A calibration method and apparatus for binocular near-eye display optical systems with long exit pupils

Abstract

This invention relates to the field of display technology and discloses a calibration method and apparatus for a binocular near-eye display optical system with a long exit pupil. It includes a method and steps for adjusting the binocular near-eye display optical system with a long exit pupil suitable for physiological protective augmented reality display helmets, and a binocular image merging test and calibration device designed based on this method. The calibration device for the binocular near-eye display optical system with a long exit pupil mainly consists of an optical calibration stand, a binocular simulated human eye camera group, anti-distortion calibration and image merging software, and a PC processor. This effectively solves the problems of display consistency and personalized adaptation calibration in existing physiological protective augmented reality display helmet binocular near-eye display optical systems.

Description

Technical Field

[0001] This invention relates to the field of display technology, and specifically to a calibration method and apparatus for a binocular near-eye display optical system with a long exit pupil. Background Technology

[0002] Near-eye display optical systems are widely used in augmented reality and mixed reality fields. Binocular near-eye display optical systems, based on the principle of binocular parallax, employ two symmetrical optical paths (left and right) to provide independent images for each eye, achieving stereoscopic vision. Near-eye display optical systems based on off-axis reflection are a type of near-eye display optical system, widely used in physiological protective augmented reality display helmets requiring high-speed flight / ground driving environments. However, compared to other near-eye display optical systems, due to the need to meet the aerodynamic characteristics of high-speed flight, the final imaging optical surface of this type of optical system is a curved surface, characterized by a long exit pupil and large optical distortion. Furthermore, due to manufacturing and installation errors of optical components and optical path fixing devices in the optical system, as well as individual differences in users, this long exit pupil binocular near-eye display optical system is more prone to imaging errors during assembly compared to other binocular near-eye display systems.

[0003] Based on the application characteristics of augmented reality display helmets in high-speed flight or ground driving environments, this invention provides a calibration method and device for binocular near-eye display optical systems with long exit pupils, effectively solving the optical calibration problem of near-eye optical display systems and physiological protective helmet structures. Summary of the Invention

[0004] The purpose of this invention is to provide a calibration method and apparatus for binocular near-eye display optical systems with long exit pupils. Through methods, steps, and installation devices such as single-optical optical axis adjustment test, single-optical virtual image distance adjustment test, anti-distortion test and correction, binocular image merging and spatial consistency measurement, this invention effectively solves the problems of display consistency and personalized adaptation calibration of existing physiological protection augmented reality display helmet binocular near-eye display optical systems.

[0005] The technical solution of this invention is implemented as follows:

[0006] A calibration method for a binocular near-eye display optical system with a long exit pupil includes the following steps:

[0007] The first step is to fix a standard projection reflection target on the optical calibration stand, and then measure the optical axis of the left and right optical engines to ensure that the center of the projection image of the left and right optical engines can be collimated and projected onto the imaging center of the test reflection target.

[0008] The second step is to conduct a consistency test of the virtual image distance of the single-optical engine of the binocular near-eye display optical system by measuring the imaging of the reflective target surface. This ensures that the imaging focal length of the left and right optical engines is within ±1% of the design value. If the target is not met, the virtual image distance is adjusted by changing the object distance by adjusting the distance between the image source and the optical lens group of the optical engine to meet the design requirements.

[0009] The third step is to adjust the relative position of the optical mask to be installed and the simulated human eye camera group so that the imaging centers of the left and right cameras of the camera group match the interpupillary distance of the human eye in the optical design, and at the same time align with the optical projection reflection center of the display mask to be installed.

[0010] The fourth step involves using the position of the simulated human eye camera group as a reference, and according to the optical design configuration, pre-installing the support structures of the left and right optical engines on the optical calibration bracket. Then, through the axial and positional fine-tuning functions of the optical calibration bracket, the poses of the left and right optical engines are adjusted respectively, so that the imaging centers of the left and right optical engines are aligned with the structural center of the aspherical optical surface.

[0011] The fifth step involves using the theoretical anti-distortion parameters obtained from optical design software such as Code-V and Z-Max to generate an anti-distortion map for the optomechanical display.

[0012] The sixth step involves the anti-distortion calibration software analyzing the true optical-mechanical distortion distribution image acquired by the distortion-free camera, calculating the true distortion grid calibration data, and generating a new anti-distortion image.

[0013] Step 7: Measure and calculate the actual distortion distribution image of the single-optical-engine again. If the center distortion and edge distortion values ​​do not meet the distortion values ​​preset by the optical design, repeat step 6.

[0014] Step 8: Using the principle of binocular parallax and the optical design parameters of the binocular near-eye display optical system, generate left and right optomechanical display images with parallax in the anti-distortion calibration software.

[0015] The ninth step involves using a distortion-free camera to acquire the parallax display images of the left and right optical engines, and then comparing them with the theoretical parallax images through anti-distortion calibration and image merging software.

[0016] Step 10: Based on the distortion calibration and the actual image offset and torsion obtained by the image merging software, determine whether the image merging parameters need to be adjusted.

[0017] Step 11: If the image merging does not reach the design value, adjust the distortion calibration and image generation parameters in the image merging software, adjust the parallax image parameters of the generated left and right optical engines, and repeat step 9.

[0018] Step 12: When the deviation between the actual parallax image generated by the left and right optical engines and the theoretical parallax image reaches the design value, the calibration of the binocular near-eye display optical system can be completed.

[0019] A calibration device for a binocular near-eye display optical system with a long exit pupil, comprising:

[0020] An optical calibration stand, a universal standard stand constructed based on the characteristics of the exit pupil of a physiological protective helmet and the protective characteristics of an imaging mask, is used to fix and adjust the catadioptric binocular near-eye display optical system and the binocular simulated human eye camera;

[0021] The binocular simulated human eye camera group consists of left and right symmetrical variable-focus distortion-free cameras that simulate the human eye to acquire projected display images from a binocular near-eye display optical system.

[0022] The anti-distortion calibration and image merging software is based on the image features acquired by the binocular simulated human eye camera group, as well as the parameters of the human eye camera and the optical measurement calculation principle. It calculates the optical indexes of the optical system, such as the imaging center, virtual image distance, and distortion distribution. At the same time, it conducts a comparative analysis of the theoretical and actual image merging effects based on the binocular parallax principle.

[0023] The PC processor is used to run the anti-distortion calibration and image merging software, and also serves as the hardware driver to provide display signals for the binocular near-eye display optical system.

[0024] As a further aspect of the present invention: the optical calibration support stage consists of five modules: an optical adjustment substrate, an optical adjustment base frame, an optical display mask position adjustment stage, a left and right anti-distortion camera group position adjustment stage, and a left and right optical engine pose adjustment stage, which are used to fix and adjust the relative relationships between other modules of the device.

[0025] As a further aspect of the present invention: the left and right anti-distortion camera group position adjustment stage is divided into left and right groups, which are respectively fixed to the optical adjustment base plate by fixing bolts. The relative positions of the left and right distortion-free zoom cameras can be changed by adjusting the stroke screws on the adjustment stage to match the interpupillary distance position of the optical design and align with the reflective display center of the optical display mask. The optical adjustment base is a rack and tooth structure, fixed on the optical adjustment base plate, and serves as a base for vertical adjustment of optical elements. The pose adjustment stage of the left and right optical engines is divided into left and right symmetrical modules. One end of each module is fixedly installed on the optical adjustment base, and the other end is provided with a mounting screw hole for fixing and adjusting the pose of the optical engine.

[0026] As a further aspect of the present invention: the pose adjustment stage of the left and right optical engines is a cantilever structure, which can provide horizontal and vertical position adjustment; the axial adjustment knob on the attitude adjustment module at the end provides optical structure fine adjustment for the left and right optical engines in three axial rotation directions.

[0027] As a further aspect of the present invention: the optical display mask position adjustment platform is also installed on the optical adjustment base frame, and is also a multi-segment cantilever structure, used for vertical adjustment, and to fix the relative position of the optical display mask reflection imaging center relative to the simulated human eye camera group.

[0028] As a further aspect of the present invention: the anti-distortion calibration and image merging software consists of a distortion camera image acquisition and processing module, a left and right optical-mechanical consistency rendering and display module, an optical axis center alignment analysis module, a virtual image distance measurement and analysis module, a distortion mesh rendering and display module, a distortion measurement and analysis module, a binocular image merging rendering and display module, and an image merging comparison analysis module.

[0029] As a further aspect of the present invention: the binocular near-eye display optical system consists of a left optical engine unit, a right optical engine unit, an optical display mask, and a support for adjusting and fixing the optical engine module support and the optical structure of the optical mask. Before adjustment, the left optical engine unit, the right optical engine unit, the optical display mask, and the support for the optical structure of the optical mask are all independent structural units whose positional relationship is not fully determined.

[0030] As a further aspect of the present invention: after confirming the optical pose structure and software parameters, the optical engine module bracket and the optical structure bracket of the optical mask are connected respectively through the left and right optical engine connecting rods to fix the optical relationship between the optical engine and the optical display mask, and the anti-distortion and image combination parameters of this adjustment are recorded.

[0031] The beneficial effects of this invention are:

[0032] 1. This invention provides a complete set of standard and rapid calibration methods for large optical distortion, binocular image merging, and personalized spatial consistency display adjustment of the long-exit pupil binocular near-eye display optical system of physiological protection augmented reality display helmet in high-speed flight / driving environment. It can realize the rapid adjustment and adaptation of the long-exit pupil binocular near-eye display optical system, which greatly improves work efficiency.

[0033] 2. This invention provides an optical alignment and assembly device for long-exit pupil binocular near-eye display optical systems, which realizes single-optical-engine virtual image distance adjustment testing, anti-distortion testing and correction, binocular image merging and spatial display consistency evaluation. It realizes the integrated and high-precision assembly of long-exit pupil binocular near-eye display optical systems and can achieve better spatial display effects.

[0034] 3. This invention provides an optical adjustment method for different interpupillary distances, which greatly improves the personalized adaptation range of fixed-structure long exit pupil binocular near-eye display optical systems.

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating the execution flow of the calibration method for the long exit pupil binocular near-eye display optical system of the present invention;

[0037] Figure 2 This is a schematic diagram of the system composition of the binocular fusion testing and calibration device for the long exit pupil near-eye display optical system of the present invention;

[0038] Figure 3 This is a front view schematic diagram of the structure of the binocular fusion testing and calibration device of the present invention;

[0039] Figure 4 This is a side view schematic diagram of the structure of the binocular fusion testing and calibration device of the present invention;

[0040] Figure 5 This is a schematic diagram of the module composition and calibration processing logic of the anti-distortion calibration and image merging software of the present invention.

[0041] Figure 6 This is a schematic diagram of the structure of the binocular near-eye display optical system of the present invention;

[0042] Figure 7 This is a schematic diagram of the binocular fusion testing and calibration device and the long exit pupil near-eye display optical system of the present invention.

[0043] The attached figures are labeled as follows: left anti-distortion camera group 301a, right anti-distortion camera group 301b, optical adjustment substrate 302, left distortion-free zoom camera 303a, right distortion-free zoom camera 303b, optical adjustment base frame 304, pose adjustment stage 305, attitude adjustment module 401, optical display mask position adjustment stage 402, left optomechanical unit 601a, right optomechanical unit 601b, optical display mask 602, adjustment and curing optomechanical module bracket 603, bracket for optical mask optical structure 604, and optomechanical connecting rod 701. Detailed Implementation

[0044] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0045] See appendix Figure 1-7 This invention provides a calibration method and device for a binocular near-eye display optical system with a long exit pupil, enabling functions such as optical-mechanical axis testing, virtual image distance adjustment testing, anti-distortion testing and correction, binocular image merging, and spatial display consistency evaluation for the long exit pupil binocular near-eye display optical system of a physiological protection augmented reality display helmet.

[0046] In the following embodiments, Embodiment 1 describes the specific steps, process, and composition of each module of the corresponding device of the invention, as well as the specific implementation case configuration. Embodiment 2 describes the specific implementation method of the method and device in a specific application scenario.

[0047] Example 1

[0048] (1) The methods and steps of the embodiments of the present invention are as follows: Figure 1 As shown, to achieve the binocular image merging display effect of the binocular near-eye display optical system with long exit pupil, the image merging and assembly of the binocular near-eye display optical system consists of the following steps:

[0049] 1) First, fix the standard projection reflection target on the optical calibration stand, and measure the optical axis of the left and right optical engines separately to ensure that the center of the projection image of the left and right optical engines can be collimated and projected onto the imaging center of the test reflection target.

[0050] 2) The second step is to perform a consistency test of the virtual image distance of the single-optical engine of the binocular near-eye display optical system by measuring the imaging of the reflective target surface. This ensures that the imaging focal length of the left and right optical engines is within ±1% of the design value. If the target is not met, the virtual image distance is adjusted by changing the object distance by adjusting the distance between the image source and the optical lens group of the optical engine, so that it meets the design requirements.

[0051] 3) The third step is to adjust the relative position of the optical mask to be installed and the simulated human eye camera group so that the imaging centers of the left and right cameras of the camera group match the interpupillary distance of the human eye in the optical design, and at the same time align with the optical projection reflection center of the display mask to be installed.

[0052] 4) The fourth step is to pre-install the support structures of the left and right optical engines on the optical calibration bracket according to the optical design configuration, based on the position of the simulated human eye camera group. Then, through the axial and position fine adjustment function of the optical calibration bracket, the pose of the left and right optical engines is adjusted so that the imaging center of the left and right optical engines is aligned with the structural center of the aspherical optical surface.

[0053] 5) The fifth step is to use the theoretical anti-distortion parameters obtained by optical design software such as Code-V and Z-Max to generate the anti-distortion map of the optomechanical display.

[0054] 6) In the sixth step, the anti-distortion calibration software analyzes the true distortion distribution image of the optomechanical system obtained by the distortion-free camera, calculates the true distortion grid calibration data, and generates a new anti-distortion image.

[0055] 7) Step 7: Measure and calculate the actual distortion distribution image of the single-optical machine again. If the center distortion and edge distortion values ​​do not meet the distortion values ​​preset by the optical design, repeat step 6.

[0056] 8) The eighth step involves using the principle of binocular parallax and the optical design parameters of the binocular near-eye display optical system to generate left and right optical-mechanical display images with parallax in the anti-distortion calibration software.

[0057] 9) In the ninth step, the distortion-free camera acquires the parallax display images of the left and right optical engines, and compares them with the theoretical parallax images through anti-distortion calibration and image merging software.

[0058] 10) The tenth step is to determine whether the image combination parameters need to be adjusted based on the distortion calibration and the actual image offset and torsion obtained by the image combination software.

[0059] 11) Step 11: If the image merging does not reach the design value, adjust the distortion calibration and image generation parameters in the image merging software, adjust the parallax image parameters of the generated left and right optical engines, and repeat step 9.

[0060] 12) Step 12: When the deviation between the actual parallax image generated by the left and right optical engines and the theoretical parallax image reaches the design value, the calibration of the binocular near-eye display optical system can be completed.

[0061] (2) Figure 2 As shown in the system composition diagram, a calibration device for a binocular near-eye display optical system with a long exit pupil consists of an optical calibration support, a simulated human eye camera group, anti-distortion calibration and image merging software, and a PC processor for software operation and display hardware driving.

[0062] The optical calibration support platform consists of five modules: an optical adjustment base plate, an optical adjustment frame, an optical display mask position adjustment platform, left and right anti-distortion camera group position adjustment platforms, and left and right optical engine pose adjustment platforms. These modules are used to fix and adjust the relative relationships between other modules of the device. The simulated human eye camera group consists of two distortion-free zoom cameras (left and right) used to simulate the human eye and capture the display images of the eye optical display system. The anti-distortion calibration and image merging software is configured on a PC processor. It generates the imaging images of the left and right optical engines of the optical system, analyzes the actual imaging images of the left and right optical engines, performs optical adjustments to obtain optical adjustment parameters, and generates new left and right optical engine anti-distortion and image merging images based on the configured adjustment parameters and optimizations. The PC processor's display interface is connected to the display driver board of the near-eye display optical system, enabling the driving display of the binocular near-eye display optical system.

[0063] (3) Figure 3The schematic diagram shows that the left and right anti-distortion camera group position adjustment stages are divided into two groups, 301a and 301b, which are fixed to the optical adjustment base plate 302 by fixing bolts. The relative left and right positions of the left and right distortion-free zoom cameras 303a and 303b can be changed by adjusting the stroke screws on the adjustment stages to match the interpupillary distance position of the optical design and align it with the reflective display center of the optical display mask. The optical adjustment base 304 has a rack and tooth structure and is fixed to the optical adjustment base plate 302, serving as a base for vertical adjustment of the optical components. The left and right optical engine pose adjustment stages 305 are divided into left and right symmetrical modules. One end of each module is fixed to the optical adjustment base 304, and the other end is provided with mounting screw holes for fixing and adjusting the pose of the optical engine.

[0064] (4) Figure 4 As shown, the pose adjustment stage 305 of the left and right optical engines is a cantilever structure, providing horizontal and vertical position adjustments. Additionally, via the attitude adjustment module 401 at the end, the optical structure can be finely adjusted in three axial rotation directions using an axial adjustment knob. The optical display mask position adjustment stage 402 is also mounted on the optical adjustment base 304, and is also a multi-segment cantilever structure, used for vertical adjustment and to fix the relative position of the optical display mask's reflection imaging center relative to the simulated human eye camera group.

[0065] (5) Figure 5 The software components of the distortion correction and image merging software shown are mainly composed of a distortion camera image acquisition and processing module, a left and right optical-mechanical consistency rendering and display module, an optical axis center alignment analysis module, a virtual image distance measurement and analysis module, a distortion mesh rendering and display module, a distortion measurement and analysis module, a binocular image merging rendering and display module, and an image merging comparison analysis module.

[0066] (6) Figure 6 As shown, the schematic diagram of the composition and structure of the long exit pupil binocular near-eye display optical system used for the assembly example mainly consists of a left optical engine unit 601a, a right optical engine unit 601b, an optical display mask 602, and a bracket 604 for adjusting and fixing the optical engine module bracket 603 and the optical structure of the optical mask. Before assembly, the left and right optical engine units 601a and 601b, the optical display mask 602, and the bracket 604 for the optical structure of the optical mask are all independent structural units whose positional relationship is not fully determined.

[0067] (7) Figure 7The diagram shows the assembly of a near-eye display optical system with an extended exit pupil in a binocular fusion testing and calibration device. Following the aforementioned method, using the binocular fusion measuring cameras 303a and 303b as a reference, the positions of the optical display mask 602 and the optical structure support 604 of the optical mask are fixed. Then, the poses of the left and right optical engine units 601a and 601b are adjusted sequentially via the pose adjustment stages 305 of the left and right optical engines to align the images and solidify the optical positions. Then, using the test feedback parameters obtained from the left and right anti-distortion camera groups 303a and 303b and the anti-distortion correction and fusion software, the anti-distortion and fusion parameters of the left and right optical engine units 601a and 601b are sequentially adjusted using software. After confirming the fusion effect, the anti-distortion and fusion parameters are solidified. After confirming the optical pose structure and software parameters, the optical engine module bracket 603 and the optical mask optical structure bracket 604 are connected by the left and right optical engine connecting rods 701 respectively to fix the optical relationship between the optical engine and the display mask, and the anti-distortion and image combination parameters of this adjustment are recorded.

[0068] Example 2

[0069] A schematic diagram of a specific embodiment of the binocular fusion testing and calibration device and the long exit pupil near-eye display optical system of the present invention is shown below. Figure 7 As shown, the specific implementation plan is as follows:

[0070] Step 1: Follow the appendix of Example 1 Figure 2 Perform hardware configuration and connection, then fix the reflective imaging target plate on the optical calibration support platform, adjust the stroke screw, and change the left, right, and up and down distances of the distortion-free zoom camera so that its relative pose with the reflective imaging target plate is consistent with the optical design pose.

[0071] Step 2: Install the left and right optical engines on the optical calibration stand, and use anti-distortion calibration and image merging software to measure the optical axis of the left optical engine to confirm that the center of the projected image of the left and right optical engines is within the design error.

[0072] Step 3: Use anti-distortion calibration and image merging software to test the consistency of the virtual image distance between the left and right optical engines, so that the imaging focal length of the left and right optical engines is kept within ±1% of the design value. If the target is not met, adjust the distance between the image source and the optical lens group of the optical engine to change the object distance and adjust the virtual image distance to meet the design requirements.

[0073] Step 4: Disassemble the left and right optical engines, and according to the optical design configuration, pre-install the optical display mask structure on the optical calibration bracket. Adjust the relative position of the simulated human eye camera group so that it is aligned with the center distance of the lens plane of the optical display mask and matches the interpupillary distance of the human eye in the optical design.

[0074] Step 5: Reinstall the left and right optical engines on the optical calibration bracket in sequence. Adjust the pose of the left and right optical engines respectively by using the axial and position fine adjustment function of the optical calibration bracket stage so that the imaging center of the left and right optical engines is aligned with the structural center of the aspherical optical surface.

[0075] Step 6: Use the optical engine fixing bracket to connect the pre-adjustment brackets of the left and right optical engines with screws respectively, and fill the gaps between the installation interfaces with light-curing adhesive to cure the optical display mask 602, the left optical engine unit 601a, and the right optical engine unit 602b into a stable optical structure.

[0076] Step 7: Disconnect the attitude adjustment module 401 at the end of the pose adjustment platform of the left and right optical engines from the left and right optical engines;

[0077] Step 8: Using the theoretical anti-distortion parameters obtained from optical design software such as Code-V and Z-Max, generate anti-distortion images for left and right optical-mechanical displays using anti-distortion calibration and image merging software;

[0078] Step 9: The anti-distortion calibration software analyzes the true optical-mechanical distortion distribution image acquired by the distortion-free camera, calculates the true distortion grid calibration data, and generates a new anti-distortion image;

[0079] Step 10: Measure and calculate the actual distortion distribution image of the single-optical machine again. If the center distortion and edge distortion values ​​do not meet the distortion values ​​preset by the optical design, repeat the adjustment of the distortion adjustment parameters so that the center distortion and edge distortion both reach the design values.

[0080] Step 11: Using the principle of binocular parallax and the optical design parameters of the binocular near-eye display optical system, generate left and right optomechanical display images with parallax in the anti-distortion calibration software;

[0081] Step 12: The distortion-free camera acquires the parallax display images of the left and right optical engines, and compares them with the theoretical parallax images through anti-distortion calibration and image merging software;

[0082] Step 13: Based on the distortion calibration and the actual image offset and torsion obtained by the image merging software, determine whether the image merging parameters need to be adjusted;

[0083] Step 14: If the image merging does not reach the design value, adjust the distortion calibration and image generation parameters in the image merging software, adjust the parallax image parameters of the generated left and right optical engines, and repeat step 11.

[0084] Step 15: When the deviation between the actual parallax image generated by the left and right optical engines and the theoretical parallax image reaches the design value, the calibration of the binocular near-eye display optical system can be completed. At this time, it can be used for the system assembly and wearing display test of the physiological protection helmet.

[0085] This invention provides a calibration method and apparatus for a binocular near-eye display optical system with a long exit pupil. Through methods, steps, and installation devices including single-optical-mechanical axis adjustment testing, single-optical-mechanical virtual image distance adjustment testing, distortion correction testing, binocular image merging, and spatial consistency measurement, it effectively solves the problems of display consistency and personalized adaptation calibration in existing physiological protective augmented reality helmet binocular near-eye display optical systems. The apparatus for the long exit pupil binocular near-eye display optical system consists of an optical calibration support platform, a simulated human eye camera group, distortion correction and image merging software, and a PC processor for software operation and display hardware driving.

[0086] In summary, this invention provides an off-axis reflective binocular near-eye display optical system for high-speed protective helmets. Through the system architecture, design principles, system structure diagrams, and application examples shown in the abstract and accompanying figures, consistent device measurement and binocular spatial assembly are integrated into a single process and mechanism. This achieves the integration and assembly of a long exit pupil binocular near-eye display optical system, fundamentally solving the problems of unclear assembly processes, the need for multiple devices, and inconsistent optical references in previous physiological protective augmented reality helmet optics. It effectively addresses the optical calibration challenges of near-eye optical display systems and physiological protective helmet structures.

[0087] Thus, the objective of this invention has been achieved.

[0088] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A calibration method for a binocular near-eye display optical system with a long exit pupil, characterized in that, Includes the following steps: The first step is to fix a standard projection reflection target on the optical calibration stand, and then measure the optical axis of the left and right optical engines to ensure that the center of the projection image of the left and right optical engines can be collimated and projected onto the imaging center of the test reflection target. The second step is to conduct a consistency test of the virtual image distance of the single-optical engine of the binocular near-eye display optical system by measuring the imaging of the reflective target surface. This ensures that the imaging focal length of the left and right optical engines is within ±1% of the design value. If the target is not met, the virtual image distance is adjusted by changing the object distance by adjusting the distance between the image source and the optical lens group of the optical engine to meet the design requirements. The third step is to adjust the relative position of the optical mask to be installed and the simulated human eye camera group so that the imaging centers of the left and right cameras of the camera group match the interpupillary distance of the human eye in the optical design, and at the same time align with the optical projection reflection center of the display mask to be installed. The fourth step involves using the position of the simulated human eye camera group as a reference, and according to the optical design configuration, pre-installing the support structures of the left and right optical engines on the optical calibration bracket. Then, through the axial and positional fine-tuning functions of the optical calibration bracket, the poses of the left and right optical engines are adjusted respectively, so that the imaging centers of the left and right optical engines are aligned with the structural center of the aspherical optical surface. The fifth step is to use the theoretical anti-distortion parameters obtained from the Code-V and Z-Max optical design software to generate an anti-distortion map for the optomechanical display. The sixth step involves the anti-distortion calibration software analyzing the true optical-mechanical distortion distribution image acquired by the distortion-free camera, calculating the true distortion grid calibration data, and generating a new anti-distortion image. Step 7: Measure and calculate the actual distortion distribution image of the single-optical-engine again. If the center distortion and edge distortion values ​​do not meet the distortion values ​​preset by the optical design, repeat step 6. Step 8: Using the principle of binocular parallax and the optical design parameters of the binocular near-eye display optical system, generate left and right optomechanical display images with parallax in the anti-distortion calibration software. The ninth step involves using a distortion-free camera to acquire the parallax display images of the left and right optical engines, and then comparing them with the theoretical parallax images through anti-distortion calibration and image merging software. Step 10: Based on the distortion calibration and the actual image offset and torsion obtained by the image merging software, determine whether the image merging parameters need to be adjusted. Step 11: If the image merging does not reach the design value, adjust the distortion calibration and image generation parameters in the image merging software, adjust the parallax image parameters of the generated left and right optical engines, and repeat step 9. Step 12: When the deviation between the actual parallax image generated by the left and right optical engines and the theoretical parallax image reaches the design value, the calibration of the binocular near-eye display optical system can be completed.

2. A calibration device for a binocular near-eye display optical system with a long exit pupil, characterized in that, The apparatus for the calibration method of the long exit pupil binocular near-eye display optical system as described in claim 1 includes: An optical calibration stand, a universal standard stand constructed based on the characteristics of the exit pupil of a physiological protective helmet and the protective characteristics of an imaging mask, is used to fix and adjust the catadioptric binocular near-eye display optical system and the binocular simulated human eye camera; The binocular simulated human eye camera group consists of left and right symmetrical variable-focus distortion-free cameras that simulate the human eye to acquire projected display images from a binocular near-eye display optical system. The anti-distortion calibration and image merging software is based on the image features acquired by the binocular simulated human eye camera group, as well as the parameters of the human eye camera and the optical measurement calculation principle. It calculates the optical indexes of the optical system, such as the imaging center, virtual image distance, and distortion distribution. At the same time, it conducts a comparative analysis of the theoretical and actual image merging effects based on the binocular parallax principle. The PC processor is used to run the anti-distortion calibration and image merging software, and also serves as the hardware driver to provide display signals for the binocular near-eye display optical system.

3. The calibration device for a binocular near-eye display optical system with a long exit pupil according to claim 2, characterized in that, The optical calibration support platform consists of five modules: an optical adjustment substrate, an optical adjustment base frame, an optical display mask position adjustment platform, a left and right anti-distortion camera group position adjustment platform, and a left and right optical engine pose adjustment platform. It is used to fix and adjust the relative relationships between other modules of the device.

4. The calibration device for a binocular near-eye display optical system with a long exit pupil according to claim 3, characterized in that, The left and right anti-distortion camera group position adjustment platforms are divided into left and right groups, which are fixed to the optical adjustment base plate by fixing bolts. The relative positions of the left and right distortion-free zoom cameras can be changed by adjusting the stroke screws on the adjustment platforms to match the interpupillary distance position of the optical design and align with the reflective display center of the optical display mask. The optical adjustment base is a rack and tooth structure, fixed on the optical adjustment base plate, and serves as a base for vertical adjustment of optical elements. The left and right optical engine pose adjustment platforms are divided into left and right symmetrical modules. One end of each module is fixedly installed on the optical adjustment base, and the other end is provided with a mounting screw hole for fixing and adjusting the pose of the optical engine.

5. A calibration device for a binocular near-eye display optical system with a long exit pupil, as described in claim 4, characterized in that, The pose adjustment platform of the left and right optical engines is a cantilever structure, which can provide horizontal and vertical position adjustment; the axial adjustment knob on the attitude adjustment module at the end provides optical structure fine adjustment for the left and right optical engines in three axial rotation directions.

6. The calibration device for a binocular near-eye display optical system with a long exit pupil according to claim 4, characterized in that, The optical display mask position adjustment platform is also mounted on the optical adjustment base frame. It is also a multi-segment cantilever structure used for vertical adjustment and to fix the relative position of the optical display mask reflection imaging center relative to the simulated human eye camera group.

7. The calibration device for a binocular near-eye display optical system with a long exit pupil according to claim 2, characterized in that, The anti-distortion calibration and image merging software consists of a distortion camera image acquisition and processing module, a left and right optical-mechanical consistency rendering and display module, an optical axis center alignment analysis module, a virtual image distance measurement and analysis module, a distortion mesh rendering and display module, a distortion measurement and analysis module, a binocular image merging rendering and display module, and an image merging comparison analysis module.

8. A calibration device for a binocular near-eye display optical system with a long exit pupil, as described in any one of claims 2-7, characterized in that, The binocular near-eye display optical system consists of a left optical engine unit, a right optical engine unit, an optical display mask, and a support for adjusting and fixing the optical engine module support and the optical structure of the optical mask. Before assembly, the left optical engine unit, the right optical engine unit, the optical display mask, and the support for the optical structure of the optical mask are all independent structural units whose positional relationship is not fully determined.

9. A calibration device for a binocular near-eye display optical system with a long exit pupil according to claim 8, characterized in that, After confirming the optical pose structure and software parameters, the optical engine module bracket and the optical mask optical structure bracket are connected by the left and right optical engine connecting rods respectively to fix the optical relationship between the optical engine and the optical display mask, and the anti-distortion and image combination parameters of this adjustment are recorded.

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