Optical module and near-to-eye display equipment

Abstract

The utility model relates to an optical module and near-to-eye display equipment, the optical module comprises a first lens, a second lens and a fourth lens which are sequentially arranged from near to far and share the same optical axis, the focal power of the first lens, the focal power of the second lens and the focal power of the fourth lens are respectively positive and negative, and the near-to-eye side and the far-to-eye side of a glued body formed by gluing the first lens and the second lens are planes. At least one of the near-human-eye side and the far-human-eye side of the third lens is an aspheric surface with an inflection point, the near-human-eye side or the far-human-eye side of the fourth lens is an aspheric surface with an inflection point, and a first quarter-wave plate and a polarization reflection film are sequentially attached to the near-human-eye side of the gluing body. A second quarter-wave plate and a first polarizing film are arranged on the side, far away from the human eye, of the gluing body, and a light splitting film is further attached to the gluing face of the gluing body. Therefore, the picture in the wide field of view can be uniformly transited along with the change of the gazing direction of the human eyes, and the use experience of the user is improved.

Description

Technical Field

[0001] This utility model relates to the field of near-eye display technology, and in particular to an optical module and a near-eye display device. Background Technology

[0002] In recent years, near-eye display devices have become increasingly popular. In addition to being lightweight and portable, people also expect optical systems with wider viewing angles and high-quality image transmission. However, existing wide-viewing-angle near-eye display devices are prone to poor clarity at large viewing angles in practical use.

[0003] Near-eye display device design optimization typically focuses on maximizing the maximum viewing angle and performance from a fixed viewpoint. However, in actual use, the human eye's high-definition viewing angle is limited, requiring eye movement to perceive a wider field of view. This means the eye's gaze angle changes when viewing the entire display image. Conventional fixed-viewpoint optimization neglects the performance requirements of eye movement, resulting in decreased clarity at wider viewing angles and significantly degrading the user experience. Utility Model Content

[0004] Given the problem of poor viewing angle clarity in existing near-eye display devices under wide viewing angle scenarios, it is necessary to provide an optical module and a near-eye display device.

[0005] An optical module comprising, arranged sequentially from near to far and coaxially:

[0006] The first lens has a positive optical power. The side of the first lens that is far from the human eye is convex and is covered with a beam splitter. The side of the first lens that is near the human eye is covered with a first quarter-wave plate and a polarizing reflective film. The polarizing reflective film is used to transmit first linearly polarized light and reflect second linearly polarized light that is perpendicular to the polarization direction of the first linearly polarized light.

[0007] The second lens is cemented to the first lens. The second lens has a negative optical power. The second lens is further provided with a second quarter-wave plate and a first polarizing film that are attached sequentially on the eye-far side. The fast axis of the second quarter-wave plate is perpendicular to the fast axis of the first quarter-wave plate. The first polarizing film is used to transmit the second linearly polarized light.

[0008] A third lens, the third lens having optical power, wherein at least one of the near-eye side and the far-eye side of the third lens is an aspherical surface with a recurve point; and

[0009] The fourth lens has positive optical power, and the side of the fourth lens near or far from the human eye is an aspherical surface with a point of inflection.

[0010] In some embodiments, a third quarter-wave plate is further attached to the eye-distant side of the first polarizing film, wherein the fast axis of the third quarter-wave plate forms an angle of 45° with the transmission axis of the first polarizing film, and the fast axis of the third quarter-wave plate extends in the same direction as the fast axis of the second quarter-wave plate.

[0011] In some embodiments, a second polarizing film is also attached to the eye-proximity side of the polarizing reflective film, the second polarizing film being used to filter the second linearly polarized light.

[0012] In some embodiments, the side of the first lens closest to the human eye is planar.

[0013] In some embodiments, the side of the second lens that is far from the human eye is planar.

[0014] In some embodiments, the fourth lens is an aspherical surface with a point of inflection on the side near the human eye and a flat surface on the side far from the human eye; the third lens is an aspherical surface with a point of inflection on both the side near the human eye and the side far from the human eye.

[0015] In some embodiments, the fourth lens is an aspherical surface with a curvature point on the far eye side, and the third lens is an aspherical surface with a curvature point on the near eye side.

[0016] In some embodiments, the eye-to-eye distance of the optical module ranges from 11 mm to 25 mm.

[0017] In some embodiments, the system focal length F of the optical module satisfies: 10mm≤F≤25mm, the focal length f1 of the first lens satisfies: |f1|≥F, the focal length f2 of the second lens satisfies: 5.5F≤|f2|≤7F, the focal length f3 of the third lens satisfies: 3.5F≤|f3|≤5F, and the focal length f4 of the fourth lens satisfies: 0.5F≤|f4|≤2F.

[0018] The optical module provided in this application constrains the surface shape and optical power of the four lenses, divides the optical path in the optical module according to the viewing direction of the human eye, and combines a polarizing reflective film, a first quarter-wave plate, and a beam splitter to fold the optical path. This improves the image quality within the human eye's field of view at different viewing angles and achieves a uniform transition between the images in the field of view at different viewing angles, avoiding the situation where the image quality deteriorates over a large field of view, making the image seen by the human eye closer to the actual scene. Among them, the first lens and the second lens are combined into a cemented body, and the near-eye side and the far-eye side of the cemented body are both planar, which facilitates the adhesion of the film layer. The entire folded optical path is realized on the same cemented body, reducing the sensitivity of the entire optical path system and enabling the lens assembly to meet the precision requirements.

[0019] A near-eye display device, comprising:

[0020] Such as the optical module mentioned above;

[0021] The aperture plane is located within the viewing distance range of the optical module; and

[0022] The image display element is located on the far eye side of the optical module;

[0023] The thickness T of the near-eye display device satisfies: 15mm≤T≤25mm.

[0024] In some embodiments, the aperture surface includes multiple sub-aperture regions with different viewing directions D, and the field of view of each sub-aperture region is D±θ, where θ≤20°.

[0025] The near-eye display device designed based on the optical module provided in this application is small in size and weight, and can provide a picture that matches the actual scene even when the human eye is rotating. It covers the range of human eye rotation with three sub-aperture areas, and the field of view of each sub-aperture area matches the field of view of the human eye, which not only facilitates production but also helps to improve the user experience. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a near-eye display device according to an embodiment of the present invention;

[0027] Figure 2 for Figure 1 The diagram shows the optical path of a near-eye display device.

[0028] Figure 3 for Figure 2 The diagram shows the optical path of a near-eye display device when the viewing angle is 0°.

[0029] Figure 4 for Figure 2 The diagram shows the optical path of a near-eye display device when the viewing angle is 15°.

[0030] Figure 5 for Figure 2 The diagram shows the optical path of a near-eye display device at a viewing angle of 25°.

[0031] Figure 6 MTF chart of the near-eye display device at a gaze angle of 0° in the embodiments provided in this application;

[0032] Figure 7 MTF chart of the near-eye display device at a viewing angle of 15° in the embodiments provided in this application;

[0033] Figure 8MTF chart of the near-eye display device at a gaze angle of 25° in the embodiments provided in this application;

[0034] Figure 9 This is a schematic diagram of the near-eye display device in another embodiment provided in this application.

[0035] Figure label:

[0036] L1, First lens; L2, Second lens; L3, Third lens; L4, Fourth lens; P1, First polarizing film; P2, Second polarizing film; Q1, First quarter-wave plate; Q2, Second quarter-wave plate; Q3, Third quarter-wave plate; RP1, Polarizing reflective film; BS1, Beam splitter; 10, Image display element; 20, Human eye. Detailed Implementation

[0037] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0038] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0041] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0043] Please see Figures 1 to 5 , Figure 1 This is a schematic diagram of the near-eye display device according to one embodiment of the present invention. Figure 2 for Figure 1 The diagram shows the optical path of a near-eye display device. Figure 3 for Figure 2 The diagram shows the optical path of a near-eye display device when the viewing angle is 0°. Figure 4 for Figure 2 The diagram shows the optical path of a near-eye display device at a viewing angle of 15°. Figure 5 for Figure 2 The diagram shows the optical path of a near-eye display device at a viewing angle of 25°.

[0044] like Figure 1As shown, the near-eye display device includes an optical module and an aperture surface and an image display element 10 located on the near-eye side and the far-eye side of the optical module. The viewing distance of the optical module is 11mm to 25mm, and the aperture surface is located within the viewing distance range of the optical module. The field of view of each sub-aperture region selected in this application is D±15°. The image display element 10 can be an image display device such as LCD, Micro-LED, or OLED.

[0045] Please see Figure 1 and Figure 2 Specifically, the optical module includes first to fourth lenses arranged sequentially from near to far and coaxial, and related coatings located between the lenses. The first lens L1 has positive optical power, the second lens L2 has negative optical power, the third lens L3 has optical power, and the fourth lens L4 has positive optical power. The side of the first lens L1 closest to the human eye is flat, while the side furthest from the human eye is convex. The side of the second lens L2 closest to the human eye is concave, while the side furthest from the human eye is flat. The first lens L1 and the second lens L2 are combined into a cemented carbide. The side of the third lens L3 furthest from the human eye and closest to the human eye are both aspherical surfaces with inflection points. The side of the fourth lens L4 furthest from the human eye is an aspherical surface with inflection points, while the side furthest from the human eye is flat. The film structure includes a first film layer and a second film layer respectively attached to the near-eye side and the far-eye side of the first lens L1, and a third film layer located between the second lens L2 and the third lens L3. The first film layer includes a polarizing reflective film RP1 and a first quarter-wave plate Q1 attached sequentially from near to far. The second film layer includes a beam-splitting film BS1. The third film layer includes a second quarter-wave plate Q2 and a first polarizing film P1 attached sequentially from near to far. In the above film layers, the fast axis of the first quarter-wave plate Q1 is perpendicular to the fast axis of the second quarter-wave plate Q2. The polarizing reflective film RP1 transmits first linearly polarized light and reflects second linearly polarized light perpendicular to the polarization direction of the first linearly polarized light. Figure 2 As shown, the light rays will undergo two reflections in the first lens L1 during their propagation toward the aperture surface. Under the focusing reflection of the concave surface on the far side of the human eye of the first lens L1, the light rays will be focused toward the aperture surface and thus reach the human eye 20.

[0046] Based on the optical module provided in the above embodiments, by constraining the optical power and surface shape of the four lenses and designing the film structure, the optical path in the optical module is partitioned according to the gaze direction of the human eye. Combined with the design of the film structure, the image quality within the field of view of the human eye under different gaze angles is improved, and the transition between the images in the field of view under different gaze angles is made uniform, avoiding the situation of deterioration of image quality in a large field of view, making the image seen by the human eye closer to the actual scene. Among them, the first lens and the second lens are combined into a cemented body, and the near-eye side and the far-eye side of the cemented body are both planar, which facilitates the adhesion of the film. The entire folded optical path is realized on the same cemented body, reducing the sensitivity of the entire optical path system and enabling the lens assembly to meet the precision requirements.

[0047] Optionally, in one embodiment provided in this application, the third film layer is attached to the eye-distal side of the second lens. This couples the entire film layer structure with the adhesive, fixing the relative positions of the film layers and further reducing the sensitivity of the entire system. It is understood that, if the sole purpose is to achieve optical path folding, the third film layer can also be attached to the third lens or spaced apart from the second and third lenses, as long as it reduces the processing difficulty.

[0048] For example, such as Figures 3 to 5 As shown, for the aspherical surfaces of the third and fourth lenses, this application defines the region between the inflection point on the lens and the optical axis as the paraxial region, and the remaining region as the far-axis region. The optical path in this optical module is mainly divided into three parts. The first part of the optical path passes through the paraxial region of the fourth lens L4 and the paraxial region of the third lens L3 in sequence towards the aperture surface. The second part of the optical path deviates from the optical axis and passes through the far-axis region of the fourth lens L4 and the paraxial region of the third lens L3 in sequence towards the aperture surface. The third part of the optical path is the farthest from the optical axis and passes through the far-axis region of the fourth lens L4 and the far-axis region of the third lens L3 in sequence towards the aperture surface. These three parts of the optical path correspond to the light emitted from different areas of the image display element 10, and correspond to three sub-aperture regions at the aperture surface. It is worth noting that, for ease of description, this application has artificially selected three specific viewing angles to partition the optical path in the optical module. In practice, other viewing angles can also be selected to re-partition the optical path. Therefore, the number of sub-aperture regions can also be multiple, two or more. Due to the characteristics of eye rotation, each sub-aperture region is symmetrical about the optical axis, and multiple sub-aperture regions can partially overlap or separate.

[0049] Based on the architecture of the aforementioned optical module, in order to obtain an optical path that matches the range of eye rotation angles while taking into account the overall thickness of the optical module, this application also constrains the focal lengths of each lens in the optical module. The system focal length F of the optical module satisfies: 10mm≤F≤25mm, the focal length f1 of the first lens L1 satisfies: |f1|≥F, the focal length f2 of the second lens L2 satisfies: 5.5F≤|f2|≤7F, the focal length f3 of the third lens L3 satisfies: 3.5F≤|f3|≤5F, and the focal length f4 of the fourth lens L4 satisfies: 0.5F≤|f4|≤2F. The first lens L1 is mainly used to converge the three optical paths, the second lens L2 is mainly used to refract light to guide more light into the first lens L1, and the third lens L3 and the fourth lens L4 work together to achieve the above-mentioned optical path partitioning. The above focal lengths all represent the overall focal lengths of the lenses.

[0050] Preferably, in some embodiments of this application, a second polarizing film P2 is also attached to the eye-proximity side of the polarizing reflective film RP1. The second polarizing film P2 is used to filter the second linearly polarized light (S-light), which can avoid the problem of screen glare caused by light leakage from the polarizing reflective film RP1 or the beam splitter BS1 and the internal reflection stray light in the lens.

[0051] Preferably, in some embodiments of this application, the third film layer further includes a third quarter-wave plate Q3 attached to the first polarizing film P1, wherein the fast axis of the third quarter-wave plate Q3 extends in the same direction as the fast axis of the second quarter-wave plate Q2.

[0052] Preferably, in some embodiments of this application, the side of the first lens L1 closest to the human eye is planar, and the side of the second lens L2 furthest from the human eye is planar. This facilitates the adhesion of the composite film and reduces the processing difficulty and cost.

[0053] Preferably, in some embodiments of this application, the far-eye side of the fourth lens L4 is planar, which facilitates the calibration of the relative position between the fourth lens L4 and the image display element 10.

[0054] Preferably, in some embodiments of this application, the eye-to-eye distance of the optical module is in the range of 11mm to 25mm. Within this range, it is convenient to adapt to the rotation of the eyeball by adjusting the surface shape and focal length of the first to fourth lenses. The thickness of the lenses is also smaller, which reduces the difficulty of lens processing.

[0055] For example, in the embodiments provided in this application, the transmission axis pol of the first polarizing film P1 is 0°, the transmission axis pol of the second polarizing film P2 is 90°, the fast axis direction of the first quarter-wave plate Q1 is 135°, the fast axis directions of the second quarter-wave plate Q2 and the third quarter-wave plate Q3 are both 45°, and the polarizing reflective film RP1 reflects the second linearly polarized light (S-ray) and transmits the first linearly polarized light (P-ray). For the sake of simplicity, P-ray represents the first linearly polarized light, S-ray represents the second linearly polarized light, C-ray represents circularly polarized light, LC-ray represents left-handed circularly polarized light, and RC-ray represents right-handed circularly polarized light. Based on the film structure and the optical power and surface design of the first to fourth lenses, the optical path between the image display element and the aperture surface is as follows: The light emitted by the image display element includes P light and S light. After passing through the third quarter-wave plate Q3, the two types of light are converted into C light. The C light continues to pass through the first polarizing film P1 and is converted into S light. The S light then passes through the second quarter-wave plate Q2 and is converted into LC light. The LC light passes through the second lens L2, the beam splitter BS1 and the first lens L1 in sequence and is converted into S light by the first quarter-wave plate Q1. Then, it is reflected twice at the polarizing reflection film RP1 and the beam splitter BS1. It is worth noting that the S light is converted into P light after passing through the first quarter-wave plate Q1 twice and exits from the second polarizing film P2, finally reaching the aperture surface.

[0056] The optical module and near-eye display device provided in this embodiment will be further described below with reference to the attached table. The optical design parameters of the near-eye display device in this embodiment are shown in Table 1.

[0057] Table 1 Optical Design Parameters

[0058]

[0059] In the table, OBJ represents the relevant design parameters of the object surface; STO represents the aperture of the optical module, with an aperture diameter of 4mm; for simplicity, Si will be used to represent the surface number in the optical module, and the numbers in the first column of the table represent the serial number i of the surface number. S3 and S4 represent the near-eye and far-eye sides of the first lens L1, respectively; S9 and S10 represent the near-eye and far-eye sides of the second lens L2, respectively; S11 and S12 represent the near-eye and far-eye sides of the third lens L3, respectively; S13 and S14 represent the near-eye and far-eye sides of the fourth lens L4, respectively; S15 and S16 represent the glass layer of the display plane in the image display element 10, respectively; IMA represents the image of the image display element 10; EVENASPH in the table represents an aspherical surface. It is worth noting that in the row containing surface number S5, a negative thickness value indicates that the light path has been reflected back at that surface, or that the direction of the light path is towards the image display element. In this embodiment, the focal length of the first lens is f1 = 18.5 mm, the focal length of the second lens is f2 = -103 mm, the focal length of the third lens is f3 = -64 mm, and the focal length of the fourth lens is f4 = 27 mm.

[0060] The formula for calculating aspherical surfaces is:

[0061]

[0062] In the above formula, x represents the distance vector from the aspherical surface at a height of h to the vertex of the aspherical surface along the optical axis, c represents the curvature, h represents the radial distance from the optical axis, k represents the conic coefficient, and Ai represents the i-th order aspherical coefficient. The aspherical coefficients in the optical module are shown in Table 2.

[0063] Table 2 Aspheric coefficients in optical modules

[0064]

[0065] Other parameters of the near-eye display device in this embodiment are shown in Table 3.

[0066] Table 3 Other parameters

[0067] Screen size C (inches) 1.35 Field of view V (°) 95 System focal length F (mm) 17.5 Eyebox eye movement range A (mm) 10 Screen resolution 1772＊1920 Optical system thickness 17.2 Eye relief (distance between eyes) 20 F# Aperture 4.3 Optical outer diameter (mm) 38 System distortion % 21

[0068] As can be seen from Table 3, based on the relevant parameters in Table 1, the system focal length F of the optical module is 17.5mm and the thickness of the optical system is 17.2mm, thus achieving a field of view of 95°. By designing the aperture in front of the optical magnification module to be 4.3, a larger eye movement range of 10mm can be obtained.

[0069] The screen is designed to be 1.35 inches in size with a viewing distance of 20mm, and the optical module has an outer diameter of 38mm. Figures 6 to 8 As shown in the MTF plot. Figure 6This is the MTF diagram of the near-eye display device in the embodiments provided in this application at the first viewing angle (D = 0°). Figure 7 The MTF diagram of the near-eye display device in the embodiments provided in this application at the second viewing angle (D = 15°) is shown. Figure 8 The MTF diagram of the near-eye display device in the embodiments provided in this application at the third viewing angle (D = 25°) shows that the optical module exhibits good resolution and uniform transition of the field of view at different viewing angles, providing users with good image quality and immersion. It is worth noting that the examples of D = 0°, 15°, and 25° in this application do not imply that the optical module only has three viewing directions. In reality, the number of sub-aperture regions can be two or more, and the field of view of the sub-aperture regions can be appropriately scaled and adjusted adaptively as needed.

[0070] like Figure 9 As shown, optionally, this application also provides another implementation of the optical module, which differs from the first implementation in the optical power and surface design of the third lens L3 and the fourth lens L4. The third lens L3 is convex on the far-eye side and aspherical with a curvature point on the near-eye side. The fourth lens L4 is convex on the near-eye side and aspherical with a curvature point on the far-eye side.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An optical module, characterized in that, Including those arranged sequentially from near to far and coaxial: The first lens has a positive optical power. The side of the first lens that is far from the human eye is convex and is covered with a beam splitter. The side of the first lens that is near the human eye is covered with a first quarter-wave plate and a polarizing reflective film. The polarizing reflective film is used to transmit first linearly polarized light and reflect second linearly polarized light that is perpendicular to the polarization direction of the first linearly polarized light. The second lens is cemented to the first lens. The second lens has a negative optical power. The second lens is further provided with a second quarter-wave plate and a first polarizing film that are attached sequentially on the eye-far side. The fast axis of the second quarter-wave plate is perpendicular to the fast axis of the first quarter-wave plate. The first polarizing film is used to transmit the second linearly polarized light. The third lens has optical power, and at least one of the near-eye side and the far-eye side of the third lens is an aspherical surface with a point of inflection. as well as The fourth lens has positive optical power, and the side of the fourth lens near or far from the human eye is an aspherical surface with a point of inflection.

2. An optical module according to claim 1, characterized in that, A third quarter-wave plate is also attached to the eye-distant side of the first polarizing film, and the fast axis of the third quarter-wave plate extends in the same direction as the fast axis of the second quarter-wave plate.

3. An optical module according to claim 1 or 2, characterized in that, A second polarizing film is also attached to the side of the polarizing reflective film closest to the human eye, and the second polarizing film is used to filter the second linearly polarized light.

4. The optical module according to claim 1, characterized in that, The side of the first lens closest to the human eye is planar; and / or The second lens is planar on the side furthest from the human eye.

5. The optical module according to claim 1, characterized in that, The fourth lens is an aspherical surface with a point of inflection on the side near the human eye, while it is a flat surface on the side far from the human eye. The third lens has aspherical surfaces with inflection points on both the near-eye side and the far-eye side.

6. The optical module according to claim 1, characterized in that, The fourth lens has an aspherical surface with a point of inflection on the side far from the human eye, and the third lens has an aspherical surface with a point of inflection on the side near the human eye.

7. The optical module according to claim 1, characterized in that, The system focal length F of the optical module satisfies: 10mm≤F≤25mm, the focal length f1 of the first lens satisfies: |f1|≥F, the focal length f2 of the second lens satisfies: 5.5F≤|f2|≤7F, the focal length f3 of the third lens satisfies: 3.5F≤|f3|≤5F, and the focal length f4 of the fourth lens satisfies: 0.5F≤|f4|≤2F.

8. The optical module according to claim 7, characterized in that, The optical module has a viewing distance range of 11mm to 25mm.

9. A near-eye display device, characterized in that, include: The optical module as described in any one of claims 1-8; The aperture plane is located within the viewing distance range of the optical module; as well as The image display element is located on the far eye side of the optical module; The thickness T of the near-eye display device satisfies: 15mm≤T≤25mm.

10. The near-eye display device according to claim 9, characterized in that, The aperture plane includes multiple sub-aperture regions with different viewing directions D, and the field of view of each sub-aperture region is D±θ, where θ≤20°.

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