Optical modules and near-eye display devices

Abstract

The embodiments of the present application provide an optical module and a near-eye display device; the optical module is used for an XR optical device, and includes a cemented prism, a lens, and a curved reflective element, wherein the lens is located between the cemented prism and the curved reflective element; the cemented prism includes a first prism and a second prism cemented to each other, and the second prism and the lens are adjacent to and spaced apart; the curved reflective element includes a sixth surface, which is adjacent to the lens, and the sixth surface is a curved surface and a partially reflective surface; the optical module also includes a polarized reflective element and a phase retarder, wherein the polarized reflective element is located between the first prism and the second prism, and the phase retarder is located between the second prism and the lens; the optical module satisfies 0.2≤EFL 15 / EFL6≤4.1,EFL 15 is the total effective focal length of the cemented prism and lens, and EFL6 is the effective focal length of the curved reflective element.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optical imaging technology. More specifically, the embodiments of the present application relate to an optical module and a near-eye display device. Background Art

[0002] With the rise of the metaverse, XR technology has developed rapidly, encompassing VR, AR, and MR technologies. As a core component of XR technology, the performance of near-eye display systems directly impacts the user experience.

[0003] However, existing near-eye display devices still have some problems in the design of optical modules, such as excessive size, poor image quality, and limited field of view. Therefore, how to design an optical module with a small size, high image quality, and a wide field of view has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The purpose of this application is to provide a new technical solution for an optical module and a near-eye display device.

[0005] In a first aspect, the present application provides an optical module. The optical module is used in an XR optical device, and the optical module includes a cemented prism, a lens, and a curved reflective element, wherein the lens is located between the cemented prism and the curved reflective element;

[0006] The cemented prism includes a first prism and a second prism cemented to each other, wherein the second prism and the lens are adjacent to and spaced apart from each other;

[0007] The curved reflective element includes a sixth surface, the sixth surface is disposed adjacent to the lens, and the sixth surface is a curved surface and a partially reflective surface;

[0008] The optical module further includes a polarizing reflective element and a phase retarder, wherein the polarizing reflective element is located between the first prism and the second prism, and the phase retarder is located between the second prism and the lens;

[0009] The optical module satisfies: 0.2≤EFL 15 / EFL6≤4.1; where EFL 15 is the total effective focal length of the cemented prism and the lens, and EFL6 is the effective focal length of the curved reflective element.

[0010] Optionally, the optical module satisfies: 0.96≤EFL 15 / EFL6≤2.16.

[0011] Optionally, the optical module satisfies: 2.1≤EFL 15 / EFL≤6.1; wherein EFL is the effective focal length of the optical module.

[0012] Optionally, the optical module satisfies: 1.04≤EFL6 / EFL≤4.6; wherein EFL is the effective focal length of the optical module.

[0013] Optionally, the lens includes a fourth surface and a fifth surface;

[0014] An air gap is provided between the fourth surface and the second prism, and the phase retarder is provided on the fourth surface.

[0015] Optionally, the fourth surface is a plane and the fifth surface is a curved surface.

[0016] Optionally, the curvature of the fifth surface is C5, the curvature of the sixth surface is C6, and 0.67<C5 / C6≤3.8.

[0017] Optionally, a light splitting element is provided on the sixth surface.

[0018] Optionally, the bonding surface between the first prism and the second prism is a second surface, the second surface is a plane, and an angle θ1 formed between the second surface and the vertical direction is an acute angle;

[0019] The polarized reflective element is disposed on the second surface.

[0020] Optionally, the first prism includes a first surface, and the first surface is a curved surface or a flat surface.

[0021] Optionally, the second prism includes a third surface and a seventh surface;

[0022] The third surface is a plane;

[0023] The seventh surface is the top surface of the second prism, and an angle θ2 formed between the optical axis of the seventh surface and the horizontal direction is an acute angle.

[0024] Optionally, the optical module further includes a display screen, and the display screen is arranged on one side of the seventh surface.

[0025] Optionally, the first surface is a curved surface;

[0026] The centers of the first surface, the fifth surface, and the sixth surface are all located on the same optical axis. The positive directions of the sag heights of the first surface, the fifth surface, and the sixth surface are directions away from the aperture along the optical axis.

[0027] Optionally, the chief ray of the 0-degree field of view coincides with the optical axes of the first surface, the fifth surface, the sixth surface, and the seventh surface.

[0028] In a second aspect, the present application provides a near-eye display device. The near-eye display device includes:

[0029] The beneficial effects of this application are:

[0030] The optical module of the present embodiment comprises two bonded prisms, a lens, and a partially reflective curved reflective element. Optical film materials such as a polarizing reflective element and a phase retarder are incorporated between these optical elements. The phase retarder further optimizes the polarization state of light. Importantly, the reflective surface of the curved reflective element not only reflects light but also exhibits partial reflective properties. This property provides users with a physical see-through experience, allowing them to perceive and interact with the real world while immersing themselves in the virtual world.

[0031] By fully utilizing the principle of total internal reflection and polarization-state folded optical path technology, this application achieves miniaturization and lightweighting of the optical module while ensuring a wide field of view. This design not only improves user wearing comfort, but also maintains excellent imaging quality, providing users with clear visual effects.

[0032] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0034] Figure 1 This is one of the structural diagrams of the optical module provided in an embodiment of the present application;

[0035] Figure 2 The second structural diagram of the optical module provided in the embodiment of the present application;

[0036] Figure 3 for Figure 2 MTF diagram of the optical module shown;

[0037] Figure 4 The third structural diagram of the optical module provided in the embodiment of the present application;

[0038] Figure 5 for Figure 4 MTF diagram of the optical module shown;

[0039] Figure 6This is a fourth structural diagram of the optical module provided in an embodiment of the present application;

[0040] Figure 7 for Figure 6 MTF diagram of the optical module shown;

[0041] Figure 8 The fifth structural diagram of the optical module provided in the embodiment of the present application;

[0042] Figure 9 for Figure 8 MTF diagram of the optical module shown;

[0043] Figure 10 The sixth structural diagram of the optical module provided in the embodiment of the present application;

[0044] Figure 11 for Figure 10 MTF diagram of the optical module shown;

[0045] Figure 12 The seventh structural diagram of the optical module provided in the embodiment of the present application;

[0046] Figure 13 for Figure 12 MTF diagram of the optical module shown;

[0047] Figure 14 The eighth structural diagram of the optical module provided in the embodiment of the present application;

[0048] Figure 15 for Figure 14 MTF diagram of the optical module is shown.

[0049] Description of reference numerals:

[0050] 1. First prism; 2. Second prism; 3. Lens; 4. Curved reflective element; 5. Beam splitter; 6. Phase retarder; 7. Polarized reflective element; 8. Display screen; 9. Protective glass.

[0051] S0, aperture; S1, first surface; S2, second surface; S3, third surface; S4, fourth surface; S5, fifth surface; S6, sixth surface; S7, seventh surface. DETAILED DESCRIPTION

[0052] 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 arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0053] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0054] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0055] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0056] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0057] The optical module and near-eye display device provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0058] According to one embodiment of the present application, an optical module is provided for use in an XR optical device. Figure 1 The optical module includes a cemented prism, a lens 3 and a curved reflective element 4, and the lens 3 is located between the cemented prism and the curved reflective element 4; the cemented prism includes a first prism 1 and a second prism 2 cemented to each other, wherein the second prism 2 and the lens 3 are adjacent to and spaced apart from each other; the curved reflective element 4 includes a sixth surface S6, which is adjacent to the lens 3 and is a curved surface and a partially reflective surface; the optical module also includes a polarized reflective element 7 and a phase retarder 6, the polarized reflective element 7 is located between the first prism 1 and the second prism 2, and the phase retarder 6 is located between the second prism 2 and the lens 3; the optical module satisfies: 0.2≤EFL 15 / EFL6≤4.1; where EFL 15 is the total effective focal length of the cemented prism and the lens 3 , and EFL6 is the effective focal length of the curved reflective element 4 .

[0059] The optical module provided in the embodiments of the present application can be applied to, for example, the field of XR technology, which covers VR technology, AR technology, and MR technology.

[0060] The optical module provided in the embodiments of the present application mainly includes the following key optical components.

[0061] The optical module provided in the embodiment of the present application includes a cemented prism, see Figure 1The cemented prism is composed of a first prism 1 and a second prism 2 cemented together. This design helps to reduce the deviation of the optical path and the increase in the volume of the entire optical module, while improving the utilization rate of light.

[0062] The second prism 2 is located between the first prism 1 and the rear lens 3, that is, the second prism 2 and the lens 3 are adjacent and spaced apart. The surface of the second prism 2, especially the surface adjacent to the lens 3 (i.e. Figure 1 The third surface S3 shown in FIG2 plays a key role in the transmission and reflection of light. Specifically, light can be totally reflected on the third surface S3 of the second prism 2.

[0063] The optical module provided in the embodiment of the present application includes a lens 3, see Figure 1 The lens 3 is located between the cemented prism and the curved reflective element 4 and is used to focus and calibrate the light to ensure that the image can be clearly presented in front of the user. Figure 1 At the aperture S0 shown in .

[0064] The optical module provided in the embodiment of the present application further comprises a curved reflective element 4, wherein the curved reflective element 4 comprises a reflective curved surface. Figure 1 , which is Figure 1 The sixth surface S6 shown in FIG. It should be noted that the sixth surface S6 is not only a reflective curved surface but also a partially reflective surface. This means that it can reflect part of the light to display an image, and also allow part of the light to pass through to achieve a physical see-through function.

[0065] The optical module provided in the embodiment of the present application also includes some optical film materials, such as a polarized reflective element 7 and a phase retarder 6. The polarized reflective element 7 is located between the first prism 1 and the second prism 2, and is used to achieve polarized reflection of light. This helps ensure that light is transmitted along a predetermined path within the prism. The phase retarder 6 is located between the second prism 2 and the lens 3, and is used to adjust the polarization state of light. This helps achieve multiple reflections and transmissions of light, thereby optimizing the optical path.

[0066] The optical module provided in the embodiment of the present application satisfies: 0.2≤EFL 15 / EFL6≤4.1; among them, EFL 15 is the total effective focal length of the cemented prism and the lens 3, and EFL6 is the effective focal length of the curved reflective element 4. This effective focal length ratio range can bring the following technical effects:

[0067] First, optimize the light path: The effective focal length ratio range designed in this application ensures that light, after passing through the cemented prism and the lens 3, can reach the curved reflective element 4 at an appropriate angle and direction. This helps reduce light loss and scattering, thereby improving imaging quality.

[0068] Second, imaging distortion can be controlled by properly constraining EFL 15 The ratio of EFL6 can control imaging distortion to a certain extent. Within this ratio range in the present application, the distortion can be well corrected, making the image clearer.

[0069] Third, improve the field of view: appropriate EFL 15 The 6 / EFL ratio helps achieve high-quality imaging at a wide field of view. This is crucial for XR optical devices such as VR and AR devices, as they need to provide users with a wide field of view to enhance immersion.

[0070] If EFL 15 If the ratio of / EFL6 is too small, such as less than 0.2, it may increase the loss of light during transmission and reduce the imaging quality.

[0071] If EFL 15 If the ratio of EFL6 is too large, for example, greater than 4.1, the light may be excessively diffused after passing through the combination of the cemented prism and the lens 3. This will result in the light being unable to be effectively reflected and focused by the curved reflective element 4, thereby reducing the imaging quality. 15 / EFL6 ratio may limit the size of the field of view, thereby reducing the user's immersion. In addition, too large EFL 15 The / EFL6 ratio will increase the difficulty of aberration correction. If these aberrations cannot be effectively corrected, it will cause problems such as image blur and distortion, further reducing the image quality.

[0072] The optical module of the embodiment of the present application utilizes a hybrid design of a cemented prism, a lens 3 and a curved reflective element 4, as well as total reflection and polarization-folded light paths, so that the entire optical module still has a relatively small volume at a large field of view.

[0073] The optical module of the embodiment of the present application ensures that light can be transmitted and reflected along a predetermined path by precisely designing the positions of various optical components, thereby presenting a clear, high-quality image.

[0074] Due to the partial reflection characteristics of the curved reflective element 4, the optical module of the embodiment of the present application also has a physical perspective function (which can be applied to AR devices), allowing users to perceive the real situation of the surrounding environment while viewing virtual images.

[0075] In addition, the present application improves the utilization rate of light and reduces light loss and interference by optimizing the light path design and the arrangement of various optical components.

[0076] The optical module of the present application ensures that light can pass through each optical element efficiently and reduce unnecessary loss and scattering through a carefully designed light path (for example, the path of light from the display screen 8 to the aperture S0 (human eye) is as follows: seventh surface S7 → third surface S3 → second surface S2 → third surface S3 → fourth surface S4 → fifth surface S5 → sixth surface S6 → fifth surface S5 → fourth surface S4 → third surface S3 → second surface S2 → first surface S1 → aperture S0).

[0077] The sixth surface S6 of the curved reflective element 4 serves as a partial reflective surface, which not only provides a physical see-through function but also further optimizes the reflection angle and direction of light through its curved surface design, thereby helping to reduce aberration and distortion.

[0078] The combination of the polarizing reflective element 7 (located between the first prism 1 and the second prism 2) and the phase retarder 6 (located between the second prism 2 and the lens 3) manages the polarization state of light. This helps reduce polarization loss during light transmission and improves image clarity.

[0079] The phase retarder 6 (e.g., a QWP film) changes the phase of light, ensuring that the light is reflected when it first reaches the polarized reflective element 7 and is transmitted when it reaches the polarized reflective element again after passing through the phase retarder 6 twice. This design helps reduce ghosting and interference, thereby improving imaging quality.

[0080] The optical module provided in the embodiments of the present application has the advantages of a compact structure, good imaging quality, physical perspective function, and efficient light utilization, and is very suitable for optical display application fields such as XR and AR.

[0081] In some examples of this application, the optical module satisfies: 0.96≤EFL 15 / EFL6≤2.16.

[0082] The optical module provided in the embodiment of the present application is preferably: 15 / EFL6 is between 0.96 and 2.16. This range ensures that the light, after passing through the cemented prism and lens, can reach the sixth surface S6 of the curved reflective element 4 at a suitable angle and direction. This design can greatly improve imaging quality.

[0083] By further optimizing EFL 15 / EFL6, distortion can be well corrected, making the image clearer and avoiding image distortion or deformation caused by distortion.

[0084] By further optimizing EFL 15 / EFL6, which helps achieve high-quality imaging with a wide field of view. This is crucial for XR (extended reality) optical devices such as VR (virtual reality) and AR (augmented reality), as they need to provide users with a wide field of view to enhance immersion.

[0085] In addition, the ratio range in this example of the present application ensures high imaging quality while ensuring the miniaturization and lightweight of the optical module.

[0086] Within the ratio range in this example of the present application, the optical module can provide users with a clear, distortion-free, and wide-field-of-view imaging experience, thereby enhancing the user's overall satisfaction and sense of immersion.

[0087] 0.96≤EFL 15 The more preferred ratio range of / EFL6≤2.16 has demonstrated significant technical effects in light path optimization, imaging distortion control, field of view improvement, volume and performance balance, and user experience improvement. It is one of the key parameters for designing high-performance near-eye display optical modules.

[0088] More preferably, EFL 15 / EFL6 is 0.96.

[0089] In some examples of this application, the optical module satisfies: 2.1≤EFL 15 / EFL≤6.1; wherein EFL is the effective focal length of the optical module.

[0090] According to this example of the present application, the total effective focal length EFL of the cemented prism and the lens 3 is 15 The effective focal length EFL of the optical module satisfies 2.1≤EFL 15 / EFL≤6.1; This effective focal length ratio range can bring the following technical effects:

[0091] First, the effective focal length ratio range in this example helps achieve high-quality imaging while maintaining a small optical module size. This is particularly important for XR or AR optical display devices, as they need to minimize size and weight while maintaining performance.

[0092] Second, by reasonably setting EFL 15 The ratio to EFL can optimize the light transmission efficiency in the optical module, which helps to reduce light loss and improve image brightness.

[0093] Third, appropriate EFL 15 The / EFL ratio can enhance the optical stability of the optical module, enabling it to provide stable imaging performance in different environments and usage scenarios.

[0094] If EFL 15 / EFL ratio is too small, which means EFL 15 The total effective focal length of the cemented prism and lens 3 is smaller than the effective focal length EFL of the entire optical module. This may cause the light to not be fully diffused and focused when passing through the optical module, thus affecting the image quality. The image may be blurred, with reduced contrast, and other problems. Smaller EFL 15 The / EFL ratio will also limit the size of the field of view. If the field of view is too small, the user may feel that the field of view is restricted, affecting the sense of immersion.

[0095] If EFL 15 / EFL ratio is too large, EFL 15 Larger relative to the EFL. This may cause the light to be over-focused when passing through the optical module, making the image too clear in some areas and blurry or distorted in other areas. This uneven imaging quality will reduce the user experience. Larger EFL 15 / EFL ratio may increase the difficulty of aberration correction, resulting in a decrease in image quality.

[0096] According to this example of the present application, it is more preferred that 2.94≤EFL 15 / EFL≤4.14. This can further improve imaging quality while ensuring a smaller optical module size.

[0097] According to this example of the present application, it is more preferred that EFL 15 / EFL is 2.94.

[0098] In some examples of the present application, the optical module satisfies: 1.04≤EFL6 / EFL≤4.6; wherein EFL is the effective focal length of the optical module.

[0099] According to this example of the present application, the effective focal length EFL6 of the curved reflective element 4 and the effective focal length EFL of the optical module satisfy 1.04≤EFL6 / EFL≤4.6; this effective focal length ratio range can bring the following technical effects:

[0100] First, the effective focal length ratio range in this example of the present application emphasizes the importance of the curved reflective element 4 in the optical module. By properly setting the ratio of EFL6 to EFL, the performance advantages of the curved reflective element 4 can be fully utilized to improve imaging quality.

[0101] Second, the curved surface design of the curved reflective element 4 helps correct aberrations. Within this ratio range, various aberrations (such as spherical aberration, coma, etc.) can be corrected more effectively, making the image clearer and more accurate.

[0102] When the ratio of EFL6 / EFL is too small, it means that EFL6 (the effective focal length of the curved reflective element 4) is very close to the effective focal length EFL of the entire optical module. This may cause the light to not be fully diffused after passing through the curved reflective element 4, thereby affecting the imaging quality.

[0103] When the EFL6 / EFL ratio is too large, light may be excessively folded after passing through the curved reflective element 4. This results in a longer light transmission path, increasing the likelihood of light loss and aberrations. Specifically, images may appear blurry, distorted, or chromatic aberration. A large EFL6 / EFL ratio may also limit the field of view.

[0104] In summary, by limiting EFL15 / EFL6, EFL 15 The ratio range of / EFL and EFL6 / EFL can optimize the overall performance of the optical module to a certain extent.

[0105] In some examples of this application, see Figure 1 The lens 3 includes a fourth surface S4 and a fifth surface S5; an air gap is provided between the fourth surface S4 and the second prism 2, and the phase retarder 6 is provided on the fourth surface S4.

[0106] The lens 3 includes a fourth surface S4 and a fifth surface S5, which work together to form the desired optical performance. The material and design of the lens 3 are to optimize the transmission and focusing of light to provide high-quality images.

[0107] See also Figure 1 , there is an air gap between the fourth surface S4 of the lens 3 and the third surface S3 (front surface) of the second prism 2. The design of this air gap is very critical, which allows the light to be totally reflected on the third surface S3. Total internal reflection is the phenomenon that when light is emitted from one medium (such as a prism) to another medium (such as air), if the angle of incidence is greater than the critical angle, the light will be completely reflected back to the original medium. In the optical module of the present application, total internal reflection is used to change the propagation path of light to achieve light folding and compact optical design.

[0108] The phase retarder 6 is disposed on the fourth surface S4 of the lens 3. Specifically, the phase retarder is an optical element capable of changing the polarization state of light. In this application, the phase retarder 6 functions to adjust the polarization direction of light to ensure that the light is correctly reflected and transmitted. In optical modules involving polarized light, the precise placement and configuration of the phase retarder is crucial to achieving the desired optical performance.

[0109] By providing air spacers and phase retarder 6, this example can optimize the transmission path and polarization state of light, which helps reduce light loss and aberration, thereby improving imaging quality.

[0110] According to this example of the present application, it is more preferred that 1.92≤EFL6 / EFL≤3.05, which can ensure imaging quality and a large FOV while reducing the volume of the entire optical module.

[0111] According to this example of the present application, it is more preferred that EFL 15 / EFL is 3.05.

[0112] In some examples of this application, see Figure 1 , the fourth surface S4 is a plane, and the fifth surface S5 is a curved surface.

[0113] The fourth surface S4 of the third lens 3 is flat. Flat surfaces are easier to manufacture and process than curved surfaces, which helps reduce production costs and improve production efficiency. Furthermore, as a surface adjacent to the second prism 2, the flat design ensures that light enters the lens 3 in a more stable and controllable manner, helping to reduce light loss and distortion during the incident process.

[0114] The fifth surface S5 of the third lens 3 is curved. This curved surface design allows for more precise adjustment of the focal length of the lens 3. Curved lenses can better correct aberrations, thereby improving image quality. Furthermore, the curved surface design more effectively refracts light, directing it along a predetermined path. This facilitates light folding and a compact optical design while maintaining good image quality.

[0115] The combination of the flat and curved surface designs of the lens 3 of the present application can optimize the transmission and focusing of light, reduce light loss and aberration, and thus improve imaging quality, thus providing users with a clearer visual experience.

[0116] In some examples of this application, see Figure 1 The curvature of the fifth surface S5 is C5, the curvature of the sixth surface S6 is C6, and 0.678≤C5 / C6≤3.8.

[0117] The fifth surface S5 is the curved surface of the lens 3 near the curved reflective element 4. The sixth surface S6 is the curved reflective surface of the curved reflective element 4, near the fifth surface S5. By controlling the curvature ratio of the fifth surface S5 to the sixth surface S6, aberrations in the optical module can be more effectively corrected. This helps ensure that light is focused at the desired position after passing through the lens 3 and the curved reflective element 4, thereby providing a clear, distortion-free image.

[0118] By adjusting the ratio of the curvature C6 of the curved reflective element 4 to the curvature C5 of the lens 3, more efficient light folding can be achieved. This helps reduce the overall size and weight of the system while maintaining imaging quality, making it more suitable for applications in near-eye display devices.

[0119] In some examples of this application, see Figure 1 , a spectroscopic element 5 is provided on the sixth surface S6.

[0120] The light splitting element 5 is, for example, a semi-transparent and semi-reflective film, so that the sixth surface S6 can form a partially reflective surface.

[0121] The sixth surface S6 acts as a partially reflective surface, allowing some external light to enter the optical module of the present application, while reflecting light from the display screen 8 to form a virtual image. In this way, the user can see the real world scene and the virtual image at the same time, realizing AR or MR functions.

[0122] In some examples of this application, see Figure 1 The bonding surface between the first prism 1 and the second prism 2 is the second surface S2, the second surface S2 is a plane, and the angle θ1 between the second surface S2 and the vertical direction is an acute angle; the polarizing reflection element 7 is arranged on the second surface S2.

[0123] By designing the second surface S2 as a plane with an acute angle to the vertical direction and serving as the bonding surface of the two prisms, the light path can be effectively folded. This helps to achieve efficient transmission of light from the display screen 8 to the aperture S0 (human eye) while maintaining the compactness of the optical module.

[0124] It should be noted that the vertical direction in this example of the present application refers to the direction perpendicular to the optical axis of the lens 3.

[0125] The polarizing reflective element 7 is disposed on the second surface S2 and can precisely control the polarization state of light. This is crucial for near-eye display devices that use polarization-folded optical paths, as it helps ensure that light propagates correctly through the optical module and reaches the aperture S0 (the human eye).

[0126] By combining the polarized reflective element 7 with the bonding surface of the prism, the reflection performance can be optimized and the reflectivity of light can be increased, which helps to reduce light loss and improve the imaging quality and brightness of the module.

[0127] Furthermore, by directly placing the polarized reflective element 7 on the bonding surface of the prism, the number of optical elements required in the system can be reduced, which not only simplifies the system structure but also helps reduce production costs.

[0128] In some examples of this application, see Figure 1 The first prism 1 includes a first surface S1, and the first surface S1 is a curved surface or a flat surface.

[0129] In some examples of this application, see Figure 1 The second prism 2 includes a third surface S3 and a seventh surface S7; the third surface S3 is a plane; the seventh surface S7 is the top surface of the second prism 2, and the angle θ2 formed by the optical axis of the seventh surface S7 and the horizontal direction is an acute angle.

[0130] The first surface S1 of the first prism 1 is a curved surface or a flat surface.

[0131] From the perspective of optimizing imaging quality: the curved surface design can more precisely control the propagation path and focal point of light, thereby optimizing imaging quality. The curved surface design enables the first surface S1 to better adapt to incident light at different viewing angles, reducing light scattering and loss within the first prism 1, and improving the viewing angle performance of the optical module.

[0132] Flat designs are easier to process and manufacture than curved designs, which helps reduce production costs. At the same time, flat designs are also easier to ensure machining accuracy and consistency.

[0133] The third surface S3 of the second prism 2 is flat. This planar design enables stable light transmission, reducing light scattering and interference within the prism. This helps maintain light intensity and directionality, improving the imaging quality of the system. The planar design also simplifies the structure of the second prism 2, making it easier to integrate and match with other optical components.

[0134] The seventh surface S7 of the second prism 2 is the top surface and forms an acute angle θ2 with the horizontal direction. The horizontal direction here refers to the optical axis direction of the lens 3.

[0135] The seventh surface S7 serves as the top surface and forms an acute angle θ2 with the horizontal direction, which helps to achieve effective transmission of light from the display screen 8 to the aperture S0 (human eye) while maintaining the compactness of the module.

[0136] In some examples of this application, see Figure 1 The optical module further includes a display screen 8, which is disposed on one side of the seventh surface S7.

[0137] The display screen 8 is disposed on one side of the seventh surface S7 of the second prism 2. This position allows light emitted from the display screen 8 to directly enter the second prism 2, and then be polarized, reflected, and refracted by the combination of the prism and lens, and finally reach the user's eyes.

[0138] Optionally, a protective glass 9 is provided on the light emitting surface of the display screen 8 .

[0139] The display screen 8 is an important component of the optical module, and its display effect directly affects the user experience. The protective glass 9 acts as a protective barrier for the display screen 8, which can resist external damage such as scratches, impacts, and wear, thereby extending the service life of the display screen 8.

[0140] In some examples of the present application, the first surface S1 is a curved surface; the centers of the first surface S1, the fifth surface S5, and the sixth surface S6 are all located on the same optical axis, and the positive direction of the sag of the first surface S1, the fifth surface S5, and the sixth surface S6 is the direction away from the aperture S0 (human eye) along the optical axis.

[0141] The optical module provided in the embodiment of the present application may include three curved surfaces, namely the first surface S1, the fifth surface S5 and the sixth surface S6 mentioned in this example of the present application.

[0142] The positive sagittal direction of the first surface S1, the fifth surface S5, and the sixth surface S6 is along the optical axis, away from the aperture S0. This design helps control the focus position and direction of light. By adjusting the curvature and sagittal direction of each curved surface, the focus position and direction of light can be precisely controlled to meet different imaging requirements.

[0143] In some examples of the present application, the chief ray of the 0-degree field of view coincides with the optical axes of the first surface S1 , the fifth surface S5 , the sixth surface S6 , and the seventh surface S7 .

[0144] According to this example of the present application, during the propagation process, although the light passes through the prism and lens, it always remains in a coaxial optical path, that is, the light always passes through the optical axis of all elements instead of forming an off-axis system.

[0145] The principal ray at a zero-degree field of view coincides with the optical axes of all critical surfaces, ensuring minimal aberration and distortion as the light passes through these surfaces. This design significantly improves image quality, resulting in clearer images. The coaxial optical path design greatly simplifies the optical design and calculation process of the optical module.

[0146] Light always propagates along the optical axis, reducing losses at the edges of prisms and lenses. This helps improve light energy utilization, allowing more light to reach the aperture S0 (the human eye), enhancing the imaging brightness of the optical module.

[0147] The coaxial optical path design simplifies the manufacturing and assembly process of optical components. Optical components can be positioned and fixed more accurately, thereby improving the stability and reliability of the entire optical module.

[0148] According to another embodiment of the present application, a near-eye display device is provided, which includes the optical module as described above.

[0149] The near-eye display device is, for example, an XR device.

[0150] The XR devices include AR devices, VR devices and MR devices.

[0151] The optical module provided by the present application is described in detail below through Examples 1 to 7.

[0152] Example 1

[0153] See also Figure 2 The optical module provided in this embodiment 1 includes a cemented prism, a lens 3 and a curved reflective element 4, and the lens 3 is located between the cemented prism and the curved reflective element 4;

[0154] The cemented prism comprises a first prism 1 and a second prism 2 cemented to each other, wherein the second prism 2 and the lens 3 are adjacent to and spaced apart from each other;

[0155] The curved reflective element 4 includes a sixth surface S6, which is disposed adjacent to the lens 3 and is a curved surface and a partially reflective surface;

[0156] The optical module further includes a polarizing reflective element 7 and a phase retarder 6 , wherein the polarizing reflective element 7 is glued between the first prism 1 and the second prism 2 ;

[0157] The lens 3 includes a fourth surface S4 and a fifth surface S5, the fourth surface S4 is a plane, and the fifth surface S5 is a curved surface; an air gap is provided between the fourth surface S4 and the second prism 2, and the phase retarder 6 is provided on the fourth surface S4;

[0158] The sixth surface S6 is provided with a light splitting element 5;

[0159] The bonding surface between the first prism 1 and the second prism 2 is a second surface S2. The second surface S2 is a plane. The angle θ1 formed between the second surface S2 and the vertical direction is an acute angle. The polarizing reflective element 7 is disposed on the second surface S2.

[0160] The first prism 1 includes a first surface S1, and the first surface S1 is a curved surface;

[0161] The second prism 2 includes a third surface S3 and a seventh surface S7; the third surface S3 is a plane, the seventh surface S7 is the top surface of the second prism 2, and the angle θ2 formed between the optical axis of the seventh surface S7 and the horizontal direction is an acute angle.

[0162] The optical module further includes a display screen 8, which is disposed on one side of the seventh surface S7;

[0163] The centers of the first surface S1, the fifth surface S5, and the sixth surface S6 are all located on the same optical axis, and the positive directions of the sag heights of the first surface S1, the fifth surface S5, and the sixth surface S6 are in the direction away from the aperture S0 along the optical axis;

[0164] The chief ray of the 0-degree field of view coincides with the optical axes of the first surface S1 , the fifth surface S5 , the sixth surface S6 , and the seventh surface S7 .

[0165] The parameters of the optical elements in the optical module provided in this embodiment 1 are shown in Table 1.

[0166] Table 1

[0167]

[0168] For Table 1, see Figure 2 The distance from S0 to S1 is t0, the distance from S1 to S2 is t1, the distance from S2 to S3 is t2, the distance from S3 to S4 is t3, the distance from S4 to S5 is t4, the distance from S5 to S6 is t5, the distance from S3 to S7 is t6, the distance from S7 to S8 is t7, and the distance from S8 to S9 is t8.

[0169] The EFL involved in this embodiment 1 15 / EFL6、EFL 15 For the optical parameter ratios such as / EFL, EFL6 / EFL, C5 / C6, etc., please refer to Table 8 shown after Example 7.

[0170] The MTF graph of an optical module shows its modulation transfer function at different spatial frequencies and is used to evaluate the performance of the optical module. Figure 3 In the low-frequency band (i.e., the area on the left side of the horizontal axis), the MTF values ​​of all curves are close to 1.0, indicating that the optical imaging quality in this area is relatively excellent.

[0171] Example 2

[0172] See also Figure 4 The optical module shown in this embodiment 2 has the same optical architecture as that of embodiment 1, except for the optical parameters in the optical module. For the optical parameters of the optical module provided in this embodiment 2, please refer to Table 2.

[0173] Table 2

[0174]

[0175] For Table 2, see Figure 4 The distance from S0 to S1 is t0, the distance from S1 to S2 is t1, the distance from S2 to S3 is t2, the distance from S3 to S4 is t3, the distance from S4 to S5 is t4, the distance from S5 to S6 is t5, the distance from S3 to S7 is t6, the distance from S7 to S8 is t7, and the distance from S8 to S9 is t8.

[0176] The EFL involved in this embodiment 2 15 / EFL6、EFL 15 For the optical parameter ratios such as / EFL, EFL6 / EFL, C5 / C6, etc., please refer to Table 8 shown after Example 7.

[0177] See also Figure 5 In the low-frequency band (i.e., the area on the left side of the horizontal axis), the MTF values ​​of all curves are close to 1.0, indicating that the optical imaging quality in this area is relatively excellent.

[0178] Example 3

[0179] See also Figure 6 The optical module shown in this embodiment 3 has the same optical architecture as that of embodiment 1, and the difference lies in the optical parameters in the optical module.

[0180] The optical parameters of the optical module provided in this embodiment 3 are shown in Table 3.

[0181] Table 3

[0182]

[0183]

[0184] For Table 3, see Figure 6The distance from S0 to S1 is t0, the distance from S1 to S2 is t1, the distance from S2 to S3 is t2, the distance from S3 to S4 is t3, the distance from S4 to S5 is t4, the distance from S5 to S6 is t5, the distance from S3 to S7 is t6, the distance from S7 to S8 is t7, and the distance from S8 to S9 is t8.

[0185] The EFL involved in this embodiment 3 15 / EFL6、EFL 15 For the optical parameter ratios such as / EFL, EFL6 / EFL, C5 / C6, etc., please refer to Table 8 shown after Example 7.

[0186] See also Figure 7 In the low-frequency band (i.e., the area on the left side of the horizontal axis), the MTF values ​​of all curves are close to 1.0, indicating that the optical imaging quality in this area is relatively excellent.

[0187] Example 4

[0188] See also Figure 8 The optical module shown in this embodiment 4 has the same optical architecture as that of embodiment 1, except for the optical parameters in the optical module. Please refer to Table 4 for the optical parameters of the optical module provided in this embodiment 4.

[0189] Table 4

[0190]

[0191] For Table 4, see Figure 8 The distance from S0 to S1 is t0, the distance from S1 to S2 is t1, the distance from S2 to S3 is t2, the distance from S3 to S4 is t3, the distance from S4 to S5 is t4, the distance from S5 to S6 is t5, the distance from S3 to S7 is t6, the distance from S7 to S8 is t7, and the distance from S8 to S9 is t8.

[0192] The EFL involved in this embodiment 4 15 / EFL6、EFL 15 For the optical parameter ratios such as / EFL, EFL6 / EFL, C5 / C6, etc., please refer to Table 8 shown after Example 7.

[0193] See also Figure 9 In the low-frequency band (i.e., the area on the left side of the horizontal axis), the MTF values ​​of all curves are close to 1.0, indicating that the optical imaging quality in this area is relatively excellent.

[0194] Example 5

[0195] See also Figure 10 The optical module shown in this embodiment 5 has an optical architecture that is the same as that of embodiment 1, and the difference lies in the optical parameters in the optical module. Please refer to Table 5 for the optical parameters of the optical module provided in this embodiment 5.

[0196] Table 5

[0197]

[0198] For Table 5, see Figure 10 The distance from S0 to S1 is t0, the distance from S1 to S2 is t1, the distance from S2 to S3 is t2, the distance from S3 to S4 is t3, the distance from S4 to S5 is t4, the distance from S5 to S6 is t5, the distance from S3 to S7 is t6, the distance from S7 to S8 is t7, and the distance from S8 to S9 is t8.

[0199] The EFL involved in this embodiment 5 15 / EFL6、EFL 15 For the optical parameter ratios such as / EFL, EFL6 / EFL, C5 / C6, etc., please refer to Table 8 shown after Example 7.

[0200] See also Figure 11 In the low-frequency band (i.e., the area on the left side of the horizontal axis), the MTF values ​​of all curves are close to 1.0, indicating that the optical imaging quality in this area is relatively excellent.

[0201] Example 6

[0202] See also Figure 12 The optical module shown in this embodiment 6 has the same optical architecture as that of embodiment 1, except for the optical parameters in the optical module. For the optical parameters of the optical module provided in this embodiment 6, please refer to Table 6.

[0203] Table 6

[0204]

[0205] For Table 6, see Figure 12 The distance from S0 to S1 is t0, the distance from S1 to S2 is t1, the distance from S2 to S3 is t2, the distance from S3 to S4 is t3, the distance from S4 to S5 is t4, the distance from S5 to S6 is t5, the distance from S3 to S7 is t6, the distance from S7 to S8 is t7, and the distance from S8 to S9 is t8.

[0206] The EFL involved in this embodiment 6 15 / EFL6、EFL 15 For the optical parameter ratios such as / EFL, EFL6 / EFL, C5 / C6, etc., please refer to Table 8 shown after Example 7.

[0207] See also Figure 13 In the low-frequency band (i.e., the area on the left side of the horizontal axis), the MTF values ​​of all curves are close to 1.0, indicating that the optical imaging quality in this area is relatively excellent.

[0208] Example 7

[0209] See also Figure 14 The optical module shown in this embodiment 7 has the same optical architecture as that of embodiment 1, except for the optical parameters in the optical module. For the optical parameters of the optical module provided in this embodiment 7, please refer to Table 7.

[0210] Table 7

[0211]

[0212]

[0213] For Table 7, see Figure 15 The distance from S0 to S1 is t0, the distance from S1 to S2 is t1, the distance from S2 to S3 is t2, the distance from S3 to S4 is t3, the distance from S4 to S5 is t4, the distance from S5 to S6 is t5, the distance from S3 to S7 is t6, the distance from S7 to S8 is t7, and the distance from S8 to S9 is t8.

[0214] The EFL involved in this embodiment 7 15 / EFL6、EFL 15 For the optical parameter ratios such as / EFL, EFL6 / EFL, C5 / C6, etc., please refer to Table 8 shown after Example 7.

[0215] See also Figure 15 In the low-frequency band (i.e., the area on the left side of the horizontal axis), the MTF values ​​of all curves are close to 1.0, indicating that the optical imaging quality in this area is relatively excellent.

[0216] Table 8 Parameters of Examples 1 to 7

[0217] <![CDATA[EFL 15 ]]> <![CDATA[EFL6]]> EFL <![CDATA[EFL 15 / EFL6]]> <![CDATA[EFL 15 / EFL]]> Example 1 4.37E+01 4.55E+01 1.49E+01 9.60E-01 2.94E+00 Example 2 4.51E+01 4.31E+01 1.49E+01 1.05E+00 3.03E+00 Example 3 5.07E+01 3.64E+01 1.50E+01 1.39E+00 3.38E+00 Example 4 6.16E+01 2.86E+01 1.49E+01 2.16E+00 4.14E+00 Example 5 9.02E+01 2.22E+01 1.49E+01 4.05E+00 6.04E+00 Example 6 3.77E+01 6.86E+01 1.49E+01 5.49E-01 2.53E+00 Example 7 3.27E+01 1.55E+02 1.49E+01 2.10E-01 2.19E+00 min 0.2104291 2.1891340 max 4.0521290 6.0397300

[0218] 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.

[0219] 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 for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above examples 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 module for XR optical equipment, characterized in that: It comprises a cemented prism, a lens (3) and a curved reflective element (4), wherein the lens (3) is located between the cemented prism and the curved reflective element (4); The glued prism comprises a first prism (1) and a second prism (2) glued to each other, wherein the second prism (2) and the lens (3) are adjacent to each other and are spaced apart. The curved reflective element (4) comprises a sixth surface (S6), the sixth surface (S6) is arranged adjacent to the lens (3), and the sixth surface (S6) is a curved surface and a partially reflective surface; The optical module further comprises a polarized reflective element (7) and a phase retarder (6), wherein the polarized reflective element (7) is located between the first prism (1) and the second prism (2), and the phase retarder (6) is located between the second prism (2) and the lens (3); The optical module satisfies: 0.2≤EFL 15 / EFL6≤4.1; where EFL 15 is the total effective focal length of the cemented prism and the lens (3), and EFL6 is the effective focal length of the curved reflective element (4).

2. The optical module according to claim 1, wherein: The optical module satisfies: 0.96≤EFL 15 / EFL6≤2.

16.

3. The optical module according to claim 1, wherein: The optical module satisfies: 2.1≤EFL 15 / EFL≤6.1; wherein EFL is the effective focal length of the optical module.

4. The optical module according to claim 1, wherein: The optical module satisfies: 1.04≤EFL6 / EFL≤4.6; wherein EFL is the effective focal length of the optical module.

5. The optical module according to any one of claims 1 to 4, characterized in that: The lens (3) includes a fourth surface (S4) and a fifth surface (S5); An air gap is provided between the fourth surface (S4) and the second prism (2), and the phase retarder (6) is provided on the fourth surface (S4).

6. The optical module according to claim 5, wherein: The fourth surface (S4) is a plane, and the fifth surface (S5) is a curved surface.

7. The optical module according to claim 6, wherein: The curvature of the fifth surface (S5) is C5, the curvature of the sixth surface (S6) is C6, and 0.67<C5 / C6≤3.

8.

8. The optical module according to claim 7, wherein: A light splitting element (5) is provided on the sixth surface (S6).

9. The optical module according to claim 7, wherein: The bonding surface between the first prism (1) and the second prism (2) is a second surface (S2), the second surface (S2) is a plane, and the angle θ1 formed between the second surface (S2) and the vertical direction is an acute angle; The polarized reflective element (7) is arranged on the second surface (S2).

10. The optical module according to claim 9, wherein: The first prism (1) comprises a first surface (S1), and the first surface (S1) is a curved surface or a flat surface.

11. The optical module according to claim 10, wherein: The second prism (2) includes a third surface (S3) and a seventh surface (S7); The third surface (S3) is a plane; The seventh surface (S7) is the top surface of the second prism (2), and an angle θ2 formed between the optical axis of the seventh surface (S7) and the horizontal direction is an acute angle.

12. The optical module according to claim 11, wherein: The optical module further comprises a display screen (8), and the display screen (8) is arranged on one side of the seventh surface (S7).

13. The optical module according to claim 12, wherein: The first surface (S1) is a curved surface; The centers of the first surface (S1), the fifth surface (S5) and the sixth surface (S6) are all located on the same optical axis, and the positive direction of the sag height of the first surface (S1), the fifth surface (S5) and the sixth surface (S6) is the direction away from the aperture (S0) along the optical axis.

14. The optical module according to claim 13, wherein: The chief ray of the 0-degree field of view coincides with the optical axes of the first surface (S1), the fifth surface (S5), the sixth surface (S6) and the seventh surface (S7).

15. A near-eye display device, characterized in that: include: The optical module according to any one of claims 1 to 14.

Images