Optical system, intelligent head-mounted device and zooming method of optical system

Abstract

The embodiment of the invention provides an optical system, intelligent head-mounted equipment and a zooming method of the optical system. The optical system is used for the intelligent head-mounted device, and the optical system comprises an imaging module, an eyeball tracking module and a processor. The imaging module comprises a zoom lens, and the eyeball tracking module is used for acquiring eyeball watching information; the processor is used for determining zoom information according to eyeball watching information provided by the eyeball tracking module and controlling the zoom lens to zoom according to the zoom information; wherein the zoom information comprises the thickness and the curvature radius of the zoom lens.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optical display technology. More specifically, the embodiments of the present application relate to an optical system, an intelligent head-mounted device, and a zoom method for an optical system. Background Art

[0002] Most existing VR head-mounted display devices present virtual images at a fixed distance, and users experience the virtual image as if they were watching a 2D rendered image, without the ability to achieve dynamic zoom effects. This not only affects the immersion and realism of the VR head-mounted display device, but may also cause visual fatigue and binocular vision convergence problems during long-term use. Summary of the invention

[0003] The purpose of this application is to provide a new technical solution for an optical system, an intelligent head-mounted device, and a zoom method for an optical system.

[0004] In a first aspect, the present application provides an optical system for a smart head mounted device, the optical system comprising:

[0005] An imaging module, including a zoom lens;

[0006] Eye tracking module, used to obtain eye gaze information; and

[0007] A processor is used to determine zoom information according to the eye gaze information provided by the eye tracking module, and control the zoom of the zoom lens according to the zoom information; wherein the zoom information includes the thickness and curvature radius of the zoom lens.

[0008] Optionally, the optical system further comprises a voltage controller;

[0009] The processor is connected to the voltage controller, and the processor is also used to determine a target voltage value based on the zoom information and a preset mapping relationship, and control the voltage controller to apply a voltage of the target voltage value to the zoom lens; wherein the preset mapping relationship is used to reflect the correspondence between the zoom information and the target voltage value, and the target voltage value is a voltage value that can drive the zoom lens to adjust to match the zoom information.

[0010] Optionally, the zoom lens is a liquid crystal lens.

[0011] Optionally, the imaging module includes a folded optical path structure, and the folded optical path structure and the zoom lens are adjacent to and spaced apart from each other along the same optical axis.

[0012] Optionally, the imaging module further includes a display screen, the folded optical path structure is located between the display screen and the zoom lens, and the display screen is used to emit light for imaging display.

[0013] Optionally, the folded optical path structure includes at least one lens, a beam splitting element and a composite film material;

[0014] The light splitting element is arranged between the display screen and the lens;

[0015] The composite film material is arranged between the lens and the zoom lens; wherein the composite film material comprises a phase delay plate, a polarization reflection element and a polarizer which are stacked in sequence.

[0016] Optionally, the light splitting element is arranged on a surface of the lens close to the display screen, and the composite film material is arranged on a surface of the lens away from the display screen.

[0017] Optionally, a polarizing element is provided on the light emitting surface of the display screen.

[0018] Optionally, the eye tracking module includes a plurality of infrared LED light sources corresponding to human eyes and at least two infrared cameras;

[0019] The plurality of infrared LED light sources are arranged around the human eye, and are used to emit infrared light and project the infrared light to the pupil of the human eye;

[0020] The at least two infrared cameras are located at the periphery of the plurality of infrared LED light sources, and are used to receive infrared light reflected by the pupil of the human eye.

[0021] Optionally, the multiple infrared LED light sources and the at least two infrared cameras are located between the zoom lens and the human eye.

[0022] Optionally, the zoom lens comprises a first transparent conductive film and a second transparent conductive film which are arranged opposite to each other, and a liquid crystal molecule layer located between the first transparent conductive film and the second transparent conductive film);

[0023] When no voltage is applied to the first transparent conductive film and the second transparent conductive film, the liquid crystal molecules in the liquid crystal molecule layer are arranged in the same direction, and the variable focus lens is a light-transmitting flat plate;

[0024] After voltage is applied to the first transparent conductive film and the second transparent conductive film, the arrangement direction of the liquid crystal molecules in the liquid crystal molecule layer changes, and the optical power of the variable focus lens changes accordingly.

[0025] In a second aspect, the present application provides a smart head-mounted device, the smart head-mounted device comprising:

[0026] casing; and

[0027] An optical system as described in the first aspect.

[0028] In a third aspect, the present application provides a zoom method for an optical system, the zoom method comprising:

[0029] Obtain eye gaze information through an eye tracking module;

[0030] Determining zoom information according to the eye gaze information provided by the eye tracking module; and

[0031] The zoom lens is controlled to zoom according to the zoom information.

[0032] Optionally, determining zoom information according to the eye gaze information provided by the eye tracking module includes:

[0033] Determine the distance of the target virtual image of the eye gaze according to the eye gaze information provided by the eye tracking module; wherein the eye gaze information includes a gaze plane and a gaze direction; and

[0034] The target virtual image distance and a first mapping relationship are used to determine zoom information corresponding to the target virtual image distance; wherein the first mapping relationship is used to reflect the relationship between the zoom information and the target virtual image distance.

[0035] Optionally, controlling the zoom lens to zoom according to the determined zoom information includes:

[0036] Determine a target voltage value according to the zoom information and a preset mapping relationship; wherein the preset mapping relationship is used to reflect the corresponding relationship between the zoom information and the target voltage value, and the target voltage value is a voltage value that can drive the zoom lens to adjust to match the zoom information;

[0037] The control voltage controller applies the voltage of the target voltage value to the zoom lens so that the zoom lens can achieve zooming.

[0038] The beneficial effects of this application are:

[0039] An embodiment of the present application provides an optical system, which can be applied to, for example, a VR smart head-mounted device. By combining lens zoom technology with an eye tracking function, the optical solution of the present application can adjust the distance from the virtual image to the human eye according to the user's actual eye movement, simulate the visual experience of observing the real world, and effectively solve the binocular vision convergence problem in traditional VR optical display devices, which can significantly improve the user's visual immersion and comfort.

[0040] 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

[0041] 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.

[0042] Figure 1 A schematic diagram of the structure of an optical system provided in an embodiment of the present application;

[0043] Figure 2 A light path diagram of an optical system provided in an embodiment of the present application;

[0044] Figure 3 A block diagram of the optical system hardware configuration provided in an embodiment of the present application;

[0045] Figure 4 A side view of a liquid crystal lens provided in an embodiment of the present application;

[0046] Figure 5 A schematic diagram of a liquid crystal lens in a non-focused state provided by an embodiment of the present application;

[0047] Figure 6 Schematic diagram of the liquid crystal lens provided in the embodiment of the present application in different zoom states.

[0048] Description of reference numerals:

[0049] 1. Imaging module; 11. Display screen; 12. Polarizing element; 13. Lens; 14. Composite film material; 15. Zoom lens; 151. First transparent conductive film; 152. Second transparent conductive film; 153. Liquid crystal molecule layer; 16. Spectral element;

[0050] 2. Eye tracking module; 21. Infrared camera; 22. Infrared LED light source;

[0051] 3. Processor;

[0052] 4. Voltage controller;

[0053] 01. Human eye; 001. First virtual image; 002. Second virtual image. DETAILED DESCRIPTION

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The optical system, the smart head-mounted device, and the zoom method of the optical system provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0060] According to one embodiment of the present application, an optical system is provided. Figures 1 to 3 The optical system is used for a smart head-mounted device, and the optical system includes an imaging module 1, an eye tracking module 2 and a processor 3; the imaging module 1 includes a zoom lens 15; the eye tracking module 2 is used to obtain eye gaze information; the processor 3 is used to determine zoom information according to the eye gaze information provided by the eye tracking module 2, and control the zoom of the zoom lens 15 according to the zoom information; wherein the zoom information includes the thickness and curvature radius of the zoom lens 15.

[0061] The optical system provided in the embodiment of the present application can be used in a smart head-mounted device, such as a VR smart head-mounted device. The optical system provided in the embodiment of the present application is a VR optical system that combines zoom lens focusing and eye tracking technology, and can realize the zoom function of the optical system according to the user's actual gaze plane and gaze direction.

[0062] The optical system provided in the embodiment of the present application is shown in FIG. Figure 1 , which includes an imaging module 1, an eye tracking module 2 and a processor 3. These key components are described separately below.

[0063] The imaging module 1 in the present application includes at least one zoom lens 15, which is a key optical component for realizing dynamic zoom of the entire optical system.

[0064] The eye tracking module 2 in the present application is used to obtain the user's eye gaze information in real time, and the eye gaze information includes the plane and direction of the user's eye gaze.

[0065] In the embodiment of the present application, the eye tracking module 2 is, for example, an external structure, see Figure 1 and Figure 2, the eye tracking module 2 is arranged on the path between the imaging module 1 and the human eye 01, rather than being embedded in the internal structure of the imaging module 1. In other words, from the layout position of the eye tracking module 2, it is arranged outside the imaging module 1 as a whole.

[0066] Of course, the position design of the eye tracking module 2 is not limited to an external structure, and a built-in structure can also be adopted. Specifically, the eye tracking module 2 can be arranged inside the imaging module 1, and its position can be located in the space between the display screen 11 and the lens assembly responsible for imaging, for example.

[0067] It should be noted that the external eye tracking module 2 is more easily adapted to imaging modules 1 of different models and specifications because it does not rely on the internal structure or design of the imaging module 1. This adaptability allows eye tracking technology to be more widely used in various devices and scenarios. In addition, placing the eye tracking module 2 outside the imaging module 1 can reduce interference with the optical components and mechanical structures inside the imaging module 1. This design helps maintain the optical performance of the imaging module 1 and ensure that the image quality and tracking accuracy are not affected.

[0068] In addition, the infrared light emitted by the infrared LED light source 22 in the eye tracking module 2 can be directly transmitted to the eyeball. Figure 2 , the infrared light emitted by the infrared LED light source 22 is directed directly toward the human eye. This belongs to the transmission type design.

[0069] Of course, an infrared reflective film layer may also be provided on the surface of the zoom lens 15, so that the infrared light can be reflected to the user's eyeball. This belongs to a reflective design.

[0070] The transmissive design allows infrared light to directly and unimpededly shine on the eyeball without passing through any intermediate reflection or refraction elements. This direct irradiation method reduces light loss and scattering, and improves light utilization and tracking accuracy.

[0071] Since infrared light is transmitted directly to the eyeball, there is no need to set additional reflective films or coatings on the zoom lens or other optical elements. This simplifies the structure of the optical system, reduces manufacturing costs and complexity, and improves the reliability and stability of the optical system.

[0072] The directly transmitted infrared light will not interfere with or affect other optical components in the imaging module, such as the light transmittance of the zoom lens, the imaging quality, etc. This design ensures the independence of the eye tracking function and the imaging function, allowing the two to work simultaneously without interfering with each other.

[0073] In summary, the transmissive eye tracking method has a good application prospect due to its advantages of directness, high efficiency, simplified system structure and avoidance of interference. This design method not only improves the accuracy and reliability of eye tracking, but also provides strong support for the development and application of eye tracking technology.

[0074] The processor 3 in the present application is used to receive and process the eye tracking data information provided by the eye tracking module 2, and determine the zoom information therefrom, and then control the zoom operation of the zoom lens 15 according to the zoom information.

[0075] The optical system provided in the embodiment of the present application obtains the user's eye gaze information in real time through the eye tracking module 2, and the processor 3 can quickly calculate and determine the required zoom parameters (such as the thickness and curvature radius of the zoom lens 15). This real-time zoom adjustment allows the user to see clear and focused images according to actual needs, enhancing the immersion and realism of the VR experience.

[0076] Compared with traditional fixed-focal-length VR head-mounted display devices, the technical solution of this application can dynamically adjust the focal length according to the user's eye gaze point, avoiding visual fatigue and discomfort caused by fixed focal length. In addition, it can also simulate the observation state of the real world, effectively avoid binocular vision convergence problems, and further enhance the user's visual experience.

[0077] The optical system provided in the embodiment of the present application realizes the dynamic zoom function of the optical system by combining the focusing of the zoom lens and the eye tracking technology, thereby helping to improve the user visual experience and immersion of the VR optical display device. At the same time, the portability, flexibility and scalability of the entire optical system also make this technical solution have a wide range of application prospects.

[0078] In some examples of this application, see Figure 3 , the optical system also includes a voltage controller 4; the processor 3 is connected to the voltage controller 4, and the processor 3 is used to determine the target voltage value according to the zoom information and the preset mapping relationship, and control the voltage controller 4 to apply the voltage of the target voltage value to the zoom lens 15; wherein the preset mapping relationship is used to reflect the correspondence between the zoom information and the target voltage value, and the target voltage value is a voltage value that can drive the zoom lens 15 to adjust to match the zoom information.

[0079] In this example of the present application, the optical system is further improved, specifically, a voltage controller 4 is added. A connection is established between the voltage controller 4 and the processor 3, forming a more sophisticated control link. Specifically, the processor 3 plays an important role in this link. It not only receives the eye gaze information provided by the eye tracking module 2, but also determines the required zoom information based on this information. In this example of the present application, the processor 3 does not directly control the zoom lens 15, but achieves the zoom effect of the zoom lens 15 through the intermediate link of the voltage controller 4 introduced.

[0080] In order to realize this control process, a pre-set preset mapping relationship is also introduced in this example of the present application. This preset mapping relationship records in detail the correspondence between the zoom information and the target voltage value. In other words, when the processor 3 determines the required zoom information, it will find the corresponding target voltage value according to this preset mapping relationship. Subsequently, the processor 3 will control the voltage controller 4 to apply this target voltage value to the zoom lens 15.

[0081] After receiving the voltage signal, the zoom lens 15 can change the focal length of the zoom lens 15. In this way, by adjusting the voltage value, the focal length of the zoom lens 15 can be flexibly controlled to achieve a dynamic zoom effect.

[0082] It can be seen that by introducing the voltage controller 4 and the preset mapping relationship, this example of the present application achieves more precise control of the zoom lens 15. This precise control can ensure that the focal length of the zoom lens 15 is completely matched with the plane and direction actually looked at by the user, thereby further enhancing the immersion and realism of the VR optical display device.

[0083] Since the voltage controller 4 can stably output the target voltage value, the focal length adjustment process of the zoom lens 15 also becomes more stable and reliable, which helps to reduce problems such as visual blur or distortion caused by improper focal length adjustment and improve the user's visual experience.

[0084] The technical solution in this example of the present application has good adaptability and can be applied to different types of VR smart head-mounted devices. At the same time, due to the existence of the voltage controller 4 and the preset mapping relationship, the optical technical solution can also be flexibly adjusted and optimized according to different zoom requirements.

[0085] In some examples of the present application, the zoom lens 15 is a liquid crystal lens.

[0086] In this example of the present application, the zoom lens 15 is embodied as a liquid crystal lens. A liquid crystal lens is an optical element based on liquid crystal material, which is characterized in that the optical focal length of the lens can be flexibly adjusted by changing the arrangement state of liquid crystal molecules, thereby achieving a zoom function.

[0087] Combination Figure 1 and Figure 2 The eye tracking module 2 can capture the user's eye gaze information in real time and transmit the information to the processor 3. After receiving the information, the processor 3 calculates the required zoom parameters such as curvature radius, thickness, etc. according to the preset algorithm and logic, and then determines the target voltage value corresponding to the zoom parameters.

[0088] Subsequently, the processor 3 controls the voltage controller 4 to apply the target voltage value to the liquid crystal lens in the imaging module 1. After receiving the voltage signal, the liquid crystal molecules inside the liquid crystal lens (i.e., the zoom lens 15) will deflect accordingly according to the magnitude and direction of the voltage value, see Figure 4 and Figure 5 , thereby changing the optical focal length of the liquid crystal lens. That is, by adjusting the voltage value, the focal length of the liquid crystal lens can be controlled to match the plane and direction that the user is actually looking at.

[0089] Since the liquid crystal lens has excellent zoom performance, it can quickly and accurately adjust its focal length, thereby adjusting the focal length of the optical system to meet the user's visual needs in different scenarios. This improvement in zoom performance enables VR optical display devices to provide users with a more natural and smooth visual experience.

[0090] Compared with the traditional mechanical zoom method, liquid crystal lenses do not require complex mechanical structures and moving parts, so the device can be designed to be thin and light. This is of great significance for improving the wearing comfort and portability of VR optical display devices.

[0091] The zoom process of the liquid crystal lens is achieved by changing the arrangement state of the liquid crystal molecules, and the power consumed in this process is relatively small. Therefore, using a liquid crystal lens as the zoom lens 15 helps to reduce the overall power consumption of the VR optical display device and extend the use time of the device.

[0092] The manufacturing process of liquid crystal lens is relatively mature and the material cost is low. Therefore, using liquid crystal lens as zoom lens 15 helps to reduce the manufacturing cost of optical system and improve the market competitiveness of VR products.

[0093] In the present application, the zoom lens 15 is a liquid crystal lens, which can adopt a single-point voltage control technology, that is, the entire liquid crystal lens is controlled by the same voltage.

[0094] It is worth noting that the present application is not limited to the single-point voltage control scheme. In fact, the liquid crystal lens also supports multi-point voltage control, that is, by dividing the liquid crystal lens into multiple areas and applying different voltages to each area independently, a more precise zoom adjustment can be achieved. This multi-point control method gives the liquid crystal lens higher adjustment flexibility and precision, further enhances the accuracy and stability of the zoom operation, and meets more sophisticated application requirements.

[0095] In some examples of the present application, the imaging module 1 includes a folded optical path structure, and the folded optical path structure is adjacent to and spaced apart from the zoom lens 15 along the same optical axis.

[0096] In this example of the present application, the imaging module 1 includes a folded optical path structure, which is adjacent to and spaced from the zoom lens 15 along the same optical axis. The folded optical path structure plays a vital role in VR optical design, as it can effectively shorten the total length of the optical path and ensure imaging quality, making the entire imaging module 1 more compact and thin while ensuring imaging quality.

[0097] In the embodiment of the present application, the zoom lens 15 is a liquid crystal lens, which can adjust the focal length by changing the arrangement state of liquid crystal molecules in the liquid crystal molecule layer 153. The folded optical path structure is located in front of the zoom lens 15, and is used to fold and guide the light from the display screen 11 so that it can be accurately projected onto the zoom lens 15.

[0098] Since the folded optical path structure and the zoom lens 15 are adjacent and spaced along the same optical axis, the relative position relationship between them is relatively stable, which helps to ensure accurate transmission of light and precise realization of zoom effect. At the same time, the design of the folded optical path structure can also effectively reduce the interference of stray light and improve imaging quality.

[0099] The application of the folded optical path structure makes the imaging module 1 more compact and thin, which is of great significance for improving the wearing comfort and portability of VR optical display devices. At the same time, the compact optical structure also helps to reduce the number and weight of optical elements (such as optical lenses), further reducing the manufacturing cost of optical devices.

[0100] The folded optical path structure can flexibly adjust the transmission path of light, making the entire optical path more optimized, which helps to reduce light loss and distortion and improve the clarity and fidelity of imaging.

[0101] The design of the imaging module 1 in this example of the present application not only realizes the compactness and lightness of the overall structure of the optical system and the optimization of the optical path, but also ensures the precise realization of the zoom effect. These features work together in the optical system to provide users with a more natural, smooth and realistic visual experience.

[0102] In some examples of this application, see Figure 1 and Figure 2 The imaging module also includes a display screen 11. The folded optical path structure is located between the display screen 11 and the zoom lens 15. The display screen 11 is used to emit light for imaging display.

[0103] The display screen 11 is the image source of the optical system and is responsible for generating the content observed by the user through the optical system.

[0104] The folded optical path structure is designed to be located between the display screen 11 and the zoom lens 15. The folded optical path structure design uses optical elements such as optical films to fold light multiple times in a small space, effectively reducing the overall thickness of the entire optical system, which helps to make VR optical display devices thinner and more portable.

[0105] For the zoom lens 15, its focal length can be dynamically adjusted according to the user's eye tracking information. This is different from the traditional fixed focal length design. The optical solution proposed in the embodiment of the present application uses, for example, a liquid lens to achieve a dynamic zoom function. The liquid lens can change its surface curvature according to a voltage signal, thereby adjusting the focus position of the light to achieve a dynamic zoom effect.

[0106] In this example of the present application, by combining eye tracking technology, the optical system can sense the user's gaze point in real time, and adjust the parameters of the zoom lens 15 accordingly, so that the virtual image is focused on the plane where the user is actually looking, enhancing the sense of immersion and reality. This dynamic zoom function imitates the way the human visual system adjusts when observing objects in a natural environment, reducing the visual discomfort caused by a fixed focal length.

[0107] The folded optical path structure is located between the display screen 11 and the zoom lens 15. By optimizing the propagation path of the light and then performing zooming, more accurate focal length adjustment can be achieved, making the virtual image observed by the user clearer and more realistic, thereby enhancing the sense of immersion.

[0108] In some examples of this application, see Figure 1 and Figure 2The folded optical path structure includes at least one lens 13, a spectroscopic element 16 and a composite film material 14; the spectroscopic element 16 is arranged between the display screen 11 and the lens 13; the composite film material 14 is arranged between the lens 13 and the zoom lens 15; wherein the composite film material 14 includes a phase delay plate, a polarization reflection element and a polarizer which are stacked in sequence.

[0109] In the folded optical path structure, the lens 13 is used to focus or adjust the direction of the light from the display screen 11 .

[0110] The light splitting element 16 is disposed between the display screen 11 and the lens 13. The light splitting element 16 is, for example, a film or coating with specific light splitting properties, and can be used to reflect and transmit incident light in a certain proportion.

[0111] The composite film material 14 is arranged between the lens 13 and the zoom lens 15 (liquid crystal lens), and the composite film material 14 includes a phase retarder, a polarizing reflective element and a polarizer which are stacked in sequence; wherein the phase retarder is to be located between the polarizing reflective element and the beam splitter 16. The phase retarder can be used to change the polarization state of light, such as for converting linear polarized light into circular polarized light, or converting circular polarized light into linear polarized light. The polarizing reflective element has specific polarization characteristics and can selectively reflect or transmit light of a specific polarization direction. By utilizing the characteristics of polarized light, the polarizing reflective element can effectively control the propagation path of light and realize the folding and redirection of light.

[0112] In this example of the present application, the light splitting element 16 is, for example, a semi-transmissive and semi-reflective film, which can allow a portion of light to be transmitted and another portion of light to be reflected.

[0113] It should be noted that the reflectivity and transmittance of the light splitting element 16 can be flexibly adjusted according to specific needs, and this is not limited in the embodiments of the present application.

[0114] In this example of the present application, the phase retarder is, for example, a quarter wave plate, which is located between the beam splitter element 16 and the polarized reflective element, and ensures that the light can be reflected or transmitted in the subsequent path by adjusting the phase of the light.

[0115] In this example of the present application, the polarized reflective element is a polarized reflective film, which is a polarized reflector that reflects horizontal linear polarized light and transmits vertical linear polarized light, or a polarized reflector that reflects linear polarized light at any other specific angle and transmits linear polarized light perpendicular to the angle. In other words, the polarized reflective element can reflect or transmit according to the polarization state of the light.

[0116] According to this example of the present application, by designing and optimizing the lens 13, the beam splitter 16 and the composite film 14 in the folded optical path structure, it is possible to minimize light loss and distortion, improve light utilization and the overall efficiency of the optical system. The application of the folded optical path structure enables the optical system to achieve complex light folding in a smaller space, thereby significantly reducing the overall thickness and weight of the VR headset and improving wearing comfort.

[0117] The combination of the polarizer, the polarized reflective element, and the phase delay plate can compensate for the phase difference caused by the refraction or reflection of light, thereby eliminating stray light and ghost images, thereby ensuring that the image observed by the user is clear and improving the quality of the VR experience.

[0118] By combining the folded optical path structure with the zoom lens 15, the optical system can sense the user's gaze point in real time and dynamically adjust the focal length, so that the virtual image observed by the user is always focused on the plane actually being gazed at. This dynamic zoom function enhances the user's sense of immersion and reality.

[0119] In some examples of this application, see Figure 1 and Figure 2 The light splitting element 16 is disposed on a surface of the lens 13 close to the display screen 11 , and the composite film material 14 is disposed on a surface of the lens 13 away from the display screen 11 .

[0120] The spectroscopic element 16 and the composite film material 14 are respectively arranged on the two side surfaces of the lens 13, so that no additional supporting elements are required during the assembly process, the optical structure can be simplified, and the assembly process can be simplified. Multiple elements can be installed at the same time.

[0121] In some examples of this application, see Figure 1 and Figure 2 A polarizing element 12 is disposed on the light emitting surface of the display screen 11 .

[0122] The introduction of the polarizing element 12 can reduce stray light, which is beneficial to improving the final imaging quality.

[0123] The polarizing element 12 is, for example, a linear polarizer, and the transmission axis direction thereof can be along the horizontal direction, the vertical direction or any other direction.

[0124] In some examples of this application, see Figure 1 and Figure 2The eye tracking module includes a plurality of infrared LED light sources 22 corresponding to the human eye 01 and at least two infrared cameras 21; the plurality of infrared LED light sources 22 are arranged around the human eye 01 to emit infrared light and project the infrared light to the pupil of the human eye 01; the at least two infrared cameras 21 are located on the periphery of the plurality of infrared LED light sources 22 to receive the infrared light reflected by the pupil of the human eye 01.

[0125] According to this example of the present application, see Figure 1 and Figure 2 , the eye tracking module is composed as follows:

[0126] Multiple infrared LED light sources 22: These light sources are designed to correspond to the human eye 01 and are used to emit infrared light and project it to the user's pupil. Infrared light has a longer wavelength and can penetrate the pupil and reflect on the retina, and then be captured by the infrared camera 21.

[0127] At least two infrared cameras 21: These cameras are configured to receive infrared light reflected by the pupil. By capturing and analyzing these reflected infrared light, the infrared cameras 21 are able to determine the position, orientation and movement of the eyeball.

[0128] The working principle of the eye tracking module is as follows:

[0129] The infrared LED light source 22 emits infrared light, which is projected onto the pupil of the human eye. The infrared light reflected by the pupil is captured by the infrared camera 21. By analyzing the angle and intensity of the reflected light, for example, the processor 3 can calculate the gaze direction and plane of the eyeball.

[0130] According to this example of the present application, by using multiple infrared LED light sources 22 and at least two infrared cameras 21, more data points can be provided for analyzing eye position and movement. This helps to improve the accuracy and reliability of tracking. Accurate eye tracking enables the optical system to respond more accurately to the user's gaze direction, thereby achieving a smoother and more natural dynamic zoom experience. This helps to enhance the user's immersion and sense of reality in the VR environment.

[0131] By tracking the position and movement of the eyeball in real time, the optical system can more effectively adjust the focal length and optical power of the liquid crystal lens to optimize the clarity and contrast of the image. This helps to improve the performance and efficiency of the overall system. The eye tracking module can quickly capture the movement of the eyeball and quickly adjust the focal length, thereby reducing system latency. This allows users to observe the changed image more immediately, improving the response speed of the system.

[0132] In some examples of this application, see Figure 1The multiple infrared LED light sources 22 and the at least two infrared cameras 21 are located between the zoom lens 15 and the human eye 01.

[0133] In this example of the present application, the eye tracking module 2 is an external structure, see Figure 1 and Figure 2 , the eye tracking module 2 is arranged on the path between the imaging module 1 and the human eye 01, rather than being embedded in the internal structure of the imaging module 1. In other words, from the layout position of the eye tracking module 2, it is arranged outside the imaging module 1 as a whole.

[0134] Of course, the position design of the eye tracking module 2 is not limited to an external structure, and a built-in structure can also be adopted. Specifically, the eye tracking module 2 can also be arranged inside the imaging module 1, and its position can be located in the space between the display screen 11 and the lens assembly responsible for imaging, for example.

[0135] In this example of the present application, the infrared light emitted by the infrared LED light source 22 in the eye tracking module 2 can be directly transmitted to the eyeball, see Figure 2 , which belongs to the transmission design. The transmission design allows the infrared light to directly and unimpededly irradiate the eyeball without passing through any intermediate reflective or refractive elements. This direct irradiation method reduces the loss and scattering of light, improves the utilization rate of light and the accuracy of tracking. Since the infrared light is directly transmitted to the eyeball, there is no need to set additional reflective films or coatings on the zoom lens or other optical elements. This simplifies the structure of the optical system, reduces the manufacturing cost and complexity, and improves the reliability and stability of the optical system. The directly transmitted infrared light will not interfere with or affect other optical elements in the imaging module, such as the light transmittance and imaging quality of the zoom lens. This design ensures the independence of the eye tracking function and the imaging function, allowing the two to work simultaneously without interfering with each other.

[0136] In some examples of this application, see Figure 4 The zoom lens 15 includes a first transparent conductive film 151 and a second transparent conductive film 152 which are arranged opposite to each other, and a liquid crystal molecule layer 153 located between the first transparent conductive film 151 and the second transparent conductive film 152;

[0137] See also Figure 5 When no voltage is applied to the first transparent conductive film 151 and the second transparent conductive film 152 , all liquid crystal molecules in the liquid crystal molecule layer 153 are arranged in the same direction. At this time, the variable focus lens 15 is a light-transmitting flat plate.

[0138] See also Figure 6After a voltage is applied to the first transparent conductive film 151 and the second transparent conductive film 152 , the arrangement direction of the liquid crystal molecules in the liquid crystal molecule layer 153 changes, and the optical power of the variable focus lens 15 changes accordingly.

[0139] When the focal length of the zoom lens 15 changes under the control of the voltage controller 4, the position of the virtual image formed by the optical system will change accordingly. Figure 2 , changing from the first virtual image 001 to the second virtual image 002.

[0140] The first transparent conductive film 151, as one end to which voltage is applied, has good conductivity and transparency, ensuring that the voltage can be uniformly and effectively transmitted to the liquid crystal molecule layer 153. The second transparent conductive film 152, which is arranged opposite to the first transparent conductive film 151, also has conductivity and transparency, and forms an electric field together with the first transparent conductive film 151 to control the arrangement of liquid crystal molecules in the liquid crystal molecule layer 153. The liquid crystal molecule layer 153 is located between two layers of transparent conductive films and is composed of a large number of liquid crystal molecules. These molecules can change their arrangement direction under the action of the electric field, thereby changing the optical focal length of the lens.

[0141] The zoom lens 15 of the present application is a liquid crystal lens, and the working principle of the liquid crystal lens is as follows:

[0142] When no voltage is applied to the liquid crystal lens, Figure 5 As shown, the liquid crystal molecules in the liquid crystal molecule layer 153 maintain a consistent arrangement direction. At this time, the function of the liquid crystal lens is similar to that of a transparent plate, and does not produce additional refraction or focusing effects on light.

[0143] However, when a voltage is applied to the liquid crystal lens, the liquid crystal molecules in the liquid crystal molecule layer 153 will present different arrangement directions according to different applied voltage values, thereby causing the distance between the formed virtual image and the human eye to change.

[0144] Specifically, if Figure 6 As shown on the left side, when a first voltage is applied to the first transparent conductive film 151 and the second transparent conductive film 152, the generated electric field causes a certain angle change in the arrangement direction of the liquid crystal molecules in the liquid crystal molecule layer 153. This change in turn causes the focal length of the zoom lens 15 to change, thereby adjusting the virtual image distance of the optical system, such as increasing the virtual image distance.

[0145] like Figure 6As shown on the right side, when a second voltage (different from the first voltage) is applied to the first transparent conductive film 151 and the second transparent conductive film 152, the generated electric field causes the arrangement direction of the liquid crystal molecules in the liquid crystal molecule layer 153 to change at a larger angle. This change also causes the focal length of the zoom lens 15 to change, thereby adjusting the virtual image distance of the optical system, such as reducing the virtual image distance.

[0146] By comparison Figure 6 From the two figures, it can be clearly seen that: when different voltages are applied to the first transparent conductive film 151 and the second transparent conductive film 152, the arrangement directions of the liquid crystal molecules in the liquid crystal molecule layer 153 will be different, and the distance between the virtual image finally formed and the human eye will also change accordingly.

[0147] Compared with the traditional mechanical zoom method, the LCD lens zoom does not require complex mechanical structures and auxiliary moving parts, so it can achieve a lighter and thinner design. This helps to reduce the weight of the optical system, improve wearing comfort, and facilitate users to carry and use.

[0148] The arrangement direction of liquid crystal molecules changes very quickly under the action of the electric field, so the response time of the zoom lens 15 is also very short. This means that users can observe the changes in the virtual image with almost no delay, further enhancing the smoothness and realism of the VR experience.

[0149] Liquid crystal lenses are compact and easy to integrate with other optical components, making the design of the entire optical system more flexible and efficient. This will help promote the further development and application of VR technology.

[0150] According to another embodiment of the present application, a smart head-mounted device is provided, wherein the smart head-mounted device includes a housing and the optical system as described above.

[0151] The smart head-mounted device provided in the embodiment of the present application is, for example, a VR smart head-mounted device, such as VR smart glasses or a VR smart helmet.

[0152] According to another embodiment of the present application, a zoom method of an optical system is provided, which is applied to Figure 1 The optical system shown in the figure, the zoom method comprises the following steps 100 to 300:

[0153] Step 100, obtaining eye gaze information through the eye tracking module 2;

[0154] Step 200, determining zoom information according to the eye gaze information provided by the eye tracking module 2; and

[0155] Step 300: Control the zoom lens 15 to zoom according to the zoom information.

[0156] In some examples of the present application, determining zoom information according to the eye gaze information provided by the eye tracking module includes the following steps 210 to 220:

[0157] Step 210: determining the distance of the target virtual image of the eye gaze according to the eye gaze information provided by the eye tracking module 2; wherein the eye gaze information includes a gaze plane and a gaze direction;

[0158] Step 220: Determine zoom information corresponding to the target virtual image distance using the target virtual image distance and a first mapping relationship; wherein the first mapping relationship is used to reflect the relationship between the zoom information and the target virtual image distance.

[0159] In some examples of the present application, controlling the zoom lens 15 to zoom according to the determined zoom information includes the following steps 230 to 240:

[0160] Step 230: determining a target voltage value according to the zoom information and a preset mapping relationship; wherein the preset mapping relationship is used to reflect the corresponding relationship between the zoom information and the target voltage value, and the target voltage value is a voltage value that can drive the zoom lens 15 to adjust to match the zoom information;

[0161] Step 240 : Control the voltage controller 4 to apply the voltage of the target voltage value to the zoom lens 15 , so that the zoom lens 15 can achieve zooming.

[0162] The zoom method of the embodiment of the present application realizes the dynamic zoom function of the optical system by combining the liquid crystal lens focusing and eye tracking technology. This means that the VR headset can adjust the position and clarity of the virtual image in real time according to the user's actual gaze direction and needs, thereby providing a more realistic and immersive VR experience. Users are no longer limited to virtual images with fixed focal lengths, but can naturally observe objects at different distances just like in real life.

[0163] The specific implementation methods of the zoom method of the intelligent head-mounted device and the optical system of the embodiments of the present application can refer to the various embodiments of the above-mentioned optical system, 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.

[0164] 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.

[0165] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An optical system for a smart head-mounted device, characterized in that: include: An imaging module (1) comprising a zoom lens (15); An eye tracking module (2), used for obtaining eye gaze information; and A processor (3) is used to determine zoom information based on eye gaze information provided by the eye tracking module (2), and to control the zoom of the zoom lens (15) based on the zoom information; wherein the zoom information includes the thickness and curvature radius of the zoom lens (15).

2. The optical system according to claim 1, characterized in that The optical system also includes a voltage controller (4); The processor (3) is connected to the voltage controller (4), and the processor (3) is also used to determine a target voltage value based on the zoom information and a preset mapping relationship, and control the voltage controller (4) to apply a voltage of the target voltage value to the zoom lens (15); wherein the preset mapping relationship is used to reflect the corresponding relationship between the zoom information and the target voltage value, and the target voltage value is a voltage value that can drive the zoom lens (15) to adjust to match the zoom information.

3. The optical system according to claim 2, characterized in that The zoom lens (15) is a liquid crystal lens.

4. The optical system according to any one of claims 1 to 3, characterized in that: The imaging module (1) comprises a folded optical path structure, wherein the folded optical path structure and the zoom lens (15) are arranged adjacent to each other along the same optical axis and at an interval.

5. The optical system according to claim 4, characterized in that The imaging module also includes a display screen (11), the folded optical path structure is located between the display screen (11) and the zoom lens (15), and the display screen (11) is used to emit light for imaging display.

6. The optical system according to claim 5, characterized in that The folded optical path structure comprises at least one lens (13), a light splitting element (16) and a composite film material (14); The light splitting element (16) is arranged between the display screen (11) and the lens (13); The composite film material (14) is arranged between the lens (13) and the zoom lens (15); wherein the composite film material (14) comprises a phase delay plate, a polarization reflection element and a polarizer which are stacked in sequence.

7. The optical system according to claim 6, characterized in that The light splitting element (16) is arranged on a surface of the lens (13) close to the display screen (11), and the composite film material is arranged on a surface of the lens (13) far from the display screen (11).

8. The optical system according to claim 7, characterized in that A polarizing element (12) is provided on the light-emitting surface of the display screen (11).

9. The optical system according to claim 1, characterized in that The eye tracking module comprises a plurality of infrared LED light sources (22) corresponding to human eyes (01) and at least two infrared cameras (21); The plurality of infrared LED light sources (22) are arranged around the human eye (01) and are used to emit infrared light and project the infrared light onto the pupil of the human eye (01); The at least two infrared cameras (21) are located on the periphery of the plurality of infrared LED light sources (22) and are used to receive infrared light reflected by the pupil of the human eye (01).

10. The optical system according to claim 9, characterized in that The plurality of infrared LED light sources (22) and the at least two infrared cameras (21) are located between the zoom lens (15) and the human eye (01).

11. The optical system according to claim 2, characterized in that The zoom lens (15) comprises a first transparent conductive film (151) and a second transparent conductive film (152) which are arranged opposite to each other, and a liquid crystal molecule layer (153) located between the first transparent conductive film (151) and the second transparent conductive film (152); When no voltage is applied to the first transparent conductive film (151) and the second transparent conductive film (152), the liquid crystal molecules in the liquid crystal molecule layer (153) are arranged in the same direction, and the variable focus lens (15) is a light-transmitting flat plate; After a voltage is applied to the first transparent conductive film (151) and the second transparent conductive film (152), the arrangement direction of the liquid crystal molecules in the liquid crystal molecule layer (153) changes, and the optical focal length of the variable focus lens (15) changes accordingly.

12. A smart head mounted device, characterized in that: include: shell; and An optical system as claimed in any one of claims 1 to 11.

13. A zoom method for an optical system, characterized in that: include: Acquiring eye gaze information through an eye tracking module (2); Determining zoom information according to the eye gaze information provided by the eye tracking module (2); and The zoom lens (15) is controlled to zoom according to the zoom information.

14. The zoom method according to claim 13, characterized in that: The determining of zoom information according to the eye gaze information provided by the eye tracking module includes: Determining the distance of the target virtual image of the eyeball according to the eyeball gaze information provided by the eyeball tracking module (2); wherein the eyeball gaze information includes a gaze plane and a gaze direction; and The target virtual image distance and a first mapping relationship are used to determine zoom information corresponding to the target virtual image distance; wherein the first mapping relationship is used to reflect the relationship between the zoom information and the target virtual image distance.

15. The zoom method according to claim 14, characterized in that: The step of controlling the zoom lens (15) to zoom according to the determined zoom information comprises: Determining a target voltage value according to the zoom information and a preset mapping relationship; wherein the preset mapping relationship is used to reflect the corresponding relationship between the zoom information and the target voltage value, and the target voltage value is a voltage value that can drive the zoom lens (15) to adjust to match the zoom information; A control voltage controller (4) applies a voltage of the target voltage value to the zoom lens (15), so that the zoom lens (15) achieves zooming.

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