Near-to-eye optical module and head-mounted display device

Abstract

The embodiment of the invention provides a near-eye optical module and head-mounted display equipment. Wherein the near-eye optical module comprises a display, a combined lens and a polarized optical element group; the display comprises a first light-emitting effective area and a second light-emitting effective area which are respectively used for providing light of different view field areas. The combined lens is mainly formed by splicing a first lens and a second lens and is used for guiding light rays emitted by the display to human eyes; wherein the first lens is a Fresnel lens, is located in a light path of the first light-emitting effective area and is used for processing light imaging with a field-of-view angle FOV larger than 100 degrees, and the second lens is located in a light path of the second light-emitting effective area and is used for processing light imaging with a field-of-view angle FOV smaller than or equal to 100 degrees; and the polarized optical element group is arranged on the second lens and is configured to be used for forming a folded light path of at least two times of refraction and reflection in the second lens.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of optical display systems. More specifically, the embodiments of the present application relate to a near-eye optical module and a head-mounted display device. Background Art

[0002] With the rapid development of virtual reality (VR) and augmented reality (AR) technologies, near-eye optical display devices are increasingly being used. In order to provide a more immersive visual experience, near-eye optical display devices have put forward higher requirements on the field of view (FOV), imaging quality, volume and weight of the optical system. However, existing optical solutions often find it difficult to simultaneously meet the requirements of large field of view, high imaging quality and compact structure. Summary of the invention

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

[0004] In a first aspect, an embodiment of the present application provides a near-eye optical module, the near-eye optical module comprising: The display comprises a first effective light emitting area and a second effective light emitting area, each used to provide light in different viewing areas; A combined lens, mainly composed of a first lens and a second lens, for directing the light emitted by the display to the human eye; wherein the first lens is a Fresnel lens, located in the optical path of the first effective light-emitting area, for processing light imaging with a field of view angle FOV>100°, and the second lens is located in the optical path of the second effective light-emitting area, for processing light imaging with a field of view angle FOV≤100°; The polarization optical element group is arranged on the second lens and is configured to form a folded light path with at least two refractions and reflections in the second lens.

[0005] Optionally, the first light emitting effective area and the second light emitting effective area are integrated into adjacent areas of the same display panel.

[0006] Optionally, the first light emitting effective area and the second light emitting effective area are respectively arranged on different display panels.

[0007] Optionally, the first lens and the second lens are formed into the combined lens by an injection molding process.

[0008] Optionally, the splicing configuration between the first lens and the second lens satisfies one of the following situations: The edges of the first lens and the second lens are directly butted against each other without any overlap; The non-optically effective area of ​​the first lens extends to the non-optically effective area of ​​the second lens to form a partially overlapping structure, and in this configuration, a width A of the overlapping area satisfies the condition of 0<A≤5mm.

[0009] Optionally, the second lens is an aspherical lens.

[0010] Optionally, the polarization optical element group includes: A light splitting element is disposed on a surface of the second lens close to the second light-emitting effective area; and A phase retarder and a polarization reflection element are sequentially stacked and arranged on a surface of the second lens away from the second light-emitting effective area; The polarization optical element group is configured to allow the circularly polarized light emitted from the second light-emitting effective area to be directed to the human eye after multiple refraction, reflection and polarization conversion by the beam splitter, the phase retarder and the polarization reflection element.

[0011] Optionally, the polarization optical element group further includes a polarizing element, and the polarizing element is arranged on a side of the polarization reflection element away from the phase retarder; The phase retarder, the polarization reflection element and the polarizing element form a multi-layer composite optical film structure.

[0012] Optionally, the first lens comprises a first surface away from the first effective light-emitting area and a second surface close to the first effective light-emitting area, and at least one of the first surface (211) and the second surface has a Fresnel tooth structure.

[0013] Optionally, the optical axis of the first lens is parallel to the optical axis of the second lens; or, The optical axis of the first lens is arranged at a preset angle relative to the optical axis of the second lens.

[0014] Optionally, the field of view FOV of the near-eye optical module is greater than 140°.

[0015] In a second aspect, an embodiment of the present application provides a head-mounted display device, the head-mounted display device comprising: casing; and A near-eye optical module as described in the first aspect.

[0016] The beneficial effects of this application are: The near-eye optical module provided in the embodiment of the present application adopts a partitioned display structure design, which divides the display into a first effective light-emitting area and a second effective light-emitting area, respectively used to provide light in different field of view areas. This design helps to achieve the partitioning of the field of view angle and improve the overall field of view angle coverage and imaging quality of the near-eye optical module.

[0017] The combined lens is composed of a first lens (Fresnel lens) and a second lens (aspherical or spherical lens, with an additional lens). The Fresnel lens is mainly used to process light imaging with a large field of view (FOV>100°), while the second lens is used to process light imaging with a small field of view (FOV≤100°). This design not only ensures the light collection efficiency under a large field of view, but also improves the imaging quality under a small field of view. In addition, a polarization optical element group is provided on the second lens to form a folded light path with at least two refractions and reflections. This design not only reduces the volume and weight of the module, but also improves the light utilization efficiency and imaging quality.

[0018] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0020] Figure 1 One of the structural schematic diagrams of the near-eye optical module provided in the embodiment of the present application; Figure 2 A schematic diagram of a composite film material for a near-eye optical module provided in an embodiment of the present application; Figure 3 for Figure 1 A dot array diagram of a near-eye optical module is shown; Figure 4 for Figure 1 MTF diagram of the near-eye optical module shown; Figure 5 for Figure 1 Field curvature and optical distortion diagram of the near-eye optical module shown; Figure 6 for Figure 1 The vertical axis chromatic aberration diagram of the near-eye optical module shown; Figure 7 The second structural schematic diagram of the near-eye optical module provided in the embodiment of the present application; Figure 8 for Figure 7 A dot array diagram of a near-eye optical module is shown; Fig. 9 for Figure 7 MTF diagram of the near-eye optical module shown; Fig.10 for Figure 7 Field curvature and optical distortion diagram of the near-eye optical module shown; Fig.11 for Figure 7 The vertical axis chromatic aberration diagram of the near-eye optical module shown; Fig.12 The third structural schematic diagram of the near-eye optical module provided in the embodiment of the present application; Fig.13 for Fig.12 A dot array diagram of a near-eye optical module is shown; Fig.14 for Fig.12 MTF diagram of the near-eye optical module shown; Fig.15 for Fig.12 Field curvature and optical distortion diagram of the near-eye optical module shown; Fig.16 for Fig.12 A diagram of vertical axis chromatic aberration of a near-eye optical module is shown.

[0021] Description of reference numerals: 1. Display; 11. First light-emitting effective area; 12. Second light-emitting effective area; 2. Combined lens; 21. First lens; 211. First surface; 212. Second surface; 22. Second lens; 221. Third surface; 2211. Anti-reflection film; 2212. Polarizing element; 2213. Polarized reflection element; 2214. Phase retarder; 222. Fourth surface; 2221. Spectral element; 01. Human eye. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0023] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0024] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0025] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0026] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0027] The near-eye optical module and head-mounted display device provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0028] According to one embodiment of the present application, a near-eye optical module is provided. Figure 1 , Figure 7 and Fig.12 , the near-eye optical module includes a display 1, a combined lens 2 and a polarization optical element group. The display 1 includes a first effective light-emitting area 11 and a second effective light-emitting area 12, which are respectively used to provide light in different fields of view. The combined lens 2 is mainly composed of a first lens 21 and a second lens 22, which are used to guide the light emitted by the display 1 to the human eye 01; wherein the first lens 21 is a Fresnel lens, which is located in the optical path of the first effective light-emitting area 11, and is used to process the imaging of light with a field of view angle FOV>100°, and the second lens 22 is located in the optical path of the second effective light-emitting area 12, and is used to process the imaging of light with a field of view angle FOV≤100°. The polarization optical element group is arranged on the second lens 22, and is configured to form a folded optical path with at least two refractions and reflections in the second lens 22.

[0029] The near-eye optical module provided in the embodiment of the present application achieves significant technical effects through the partitioned display design, specific combined lens configuration and application of polarization optical element group, as specifically analyzed as follows.

[0030] In the embodiment of the present application, the display 1 is divided into a first effective light-emitting area 11 and a second effective light-emitting area 12, which correspond to light processing of a large field of view (FOV>100°) and a small field of view (FOV≤100°), respectively. This design enables the entire near-eye optical module to cover a wider field of view angle range, while adopting different optical processing designs for different field of view areas, which helps to improve the overall imaging quality. In short, the optical design provided in the embodiment of the present application can achieve field of view expansion and imaging quality improvement.

[0031] A specially designed combined lens 2 is introduced in the embodiment of the present application. Specifically, the combined lens 2 is designed to be composed of a first lens 21 and a second lens 22 spliced ​​up and down; wherein, the first lens 21 is designed to be located above the second lens 22, and the first lens 21 adopts a Fresnel lens, which is specially used to process the imaging of large field of view light (i.e., edge field of view light). This design effectively improves the light collection efficiency and imaging clarity under a large field of view. The second lens 22 is used to process the imaging of small field of view light (i.e., center field of view light). The second lens 22 can be designed as an aspherical lens or a spherical lens (when a spherical lens is used, at least one lens needs to be added) to further optimize the imaging quality under a small field of view angle.

[0032] A polarization optical element group is also introduced in the embodiment of the present application. Specifically, the polarization optical element group is designed to be arranged on the two surfaces of the second lens 22, so as to form a folded light path of at least two refractions and reflections in the second lens 22. This design not only significantly reduces the volume and weight of the near-eye optical module, making the near-eye optical module more convenient to carry and wear, but also improves the utilization efficiency of light and the imaging quality. By precisely controlling the refraction and reflection path of light, light loss and aberration can be effectively reduced, and the overall imaging performance can be improved.

[0033] It should be noted that, considering that the human eye has relatively low requirements for the imaging quality of light in the area with a large field of view (FOV>100°), in the optical design of the present application, the optical elements for this area (such as the first lens 21) mainly focus on achieving the effective collection and imaging functions of light, and the requirements for the fineness of the imaging quality can be appropriately relaxed to ensure the compactness and cost-effectiveness of the overall near-eye optical module.

[0034] In the embodiment of the present application, the combined lens 2 is formed by the first lens 21 and the second lens 22 in one piece by an injection molding process, thus forming a combined lens structure with a close splicing relationship. This design not only ensures the structural strength of the formed combined lens, but also provides a flexible splicing configuration. For the two spliced ​​lenses, whether the edges are directly butted without overlap or partially overlapped, the requirements of different application scenarios can be met.

[0035] Through the above series of optical designs, the near-eye optical module provided in the embodiment of the present application achieves a field of view coverage of more than 140°, which can provide users with a more immersive visual experience. In applications such as virtual reality (VR) and augmented reality (AR), a larger field of view can significantly enhance the user's immersion and interactive experience.

[0036] Optimized optical processing designs are used for large field of view and small field of view areas respectively, making the imaging quality of the entire module more uniform, avoiding the uneven imaging quality problem that may occur in traditional optical modules.

[0037] In summary, the near-eye optical module provided in the embodiment of the present application achieves a significant expansion of the field of view of the entire module, a significant improvement in imaging quality, a compact module structure, and an optimization of user experience through a new partitioned display 1 structural design, a specific combined lens 2 configuration, and a matching application of a polarization optical element group, and has significant technical effects and application prospects.

[0038] In some examples of this application, see Figure 1 and Fig.12The first light emitting effective area 11 and the second light emitting effective area 12 are integrated in adjacent areas of the same display panel.

[0039] By integrating two effective light-emitting areas on the same display panel, the integration of the near-eye optical module can be improved. This integrated design reduces the number of display panels and connecting components, thereby simplifying the overall structure of the near-eye optical module, thereby reducing production costs and manufacturing complexity.

[0040] Since the two luminous active areas are located on the same display panel, they are more consistent in display performance, brightness, color, etc., which helps to improve the overall visual experience.

[0041] The design in this example of the present application is suitable for application scenarios that have requirements on volume and weight, such as portable VR / AR devices, wearable devices, etc.

[0042] In some examples of this application, see Figure 7 The first light emitting effective area 11 and the second light emitting effective area 12 are respectively arranged on different display panels.

[0043] By setting the two effective light-emitting areas on different display panels, you can flexibly select display panels of different performance, size and type according to actual needs to meet specific display needs. In addition, using multiple display panels can disperse heat, improve heat dissipation efficiency, and help extend the service life of optical display devices. In addition, if a display panel fails, it can be replaced separately without replacing the entire display module, reducing maintenance costs and difficulties.

[0044] This design in this example of the present application is suitable for application scenarios with high requirements for display performance, such as high-end VR / AR devices, professional display devices, etc. At the same time, it is also suitable for devices that need to run for a long time or in a high-intensity use environment.

[0045] In this example of the present application, the first effective light emitting area 11 is located in the side field of view, and its resolution may be >1080×720. The second effective light emitting area 12 is located in the central field of view, and its resolution may be >2000×2000.

[0046] In summary, the integrated design in the above example is suitable for application scenarios with strict requirements on volume, weight and integration, and has the advantages of compact structure, low cost and high consistency. The split design in this example is suitable for application scenarios with high requirements on display performance, flexibility and heat dissipation, and has the advantages of high flexibility, good heat dissipation and convenient maintenance. In actual applications, the appropriate design scheme should be selected according to specific needs and scenarios to give full play to its advantages and meet user needs.

[0047] In some examples of the present application, the first lens 21 and the second lens 22 are formed into the combined lens 2 by an injection molding process.

[0048] The first lens 21 and the second lens 22 are directly combined into one body through the injection molding process to form a compact and integrated combined lens 2. This integrated design not only simplifies the overall structure of the near-eye optical module, but also significantly improves the structural strength of the combined lens 2. Compared with traditional split lenses, this injection-molded combined lens 2 exhibits stronger stability in resisting external impact and deformation, which helps to protect the lens from damage and extend the service life of the device.

[0049] The injection molding process is an efficient, high-volume manufacturing process suitable for mass production of optical lenses. By molding the combined lens 2 through the injection molding process, production efficiency can be greatly improved and manufacturing costs can be reduced. At the same time, the integrated design reduces the number of additional assembly steps and parts, further reducing production costs and complexity.

[0050] In some examples of the present application, the splicing configuration between the first lens 21 and the second lens 22 satisfies one of the following situations: The edges of the first lens 21 and the second lens 22 are directly butted against each other without any overlap; The non-optically effective area of ​​the first lens 21 extends to the non-optically effective area of ​​the second lens 22 to form a partially overlapping structure, and in this configuration, the width A of the overlapping area satisfies the condition of 0<A≤5mm.

[0051] In the example of the present application, one of the splicing configurations between the first lens 21 and the second lens 22 is that the lens edges are directly butted together without overlap. This splicing method is the simplest and most direct, with no overlapping area, making the structure of the entire combined lens 2 more concise and clear. Since the two lenses have no overlapping area, the light scattering and reflection that may be generated at the lens interface is reduced, which helps to improve the light transmittance and imaging quality.

[0052] In addition, during the manufacturing process, this splicing method makes it easier to achieve precise alignment and fixation, reducing manufacturing difficulty and cost.

[0053] In the example of the present application, the second splicing configuration between the first lens 21 and the second lens 22 is to form a partially overlapping structure (the overlapping area width A satisfies 0<A≤5mm, where the width is along the diameter direction of the lens). Through the partially overlapping design, the contact area between the first lens 21 and the second lens 22 is increased, thereby enhancing the structural stability of the entire combined lens 2. This design is particularly suitable for application scenarios that need to resist external impact and vibration.

[0054] The overlapping area can act as a buffer zone for light transition, helping to reduce the sudden change and scattering of light at the lens interface and improve image quality. Especially when the two lenses are made of different materials or have different curvatures, the overlapping area can optimize the propagation path of light at these differences.

[0055] The width A of the overlap region can be flexibly adjusted within the range of 0<A≤5 mm to adapt to different application requirements and manufacturing conditions. For example, when higher structural stability or better imaging quality is required, the width of the overlap region can be appropriately increased.

[0056] In addition, the control of the overlapping area also affects the volume of the near-eye optical module. Properly increasing the overlapping area can reduce the longitudinal volume of the near-eye optical module.

[0057] In some examples of the present application, the second lens 22 is an aspherical lens.

[0058] In the example provided in this application, the second lens 22 is designed as an aspherical lens. This design brings significant technical effects, which are specifically reflected in the following aspects: (1) Reduce aberration and improve image quality: Compared with spherical lenses, aspherical lenses can better correct aberrations, such as spherical aberration and coma. In optical modules, these aberrations are important factors affecting imaging quality. By adopting aspherical lenses, this application can effectively reduce these aberrations, thereby improving the imaging quality of the module, especially when processing light imaging with a field of view angle FOV≤100°, it can provide clearer and sharper images.

[0059] (2) Expand the field of view: In the present application, since the second lens 22 is specifically used to process light imaging with a field of view angle FOV≤100°, the use of an aspherical lens can further optimize the imaging effect in this area and improve the utilization rate of the field of view angle.

[0060] (3) Optimizing the light propagation path: Aspherical lenses can be precisely designed according to the propagation path of light, so that light can transition more smoothly when passing through the lens, reducing scattering and reflection losses. This is of great significance for improving light transmittance and imaging contrast. Especially under the action of the polarization optical element group, aspherical lenses can better cooperate with the design of the refractive-reflective optical path to achieve more efficient light collection and utilization.

[0061] In summary, designing the second lens 22 as an aspherical lens has shown significant technical effects in reducing aberrations, improving imaging quality, expanding the field of view angle range, optimizing the light propagation path, and enhancing design flexibility. This design choice is of great significance for improving the overall performance of the near-eye optical module.

[0062] Of course, the second lens 22 in the present application includes but is not limited to being an aspherical lens.

[0063] For example, the second lens 22 may also be a spherical lens. When the second lens 22 is a spherical lens, in order to ensure the imaging quality, at least one lens may be added between the second lens 22 and the second light-emitting effective area 12 .

[0064] In some examples of this application, see Figure 1 and Figure 2 , the polarization optical element group includes: a beam splitter 2221, a phase retarder 2214 and a polarization reflection element 2213; wherein the beam splitter 2221 is arranged on the surface of the second lens 22 close to the second light-emitting effective area 12; the phase retarder 2214 and the polarization reflection element 2213 are sequentially stacked and arranged on the surface of the second lens 22 away from the second light-emitting effective area 12. The polarization optical element group is configured to allow the circularly polarized light emitted from the second light-emitting effective area 12 to be finally directed to the human eye 01 after multiple refractions, reflections and polarization conversions of the beam splitter 2221, the phase retarder 2214 and the polarization reflection element 2213.

[0065] See also Figure 1 , Figure 7 and Fig.12 The beam splitter 2221 is disposed on the fourth surface 222 of the second lens 22, and is, for example, a semi-transparent and semi-reflective film. The beam splitter 2221 can transmit a portion of the light and reflect a portion of the light, and can split the light into different paths or change the propagation direction of the light.

[0066] See also Figure 2 The phase retarder 2214 and the polarized reflective element 2213 form a part of a composite film material and are disposed on the third surface 221 of the second lens 22. The phase retarder 2214 is, for example, a quarter wave plate. The polarized reflective element 2213 is, for example, a polarized reflective film.

[0067] The phase retarder 2214 is used to phase-retard the light and change the polarization state of the light. This is a key element for achieving specific optical functions (such as circular polarization conversion). For example, the phase retarder 2214 is used to convert linear polarization into circular polarization or vice versa.

[0068] The polarized reflective element 2213 can reflect or transmit light according to the polarization state of the light.

[0069] Through multiple refraction, reflection and polarization conversion of the polarization optical element group, light can form a complex refraction and reflection light path in the second lens 22, thereby optimizing the light propagation path, reducing light loss and improving light utilization.

[0070] The precise configuration of the polarization optical element group can ensure that the light can maintain a high imaging quality after multiple refractions, reflections and polarization conversions. In particular, the coordinated use of the phase retarder 2214 and the polarization reflection element 2213 can effectively reduce scattering and reflection losses and improve imaging contrast.

[0071] In some examples of this application, see Figure 2 The polarization optical element group also includes a polarizing element 2212, and the polarizing element 2212 is arranged on the side of the polarizing reflection element 2213 away from the phase retarder 2214; the phase retarder 2214, the polarizing reflection element 2213 and the polarizing element 2212 form a multi-layer composite optical film structure.

[0072] The polarizing element 2212 is an optical element that can filter out light of a specific polarization direction. In the optical design of the present application, the polarizing element 2212 can be used to further purify the light reflected by the polarizing reflective element 2213 to ensure that only light of a specific polarization direction can continue to propagate.

[0073] By integrating the phase retarder 2214, the polarized reflective element 2213 and the polarizing element 2212 to form a multi-layer composite optical film structure, light can be used more efficiently. The phase retarder 2214 converts the incident light into a specific polarization direction, the polarized reflective element 2213 selectively reflects the light in the polarization direction, and the polarizing element 2212 further purifies the reflected light, reduces light loss, and improves the overall light utilization efficiency.

[0074] Stray light and ghost images are common problems in optical modules, which reduce the clarity and contrast of images. The composite film material in this application effectively reduces the generation of stray light and ghost images by selectively reflecting and transmitting light in a specific polarization direction, thereby improving the purity and clarity of the image.

[0075] In addition, the phase retarder 2214, the polarized reflective element 2213 and the polarizing element 2212 are integrated together to form a composite film material, which can also simplify the optical design. This integrated design reduces the number and complexity of optical elements, reduces manufacturing costs and difficulty, and improves the stability and reliability of the optical module.

[0076] Optionally, the multi-layer composite optical film structure may further include an anti-reflection film 2211, see Figure 2 .

[0077] Anti-reflection film is an optical film coated on the surface of optical components to reduce light reflection and increase light transmittance. It improves the transmission efficiency of light by reducing the reflection caused by the difference in refractive index when light propagates from one medium to another.

[0078] In the multi-layer composite optical film structure provided in the present application, the anti-reflection film 2211 can effectively reduce the reflection loss of light on the surface of the optical element (such as the second lens 22). The application of the anti-reflection film 2211 can significantly improve the transmittance of light, so that more light can propagate along the designed path and finally enter the human eye 01, thereby improving the imaging brightness and contrast.

[0079] The reduction of reflected light not only improves the transmittance of light, but also helps to reduce the generation of glare and stray light. Glare and stray light will reduce the clarity and contrast of the image and affect the user's visual experience. The application of the anti-reflection film 2211 can effectively suppress the generation of these bad lights and improve the purity and quality of the image. In addition, the anti-reflection film can also serve as a protective layer to provide an additional layer of protection for optical components and extend their service life.

[0080] In the composite film material provided in the present application, the anti-reflection film 2211 works together with other optical elements (such as the phase retarder 2214, the polarized reflection element 2213 and the polarizing element 2212) to jointly optimize the optical performance. By reducing reflection and improving transmittance, the anti-reflection film 2211 helps to achieve more precise light control and higher quality imaging effects.

[0081] In some examples of the present application, the first lens 21 includes a first surface 211 away from the first light-emitting effective area 11 and a second surface 212 close to the first light-emitting effective area 11, and at least one of the first surface 211 and the second surface 212 has a Fresnel tooth structure.

[0082] The Fresnel tooth-shaped structure can effectively refract and reflect light, thereby expanding the field of view of the optical module without significantly increasing the thickness of the lens. This is crucial to improving the immersion and user experience of VR / AR devices. In the present application, the Fresnel tooth-shaped structure on at least one surface of the first lens 21 helps to expand the part of the field of view greater than 100° and achieve a wider field of view.

[0083] Compared with traditional spherical or aspherical lenses, the Fresnel tooth structure can achieve the same optical effect in a more compact manner, thereby reducing the size and weight of the lens. This is especially important for near-eye optical modules that require a lightweight and compact design, helping to improve the portability and comfort of the device.

[0084] The Fresnel tooth structure can increase the effective refractive area of ​​the lens surface, thereby improving the light collection efficiency. This is of great significance for enhancing the brightness performance of near-eye optical modules and improving image contrast and clarity. Especially when processing light with a field of view angle greater than 100°, the Fresnel tooth structure can effectively collect more light and ensure image quality.

[0085] In some examples of this application, see Figure 1 and Figure 7 , the optical axis of the first lens 21 and the optical axis of the second lens 22 are parallel to each other; or, see Fig.12 The optical axis of the first lens 21 is arranged at a preset angle relative to the optical axis of the second lens 22.

[0086] In the example provided in this application, there are two configuration modes for the optical axis relationship between the first lens 21 and the second lens 22: one is that the optical axes of the two are parallel to each other, see Figure 1 and Figure 7 The other is that the optical axis of the first lens 21 is set at a preset angle relative to the optical axis of the second lens 22, see Fig.12 The following is a detailed analysis of the two configurations, each with its own unique advantages and applicable scenarios, especially the case where the optical axis of the first lens is tilted relative to the second lens, and how this tilted setting helps to reduce the volume of the near-eye optical module.

[0087] See also Figure 1 and Figure 7 The configuration of the optical axes being parallel to each other makes the structure of the entire near-eye optical module simpler and clearer, and easier to manufacture and assemble. Since the optical axes of the two lenses are parallel, the relative position between the lenses is more stable, which helps to reduce the degradation of image quality caused by lens position offset.

[0088] See also Fig.12 When the optical axis of the first lens 21 is set at a preset angle relative to the optical axis of the second lens 22, the layout of the entire near-eye optical module in three-dimensional space can be made more compact by adjusting the angle of the angle and the position relationship of the lenses. This tilt setting can effectively reduce the size of the module in a certain direction (such as the height direction), thereby reducing the total volume of the module. This is particularly important for devices that need to be embedded in space-constrained devices (such as VR helmets, AR glasses, etc.).

[0089] In some examples of the present application, the field of view FOV of the near-eye optical module is greater than 140°.

[0090] The field of view is one of the important indicators for measuring the immersion of near-eye optical modules. The design of FOV greater than 140° enables users to see a wider field of view, thereby enhancing the sense of immersion, which is of great significance for improving user experience.

[0091] According to the optical module provided in the embodiment of the present application, see Figure 1 , the optical path propagation process is as follows: Initial stage: the display 1 (mainly the second light-emitting effective area 12) emits circularly polarized light, which can be circularly polarized light converted from natural light by a polarization conversion element (such as a polarizer).

[0092] First polarization conversion: the circularly polarized light is first incident on the phase retarder 2214 (such as a quarter wave plate) on the third surface 221 of the second lens 22, and the phase retarder 2214 converts the circularly polarized light into linearly polarized light, such as S light.

[0093] First reflection: The converted S light is then incident on the polarized reflection element 2213 (such as a polarized reflection film), and the polarized reflection element 2213 reflects the light according to the polarization direction of the light, so that the S light is reflected back into the light path.

[0094] Second polarization conversion: The reflected S light passes through the phase retarder 2214 (such as a quarter wave plate) again, and the phase retarder 2214 is used to convert the S light into circularly polarized light again. This step ensures that the light maintains a circular polarization state during the subsequent reflection and transmission process, which is beneficial to reduce scattering and reflection losses.

[0095] Second reflection: The circularly polarized light is then incident on the beam splitter 2221 (such as a semi-transparent and semi-reflective film) on the fourth surface 222 of the second lens 22, and the beam splitter 2221 reflects the light back into the light path to form a refractive-reflective light path.

[0096] Third polarization conversion: The circularly polarized light reflected back passes through the phase retarder 2214 (such as a quarter wave plate) again, and the phase retarder 2214 converts the circularly polarized light into another linearly polarized light, such as P light. The polarization direction of the P light is perpendicular to the previous S light, which helps to reduce interference with other light in the subsequent transmission process.

[0097] Transmission stage: The converted P light is then transmitted through the second lens 22 and finally directed to the human eye 01, forming a clear visual image.

[0098] The light emitted from the first light-emitting effective area 11 of the display 1 directly passes through the first lens 21 (Fresnel lens) and is finally directed to the human eye 01 .

[0099] According to another embodiment of the present application, a head mounted display device is provided, the head mounted display device comprising a housing and the near-eye optical module as described above. The near-eye optical module is disposed in the housing.

[0100] The head-mounted display device provided in the embodiment of the present application may be, for example, a VR head-mounted device.

[0101] The specific implementation of the head-mounted display device of the embodiment of the present application can refer to the various embodiments of the near-eye optical module mentioned above, so it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0102] The optical module of the present application is described below through Examples 1 to 3 respectively.

[0103] Example 1 The optical module provided in this embodiment 1 is shown in FIG. Figure 1 , comprising a display 1, a combined lens 2 and a polarization optical element group; the display 1 comprises a first light-emitting effective area 11 and a second light-emitting effective area 12, which are respectively used to provide light in different viewing areas; wherein the first light-emitting effective area 11 and the second light-emitting effective area 12 are integrated in adjacent areas of the same display panel; The combined lens 2 is composed of a first lens 21 and a second lens 22, and is used to guide the light emitted by the display 1 to the human eye 01; wherein the first lens 21 is a Fresnel lens, located in the light path of the first effective light emitting area 11, and is used to process the light imaging with a field of view angle FOV>100°; the second lens 22 is an aspherical lens, located in the light path of the second effective light emitting area 12, and is used to process the light imaging with a field of view angle FOV≤100°; The non-optically effective area of ​​the first lens 21 extends to the non-optically effective area of ​​the second lens 22 to form a partially overlapping structure, and the optical axis of the first lens 21 and the optical axis of the second lens 22 are parallel to each other; See also Figure 2The polarization optical element group includes a beam splitter 2221, a phase retarder 2214, a polarization reflection element 2213, a polarization element 2212 and an anti-reflection film 2211; the beam splitter 2221 is arranged on the surface of the second lens 22 close to the second light-emitting effective area 12; the phase retarder 2214 and the polarization reflection element 2213 are stacked in sequence on the surface of the second lens 22 away from the second light-emitting effective area 12; the polarization element 2212 is arranged on the side of the polarization reflection element 2213 away from the phase retarder 2214, and the phase retarder 2214, the polarization reflection element 2213 and the polarization element 2212 form a multi-layer composite optical film structure The polarization optical element group is configured to allow the circularly polarized light emitted from the second light-emitting effective area 12 to be directed to the human eye 01 after multiple refraction, reflection and polarization conversion by the beam splitter 2221 , the phase retarder 2214 and the polarization reflection element 2213 .

[0104] The optical parameters of the first lens 21 and the second lens 22 in the optical module provided in this embodiment 1 are shown in Table 1 below.

[0105] Table 1

[0106] The near-eye optical module provided in this embodiment 1 has an optical performance such as Figures 3 to 6 Show: Figure 3 is a schematic diagram of the point diagram. Figure 4 is the MTF curve graph, Figure 5 is the field curvature and distortion diagram, Figure 6 This is the vertical axis chromatic aberration diagram.

[0107] The spot diagram refers to a diffuse diagram formed by the intersection of many light rays emitted from one point and the image plane after passing through the optical module. Due to aberration, the intersection points of the light rays with the image plane are no longer concentrated at the same point, but are spread over a certain range. It is used to evaluate the imaging quality of the projection optical module. Figure 3 In the near-eye optical module provided in the first embodiment, the maximum value of the image point in the point diagram is less than 51 μm.

[0108] The MTF curve is a modulation transfer function graph that characterizes the imaging clarity of an optical module through the contrast of black and white line pairs. Figure 4 The near-eye optical module provided in this embodiment 1 has an MTF of >0.25 at 16lp / mm.

[0109] See also Figure 5 In the near-eye optical module provided in this embodiment 1, the maximum distortion occurs in 1 field of view, and the absolute value is less than 30%.

[0110] Vertical axis chromatic aberration is also called magnification chromatic aberration. It mainly refers to the difference between the focal positions of blue light and red light on the image plane. Figure 6 The near-eye optical module provided in this embodiment 1 has a maximum chromatic aberration value of less than 330 μm.

[0111] Example 2 The optical module provided in this embodiment 2 is shown in FIG. Figure 7 , comprising a display 1, a combined lens 2 and a polarization optical element group; the display 1 comprises a first light-emitting effective area 11 and a second light-emitting effective area 12, which are respectively used to provide light in different viewing areas; wherein the first light-emitting effective area 11 and the second light-emitting effective area 12 are respectively arranged on different display panels; The combined lens 2 is composed of a first lens 21 and a second lens 22, and is used to guide the light emitted by the display 1 to the human eye 01; wherein the first lens 21 is a Fresnel lens, located in the light path of the first effective light emitting area 11, and is used to process the light imaging with a field of view angle FOV>100°; the second lens 22 is an aspherical lens, located in the light path of the second effective light emitting area 12, and is used to process the light imaging with a field of view angle FOV≤100°; The non-optically effective area of ​​the first lens 21 extends to the non-optically effective area of ​​the second lens 22 to form a partially overlapping structure, and the optical axis of the first lens 21 and the optical axis of the second lens 22 are parallel to each other; See also Figure 2 The polarization optical element group includes a beam splitter 2221, a phase retarder 2214, a polarization reflection element 2213, a polarization element 2212 and an anti-reflection film 2211; the beam splitter 2221 is arranged on the surface of the second lens 22 close to the second light-emitting effective area 12; the phase retarder 2214 and the polarization reflection element 2213 are stacked in sequence on the surface of the second lens 22 away from the second light-emitting effective area 12; the polarization element 2212 is arranged on the side of the polarization reflection element 2213 away from the phase retarder 2214, and the phase retarder 2214, the polarization reflection element 2213 and the polarization element 2212 form a multi-layer composite optical film structure The polarization optical element group is configured to allow the circularly polarized light emitted from the second light-emitting effective area 12 to be directed to the human eye 01 after multiple refraction, reflection and polarization conversion by the beam splitter 2221 , the phase retarder 2214 and the polarization reflection element 2213 .

[0112] The optical parameters of the first lens 21 and the second lens 22 in the near-eye optical module provided in this embodiment 2 are shown in Table 2 below.

[0113] Table 2

[0114] The near-ophthalmology module provided in this embodiment 2 has an optical performance such as Figures 8 to 11 As shown: Figure 8 is a schematic diagram of the point diagram. Fig. 9 is the MTF curve graph, Fig.10 is the field curvature and distortion diagram, Fig.11 This is the vertical axis chromatic aberration diagram.

[0115] See also Figure 8 In the near-eye optical module provided in the second embodiment, the maximum value of the image point in the point diagram is less than 51 μm.

[0116] See also Fig. 9 The near-eye optical module provided in this embodiment 2 has an MTF of >0.25 at 16lp / mm.

[0117] See also Fig.10 In the near-eye optical module provided in this embodiment 2, the maximum distortion occurs in 1 field of view, and the absolute value is less than 30%.

[0118] See also Fig.11 , the near-eye optical module provided in this embodiment 2 has a maximum chromatic aberration value of less than 330m.

[0119] Example 3 The optical module provided in this embodiment 3 is shown in FIG. Fig.12 , comprising a display 1, a combined lens 2 and a polarization optical element group; the display 1 comprises a first light-emitting effective area 11 and a second light-emitting effective area 12, which are respectively used to provide light in different viewing areas; wherein the first light-emitting effective area 11 and the second light-emitting effective area 12 are integrated in adjacent areas of the same display panel; The combined lens 2 is composed of a first lens 21 and a second lens 22, and is used to guide the light emitted by the display 1 to the human eye 01; wherein the first lens 21 is a Fresnel lens, located in the light path of the first effective light emitting area 11, and is used to process the light imaging with a field of view angle FOV>100°; the second lens 22 is an aspherical lens, located in the light path of the second effective light emitting area 12, and is used to process the light imaging with a field of view angle FOV≤100°; The non-optically effective area of ​​the first lens 21 partially extends to the non-optically effective area of ​​the second lens 22 to form a partially overlapping structure, and the optical axis of the first lens 21 is arranged at a preset angle relative to the optical axis of the second lens 22. Fig.12 ; See also Figure 2The polarization optical element group includes a beam splitter 2221, a phase retarder 2214, a polarization reflection element 2213, a polarization element 2212 and an anti-reflection film 2211; the beam splitter 2221 is arranged on the surface of the second lens 22 close to the second light-emitting effective area 12; the phase retarder 2214 and the polarization reflection element 2213 are stacked in sequence on the surface of the second lens 22 away from the second light-emitting effective area 12; the polarization element 2212 is arranged on the side of the polarization reflection element 2213 away from the phase retarder 2214, and the phase retarder 2214, the polarization reflection element 2213 and the polarization element 2212 form a multi-layer composite optical film structure The polarization optical element group is configured to allow the circularly polarized light emitted from the second light-emitting effective area 12 to be directed to the human eye 01 after multiple refraction, reflection and polarization conversion by the beam splitter 2221 , the phase retarder 2214 and the polarization reflection element 2213 .

[0120] The optical parameters of the first lens 21 and the second lens 22 in the near-eye optical module provided in this embodiment 3 are shown in Table 3 below.

[0121] Table 3

[0122] The near-ophthalmology module provided in this embodiment 3 has an optical performance such as Figures 13 to 16 As shown: Fig.13 is a schematic diagram of the point diagram. Fig.14 is the MTF curve graph, Fig.15 is the field curvature and distortion diagram, Fig.16 This is the vertical axis chromatic aberration diagram.

[0123] See also Fig.13 In the near-eye optical module provided in the third embodiment, the maximum value of the image point in the point diagram is less than 51 μm.

[0124] See also Fig.14 The near-eye optical module provided in this embodiment 3 has an MTF of >0.1 at 16lp / mm. See also Fig.15 In the near-eye optical module provided in this embodiment 3, the maximum distortion occurs in 1 field of view, and the absolute value is less than 30%.

[0125] See also Fig.16 , the near-eye optical module provided in this embodiment 3 has a maximum chromatic aberration value of less than 330m.

[0126] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0127] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A near-eye optical module, characterized in that: include: A display (1) comprises a first effective light-emitting area (11) and a second effective light-emitting area (12), each used to provide light in different viewing areas; A combined lens (2), mainly composed of a first lens (21) and a second lens (22), for directing light emitted by the display (1) to a human eye (01); wherein the first lens (21) is a Fresnel lens, located in the light path of the first effective light emitting area (11), and is used to process light imaging with a field of view angle FOV>100°, and the second lens (22) is located in the light path of the second effective light emitting area (12), and is used to process light imaging with a field of view angle FOV≤100°; A polarizing optical element group is arranged on the second lens (22) and is configured to form a folded light path with at least two refractions and reflections in the second lens (22).

2. The near-eye optical module according to claim 1, characterized in that: The first effective light-emitting area (11) and the second effective light-emitting area (12) are integrated in adjacent areas of the same display panel.

3. The near-eye optical module according to claim 1, characterized in that: The first effective light-emitting area (11) and the second effective light-emitting area (12) are respectively arranged on different display panels.

4. The near-eye optical module according to claim 1, characterized in that: The first lens (21) and the second lens (22) are formed into the combined lens (2) through an injection molding process.

5. The near-eye optical module according to claim 4, characterized in that: The splicing configuration between the first lens (21) and the second lens (22) satisfies one of the following conditions: The edges of the first lens (21) and the second lens (22) are directly butted against each other without any overlap; The non-optically effective area of ​​the first lens (21) extends to the non-optically effective area of ​​the second lens (22), forming a partially overlapping structure, and in this configuration, the width A of the overlapping area satisfies the condition of 0<A≤5mm.

6. The near-eye optical module according to any one of claims 1 to 5, characterized in that: The second lens (22) is an aspherical lens.

7. The near-eye optical module according to claim 6, characterized in that: The polarization optical element group comprises: a light splitting element (2221) disposed on a surface of the second lens (22) close to the second light-emitting effective area (12); and A phase retarder (2214) and a polarized reflective element (2213) are sequentially stacked and arranged on a surface of the second lens (22) away from the second light-emitting effective area (12); The polarization optical element group is configured so that the circularly polarized light emitted by the second light-emitting effective area (12) is finally directed to the human eye (01) after undergoing multiple refraction and reflection and polarization conversion by the beam splitter (2221), the phase retarder (2214) and the polarization reflection element (2213).

8. The near-eye optical module according to claim 7, characterized in that: The polarization optical element group further comprises a polarization element (2212), wherein the polarization element (2212) is arranged on a side of the polarization reflection element (2213) away from the phase retarder (2214); The phase retarder (2214), the polarized reflection element (2213) and the polarizing element (2212) form a multi-layer composite optical film structure.

9. The near-eye optical module according to claim 1, characterized in that: The first lens (21) comprises a first surface (211) away from the first effective light-emitting area (11) and a second surface (212) close to the first effective light-emitting area (11), and at least one of the first surface (211) and the second surface (212) has a Fresnel tooth structure.

10. The near-eye optical module according to claim 1, characterized in that: The optical axis of the first lens (21) and the optical axis of the second lens (22) are parallel to each other; or, The optical axis of the first lens (21) is arranged at a preset angle relative to the optical axis of the second lens (22).

11. The near-eye optical module according to claim 1, characterized in that: The field of view FOV of the near-eye optical module is greater than 140°.

12. A head mounted display device, characterized in that: include: shell; and A near-eye optical module as described in any one of claims 1 to 11.

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