Optical module and near-eye display device

Abstract

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 the optical module comprises a first lens, a second lens, and a cemented prism located between the two lenses; the cemented prism mainly comprises 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 partially reflective surface; the optical module satisfies: 2.3≤EFL 12 / EFL 67 ≤24.1; wherein, EFL 12 is an effective focal length of the first lens, and EFL 67 is an effective focal length of a light ray incident from the sixth surface, reflected by the seventh surface, and then emitted from the sixth surface.

Description

Technical Field

[0001] This application relates to the field of optical imaging technology, and more specifically, to an optical module and a near-eye display device. Background Technology

[0002] With the advancement of technology, XR technology is gradually showing broad application prospects in entertainment, education, and healthcare. XR technology encompasses AR, VR, and MR technologies and has wide applications in near-eye display devices. As a key carrier of XR technology, the performance improvement of near-eye display devices is crucial for user experience. Traditional near-eye display devices have certain limitations in terms of size, image quality, and field of view, making it difficult to meet users' pursuit of immersive experiences. 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, this application provides an optical module. The optical module is used in XR optical devices and includes a first lens, a second lens, and a cemented prism located between the two lenses;

[0005] The cemented prism mainly consists of two prisms and a polarizing reflective 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, and a phase retarder is provided between the sixth surface and the cemented prism. The seventh surface is a partially reflective surface.

[0007] The optical module satisfies: 2.3 ≤ EFL 12 / EFL 67 ≤24.1; where EFL 12 EFL is the effective focal length of the first lens. 67 The effective focal length is the distance from which light enters from the sixth surface, is reflected by the seventh surface, and then exits 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; where EFL 35 The effective focal length of the cemented prism is given.

[0010] Optionally, the optical module satisfies: 3.2 ≤ EFL 12 / EFL≤31.4; where 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; where 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 being away from the cemented prism, the second surface being adjacent to the cemented prism, the curvature of the first surface being C1, the curvature of the second surface being C2, and C1 / C2 ≥ -0.9.

[0014] Optionally, the curvature of the seventh surface is C7, and |C1 / C7|≤1.2.

[0015] Optionally, the glued prism includes a first prism and a second prism glued together.

[0016] The first prism includes a third surface adjacent to the first lens, the curvature of the third surface being C3, and |C3 / C7|≤2.

[0017] Optionally, the bonding surface between the first prism and the second prism is a fourth surface, and the polarizing reflective element is disposed on the fourth surface;

[0018] The phase delayer is disposed on the sixth surface;

[0019] A beam-splitting element is disposed on the seventh surface.

[0020] Optionally, the angle θ1 formed between the fourth surface and the vertical direction 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 undergoes total internal reflection;

[0023] The optical module satisfies: EFL / EFL 35 ≤0.1; where EFL is the effective focal length of the optical module. 35 The effective focal length from which light enters from the third surface and exits from the fifth surface.

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

[0025] The optical module also includes a display screen, which is located on one side of the eighth surface, and the angle θ2 formed by the optical axis of the eighth surface and the horizontal direction is an acute angle.

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

[0027] Optionally, the optical module includes three or four curved surfaces.

[0028] Optionally, the first surface and the second surface of the first lens are planar 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 plane;

[0031] The bonding surface between 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, the 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 height of the first surface, the third surface, and the seventh surface is along the optical axis away from the human eye.

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

[0035] Secondly, this application provides a near-eye display device. The near-eye display device includes the optical module as described in the first aspect.

[0036] The beneficial effects of this application are as follows:

[0037] This application provides an optical module suitable for XR technology, addressing the shortcomings of existing near-eye display devices in terms of size, image quality, and field of view. The optical module provided in this application boasts advantages such as small size, high image quality, and a wide field of view. By employing a specially designed optical module, near-eye display devices can achieve a compact design with a wide field of view while maintaining good image quality, providing users with a more immersive virtual reality or augmented reality experience.

[0038] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

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

[0040] Figure 1 This is one of the structural schematic diagrams of the optical module provided in the embodiments of this application;

[0041] Figure 2 This is the second schematic diagram of the structure of the optical module provided in the embodiments of this application;

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

[0043] Figure 4 The third schematic diagram of the structure of the optical module provided in the embodiments of this application;

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

[0045] Figure 6 Fourth schematic diagram of the structure of the optical module provided in the embodiments of this application;

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

[0047] Figure 8 Fifth schematic diagram of the structure of the optical module provided in the embodiments of this application;

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

[0049] Explanation of reference numerals in the attached figures:

[0050] 1. First lens; 2. Second lens; 3. First prism; 4. Second prism; 5. Beam splitter; 6. Phase retarder; 7. Polarizing reflector; 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 Implementation

[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, numerical expressions, and values ​​of the components and steps 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 and is in no way intended to limit the scope of this application and its application or use.

[0054] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

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

[0056] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

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

[0058] According to one embodiment of this application, an optical module is provided, see [link to relevant documentation]. 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 mainly consists of two prisms and a polarizing reflective 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; the seventh surface S7 is a partial reflective surface; the optical module satisfies: 2.3 ≤ EFL 12 / EFL 67 ≤24.1; where EFL 12 EFL is the effective focal length of the first lens 1. 67 The effective focal length is the distance from which light enters from the sixth surface S6, is reflected by the seventh surface S7, and then exits from the sixth surface S6.

[0059] The optical module provided in this application embodiment 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 this application embodiment is referred to [reference needed]. Figure 1 It mainly consists of a cemented prism and two lenses, and also incorporates key optical components such as a phase retarder 6 and a polarization reflection element 7 into the optical module. The main optical components in the optical module of this application are described below.

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

[0062] See Figure 1 The second lens 2 includes a sixth surface S6 and a seventh surface S7, wherein the seventh surface S7 is a partially reflective surface used to reflect part of the light, which is beneficial for realizing optical path folding.

[0063] The optical module of this embodiment further includes a cemented prism, which is disposed between the first lens 1 and the second lens 2. Specifically, the cemented prism is mainly composed of two prisms cemented together and includes a polarizing reflective element 7, wherein the polarizing reflective element 7 can be disposed on the cementing surface of the two prisms. Because the cemented prism includes the polarizing reflective element 7, it plays a crucial role in optical path folding and polarization control within the optical module.

[0064] In the optical module provided in this application embodiment, an air gap is provided between the cemented prism and the second lens 2. Specifically, see... Figure 1 An air gap is provided between the fifth surface S5 of the second prism 4 and the sixth surface S6 of the second lens 2, which enables light to undergo total internal reflection on the fifth surface S5. In other words, in the optical module, the fifth surface S5 is a total internal reflection surface.

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

[0066] Of course, the phase delayer 6 can also be adjusted to a half-wave plate or the like as needed, and this application does not impose any restrictions on this.

[0067] The optical module in this embodiment also satisfies a specific effective focal length ratio, namely 2.3 ≤ EFL. 12 / EFL 67 ≤24.1; where EFL 12 The effective focal length (EFL) of the first lens 1 is... 12 This represents the effective focal length of light rays entering from the first surface S1 and exiting from the second surface S2 of the first lens 1; while EFL 67 The effective focal length of light rays entering from the sixth surface S6, being reflected by the seventh surface S7, and then exiting from the sixth surface S6 (the light rays are folded in the second lens 2).

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

[0069] Specifically, in this embodiment of the application, by controlling the EFL 12 and EFL 67 The ratio of light to prisms ensures accurate focusing of light after passing through lenses and prisms, thereby reducing aberrations and distortions and improving image quality. This ratio also helps balance the magnification and field of view of the optical module, resulting in images that are both clear and wide.

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

[0071] The effective focal length range proposed in this embodiment allows for a more compact optical module while ensuring image quality and field of view. This is particularly important for near-eye display devices, as a smaller size improves user comfort.

[0072] By comparing the EFL in different embodiments (Examples 1 to 4 below), 12 and EFL 67 The values ​​show that the ratio between them consistently remains between 2.3 and 24.1. This verifies the effectiveness and feasibility of this ratio in practical design.

[0073] The optical module provided in this application can optimize image 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 in this embodiment can optimize imaging quality and reduce aberrations and distortions while ensuring a large field of view.

[0074] The optical module provided in this application embodiment has a compact module structure. Specifically, by rationally designing the positional relationship between the two lenses and the cemented prism, and especially by utilizing the air gap and the partial reflection characteristics of the phase retarder 6, the polarization reflection element 7, and the seventh surface S7, the optical module of this embodiment achieves a more compact module structure, which is beneficial for integrating higher-performance optical components within a limited space.

[0075] The optical module provided in this application embodiment can improve light utilization. Specifically, in the optical module, the seventh surface S7 serves as a partial reflective surface, capable of reflecting part of the light, achieving optical path folding, thereby improving light utilization, reducing light loss, and enhancing the overall brightness of the module.

[0076] Furthermore, the polarization reflection element 7 in the cemented prism can control the polarization state of light, which is crucial for improving the contrast and clarity of the displayed image, especially in XR applications that require accurate color reproduction and depth perception.

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

[0078] The principle behind the ability of optical modules to achieve a small size is as follows:

[0079] (1) The cemented prism mainly consists of two prisms and a polarizing reflective element 7. This design reduces the gap between the prisms by cementing them together, thereby saving space. The compact structure of the cemented prism allows the entire optical module to maintain high performance while significantly reducing its size.

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

[0081] The principle behind the optical module's ability to achieve a wide viewing angle is as follows:

[0082] The seventh surface S7 of the second lens 2 is a partially reflective surface, meaning that when light reaches this surface, part of it is reflected back to the sixth surface, while the other part continues to propagate. This design not only increases the utilization rate of light but also achieves light folding through multiple reflections, thereby increasing the viewing angle.

[0083] The principle behind achieving high imaging quality using optical modules is as follows:

[0084] The optical module of this application satisfies 2.3≤EFL 12 / EFL 67 The ratio ≤24.1 means that the effective focal length of the first lens 1 is maintained in a reasonable ratio to the effective focal length of the light rays incident on the sixth surface S6, reflected by the seventh surface S7, and then exiting from the sixth surface S6. This matching relationship helps to maintain the parallelism and focusing of the light rays, reduces aberrations and distortions, and thus improves image quality.

[0085] This application provides an optical module applicable to XR technology, addressing the shortcomings of existing near-eye display devices in terms of size, image quality, and field of view. The optical module provided in this application boasts advantages such as small size, high image quality, and a wide field of view. By employing a specially designed optical module, near-eye display devices can achieve a compact design with a wide field of view while maintaining good image quality, providing users with a more immersive virtual reality or augmented reality experience.

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

[0087] EFL 12 This represents the effective focal length of the first lens 1, while EFL... 67 This represents the effective focal length of light rays entering from the sixth surface S6 of the second lens 2, being reflected by the seventh surface S7, and then exiting from the sixth surface S6. Further setting the EFL... 12 With EFL 67 A ratio between 2.77 and 5 ensures that light, after being refracted and reflected by lenses and prisms inside the optical module, maintains excellent focusing performance, reduces aberrations and distortions, and thus improves image quality.

[0088] At the same time, this optimized scaling range also helps control the overall size of the optical module. If EFL 12 / EFL 67 If the focal length is too small, it may be necessary to increase the lens thickness or change the lens curvature to meet the focal length requirements, which would undoubtedly increase the size and weight of the module. Setting an upper limit of 5, on the other hand, can prevent the module from becoming too large while ensuring image quality, thus improving the user's wearing comfort.

[0089] The seventh surface S7 of the second lens 2 is a partially reflective surface, used to reflect part of the light rays to achieve optical path folding. In EFL 12 / EFL 67 When the ratio is controlled between 2.77 and 5, the reflection angle and reflection efficiency of light on the seventh surface S7 can be optimized, thereby improving the utilization rate of 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 image quality, and 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 By controlling the parameters within the preferred range of this example, the manufacturing process of the optical module can be simplified. This range ensures a relatively stable light transmission path within the module, reducing the requirements for lens and prism processing precision and thus lowering manufacturing costs.

[0092] In conclusion, the proportional relationship is 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 this application, the optical module satisfies: EFL 12 / EFL 35 ≤3.2; where EFL 35 The effective focal length of the cemented prism is given.

[0094] The effective focal length ratio described in this example refers to the ratio of the effective focal lengths of 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 The upper limit of the ratio between ).

[0095] Regarding EFL in this application 12 With EFL 35 The proportional relationship essentially controls the refraction and focusing behavior of light after passing through the first lens and the cemented prism. By limiting this ratio, it can be ensured that light travels along a predetermined path within the optical module, reducing aberrations and distortion.

[0096] Specifically, when EFL 12 With EFL 35 When the ratio is controlled within the range provided in this example, the aberrations generated after light passes through the optical module can be reduced. This is because aberrations are often related to the refraction angle and focusing position of light, while EFL... 12 and EFL 35 The proportional relationship is a manifestation of precise control over these factors.

[0097] While ensuring image quality, through reasonable design of EFL 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, as a smaller, lighter design can improve user comfort.

[0098] In practical applications, EFL may need to be adapted to different usage scenarios and user needs. 12 / EFL 35 The proportional relationship can be adjusted accordingly. For example, when pursuing higher resolution, the EFL can be appropriately reduced. 12 With EFL 35 The proportion of the viewpoint is relatively small; when a wider perspective is needed, this proportion may need to be increased appropriately.

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

[0100] In the examples of this application, it is proposed that the optical module satisfies the proportional relationship 3.2 ≤ EFL. 12 / EFL≤31.4; where EFL 12 The effective focal length (EFL) represents the effective focal length of the first lens 1, while the effective focal length (EFL) represents the effective focal length of the entire optical module. This ratio is proposed to achieve specific technical effects by precisely controlling the ratio of the effective focal length of the first lens 1 to that of the entire optical module.

[0101] Regarding EFL 12 The ratio of EFL to the image quality of the optical module is actually a matter of balancing the image quality and size of the optical module. A larger EFL... 12 The / EFL ratio indicates that the first lens 1 has a strong focusing ability for light, which helps improve image quality, but may also lead to an increase in the size of the optical module. Conversely, a smaller ratio may make the module more compact, but the image quality may be affected. Therefore, by setting this ratio range in this application, the overall size of the optical module can be minimized while ensuring image quality.

[0102] Different application scenarios have different requirements for the imaging quality and size of optical modules. By adjusting the EFL... 12 The ratio of optical module to EFL allows it to adapt to different application scenarios.

[0103] According to this example in this application, in the ratio 3.2 ≤ EFL 12 Under the constraint of / EFL≤31.4, the focusing capability of the first lens 1 is reasonably controlled, which helps to reduce aberrations and distortions and improve image clarity. 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 within the optical module, further improving image quality.

[0104] Furthermore, by using EFL 12By limiting the ratio to the EFL (Eye Fluorescent Lens) within a certain range, the size of the optical module can be effectively controlled. This helps improve user comfort and overall experience. This ratio is particularly important in applications with strict size requirements, such as near-eye display devices.

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

[0106] EFL 12 EFL represents the effective focal length of the first lens 1, that is, the effective focal length of the light rays incident from the first surface S1 and exiting from the second surface S2 of the first lens 1. EFL represents the effective focal length of the entire optical module and is an important indicator describing the imaging capability of the optical module. By setting the EFL... 12 With a ratio of 3.42 to 6.84 to EFL, more precise control over the imaging performance of the optical module can be achieved.

[0107] Within the scale range proposed in this example of the application, the focusing effect of the first lens 1 is fully utilized, effectively reducing aberrations and improving image clarity and contrast. This is crucial for near-eye display devices, as it directly relates to the user's visual experience.

[0108] By properly matching EFL 12 The ratio of light to EFL ensures that light can maintain high focusing performance even after multiple refractions and reflections within the optical module, reducing light loss and stray light effects, thereby further improving image quality.

[0109] This aspect ratio range, while maintaining image quality, facilitates the compact design of the optical module. If EFL... 12 An excessively large focal length ratio to EFL might necessitate increasing lens thickness or altering lens curvature to meet focal length requirements, thus increasing the module's size and weight. Setting an upper limit of 6.84, however, ensures image quality while preventing an excessively large module, thereby improving user comfort.

[0110] 3.42≤EFL 12 An EFL of ≤6.84, considered an optimization range, demonstrates significant technical benefits in improving image quality, controlling the size of the optical module, and increasing light utilization. These combined effects make this optical module an excellent choice for high-performance near-eye display devices.

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

[0112] In the examples of this application, it is proposed that the optical module satisfies the proportional relationship 1.2 ≤ EFL. 67 / EFL≤1.4, where EFL 67 The effective focal length (EFL) represents the effective focal length of the second lens 2 in the optical module, while the EFL represents the effective focal length of the entire optical module. This ratio is proposed to achieve specific technical effects by controlling the ratio of the effective focal length of the second lens 2 to the effective focal length of the entire optical module.

[0113] By properly controlling EFL 67 The ratio of the second lens to the EFL ensures that the second lens 2 refracts and focuses light effectively, thereby reducing aberrations and improving image clarity.

[0114] In the optical module provided in this application, the focal lengths of each lens need to be matched to ensure accurate light transmission path and focusing position. This is achieved by setting the EFL (Electronic Fluid Dynamics). 67 The proportional relationship with EFL ensures 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 three examples described in this application, by defining different effective focal length ratios, respectively achieve technical effects such as optimizing optical path design, balancing image quality and optical module size, ensuring light utilization, and optimizing the field of view. These technical effects collectively improve the overall performance of the optical module, thereby providing a better optical solution for near-eye display devices.

[0116] A more preferred value is 1.3 ≤ EFL 67 / EFL≤1.37. This allows for a better balance between image quality and optical module size, while also ensuring light utilization and increasing the field of view.

[0117] See some examples in this application. 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, and the second surface S2 is adjacent to the cemented prism. The curvature of the first surface S1 is C1, and the curvature of the second surface S2 is C2, and C1 / C2 ≥ -0.9.

[0118] The example in this application describes the surface features of the first lens 1, particularly the curvature relationship between its first surface S1 and second surface S2. Specifically, the first surface S1 faces away from the cemented prism, while the second surface S2 is adjacent to the cemented prism, and the curvatures C1 and C2 of these two surfaces satisfy a proportional relationship of C1 / C2 ≥ -0.9. This design aims to achieve the following technical effects by controlling the curvature relationship between the two surfaces of the first lens 1.

[0119] Under the constraint that C1 / C2 ≥ -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 allows light to be better controlled and guided when passing through the first lens 1, reducing light scattering and loss. At the same time, this design also helps to improve the transmission efficiency of light within 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 aberrations and distortions can be significantly reduced. This results in clearer images and improves the user's visual experience.

[0121] The ratio of C1 / C2 ≥ -0.9 also helps to optimize the focusing effect of light, making the image distribution within the field of view more uniform and further improving the imaging quality.

[0122] Furthermore, curvature is also related to lens thickness: to achieve a specific focal length and image quality, the values ​​of C1 and C2 need to be carefully matched. This 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 image quality, thereby helping to reduce the size and weight of the entire optical module.

[0123] In this example of the application, the curvature ratio C1 / C2 of the first surface S1 and the second surface S2 of the first lens 1 is negative, meaning that the curvature directions of the two surfaces are opposite. This indicates that one surface is convex and the other is concave. Due to the different curvature directions, light will be refracted differently when passing through these two surfaces. The convex surface will focus the light towards 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 this application, the curvature of the seventh surface S7 is C7, and |C1 / C7|≤1.2.

[0125] The curvature of the first surface S1 of the first lens 1 is C1, and the first surface S1 is located on the side closer to the human eye S0. The curvature of the seventh surface S7 of the second lens 2 is C7, and the seventh surface S7 is located on the side farther away from the human eye S0.

[0126] The curvature C1 of the first surface S1 of the first lens 1, which is close to the human eye S0, is crucial for the focusing of light. Under the constraint that |C1 / C7|≤1.2, the size of C1 is limited by C7, which helps to ensure that the light is correctly focused on the retina of the human eye after passing through the first lens 1, thereby improving the clarity of the image.

[0127] The curvature of a lens directly affects the imaging quality of an optical module. Under the constraint of |C1 / C7|≤1.2, by controlling the curvature ratio of the two key surfaces, imaging problems such as aberrations and distortions can be significantly reduced, thereby improving image clarity and accuracy.

[0128] Field of view is one of the important performance indicators of near-eye displays. 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 image quality, allowing users to see a wider scene.

[0129] Furthermore, by constraining the curvature of the first lens 1 and the second lens 2 within the range of the above example, the thickness of the two lenses can be well controlled, thereby facilitating the thinning of the entire optical module.

[0130] In this example of the application, setting |C1 / C7≤1.2 helps to achieve high imaging quality while maintaining the compactness of the optical module.

[0131] See some examples in this application. Figure 1 The cemented prism includes a first prism 3 and a second prism 4 cemented together; wherein the first prism 3 includes a third surface S3 adjacent to the first lens 1, the curvature of the third surface S3 is C3, and |C3 / C7|≤2.

[0132] By precisely controlling the ratio between the curvature C3 of the third surface S3 and the curvature C7 of the seventh surface S7, it can be ensured that light undergoes appropriate refraction and reflection when passing through these two surfaces, thereby reducing light loss during transmission. This is significant for improving the brightness and contrast of near-eye display devices. The appropriate curvature ratio in this example helps reduce imaging problems such as aberrations and distortions, thereby improving image clarity. This is crucial for enhancing the user's visual experience.

[0133] The seventh surface S7, as a partial reflective surface, has a significant impact on the widening of the field of view due to its curvature C7. By controlling the size of C7 and maintaining an appropriate proportional relationship with the curvature C3 of the third surface S3, it can be ensured that light retains good divergence after passing through the second lens 2, thereby widening the field of view. This is of great importance for enhancing the user's immersive experience.

[0134] Furthermore, by optimizing the curvature ratio of the lens and prism, the risk of damage caused by stress concentration can be reduced, thereby improving the durability and reliability of the entire optical module.

[0135] In the manufacturing process of optical modules, precise control of the curvature ratio of lenses and prisms ensures the matching and consistency between various components. This helps reduce manufacturing difficulty and cost, and improves product quality and reliability.

[0136] See some examples in this application. Figure 1 The bonding surface between the first prism 3 and the second prism 4 is the fourth surface S4, and the polarization reflection element 7 is disposed on the fourth surface S4; the phase delayer 6 is disposed on the sixth surface S6; and the beam splitter 5 is disposed on the seventh surface S7.

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

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

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

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

[0141] In this application, the optical path can be folded by combining the first prism 3 and the second prism 4, as well as by arranging the components on each surface. This helps to construct a compact and efficient optical module within a limited space, making it particularly suitable for applications such as near-eye displays.

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

[0143] See some examples in this application. Figure 1 The angle θ1 formed between the fourth surface S4 and the vertical direction is an acute angle.

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

[0145] The optical module provided in this application allows light to originate from the display screen, pass through multiple optical surfaces (such as the fourth surface S4, the fifth surface S5, and the sixth surface S6), and finally enter the human eye S0 to form an image. The acute angle θ1 formed by the fourth surface S4 and the vertical direction means that the light is deflected at a certain angle when passing through the fourth surface S4. This deflection helps 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. The design of the acute angle θ1 in this application helps to better control the refraction direction of light as it passes through the fourth surface S4, thereby reducing aberrations caused by improper light deflection and improving image sharpness.

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

[0148] The optical module needs to adapt to individual differences in eye distance, pupil distance, and other parameters among different users, as well as different usage environments. The design of the acute angle θ1 provides the optical module with a certain degree of flexibility and adaptability. By adjusting the angle of the fourth surface S4, the light path can be altered to some extent, thereby meeting the needs of different users and usage environments.

[0149] See some examples in this application. 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 light incident on the fifth surface S5 undergoes total internal reflection; the optical module satisfies: EFL / EFL 35 ≤0.1; where EFL is the effective focal length of the optical module. 35 The effective focal length is the distance from which light enters from the third surface S3 and exits from the fifth surface S5.

[0150] In this example of the application, see Figure 1 An 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 allows light incident on the fifth surface S5 to undergo total internal reflection. This mechanism helps reduce light loss and improve light utilization, thereby enhancing image brightness. Furthermore, total internal reflection allows light to travel along a specific path inside the prism, which facilitates precise control and guidance of the light. By rationally designing the shape and surface parameters of the prism, the light transmission path can be further optimized to meet specific imaging requirements.

[0151] It should be noted that total internal reflection preserves the original properties of light, such as polarization state and intensity, which is crucial for maintaining high-quality images. By precisely controlling the conditions and path of total internal reflection, aberrations and distortions can be further reduced, thereby improving image sharpness and accuracy.

[0152] The effective focal length (EFL) of the optical module is an important indicator describing its imaging capability. 35 This represents the effective focal length of light rays entering from the third surface S3 and exiting from the fifth surface S5. This is achieved by satisfying EFL / EFL. 35 The condition of ≤0.1 ensures that the optical module has consistent imaging performance at different field of view angles. In addition, the matching and reasonable constraint of focal length helps to optimize the design of the optical module, making it more compact and lightweight while meeting imaging requirements.

[0153] See some examples in this application. Figure 1 The second prism 4 also includes an eighth surface S8, the angle θ2 formed by the optical axis of the eighth surface S8 and the horizontal direction is an acute angle; the optical module also includes a display screen 8, 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 θ2 with the horizontal direction. This design allows light to be effectively deflected when passing through the eighth surface S8. This deflection not only optimizes the light path, making it more suitable for 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 this application example refers to the optical axis direction of the first lens 1 and the second lens.

[0156] By controlling the angle θ2 to be an acute angle, the direction of light propagation can be finely adjusted, thereby ensuring that the light can be accurately projected onto the human retina to form a clear image.

[0157] The acute angle θ2 design also helps to expand the field of view of the optical module. The field of view is an important indicator of 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, thus allowing the user to view a wider range of image content.

[0158] While maintaining image quality, optical modules also face limitations in weight and size. By designing the eighth surface S8 (belonging to the second prism 2) 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 size of the entire optical module. This is crucial for improving user experience and portability.

[0159] In the optical module provided in this application, the display screen 8 is located on one side of the eighth surface S8. This arrangement allows light to be emitted directly from the display screen 8, deflected by the eighth surface S8, and then projected onto the human eye S0. This direct light path reduces the number of refractions and reflections of light, thereby reducing the possibility of aberrations and distortions and improving image quality.

[0160] In some examples of this 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 describing the imaging capability of an optical module.

[0162] The optical module of this application has an effective focal length ranging from 13.4mm to 15.2mm, ensuring high-quality imaging at various viewing angles. This focal length range helps reduce aberrations and distortions, thereby maintaining image sharpness and accuracy. This is particularly important for near-eye display devices, as it directly affects the user's visual experience.

[0163] Furthermore, limiting the effective focal length helps optimize the compactness of the optical module. By selecting an appropriate focal length range while maintaining image quality, the size of prisms and lenses can be reduced, thereby decreasing the weight and volume of the entire optical module. This is crucial for improving the wearing comfort of near-eye display devices, especially in applications such as XR / AR that require prolonged wear.

[0164] In some examples of this application, the optical module includes three or four curved surfaces.

[0165] In optical modules, the advantages of having multiple curved surfaces are numerous, which will be described below.

[0166] From the perspective of improving image quality, multiple curved surfaces can more precisely control the refraction and reflection paths of light, thereby reducing aberrations and distortions and improving image quality.

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

[0168] Furthermore, in certain complex applications, such as near-eye display devices requiring a large field of view or high resolution, multiple curved surfaces can provide better optical performance.

[0169] However, excessive use of curved surfaces in optical modules can also lead to some drawbacks, as detailed below:

[0170] Multiple curved surfaces imply more complex optical designs, requiring more computation and optimization work. This can lead to longer optical design cycles and increased design costs.

[0171] The presence of multiple curved surfaces increases the difficulty of machining and assembly, requiring higher precision and more complex processes. This leads to increased production costs and introduces certain risks of machining errors.

[0172] An increase in the number of curved surfaces may lead to an increase in the weight and size of optical components, which is detrimental to lightweight and miniaturized near-eye display devices.

[0173] The optical module design of this application includes 3 to 4 curved surfaces. This design with 3 to 4 curved surfaces optimizes the light path while ensuring effective light transmission, reducing unnecessary refraction and reflection, thereby minimizing light loss. By precisely designing the shape and parameters of the curved surfaces, aberrations and distortions can be reduced, improving image quality and providing users with a clearer visual experience. Compared to designs with more curved surfaces, optical modules with 3 to 4 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, the design with 3 to 4 curved surfaces allows the optical module to maintain certain performance while offering better flexibility and adaptability.

[0174] 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 suitable number of curved surfaces. In this application, it is preferred to use 3 to 4 curved surfaces.

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

[0176] When the optical module of this application includes three curved surfaces, one of them is the seventh surface S7 of the second lens 2. The sixth surface S6 of the second lens 2 is flat, and its combination with the seventh surface S7 (curved surface) helps to control the light path more effectively. 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) ensures 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 image quality. The curved design of the seventh surface S7 helps reduce aberrations, which is crucial for providing high-quality near-eye displays.

[0178] While curved lenses are generally more complex and expensive than flat lenses, the design in this application combines flat and curved surfaces to achieve a large field of view and high image quality while maintaining a small size. This is a significant advantage for near-eye display devices that require a compact design.

[0179] When it is necessary to increase the number of curved surfaces in the optical module, at least one of the two surfaces of the first lens 1 can be made curved.

[0180] By setting at least one of the two surfaces of the first lens 1 as a curved surface, advantages such as optimized image quality, increased field of view, reduced optical module size, improved wearing comfort, and enhanced immersion can be achieved. These advantages collectively improve the performance and user experience of near-eye display devices.

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

[0182] The third surface S3 of the first prism 1 can be curved or flat, offering great flexibility. A curved surface helps to better control the refraction and reflection of light, thereby optimizing image quality, especially at large field-of-view angles. A flat surface, on the other hand, may be easier to manufacture and calibrate, helping to reduce costs and improve production efficiency.

[0183] In other words, 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 the surfaces on which the first prism 3 and the second prism 4 are glued together. Both the fourth surface S4 and the fifth surface S5 are planar, which helps simplify the design of the optical path. The reflection and refraction of light on a planar surface are more regular and therefore easier to predict and control. This helps ensure that the light can propagate along the expected path, thereby providing a clear and stable image.

[0185] Furthermore, the fourth surface S4 and the fifth surface S5 are planar designs, which are easier to manufacture and calibrate than curved surface designs. Using planar surfaces makes high-precision manufacturing and assembly easier, thus ensuring the overall performance of the cemented prism. Planar designs are generally more advantageous in terms of material and processing costs. By reducing the need for complex curved surface machining, production costs can be reduced, and the product's market competitiveness can be improved.

[0186] In some examples of this 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 height of the first surface S1, the third surface S3, and the seventh surface S7 is along the optical axis away from the human eye S0.

[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, ensuring a high degree of consistency and accuracy in the light as it passes through these surfaces. The optical axis, as the reference path for light, is crucial for ensuring image quality. The positive sag direction of these surfaces is along the optical axis away from the human eye S0, meaning that light is refracted or reflected away from the eye as it passes through these surfaces. This design helps optimize the light path, ensuring that light propagates to the eye in the intended manner, thus providing a clear image.

[0188] In some examples of this application, the principal ray of the 0-degree field of view coincides with the optical axis 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 application, during the propagation of light, although it is deflected by prisms and lenses, it always remains in a coaxial optical path, that is, the light always passes through the optical axis of all the elements, rather than forming an off-axis system.

[0190] The principal ray in the 0-degree field of view coincides with the optical axis of all critical surfaces, ensuring minimal aberrations and distortions as the light passes through these surfaces. This design significantly improves image quality, resulting in sharper images. The coaxial optical path design greatly simplifies the optical design and computational process of the optical module.

[0191] Light always travels 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.

[0192] The coaxial optical path design simplifies the manufacturing and assembly process of optical components. Optical components can be positioned and fixed more precisely, thereby improving the stability and reliability of the entire optical module.

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

[0194] As an important component of the optical module, the display screen 8 directly affects the user experience. The protective glass 9 acts as a protective barrier for the display screen 8, resisting external damage such as scratches, impacts, and wear, thereby extending the service life of the display screen 8.

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

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

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

[0198] Example 1

[0199] See 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. The cemented prism is mainly composed of two prisms and a polarizing 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 C1, and the curvature of the second surface S2 is C2.

[0201] The second lens 2 includes a sixth surface S6 and a seventh surface S7. A phase delayer 6 is disposed on the sixth surface S6, and a beam splitter 5 is disposed on the seventh surface S7.

[0202] The cemented prism includes a first prism 3 and a second prism 4 cemented together. The first prism 3 includes a third surface S3 adjacent to the first lens 1, and the curvature of the third surface S3 is C3. The cemented surface of the first prism 3 and the second prism 4 is a fourth surface S4, and the polarizing reflection element 7 is disposed on the fourth surface S4. The angle θ1 formed between the fourth surface S4 and the vertical direction 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 undergoes total internal reflection; the second prism 4 also includes an eighth surface S8, and the angle θ2 formed by the optical axis of the eighth surface S8 and the horizontal direction is an acute angle;

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

[0205] The principal ray of the 0-degree field of view coincides with the optical axis 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] Please refer to Table 1 for the parameters of each optical element in the optical module of this embodiment 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, C1 / C2, |C1 / C7|, |C3 / C7|, EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0211] See Figure 3 The MTF plot of the optical module in Embodiment 1 is shown, illustrating the modulation transfer function at different spatial frequencies to evaluate the performance of the optical module. The horizontal axis represents the spatial frequency, measured in periods per millimeter; higher frequencies indicate richer image details. The vertical axis represents the modulation value, or MTF value, ranging from 0 to 1; higher MTF values ​​indicate better preservation of image contrast. Figure 3 As can be seen, the optical module of this embodiment 1 has good imaging performance.

[0212] Example 2

[0213] See Figure 4 The optical module shown in this embodiment 2 has the same optical architecture as that in embodiment 1 above. The difference lies in the specific optical parameters of 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] EFL in this embodiment 2 12 / EFL 67 EFL 12 / EFL35 EFL 12 / EFL、EFL 67 / EFL, C1 / C2, |C1 / C7|, |C3 / C7|, EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0218] See Figure 5 The MTF diagram of the optical module shown is from Figure 5 As can be seen, the optical module of this embodiment 2 has good imaging performance.

[0219] Example 3

[0220] See Figure 6 The optical module shown in this embodiment 3 has the same optical architecture as that in embodiment 1. The difference lies in the optical parameters of 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] EFL in Example 3 12 / EFL 67 EFL 12 / EFL 35 EFL 12 / EFL、EFL 67 / EFL, C1 / C2, |C1 / C7|, |C3 / C7|, EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0225] See Figure 7 The MTF diagram of the optical module shown is from Figure 7 As can be seen, the optical module of this embodiment 3 has good imaging performance.

[0226] Example 4

[0227] See Figure 8The optical module shown in this embodiment 4 has the same optical architecture as that in embodiment 1. The difference lies in the optical parameters of 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] EFL in Example 4 12 / EFL 67 EFL 12 / EFL 35 EFL 12 / EFL、EFL 67 / EFL, C1 / C2, |C1 / C7|, |C3 / C7|, EFL / EFL 35 For parameters such as EFL, please refer to Table 5 shown after Example 4.

[0232] See Figure 9 The MTF diagram of the optical module shown is from Figure 9 As can be seen, the optical module of this embodiment 4 has good imaging performance.

[0233] Table 5 Parameters from Examples 1 to 4

[0234]

[0235]

[0236] The above embodiments mainly describe 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. For the sake of brevity, they will not be elaborated here.

[0237] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. An optical module for XR optical devices, characterized in that, Includes a first lens (1), a second lens (2), and a cemented prism located between the two lenses; The cemented prism consists of two prisms and a polarizing reflective 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 delayer (6) is provided between the sixth surface (S6) and the cemented prism. The seventh surface (S7) is a partially reflective surface. The optical module satisfies: 2.3 ≤ EFL 12 / EFL 67 ≤24.1; where EFL 12 EFL is the effective focal length of the first lens (1). 67 The effective focal length is the distance from which light enters from the sixth surface (S6), is reflected by the seventh surface (S7), and exits 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 satisfies: EFL 12 / EFL 35 ≤3.2; where EFL 35 The effective focal length of the cemented prism is given.

4. The optical module according to claim 1, characterized in that, The optical module satisfies: 3.2 ≤ EFL 12 / EFL≤31.4; where 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; where 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) 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 C1, and 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 includes a first prism (3) and a second prism (4) glued together; The first prism (3) includes 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 between the first prism (3) and the second prism (4) is the fourth surface (S4), and the polarizing reflective element (7) is disposed on the fourth surface (S4); The phase delayer (6) is disposed on the sixth surface (S6); A beam splitting element (5) is provided on the seventh surface (S7).

11. The optical module according to claim 10, characterized in that, The angle θ1 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) also includes 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) undergoes total internal reflection; The optical module satisfies: EFL / EFL 35 ≤0.1; where EFL is the effective focal length of the optical module. 35 The effective focal length is the distance from which light enters from the third surface (S3) and exits from the fifth surface (S5).

13. The optical module according to claim 12, characterized in that, The second prism (4) also includes an eighth surface (S8); The optical module also includes a display screen (8), which is located on one side of the eighth surface (S8), and the angle θ2 formed by 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 13.4mm ≤ EFL ≤ 15.2mm.

15. The optical module according to claim 13, characterized in that, The optical module includes three or four 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 planar 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 plane; The bonding surface between the first prism (3) and the second prism (4) is the 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 height of the first surface (S1), the third surface (S3), and the seventh surface (S7) is along the optical axis away from the human eye (S0).

19. The optical module according to claim 17, characterized in that, The principal ray of the 0-degree field of view coincides with the optical axis 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, Includes the optical module as described in any one of claims 1-19.

Images