Optical projection system and AR optical equipment

Abstract

The embodiment of the invention discloses an optical projection system and AR optical equipment. The optical projection system comprises an AR light machine; the AR light machine comprises a polarization reflection element, a first phase delayer and a light splitting element which are arranged along the same optical axis, and the first phase delayer is located between the polarization reflection element and the light splitting element. The optical projection system further comprises a first lens, the first lens is located between the first phase retarder and the light splitting element, the polarization reflection element and the first phase retarder are arranged in a stacked mode to form a stacked element, and the stacked element is arranged on the surface of the side, away from the light splitting element, of the first lens.

Description

Technical Field

[0001] The present application belongs to the field of optical display technology. Specifically, the present application relates to an optical projection system and an AR optical device. Background Art

[0002] In AR optical devices, AR optical machines are key optical components, and their performance and size directly affect the user experience. The miniaturization of AR optical machines has always been an important goal pursued by the industry. In the existing technology, optical machines based on μLED technology (i.e., based on Micro-LED technology) are considered by the industry to be the development direction for miniaturization of AR optical machines due to their small size and huge display performance potential.

[0003] At present, the industry has achieved mass production of single green optical engines based on μLED technology, with about 4 to 5 optical lenses, an overall optical length of about 7.5mm, and a corresponding optical engine volume of about 0.3cc. However, in pursuit of more extreme volume compression, the industry is actively exploring new technical solutions. By introducing more aspherical lenses, the lens length based on 5 aspherical lenses has been successfully compressed to 5.6mm, and the corresponding optical engine volume has also been reduced to 0.15cc, which is already the limit of traditional optical engine design. It can be seen that although the volume of the optical engine has been reduced, there is still room for further optimization. Summary of the invention

[0004] The purpose of this application is to provide a new technical solution for an optical projection system and AR optical equipment.

[0005] According to a first aspect of the present application, an optical projection system is provided, the optical projection system comprising an AR optical machine;

[0006] The AR optical machine includes a polarization reflection element, a first phase retarder, and a beam splitter element arranged along the same optical axis, and the first phase retarder is located between the polarization reflection element and the beam splitter element;

[0007] The optical projection system also includes a first lens, which is located between the first phase retarder and the beam splitter. The polarized reflection element and the first phase retarder are stacked to form a superimposed element, and the superimposed element is arranged on a side surface of the first lens away from the beam splitter.

[0008] Optionally, the optical projection system includes a light waveguide, and the light waveguide is used to propagate the projection light emitted by the AR optical machine to a target position for imaging;

[0009] The distance between the exit pupil position of the AR optical machine and the entrance pupil position of the optical waveguide sheet is 2 mm to 5 mm.

[0010] Optionally, the curvature radius of the surface of the first lens setting the overlapping element is R1, and R1>15mm.

[0011] Optionally, the AR optical machine includes a screen, and the screen is arranged along the optical axis on a side of the beam splitting element away from the first phase retarder, and the image height of the screen is H, 0<H≤7.7mm.

[0012] Optionally, the light splitting element is arranged on the light emitting surface of the screen.

[0013] Optionally, a second phase retarder and a polarizing element are stacked on the light emitting surface of the screen, and the second phase retarder and the polarizing element are used to convert the light emitted from the screen into circularly polarized light;

[0014] The beam splitter element is stacked on a side of the second phase retarder away from the polarizing element. The beam splitter element, the second phase retarder and the polarizing element form a composite film material.

[0015] Optionally, a protective glass is provided on the light emitting surface of the screen, and the protective glass is located between the composite film material and the light emitting surface of the screen.

[0016] Optionally, along the optical axis direction, a distance from the light splitting element to the light emitting surface of the screen is L1, and 0.1 mm≤L1≤1.5 mm.

[0017] Optionally, the screen and the first lens are arranged adjacent to each other, and an air gap between the screen and the first lens is ≥0.1 mm;

[0018] The focal length of the first lens is F1, 5mm≤F1≤20mm.

[0019] Optionally, the AR optical machine further includes a second lens, the second lens is located between the first lens and the screen, the screen and the second lens are adjacently arranged, and an air gap between the screen and the second lens is ≥0.1 mm;

[0020] The combined focal length of the first lens and the second lens is F 12 , 5mm≤F 12 ≤20mm.

[0021] Optionally, the focal length of the first lens is F1, 2mm≤F1≤10mm;

[0022] The focal length of the second lens is F2, 20mm≤F2≤50mm.

[0023] Optionally, the AR optical machine further includes a second lens and a third lens, the screen and the third lens are adjacently arranged, and the second lens is located between the first lens and the third lens, and the air gap between the screen and the third lens is ≥0.1 mm;

[0024] The combined focal length of the first lens, the second lens and the third lens is F 123 , 5mm≤F 123 ≤15mm.

[0025] Optionally, the focal length of the first lens is F1, 1mm≤F1≤5mm;

[0026] The focal length of the second lens is F2, -10mm≤F2≤-1mm;

[0027] The focal length of the third lens is F3, 15mm≤F3≤350mm.

[0028] Optionally, the curvature radius of the surface of the first lens setting the overlapping element is R1, and R1>20mm.

[0029] Optionally, the total optical length of the AR optical machine is L, 1mm≤L≤6mm.

[0030] Optionally, the distance from the polarized reflection element to the exit pupil position of the AR optical machine is PD, 0≤PD≤10mm.

[0031] Optionally, the total focal length of the AR optical machine is F, 2.5mm≤F≤10mm.

[0032] According to a second aspect of the present application, an AR optical device is provided, wherein the AR optical device comprises the optical projection system as described in the first aspect.

[0033] One beneficial effect of the embodiments of the present application is:

[0034] According to the optical projection system proposed in the embodiment of the present application, the AR optical machine is an optical machine based on μLED technology (i.e., based on Micro-LED technology). By cleverly introducing polarized reflection elements, first phase delay elements, and beam splitting elements at key positions in its optical architecture, an efficient folded optical path system is built, while optimizing the number of lenses used, thereby creating a compact and efficient optical architecture layout, which can ultimately achieve a miniaturized design of the optical projection system while maintaining good imaging display performance. This application provides strong support for improving the wearing comfort of AR optical devices.

[0035] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0037] Figure 1 A schematic diagram of the structure of an optical projection system provided in an embodiment of the present application;

[0038] Figure 2 The optical architecture and optical path diagram of the AR optical machine provided in one embodiment of the present application;

[0039] Figure 3 for Figure 2 An optical architecture and optical path diagram of an AR optical machine shown;

[0040] Figure 4 for Figure 3 The MTF diagram of the AR optical machine shown;

[0041] Figure 5 for Figure 3 The dot array diagram of the AR optical machine shown;

[0042] Figure 6 for Figure 3 Optical distortion diagram of the AR optical machine shown;

[0043] Figure 7 for Figure 3 Relative illumination diagram of the AR light machine shown;

[0044] Figure 8 The optical architecture and optical path diagram of an AR optical machine provided by another embodiment of the present application;

[0045] Fig. 9 for Figure 8 An optical architecture and optical path diagram of an AR optical machine shown;

[0046] Fig.10 for Fig. 9 The MTF diagram of the AR optical machine shown;

[0047] Fig.11 for Fig. 9 The dot array diagram of the AR optical machine shown;

[0048] Fig.12 for Fig. 9 Optical distortion diagram of the AR optical machine shown;

[0049] Fig.13 for Fig. 9 Relative illumination diagram of the AR light machine shown;

[0050] Fig.14The optical architecture and optical path diagram of an AR optical machine provided in another embodiment of the present application;

[0051] Fig.15 for Fig.14 An optical architecture and optical path diagram of an AR optical machine shown;

[0052] Fig.16 for Fig.15 The MTF diagram of the AR optical machine shown;

[0053] Fig.17 for Fig.15 The dot array diagram of the AR optical machine shown;

[0054] Fig.18 for Fig.15 Optical distortion diagram of the AR optical machine shown;

[0055] Fig.19 for Fig.15 Relative illumination diagram of the AR light machine shown.

[0056] Description of reference numerals:

[0057] 1. First lens; 101. First surface; 102. Second surface; 2. Second lens; 3. Third lens; 4. Screen; 5. Polarization reflection element; 6. First phase retarder; 7. Spectral element; 8. Second phase retarder; 9. Polarization element; 10. Protective glass; 12. Optical waveguide; 13. Lens group; 14. Projection imaging light; 01. Human eye. DETAILED DESCRIPTION

[0058] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0059] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0060] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0061] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0062] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0063] The optical projection system and AR optical device provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0064] According to one embodiment of the present application, an optical projection system is provided. Figures 1 to 3 , the optical projection system includes an AR optical machine; the AR optical machine includes a polarization reflection element 5, a first phase retarder 6, and a beam splitter 7 arranged along the same optical axis, and the first phase retarder 6 is located between the polarization reflection element 5 and the beam splitter 7; the optical projection system also includes a first lens 1, the first lens 1 is located between the first phase retarder 6 and the beam splitter 7, the polarization reflection element 5 and the first phase retarder 6 are stacked to form a superimposed element, and the superimposed element is arranged on a side surface of the first lens 1 away from the beam splitter 7.

[0065] It should be noted that the optical projection system provided in the embodiment of the present application is designed based on the optical waveguide architecture, which is the design of the output lens part of the AR optical machine under the optical waveguide architecture.

[0066] The optical projection system provided in the embodiment of the present application is shown in FIG. Figures 1 to 3 , demonstrating its unique and efficient optical architecture. First, a polarization reflection element 5, a first phase retarder 6, at least a first lens 1 and a beam splitter 7 arranged along the same optical axis are introduced into the optical architecture of the AR optical machine, ensuring that the light can propagate along a predetermined folding path inside the AR optical machine. Among them, the first phase retarder 6 is located between the polarization reflection element 5 and the beam splitter 7. This layout provides a basis for polarization control and path separation of light.

[0067] In the optical scheme provided in the embodiment of the present application, see Figure 2 and Figure 3 The optical architecture of the AR optical machine shown in the figure can use at least one lens, namely, the first lens 1. Specifically, the first lens 1 is located between the first phase retarder 6 and the beam splitter 7. The projection light entering the AR optical machine can pass through the first lens 1 three times during the return process. Figure 3. This layout can extend the propagation path of light, so that the light can be more fully regulated and optimized inside the optical projection system. This way of light passing through the same lens three times not only enhances the utilization rate of light, but also helps to eliminate aberrations and improve the clarity of imaging. Through such an efficient and compact optical architecture, the optical projection system provided by the embodiment of the present application achieves excellent optical performance while maintaining miniaturization and compactness, and can provide users with a clearer visual experience.

[0068] Regarding the design of the number of lenses, the AR optical machine provided in the embodiment of the present application can use at least one lens, that is, Figure 2 In practical applications, in order to meet more complex optical performance requirements, 1 to 2 more lenses may be added to the AR optical machine, see Figure 8 and Fig.14 These additional lenses can be selected and designed as needed to further optimize the optical path, improve imaging quality or achieve other special optical functions.

[0069] For example, when two or more lenses are used in an AR optical machine, the following can be formed: Figure 1 The lens group 13 shown in FIG. As the number of lenses increases appropriately, the final image quality can be improved.

[0070] The optical projection system provided in the embodiment of the present application, wherein the AR optical engine is based on the folded optical path optical design, can use a single lens, which significantly reduces the items in the BOM material list of the optical projection system, not only simplifies the manufacturing process, but also directly and effectively reduces the cost of the product. This cost optimization is of great significance to improving the market competitiveness of the product.

[0071] By flexibly adjusting the number and layout of lenses, the optical projection system provided by the embodiment of the present application can achieve high-performance imaging effects while ensuring compactness. In addition, due to the precise layout and combination of optical elements inside the optical projection system, the optical projection system also has good stability and reliability, and can meet the use requirements in various complex environments.

[0072] The light splitting element 7 is, for example, a semi-transparent and semi-reflective film, which allows a portion of light to be transmitted and another portion of light to be reflected. It should be noted that the reflectivity and transmittance of the light splitting element 7 can be flexibly adjusted according to specific needs, and this is not limited in the embodiments of the present application.

[0073] The first phase retarder 6 can be used to change the polarization state of light. For example, it can be used to convert linearly polarized light into circularly polarized light, or to convert circularly polarized light into linearly polarized light. The first phase retarder 6 in the present application is, for example, a quarter wave plate. Of course, the first phase retarder 6 can be set to other phase retarder films as needed.

[0074] The polarized reflective element 5 is a polarized reflector that reflects horizontal linear polarized light and transmits vertical linear polarized light, or a polarized reflector that reflects linear polarized light at any other specific angle and transmits linear polarized light perpendicular to the angle.

[0075] In the AR optical machine provided in the embodiment of the present application, see Figure 2 The synergistic effect of the beam splitter element 7, the first lens 1, the first phase retarder 6 and the polarization reflection element 5 can accurately control the propagation and polarization state of light, thereby obtaining a clear and accurate image.

[0076] It is worth noting that, in the design of the present application, the polarized reflective element 5 and the first phase retarder 6 are stacked to form a superimposed element. This superimposed arrangement saves space inside the AR optical machine, which is conducive to making the structure of the AR optical machine more compact, and at the same time helps to reduce the assembly complexity of the optical projection system.

[0077] The polarizing reflective element 5 and the first phase retarder 6 are attached to the left side surface of the first lens 1 (ie, the first surface 101), see Figure 2 This layout enables the light to be completely folded and pass through the two surfaces of the first lens 1. This design not only optimizes the optical path, but also makes full use of the aberration correction capability of the lens surface, thereby significantly improving the imaging quality and user experience.

[0078] In addition, the above-mentioned overlapping element is arranged on a surface of the first lens 1 facing away from the beam splitter 7. Such a layout allows the light to be folded back and pass through the first lens 1 three times, which can effectively eliminate aberrations.

[0079] See also Figure 2 and Figure 3The optical path of the optical projection system is as follows: the screen 4 emits light, which is modulated into circularly polarized light → the circularly polarized light passes through the beam splitter 7 and is 50% transmitted and 50% reflected → the circularly polarized light passes through (in addition, the reflected circularly polarized light passes through the second phase retarder 8 on the surface of the screen 4 and becomes P light, and then the P light is absorbed by the polarizing element 9) → passes through the first lens 1 for the first time to eliminate aberrations → passes through the first phase retarder 6 to become P light → the P light reaches the polarizing reflection element 5 (reflects P light and transmits S light) and is reflected → the P light passes through the first phase retarder 6 and becomes circularly polarized light → passes through the first lens 1 for the second time to eliminate aberrations → passes through the beam splitter 7 and is 50% reflected → passes through the first lens 1 for the third time to eliminate aberrations → passes through the first phase retarder 6 and becomes S light → the S light passes through the polarizing reflection element 5 → is emitted to the optical transmission device (such as the optical waveguide plate 12), and finally forms an image in the human eye 01.

[0080] The optical projection system provided in the embodiment of the present application, wherein the AR optical machine is an optical machine based on μLED technology (i.e., based on Micro-LED technology), constructs an efficient folded optical path system by cleverly introducing a polarized reflection element 5, a first phase retarder 6, and a beam splitter 7 at key positions in its optical architecture, while optimizing the number of lenses used, thereby creating a compact and efficient AR optical machine optical architecture layout, which can realize the miniaturization design of the optical projection system while maintaining good imaging display performance. The optical projection system provided in the present application provides strong support for improving the wearing comfort of AR optical equipment.

[0081] The technical solution provided by the embodiment of the present application not only realizes the miniaturization of the optical projection system, but also does not compromise its optical display performance while maintaining compactness, ensuring that users can enjoy a good visual experience during use. The miniaturized design of this optical projection system brings advantages to the wearing comfort of AR optical devices, allowing users to feel relaxed when wearing and using them for a long time.

[0082] The optical projection system provided in the embodiment of the present application is designed based on an optical waveguide architecture, and the light emitted by the optical projection system is transmitted through the optical waveguide sheet 12 to the human eye 01 for imaging.

[0083] In some examples of this application, see Figure 1 The optical projection system includes a light waveguide plate 12, which is used to propagate the projection light emitted by the AR optical machine to the target position for imaging; the distance between the exit pupil position of the AR optical machine and the entrance pupil position of the light waveguide plate 12 is 2mm to 5mm.

[0084] In the optical projection system, it is necessary to introduce a light waveguide (such as a diffraction light waveguide) to propagate the projection light emitted by the optical machine to the target position for imaging. In the present application, the exit pupil of the AR optical machine needs to match the entrance pupil of the light waveguide 12.

[0085] It should be noted that the optical waveguide is a special optical transmission device that uses the principle of total internal reflection to propagate light (such as projection light) along a specific path.

[0086] In the embodiment of the present application, the main function of the optical waveguide sheet 12 is to effectively propagate the projection light emitted by the AR optical machine to the target position (such as Figure 1 The optical waveguide sheet 12 can couple out the projected imaging light 14. This allows the AR image to be presented at a specific position and angle in the user's field of view.

[0087] The design and optimization of the optical waveguide sheet 12 is crucial to improving optical efficiency. An efficient optical waveguide sheet can reduce the loss of light during propagation and ensure that the projected light reaches the target position with sufficient brightness and clarity.

[0088] According to the above example of the present application, it is mentioned that the distance between the exit pupil position of the AR optical machine in the optical projection system and the entrance pupil position of the optical waveguide sheet 12 is 2 mm to 5 mm. This distance range is crucial to ensure the compactness and optical imaging performance of the entire optical projection system.

[0089] In addition, since the AR optical machine needs to match the optical waveguide plate 12, the optical waveguide plate 12 requires parallel light to be incident, that is, the AR optical machine emits parallel light, and the imaging distance corresponds to infinity.

[0090] See also Figure 1 , Figure 1 The projection optical machine shown includes a lens group 13, which includes a plurality of lenses, such as Figure 1 Of course, only one lens may be used in the projection optical machine of the present application, such as Figure 2 The first lens 1 is shown in FIG.

[0091] In some examples of the present application, the curvature radius of the surface of the first lens 1 setting the overlapping element is R1, and R1>15mm.

[0092] In the example provided in the present application, the curvature radius of the film lens in the AR optical machine, namely, the first lens 1, is optimized.

[0093] For example, for the first lens 1 in the AR optical machine, the curvature radius R1 of the surface on which the polarization reflection element 5 and the first phase retarder 6 are attached is specified to be greater than 15 mm. This design choice ensures that the first lens 1 can effectively realize the polarization reflection of light, which is beneficial to improving the imaging quality.

[0094] The polarized reflective element 5 is, for example, a polarized reflective film.

[0095] The first phase retarder 6 is, for example, a quarter-wave plate.

[0096] See also Figure 2 , the first lens 1 includes a first surface 101 located on the left and a second surface 102 located on the right, and the superimposed element (i.e., the polarized reflection element 5 and the first phase retarder 6) is arranged on the first surface 101. It should be noted that, since the light splitting element 7 is located outside the second surface 102 of the first lens 1, the light entering the optical projection system can pass through the first lens 1 three times during the folding process, which can play a good aberration elimination role, which is beneficial to improving the imaging quality.

[0097] When only one optical lens is used in the AR optical machine, that is, Figure 2 In the first lens 1 shown in FIG. 1 , the curvature radius of the first surface 101 (left side surface) of the first lens 1 is designed to be greater than 15 mm. This design can reduce the difficulty of the curved surface film lamination process, thereby improving the efficiency and yield of mass production. That is, this optimization not only improves the manufacturing efficiency of the product, but also ensures the stability of product quality.

[0098] In some examples of this application, see Figure 2 , Figure 8 and Fig.14 The AR optical machine includes a screen 4, which is arranged along the optical axis on the side of the beam splitter 7 away from the first phase retarder 6, and the image height of the screen 4 is H, 0<H≤7.7mm.

[0099] In the example provided in this application, the design of the optical projection system pays special attention to the matching and optimization of the screen size (image height) and the entire optical path system. Figure 2 , Figure 8 and Fig.14 As can be seen from the reference, the AR optical machine provided by the present application includes a screen 4, which is arranged along the optical axis on the side of the beam splitter 7 away from the first phase retarder 6. In particular, the matching image height H of the screen 4 is limited to the range of 0<H≤7.7mm. This design choice is based on the requirements of miniaturization design of AR optical machine.

[0100] It should be noted that in AR optical devices, the size and weight of the optical projection system in the AR optical device are limited due to the need to consider the user's wearing comfort and portability. The screen size (image height) is a key parameter in the optical projection system, and its size directly affects the overall size and performance of the entire optical projection system.

[0101] Screens used in optical projection systems can be described in inches as their diagonal dimensions.

[0102] With the miniaturization trend of AR optical machines, the matching screen size is getting smaller and smaller. For example, in this application, a screen smaller than 0.3 inches is used, which corresponds to a matching image height range of 0 to 7.7 mm. This screen size range not only meets the requirements of miniaturization of AR optical projection systems, but also ensures sufficient imaging display clarity and user visual experience.

[0103] The optical projection system provided in the embodiment of the present application is equipped with a small-sized screen 4. By limiting the matching image height H of the screen 4 to the range of 0<H≤7.7mm, the optical projection system can maintain a small volume and weight, meeting the requirements of AR optical equipment for portability and wearing comfort. The matching design of the screen size enables the various components in the optical path system to work better together, reduce light energy loss, and improve imaging quality. The smaller screen size does not significantly affect the user's visual experience. On the contrary, by optimizing the optical path system and display technology, it can provide clearer and more realistic virtual images and enhance the user's sense of immersion.

[0104] It should be noted that the miniaturized optical projection system is not only suitable for AR optical devices, but can also be applied to other fields that require compact optical systems, such as micro projectors.

[0105] The screen 4 mentioned in the present application is, for example, a light-emitting chip.

[0106] In some examples of this application, see Figure 2 The light splitting element 7 is arranged on the light emitting surface of the screen 4 .

[0107] In the design of optical projection systems, see Figure 2 The light splitting element 7 is plated or directly attached to the light emitting surface of the screen 4. The light splitting element 7 adopts the semi-transparent and semi-reflective film technology, which not only ensures the reasonable distribution of light, but also significantly optimizes the optical path layout.

[0108] In particular, the beam splitter 7 works together with the first phase retarder 6 and the polarized reflective element 5 located on the surface of the first lens 1 away from the screen 4 to jointly construct a folded optical path system. This design allows the first lens 1 to be located in the folded optical path, and the light can pass through the lens three times during the folding process. This design greatly improves the performance of the AR optical machine, especially in terms of aberration elimination. The light is finely adjusted after passing through the first lens 1 three times, which not only reduces the distortion and chromatic aberration in the optical path, but also significantly improves the clarity and accuracy of the imaging.

[0109] Furthermore, by directly arranging the light splitting element 7 on the light emitting surface of the screen 4, the loss of light during transmission can be minimized and the utilization rate of light energy can be improved. This is because after the light is emitted from the screen 4, it can directly encounter the light splitting element 7 without passing through an additional air layer, thereby reducing the refraction and scattering of the light.

[0110] In addition, the light splitting element 7 is arranged on the screen 4, and no additional supporting elements are required, which can simplify the assembly of the optical projection system and reduce the manufacturing cost and maintenance difficulty.

[0111] In some examples of this application, see Figure 2 The light emitting surface of the screen 4 is stacked with a second phase retarder 8 and a polarizing element 9, and the second phase retarder 8 and the polarizing element 9 are used to convert the light emitted from the screen 4 into circularly polarized light; the spectroscopic element 7 is stacked on the side of the second phase retarder 8 away from the polarizing element 9, and the spectroscopic element 7, the second phase retarder 8 and the polarizing element 9 form a composite film material.

[0112] See also Figure 2 The light-emitting surface of the screen 4 is designed with a composite film material, which is mainly composed of a second phase retarder 8, a polarizing element 9 and a beam splitter 7. This integrated design greatly simplifies the assembly process of the optical projection system, and multiple key optical elements can be efficiently integrated into the optical projection system in one assembly.

[0113] It is worth noting that the light splitting element 7 works together with the first phase retarder 6 and the polarization reflection element 5 to construct an efficient folded optical path. This design not only optimizes the optical path layout, but also improves the light energy utilization rate.

[0114] In particular, the second phase retarder 8 and the polarizing element 9 are used together to convert the light emitted from the screen 4 into circularly polarized light through optical control technology. This conversion not only enhances the stability and consistency of the light, but also improves the clarity and contrast of the final image, which can bring a better visual experience to the user.

[0115] Furthermore, the second phase retarder 8 is stacked on the light-emitting surface of the screen 4, and its main function is to phase-retard the light. The second phase retarder 8 is, for example, a quarter-wave plate. The polarizing element 9 is, for example, a polarizing film, and its function is to further adjust the polarization state of the light and finally convert the light into circularly polarized light.

[0116] The beam splitter element 7 is stacked on the surface of the second phase retarder 8 on the side away from the polarizing element 9, that is, located at the outermost layer of the composite film. This design allows the light emitted from the screen 4 to be first converted into circularly polarized light when passing through the composite film, and then split by the beam splitter element 7. As a semi-transparent and semi-reflective film, the beam splitter element 7 can reflect part of the circularly polarized light into the aperture or the human eye to form a virtual image for the user to watch, while allowing another part of the light to be transmitted for other optical processing or imaging.

[0117] In the present application, by converting the light emitted from the screen 4 into circularly polarized light, the loss and interference of the light during transmission can be reduced, the brightness and contrast of the virtual image can be improved, and the user's visual experience can be enhanced. The composite film composed of the beam splitter element 7, the second phase retarder 8 and the polarization element 9 is arranged on the light-emitting surface of the screen 4, which simplifies the structure of the optical path system and improves the integration of the optical projection system. At the same time, this design also enables light to be transmitted and processed more efficiently, reducing the loss of light energy.

[0118] In some examples of this application, see Figure 2 A protective glass 10 is disposed on the light emitting surface of the screen 4 , and the protective glass 10 is located between the composite film material and the light emitting surface of the screen 4 .

[0119] Figure 2 The design of providing a layer of protective glass 10 on the light-emitting surface of the screen 4 is shown, and the protective glass 10 is located between the composite film material (including the second phase retarder 8, the polarizing element 9 and the beam splitting element 7) and the light-emitting surface of the screen 4. This layout not only enhances the overall structural stability of the optical projection system, but also brings the following significant technical effects:

[0120] (1) The protective glass 10 can effectively prevent the light-emitting surface of the screen 4 from being scratched, impacted, or contaminated, thereby extending the service life of the optical projection system.

[0121] (2) The protective glass 10 is usually made of a material with high light transmittance, which can ensure that the optical performance of the light emitted by the screen 4 will not be significantly affected when passing through the protective glass. This helps to maintain the clarity and brightness of the light output by the optical projection system.

[0122] (3) By directly placing the protective glass 10 on the light-emitting surface of the screen 4 and assembling it together with the composite film material, the assembly process of the optical projection system can be simplified and the production efficiency can be improved.

[0123] In some examples of this application, see Figure 2 , Figure 8 and Fig.14 Along the optical axis direction, the distance from the light splitting element 7 to the light emitting surface of the screen 4 is L1, 0.1mm≤L1≤1.5mm.

[0124] Combination Figure 2 , Figure 8 and Fig.14 It can be seen that along the optical axis, there is a certain distance between the light splitting element 7 and the light emitting surface of the screen 4, which is defined as L1, and L1 is controlled within the range of 0.1mm to 1.5mm. The setting of this design parameter is based on a comprehensive consideration of a series of practical processes and technical requirements.

[0125] First of all, the setting of this distance range takes into account the adaptability of different screens (panels) and their process requirements. The screen 4 may come from different suppliers and have different thicknesses, transmittances, and surface treatments. At the same time, between the screen 4 and the spectroscopic element 7, there may also be multiple layers of glue, a second phase retarder 8 (QWP film), a polarizing element 9 (POL film), a film-mounted base glass sheet, and a protective glass 10 for the screen 4. These intermediate layers have a significant effect on the transmittance, reflection, and polarization state of light.

[0126] By controlling the distance L1 from the light splitting element 7 to the light emitting surface of the screen 4 within the range of 0.1 mm to 1.5 mm, it can be ensured that the optical properties (such as brightness, contrast and color saturation) of the light are maintained to the greatest extent when the light passes through these intermediate layers. Too short or too long a distance may cause unnecessary attenuation, scattering or change of polarization state of the light during transmission, thereby affecting the final optical effect.

[0127] In addition, the setting of this distance range also takes into account the convenience and reliability of assembly. During the assembly process of the optical projection system, it is necessary to ensure the precise alignment and fixation between the beam splitter 7 and the screen 4. The appropriate distance range can provide sufficient operating space while ensuring the accuracy and stability of assembly.

[0128] In some examples of this application, see Figure 2 and Figure 3 The screen 4 and the first lens 1 are arranged adjacent to each other, and the air interval between the screen 4 and the first lens 1 is ≥0.1 mm. The focal length of the first lens 1 is F1, 5mm≤F1≤20mm.

[0129] See also Figure 1 When only one optical lens, namely the first lens 1, is used in the optical projection system, the first lens 1 is adjacent to the screen 4, and the first lens 1 is also the first lens on the near-screen side. At this time, the air gap between them is designed to be greater than or equal to 0.1 mm.

[0130] Only the first lens 1 is used in the AR optical machine, which helps to reduce the volume and weight, thus meeting the design goal of miniaturization of the optical machine. However, in order to ensure that necessary performance adjustments can be made during the actual assembly process, such as using the six-axis AA (Active Alignment) of the screen and optical lens to adjust the MTF (Modulation Transfer Function) and other performance, a certain gap must be left between the screen 4 and the first lens 1. The minimum value of this gap is set to 0.1mm, which is based on the current process limit.

[0131] The focal length F1 of the first lens 1 is set in the range of 5 mm to 20 mm. Such a design is based on the pursuit of the goal of miniaturization of the optical machine and the consideration of actual assembly and performance adjustment. Selecting a suitable focal length within the above range can achieve miniaturization and lightness of the entire optical projection system while ensuring the imaging quality.

[0132] In some examples of this application, see Figure 8 and Fig. 9 The optical projection system further includes a second lens 2, which is located between the first lens 1 and the screen 4. The screen 4 and the second lens 2 are adjacently arranged, and the air gap between the screen 4 and the second lens 2 is ≥0.1 mm. The combined focal length of the first lens 1 and the second lens 2 is F 12 , 5mm≤F 12 ≤20mm.

[0133] See also Figure 8 and Fig. 9 , a second lens 2 is added to the AR optical machine, and the second lens 2 is designed to be located between the first lens 1 and the screen 4. In other words, in this example, two lenses are used in the AR optical machine, and the newly added second lens 2 is located on the near-screen side, which becomes the lens closest to the screen 4. At this time, the first lens 1 is the lens far away from the screen 4. Based on this, the screen 4 and the second lens 2 are adjacently arranged, and the air gap between them is designed to be greater than or equal to 0.1 mm.

[0134] The air gap between the screen 4 and the second lens 2 is designed to be greater than or equal to 0.1 mm, which is based on the current process limit. This design ensures that necessary performance adjustments can be made during the actual assembly process, such as using the six-axis AA (Active Alignment) of the screen and optical lens to adjust the MTF (Modulation Transfer Function) and other performance. At the same time, the appropriate gap also improves the convenience and reliability of assembly.

[0135] By adding a second lens 2 to the optical projection system, the AR optical machine can achieve more precise control of light. The second lens 2 can adjust the degree of convergence or divergence of light as needed, thereby improving the imaging quality of the entire optical projection system. This design has a positive impact on improving image clarity, contrast, and color reproduction.

[0136] In this example of the present application, when two optical lenses are used in the AR optical machine: a first lens 1 and a second lens 2, the combined focal length F of the first lens 1 and the second lens 2 is 12 The focal length is set in the range of 5mm to 20mm. This focal length selection enables the AR optical machine to achieve better optical performance while maintaining a smaller size, thereby improving the optical performance of the optical projection system.

[0137] In some examples of this application, see Figure 8 and Fig. 9 The focal length of the first lens 1 is F1, 2mm≤F1≤10mm; the focal length of the second lens 2 is F2, 20mm≤F2≤50mm.

[0138] In the example provided in the present application, the focal length F1 of the first lens 1 is designed to be within the range of 2 mm to 10 mm, and the focal length F2 of the second lens 2 is designed to be within the range of 20 mm to 50 mm. In this way, by matching the two lenses, a combined focal length F 12 Satisfy: 5mm≤F 12 ≤20mm.

[0139] Specifically, the first lens 1 is designed with a short focal length (2mm-10mm), and the second lens 2 is designed with a long focal length (20mm-50mm). By properly matching the focal lengths of the first lens 1 and the second lens 2, the imaging quality of the optical projection system can be optimized. The combination of short focal length and long focal length helps to reduce optical distortion and chromatic aberration, and improve image clarity and color reproduction.

[0140] At the same time, by adjusting the relative position between the two lenses (the first lens 1 and the second lens 2), the imaging performance of the optical projection system can be further adjusted to achieve more accurate image focusing and higher imaging quality.

[0141] The example provided in this application can reasonably design the combined focal length F of the first lens 1 and the second lens 2 by carefully selecting the focal lengths of the first lens 1 and the second lens 2. 12 The scope of the optical projection system has been significantly improved in terms of imaging quality, system flexibility, miniaturization, and ease of assembly and adjustment.

[0142] In some examples of this application, see Fig.14 and Fig.15 , the AR optical machine also includes a second lens 2 and a third lens 3, the screen 4 and the third lens 3 are adjacently arranged, and the second lens 2 is located between the first lens 1 and the third lens 3, and the air gap between the screen 4 and the third lens 3 is ≥0.1mm. The combined focal length of the first lens 1, the second lens 2 and the third lens 3 is F 123 , 5mm≤F 123 ≤15mm.

[0143] In this example of the present application, the AR optical machine adopts a three-piece optical lens design, namely Fig.14 The first lens 1, the second lens 2 and the third lens 3 are shown in FIG. This design has a higher potential for optimizing optical performance than a single lens or a double lens. Moreover, the design of the three-lens combination also enables the AR optical machine to have a larger focal length adjustment range.

[0144] The optical projection system provided in the embodiment of the present application can use only 1 to 3 lenses, which significantly reduces the number of optical lenses used compared to 4 to 5 lenses in conventional designs. This simplification not only reduces costs, but also makes the entire optical structure more compact due to the reduction in optical lenses, which is conducive to the miniaturization and lightweight of the optical projection system.

[0145] It should be noted that the optical projection system provided in the embodiment of the present application can improve the imaging quality as the number of lenses increases.

[0146] In this example of the present application, see Fig.14 and Fig.15, the third lens 3 is the optical lens closest to the screen 4. At this time, the screen 4 and the third lens 3 are adjacent to each other, and the air gap between them is designed to be greater than or equal to 0.1 mm. This is based on the current process limit. This design ensures that necessary performance adjustments can be made during the actual assembly process, such as using six-axis AA (Active Alignment) of the screen and optical lens to adjust MTF (Modulation Transfer Function) and other performance. At the same time, the appropriate air gap improves the convenience and reliability of assembly.

[0147] In addition, proper air spacing also helps prevent direct contact between the screen and adjacent lenses, avoiding scratches or contamination, and maintaining stable optical performance of the optical projection system.

[0148] In this example of the present application, the combined focal length F of the first lens 1, the second lens 2 and the third lens 3 is 123 It is designed to be in the range of 5mm to 15mm. Through the combined design and optimization of three lenses, the AR optical machine can achieve high-quality imaging in a wider focal length range. This design helps to reduce optical distortion, chromatic aberration and blur, and improve image clarity and color reproduction.

[0149] In some examples of this application, see Fig.13 and Fig.14 The focal length of the first lens 1 is F1, 1mm≤F1≤5mm; the focal length of the second lens 2 is F2, -10mm≤F2≤-1mm; the focal length of the third lens 3 is F3, 15mm≤F3≤350mm.

[0150] According to the above example, the focal length F1 of the first lens 1 is in the range of 1mm to 5mm, which is a relatively short focal length range. The focal length F2 of the second lens 2 is in the range of -10mm to -1mm, indicating that this is a negative focal length lens (concave lens). Negative focal length lenses are often used to correct aberrations, expand the field of view or reduce the focal length of the system. The focal length F3 of the third lens 3 is in the range of 15mm to 350mm, which is a relatively large focal length range. In this way, the combined focal length F of the three lenses is 123 It can be in the above-mentioned range of 5 mm to 15 mm.

[0151] The combination of different focal lengths of the three lenses makes the AR optical machine highly flexible in optical design. Combining positive and negative focal length lenses can shorten or lengthen the focal length of the system and correct optical distortion.

[0152] Through the precise combination of three lenses and the optimization of focal length, the optical projection system can achieve high-quality imaging within a wide focal length range. The combination of positive and negative focal length lenses helps to correct system aberrations and chromatic aberrations, improving image clarity and color reproduction.

[0153] In some examples of this application, see Figure 8 and Fig.14 The curvature radius of the surface of the first lens 1 setting the overlapping element is R1, and R1>20mm.

[0154] It is worth noting that when the second lens 2 and / or the third lens 3 are introduced into the AR optical machine, a higher requirement is placed on the curvature radius R1 of the first lens 1. Specifically, the curvature radius R1 of the first lens 1 should be greater than 20 mm. This adjustment is mainly based on the consideration of the distribution of optical power.

[0155] See also Figure 8 and Fig.14 In the two examples shown, by distributing the optical power to the second lens 2 and / or the third lens 3, the layout and performance of the optical path can be further optimized.

[0156] Specifically, a larger R1 value means that the surface curvature of the first lens 1 is smaller, which helps to reduce its optical power, thereby allocating more optical power to the subsequent second lens 2 and / or the third lens 3. Such an allocation method helps to reduce the optical distortion of a single lens, and ultimately helps to improve the imaging quality of the optical projection system.

[0157] This example of the present application shows that by introducing the second lens 2 and the third lens 3 and adjusting the curvature radius R1 of the first lens 1, the layout of the optical path is optimized, so that the light is more effectively regulated and optimized inside the entire AR optical machine.

[0158] The coordinated work of multiple lenses enhances the AR optical machine's resistance to external interference and improves the stability and reliability of the system. Although more lenses are introduced, the miniaturization design of the optical projection system is still maintained through fine adjustment and optimization of the parameters of each lens.

[0159] In some examples of this application, see Figure 2 , Figure 8 and Fig.14 The total optical length of the AR optical machine is L, 1mm≤L≤6mm.

[0160] The AR optical machine provided in the embodiment of the present application has a shorter total optical length, which greatly promotes the miniaturization of the optical projection system. In AR optical devices, miniaturization is a key factor because it directly affects the portability of the device and the wearing comfort of the user. The shorter total optical length means that the optical projection system can be more easily integrated into various AR devices.

[0161] Considering that the shortest length of the non-folded optical path design on the current market has reached a total optical length of 5.6mm for a single green optical machine, and a color estimated length of about 8mm, the optical projection system design in this application has made significant progress in total optical length.

[0162] This application can achieve miniaturization while ensuring image quality through precise optical design and lens combination. This means that the optical projection system can achieve miniaturization and portability without sacrificing image clarity, color reproduction or other imaging performance indicators.

[0163] With the continuous development of AR technology and the increasing maturity of the market, the demand for miniaturized, high-performance optical projection systems will continue to increase. The optical projection system design in this application just meets this market demand and has broad market prospects and application potential.

[0164] In addition, the optical projection system provided in the embodiment of the present application, see Figure 1 , Figure 7 and Fig.13 As shown, the polarized reflective element 5 is arranged at the leftmost side of the optical projection system, that is, the frontmost side of the optical projection system. Based on this, it can be considered that the distance from the polarized reflective element 5 to the light-emitting surface of the screen 4 is ≈ the total optical length, that is, 1 to 6 mm.

[0165] The position of the polarizing reflective element 5 in the optical path ensures that it can effectively manage the polarization of light. This is crucial to ensure image quality and color accuracy. The position and function of the polarizing reflective element 5 also help to reduce stray light. In an optical projection system, stray light may reduce the contrast and clarity of the image. By placing the polarizing reflective element 5 at the forefront of the optical path, unwanted light can be effectively reflected and filtered out, thereby improving the image quality.

[0166] In some examples of the present application, the distance from the polarized reflective element 5 to the exit pupil position of the AR optical machine is PD, 0≤PD≤10mm.

[0167] The AR optical system needs to be used together with a light-guiding device such as an optical waveguide sheet 12 .

[0168] When PD is 0 mm, it means that the exit pupil position of the AR optical machine completely coincides with the entrance pupil position of the optical waveguide sheet 12. This close match can ensure that light from the optical projection system enters the optical waveguide directly and efficiently, reducing light energy loss and improving imaging brightness and quality.

[0169] When PD is greater than 0 mm, it indicates that there is a certain distance between the exit pupil position of the AR optical engine and the entrance pupil position of the optical waveguide sheet 12. This reserved distance can provide a larger tolerance for the assembly between the AR optical engine and the optical waveguide sheet 12, facilitate precise adjustment and calibration, and ensure that the light output by the AR optical engine can accurately enter the optical waveguide.

[0170] AR optical devices such as AR glasses need to take into account the wearing comfort and portability of users, so their appearance design should be relatively compact. Limiting the above-mentioned PD to within 10mm is conducive to the design of the bend of the AR glasses' temples. This design ensures that the overall appearance of the AR glasses is both ergonomic and can accommodate key components such as optical projection systems and optical waveguides.

[0171] The appropriate PD range can ensure that the light maintains a high quality during transmission. Too long or too short PD may cause problems such as light loss and increased aberration, affecting the final imaging effect. Therefore, limiting the PD to the range of 0mm to 10mm helps maintain the stability and consistency of imaging quality.

[0172] By optimizing the coordination of the AR optical machine and the optical waveguide sheet 12 and the appearance design of the AR glasses, the optical projection system in the example of the present application can bring a more comfortable and natural AR experience to the user. At the same time, due to the improvement of imaging quality and the improvement of light energy utilization, the user can obtain a clearer and brighter virtual image when using AR glasses.

[0173] In some examples of the present application, the focal length of the AR optical machine is F, 2.5mm≤F≤10mm.

[0174] Focal length is a key parameter in optical systems, which determines the magnification and viewing angle of the image.

[0175] By properly designing the total focal length of the AR optical machine, the optical projection system can adapt to different imaging requirements, thereby providing a flexible viewing angle and imaging range. A shorter total focal length (such as 2.5mm) allows the optical projection system to work at a closer working distance, while a longer total focal length (such as 10mm) can provide clear imaging at a longer working distance. Therefore, the focal length range of 2.5mm to 10mm can adapt to the needs of different working distances.

[0176] At the appropriate working distance and focal length, the optical projection system can provide better image clarity, contrast and color accuracy. By carefully designing the focal length range, it can be ensured that the optical projection system can provide high-quality imaging effects in different application scenarios.

[0177] In addition, when the AR optical machine has a shorter focal length, it helps to reduce the overall size of the optical projection system, making it more compact. This is very important for AR optical devices such as AR glasses, because they usually need to take into account the user's wearing comfort and portability. The shorter focal length can make the optical projection system easier to integrate into these optical devices while maintaining a small size and weight.

[0178] In some examples of this application, see Figure 2 , Figure 6 and Fig.12 The field of view FOV of the AR optical machine is between 20° and 50°.

[0179] The size of the field of view directly affects the user's immersion and sense of reality in the virtual environment. A field of view that is too small may make the user feel confined to a narrow field of view, while a field of view that is too large may cause image distortion or eye fatigue. A field of view range of 20° to 50° is considered to provide a more comfortable and natural user experience.

[0180] The 20° to 50° field of view angle range can adapt to different application scenarios. For example, in games that require a high sense of immersion, a larger field of view angle can provide a wider field of view; while in some applications that require fine operation, a smaller field of view angle may be more suitable.

[0181] The optical projection system provided by the present application is described in detail below through Examples 1 to 3.

[0182] Example 1

[0183] See also Figure 1 and Figure 3 , the optical projection system includes an AR optical machine and an optical waveguide sheet 12; the AR optical machine includes a polarization reflection element 5, a first phase retarder 6, a first lens 1, a first beam splitter element 7, a second phase retarder 8, a polarization element 9, a protective glass 10 and a screen 4 which are sequentially arranged along the same optical axis;

[0184] The polarized reflective element 5 and the first phase retarder 6 are stacked to form a superimposed element, and the superimposed element is arranged on the first surface 101 of the first lens 1. The curvature radius of the first surface 101 of the first lens 1 is R1, and R1>15mm;

[0185] Wherein, the light splitting element 7 is arranged on the light emitting surface of the screen 4;

[0186] The light-emitting surface of the screen 4 is further stacked with a second phase retarder 8 and a polarizing element 9, and the second phase retarder 8 and the polarizing element 9 are used to convert the light emitted from the screen 4 into circularly polarized light; the beam splitter 7 is stacked on the side of the second phase retarder 8 away from the polarizing element 9, and the beam splitter 7, the second phase retarder 8 and the polarizing element 9 form a composite film material;

[0187] Wherein, the protective glass 10 is located between the composite film material and the light emitting surface of the screen 4;

[0188] The distance between the exit pupil position of the AR optical machine and the entrance pupil position of the optical waveguide sheet 12 is 3.3 mm;

[0189] The distance PD from the polarized reflective element 5 to the exit pupil position of the AR optical machine is 0.02 mm;

[0190] The total optical length L of the AR optical machine is 4.09 mm;

[0191] The FOV of the AR optical machine is 30°.

[0192] Table 1 shows the specific optical parameters of the optical projection system of this embodiment 1.

[0193] Table 1

[0194]

[0195]

[0196]

[0197] See also Figure 1 and Figure 3 , the optical projection system light path from right to left:

[0198] The screen 4 emits natural circularly polarized light → after passing through the polarizing element 9, the S light is transmitted (the P light is absorbed) → after passing through the second phase retarder 8, it becomes circularly polarized light → after passing through the spectroscopic element 7 (split film, 50% transmission, 50% reflection), the circularly polarized light is transmitted (in addition, the reflected part of the circularly polarized light passes through the second phase retarder 8 and becomes P light, and then after reaching the polarizing element 9, the P light is absorbed) → the first time it passes through the first lens 1 to eliminate aberrations → passes through the first phase retarder 6 to become P light → the P light reaches the polarization reflection element 5 (reflects P light and transmits S light) and is reflected → the P light becomes circularly polarized light after passing through the first phase retarder → the second time it passes through the first lens 1 to eliminate aberrations → after passing through the spectroscopic element 7, 50% of the light is reflected → the third time it passes through the first lens 1 to eliminate aberrations → after passing through the first phase retarder 6, the circularly polarized light becomes S light → the S light passes through the polarization reflection element 5 → is emitted to the optical waveguide plate 12, and finally forms an image in the human eye 01.

[0199] The optical projection system provided in this embodiment 1 has an optical performance as shown in FIG. Figures 4 to 7 As shown:

[0200] Figure 4 This is the MTF diagram of the optical projection system shown in Example 1. The average MTF of each field of view is greater than 0.49@125lp / mm, and the imaging effect is good.

[0201] Figure 5 This is the point diagram of the optical projection system shown in Example 1. The RMS value of each field of view is much smaller than 1 pixel, and the imaging effect is excellent.

[0202] Figure 6 This is an optical distortion diagram of the optical projection system shown in Example 1. The optical distortion is less than 0.8%, which meets the viewing level of human eyes.

[0203] Figure 7 This is a relative illumination diagram of the optical projection system shown in Example 1. The relative illumination is greater than 76%, which meets the conventional requirements of optical machine brightness and uniformity.

[0204] Example 2

[0205] See also Figure 1 and Fig. 9 , the optical projection system includes an AR optical machine and an optical waveguide sheet 12; the AR optical machine includes a polarization reflection element 5, a first phase retarder 6, a first lens 1, a second lens 2, a first beam splitter element 7, a second phase retarder 8, a polarization element 9, a protective glass 10 and a screen 4 arranged in sequence along the same optical axis; wherein the first lens 1 and the second lens 2 form a lens group 13;

[0206] The polarized reflective element 5 and the first phase retarder 6 are stacked to form a superimposed element, and the superimposed element is arranged on the first surface 101 of the first lens 1. The curvature radius of the first surface 101 of the first lens 1 is R1, and R1>20mm;

[0207] Wherein, the light splitting element 7 is arranged on the light emitting surface of the screen 4;

[0208] The light-emitting surface of the screen 4 is further stacked with a second phase retarder 8 and a polarizing element 9, and the second phase retarder 8 and the polarizing element 9 are used to convert the light emitted from the screen 4 into circularly polarized light; the beam splitter 7 is stacked on the side of the second phase retarder 8 away from the polarizing element 9, and the beam splitter 7, the second phase retarder 8 and the polarizing element 9 form a composite film material;

[0209] Wherein, the protective glass 10 is located between the composite film material and the light emitting surface of the screen 4;

[0210] The distance between the exit pupil position of the AR optical machine and the entrance pupil position of the optical waveguide sheet 12 is 3.3 mm;

[0211] The distance PD from the polarized reflective element 5 to the exit pupil position of the AR optical machine is 0.02 mm;

[0212] The total optical length L of the AR optical machine is 3.53 mm;

[0213] The FOV of the AR optical machine is 30°.

[0214] Table 2 shows the specific optical parameters of the optical projection system of this embodiment 2.

[0215] Table 2

[0216]

[0217]

[0218]

[0219]

[0220] See also Figure 1 and Fig. 9 , the optical projection system light path from right to left:

[0221] The screen 4 emits natural circularly polarized light → after passing through the polarizing element 9, the S light is transmitted (the P light is absorbed) → after passing through the second phase retarder 8, it becomes circularly polarized light → after passing through the beam splitter 7 (50% transmission, 50% reflection), the circularly polarized light is transmitted (in addition, the reflected circularly polarized light passes through the second phase retarder 8 and becomes P light, and then after passing through the polarizing element 9, the P light is absorbed) → it passes through the second lens 2 and the first lens 1 for the first time to eliminate aberrations → after passing through the first phase retarder 6, it becomes P light → the P light reaches the polarization reflection element 5 (reflects P light and transmits S light) and is reflected → after passing through the first phase retarder 6, the P light becomes circularly polarized light → after passing through the first lens 1 and the second lens 2 for the second time to eliminate aberrations → after passing through the beam splitter 7, 50% of the light is reflected → after passing through the second lens 2 and the first lens 1 for the third time to eliminate aberrations → after passing through the first phase retarder 6, the circularly polarized light becomes S light → the S light passes through the polarization reflection element 5 → is emitted to the optical waveguide plate 12, and finally forms an image in the human eye 01.

[0222] The optical projection system provided in this embodiment 2 has an optical performance as shown in FIG. Figures 10 to 13 As shown:

[0223] Fig.10 This is the MTF diagram of the optical projection system shown in Example 2. The average MTF of each field of view is greater than 0.7@125lp / mm, and the imaging effect is excellent.

[0224] Fig.11 This is the point diagram of the optical projection system shown in Example 2. The RMS value of each field of view is much smaller than 1 pixel, and the imaging effect is excellent.

[0225] Fig.12 This is an optical distortion diagram of the optical projection system shown in Example 2. The optical distortion is less than 2%, which meets the viewing level of human eyes.

[0226] Fig.13 This is a relative illumination diagram of the optical projection system shown in Example 2. The relative illumination is greater than 80%, which meets the conventional requirements of optical machine brightness and uniformity.

[0227] Example 3

[0228] See also Figure 1 and Fig.15 , the optical projection system includes an AR optical machine and an optical waveguide sheet 12; the AR optical machine includes a polarization reflection element 5, a first phase retarder 6, a first lens 1, a second lens 2, a third lens 3, a first beam splitter element 7, a second phase retarder 8, a polarization element 9, a protective glass 10 and a screen 4 arranged in sequence along the same optical axis; wherein the first lens 1, the second lens 2 and the third lens 3 form a lens group 13;

[0229] The polarized reflective element 5 and the first phase retarder 6 are stacked to form a superimposed element, and the superimposed element is arranged on the first surface 101 of the first lens 1. The curvature radius of the first surface 101 of the first lens 1 is R1, and R1>20mm;

[0230] Wherein, the light splitting element 7 is arranged on the light emitting surface of the screen 4;

[0231] The light-emitting surface of the screen 4 is further stacked with a second phase retarder 8 and a polarizing element 9, and the second phase retarder 8 and the polarizing element 9 are used to convert the light emitted from the screen 4 into circularly polarized light; the beam splitter 7 is stacked on the side of the second phase retarder 8 away from the polarizing element 9, and the beam splitter 7, the second phase retarder 8 and the polarizing element 9 form a composite film material;

[0232] Wherein, the protective glass 10 is located between the composite film material and the light emitting surface of the screen 4;

[0233] The distance between the exit pupil position of the AR optical machine and the entrance pupil position of the optical waveguide sheet 12 is 3.3 mm;

[0234] The distance PD from the polarized reflective element 5 to the exit pupil position of the AR optical machine is 0.02 mm;

[0235] The total optical length L of the AR optical machine is 3.25 mm;

[0236] The FOV of the AR optical machine is 30°.

[0237] Table 3 shows the specific optical parameters of the optical projection system of this embodiment 3.

[0238] Table 3

[0239]

[0240]

[0241]

[0242]

[0243] See also Figure 1 and Fig.15 , the optical projection system light path from right to left:

[0244] The screen 4 emits natural circularly polarized light → after passing through the polarizing element 9, the S light is transmitted (the P light is absorbed) → after passing through the second phase retarder 8, it becomes circularly polarized light → after passing through the beam splitter 7 (50% transmission, 50% reflection), the circularly polarized light is transmitted (in addition, the reflected part of the circularly polarized light passes through the second phase retarder 8 and becomes P light, and then after passing through the polarizing element 9, the P light is absorbed) → after passing through the third lens 3, the second lens 2 and the first lens 1 for the first time to eliminate aberrations → after passing through the first phase retarder 6, it becomes P light → the P light reaches the polarization reflection element 5 (reflects P light and transmits S light) and is reflected → after passing through the first phase retarder 6, the P light becomes circularly polarized light → after passing through the first lens 1, the second lens 2 and the third lens 3 for the second time to eliminate aberrations → after passing through the beam splitter 7, 50% of the light is reflected → after passing through the third lens 3, the second lens 2 and the first lens 1 for the third time to eliminate aberrations → after passing through the first phase retarder 6, the circularly polarized light becomes S light → the S light passes through the polarization reflection element 5 → is emitted to the optical waveguide plate 12, and finally forms an image in the human eye 01.

[0245] The optical projection system provided in this embodiment 3 has an optical performance as shown in FIG. Figures 16 to 19 As shown:

[0246] Fig.16 This is the MTF diagram of the optical projection system shown in Example 3. The average MTF of each field of view is greater than 0.7@125lp / mm, and the imaging effect is excellent.

[0247] Fig.17 This is the point diagram of the optical projection system shown in Example 3. The RMS value of each field of view is much smaller than 1 pixel, and the imaging effect is excellent.

[0248] Fig.18 This is an optical distortion diagram of the optical projection system shown in Example 3. The optical distortion is less than 1.3%, which meets the viewing level of human eyes.

[0249] Fig.19 This is a relative illumination diagram of the optical projection system shown in Example 3. The relative illumination is greater than 92%, which meets the conventional requirements of optical machine brightness and uniformity.

[0250] According to another embodiment of the embodiments of the present application, an AR optical device is provided, wherein the AR optical device includes the optical projection system as described above.

[0251] It should be noted that the AR optical device provided in the embodiment of the present application is, for example, an AR head mounted display device. Further, the AR head mounted display device is, for example, AR smart glasses or an AR smart helmet.

[0252] The specific implementation of the AR optical device in the embodiment of the present application can refer to the above-mentioned embodiments of the optical projection system, so it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0253] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0254] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An optical projection system, characterized in that: Including AR optical machine; The AR optical machine comprises a polarization reflection element (5), a first phase retarder (6), and a beam splitter (7) arranged along the same optical axis, and the first phase retarder (6) is located between the polarization reflection element (5) and the beam splitter (7); The optical projection system further comprises a first lens (1), wherein the first lens (1) is located between the first phase retarder (6) and the beam splitter (7), the polarized reflection element (5) and the first phase retarder (6) are stacked to form a superimposed element, and the superimposed element is arranged on a side surface of the first lens (1) facing away from the beam splitter (7).

2. The optical projection system according to claim 1, characterized in that: The optical projection system comprises a light waveguide plate (12), and the light waveguide plate (12) is used to propagate the projection light emitted by the AR optical machine to a target position for imaging; The distance between the exit pupil position of the AR optical machine and the entrance pupil position of the optical waveguide plate (12) is 2 mm to 5 mm.

3. The optical projection system according to claim 1, characterized in that: The curvature radius of the surface of the first lens (1) setting the overlapping element is R1, and R1>15mm.

4. The optical projection system according to claim 1, characterized in that: The AR optical machine comprises a screen (4), wherein the screen (4) is arranged along the optical axis on a side of the beam splitter (7) away from the first phase retarder (6), and an image height of the screen (4) is H, 0<H≤7.7mm.

5. The optical projection system according to claim 4, characterized in that: The light splitting element (7) is arranged on the light emitting surface of the screen (4).

6. The optical projection system according to claim 5, characterized in that: A second phase retarder (8) and a polarizing element (9) are stacked on the light-emitting surface of the screen (4), and the second phase retarder (8) and the polarizing element (9) are used to convert the light emitted from the screen (4) into circularly polarized light; The beam splitter element (7) is stacked on a side of the second phase retarder (8) away from the polarizing element (9); the beam splitter element (7), the second phase retarder (8) and the polarizing element (9) form a composite film material.

7. The optical projection system according to claim 6, characterized in that: A protective glass (10) is provided on the light-emitting surface of the screen (4), and the protective glass (10) is located between the composite film material and the light-emitting surface of the screen (4).

8. The optical projection system according to claim 7, characterized in that: Along the optical axis direction, the distance from the light splitting element (7) to the light emitting surface of the screen (4) is L1, and 0.1 mm ≤ L1 ≤ 1.5 mm.

9. The optical projection system according to claim 5, characterized in that: The screen (4) and the first lens (1) are arranged adjacent to each other, and the air gap between the screen (4) and the first lens (1) is ≥0.1 mm; The focal length of the first lens (1) is F1, 5mm≤F1≤20mm.

10. The optical projection system according to claim 5, characterized in that: The AR optical machine further comprises a second lens (2), wherein the second lens (2) is located between the first lens (1) and the screen (4), the screen (4) and the second lens (2) are arranged adjacent to each other, and an air gap between the screen (4) and the second lens (2) is ≥0.1 mm; The combined focal length of the first lens (1) and the second lens (2) is F 12 , 5mm≤F 12 ≤20mm.

11. The optical projection system according to claim 10, characterized in that: The focal length of the first lens (1) is F1, 2mm≤F1≤10mm; The focal length of the second lens (2) is F2, 20mm≤F2≤50mm.

12. The optical projection system according to claim 5, characterized in that: The AR optical machine further comprises a second lens (2) and a third lens (3), the screen (4) and the third lens (3) are arranged adjacent to each other, and the second lens (2) is located between the first lens (1) and the third lens (3), and the air gap between the screen (4) and the third lens (3) is ≥0.1 mm; The combined focal length of the first lens (1), the second lens (2) and the third lens (3) is F 123 , 5mm≤F 123 ≤15mm.

13. The optical projection system according to claim 12, characterized in that: The focal length of the first lens (1) is F1, 1mm≤F1≤5mm; The focal length of the second lens (2) is F2, -10mm≤F2≤-1mm; The focal length of the third lens (3) is F3, 15mm≤F3≤350mm.

14. The optical projection system according to any one of claims 10 to 13, characterized in that: The curvature radius of the surface of the first lens (1) setting the overlapping element is R1, and R1>20mm.

15. The optical projection system according to any one of claims 1 to 13, characterized in that: The total optical length of the AR optical machine is L, 1mm≤L≤6mm.

16. The optical projection system according to any one of claims 1 to 13, characterized in that: The distance from the polarized reflection element (5) to the exit pupil position of the AR optical machine is PD, 0≤PD≤10mm.

17. The optical projection system according to any one of claims 1 to 13, characterized in that: The total focal length of the AR optical machine is F, 2.5mm≤F≤10mm.

18. An AR optical device, characterized in that: include: An optical projection system as claimed in any one of claims 1 to 17.

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