Head-mounted device combined with eyeball tracking and eyeball tracking method

Abstract

The embodiment of the invention provides head-mounted equipment combined with eyeball tracking and an eyeball tracking method. The head-mounted equipment combined with eyeball tracking comprises a light guide sheet and an optical tracking assembly, the optical tracking assembly comprises a light source and an infrared camera; the light guide sheet comprises a diffractive optical element and a first coupling area; the diffractive optical element is used for diffracting infrared light emitted by the light source to form an optical pattern with set light spot distribution and projecting the optical pattern to human eyes; the first coupling-in area is used for receiving infrared light reflected by human eyes and coupling the infrared light into the light guide sheet, and the light guide sheet is used for transmitting the infrared light from the first coupling-in area to the infrared camera.

Description

Technical Field

[0001] This application relates to the field of optical display technology, and more specifically, to a head-mounted device and eye-tracking method that incorporates eye tracking. Background Technology

[0002] With the development of augmented reality (AR) technology, achieving more accurate and efficient interaction between users and the virtual world has become a hot research topic in the industry. In particular, capturing and acquiring users' eye movement information can enhance their immersion and interactive experience in AR environments. In AR glasses, the mainstream eye-tracking solution uses an infrared LED array to illuminate the pupil, determining the direction of eye movement by analyzing the relative position of the Pullchin spot reflected from the cornea and the pupil. Simultaneously, by analyzing the captured pupil size, the eye's focal position can be determined, thus acquiring the eye's movement state.

[0003] Existing eye-tracking solutions typically consist of two parts: an infrared LED array and an infrared camera. The infrared LED array needs to be arranged according to specific algorithm requirements and the structural clearance needs of the lens frame, and is mounted on a ring-shaped FPC using a patch method. The infrared camera is responsible for capturing the light spots reflected from the pupil and cornea, and sending the captured data back to the processor for analysis to obtain eye behavior data. However, this solution has the following drawbacks: First, the infrared LED array and infrared camera are independent hardware components, which increases the complexity of the hardware structure design; second, the infrared LED array has relatively high power consumption, which is not conducive to reducing the overall power consumption of the device; finally, because the infrared LED array occupies a certain amount of space, the space available for the light guide plate on the head-mounted device is reduced. Summary of the Invention

[0004] The purpose of this application is to provide a new technical solution that combines an eye-tracking head-mounted device and an eye-tracking method.

[0005] In a first aspect, embodiments of this application provide a head-mounted device incorporating eye tracking, the head-mounted display device including a light guide sheet and an optical tracking component;

[0006] The optical tracking component includes a light source and an infrared camera;

[0007] The light guide sheet includes a diffractive optical element and a first coupling region;

[0008] The diffractive optical element is used to diffract the infrared light emitted from the light source to form an optical pattern with a predetermined light spot distribution and project it into the human eye;

[0009] The first coupling region is used to receive infrared light reflected by the human eye and couple it into the interior of the light guide sheet, and the light guide sheet is used to transmit the infrared light from the first coupling region to the infrared camera.

[0010] Optionally, the diffractive optical element is used to diffract the infrared light emitted from the light source to form an optical pattern with a ring-shaped light spot distribution.

[0011] Optionally, the diffractive optical element and the first coupling region are disposed in the edge region of the light guide sheet, and the diffractive optical element and the first coupling region are disposed at intervals.

[0012] Optionally, the light guide sheet further includes a first coupling region, which is located at the edge region of the light guide sheet, and the infrared camera is located on the light-emitting side of the first coupling region;

[0013] The first coupling region is used to couple out the infrared light reflected by the human eye transmitted by the light guide sheet, and the infrared camera is able to receive the infrared light coupled out through the first coupling region.

[0014] Optionally, the light guide sheet further includes a second coupling-in region and a second coupling-out region;

[0015] The second coupling-in region is used to couple the light from the imaging display into the interior of the light guide sheet, and the second coupling-out region is used to couple the light from the second coupling-in region into the light guide sheet.

[0016] Optionally, in the thickness direction of the light guide sheet, the first coupling area is disposed opposite to the infrared camera, and the light rays coupled out through the first coupling area are perpendicularly projected onto the infrared camera.

[0017] Optionally, the light source is disposed on one side of the light guide sheet;

[0018] Infrared light emitted from the light source enters the diffractive optical element from one side, parallel to the light guide plate. After being diffracted by the diffractive optical element, the infrared light is reflected by the human eye to the first coupling area. The light guide plate transmits the infrared light reflected by the human eye through total internal reflection to the first coupling area. The first coupling area couples out the infrared light and projects it vertically onto the infrared camera.

[0019] Optionally, the light guide sheet further includes an infrared light input area, which is disposed on the edge region of the light guide sheet. In the thickness direction of the light guide sheet, the light source and the infrared light input area are disposed opposite to each other.

[0020] The infrared light emitted from the light source is vertically projected onto the infrared light input area. The infrared light input area transmits the infrared light to the diffractive optical element. The infrared light diffracted by the diffractive optical element is reflected by the human eye to the first coupling area. The light guide plate transmits the infrared light reflected by the human eye through total internal reflection to the first coupling area. The first coupling area couples out the infrared light and projects it vertically onto the infrared camera.

[0021] Optionally, the infrared camera is located on one side of the light guide plate, and the infrared light transmitted by the light guide plate and reflected by the human eye is projected onto the infrared camera in a direction parallel to the light guide plate.

[0022] Optionally, both the light source and the infrared camera are disposed on one side of the light guide sheet;

[0023] The infrared light emitted from the light source is projected onto the diffractive optical element from one side in a direction parallel to the light guide. The infrared light, after being diffracted by the diffractive optical element, is reflected by the human eye to the first coupling region. The light guide is used to transmit the infrared light reflected by the human eye through total internal reflection and project it onto the infrared camera in a direction parallel to the light guide.

[0024] Optionally, the light guide sheet further includes an infrared light input area, which is disposed on the edge region of the light guide sheet. In the thickness direction of the light guide sheet, the light source and the infrared light input area are disposed opposite to each other.

[0025] The infrared light emitted from the light source is vertically projected onto the infrared light input area. The infrared light input area transmits the infrared light to the diffractive optical element. The infrared light diffracted by the diffractive optical element is reflected by the human eye to the first coupling area. The light guide is used to transmit the infrared light reflected by the human eye through total internal reflection and project it onto the infrared camera along a direction parallel to the light guide.

[0026] Optionally, the head-mounted device further includes an optical engine, the light emitted by which for imaging display can be projected onto the second coupling region.

[0027] Optionally, the head-mounted device further includes an eyeglass body, which includes a frame and temples;

[0028] The light guide sheet is disposed on the mirror frame;

[0029] The optical engine and the infrared camera are located on the side of the lens frame near the temple.

[0030] Optionally, the diffractive optical element, the first coupling region, the second coupling region, and the second coupling out region are located on the same surface of the light guide sheet;

[0031] The diffractive optical element is adjacent to the lens frame;

[0032] The first coupling-in region is located between the diffractive optical element and the second coupling-out region;

[0033] The second coupling-in region is disposed on one side of the second coupling-out region and is located in the edge region of the light guide sheet near the temple.

[0034] Optionally, the light guide sheet further includes a first coupling area, which is disposed on one side of the first coupling area and located in the edge region of the light guide sheet near the temple.

[0035] The first coupling region is used to couple out the infrared light reflected from the human eye transmitted by the light guide sheet to the infrared camera.

[0036] Optionally, the light guide sheet further includes an infrared light input area, which is disposed on one side of the diffractive optical element and close to the lens frame.

[0037] Optionally, two light guides are provided, namely a left light guide and a right light guide, which are disposed in the lens frame;

[0038] The optical tracking component is provided in two parts: a left-eye optical tracking component and a right-eye optical tracking component.

[0039] There are two optical engines, one of which is opposite to the second coupling area of ​​the left light guide plate, and the other is opposite to the second coupling area of ​​the right light guide plate.

[0040] Optionally, the light guide sheet is a diffractive waveguide sheet or an arrayed reflective waveguide sheet.

[0041] Secondly, embodiments of this application provide an eye-tracking method for a head-mounted device as described in the first aspect, the eye-tracking method comprising:

[0042] The infrared light emitted by the light source is diffracted by diffractive optical elements to form an optical pattern with a set light spot distribution and projected onto the human eye;

[0043] The infrared light is reflected by the human eye to the first coupling area of ​​the light guide plate;

[0044] The infrared light reflected from the human eye is coupled into the interior of the light guide sheet by the first coupling area, and the light guide sheet transmits the infrared light reflected from the human eye to the infrared camera;

[0045] The infrared camera receives infrared light reflected from the human eye transmitted through the light guide sheet and obtains the position information of the user's eyeball.

[0046] The beneficial effects of this application are as follows:

[0047] This application provides a head-mounted device that integrates eye tracking, combining imaging and eye tracking functions. The head-mounted device uniquely integrates the infrared light source (illumination area) required for eye tracking. Specifically, it uses a combination of an infrared laser light source and diffractive optical elements, employing diffraction technology to design an infrared light spot array. This innovative design eliminates the need for an additional infrared LED array, greatly simplifying the hardware structure design and significantly reducing overall power consumption. Furthermore, the complex light spot design of the illumination area of ​​the optical tracking component enables the capture of more precise eye tracking data, improving eye tracking accuracy and further enhancing the user's interactive experience in visual perception.

[0048] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0050] Figure 1 This is one of the partial structural schematic diagrams of the head-mounted device provided in the embodiments of this application;

[0051] Figure 2 This is a schematic diagram illustrating the working principle of the light source and diffractive optical element provided in the embodiments of this application;

[0052] Figure 3 This is a second partial structural schematic diagram of the head-mounted device provided in the embodiments of this application;

[0053] Figure 4 This is the third partial structural schematic diagram of the head-mounted device provided in the embodiments of this application;

[0054] Figure 5 Fourth partial structural schematic diagram of the head-mounted device provided in the embodiments of this application;

[0055] Figure 6 The fifth partial structural schematic diagram of the head-mounted device provided in the embodiments of this application.

[0056] Explanation of reference numerals in the attached figures:

[0057] 1. Light guide plate; 11. Diffractive optical element; 12. First coupling region; 13. First coupling region; 14. Second coupling region; 15. Second coupling region; 16. Infrared light input region;

[0058] 2. Light source; 3. Infrared camera; 4. Optical engine; 5. Frame. Detailed Implementation

[0059] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0060] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0061] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0062] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0063] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0064] The following description, in conjunction with the accompanying drawings, details the head-mounted device and eye-tracking method combined with eye tracking provided in the embodiments of this application.

[0065] The head-mounted device incorporating eye tracking provided in this application embodiment is described in [reference]. Figures 1 to 5 The head-mounted device includes a light guide 1 and an optical tracking assembly; wherein, the optical tracking assembly includes a light source 2 and an infrared camera 3; the light guide 1 includes a diffractive optical element 11 and a first coupling region 12; the diffractive optical element 11 is used to diffract the infrared light emitted from the light source 2 to form an optical pattern with a set light spot distribution and project it onto the human eye; the first coupling region 12 is used to receive the infrared light reflected by the human eye and couple it into the interior of the light guide 1, and the light guide 1 is used to transmit the infrared light from the first coupling region 12 to the infrared camera 3.

[0066] According to the embodiments of this application, the head-mounted device incorporating eye tracking, in terms of its main structural components, includes, for example, a light guide sheet 1 and an optical tracking component. The light guide sheet 1 is one of the core components of the head-mounted device, primarily used for light transmission. The optical tracking component is used to track the position information of the user's eyes.

[0067] In this embodiment of the application, the light guide sheet 1 is, for example, a diffractive waveguide sheet.

[0068] See Figure 1 A diffractive optical element 11 is introduced onto the light guide plate 1. Its function is to receive infrared light emitted from the light source 2 and, after diffraction, form an optical pattern with a predetermined light spot distribution, such as... Figure 2 The circular speckle pattern shown in the image, an optical scheme in which the light spot distribution helps the infrared camera 3 to track eye movements more accurately.

[0069] Specifically, see Figure 2 The light source 2 is, for example, an infrared VCSEL light source, which can generate infrared laser light with a wavelength of 850nm or 950nm.

[0070] It should be noted that VCSEL (Vertical-Cavity Surface-Emitting Laser) light sources are renowned for their high collimation and extremely small beam divergence angle. When the numerical aperture condition for coupling the light guide is met, the infrared light generated by the light source 2 can be efficiently coupled into the interior of the light guide 1, greatly reducing light energy loss. Furthermore, the diffractive optical element 11, through carefully designed different diffraction microstructures, can achieve diverse light spot distribution effects, allowing these spots to precisely illuminate target areas such as the human eye (i.e., the user's eyeball).

[0071] Please continue reading Figure 1 A first coupling region 12 is introduced on the light guide 1. The first coupling region 12 is used to receive infrared light reflected by the human eye (i.e., the user's eyeball) and couple it into the interior of the light guide 1. In this way, the infrared light reflected by the human eye can be transmitted to the infrared camera 3 almost without loss through the light guide 1.

[0072] Specifically, the first coupling region 12 is used to collect infrared light reflected from the user's cornea and pupil. The first coupling region 12, through the design of a grating microstructure, ensures that the field of view (FOV) of the infrared light reflected from the human eye is maximized when it enters the light guide 1. The grating design of the first coupling region 12 is based on a wavelength of 950nm, which is less difficult to design and manufacture than the visible light band. After being transmitted through the light guide 1, the infrared light reflected from the human eye can finally enter the infrared camera 3.

[0073] The head-mounted device provided in this application embodiment is equipped with an optical tracking component; see [link / reference]. Figure 4 The optical tracking component includes a light source 2 (e.g., an infrared VCSEL light source) and an infrared camera 3.

[0074] The light source 2 emits infrared light, which, after being diffracted by the diffractive optical element 11, forms a predetermined optical pattern (such as an optical pattern formed by annular speckle) and can be directly projected onto the human eye (i.e., the user's eyeball). The infrared camera 3 captures the infrared light reflected back from the human eye. Then, by analyzing this reflected infrared light, for example, through a processor, accurate tracking of the user's eye movements can be achieved.

[0075] The head-mounted device provided in this application relates to technologies such as accurate infrared light projection and infrared light reflection capture. Specifically, infrared light is emitted by the light source 2 (e.g., an infrared VCSEL light source). This infrared light is collected by the diffractive optical element 11 and projected onto the human eye (i.e., the user's eyeball) after forming a specific speckle pattern through the diffraction effect of the diffractive optical element 11. When the human eye comes into contact with this infrared light, the infrared light is reflected back. This infrared light reflected by the human eye is received by the first coupling region 12 and coupled into the interior of the light guide plate 1. The light guide plate 1 can transmit the infrared light from the first coupling region 12 through total internal reflection to the infrared camera 3. After the infrared camera 3 captures this infrared light reflected by the human eye, the processor analyzes the intensity, direction, and other information of the infrared light to accurately track the user's eye movements.

[0076] The head-mounted device provided in this application has the following main technical advantages:

[0077] (1) Accuracy of eye tracking: Infrared light emitted from the light source 2 (e.g., an infrared VCSEL light source) is diffracted by the diffractive optical element 11 (DOE) to form an optical pattern (or speckle pattern) with a set light spot distribution and projected onto the human eye (i.e., the user's eyeball). This pattern design helps the infrared camera 3 to more accurately track the movement trajectory and position of the user's eyeball.

[0078] (2) Low power consumption: By using a single light source 2 combined with a diffractive optical element 11, there is no need to rely on multiple infrared LEDs to provide infrared illumination. This not only reduces the overall power consumption of the device, but also improves the integration level of the device, making the device lighter and more efficient.

[0079] (3) Efficient transmission of infrared light: The use of the light guide plate 1 enables the infrared light received from the first coupling area 12 and reflected by the human eye to be efficiently transmitted to the infrared camera 3. This design ensures the efficiency of light transmission and reduces light energy loss.

[0080] (4) Enhanced user immersion and improved interactivity: Through precise eye tracking, head-mounted devices can accurately perceive the user's gaze direction, thereby providing a more personalized visual experience. For example, when a user shifts their gaze to a corner of the device, the head-mounted device can quickly adjust the displayed image to better meet the user's expectations, thus enhancing the user's immersion. Furthermore, eye-tracking technology can also be used to enhance the interactivity of head-mounted devices. By recognizing the user's eye movements, the head-mounted device can execute various commands or operations, such as turning pages or selecting menu items, thereby achieving a more natural and intuitive interaction method.

[0081] The head-mounted device combining eye-tracking technology provided in this application embodiment is based on the design of the light guide 1 and the use of a special infrared light source—an infrared VCSEL light source. The light guide 1 not only retains the coupling-in and coupling-out regions required for traditional imaging, but also cleverly integrates a diffractive optical element 11 (DOE) design with a specific infrared coupling region, namely the first coupling region 12. This design achieves a perfect integration of imaging and eye-tracking functions.

[0082] This application provides a head-mounted device that integrates eye tracking, cleverly combining imaging and eye tracking functions. The head-mounted device uniquely integrates an infrared light source (i.e., an infrared illumination area) required for eye tracking. Through the combination of the light source 2 and the diffractive optical element 11, an infrared light spot array is designed using diffraction technology. This innovative design eliminates the need for an additional infrared LED array, greatly simplifying the hardware structure design and significantly reducing overall power consumption. Furthermore, the complex light spot design of the illumination area of ​​the optical tracking component enables the capture of more precise eye tracking data, improving eye tracking accuracy and further enhancing the user's interactive experience in visual perception.

[0083] More importantly, thanks to the structural innovation of the light guide sheet and the use of the infrared VCSEL light source in this application, the infrared light source used for eye tracking can be designed with a more complex spot pattern, thereby achieving more accurate and efficient eye tracking data acquisition.

[0084] See some examples in this application. Figure 2 The diffractive optical element 11 is used to diffract the infrared light emitted from the light source 2 to form an optical pattern with a ring-shaped light spot distribution.

[0085] According to the example provided in this application, after being diffracted by the diffractive optical element 11, infrared light can form a circular spot distribution, and the optical pattern of this spot distribution helps the infrared camera 3 to track eye movements more accurately.

[0086] See some examples in this application. Figure 1 The diffractive optical element 11 and the first coupling region 12 are disposed on the edge region of the light guide plate 1, and the diffractive optical element 11 and the first coupling region 12 are disposed at intervals.

[0087] Based on the examples mentioned in this application, see Figure 1 The diffractive optical element 11 and the first coupling region 12 are respectively disposed at different positions in the edge region of the light guide plate 1, that is, they are spaced apart. In other words, the diffractive optical element 11 and the first coupling region 12 do not overlap on the edge region of the light guide plate 1, but are staggered by a certain distance from each other.

[0088] Both the diffractive optical element 11 and the first coupling region 12 are used for the input of infrared light. By designing them to be located in the edge region of the light guide plate 1, interference with the imaging light received by the human eye can be effectively avoided, thus ensuring both imaging quality and the accuracy of eye tracking.

[0089] Specifically, placing the diffractive optical element 11 for eye tracking and the first coupling region 12 at the edge of the light guide 1 reduces interference with the user's line of sight and improves the user's comfort for visual experience after wearing the device. Since eye tracking typically does not require direct eye contact, placing it at the edge of the light guide 1 ensures that the user can focus more on the visual content provided by the head-mounted display.

[0090] The infrared light emitted from the light source 2 (e.g., an infrared VCSEL light source) is received by the diffractive optical element 11. The diffractive optical element 11 forms a speckle pattern through diffraction technology and projects it onto the human eye. The infrared light reflected by the human eye is received by the first coupling region 12 on the light guide plate 1. Since the diffractive optical element 11 and the first coupling region 12 are spaced apart, the light crossing or interference between them can be reduced, thereby improving the accuracy of the infrared camera 3 in capturing the infrared light reflected by the human eye, and thus improving the accuracy of eye tracking.

[0091] See some examples in this application. Figure 1 and Figure 3The light guide sheet 1 further includes a first coupling region 13, which is located at the edge region of the light guide sheet 1. The infrared camera 3 is located on the light-emitting side of the first coupling region 13. The first coupling region 13 is used to couple out the infrared light reflected by the human eye transmitted by the light guide sheet 1. The infrared camera 3 is able to receive the infrared light coupled out through the first coupling region 13.

[0092] Based on the examples provided in this application, see [link to example]. Figure 1 and Figure 3 A first coupling region 13 can also be introduced on the light guide 1. The design of the first coupling region 13 is to enable the infrared light reflected by the human eye transmitted by the light guide 1 to be accurately projected onto the infrared camera 3.

[0093] See Figure 1 and Figure 3 The first coupling region 13 is located at the edge of the light guide 1. This design ensures that infrared light reflected from the human eye is effectively coupled out from the interior of the light guide 1 without affecting the imaging area. The infrared camera 3 is located on the light-emitting side of the first coupling region 13, enabling it to directly receive the infrared light coupled out from the first coupling region 13.

[0094] From a technical perspective: based on the existence of the first coupling region 13, the infrared camera 3 can receive infrared light reflected from the human eye more directly, thereby enhancing the efficiency and accuracy of eye tracking.

[0095] It should be noted that the first coupling area 13 can be optionally provided or omitted as needed. The light guide 1 can directly transmit the infrared light reflected from the human eye to the infrared camera 3 in a direction parallel to the light guide 1; in this case, the first coupling area 13 is not required (see section 4). Figure 5 This can simplify the design of the light guide sheet 1.

[0096] The first coupling-in region 12 and the first coupling-out region 13 can be diffractive optical structures, such as grating structures.

[0097] See some examples in this application. Figure 1 ,as well as Figures 3 to 5 The light guide 1 further includes a second coupling region 14 and a second coupling region 15; the second coupling region 14 is used to couple the light of the imaging display into the interior of the light guide 1, and the second coupling region 15 is used to couple the light coupled into the light guide 1 from the second coupling region 14.

[0098] In the example provided in this application, the light guide sheet 1 is designed with functional zones. Specifically, the design of the light guide sheet 1 implements the imaging display function and the eye-tracking function in separate zones, which ensures both the clarity and accuracy of the imaging and the sensitivity and reliability of the eye-tracking.

[0099] The second coupling-in region 14 and the second coupling-out region 15: These two regions are respectively responsible for coupling the light for imaging display into the interior of the light guide 1 and coupling the light coupled into the light guide 1 from the second coupling-in region 14. This design ensures the effective transmission of light for imaging display.

[0100] It should be noted that, in the edge region of the light guide plate 1, the infrared illumination spot is precisely controlled through the structural design of the diffraction grating. Specifically, the diffraction optical element 11 on the light guide plate 1 can be freely designed as needed, and works in conjunction with the light source 2 (e.g., an infrared VCSEL light source) to generate a specific light spot array, thereby improving the accuracy of the eye-tracking algorithm.

[0101] The solution provided in this application example implements a novel light guide sheet (such as a waveguide sheet) structure design. This structure adds eye-tracking function while retaining the imaging function, and improves the accuracy of the algorithm and reduces the power consumption of the whole machine through the diffraction grating design of the diffraction optical element 11.

[0102] In some examples of this application, in the thickness direction of the light guide sheet 1, the first coupling region 13 is disposed opposite to the infrared camera 3, and the light rays coupled out through the first coupling region 13 are vertically projected onto the infrared camera 3.

[0103] In the example mentioned in this application, in the thickness direction of the light guide 1, the first coupling region 13 is specifically designed to face the infrared camera 3, ensuring that the light rays coupled from the first coupling region 13 can be projected perpendicularly onto the infrared camera 3. This design can bring the following technical effects:

[0104] (1) Improved light transmission efficiency: By vertically aligning the first coupling region 13 with the infrared camera 3, light does not need to undergo complex refraction or reflection when leaving the light guide 1, thereby reducing light energy loss. The vertical projection method ensures that light can reach the infrared camera 3 to the maximum extent, thereby improving the sensitivity and accuracy of eye tracking or infrared imaging.

[0105] (2) Reduced image distortion: The infrared light reflected from the human eye is transmitted by total internal reflection through the light guide plate 1 and then vertically projected onto the infrared camera 3 through the first coupling area 13, which can reduce image deformation or distortion caused by angular deviation. This is especially important for eye-tracking systems, because any slight image distortion may affect the accuracy of tracking.

[0106] (3) Simplified optical system design: Since the infrared light reflected by the human eye is projected perpendicularly, the optical path design can be simpler and more direct. This helps to reduce the manufacturing difficulty and cost of head-mounted display devices.

[0107] See some examples in this application. Figure 1 The light source 2 is disposed on one side of the light guide plate 1; the infrared light emitted from the light source 2 enters the diffractive optical element 11 from one side of the diffractive optical element 11 in a direction parallel to the light guide plate 1, and the infrared light after being diffracted by the diffractive optical element 11 is reflected by the human eye to the first coupling area 12. The light guide plate 1 transmits the infrared light reflected by the human eye through total internal reflection to the first coupling area 13. The first coupling area 13 couples out the infrared light and projects it vertically onto the infrared camera 3.

[0108] Based on the examples provided in this application, see [link to example]. Figure 1 The infrared light emitted from the light source 2 is projected onto the diffractive optical element 11 along a direction parallel to the light guide plate 1, while the infrared light propagating through the light guide plate 1 is vertically coupled out through the first coupling region 13.

[0109] The specific infrared light path is as follows: The light source 2 is located on one side of the light guide plate 1 and emits infrared light. This infrared light is incident on the diffractive optical element 11 in a direction parallel to the light guide plate 1. After diffraction by the diffractive optical element 11, the infrared light forms a specific light spot distribution and is projected onto the human eye. The infrared light reflected by the human eye is captured by the first coupling region 12 and transmitted into the interior of the light guide plate 1. The light guide plate 1 uses the principle of total internal reflection to transmit the infrared light reflected by the human eye to the first coupling region 13. The first coupling region 13 vertically couples out the infrared light and projects it directly onto the infrared camera 3.

[0110] In other words, see Figure 1 Infrared light originates from the light source 2, is first diffracted by the diffractive optical element 11, then reflected by the human eye, and transmitted and coupled out by the light guide plate 1. The light energy loss is small throughout the process, ensuring the signal strength received by the infrared camera 3, thereby improving the accuracy and stability of eye tracking.

[0111] Among them, light source 2 is used as the infrared light source, which has low power consumption, and unnecessary energy loss is reduced through efficient optical design, which helps to reduce the overall system energy consumption. The diffractive optical element 11 can be designed with different grating structures to produce specific light spot distributions, see [reference needed]. Figure 2 This optimizes the characteristics of infrared light reflected by the human eye, thereby improving the accuracy and sensitivity of eye tracking.

[0112] An efficient eye-tracking system can bring users a more intuitive interactive experience, especially in AR technology applications, where users can control the device with simple eye movements, improving ease of use.

[0113] See some examples in this application. Figure 3 The light guide plate 1 further includes an infrared light input area 16, which is disposed on the edge region of the light guide plate 1. The light source 2 and the infrared light input area 16 are positioned opposite each other along the thickness direction of the light guide plate 1. Infrared light emitted from the light source 2 is perpendicularly projected onto the infrared light input area 16. The infrared light input area 16 transmits the infrared light to the diffractive optical element 11. The infrared light diffracted by the diffractive optical element 11 is reflected by the human eye to the first coupling area 12. The light guide plate 1 then transmits the infrared light reflected by the human eye via total internal reflection to the first coupling area 13. The first coupling area 13 couples out the transmitted infrared light and projects it perpendicularly onto the infrared camera 3.

[0114] Based on the examples provided in this application, see [link to example]. Figure 3 The infrared light emitted from the light source 2 is perpendicularly incident on the newly added infrared light input area 16, and then is redirected by the infrared light input area 16 to propagate to the first coupling area 12. After being coupled into the first coupling area 12, the infrared light propagating through the light guide plate 1 is perpendicularly coupled out through the first coupling area 13.

[0115] The technical solution provided in this application example can bring the following technical effects:

[0116] (1) Efficient infrared light transmission: The introduction of the infrared light input area 16 enables the infrared light emitted by the light source 2 to be vertically projected and efficiently transmitted to the diffractive optical element 11, which can also reduce the loss of light during transmission and improve the light energy utilization rate.

[0117] (2) Precise eye tracking: Because the infrared light emitted by the light source 2 is diffracted by the diffraction optical element 11, a specific light spot distribution can be formed, see [reference needed]. Figure 2 This helps the infrared camera 3 to capture infrared light reflected from the human eye more accurately, thereby improving the accuracy and stability of eye tracking.

[0118] (3) Optimized optical design: The infrared light is coupled in vertically and coupled out vertically. This design ensures precise control and efficient transmission of the light.

[0119] (4) Enhanced user experience: An efficient and accurate eye-tracking system can bring users a more natural and intuitive interactive experience. Especially in AR technology applications, users can control the device through simple eye movements, which improves the convenience and comfort of use.

[0120] See some examples in this application. Figure 4 and Figure 5 The infrared camera 3 is located on one side of the light guide plate 1, and the infrared light transmitted by the light guide plate 1 and reflected by the human eye is projected onto the infrared camera 3 in a direction parallel to the light guide plate 1.

[0121] In the example of this application, the infrared camera 3 is located on one side of the light guide plate 1 and is responsible for receiving and capturing infrared light reflected by the human eye. The light guide plate 1 transmits infrared light from the position reflected by the human eye to the side where the infrared camera 3 is located through total internal reflection. The infrared light reflected by the human eye is captured by the light guide plate 1 and transmitted in a direction parallel to the light guide plate 1, and finally projected onto the photosensitive element of the infrared camera 3.

[0122] By placing the infrared camera 3 on one side of the light guide plate 1, the infrared light reflected by the human eye can be directly projected onto the infrared camera 3 in a direction parallel to the light guide plate 1, without the need for additional optical elements such as the first coupling area 13 to redirect or focus the light, thus simplifying the optical path and reducing the structural complexity of the light guide plate 1.

[0123] The infrared light reflected by the human eye is transmitted to the infrared camera 3 in a direction parallel to the light guide plate 1, which can reduce the loss and scattering of light during transmission, improve the utilization rate of infrared light, and thus enhance the imaging effect of the infrared camera 3.

[0124] See some examples in this application. Figure 4 The light source 2 and the infrared camera 3 are both disposed on one side of the light guide plate 1. The infrared light emitted from the light source 2 is projected onto the diffractive optical element 11 from one side of the diffractive optical element 11 in a direction parallel to the light guide plate 1. The infrared light after being diffracted by the diffractive optical element 11 is reflected by the human eye to the first coupling region 12. The light guide plate 1 is used to transmit the infrared light reflected by the human eye through total internal reflection and project it onto the infrared camera 3 in a direction parallel to the light guide plate 1.

[0125] See Figure 4As shown in the example, the light source 2 and the infrared camera 3 are both located on the same side of the light guide plate 1. This layout not only optimizes the overall structure of the head-mounted device, but also improves the efficiency of light transmission.

[0126] The light source 2 is located on one side of the light guide plate 1, and the infrared light emitted from it can be projected onto the diffractive optical element 11 in a direction parallel to the light guide plate 1. After receiving the infrared light, the diffractive optical element 11 diffracts it, forming a specific light spot distribution and projecting it onto the human eye. The infrared light reflected by the human eye is captured by the first coupling region 12. The light guide plate 1 transmits the captured infrared light to the infrared camera 3 in a direction parallel to the light guide plate 1 through total internal reflection. The infrared camera 3 receives the infrared light transmitted from the light guide plate 1 and performs image capture and processing to achieve eye tracking or other functions.

[0127] The infrared light originates from the light source 2, undergoes diffraction by the diffractive optical element 11, reflection by the human eye, and transmission through the light guide plate 1, finally reaching the infrared camera 3. Throughout the transmission process, the infrared light remains parallel to the light guide plate 1, reducing light loss and scattering and improving transmission efficiency. Due to this high transmission efficiency, the infrared camera 3 can receive more and stronger reflected light, thereby improving the accuracy and stability of eye tracking. By improving the performance and stability of eye tracking, the head-mounted display device in this example can provide users with a more accurate interactive experience and enhance their immersion when using the head-mounted display device.

[0128] See some examples in this application. Figure 5 The light guide 1 further includes an infrared light input area 16, which is disposed on the edge region of the light guide 1. In the thickness direction of the light guide 1, the light source 2 and the infrared light input area 16 are disposed opposite each other. The infrared light emitted from the light source 2 is perpendicularly projected onto the infrared light input area 16, and the infrared light input area 16 transmits the infrared light to the diffractive optical element 11. The infrared light diffracted by the diffractive optical element 11 is reflected by the human eye to the first coupling area 12. The light guide 1 is used to transmit the infrared light reflected by the human eye through total internal reflection and project it onto the infrared camera 3 in a direction parallel to the light guide 1.

[0129] See Figure 5As shown in the example, an infrared light input area 16 is introduced on the light guide plate 1, so that the infrared light emitted by the light source 2 can be projected perpendicularly to the infrared light input area 16. After being diffracted by the diffractive optical element 11, the infrared light reflected by the human eye is transmitted through total internal reflection of the light guide plate 1 and finally projected to the infrared camera 3 in a direction parallel to the light guide plate 1.

[0130] The infrared light input area 16 is located at the edge of the light guide plate 1 and is designed to receive infrared light emitted by the light source 2. The infrared light emitted by the light source 2 is projected perpendicularly onto the infrared light input area 16, ensuring efficient and direct light input. The infrared light input area 16 transmits the received infrared light to the diffractive optical element 11. The diffractive optical element 11 diffracts the infrared light, forming a specific light spot distribution and projecting it onto the human eye. The infrared light reflected by the human eye is captured by the first coupling area 12 and transmitted through total internal reflection inside the light guide plate 1. The light guide plate 1 transmits the infrared light in a direction parallel to itself and finally projects it onto the infrared camera 3.

[0131] Due to the efficient transmission and precise control of infrared light, the infrared camera 3 can receive more and stronger reflected light, thereby improving the accuracy and stability of eye tracking.

[0132] See some examples in this application. Figure 6 The head-mounted device also includes an optical engine 4, the light emitted by the optical engine 4 for imaging display being able to be projected onto the second coupling region 14.

[0133] See Figure 6 The head-mounted device provided in this application also includes an optical engine 4. The light emitted by the optical engine 4 for imaging display can be directly projected to the second coupling area 14 of the light guide plate 1. After passing through the second coupling area 14, the light for imaging display will be transmitted through the light guide plate 1 and finally coupled out from the second coupling area 15, entering the user's field of vision to realize the image display function.

[0134] Through the integration of the optomechanism 4, the head-mounted device can provide high-quality image display. The light emitted from the optomechanism 4 is precisely controlled and projected onto the second coupling region 14 to ensure the clarity and brightness of the image display.

[0135] The close cooperation between the optical engine 4 and the light guide plate 1 ensures that the light used for imaging display can be projected into the user's eyes efficiently and accurately, providing a clear and realistic image display effect.

[0136] See some examples in this application. Figure 6The head-mounted device also includes a glasses body, which includes a frame 5 and temples; a light guide 1 is disposed on the frame 5; and an optical engine 4 and an infrared camera 3 are disposed on the side of the frame 5 near the temples.

[0137] The head-mounted device provided in this application embodiment is, for example, smart glasses, such as AR glasses.

[0138] The head-mounted device of this application embodiment includes an eyeglass body, which consists of a frame 5 and temples, providing the user with a comfortable and stable wearing method.

[0139] See Figure 6 The main body of the glasses includes a frame 5 and temples, while the light guide 1, the optical engine 4, and the infrared camera 3 are arranged at specific positions on the frame 5.

[0140] The light guide 1 is positioned on the frame 5. This position allows the light guide 1 to be easily aligned with the human eye, ensuring effective transmission of infrared light and clear display of the image.

[0141] The optical engine 4 and the infrared camera 3 are positioned on the side of the frame 5 near the temple. This arrangement not only saves space but also facilitates the direct projection of light emitted from the optical engine 4 onto the second coupling area 14 of the light guide 1, and the capture of infrared light reflected by the human eye by the infrared camera 3.

[0142] The design of the main body of the glasses allows the head-mounted display device to be worn like ordinary glasses, providing greater comfort and portability.

[0143] In addition, the light source 2 is also disposed on the frame 5. The specific position of the light source 2 is not limited in this application. The main purpose is to enable the infrared light emitted by the light source to be introduced in a direction parallel to or perpendicular to the light guide 1.

[0144] The infrared camera 3 is positioned appropriately to accurately capture infrared light reflected from the human eye, thereby achieving precise eye tracking and providing a more natural and intuitive interaction method for applications such as virtual reality and augmented reality.

[0145] By integrating the light guide 1, the optical engine 4, the light source 2, and the infrared camera 3 onto the frame 5 of the glasses body and optimizing their layout, Figure 6 The example shown not only provides a comfortable wearing experience and a compact structural design, but also achieves efficient light transmission, image display, and precise eye tracking, thereby significantly improving the overall performance and user experience of the head-mounted device.

[0146] See some examples in this application. Figure 1 ,as well as Figures 3 to 5 The diffractive optical element 11, the first coupling region 12, the second coupling region 14, and the second coupling region 15 are located on the same surface of the light guide plate 1; the diffractive optical element 11 is adjacent to the lens frame; the first coupling region 12 is located between the diffractive optical element 11 and the second coupling region 15; the second coupling region 14 is disposed on one side of the second coupling region 15 and is located in the edge region of the light guide plate 1 near the temple.

[0147] Both the diffractive optical element 11 and the second coupling region 14 are distributed in the edge region of the light guide plate 1. The diffractive optical element 11 is adjacent to the first coupling region 12, and the light emitted by the light source 2 can be modulated by the diffractive optical element 11 and then enter the interior of the light guide plate 1 through the first coupling region 12 for transmission.

[0148] The light emitted by the optical engine 4 can be directly and efficiently projected onto the second coupling area 14, reducing light loss and scattering during transmission and thus improving light transmission efficiency. Due to the improved light transmission efficiency, the light emitted by the optical engine 4 can be projected onto the light guide plate 1 more completely and enter the user's field of vision through the second coupling area 15, thereby presenting a higher quality image.

[0149] See some examples in this application. Figure 1 and Figure 3 The light guide 1 further includes a first coupling region 13, which is disposed on one side of the first coupling region 12 and located in the edge region of the light guide 1 near the temple; the first coupling region 13 is used to couple out the infrared light reflected by the human eye transmitted by the light guide 1 to the infrared camera 3.

[0150] The first coupling region 13 is responsible for coupling out the infrared light reflected from the human eye transmitted inside the light guide 1 to the infrared camera 3. Because this region is close to the infrared camera 3, it can reduce the loss and interference of infrared light during transmission, and improve the intensity and clarity of the infrared light received by the infrared camera 3.

[0151] The precise location and efficient infrared light processing capabilities of the first coupling region 13 ensure that the infrared camera 3 can accurately receive the infrared light reflected from the human eye. This is crucial for the accuracy and stability of the eye-tracking system and helps improve the overall system performance.

[0152] By setting the first coupling region 13 in the edge area near the temple side and closely cooperating with the infrared camera 3, the rapid and efficient transmission and processing of infrared light is achieved, improving the efficiency of the entire system.

[0153] Efficient infrared light processing and precise eye-tracking capabilities enable head-mounted displays to provide users with a more natural and intuitive interactive experience. Users can control the device with simple eye movements, improving ease of use and comfort. The more efficient and stable transmission and processing of infrared light also enhances the overall stability of the eye-tracking system.

[0154] See some examples in this application. Figure 3 and Figure 5 The light guide plate 1 also includes an infrared light input area 16, which is disposed on one side of the diffractive optical element 11 and close to the lens frame.

[0155] The infrared light input area 16 is used to receive infrared light and propagate the infrared light to the position of the diffractive optical element 11.

[0156] In some examples of this application, two light guides 1 are provided, namely a left light guide and a right light guide, which are disposed in the lens frame; two optical tracking components are provided, namely a left eye optical tracking component and a right eye optical tracking component; two optical engines are provided, one of which is opposite to the second coupling area 14 of the left light guide and the other is opposite to the second coupling area 14 of the right light guide.

[0157] As a complete head-mounted display device, it includes a glasses body, which includes a frame 5 and two temples, namely the left temple and the right temple, so that the user can wear smart glasses, such as AR glasses, stably.

[0158] The AR glasses feature two light guides: a left light guide and a right light guide. These two light guides are located on the left and right sides of the glasses' frame, respectively. The left and right light guides are likely used to transmit visible light from different optical sensors 4 to the user's left and right eyes respectively. By controlling these two light guides, the AR glasses can display stereoscopic images or content, providing a more immersive experience for the user.

[0159] Regarding the optical tracking components, the AR glasses are equipped with two optical tracking components: a left-eye optical tracking component and a right-eye optical tracking component. These two components are responsible for tracking the user's left and right eye movements, respectively. This design allows the AR glasses to accurately track the user's eye movements, thereby more accurately determining the user's gaze point and direction of gaze.

[0160] AR glasses also include two optical engines. These two engines are responsible for providing images or information sources to the left and right light guides, respectively. By independently controlling these two optical engines, AR glasses can display corresponding content or perspectives for each of the user's eyes, thereby achieving stereoscopic display or multi-view viewing.

[0161] In summary, the AR glasses designed with dual light guides, a binocular tracking system, and dual optical engines can provide users with a more realistic and natural viewing experience. Users can perceive more immersive images and more accurate interactive feedback.

[0162] In some examples of this application, the light guide 1 is a diffractive waveguide or an array reflective waveguide.

[0163] A diffractive waveguide is a dielectric device designed based on the principle of light diffraction, used to guide the propagation of light waves. When light encounters an obstacle or gap during propagation, its direction of propagation changes; this phenomenon is called diffraction. Diffractive waveguides utilize this physical phenomenon and, through a precisely designed grating structure, achieve effective control over the direction of light wave propagation.

[0164] The core component of the diffractive waveguide is the diffraction grating, which is an optical element with a periodic structure. All coupling-in regions and all coupling-out regions on the waveguide 1 are, for example, diffraction gratings.

[0165] Diffractive waveguides have the ability to precisely control the direction of light propagation, and the optical parameters of the gratings on them can be designed as needed (such as material refractive index, grating shape, thickness, duty cycle, etc.).

[0166] Arrayed reflective waveguides primarily utilize the principle of total internal reflection. Through a semi-transparent, semi-reflective film within the waveguide structure, light is horizontally replicated multiple times to achieve a stable image display in the human eye. The design focus of arrayed reflective waveguides lies in precisely controlling the reflection and transmission ratio of light to ensure consistent brightness across the entire image. Due to the reflective imaging principle, arrayed reflective waveguides exhibit no dispersion of the three primary colors of incident light required for full-color displays, thus guaranteeing no significant color deviation in the displayed image. Furthermore, arrayed reflective waveguides possess high optical transmittance and low light leakage, resulting in a superior visual experience.

[0167] According to another embodiment of this application, an eye-tracking method for a head-mounted device is provided, the eye-tracking method comprising the following steps:

[0168] Step 1, see Figure 1 and Figure 2 The infrared light emitted by the light source 2 is diffracted by the diffractive optical element 11 to form an optical pattern with a set light spot distribution and projected onto the human eye;

[0169] Step 2: The infrared light is reflected by the human eye to the first coupling area 12 of the light guide plate 1;

[0170] Step 3: The infrared light reflected by the human eye is coupled into the light guide sheet 1 by the first coupling area 12, and the light guide sheet 1 transmits the infrared light reflected by the human eye to the infrared camera 3.

[0171] Step 4: Receive the infrared light reflected from the human eye transmitted by the light guide sheet 1 through the infrared camera 3, and obtain the position information of the user's eyeball.

[0172] The infrared camera 3 captures images of the pupil and corneal reflective spots, and transmits the captured data back to the processor for analysis of eye behavior data.

[0173] It should be noted that steps 1 to 4 above can be found in [reference needed]. Figures 1 to 6 The head-mounted device shown.

[0174] This application provides a novel eye-tracking method that integrates an AR display area and an infrared illumination source for eye tracking onto a light guide sheet. This reduces the complexity of the hardware structure design, lowers the overall power consumption, and improves the utilization rate of the waveguide. The illumination area for optical tracking can be designed as a more complex light spot, enabling more precise acquisition of eye-tracking data.

[0175] The specific implementation of the eye-tracking method of the head-mounted device in this application can refer to the above-described embodiments of the head-mounted device. Therefore, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0176] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0177] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A head-mounted device incorporating eye tracking, characterized in that, Includes a light guide sheet (1) and an optical tracking assembly; The optical tracking component includes a light source (2) and an infrared camera (3); The light guide sheet (1) includes a diffractive optical element (11) and a first coupling region (12); The diffractive optical element (11) is used to diffract the infrared light emitted from the light source (2) to form an optical pattern with a set light spot distribution and project it into the human eye; The first coupling region (12) is used to receive infrared light reflected by the human eye and couple it into the interior of the light guide (1), and the light guide (1) is used to transmit the infrared light from the first coupling region (12) to the infrared camera (3).

2. The head-mounted device according to claim 1, characterized in that, The diffractive optical element (11) is used to diffract the infrared light emitted from the light source (2) to form an optical pattern with a ring-shaped light spot distribution.

3. The head-mounted device according to claim 1, characterized in that, The diffractive optical element (11) and the first coupling region (12) are disposed on the edge region of the light guide plate (1), and the diffractive optical element (11) and the first coupling region (12) are disposed at intervals.

4. The head-mounted device according to claim 1, characterized in that, The light guide sheet (1) further includes a first coupling area (13), which is located in the edge region of the light guide sheet (1), and the infrared camera (3) is located on the light-emitting side of the first coupling area (13). The first coupling region (13) is used to couple out the infrared light reflected by the human eye transmitted by the light guide sheet (1), and the infrared camera (3) is able to receive the infrared light coupled out through the first coupling region (13).

5. The head-mounted device according to claim 1, characterized in that, The light guide sheet (1) further includes a second coupling region (14) and a second coupling region (15); The second coupling region (14) is used to couple the light of the imaging display into the interior of the light guide (1), and the second coupling region (15) is used to couple the light that is coupled into the light guide (1) from the second coupling region (14).

6. The head-mounted device according to claim 4, characterized in that, In the thickness direction of the light guide sheet (1), the first coupling area (13) is arranged opposite to the infrared camera (3), and the light rays coupled out through the first coupling area (13) are vertically projected onto the infrared camera (3).

7. The head-mounted device according to claim 6, characterized in that, The light source (2) is disposed on one side of the light guide plate (1); Infrared light emitted from the light source (2) is incident on the diffractive optical element (11) from one side, in a direction parallel to the light guide plate (1). The infrared light after being diffracted by the diffractive optical element (11) is reflected by the human eye to the first coupling area (12). The light guide plate (1) transmits the infrared light reflected by the human eye through total internal reflection to the first coupling area (13). The first coupling area (13) couples out the infrared light and projects it vertically onto the infrared camera (3).

8. The head-mounted device according to claim 6, characterized in that, The light guide sheet (1) further includes an infrared light input area (16), which is disposed on the edge region of the light guide sheet (1). In the thickness direction of the light guide sheet (1), the light source (2) and the infrared light input area (16) are disposed opposite to each other. The infrared light emitted from the light source (2) is vertically projected onto the infrared light input area (16). The infrared light input area (16) transmits the infrared light to the diffractive optical element (11). The infrared light diffracted by the diffractive optical element (11) is reflected by the human eye to the first coupling area (12). The light guide plate (1) transmits the infrared light reflected by the human eye through total internal reflection to the first coupling area (13). The first coupling area (13) couples out the infrared light and projects it vertically onto the infrared camera (3).

9. The head-mounted device according to claim 3, characterized in that, The infrared camera (3) is located on one side of the light guide plate (1), and the infrared light transmitted by the light guide plate (1) and reflected by the human eye is projected onto the infrared camera (3) in a direction parallel to the light guide plate (1).

10. The head-mounted device according to claim 9, characterized in that, The light source (2) and the infrared camera (3) are both located on one side of the light guide plate (1); The infrared light emitted from the light source (2) is projected onto the diffractive optical element (11) from one side of the diffractive optical element (11) in a direction parallel to the light guide plate (1). The infrared light after being diffracted by the diffractive optical element (11) is reflected by the human eye to the first coupling region (12). The light guide plate (1) is used to transmit the infrared light reflected by the human eye through total internal reflection and project it onto the infrared camera (3) in a direction parallel to the light guide plate (1).

11. The head-mounted device according to claim 9, characterized in that, The light guide sheet (1) further includes an infrared light input area (16), which is disposed on the edge region of the light guide sheet (1). In the thickness direction of the light guide sheet (1), the light source (2) and the infrared light input area (16) are disposed opposite to each other. The infrared light emitted from the light source (2) is vertically projected onto the infrared light input area (16), and the infrared light input area (16) transmits the infrared light to the diffractive optical element (11). The infrared light diffracted by the diffractive optical element (11) is reflected by the human eye to the first coupling area (12). The light guide (1) is used to transmit the infrared light reflected by the human eye through total internal reflection and project it onto the infrared camera (3) in a direction parallel to the light guide (1).

12. The head-mounted device according to claim 5, characterized in that, The head-mounted device also includes an optical engine (4), the light emitted by which for imaging display can be projected onto the second coupling region (14).

13. The head-mounted device according to claim 12, characterized in that, The head-mounted device also includes a glasses body, which includes a frame and temples; The light guide sheet (1) is disposed on the mirror frame; The optical engine (4) and the infrared camera (3) are located on the side of the lens frame near the temple.

14. The head-mounted device according to claim 13, characterized in that, The diffractive optical element (11), the first coupling region (12), the second coupling region (14) and the second coupling region (15) are located on the same surface of the light guide (1); The diffractive optical element (11) is adjacent to the lens frame; The first coupling-in region (12) is located between the diffractive optical element (11) and the second coupling-out region (15); The second coupling in region (14) is disposed on one side of the second coupling out region (15) and located in the edge region of the light guide sheet (1) near the temple.

15. The head-mounted device according to claim 14, characterized in that, The light guide (1) further includes a first coupling region (13), which is disposed on one side of the first coupling region (12) and located in the edge region of the light guide (1) near the temple. The first coupling region (13) is used to couple out the infrared light reflected by the human eye transmitted by the light guide sheet (1) to the infrared camera (3).

16. The head-mounted device according to claim 13, characterized in that, The light guide (1) also includes an infrared light input area (16), which is disposed on one side of the diffractive optical element (11) and close to the lens frame.

17. The head-mounted device according to claim 13, characterized in that, Two light guides (1) are provided, namely a left light guide and a right light guide, which are disposed in the mirror frame; The optical tracking component is provided in two parts: a left-eye optical tracking component and a right-eye optical tracking component. There are two optical engines, one of which is opposite to the second coupling area (14) of the left light guide plate, and the other is opposite to the second coupling area (14) of the right light guide plate.

18. The head-mounted device according to claim 1, characterized in that, The light guide sheet (1) is a diffractive waveguide sheet or an array reflective waveguide sheet.

19. An eye-tracking method for a head-mounted device as described in any one of claims 1-18, characterized in that, The eye-tracking method includes: The infrared light emitted by the light source is diffracted by diffractive optical elements to form an optical pattern with a set light spot distribution and projected onto the human eye; The infrared light is reflected by the human eye to the first coupling area of ​​the light guide plate; The infrared light reflected from the human eye is coupled into the interior of the light guide sheet by the first coupling area, and the light guide sheet transmits the infrared light reflected from the human eye to the infrared camera; The infrared camera receives infrared light reflected from the human eye transmitted through the light guide sheet and obtains the position information of the user's eyeball.

Images