现方式中，所述光学组件还包括第二光学元件，所述第二光学元件具有第二贴合面、设置面、和出光面；所述第二贴合面与所述偏振分光膜背离所述第一光学元件的一侧贴合；所述设置面的法线沿所述第二方向；所述出光面背向所述第一光学元件，所述出光面 的法线沿所述第一方向；所述相位延迟片设在所述设置面上；所述光学4f系统位于所述第二光学元件背离所述第一光学元件的一侧，所述光学4f系统与所述出光面具有间隔。设置第二光学元件能限制激光束的传播距离，有利于约束光学4f系统的体积。
在一种实现方式中，所述第二贴合面超出所述第一贴合面，所述第二贴面超出所述第一贴合面的部分与所述元件反射面围成豁口区域。构造豁口区域能够为全反射创造条件，从而满足特定的产品需求。本是实现方式的设计结构可靠，可制造性高，光学性能较好。
第二方面，本申请提供了一种光学组件，所述光学组件包括第一偏振分光膜、第一相位延迟片、微机电系统振镜、第二相位延迟片、第一曲面反射镜、第二偏振分光膜、第三相位延迟片、平面反射镜、第四相位延迟片和第二曲面反射镜；所述第一偏振分光膜与第一方向形成第二夹角；所述第一相位延迟片垂直于第二方向，所述第一相位延迟片位于所述第一偏振分光膜与所述微机电系统振镜之间，并与所述微机电系统振镜间隔设置，其中所述第二方向与所述第一方向正交；所述微机电系统振镜的反射面朝向所述第一相位延迟片；所述第二相位延迟片平行于所述第一相位延迟片，并与所述第一相位延迟片分别位于所述第一偏振分光膜的两侧；所述第二相位延迟片位于所述第一偏振分光膜与所述第一曲面反射镜之间，并与所述第一曲面反射镜间隔设置；所述第一曲面反射镜具有朝背离所述第二相位延迟片的方向拱起的表面，所述第一曲面反射镜的中心线沿所述第二方向；所述第二偏振分光膜与所述第一偏振分光膜垂直设置；所述第三相位延迟片平行于所述第二相位延迟片，所述第三相位延迟片位于所述第二偏振分光膜与所述平面反射镜之间，并与所述平面反射镜平行且间隔设置；所述第四相位延迟片平行于所述第三相位延迟片，并与所述第三相位延迟片分别位于所述第二偏振分光膜的两侧；所述第四相位延迟片位于所述第二偏振分光膜与所述第二曲面反射镜之间；所述第二曲面反射镜具有朝背离所述第四相位延迟片的方向拱起的表面；所述光学组件用于处理光线；其中，光源发出的光线射到所述第一偏振分光膜上后被所述第一偏振分光膜反射，反射光线透过所述第一相位延迟片，射到所述微机电系统振镜的反射面上；所述微机电系统振镜用于通过振动将光线反射到不同方向，不同方向的反射光线再次透过所述第一相位延迟片的不同区域后，依次穿过所述第一偏振分光膜与所述第二相位延迟片，射到所述第一曲面反射镜上的不同位置；所述第一曲面反射镜将光线进行反射，反射光线再次穿过所述第二相位延迟片后，分别被所述第一偏振分光膜反射并汇聚至所述第二偏振分光膜上的不同位置；所述第二偏振分光膜将光线进行反射，反射光线穿过第三相位延迟片，射到所述第三平面反射镜上的不同位置；所述第三平面反射镜将光线进行反射，反射光线再次穿过第三相位延迟片的不同区域后，依次穿过所述第二偏振分光膜和所述第四相位延迟片，射到所述第二曲面反射镜上的不同位置；所述第二曲面反射镜将光线进行反射，反射光线再次穿过第四相位延迟片后，被所述第二偏振分光膜反射并汇聚。
本申请的光学组件是一种由棱镜和反射镜构成的反射式光学4f系统。本申请的方案也能够使照射到MEMS振镜上的平行激光束的入射角为零，由此实现零度入射。零度入射设计有利于减小光束在MEMS振镜上的光斑口径，因而能够使得MEMS振镜的体积减小。另外，本申请的方案通过设计反射式光学4f系统，能够将不同方向的平行光束汇聚在波导结构上耦入结构上的同一出瞳位置，实现不同方向的平行光束的共同出瞳，这能够减小耦入结构的面积。
在一种实现方式中，所述光学组件包括第一棱镜；所述第一棱镜具有受光面、第一贴合面和第一设置面；所述受光面的法线沿所述第一方向；所述第一贴合面与所述受光面形成所述第二夹角；所述第一设置面的法线沿所述第二方向；所述第一偏振分光膜设在所述第一贴合面上；所述第一相位延迟片设在所述第一设置面上。使用第一棱镜能够支撑第一偏振分光 膜与第一相位延迟片，增加光学组件的结构稳定性，保证光学组件的光学性能。
在一种实现方式中，所述光学组件包括第二棱镜；所述第二棱镜与所述第一棱镜间隔设置；所述第二棱镜具有第二贴合面、第二设置面和出光面；所述第二贴合面与所述第一贴合面垂直；所述第二设置面与所述第一设置面平行；所述出光面与所述受光面平行，且背向所述受光面；所述第二偏振分光膜设在所述第二贴合面上；所述第四相位延迟片设在所述第二设置面上。使用第二棱镜能够支撑第二偏振分光膜与第四相位延迟片，增加光学组件的结构稳定性，保证光学组件的光学性能。
在一种实现方式中，所述光学组件包括第三棱镜，所述第三棱镜连接所述第一棱镜与所述第二棱镜；所述第一偏振分光膜位于所述第一贴合面与所述第三棱镜的表面之间；所述第二偏振分光膜位于所述第二贴合面与所述第三棱镜的表面之间；所述第二相位延迟片与所述第三相位延迟片均设于所述第三棱镜的表面。使用第三棱镜能够便于调控第一棱镜与第二棱镜的间距，并支撑第二相位延迟片与所述第三相位延迟片，增加光学组件的结构稳定性，保证光学组件的光学性能。
在一种实现方式中，所述第一曲面反射镜朝向所述第二相位延迟片的表面与所述第二相位延迟片贴合，所述第一曲面反射镜背向所述第二相位延迟片的表面朝背离所述第二相位延迟片的方向拱起；和/或，所述第二曲面反射镜朝向所述第四相位延迟片的表面与所述第四相位延迟片贴合，所述第一曲面反射镜背向所述第四相位延迟片的表面朝背离所述第二相位延迟片的方向拱起；和/或，所述平面反射镜与所述第三相位延迟片贴合。使得曲面反射镜、平面反射镜与相应的相位延迟片贴合，能够保证光学性能，减小结构尺寸，增加结构可靠性。
在一种实现方式中，所述第二夹角的范围为[25°，65°]。该范围有利于保证光学组件的光学性能，也能够确保光学组件的结构符合实际需要。
第三方面，本申请提供了一种光学组件，所述光学组件包括偏振分光膜、第一相位延迟片、微机电系统振镜、第二相位延迟片和曲面反射镜；所述偏振分光膜与第一方向形成第三夹角；所述第一相位延迟片垂直于第二方向，所述第一相位延迟片位于所述偏振分光膜与所述微机电系统振镜之间，并与所述微机电系统振镜间隔设置,其中所述第二方向与所述第一方向正交；所述微机电系统振镜的反射面朝向所述第一相位延迟片；所述第二相位延迟片平行于所述第一相位延迟片，并与所述第一相位延迟片分别位于所述偏振分光膜的两侧；所述第二相位延迟片位于所述偏振分光膜与所述曲面反射镜之间，并与所述曲面反射镜间隔设置；所述曲面反射镜具有朝背离所述第二相位延迟片的方向拱起的表面，所述曲面反射镜的中心线沿所述第二方向；所述光学组件用于处理光线；其中，光源发出的光线射到所述偏振分光膜上后被所述偏振分光膜反射，反射光线透过所述第一相位延迟片，射到所述微机电系统振镜的反射面上；所述微机电系统振镜用于通过振动将光线反射到不同方向，不同方向的反射光线再次透过所述第一相位延迟片的不同区域后，依次穿过所述偏振分光膜与所述第二相位延迟片，汇聚到所述曲面反射镜上的不同位置；所述曲面反射镜将光线进行反射，反射光线再次穿过所述第二相位延迟片后，被所述偏振分光膜反射并汇聚。
本申请的光学组件是一种棱镜、反射镜和透镜构成的反射透射混合型光学4f系统。本申请的方案能够使照射到MEMS振镜上的激光束呈聚拢状，有利于减小光束在MEMS振镜上的光斑口径，因而能够使得MEMS振镜的体积减小。另外，本申请的方案通过设计反射透射混合型光学4f系统，能够将不同方向的平行光束汇聚在波导结构上耦入结构上的同一出瞳位置，实现不同方向的平行光束的共同出瞳，这能够减小耦入结构的面积。
在一种实现方式中，所述光学组件包括第一平凸透镜，所述第一平凸透镜位于所述微机 电系统振镜与所述第一相位延迟片之间，所述第一平凸透镜与所述微机电系统振镜间隔设置，所述第一平凸透镜的中心线沿所述第二方向。使用第一平凸透镜能够提升成像质量。
在一种实现方式中，所述光学组件包括第二平凸透镜，所述第二平凸透镜与所述偏振分光膜间隔设置，所述第二平凸透镜的中心线沿所述第一方向；其中，被所述偏振分光膜反射的光线透过所述第二平凸透镜后被汇聚。使用第二平凸透镜能够提升成像质量。
在一种实现方式中，所述第一平凸透镜朝向所述第一相位延迟片的表面与所述第一相位延迟片贴合；和/或，所述第二平凸透镜朝向所述第二棱镜的表面与所述第二棱镜贴合。平凸透镜的贴合设计能够使结构紧凑，提升可制造性，保证光学性能。
在一种实现方式中，所述光学组件包括间隔设置的凸透镜和凹透镜，所述凸透镜位于位于所述偏振分光膜与所述凹透镜之间，所述凸透镜与所述凹透镜的中心线沿所述第一方向；所述凸透镜的焦距为5mm-15mm，所述凹透镜的焦距为-5mm至-20mm；其中，光源发出的光线依次透过所述凹透镜与所述凸透镜，然后射到所述偏振分光膜上。使用凹透镜能够对光束进行扩束，优化像差。使用凸透镜能够聚焦激光束，优化像差。
在一种实现方式中，所述光学组件包括第一棱镜，所述第一棱镜具有受光面、第一贴合面和第一设置面；所述受光面的法线沿所述第一方向；所述第一贴合面与所述受光面形成所述第三夹角；所述第一设置面的法线沿所述第二方向；所述偏振分光膜设在所述第一贴合面上；所述第一相位延迟片设在所述第一设置面上。使用第一棱镜能够支撑偏振分光膜与第一相位延迟片，增加光学组件的结构稳定性，保证光学组件的光学性能。
在一种实现方式中，所述光学组件包括第二棱镜，所述第二棱镜具有第二贴合面、第二设置面和出光面；所述第二贴合面与所述第一贴合面平行，且朝向所述第一贴合面；所述第二设置面与所述第一设置面平行，且背向所述第一设置面；所述出光面与所述受光面平行，且背向所述受光面；所述偏振分光膜设在所述第一贴合面与所述第二贴合面之间；所述第二相位延迟片设在所述第二设置面上。使用第二棱镜能够支撑偏振分光膜与第二相位延迟片，增加光学组件的结构稳定性，保证光学组件的光学性能。
在一种实现方式中，所述曲面反射镜朝向所述第二相位延迟片的表面与所述第二相位延迟片贴合。贴合设计能够使结构紧凑，提升可制造性，保证光学性能。
在一种实现方式中，所述第三夹角的范围为[25°，65°]。该范围有利于保证光学组件的光学性能，也能够确保光学组件的结构符合实际需要。
第四方面，本申请提供了一种投影模组，包括激光器、波导结构和所述光学组件，所述激光器与所述波导结构分别位于所述光学组件在所述第一方向上的相对两侧；所述激光器用于向所述光学组件发射沿所述第一方向传播的平行激光束；所述波导结构具有出瞳位置，所述出瞳位置用于接收所述光学组件射出的激光。
本申请的方案中，波导结构可以包括波导、耦出结构和耦入结构，耦出结构和耦入结构均可以设在波导上。其中，耦入结构可以将光学组件射出的激光束耦入波导。波导中的激光束可以从耦出结构射出，并投射到人眼，使用户产生视觉。本申请的方案，由于能够将光学组件中的MEMS振镜的体积做小，因此能够减小投影模组的体积。
第五方面，本申请提供了一种增强现实设备，包括结构件和所述投影模组，所述投影模组安装于所述结构件。本申请的方案中，结构件用于对投影模组进行固定、收容和/或承载。当增强现实设备例如是AR眼睛时，结构件例如可以包括镜框与镜腿。本申请的方案，由于能够将投影模组的体积做小，因此能够减小增强现实设备的整机体积。
附图说明
图1是实施例一的增强现实设备的立体结构示意图；
图2是表示图1的增强现实设备的投影模组将图像投射至人眼的原理示意图；
图3是图2中的投影模组的一种光路示意图；
图4A是常规增强现实设备的投影模组将图像投射至人眼的原理示意图；
图4B是MEMS振镜在默认姿态下，不同方向的激光束在MEMS振镜上的光斑口径对比；
图4C是MEMS振镜在偏转姿态下，不同方向的激光束在MEMS振镜上的光斑口径对比；
图5是图2的投影模组中的另一种光路示意图；
图6是图2的投影模组中的另一种光路示意图；
图7是图2的投影模组中的三种光路对比示意图；
图8表示实施例一的投影模组的第一棱镜的一种变形结构示意；
图9是实施例二的投影模组中的一种光路示意图；
图10是实施例二的投影模组中的另一种光路示意图；
图11实施例二的投影模组中的另一种光路示意图；
图12是实施例二的投影模组中的三种光路对比示意图；
图13是实施例三的投影模组中的一种光路示意图；
图14是实施例三的投影模组中的另一种光路示意图；
图15是实施例三的投影模组中的另一种光路示意图；
图16是实施例三的投影模组中的三种光路对比示意图；
图17是实施例四的投影模组中的一种光路示意图；
图18是实施例四的投影模组中的另一种光路示意图；
图19是实施例四的投影模组中的另一种光路示意图；
图20是实施例四的投影模组中的三种光路对比示意图。
具体实施方式
本申请以下实施例提供了一种增强现实(Augmented Reality，AR)电子设备，包括但不限于智能眼镜、头戴式AR设备。下文以该AR设备是智能眼镜为例进行描述。
如图1所示，实施例一的AR设备10可以包括结构件11与投影模组12。
结构件11用于固定、承载和收容投影模组12。结构件11例如可以包括镜框111与镜腿112。当AR设备10被佩戴于用户时，镜框111可以朝向用户的双眼，镜腿112则搭在用户的双耳处。结构件11的上述结构仅仅是一种举例，在其他实施例中可以根据需要进行设计。
投影模组12可以包括波导结构12a，波导结构12a的至少大部分可以固定在镜框111内(例如下文将会描述的波导121及耦出结构122可以全部固定在镜框111内)。波导结构12a可作为智能眼镜的“镜片”，其能够显示图像，还能透过外界光线以使人眼看到外界环境。投影模组12还可以包括部分12b，部分12b例如可以收容在镜腿112内。部分12b用于向波导结构12a耦入光线。部分12b的上述安装位置仅仅是一种举例，并非是对本实施例方案的限制。
图2表示投影模组12将图像投射至人眼的原理示意图。如图2所示，投影模组12中的波导结构12a可以包括波导121、耦出结构122和耦入结构123，其中耦出结构122和耦入结构123均设在波导121上。投影模组12中的部分12b可以包括光学组件13和激光器124。激光器124例如可以是RGB激光器。激光器124能够发出激光束，激光束经过光学组件13后 照射到耦入结构123上，耦入结构123将激光束耦入波导121。激光束在波导121中以全反射方式进行传播，最终从耦出结构122处射出，并投射到人眼，从而使用户产生视觉。
图2中耦出结构122、耦入结构123及部分12b均位于靠近人眼的一侧，这仅仅是一种举例。实际上根据产品设计需要，上述三者中的任一个均可以在靠近人眼的一侧或者远离人眼的一侧。对于耦出结构122和耦入结构123中的任一个，还可以将其设在波导121的内部。
以上说明了实施例一的AR设备10及投影模组12的基本结构，下面将详细描述投影模组12中的光学组件13的结构。
实施例一中，可以对光学组件13定义第一方向Z和第二方向X，第一方向Z与第二方向X正交。第一方向Z可以包括坐标轴Z上的两个方向，第二方向X可以包括坐标轴X上的两个方向。第一方向Z例如可以大致为镜腿112的长度方向，第二方向X例如可以大致为镜腿112的其他两个方向之一(如高度方向，例如在图1视角中该高度方向可以是竖直方向)。
如图3所示，光学组件13可以包括第一光学元件131、偏振分光膜139、第二光学元件136、相位延迟片138、MEMS振镜137和透镜组132。下面将逐一说明。
如图3所示，第一光学元件131与第二光学元件136均可以为棱镜，二者可以贴靠在一起。
如图3所示，第一光学元件131可以具有依次首尾相连的受光面131a、连接面131b、元件反射面131c和第一贴合面131d。
受光面131a可以为平面，其法线可以基本沿第一方向Z。受光面131a朝向激光器124，以便接收激光束。连接面131b可以为平面，其法线可以基本沿第二方向X，或者也可以是其他方向。连接面131b连接受光面131a与元件反射面131c。元件反射面131c可以为平面，其可以与第一方向Z形成45°的第一夹角，也即元件反射面131c可与连接面131b形成135°夹角。该45°的第一夹角仅仅是一种举例。根据产品实际需要，还可以是其他数值的第一夹角，该第一夹角的单位为度，该第一夹角的范围可以为
Figure PCTCN2022076625-appb-000002
(不含端点值)。其中，n为第一光学元件131的折射率。例如当n＝1.67时，该第一夹角的范围可以是(36.78°,90°)，具体可以取38°、45°、60°或者75°。该第一夹角在上述范围内，有利于保证光学组件13的光学性能，也能够确保光学组件13的结构符合实际需要。下文将主要以该第一夹角取45°为例进行描述。
第一贴合面131d连接元件反射面131c与受光面131a。第一贴合面131d可以是平面，其可与元件反射面131c基本垂直。
如图3所示，第一光学元件131可近似看成是缺失了一角的“三棱镜”，受光面131a、连接面131b、元件反射面131c和第一贴合面131d均为该“三棱镜”的侧面。
在其他实施例中，在保证第一光学元件131的受光面131a、元件反射面131c和第一贴合面131d的位置关系的前提下，可以根据产品需要，灵活调整受光面131a、元件反射面131c、第一贴合面131d的连接关系。例如，可以取消连接面131b，使受光面131a与元件反射面131c相交。或者，可以增加表面，使元件反射面131c通过增加的该表面与第一贴合面131d连接，而不是元件反射面131c与第一贴合面131d相交。
如图3所示，第二光学元件136可以为三棱镜。第二光学元件136可以具有依次首尾连接的第二贴合面136a、设置面136b和出光面136c，第二贴合面136a、设置面136b和出光面136c均为三棱镜的侧面。
第二贴合面136a可以平行并贴靠第一贴合面131d。第二贴合面136a的一边可以与第一贴合面131d的边界基本重合，第二贴合面136a的另一边可超出第一贴合面131d。由此，第二贴合面136a超出第一贴合面131d的部分可与元件反射面131c围成豁口区域13a。豁口区 域13a内填充的是空气介质。设置面136b可以为平面，其法线可以沿第二方向X。出光面136c可以为平面，其法线可以沿第一方向Z。
在其他实施例中，在保证第二光学元件136的第二贴合面136a、设置面136b和出光面136c的位置关系的前提下，可以根据产品需要，灵活调整第二贴合面136a、设置面136b、出光面136c的连接关系。例如，可以增加表面，使第二贴合面136a通过增加的该表面与出光面136c连接，而不是第二贴合面136a与出光面136c相交。此种第二光学元件136不是三棱镜。
如图3所示，偏振分光膜139可以为平整膜层，其可以位于第一贴合面131d与第二贴合面136a之间，其既贴靠第一贴合面131d，又贴靠第二贴合面136a。偏振分光膜139可以布满整个第二贴合面136a，也可以仅覆盖第二贴合面136a的部分区域(该部分区域包括第二贴合面136a与第一贴合面131d重合的部分)。偏振分光膜139可以通过贴合工艺粘贴在第一贴合面131d与第二贴合面136a之间；或者偏振分光膜139可以是形成在第一贴合面131d上的镀膜。
如图3所示，相位延迟片138可以为平整片状，其可以设在第二光学元件136的设置面136b上。相位延迟片138用于改变透过相位延迟片138的光的偏振态。例如相位延迟片138可以是四分之一玻片，光每透过其一次，光的相位变化λ/4，其中λ为光的波长。
以上所述的第一光学元件131与第二光学元件136的结构，以及第一光学元件131、第二光学元件136、偏振分光膜139、相位延迟片138之间的连接关系仅仅是一种举例，并非是对本申请实施例的限制。在其他实施例中，以上设计可以根据产品需要进行调整和变形，该变形设计将在下文继续说明。
如图3所示，MEMS振镜137与相位延迟片138间隔相对。MEMS振镜137能够在信号控制下发生往复偏转(可将该往复偏转称为振动)，以将射到MEMS振镜137的反射面137a的光线以不同角度反射出去，实现扫描成像。MEMS振镜137的最大振动角度称为扫描角度。
本实施例中，在未通电状态下，MEMS振镜137的反射面137a的法线沿第二方向X，可将MEMS振镜137此时的姿态称为默认姿态。
如图3所示，透镜组132可位于第二光学元件136与耦入结构123之间。透镜组132可与第二光学元件136的出光面136c间隔相对，透镜组132与耦入结构123也具有间隔。透镜组132的中心线可基本沿第一方向Z。
如图3所示，透镜组132可由若干个透镜构成，各个透镜的中心线可以基本重合。例如，透镜组132可以包括依次排列的第一双胶合透镜133、第一非球面透镜134、第二非球面透镜135、第三非球面透镜135’、第四非球面透镜134’和第二双胶合透镜133’，以上各个透镜两两之间具有间隔。第一双胶合透镜133靠近第二光学元件136，第二双胶合透镜133’远离第二光学元件136。
如图3所示，第一双胶合透镜133可由两个透镜胶合而成，例如可由一个双凸透镜与一个平凹透镜胶合而成(图3中第一双胶合透镜133中的弧形虚线表示该平凹透镜的内凹曲面，或者表示该双凸透镜的一个外凸表面)。第一双胶合透镜133中的两个透镜的折射率可以相同。第一双胶合透镜133的阿贝数(表示透明介质色散能力的物理量)例如可以大于或等于20。第一非球面透镜134例如可以是凸透镜，其曲率从中心到边缘可以连续变化。第一非球面透镜134的折射率例如可以是1.3-2.0(含端点值)。第二非球面透镜135朝向第一非球面透镜134的折射面例如可以是外凸曲面，第二非球面透镜135背向第一非球面透镜134的折射面例如可以是内凹曲面。第二非球面透镜135的折射率例如可以是1.4-2.0(含端点值)。
实施例一中，第一双胶合透镜133、第一非球面透镜134及第二非球面透镜135可构成第一透镜组132a。该第一透镜组132a的焦距可以为3mm-10mm(含端点值)。该第一透镜组132a用于对光线进行聚焦。
如图3所示，第三非球面透镜135’与第二非球面透镜135，二者的结构、材料、光学参数可以相同，二者可以镜像设置(本实施例中，镜像设置的含义是两个部件关于一个镜像面镜像对称，且这两个部件的结构、材料、光学参数相同。下同)。第四非球面透镜134’与第一非球面透镜134，二者的结构、材料、光学参数可以相同，二者可以镜像设置。第二双胶合透镜133’与第一双胶合透镜133，二者的结构、材料、光学参数可以相同，二者可以镜像设置。上述镜像设置的三组透镜的镜像面可以为同一个面，该镜像面的法线可沿第一方向Z。该镜像面经过该第一透镜组132a的焦点，也即该镜像面为第一透镜组132a的像方焦平面。
实施例一中，第三非球面透镜135’、第四非球面透镜134’和第二双胶合透镜133’可以构成第二透镜组132b。该第二透镜组132b的焦距可以为3mm-10mm(含端点值)。该第二透镜组132b与该第一透镜组132a是镜像设置的，二者的镜像面即上文所述的像方焦平面。该第二透镜组132b用于将从第一透镜组132a的焦平面发出的发散光线转换成平行光线，并汇聚在同一出瞳位置(下文将会描述)。
实施例一中，第一双胶合透镜133与第二双胶合透镜133’可用于校正色差。第一非球面透镜134、第二非球面透镜135、第三非球面透镜135’及第四非球面透镜134’可用于校正像差。使用上述的多个透镜有利于改善成像质量。在其他实施例中，可以无需采用实施例一的透镜镜像设计，而是根据需要设置各个透镜的位置。另外，各个透镜的结构及类型，也可以根据需要灵活设计，不限于上文所述。
实施例一中，透镜组132可以构成一种光学4f系统，该光学4f系统有如下特点：MEMS振镜137的中心线可经过该第一透镜组132a的物方焦点；该第一透镜组132a的像方焦点可与该第二透镜组132b的物方焦点重合；第二透镜组132b的像方焦点可与耦入结构123上的出瞳位置重合。从MEMS振镜137的中心线到耦入结构123(即像面)的间距＝2*(由第一双胶合透镜133、第一非球面透镜134、第二非球面透镜135构成的第一透镜组132a的焦距)+2*(由第三非球面透镜135’、第四非球面透镜134’、第二双胶合透镜133’构成的第二透镜组132b的焦距)。由于透镜的镜像设计，该第一透镜组132a的焦距等于该第二透镜组132b的焦距，因此从MEMS振镜137的中心线到耦入结构123的间距＝4*第一透镜组132a的焦距。
实施例一中，使用透镜组132构成光学4f系统，这仅仅是一种举例。在其他实施例中，可以由两个透镜构成光学4f系统。可将这两个透镜分别称为第一透镜与第二透镜，第一透镜与第二透镜可以镜像并间隔设置，第一透镜的焦距例如可以是3mm-10mm(含端点值)，第二透镜的焦距例如可以是3mm-10mm(含端点值)。第一透镜相当于由第一双胶合透镜133、第一非球面透镜134与第二非球面透镜135构成的第一透镜组132a，第二透镜相当于由第三非球面透镜135’、第四非球面透镜134’、第二双胶合透镜133’构成的第二透镜组132b。由该第一透镜与该第二透镜构成的光学4f系统的特性可与上文所述相同，此处不再重复。
或者在其他实施例中，还可以采用其他光学元件构成光学4f系统，例如可使用液晶透镜、超表面、反射镜、透镜等构建光学4f系统。
实施例一中，通过第一分光元件131、偏振分光膜139、第二分光元件136及相位延迟片138的上述结构设计，能够使平行激光束垂直射到处于默认姿态下的MEMS振镜137的反射面137a上，也即使得平行激光束在反射面137a上的入射角为零度。可将这一特性称为零度入 射。零度入射有利于减小MEMS振镜137的反射面137a的面积，进而减小MEMS振镜137的体积。另外，使用透镜组132构成光学4f系统，能够将不同方向的平行激光束汇聚到耦入结构123上的同一口径范围内，使不同方向的平行激光束能均能在耦入结构123上的同一口径范围内形成出瞳。可将这一特性称为共同出瞳，耦入结构123上形成出瞳的位置称为出瞳位置。共同出瞳有利于减小耦入结构123的面积。以下将结合激光束的光路分析进行详细说明。
图3可以表示MEMS振镜137在默认姿态下激光束的传输光路。如图3所示，在元件反射面131c与第一方向Z形成的第一夹角是45°的条件下，激光器124可以发射沿第一方向Z传播的平行激光束，平行激光束垂直于第一光学元件131的受光面131a进入第一光学元件131。由于第一光学元件131的零度入射面131c的45°倾角设计，以及豁口区域13a的设计，平行激光束将在零度入射面131c上发生全反射，且被零度入射面131c全反射的激光束沿第二方向X传播。沿第二方向X的激光束将依次透过偏振分光膜139、进入第二光学元件136、透过相位延迟片138，并平行照射到MEMS振镜137的反射面137a上。由于透过相位延迟片138的激光束沿第二方向X，因此照射到MEMS振镜137的反射面137a上的平行激光束的入射角为零，由此实现零度入射。
图4A表示常规的增强现实设备中的投影模组将图像投射至人眼的原理示意图。如图4A所示，由于常规增强现实设备中MEMS振镜137的默认姿态设计，使得激光器124发出的平行激光束在任意时刻均是倾斜照射到MEMS振镜137上，也即激光束在MEMS振镜137上的入射角不等于零。这会导致激光束在MEMS振镜137上的光斑口径较大。而实施例一中通过激光束的零度入射设计，使得激光束在MEMS振镜137上的光斑口径较小。下面将分析该原理。
图4B表示平行激光束沿第二方向X以及偏离第二方向X的方向照射MEMS振镜137的反射面137a时，平行激光束在反射面137a上形成的光斑的口径对比。如图4B所示，可用平行激光束最外侧的光线L1与光线L2表示沿第二方向X的平行激光束，沿第二方向X的平行激光束可称为零度入射的平行激光束；用平行激光束最外侧的光线L1’与光线L2’表示偏离第二方向X的平行激光束，偏离第二方向X的激光束可称为非零度入射的平行激光束。两个方向的平行激光束的束径相等，用d表示。由图4B的对比可知，沿第二方向X的平行激光束在反射面137a上的光斑口径较小。反之，偏离第二方向X的平行激光束在反射面137a上的光斑口径较大。图4B中两个方向的激光束的光斑口径较小，可认为图4B表征了两个方向的激光束在反射面137a上的光斑口径的极小值。
MEMS振镜137能够偏转设定的扫描角度，可称偏转后的MEMS振镜137处于偏转姿态。图4C表示MEMS振镜137偏转设定的扫描角度后(例如相较图4A中的MEMS振镜137沿逆时针方向偏转了一定扫描角度，其中将图4A中的MEMS振镜137使用虚线表示)，沿第二方向X的平行激光束与偏离第二方向X的平行激光束，在反射面137a上的光斑口径对比。图4C中两个方向的激光束的光斑口径相较图4A而言均较大，可认为图4C表征了两个方向的激光束在反射面137a上的光斑口径的极大值。
由图4C的对比可知，沿第二方向X的平行激光束在反射面137a上的光斑口径较小；偏离第二方向X的平行激光束在反射面137a上的光斑口径较大。
当MEMS振镜137连续偏转时，激光束在MEMS振镜137的反射面137a上的光斑口径也连续变化，因而从图4B到图4C可以表示激光束在反射面137a上的光斑口径的范围，该范围的两个端点值分别为上文所述的极小值与极大值。综合图4B至图4C可知，无论MEMS振镜137处于默认姿态还是偏转姿态，当平行激光束沿第二方向X照射MEMS振镜137反射面137a时，平行激光束在反射面137a上的光斑口径范围的极大值，均比偏离第二方向X的平行激光束在 反射面137a上的光斑口径范围的极大值小。这使得实施例一中反射面137a的面积可以做的较小，进而使得MEMS振镜137的体积可以做小；反之，常规方案中要求反射面137a具有较大的面积，导致MEMS振镜137需具有较大体积。
实施例一中，由于零度入射的激光束就是沿第二方向X的平行激光束，因而也可以认为激光束零度入射的设计，能够使得MEMS振镜137的体积得以减小。
另外，常规的投影模组若需要提升视场角，往往需要通过增加MEMS振镜的扫描角度来实现，这会导致MEMS振镜的体积增大。但是实施例一中，当激光束零度入射时，投影模组12的视场角可以等于2*MEMS振镜137的扫描角，也即MEMS振镜137在同等扫描角度(与常规的MEMS振镜相比)就能获得较大的视场角，但是无需增加MEMS振镜137的体积。因此，实施例一的方案能够在不增加MEMS振镜137的扫描角度与体积的前提下提升视场角，从而扩大用户视野，增强用户体验。
如图3所示，零度入射到MEMS振镜137的反射面137a上的激光束被MEMS振镜137反射回来，并再次透过相位延迟片138。再次透过相位延迟片138后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到偏振分光膜139上时，激光束会被偏振分光膜139反射(反射光束沿第一方向Z)，而非透过偏振分光膜139。在以上光路中，偏振分光膜139能使来自激光器124一侧的激光束透过，而将透过相位延迟片138的激光束反射。依照此种原理，可以对激光器124所发射的激光类型(如P光、S光)、偏振分光膜139的类型及相位延迟片138的类型进行组合搭配，只要能实现上述光路即可。
如图3所示，被偏振分光膜139反射的激光束将沿第一方向Z从第二光学元件136的出光面136c射出，并沿第一方向Z射入第一双胶合透镜133，进入透镜组132。激光束在经过第一双胶合透镜133、第一非球面透镜134和第二非球面透镜135后，可以被聚焦于第一透镜组132a的像方焦点，该像方焦点位于第一透镜组132a的像方焦平面上。从该像方焦平面出射的光线呈发散状，并以此进入第三非球面透镜135’、第四非球面透镜134’和第二双胶合透镜133’，最终从第二双胶合透镜133’中射出，由此完成在光学组件13中的传输。从第二双胶合透镜133’出射的激光束为沿第一方向Z的平行激光束，该平行激光束射入耦合结构123上的出瞳位置(也即第二透镜组132b的像方焦点处)。
图5和图6分别表示MEMS振镜137在不同偏转姿态下激光束的传输光路，图5与图6中激光束的传播规律同图3，因而不再赘述。但与图3不同的是，由于MEMS振镜137发生了偏转，导致射到偏振分光膜139上的激光束不再沿第二方向X，因此射入第一双胶合透镜133的激光束也偏离第一方向Z。
例如图5所示，MEMS振镜137由图3中的默认姿态顺时针偏转一定角度后，达到第一偏转姿态。在第一偏转姿态下，被MEMS振镜137反射的激光束可偏离第二方向X。进而，被偏振分光膜139反射的激光束偏离第一方向Z，从第二光学元件136的出光面136c射出的激光束偏离第一方向Z。来自第二光学元件136的出光面136c的激光束依次透过第一双胶合透镜133、第一非球面透镜134和第二非球面透镜135后，被聚焦于第一透镜组132a的像方焦平面上的另一位置(与图3相比)。从该像方焦平面出射的光线呈发散状，并射入第三非球面透镜135’的另一位置(与图3相比)，最终从第二双胶合透镜133’的另一位置(与图3相比)射出，由此完成在光学组件13中的传输。从第二双胶合透镜133’出射的激光束依然是平行激光束，但该平行光束偏离第一方向Z。例如在图5视角中，从第二双胶合透镜133’射出的激光束可相较第一方向Z沿顺时针方向偏转一定角度。MEMS振镜137处于第一偏转姿态下，从第二双胶合透镜133’射出的激光束同样能照射到耦入结构123上的出瞳位置(也即第二 透镜组132b的像方焦点处)。MEMS振镜137在第一偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜137在默认姿态下耦入结构123上被激光束照射的区域基本相同。
类似地，如图6所示，MEMS振镜137由图3中的默认姿态逆时针偏转一定角度后，达到第二偏转姿态。在第二偏转姿态下，被MEMS振镜137反射的激光束可偏离第二方向X。进而，被偏振分光膜139反射的激光束偏离第一方向Z，从第二光学元件136的出光面136c射出的激光束偏离第一方向Z。来自第二光学元件136的出光面136c的激光束依次透过第一双胶合透镜133、第一非球面透镜134和第二非球面透镜135后，被聚焦于第一透镜组132a的像方焦平面上的另一个位置(与图5相比)。从该像方焦平面出射的光线呈发散状，并射入第三非球面透镜135’的另一位置(与图5相比)，最终从第二双胶合透镜133’的另一位置(与图5相比)射出，由此完成在光学组件13中的传输。从第二双胶合透镜133’出射的激光束依然是平行激光束，但该平行光束偏离第一方向Z。例如在图6视角中，从第二双胶合透镜133’射出的激光束可相较第一方向Z沿逆时针方向偏转一定角度。MEMS振镜137处于第二偏转姿态下，从第二双胶合透镜133’射出的激光束同样能照射到耦入结构123上的出瞳位置(也即第二透镜组132b的像方焦点处)。MEMS振镜137在第二偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜137在默认姿态下耦入结构123上被激光束照射的区域基本相同。
图7表示MEMS振镜137在默认姿态、第一偏转姿态和第二偏转姿态下，激光束的传输光路对比。如图7所示，随着MEMS振镜137在振动时改变姿态，第二光学元件136的出光面136c射出的激光束将会分别沿不同方向传播，这些激光束是发散的。但是，由于设计了由透镜组132构成的光学4f系统，能够使沿不同方向传播的激光束汇聚到耦入结构123上的同一出瞳区域，也即使不同方向的激光束能均能在耦入结构123上的同一口径范围内形成出瞳，从而实现共同出瞳。因此，实施例一能够实现共同出瞳，有利于减小耦入结构123的面积。
在实施例一中，元件反射面131c与第一方向Z形成的第一夹角可以是其他数值，可以通过调整激光器124的位置与姿态，保证被元件反射面131c全反射的激光束仍然沿第二方向X传播，这样能够保证光学组件13的光学性能基本不变。例如，若第一夹角大于45°，则可以将激光器124的位置与姿态进行调整，使其发出的激光束沿右上方传播(以图7视角为例)；反之，若第一夹角小于45°，则可以将激光器124的位置与姿态进行调整，使其发出的激光束沿右下方传播(以图7视角为例)。
另外，实施例一通过使光学组件13沿第一方向Z布置，能够充分利用AR设备10的镜腿112的长度尺寸布置光学组件13，保证AR设备10的整体尺寸可控。
在其他实施例中，基于以上的光路原理，可以设计出实施例一的光学组件13的若干替代结构。例如在一些实施例中，可以保持第二光学元件136、偏振分光膜139和相位延迟片138不变，对第一光学元件131做出一些结构变形。例如在图8所示的实施例中，可以使用第一光学元件131’替代第一光学元件131，第一光学元件131’的轮廓外形可与图7中的豁口区域13a的轮廓基本一致。第一光学元件131’可以是三棱镜，可以具有依次首尾相连的设置面131’a、连接面131’b和第一贴合面131’c。其中，连接面131’b法线沿第二方向X。设置面131’a与第一方向Z形成45°的第一夹角，也即设置面131’a可与连接面131’b形成45°夹角。该45°的第一夹角仅仅是一种举例。实际上根据产品需要，还可以是其他数值的设定角度，该设定角度的范围可以是(22.5°,90°)(不含端点值)。例如，该设定角度可以取30°、45°、60°等。该第一夹角在上述范围内，有利于保证光学组件的光学性能，也能够确保光学组件的结构符合实际需要。第一贴合面131’c与第二光学元件136的第二贴合面136a平行。
如图8所示，设置面131’a上可以设置反射膜140，反射膜140可以通过贴合工艺或者镀膜工艺形成在设置面131’a上。反射膜140起到反射激光器124发射的激光束的作用，经反射膜140反射后的激光束沿第二方向X。可见，反射膜140替代了能进行全反射的元件反射面131c。在图8所示的实施例中，反射膜140中用于反射激光束的面也可以称为元件反射面，反射膜140中的该元件反射面具有与元件反射面131c等效的反射性能。
在图8所示的实施例中，设置面131’a与第一方向Z形成的第一夹角可以是其他数值，可以通过调整激光器124的位置与姿态，保证被设置面131’a反射的激光束仍然沿第二方向X传播，这样能够保证光学组件的光学性能基本不变。例如，若第一夹角大于45°，则可以将激光器124的位置与姿态进行调整，使其发出的激光束沿右上方传播(以图8视角为例)；反之，若第一夹角小于45°，则可以将激光器124的位置与姿态进行调整，使其发出的激光束沿右下方传播(以图8视角为例)。
或者在另一种实施例中，可以使用平面反射镜替代第一光学元件131。该平面反射镜平行于图7中的第一贴合面131c，该平面反射镜将激光器124发射的激光束进行反射，经该平面反射镜反射后的激光束沿第二方向X。该平面反射镜等同于图8所示实施例中的反射膜140。
实施例一中，设计第二光学元件136，能限制激光束的传播距离，有利于约束透镜组132的体积。若其他实施例中无需考虑这点，则可以取消第二光学元件136。在该其他实施例中，偏振分光膜139可设在第一光学元件131的第一贴合面131d上。可以设计相应的支撑结构(例如支架)来支撑相位延迟片138。在该实施例中，可以使用上述的第一光学元件131，或者上述的第一光学元件131’或该反射镜。
如图9所示，实施例二提供了一种光学组件23，同样可以实现激光束的零度入射和共同出瞳。与实施例一不同的是，该光学组件23是一种由棱镜和反射镜构成的反射式光学4f系统。下面将详细描述光学组件23的结构。
如图9所示，光学组件23可以包括第一棱镜232、第三棱镜234、第二棱镜235、平面反射镜240、第一曲面反射镜241、MEMS振镜233、第二曲面反射镜237、第一偏振分光膜243、第一相位延迟片231、第三相位延迟片239、第二偏振分光膜238、第四相位延迟片236和第二相位延迟片242。下面将逐一描述。
如图9所示，第一棱镜232与第二棱镜235均可以是三棱镜，二者分别与第三棱镜234的相对两侧连接。第一棱镜232与第二棱镜235的结构可以基本一致，二者可以镜像分布，镜像面可以是第三棱镜234的对称面。第三棱镜234用于使激光束按设定光路行进，以及限定第一棱镜232与第二棱镜235的间距，以满足反射式光学4f系统的光程要求。
其中，第一棱镜232可以具有依次首尾相连的受光面232a、第一设置面232b和第一贴合面232c。受光面232a可以是平面，其法线可沿第一方向Z。第一设置面232b可以是平面，其法线可沿第二方向X。第一贴合面232c可以是平面，其可与受光面232a形成45°夹角，也即第一贴合面232c与第一方向Z形成45°的第二夹角。第二夹角为45°仅仅是一种举例。根据产品实际需要，第二夹角还可以是其他数值，该第二夹角的范围可以是[25°，65°](含端点值)。例如该第二夹角具体可以取25°、35°、45°、55°或者65°。该第二夹角在上述范围内，有利于保证光学组件23的光学性能，也能够确保光学组件23的结构符合实际需要。下文将主要以该第二夹角取45°为例进行描述。第一贴合面232c贴靠第三棱镜234的一侧。
在其他实施例中，在保证第一棱镜232的受光面232a、第一设置面232b和第一贴合面232c的位置关系(各自相对第一方向Z、第二方向X的绝对位置关系，以及各自之间的相对 位置关系)的前提下，可以根据产品需要，灵活调整受光面232a、第一设置面232b和第一贴合面232c的连接关系。例如，第一棱镜232可以不是三棱镜，其侧面的数量可以大于三。例如，受光面232a与第一设置面232b之间可通过一个表面连接，该表面与受光面232a、第一设置面232b均不垂直。
第二棱镜235可以具有依次首尾相连的出光面235a、第二设置面235b和第二贴合面235c。出光面235a可以是平面，其与受光面232a平行，并背向受光面232a。第二设置面235b可以是平面，其可与第一设置面232b平行且共面。第二贴合面235c与出光面235a形成45°夹角。第二贴合面235c与第一贴合面232c镜像设置，在本实施例中第二贴合面235c可与第一贴合面232c垂直。第二贴合面235c可贴靠第三棱镜234的另一侧。设计第二棱镜235能够能限制激光束的传播距离，有利于约束第一曲面反射镜241与第二曲面反射镜237的体积。
在其他实施例中，在保证第二棱镜235的出光面235a、第二设置面235b和第二贴合面235c的位置关系(各自相对第一方向Z、第二方向X的绝对位置关系，以及各自之间的相对位置关系)的前提下，可以根据产品需要，灵活调整出光面235a、第二设置面235b和第二贴合面235c的连接关系。例如，第二棱镜235可以不是三棱镜，其侧面的数量可以大于三。例如，出光面235a与第二设置面235b之间可通过一个表面连接，该表面与出光面235a、第二设置面235b均不垂直。其中，第二设置面235b可以仅与第一设置面232b，但二者可以不共面(或称不平齐)。
如图9所示，第一偏振分光膜243位于第一贴合面232c上，并可以设在第一贴合面232c与第三棱镜234的表面之间。第一偏振分光膜243可以为平整膜层，其可以布满整个第一贴合面232c，也可以仅覆盖第一贴合面232c的部分区域(该部分区域包括第一贴合面232c与第三棱镜234的表面相重合的部分)。第一偏振分光膜243可以通过贴合工艺或镀膜工艺制得。
如图9所示，第二偏振分光膜238位于第二贴合面235c上，并可以设在第二贴合面235c与第三棱镜234的表面之间。第二偏振分光膜238可以为平整膜层，其可以布满整个第二贴合面235c，也可以仅覆盖第二贴合面235c的部分区域(该部分区域包括第二贴合面235c与第三棱镜234的表面相重合的部分)。第二偏振分光膜238可以通过贴合工艺或镀膜工艺制得。
如图9所示，第一相位延迟片231可以为平整片状，其可以设在第一棱镜232的第一设置面232b上。第一相位延迟片231用于改变透过第一相位延迟片231的光的偏振态。例如第一相位延迟片231可以是四分之一玻片，光每透过其一次，光的相位变化λ/4。
如图9所示，MEMS振镜233位于第一相位延迟片231背离第一棱镜232的一侧，MEMS振镜233与第一相位延迟片231间隔相对。MEMS振镜233能够在信号控制下发生往复偏转(可将该往复偏转称为振动)，以将射到MEMS振镜233的反射面233a的光线以不同角度反射出去，实现扫描成像。本实施例中，在未通电状态下，MEMS振镜233的反射面233a的法线沿第二方向X，可将MEMS振镜233此时的姿态称为默认姿态。
如图9所示，第三相位延迟片239可以为平整片状，其可以设在第二棱镜235的第一设置面235b上。第三相位延迟片239用于改变透过第三相位延迟片239的光的偏振态。例如第三相位延迟片239可以是四分之一玻片，光每透过其一次，光的相位变化λ/4。
如图9所示，第二曲面反射镜237可以位于第四相位延迟片236背离第二棱镜235的一侧。第二曲面反射镜237可以具有曲面反射面，例如非球面的曲面反射面。第二曲面反射镜237的该曲面反射面(图9中用黑色区域表示第二曲面反射镜237中的反射层)可以朝背离第四相位延迟片236的方向拱起。第二曲面反射镜237的中心线可以沿第二方向X。第二曲面反射镜237朝向第四相位延迟片236的一侧表面与第四相位延迟片236贴合，第二曲面反 射镜237与第四相位延迟片236连接的表面为平面。第二曲面反射镜237与第四相位延迟片236贴合，能够使得结构紧凑，具有较好的可制造性。
在其他实施例中，第二曲面反射镜整体可以是弧形板状结构，第二曲面反射镜与第四相位延迟片236间隔设置。此种设计可以满足相应的产品需要求。
如图9所示，第二相位延迟片242与第四相位延迟片236均可以为平整片状，二者可以均设在第三棱镜234上法线沿第二方向X的表面。其中，第二相位延迟片242可以对应第一棱镜232，第四相位延迟片236可以对应第二棱镜235。第二相位延迟片242与第四相位延迟片236均用于改变光线的偏振态。例如第三相位延迟片239与第四相位延迟片236均可以是四分之一玻片，光每透过其一次，光的相位变化λ/4。
实施例二中，第二相位延迟片242与第四相位延迟片236可以连为一体，二者可以合为一个相位延迟片，即一个相位延迟片覆盖第三棱镜234上法线沿第二方向X的表面，该相位延迟片对应第一棱镜232与第二棱镜235。或者，第二相位延迟片242与第四相位延迟片236也可以是单独的相位延迟片，二者可以不相连。
如图9所示，平面反射镜240可以呈平整板状。平面反射镜240与第二曲面反射镜237分别位于第二棱镜235在第二方向X上的相对两侧。平面反射镜240可位于第四相位延迟片236背离第三棱镜234的一侧，并与第四相位延迟片236贴合在一起。平面反射镜240与第四相位延迟片236贴合，能够使得结构紧凑，具有较好的可制造性。平面反射镜240用于控制光程，以满足光学组件23的光程需要。
在其他实施例中，平面反射镜240也可以与第四相位延迟片236间隔设置，以满足一定的产品需要。
如图9所示，第一曲面反射镜241可以位于第二相位延迟片242背离第三棱镜234的一侧，第一曲面反射镜241与MEMS振镜233，分别位于第一棱镜232在第二方向X上的相对两侧。第一曲面反射镜241可以具有曲面反射面(图9中用黑色区域表示第一曲面反射镜241中的反射层)，例如非球面的曲面反射面。第一曲面反射镜241的该曲面反射面可以朝背离第二相位延迟片242的方向拱起。第一曲面反射镜241的中心线可以沿第二方向X。第一曲面反射镜241朝向第二相位延迟片242的一侧表面可与第二相位延迟片242贴合在一起，第一曲面反射镜241与第二相位延迟片242连接的表面可以是平面。第一曲面反射镜241与第二相位延迟片242贴合，能够使得结构紧凑，具有较好的可制造性。
在其他实施例中，第一曲面反射镜整体可以是弧形板状结构，第一曲面反射镜与第二相位延迟片242间隔设置。此种设计可以满足相应的产品需要求。
上文对实施例二的光学组件23的结构进行了详细描述。下面将通过分析光路，对光学组件23的工作原理进行说明。
图9可表示MEMS振镜233在默认姿态下激光束的传输光路。如图9所述，在第一贴合面232c与第一方向Z形成的第二夹角是45°的条件下，激光器124发射沿第一方向Z传播的平行激光束，平行激光束垂直于第一棱镜232的受光面232a进入第一棱镜232，并照射到第一偏振分光膜243上。由于第一偏振分光膜243与受光面232a形成45°夹角，因此第一偏振分光膜243能够将平行激光束沿第二方向X反射。沿第二方向X的平行激光束将透过第一相位延迟片231，并照射到MEMS振镜233的反射面233a上。由于透过第一相位延迟片231的平行激光束沿第二方向X，因此照射到MEMS振镜233的反射面233a上的平行激光束的入射角为零，由此实现零度入射。
同上文所述的原理，实施例二的方案通过实现零度入射，能够减小MEMS振镜233的体积， 还能在不增加MEMS振镜233的体积与扫描角度的前提下提升视场角，以扩大用户视野，增强用户体验。
如图9所示，零度入射到MEMS振镜233的反射面233a上的平行激光束被MEMS振镜233反射回来，将沿第二方向X再次透过第一相位延迟片231。再次透过第一相位延迟片231后，平行激光束的偏振态发生变化，平行激光束的相位变化λ/2。这使得平行激光束再次照射到第一偏振分光膜243上时，平行激光束会透过第一偏振分光膜243，而非被第一偏振分光膜243反射。
如图9所示，透过第一偏振分光膜243的平行激光束将进入第三棱镜234，并穿透第二相位延迟片242，照射到第一曲面反射镜241上。第一曲面反射镜241平行激光束反射进行反射。反射激光束再次透过第二相位延迟片242后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到第一偏振分光膜243上时，激光束会被第一偏振分光膜243反射，而非透过第一偏振分光膜243。被第一偏振分光膜243反射的激光束射向第二偏振分光膜238。第二偏振分光膜238将激光束向第四相位延迟片236反射。激光束能透过第四相位延迟片236，并射到平面反射镜240上。
如图9所示，平面反射镜240将激光束反射回来。反射激光束再次透过第四相位延迟片236后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到第二偏振分光膜238上时，激光束会透过第二偏振分光膜238，而非被第二偏振分光膜238反射。透过第二偏振分光膜238的激光束将进入第二棱镜235，并透过第三相位延迟片239，照射到第二曲面反射镜237上。第二曲面反射镜237激光束反射回来。
如图9所示，反射激光束再次透过第三相位延迟片239后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到第二偏振分光膜238上时，激光束会被第二偏振分光膜238反射，而非透过第二偏振分光膜238。被第二偏振分光膜238反射的激光束从第二棱镜235的出光面235a射出，由此完成在光学组件23中的传输。从出光面235a射出的激光束为沿第一方向Z的平行激光束，该平行激光束照射到耦入结构123上。
图10与图11分别表示MEMS振镜233在不同偏转姿态下激光束的传输光路，图10与图11中激光束的传播规律同图9，因而不再赘述。但与图9不同的是，由于MEMS振镜233发生了偏转，被MEMS振镜233反射的平行激光束不再沿第二方向X，因此从第二棱镜235射出的平行激光束也不再沿第一方向Z。
例如图10所示，MEMS振镜233由图9中的默认姿态顺时针偏转一定角度后，达到第一偏转姿态。在第一偏转姿态下，被MEMS振镜233反射的平行激光束可偏离第二方向X。最终，从第二棱镜235射出的平行激光束也偏离第一方向Z。例如在图10视角中，从第二棱镜235射出的平行激光束可相较第一方向Z沿逆时针方向偏转一定角度。MEMS振镜233处于第一偏转姿态下，从第二棱镜235射出的激光束同样能照射到耦入结构123上。并且，MEMS振镜233在第一偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜233在默认姿态下耦入结构123上被激光束照射的区域基本相同。
类似地，如图11所示，MEMS振镜233由图3中的默认姿态逆时针偏转一定角度后，达到第二偏转姿态。在第二偏转姿态下，被MEMS振镜233反射的平行激光束可偏离第二方向X。最终，从第二棱镜235射出的平行激光束也偏离第一方向Z。例如在图11视角中，从第二棱镜235射出的平行激光束可相较第一方向Z沿顺时针方向偏转一定角度。MEMS振镜233处于第二偏转姿态下，从第二棱镜235射出的激光束同样能照射到耦入结构123上。并且，MEMS振镜233在第二偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜233在默认姿 态下耦入结构123上被激光束照射的区域基本相同。
图12表示MEMS振镜233在默认姿态、第一偏转姿态和第二偏转姿态下，激光束的传输光路对比。如图12所示，随着MEMS振镜233在振动时改变姿态，被MEMS振镜233反射的平行激光束将会分别沿不同方向传播，因此这些平行激光束总体上是发散的。但是，由于实施例二的光学组件23的结构设计，光学组件23整体构成一种光学4f系统，能够使沿不同方向传播的平行激光束汇聚到耦入结构123上的同一区域，也即使不同方向的平行激光束能均能在耦入结构123上的同一口径范围内形成出瞳，从而实现共同出瞳。因此，实施例二能够实现共同出瞳，有利于减小耦入结构123的面积。
在实施例二中，第一贴合面232c与第一方向Z形成的第二夹角可以是其他数值。可以通过调整激光器124的位置与姿态，并对第一曲面反射镜241、平面反射镜240和第二曲面反射镜237的具体结构与位置做适应性调整，保证被第一贴合面232c上的第一偏振分光膜243反射的激光束仍然沿第二方向X传播，保证光学组件23内的光路基本不变，这样能够保证光学组件23的光学性能基本不变。
另外，实施例二的光学组件23在第一方向Z上布置的元件较少，占用尺寸较小；在第二方向X上布置的元件较多，占用了一定尺寸(相较实施例一的光学组件13而言)。这是一种根据产品需要进行的结构设计。
在其他实施例中，基于以上的光路原理，可以设计出实施例二的光学组件23的若干替代结构。
例如在一种实施例中，可以取消第三棱镜234，保留其他元件。此时，可以设计相应的支撑结构(例如支架)来支撑第二相位延迟片242和第四相位延迟片236。该实施例中的光路可与实施例二基本相同。
或者在另一种实施例中，可以取消第二棱镜235、第三棱镜234、第三相位延迟片239、第四相位延迟片236、第二偏振分光膜238、平面反射镜240和第二曲面反射镜237，保留其他元件。此时，可以设计相应的支撑结构(例如支架)来支撑第二相位延迟片242。该实施例中的光路可与实施例二基本相同。
或者在另一种实施例中，可以取消第一棱镜232、第二棱镜235和第三棱镜234，保留其他元件。此时，可以设计相应的支撑结构(例如支架)来支撑第一偏振分光膜243、第一相位延迟片231、第三相位延迟片239、第二偏振分光膜238、第四相位延迟片236和第二相位延迟片242。该实施例中的光路可与实施例二基本相同。
如图13所示，实施例三提供了一种光学组件33，同样可以减小MEMS振镜的体积和实现共同出瞳。与实施例二不同的是，光学组件33是一种由棱镜、反射镜和透镜构成的反射透射混合型光学4f系统。下面将详细描述光学组件33的结构。
如图13所示，光学组件33可以包括第一棱镜337、第二棱镜332、曲面反射镜331、第一平凸透镜335和第二平凸透镜333、偏振分光膜338、第一相位延迟片336和第二相位延迟片339。下面将逐一说明。
如图13所示，第一棱镜337与第二棱镜332均可以是三棱镜，二者可以贴靠在一起。
其中，第一棱镜337可以具有依次首尾相连的受光面337b、第一设置面337c和第一贴合面337a。受光面337b可以是平面，其法线可沿第一方向Z。第一设置面337c可以是平面，其法线可沿第二方向X。第一贴合面337a可以是平面，其可与受光面337b形成45°夹角，也即第一贴合面337a与第一方向Z形成45°的第三夹角。第三夹角为45°仅仅是一种举例。根据产品实际需要，第三夹角还可以是其他数值，该第二夹角的范围可以是[25°，65°](含 端点值)。例如该第二夹角具体可以取25°、35°、45°、55°或者65°。该第三夹角在上述范围内，有利于保证光学组件33的光学性能，也能够确保光学组件33的结构符合实际需要。下文将主要以该第三夹角取45°为例进行描述。
第二棱镜332可以具有依次首尾相连的出光面332b、第二设置面332a和第二贴合面332c。出光面332b可以是平面，其可与受光面337b平行，且背向受光面337b。第二设置面332a可以是平面，其可与第一设置面337c平行，且背向第一设置面337c。第二贴合面332c可以是平面，其可与第一贴合面337a平行，且朝向第一贴合面337a。
在其他实施例中，在保证第一棱镜337的上述各面的位置关系(各自相对第一方向Z、第二方向X的绝对位置关系，以及各自之间的相对位置关系)，以及保证第二棱镜332的上述各面的位置关系(各自相对第一方向Z、第二方向X的绝对位置关系，以及各自之间的相对位置关系)的前提下，可以根据产品需要，灵活调整第一棱镜337与第二棱镜332的结构。例如，第一棱镜337和/或第二棱镜332可以不是三棱镜。
如图13所示，偏振分光膜338可以位于第一贴合面337a与第二贴合面332c之间，可以认为偏振分光膜338设于第一贴合面337a或第二贴合面332c上。偏振分光膜338可以通过贴合工艺或镀膜工艺制得。
如图13所示，第一相位延迟片336设在第一棱镜337的第一设置面337a上。第一相位延迟片336用于改变透过光的偏振态。例如第一相位延迟片336可以是四分之一玻片，光每透过其一次，光的相位变化λ/4。
如图13所示，第二相位延迟片339设在第二棱镜332的第二设置面332a上。第二相位延迟片339用于改变透过光的偏振态。例如第二相位延迟片339可以是四分之一玻片，光每透过其一次，光的相位变化λ/4。
如图13所示，曲面反射镜331可以位于第二相位延迟片339背离第二棱镜332的一侧。曲面反射镜331可以具有曲面反射面，例如非球面的曲面反射面。曲面反射镜331的该曲面反射面可朝背离第二相位延迟片339的方向拱起。曲面反射镜331的中心线可以沿第二方向X。曲面反射镜331朝向第二相位延迟片339的表面可与第二相位延迟片339贴合，曲面反射镜331与第二相位延迟片339连接的表面可以是平面。贴合设计能使结构紧凑，有利于提升可制造性。
在其他实施例中，曲面反射镜331整体可以呈弧形板结构，曲面反射镜331可与第二相位延迟片339间隔相对。此种设计能满足一定的产品需求。
如图13所示，第一平凸透镜335可以位于第一相位延迟片336背离第一棱镜337的一侧。第一平凸透镜335朝向第一相位延迟片336的表面可与第一相位延迟片336贴合。贴合设计能使结构紧凑，有利于提升可制造性。第一平凸透镜335背向第一相位延迟片336的表面可以朝远离第一相位延迟片336的方向拱起。第一平凸透镜335的中心线可以沿第二方向X。
在其他实施例中，第一平凸透镜335可与第二相位延迟片339间隔相对。此种设计能满足一定的产品需求。
如图13所示，MEMS振镜334可以位于第一平凸透镜335背离第一棱镜337的一侧，MEMS振镜334可以与第一平凸透镜335间隔相对。MEMS振镜334能够在信号控制下发生往复偏转(可将该往复偏转称为振动)，以将射到MEMS振镜334的反射面334a的光线以不同角度反射出去，实现扫描成像。本实施例中，在未通电状态下，MEMS振镜334的反射面334a的法线沿第二方向X，可将MEMS振镜334此时的姿态称为默认姿态。
如图13所示，第二平凸透镜333可位于第二棱镜332的出光面332b远离第一棱镜337 的一侧。第二平凸透镜333朝向出光面332b的表面可与出光面332b贴合。贴合设计能使结构紧凑，有利于提升可制造性。第二平凸透镜333背向第二棱镜332的表面可以朝背离第二棱镜332的方向拱起。第二平凸透镜333的中心线可沿第一方向Z。
在其他实施例中，第二平凸透镜333可与第二棱镜332的出光面332b间隔相对，此种设计能满足一定的产品需求。
上文对实施例三的光学组件33的结构进行了详细描述。下面将通过分析光路，对光学组件33的工作原理进行说明。
图13可表示MEMS振镜334在默认姿态下激光束的传输光路。如图13所示，在第一贴合面337a与第一方向Z形成的第三夹角是45°的条件下，激光器124发射沿第一方向Z传播的平行激光束，平行激光束垂直于第一棱镜337的受光面337b进入第一棱镜337，并照射到偏振分光膜338上。由于偏振分光膜338与受光面337b形成45°夹角，因而偏振分光膜338能够将平行激光束沿第二方向X反射。沿第二方向X的平行激光束将透过第一相位延迟片336，并照射到第一平凸透镜335上。第一平凸透镜335能将该平行激光束聚拢，使得从第一平凸透镜335射出的激光束的口径逐渐收缩，并照射到MEMS振镜334的反射面334a上。
参考图4A至图4C所示的原理，通过使MEMS振镜334在默认姿态下，MEMS振镜334的反射面334a的法线沿第二方向X，并使聚拢激光束照射到反射面334a上，能够使得反射面334a的面积做的较小，从而减小MEMS振镜334的体积。
如图13所示，MEMS振镜334的反射面334a将激光束反射回去，反射激光束再次透过第一平凸透镜335和第一相位延迟片336。再次透过第一相位延迟片336后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到偏振分光膜338上时，激光束会透过偏振分光膜338，而非被偏振分光膜338反射。
如图13所示，透过偏振分光膜338的激光束将进入第二棱镜332，并穿透第二相位延迟片339，照射到曲面反射镜331上。曲面反射镜331将激光束反射回来。反射激光束再次透过第二相位延迟片339后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到偏振分光膜338上时，激光束会被偏振分光膜338反射，而非透过偏振分光膜338。
如图13所示，被偏振分光膜338反射的激光束从第二棱镜332的出光面332b射出，并穿过第二平凸透镜333，由此完成在光学组件23中的传输。从第二平凸透镜333射出的激光束是沿第一方向Z的平行激光束，该平行激光束射到耦入结构123上。
图14与图15分别表示，MEMS振镜334的在不同偏转姿态下激光束的传输光路，图14与图15中激光束的传播规律同图13，因而不再赘述。但与图13不同的是，由于MEMS振镜334发生了偏转，因此从第二平凸透镜333射出的平行激光束也不再沿第一方向Z。
例如图14所示，MEMS振镜334由图13中的默认姿态顺时针偏转一定角度后，达到第一偏转姿态。在第一偏转姿态下，从第二平凸透镜333射出的平行激光束也偏离第一方向Z。例如在图14视角中，从第二平凸透镜333射出的平行激光束可相较第一方向Z沿逆时针方向偏转一定角度。MEMS振镜334处于第一偏转姿态下，从第二平凸透镜333射出的激光束同样能照射到耦入结构123上。并且，MEMS振镜334在第一偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜334在默认姿态下耦入结构123上被激光束照射的区域基本相同。
类似地，如图15所示，MEMS振镜334由图13中的默认姿态逆时针偏转一定角度后，达到第二偏转姿态。在第二偏转姿态下，从第二平凸透镜333射出的平行激光束也偏离第一方向Z。例如在图15视角中，从第二平凸透镜333射出的平行激光束可相较第一方向Z沿顺时 针方向偏转一定角度。MEMS振镜334处于第二偏转姿态下，从第二平凸透镜333射出的激光束同样能照射到耦入结构123上。并且，MEMS振镜334在第二偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜334在默认姿态下耦入结构123上被激光束照射的区域基本相同。
图16表示MEMS振镜334在默认姿态、第一偏转姿态和第二偏转姿态下，激光束的传输光路对比。如图16所示，随着MEMS振镜334在振动时改变姿态，被MEMS振镜334反射的激光束将会分别沿不同方向传播，因此这些激光束是发散的。但是，由于实施例三的光学组件33的结构设计，光学组件33整体能构成一种反射透射混合型光学4f系统，能够使沿不同方向传播的激光束汇聚到耦入结构123上的同一区域，也即使不同方向的激光束能均能在耦入结构123上的同一口径范围内形成出瞳，从而实现共同出瞳。因此，实施例三能够实现共同出瞳，有利于减小耦入结构123的面积。
在实施例三中，第一贴合面337a与第一方向Z形成的第三夹角可以是其他数值。可以通过调整激光器124的位置与姿态，并对曲面反射镜331、第一平凸透镜335和第二平凸透镜333的具体结构与位置做适应性调整，保证被第一贴合面337a上的偏振分光膜338反射的激光束仍然沿第二方向X传播，保证光学组件33内的光路基本不变，这样能够保证光学组件33的光学性能基本不变。
另外，实施例三的光学组件33在第一方向Z上布置的元件较少，占用尺寸较小；在第二方向X上布置的元件较多，占用了一定尺寸(相较实施例一的光学组件13而言)。这是一种根据产品需要进行的结构设计。
实施例三中，使用第一平凸透镜335与第二平凸透镜333能够提升成像质量。在其他实施例中，可以取消第一平凸透镜335和/或第二平凸透镜333。
实施例三中，第二棱镜332能限制激光束的传播距离，有利于约束第一平凸透镜335和第二平凸透镜333的体积。若其他实施例中无需考虑这点，可以取消第二棱镜332。其中，可以设计相应的支撑结构(例如支架)，来支撑第二相位延迟片339。
在其他实施例中，还可以取消第一棱镜337。其中，可以设计相应的支撑结构(例如支架)，来支撑偏振分光膜338和第一相位延迟片336。
如图17所示，实施例四提供了一种光学组件43，同样能够减小MEMS振镜的体积和实现共同出瞳。光学组件43也是一种由棱镜、反射镜和透镜构成的反射透射混合型光学4f系统。但与实施例三不同的是，光学组件43中的透镜的位置与光学组件33中的透镜的位置不同。下面将详细描述光学组件43的结构。
如图17所示，光学组件43可以包括凹透镜431、凸透镜432、第一棱镜433、第二棱镜436、第一偏振分光膜439、第一相位延迟片434、第二相位延迟片437、MEMS振镜435和曲面反射镜438。下面将逐一说明。
如图17所示，凹透镜431与凸透镜432间隔排列，二者的中心线均可沿第一方向Z。其中，凸透镜432位于凹透镜431与第一棱镜433之间，凸透镜432与第一棱镜433间隔设置。凹透镜431的焦距例如可以是-5mm至-20mm。凸透镜432的焦距例如可以是5mm至15mm。凹透镜431用于对激光束进行扩束，优化像差。凸透镜432用于聚焦激光束，优化像差。凹透镜431与凸透镜432构成的透镜组，相当于实施例一中由第一双胶合透镜133、第一非球面透镜134、第二非球面透镜135构成的第一透镜组132a。
在其他实施例中，不限于由凹透镜431与凸透镜432这两个透镜构成透镜组，透镜组中透镜的数量及类型均可以根据需要设计。
如图17所示，第一棱镜433具有依次首尾相连的受光面433b、第一设置面433c和第一贴合面433a。受光面433b可以是平面，其法线可沿第一方向Z。第一设置面433c可以是平面，其法线可沿第二方向X。第一贴合面433a可以是平面，其可与受光面433b形成45°夹角，也即第一贴合面433a与第一方向Z形成45°的第三夹角。第三夹角为45°仅仅是一种举例。根据产品实际需要，第三夹角还可以是其他数值，该第二夹角的范围可以是[25°，65°](含端点值)。例如该第二夹角具体可以取25°、35°、45°、55°或者65°。该第三夹角在上述范围内，有利于保证光学组件43的光学性能，也能够确保光学组件43的结构符合实际需要。下文将主要以该第三夹角取45°为例进行描述。
第二棱镜436可以具有依次首尾相连的出光面436b、第二设置面436c和第二贴合面436a。出光面436b可以是平面，其可与受光面433b平行，且背向受光面433b。第二设置面436c可以是平面，其可与第一设置面433c平行，且背向第一设置面433c。第二贴合面436a可以是平面，其可与第一贴合面433a平行，且朝向第一贴合面433a。
在其他实施例中，在保证第一棱镜433的上述各面的位置关系(各自相对第一方向Z、第二方向X的绝对位置关系，以及各自之间的相对位置关系)，以及保证第二棱镜436的上述各面的位置关系(各自相对第一方向Z、第二方向X的绝对位置关系，以及各自之间的相对位置关系)的前提下，可以根据产品需要，灵活调整第一棱镜436与第二棱镜436的结构。例如，第一棱镜433和/或第二棱镜436可以不是三棱镜。
如图17所示，第一偏振分光膜439可以位于第一贴合面433a与第二贴合面436a之间，可以认为第一偏振分光膜439设于第一贴合面337a或第二贴合面332c上。第一偏振分光膜439可以通过贴合工艺或镀膜工艺制得。
如图17所示，第一相位延迟片434设在第一棱镜433的第一设置面433c上。第一相位延迟片434用于改变透过光的偏振态。例如第一相位延迟片434可以是四分之一玻片，光每透过其一次，光的相位变化λ/4。
如图17所示，第二相位延迟片437设在第二棱镜436的第二设置面436c上。第二相位延迟片437用于改变透过光的偏振态。例如第二相位延迟片437可以是四分之一玻片，光每透过其一次，光的相位变化λ/4。
如图17所示，曲面反射镜438可以位于第二相位延迟片437背离第二棱镜436的一侧。曲面反射镜438朝向第二相位延迟片437的表面可与第二相位延迟片437贴合，贴合设计可以使得结构紧凑，提升可制造性。曲面反射镜438可以具有曲面反射面，例如非球面的曲面反射面。曲面反射镜438的该曲面反射面可以朝背离第二相位延迟片437的方向拱起。曲面反射镜438的中心线可沿第二方向X。
在其他实施例中，曲面反射镜可以呈弧形板状结构，曲面反射镜可与第二相位延迟片437间隔相对。
如图17所示，MEMS振镜435可以位于第一相位延迟片434背离第一棱镜433的一侧，MEMS振镜435可以与第一相位延迟片434间隔相对。MEMS振镜435能够在信号控制下发生往复偏转(可将该往复偏转称为振动)，以将射到MEMS振镜435的反射面435a的光线以不同角度反射出去，实现扫描成像。本实施例中，在未通电状态下，MEMS振镜435的反射面435a的法线沿第二方向X，可将MEMS振镜435此时的姿态称为默认姿态。
上文对实施例四的光学组件43的结构进行了详细描述。下面将通过分析光路，对光学组件43的工作原理进行说明。
图17可表示MEMS振镜435在默认姿态下激光束的传输光路。如图17所示，在第一贴合 面433a与第一方向Z形成的第三夹角是45°的条件下，激光器124发射沿第一方向Z传播的平行激光束，平行激光束依次穿过凹透镜431和凸透镜432后，成为聚拢的激光束。该聚拢激光束从第一棱镜433的受光面433b进入第一棱镜433，并照射到第一偏振分光膜439上。由于第一偏振分光膜439与受光面433b形成45°夹角，因而第一偏振分光膜439能够将聚拢激光束向第一相位延迟片434反射。激光束透过第一相位延迟片434后，可以照射到MEMS振镜435的反射面435a上，且从第一相位延迟片434出射的激光束的口径可以逐渐收缩。
参考图4A至图4C所示的原理，通过使MEMS振镜435在默认姿态下，MEMS振镜435的反射面435a的法线沿第二方向X，并使聚拢激光束照射到反射面435a上，能够使得反射面435a的面积做的较小，从而减小MEMS振镜435的体积。
如图17所示，被MEMS振镜435反射回来的激光束将再次穿过第一相位延迟片434。再次透过第一相位延迟片434后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到第一偏振分光膜439上时，激光束会透过第一偏振分光膜439，而非被第一偏振分光膜439反射。
如图17所示，透过第一偏振分光膜439的激光束将进入第二棱镜436，并穿透第二相位延迟片437，照射到曲面反射镜438上。曲面反射镜438将激光束反射回来。反射激光束再次透过第二相位延迟片437后，激光束的偏振态发生变化，激光束的相位变化λ/2。这使得激光束再次照射到第一偏振分光膜439上时，激光束会被第一偏振分光膜439反射，而非透过第一偏振分光膜439。
如图17所示，被偏振分光膜338反射的激光束从第二棱镜436的出光面436b射出，由此完成在光学组件43中的传输。从出光面436b射出的激光束是沿第一方向Z的平行激光束，该平行激光束射到耦入结构123上。
图18与图19分别表示，MEMS振镜435的在不同偏转姿态下激光束的传输光路，图18与图19中激光束的传播规律同图17，因而不再赘述。但与图17不同的是，由于MEMS振镜435发生了偏转，因此从出光面436b射出的平行激光束也不再沿第一方向Z。
例如图18所示，MEMS振镜435由图17中的默认姿态顺时针偏转一定角度后，达到第一偏转姿态。在第一偏转姿态下，从第二棱镜436射出的平行激光束也偏离第一方向Z。例如在图18视角中，从出光面436b射出的平行激光束可相较第一方向Z沿逆时针方向偏转一定角度。MEMS振镜435处于第一偏转姿态下，从出光面436b射出的激光束同样能照射到耦入结构123上。并且，MEMS振镜435在第一偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜435在默认姿态下耦入结构123上被激光束照射的区域基本相同。
类似地，如图19所示，MEMS振镜435由图17中的默认姿态逆时针偏转一定角度后，达到第二偏转姿态。在第二偏转姿态下，从出光面432b射出的平行激光束也偏离第一方向Z。例如在图19视角中，从出光面436b射出的平行激光束可相较第一方向Z沿顺时针方向偏转一定角度。MEMS振镜435处于第二偏转姿态下，从出光面436b射出的激光束同样能照射到耦入结构123上。并且，MEMS振镜435在第二偏转姿态下耦入结构123上被激光束照射的区域，与MEMS振镜435在默认姿态下耦入结构123上被激光束照射的区域基本相同。
图20表示MEMS振镜435在默认姿态、第一偏转姿态和第二偏转姿态下，激光束的传输光路对比。如图20所示，随着MEMS振镜435在振动时改变姿态，被MEMS振镜435反射的激光束将会分别沿不同方向传播，因此这些激光束是发散的。但是由于光学组件43的结构设计，能够使沿不同方向传播的激光束汇聚到耦入结构123上的同一区域，也即使不同方向的激光束能均能在耦入结构123上的同一口径范围内形成出瞳，从而实现共同出瞳。因此，实施例 四能够实现共同出瞳，有利于减小耦入结构123的面积。
在实施例四中，第一贴合面433a与第一方向Z形成的第三夹角可以是其他数值。可以通过调整激光器124的位置与姿态，并对凸透镜432和曲面反射镜438的具体结构与位置做适应性调整，保证被第一贴合面433a上的第一偏振分光膜439反射的激光束仍然近似沿第二方向X传播，保证光学组件43内的光路基本不变，这样能够保证光学组件43的光学性能基本不变。
在其他实施例中，也可以在第二棱镜436的出光面436b与耦入结构123之间设置透镜，从出光面436b出射的激光束穿过该透镜照射到耦入结构123上。实际上，可以在出光面436b与耦入结构123之间、MEMS振镜435与第一棱镜433之间、第二棱镜436与曲面反射镜438之间、第一棱镜433与激光器124之间这四处中的任一处或任几处设计透镜。或者，也可以在以上所有位置均不设透镜。
以上所述，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所述权利要求的保护范围为准。

Claims (27)

  1. 一种光学组件，其特征在于，
    所述光学组件包括第一光学元件、偏振分光膜、相位延迟片、微机电系统振镜和光学4f系统；
    所述第一光学元件具有元件反射面，所述元件反射面与第一方向形成第一夹角；
    所述偏振分光膜与所述元件反射面垂直；
    所述相位延迟片位于所述偏振分光膜与所述微机电系统振镜之间，所述相位延迟片的法线沿第二方向，所述第二方向与所述第一方向正交；
    所述微机电系统振镜与所述相位延迟片具有间隔，所述微机电系统振镜的反射面朝向所述相位延迟片；
    所述光学4f系统位于所述偏振分光膜远离所述第一光学元件的一侧，所述光学4f系统与所述偏振分光膜具有间隔，所述光学4f系统的中心线沿所述第一方向；
    所述光学组件用于处理光线；其中，光源发出的光线从所述元件反射面进入所述第一光学元件，并透过所述偏振分光膜，穿过所述相位延迟片，射到所述微机电系统振镜的反射面上；所述微机电系统振镜用于通过振动将光线反射到不同方向，不同方向的反射光线再次穿过所述相位延迟片后被所述偏振分光膜反射，并进入所述光学4f系统，所述光学4f系统用于将不同方向的光线进行汇聚。
  2. 根据权利要求1所述的光学组件，其特征在于，
    所述光学4f系统包括第一透镜和第二透镜，所述第一透镜位于所述偏振分光膜与所述第二透镜之间，所述第二透镜与所述第一透镜间隔设置；
    所述微机电系统振镜的中心线经过所述第一透镜的物方焦点；
    所述第一透镜的像方焦点与所述第二透镜的物方焦点重合；
    不同方向的光线穿过所述第一透镜后，分别聚焦在所述第一透镜的像方焦平面上的不同位置，并从所述第二透镜的不同位置进入所述第二透镜；所述第二透镜用于将从不同位置进入所述第二透镜的光线汇聚在所述第二透镜的像方焦点处，以使得不同方向的光线进行汇聚。
  3. 根据权利要求2所述的光学组件，其特征在于，
    所述第一透镜包括依次间隔排列的双胶合透镜、第一非球面透镜和第二非球面透镜，所述双胶合透镜靠近所述偏振分光膜，所述非球面透镜远离所述偏振分光膜。
  4. 根据权利要求3所述的光学组件，其特征在于，
    所述双胶合透镜的阿贝数大于或等于20。
  5. 根据权利要求2-4任一项所述的光学组件，其特征在于，
    所述第一透镜与所述第二透镜的结构相同。
  6. 根据权利要求1-5任一项所述的光学组件，其特征在于，
    所述第一光学元件为棱镜，所述第一光学元件具有受光面和第一贴合面；所述受光面的法线沿所述第一方向；所述第一贴合面与所述元件反射面垂直；
    所述偏振分光膜设在所述第一贴合面上；
    所述受光面用于接收光线；所述元件反射面用于对从所述受光面射入所述第一光学元件的光线进行全反射；所述第一夹角的范围为(
    Figure PCTCN2022076625-appb-100001
    90)，其中n为所述第一光学元件的折射率，所述第一夹角的单位为度。
  7. 根据权利要求6所述的光学组件，其特征在于，
    所述第一光学元件包括连接面，所述连接面连接所述受光面与所述元件反射面。
  8. 根据权利要求1-5任一项所述的光学组件，其特征在于，
    所述第一光学元件包括棱镜和反射膜，所述反射膜设于所述棱镜的表面，所述反射膜具有所述元件反射面；所述第一夹角的范围为(22.5°，90°)。
  9. 根据权利要求1-8任一项所述的光学组件，其特征在于，
    所述光学组件还包括第二光学元件，所述第二光学元件具有第二贴合面、设置面、和出光面；所述第二贴合面与所述偏振分光膜背离所述第一光学元件的一侧贴合；所述设置面的法线沿所述第二方向；所述出光面背向所述第一光学元件，所述出光面的法线沿所述第一方向；
    所述相位延迟片设在所述设置面上；
    所述光学4f系统位于所述第二光学元件背离所述第一光学元件的一侧，所述光学4f系统与所述出光面具有间隔。
  10. 根据权利要求9所述的光学组件，其特征在于，
    所述第二贴合面超出所述第一贴合面，所述第二贴面超出所述第一贴合面的部分与所述元件反射面围成豁口区域。
  11. 一种光学组件，其特征在于，
    所述光学组件包括第一偏振分光膜、第一相位延迟片、微机电系统振镜、第二相位延迟片、第一曲面反射镜、第二偏振分光膜、第三相位延迟片、平面反射镜、第四相位延迟片和第二曲面反射镜；
    所述第一偏振分光膜与第一方向形成第二夹角；
    所述第一相位延迟片垂直于第二方向，所述第一相位延迟片位于所述第一偏振分光膜与所述微机电系统振镜之间，并与所述微机电系统振镜间隔设置，其中所述第二方向与所述第一方向正交；
    所述微机电系统振镜的反射面朝向所述第一相位延迟片；
    所述第二相位延迟片平行于所述第一相位延迟片，并与所述第一相位延迟片分别位于所述第一偏振分光膜的两侧；所述第二相位延迟片位于所述第一偏振分光膜与所述第一曲面反射镜之间，并与所述第一曲面反射镜间隔设置；
    所述第一曲面反射镜具有朝背离所述第二相位延迟片的方向拱起的表面，所述第一曲面反射镜的中心线沿所述第二方向；
    所述第二偏振分光膜与所述第一偏振分光膜镜像设置；
    所述第三相位延迟片平行于所述第二相位延迟片，所述第三相位延迟片位于所述第二偏振分光膜与所述平面反射镜之间，并与所述平面反射镜平行且间隔设置；
    所述第四相位延迟片平行于所述第三相位延迟片，并与所述第三相位延迟片分别位于所述第二偏振分光膜的两侧；所述第四相位延迟片位于所述第二偏振分光膜与所述第二曲面反射镜之间；
    所述第二曲面反射镜具有朝背离所述第四相位延迟片的方向拱起的表面；
    所述光学组件用于处理光线；其中，光源发出的光线射到所述第一偏振分光膜上后被所述第一偏振分光膜反射，反射光线透过所述第一相位延迟片，射到所述微机电系统振镜的反射面上；所述微机电系统振镜用于通过振动将光线反射到不同方向，不同方向的反射光线再次透过所述第一相位延迟片的不同区域后，依次穿过所述第一偏振分光膜与所述第二相位延迟片，射到所述第一曲面反射镜上的不同位置；所述第一曲面反射镜将光线进行反射，反射光线再次穿过所述第二相位延迟片后，分别被所述第一偏振分光膜反射并汇聚至所述第二偏 振分光膜上的不同位置；所述第二偏振分光膜将光线进行反射，反射光线穿过第三相位延迟片，射到所述第三平面反射镜上的不同位置；所述第三平面反射镜将光线进行反射，反射光线再次穿过第三相位延迟片的不同区域后，依次穿过所述第二偏振分光膜和所述第四相位延迟片，射到所述第二曲面反射镜上的不同位置；所述第二曲面反射镜将光线进行反射，反射光线再次穿过第四相位延迟片后，被所述第二偏振分光膜反射并汇聚。
  12. 根据权利要求11所述的光学组件，其特征在于，
    所述光学组件包括第一棱镜；所述第一棱镜具有受光面、第一贴合面和第一设置面；所述受光面的法线沿所述第一方向；所述第一贴合面与所述受光面形成所述第二夹角；所述第一设置面的法线沿所述第二方向；
    所述第一偏振分光膜设在所述第一贴合面上；
    所述第一相位延迟片设在所述第一设置面上。
  13. 根据权利要求12所述的光学组件，其特征在于，
    所述光学组件包括第二棱镜；所述第二棱镜与所述第一棱镜间隔设置；所述第二棱镜具有第二贴合面、第二设置面和出光面；所述第二贴合面与所述第一贴合面镜像；所述第二设置面与所述第一设置面平行；所述出光面与所述受光面平行，且背向所述受光面；
    所述第二偏振分光膜设在所述第二贴合面上；
    所述第四相位延迟片设在所述第二设置面上。
  14. 根据权利要求13所述的光学组件，其特征在于，
    所述光学组件包括第三棱镜，所述第三棱镜连接所述第一棱镜与所述第二棱镜；
    所述第一偏振分光膜位于所述第一贴合面与所述第三棱镜的表面之间；
    所述第二偏振分光膜位于所述第二贴合面与所述第三棱镜的表面之间；
    所述第二相位延迟片与所述第三相位延迟片均设于所述第三棱镜的表面。
  15. 根据权利要求11-14任一项所述的光学组件，其特征在于，
    所述第一曲面反射镜朝向所述第二相位延迟片的表面与所述第二相位延迟片贴合，所述第一曲面反射镜背向所述第二相位延迟片的表面朝背离所述第二相位延迟片的方向拱起；和/或，
    所述第二曲面反射镜朝向所述第四相位延迟片的表面与所述第四相位延迟片贴合，所述第一曲面反射镜背向所述第四相位延迟片的表面朝背离所述第二相位延迟片的方向拱起；和/或，
    所述平面反射镜与所述第三相位延迟片贴合。
  16. 根据权利要求11-15任一项所述的光学组件，其特征在于，
    所述第二夹角的范围为[25°，65°]。
  17. 一种光学组件，其特征在于，
    所述光学组件包括偏振分光膜、第一相位延迟片、微机电系统振镜、第二相位延迟片和曲面反射镜；
    所述偏振分光膜与第一方向形成第三夹角；
    所述第一相位延迟片垂直于第二方向，所述第一相位延迟片位于所述偏振分光膜与所述微机电系统振镜之间，并与所述微机电系统振镜间隔设置,其中所述第二方向与所述第一方向正交；
    所述微机电系统振镜的反射面朝向所述第一相位延迟片；
    所述第二相位延迟片平行于所述第一相位延迟片，并与所述第一相位延迟片分别位于所 述偏振分光膜的两侧；所述第二相位延迟片位于所述偏振分光膜与所述曲面反射镜之间，并与所述曲面反射镜间隔设置；
    所述曲面反射镜具有朝背离所述第二相位延迟片的方向拱起的表面，所述曲面反射镜的中心线沿所述第二方向；
    所述光学组件用于处理光线；其中，光源发出的光线射到所述偏振分光膜上后被所述偏振分光膜反射，反射光线透过所述第一相位延迟片，射到所述微机电系统振镜的反射面上；所述微机电系统振镜用于通过振动将光线反射到不同方向，不同方向的反射光线再次透过所述第一相位延迟片的不同区域后，依次穿过所述偏振分光膜与所述第二相位延迟片，汇聚到所述曲面反射镜上的不同位置；所述曲面反射镜将光线进行反射，反射光线再次穿过所述第二相位延迟片后，被所述偏振分光膜反射并汇聚。
  18. 根据权利要求17所述的光学组件，其特征在于，
    所述光学组件包括第一平凸透镜，所述第一平凸透镜位于所述微机电系统振镜与所述第一相位延迟片之间，所述第一平凸透镜与所述微机电系统振镜间隔设置，所述第一平凸透镜的中心线沿所述第二方向。
  19. 根据权利要求18所述的光学组件，其特征在于，
    所述光学组件包括第二平凸透镜，所述第二平凸透镜与所述偏振分光膜间隔设置，所述第二平凸透镜的中心线沿所述第一方向；其中，被所述偏振分光膜反射的光线透过所述第二平凸透镜后被汇聚。
  20. 根据权利要求19所述的光学组件，其特征在于，
    所述第一平凸透镜朝向所述第一相位延迟片的表面与所述第一相位延迟片贴合；和/或，
    所述第二平凸透镜朝向所述第二棱镜的表面与所述第二棱镜贴合。
  21. 根据权利要求17-20任一项所述的光学组件，其特征在于，
    所述光学组件包括间隔设置的凸透镜和凹透镜，所述凸透镜位于位于所述偏振分光膜与所述凹透镜之间，所述凸透镜与所述凹透镜的中心线沿所述第一方向；所述凸透镜的焦距为5mm-15mm，所述凹透镜的焦距为-5mm至-20mm；其中，光源发出的光线依次透过所述凹透镜与所述凸透镜，然后射到所述偏振分光膜上。
  22. 根据权利要求17-21任一项所述的光学组件，其特征在于，
    所述光学组件包括第一棱镜，所述第一棱镜具有受光面、第一贴合面和第一设置面；所述受光面的法线沿所述第一方向；所述第一贴合面与所述受光面形成所述第三夹角；所述第一设置面的法线沿所述第二方向；
    所述偏振分光膜设在所述第一贴合面上；
    所述第一相位延迟片设在所述第一设置面上。
  23. 根据权利要求22所述的光学组件，其特征在于，
    所述光学组件包括第二棱镜，所述第二棱镜具有第二贴合面、第二设置面和出光面；所述第二贴合面与所述第一贴合面平行，且朝向所述第一贴合面；所述第二设置面与所述第一设置面平行，且背向所述第一设置面；所述出光面与所述受光面平行，且背向所述受光面；
    所述偏振分光膜设在所述第一贴合面与所述第二贴合面之间；
    所述第二相位延迟片设在所述第二设置面上。
  24. 根据权利要求17-23任一项所述的光学组件，其特征在于，
    所述曲面反射镜朝向所述第二相位延迟片的表面与所述第二相位延迟片贴合。
  25. 根据权利要求17-24任一项所述的光学组件，其特征在于，
    所述第三夹角的范围为[25°，65°]。
  26. 一种投影模组，其特征在于，
    包括激光器、波导结构和权利要求1-25任一项所述的光学组件，所述激光器与所述波导结构分别位于所述光学组件在所述第一方向上的相对两侧；所述激光器用于向所述光学组件发射沿所述第一方向传播的平行激光束；所述波导结构具有出瞳位置，所述出瞳位置用于接收所述光学组件射出的激光。
  27. 一种增强现实设备，其特征在于，
    包括结构件和权利要求26所述的投影模组，所述投影模组安装于所述结构件。
PCT/CN2022/076625 2021-02-26 2022-02-17 光学组件、投影模组和增强现实设备 WO2022179428A1 (zh)

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