AR glasses and corresponding foldable projection module

Abstract

This invention relates to a foldable projection module, comprising: an output optical component, a light source optical component, and an optical path folding structure disposed between the two; the output optical component and the light source optical component are respectively connected and fixed to one of a first mounting surface and a second mounting surface of the optical path folding structure. The optical path folding structure includes a bushing and a composite rotating shaft. The outer shell of the bushing has a first mounting surface, and a window is provided on its side facing away from the first mounting surface; the composite rotating shaft has a columnar portion embedded in the inner cavity of the bushing, an extension portion extending outward from the columnar portion through the window, and its end face serving as a second mounting surface; a light-transmitting hole penetrates the columnar portion and the extension portion. The composite rotating shaft rotates within the bushing, switching the foldable projection module to a folded state or an unfolded state. This invention also provides corresponding AR glasses. This invention achieves folding of the projection optical path while maintaining anti-light leakage performance, thus facilitating carrying and storage.

Description

Technical Field

[0001] This invention relates to the field of augmented reality (AR) technology, and more specifically, to an AR glasses and a corresponding foldable projection module. Background Technology

[0002] Augmented Reality (AR) technology is a relatively new technology that integrates information from the real world and the virtual world. It uses computer technology to simulate and overlay virtual information onto the real world, making it perceptible to human senses and creating a sensory experience that transcends reality. The real environment and virtual objects can coexist in the same scene and space after being superimposed.

[0003] Augmented reality (AR) technology not only effectively reflects real-world content but also enables the display of virtual information, with these detailed elements complementing and overlaying each other. In visual AR, users need to ensure that real-world content overlaps with computer graphics on a head-mounted display, allowing them to fully perceive the real world surrounding them.

[0004] Currently, the main AR head-mounted products on the market are AR glasses and AR helmets. Among them, AR glasses are widely welcomed by the market due to their advantages such as lightweight design and portability. AR glasses typically require a projection light path, which projects virtual images onto the lenses of the AR glasses, thereby superimposing virtual information onto the real world. In typical existing technologies, the various optical components of the projection light path are encapsulated in the temples on both sides of the glasses. Specifically, a receiving cavity can be set inside the temple, and the various optical components of the projection light path are arranged and fixed in the receiving cavity in sequence. The output end of the projection light path transmits the image to the lenses of the AR glasses through a waveguide, thereby displaying the required virtual information. However, the AR projection light path often occupies a large space along the length of the temple, making it difficult to fold the temple. Therefore, the temples of existing AR glasses are often fixed to the frame. This results in AR glasses with fixed temples occupying a large volume, making them inconvenient to carry and store.

[0005] To achieve folding temples in AR glasses, one approach is to minimize the axial length of the AR projection light path. For example, using OLED (Organic Light-Emitting Diode) display chips to output virtual images. Since OLEDs are self-emissive, an additional rear-projection light source can be eliminated, thus shortening the axial length of the AR projection light path. However, OLED-based AR glasses also have inherent drawbacks. For instance, OLED display chips suffer from low brightness. Because AR technology needs to overlay virtual information onto the real world, many AR glasses lenses directly receive and transmit natural light. The low brightness of OLED projection technology in this case results in insufficient brightness of the virtual information, leading to a poor user experience. Furthermore, compared to other mature projection technologies, OLED projection technology has relatively lower reliability.

[0006] The applicant proposed a novel approach to folding the AR projection optical path. Based on this folding characteristic, the AR projection optical path can have sufficient length to accommodate the necessary optical components, thereby achieving optimal virtual information display effects, especially optimal overlay effects between virtual information and the real world. For example, due to the sufficient length of the AR projection optical path, the relatively mature LCOS technology can be used to project virtual information. LCOS stands for Liquid Crystal On Silicon, meaning silicon-based liquid crystal encapsulation glass. In existing technologies, the upper substrate of an LCOS panel is typically ITO conductive glass, and the lower substrate is a CMOS substrate coated with liquid crystal silicon. The lower substrate of an LCOS panel is usually made of monocrystalline silicon, thus possessing good electron mobility. Furthermore, monocrystalline silicon can form finer circuits, making it easier to achieve higher resolutions compared to traditional LCD and DLP projection panels. Moreover, LCOS panels offer numerous advantages over OLED panels, such as higher brightness and wider color gamut.

[0007] However, folding the AR projection optical path presents numerous technical challenges, such as ensuring collimation, preventing light leakage, and protecting against dust, to guarantee the optical performance of the AR projection optical path. Furthermore, since it needs to be compatible with AR glasses, the structure for folding the AR projection optical path also needs to be miniaturized to prevent the AR glasses' temples from becoming too thick, which would result in a poor user experience.

[0008] In conclusion, there is an urgent need for a solution that can achieve a foldable AR projection optical path (which can be integrated into the temple of glasses) while ensuring the optical performance of the AR projection optical path. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a solution that enables a foldable AR projection optical path (which can be integrated into the temple of eyeglasses) while ensuring the optical performance of the AR projection optical path.

[0010] To address the aforementioned technical problems, this invention provides a foldable projection module, comprising: a projection end housing, a projection end optical component disposed within the projection end housing, a light source end housing, a light source end optical component disposed within the light source end housing, and an optical path folding structure disposed between the projection end optical component and the light source end optical component; the optical path folding structure has a first mounting surface and a second mounting surface, and the projection end optical component and the light source end optical component are respectively connected and fixed to one of the first mounting surface and the second mounting surface; the optical path folding structure includes a bushing and a composite rotating shaft, the outer shell of the bushing has a first end face serving as the first mounting surface, the inner cavity of the outer shell is formed, and a window is provided on the side of the outer shell facing away from the first end face; the composite rotating shaft has a columnar portion, the columnar portion being embedded in the inner cavity. The composite rotating shaft also has an extension portion extending outward from the columnar portion and passing through the window, the end face of the extension portion serving as the second mounting surface; a light-transmitting hole passes through the columnar portion and the extension portion; the composite rotating shaft is adapted to rotate relative to the bushing about the axis of the columnar portion, and the shape and size of the window of the bushing allow the extension portion to rotate about the axis of the columnar portion within the window, thereby driving the projection end optical component and the light source end optical component to rotate relative to each other, thereby switching the foldable projection module to a folded state or an unfolded state.

[0011] The folded state is a state in which the optical axis of the projection end optical component and the optical axis of the light source end optical component overlap each other; the unfolded state is a state in which the optical axis of the projection end optical component, the optical axis of the light source end optical component, and the axial direction of the light-transmitting aperture are all consistent. In the unfolded state, the emitted light from the light source end optical component passes through the light-transmitting aperture and is then received by the incident end of the projection end optical component.

[0012] The inner surface of the bushing is adapted to the shape and size of the outer surface of the columnar portion to achieve a pivotal connection between the columnar portion and the bushing. The first mounting surface of the bushing is provided with a first through hole. In the unfolded state, the outlet of the light-transmitting hole located in the columnar portion is aligned with the first through hole. In the folded state, the outlet of the light-transmitting hole located in the columnar portion is blocked by the inner surface of the bushing. The portion of the bushing other than the first through hole and the window has a closed inner surface.

[0013] The extension portion includes a neck and a mounting portion. One end of the neck is connected to the middle section of the columnar portion, and the other end extends along the optical axis and protrudes outward from the window. The end of the neck that protrudes from the window forms the mounting portion. The light-transmitting hole penetrates the columnar portion, the neck, and the mounting portion, and the axial direction of the light-transmitting hole is perpendicular to the axial direction of the columnar portion.

[0014] The bushing includes a first bushing component and a second bushing component; the first bushing component has a vertical mounting surface and a first inclined mounting surface for assembling the second bushing component, the second bushing component has the window and a second inclined mounting surface for assembling the first bushing component, both the first inclined mounting surface and the second inclined mounting surface are inclined relative to the optical axis of the AR projection light path; the first inclined mounting surface and the second inclined mounting surface are fastened and assembled to form the bushing, both the first inclined mounting surface and the second inclined mounting surface are provided with openings for inserting the columnar portion.

[0015] The first inclined mounting surface has a first mounting groove for a sealing ring around its opening, and the second inclined mounting surface has a second mounting groove for a sealing ring around its opening. An elastic second sealing ring is disposed in both the first and second mounting grooves. After the columnar portion of the composite shaft is inserted and the first and second bushing components are fastened together, the inner surface of the second sealing ring contacts the outer surface of the columnar portion, and the second sealing ring is deformed by the columnar portion from the inside out, thus sealing the gap between the columnar portion and the bushing. The shapes of the inner surfaces of both the first and second bushing components are adapted to the shape of the outer surface of the columnar portion.

[0016] In the composite shaft, the mounting part is flat.

[0017] The composite shaft is integrally formed.

[0018] The composite shaft is either an injection-molded part formed integrally by injection molding or a composite material part, which includes a metal skeleton and a molded material attached to the metal skeleton, and the shape of the composite shaft and the light-transmitting hole penetrating the columnar part, the neck and the mounting part are constructed by the shape of the molded material.

[0019] The second bushing component is provided with a magnet, which is used to generate an attractive force to fix the composite shaft in the unfolded state.

[0020] In the composite shaft, the height of the columnar portion is no greater than 13mm; the cross-sectional area of ​​the columnar portion is no greater than 150mm². 2 .

[0021] This application also provides AR glasses, comprising: lenses, a frame, temples, and an AR projection optical path, wherein the AR projection optical path includes optical components at the end of the frame and a rear projection light source; the AR glasses further include an optical path folding structure, wherein the optical path folding structure includes a bushing and a composite pivot, the bushing having an inner cavity and a perpendicular to the AR... The projection light path has a vertical mounting surface for the optical axis, and the end of the bushing facing away from its vertical mounting surface is provided with a window; the composite rotating shaft has a columnar portion, which is embedded in the inner cavity of the bushing; the composite rotating shaft also has an extension portion extending outward from the columnar portion and passing through the window, the extension portion extending out of the window being fixedly connected to the frame or the temple, a light-transmitting hole passing through the columnar portion and the extension portion, and the axial direction of the light-transmitting hole being perpendicular to the axial direction of the columnar portion; the frame-end optical component and the rear projection light source are respectively disposed on the frame and the temple, and the frame-end optical component and the rear projection light source are separated by the optical path folding structure; the composite rotating shaft is adapted to rotate relative to the bushing about the axis of the columnar portion as the pivot, so as to drive the temple to fold and unfold relative to the frame.

[0022] The frame has an optical component housing at each of its left and right ends, and the optical component is housed within the optical component housing. The rear projection light source is installed inside the temple. When the temple is extended relative to the frame, the axial direction of the light-transmitting hole is aligned with the optical axis of the AR projection light path.

[0023] Wherein, the extension portion is fixedly connected to the end of the temple, and the vertical mounting surface is fixedly connected to the housing of the optical component at the end of the frame; or, the extension portion is fixedly connected to the housing of the optical component at the end of the frame, and the vertical mounting surface is fixedly connected to the end of the temple.

[0024] The extended portion includes a neck and a mounting portion. One end of the neck connects to the middle section of the columnar portion, and the other end extends along the optical axis and protrudes outward from the window. The end of the neck that protrudes from the window forms the mounting portion. The light-transmitting hole passes through the columnar portion, the neck, and the mounting portion. In a horizontal view, the outline of the window of the bushing is rectangular. When the temple is unfolded relative to the frame, the opening of the window is tilted inward relative to the optical axis of the AR projection light path. The width of the window is adapted to the height of the neck of the composite pivot. The length of the window is adapted to the movable distance of the neck. In a top-view view, the outline of the window is arc-shaped, consistent with the movement trajectory of the root of the neck.

[0025] Compared with the prior art, this application has at least one of the following technical effects: 1. This application achieves folding of the projection optical path through an optical path folding structure, while ensuring collimation of the projection optical path in use and taking into account the light leakage prevention performance of the projection optical path. This achieves a small, foldable AR projection optical path while maintaining the optical performance of the AR projection optical path, making AR glasses more portable and easier to store, thus improving the user experience. Specifically, in some embodiments of this application, light from the outside of the bushing can be guided into the inside of the bushing through a light-transmitting hole penetrating the outer extension and columnar portion of the composite rotating shaft, thereby connecting the optical path between the light source end optical component and the projection end optical component of the AR projection optical path. Furthermore, under this design, the light passing through the optical path folding structure is doubly shielded by the composite rotating shaft and the bushing, so the entire light transmission process can be completed in a well-sealed environment, exhibiting excellent light leakage prevention performance.

[0026] 2. In some embodiments of this application, in addition to realizing the foldability of AR glasses, the sealing performance of the optical path folding structure is also improved, achieving better dust and dirt prevention effects and better ensuring the optical quality of the AR projection optical path.

[0027] 3. In some embodiments of this application, by optimizing the manufacturing process of the optical path folding structure, the structural strength and reliability are taken into account while reducing the space occupied by the optical path folding structure, and it can withstand a large number of folds.

[0028] 4. In some embodiments of this application, by optimizing the manufacturing process, a small, complex rotating shaft structure with high reliability is achieved at a lower cost, which is particularly suitable for mass production.

[0029] 5. In some embodiments of this application, the optical path folding structure is easy to disassemble and separate from the temples and frame, thereby facilitating the maintenance, upkeep and replacement of the optical path folding structure, and thus improving the reliability and service life of the AR glasses. Attached Figure Description

[0030] Figure 1 shows a schematic diagram of the appearance of AR glasses according to an embodiment of this application.

[0031] Figure 2 shows an exploded view of an AR glasses according to an embodiment of this application.

[0032] Figure 3 shows an exploded view of an AR glasses according to an embodiment of this application with the temples hidden.

[0033] Figure 4 shows a perspective view of an AR projection optical component, a first bushing component, and a second bushing component in one embodiment of this application.

[0034] Figure 5 shows a cross-sectional schematic diagram of the various optical elements and related structural components constituting the AR projection optical path in one embodiment of this application.

[0035] Figure 6 shows an exploded view of the optical path folding structure in one embodiment of this application.

[0036] Figure 7 shows a partially enlarged three-dimensional schematic diagram of the frame, optical path folding structure and temples assembled in one embodiment of this application.

[0037] Figure 8 shows a cross-sectional view of the frame, optical path folding structure and temple portion along the optical axis of the AR projection optical path in another embodiment of this application.

[0038] Figure 9 shows an exploded schematic diagram of the optical path folding structure and related optical elements in another embodiment of this application.

[0039] Figure 10 shows a three-dimensional schematic diagram of the optical path folding structure and related optical elements after assembly in another embodiment of this application.

[0040] Figure 11 shows a perspective view of the bushing in one embodiment of this application; the window on its back and its surrounding structure can be observed more clearly from this view.

[0041] Figure 12 shows a perspective view of the first bushing component in one embodiment of this application; its inclined mounting surface and its inner surface can be observed more clearly from this perspective. Detailed Implementation

[0042] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0043] It should be noted that in this specification, the terms "first," "second," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first subject discussed below may also be referred to as the second subject.

[0044] In the accompanying drawings, the thickness, size, and shape of the objects have been slightly exaggerated for ease of illustration. The drawings are for illustrative purposes only and are not drawn to scale.

[0045] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed feature, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0046] As used herein, the terms “basically,” “approximately,” and similar terms are used as terms of approximation rather than as terms of degree, and are intended to describe inherent biases in measured or calculated values ​​that will be recognized by those skilled in the art.

[0047] Unless otherwise specified, all terms used herein (including technical terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0048] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0049] This application provides a light path folding structure with an internal light-transmitting hole. This structure connects the frame and temples of AR glasses. The optical elements of the AR projection light path are respectively mounted on the temples and frame ends, thereby achieving folding of the projection light path. This application also ensures the collimation of the AR projection light path in use and takes into account the light leakage prevention performance of the projection light path. This ensures the optical performance of the AR projection light path, making the AR glasses more portable and easier to store, thus improving the user experience. The invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0050] Figure 1 shows a schematic diagram of the appearance of AR glasses according to an embodiment of this application, Figure 2 shows an exploded schematic diagram of AR glasses according to an embodiment of this application, and Figure 3 shows an exploded schematic diagram of AR glasses according to an embodiment of this application with the temples hidden. Referring to Figures 1, 2, and 3, in this embodiment, AR glasses 1 includes AR lenses 10, a frame 20, an optical path folding structure 99, temples 90, and an AR projection optical path. The AR projection optical path may include a frame-end optical component 30 mounted on the frame end and a light source component 80 mounted inside the temples 90. The frame-end optical component 30 may be disposed within an optical component housing 21 located on one side of the frame. The frame-end optical component is the main component for generating the AR projected image; its specific structure will be further described below in conjunction with other embodiments, and will not be repeated here. In this embodiment, the optical path folding structure 99 mainly consists of a bushing 98 with an inner cavity and a composite rotating shaft 70 embedded in the bushing 98. The composite pivot 70 is rotatable relative to the bushing 98. The composite pivot 70 includes a columnar portion 71, a neck 72, and a mounting portion 73. The columnar portion 71 is embedded in the inner cavity of the bushing 98. For ease of description, in this application, the six directions of front, back, left, right, up, and down are determined by the wearer's perspective when the AR glasses are worn; that is, the wearer's front, back, left, right, up, and down directions are the same as the AR glasses' front, back, left, right, up, and down directions. Under this definition, the AR projection light paths corresponding to the left and right eyes are respectively arranged on the left and right sides of the frame 20, and the optical axis of the AR projection light path extends along the front-back direction (i.e., the optical axis runs front-back). In this embodiment, the axial direction of the columnar portion 71 of the composite pivot 70 extends along the up-down direction (i.e., the axis of the columnar portion runs up-down). The bushing 98 has a vertical mounting surface 51 perpendicular to the optical axis of the AR projection light path. This vertical mounting surface 51 can be connected to and fixed to the optical component housing 21 of the lens frame 20. The end of the bushing 98 facing away from the lens frame has a window 64. The neck 72 of the composite pivot 70 extends along the optical axis (i.e., the optical axis of the AR projection light path) and extends out of the bushing 98 from the window 64. The axis of the neck 72 is perpendicular to the axis of the columnar portion 71, and the end face of the neck 72 facing away from the columnar portion 71 forms a flat mounting portion 73. In this embodiment, the two ends of the neck 72 connect the middle section of the columnar portion 71 and the center portion of the mounting portion 73. A light-transmitting hole 74 passes through the mounting portion 73, the neck 72, and the columnar portion 71 along the optical axis. The mounting portion 73 is used to connect to and fix the temple 90.In this embodiment, the columnar portion 71 can rotate within the bushing 98 using its vertical axis as a pivot, thereby causing the neck 72, the mounting portion 73, and the temple 90 fixed to the mounting portion to rotate together. In this embodiment, the window 64 has a roughly rectangular outline, and its opening is not perpendicular to the optical axis of the AR projection light path, but rather tilted inward relative to that optical axis. This inward tilt refers to tilting towards the side closer to the center of the AR glasses. The width of the window 64 matches the height of the neck 72 of the composite pivot 70 (i.e., the vertical dimension of the neck 72). The length of the window 64 matches the movable distance of the neck 72. Specifically, in the temple extended state, the axis of the neck 72 runs forward and backward; in the temple folded state, the axis of the neck 72 runs roughly left and right. The movable distance of the neck 72 is the distance it moves from a forward-backward orientation to a left-right orientation. The length of window 64 is adapted to the movable distance of neck 72, thereby allowing neck 72 to move within its movable distance. In a top-down view, the outline of window 64 can be curved, meaning that the outline of window 64 in a top-down view follows the movement trajectory of the root of neck 72 (which refers to the end of the connecting column 71 of neck 72).

[0051] In existing technologies, AR glasses either have non-foldable temples or use ordinary cylindrical hinges to achieve temple folding. In existing temple folding solutions, the ordinary cylindrical hinges used are typically simple small bolts or screws suitable for eyeglasses. These small bolts or screws connect the temples to the frame and allow the temples to rotate around them, thus enabling folding. In this case, the entire AR projection optical path needs to be integrated into a single cavity fixed to the frame, making it difficult to integrate any optical elements for the AR projection optical path into the temples or the foldable portion of the temples. However, in the embodiments described above, the AR projection optical path is folded through an optical path folding structure. Furthermore, in the above embodiments, light is emitted from the rear projection light source of the temples, passes through the light-transmitting hole 74 penetrating the mounting portion 73, the neck 72, and the columnar portion 71, then enters the projection optical component 30 at the end of the frame, and finally couples and transmits to the lens 10, thereby displaying the desired virtual information in front of the user. Because light rays are surrounded by the composite pivot 70 when passing through the foldable structure (i.e., the optical path folding structure 99 mentioned above), and the outer layer of the columnar portion 71 of the composite pivot 70 is further surrounded by a bushing 98, this foldable structure has excellent light leakage prevention characteristics, making it particularly suitable for folding AR projection optical paths. In other words, in the above embodiments of this application, the optical path folding structure 99 not only achieves the folding of the AR projection optical path but also takes into account the light leakage prevention performance required by the projection optical path. Thus, a small, foldable AR projection optical path is achieved while ensuring the optical performance of the AR projection optical path, making AR glasses more portable and easier to store, thereby improving the user experience.

[0052] Furthermore, still referring to Figures 1 and 2, and Figure 3In one embodiment of this application, the optical path folding structure 99 includes a first bushing member 50, a second bushing member 60, and a composite rotating shaft 70. The first bushing member 50 has a vertical mounting surface 51 perpendicular to the optical axis of the AR projection optical path and a first inclined mounting surface 52 for assembling the second bushing member 60 (refer to FIG. 12, which shows a perspective view of the first bushing member in one embodiment of this application; its inclined mounting surface and its inner surface can be observed more clearly from this perspective). The first inclined mounting surface 52 is inclined relative to the optical axis of the AR projection optical path, for example, at a 45-degree angle. The second bushing member 60 has a second inclined mounting surface 61 for assembling the first bushing member 50, which is also inclined relative to the optical axis of the AR projection optical path, for example, at a 45-degree angle. By fastening the first inclined mounting surface 52 and the second inclined mounting surface 61 with screws or bolts (or other connection methods), the first bushing component 50 and the second bushing component 60 can be assembled together to form a complete bushing 98. This complete bushing 98 has an inner cavity to accommodate the columnar portion 71 of the composite rotating shaft 70. The back side of the second bushing component 60 (i.e., the side away from the first bushing component 50) has a window 64. The neck 72 of the composite rotating shaft 70 extends along the optical axis (i.e., the optical axis of the AR projection light path) and protrudes from the window 64 to the outside of the second bushing component 60. The axis of the neck 72 is perpendicular to the axis of the columnar portion 71, and the end face of the neck 72 facing away from the columnar portion 71 forms a flat mounting portion 73. That is, the composite shaft 70 can be composed of a columnar portion 71, a neck 72, and a flat mounting portion 73, wherein the two ends of the neck 72 connect the columnar portion 71 and the mounting portion 73. A light-transmitting hole 74 passes through the mounting portion 73, the neck 72, and the columnar portion 71 along the optical axis.

[0053] Further, Figure 4 shows a perspective view of the AR projection optical component, the first bushing member, and the second bushing member in one embodiment of this application; Figure 5 shows a cross-sectional view of the various optical elements and related structural components constituting the AR projection optical path in one embodiment of this application; Figure 6 shows an exploded view of the optical path folding structure in one embodiment of this application. Referring to Figures 1-6, in one embodiment of this application, the first inclined mounting surface 52 of the first bushing member 50 has an opening for inserting the columnar portion 71, the shape and size of which approximately match the contour of the longitudinal section of the columnar portion 71 (the longitudinal section is the section where the axis of the columnar portion 71 is located, i.e., the section obtained after cutting the columnar portion 71 from top to bottom or bottom to top). When the columnar portion 71 is cylindrical, the opening of the first inclined mounting surface 52 is rectangular. A first mounting groove 54 for a sealing ring can be provided around the periphery of the opening of the first inclined mounting surface 52 for embedding a second sealing ring 42. The second sealing ring 42 is disposed between the first inclined mounting surface 52 and the second inclined mounting surface 61, and surrounds the opening of the first inclined mounting surface 52. The second sealing ring 42 is elastic. After the columnar portion 71 of the composite rotating shaft 70 is inserted and the first bushing member 50 and the second bushing member 60 are fastened together, the second sealing ring 42 is sandwiched between the first inclined mounting surface 52 and the second inclined mounting surface 61. Furthermore, the inner surface of the second sealing ring 42 contacts the outer surface of the columnar portion 71, and the second sealing ring 42 is compressed from the inside to the outside by the columnar portion 71, thereby causing deformation. In this way, the second sealing ring 42 can seal the gap between the columnar portion 71 and the bushing 98, thereby better preventing light leakage and improving the dust and dirt resistance of the AR projection light path, effectively enhancing the optical quality of the AR projection light path. Furthermore, lubricating oil can be applied to the contact surfaces of the second sealing ring 42 and the columnar portion 71 to reduce the resistance encountered when the composite shaft pivots. This lubricating oil can be, for example, grease-like to prevent it from flowing to the periphery of the light-transmitting hole.

[0054] Furthermore, the shape of the inner surface of the first bushing member 50 can be adapted to the outer surface of the columnar portion 71. When the columnar portion 71 is cylindrical, the inner surface of the first bushing member 50 is also correspondingly arc-shaped (referring to Figure 12, the first inner surface 55 of the first bushing member 50 is arc-shaped to facilitate the adaptation of the outer surface shape of the columnar portion 71; the first inner surface 55 and the outer surface of the columnar portion 71 can be smooth to reduce the resistance of pivot rotation and prevent powder or particle contamination of the AR projection optical path due to wear). The vertical mounting surface 51 of the first bushing member 50 has a first through hole 56 that penetrates the vertical mounting surface 51, thereby allowing light passing through the light aperture 74 of the composite pivot 70 to exit from the vertical mounting surface 51 of the first bushing member 50 and enter the AR projection optical assembly 30 at the frame end. In this embodiment, the vertical mounting surface 51 can be assembled with the end of the lens frame optical component housing 21 of the lens frame 20. A first sealing ring 41 can be provided between the vertical mounting surface 51 and the end of the lens frame optical component housing 21 to achieve a sealed connection between the vertical mounting surface 51 and the lens frame optical component housing 21.

[0055] Furthermore, in one embodiment of this application, the first bushing member 50 and the second bushing member 60 can be assembled using a first fastener 43. The first bushing member 50 may have a first side extension 57 that matches a corresponding portion of the second bushing member 60 for mounting the first fastener 43. The first fastener 43 may be, for example, a bolt or screw. The first side extension 57 may be vertical, and its length direction may be from top to bottom. Here, the top and bottom directions refer to the top and bottom directions perceived by the wearer when the AR glasses are worn.

[0056] Further, in one embodiment of this application, the second bushing member 60 has a second inclined mounting surface 61, which is adapted to the first inclined mounting surface 52. The second inclined mounting surface 61 also has an opening for inserting the columnar portion 71. A second mounting groove 67 for sealing rings can be provided around the periphery of the opening, which is adapted to the first mounting groove 54 for sealing rings. The second sealing ring 42 is embedded between the second mounting groove 67 and the first mounting groove 54 for sealing rings, and is arranged in a manner inclined to the optical axis of the AR projection light path. In this embodiment, since a window 64 is provided on the back of the second bushing member 60, the internal space of the second bushing member 60 can be divided into an upper end receiving cavity 62 and a lower end receiving cavity 63, which are respectively used to insert the upper end and lower end of the columnar portion 71. Here, the upper end refers to the upper part of the columnar body 71, and the lower end refers to the lower part of the columnar body 71. The up and down directions refer to the up and down directions perceived by the wearer when the AR glasses are being worn. The shape of the inner surface of the second bushing member 60 can be adapted to the outer surface of the columnar part 71. When the columnar part 71 is cylindrical, the inner surface of the second bushing member 60 is also correspondingly arc-shaped.

[0057] In the above embodiments, based on excellent design, the columnar portion of the composite hinge 70 can be no larger than 13mm, and while having a light-transmitting hole adapted to the AR projection light path inside, it can still maintain excellent structural strength. Even after numerous folding and unfolding cycles, the composite hinge 70 retains good reliability. In other words, the composite hinge 70 and the corresponding bushing 98 in the above embodiments are particularly suitable for realizing miniaturized light path folding structures, and thus for use in AR glasses. The AR projection light path of these AR glasses has excellent light leakage prevention performance, not only exhibiting superior optical performance but also being more portable and easier to store, thus improving the user experience. In one embodiment, the height of the columnar portion can be approximately 11mm, and the overall length of the composite hinge 70 (i.e., the dimension along the axis of the light-transmitting hole 74) can be approximately 11mm. Generally, the height of the columnar portion can be controlled to be no larger than 13mm, and the cross-sectional area of ​​the columnar portion can be controlled to be no larger than 150mm². 2 .

[0058] Furthermore, in one embodiment of this application, the second bushing member 60 also has a second side extension 66, which matches a corresponding portion of the first bushing member 50 for mounting the first fastener 43. The first fastener 43 may be, for example, a bolt or screw. The second side extension 66 may be vertical, and its length direction may be from top to bottom. Here, the top and bottom directions refer to the top and bottom directions perceived by the wearer when the AR glasses are worn.

[0059] Furthermore, in one embodiment of this application, the mounting portion 73 of the composite hinge 70 is used to assemble the temple 90. The mounting portion 73 can be flat to achieve better parallelism with the mounting surface at the end of the temple 90 (Figure 7 shows a partially enlarged perspective view of the frame end optical components, optical path folding structure, and temple assembly in one embodiment of this application). The light source assembly 80 is installed in the inner cavity of the temple 90. A third sealing ring 46 can be provided between the mounting portion 73 and the end of the temple 90. The mounting portion 73 and the end of the temple 90 can be assembled and fixed together by a second fastener 45. The second fastener 45 can be a bolt or a screw. The light source assembly 80 can be an LCOS light source. Generally speaking, LCOS light sources require a large length space, but they can also help LCOS panel-based projection light paths provide many advantages such as high brightness and high color gamut. In this embodiment, since the LCOS light source can be integrated into the foldable temple cavity, its length will not affect the portability of the AR glasses, thus having better application value. Furthermore, for the foldable AR glasses with an AR projection optical path in this embodiment, the LCOS light source is positioned closer to the rear, which helps to achieve weight balance and provides a more comfortable wearing experience for the wearer. It should be noted that in this application, the light source component 80 can also be other rear-projection light sources besides LCOS, such as LCD rear-projection light sources or DLP rear-projection light sources.

[0060] Furthermore, in one embodiment of this application, the second bushing member 60 also has a bracket 65, which can be used to mount a magnet 44. The attraction force generated by the magnet 44 can fix the temple 90 in the unfolded state. In this way, when the AR glasses are worn, their AR projection light path can have good collimation, avoiding the influence of the wearer's own movements or the size of their head on the optical performance of the AR projection light path. Specifically, the magnet 44 can attract the flat mounting part 73 of the composite rotating shaft 70, thereby fixing the bushing 98 and the composite rotating shaft 70 in the unfolded state. Since the temple 90 and the composite rotating shaft 70 are fixedly connected in this embodiment, the temple 90 is fixed in the unfolded state, ensuring that the AR projection light path of the AR glasses has good collimation when worn.

[0061] Furthermore, in one embodiment of this application, the columnar portion 71, neck 72, and mounting portion 73 of the composite shaft 70 can be integrally formed, and the internal light-transmitting hole 74 can be directly formed, rather than drilled in a solid material. For example, the composite shaft 70 can be manufactured by injection molding. The injection molding process is particularly suitable for manufacturing the composite shaft 70 with its complex structure, wherein the internal light-transmitting hole 74 of the composite shaft 70 can be integrally formed during the injection molding process, thus avoiding many defects caused by drilling. For example, the drilling process may result in some residual powder or particles in the light-transmitting hole 74 of some products, causing a decrease in the optical quality of the AR projection light path or even scrapping it. In addition, the composite shaft 70 is integrally formed by injection molding, avoiding drilling, which can also avoid cracking or a decrease in structural strength caused by drilling, thereby better ensuring the repeated rotational movement of the composite shaft and improving its reliability.

[0062] Furthermore, in another embodiment of this application, the composite pivot 70 may have a metal frame. A molded part with a metal frame (e.g., a steel frame) is obtained by molding based on this metal frame. This molded part has the required shape of the composite pivot 70, and its internal light-transmitting hole 74 is directly formed, rather than drilled into a solid material. Compared to injection-molded parts, this molded part formed by attaching molding material to a metal frame can improve the structural strength of the composite pivot 70. Thus, the composite pivot 70 can ensure the reliability of a large number of rotational movements with a relatively small wall thickness, thereby helping to reduce the volume of the composite pivot 74, and consequently the volume of the bushing 98 and the corresponding temple 90, thereby reducing the overall volume of the AR glasses and improving their wearing comfort. The steel frame may, for example, be cylindrical, and its axis may be aligned with the axis of the light-transmitting hole 74. This simple shape is easy to manufacture and suitable for low-cost mass production. The molded part, based on this steel frame, only needs to conform to the aforementioned shape of the composite pivot 70. The cylindrical steel frame extends through the mounting portion 73, the neck 72, and the columnar portion 71 of the composite hinge 70, thereby enhancing the structural strength of the entire composite hinge 70. Further, in some embodiments, the cylindrical steel frame can be deformed, for example, by creating radially extending extensions at both ends of the cylinder using a stamping or die-casting integrated process. For ease of description, these extensions are referred to as the front-end extension and the rear-end extension, respectively. The rear-end extension can serve as the frame for the flat mounting portion 73 (i.e., the mounting portion 73 can be attached around the rear-end extension of the steel frame), and the front-end extension can serve as the frame for the columnar body 71 (i.e., the columnar body 71 can be attached around the front-end extension of the steel frame). This shape of steel frame helps to further enhance the structural strength of the composite hinge 70, reduce the volume of the composite hinge 70 and its external bushing 98, thereby helping to reduce the overall size of the AR glasses and improve the user experience.

[0063] Besides the two composite hinge manufacturing processes described above, other embodiments of this application may also employ other materials and processes, such as metal components. These metal components can be solid, and the required light-transmitting holes 74 are then machined using laser drilling. The composite hinge 70 with metal components exhibits excellent structural strength, which helps reduce its size; however, its cost may also be higher, thus it is generally suitable for high-end product lines.

[0064] In other embodiments of this application, the columnar portion of the composite shaft may also be a shape other than a cylinder. For example, the columnar portion 71 may be a polygonal column. When the columnar portion 71 is a polygonal column, the inner surface of the first bushing member 50 is also polygonal. The space within the first bushing member 50 for accommodating the columnar portion 71 forms a shaft receiving cavity 53. When the columnar portion 71 is a polygonal column, the size of the shaft receiving cavity 53 may be slightly larger than the columnar portion 71, thereby creating a loose fit to allow the columnar portion 71 to rotate within the shaft receiving cavity 53. Correspondingly, when the columnar portion 71 is a polygonal column, the inner surface of the second bushing member 60 is also polygonal. The first bushing member 50 and the second bushing member 60 can be made of plastic. In this way, when the columnar portion 71 of the polygonal column rotates, the inner surfaces of the first bushing member 50 and the second bushing member 60 can be slightly lifted up, thereby allowing the corners of the columnar portion 71 to pass through. Furthermore, the inner surfaces of the first bushing member 50 and the second bushing member 60 can return to their original shape after passing through the corners of the columnar portion 71.

[0065] Further, in the above embodiments, the optical component 80 at the frame end may include a projection lens, a prism group, and an image generation panel for receiving back-projected light and generating an image. The prism group can be used to reflect the image generated by the image generation panel. The projection lens is used to project and couple the image to the lens 10. The lens 10 may have a waveguide structure for transmitting the image from the coupling point to the main body of the lens 10, thereby displaying the image at an appropriate location in front of the viewer's eyes. In AR glasses, the image generated and projected by the optical component 80 is usually a virtual information screen. This virtual information screen is superimposed on the real image directly observed by the viewer through the lens 10 to obtain an augmented reality effect, i.e., an AR effect. In some embodiments, the image generation panel may be an LCOS panel (in AR glasses, this LCOS panel has a small volume, so it is sometimes also called an LCOS chip). The image generation panel may be a liquid crystal spatial light modulator. An LCOS panel is actually a type of liquid crystal spatial light modulator. LCOS stands for Liquid Crystal On Silicon, which is silicon-based liquid crystal encapsulated glass. The upper substrate of the LCOS panel can be ITO conductive glass, and the lower substrate can be a CMOS substrate coated with liquid crystal silicon. The material of the lower substrate of the LCOS panel can be monocrystalline silicon, thus possessing good electron mobility. Moreover, monocrystalline silicon can form finer lines, facilitating light transmission. In some embodiments, the image generation panel can be directly attached to the vertical mounting surface 52 of the first bushing member 50, which can avoid the decrease in AR projection light path collimation caused by the relative displacement between the first bushing member 50 and the frame 20.

[0066] Further, Figure 8 shows a cross-sectional view of the frame, optical path folding structure, and temple portion along the optical axis of the AR projection optical path in another embodiment of this application; Figure 9 shows an exploded view of the optical path folding structure and related optical elements in another embodiment of this application; Figure 10 shows a three-dimensional view of the assembled optical path folding structure and related optical elements in another embodiment of this application. Referring to Figures 8-10, in another embodiment of this application, a scheme is provided in which the optical path folding structure 99 is reversed. That is, the first bushing member 50 faces the temple end, and the mounting portion 73 of the composite rotating shaft 70 faces the frame end. In this embodiment, after the columnar portion 71 of the composite rotating shaft 70 is embedded, the first bushing member 50 and the second bushing member 60 are connected and fixed by the first fastener 43 (e.g., by sealing assembly with a sealing ring). The vertical mounting surface 52 of the first bushing component 50 is connected and fixed to the end of the temple 90, and the mounting part 73 of the composite rotating shaft 70 is connected and fixed to the optical component housing 21 at the end of the frame of the frame 20 (via the second fastener 45).

[0067] Furthermore, in the embodiment where the optical path folding structure 99 is reversed, the optical component 80 at the frame end may include a projection lens, a prism group, and an image generation panel for receiving back-projected light and generating an image. The image generation panel may be an LCOS panel (in AR glasses, this LCOS panel has a small volume and is therefore sometimes referred to as an LCOS chip). The image generation panel may be a liquid crystal spatial light modulator. An LCOS panel is actually a type of liquid crystal spatial light modulator. LCOS stands for Liquid Crystal On Silicon, i.e., silicon-based liquid crystal encapsulation glass. The upper substrate of the LCOS panel may be ITO conductive glass, and the lower substrate may be a CMOS substrate coated with liquid crystal silicon. The material of the lower substrate of the LCOS panel may be single-crystal silicon, thus possessing good electron mobility, and single-crystal silicon can form finer lines, facilitating light transmission. In some embodiments, the image generation panel can be directly attached to the mounting portion 73 of the composite pivot 70, which can avoid the decrease in the collimation of the AR projection light path caused by the relative displacement between the composite pivot 70 and the frame 20.

[0068] In other embodiments, the image generation panel can also operate in a reflective manner. For example, a reflective prism (or prism group) can be placed at the light outlet of the optical path folding structure 99, and the reflective LCOS panel (or reflective LCOS chip) can be placed on the outside of the reflective prism (for the AR projection optical path of the left lens, the outside is the left side; for the AR projection optical path of the right lens, the outside is the right side). The reflective LCOS panel can receive the light reflected by the reflective prism and output the required virtual image, which is then transmitted to the projection lens through the reflective prism (or prism group). In this embodiment, the light source component is placed inside the temple, and this light source component can fold along with the temple in the retracted state, thereby reducing the volume occupied. In this embodiment, the display panel (i.e., the display chip) is placed on the outer side away from the user's head, and the total internal reflection prism is placed on the inner side, so that the display chip, which generates a lot of heat, has sufficient heat dissipation space and protects the user from being burned by overheating.

[0069] In this application, the shape of the mounting portion 73 in the composite pivot 70 is not limited to a flat plate. For example, in some modified embodiments, the mounting portion 73 can be any shape suitable for mounting the temple. For instance, the size of the mounting portion 73 can be substantially the same as the neck 72. In this case, from the external appearance, there is no obvious difference between the neck 72 and the mounting portion 73. Therefore, the portion of the composite pivot 70 extending outward from the columnar portion 71 and passing through the window 64 can be collectively referred to as the extension portion. The light-transmitting hole 74 passes through the extension portion and the columnar portion. The extension portion can include the neck 72 and the mounting portion 73. The portion of the extension portion that passes through the window 64 is considered the neck, and the portion used to mount the AR optical component housing of the temple or frame is considered the mounting portion.

[0070] Further, Figure 11 shows a perspective view of the bushing in one embodiment of this application; the window on its back and its surrounding structure can be observed more clearly from this perspective. Referring to Figure 11, in some embodiments of this application, the housing of the second bushing member 60 may have two arched protrusions 68, the interiors of which respectively constitute the upper end receiving cavity 62 and the lower end receiving cavity 63 of the shaft, and the window between the two arched protrusions 68 constitutes the window 64. The window 64 allows the extension of the composite shaft 70 to extend out and allows the extension to pivot about the columnar portion 71 (see reference). Figure 4 (and Figure 5).

[0071] Based on the various embodiments described above, it is easy to see that a foldable projection module independent of AR glasses can be constructed using the optical path folding structure and the optical components at both ends provided in this application as the core. Specifically, the foldable projection module may include a projection end housing, a projection end optical component disposed within the projection end housing, a light source end housing, a light source end optical component disposed within the light source end housing, and an optical path folding structure disposed between the projection end optical component and the light source end optical component; the optical path folding structure has a first mounting surface and a second mounting surface, and the projection end optical component and the optical component are respectively connected and fixed to one of the first mounting surface and the second mounting surface. Here, the projection end optical component corresponds to the frame end optical component in the AR glasses described above, and the light source end optical component corresponds to the rear projection light source in the AR glasses described above. The projection end housing corresponds to the frame end shell (i.e., optical component shell 21) in the AR glasses described above, and the light source end housing corresponds to the temple in the AR glasses described above. In some embodiments, a light source and other optical elements besides the light source may be disposed within the light source end housing; that is, the light source and other optical elements may jointly constitute the light source end optical component. Optical components at the light source end may include, for example, a light-diffusing element such as a collimating lens. This element adjusts the light emitted from the light source. Since the light emitted from the light source is generally natural light, which is diffused and has a certain emission angle, this light-diffusing element can be placed between the light source and the image panel (or prism) to adjust the diverging light and reduce the divergence angle. This ensures that the light from the light source enters the rear optical components (e.g., the lens frame end optical components) uniformly, improving the efficiency of the light source. In some embodiments, the side of the light-diffusing element facing the light source is a plane, and the side facing away from the light source is a convex surface. The area of ​​the plane is larger than the light-emitting area of ​​the light source.

[0072] Furthermore, in the foldable projection module, the optical path folding structure includes a bushing and a composite pivot. The outer shell of the bushing has a first end face that serves as the first mounting surface. An inner cavity is formed inside the outer shell, and a window is provided on the side of the outer shell facing away from the first end face. The composite pivot has a columnar portion that is embedded in the inner cavity. The composite pivot also has an extension portion that extends outward from the columnar portion and passes through the window, with the end face of the extension portion serving as the second mounting surface. A light-transmitting hole passes through the columnar portion and the extension portion. The composite rotating shaft is adapted to rotate relative to the bushing about the axis of the columnar portion, and the shape and size of the window of the bushing allow the extension portion to rotate within the window about the axis of the columnar portion, thereby causing the projection end optical component and the light source end optical component to rotate relative to each other, thus switching the foldable projection module to a folded state or an unfolded state. In the folded state, the optical axis directions of the projection end optical component and the light source end optical component overlap. In the unfolded state, the optical axis directions of the projection end optical component, the light source end optical component, and the axis direction of the light-transmitting aperture are all aligned. In the unfolded state, the emitted light from the light source end optical component passes through the light-transmitting aperture and is received by the incident end of the projection end optical component. The optical axis of the projection end optical component can be the optical axis of its light incident surface (e.g., the surface of its image generating panel). The optical axis of the light source end optical component can be the optical axis of its light emitting surface.

[0073] In some embodiments, in the foldable projection module, the shape and size of the inner surface of the bushing are adapted to the shape and size of the outer surface of the columnar portion to achieve a pivotal connection between the columnar portion and the bushing. The first mounting surface of the bushing is provided with a first through hole. In the unfolded state, the outlet of the light-transmitting hole located in the columnar portion is aligned with the first through hole. In the folded state, the outlet of the light-transmitting hole located in the columnar portion is blocked by the inner surface of the bushing. The portion of the bushing other than the first through hole and the window has a closed inner surface. The bushing can be assembled from two bushing components. During assembly, the composite shaft is first inserted into one bushing component, and then the other bushing component is fastened together to complete the assembly. The two bushing components can be fastened with bolts (see the previous embodiments for details). In other embodiments, the assembly of the two bushing components can also be completed by other means, such as high-precision assembly by gluing or laser welding. This gluing or laser welding can be combined with active calibration technology to achieve high-precision assembly of the two bushing components, thereby enabling the foldable projection module to have extremely high collimation in its unfolded state. Specifically, in the field of camera modules, the applicant has invented a split-type camera module assembly technology based on active calibration technology. Its core lies in optimizing and adjusting the relative positions of the two (or more) separate sub-lenses based on actual imaging results to compensate for manufacturing and assembly tolerances of each lens within the sub-lenses. In some embodiments, this active calibration technology can also be applied to the high-precision assembly of foldable projection modules.

[0074] In addition to fastener-based (e.g., bolt) fixing connections, snap-fit ​​connections can also be used in other embodiments of this application. For example, a snap-fit ​​connection can be used to achieve a sealed connection between the light source housing (e.g., temple) and the second mounting surface of the mounting portion (extension portion). A snap-fit ​​connection can also be used to fix the projection housing (e.g., optical component housing 21) and the first mounting surface of the bushing.

[0075] All the technical details described in the various embodiments of the aforementioned AR glasses can be applied to the foldable projection module, and will not be repeated here.

[0076] It should be noted that in the above embodiments, the AR glasses achieve an AR effect (i.e., optical transmission-type virtual reality effect) by superimposing the virtual image output by the foldable projection module (which can also be called an AR optical engine) onto the real world directly observed by the human eye through the lenses. However, it should be noted that the foldable projection module of this application can also achieve an AR effect (i.e., video perspective-type virtual reality effect) by superimposing the real-world image captured by a camera installed on the front of the glasses and displaying the superimposed image in front of the human eye.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A foldable projection module, comprising: The projection end housing, the projection end optical component disposed within the projection end housing, the light source end housing, the light source end optical component disposed within the light source end housing, and the optical path folding structure disposed between the projection end optical component and the light source end optical component; The optical path folding structure has a first mounting surface and a second mounting surface, and the projection end optical component and the light source end optical component are respectively connected and fixed to one of the first mounting surface and the second mounting surface; The optical path folding structure includes a bushing and a composite rotating shaft. The bushing has an inner cavity and a vertical mounting surface perpendicular to the optical axis of the AR projection optical path. The outer shell of the bushing has a first end face that serves as the first mounting surface. The inner cavity is formed inside the outer shell, and a window is provided on the side of the outer shell facing away from the first end face. The composite shaft has a columnar portion that is embedded in the inner cavity; the composite shaft also has an extension portion that extends outward from the columnar portion and passes through the window, the end face of the extension portion serving as the second mounting surface; a light-transmitting hole passes through the columnar portion and the extension portion; The composite pivot is adapted to rotate relative to the bushing with the axis of the columnar portion as the pivot, and the shape and size of the window of the bushing allow the extension portion to rotate within the window with the axis of the columnar portion as the pivot, thereby driving the projection end optical component and the light source end optical component to rotate relative to each other, thereby switching the foldable projection module to a folded state or an unfolded state.

2. The foldable projection module according to claim 1, characterized in that, The folded state is a state in which the optical axis of the projection end optical component and the optical axis of the light source end optical component overlap each other; the unfolded state is a state in which the optical axis of the projection end optical component, the optical axis of the light source end optical component, and the axial direction of the light-transmitting aperture are all consistent. In the unfolded state, the emitted light from the light source end optical component passes through the light-transmitting aperture and is then received by the incident end of the projection end optical component.

3. The foldable projection module according to claim 1, characterized in that, The shape and size of the inner surface of the bushing are adapted to the shape and size of the outer surface of the columnar part to realize the pivotal connection between the columnar part and the bushing. The first mounting surface of the bushing is provided with a first through hole. In the unfolded state, the outlet of the light-transmitting hole located in the columnar part is aligned with the first through hole. In the folded state, the outlet of the light-transmitting hole located in the columnar part is blocked by the inner surface of the bushing. The part of the bushing except for the first through hole and the window has a closed inner surface.

4. The foldable projection module according to claim 1, characterized in that, The extension includes a neck and a mounting portion. One end of the neck is connected to the middle section of the columnar portion, and the other end extends along the optical axis and protrudes outward from the window. The end of the neck that protrudes from the window forms the mounting portion. The light-transmitting hole penetrates the columnar portion, the neck, and the mounting portion, and the axial direction of the light-transmitting hole is perpendicular to the axial direction of the columnar portion.

5. The foldable projection module according to claim 2, characterized in that, The bushing includes: a first bushing component and a second bushing component; The first bushing component has the vertical mounting surface and a first inclined mounting surface for assembling the second bushing component. The second bushing component has the window and a second inclined mounting surface for assembling the first bushing component. Both the first inclined mounting surface and the second inclined mounting surface are inclined relative to the optical axis of the AR projection light path. The first inclined mounting surface and the second inclined mounting surface are fastened and assembled to form the bushing. Both the first inclined mounting surface and the second inclined mounting surface are provided with openings for inserting the columnar portion.

6. The foldable projection module according to claim 5, characterized in that, A first mounting groove for a sealing ring is provided around the opening of the first inclined mounting surface, and a second mounting groove for a sealing ring is provided around the opening of the second inclined mounting surface. An elastic second sealing ring is disposed in the first mounting groove and the second mounting groove. After the columnar part of the composite shaft is inserted and the first bushing component and the second bushing component are fastened together, the inner side of the second sealing ring contacts the outer side of the columnar part, and the second sealing ring is squeezed from the inside to the outside by the columnar part to generate deformation, thereby sealing the gap between the columnar part and the bushing. The inner surfaces of the first bushing member and the second bushing member are both adapted to the shape of the outer surface of the columnar portion.

7. The foldable projection module according to claim 4, characterized in that, In the composite shaft, the mounting portion is flat.

8. The foldable projection module according to claim 1, characterized in that, The composite shaft is integrally formed.

9. The foldable projection module according to claim 4, characterized in that, The composite shaft is an injection-molded part formed integrally by injection molding process; or it is a composite material part, which includes a metal skeleton and a molded material attached to the metal skeleton, and the shape of the composite shaft and the light-transmitting hole penetrating the columnar part, the neck and the mounting part are constructed by the shape of the molded material.

10. The foldable projection module according to claim 5, characterized in that, The second bushing component is provided with a magnet, which is used to generate an attractive force to fix the composite shaft in the unfolded state.

11. The foldable projection module according to claim 2, characterized in that, In the composite shaft, the height of the columnar portion is no greater than 13mm; the cross-sectional area of ​​the columnar portion is no greater than 150mm². 2 .

12. An AR glasses device comprising: Lenses, frames, temples, and an AR projection optical path, wherein the AR projection optical path includes optical components at the frame end and a rear projection light source; characterized in that, The AR glasses also include an optical path folding structure, which includes a bushing and a composite pivot. The bushing has an inner cavity and a vertical mounting surface perpendicular to the optical axis of the AR projection optical path, and a window is provided at one end of the bushing facing away from its vertical mounting surface. The composite pivot has a columnar portion that is embedded in the inner cavity of the bushing; the composite pivot also has an extension portion that extends outward from the columnar portion and passes through the window, the extension portion extending out of the window is fixedly connected to the frame or the temple, and a light-transmitting hole passes through the columnar portion and the extension portion, and the axial direction of the light-transmitting hole is perpendicular to the axial direction of the columnar portion. The optical component at the end of the lens frame and the rear projection light source are respectively disposed on the lens frame and the temple, and the optical component at the end of the lens frame and the rear projection light source are separated by the optical path folding structure; The composite pivot is adapted to rotate relative to the bushing with the axis of the columnar part as the pivot, so as to drive the temple to fold and unfold relative to the frame.

13. The AR glasses according to claim 12, characterized in that, The left and right ends of the frame are respectively provided with a frame end optical component housing, the frame end optical component is disposed inside the frame end optical component housing, and the rear projection light source is installed inside the temple; when the temple is unfolded relative to the frame, the axial direction of the light-transmitting hole is consistent with the optical axis direction of the AR projection light path.

14. The AR glasses according to claim 13, characterized in that, The extension portion is fixedly connected to the end of the temple, and the vertical mounting surface is fixedly connected to the housing of the optical component at the end of the frame; or, the extension portion is fixedly connected to the housing of the optical component at the end of the frame, and the vertical mounting surface is fixedly connected to the end of the temple.

15. The AR glasses according to claim 14, characterized in that, The extension includes a neck and a mounting portion. One end of the neck is connected to the middle section of the columnar portion, and the other end extends along the optical axis and protrudes outward from the window. The end of the neck that protrudes from the window forms the mounting portion. The light-transmitting hole passes through the columnar portion, the neck, and the mounting portion. From a horizontal perspective, the outline of the window of the bushing is rectangular; when the temple is unfolded relative to the frame, the opening of the window is tilted inward relative to the optical axis of the AR projection light path, and the width of the window is adapted to the height of the neck of the composite pivot; the length of the window is adapted to the movable distance of the neck; from a top-down perspective, the outline of the window is arc-shaped, and its movement trajectory is consistent with that of the root of the neck.

Images