Method and device for measuring visual magnification of near-eye display equipment and medium

Abstract

The invention provides a method and device for measuring the visual magnification of near-eye display equipment and a medium. A first rotatable laser module in the device is used for guiding a light beam of the first rotatable laser module to pass through an eyepiece of the near-eye display equipment; the second rotatable laser module is used for guiding the light beam to a physical target; the angle encoder is coupled with the first rotatable laser module and the second rotatable laser module so as to measure a rotation angle; the processor is in communication connection with the first rotatable laser module, the second rotatable laser module and the angle encoder, and the processor is used for controlling the first rotatable laser module to rotate so as to use the angle encoder to obtain a first angle difference corresponding to a virtual target observed through the near-eye display device; and controlling the second rotatable laser module to rotate so as to obtain a second angle difference corresponding to the physical target by using the angle encoder, and calculating the visual magnification of the near-to-eye display device based on the first angle difference and the second angle difference.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of optical metrology, and in particular to a method, apparatus and medium for measuring visual magnification of near-eye display devices. BACKGROUND

[0002] Near-eye display (NED) devices, such as head-mounted displays (HMDs), create immersive visual experiences by projecting virtual images close to the user's eyes. These devices have found wide applications in consumer electronics, medical, industrial, and military fields. To ensure high-quality user experiences, their key optical performance parameters must be accurately measured and controlled.

[0003] Visual magnification is a core metric for measuring NED performance. It is defined as the ratio of the apparent size of a virtual image observed by a user through a NED to the apparent size of the same physical object observed directly. This parameter directly affects the perceived image size, clarity, and immersion. Inaccurate or inconsistent visual magnification can lead to visual distortion, user discomfort, and even reduced task performance.

[0004] However, existing methods for detecting NED visual magnification have significant limitations. Many traditional methods rely heavily on human judgment and manual adjustments by operators. For example, operators may need to observe through an eyepiece, manually align a reticle or target feature, and record readings. This approach is not only time-consuming and labor-intensive, but also introduces significant measurement errors due to subjective differences between operators and operational fatigue, leading to poor repeatability and reliability of test results. SUMMARY

[0005] The present disclosure provides a method, apparatus and medium for measuring visual magnification of near-eye display devices, which can solve the technical problem of poor repeatability and reliability of test results in the prior art.

[0006] The technical solution of the present disclosure is implemented as follows: In a first aspect, the present disclosure provides an apparatus for measuring visual magnification of near-eye display devices, comprising: a first rotatable laser module configured to direct its beam through an eyepiece of the near-eye display device; a second rotatable laser module configured to direct its beam to a physical target; an angle encoder coupled to the first and second rotatable laser modules to measure their rotation angles; and a processor communicatively connected with the first rotatable laser module, the second rotatable laser module, and the angle encoder, wherein the processor is configured to perform the following operations: controlling the first rotatable laser module to rotate to obtain, with the angle encoder, a first angle difference corresponding to a virtual target observed through the near-eye display device; controlling the second rotatable laser module to rotate to obtain, with the angle encoder, a second angle difference corresponding to a physical target, wherein the virtual target is an image formed by observing the physical target through the near-eye display device; calculating the eye magnification of the near-eye display device based on the first angle difference and the second angle difference.

[0007] In a second aspect, the present disclosure provides a method for measuring the eye magnification of a near-eye display device, comprising: controlling a first rotatable laser module to rotate to direct its light beam through an ocular lens of the near-eye display device; determining a first angle difference corresponding to a virtual target observed through the near-eye display device based on a rotation angle corresponding to the rotation of the first rotatable laser module measured by an angle encoder; controlling a second rotatable laser module to rotate to direct its light beam to a physical target; determining a second angle difference corresponding to the physical target based on a rotation angle corresponding to the rotation of the second rotatable laser module measured by the angle encoder; wherein the virtual target is an image formed by observing the physical target through the near-eye display device; calculating the eye magnification based on the first angle difference and the second angle difference.

[0008] In a third aspect, the present disclosure provides a computer storage medium storing at least one instruction for being executed by a processor to implement the method for measuring the eye magnification of a near-eye display device according to the second aspect.

[0009] The present disclosure provides a method, device and medium for measuring the eye magnification of a near-eye display device; by using a double laser module for differential angle measurement, combined with a high-precision angle encoder and an automatic control system, the accurate, fast and repeatable measurement of the eye magnification is realized. By integrating a multi-axis adjustable platform, the device can automatically complete the precise alignment of the measured device and the measurement system, greatly simplifying the operation process and reducing human error. The entire alignment and measurement process can be automatically controlled by the processor, significantly shortening the single test time, and suitable for high-throughput detection requirements on the production line. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 A schematic diagram of a method for detecting using a total station in an embodiment of the present disclosure.

[0011] Figure 2 A schematic diagram of the principle of a method for detecting using the device of the present disclosure in an embodiment of the present disclosure.

[0012] Figure 3 An isometric side view of the detection device in an embodiment of the present disclosure.

[0013] Figure 4 A front view of the detection device in an embodiment of the present disclosure.

[0014] Figure 5 A top view of the detection device in an embodiment of the present disclosure.

[0015] Figure 6 A cross-sectional view of the detection device along line A-A in an embodiment of the present disclosure. Figure 5

[0016] A cross-sectional view of the detection device along line A-A in an embodiment of the present disclosure. Figure 7

[0017] A hardware block diagram of the detection device in an embodiment of the present disclosure. Figure 8

[0018] A software flowchart of the detection device in an automatic control mode in an embodiment of the present disclosure. Figure 9

[0019] A software flowchart of the detection device in a manual control mode in an embodiment of the present disclosure. Figure 10

[0020] A start-up screen of the user interface in an embodiment of the present disclosure. Figure 11

[0021] A test mode selection page of the user interface in an embodiment of the present disclosure. Figure 12

[0022] An automatic test page of the user interface in an embodiment of the present disclosure. Figure 13

[0023] A manual test confirmation page of the user interface in an embodiment of the present disclosure. Figure 14

[0024] A manual test result page of the user interface in an embodiment of the present disclosure. Figure 15 A flowchart of a method for measuring the eye-relief of a near-eye display device in an embodiment of the present disclosure.DETAILED DESCRIPTION

[0025] The technical solutions in the present disclosure will be clearly and completely described below with reference to the drawings in the present disclosure.

[0026] In the evaluation of the optical performance of near-eye display devices, the visual magnification is a crucial indicator. It defines the ratio of the image viewing angle observed by the human eye through the device to the viewing angle when directly observing the same object, and is directly related to the perceived image size and the strength of the sense of immersion. However, the existing detection methods for the visual magnification of near-eye display devices have significant limitations. Traditional detection schemes mainly rely on manual observation and manual adjustment, which not only have a cumbersome operation process, time-consuming and laborious, but also are easily affected by the subjective factors of the operator, resulting in low precision and poor repeatability. Such inefficient and unreliable detection methods have become a major bottleneck restricting the development iteration of near-eye display devices and the quality control of large-scale production. Especially for consumer-level AR / VR products that pursue extreme user experience, accurate and consistent visual magnification is the basis for ensuring product quality. Therefore, the industry urgently needs a solution that can overcome the shortcomings of existing technologies and achieve automated, high-precision, and efficient detection.

[0027] The embodiments of the present disclosure provide a near-eye display device visual magnification detection method based on high-precision measuring instruments and total stations. This method solves the core problem of accurately aligning the optical systems between the test system and the device under test by using the autocollimation function of the total station, laying the foundation for high-precision measurement. This method is the theoretical basis and principle verification for the design of subsequent automated detection devices.

[0028] Referring to Figure 1 which shows a detection scene schematic diagram using the method of the present embodiment. Taking a night vision device 10 as an example, the method specifically includes the following steps: Step 1: Test system setup and preliminary alignment.

[0029] Two total stations (first total station 11 and second total station 12) are stably installed on the plane of the optical test platform. Through precise adjustment, the optical axes of the two total stations are ensured to be at the same horizontal height. This is a prerequisite for all subsequent angle measurements to be performed in the same reference plane.

[0030] Step 2: Installation of the device under test.

[0031] A cloud platform with five-dimensional adjustment function is installed on the test platform. The cloud platform should at least support up and down (Z-axis translation), left and right (Y-axis translation), pitch (rotation around Y-axis), rotation (rotation around Z-axis), and roll (rotation around X-axis) adjustments. The near-eye display device to be tested (in this embodiment, the night vision device 10 is taken as an example) is installed on the cloud platform. Through visual preliminary adjustment, the height of the central axis of the night vision device 10 is roughly equivalent to the height of the optical axis of the total station.

[0032] Step 3: First total station 11 reference calibration.

[0033] Turn on the first total station 11 and use its autocollimation function to accurately align the centerline of a distant target. This step establishes a precise measurement reference direction for the first total station 11.

[0034] Step 4: Night vision device 10 and first total station 11 optical axis coaxial adjustment.

[0035] This step is the core and key of the entire method. First, place a high flatness plane mirror 13 tightly in front of the objective lens of the night vision device 10. Then, rotate the first total station 11 by 180 degrees so that it faces the night vision device 10. Again, use the autocollimation function of the first total station 11, at this time the light beam emitted by the total station is reflected back to itself via the plane mirror 13. By finely adjusting the gimbal in step 2, change the attitude of the night vision device 10 until the reflected light beam received by the first total station 11 is completely coincident with its own outgoing light beam. When this condition is met, it indicates that the mirror surface of the plane mirror 13 is strictly perpendicular to the optical axis of the first total station 11, thereby indirectly proving that the optical axis of the night vision device 10 and the optical axis of the first total station 11 have been accurately aligned (parallel and collinear). This step ingeniously converts the complex double optical axis alignment problem into a zero position finding process that can be closed-loop adjusted through instrument feedback, greatly improving the accuracy and reliability of the alignment.

[0036] Step 5: Crosshair alignment.

[0037] Remove the plane mirror 13 in front of the objective lens of the night vision device 10. Turn on the night vision device 10 and call up the crosshair displayed inside it. Fine-tune the gimbal to make the night vision device 10 translate in the horizontal and vertical directions until the laser light point emitted by the first total station 11 is accurately projected on the center of the crosshair inside the night vision device 10. After completing this step, it can be ensured that the optical axis of the first total station 11 and the optical axis of the night vision device 10 are not only parallel, but also completely consistent in height.

[0038] Step 6: Second total station 12 reference calibration.

[0039] Place the second total station 12 in a position roughly parallel to the night vision device 10 support and turn it on. Similar to step 3, use its autocollimation function to align the target centerline to establish a measurement reference for the second total station 12.

[0040] Step 7: Second total station 12 and night vision device 10 rotation center alignment.

[0041] Rotate the second total station 12 90 degrees towards the night vision device 10, and translate it on the test platform so that the laser spot emitted by the second total station 12 precisely aims at the rotation center of the night vision device 10 support. This alignment ensures that the measurement base point is stable and correct when subsequent angle measurement is performed by rotating the night vision device 10.

[0042] Step 8: System collaborative calibration.

[0043] Rotate the first total station 11 and the second total station 12 simultaneously, and check whether the laser beams of the two can be precisely aligned in space. If not, it means that there is still a small alignment error in the system, and steps 4 to 7 need to be repeated for fine adjustment until the two light beams can be superimposed.

[0044] Step 9: Angle measurement.

[0045] After all the alignment is completed, remove the first total station 11. The operator rotates the support of the night vision device 10 and the second total station 12 respectively, and uses the second total station 12 to measure the angles corresponding to the upper and lower feature points of the target 14 observed through the night vision device 10, and records them as Δα and Δβ respectively.

[0046] Step 10: Calculation of visual magnification.

[0047] According to the measured angle values, the visual magnification Γ of the instrument is calculated by the following formula

[0048] Where Δα and Δβ represent the viewing angles of the upper and lower edges of the object observed through the near-eye device respectively. This formula is equivalent to the ratio of the viewing angles under small-angle approximation, and accurately reflects the magnification capability of the device.

[0049] The method of the embodiment, through a series of optical alignment steps, especially creatively uses the autocollimation function of the total station in cooperation with the plane mirror 13, realizes the accurate measurement of the visual magnification of the near-eye display device, and effectively overcomes the precision problem caused by the difficulty of alignment in the prior art.

[0050] In order to transform the measurement method into an efficient, convenient and automated industrial detection tool, the embodiment of the disclosure further provides a device for measuring the visual magnification of a near-eye display device. The device integrates precision machinery, servo control, laser measurement and intelligent computing system, aiming to greatly improve the detection efficiency and accuracy, and reduce the professional skill requirements for the operator.

[0051] The device and method of the disclosure, the core of which is to determine the visual magnification by precisely comparing two viewing angles. Referring to Figure 2The figure shows the principle of the method of detection using the device of the present disclosure. The two perspectives are the perspective of the virtual target and the perspective of the physical target, respectively.

[0052] The perspective of the virtual target is the image presented by the internal optical system of the near-eye display device when viewed through the eyepiece by an observer, i.e. the "virtual target", which subtends an angle in the observer's eye.

[0053] The perspective of the physical target is the angle subtended in the observer's eye when the observer directly observes a reference object in the real world, i.e. the "physical target".

[0054] The visual magnification is the ratio of the two perspective size-related functions. The embodiments of the present disclosure use a double optical path design to accurately measure the two perspectives. Specifically, a first rotatable laser module 21 emits a light beam that passes through the eyepiece of the near-eye display device to simulate the observation of the human eye and measure the perspective of the virtual target, thereby obtaining a first angle difference. At the same time, a second rotatable laser module 22 emits a light beam that directly points to a physical target (target) in the distance to measure the real perspective of the physical target, thereby obtaining a second angle difference.

[0055] The virtual target is the image formed by observing the physical target through the near-eye display device. This means that the two measurement processes are not for two independent and unrelated objects, but for the same source target (physical target) and its image (virtual target) formed after magnification by the optical system of the near-eye display device. In this way, the technical solution of the present disclosure ensures the uniformity of the measurement reference and the logical rigor.

[0056] The present embodiment describes in detail the hardware configuration of the detection device of the present disclosure, which integrates mechanical, optical and electronic components to achieve high-precision automated measurement. Referring to Figures 3 to 7 , Figure 3 is an isometric side view. Figure 4 is a front view of the device, Figure 5 is a top view, Figure 6 is a sectional view along the line A-A.

[0057] The device for measuring the visual magnification of the near-eye display device includes a first rotatable laser module 21, a second rotatable laser module 22, an angle encoder 45 and a processor.

[0058] The first and second rotatable laser modules 21 and 22 are the core measurement units of the device, and are both installed inside the outer housing 40. The first rotatable laser module 21 is configured to direct its beam through the eyepiece of the near-eye display device to measure the viewing angle of a virtual target. The second rotatable laser module 22 is configured to direct its beam to a physical target to measure the viewing angle of the physical target. Both modules are driven by a drive motor 46 to perform precise rotational movement about their respective rotational axes. To ensure smooth and precise rotation, the rotational axes are supported by self-lubricating bearings.

[0059] To accurately measure the rotation angle, the device is equipped with an angle encoder 45. The angle encoder 45 is coupled to the first and second rotatable laser modules 21 and 22. In this embodiment, a two-piece high-precision angle encoder 45 is coupled to the rotational axis of each laser module. One piece of the encoder is fixed on the rotational axis to follow the rotation, and the other piece is fixed on the outer housing 40. When the laser module rotates, the encoder converts the rotation angle into a high-resolution electrical signal in real time. This non-contact measurement method, such as using a Hall effect encoder (e.g., MT6620 chip), is not sensitive to dust, oil, and other environmental factors, thereby ensuring long-term stability and high accuracy of the angle readings.

[0060] The physical entity of the processor is integrated on the control board 47. The processor is in communication connection with the first and second rotatable laser modules 21 and 22 and the angle encoder 45. Referring to the hardware block diagram of Figure 7 , the processor realizes the coordinated control and data processing of the entire device through various functional modules inside.

[0061] The device also includes a multi-axis platform. The platform is used to fix the near-eye display device being measured, and is configured to adjust the position and attitude of the near-eye display device along or around at least three axes.

[0062] The multi-axis platform can be composed of a series of precision motion components driven by servo motors, which can specifically include an electric lifting platform 31, an electric elevatable / left-right movable gimbal 32, an electric rolling gimbal 33, an electric tilting platform 34, and an electric rotating platform 35, which together constitute the multi-axis platform, which is connected to the outer housing 40 through a centering plate 36. Specifically: The electric lifting platform 31 and the electric elevatable / left-right movable gimbal 32 together provide translational movement along the Z-axis (vertical) and the Y-axis (horizontal).

[0063] The electric rolling gimbal 33, the electric tilting platform 34, and the electric rotating platform 35, respectively, provide rotational adjustment capabilities around the X-axis, the Y-axis, and the Z-axis.

[0064] The system constitutes a six-degree-of-freedom adjustment mechanism, which can move the near-eye display device to any position in the working space and orient it in any posture. This design, especially its parallel kinematic structure, has the advantages of high rigidity and high stability, and allows a virtual rotation center point to be defined by software, thereby enabling the near-eye display device to be precisely rotated and aligned around its own optical center or exit pupil position, which is crucial to ensuring measurement accuracy.

[0065] In some examples, the processor is further configured to perform an automatic alignment operation. Specifically, the processor controls the multi-axis platform to automatically align the optical axis of the near-eye display device with the optical axis of the first rotatable laser module 21 based on a detected positional deviation between the light beam emitted by the first rotatable laser module 21 and a reference point on the near-eye display device.

[0066] The processor instructs the first rotatable laser module 21 to emit a light beam (which can include a crosshair pattern) through the eyepiece of the near-eye display device under test. At the same time, the near-eye display device itself also displays a crosshair cursor as a reference point. The image contrast module in the processor analyzes the positional deviation between the two crosshairs. If a deviation is detected, the processor calculates the correction amount and sends instructions to the motor control module to drive the multi-axis platform to fine-tune until the two crosshair cursors completely coincide.

[0067] The first angle difference includes the angle between the upper and lower edges of the virtual target; and the second angle difference includes the angle between the upper and lower edges of the physical target corresponding to the upper and lower edges of the virtual target.

[0068] The device also includes a touch screen 39. The touch screen 39 is connected to the processor and is used to receive user input to control the movement of the first rotatable laser module 21 and the second rotatable laser module 22.

[0069] The device is also provided with a shell upper cover plate 37, a power interface 41, and a switch button 42 for device functions. In addition, self-lubricating bearings 44 can also be provided, which are generally made of self-lubricating plastic materials such as POM, PEEK, etc., and are tightly fastened with the shell body 40, and are in small clearance with the rotating shafts of the first rotatable laser module 21 and the second rotatable laser module 22, playing a supporting role and a lubricating role during rotation. The drive motor 46 is fixed on the shell body 11, and the rotating shaft is fixed with the rotating shafts of the first rotatable laser module 21 and the second rotatable laser module 22. After receiving the rotation command, the drive motor 46 rotates, driving the first rotatable laser module 21 and the second rotatable laser module 22 to rotate.

[0070] Please refer to Figure 7which is a hardware block diagram of the device of the present embodiment. The diagram clearly shows the various functional modules inside the control board 47 and the information flow between them. The control board 47 can include a power module 71, a switch module 72, a touch screen control display module 73, an angle encoder angle value receiving module 74, a motor control module 75, and an image contrast and angle information calculation module 76.

[0071] The power module 71 is responsible for converting the 220V mains input into 12V stable DC power required by the system. In the present embodiment, a high-efficiency step-down constant-voltage chip such as AH8665 can be used, and its high integration simplifies the power design.

[0072] The switch module 72 receives physical signals from the switch-on button and controls the power on / off of the entire system.

[0073] The touch screen control display module 73 drives the touch screen 39, is responsible for rendering and displaying the graphical user interface (GUI), and processes touch input events from the user and converts them into control instructions.

[0074] The angle encoder angle value receiving module 74 is used to receive real-time angle data from two high-precision angle encoders 45. In the present embodiment, a Hall sensor chip such as MT6620 can be used. This type of chip can collect angle signals at very high resolution and speed, and transmit data to the main processor through a standard interface such as SPI.

[0075] The motor control module 75 receives instructions from the main processor and accurately controls the rotation direction, speed, and position of the seven servo motors. In the present embodiment, an industrial-grade motor microcontroller such as CH32M007G8R6 with high integration can be used. Its rich built-in peripherals and powerful driving capability enable it to efficiently manage multiple motors with a single chip solution.

[0076] The image contrast and angle information calculation module 76 can be undertaken by a high-performance microcontroller (MCU) or processor. It is used to execute all core algorithms of the present disclosure. In the present embodiment, the N32G455 processor of National Technology is selected, and the selection behind it reflects a thoughtful system design. The chip is based on the ARM Cortex-M4F core, with a built-in floating-point operation unit (FPU) and a digital signal processing (DSP) instruction set. The FPU is crucial for quickly completing a large number of trigonometric function (such as tan) operations involved in the visual magnification formula; and the DSP capability helps to filter sensor data and implement complex closed-loop motor control algorithms. This module performs the following key tasks: In the automatic alignment stage, the feedback signal about the deviation of the crosshair from the laser module receiving end is received, the position and attitude deviation is calculated through the image contrast algorithm, and the corresponding control instruction is generated and sent to the motor control module to drive the multi-axis platform to perform compensation movement until the alignment is completed.

[0077] In the measurement stage, the motor control module is controlled to drive the driving motor 46, so that the first rotatable laser module 21 and the second rotatable laser module 22 can scan the target feature points.

[0078] Real-time angle data (α1, α2, β1, β2) from the angle encoder 45 angle value receiving module is received. The final calculation result is sent to the touch screen 39 control display module for display. The device supports two operation modes of full automation and manual to adapt to different testing requirements, such as rapid batch detection or special sample research and development debugging.

[0079] The general process of using the device for visual magnification detection is as follows, and the specific execution logic is as follows: Preparation stage: Place the device on the test platform and adjust it to be horizontal. Install the night vision device 10 to be tested on the multi-axis platform of the device.

[0080] Exit pupil distance setting: According to the specification book of the night vision device 10 to be tested, the distance between the eyepiece of the night vision device 10 and the first rotatable laser module 21 is automatically or manually adjusted by the system, so that it is exactly equal to the exit pupil distance of the product.

[0081] Automatic alignment: Start the automatic alignment program. The first rotatable laser module 21 emits horizontal laser, and the system detects the deviation of the laser cross and the crosshair inside the night vision device 10 through its receiving module, and automatically controls the movement of the multi-axis platform until the two are completely coincident.

[0082] Image view angle measurement: After alignment, the system automatically controls the first rotatable laser module 21 to rotate, so that it is respectively aligned with the upper and lower edges of the target displayed in the night vision device 10, and the two angle values α1 and α2 are automatically recorded by the angle encoder 45.

[0083] Target view angle measurement: The second rotatable laser module 22 is automatically controlled to rotate, so that it is respectively aligned with the upper and lower edges of the actual target, and the two angle values β1 and β2 are automatically recorded.

[0084] Calculation and display: The system automatically calculates the visual magnification according to the formula (where Δα = α1-α2, Δβ = β1-β2) and displays the result on the touch screen 39 in real time.

[0085] Please refer to Figure 8which is a software control flow chart of the device in automatic mode. The flow converts the above measurement steps into precise algorithm logic: Firstly, the execution step S810 performs the power-on step, turning on the power of the device and pressing the switch key. Then, the execution step S820 performs the zeroing step, the processor controls the multi-axis platform and the driving motor to move to the preset zero position. Next, the automatic alignment cycle is entered, and the execution step S830 performs the alignment detection step, the processor confirms whether the crosshair projected by the first rotatable laser module coincides with the reference point cross in the near-eye display device, and calculates the deviation. Subsequently, the execution step S840 performs the platform correction step, the processor controls the corresponding motor of the multi-axis platform to operate for correction according to the deviation result fed back by the step S830. Then, the execution step S850 performs the cycle judgment step, continuously detects whether the cross is coincided, if not, returns to the execution step S830 for fine adjustment; if yes, enters the next step. After the alignment is completed, the automatic measurement flow is started, and first, the execution step S861 drives the second rotatable laser module to rotate until the upper edge of the physical target is aligned, and reads and stores the angle value β1. Then, the execution step S862 drives the second rotatable laser module to rotate until the lower edge of the physical target is aligned, and reads and stores the angle value β2. Subsequently, the execution step S871 drives the first rotatable laser module to rotate until the upper edge of the virtual target is aligned, and reads and stores the angle value α1. Next, the execution step S872 drives the first rotatable laser module to rotate until the lower edge of the virtual target is aligned, and reads and stores the angle value α2. After all the angle values are obtained, the execution step S880 performs the calculation step, and the visual magnification is calculated according to the preset formula. Then, the execution step S890 performs the result display step, and the calculation result is output to the display module for display.

[0086] Please refer to Figure 9 which is a software control flow chart of the device in manual mode. The manual mode gives the operator higher flexibility, which is suitable for research and development, debugging or processing of non-standard samples that cannot be recognized by the automatic mode.

[0087] Firstly, the execution step S910 executes the mode switching step, the user selects to switch to the manual control mode through the touch screen. Then, the execution step S920 is executed. The initialization zeroing step is executed, and the processor zeros all the positions of the multi-axis platform and the angle encoder 45. Next, the execution step S930 is executed, the manual alignment step is executed, the user manually controls the position of the multi-axis platform through the user interface on the touch screen and observes through the eyepiece group until the center reference point of the near-eye display device and the cross emitted by the laser coincide, and then stops adjusting. Subsequently, the manual measurement phase is entered, and first, the execution steps S941 to S943 for recording the first angle value are executed. In the step S941, the user manually adjusts the upper edge of the second rotatable laser module to align with the physical target. In the step S942, it is judged whether the confirmation is pressed on the touch screen. If yes, the step S943 is executed to record the current angle value β1. If no, the step S944 is executed to prompt on the screen. Then, the execution steps S951 to S953 for recording the second angle value are executed. In the step S951, the user manually adjusts the lower edge of the second rotatable laser module to align with the physical target. In the step S952, it is judged whether the confirmation is pressed on the touch screen. If yes, the step S953 is executed to record the current angle value β2. If no, the step S944 is executed to prompt on the screen. The execution steps S961 to S963 for recording the third angle value are executed. In the step S961, the user manually adjusts the upper edge of the first rotatable laser module to align with the physical target. In the step S962, it is judged whether the confirmation is pressed on the touch screen. If yes, the step S963 is executed to record the current angle value α1. If no, the step S944 is executed to prompt on the screen. Then, the execution steps S971 to S973 for recording the first angle value are executed. In the step S971, the user manually adjusts the lower edge of the first rotatable laser module to align with the physical target. In the step S972, it is judged whether the confirmation is pressed on the touch screen. If yes, the step S973 is executed to record the current angle value α2. If no, the step S944 is executed to prompt on the screen. After all the angle values are obtained, the execution step S980 is executed to perform the calculation step, and the processor calculates the visual magnification according to the preset formula. Then, the execution step S990 is executed to perform the result display step, and the calculation result is output to the display module for display.

[0088] The user interface of the device is designed to be simple and intuitive, aiming to reduce the difficulty of operation. All interfaces are displayed on the touch screen. Referring to Figure 10 , the startup screen is a welcome interface or brand logo displayed when the device is started. Figure 11 It is a mode selection page. After starting, the main menu is entered, providing two touchable options of "automatic test" and "manual test". The user selects according to the needs. Figure 12Auto Test Page The interface displayed after entering the Auto Mode. During the test, status information such as "Testing..." may be displayed; after the test, the final calculated visual magnification value such as "Visual Magnification" will be displayed clearly. There is usually a "Return" button below, allowing the user to return to the Mode Selection Page. Figure 11

[0089] Figure 13 Manual Test Page The core interaction interface in Manual Mode. Figure 14 The pop-up dialog box when performing angle confirmation, containing "Confirm" and "Cancel" buttons. When the user manually aligns the laser to the target, clicking "Confirm" can lock and record the current angle. Figure 13 The main interface for manual test, in addition to displaying the recorded angle value and the final calculation result, it may also contain virtual joysticks or directional keys for controlling the movement of the platform and laser module. Figure 14

[0090] Compared with the prior art, the device for measuring the visual magnification of a near-eye display device provided by the embodiments of the present disclosure fundamentally eliminates the subjective error caused by manual judgment by adopting an alignment method based on the self-collimation principle of a total station, and integrating a high-precision angle encoder 45 and a driving motor 46 closed-loop control system in the device, thereby realizing accurate and repeatable measurement of the visual magnification. The automatic process, especially the automatic alignment and automatic angle reading functions, shortens the complex operation that originally takes several minutes or even longer for a professional to complete to within tens of seconds. The dual-channel measurement architecture avoids the movement and reconfiguration of the instrument, further accelerating the test pace, and is suitable for batch detection on the production line. The integrated one-piece design and intuitive graphical user interface greatly simplify the operation process. The operator does not need to have deep optical knowledge, and only needs to follow the screen prompts to perform simple sample clamping and mode selection, to complete high-precision test work. The device carrying platform can adapt to near-eye display devices of different structures and sizes. At the same time, automatic and manual test modes are provided, taking into account production efficiency and flexibility of research and development debugging, and can meet the needs of various application scenarios from the laboratory to the factory. The device can automatically complete calculation and display and record the results in digital form, avoiding errors that may be introduced by manual calculation, and providing objective and reliable data support for product quality control, performance evaluation and process improvement, thereby effectively promoting the overall development of near-eye display technology and the improvement of product quality.

[0091] Further, the present disclosure also provides a new method for measuring the visual magnification of a near-eye display device, referring to Figure 15 The method can include steps S1510 to S1550.

[0092] ​​In step S1510, the first rotatable laser module is controlled to rotate so as to direct its beam through the eyepiece of the near-eye display device.

[0093] In step S1520, a first angle difference corresponding to a virtual target observed through the near-eye display device is determined based on a rotation angle corresponding to the rotation of the first rotatable laser module measured by the angle encoder.

[0094] In step S1530, the second rotatable laser module is controlled to rotate so as to direct its beam to a physical target.

[0095] In step S1540, a second angle difference corresponding to the physical target is determined based on a rotation angle corresponding to the rotation of the second rotatable laser module measured by the angle encoder.

[0096] The virtual target is an image formed by observing the physical target through the near-eye display device.

[0097] In step S1550, the eye magnification is calculated based on the first angle difference and the second angle difference.

[0098] It should be noted that each of steps S1510 to S1550 has been described in detail in the above-described device for measuring the eye magnification of a near-eye display device, and will not be described here.

[0099] The present disclosure also provides a computer-readable storage medium storing at least one instruction for being executed by a processor to implement the method for measuring the eye magnification of a near-eye display device according to any of the above embodiments.

[0100] The present disclosure also provides a computer program product including computer instructions stored in a computer-readable storage medium; a processor of a computing device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to cause the computing device to perform the method for measuring the eye magnification of a near-eye display device according to any of the above embodiments.

[0101] Those skilled in the art should be aware that the functions described in the above one or more examples can be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. The computer-readable medium includes a computer storage medium and a communication medium, and the communication medium includes any medium that facilitates the transfer of a computer program from one place to another. The storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0102] It should be noted that the technical solutions disclosed in the present disclosure can be combined arbitrarily without conflict.

[0103] The above merely provides a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present disclosure, which should be covered in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. An apparatus for measuring the eye-relief of a near-eye display device, the apparatus comprising: comprising: a first rotatable laser module configured to direct its beam through an eyepiece of the near-eye display device; a second rotatable laser module configured to direct its beam to a physical target; an angle encoder coupled to the first and second rotatable laser modules to measure their rotation angles; and a processor in communication with the first and second rotatable laser modules and the angle encoder, wherein the processor is configured to: control the first rotatable laser module to rotate to obtain, with the angle encoder, a first angle difference corresponding to a virtual target viewed through the near-eye display device; control the second rotatable laser module to rotate to obtain, with the angle encoder, a second angle difference corresponding to the physical target, wherein the virtual target is an image formed by viewing the physical target through the near-eye display device; calculate, based on the first and second angle differences, a magnification of the near-eye display device.

2. The apparatus for measuring the eye-relief of a near-eye display device of claim 1, wherein, The apparatus further comprises: a multi-axis stage configured to adjust a position and an orientation of the near-eye display device along or around at least three axes.

3. The apparatus for measuring the eye-relief of a near-eye display device of claim 2, wherein, The processor is further configured to: control the multi-axis stage to automatically align an optical axis of the near-eye display device with an optical axis of the first rotatable laser module based on a detected positional deviation between a beam emitted by the first rotatable laser module and a reference point on the near-eye display device.

4. The apparatus for measuring the eye-relief of a near-eye display device of claim 1, wherein, The first angle difference comprises an angle between an upper edge and a lower edge of the virtual target; The second angle difference comprises an angle between an upper edge and a lower edge of the physical target corresponding to the upper and lower edges of the virtual target.

5. The apparatus for measuring the eye-relief of a near-eye display device of claim 1, wherein, The apparatus further comprises: a touch screen connected to the processor to receive user inputs to control movements of the first and second rotatable laser modules.

6. The apparatus for measuring the eye-relief of a near-eye display device of claim 1, wherein, The processor is further configured to: calculate the magnification of the near-eye display device by determining a ratio of a tangent of the first angle difference to a tangent of the second angle difference.

7. A method for measuring the eye-relief of a near-eye display device, characterized in that, comprising: controlling a first rotatable laser module to rotate to direct its beam through an eyepiece of the near-eye display device; determining, based on a rotation angle corresponding to a rotation of the first rotatable laser module measured by an angle encoder, a first angle difference corresponding to a virtual target viewed through the near-eye display device; controlling a second rotatable laser module to rotate to direct its beam to a physical target; determining, based on a rotation angle corresponding to a rotation of the second rotatable laser module measured by the angle encoder, a second angle difference corresponding to the physical target, wherein the virtual target is an image formed by viewing the physical target through the near-eye display device; calculating, based on the first and second angle differences, a magnification.

8. The method for measuring the eye-relief of a near-eye display device of claim 7, wherein, The method further comprises: controlling a position and an orientation of the near-eye display device based on a detected positional deviation between a beam emitted by the first rotatable laser module and a reference point on the near-eye display device.

9. The method for measuring the eye-relief of a near-eye display device of claim 7, wherein, the first angle difference comprises an angle between an upper edge and a lower edge of the virtual target; the second angle difference comprises an angle between an upper edge and a lower edge of the physical target corresponding to the upper edge and the lower edge of the virtual target.

10. The method for measuring the eye-relief of a near-eye display device of claim 7, wherein, The method further comprises: receiving, via a touch screen, a user input to control rotation of the first rotatable laser module and the second rotatable laser module in a manual control mode.

11. A computer storage medium, characterized in that The computer storage medium stores at least one instruction for execution by a processor to implement a method for measuring an eye-relay of a near-eye display device according to any one of claims 7 to 10.

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