Optical module and near-to-eye display equipment

Abstract

The embodiment of the invention provides an optical module and near-to-eye display equipment. The optical module is used for XR optical equipment and comprises a first lens, a second lens and a cemented prism located between the first lens and the second lens. The cemented prism is mainly composed of two prisms and a polarization reflection element. The second lens comprises a sixth surface and a seventh surface, an air gap is arranged between the sixth surface and the cemented prism, a phase retarder is arranged between the sixth surface and the cemented prism, and the seventh surface is a partial reflection surface; the optical module meets the following conditions: EFL12 / EFL67 is more than or equal to 2.3 and less than or equal to 24.1; wherein the EFL12 is the effective focal length of the first lens, and the EFL67 is the effective focal length of light which enters from the sixth surface, is reflected by the seventh surface and then exits from the sixth surface.

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 advancement of science and technology, XR technology has gradually shown broad application prospects in the fields of entertainment, education, and medical care. XR technology covers technologies such as AR, VR, and MR, and is widely used in near-eye display devices. As a key carrier of XR technology, the performance improvement of near-eye display devices is crucial to user experience. Traditional near-eye display devices have certain limitations in terms of size, imaging quality, and field of view, which makes it difficult to meet users' pursuit of immersive experience. Summary of the invention

[0003] The purpose of this application is to provide a new technical solution for an optical module and a near-eye display device.

[0004] In a first aspect, the present application provides an optical module. The optical module is used for an XR optical device, comprising a first lens, a second lens, and a cemented prism located between the two lenses;

[0005] The cemented prism is mainly composed of two prisms and a polarized reflection element;

[0006] The second lens includes a sixth surface and a seventh surface, an air gap is provided between the sixth surface and the cemented prism, a phase retarder is provided between the sixth surface and the cemented prism, and the seventh surface is a partial reflection surface;

[0007] The optical module meets the following conditions: 2.3≤EFL 12 / EFL 67 ≤24.1; among which, EFL 12 is the effective focal length of the first lens, EFL 67 It is the effective focal length of the light incident from the sixth surface, reflected by the seventh surface, and then emitted from the sixth surface.

[0008] Optionally, the optical module satisfies: 2.77≤EFL 12 / EFL 67 ≤5.

[0009] Optionally, the optical module satisfies: EFL 12 / EFL 35 ≤3.2; among which, EFL 35 is the effective focal length of the cemented prism.

[0010] Optionally, the optical module satisfies: 3.2≤EFL 12 / EFL≤31.4; wherein EFL is the effective focal length of the optical module.

[0011] Optionally, the optical module satisfies: 3.42≤EFL 12 / EFL≤6.84.

[0012] Optionally, the optical module satisfies: 1.2≤EFL 67 / EFL≤1.4; wherein EFL is the effective focal length of the optical module.

[0013] Optionally, the first lens includes a first surface and a second surface, the first surface faces away from the cemented prism, the second surface is adjacent to the cemented prism, and the curvature of the first surface is C 1 , the curvature of the second surface is C 2 , and C 1 / C 2 ≥-0.9.

[0014] Optionally, the curvature of the seventh surface is C 7 , and |C 1 / C 7 |≤1.2.

[0015] Optionally, the glued prism includes a first prism and a second prism glued to each other;

[0016] The first prism includes a third surface adjacent to the first lens, and the curvature of the third surface is C 3 , and |C 3 / C 7 |≤2.

[0017] Optionally, the bonding surface of the first prism and the second prism is a fourth surface, and the polarized reflection element is arranged on the fourth surface;

[0018] The phase retarder is arranged on the sixth surface;

[0019] The seventh surface is provided with a light splitting element.

[0020] Optionally, the angle θ between the fourth surface and the vertical direction is 1 It is an acute angle.

[0021] Optionally, the second prism further includes a fifth surface;

[0022] An air gap is provided between the fifth surface and the sixth surface so that light incident on the fifth surface is totally reflected;

[0023] The optical module meets: EFL / EFL 35≤0.1; wherein EFL is the effective focal length of the optical module, EFL 35 is the effective focal length of light incident from the third surface and emitted from the fifth surface.

[0024] Optionally, the second prism further includes an eighth surface;

[0025] The optical module further includes a display screen, which is located on one side of the eighth surface. The angle θ formed by the optical axis of the eighth surface and the horizontal direction is 2 It is an acute angle.

[0026] Optionally, the effective focal length EFL of the optical module is 13.4 mm ≤ EFL ≤ 15.2 mm.

[0027] Optionally, the optical module includes 3 or 4 curved surfaces.

[0028] Optionally, the first surface and the second surface of the first lens are flat surfaces or curved surfaces;

[0029] The sixth surface is a plane, and the seventh surface is a curved surface.

[0030] Optionally, the third surface of the first prism is a curved surface or a flat surface;

[0031] The bonding surface of the first prism and the second prism is a fourth surface, and the fourth surface is a plane;

[0032] The fifth surface of the second prism is a plane.

[0033] Optionally, centers of the first surface, the third surface and the seventh surface are all located on the same optical axis, and the positive direction of the vector height of the first surface, the third surface and the seventh surface is a direction away from the human eye along the optical axis.

[0034] Optionally, the chief ray of the 0 degree field of view coincides with the optical axes of the first surface, the second surface, the third surface, the sixth surface, the seventh surface and the eighth surface.

[0035] In a second aspect, the present application provides a near-eye display device, wherein the near-eye display device comprises the optical module as described in the first aspect.

[0036] The beneficial effects of this application are:

[0037] The embodiment of the present application provides an optical module, which is suitable for XR technology. It aims to solve the shortcomings of the existing near-eye display devices in terms of volume, imaging quality and field of view. The optical module provided by the embodiment of the present application has the advantages of small volume, high imaging quality and large field of view. By adopting a specially designed optical module, the near-eye display device can achieve a compact design with a large field of view while ensuring good imaging quality, providing users with a more immersive virtual reality or augmented reality experience.

[0038] 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

[0039] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0040] Figure 1 One of the structural schematic diagrams of the optical module provided in the embodiment of the present application;

[0041] Figure 2 The second structural diagram of the optical module provided in the embodiment of the present application;

[0042] Figure 3 for Figure 2 MTF diagram of the optical module shown;

[0043] Figure 4 The third structural diagram of the optical module provided in the embodiment of the present application;

[0044] Figure 5 for Figure 4 MTF diagram of the optical module shown;

[0045] Figure 6 A fourth structural diagram of an optical module provided in an embodiment of the present application;

[0046] Figure 7 for Figure 6 MTF diagram of the optical module shown;

[0047] Figure 8 A fifth structural diagram of an optical module provided in an embodiment of the present application;

[0048] Fig. 9 for Figure 8 MTF diagram of the optical module is shown.

[0049] Description of reference numerals:

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

[0051] S0, human eye; S1, first surface; S2, second surface; S3, third surface; S4, fourth surface; S5, fifth surface; S6, sixth surface; S7, seventh surface; S8, eighth 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 arrangement 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 application, 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 similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

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

[0058] According to one embodiment of the present application, an optical module is provided. Figure 1 , the optical module includes a first lens 1, a second lens 2 and a cemented prism located between the two lenses; the cemented prism is mainly composed of two prisms and a polarized reflection element 7; the second lens 2 includes a sixth surface S6 and a seventh surface S7, an air gap is provided between the sixth surface S6 and the cemented prism, and a phase retarder 6 is provided between the sixth surface S6 and the cemented prism, and the seventh surface S7 is a partial reflection surface; the optical module satisfies: 2.3≤EFL 12 / EFL 67 ≤24.1; among which, EFL 12 is the effective focal length of the first lens 1, EFL 67It is the effective focal length of the light incident from the sixth surface S6, reflected from the seventh surface S7, and then emitted from the sixth surface S6.

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

[0060] The optical module provided in the embodiment of the present application is shown in FIG. Figure 1 , which is mainly composed of a cemented prism and two lenses, and also introduces key optical elements such as a phase retarder 6 and a polarization reflection element 7 into the optical module. The main optical elements in the optical module of the present application are described below.

[0061] The optical module of the embodiment of the present application includes two lenses: a first lens 1 and a second lens 5; wherein the first lens 1 and the second lens 2 are part of the optical module, and are respectively located on a side close to the human eye S0 and a side away from the human eye S0.

[0062] See also Figure 1 The second lens 2 includes a sixth surface S6 and a seventh surface S7, wherein the seventh surface S7 is a partial reflection surface for reflecting part of the light, thereby facilitating the folding of the light path.

[0063] The optical module of the embodiment of the present application further includes a glued prism, which is disposed between the first lens 1 and the second lens 2. Specifically, the glued prism is mainly formed by gluing two prisms and includes a polarized reflective element 7, wherein the polarized reflective element 7 can be disposed on the gluing surface of the two prisms. Since the glued prism includes the polarized reflective element 7, the glued prism 7 plays a key role in light path folding and polarization control in the optical module.

[0064] In the optical module provided in the embodiment of the present application, an air gap is provided between the cemented prism and the second lens 2. Figure 1 A certain air gap is provided between the fifth surface S5 of the second prism 4 and the sixth surface S6 of the second lens 2, so that light can be totally reflected on the fifth surface S5. In other words, in the optical module, the fifth surface S5 is a totally reflecting surface.

[0065] The optical module provided in the embodiment of the present application further includes a phase retarder 6, which is disposed between the sixth surface S6 and the fifth surface S5 and can be used to adjust the phase of light to further optimize the imaging quality. The phase retarder 6 is, for example, a quarter wave plate.

[0066] Of course, the phase retarder 6 can also be adjusted to a half-wave plate or the like according to requirements, and this application does not impose any limitation on this.

[0067] The optical module of the embodiment of the present application also satisfies a specific effective focal length ratio relationship, namely 2.3≤EFL 12 / EFL 67 ≤24.1; among which, EFL 12 is the effective focal length of the first lens 1, that is, EFL 12 represents the effective focal length of the light incident from the first surface S1 of the first lens 1 and emitted from the second surface S2; and EFL 67 It is the effective focal length of light incident from the sixth surface S6, reflected by the seventh surface S7, and then emitted from the sixth surface S6 (the light is folded in the second lens 2).

[0068] Regarding the above effective focal length relationship: EFL 12 / EFL 67 , which is a key parameter, is limited to between 2.3 and 24.1. This range ensures that the optical module can maintain a small size and high imaging quality while providing a sufficient field of view.

[0069] Specifically, in the embodiment of the present application, by controlling EFL 12 and EFL 67 The ratio of 1:1 to 1:1 ensures that light can be accurately focused after passing through the lens and prism, thereby reducing aberration and distortion and improving image quality. This ratio also helps to balance the magnification and field of view of the optical module, making the image clear and wide.

[0070] The above effective focal length ratio can affect the field of view of the optical module. By adjusting this ratio, different field of view angles can be achieved while ensuring image quality. For near-eye display devices, an appropriate field of view angle can provide a more immersive user visual experience.

[0071] The ratio range of effective focal lengths proposed in the embodiments of the present application can make the volume of the optical module more compact while ensuring the imaging quality and field of view. This is particularly important for near-eye display devices, because the compact volume can improve the wearing comfort of users.

[0072] By comparing the EFL in different embodiments (hereinafter referred to as Embodiment 1 to Embodiment 4) 12 and EFL 67 By comparing the values, we can find that the proportional relationship between them is always between 2.3 and 24.1. This verifies the application effect and feasibility of this proportional relationship in actual design.

[0073] The optical module provided in the embodiment of the present application can optimize the imaging quality. Specifically, by controlling the effective focal length ratio (EFL) of the first lens 1 and the second lens 2 12 / EFL 67 ), the optical module of this embodiment can optimize the imaging quality and reduce aberration and distortion while ensuring a large field of view.

[0074] The optical module provided in the embodiment of the present application has a compact module structure. Specifically, by reasonably designing the positional relationship between the two lenses and the cemented prism, and in particular by utilizing the air gap and the phase retarder 6, the polarized reflective element 7 and the partial reflective characteristics of the seventh surface S7, the optical module of this embodiment achieves a more compact module structure, which is conducive to integrating higher performance optical elements in a limited space.

[0075] The optical module provided by the embodiment of the present application can improve the utilization rate of light. Specifically, in the optical module, the seventh surface S7 is used as a partial reflection surface, which can reflect part of the light and realize the folding of the light path, thereby improving the utilization rate of light, reducing light loss, and enhancing the overall brightness of the module.

[0076] In addition, the polarized reflective element 7 in the glued prism is capable of controlling the polarization state of light, which is crucial for improving the contrast and clarity of displayed images, especially in XR applications that require accurate color reproduction and depth perception.

[0077] The optical module of the present application can achieve the goals of small size, large viewing angle and high imaging quality.

[0078] The principle of how the optical module can achieve a small size is as follows:

[0079] (1) The bonded prism is mainly composed of two prisms and a polarized reflective element 7. This design reduces the gap between the prisms by bonding, thereby saving space. The compact structure of the bonded prism enables the entire optical module to be significantly reduced in size while maintaining high performance.

[0080] (2) The close fit between the first lens 1 and the second lens 2 and the cemented prism reduces light loss and stray light generation, and also helps to reduce the size of the module.

[0081] The principle of how the optical module can achieve a wide viewing angle is as follows:

[0082] The seventh surface S7 of the second lens 2 is a partially reflective surface, which means that when the light reaches this surface, part of it will be reflected back to the sixth surface, and the other part will continue to be transmitted. This design not only increases the utilization rate of light, but also realizes the folding of light through multiple refractions, thereby increasing the viewing angle.

[0083] The principle of optical module to achieve high imaging quality is as follows:

[0084] The optical module of this application satisfies 2.3≤EFL 12 / EFL 67 ≤24.1, which means that a reasonable ratio is maintained between the effective focal length of the first lens 1 and the effective focal length of the light incident from the sixth surface S6, reflected from the seventh surface S7, and then emitted from the sixth surface S6. This matching relationship helps to maintain the parallelism and focusing of the light, can reduce aberrations and distortions, and thus improve the imaging quality.

[0085] The embodiment of the present application provides an optical module that can be applied to XR technology. It aims to solve the shortcomings of existing near-eye display devices in terms of volume, imaging quality, and field of view. The optical module provided by the embodiment of the present application has the advantages of small volume, high imaging quality, and large field of view. By adopting a specially designed optical module, the near-eye display device can achieve a compact design with a large field of view while ensuring good imaging quality, providing users with a more immersive virtual reality or augmented reality experience.

[0086] In some examples of the present application, the optical module satisfies: 2.77≤EFL 12 / EFL 67 ≤5.

[0087] EFL 12 represents the effective focal length of the first lens 1, and EFL 67 represents the effective focal length of the light incident from the sixth surface S6 of the second lens 2, reflected from the seventh surface S7, and then emitted from the sixth surface S6. By further setting EFL 12 With EFL 67 The ratio is between 2.77 and 5, which can ensure that after the light is refracted and reflected by the lens and prism inside the optical module, it can maintain very good focusing performance, reduce aberration and distortion, and thus improve imaging quality.

[0088] At the same time, this optimized ratio range also helps to control the overall volume of the optical module. 12 / EFL 67 If the ratio is too small, it may be necessary to increase the thickness of the lens or change the curvature of the lens to meet the focal length requirements, which will undoubtedly increase the size and weight of the module. Setting the upper limit value to 5 can avoid excessive module size while ensuring imaging quality and improve user wearing comfort.

[0089] The seventh surface S7 of the second lens 2 is a partial reflection surface, which is used to reflect part of the light to achieve light path folding. 12 / EFL 67 When the ratio is controlled within a range of 2.77 to 5, it can ensure that the reflection angle and reflection efficiency of the light on the seventh surface S7 reach the optimal state, thereby improving the utilization rate of the light, reducing light loss, and enhancing the overall brightness of the optical module.

[0090] By optimizing EFL 12 With EFL 67 The proportional relationship can further expand the field of view of the optical module while ensuring the imaging quality. A larger field of view can provide a wider field of view and enhance the user's sense of immersion.

[0091] In addition, when EFL 12 / EFL 67 When the ratio is controlled within the preferred range of this example of the present application, the manufacturing process of the optical module can be simplified, because this ratio range can ensure that the transmission path of light inside the module is relatively stable, reduce the requirements for the processing accuracy of lenses and prisms, and thus reduce the manufacturing cost.

[0092] In summary, the proportional relationship 2.77≤EFL 12 / EFL 67 ≤5 is the preferred range, which has significant advantages in balancing imaging quality and volume, improving light utilization, expanding the field of view and reducing manufacturing costs.

[0093] In some examples of the present application, the optical module satisfies: EFL 12 / EFL 35 ≤3.2; among which, EFL 35 is the effective focal length of the cemented prism.

[0094] The effective focal length ratio described in this example of the present application refers to the effective focal length ratio relationship between the first lens 1 and the cemented prism, which defines the effective focal length (EFL) of the first lens 1. 12 ) and the effective focal length (EFL) of the cemented prism 35 ) between them.

[0095] For this application EFL 12 With EFL 35 The ratio of is essentially to control the refraction and focusing behavior of the light after passing through the first lens and the cemented prism. By limiting this ratio, it can be ensured that the light is transmitted along a predetermined path inside the optical module, reducing aberration and distortion.

[0096] Specifically, when EFL 12 With EFL35 When the ratio of is controlled within the range provided in this example of the present application, the aberration generated after the light passes through the optical module can be reduced. This is because the aberration is often related to the refraction angle and focus position of the light, and EFL 12 and EFL 35 The proportional relationship is the embodiment of precise control of these factors.

[0097] Under the premise of satisfying imaging quality, the EFL is reasonably designed. 12 and EFL 35 The proportional relationship also helps to reduce the size and weight of the optical module. This is especially important for near-eye display devices, because a smaller and lighter design can improve the wearing comfort of users.

[0098] In practical applications, it may be necessary to adjust EFL according to different usage scenarios and user needs. 12 / EFL 35 For example, when pursuing higher definition, EFL can be appropriately reduced. 12 With EFL 35 ratio; when a larger viewing angle is required, it may be necessary to increase this ratio appropriately.

[0099] In some examples of the present application, the optical module satisfies: 3.2≤EFL 12 / EFL≤31.4; wherein EFL is the effective focal length of the optical module.

[0100] In the example of the present application, it is proposed that the optical module satisfies the proportional relationship of 3.2≤EFL 12 / EFL≤31.4; where EFL 12 represents the effective focal length of the first lens 1, and EFL represents the effective focal length of the entire optical module. This ratio is proposed to achieve a specific technical effect by accurately controlling the ratio of the effective focal length of the first lens 1 to the entire optical module.

[0101] About EFL 12 The ratio with EFL is actually to balance the imaging quality and size of the optical module. Larger EFL 12 The ratio of / EFL means that the first lens 1 has a strong focusing ability on light, which helps to improve the image quality, but it may also cause the size of the optical module to increase. Conversely, a smaller ratio may make the module more compact, but the image quality may be affected. Therefore, by setting this ratio range in the present application, the size of the entire optical module can be minimized while ensuring the image quality.

[0102] Different application scenarios have different requirements for the imaging quality and size of the optical module. 12 The proportional relationship with EFL can make the optical module adapt to different application scenarios.

[0103] According to this example of the present application, in the proportional relationship 3.2≤EFL 12 Under the constraint of / EFL≤31.4, the focusing ability of the first lens 1 is reasonably controlled, which helps to reduce aberrations and distortions and improve the clarity of imaging. At the same time, the effective focal length of the entire optical module is also optimized, ensuring that light can be transmitted along a predetermined path inside the optical module, further improving the imaging quality.

[0104] And, by putting EFL 12 The ratio with EFL is limited to a certain range, which can effectively control the size of the optical module. This helps to improve the wearing comfort and user experience of users. Especially in application scenarios with strict requirements on volume such as near-eye display devices, the setting of this ratio is particularly important.

[0105] In some examples of the present application, the optical module satisfies: 3.42≤EFL 12 / EFL≤6.84.

[0106] EFL 12 represents the effective focal length of the first lens 1, that is, the effective focal length of the light incident from the first surface S1 of the first lens 1 and emitted from the second surface S2. EFL represents the effective focal length of the entire optical module and is an important indicator for describing the imaging capability of the optical module. By setting EFL 12 The ratio with EFL is between 3.42 and 6.84, which can achieve more precise control of the imaging performance of the optical module.

[0107] Within the ratio range proposed in this example of the present application, the focusing effect of the first lens 1 on light is fully exerted, which can effectively reduce aberrations and improve image clarity and contrast. This is crucial for near-eye display devices because it is directly related to the user's visual experience.

[0108] By reasonably matching EFL 12 The ratio with EFL can ensure that the light can still maintain a high focusing performance after multiple refractions and reflections inside the optical module, reduce the light loss and the influence of stray light, and thus further improve the imaging quality.

[0109] Under the premise of satisfying imaging quality, this ratio range helps to achieve a compact design of the optical module. 12If the ratio to EFL is too large, it may be necessary to increase the thickness of the lens or change the curvature of the lens to meet the focal length requirements, which will increase the size and weight of the module. Setting the upper limit to 6.84 can ensure the imaging quality while avoiding excessive module size and improving the wearing comfort of users.

[0110] 3.42≤EFL 12 / EFL≤6.84 as the optimization range has significant technical effects in improving imaging quality, controlling the volume of the optical module, and improving light utilization. These effects together make the optical module an excellent choice for high-performance near-eye display devices.

[0111] In some examples of the present application, the optical module satisfies: 1.2≤EFL 67 / EFL≤1.4; wherein EFL is the effective focal length of the optical module.

[0112] In the example of the present application, it is proposed that the optical module satisfies the proportional relationship 1.2≤EFL 67 / EFL≤1.4, where EFL 67 represents the effective focal length of the second lens 2 in the optical module, and EFL represents the effective focal length of the entire optical module. This proportional relationship is proposed to achieve a specific technical effect by controlling the ratio of the effective focal length of the second lens 2 to the entire optical module.

[0113] By reasonably controlling EFL 67 The ratio with EFL can ensure that the second lens 2 has good refraction and focusing effects on light, thereby effectively reducing aberrations and further improving the clarity of imaging.

[0114] In the optical module provided in this application, the focal lengths of the lenses need to match each other to ensure that the light transmission path and focus position are accurate. 67 The proportional relationship with the EFL can ensure that the focal length of the second lens 2 maintains an appropriate match with the focal length of the entire optical module, thereby enhancing the optical performance stability of the optical module.

[0115] The above three examples in the embodiments of the present application respectively achieve the technical effects of optimizing the optical path design, balancing the imaging quality and the volume of the optical module, ensuring the utilization rate of light, optimizing the field of view, etc. by defining different effective focal length ratios. These technical effects jointly improve the overall performance of the optical module, thereby providing a better optical solution for near-eye display devices.

[0116] More preferably, 1.3 ≤ EFL 67 / EFL≤1.37. It can better balance the imaging quality and the volume of the optical module, while ensuring the light utilization rate and increasing the field of view.

[0117] In some examples of this application, see Figure 1 The first lens 1 includes a first surface S1 and a second surface S2, the first surface S1 is away from the cemented prism, the second surface S2 is adjacent to the cemented prism, and the curvature of the first surface S1 is C 1 , the curvature of the second surface S2 is C 2 , and C 1 / C 2 ≥-0.9.

[0118] In the example of the present application, the surface characteristics of the first lens 1, in particular the curvature relationship between the first surface S1 and the second surface S2, are described. Specifically, the first surface S1 is away from the cemented prism, while the second surface S2 is adjacent to the cemented prism, and the curvatures C of the two surfaces are 1 and C 2 Between 1 / C 2 This design aims to achieve the following technical effects by controlling the curvature relationship between the two surfaces of the first lens 1.

[0119] In C 1 / C 2 Under the constraint of ≥-0.9, the curvatures of the first surface S1 and the second surface S2 of the first lens 1 are reasonably matched. This matching relationship enables the light to be better controlled and guided when passing through the first lens 1, reducing the scattering and loss of light. At the same time, this design also helps to improve the transmission efficiency of light inside the optical module, allowing more light to reach the human eye, thereby enhancing the display effect.

[0120] By controlling the curvature relationship between the two surfaces of the first lens 1, imaging defects such as aberration and distortion can be significantly reduced, which makes the imaging clearer and improves the user's visual experience.

[0121] C 1 / C 2 The ratio of ≥-0.9 also helps to optimize the focusing effect of light, making the image more evenly distributed in the field of view, further improving the imaging quality.

[0122] In addition, the curvature has a certain relationship with the lens thickness: in order to achieve a specific focal length and image quality, C needs to be carefully matched. 1 and C 2This matching not only affects the optical performance of the first lens 1, but also directly determines the thickness of the first lens 1. Through reasonable curvature matching, the thickness of the first lens 1 can be reduced as much as possible while ensuring the imaging quality, thereby helping to reduce the volume and weight of the entire optical module.

[0123] In this example of the present application, the curvature ratio C of the first surface S1 and the second surface S2 of the first lens 1 is 1 / C 2 Negative means that the curvatures of the two surfaces are in opposite directions. This indicates that one surface is convex and the other is concave. Due to the different directions of curvature, light will be refracted differently when passing through the two surfaces. The convex surface will focus the light toward the center of the first lens 1, while the concave surface will diverge the light. This difference is very important for improving the imaging effect.

[0124] In some examples of the present application, the curvature of the seventh surface S7 is C 7 , and |C 1 / C 7 |≤1.2.

[0125] The curvature of the first surface S1 of the first lens 1 is C 1 The first surface S1 is located on the side close to the human eye S0. The curvature of the seventh surface S7 of the second lens 2 is C 7 , the seventh surface S7 is located on the side away from the human eye S0.

[0126] The first surface S1 of the first lens 1 is the surface close to the human eye S0, and its curvature C 1 The design of the light source is crucial to focus the light. 1 / C 7 |≤1.2, C 1 The size of C 7 This helps to ensure that the light can be correctly focused on the retina of the human eye after passing through the first lens 1, thereby improving the clarity of the imaging.

[0127] The curvature of the lens directly affects the imaging quality of the optical module. 1 / C 7 Under the constraint of |≤1.2, by controlling the curvature ratio of the two key surfaces, imaging problems such as aberration and distortion can be significantly reduced, thereby improving image clarity and accuracy.

[0128] The field of view is one of the important performance indicators of near-eye display. By optimizing the curvature ratio of the first lens 1 and the second lens 2, the field of view can be further expanded while maintaining high imaging quality, so that users can see a wider scene.

[0129] In addition, by constraining the curvatures of the first lens 1 and the second lens 2 to be within the above-mentioned range, the thickness of the two lenses can be well controlled, thereby facilitating the thinning and lightening of the entire optical module.

[0130] In this example of the present application, by setting |C 1 / C 7 ≤1.2, which helps to achieve high imaging quality while maintaining the compactness of the optical module.

[0131] In some examples of this application, see Figure 1 The cemented prism includes a first prism 3 and a second prism 4 that are cemented to each other; wherein the first prism 3 includes a third surface S3 adjacent to the first lens 1, and the curvature of the third surface S3 is C 3 , and |C 3 / C 7 |≤2.

[0132] By precisely controlling the curvature C of the third surface S3 3 and the curvature C of the seventh surface S7 7 The proportional relationship between them can ensure that the light is properly refracted and reflected when passing through the two surfaces, thereby reducing the loss of light during transmission. This is of great significance for improving the brightness and contrast of near-eye display devices. The appropriate curvature proportional relationship in this example of the present application helps to reduce imaging problems such as aberrations and distortions, thereby improving the clarity of the image. This is crucial to improving the user's visual experience.

[0133] The seventh surface S7 is a partially reflective surface, and its curvature C 7 The design of has an important influence on the expansion of the field of view. 7 and make it consistent with the curvature C of the third surface S3 3 Maintaining a proper ratio relationship can ensure that the light still maintains good divergence after passing through the second lens 2, thereby expanding the field of view, which is of great significance for improving the user's immersion.

[0134] In addition, by optimizing the curvature ratio of lenses and prisms, the risk of damage due to stress concentration can be reduced, thereby improving the durability and reliability of the entire optical module.

[0135] In the manufacturing process of optical modules, the matching and consistency between various components can be ensured by precisely controlling the curvature ratio of lenses and prisms. This helps reduce manufacturing difficulty and cost and improve product quality and reliability.

[0136] In some examples of this application, see Figure 1 The bonding surface of the first prism 3 and the second prism 4 is the fourth surface S4, the polarized reflection element 7 is arranged on the fourth surface S4; the phase retarder 6 is arranged on the sixth surface S6; and the beam splitter element 5 is arranged on the seventh surface S7.

[0137] In the example of the present application, the bonding surface of the first prism 3 and the second prism 4 is set as the fourth surface S4, and the polarization reflection element 7 is arranged on the fourth surface S4. The phase retarder 6 is arranged on the sixth surface S6, and the beam splitter 5 is arranged on the seventh surface S7.

[0138] The polarization reflective element 7 disposed on the fourth surface S4 (i.e., the bonding surface of the two prisms) can effectively manage the polarization state of the light. It can selectively reflect or transmit light of a specific polarization direction, thereby achieving polarization control of the light. This is of great significance for improving clarity.

[0139] The phase retarder 6 is disposed on the sixth surface S6 (a surface of the second lens 2) and can adjust the phase of light. The phase retarder 6 is, for example, a quarter wave plate.

[0140] The light splitting element 5 disposed on the seventh surface S7 makes the seventh surface S7 form a partial reflection surface. The light splitting element 5 is, for example, a semi-transparent and semi-reflective film. The light splitting element 5 can be disposed on the seventh surface S7 by coating or mounting.

[0141] In the present application, the folding of the optical path can be achieved by the combination of the first prism 3 and the second prism 4 and the arrangement of elements on each surface. This helps to build a compact and efficient optical module in a limited space, and is particularly suitable for application scenarios such as near-eye display.

[0142] Integrating the polarized reflection element 7, the phase retarder 6 and the beam splitter 5 on the specific surfaces of the prism and the lens helps to simplify the design and manufacturing process and improve production efficiency. By optimizing the component configuration and reducing the number of unnecessary parts, the production cost of the optical module can be reduced.

[0143] In some examples of this application, see Figure 1 , the angle θ between the fourth surface S4 and the vertical direction 1 It is an acute angle.

[0144] See also Figure 1 , the vertical direction in this example of the present application refers to the direction perpendicular to the optical axes of the first lens 1 and the second lens 2.

[0145] In the optical module provided in the embodiment of the present application, light starts from the display screen, passes through the refraction and reflection of multiple optical surfaces (such as the fourth surface S4, the fifth surface S5 and the sixth surface S6, etc.), and finally enters the human eye S0 to form an image. 1 The design means that the light will be deflected at a certain angle when passing through the fourth surface S4. This deflection helps to optimize the light path and reduce unnecessary energy loss.

[0146] Image quality is a key indicator of optical module performance. By precisely controlling the angle and curvature of each optical surface, aberrations can be significantly reduced, thereby improving image quality. 1 The design helps to better control the refraction direction of light when it passes through the fourth surface S4, thereby reducing the aberration caused by improper deflection of light and improving the clarity of the image.

[0147] While maintaining the imaging quality, the optical module also faces the challenge of compactness and lightness. By designing the fourth surface S4 to form an acute angle with the vertical direction, the volume of the prism can be reduced to a certain extent, thereby reducing the weight and volume of the entire optical module. This is of great significance for improving the wearing comfort of users.

[0148] The optical module needs to adapt to individual differences in eye distance, pupil distance, and other factors of different users, as well as different usage environments. 1 The design provides certain flexibility and adaptability for the optical module. By adjusting the angle of the fourth surface S4, the light path can be changed to a certain extent, thereby meeting the needs of different users and usage environments.

[0149] In some examples of this application, see Figure 1 , the second prism 4 further includes a fifth surface S5; an air gap is provided between the fifth surface S5 and the sixth surface S6, so that the light incident on the fifth surface S5 is totally reflected; the optical module satisfies: EFL / EFL 35 ≤0.1; wherein EFL is the effective focal length of the optical module, EFL 35 It is the effective focal length of the light incident from the third surface S3 and emitted from the fifth surface S5.

[0150] In this example of the present application, see Figure 1An air gap is provided between the fifth surface S5 of the second prism 4 and the sixth surface S6 of the second lens 2. This design enables the light incident on the fifth surface S5 to be totally reflected. This mechanism helps to reduce the loss of light and improve the utilization rate of light, thereby enhancing the brightness of the image. In addition, the occurrence of total reflection enables the light to be transmitted along a specific path inside the prism, which helps to achieve precise control and guidance of the light. By reasonably designing the shape and surface parameters of the prism, the transmission path of the light can be further optimized to meet specific imaging requirements.

[0151] It should be noted that total reflection can maintain the original properties of light, such as polarization state and intensity, which is crucial to maintaining high-quality images. By precisely controlling the conditions and paths of total reflection, aberrations and distortions can be further reduced, thereby improving the clarity and accuracy of imaging.

[0152] The effective focal length EFL of the optical module is an important indicator to describe its imaging capability. 35 represents the effective focal length of the light incident from the third surface S3 and emitted from the fifth surface S5. By satisfying EFL / EFL 35 The condition of ≤0.1 can ensure that the optical module has consistent imaging performance at different field angles. In addition, focal length matching and reasonable constraints help optimize the design of the optical module, making it more compact and lightweight while meeting imaging requirements.

[0153] In some examples of this application, see Figure 1 The second prism 4 further includes an eighth surface S8, and the angle θ formed by the optical axis of the eighth surface S8 and the horizontal direction is 2 The optical module further comprises a display screen 8, and the display screen 8 is located on one side of the eighth surface S8.

[0154] The optical axis of the eighth surface S8 forms an acute angle θ with the horizontal direction. 2 This design allows the light to be effectively deflected when passing through the eighth surface S8. This deflection not only optimizes the light path to make it more in line with the imaging requirements of the optical module, but also helps to reduce unnecessary energy loss.

[0155] It should be noted that the horizontal direction in the example of the present application refers to the optical axis direction of the first lens 1 and the second lens.

[0156] By controlling the above θ 2 The angle is acute, which can fine-tune the direction of light propagation, thereby ensuring that the light can be accurately projected onto the retina of the human eye to form a clear image.

[0157] Acute angle θ 2The design also helps to expand the field of view of the optical module. The field of view is an important indicator for measuring the range of images that a user can see. By adjusting the angle of the eighth surface S8, the range of light entering the human eye S0 can be increased, so that the user can view a wider range of image content.

[0158] While maintaining the imaging quality, the optical module is also faced with weight and volume limitations. By designing the eighth surface S8 (belonging to the second prism 2) to be at an acute angle to the horizontal direction, the volume of the prism can be reduced to a certain extent, thereby reducing the weight and volume of the entire optical module. This is crucial to improving user experience and portability.

[0159] In the optical module provided by the present application, the display screen 8 is located on one side of the eighth surface S8. This layout enables light to be emitted directly from the display screen 8 and projected to the human eye S0 after being deflected by the eighth surface S8. This direct light path reduces the number of refractions and reflections of light, thereby reducing the possibility of aberrations and distortions and improving imaging quality.

[0160] In some examples of the present application, the effective focal length EFL of the optical module is 13.4 mm ≤ EFL ≤ 15.2 mm.

[0161] Effective focal length EFL is an important indicator to describe the imaging capability of optical modules.

[0162] The effective focal length of the optical module of the present application is in the range of 13.4mm to 15.2mm, which can ensure that the optical module can provide high-quality imaging at different field angles. This focal length range helps to reduce aberrations and distortions, thereby maintaining image clarity and accuracy. This is particularly important for near-eye display devices because it is directly related to the user's visual experience.

[0163] In addition, limiting the effective focal length also helps optimize the compactness of the optical module. While maintaining image quality, by selecting the appropriate focal length range, the size of the prism and lens can be reduced, thereby reducing the weight and volume of the entire optical module. This is crucial for improving the wearing comfort of near-eye display devices, especially in application scenarios such as XR / AR that require long-term wear.

[0164] In some examples of the present application, the optical module includes 3 or 4 curved surfaces.

[0165] In an optical module, the advantages of having multiple curved surfaces include many aspects, which are described below.

[0166] 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 distortions and improving imaging quality.

[0167] From the perspective of enhancing the flexibility of optical module design: more curved surfaces mean more design parameters that can be adjusted, thus enhancing the design flexibility of the module. For example, the performance of the module, such as field of view and resolution, can be optimized by adjusting the curved surface parameters.

[0168] 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.

[0169] However, in optical modules, too many curved surfaces can also bring some defects, as follows:

[0170] 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.

[0171] Multiple curved surfaces increase the difficulty of processing and assembly, requiring higher precision and more complex processes. This will lead to higher production costs and a certain risk of processing errors.

[0172] The 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.

[0173] The optical module design of the embodiment of the present application includes 3 to 4 curved surfaces. The design of 3 to 4 curved surfaces can optimize the light path while ensuring the effective transmission of light, reduce unnecessary refraction and reflection, and thus reduce light loss. By precisely designing the shape and parameters of the curved surfaces, aberrations and distortions can be reduced, the imaging quality can be improved, and a clearer visual experience can be provided to users. Compared with designs with more curved surfaces, optical modules with 3 to 4 curved surfaces are simpler in design and processing. This not only reduces the design cost, but also reduces the complexity and potential errors in the processing process, and improves production efficiency and yield. In addition, the design of 3 to 4 curved surfaces enables the optical module to have better flexibility and adaptability while maintaining certain performance.

[0174] In practical applications, it is necessary to comprehensively consider factors such as specific needs, design cost, production cost, and optical module performance to select the most appropriate number of surfaces. In this application, 3 to 4 surfaces are preferably used.

[0175] In some examples of the present application, the first surface S1 and the second surface S2 of the first lens 1 are planes or curved surfaces; the sixth surface S6 of the second lens 2 is a plane, and the seventh surface S7 of the second lens 2 is a curved surface.

[0176] When the optical module of the present application includes three curved surfaces, one of the curved surfaces is the seventh surface S7 of the second lens 2. The sixth surface S6 of the second lens 2 is a plane, and its combination with the seventh surface S7 (curved surface) helps to more effectively control the light path. In particular, when light enters from the display screen 8 through the eighth surface S8 of the second prism 4, the seventh surface S7 (curved surface) can ensure that the light is guided to the human eye S0 at the correct angle and direction, thereby providing a clear, distortion-free image.

[0177] By controlling the shapes of the sixth surface S6 and the seventh surface S7, the focal length and aberration correction of the optical module can be optimized, thereby significantly improving the imaging quality. The curved design of the seventh surface S7 helps to reduce aberrations, which is crucial for providing high-quality near-eye display.

[0178] Although curved lenses are usually more complex and costly than flat lenses, in the design of this application, by combining flat and curved surfaces, a large field of view and high imaging quality can be achieved while maintaining a small volume. This is an important advantage for near-eye display devices that require a compact design.

[0179] When the number of curved surfaces in the optical module needs to be increased, at least one of the two surfaces of the first lens 1 may be provided with a curved surface.

[0180] By setting at least one of the two surfaces of the first lens 1 as a curved surface, it is possible to optimize imaging quality, increase the field of view, reduce the volume of the optical module, improve wearing comfort and enhance immersion, etc. These advantages together improve the performance and user experience of near-eye display devices.

[0181] In some examples of the present application, the third surface S3 of the first prism 3 is a curved surface or a flat surface; the bonding surface of the first prism 3 and the second prism 4 is a fourth surface S4, and the fourth surface S4 is a flat surface; the fifth surface S5 of the second prism 4 is a flat surface.

[0182] The third surface S3 of the first prism 1 can be a curved surface or a flat surface, and this design provides great flexibility. The curved surface design helps to better control the refraction and reflection of light, thereby optimizing the imaging quality, especially at a large field of view. The flat surface design may be easier to manufacture and calibrate, which helps to reduce costs and improve production efficiency.

[0183] That is to say, when a curved surface needs to be added to the optical module, the third surface S3 of the first prism 3 can be designed as a curved surface.

[0184] The fourth surface S4 and the fifth surface S5 are surfaces on which the first prism 3 and the second prism 4 are glued to each other. The fourth surface S4 and the fifth surface S5 are both planes, which helps to simplify the design of the optical path. The reflection and refraction behavior of light on a plane surface is more regular, and therefore easier to predict and control, which helps to ensure that the light can propagate along the expected path, thereby providing a clear and stable image.

[0185] In addition, the fourth surface S4 and the fifth surface S5 are flat designs, which are easier to manufacture and calibrate than curved designs. By using flat surfaces, high-precision manufacturing and assembly can be more easily achieved, thereby ensuring the overall performance of the glued prism. Flat designs are generally more advantageous in terms of material and processing costs. By reducing the need for complex curved surface processing, production costs can be reduced and the market competitiveness of products can be improved.

[0186] In some examples of the present application, the centers of the first surface S1, the third surface S3 and the seventh surface S7 are all located on the same optical axis, and the positive direction of the vector height of the first surface S1, the third surface S3 and the seventh surface S7 is the direction away from the human eye S0 along the optical axis.

[0187] The centers of the first surface S1, the third surface S3, and the seventh surface S7 are all located on the same optical axis, which ensures that the light can maintain a high degree of consistency and accuracy when passing through these surfaces. The optical axis, as the reference path of the light, is crucial to ensuring the imaging quality. The positive direction of the vector height of these surfaces is the direction away from the human eye S0 along the optical axis, which means that the light will be refracted or reflected away from the human eye when passing through these surfaces. This design helps to optimize the light path and ensure that the light can be transmitted to the human eye in the expected manner, thereby providing a clear image.

[0188] 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 second surface S2 , the third surface S3 , the sixth surface S6 , the seventh surface S7 , and the eighth surface S8 .

[0189] According to this example of the present application, during the propagation process, although the light passes through the deflections of prisms and lenses, it always remains in a coaxial optical path, that is, the light always passes through the optical axes of all elements instead of forming an off-axis system.

[0190] The main light of the 0-degree field of view coincides with the optical axis of all key surfaces, which ensures that the light has minimal aberration and distortion when passing through these surfaces. This design can significantly improve the imaging quality and make the image clearer. The design of the coaxial optical path greatly simplifies the optical design and calculation process of the optical module.

[0191] The light always propagates along the optical axis, reducing the loss at the edge of the prism and lens. This helps to improve the utilization of light energy, allowing more light to reach the human eye and enhance the imaging brightness of the optical module.

[0192] The design of the coaxial optical path 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.

[0193] In some examples of the present application, a protective glass 9 is provided on the light emitting surface of the display screen 8 .

[0194] 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 serves as a protective barrier for the display screen 8 and can resist external damages such as scratches, impacts and abrasion, thereby extending the service life of the display screen 8.

[0195] According to another embodiment of the present application, a near-eye display device is also provided, and the near-eye display device includes the optical module as described above.

[0196] The near-eye display device is, for example, an XR device. The XR device includes an AR device, a VR device or an MR device.

[0197] The optical module provided by the present application is described in detail below through Examples 1 to 4.

[0198] Example 1

[0199] See also Figure 2 The optical module provided in this embodiment 1 includes a first lens 1, a second lens 2 and a cemented prism located between the two lenses, wherein the cemented prism mainly consists of two prisms and a polarized reflection element 7;

[0200] The first lens 1 includes a first surface S1 and a second surface S2. The first surface S1 is away from the cemented prism, and the second surface S2 is adjacent to the cemented prism. The curvature of the first surface S1 is C 1 , the curvature of the second surface S2 is C 2 ;

[0201] The second lens 2 includes a sixth surface S6 and a seventh surface S7, the sixth surface S6 is provided with a phase retarder 6, and the seventh surface S7 is provided with a beam splitter 5;

[0202] The cemented prism includes a first prism 3 and a second prism 4 that are cemented to each other. The first prism 3 includes a third surface S3 adjacent to the first lens 1. The curvature of the third surface S3 is C 3The bonding surface of the first prism 3 and the second prism 4 is a fourth surface S4, and the polarized reflective element 7 is disposed on the fourth surface S4; the angle θ between the fourth surface S4 and the vertical direction is 1 is an acute angle;

[0203] The second prism 4 includes a fifth surface S5, and an air gap is provided between the fifth surface S5 and the sixth surface S6, so that the light incident on the fifth surface S5 is totally reflected; the second prism 4 also includes an eighth surface S8, and the angle θ formed by the optical axis of the eighth surface S8 and the horizontal direction is 2 is an acute angle;

[0204] The optical module further includes a display screen 8, and the display screen 8 is located on one side of the eighth surface S8;

[0205] The chief ray of the 0 degree field of view coincides with the optical axes of the first surface S1 , the second surface S2 , the third surface S3 , the sixth surface S6 , the seventh surface S7 , and the eighth surface S8 .

[0206] The parameters of each optical element in the optical module of this embodiment 1 are shown in Table 1.

[0207] Table 1

[0208]

[0209] 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.

[0210] The EFL involved in this embodiment 1 12 / EFL 67 , EFL 12 / EFL 35 , EFL 12 / EFL, EFL 67 / EFL, C 1 / C 2 、|C 1 / C 7 |、|C 3 / C 7 |、EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0211] See also Figure 3The MTF diagram of the optical module of the present embodiment 1 is shown, which shows the modulation transfer function at different spatial frequencies, and is used to evaluate the performance of the optical module; wherein the horizontal axis represents the spatial frequency, and the unit is cycles per millimeter. The higher the frequency, the richer the image details; the vertical axis represents the modulation value, that is, the MTF value, ranging from 0 to 1. The higher the MTF value, the better the image contrast is maintained. Figure 3 It can be seen that the optical module of this embodiment 1 has good imaging performance.

[0212] Example 2

[0213] See also Figure 4 The optical module shown in this embodiment 2 has an optical architecture that is the same as that of the above-mentioned embodiment 1, except for the specific optical parameters in the optical module. Please refer to Table 2 for the optical parameters of the optical module provided in this embodiment 2.

[0214] Table 2

[0215]

[0216] 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.

[0217] In this embodiment 2, EFL 12 / EFL 67 , EFL 12 / EFL 35 , EFL 12 / EFL, EFL 67 / EFL, C 1 / C 2 、|C 1 / C 7 |、|C 3 / C 7 |、EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0218] See also Figure 5 The MTF diagram of the optical module is shown in Figure 5 It can be seen that the optical module of this embodiment 2 has good imaging performance.

[0219] Example 3

[0220] See also Figure 6The optical module shown in this embodiment 3 has an optical architecture that is the same as that of embodiment 1, except for the optical parameters in the optical module. Please refer to Table 3 for the optical parameters of the optical module provided in this embodiment 3.

[0221] Table 3

[0222]

[0223] 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.

[0224] In this embodiment 3, EFL 12 / EFL 67 , EFL 12 / EFL 35 , EFL 12 / EFL, EFL 67 / EFL, C 1 / C 2 、|C 1 / C 7 |、|C 3 / C 7 |、EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0225] See also Figure 7 The MTF diagram of the optical module is shown in Figure 7 It can be seen that the optical module of this embodiment 3 has good imaging performance.

[0226] Example 4

[0227] See also Figure 8 The optical module shown in this embodiment 4 has an optical architecture that is the same 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.

[0228] Table 4

[0229]

[0230] 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.

[0231] In this embodiment 4, EFL 12 / EFL 67 , EFL 12 / EFL 35 , EFL 12 / EFL, EFL 67 / EFL, C 1 / C 2 、|C 1 / C 7 |、|C 3 / C 7 |、EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0232] See also Fig. 9 The MTF diagram of the optical module is shown in Fig. 9 It can be seen that the optical module of this embodiment 4 has good imaging performance.

[0233] Table 5 Parameters in Examples 1 to 4

[0234]

[0235]

[0236] 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.

[0237] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An optical module for XR optical equipment, characterized in that: It comprises a first lens (1), a second lens (2) and a cemented prism located between the two lenses; The cemented prism mainly consists of two prisms and a polarized reflection element (7); The second lens (2) comprises a sixth surface (S6) and a seventh surface (S7), an air gap is provided between the sixth surface (S6) and the cemented prism, a phase retarder (6) is provided between the sixth surface (S6) and the cemented prism, and the seventh surface (S7) is a partial reflection surface; The optical module meets the following conditions: 2.3≤EFL 12 / EFL 67 ≤24.1; among which, EFL 12 is the effective focal length of the first lens (1), 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).

2. The optical module according to claim 1, characterized in that: The optical module satisfies: 2.77≤EFL 12 / EFL 67 ≤5.

3. The optical module according to claim 1, characterized in that: The optical module meets: EFL 12 / EFL 35 ≤3.2; among which, EFL 35 is the effective focal length of the cemented prism.

4. The optical module according to claim 1, characterized in that: The optical module meets the following conditions: 3.2≤EFL 12 / EFL≤31.4; wherein EFL is the effective focal length of the optical module.

5. The optical module according to claim 4, characterized in that: The optical module satisfies: 3.42≤EFL 12 / EFL≤6.

84.

6. The optical module according to claim 1, characterized in that: The optical module satisfies: 1.2≤EFL 67 / EFL≤1.4; wherein EFL is the effective focal length of the optical module.

7. The optical module according to claim 1, characterized in that: The first lens (1) comprises a first surface (S1) and a second surface (S2), the first surface (S1) is away from the cemented prism, the second surface (S2) is adjacent to the cemented prism, the curvature of the first surface (S1) is C1, the curvature of the second surface (S2) is C2, and C1 / C2≥-0.

9.

8. The optical module according to claim 7, characterized in that: The curvature of the seventh surface (S7) is C7, and |C1 / C7|≤1.

2.

9. The optical module according to claim 8, characterized in that: The glued prism comprises a first prism (3) and a second prism (4) glued to each other; The first prism (3) comprises a third surface (S3) adjacent to the first lens (1), the curvature of the third surface (S3) is C3, and |C3 / C7|≤2.

10. The optical module according to claim 9, characterized in that: The bonding surface of the first prism (3) and the second prism (4) is a fourth surface (S4), and the polarized reflection element (7) is arranged on the fourth surface (S4); The phase retarder (6) is arranged on the sixth surface (S6); A light splitting element (5) is arranged on the seventh surface (S7).

11. The optical module according to claim 10, characterized in that: An angle θ1 formed between the fourth surface (S4) and the vertical direction is an acute angle.

12. The optical module according to claim 10, characterized in that: The second prism (4) further comprises a fifth surface (S5); An air gap is provided between the fifth surface (S5) and the sixth surface (S6), so that light incident on the fifth surface (S5) is totally reflected; The optical module meets: EFL / EFL 35 ≤0.1; wherein EFL is the effective focal length of the optical module, EFL 35 It is the effective focal length of light incident from the third surface (S3) and emitted from the fifth surface (S5).

13. The optical module according to claim 12, characterized in that: The second prism (4) further comprises an eighth surface (S8); The optical module further comprises a display screen (8), wherein the display screen (8) is located on one side of the eighth surface (S8), and an angle θ2 formed between the optical axis of the eighth surface (S8) and the horizontal direction is an acute angle.

14. The optical module according to claim 13, characterized in that: The effective focal length EFL of the optical module is 13.4 mm ≤ EFL ≤ 15.2 mm.

15. The optical module according to claim 13, characterized in that: The optical module includes 3 or 4 curved surfaces.

16. The optical module according to claim 15, characterized in that: The first surface (S1) and the second surface (S2) of the first lens (1) are flat surfaces or curved surfaces; The sixth surface (S6) is a plane, and the seventh surface (S7) is a curved surface.

17. The optical module according to claim 16, characterized in that: The third surface (S3) of the first prism (3) is a curved surface or a flat surface; The bonding surface of the first prism (3) and the second prism (4) is a fourth surface (S4), and the fourth surface (S4) is a plane; The fifth surface (S5) of the second prism (4) is a plane.

18. The optical module according to claim 17, characterized in that: The centers of the first surface (S1), the third surface (S3) and the seventh surface (S7) are all located on the same optical axis, and the positive direction of the vector height of the first surface (S1), the third surface (S3) and the seventh surface (S7) is the direction away from the human eye (S0) along the optical axis.

19. The optical module according to claim 17, characterized in that: The chief ray of the 0 degree field of view coincides with the optical axes of the first surface (S1), the second surface (S2), the third surface (S3), the sixth surface (S6), the seventh surface (S7) and the eighth surface (S8).

20. A near-eye display device, characterized in that: Comprising the optical module as described in any one of claims 1-19.

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