Methods, apparatuses, and media for measuring eye-relief of near-eye display devices

Abstract

The present disclosure provides a method, device and medium for measuring the eye-relief of a near-eye display device. The first rotatable laser module in the device is used to direct its light beam through the eyepiece of the near-eye display device; the second rotatable laser module is used to direct its light beam to a physical target; the angle encoder is coupled with the first rotatable laser module and the second rotatable laser module to measure the rotation angle; the processor is in communication connection with the first rotatable laser module, the second rotatable laser module and the angle encoder, wherein the processor is used to control the rotation of the first rotatable laser module to obtain the first angle difference corresponding to the virtual target observed through the near-eye display device by using the angle encoder; control the rotation of the second rotatable laser module to obtain the second angle difference corresponding to the physical target by using the angle encoder, and calculate the eye-relief of the near-eye display device based on the first angle difference and the second angle difference.

Description

Technical Field

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

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

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

[0004] However, existing methods for measuring NED magnification have significant limitations. Many traditional methods rely heavily on operator judgment and manual adjustments. For example, the operator may need to observe through an eyepiece, manually align the reticle or target feature, and record the reading. This method is not only time-consuming and labor-intensive, but also prone to introducing significant measurement errors due to subjective differences between operators and operator fatigue, resulting in poor repeatability and reliability of the test results. Summary of the Invention

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

[0006] The technical solution disclosed herein is implemented as follows:

[0007] In a first aspect, this disclosure provides an apparatus for measuring the visual magnification of a near-eye display device, comprising:

[0008] A first rotatable laser module is configured to guide its beam through the eyepiece of the near-eye display device;

[0009] The second rotatable laser module is configured to guide its beam toward a physical target;

[0010] An angle encoder, coupled to the first rotatable laser module and the second rotatable laser module, measures their rotation angle; and

[0011] A processor is communicatively connected to the first rotatable laser module, the second rotatable laser module, and the angle encoder, wherein the processor is configured to perform the following operations:

[0012] The first rotatable laser module is controlled to rotate in order to obtain a first angular difference corresponding to a virtual target observed through the near-eye display device using the angle encoder;

[0013] The second rotatable laser module is controlled to rotate in order to obtain a second angle difference corresponding to the physical target using the angle encoder, wherein the virtual target is an image formed by observing the physical target through the near-eye display device;

[0014] The magnification of the near-eye display device is calculated based on the first angle difference and the second angle difference.

[0015] Secondly, this disclosure provides a method for measuring the visual magnification of a near-eye display device, comprising:

[0016] Control the rotation of the first rotatable laser module to guide its beam through the eyepiece of the near-eye display device;

[0017] Based on the rotation angle measured by the angle encoder, which corresponds to the rotation of the first rotatable laser module, a first angle difference corresponding to the virtual target observed through the near-eye display device is determined;

[0018] Control the rotation of the second rotatable laser module to guide its beam toward a physical target;

[0019] Based on the rotation angle measured by the angle encoder and corresponding to the rotation of the second rotatable laser module, a second angle difference corresponding to the physical target is determined; wherein, the virtual target is an image formed by observing the physical target through the near-eye display device;

[0020] The magnification is calculated based on the first angular difference and the second angular difference.

[0021] Thirdly, embodiments of this disclosure provide a computer storage medium storing at least one instruction, which is executed by a processor to implement the method for measuring the visual magnification of a near-eye display device as described in the second aspect.

[0022] This disclosure provides a method, apparatus, and medium for measuring the visual magnification of near-eye display devices. By employing dual laser modules for differential angle measurement, combined with a high-precision angle encoder and an automated control system, accurate, rapid, and repeatable measurement of visual magnification is achieved. Through the integration of a multi-axis adjustable platform, the apparatus can automatically and precisely align the device under test with the measurement system, greatly simplifying the operation process and reducing human error. The entire alignment and measurement process can be automatically controlled by a processor, significantly shortening the single-test time and making it suitable for high-throughput testing needs on production lines. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a method for testing using a total station according to an embodiment of this disclosure.

[0024] Figure 2 This is a schematic diagram illustrating the principle of a detection method using the device disclosed herein, as described in an embodiment of this disclosure.

[0025] Figure 3 This is an isometric side view of the detection device in an embodiment of this disclosure.

[0026] Figure 4 This is a front view of the detection device in an embodiment of this disclosure.

[0027] Figure 5 This is a top view of the detection device in an embodiment of this disclosure.

[0028] Figure 6 For the detection device in the embodiments of this disclosure along Figure 5 Cross-sectional view of line AA in the middle.

[0029] Figure 7 This is a hardware block diagram of the detection device in an embodiment of this disclosure.

[0030] Figure 8 This is a software flowchart of the detection device in automatic control mode in an embodiment of this disclosure.

[0031] Figure 9 This is a software flowchart of the detection device in manual control mode in an embodiment of this disclosure.

[0032] Figure 10 This is a schematic diagram of the boot screen of the user interface in an embodiment of this disclosure.

[0033] Figure 11 This is a schematic diagram of the test mode selection page of the user interface in an embodiment of this disclosure.

[0034] Figure 12 This is a schematic diagram of the automatic test page of the user interface in an embodiment of this disclosure.

[0035] Figure 13 This is a schematic diagram of the manual test confirmation page of the user interface in an embodiment of this disclosure.

[0036] Figure 14 This is a schematic diagram of the manual test results page of the user interface in an embodiment of this disclosure.

[0037] Figure 15 This is a flowchart of a method for measuring the visual magnification of a near-eye display device according to an embodiment of this disclosure. Detailed Implementation

[0038] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.

[0039] In the optical performance evaluation of near-eye display devices, visual magnification is a crucial indicator. It defines the ratio of the viewing angle of the image observed by the human eye through the device to the viewing angle when directly observing the same object, directly affecting the perceived image size and the degree of immersion. However, existing methods for detecting visual magnification in near-eye display devices have significant limitations. Traditional testing schemes rely primarily on manual observation and adjustment, which is not only cumbersome and time-consuming, but also highly susceptible to the influence of operator subjectivity, resulting in low accuracy and poor repeatability. This inefficient and unreliable testing method has become a major bottleneck restricting the R&D iteration and mass production quality control of near-eye display devices. Especially for consumer-grade AR / VR products that pursue the ultimate user experience, accurate and consistent visual magnification is fundamental to ensuring product quality. Therefore, the industry urgently needs a solution that can overcome the shortcomings of existing technologies and achieve automated, high-precision, and high-efficiency testing.

[0040] This disclosure provides a method for detecting the visual magnification of near-eye display devices based on a high-precision measuring instrument, a total station. This method utilizes the autocollimation function of the total station to solve the core problem of precise alignment between the optical systems of the testing system and the device under test, laying the foundation for high-precision measurement. This method serves as the theoretical basis and principle verification for the subsequent design of automated testing devices.

[0041] See Figure 1 It illustrates a detection scenario using the method of this embodiment. Taking a night vision device 10 as an example, the method specifically includes the following steps:

[0042] Step 1: Test system setup and initial alignment.

[0043] Two total stations (total station 11 and total station 12) are securely mounted on the plane of the optical testing platform. Through precise adjustments, ensure that the optical axes of both total stations are at the same horizontal level. This is a prerequisite for ensuring that all subsequent angle measurements are performed within the same reference plane.

[0044] Step 2: Install the device under test.

[0045] Install a pan-tilt unit with five-dimensional adjustment capabilities on the test platform. This unit should support at least the following adjustments: vertical (Z-axis translation), horizontal (Y-axis translation), pitch (rotation around the Y-axis), rotation (around the Z-axis), and roll (around the X-axis). Mount the near-eye display device under test (night vision device 10 in this embodiment) on this pan-tilt unit. Visually adjust the pan-tilt unit until the height of the central axis of the night vision device 10 is approximately equal to the height of the optical axis of the total station.

[0046] Step 3: First total station 11 reference calibration.

[0047] Turn on the first total station 11 and use its autocollimation function to accurately align it with the center line of the distant target. This step establishes an accurate measurement reference direction for the first total station 11.

[0048] Step 4: Adjust the optical axes of the night vision device 10 and the first total station 11 to be coaxial.

[0049] This step is the core and key of the entire method. First, a highly flat plane mirror 13 is placed close to the objective lens of the night vision device 10. Then, the first total station 11 is rotated 180 degrees so that it faces the night vision device 10. Utilizing the autocollimation function of the first total station 11 again, the beam emitted by the total station is reflected back to itself via the plane mirror 13. By finely adjusting the pan-tilt head in step 2, the attitude of the night vision device 10 is changed until the reflected beam received by the first total station 11 completely coincides with its own emitted beam. When this condition is met, it indicates that the surface of the plane mirror 13 is strictly perpendicular to the optical axis of the first total station 11, thus indirectly proving that the optical axis of the night vision device 10 and the optical axis of the first total station 11 are precisely aligned (parallel and collinear). This step cleverly transforms the complex problem of dual-optical-axis alignment into a zero-position finding process that can be adjusted in a closed loop through instrument feedback, greatly improving the accuracy and reliability of the alignment.

[0050] Step 5: Align the crosshair cursor.

[0051] 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 bring up the crosshair displayed inside. Fine-tune the pan-tilt head to move the night vision device 10 horizontally and vertically until the laser spot emitted by the first total station 11 is precisely projected onto 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 perfectly aligned in height.

[0052] Step 6: Second total station 12-base calibration.

[0053] Place the second total station 12 roughly parallel to the night vision device 10 support and turn it on. Similar to step 3, use its autocollimation function to align with the target centerline to establish a measurement reference for the second total station 12.

[0054] Step 7: Align the rotation centers of the second total station 12 and the night vision device 10.

[0055] The second total station 12 is rotated 90 degrees toward the night vision device 10, and then translated onto the test platform so that the laser spot it emits is precisely aligned with the rotation center of the night vision device 10 bracket. This alignment ensures that the measurement reference point is stable and correct when subsequently performing angle measurements by rotating the night vision device 10.

[0056] Step 8: System Co-calibration.

[0057] Simultaneously rotate the first total station 11 and the second total station 12 to check whether their laser beams can be precisely aligned in space. If they cannot be aligned, it indicates that there is still a slight alignment error in the system. In this case, steps 4 to 7 need to be repeated for fine-tuning until the two beams can overlap.

[0058] Step 9: Angle measurement.

[0059] After all alignments are completed, the first total station 11 is removed. 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.

[0060] Step 10: Calculate the apparent magnification.

[0061] Based on the measured angle value, the instrument's apparent magnification Γ is calculated using the following formula.

[0062]

[0063] Here, Δα and Δβ represent the visual angles of the top and bottom edges of an object as observed through a near-eye device, respectively. This formula, with a small angular approximation, is equivalent to the ratio of visual angles and accurately reflects the magnification capability of the device.

[0064] The method of this embodiment, through a series of optical alignment steps, especially by creatively utilizing the autocollimation function of the total station in conjunction with the plane mirror 13, achieves accurate measurement of the visual magnification of the near-eye display device, effectively overcoming the accuracy problem caused by alignment difficulties in the prior art.

[0065] To transform the measurement method into an efficient, convenient, and automated industrial inspection tool, embodiments of this disclosure further provide an apparatus for measuring the visual magnification of near-eye display devices. This apparatus integrates precision mechanics, servo control, laser measurement, and intelligent computing systems, aiming to significantly improve inspection efficiency and accuracy while reducing the professional skill requirements for operators.

[0066] The core of the apparatus and method disclosed herein lies in determining the visual magnification by precisely comparing two viewing angles. (Refer to...) Figure 2 The figure illustrates the principle of the detection method using the apparatus disclosed herein. The two perspectives are the perspective of the virtual target and the perspective of the physical target, respectively.

[0067] The perspective of a virtual target is the image presented by the internal optical system of a near-eye display device when viewed by an observer through the eyepiece; that is, the "virtual target" and the angle it appears to the observer.

[0068] The perspective of a physical target is the angle that an object appears to an observer when the observer directly observes a reference object in the real world, i.e., the "physical target".

[0069] The magnification is the ratio of the correlation function between these two viewing angles. This embodiment employs a dual-optical-path design to accurately measure these two viewing angles. Specifically, a beam emitted from a first rotatable laser module 21 passes through the eyepiece of a near-eye display device to simulate the human eye's observation and measurement of the viewing angle of a virtual target, thereby obtaining the first angular difference. Simultaneously, a beam emitted from a second rotatable laser module 22 is directly pointed at a distant physical target (target) to measure the physical target's true viewing angle, thereby obtaining the second angular difference.

[0070] The virtual target is the image formed by observing the physical target through a 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 being magnified by the optical system of the near-eye display device. In this way, the technical solution of this disclosure ensures the uniformity of the measurement benchmark and the rigor of the logic.

[0071] This embodiment details the hardware configuration of the detection device of this disclosure, which integrates mechanical, optical, and electronic components to achieve high-precision automated measurement. (Refer to...) Figures 3 to 7 , Figure 3This is an isometric side view. Figure 4 This is a front view of the device. Figure 5 This is a top view. Figure 6 This is a cross-sectional view along line AA.

[0072] The apparatus for measuring the visual magnification of a near-eye display device includes a first rotatable laser module 21, a second rotatable laser module 22, an angle encoder 45, and a processor.

[0073] The first rotatable laser module 21 and the second rotatable laser module 22 are the core measurement units of the device, both installed inside the housing 40. The first rotatable laser module 21 is configured to guide 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 guide its beam to a physical target to measure the viewing angle of the physical target. Both modules are driven by a drive motor 46 and are capable of precise rotation around their respective axes. To ensure smooth and accurate rotation, the axes are supported by self-lubricating bearings.

[0074] To accurately measure the rotation angle, the device is equipped with an angle encoder 45. This angle encoder 45 is coupled to the first rotatable laser module 21 and the second rotatable laser module 22. In this embodiment, a dual-chip high-precision angle encoder 45 is coupled to the rotation shaft of each laser module. One encoder is fixed to the rotation shaft and moves with it, while the other is fixed to the 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., the MT6620 chip), is insensitive to environmental factors such as dust and oil, thus ensuring long-term stability and high accuracy of the angle readings.

[0075] The processor is physically integrated onto the control board 47. This processor communicates with the first rotatable laser module 21, the second rotatable laser module 22, and the angle encoder 45. (See reference...) Figure 7 The hardware block diagram shows that the processor achieves coordinated control and data processing of the entire device through its various internal functional modules.

[0076] The device also includes a multi-axis platform. This platform is used to fix the near-eye display device under test and is configured to adjust the position and orientation of the near-eye display device along or around at least three axes.

[0077] The multi-axis platform can be composed of a series of precision motion components driven by servo motors. Specifically, it may include an electric lifting platform 31, an electric liftable / left-right movable gimbal 32, an electric tilting gimbal 33, an electric pitching platform 34, and an electric rotating platform 35. The multi-axis platform is connected to the outer casing 40 via a centering plate 36. Specifically:

[0078] The electric lifting platform 31 and the electric liftable / left-right movable gimbal 32 together provide translational movement along the Z-axis (vertical) and Y-axis (horizontal).

[0079] The electric tumble head 33, the electric pitch platform 34, and the electric rotation platform 35 provide rotational adjustment capabilities around the X-axis, Y-axis, and Z-axis, respectively.

[0080] This system constitutes a six-degree-of-freedom adjustment mechanism, capable of moving the near-eye display device to any position within the workspace and orienting it in any orientation. This design, especially its parallel kinematic structure, offers advantages in terms of high rigidity and stability, and allows for the precise rotation and alignment of the near-eye display device around its own optical center or exit pupil position via software-defined virtual rotation center, which is crucial for ensuring measurement accuracy.

[0081] In some examples, the processor is also configured to perform an automatic alignment operation. Specifically, based on the detected positional deviation between the beam emitted by the first rotatable laser module 21 and a reference point on the near-eye display device, 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.

[0082] The processor instructs the first rotatable laser module 21 to emit a beam of light (which may include a crosshair pattern) that passes through the eyepiece of the near-eye display device under test. Simultaneously, the near-eye display device itself displays a crosshair as a reference point. The image comparison module within the processor analyzes the positional deviation between the two crosshairs. If a deviation is detected, the processor calculates a correction amount and sends a command to the motor control module to drive the multi-axis platform to perform fine-tuning until the two crosshairs are perfectly aligned.

[0083] 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, which correspond to the upper and lower edges of the virtual target.

[0084] 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.

[0085] The device also includes a housing cover plate 37, a power interface 41, and a switch button 42 for device functions. Additionally, a self-lubricating bearing 44 may be included. The self-lubricating bearing 44 is typically made of self-lubricating plastic materials such as POM or PEEK. It is interference-fitted to the housing 40 and has a small clearance fit with the rotation shafts of the first rotatable laser module 21 and the second rotatable laser module 22, providing support and lubrication during rotation. A drive motor 46 is fixed to the housing 11, and its shaft is fixed to the rotation shafts of the first rotatable laser module 21 and the second rotatable laser module 22. Upon receiving a rotation command, the drive motor 46 rotates, driving the first rotatable laser module 21 and the second rotatable laser module 22 to rotate.

[0086] Please see Figure 7 This is a hardware block diagram of the device in this embodiment. The diagram clearly shows the various functional modules inside the control board 47 and the information flow between them. The control board 47 may include a power supply module 71, a switch module 72, a touch screen control and display module 73, an angle encoder angle value receiving module 74, a motor control module 75, and an image comparison and angle information calculation module 76.

[0087] The power module 71 is responsible for converting the externally input 220V AC mains power into a stable 12V DC power required by the system. In this embodiment, a high-efficiency step-down constant voltage chip such as the AH8665 can be used, whose highly integrated characteristics simplify the power supply design.

[0088] The switch module 72 receives physical signals from the power on / off button and controls the power supply of the entire system.

[0089] 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 the user's touch input events, converting them into control commands.

[0090] The angle encoder angle value receiving module 74 is used to receive real-time angle data from two high-precision angle encoders 45. In this embodiment, a Hall effect sensor chip such as the MT6620 can be used. This type of chip can acquire angle signals with extremely high resolution and speed, and transmit the data to the main processor through standard interfaces such as SPI.

[0091] The motor control module 75 receives instructions from the main processor to precisely control the rotation direction, speed, and position of the seven servo motors. In this embodiment, a highly integrated industrial-grade motor microcontroller such as the CH32M007G8R6 can be used. Its rich built-in peripherals and powerful driving capabilities enable it to efficiently manage multiple motors with a single chip solution.

[0092] The image comparison and angle information calculation module 76 can be handled by a high-performance microcontroller (MCU) or processor. It is used to execute all the core algorithms of this disclosure. In this embodiment, the N32G455 processor from National Technologies is selected, a choice reflecting a well-thought-out system design. This chip is based on the ARM Cortex-M4F core and integrates a floating-point unit (FPU) and a digital signal processing (DSP) instruction set. The FPU is crucial for quickly completing the numerous trigonometric function calculations (such as tan) involved in the magnification formula; while the DSP capabilities help filter sensor data and implement complex closed-loop motor control algorithms. This module performs the following key tasks:

[0093] During the automatic alignment phase, feedback signals regarding the deviation of the crosshair are received from the laser module receiver. The position and attitude deviations are calculated using an image comparison algorithm, and corresponding control commands are generated and sent to the motor control module to drive the multi-axis platform to perform compensating motion until alignment is completed.

[0094] During the measurement phase, the control motor module drives the drive motor 46, enabling the first rotatable laser module 21 to scan the target feature points with the second rotatable laser module 22.

[0095] The device receives real-time angle data (α1, α2, β1, β2) from the angle encoder's 45-degree angle value receiving module. The final calculation result is then sent to the touchscreen 39 for display. This device supports both fully automatic and manual operation modes to adapt to different testing needs, such as rapid batch testing or the research and development and debugging of special samples.

[0096] The general procedure for using the device to detect visual magnification is as follows, and the specific execution logic is as follows:

[0097] Preparation phase: Place the device on the test platform and adjust it to be level. Mount the night vision device 10 under test on the multi-axis platform of the device.

[0098] Exit pupil distance setting: According to the specifications of the night vision device 10 under test, the distance between the eyepiece of the night vision device 10 and the first rotatable laser module 21 is adjusted automatically or manually by the system to make it exactly equal to the product's exit pupil distance.

[0099] Automatic alignment: Initiate the automatic alignment program. The first rotatable laser module 21 emits a horizontal laser. The system detects the deviation between the laser crosshair and the crosshair cursor inside the night vision device 10 through its receiving module, and automatically controls the multi-axis platform to move until the two are completely aligned.

[0100] Image viewing angle measurement: After alignment, the system automatically controls the first rotatable laser module 21 to rotate so that it is aligned with the upper and lower edges of the target displayed in the night vision device 10, and the angle encoder 45 automatically records two angle values ​​α1 and α2.

[0101] Target viewing angle measurement: The second rotatable laser module 22 is automatically controlled to rotate so that it is aligned with the upper and lower edges of the actual target, and two angle values ​​β1 and β2 are automatically recorded.

[0102] Calculation and display: The system calculates and displays according to the formula. (Where Δα=α1-α2, Δβ=β1-β2) The magnification is automatically calculated and the result is displayed on the touch screen 39 in real time.

[0103] Please see Figure 8 This is a flowchart of the software control process for the device in automatic mode. This process translates the aforementioned measurement steps into precise algorithmic logic:

[0104] First, step S810 is executed to power on the device by pressing the power button. Then, step S820 is executed to zero the device, where the processor controls the multi-axis platform and drive motor to move to a preset zero position. Next, the automatic alignment cycle begins. Step S830 is executed to perform an alignment detection step, where the processor uses the detection results from the first rotatable laser module to confirm whether the projected crosshair coincides with the reference crosshair inside the near-eye display device and calculates the deviation. Then, step S840 is executed to perform a platform calibration step, where the processor controls the corresponding motors of the multi-axis platform to perform calibration based on the deviation feedback from step S830. Then, step S850 is executed to perform a loop judgment step, continuously checking whether the crosshairs coincide. If they do not coincide, the process returns to step S830 for fine-tuning; if they coincide, the process proceeds to the next step. After alignment, the automatic measurement process begins. Step S861 is executed to drive the second rotatable laser module to rotate until it aligns with the upper edge of the physical target and reads the stored angle value β1. Then, step S862 is executed, driving the second rotatable laser module to rotate until it is aligned with the lower edge of the physical target, and reading the stored angle value β2. Next, step S871 is executed, driving the first rotatable laser module to rotate until it is aligned with the upper edge of the virtual target, and reading the stored angle value α1. Then, step S872 is executed, driving the first rotatable laser module to rotate until it is aligned with the lower edge of the virtual target, and reading the stored angle value α2. After all angle values ​​are acquired, step S880 is executed to perform the calculation step, calculating the magnification according to a preset formula. Then, step S890 is executed to perform the result display step, outputting the calculation result to the display module for display.

[0105] Please see Figure 9This is a flowchart of the software control process for the device in manual mode. Manual mode provides operators with greater flexibility and is suitable for developing, debugging, or handling non-standard samples that cannot be recognized by automatic mode.

[0106] First, step S910 is executed to switch the mode; the user selects and switches to manual control mode via the touchscreen. Then, step S920 is executed to initialize and zero the multi-axis platform position and the angle encoder 45 position. Next, step S930 is executed to perform manual alignment; the user manually controls the position of the multi-axis platform via the user interface on the touchscreen and observes through the eyepiece group until the center reference point of the near-eye display device coincides with the crosshair of the laser emission, at which point adjustment stops. Following this, the manual measurement stage begins. Steps S941 to S943 are executed to record the first angle value. In step S941, the user manually adjusts the second rotatable laser module to align with the upper edge of the physical target. In step S942, it is determined whether a confirmation press is made on the touchscreen; if yes, step S943 is executed to record the current angle value β1; otherwise, step S944 is executed, and a screen prompt appears. Then, steps S951 to S953 are executed to record the second angle value. The user manually adjusts the second rotatable laser module to align with the lower edge of the physical target. In step S952, it is determined whether the touchscreen is pressed for confirmation. If yes, step S953 is executed to record the current angle value β2; otherwise, step S944 is executed, and a screen prompt is displayed. Steps S961 to S963 are executed to record the third angle value. In step S961, the user manually adjusts the first rotatable laser module to align with the upper edge of the physical target. In step S962, it is determined whether the touchscreen is pressed for confirmation. If yes, step S963 is executed, and the current angle value α1 is recorded; otherwise, step S944 is executed, and a screen prompt is displayed. Then, steps S971 to S973 are executed to record the first angle value. In step S971, the user manually adjusts the first rotatable laser module to align with the lower edge of the physical target. In step S972, it is determined whether the touchscreen is pressed for confirmation. If yes, step S973 is executed, and the current angle value α2 is recorded; otherwise, step S944 is executed, and a screen prompt is displayed. After all angle values ​​have been acquired, step S980 is executed to perform the calculation step, whereby the processor calculates the magnification according to a preset formula. Then, step S990 is executed to perform the result display step, outputting the calculation result to the display module for display.

[0107] The device's user interface is designed to be simple and intuitive, aiming to reduce the difficulty of operation. All interfaces are displayed on the touchscreen. (See reference) Figure 10 The boot screen, the welcome screen or brand logo displayed when the device starts up. Figure 11The mode selection page, which appears after powering on, leads to the main menu and offers two touch-sensitive options: "Automatic Test" and "Manual Test," allowing users to choose according to their needs. Figure 12 This is the automatic testing page, the interface displayed after entering automatic mode. During the test, status information such as "Testing..." may be displayed; after the test is completed, the final calculated magnification value will be clearly displayed, such as "Visual Magnification". There is usually a "Back" button at the bottom, allowing users to return to the previous screen. Figure 11 The mode selection page.

[0108] Figure 13 and Figure 14 This is the core interactive interface for manual testing, in manual mode. Figure 13 The example demonstrates a pop-up dialog box for angle confirmation, containing "Confirm" and "Cancel" buttons. After the user manually aligns the laser with the target, clicking "Confirm" locks and records the current angle. Figure 14 This is the main interface for manual testing. In addition to displaying the recorded angle values ​​and the final calculation results, it may also include a virtual joystick or directional keys for controlling the movement of the platform and laser module.

[0109] Compared with existing technologies, the apparatus for measuring the visual magnification of near-eye display devices provided in this disclosure eliminates subjective errors caused by manual judgment by employing an alignment method based on the autocollimation principle of a total station and integrating a high-precision angle encoder 45 and a drive motor 46 closed-loop control system within the device. This achieves accurate and repeatable measurement of visual magnification. The automated process, especially the automatic alignment and automatic angle reading functions, reduces complex operations that previously required several minutes or even longer for professionals to within tens of seconds. The dual-channel measurement architecture avoids instrument movement and reconfiguration, further accelerating the testing cycle and making it suitable for batch testing on production lines. The integrated design and intuitive graphical user interface greatly simplify the operation process. Operators do not need extensive optical knowledge; they can complete high-precision testing simply by following the on-screen prompts for sample clamping and mode selection. The device-under-test platform can adapt to near-eye display devices of different structures and sizes. It provides both automatic and manual testing modes, balancing production efficiency and R&D debugging flexibility, and can meet the needs of various application scenarios from the laboratory to the factory. The device can automatically complete calculations and display and record the results in digital form, avoiding errors that may be introduced by manual calculations. It provides objective and reliable data support for product quality control, performance evaluation and process improvement, thereby powerfully promoting the overall development of near-eye display technology and the improvement of product quality.

[0110] Furthermore, this disclosure also provides a new method for measuring the visual magnification of near-eye display devices, referring to... Figure 15The method may include steps S1510 to S1550.

[0111] In step S1510, the first rotatable laser module is controlled to rotate so as to guide its beam through the eyepiece of the near-eye display device.

[0112] In step S1520, a first angle difference corresponding to the virtual target observed through the near-eye display device is determined based on the rotation angle measured by the angle encoder that corresponds to the rotation of the first rotatable laser module.

[0113] In step S1530, the second rotatable laser module is controlled to rotate in order to guide its beam to a physical target.

[0114] In step S1540, a second angle difference corresponding to the physical target is determined based on the rotation angle measured by the angle encoder that corresponds to the rotation of the second rotatable laser module.

[0115] Virtual targets are images formed by observing physical targets through near-eye display devices.

[0116] In step S1550, the visual magnification is calculated based on the first angular difference and the second angular difference.

[0117] It should be noted that each step in steps S1510 to S1550 has been described in detail in the above-mentioned apparatus for measuring the visual magnification of near-eye display devices, and will not be repeated here.

[0118] This disclosure also provides a computer-readable storage medium storing at least one instruction, which is executed by a processor to implement the method for measuring the visual magnification of a near-eye display device as described in the various embodiments above.

[0119] This 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 executes the computer instructions, causing the computing device to perform the method for measuring the visual magnification of a near-eye display device as described in the various embodiments above.

[0120] Those skilled in the art will recognize that the functions described in this disclosure in one or more of the examples above can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0121] It should be noted that the technical solutions described in this disclosure can be combined arbitrarily as long as they do not conflict.

[0122] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A device for measuring the visual magnification of a near-eye display device, characterized in that, include: A first rotatable laser module is configured to guide its beam through the eyepiece of the near-eye display device; The second rotatable laser module is configured to guide its beam toward a physical target; An angle encoder is coupled to the first rotatable laser module and the second rotatable laser module to measure their rotation angle; as well as A processor is communicatively connected to the first rotatable laser module, the second rotatable laser module, and the angle encoder, wherein the processor is configured to perform the following operations: The first rotatable laser module is controlled to rotate in order to obtain a first angular difference corresponding to a virtual target observed through the near-eye display device using the angle encoder; The second rotatable laser module is controlled to rotate in order to obtain a second angle difference corresponding to the physical target using the angle encoder, wherein the virtual target is an image formed by observing the physical target through the near-eye display device; The magnification of the near-eye display device is calculated based on the first angle difference and the second angle difference.

2. The apparatus for measuring the visual magnification of a near-eye display device according to claim 1, characterized in that, The device further includes: A multi-axis platform configured to adjust the position and orientation of the near-eye display device along or around at least three axes.

3. The apparatus for measuring the visual magnification of a near-eye display device according to claim 2, characterized in that, The processor is also configured to: Based on the detected positional deviation between the beam emitted by the first rotatable laser module and a reference point on the near-eye display device, the multi-axis platform is controlled to automatically align the optical axis of the near-eye display device with the optical axis of the first rotatable laser module.

4. The apparatus for measuring the visual magnification of a near-eye display device according to claim 1, characterized in that, The first angle difference includes the angle between the upper and lower edges of the virtual target; The second angle difference includes the angle between the upper and lower edges of the physical target, which correspond to the upper and lower edges of the virtual target.

5. The apparatus for measuring the visual magnification of a near-eye display device according to claim 1, characterized in that, The device further includes: A touchscreen, connected to the processor, is used to receive user input to control the movement of the first rotatable laser module and the second rotatable laser module.

6. The apparatus for measuring the visual magnification of a near-eye display device according to claim 1, characterized in that, The processor is also configured as follows: The magnification of the near-eye display device is calculated by determining the ratio of the tangent of the first angle difference to the tangent of the second angle difference.

7. A method for measuring the visual magnification of a near-eye display device, characterized in that, include: Control the rotation of the first rotatable laser module to guide its beam through the eyepiece of the near-eye display device; Based on the rotation angle measured by the angle encoder, which corresponds to the rotation of the first rotatable laser module, a first angle difference corresponding to the virtual target observed through the near-eye display device is determined; Control the rotation of the second rotatable laser module to guide its beam toward a physical target; Based on the rotation angle measured by the angle encoder and corresponding to the rotation of the second rotatable laser module, a second angle difference corresponding to the physical target is determined; wherein, the virtual target is an image formed by observing the physical target through the near-eye display device; The magnification is calculated based on the first angular difference and the second angular difference.

8. The method for measuring the visual magnification of a near-eye display device according to claim 7, characterized in that, The method further includes: The position and orientation of the near-eye display device are controlled based on the detected positional deviation between the beam emitted by the first rotatable laser module and a reference point on the near-eye display device.

9. The method for measuring the visual magnification of a near-eye display device according to claim 7, characterized in that, The first angle difference includes the angle between the upper and lower edges of the virtual target; The second angle difference includes the angle between the upper and lower edges of the physical target, which correspond to the upper and lower edges of the virtual target.

10. The method for measuring the visual magnification of a near-eye display device according to claim 7, characterized in that, The method further includes: User input is received via a touchscreen to control the rotation of the first and second rotatable laser modules in manual control mode.

11. A computer storage medium, characterized in that, The computer storage medium stores at least one instruction, which is executed by a processor to implement the method for measuring the visual magnification of a near-eye display device as described in any one of claims 7 to 10.

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