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 first lens and a second lens, the first lens is located between the cemented prism and the second lens; the cemented prism includes a first prism, a second prism and a polarizing reflective element cemented between the two prisms; the first lens includes a fourth surface and a fifth surface, the fourth surface and the second prism are adjacent and spaced apart; the second lens includes a sixth surface and a seventh surface, the seventh surface is away from the first lens, and the seventh surface is a partially reflecting surface; a phase retarder is provided on the fourth surface or the sixth surface; the optical module satisfies 1.9≤EFL 15 / EFL≤5.4,EFL 15 is the total effective focal length of the cemented prism and the first lens, and EFL is the effective focal length of the optical module.

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 first lens, and a second lens, wherein the first lens is located between the cemented prism and the second lens;

[0006] The cemented prism includes a first prism, a second prism, and a polarizing reflective element cemented between the two prisms;

[0007] The first lens includes a fourth surface and a fifth surface, and the fourth surface and the second prism are adjacent to and spaced apart from each other;

[0008] The second lens includes a sixth surface and a seventh surface, the seventh surface is away from the first lens, and the seventh surface is a partially reflective surface;

[0009] A phase retarder is provided on the fourth surface or the sixth surface;

[0010] The optical module satisfies: 1.9≤EFL 15 / EFL≤5.4; where EFL 15 is the total effective focal length of the cemented prism and the first lens, and EFL is the effective focal length of the optical module.

[0011] Optionally, the optical module satisfies: 1.5≤EFL 67 / EFL≤51.4; among which, EFL 67 It is the effective focal length of light incident from the sixth surface, reflected by the seventh surface, and then emitted from the sixth surface.

[0012] Optionally, the optical module satisfies: 1.78≤EFL 67 / EFL≤7.32.

[0013] Optionally, the optical module satisfies: 0≤EFL 45 / EFL 67 ≤3.6; among them, EFL 45 is the effective focal length of light incident from the fourth surface and emitted from the fifth surface.

[0014] Optionally, a curvature of the fifth surface is CV5, a curvature of the seventh surface is CV7, and 1.5≤CV5 / CV7≤4.

[0015] Optionally, the curvature of the sixth surface is CV6, the curvature of the seventh surface is CV7, and 0≤CV6 / CV7≤2.9.

[0016] Optionally, the first prism includes a first surface and a second surface, wherein the second surface is a bonding surface where the first prism and the second prism are bonded to each other, and the polarized reflective element is disposed on the second surface;

[0017] The curvature of the first surface is CV1, the curvature of the seventh surface is CV7, and 0≤|CV1 / CV7|≤0.4.

[0018] Optionally, the first surface is a curved surface or a flat surface, and the second surface is a flat surface.

[0019] Optionally, an angle θ1 formed between the second surface and the vertical direction is an acute angle.

[0020] Optionally, the second prism further includes a third surface and an eighth surface;

[0021] An air gap is provided between the third surface and the fourth surface, and the third surface is a plane;

[0022] The eighth surface is the top surface of the second prism, and an angle θ2 formed between the optical axis of the eighth surface and the horizontal direction is an acute angle.

[0023] Optionally, the optical module further includes a display screen, and the display screen is arranged on one side of the eighth surface.

[0024] Optionally, the fourth surface is a plane and the fifth surface is a curved surface.

[0025] Optionally, the sixth surface is a plane, and the seventh surface is a plane or a curved surface.

[0026] Optionally, the optical module includes at most 4 curved surfaces.

[0027] Optionally, the centers of the first surface, the fifth surface, the sixth surface and the seventh surface are all located on the same optical axis, and the positive direction of the sagittal height of the first surface, the fifth surface, the sixth surface and the seventh surface is the direction away from the human eye along the optical axis.

[0028] Optionally, the chief ray of the 0-degree field of view coincides with the optical axes of the fifth surface, the sixth surface, the seventh surface, and the eighth surface.

[0029] In a second aspect, the present application provides a near-eye display device, which includes the optical module as described in the first aspect.

[0030] The beneficial effects of this application are:

[0031] An embodiment of the present application provides an optical module, which is mainly used in near-eye display devices, particularly in the field of XR / AR (mixed reality / augmented display) technology. Through optical parameter design and optical component combination, it achieves improved imaging quality while maintaining a small volume.

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

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

[0041] Figure 8 This is a fifth structural diagram of the optical module provided in an 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 is shown.

[0047] Description of reference numerals:

[0048] 1. First prism; 2. Second prism; 3. First lens; 4. Second lens; 5. Beam splitter; 6. Phase retarder; 7. Polarized reflective element; 8. Display screen; 9. Protective glass.

[0049] S0, human eye; S1, first surface; S2, second surface; S3, third surface; S4, fourth surface; S5, fifth surface; S6, sixth surface; S7, seventh surface. DETAILED DESCRIPTION

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] According to one embodiment of the present application, an optical module is provided. Figure 1 The optical module includes a cemented prism, a first lens 3 and a second lens 4, and the first lens 3 is located between the cemented prism and the second lens 4; the cemented prism includes a first prism 1, a second prism 2 and a polarizing reflection element 7 cemented between the two prisms; the first lens 3 includes a fourth surface S4 and a fifth surface S5, and the fourth surface S4 is adjacent to and spaced from the second prism 2; the second lens 4 includes a sixth surface S6 and a seventh surface S7, and the seventh surface S7 is away from the first lens 3, and the seventh surface S7 is a partially reflecting surface; a phase retarder 6 is provided on the fourth surface S4 or the sixth surface S6; the optical module satisfies: 1.9≤EFL 15 / EFL≤5.4; where EFL 15 is the total effective focal length of the cemented prism and the first lens 3, and EFL is the effective focal length of the optical module.

[0057] The optical module provided in the embodiments of the present application is mainly used in near-eye display devices, and is particularly suitable for fields such as XR (mixed reality or augmented display) technology. XR technology covers VR technology, AR technology, and MR technology.

[0058] The optical module provided in the embodiment of the present application includes a cemented prism, which is mainly composed of a first prism 1, a second prism 2, and a polarizing reflective element 7 cemented therebetween. These three optical elements are tightly cemented together to form an integrated optical element.

[0059] The polarized reflective element 7 is used to achieve polarized reflection of light. Specifically, the polarized reflective element 7 can ensure that the light is reflected when it first arrives and is transmitted when it arrives again after passing through the phase retarder 6 (such as a quarter wave plate) twice.

[0060] The polarized reflective element 7 is a key component in the optical module, and works together with other optical elements such as two prisms, two lenses, and a phase retarder 6. The synergistic effect of these optical elements enables the module to maintain a small size and good imaging quality at a large field of view.

[0061] The optical module of the embodiment of the present application further includes two lenses, namely a first lens 3 and a second lens 4 ; wherein the first lens 3 is disposed adjacent to the cemented prism, and the second lens 4 is disposed adjacent to the first lens 3 .

[0062] Regarding the first lens 3, specifically:

[0063] See also Figure 1 The first lens 3 includes a fourth surface S4 and a fifth surface S5, which together determine the optical performance of the first lens 3. The main function of the first lens 3 is to focus the light from the cemented prism to ensure that the light can continue to be projected onto the second lens 4.

[0064] Regarding the second lens 4, specifically:

[0065] Please continue to see Figure 1 The second lens 4 has a sixth surface S6 and a seventh surface S7, wherein the sixth surface S6 is adjacent to the fifth surface S5 of the first lens 3, and the seventh surface S7 is a partially reflective surface. The partially reflective property of the seventh surface S7 allows some light to pass through while reflecting some light. For example, a semi-transparent and semi-reflective film can be provided on the seventh surface S7 to impart both partially reflective and transmissive properties to the seventh surface S7.

[0066] The optical module of the present application further includes a phase retarder 6 , which is disposed on the fourth surface S4 or the sixth surface S6 , which means that it is located on the front surface of the first lens 3 or the front surface of the second lens 4 .

[0067] The phase retarder 6, for example, a quarter-wave plate (QWP), can be used to change the polarization state of light. In the present application, the phase retarder 6 works together with the polarizing reflective element 7 to achieve polarized reflection and transmission of light. When light first reaches the polarizing reflective element 7, it is reflected. The light then passes through the phase retarder 6 twice, causing its polarization state to change. When it reaches the polarizing reflective element 7 a second time, the light is transmitted rather than reflected again due to the change in polarization state.

[0068] By controlling the polarization state of light, the phase retarder 6 helps achieve the correct folding and transmission of light in the optical module. This is crucial for maintaining the imaging quality of the optical module, reducing stray light, and ensuring that users can see clear, undistorted images.

[0069] In the present application, the phase retarder 6 is designed to be directly arranged on the fourth surface S4 or the sixth surface S6. This arrangement makes the optical module compact and stable, and can achieve a large field of view and good imaging quality while maintaining a small volume.

[0070] In the optical module provided in the embodiment of the present application, EFL is also described. 15 The ratio between (the total effective focal length of the cemented prism and the first lens 3) and EFL (the effective focal length of the optical module of the present application), that is, 1.9≤EFL 15 / EFL≤5.4. This effective focal length ratio is crucial to ensuring the optical module has excellent optical performance.

[0071] Specifically, 1.9≤EFL 15 / EFL≤5.4 describes the ratio of the cemented prism and the first lens 3 (EFL 15 ) relative to the focusing capability of the entire optical module (EFL). By controlling this ratio, a larger field of view can be achieved while maintaining a small optical module size, enhancing user immersion and comfort. Furthermore, this ratio helps ensure that light maintains good convergence performance after passing through the prism and first lens 3, forming a clear, distortion-free image at the human eye S0.

[0072] According to the 1.9≤EFL described in this application 15 / EFL≤5.4, EFL 15 The lower limit of / EFL is 1.9, which ensures that EFL 15 It will not be much smaller than EFL, thus avoiding excessive focusing of light after passing through the cemented prism and the first lens 3. The upper limit of this ratio is 5.4, which limits EFL 15 It will not be much larger than the EFL, preventing the light from diverging excessively after passing through these components.

[0073] The appropriate effective focal length ratio range provided in this application helps maintain the imaging quality of the optical module across the entire field of view. If this ratio is too small, the image in the center of the field of view may be too sharp while the image in the edge of the field of view may be distorted. If the ratio is too large, the image in the entire field of view may appear blurry.

[0074] In summary, the effective focal length ratio shown in the embodiment of the present application is 1.9≤EFL 15 / EFL≤5.4 is a critical optical parameter when designing optical modules. By precisely controlling this ratio, we can ensure that the optical module provides high-quality imaging while maintaining a small size.

[0075] Furthermore, 2.21≤EFL15 / EFL≤4.34. By setting EFL 15 Controlling the ratio of α / EFL within this preferred range ensures that light maintains good convergence performance after passing through the cemented prism and the first lens 3, reducing aberrations and distortion. This helps form a clear, distortion-free image at the human eye, enhancing the user's visual experience. This range achieves a larger field of view while maintaining a small optical module size, which can enhance the user's sense of immersion. The smaller size helps achieve lightweight and miniaturization of near-eye display devices, improving wearing comfort.

[0076] Optimized EFL 15 The / EFL range helps reduce light loss during transmission and improves light energy utilization, which means more light can reach the human eye and enhance image brightness.

[0077] In summary, 2.21≤EFL 15 The design range of / EFL≤4.34 plays a vital role in the design of optical modules. It not only optimizes imaging quality, but also balances the field of view and volume, improves light energy utilization, and ultimately enhances user experience.

[0078] An embodiment of the present application provides an optical module, which is mainly used in near-eye display devices, particularly in the field of XR (mixed reality or augmented display) technology. Through optical parameter design and optical component combination, it achieves improved imaging quality while maintaining a small volume.

[0079] In some examples of this application, the optical module satisfies: 1.5≤EFL 67 / EFL≤51.4; among which, EFL 67 It is the effective focal length of light incident from the sixth surface S6, reflected from the seventh surface S7, and then emitted from the sixth surface S6.

[0080] Among them, EFL 67 is the effective focal length of light incident on the sixth surface S6 of the second lens 4, reflected by the seventh surface S7, and then emitted from the sixth surface S6 (the light is folded in the second lens 4). This light transmission also involves the special design of one surface of the second lens 4, namely, the seventh surface S7 is designed to be a partially reflective surface.

[0081] The optical module provided by the present application includes a cemented prism (the cemented prism is formed by cementing a first prism 1 and a second prism 2 and includes a polarizing reflective element 7), a first lens 3 and a second lens 4. The first lens 3 is located between the cemented prism and the second lens 4, and the sixth surface S6 and the seventh surface S7 are the front and back surfaces of the second lens 4, respectively. Figure 1 .

[0082] The analysis of the effective focal length ratio proposed in this example of the present application is as follows:

[0083] EFL 67 The ratio / EFL reflects the relative relationship between the focusing ability of light passing through a specific path (sixth surface S6 → seventh surface S7 → sixth surface S6) inside the second lens 4 and the focusing ability of the entire optical module. From the ratio range in this example of the present application:

[0084] When EFL 67 When / EFL is close to or greater than 1.5, the second lens 4 plays a relatively important role in the optical module. In particular, when achieving the superimposed display of physical perspective and virtual images, the second lens 4 can effectively adjust the light path and focus performance, ensuring that the user can see a clear virtual image while also being aware of the external environment. This lower limit ensures that the entire optical module provides a sufficient field of view and image quality without causing image distortion or limiting the field of view due to excessive action of the second lens 4.

[0085] When EFL 67 When / EFL is close to or greater than 5.14, the upper limit is set to prevent the second lens 4 from excessively refraction and reflection of light, which could disrupt the overall imaging effect of the optical module. By setting this upper limit, the optical module can achieve good imaging quality and user experience while maintaining a small size and weight.

[0086] According to this example of the present application, by precisely controlling the EFL 67 The ratio range of 0.5 / EFL can optimize the imaging quality of the optical module under different fields of view. This helps reduce image distortion and improve image clarity, thereby providing a better visual experience.

[0087] In augmented reality (AR) applications, by properly designing EFL 67 The ratio of / EFL can ensure that the optical module provided in this application can accurately superimpose virtual images on the real-world view, thereby providing a realistic and natural augmented reality experience.

[0088] The effective focal length ratio provided in this example of the present application helps achieve a compact design of the optical module while maintaining high-quality imaging. This is particularly important for near-eye display devices that require high integration, such as smart glasses.

[0089] In some examples of this application, the optical module satisfies: 1.78≤EFL 67 / EFL≤7.32.

[0090] By incorporating EFL 67 Controlling the / EFL within this range in this example ensures that light maintains good focusing capability after undergoing specific reflection and refraction paths within the second lens 4. This helps reduce light loss and distortion during transmission, improving imaging quality.

[0091] For example, in augmented reality (AR) or mixed reality (MR) applications, the optical module needs to process both virtual images and real-world light. This range of design in this example of the present application helps ensure that virtual images can be accurately superimposed on the real-world view while maintaining clarity and contrast between the two, thereby enhancing the user's immersion and sense of reality.

[0092] In addition, this ratio range in this example of the present application can ensure that the imaging quality does not decrease significantly while maintaining a larger field of view, thereby meeting the user's demand for high-quality visual experience.

[0093] In some examples of this application, the optical module satisfies: 0≤EFL 45 / EFL 67 ≤3.6; among them, EFL 45 It is the effective focal length of light incident from the fourth surface S4 and emitted from the fifth surface S5.

[0094] EFL 45 It refers to the effective focal length of light entering from the fourth surface S4 of the first lens 3 and exiting from its fifth surface S5, that is, the effective focal length of the first lens 3. Therefore, this involves the optical design of the first lens 3, especially the surface shape and material selection of its fourth surface S4 and fifth surface S5.

[0095] EFL 67 This refers to the effective focal length of light entering the sixth surface S6 of the second lens 4, reflecting from the seventh surface S7, and then exiting from the sixth surface S6. This reflects the optical design of the second lens 4. The seventh surface S7 acts as a partially reflective surface, allowing light to be reflected within the second lens 4.

[0096] The optical module includes a cemented prism (composed of a first prism 1 and a second prism 2, with a polarizing reflective element 7 sandwiched between them), a first lens 3 and a second lens 4. These components work together to achieve transmission, polarization and focusing of light.

[0097] Regarding the effective focal length ratio mentioned in this example of this application:

[0098] EFL 45 / EFL 67This ratio reflects the relative relationship between the focusing powers of light passing through different paths inside the first lens 3 (fourth surface S4→fifth surface S5) and inside the second lens 4 (sixth surface S6→seventh surface S7→sixth surface S6).

[0099] When EFL 45 / EFL 67 When it is close to 0, it means EFL 45 Relative to EFL 67 The first lens 3 has a relatively weak refraction effect on light in the entire optical module. This may be because the first lens 3 mainly plays the role of adjusting the direction of light rather than strongly focusing the light.

[0100] The upper limit is set to ensure that the refractive effect of the first lens 3 is not too strong, thereby avoiding adverse effects on the overall imaging effect of the optical module. 45 / EFL 67 If the value exceeds 3.6, the first lens 3 may refract light excessively, resulting in virtual image distortion or a limited field of view. By setting this upper limit, the interaction between the first lens 3 and the second lens 4 can be kept within a reasonable range, thereby achieving good imaging quality and user experience.

[0101] According to the ratio range of the effective focal length provided in this example of the present application, by reasonably controlling the EFL 45 with EFL 67 The ratio between the first lens 3 and the second lens 4 ensures that light maintains good convergence performance after passing through the first lens 3 and the second lens 4, thereby forming a clear, distortion-free image at the human eye S0. In addition, while ensuring image quality, by adjusting the refraction and reflection of the first lens 3 and the second lens 4, the physical perspective effect can be enhanced, allowing users to more naturally perceive the superposition of the external environment and the virtual image.

[0102] Excellent optical performance and clear imaging quality can enhance users' immersion and comfort in application scenarios such as XR / AR.

[0103] Furthermore, the optical module satisfies: 0.302≤EFL 45 / EFL 67 ≤2.52. By setting EFL 45 / EFL 67 Controlling the ratio within this range can optimize the light transmission path within the optical module. An appropriate ratio ensures that light can be transmitted along the intended path when passing through the first lens 3 and the second lens 4, reducing unnecessary refraction and reflection, thereby improving imaging quality.

[0104] EFL 45 It mainly affects the imaging quality of the optical module in the central field of view, while EFL 67 It is closely related to the light transmission and imaging within the entire field of view. 45 / EFL 67 The ratio is set between 0.302 and 2.52, which can ensure that the imaging quality of the central field of view will not be significantly reduced while maintaining a large field of view angle, achieving a good balance between field of view angle and imaging quality.

[0105] For near-eye display devices, imaging quality and field of view are key factors that directly affect user experience. 45 / EFL 67 The ratio can provide high-quality imaging effects while ensuring a larger field of view, thereby enhancing the user's immersion and comfort.

[0106] In some examples of the present application, a curvature of the fifth surface S5 is CV5, a curvature of the seventh surface S7 is CV7, and 1.5≤CV5 / CV7≤4.

[0107] Wherein, CV5 represents the curvature of the fifth surface S5 of the first lens 3, and CV7 represents the curvature of the seventh surface S7 of the second lens 4. It should be noted that curvature is an important parameter that describes the degree of curvature of the lens surface and directly affects the focusing and imaging characteristics of light.

[0108] The ratio CV5 / CV7 reflects the relative curvature relationship between the fifth surface S5 of the first lens 3 and the seventh surface S7 of the second lens 4. This effective focal length ratio range is crucial for controlling the focus, polarization, and transmission path of light.

[0109] When CV5 / CV7 is close to or greater than 1.5, the curvature of the fifth surface S5 is greater than that of the seventh surface S7. This means that the fifth surface S5 refracts light more strongly, helping to more accurately direct light to the eye, thereby improving imaging quality. When designing an optical module, a larger curvature of the fifth surface S5 can compensate for aberrations in other optical components, resulting in superior imaging performance for the entire system.

[0110] The upper limit is set to prevent excessive curvature of the fifth surface S5, which could cause excessive refraction or distortion of light as it passes through it. If CV5 / CV7 exceeds 4, the fifth surface S5 could adversely affect light, reducing imaging quality. By setting this upper limit, the curvature relationship between the fifth surface S5 and the sixth surface S7 remains within a reasonable range, thereby achieving good imaging effects and a good user experience.

[0111] The effective focal length ratio provided in this example of this application helps optimize image quality. Specifically, by precisely controlling the CV5 / CV7 ratio range, the optical module's imaging quality can be optimized under different fields of view and lighting conditions. This helps reduce image distortion and improve image clarity, thereby providing a superior visual experience.

[0112] Furthermore, the optical module satisfies the following condition: 1.89 ≤ CV5 / CV7 ≤ 3.67. By controlling the ratio of the curvature CV5 of the fifth surface S5 of the first lens 3 to the curvature CV7 of the seventh surface S7 of the second lens 4 within this range, the imaging quality of the optical module can be effectively optimized. A suitable curvature ratio helps reduce aberrations and distortions during light transmission, resulting in clearer and more accurate imaging. In addition, by adjusting the ratio of CV5 to CV7, the curvature combination that best suits the current application scenario can be found within this range, thereby meeting diverse needs.

[0113] In some examples of the present application, the curvature of the sixth surface S6 is CV6, the curvature of the seventh surface S7 is CV7, and 0≤CV6 / CV7≤2.9.

[0114] The ratio CV6 / CV7 reflects the relative relationship in curvature between the two surfaces of the second lens 4, ie, the sixth surface S6 and the seventh surface S7.

[0115] When CV6 / CV7 approaches 0, the curvature of the sixth surface S6 is very small relative to the curvature of the seventh surface S7, potentially even approaching a plane. This design may be used to reduce the refraction of light by the sixth surface S6, allowing it to rely more on the reflection of S7 for light guidance and imaging. In certain application scenarios, such as when emphasizing physical perspective, a smaller curvature of the sixth surface S6 is more advantageous because it can reduce interference with the virtual image while maintaining a better perception of the external environment.

[0116] The upper limit is set to prevent the curvature of the sixth surface S6 from being too large, which could cause excessive refraction or distortion of light passing through it. If CV6 / CV7 exceeds 2.9, the sixth surface S6 could adversely affect light, reducing imaging quality or interfering with the physical perspective effect. By setting this upper limit, the curvature relationship between the sixth surface S6 and the seventh surface S7 remains within a reasonable range, thereby achieving a good imaging effect and user experience.

[0117] It should be noted that, based on the two examples above, the ratio range of 1.5 ≤ CV5 / CV7 ≤ 4 helps optimize the optical module's imaging quality, enhance light focusing capabilities, and improve its stability. By properly designing the curvature ratio of CV5 to CV7, consistent focusing characteristics can be ensured when light passes through the first lens 3 and the second lens 4, providing a high-quality visual experience.

[0118] In the case of a combination of 0≤CV6 / CV7≤2.9 and the CV5 / CV7 ratio, that is, when both ratio ranges are met simultaneously, the overall performance of the optical module can be further optimized. By controlling the curvature ratio of the three surfaces (fifth surface S5, sixth surface S6, and seventh surface S7), more efficient light transmission, more accurate focusing, and better imaging quality can be achieved. This helps to improve the overall performance and user experience of near-eye display devices.

[0119] Furthermore, the optical module satisfies the following conditions: 0.454 ≤ CV6 / CV7 ≤ 2.34. Controlling the ratio of the curvature CV6 of the sixth surface S6 of the second lens 4 to the curvature CV7 of the seventh surface S6 within this range helps optimize the light transmission path and focusing effect within the second lens 4. An appropriate curvature ratio ensures that light maintains a suitable refraction angle and focus position when passing through the sixth and seventh surfaces S6 and S7, thereby improving imaging quality. A reasonable CV6 / CV7 ratio design can reduce aberrations and distortion caused by curvature mismatch.

[0120] In some examples of this application, see Figure 1 The first prism 1 includes a first surface S1 and a second surface S2, wherein the second surface S2 is a bonding surface where the first prism 1 and the second prism 2 are bonded to each other, and the polarizing reflection element 7 is arranged on the second surface S2; the curvature of the first surface S1 is CV1, the curvature of the seventh surface S7 is CV7, and 0≤|CV1 / CV7|≤0.4.

[0121] According to this example of the present application, the prism structure is specifically as follows:

[0122] See also Figure 1 The first prism 1 includes a first surface S1 and a second surface S2. The second surface S2 is the bonding surface between the first prism 1 and the second prism 2, and the polarizing reflective element 7 is disposed on this surface. The seventh surface S7 is a surface of the second lens 4, which is a partially reflective surface and has a specific curvature CV7.

[0123] The ratio 0≤|CV1 / CV7|≤0.4 indicates that the absolute value of CV1 will not exceed 0.4 times the absolute value of CV7. This means that the curvature of the first surface S1 is smaller than that of the seventh surface S7, or in other words, the first surface S1 can be closer to a plane than the seventh surface S7.

[0124] When |CV1 / CV7| is close to 0, it means that the curvature of the first surface S1 is almost 0, that is, the first surface S1 is close to a plane. This design can simplify the processing and manufacturing process of the first prism 1 and reduce the light refraction error caused by the curved surface.

[0125] The upper limit is set to prevent the curvature of the first surface S1 from being too large, which would cause excessive refraction or distortion of light when passing through the first surface S1. If the absolute value of CV1 / CV7 exceeds 0.4, the first surface S1 will have a negative impact on the light, reducing the imaging quality of the entire optical module.

[0126] According to this example of the present application, by properly controlling the ratio between CV1 and CV7, it is possible to ensure that light maintains a favorable refraction direction when passing through the first prism 1, providing a good foundation for the subsequent light path. The smaller curvature of the first surface S1 helps reduce aberrations caused by curved refraction, thereby improving the imaging quality of the optical module.

[0127] In addition, a reasonable curvature ratio relationship helps to enhance the stability of the optical module, enabling it to maintain good performance in various environments and usage conditions.

[0128] In some examples of this application, see Figure 1 , the first surface S1 is a curved surface or a flat surface, and the second surface S2 is a flat surface.

[0129] In the optical module provided in the embodiment of the present application, the first surface S1 of the first prism 1 can be a curved surface or a flat surface. The curved surface design can further adjust the light path and focusing characteristics, while the flat surface design simplifies the manufacturing process.

[0130] As described in the above example, when |CV1 / CV7| is close to 0, the first surface S1 is a plane.

[0131] The second surface S2 serves as the bonding surface between the first prism 1 and the second prism 2. Designing it as a plane can ensure precise alignment and stable bonding between the two prisms. The plane design also facilitates the attachment and positioning of the polarizing reflective element 7.

[0132] In addition, by optimizing the design of the first surface S1 and the second surface S2 of the first prism 1, light distortion and stray light interference can be reduced, thereby improving image clarity.

[0133] That is, the first prism 1 may include two flat surfaces or at least one curved surface.

[0134] In some examples of this application, see Figure 1 , the angle θ1 formed between the second surface S2 and the vertical direction is an acute angle.

[0135] In this example of the present application, the angle θ1 between the second surface S2 and the vertical direction is designed to be an acute angle. The design of this angle has a crucial influence on the refraction path of light inside the first prism 1.

[0136] When light enters the first prism from air or other media, it refracts based on the angle of incidence and the refractive index of the prism material. The angle θ1 is designed to ensure that the light refracts along the intended path within the first prism 1 and then passes through subsequent optical components to reach the human eye S0.

[0137] The sharp θ1 angle design allows the cemented prism to achieve a more compact structure while maintaining a large field of view. This is of great significance for the lightweight and miniaturization of near-eye display devices.

[0138] In some examples of this application, see Figure 1 The second prism 2 also includes a third surface S3 and an eighth surface S8; an air gap is provided between the third surface S3 and the fourth surface S4, and the third surface S3 is a plane; the eighth surface S8 is the top surface of the second prism 2, and the angle θ2 formed by the optical axis of the eighth surface S8 and the horizontal direction is an acute angle.

[0139] The third surface S3 is a plane, which helps the light to be totally reflected on the third surface S3, thereby optimizing the light path. The plane design also simplifies the manufacturing and processing of the second prism 2.

[0140] Regarding the air gap: An air gap is provided between the third surface S3 of the second prism 2 and the fourth surface S4 of the first lens 3. This air gap is designed to exploit the difference in refractive index between air and the prism material, causing light to be totally reflected off the third surface S3. This reduces light loss within the second prism 2 and improves light utilization. Total internal reflection also helps maintain the polarization state of light, which is crucial for achieving efficient polarization conversion and reducing stray light.

[0141] Regarding the eighth surface S8 of the second prism 2, which serves as the top surface of the second prism 2, the angle θ2 formed between its optical axis and the horizontal direction is acute. The light path can be further adjusted to meet specific imaging requirements and field of view requirements. In addition, the acute angle θ2 design also facilitates a more compact optical structure.

[0142] It should be noted that the horizontal direction here refers to the optical axis direction of the first lens 3 and the second lens 4 .

[0143] The planar design of the third surface S3 of the second prism 2, the air gap between it and the fourth surface S4, and the acute angle of the eighth surface S8 collectively optimize the light path, utilize total internal reflection, improve imaging quality, and enhance the stability of the entire optical module. These designs not only enhance the optical performance of the near-eye display device, but also provide users with a clearer and higher-quality visual experience.

[0144] 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 eighth surface S8.

[0145] The display screen 8 is disposed on one side of the eighth surface S8 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.

[0146] Optionally, a protective glass 9 is provided on the light emitting surface of the display screen 8 .

[0147] 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.

[0148] 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.

[0149] The surface of the first lens 3 close to the second prism 2 is the fourth surface S4, and the fourth surface S4 is a plane: the planar design simplifies the manufacturing and processing process, and helps light to be incident on the first lens 3 in a more uniform manner.

[0150] The other surface of the first lens 3 is a fifth surface S5, which is designed to be curved. This curved surface design allows for more precise refraction and focusing of light, thereby optimizing image quality. The curved surface S5 can better control the refraction and focusing of light, thereby reducing aberrations and distortion, and improving image clarity.

[0151] The first lens 3 adopts a combination of flat surface design and curved surface design, which achieves precise control of the light propagation path and optimizes the optical performance of the optical module.

[0152] In some examples of the present application, the sixth surface S6 is a plane, and the seventh surface S7 is a plane or a curved surface.

[0153] The sixth surface S6 and the seventh surface S7 are two surfaces of the second lens 4 respectively; wherein, the sixth surface S6 is a plane: the planar design makes this part of the second lens 4 easier to manufacture and process, and helps to maintain the stability of light inside the lens.

[0154] The seventh surface S7 can be flat or curved: the design flexibility of the seventh surface allows adjustment according to specific application requirements. A flat design simplifies the manufacturing process, while a curved design provides more precise light control.

[0155] The two examples above demonstrate how different surface designs for the first lens 3 and the second lens 4 affect the performance of near-eye display devices. By controlling the lens surface design, image quality can be optimized and manufacturing costs can be reduced. These designs not only improve the optical performance of the optical module but also provide users with a clearer, higher-quality visual experience.

[0156] In some examples of the present application, the optical module includes at most 4 curved surfaces.

[0157] The advantages of having multiple curved surfaces in an optical module include many aspects, which are described below.

[0158] From the perspective of improving imaging quality, multiple curved surfaces can more accurately control the refraction and reflection paths of light, thereby reducing aberrations and distortion and improving imaging quality.

[0159] From the perspective of enhancing the flexibility of optical module design: More curved surfaces mean more design parameters can be adjusted, thus enhancing module design flexibility. For example, by adjusting the curved surface parameters, module performance such as field of view and resolution can be optimized.

[0160] In addition, in some complex application scenarios, such as near-eye display devices that require a large field of view or high resolution, multiple curved surfaces can provide better optical performance.

[0161] However, in optical modules, too many curved surfaces can also lead to some defects, as detailed below:

[0162] Multiple curved surfaces mean more complex optical designs, requiring more calculations and optimization work, which can lead to longer optical design cycles and increased design costs.

[0163] Multiple curved surfaces increase the difficulty of machining and assembly, requiring higher precision and more complex processes. This leads to higher production costs and a certain risk of machining errors.

[0164] An increase in the number of curved surfaces may lead to an increase in the weight and volume of optical components, which is not conducive to lightweight and miniaturized near-eye display devices.

[0165] The optical module design of the embodiment of the present application includes at most 4 curved surfaces.

[0166] For example, the first surface S1 of the first prism 1 is curved, the fifth surface S5 of the first lens 3 is curved, and the sixth and seventh surfaces S6 and S7 of the second lens 4 are also curved. This design optimizes the light path while ensuring efficient light transmission, reducing unnecessary refraction and reflection, and thus reducing light loss. By designing the shape and parameters of the curved surfaces, aberrations and distortion can be reduced, image quality can be improved, and users can have a clearer visual experience.

[0167] Compared to designs with more curved surfaces, optical modules with up to four curved surfaces are simpler to design and manufacture. This not only reduces design costs but also reduces complexity and potential errors during manufacturing, improving production efficiency and yield. Furthermore, a design with up to four curved surfaces allows for greater flexibility and adaptability while maintaining consistent performance.

[0168] In practical applications, it is necessary to comprehensively consider factors such as specific needs, design costs, production costs, and optical module performance to select the most appropriate number of surfaces. In this application, it is preferred to use up to 4 surfaces.

[0169] In some examples of the present application, the centers of the first surface S1, the fifth surface S5, the sixth surface S6, and the seventh surface S7 are all located on the same optical axis, and the positive direction of the sag of the first surface S1, the fifth surface S5, the sixth surface S6, and the seventh surface S7 is the direction away from the human eye S0 along the optical axis.

[0170] In the present application, the first surface S1, the fifth surface S5, the sixth surface S6, and the seventh surface S7 may be curved surfaces, with their positive sagittal directions defined as directions away from the human eye S0 along the optical axis. This means that after light is emitted from the display screen 8, it propagates along these surfaces in a direction away from the human eye S0 and, after a series of reflections and refractions, reaches the human eye to form a clear image.

[0171] The design of the positive sagittal height is crucial for controlling the propagation path and focal point of light. By ensuring the positive sagittal height of each surface is consistent, the light can maintain a certain directionality and focus during propagation, thereby improving imaging quality.

[0172] In some examples of this application, see Figure 1 , the chief ray of the 0-degree field of view coincides with the optical axes of the fifth surface S5, the sixth surface S6, the seventh surface S7, and the eighth surface S8.

[0173] 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.

[0174] 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.

[0175] 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 human eye and enhancing the imaging brightness of the optical module.

[0176] 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.

[0177] According to another embodiment of the present application, a near-eye display device is provided, which includes the optical module as described above.

[0178] The near-eye display device is, for example, an AR device or an XR device.

[0179] The optical module provided by the present application is described in detail below through Examples 1 to 6.

[0180] Example 1

[0181] See also Figure 2The optical module provided in this embodiment 1 includes a cemented prism, a first lens 3 and a second lens 4, and the first lens 3 is located between the cemented prism and the second lens 4;

[0182] The cemented prism includes a first prism 1, a second prism 2, and a polarizing reflective element 7 cemented between the two prisms;

[0183] The first lens 3 includes a fourth surface S4 and a fifth surface S5. The fourth surface S4 is adjacent to and spaced from the second prism 2. The fourth surface S4 is a plane, and the fifth surface S5 is a curved surface.

[0184] The second lens 4 includes a sixth surface S6 and a seventh surface S7. The seventh surface S7 faces away from the first lens 3 and is a partially reflective surface. The sixth surface S6 is a plane, and the seventh surface S7 is a plane or a curved surface.

[0185] A phase retarder 6 is provided on the fourth surface S4;

[0186] The first prism 1 includes a first surface S1 and a second surface S2. The second surface S2 is a bonding surface between the first prism 1 and the second prism 2. The polarizing reflective element 7 is disposed on the second surface S2. The first surface S1 is a curved surface or a flat surface. The second surface S2 is a flat surface. The angle θ1 formed between the second surface S2 and the vertical direction is an acute angle.

[0187] The second prism 2 includes a third surface S3 and an eighth surface S8; an air gap is provided between the third surface S3 and the fourth surface S4, and the third surface S3 is a plane; the eighth surface S8 is the top surface of the second prism 2, and an angle θ2 formed between the optical axis of the eighth surface S8 and the horizontal direction is an acute angle;

[0188] The optical module further includes a display screen 8, which is disposed on one side of the eighth surface S8;

[0189] The centers of the first surface S1, the fifth surface S5, the sixth surface S6, and the seventh surface S7 are all located on the same optical axis, and the positive directions of the sags of the first surface S1, the fifth surface S5, the sixth surface S6, and the seventh surface S7 are in the direction away from the human eye S0 along the optical axis.

[0190] The chief ray of the 0-degree field of view coincides with the optical axes of the fifth surface S5 , the sixth surface S6 , the seventh surface S7 , and the eighth surface S8 .

[0191] The parameters of the optical elements in the optical module provided in this embodiment 1 are shown in Table 1.

[0192] Table 1

[0193]

[0194] 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 S6 to S7 is t6, the distance from S5 to S8 is t7, the distance from S8 to S9 is t8, and the distance from S9 to S10 is t9.

[0195] The EFL involved in this embodiment 1 15 / EFL, EFL 67 / EFL, EFL 45 / EFL 67 For the optical parameter ratios such as |CV5 / CV7|, |CV6 / CV7|, etc., please refer to Table 7 shown after Example 6.

[0196] See also Figure 3 The MTF diagram of the optical module shown in the figure shows the modulation transfer function at different spatial frequencies and is used to evaluate the performance of the optical module. Figure 3 In the figure, the horizontal axis represents spatial frequency, and the vertical axis shows modulation, with values ​​ranging from 1.0 (representing perfect imaging) to close to 0 (indicating no imaging). Figure 3 There are multiple curves in the chart, each corresponding to the MTF value under different conditions. These conditions are indicated by the symbols next to the curves, which reflect the measured data at different wavelengths and angles. Figure 3 It can be seen that 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.

[0197] Example 2

[0198] 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.

[0199] Table 2

[0200]

[0201] 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 S6 to S7 is t6, the distance from S5 to S8 is t7, the distance from S8 to S9 is t8, and the distance from S9 to S10 is t9.

[0202] The EFL involved in this embodiment 2 15 / EFL, EFL 67 / EFL, EFL 45 / EFL 67 For the optical parameter ratios such as |CV5 / CV7|, |CV6 / CV7|, etc., please refer to Table 7 shown after Example 6.

[0203] Figure 5 Contains multiple curves, each curve corresponds to the MTF value under different conditions. Figure 5 It can be seen that 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.

[0204] Example 3

[0205] See also Figure 6 The optical module shown in this embodiment 3 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 3, please refer to Table 3.

[0206] Table 3

[0207]

[0208] For Table 3, see Figure 6 , 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 S6 to S7 is t6, the distance from S5 to S8 is t7, the distance from S8 to S9 is t8, and the distance from S9 to S10 is t9.

[0209] The EFL involved in this embodiment 3 15 / EFL, EFL 67 / EFL, EFL 45 / EFL 67 For the optical parameter ratios such as |CV5 / CV7|, |CV6 / CV7|, etc., please refer to Table 7 shown after Example 6.

[0210] Figure 7 Contains multiple curves, each curve corresponds to the MTF value under different conditions. Figure 7It can be seen that 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.

[0211] Example 4

[0212] 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.

[0213] Table 4

[0214]

[0215] 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 S6 to S7 is t6, the distance from S5 to S8 is t7, the distance from S8 to S9 is t8, and the distance from S9 to S10 is t9.

[0216] The EFL involved in this embodiment 4 15 / EFL, EFL 67 / EFL, EFL 45 / EFL 67 For the optical parameter ratios such as |CV5 / CV7|, |CV6 / CV7|, etc., please refer to Table 7 shown after Example 6.

[0217] Figure 9 Contains multiple curves, each curve corresponds to the MTF value under different conditions. Figure 9 It can be seen that 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.

[0218] Example 5

[0219] 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.

[0220] Table 5

[0221]

[0222] 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 S6 to S7 is t6, the distance from S5 to S8 is t7, the distance from S8 to S9 is t8, and the distance from S9 to S10 is t9.

[0223] The EFL involved in this embodiment 5 15 / EFL, EFL 67 / EFL, EFL 45 / EFL 67 For the optical parameter ratios such as |CV5 / CV7|, |CV6 / CV7|, etc., please refer to Table 7 shown after Example 6.

[0224] Figure 11 Contains multiple curves, each curve corresponds to the MTF value under different conditions. Figure 11 It can be seen that 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.

[0225] Example 6

[0226] 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.

[0227] Table 6

[0228]

[0229] 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 S6 to S7 is t6, the distance from S5 to S8 is t7, the distance from S8 to S9 is t8, and the distance from S9 to S10 is t9.

[0230] The EFL involved in this embodiment 6 15 / EFL, EFL 67 / EFL, EFL 45 / EFL 67 For the optical parameter ratios such as |CV5 / CV7|, |CV6 / CV7|, etc., please refer to Table 7 shown after Example 6.

[0231] Figure 13There are multiple curves in the chart, each corresponding to the MTF value under different conditions. These conditions are indicated by the symbols next to the curves, which reflect the measured data at different wavelengths and angles. Figure 13 It can be seen that 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.

[0232] Table 7 Optical parameters of Examples 1 to 6

[0233]

[0234] 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.

[0235] 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 first lens (3) and a second lens (4), wherein the first lens (3) is located between the cemented prism and the second lens (4); The glued prism comprises a first prism (1), a second prism (2), and a polarizing reflection element (7) glued between the two prisms; The first lens (3) comprises a fourth surface (S4) and a fifth surface (S5), and the fourth surface (S4) and the second prism (2) are adjacent and spaced apart. The second lens (4) comprises a sixth surface (S6) and a seventh surface (S7), the seventh surface (S7) is away from the first lens (3), and the seventh surface (S7) is a partially reflective surface; A phase retarder (6) is provided on the fourth surface (S4) or the sixth surface (S6); The optical module satisfies: 1.9≤EFL 15 / EFL≤5.4; where EFL 15 is the total effective focal length of the cemented prism and the first lens (3), and EFL is the effective focal length of the optical module.

2. The optical module according to claim 1, wherein: The optical module satisfies: 1.5≤EFL 67 / EFL≤51.4; among which, EFL 67 It is the effective focal length of light incident from the sixth surface (S6), reflected from the seventh surface (S7), and then emitted from the sixth surface (S6).

3. The optical module according to claim 2, wherein: The optical module satisfies: 1.78≤EFL 67 / EFL≤7.

32.

4. The optical module according to claim 2, wherein: The optical module satisfies: 0≤EFL 45 / EFL 67 ≤3.6; among them, EFL 45 It is the effective focal length of light incident from the fourth surface (S4) and emitted from the fifth surface (S5).

5. The optical module according to claim 1, wherein: The curvature of the fifth surface (S5) is CV5, the curvature of the seventh surface (S7) is CV7, and 1.5≤CV5 / CV7≤4.

6. The optical module according to claim 1, wherein: The curvature of the sixth surface (S6) is CV6, the curvature of the seventh surface (S7) is CV7, and 0≤CV6 / CV7≤2.

9.

7. The optical module according to claim 1, wherein: The first prism (1) comprises a first surface (S1) and a second surface (S2), wherein the second surface (S2) is a bonding surface where the first prism (1) and the second prism (2) are bonded to each other, and the polarized reflective element (7) is arranged on the second surface (S2); The curvature of the first surface (S1) is CV1, the curvature of the seventh surface (S7) is CV7, and 0≤|CV1 / CV7|≤0.

4.

8. The optical module according to claim 7, wherein: The first surface (S1) is a curved surface or a flat surface, and the second surface (S2) is a flat surface.

9. The optical module according to claim 8, wherein: An angle θ1 formed between the second surface (S2) and the vertical direction is an acute angle.

10. The optical module according to claim 8, wherein: The second prism (2) further includes a third surface (S3) and an eighth surface (S8); An air gap is provided between the third surface (S3) and the fourth surface (S4), and the third surface (S3) is a plane; The eighth surface (S8) is the top surface of the second prism (2), and the angle θ2 formed by the optical axis of the eighth surface (S8) and the horizontal direction is an acute angle.

11. The optical module according to claim 10, wherein: The optical module further comprises a display screen (8), and the display screen (8) is arranged on one side of the eighth surface (S8).

12. The optical module according to claim 1, wherein: The fourth surface (S4) is a plane, and the fifth surface (S5) is a curved surface.

13. The optical module according to claim 1, wherein: The sixth surface (S6) is a plane, and the seventh surface (S7) is a plane or a curved surface.

14. The optical module according to claim 1, wherein: The optical module includes at most four curved surfaces.

15. The optical module according to claim 11, wherein: The centers of the first surface (S1), the fifth surface (S5), the sixth surface (S6) and the seventh surface (S7) 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), the sixth surface (S6) and the seventh surface (S7) is the direction away from the human eye (S0) along the optical axis.

16. The optical module according to claim 15, wherein: The chief ray of the 0-degree field of view coincides with the optical axes of the fifth surface (S5), the sixth surface (S6), the seventh surface (S7), and the eighth surface (S8).

17. A near-eye display device, characterized in that: The optical module comprises the optical module as claimed in any one of claims 1 to 16.

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