System and method for testing rainbow stripes of holographic waveguide AR near-to-eye display device

Abstract

The invention discloses a holographic waveguide AR near-to-eye display device rainbow fringe test system and method, and belongs to the field of holographic waveguide rainbow fringe test. Different light environments are simulated and reconstructed on the other side of the observation position of the holographic waveguide lens, possible light environment characteristics of an AR glasses wearer are accurately and comprehensively restored, rainbow stripe pictures formed under different environment light conditions are respectively captured at the eye positions of the holographic waveguide AR display device, and the visual effect of the holographic waveguide AR display device is improved. Finally, the rainbow effect degrees of the holographic waveguide lens in different light environments can be obtained, the brightness of rainbow stripes is quantitatively represented, and the angle range of the rainbow stripes is calculated by adopting an irregular graph region area algorithm. According to the invention, rainbow stripes generated at the holographic waveguide out-coupling grating can be accurately measured, and design optimization of the out-coupling grating is supported.

Description

Technical Field

[0001] The present invention relates to the technical field of holographic waveguide rainbow stripe testing, and particularly to a testing system and method for rainbow stripes of a holographic waveguide AR near-eye display device. Background Art

[0002] At present, the holographic waveguide AR near-eye display technology has received extensive attention from researchers because it can provide display effects of ultra-thinness, high display brightness, high resolution, and wide viewing angle. Due to the dispersion effect of the out-coupling holographic grating of the holographic waveguide AR display, when ambient light on the same side or the opposite side of the human eye is incident on the holographic grating in the out-coupling region, rainbow stripes will be generated within the viewing range of the human eye. Therefore, rainbow effects are currently common in holographic waveguide AR glasses, which will affect the observer's normal viewing of the display screen.

[0003] Regarding the testing standards and methods for AR / VR near-eye display devices, in-depth research has also been carried out synchronously. At present, the IEC International Standards Organization has officially released IEC 63145-20-10, which details the testing methods for the optical parameters of eye-worn display devices. In China, relevant industry or group testing standards for near-eye displays have also been formulated, such as "T / CARA0004—2022 Testing Method for Optical Display Performance of Near-Eye Display Devices" released by the Augmented Reality Core Technology Industry Alliance, and "T / CSMT-DZ 004.1-2023 Near-Eye Display Devices Part 1: Testing and Evaluation Method for Optical Performance" released by the Chinese Society for Measurement and Testing, etc. However, these near-eye display testing standards do not stipulate how to test and characterize rainbow stripes.

[0004] In related technologies, a detection system and method for optical waveguide rainbow stripes are provided. This method is to emit optical signals to an optical waveguide device, collect rainbow stripes through a rainbow stripe collection device (such as an integrating sphere), and detect the optical parameters of the rainbow stripes, so as to achieve a quantitative evaluation of the strength of the rainbow stripe effect. This patent only simply analyzes the light intensity of rainbow stripes in a certain area, and cannot obtain the position of rainbow stripes, the brightness at a certain point, the size or chromaticity information of rainbow stripes.

[0005] At the same time, another related technology provides a detection system and method for diffraction optical waveguide rainbow stripes. Through a rainbow stripe image detection component, the rainbow stripe images under illumination at different longitudes or latitudes are analyzed, and multi-dimensional information such as the area size, position of the area, and brightness of the diffraction optical waveguide rainbow stripes can be objectively measured. However, the light source of this system only simulates the rising and setting of the sun, and cannot adjust the optical characteristics of the light source (such as light source shape, color, outgoing light angle, etc.). At the same time, it cannot quantitatively evaluate the strength and discomfort of rainbow stripes under the subjective perception of the human eye, and cannot meet the current analysis requirements.

[0006] Therefore, it is necessary not only to measure the objective parameters of the holographic waveguide rainbow pattern, such as the area size, the position of the region, and the brightness, under different ambient light conditions, but also to quantitatively evaluate the subjective parameters of the human eye's perception of the strength and discomfort of the rainbow pattern under different light environments, so as to comprehensively reflect the display situation of the rainbow pattern. This is important for those skilled in the art and an urgent problem to be solved. Summary of the Invention

[0007] The present invention provides a test system and method for rainbow stripes of a holographic waveguide AR near-eye display device, which can overcome the problem of being unable to test the optical parameters of the holographic waveguide rainbow pattern under different ambient light conditions, and can quantitatively evaluate the subjective perception degrees such as the subjective strength and discomfort of the rainbow pattern under different light environments, so as to help the grating designers optimize the coupling grating design and better solve the problem of the rainbow stripes of the holographic waveguide.

[0008] The first aspect embodiment of the present invention provides a test system for rainbow stripes of a holographic waveguide AR near-eye display device, including: a light source assembly, a holographic waveguide, a rainbow stripe image acquisition assembly, a rainbow stripe detection assembly, and a structure bearing assembly;

[0009] The light source assembly is used to emit light rays with different shapes, emission angle ranges, color temperatures, and brightnesses towards the out-coupling region of the holographic waveguide;

[0010] The holographic waveguide is fixed by a holographic waveguide clamping assembly, and the pitch angle and azimuth angle of the holographic waveguide are arbitrarily adjusted;

[0011] The rainbow stripe image acquisition assembly is arranged at the eye point position of the holographic waveguide, and is used to collect the holographic waveguide rainbow stripe image and transmit the collected rainbow stripe image to the rainbow stripe detection assembly, so that the rainbow stripe detection assembly processes the rainbow stripe image to obtain the rainbow effect degree of the holographic waveguide lens under different light environments, quantitatively characterize the brightness of the rainbow stripe, and calculate the angular range of the rainbow stripe by using an irregular graphic area algorithm;

[0012] The structure bearing assembly is used to adjust the relative position and angle between the holographic waveguide and the light source assembly, and at the same time is used to fix the rainbow stripe image acquisition assembly at the eye point position of the holographic waveguide.

[0013] Optionally, in an embodiment of the present invention, the light source assembly includes a light source and an optical lens group;

[0014] The light source includes a point light source, a strip light source, and a surface light source;

[0015] The optical lens group is used for zooming in on light. The LED bead array of the light source is controlled by the FPGA circuit driving panel to switch the shape of the light source to a dot shape, a surface shape, or a strip shape. The divergence angle of the light emitted by the light source is controlled within the range of 0 degrees to 60 degrees by the zoom optical lens group.

[0016] Optionally, in an embodiment of the present invention, the rainbow stripe detection component includes an objective evaluation module and a subjective evaluation module. The objective evaluation module reads the collected holographic waveguide rainbow stripe image by using the imread function, converts it into a grayscale image, and then converts the grayscale image into a binary image by using a thresholding method. The subjective evaluation module is used to collect and count the subjective feeling scores of observers corresponding to multiple test holographic waveguide rainbow stripe images under different ambient light conditions, and calculates the comprehensive score under different ambient light conditions by using a weighted average function.

[0017] Optionally, in an embodiment of the present invention, in the objective evaluation module, the pixel values in the holographic waveguide rainbow stripe image are converted to 0 or 1 by using the imbinarize function, and the area, brightness, and contrast of the rainbow stripes are adjusted by controlling the threshold.

[0018] Optionally, in an embodiment of the present invention, in the objective evaluation module, the bwboundaries function is used to calculate the boundaries of irregular shapes in the binary image, and the coordinates of the boundary pixels of the rainbow stripes are returned for calculating the perimeter and area of the rainbow stripe shape.

[0019] Optionally, in an embodiment of the present invention, the structure bearing component is further used to control the light source component to translate away from or close to the holographic waveguide at any azimuth angle or pitch angle.

[0020] An embodiment of the second aspect of the present invention provides a method for testing rainbow stripes of a holographic waveguide AR near-eye display device, which is used for the testing system of the rainbow stripes of the holographic waveguide AR near-eye display device described in the above embodiment, and includes the following steps:

[0021] Emit light with different shapes, exit angle ranges, color temperatures, and brightnesses towards the out-coupling area of the holographic waveguide;

[0022] Collect the holographic waveguide rainbow stripe image at the eye point position of the holographic waveguide, process the rainbow stripe image, obtain the rainbow effect degree of the holographic waveguide lens in different light environments, quantitatively characterize the brightness of the rainbow stripes, and calculate the angular range of the rainbow stripes by using an irregular graphic area algorithm.

[0023] Compared with the prior art, the present invention adopts the above technical solutions and has the following technical effects:

[0024] The test system and method for rainbow fringes of a holographic waveguide near-eye display device provided by the present invention can accurately test and evaluate the intensity of rainbow fringes under different lighting conditions and test pictures from both subjective and objective dimensions. Specifically, objectively, the optical parameters of holographic waveguide rainbow fringes under different ambient light conditions can be measured (such as brightness, the area of the rainbow fringe occupying the human eye viewing angle range, specific position, color coordinates, exit pupil size, etc.); subjectively, the subjective intensity, discomfort, and other subjective perception degrees of rainbow fringes under different light environments can also be quantitatively evaluated. Therefore, the present invention truly and comprehensively simulates various light environment situations when a user wears a holographic waveguide near-eye display device, reflects the rainbow fringe conditions under light environments with different parameters from both subjective and objective dimensions, so as to obtain multi-dimensional information such as the objective brightness, area, color coordinates, subjective brightness, and the degree of human eye discomfort of holographic waveguide rainbow fringes, providing a technical reference for those skilled in the art when designing grating parameters; through the present invention, the display image quality and product qualified inspection efficiency of holographic waveguide devices can be further improved, which has extremely high economic value.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0027] Figure 1 It is a structural diagram of a test system for rainbow fringes of a holographic waveguide AR near-eye display device according to an embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of the light source component of the test system according to an embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of the method for calculating the perimeter and area of rainbow fringes according to an embodiment of the present invention;

[0030] Figure 4 It is a flowchart for evaluating the objective and subjective optical parameters of rainbow fringes according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0032] Figure 1It is a structural diagram of a test system for rainbow fringes of a holographic waveguide AR near-eye display device provided according to an embodiment of the present invention.

[0033] As Figure 1 shown, the test system for rainbow fringes of the holographic waveguide AR near-eye display device includes: a light source assembly 101, a holographic waveguide 2, a rainbow fringe image acquisition assembly 103, a rainbow fringe detection assembly 104, and a structure bearing assembly 105;

[0034] The light source assembly 101 is used to emit light with different shapes, emission angle ranges, color temperatures, and brightnesses towards the out-coupling region of the holographic waveguide;

[0035] The holographic waveguide 2 is fixed by a holographic waveguide clamping assembly 102, and the pitch angle and azimuth angle of the holographic waveguide 2 can be adjusted arbitrarily;

[0036] The rainbow fringe image acquisition assembly 103 is arranged at the eye point position of the holographic waveguide 2, and is used to collect the holographic waveguide rainbow fringe image and transmit the collected rainbow fringe image to the rainbow fringe detection assembly 104, so that the rainbow fringe detection assembly 104 processes the rainbow fringe image to obtain the degree of rainbow effect of the holographic waveguide lens in different light environments, quantitatively characterize the brightness of the rainbow fringes, and calculate the angular range of the rainbow fringes by using the irregular graphic area algorithm;

[0037] The structure bearing assembly 105 is used to adjust the relative position and angle between the holographic waveguide and the light source assembly, and at the same time is used to fix the rainbow fringe image acquisition assembly at the eye point position of the holographic waveguide, and can control the light source assembly to smoothly translate away from or close to the holographic waveguide assembly along any azimuth angle or pitch angle.

[0038] In an embodiment of the present invention, the rainbow fringe image acquisition assembly 103 can be a camera.

[0039] In an embodiment of the present invention, the light source assembly 101 includes a light source 1 and an optical lens group; the light source 1 includes a point light source, a strip light source, and a surface light source. The optical lens group is used to zoom the light.

[0040] The light source 1 in the light source assembly 101 is configured to face the other side of the out-coupling grating observation eye point of the holographic waveguide, and is used to output light with different shapes, emission angle ranges, color temperatures, and brightnesses.

[0041] The light source is an m×n LED lamp bead array, and the brightness of each LED lamp bead can be controlled by an FPGA circuit driving panel. The light emission direction of the light source is towards the out-coupling region of the holographic waveguide, and the light source can be switched to a dot shape, a surface shape, a strip shape or other shapes, etc. The brightness of the light source, the RGB flux ratio (color temperature, color coordinates) can be set arbitrarily, and the divergence angle of the light emitted by the light source is controlled within the range of 0 degrees to 60 degrees by a zoom optical lens group.

[0042] The holographic waveguide clamping assembly 102 is used to fix the holographic waveguide 2, and can flip the holographic waveguide 2 up and down and rotate it left and right, realizing arbitrary adjustment of the pitch angle and azimuth angle. The rotation angle and flipping angle can be accurate to within 0.1 degrees.

[0043] The rainbow stripe image acquisition component 103 is located at the position of the out-coupling grating observation eye point of the holographic waveguide. When the holographic waveguide 2 rotates or flips, the relative angle and position between the rainbow stripe image acquisition component 103 and the holographic waveguide 2 remain unchanged, and only the relative position relationship with the light source 1 is changed.

[0044] In some embodiments, as Figure 2 shown, the light source assembly 101 includes a light source 1 and an optical lens group. The light source 1 is installed on the structural bearing assembly 105. The structural bearing assembly 105 includes two guide rails. The included angle between the guide rails can be adjusted within the range of 0 degrees to 180 degrees, and the adjustment accuracy is 0.1 degrees. The light source is fixed to the guide rails through fixing parts, and the light source can slide along these two guide rails relative to the out-coupling grating area of the holographic waveguide, changing the relative distances in the horizontal and vertical directions between the light source assembly and the holographic waveguide, realizing that the light source approaches or moves away from the holographic waveguide lens in any direction. The light source assembly is composed of a light source and an optical lens group. The light source includes an m×n LED lamp bead array, and the brightness of each LED lamp bead can be controlled through the FPGA circuit driving panel. The light emitting direction of the light source is towards the out-coupling area of the holographic waveguide, and the light source can be a point light source, a strip light source, a surface light source, etc. The brightness, RGB flux ratio (color temperature, color coordinates) of the light source can be arbitrarily set to output light with different shapes, emission angle ranges, color temperatures, and brightnesses.

[0045] The rainbow stripe image acquisition component 103 of the present invention can obtain rainbow stripe multi-dimensional image information corresponding to different light environments, including but not limited to the color temperature, brightness, area, color coordinate distribution, two-dimensional brightness distribution, and azimuth angle of the rainbow stripes.

[0046] The rainbow stripe detection component 104 is divided into an objective evaluation module and a subjective evaluation module. As Figure 3 shown, the objective evaluation module reads the collected rainbow stripe image with the imread function, converts it into a grayscale image, and then converts the grayscale image into a binary image by the thresholding method; the subjective evaluation module is used to collect and statistically analyze the subjective feeling scores of observers corresponding to multiple test holographic waveguide rainbow stripe images under different ambient light conditions, and calculates the comprehensive score under different ambient light conditions by using a weighted average function.

[0047] Specifically, the imbinarize function is used to convert the pixel values in the image into 0 or 1, and the area, brightness, and contrast of the rainbow stripes are adjusted by controlling the threshold.

[0048] Specifically, the bwboundaries function is used to calculate the boundaries of irregular shapes in a binary image. This function will return the coordinates of the boundary pixels of the rainbow stripe, which can be used to calculate the perimeter and area of the rainbow stripe shape.

[0049] As Figure 4 shown, the rainbow stripe image detection component 103 obtains different rainbow stripe images and analyzes information such as the brightness, area, and image region position of different rainbow stripes in the image based on this image.

[0050] Specifically, the subjective evaluation module generates 10 test pictures. Analyze the influence degree of rainbow stripes under different ambient light conditions on the viewing comfort of observers, and let the observers score, with the scoring range being 1 - 10 points; the subjective evaluation module collects and statistics the subjective feeling scores of the observers corresponding to the 10 test pictures under different ambient light conditions, and uses a weighted average function to calculate the comprehensive score under different ambient light conditions.

[0051] The test system for rainbow stripes of the holographic waveguide near-eye display device of the present invention gives priority to considering the rainbow stripe effect of the holographic waveguide under different light environments and the influence on viewing comfort, overcomes the problem in the prior art that only the analysis of the objective physical parameters of rainbow stripes under a single light source can be achieved. By adjusting the relative position relationship between the holographic waveguide and different types of light sources, and simultaneously adjusting optical parameters such as the brightness, color temperature, and light emission angle range of the light source, as well as the azimuth angle and rotation angle between the light source and the holographic waveguide to simulate different light environments, comprehensively reflect the rainbow stripe phenomenon under different light environments from multiple dimensions, so as to obtain multi-dimensional information such as the brightness, area, color coordinate distribution, and brightness distribution of the holographic waveguide rainbow stripes. At the same time, the present invention collects the subjective feelings of observers' viewing comfort through the subjective evaluation module, so as to obtain the influence of the holographic waveguide on the viewing comfort of observers under different light environments. The above can provide a technical reference for those skilled in the art to optimize the grating parameters.

[0052] Next, describe the test method for rainbow stripes of the holographic waveguide AR near-eye display device proposed in the embodiment of the present invention.

[0053] The test method for rainbow stripes of the holographic waveguide AR near-eye display device includes the following steps:

[0054] Emit light with different shapes, emission angle ranges, color temperatures, and brightnesses towards the out-coupling region of the holographic waveguide;

[0055] Collect the holographic waveguide rainbow stripe image at the eye point position of the holographic waveguide, process the rainbow stripe image, obtain the degree of rainbow effect of the holographic waveguide lens under different light environments, quantitatively characterize the brightness of the rainbow stripe, and calculate the angle range of the rainbow stripe using the irregular graphic area algorithm.

[0056] It should be noted that the foregoing explanatory description of the test system embodiment for the rainbow fringes of the holographic waveguide AR near-eye display device is also applicable to the test method for the rainbow fringes of the holographic waveguide AR near-eye display device of this embodiment, and will not be elaborated here.

[0057] The test method for the rainbow fringes of the holographic waveguide near-eye display device of the present invention simulates and reconstructs different light environments on the other side of the observation position of the holographic waveguide lens, accurately and comprehensively restoring the possible light environment characteristics of the AR glasses wearer. At the eye position of the holographic waveguide AR display device, the rainbow fringe images formed under different ambient light conditions are captured respectively. Finally, the degree of the rainbow effect of the holographic waveguide lens under different light environments can be obtained, quantitatively characterizing the brightness of the rainbow fringes, and the angular range of the rainbow fringes is calculated using the irregular graphic area algorithm. The present invention can accurately measure the rainbow fringes generated at the output coupling grating of the holographic waveguide, supporting the design optimization of the output coupling grating.

[0058] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or N embodiments or examples. In addition, without conflict, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0059] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0060] Any process or method description shown in the flowchart or described in other ways herein can be understood as representing a module, segment, or part of the code including one or N executable instructions for implementing a customized logical function or process. The scope of the preferred embodiments of the present invention includes additional implementations, where the functions can be executed in a substantially simultaneous manner or in a reverse order according to the involved functions, rather than in the order shown or discussed, which should be understood by those skilled in the art of the embodiments of the present invention.

Claims

1. A test system for rainbow fringes of a holographic waveguide AR near-eye display device, characterized in that Including: A light source component, a holographic waveguide, a rainbow stripe image acquisition component, a rainbow stripe detection component, and a structural support component; The light source component is used to emit light rays of different shapes, exit angle ranges, color temperatures, and brightnesses towards the out-coupling region of the holographic waveguide; The holographic waveguide is fixed by a holographic waveguide clamping component, and the pitch angle and azimuth angle of the holographic waveguide can be adjusted arbitrarily; The rainbow stripe image acquisition component is arranged at the eye point position of the holographic waveguide, and is used to collect the holographic waveguide rainbow stripe image and transmit the collected rainbow stripe image to the rainbow stripe detection component, so that the rainbow stripe detection component processes the rainbow stripe image to obtain the rainbow effect degree of the holographic waveguide lens in different light environments, quantitatively characterize the brightness of the rainbow stripe, and calculate the angle range of the rainbow stripe by using an irregular graphic area algorithm; The structural support component is used to adjust the relative position and angle between the holographic waveguide and the light source component, and at the same time is used to fix the rainbow stripe image acquisition component at the eye point position of the holographic waveguide.

2. The system according to claim 1, wherein The light source component includes a light source and an optical lens group; The light source includes a point light source, a strip light source, and a surface light source; The optical lens group is used to zoom the light rays.

3. The system according to claim 2, wherein The LED lamp bead array of the light source is controlled by an FPGA circuit driving panel to switch the shape of the light source to a dot shape, a surface shape, and a strip shape, and the divergence angle of the light rays emitted by the light source is controlled within the range of 0 degrees to 60 degrees by a zoom optical lens group.

4. The system according to claim 1, wherein The rainbow stripe detection component includes an objective evaluation module and a subjective evaluation module. The objective evaluation module uses the imread function to read the collected holographic waveguide rainbow stripe image and converts it into a grayscale image, and then uses a thresholding method to convert the grayscale image into a binary image; the subjective evaluation module is used to collect and count the subjective feeling scores of observers corresponding to multiple test holographic waveguide rainbow stripe images under different ambient light conditions, and calculates the comprehensive score under different ambient light conditions by using a weighted average function.

5. The system according to claim 4, wherein In the objective evaluation module, the imbinarize function is used to convert the pixel values in the holographic waveguide rainbow stripe image into 0 or 1, and the area, brightness, and contrast of the rainbow stripe are adjusted by controlling the threshold.

6. The system according to claim 5, wherein In the objective evaluation module, the bwboundaries function is used to calculate the boundary of the irregular shape in the binary image, and the coordinates of the boundary pixels of the rainbow stripe are returned for calculating the perimeter and area of the rainbow stripe shape.

7. The system according to claim 1, wherein The structural support component is further used to control the light source component to translate away from or close to the holographic waveguide along an arbitrary azimuth angle or pitch angle.

8. A testing method for rainbow fringes of a holographic waveguide AR near-eye display device, which is used for the testing system of rainbow fringes of the holographic waveguide AR near-eye display device according to any one of claims 1-7, characterized in that, The test method includes the following steps: Emitting light rays of different shapes, exit angle ranges, color temperatures, and brightnesses towards the out-coupling region of the holographic waveguide; Collecting the holographic waveguide rainbow stripe image at the eye point position of the holographic waveguide, processing the rainbow stripe image to obtain the rainbow effect degree of the holographic waveguide lens in different light environments, quantitatively characterizing the brightness of the rainbow stripe, and calculating the angle range of the rainbow stripe by using an irregular graphic area algorithm.

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