VR optical module and head-mounted display device

Abstract

The embodiment of the invention discloses a VR optical module and a head-mounted display device. Wherein the VR optical module comprises a display assembly, a variable-focus lens array and an imaging assembly which are sequentially arranged along the same optical axis; the display assembly is used for emitting image light; the imaging assembly is used for forming a virtual image from the image light; the variable-focus lens array comprises a plurality of variable-focus lenses, and the variable-focus lens array is configured to be capable of adjusting the focal length of the variable-focus lens array under driving so as to adapt to the diopter of a wearer.

Description

Technical Field

[0001] The present application belongs to the field of VR optical display technology. Specifically, the present application relates to a VR optical module and a head-mounted display device. Background Art

[0002] In the current VR technology field, traditional VR head-mounted display devices generally face a challenge: their core component, the VR optical module, lacks the diopter adjustment function. For myopic or hyperopic users, in order to ensure a clear visual experience, they often need to wear glasses to correct their vision while wearing the VR head-mounted display device. This not only adds to the cumbersomeness of using VR head-mounted display devices, but may also reduce visual comfort due to the superposition of double-layer lenses, and even affect the overall visual effect and immersion. Summary of the invention

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

[0004] According to a first aspect of the present application, an embodiment of the present application provides a VR optical module, wherein the VR optical module comprises a display component, a variable focus lens array, and an imaging component sequentially arranged along the same optical axis;

[0005] The display component is used to emit image light;

[0006] The imaging component is used to form a virtual image from the image light;

[0007] The variable focus lens array includes a plurality of variable focus lenses, and the variable focus lens array is configured to be able to adjust its own focal length under driving, so as to adapt to the wearer's vision.

[0008] Optionally, the variable focus lens array is a liquid lens array, and the liquid lens array includes a plurality of liquid lens units.

[0009] Optionally, the display assembly includes a display screen, and the liquid lens array is arranged on a light-emitting surface of the display screen;

[0010] The number of the liquid lens units is less than or equal to the number of pixels of the display screen.

[0011] Optionally, the imaging component is a folded light path lens module;

[0012] The imaging assembly includes at least one lens, the refractive power of the lens is D 2 The diopter of the liquid lens unit is D 1 , D 1 With D 2 Satisfy: 300≤D 1 / D2 ≤700.

[0013] Optionally, the central thickness of the liquid lens unit is T 1 , the center thickness of the lens is T 2 , T 1 With T 2 Satisfy: 0.03≤T 1 / T 2 ≤0.12.

[0014] Optionally, the radius of curvature R of the liquid lens unit and the virtual image distance VID of the VR optical module satisfy: 0<R / VID≤0.01; wherein, the radius of curvature R of the liquid lens unit is 0.1mm≤R≤0.3mm.

[0015] Optionally, the imaging component further comprises a polarizing reflector, a first phase retarder and a beam splitter, and the first phase retarder is located between the polarizing reflector and the beam splitter;

[0016] The polarization reflector and the first phase retarder are located on a side of the lens away from the display component, and the beam splitter is located on a side of the lens close to the display component.

[0017] Optionally, the polarized reflector is a polarized reflective film, the first phase retarder is a quarter wave plate, the polarized reflective film and the quarter wave plate are stacked and arranged together on a surface of the lens away from the display component;

[0018] The light splitting element is a semi-transparent and semi-reflective film, and the semi-transparent and semi-reflective film is arranged on the surface of the lens close to the display component.

[0019] Optionally, the display component further includes a polarizer and a second phase retarder, and the polarizer and the second phase retarder are located between the display screen and the variable focus lens array.

[0020] Optionally, the second phase retarder is a 1 / 4 wave plate, the polarizer is a polarizing film, and the 1 / 4 wave plate and the polarizing film are stacked and arranged on the light-emitting surface of the display screen.

[0021] According to a second aspect of the present application, an embodiment of the present application provides a head-mounted display device, the head-mounted display device comprising:

[0022] casing; and

[0023] A VR optical module as described in the first aspect.

[0024] One beneficial effect of the embodiments of the present application is:

[0025] The embodiment of the present application provides a VR optical module, which improves the function of the traditional VR optical module by introducing a variable focus lens array. Specifically, the VR optical module sequentially arranges a display component, a variable focus lens array and an imaging component along the optical axis. The variable focus lens array can flexibly adjust its focal length under external drive to meet the vision needs of different wearers, including myopic and hyperopic users. This feature greatly improves the user experience of the VR head-mounted display device, allowing users to experience virtual reality without wearing additional glasses.

[0026] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0028] Figure 1 A schematic diagram of the structure of a VR optical module provided in an embodiment of the present application;

[0029] Figure 2 One of the MTF graphs of the VR optical module provided in the embodiment of the present application;

[0030] Figure 3 The second MTF diagram of the VR optical module provided in the embodiment of the present application;

[0031] Figure 4 This is the third MTF diagram of the VR optical module provided in the embodiment of the present application.

[0032] Description of reference numerals:

[0033] 1. Optical axis; 2. Aperture; 3. Lens; 31. First surface; 32. Second surface; 4. Display screen; 5. Image light; 6. Polarization reflector; 7. First phase retarder; 8. Spectral element; 9. Second phase retarder; 10. Polarizer; 11. Variable focus lens array. DETAILED DESCRIPTION

[0034] 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.

[0035] 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.

[0036] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0037] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0038] 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.

[0039] The VR 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.

[0040] According to an embodiment of the present application, a VR optical module is provided. Figure 1 The VR optical module includes a display component, a variable focus lens array 11 and an imaging component which are sequentially arranged along the same optical axis 1; the display component is used to emit image light 5; the imaging component is used to form a virtual image of the image light 5; the variable focus lens array 11 includes a plurality of variable focus lenses, and the variable focus lens array 11 is configured to be able to adjust its own focal length under driving, so as to adapt to the wearer's vision.

[0041] The VR optical module provided in the embodiment of the present application mainly includes the following key components: a display component, a variable focus lens array 11 and an imaging component, and these parts are arranged in sequence along the same optical axis 1.

[0042] In the VR optical module provided in the embodiment of the present application, the display component is located on the side away from the aperture 2. The main function of the display component is to emit image light 5. Figure 1 The display component may include, for example, a display screen 4 which serves as the original light source of the image.

[0043] In the VR optical module provided in the embodiment of the present application, the imaging component is located on a side close to the aperture 2, and the imaging component is used to form a virtual image from the image light 5 emitted by the display component.

[0044] In the VR optical module provided in the embodiment of the present application, the variable focus lens array 11 is located between the display component and the imaging component, and is designed to include a plurality of variable focus lenses arranged in an array, which can change their own shape / surface shape under external drive to adjust the focal length. This enables the entire VR optical module to automatically adjust the focal length according to the wearer's myopia or hyperopia, thereby achieving personalized clear imaging.

[0045] Most traditional VR optical modules do not have a diopter adjustment function, and myopic or hyperopic users need to wear glasses to see clear images. In the embodiment of the present application, by introducing a variable focus lens array 11, the VR optical module can automatically adjust the focal length according to the wearer's myopia or hyperopia, achieving personalized clear imaging without the need for additional glasses, which greatly improves the user experience.

[0046] The variable focus lens array provided in the embodiment of the present application has a focal length adjustment function, so that the clarity of the image can be maintained under different diopters.

[0047] The focal length adjustment of the variable focus lens array 11 can be achieved, for example, by non-mechanical driving methods such as electric field or magnetic field, which can have a faster response speed and higher adjustment accuracy. Users can achieve precise adjustment of the focal length in a short time, thereby quickly adapting to different visual needs.

[0048] In the optical solution provided in the embodiment of the present application, by introducing the variable focus lens array 11, the VR optical module not only solves the problem of diopter adjustment, but also improves the light utilization rate and enhances the visual experience by coordinating the optical path design. Users can get a clearer and more comfortable VR visual experience without the need for additional glasses.

[0049] For the VR optical module with built-in diopter adjustment function of this application, the user does not need to wear additional myopia or hyperopia glasses, thereby simplifying the overall use process of the VR head-mounted display device. This not only improves the convenience of the user, but also reduces the visual interference and discomfort that may be caused by the superposition of multiple layers of lenses. Since there is no constraint of additional glasses, users can feel higher comfort when wearing the VR optical module provided by this application.

[0050] The VR optical module proposed in the embodiment of the present application achieves accurate adaptation of the wearer's vision and optimization of clear imaging by introducing the design of a variable focus lens array 11 in its optical architecture, thus providing users with a more convenient, comfortable and high-quality virtual reality experience. This design has shown significant beneficial effects in improving user experience.

[0051] In some examples of the present application, the variable focus lens array 11 is a liquid lens array, and the liquid lens array includes a plurality of liquid lens units.

[0052] That is to say, in the VR optical module provided in the embodiment of the present application, adaptation to the wearer's vision is achieved by integrating a variable-focus liquid lens array.

[0053] Specifically, in the VR optical module provided in the present application, the liquid lens array is located between the display component and the imaging component, and its design includes a plurality of liquid lens units (see Figure 1 These liquid lens units can change shape (or change the surface shape) under the driving action of electric or magnetic fields, thereby changing the focal length. This enables the VR optical module to automatically adjust the focal length according to the wearer's myopia and achieve personalized clear imaging.

[0054] According to this example of the present application, the liquid lens unit in the liquid lens array has a focal length adjustment performance. By precisely controlling the curvature radius of the liquid lens, continuous adjustment of the optical focal length can be achieved, thereby maintaining the clarity of the imaging at different refractive powers.

[0055] In this example of the present application, the variable focus lens array 11 is set as a liquid lens array, which can bring the following technical effects:

[0056] (1) Due to its material properties, liquid lenses can quickly change shape under the action of electric or magnetic fields, thereby achieving continuous adjustment of focal length. Compared with traditional mechanical zoom methods, liquid lenses have higher adjustment accuracy and faster response speed. This high-precision focal length adjustment capability enables VR optical modules to more accurately match the vision needs of users with different myopia degrees.

[0057] (2) By using liquid lens units to form an array, the volume and weight of the variable focus lens array are greatly reduced. This is not only conducive to the overall lightweight and miniaturized design of VR head-mounted display devices, but also improves the wearing comfort of users.

[0058] The liquid lens array of the present application, all the liquid lens units contained therein can achieve unified focusing. This design not only simplifies the focusing process, but also ensures that the entire liquid lens array can maintain a high degree of synchronization and consistency during the focusing process. Through a single control command, the focal length of all liquid lens units can be adjusted synchronously, thereby quickly matching personal vision needs and achieving a clear and comfortable visual experience. In addition, the unified focusing feature further improves the overall performance and stability of the VR optical module, bringing users a smoother virtual reality interaction experience.

[0059] Of course, if necessary, each microlens in the liquid lens array can adjust its focal length independently. This personalized adjustment can more accurately match the user's vision differences, such as different myopia degrees in different areas, or complex vision problems such as astigmatism, thereby providing a more accurate and comfortable visual experience. In addition, each liquid lens unit independently adjusts its focal length, which also helps to reduce aberrations and distortions caused by overall focusing. By fine-tuning the focal length of each lens, the image quality can be optimized across the entire field of view.

[0060] In some examples of this application, see Figure 1 The display component includes a display screen 4, and the liquid lens array is arranged on the light-emitting surface of the display screen 4; the number of the liquid lens units is less than or equal to the number of pixels of the display screen 4.

[0061] According to this example of the present application, the number of the liquid lens units is less than or equal to the number of pixels of the display screen 4. This design is beneficial to improving the resolution and clarity of the VR optical module.

[0062] Specifically, the variable focus lens array 11 is a liquid lens array, and the liquid lens array includes a plurality of liquid lens units. In the VR optical module, the liquid lens array can be directly arranged on the light-emitting surface of the display screen 4 of the display assembly. Since the number of liquid lens units is set to match or be less than the number of pixels of the display screen 4, this design ensures that each pixel or most pixels can be covered by an independent liquid lens unit. This reduces the crosstalk of light and the interference between pixels, thereby significantly improving the clarity and resolution of the image.

[0063] Preferably, there is a one-to-one correspondence between the liquid lens units and the pixels of the display screen 4 , that is, each pixel on the display screen 4 corresponds to one liquid lens unit.

[0064] Matching the number of liquid lens units in the liquid lens array with the number of pixels of the display screen 4 helps optimize the optical performance of the entire VR optical module. The liquid lens unit can adjust the focus and diffusion of light as needed, reduce optical problems such as aberration and distortion, and further improve the contrast, color reproduction and field of view of the imaging.

[0065] In addition, the liquid lens array is directly arranged on the light-emitting surface of the display screen 4, which reduces the additional space occupied and helps to achieve the miniaturization and lightness of the VR optical module. This not only improves the portability of the device, but also reduces the manufacturing cost and complexity.

[0066] It should be noted that the liquid lens array has a smaller volume and lighter weight than the traditional mechanical zoom system, which makes the structure of the VR optical module more compact, which is conducive to the lightweight and miniaturization of the equipment. This is of great significance for improving wearing comfort.

[0067] In some examples of this application, see Figure 1 The imaging component is a folded optical path lens module; the imaging component includes at least one lens 3, the refractive power of the lens 3 is D 2 The diopter of the liquid lens unit is D 1 , D 1 With D 2 Satisfy: 300≤D 1 / D 2 ≤700.

[0068] In this example of the present application, see Figure 1 The imaging component is designed as a folded light path lens module, which includes one or more lenses. The number of lenses in the imaging component can be flexibly adjusted as needed, and this application does not impose any restrictions on this. However, the optical solution design of this application can achieve good imaging effects based on the folded light path using only one lens.

[0069] In the present application, the imaging assembly adopts a folded optical path lens module, and the design of the folded optical path lens module helps to achieve the compactness and miniaturization of VR optical head-mounted display devices. In a limited space, by precisely controlling the size and position relationship of each optical element, the volume and weight of the device can be reduced without sacrificing imaging quality. This compact structural design not only improves the portability of the device, but also reduces manufacturing costs and complexity.

[0070] In this example of the present application, the diopter of the liquid lens unit is D 1 , the refractive power of the lens 3 is D 2 , D 1 With D 2 Satisfy: 300≤D 1 / D 2 ≤700.

[0071] It should be noted that the diopter is the reciprocal of the radius of curvature.

[0072] In the present application, the diopter D of the liquid lens unit is 1 The diopter D of the lens 3 2 The ratio is set in the range of 300 to 700, which is conducive to improving imaging clarity.

[0073] Specifically, the diopter ratio (D 1 / D 2 ) ensures the optical matching between the liquid lens unit and the lens 3 within the above range. This matching not only reduces aberration and distortion, but also improves the focusing accuracy of light, making the image clearer.

[0074] However, when D 1 / D 2 When the ratio is too high or too low, it may cause inaccurate light focusing, thus affecting the image quality. However, if it is set within the above range of 300 to 700, these problems can be effectively avoided and high-definition images can be ensured.

[0075] By precisely controlling the diopter ratio between the liquid lens unit and the lens 3 , the performance of the entire optical module can be further optimized.

[0076] One of the original intentions of the VR module provided in the embodiment of the present application is to meet the vision requirements of different users. The liquid lens unit has the characteristic of variable focal length, and combined with the optimized design of the lens 3, the entire VR module can maintain imaging clarity in a wider range of diopters, thereby adapting to the vision conditions of more wearers.

[0077] Clear imaging quality is one of the key factors to improve user experience. By properly setting the diopter ratio of the liquid lens unit to the lens 3, the VR module can provide stable and high-quality image output in different scenarios, thereby enhancing the user's immersion and comfort.

[0078] In some examples of the present application, the central thickness of the liquid lens unit is T 1 , the center thickness of the lens 3 is T 2 , T 1 With T 2 Satisfy: 0.03≤T 1 / T 2 ≤0.12.

[0079] In the present application, the central thickness T of the liquid lens unit is 1 The center thickness T of the lens 3 2 The ratio between them is set in the range of 0.03 to 0.12. This design is not only related to the optical performance, but also directly affects the volume of the VR module.

[0080] Specifically, the center thickness T of the liquid lens unit 1 The center thickness T of the lens 3 3 The ratio is controlled between 0.03 and 0.12, which helps to achieve the miniaturization of the VR module as a whole. The thinner liquid lens unit reduces the space occupied by the optical components in the optical axis direction, making the entire VR optical module more compact.

[0081] The miniaturization of VR optical modules not only improves the user's wearing comfort, but also facilitates the portability and mobility of VR equipment, allowing users to easily carry and use it in different scenarios.

[0082] Although the center thickness of the liquid lens unit is reduced, sufficient imaging clarity can still be maintained within this ratio range. This is due to the unique adjustable focal length characteristics of the liquid lens unit and the precise coordination with other optical elements.

[0083] The miniaturization of VR modules directly improves the user's wearing experience. Smaller devices are lighter, reducing fatigue caused by long-term wearing; at the same time, the compact design is more ergonomic, improving wearing stability and comfort.

[0084] In some examples of the present application, the radius of curvature R of the liquid lens unit and the virtual image distance VID of the VR optical module satisfy: 0<R / VID≤0.01; wherein, the radius of curvature R of the liquid lens unit is 0.1mm≤R≤0.3mm.

[0085] In the example of the present application, the relationship between the curvature radius R of the liquid lens unit and the virtual image distance VID of the VR optical module is set to 0<R / VID≤0.01, and the curvature radius R of the liquid lens unit is limited to the range of 0.1mm to 0.3mm. This design not only improves the imaging quality, but also brings significant advantages in the manufacturing process, especially with regard to the difficulty of processing liquid lenses.

[0086] When the ratio of the curvature radius R of the liquid lens unit to the virtual image distance VID of the VR optical module is maintained in the range of 0 to 0.01, the shape design of the liquid lens unit is relatively simple and the processing difficulty is greatly reduced. A smaller curvature radius ratio means that the surface change of the liquid lens unit is relatively gentle, which can be achieved without the need for highly precise processing technology.

[0087] Within the ratio range mentioned in the above example, the processing of the liquid lens unit is easier to control, which can reduce processing errors and improve the yield rate. This is of great significance for large-scale production and can significantly reduce production costs and improve production efficiency.

[0088] The ratio between the curvature radius R of the liquid lens unit and the virtual image distance VID of the VR optical module is controlled within the range of 0 to 0.01, and the curvature radius R of the liquid lens is limited to between 0.1 mm and 0.3 mm. This design plays an important role in reducing processing difficulty, ensuring imaging quality, improving design flexibility and enhancing module adaptability. In particular, this ratio range makes the shape of the liquid lens easier to process, thereby reducing manufacturing costs and improving production efficiency.

[0089] In this example of the present application, the curvature radius R of the liquid lens unit is set in the range of 0.1 mm to 0.3 mm (including the two end values ​​of 0.1 mm and 0.3 mm). This design is related to the focal length adjustment function of the liquid lens array in the above example. The specific analysis is as follows:

[0090] The focal length adjustment function of the liquid lens array is one of its core advantages, and the curvature radius R of the liquid lens unit is set in the range of 0.1mm to 0.3mm, which is the key to achieving a wide range of diopter adjustment. This curvature radius range in the example of this application allows the liquid lens array to achieve optical focal adjustment such as -5D to 0D. This means that the VR optical module can adapt to a wide range of user groups from high myopia (up to -5D) to no myopia (0D), providing users with personalized diopter adjustment solutions.

[0091] Within the curvature radius range provided in this example of the present application, the liquid lens array can accurately adjust the focal length to ensure that the light can be accurately focused on the user's retina after passing through the liquid lens array, thereby achieving a clear imaging effect. This is crucial to enhancing the immersion of the VR experience, because blurred or distorted images will seriously affect the user's visual comfort and experience quality.

[0092] Within the curvature radius range provided in this example of the present application, the optical performance of the liquid lens array is optimized, including reducing optical problems such as aberrations and distortions. These optimization measures work together on the entire VR optical module to bring users a more comfortable visual experience.

[0093] In summary, in this application, the curvature radius R of the liquid lens unit constituting the liquid lens array is set within the range of 0.1 mm to 0.3 mm, and combined with the focal length adjustment function of the liquid lens array, a wide range of diopter adjustment and clear imaging effects are achieved. This design improves the adaptability and user experience of the VR module.

[0094] It should be noted that by setting the curvature radius R of the liquid lens unit in the liquid lens array to between 0.1 mm and 0.3 mm, the optical focal length adjustment from -5D to 0D can be achieved, and the number thereof is less than or equal to the number of pixels of the display screen 4, which can ensure image resolution and clarity.

[0095] In some examples of this application, see Figure 1 The imaging component also includes a polarizing reflector 6, a first phase retarder 7 and a spectroscopic element 8, and the first phase retarder 7 is located between the polarizing reflector 6 and the spectroscopic element 8; wherein the polarizing reflector 6 and the first phase retarder 7 are located on the side of the lens 3 away from the display component, and the spectroscopic element 8 is located on the side of the lens 3 close to the display component.

[0096] According to this example of the present application, in addition to the lens, the imaging assembly also introduces a combination of a polarizing reflector 6, a first phase retarder 7, and a beam splitter 8, which together constitute a folded optical path system, achieving multiple foldings of the optical path. This folded optical path design reduces the overall size of the VR optical module, making the module more compact, which is conducive to achieving lightweight and portability.

[0097] By precisely controlling the polarization state and optical path of the light, this design effectively reduces the loss and distortion of the light during propagation, thereby improving the imaging quality. The polarization reflector 6 can selectively reflect light of a specific polarization state, while the first phase retarder 7 can convert linear polarization into circular polarization, increasing the stability and uniformity of the light. The beam splitter 8 achieves partial transmission and partial reflection of the light.

[0098] In the VR optical module provided in the embodiment of the present application, the imaging component adopts a folded optical path design, and the light undergoes multiple reflections and transmissions inside the VR optical module, and finally forms a clear image in front of the user. This design makes the image closer to the user's visual focus and enhances the visual immersion.

[0099] The folded optical path design not only reduces the volume and weight of the VR optical module, but also simplifies the structure of the VR optical module. This makes the VR head-mounted display device using the VR optical module lighter, easier to carry and use. At the same time, due to the improvement of imaging quality and enhanced visual immersion, users can get a more realistic and comfortable visual experience during use.

[0100] For some examples in this application, please continue to see Figure 1The polarized reflector 6 is a polarized reflective film, the first phase retarder 7 is a 1 / 4 wave plate, the polarized reflective film and the 1 / 4 wave plate are stacked and arranged together on the surface of the lens 3 away from the display component; the spectrometer element 8 is a semi-transparent and semi-reflective film, and the semi-transparent and semi-reflective film is arranged on the surface of the lens 3 close to the display component.

[0101] See also Figure 1 , the polarized reflective film and the 1 / 4 wave plate are stacked and arranged on the side of the lens 3 away from the display screen 4. This layout allows the light to be converted into a polarization state (realized by the 1 / 4 wave plate) after passing through the lens 3, and then reflected by the polarized reflective film. At the same time, the light splitting element 8, i.e., the semi-transparent and semi-reflective film, is arranged on the side of the lens 3 close to the display screen 4, realizing partial transmission and partial reflection of the light, thereby constructing an efficient folded optical path. This folded optical path design helps to reduce the overall volume of the VR optical module while maintaining or improving the imaging quality.

[0102] Among them, the 1 / 4 wave plate can convert incident linear polarization into circular polarization (or vice versa). This conversion helps to reduce the reflection loss and scattering of light during propagation, improve the utilization rate of light and the clarity of imaging. At the same time, the polarized reflective film can selectively reflect light of a specific polarization state, further reduce the interference of stray light, and improve the contrast and color reproduction of imaging.

[0103] Through the precise layout and coordination of the above optical components, clear and realistic images can be produced, providing users with an immersive visual experience. In particular, when adjusting the focal length to accommodate users with different myopia, the design can maintain stable imaging quality, ensuring that users can get a good visual experience under different vision conditions.

[0104] In addition, the polarized reflective film and the quarter wave plate layer are stacked on the surface of the lens 3 away from the display screen 4, and the semi-transparent and semi-reflective film is arranged on the surface of the lens 3 close to the display screen 4. This specific layout helps to simplify the manufacturing process of the VR optical module. This design allows the optical components to be more closely combined, reduces the errors and complexity in the assembly process, and improves production efficiency and product quality.

[0105] In some examples of this application, see Figure 1 The display component also includes a polarizer 10 and a second phase retarder 9, and the polarizer 10 and the second phase retarder 9 are located between the display screen 4 and the variable focus lens array 11.

[0106] In this example of the present application, the display assembly includes a polarizer 10 and a second phase retarder 9, which are located between the display screen 4 and the variable focus lens array 11. This layout ensures that the light emitted from the display screen 4 is first processed by the polarizer 10 and the second phase retarder 9, and then enters the variable focus lens array 11 for further adjustment.

[0107] The polarizer 10 can selectively allow light in a specific direction to pass through, reduce the interference of stray light, and improve the utilization rate of light. The second phase retarder 9 (1 / 4 wave plate) can convert linear polarization into circular polarization (or vice versa), which helps to reduce the reflection loss of light in subsequent optical elements and further improve the utilization efficiency of light.

[0108] Through the synergistic effect of the polarizer 10 and the second phase retarder 9, the light emitted by the display screen 4 can be preliminarily optically processed so that the light has a good polarization state and phase distribution before entering the variable focus lens array 11. This helps to reduce the distortion and dispersion of the light during transmission and improve the clarity and contrast of the imaging.

[0109] The light processed by the polarizer 10 and the second phase retarder 9 has better visual quality when entering the user's eyes, can reduce phenomena such as glare and ghosting, and enhance the user's visual comfort and immersion when using a VR head-mounted display device.

[0110] In some examples of the present application, the second phase retarder 9 is a 1 / 4 wave plate, the polarizer 10 is a polarizing film, and the 1 / 4 wave plate and the polarizing film are stacked and arranged on the light-emitting surface of the display screen 4 .

[0111] In this example of the present application, it is further clarified that the second phase retarder 9 is a 1 / 4 wave plate, the polarizer 10 is a polarizing film, and they are arranged in a stacked manner on the light-emitting surface of the display screen 4. This stacked layout makes the cooperation between the optical elements closer.

[0112] Specifically, directly stacking the quarter wave plate and the polarizing film on the light-emitting surface of the display screen 4 can simplify the overall structure of the VR optical module, which is conducive to miniaturization and light weight of the device. In addition, directly integrating the above optical elements on the display screen 4 can enhance the stability and reliability of the entire VR optical module. This design reduces the risk of optical performance degradation caused by loose components or positional displacement.

[0113] In this application, the use of a liquid lens array has many advantages over directly using a single liquid lens, which are specifically analyzed as follows:

[0114] Liquid lens arrays can better control the propagation path and focusing effect of light through the synergistic effect of multiple liquid lens units. This distributed adjustment mechanism helps to reduce aberrations and distortions during imaging, thereby improving the clarity and quality of imaging. In addition, liquid lens arrays can further improve imaging effects by optimizing the spacing and arrangement between units.

[0115] The design of liquid lens arrays has a high degree of freedom and can be customized according to specific application scenarios and requirements. For example, the number, size, shape and arrangement of lens units can be adjusted to adapt to different VR module structures and optical designs.

[0116] The liquid lens array adopts a design of multiple independent units, so that even if a unit fails or its performance degrades, it will not have a fatal impact on the entire system. In contrast, once a single liquid lens has a problem, it may have a greater impact on the imaging effect of the entire VR module. Therefore, the liquid lens array improves the stability and reliability of the system to a certain extent.

[0117] The VR optical module provided in the embodiment of the present application is shown in Figure 1 , and its light propagation path is as follows:

[0118] The image light 5 emitted by the display screen 4 first passes through the polarizer 10 to become horizontal linear polarization, then passes through the second phase retarder 9 (1 / 4 wave plate) to become left-handed circular polarization, passes through the liquid lens array, and then passes through the spectroscopic element 8 (semi-reflective and semi-transparent membrane) to become left-handed circular polarization, passes through the lens 3 and the first phase retarder 7 (1 / 4 wave plate), becomes horizontal linear polarization, is reflected by the polarization reflector 6, passes through the first phase retarder 7 and the lens 3 again to become left-handed circular polarization, is reflected by the spectroscopic element 8 (semi-reflective and semi-transparent membrane), becomes right-handed circular polarization, then passes through the lens 3 and the first phase retarder 7 (1 / 4 wave plate) again to become vertical polarization, and then passes through the polarization reflector 6 to irradiate the aperture 2.

[0119] The VR optical module of the present application is described below through a specific example.

[0120] For a specific example, see Figure 1 The VR optical module comprises a display component, a liquid lens array and an imaging component which are sequentially arranged along the same optical axis 1; the display component is located on a side away from the aperture 2, and the display component is used to emit an image light 5; the imaging component is used to form a virtual image with the image light 5; the liquid lens array comprises a plurality of liquid lens units, and the liquid lens array is configured to be able to adjust its focal length under driving, so as to adapt to the wearer's vision;

[0121] Wherein, the display assembly includes a display screen 4, and the liquid lens array is arranged on the light-emitting surface of the display screen 4; the number of the liquid lens units is equal to the number of pixels of the display screen 4;

[0122] The imaging component is a folded optical path lens module, and the imaging component includes a lens 3; the imaging component also includes a polarizing reflector 6, a first phase retarder 7 and a beam splitter 8, the polarizing reflector 6 is a polarizing reflective film, the first phase retarder 7 is a quarter wave plate, the polarizing reflective film and the quarter wave plate are stacked and arranged together on the surface of the lens 3 away from the display component (the first surface 31, i.e., the front surface); the beam splitter 8 is a semi-transparent and semi-reflective film, and the semi-transparent and semi-reflective film is arranged on the surface of the lens 3 close to the display component (the second surface 32, i.e., the rear surface);

[0123] Wherein, the curvature radius R of the liquid lens unit is 0.1 mm ≤ R ≤ 0.3 mm;

[0124] Among them, the display component also includes a polarizer 10 and a second phase retarder 9, the second phase retarder 9 is a 1 / 4 wave plate, the polarizer 10 is a polarizing film, the 1 / 4 wave plate and the polarizing film are stacked and arranged on the light-emitting surface of the display screen 4, and the liquid lens array is located on the side of the two film materials away from the light-emitting surface.

[0125] Table 1 shows the optical parameters of this specific example.

[0126] Table 1

[0127]

[0128]

[0129] Figure 2 , Figure 3 , Figure 4 The modulation transfer function MTF curves of the VR optical module shown in this specific example at 450nm, 540nm, and 610nm are respectively Figures 2 to 4 It can be seen that:

[0130] At a spatial frequency of 15lp / mm, at a wavelength of 450nm, the MTF value of the VR optical module is higher than 0.5, at a wavelength of 540nm, the MTF value of the VR optical module is higher than 0.7, and at a wavelength of 610nm, the MTF value of the VR optical module is higher than 0.7.

[0131] against Figures 2 to 4Specifically, the MTF value (modulation transfer function value) is an important indicator to measure the optical performance of VR optical modules. It reflects the module's ability to transmit image details (i.e. high-frequency information). The higher the MTF value, the stronger the module's ability to transmit image details and the better the imaging quality.

[0132] MTF value at 450nm wavelength: At a spatial frequency of 15lp / mm, the MTF value of the VR optical module of the present application is higher than 0.7. This indicates that in the blue light region (450nm is close to the wavelength of blue light), the VR optical module can well transmit the high-frequency details of the image and has high imaging clarity.

[0133] MTF value at 540nm wavelength: At 15lp / mm spatial frequency, the MTF value of the VR optical module is higher than 0.7. In the green light region (540nm is within the green light wavelength range), the VR optical module of this application maintains a high imaging quality, further verifying its excellent performance in a wide spectral range.

[0134] MTF value at 610nm wavelength: In the red light region (610nm is close to the wavelength of red light), the MTF value of the VR optical module at a spatial frequency of 15lp / mm is still higher than 0.7. This shows that the VR optical module can also effectively transmit the high-frequency information of the image in the red light band, ensuring the clarity and color reproduction of the full-color image.

[0135] In summary, Figures 2 to 4 The MTF curve analysis shows that the VR optical module has excellent imaging performance in the visible light range (especially the three wavelengths of 450nm, 540nm and 610nm), and can maintain a high MTF value at different wavelengths, thereby ensuring the clarity and color accuracy of the imaging. This is crucial for augmented reality (VR) applications, as it requires the VR optical module to accurately and clearly reproduce the fusion effect of virtual information and the real world.

[0136] According to another embodiment of the present application, a head mounted display device is provided, wherein the head mounted display device comprises a housing and the VR optical module as described above.

[0137] The head-mounted display device provided in the embodiment of the present application is, for example, VR smart glasses or a VR smart helmet.

[0138] The specific implementation of the head-mounted display device of the embodiment of the present application can refer to the above-mentioned VR optical module embodiments, so it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0139] 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.

[0140] 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 VR optical module, characterized in that: It comprises a display component, a variable focus lens array (11) and an imaging component which are arranged in sequence along the same optical axis (1); The display component is used to emit image light (5); The imaging component is used to form a virtual image from the image light (5); The variable focus lens array (11) comprises a plurality of variable focus lenses, and the variable focus lens array (11) is configured to be able to adjust its own focal length under driving, so as to adapt to the vision of the wearer.

2. The VR optical module according to claim 1, characterized in that: The variable focus lens array (11) is a liquid lens array, and the liquid lens array comprises a plurality of liquid lens units.

3. The VR optical module according to claim 2, characterized in that: The display component comprises a display screen (4), and the liquid lens array is arranged on the light-emitting surface of the display screen (4); The number of the liquid lens units is less than or equal to the number of pixels of the display screen (4).

4. The VR optical module according to claim 2, characterized in that: The imaging component is a folded light path lens module; The imaging component comprises at least one lens (3), the refractive power of the lens (3) is D2, the refractive power of the liquid lens unit is D1, and D1 and D2 satisfy: 300≤D1 / D2≤700.

5. The VR optical module according to claim 2, characterized in that: The central thickness of the liquid lens unit is T1, the central thickness of the lens (3) is T2, and T1 and T2 satisfy: 0.03≤T1 / T2≤0.

12.

6. The VR optical module according to claim 2, characterized in that: The curvature radius R of the liquid lens unit and the virtual image distance VID of the VR optical module satisfy: 0<R / VID≤0.01; wherein, the curvature radius R of the liquid lens unit is 0.1mm≤R≤0.3mm.

7. The VR optical module according to any one of claims 1 to 6, characterized in that: The imaging component further comprises a polarizing reflector (6), a first phase retarder (7) and a beam splitter (8), and the first phase retarder (7) is located between the polarizing reflector (6) and the beam splitter (8); The polarizing reflector (6) and the first phase retarder (7) are located on a side of the lens (3) away from the display component, and the beam splitter (8) is located on a side of the lens (3) close to the display component.

8. The VR optical module according to claim 7, characterized in that: The polarizing reflector (6) is a polarizing reflective film, the first phase retarder (7) is a quarter wave plate, the polarizing reflective film and the quarter wave plate are stacked and arranged together on a surface of the lens (3) away from the display component; The light splitting element (8) is a semi-transparent and semi-reflective film, and the semi-transparent and semi-reflective film is arranged on the surface of the lens (3) close to the display component.

9. The VR optical module according to claim 3, characterized in that: The display component further comprises a polarizer (10) and a second phase retarder (9), wherein the polarizer (10) and the second phase retarder (9) are located between the display screen (4) and the variable focus lens array (11).

10. The VR optical module according to claim 9, characterized in that: The second phase retarder (9) is a quarter wave plate, the polarizer (10) is a polarizing film, and the quarter wave plate and the polarizing film are stacked and arranged on the light-emitting surface of the display screen (4).

11. A head mounted display device, characterized in that: include: shell; and A VR optical module as described in any one of claims 1-10.

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