An ultra-thin optical engine based on polarization volume holography and AR display device

Abstract

The application discloses an ultrathin optical engine based on a polarization volume hologram and an AR display device, and relates to the technical field of AR display devices.The application comprises an optical engine body, which comprises a light source module, a micro display panel, a relay imaging optical group, a polarization volume hologram and a polarization compensation element; the light source module is used for providing an initial light beam with high purity and high directionality; the micro display panel is used for carrying a digital image signal and modulating an electric signal into an optical field carrying image information; and the relay imaging optical group expands, collimates or focuses the image emitted by the micro display panel.The application realizes active interference type anti-peeping during use of the AR display device, significantly improves the privacy protection effect, can realize physical level rapid blocking of an optical path, provides data security guarantee in an extreme scene, and enables the application to cope with various extreme scenes such as loss, theft, illegal disassembly and out-of-bound use of the device, thereby providing all-weather and all-around security guarantee for the AR display device.

Description

Technical Field

[0001] This invention relates to the field of AR display device technology, specifically to an ultra-thin optical engine based on polarizer holography and an AR display device. Background Technology

[0002] Augmented reality (AR) display devices, especially AR glasses, can overlay computer-generated text, images, 3D models, and other virtual information onto the real world in real time. They have broad application prospects in fields such as industrial production, healthcare, public safety, cultural tourism and education, and consumer life. In recent years, optical waveguide technology based on polarization volume holographic gratings (PVGs) has become a research hotspot in the AR display field due to its advantages such as high diffraction efficiency, low cost, and simple fabrication. As a type of volume holographic grating, PVG has low haze, excellent diffraction characteristics, and a larger field of view than general volume holographic gratings, making it suitable for fabricating AR waveguide lenses. In the existing technology, a variety of AR optical waveguide display devices based on PVGs have been disclosed. For example, the polarization state of the transmitted light is modulated and converted by the diffraction modulation of the coupled-in and coupled-out gratings and the polarization state control device to improve the light energy utilization rate.

[0003] However, as AR display devices gradually move from professional fields to everyday consumer scenarios, privacy and security issues when used in public places are becoming increasingly prominent. When users wear AR glasses in public places such as subways, cafes, and offices, others may be able to see the image content displayed on the lenses from the side or front, leading to the leakage of personal privacy or trade secrets. It is also impossible to flexibly switch between "shared display" and "privacy protection" according to the user's actual usage scenario. Furthermore, existing technologies lack effective response mechanisms for extreme security incidents such as device loss, theft, or illegal dismantling. Once a device is out of the control of a legitimate user, sensitive data stored in the device (such as user identity information, authentication credentials, encryption keys, etc.) will face serious risks of leakage. With the promotion and application of AR display devices in high-security scenarios such as military, industry, and medical fields, the data security of the device itself is becoming an increasingly critical issue.

[0004] In summary, existing AR display devices lack a physical-level rapid blocking mechanism for the displayed content itself, and even more so, they lack a hardware-level emergency solution to achieve data self-destruction in the event of extreme security incidents. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-thin optical engine and AR display device based on polarizer holography, which solves the problems of existing AR display devices lacking a physical-level rapid blocking mechanism for the displayed content itself, and even more so lacking a hardware-level emergency solution to achieve data self-destruction in extreme security events.

[0006] This invention solves the above-mentioned technical problems through the following technical solution: an ultrathin optical engine based on polarizer holography, comprising: The optical engine body includes a light source module, a micro-display panel, a relay imaging optical group, a polarizing hologram, and a polarization compensation element. The light source module is used to provide a high-purity, highly directional initial beam of light; The micro-display panel is used to carry digital image signals and modulate electrical signals into a light field carrying image information. The relay imaging optical group expands, collimates, or focuses the image emitted by the micro-display panel to ensure that the light is incident at a specific angle. The polarizing hologram utilizes its internal spiral liquid crystal structure to selectively diffract specific chiral circularly polarized light into the waveguide. The polarization compensation element precisely adjusts the polarization state of the incident light to ensure that the half-wave condition of the PVG is met in order to achieve maximum diffraction efficiency.

[0007] An AR display device based on polarizer holography includes the aforementioned optical engine body, a waveguide lens with a polarizer holographic grating, a security status management module, a data erasure module, a mode switching module, and a brightness compensation control module. The waveguide lens is provided with a coupling-in region and a coupling-out region. The safety status management module is connected to the optical engine body and the optical waveguide lens. The safety status management module includes a privacy grating assembly disposed on the side of the optical waveguide lens facing the external environment, an optical path blocker disposed on the optical path between the coupling area of ​​the optical engine body and the optical waveguide lens, and a safety triggering unit. The privacy grating assembly is used to optically control the first polarized light coupled from the optical waveguide lens and the natural light incident from the external environment in a privacy protection state, so as to make the displayed content invisible to the outside world. The optical path blocker is used to block the propagation of the first polarized light from the optical engine body to the optical waveguide lens in a data security state. The security triggering unit is electrically connected to the privacy grating assembly and the optical path blocker, and is used to receive trigger signals and control the working state of the privacy grating assembly and the optical path blocker.

[0008] Preferably, the privacy grating assembly includes a first polarizing holographic grating layer, a liquid crystal polarization rotation layer, and a second polarizing holographic grating layer stacked together. A light-absorbing layer is disposed between the first polarizing holographic grating layer and the second polarizing holographic grating layer, and the light-absorbing layer is used to absorb stray light that escapes after being diffracted by the second polarizing holographic grating layer.

[0009] Preferably, the optical path blocker includes an electrically controlled polarization rotator, a polarizer, and an electrically controlled scattering layer disposed on the surface of the optical waveguide lens. The electrically controlled scattering layer scatters ambient light incident on the optical waveguide lens, causing the optical waveguide lens to appear foggy or opaque.

[0010] Preferably, the safety triggering unit includes a sensor module and a signal generation module. The sensor module is used to collect status data and environmental data of the AR display device. The signal generation module is electrically connected to the sensor module and is used to determine whether the preset safety event triggering conditions are met based on the status data and environmental data, and to generate a data safety triggering signal when the conditions are met.

[0011] Preferably, the sensor module includes a positioning module, a biometric recognition module, an accelerometer, and an anti-tamper sensor; the signal generation module includes a microcontroller and a security chip; and the biometric recognition module includes a fingerprint recognition module, an iris recognition module, a facial recognition module, and a voiceprint recognition module.

[0012] Preferably, the tamper-proof sensor includes a micro switch, a conductive wire mesh, and a photoelectric sensor.

[0013] Preferably, the data erasure module is electrically connected to the security trigger unit. When the duration of the data security trigger signal received by the security trigger unit exceeds a preset threshold, the data erasure module will be activated.

[0014] Preferably, the mode switching module is electrically connected to the liquid crystal polarization rotation layer and is used to control the AR display device to switch between a shared display mode and a privacy protection state in response to user input or environmental perception signals.

[0015] Preferably, the brightness compensation control module is electrically connected to the optical engine body and the privacy grating assembly, and is used to synchronously control the output brightness of the optical engine body to increase when the privacy protection state is triggered.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention achieves active interference-based anti-peeping during the use of AR display devices through a security status management module and a mode switching module, significantly improving privacy protection. It actively uses ambient light to form an interference light field, making it impossible for bystanders to recognize the displayed content. Even under high-intensity ambient light or extreme viewing angles, it can effectively protect user privacy.

[0017] 2. This invention can achieve physical-level rapid blocking of optical paths, providing data security in extreme scenarios. Even if the device falls into the hands of unauthorized personnel, the displayed content cannot be seen, fundamentally eliminating the possibility of stealing information through the display interface. This invention can cope with various extreme scenarios such as device loss, theft, illegal disassembly, and unauthorized use, providing all-weather, all-round security for AR display devices. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the safety status management module and its connection modules in this invention.

[0019] Figure 2 This is a schematic diagram of the privacy grating component in this invention.

[0020] Figure 3 This is a schematic diagram of the optical path blocker module in this invention.

[0021] Figure 4 This is a schematic diagram of the safety triggering unit in this invention.

[0022] Figure 5 This is a schematic diagram of the structure of the optical waveguide lens and the optical engine body in this invention.

[0023] The numbers in the image represent: 1. Optical engine body; 2. Optical waveguide lens. Detailed Implementation

[0024] The above-mentioned and other technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings.

[0025] This embodiment provides a technical solution: an ultrathin optical engine based on polarizer holography, such as... Figure 5As shown, the system includes an optical engine body 1, which comprises a light source module 11, a micro-display panel 12, a relay imaging optical group 13, a polarizer hologram 14, and a polarization compensation element 15. The light source module 11 provides a high-purity, highly directional initial beam. The laser light source is used due to its good monochromaticity and small size. The micro-display panel 12 carries digital image signals, modulating electrical signals into a light field carrying image information; it is the source of the image and determines the resolution and refresh rate. The relay imaging optical group 13 expands, collimates, or focuses the image emitted from the micro-display panel 12, adjusting the beam angle and size to match the Bragg condition of the PVG (polarizer grating) coupler, ensuring the light enters at a specific angle. The polarizer hologram 14 utilizes its internal spiral... The liquid crystal structure selectively diffracts specific chiral circularly polarized light into the waveguide, and converts the transmitted light into a couplerable state through anomalous polarization conversion during the secondary reflection of the light, breaking through the traditional coupling efficiency limit, suppressing back leakage (privacy protection), and ensuring field uniformity. The polarization compensation element 15 works in conjunction with the PVG to precisely adjust the polarization state of the incident light (such as linear polarization to circular polarization) to ensure that the half-wave condition of the PVG is met to achieve maximum diffraction efficiency. The optical engine body 1 mentioned above and the mechanisms contained within the optical engine body 1 are all conventional means or common knowledge known to those skilled in the art. Their working principles and wiring methods are commonplace and will not be described in detail here. Those skilled in the art can make any selections according to their needs or convenience.

[0026] An AR display device based on polarizer holography, such as Figures 1-4 As shown, it includes an optical engine body 1, an optical waveguide lens 2 with a polarizing holographic grating, a safety status management module, a data erasure module, a mode switching module, and a brightness compensation control module. The optical engine body 1 is used to generate and output first polarized light carrying image information. The optical waveguide lens 2 is provided with an insertion region and an output region, and both the insertion region and the output region are provided with polarizing holographic gratings.

[0027] The security status management module is connected to the optical engine body 1 and the optical waveguide lens 2. The security status management module is used to control the AR display device to switch between two security states, namely privacy protection state and data security state. In the privacy protection state, the security status management module controls the AR display device to reduce or eliminate the leakage of the first polarized light to the external environment, so that the displayed content is invisible or unrecognizable to onlookers. In the data security state, the security state management module controls the AR display device to block the propagation of the first polarized light from the optical engine body 1 to the optical waveguide lens 2, so that the AR display device enters the display blocking state. The security state management module includes a privacy grating component set on the side of the optical waveguide lens 2 facing the external environment, an optical path blocker set on the optical path between the coupling area of ​​the optical engine body 1 and the optical waveguide lens 2, and a security triggering unit. The privacy grating assembly is used to optically control the first polarized light coupled from the optical waveguide lens 2 and the natural light incident from the external environment in a privacy protection state, so as to make the displayed content invisible to the outside world. The optical path blocker is used to block the propagation of the first polarized light from the optical engine body 1 to the optical waveguide lens 2 in a data security state. The security trigger unit is electrically connected to the privacy grating assembly and the optical path blocker, and is used to receive the trigger signal and control the working state of the privacy grating assembly and the optical path blocker.

[0028] The privacy grating assembly includes a first polarizing holographic grating layer, a liquid crystal polarization rotation layer, and a second polarizing holographic grating layer stacked together. The first polarizing holographic grating layer and the second polarizing holographic grating layer are PVG layers. The PVG layer is essentially a chiral nematic liquid crystal film with a periodic spiral structure. A light-absorbing layer is disposed between the first polarizing holographic grating layer and the second polarizing holographic grating layer. The visual interference light field is a uniformly distributed white light screen or a scattered light field with a dynamically changing pattern. The light-absorbing layer is used to absorb stray light, improve contrast, and absorb useless light transmitted from the first polarizing holographic grating layer, preventing these lights from re-entering the optical path and causing interference, thereby effectively improving the contrast and clarity of the image. It can also absorb stray light that constitutes the visual interference light field, making the interference light field more uniform and cleaner, making it more difficult for others to see the displayed content. Nano black phosphorus light-absorbing material, black photoresist / resin, metal or metal oxide film, or composite light-absorbing layer can be selected. In the privacy protection state, a first driving voltage is applied to the liquid crystal polarization rotation layer, causing the polarization direction of the first polarized light passing through it to rotate. The first polarizing holographic grating layer and the second polarizing holographic grating layer diffract and re-diffract the first polarized light after the polarization direction is rotated, respectively, forming an optical path cutoff state inside the privacy grating assembly, preventing the first polarized light from passing through the privacy grating assembly and escaping to the external environment. At the same time, the privacy grating assembly scatters specific polarization components in the natural light incident from the external environment, forming a visual interference light field on the outside of the optical waveguide lens 2, making it impossible for bystanders to recognize the image content displayed by the AR display device.

[0029] The first polarizer holographic grating layer and the second polarizer holographic grating layer have opposite axial selectivity for circularly polarized light. In the privacy protection state, after the first polarized light passes through the diffraction of the first polarizer holographic grating layer, the polarization rotation of the liquid crystal polarization rotation layer, and the re-diffraction of the second polarizer holographic grating layer in sequence, its propagation direction is deflected to an angle away from the user's field of view. In the shared display mode, the liquid crystal polarization rotation layer is in the initial state without applied voltage, and the privacy grating assembly has a transmittance of not less than 80% for both the first polarized light and external ambient light.

[0030] The optical path blocker includes an electrically controlled polarization rotator, a polarizer, and an electrically controlled scattering layer disposed on the surface of the optical waveguide lens 2. The electrically controlled polarization rotator is disposed on the propagation path of the first polarized light, and the polarizer is disposed on the light-emitting side of the electrically controlled polarization rotator. When the AR display device is in normal working condition, the electrically controlled polarization rotator is in an initial state without applied voltage, and the first polarized light maintains its original polarization direction as it passes through the polarizer. When the security trigger unit receives a data security trigger signal, the electrically controlled polarization rotator is driven by a driving voltage, causing the polarization direction of the first polarized light passing through it to rotate. The transmission axis direction of the polarizer is aligned with the rotated first polarized light. The polarization direction of the oscillating light is perpendicular, blocking the passage of the first polarized light, causing the AR display device to enter the display blocking state within a preset response time. In the display blocking state, the electrically controlled scattering layer is driven by a voltage, which scatters the ambient light incident on the optical waveguide lens 2, causing the optical waveguide lens 2 to appear fogged or opaque. The display blocking state is reversible. When the data security trigger signal disappears, the driving voltage of the electrically controlled polarization rotator is removed, and the AR display device returns to normal operation in a short time. The optical path blocker is an emergency brake valve for the optical path. Its function is to physically cut off the image light in extreme cases, achieving self-destructive anti-leakage.

[0031] The security trigger unit is responsible for monitoring the environment and determining whether to trigger self-destruction. The security trigger unit includes a sensor module and a signal generation module. The sensor module is used to collect the status data and environmental data of the AR display device. The signal generation module is electrically connected to the sensor module and is used to determine whether the preset security event trigger conditions are met based on the status data and environmental data, and generate a data security trigger signal when the conditions are met. The sensor module includes a positioning module, a biometric recognition module, an accelerometer, and an anti-tamper sensor. The signal generation module includes a microcontroller and a security chip. The biometric recognition module includes a fingerprint recognition module, an iris recognition module, a facial recognition module, and a voiceprint recognition module. The positioning module can be GPS, which is used to detect whether the device's location exceeds a preset area. The biometric recognition module can be composed of a fingerprint sensor, an iris camera, and a facial recognition camera. It is mainly used to verify whether the current wearer is an authorized user. The biometric features are at least one of the following: fingerprint information, iris information, and facial feature information. The accelerometer is implemented by a MEMS inertial measurement unit. It can be used to detect whether the device has experienced a violent impact, free fall, or abnormal movement. The tamper-proof sensor is used to detect whether the device casing has been illegally opened or disassembled.

[0032] The tamper-proof sensor includes a micro switch located at the seam of the AR display device's housing, a conductive wire mesh surrounding the internal components of the AR display device, and a photoelectric sensor located inside the AR display device. When the housing is opened, the state of the micro switch changes; when the housing is illegally disassembled, the conductive wire mesh breaks; and when the housing is opened, external light enters the photoelectric sensor.

[0033] The data erasure module is electrically connected to the security trigger unit. When the duration of the data security trigger signal received by the security trigger unit exceeds a preset threshold, the data erasure module will be activated to erase the sensitive data stored in the AR display device. The sensitive data erased by the data erasure module includes at least one of the following: user identity information, cached historical display content, authentication credentials, and locally stored encryption keys. The data erasure module can protect personal privacy, including completely deleting the user's facial features, voiceprints, and other biometric features, as well as personal data such as location and browsing history. It can also protect business secrets and prevent the deletion of core data such as enterprise-level project materials and design drawings.

[0034] The mode switching module is electrically connected to the liquid crystal polarization rotation layer and is used to control the AR display device to switch between shared display mode and privacy protection mode in response to user input or environmental perception signals. The mode switching module is the control switch for privacy mode. Its function is to respond to commands and control the AR glasses to switch between shared and privacy modes. A command input interface can be set to receive user commands, such as physical buttons or voice, to send corresponding electrical signals to the privacy grating component.

[0035] The brightness compensation control module is electrically connected to the optical engine body 1 and the privacy grating assembly. It is used to synchronously control the output brightness of the optical engine body 1 when the privacy protection state is triggered. In the privacy protection state, the optical engine body 1 automatically increases the output brightness to compensate for the user-side brightness loss caused by the reduced transmittance of the privacy grating assembly to the first polarized light.

[0036] In normal use, the AR display device enters the shared display mode, i.e., the default state. At this time, the liquid crystal polarization rotation layer in the privacy grating assembly is in the initial state without applied voltage, the optical path between the first polarizer holographic grating layer and the second polarizer holographic grating layer is in a straight-through state, the privacy grating assembly has high transmittance to visible light, the optical waveguide lens 2 is in a transparent state, the electrically controlled polarization rotator in the optical path blocker is in the initial state without applied voltage, the first polarized light maintains its original polarization direction and passes through the polarizer, the optical path is unobstructed, at that time the safety trigger unit begins to monitor various sensor data, the optical engine body 1 generates the original image, the light source module 11 provides illumination, the polarization control element 14 controls the light to be emitted with the first polarization state, outputs through the emission pupil, enters the coupling area of ​​the optical waveguide lens 2, and is coupled out through the polarizer holographic grating in the coupling area to the user's eye.

[0037] If a user uses AR glasses in a public place and does not want others to see the content displayed on the waveguide lens 2, they can switch the waveguide lens 2 to a privacy protection state through the mode switching module. At that time, the mode switching module sends a switching signal to the privacy grating component, the privacy grating component executes the switch, and the control circuit applies a first driving voltage to the liquid crystal polarization rotation layer. The polarization direction of the first polarized light passing through it rotates by 90 degrees. Subsequently, the first polarized light passes through the diffraction of the first polarizing body holographic grating layer, the polarization rotation of the liquid crystal polarization rotation layer, and the second diffraction of the second polarizing body holographic grating layer in sequence. Its propagation direction is deflected to an angle away from the user's field of view, and it cannot pass through the privacy grating component to the external environment. At the same time, the privacy grating component forms a uniform white light curtain on the outside of the lens. By creating a visual interference light field, the content on the optical waveguide lens 2 cannot be recognized by anyone other than the user, thus achieving a privacy mode to prevent peeping. When this privacy mode is activated, the brightness compensation control module simultaneously sends a compensation command to the drive circuit of the optical engine body 1, which will increase the output brightness of the optical engine body 1 to compensate for the brightness loss caused by the light path obstruction on the user side. This ensures that the user sees a clear and bright image, while others see a white light screen and cannot recognize the content, thus maintaining a continuous privacy state. As long as the user does not actively switch back to the sharing mode through the mode switching module, the optical waveguide lens 2 can remain in the privacy mode to prevent peeping. If the user switches back to the sharing mode, the optical waveguide lens 2 becomes transparent again, the visual interference light field disappears, and the brightness compensation control module will also turn off brightness compensation.

[0038] When the device is lost or stolen, or when a thief or finder attempts to use it, takes the device out of a specific area, or forcibly dismantles it, the biometric identification module in the security trigger unit will use fingerprint, iris, facial, or voiceprint recognition modules to check whether the current wearer's biometric features match those of authorized users stored in the database. If the biometric identification module detects a mismatch with authorized user features more than twice, the data erasure module will be activated first. After receiving the data security trigger signal, the data erasure module will detect the duration of the signal. When the duration of the signal exceeds a preset threshold, such as 20 seconds, the data erasure module will activate to destroy sensitive data such as user identity information, cached historical display content, and authentication credentials, thus achieving a self-destructive anti-leakage function after an extreme security incident.

[0039] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. An ultrathin optical engine based on polarizer holography, characterized in that, include: The optical engine body (1) includes a light source module, a micro-display panel, a relay imaging optical group, a polarizer hologram, and a polarization compensation element. The light source module is used to provide a high-purity, highly directional initial beam of light; The micro-display panel is used to carry digital image signals and modulate electrical signals into a light field carrying image information. The relay imaging optical group expands, collimates, or focuses the image emitted by the micro-display panel to ensure that the light is incident at a specific angle. The polarizing hologram utilizes its internal spiral liquid crystal structure to selectively diffract specific chiral circularly polarized light into the waveguide. The polarization compensation element precisely adjusts the polarization state of the incident light to ensure that the half-wave condition of the PVG is met in order to achieve maximum diffraction efficiency.

2. An AR display device based on polarizer holography, characterized in that, Includes the optical engine body (1) as described in claim 1, an optical waveguide lens (2) provided with a polarizer holographic grating, a security status management module, a data erasure module, a mode switching module, and a brightness compensation control module, wherein the optical waveguide lens (2) is provided with a coupling-in region and a coupling-out region; The safety status management module is connected to the optical engine body (1) and the optical waveguide lens (2). The safety status management module includes a privacy grating assembly disposed on the side of the optical waveguide lens (2) facing the external environment, an optical path blocker disposed on the optical path between the coupling area of ​​the optical engine body (1) and the optical waveguide lens (2), and a safety triggering unit. The privacy grating assembly is used to optically control the first polarized light coupled from the optical waveguide lens (2) and the natural light incident from the external environment in a privacy protection state, so as to make the displayed content invisible to the outside world. The optical path blocker is used to block the propagation of the first polarized light from the optical engine body (1) to the optical waveguide lens (2) in a data security state. The security triggering unit is electrically connected to the privacy grating assembly and the optical path blocker, and is used to receive the trigger signal and control the working state of the privacy grating assembly and the optical path blocker.

3. The AR display device based on polarizer holography as described in claim 2, characterized in that, The privacy grating assembly includes a first polarizing holographic grating layer, a liquid crystal polarization rotation layer, and a second polarizing holographic grating layer stacked together. A light-absorbing layer is disposed between the first polarizing holographic grating layer and the second polarizing holographic grating layer. The light-absorbing layer is used to absorb stray light that escapes after being diffracted by the second polarizing holographic grating layer.

4. An AR display device based on polarizer holography as described in claim 2, characterized in that, The optical path blocker includes an electrically controlled polarization rotator, a polarizer, and an electrically controlled scattering layer disposed on the surface of the optical waveguide lens (2). The electrically controlled scattering layer scatters ambient light incident on the optical waveguide lens (2), causing the optical waveguide lens (2) to appear foggy or opaque.

5. An AR display device based on polarizer holography as described in claim 2, characterized in that, The safety triggering unit includes a sensor module and a signal generation module. The sensor module is used to collect status data and environmental data of the AR display device. The signal generation module is electrically connected to the sensor module and is used to determine whether the preset safety event triggering conditions are met based on the status data and environmental data, and generate a data safety triggering signal when the conditions are met.

6. An AR display device based on polarizer holography as described in claim 5, characterized in that, The sensor module includes a positioning module, a biometric recognition module, an accelerometer, and an anti-tamper sensor. The signal generation module includes a microcontroller and a security chip. The biometric recognition module includes a fingerprint recognition module, an iris recognition module, a facial recognition module, and a voiceprint recognition module.

7. An AR display device based on polarizer holography as described in claim 6, characterized in that, The tamper-proof sensor includes a micro switch, a conductive wire mesh, and a photoelectric sensor.

8. An AR display device based on polarizer holography as described in claim 2, characterized in that, The data erasure module is electrically connected to the security trigger unit. When the duration of the data security trigger signal received by the security trigger unit exceeds a preset threshold, the data erasure module will be activated.

9. An AR display device based on polarizer holography as described in claim 2, characterized in that, The mode switching module is electrically connected to the liquid crystal polarization rotation layer and is used to control the AR display device to switch between shared display mode and privacy protection mode in response to user input or environmental perception signals.

10. An AR display device based on polarizer holography as described in claim 2, characterized in that, The brightness compensation control module is electrically connected to the optical engine body (1) and the privacy grating assembly, and is used to synchronously control the output brightness of the optical engine body (1) when the privacy protection state is triggered.

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