Bidirectional scanning eyeball tracking device and head-mounted display equipment

Abstract

The utility model relates to a bidirectional scanning eyeball tracking device and head-mounted display equipment. The device comprises a light scanning module, a light guiding module and a photoelectric detection module. The optical scanning module comprises an infrared light source and a bidirectional scanning unit; the infrared light source is arranged in front of the sight of a user; the bidirectional scanning unit is arranged opposite to the infrared light source and is used for dividing infrared light from the infrared light source into first scanning light and second scanning light; the first scanning light is incident to one eye of a user; the second scanning light is incident to the other eye of the user; the light incident end of the light guide module is arranged in front of the sight line of a user; the light emitting end of the light guide module is arranged opposite to the photoelectric detection module, so that eyeball tracking of bidirectional scanning is realized, the problem that the number of devices in related devices is large is solved, the weight and the size of the eyeball tracking device are reduced, and the eyeball tracking device is easy to integrate.

Description

Technical Field

[0001] The present application relates to the field of eye tracking technology, and in particular to a bidirectional scanning eye tracking device and a head-mounted display device. Background Art

[0002] Eye tracking is a technology that detects eye movement and can determine a person's gaze point. Eye tracking can also be applied to various fields such as psychology research, human-computer interaction, virtual reality, and augmented reality. For example, in aviation flight, by measuring the direction of the pilot's eye line of sight in real time, the system can track and lock the target more quickly and improve the control speed. In psychological research, eye tracking can be used to study the psychological mechanisms of human cognitive processes, attention mechanisms, and decision-making. In human-computer interaction, eye tracking can help researchers understand the user's visual focus, reading speed, recognition accuracy, and other information when using the human-computer interaction interface, thereby optimizing the human-computer interaction design.

[0003] Currently, eye tracking can be achieved based on optical principles. For example, when our eyes are illuminated by an infrared light source, the cornea of ​​the eyeball will reflect a bright spot, and this reflection point is tracked by a high-speed camera to record the position and movement direction of the eye in real time; or a scanner is used to configure the infrared light source as a scanning beam, and an optical element is used to receive the infrared light reflected from the eyeball and emitted at a certain angle, and a photodetector is used to sense the light from the optical element, thereby obtaining an electrical signal carrying the movement of the eye.

[0004] However, in order to capture light spots under different eye movement states, existing eye tracking devices usually need to be equipped with multiple infrared light sources and high-speed cameras, or need to configure separate scanners for the left eye and the right eye to perform independent scanning to achieve full coverage detection of the human eye, resulting in a large number of components in the eye tracking device, causing the overall weight and volume to be larger. Utility Model Content

[0005] Based on this, it is necessary to provide a bidirectional scanning eye tracking device and head-mounted display device that can reduce the number of components in order to address the above technical problems.

[0006] In a first aspect, the present application proposes a bidirectional scanning eye tracking device, the device comprising: a light scanning module, a light guiding module and a photoelectric detection module; the light scanning module comprises an infrared light source and a bidirectional scanning unit;

[0007] The infrared light source is arranged in front of the user's sight line and is used to emit infrared light;

[0008] The bidirectional scanning unit is arranged opposite to the infrared light source, and is used to divide the infrared light into a first scanning light and a second scanning light; the first scanning light is incident on one eye of the user; and the second scanning light is incident on the other eye of the user;

[0009] The light incident end of the light guiding module is arranged in front of the user's line of sight, and is used to receive the first scanning light and the second scanning light reflected from the two eyes; the light emitting end of the light guiding module is arranged opposite to the photoelectric detection module, and is used to emit the first scanning light and the second scanning light to the photoelectric detection module;

[0010] The photoelectric detection module is used to convert the first scanning light and the second scanning light into electrical signals.

[0011] In one of the embodiments, the bidirectional scanning unit includes a first scanning device and a second scanning device;

[0012] The first scanning device is arranged opposite to the infrared light source, and is used to convert the infrared light emitted by the infrared light source into two-dimensional scanning light, and emit the two-dimensional scanning light to the second scanning device;

[0013] The second scanning device is arranged opposite to the first scanning device, and is used for dividing the two-dimensional scanning light into the first scanning light and the second scanning light.

[0014] In one of the embodiments, the first scanning device includes an acousto-optic modulator, and the acousto-optic modulator is arranged in the light emission direction of the infrared light source.

[0015] In one of the embodiments, the first scanning device includes a galvanometer mirror, and the galvanometer mirror is arranged in the light emitting direction of the infrared light source.

[0016] In one of the embodiments, the second scanning device comprises a metasurface, and the metasurface is placed in the light emission direction of the first scanning device.

[0017] In one embodiment, the light guiding module includes a first guiding module and a second guiding module; the photoelectric detection module includes a first detection module and a second detection module;

[0018] One end of the first guiding module is arranged in front of one eye of the user; the other end of the first guiding module is arranged opposite to the first detecting module;

[0019] One end of the second guiding module is arranged in front of the other eye of the user; the other end of the second guiding module is arranged opposite to the second detecting module.

[0020] In one embodiment, the first guiding module includes a first input coupling diffraction grating, a first transparent waveguide, and a first output coupling diffraction grating; the second guiding module includes a second input coupling diffraction grating, a second transparent waveguide, and a second output coupling diffraction grating;

[0021] The first input coupling diffraction grating is arranged at one end of the first transparent waveguide, in front of one eye of the user; the first output coupling diffraction grating is arranged at the other end of the first transparent waveguide, opposite to the first detection module;

[0022] The second input coupling diffraction grating is arranged at one end of the second transparent waveguide, in front of the other eye of the user; the second output coupling diffraction grating is arranged at the other end of the second transparent waveguide, opposite to the second detection module.

[0023] In one embodiment, the first input coupling diffraction grating and the first output coupling diffraction grating are respectively disposed inside the first transparent waveguide;

[0024] The second input coupling diffraction grating and the second output coupling diffraction grating are respectively arranged inside the second transparent waveguide.

[0025] In a second aspect, the present application also provides a head-mounted display device, comprising: a frame and the bidirectional scanning eye tracking device described in the first aspect above; the optical scanning module in the bidirectional scanning eye tracking device is arranged on the frame in front of the user's line of sight.

[0026] In one embodiment, the device further comprises a transparent visual component; the light guiding module in the bidirectional scanning eye tracking device is arranged on the transparent visual component in front of the user's line of sight.

[0027] The above-mentioned bidirectional scanning eye tracking device and head-mounted display device, by setting an infrared light source in front of the user's line of sight to emit infrared light; setting a bidirectional scanning unit opposite to the infrared light source to divide the infrared light into a first scanning light and a second scanning light; the first scanning light is incident on one eye of the user; the second scanning light is incident on the other eye of the user; setting the light incident end of the light guiding module in front of the user's line of sight to receive the first scanning light and the second scanning light reflected from the two eyes; the light emitting end of the light guiding module is set opposite to the photoelectric detection module to emit the first scanning light and the second scanning light to the photoelectric detection module; the photoelectric detection module is used to convert the first scanning light and the second scanning light into electrical signals, thereby solving the problem of a large number of components in related devices, reducing the weight and volume of the eye tracking device, and making the eye tracking device easy to integrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 is a schematic structural diagram of a bidirectional scanning eye tracking device in one embodiment;

[0030] Figure 2 It is a structural schematic diagram of an eye tracking device in the prior art;

[0031] Figure 3 is a schematic diagram of the structure of another eye tracking device in the prior art;

[0032] Figure 4 is a schematic structural diagram of a bidirectional scanning unit in one embodiment;

[0033] Figure 5 Schematic diagram of the application principle of the metasurface;

[0034] Figure 6 It is a schematic diagram of the structure of a bidirectional scanning eye tracking device in a preferred embodiment;

[0035] Figure 7 is a schematic structural diagram of a first guiding module in an embodiment;

[0036] Figure 8 Schematic diagram of the application principle of diffraction grating;

[0037] Fig. 9 Schematic diagram of the structure of a head mounted display device in one embodiment.

[0038] Figure numerals: 100, optical scanning module; 110, infrared light source; 120, bidirectional scanning unit; 121, first scanning device; 122, second scanning device; 200, optical guiding module; 210, first guiding module; 211, first input coupling diffraction grating; 212, first transparent waveguide; 213, first output coupling diffraction grating; 220, second guiding module; 300, photoelectric detection module; 310, first detection module; 320, second detection module; 400, eye; 500, frame; 600, transparent visual component. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0040] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as the content disclosed in this application is insufficient.

[0041] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0042] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0043] In this embodiment, a bidirectional scanning eye tracking device is provided. Figure 1 The device includes: a light scanning module 100, a light guiding module 200 and a photoelectric detection module 300; the light scanning module 100 includes an infrared light source 110 and a bidirectional scanning unit 120.

[0044] The infrared light source 110 is disposed in front of the user's sight line and is used to emit infrared light.

[0045] The bidirectional scanning unit 120 is disposed opposite to the infrared light source 110 and is used to divide the infrared light into a first scanning light and a second scanning light; the first scanning light is incident on one eye 400 of the user; and the second scanning light is incident on the other eye 400 of the user.

[0046] The light incident end of the light guiding module 200 is arranged in front of the user's line of sight, and is used to receive the first scanning light and the second scanning light reflected from the eyes; the light emitting end of the light guiding module 200 is arranged opposite to the photoelectric detection module, and is used to direct the first scanning light and the second scanning light to the photoelectric detection module 300.

[0047] The photoelectric detection module 300 is used to convert the first scanning light and the second scanning light into electrical signals.

[0048] The front of the user's line of sight includes the area within the user's line of sight, such as the area directly in front of the eye 400 and the area on the left and right sides.

[0049] The bidirectional scanning unit 120 can realize bidirectional scanning of both eyes by cascading an acousto-optic modulator and an optical beam splitter, wherein the optical beam splitter includes an element with a splitting function such as a metasurface or a prism; or a beam of infrared light can be divided into two scanning lights by controlling the rotation or translation of the reflector array. The specific implementation method of the bidirectional scanning unit 120 is not limited in this embodiment.

[0050] The light guiding module 200 can guide light to be transmitted along a specific path through an optical waveguide, or change the path of light through devices such as optical lenses and reflectors to guide it to a target location, so that it is finally directed to a photoelectric sensor at the light output end of the light guiding module 200.

[0051] The photoelectric detection module 300 can use components such as photodiodes or phototransistors, and cooperate with related circuits such as amplifiers and filters to convert optical signals into electrical signals that can be used for subsequent processing based on the photoconductive effect. The calculation process of photoelectric conversion can be implemented based on existing algorithms, including but not limited to integral algorithms, proportional algorithms, etc. The electrical signal can reflect the movement information of the eyes through optical power.

[0052] In the prior art, see Figure 2 , an eye tracking device usually includes an illumination source and a camera. The illumination source is used to emit infrared light from a specific position at a certain angle to the eyeball, and the camera is used to capture the reflection point reflected by the cornea of ​​the eyeball. Figure 3 , the eye tracking device can also be configured as a structure including a scanner, an optical element, and a photodetector, using the scanner to emit an infrared scanning beam, using the optical element to receive the infrared scanning light reflected from the eyeball and emitted at a certain angle, and using the photodetector to sense the infrared scanning light from the optical element. However, in order to collect infrared light spots when the eyeball rotates to different angles, the above solution usually requires the use of multiple illumination sources, and the left and right eyes need to be equipped with scanners at the same time, resulting in a large number of components in the eye tracking device, resulting in a large overall weight and volume.

[0053] Compared with the prior art, the present embodiment realizes accurate eye tracking through bidirectionally scanned infrared polarized light, specifically, by setting the infrared light source 110 in front of the user's line of sight to emit infrared light; setting the bidirectional scanning unit 120 opposite to the infrared light source 110 to divide the infrared light into a first scanning light and a second scanning light; the first scanning light is incident on one eye 400 of the user; the second scanning light is incident on the other eye 400 of the user; the light incident end of the light guiding module 200 is set in front of the user's line of sight to receive the first scanning light and the second scanning light reflected from the two eyes 400; the light emitting end of the light guiding module 200 is set opposite to the photoelectric detection module to emit the first scanning light and the second scanning light to the photoelectric detection module 300; the photoelectric detection module 300 is used to convert the first scanning light and the second scanning light into electrical signals, thereby solving the problem of a large number of components in the relevant device, reducing the weight and volume of the eye tracking device, and making the eye tracking device easy to integrate.

[0054] In one embodiment, see Figure 4 The bidirectional scanning unit 120 includes a first scanning device 121 and a second scanning device 122 .

[0055] The first scanning device 121 is disposed opposite to the infrared light source 110 , and is used to convert the infrared light emitted by the infrared light source 110 into two-dimensional scanning light, and emit the two-dimensional scanning light to the second scanning device 122 .

[0056] The second scanning device 122 is disposed opposite to the first scanning device 121 , and is used to separate the two-dimensional scanning light into the first scanning light and the second scanning light.

[0057] Specifically, the first scanning device 121 can be an acousto-optic modulator or a galvanometer. However, since the two-dimensional scanning light field of view formed by the first scanning device 121 is small, a larger two-dimensional scanning range can be achieved through the second scanning device 122. The second scanning device 122 can be a metasurface. The metasurface has a microstructure array that can deflect the angle of the incident light. The principle is based on the generalized Snell's law. Figure 5 , according to the generalized Snell's law:

[0058]

[0059] In the formula, θ i is the incident angle, θ t is the exit angle, n i is the refractive index of the incident medium, n t is the refractive index of the output medium, λ 0 is the wavelength, is the derivative of the phase mutation brought by the metasurface to the incident light in the x direction. By reasonably setting the phase arrangement of the microstructure, we can obtain The target value can be achieved for a specific incident angle θ i Deflection direction θ when emitted t control.

[0060] Specifically, the transmission-geometric phase multiplexing polarization control function of the metasurface is used to divide the scanned linear polarized light beam into left-handed polarized light and right-handed polarized light. At the same time, the surface microstructure array of the metasurface is used to control the incident light on the surface, and the light with different incident angles and two orthogonal polarization states is deflected to the direction of 400 degrees for the two eyes, respectively, to achieve large-scale two-dimensional scanning of the left and right eyes at the same time. The metasurface can adopt semiconductor production processes such as photolithography / nanoimprinting, and the production cost is low when it is mass-produced, making the overall cost of the scanning solution using the metasurface low and controllable.

[0061] In one embodiment, the first scanning device 121 includes an acousto-optic modulator, which is disposed in the light emitting direction of the infrared light source 110. The second scanning device 122 includes a metasurface, which is disposed in the light emitting direction of the first scanning device 121.

[0062] As a solid-state scanning device, the AOM does not have mechanical motion and has a high scanning frequency; however, its maximum scanning angle is very small, so the deflection angle of the AOM is efficiently amplified by using a passive device called a metasurface. In this way, the pure solid-state scanning solution of the AOM and metasurface cascade can effectively improve the stability of the system.

[0063] In one embodiment, the first scanning device 121 includes a galvanometer, which is disposed in the light emitting direction of the infrared light source 110. The second scanning device 122 includes a metasurface, which is disposed in the light emitting direction of the first scanning device 121.

[0064] The galvanometer can quickly control and adjust the propagation direction of infrared light, and the metasurface can further expand the scanning field of view of the galvanometer to achieve full coverage scanning of the human eye.

[0065] In one embodiment, see Figure 6 The light guiding module 200 includes a first guiding module 210 and a second guiding module 220 ; the photoelectric detection module includes a first detection module 310 and a second detection module 320 .

[0066] One end of the first guiding module 210 is disposed in front of one eye 400 of the user; the other end of the first guiding module 210 is disposed opposite to the first detecting module 310 .

[0067] One end of the second guiding module 220 is disposed in front of the other eye 400 of the user; the other end of the second guiding module 220 is disposed opposite to the second detecting module 320 .

[0068] In this way, by processing the reflected light of the two eyes 400 respectively, the movement information of the two eyes 400 can be collected more accurately.

[0069] In one embodiment, see Figure 7 The first guiding module 210 includes a first input coupling diffraction grating 211, a first transparent waveguide 212 and a first output coupling diffraction grating 213; the first input coupling diffraction grating 211 is arranged at one end of the first transparent waveguide 212, in front of one eye 400 of the user; the first output coupling diffraction grating 213 is arranged at the other end of the first transparent waveguide 212, opposite to the first detection module 310.

[0070] Specifically, the first input coupling diffraction grating 211 is used to modulate each light incident on the surface of the first input coupling diffraction grating 211 to a specified angle for emission, so that the first scanning light is coupled to the first transparent waveguide 212 and is totally reflected in the first transparent waveguide 212. When the first scanning light is transmitted in the first transparent waveguide 212 to the first output coupling diffraction grating 213, the first output coupling diffraction grating 213 decodes the incident position of each light based on the diffraction angle of the light incident on its surface, and the emission angle and position of each light are related to its incident position.

[0071] Among them, Figure 8 As shown, the diffraction gratings used by the first input coupling diffraction grating 211 and the first output coupling diffraction grating 213 may be periodic micro-nano structures to couple the incident light into or out of the waveguide. The grating equation and principle analysis are as follows:

[0072] mλ=Λ(sinθ i +sinθ t );

[0073] Where λ is the wavelength, Λ is the grating period, and θ i is the incident angle, θ t is the diffraction angle, and m is the diffraction order. By reasonably selecting the grating period and wavelength, the diffraction light energy of the grating can be adjusted to be mainly concentrated in two diffraction orders; and by designing the nanostructure of the grating ruler, the phase of the incident light passing through the grating teeth is adjusted to concentrate the energy in a certain diffraction order (theoretically, the diffraction light energy of the +1st or -1st order of the tilted grating can be as high as 99%). At the same time, according to the grating equation, the direction of the diffracted light is different for light incident at different angles. The angular bandwidth of the tilted grating can be adjusted by the tilt angle of the grating teeth. Diffraction gratings can be mass-produced by nanoimprinting, with high production efficiency and low cost.

[0074] Similar to the installation mode of the first guiding module 210, the second guiding module 220 includes a second input coupling diffraction grating, a second transparent waveguide and a second output coupling diffraction grating. The second input coupling diffraction grating is arranged at one end of the second transparent waveguide, in front of the other eye 400 of the user; the second output coupling diffraction grating is arranged at the other end of the second transparent waveguide, opposite to the second detection module 320.

[0075] Based on the arrangement positions of the first guiding module 210 and the second guiding module 220 , the first transparent waveguide 212 and the second transparent waveguide may respectively adopt planar waveguides or curved waveguides.

[0076] In one embodiment, the first input coupling diffraction grating 211 and the first output coupling diffraction grating 213 are respectively disposed inside the first transparent waveguide 212 .

[0077] The second input coupling diffraction grating and the second output coupling diffraction grating are respectively arranged inside the second transparent waveguide.

[0078] In one embodiment, the first input coupling diffraction grating 211 and the first output coupling diffraction grating 213 are respectively disposed outside the first transparent waveguide 212 .

[0079] In this embodiment, a head mounted display device is also provided. Fig. 9 , the device includes: a frame 500 of any of the above-mentioned embodiments of the bidirectional scanning eye tracking device.

[0080] The optical scanning module 100 in the bidirectional scanning eye tracking device is disposed on a frame 500 in front of the user's line of sight.

[0081] In one embodiment, the device further includes a transparent visual component 600; the light guiding module 200 in the bidirectional scanning eye tracking device is disposed on the transparent visual component 600 in front of the user's line of sight.

[0082] Through the design of this embodiment, the number of eye tracking components can be effectively reduced, and the size and weight of the head-mounted display device can be reduced.

[0083] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A bidirectional scanning eye tracking device, characterized in that: The device comprises: a light scanning module, a light guiding module and a photoelectric detection module; the light scanning module comprises an infrared light source and a bidirectional scanning unit; The infrared light source is arranged in front of the user's sight line and is used to emit infrared light; The bidirectional scanning unit is arranged opposite to the infrared light source, and is used to divide the infrared light into a first scanning light and a second scanning light; the first scanning light is incident on one eye of the user; and the second scanning light is incident on the other eye of the user; The light incident end of the light guiding module is arranged in front of the user's line of sight, and is used to receive the first scanning light and the second scanning light reflected from the two eyes; the light emitting end of the light guiding module is arranged opposite to the photoelectric detection module, and is used to emit the first scanning light and the second scanning light to the photoelectric detection module; The photoelectric detection module is used to convert the first scanning light and the second scanning light into electrical signals.

2. The bidirectional scanning eye tracking device according to claim 1, characterized in that: The bidirectional scanning unit comprises a first scanning device and a second scanning device; The first scanning device is arranged opposite to the infrared light source, and is used to convert the infrared light emitted by the infrared light source into two-dimensional scanning light, and emit the two-dimensional scanning light to the second scanning device; The second scanning device is arranged opposite to the first scanning device, and is used for dividing the two-dimensional scanning light into the first scanning light and the second scanning light.

3. The bidirectional scanning eye tracking device according to claim 2, characterized in that: The first scanning device includes an acousto-optic modulator, and the acousto-optic modulator is arranged in the light emitting direction of the infrared light source.

4. The bidirectional scanning eye tracking device according to claim 2, characterized in that: The first scanning device includes a galvanometer mirror, and the galvanometer mirror is arranged in the light emitting direction of the infrared light source.

5. The bidirectional scanning eye tracking device according to claim 2, characterized in that: The second scanning device comprises a metasurface, and the metasurface is disposed in the light emitting direction of the first scanning device.

6. The bidirectional scanning eye tracking device according to claim 1, characterized in that: The light guiding module includes a first guiding module and a second guiding module; the photoelectric detection module includes a first detection module and a second detection module; One end of the first guiding module is arranged in front of one eye of the user; The other end of the first guiding module is arranged opposite to the first detecting module; One end of the second guiding module is arranged in front of the other eye of the user; The other end of the second guiding module is arranged opposite to the second detecting module.

7. The bidirectional scanning eye tracking device according to claim 6, characterized in that: The first guiding module comprises a first input coupling diffraction grating, a first transparent waveguide and a first output coupling diffraction grating; The second guiding module comprises a second input coupling diffraction grating, a second transparent waveguide and a second output coupling diffraction grating; The first input coupling diffraction grating is disposed at one end of the first transparent waveguide and is located in front of one eye of the user; The first output coupling diffraction grating is arranged at the other end of the first transparent waveguide, and is arranged opposite to the first detection module; The second input coupling diffraction grating is disposed at one end of the second transparent waveguide and is located in front of the other eye of the user; The second output coupling diffraction grating is arranged at the other end of the second transparent waveguide, and is arranged opposite to the second detection module.

8. The bidirectional scanning eye tracking device according to claim 7, characterized in that: The first input coupling diffraction grating and the first output coupling diffraction grating are respectively arranged inside the first transparent waveguide; The second input coupling diffraction grating and the second output coupling diffraction grating are respectively arranged inside the second transparent waveguide.

9. A head mounted display device, characterized in that: The device comprises: a frame and a bidirectional scanning eye tracking device as claimed in any one of claims 1 to 8; The optical scanning module in the bidirectional scanning eye tracking device is arranged on the frame in front of the user's sight line.

10. The head mounted display device according to claim 9, characterized in that: The device also includes a transparent vision component; The light guiding module in the bidirectional scanning eye tracking device is arranged on the transparent visual component in front of the user's line of sight.

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