Glass edge stress detector, measurement method and computer storage medium and device

Abstract

The application discloses a glass edge stress detector, which comprises an illumination unit, a detection unit and a detection opening arranged between the two. The illumination unit comprises a light source and a polarizer, and the polarization direction of the polarizer is at an angle of about 45 degrees with the X and Y axes which are perpendicular to the optical axis and orthogonal to each other; the detection unit comprises a photo wedge and a polarimeter arranged in sequence along the optical path, the phase difference introduced by the photo wedge varies along the X axis and is constant along the Y axis, and the polarimeter has the same or orthogonal polarization direction as the polarizer; the detection opening is used for receiving the edge of the glass to be detected in a direction substantially perpendicular to the optical axis, and the edge of the glass to be detected is positioned in parallel to the X axis direction. The application also discloses a glass edge stress calculation method and corresponding computer storage medium and computer equipment. According to the application, convenient and accurate detection can be realized for the glass edge stress.

Description

Technical Field

[0001] This invention relates to optical inspection technology, and more specifically, to a glass edge stress detector, a glass edge stress calculation method, a computer storage medium, and a computer device. Background Technology

[0002] Glass is a common material in daily life and industrial production. During the forming and subsequent processing of glass, stress is generated due to bending, uneven cooling, and other factors. Because of the birefringence property of glass, the stress state at the glass edges can be calculated by measuring the optical path difference of polarized light. A glass stress detector is an optical testing device that detects surface stress by detecting the birefringence phenomenon on the glass surface. Currently, relatively mature glass surface stress detectors are available on the market.

[0003] However, there is currently no suitable testing device for stress detection at the edges of glass. During the forming and processing of glass, compressive stress is typically generated at the edges, and tensile stress is generated near the edges; the stress varies with location. As tensile stress increases, the glass strength decreases, and the risk of spontaneous breakage increases. Therefore, it is necessary to detect and control the stress at the glass edges to improve strength and reduce the risk of spontaneous breakage.

[0004] Currently, there is an urgent need for a stress detection technology suitable for detecting stress at the edges of glass. Summary of the Invention

[0005] The purpose of this invention is to provide a glass edge stress detector, a glass edge stress calculation method, a computer storage medium, and a computer device, which can at least partially overcome the deficiencies in the prior art.

[0006] According to one aspect of the present invention, a glass edge stress detector is provided, comprising:

[0007] An illumination unit includes a light source and a polarizer, the polarizer receiving light from the light source and making it linearly polarized, wherein the polarization direction of the polarizer forms an angle of approximately 45° with the X-axis and Y-axis, which are perpendicular to the optical axis and orthogonal to each other.

[0008] A detection unit includes an optical wedge and a polarizer arranged sequentially along the optical path. The optical wedge is configured such that the phase difference it introduces varies along the X-axis and remains constant along the Y-axis. The polarizer has a polarization direction that is the same as or orthogonal to the polarizer.

[0009] A detection opening is formed between the illumination unit and the detection unit for receiving the edge of the glass to be tested in a direction substantially perpendicular to the optical axis, such that the edge of the glass to be tested is positioned parallel to the X-axis direction.

[0010] Preferably, the lighting unit further includes a light-diffusing plate disposed between the light source and the polarizer.

[0011] Preferably, a positioning block is provided on one side of the detection opening, and the positioning block has a positioning surface perpendicular to the Y-axis for the edge of the glass to be tested to abut against.

[0012] Preferably, the detection opening has a flat shape perpendicular to the optical axis.

[0013] The glass edge stress detector may further include a housing, preferably an upper housing and a lower housing arranged opposite each other, the illumination unit is disposed in the lower housing, the detection unit is disposed in the upper housing, and the detection opening is formed between the upper housing and the lower housing.

[0014] Preferably, the upper housing and the lower housing are connected to each other on one side of the detection opening, and a positioning block is provided on the side of the detection opening. The positioning block has a positioning surface perpendicular to the Y-axis for the edge of the glass to be tested to abut against.

[0015] Preferably, at least one of the bottom surface of the upper housing and the top surface of the lower housing is formed as a plane perpendicular to the optical axis.

[0016] Preferably, the glass edge stress detector further includes an observation device disposed downstream of the detection unit for observing interference fringes formed by the detection unit.

[0017] Preferably, the glass edge stress detector further includes a filter, which is disposed between the light source and the observation device.

[0018] Preferably, the glass edge stress detector further includes a filter switching device for moving the filter to switch between a first position in the optical path and a second position away from the optical path.

[0019] Preferably, the glass edge stress detector further includes a housing, which comprises an upper housing and a lower housing arranged opposite each other. The illumination unit is disposed in the lower housing, and the detection unit and the observation device are disposed in the upper housing. The detection opening is formed between the upper housing and the lower housing.

[0020] Preferably, the observation device includes an image acquisition device that acquires an image of the interference fringes formed by the detection unit.

[0021] Preferably, the glass edge stress detector further includes a calculation unit that calculates the stress at the edge of the glass to be tested based on the image, wherein the calculation unit is configured to perform the following processing:

[0022] (1) Acquire a first image and a second image, wherein the first image and the second image are interference fringe images acquired when a first specified optical path difference and a second specified optical path difference are introduced in the detection opening, respectively;

[0023] (2) Obtain a third image, wherein the third image is an interference fringe image obtained when the edge of the glass to be tested is inserted into the detection opening;

[0024] (3) Identify stripes of corresponding order in the first image, the second image, and the third image, and determine the X-axis positions of points with the same Y-axis position on the stripes in the first image, the second image, and the third image; and

[0025] (4) Based on the X-axis position of the stripes with corresponding order in the first image, the second image and the third image, calculate the stress value of the edge of the glass to be detected corresponding to the Y-axis position.

[0026] According to another aspect of the present invention, a method for calculating glass edge stress is provided, comprising:

[0027] (1) Acquire a first image and a second image. The first image and the second image are interference fringe images obtained by using the glass edge stress detector described above to introduce a first specified optical path difference and a second specified optical path difference in the detection opening, respectively. The first specified optical path difference and the second specified optical path difference are not equal.

[0028] (2) Obtain a third image, which is an interference fringe image obtained by inserting the edge of the glass to be tested into the detection opening using the glass edge stress detector;

[0029] (3) Identify stripes of corresponding order in the first, second, and third images, and determine the X-axis positions of points with the same Y-axis position on the stripes in the first, second, and third images; and

[0030] (4) Based on the X-axis position of the stripes with corresponding order in the first image, second image and third image, calculate the stress value of the edge of the glass to be detected corresponding to the Y-axis position.

[0031] According to another aspect of the present invention, a computer storage medium is also provided, which stores a computer program that, when executed by a processor, implements the method described above.

[0032] According to another aspect of the present invention, a computer device is also provided, comprising a processor and a storage medium storing a computer program that, when executed by the processor, implements the method as described above.

[0033] According to embodiments of the present invention, convenient and accurate detection of glass edge stress can be achieved. Attached Figure Description

[0034] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0035] Figure 1 A perspective view of an example of a glass edge stress detector according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the optical system of a glass edge stress detector according to an embodiment of the present invention;

[0037] Figure 3 for Figure 1 Another perspective view of the glass edge stress detector shown;

[0038] Figure 4 for Figure 1 Side view of the glass edge stress detector;

[0039] Figure 5 This is a schematic diagram of an exemplary processing method for a calculation unit of a glass edge stress detector that can be used in an embodiment of the present invention;

[0040] Figure 6 , Figure 7 and Figure 8 Examples of the first, second, and third images detected by the glass edge stress detector according to an embodiment of the present invention;

[0041] Figure 9 An example of a glass edge stress value curve obtained using a glass edge stress detector according to an embodiment of the present invention is shown. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. For ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0044] The following is for reference Figures 1 to 4 A glass edge stress detector 1 according to an embodiment of the present invention is introduced. Figure 1 A perspective view of a glass edge stress detector 1 according to an embodiment of the present invention is shown. Figure 2 This is a schematic diagram of the optical system of a glass edge stress detector according to an embodiment of the present invention. Figure 3 and Figure 4 This is another perspective view and side view of the glass edge stress detector 1.

[0045] like Figure 1 As shown, the glass edge stress detector 1 includes an illumination unit 10, a detection unit 20, and a detection opening 30 formed between the illumination unit 10 and the detection unit 20.

[0046] The illumination unit 10 includes a light source 11 and a polarizer 12. The polarizer 12 receives light from the light source 11 and polarizes it into linearly polarized light. See also Figure 2 The polarization direction p1 of the polarizer 12 forms an approximately 45° angle with the X and Y axes, which are orthogonal to each other and perpendicular to the optical axis (the Z-axis direction shown in the figure). The light source 11 can be a white light source. To provide a larger illumination range for detecting a larger area of ​​the glass edge (rather than single-point detection), the light source 11 is preferably configured to provide approximately surface illumination. For example, the light source 11 may include an array of light-emitting devices, such as an LED array. More preferably, as... Figure 1 As shown, the lighting unit 10 may also include a light-diffusing plate 13, which is disposed between the light source 11 and the polarizer 12.

[0047] The detection unit 20 includes an optical wedge 21 and an analyzer 22 arranged sequentially along the optical path. The optical wedge 21 is configured such that the phase difference it introduces varies along the X-axis and remains constant along the Y-axis. In other words, the wedge angle axis of the optical wedge 21 is parallel to the Y-axis, and the thickness or refractive index of the optical wedge 21 varies along the X-axis but remains constant along the Y-axis. The optical wedge 21 can be, for example, a quartz wedge. Figure 1 In the example shown, the analyzer 22 is a polarizing film formed on the surface of the optical wedge 21. It should be understood that the analyzer 22 can also be formed as a separate element from the optical wedge 21. For example... Figure 2 As shown, the polarization direction p2 of the analyzer 22 is the same as the polarization direction p1 of the polarizer 12. In other cases, the polarization direction p2 of the analyzer 22 can also be at a 90° angle (i.e., orthogonal) to the polarization direction p1 of the polarizer 12.

[0048] A detection opening 30 is formed between the illumination unit 10 and the detection unit 20. For example... Figure 4 As shown more clearly in the image, the detection opening 30 is formed to receive the edge b of the glass G to be detected in a direction substantially perpendicular to the optical axis (see image). Figure 4This ensures that the edge b of the glass G to be tested is positioned parallel to the X-axis direction. For example... Figure 3 and Figure 4 As shown more clearly in the figure, the detection opening 30 preferably has a flat shape that is perpendicular to the optical axis (the optical axis is along the Z-axis direction shown in the figure).

[0049] Return to reference Figure 2 After light is emitted from the light source 11, it passes through the light homogenizer 13 to form uniform illumination light. This illumination light then passes through the polarizer 12 to form linearly polarized light at approximately 45° angles to the X and Y axes (which can be decomposed into linearly polarized light along the X-axis and along the Y-axis). After this linearly polarized light passes through the edge b of the glass to be tested G, the linearly polarized light along the X-axis and along the Y-axis introduces a first optical path difference DL1 caused by the stress birefringence effect at the glass edge. By detecting the first optical path difference DL1, the stress at the glass edge can be calculated accordingly.

[0050] Continue to refer to Figure 2 The light, which introduces the first optical path difference DL1, is received by the optical wedge 21. After passing through the optical wedge 21, a second optical path difference DL2, introduced by the optical wedge 21, is further introduced. The optical path difference DL2 introduced by the optical wedge 21 increases along the X-axis but remains unchanged along the Y-axis. After passing through the analyzer 22, bright spots are formed at positions where the total optical path difference DL = DL1 + DL2 is n times the wavelength (n is an integer), and dark spots are formed at positions where the total optical path difference is n + 1 / 2 times the wavelength. The lines connecting the bright spots form bright fringes, and the lines connecting the dark spots form dark fringes, thus forming observable interference fringes.

[0051] The order of each fringe can be identified based on the brightness relationship of the fringes, thereby obtaining the corresponding total optical path difference DL. Given the total optical path difference DL, it is also necessary to calculate the second optical path difference DL2 introduced by the optical wedge 21 at that point. Since the wedge angle is assumed to be constant, the second optical path difference introduced by the optical wedge 21 at any X-axis position can be calculated by interpolation using waveplates with known optical path differences. For example, two waveplates with known optical path differences can be inserted into the detection opening 30 to obtain two interference fringe images. The X-axis coordinates of the same predetermined order fringes in the two interference fringe images are determined, i.e., coordinates x' and x”. Then, using the formula DL2 = DL - DL1 (where DL1 is the optical path difference introduced by the waveplate), the optical path difference introduced by the optical wedge 21 at coordinates x' and x” can be obtained. Through interpolation, the second optical path difference DL2 of the optical wedge 21 at any X-axis position x is obtained. However, it should be understood that the stress detector and detection method of the present invention are not limited to using the above interpolation method to calculate the optical path difference introduced by the optical wedge.

[0052] Given the total optical path difference DL and the second optical path difference DL2, the first optical path difference DL1 can be obtained, which is the optical path difference introduced at a certain point on the edge b of the glass to be tested. Dividing the first optical path difference DL1 by the thickness of the glass G, and then by the photoelastic coefficient of the glass G, yields the stress value at that point.

[0053] Preferably, such as Figure 3 and Figure 4 As shown, a positioning block 40 is provided on one side of the detection opening 30. The positioning block 40 has a positioning surface 40a perpendicular to the Y-axis, which is used for the edge b of the glass G to be tested to abut against, so as to more conveniently and stably position the edge b of the glass G to be tested parallel to the X-axis direction.

[0054] In the glass edge stress detector 1 according to an embodiment of the present invention, the detection opening 30 is configured such that the edge b of the glass G to be tested can be positioned parallel to the X-axis direction. At the same time, the optical wedge 21 is configured such that the optical path difference it introduces varies along the X-axis direction but remains constant along the Y-axis direction. This allows the glass edge stress detector 1 according to the embodiment of the present invention to detect stress within a certain width range along the Y-axis direction, thereby enabling accurate and convenient detection of the stress at the glass edge that changes with the distance relative to the edge (the outermost edge of the glass) (from compressive stress to tensile stress and the stress magnitude also changes).

[0055] Return to reference Figure 1 The glass edge stress detector 1 preferably further includes an observation device 50, which is disposed downstream of the detection unit 20 along the optical path and is used to observe the interference fringes formed by the detection unit 20. Figure 1 In the example shown, the observation device 50 includes an image acquisition device, such as a camera, which acquires an image of the interference fringes formed by the detection unit 20. In other examples, the observation device 50 may also be, for example, an eyepiece system with position scales along the X and Y axes arranged in the field of view.

[0056] Preferably, the glass edge stress detector 1 may further include a filter F (see...) Figure 2 , Figure 1 (Not shown in the image). The filter F can be positioned anywhere between the light source 11 and the observation device 50. The filter F only allows light within a narrow wavelength range relative to the light source 11 to pass through, thereby enabling the observation device 50 to observe a greater number of interference fringes, which is beneficial for improving the accuracy of optical path difference calculation.

[0057] Preferably, the glass edge stress detector 1 may further include a filter switching device (not shown) for moving the filter F to switch between a first position in the optical path and a second position away from the optical path. This allows the user to select different interference fringe patterns as needed, providing greater flexibility.

[0058] Refer again Figure 3 and Figure 4 The glass edge stress detector 1 includes a housing 90, which preferably includes an upper housing 91 and a lower housing 92 arranged opposite to each other. (See reference for comparison.) Figure 1 and Figure 3 In the illustrated example, the lighting unit 10 is disposed in the lower housing 92, the detection unit 20 is disposed in the upper housing 91, and a detection opening 30 is formed between the upper housing 91 and the lower housing 92.

[0059] like Figure 3 and Figure 4 As shown, the upper housing 91 and the lower housing 92 can be connected to each other on one side of the detection opening 30. Preferably, a positioning block 40 is provided on this side of the detection opening 30, and the positioning surface 40a of the positioning block 40 is used for the edge of the glass G to be tested to abut against.

[0060] Preferably, such as Figure 4 As shown, the top surface 92a of the lower housing is formed as a plane perpendicular to the optical axis. This allows the edge of the glass G to be tested to be conveniently placed on the top surface 92a and kept perpendicular to the optical axis of the detection optical path during testing, which improves the convenience of operation and the accuracy of testing.

[0061] Preferably, such as Figure 1 As shown, the observation device 50 is also housed in the upper casing 91. Furthermore, a reflector M can be further installed in the glass edge stress detector 1 to deflect the light path, forming a folded light path. This saves space and facilitates miniaturization.

[0062] exist Figure 1 In the example shown, the observation device 50 is an image acquisition unit (e.g., a camera), and the image acquired by the image acquisition unit can be sent to a computing device for processing and calculation through the image output interface 50a, thereby calculating the stress value of the edge of the glass to be detected.

[0063] Although not shown, the glass edge stress detector 1 according to an embodiment of the present invention may further include a calculation unit that calculates the stress at the edge b of the glass G to be detected based on an image acquired by the image acquisition unit (observation device) 50. The calculation unit (not shown) may be integrated into the housing 90 or may be a separate unit. For example, in Figure 1 In the example shown, the image acquired by the image acquisition unit (observation device) 50 can be sent to the computing unit via the image output interface 50a, for example, by wired or wireless means.

[0064] Figure 5This is a schematic diagram of an exemplary processing method 100 that can be used in the calculation unit of a glass edge stress detector according to an embodiment of the present invention.

[0065] like Figure 5 As shown, the calculation unit of the glass edge stress detector 1 is configured to execute processing method 100, which includes:

[0066] (1) Acquire a first image and a second image, wherein the first image and the second image are interference fringe images acquired when a first specified optical path difference and a second specified optical path difference are introduced into the detection opening, respectively, and the first specified optical path difference and the second specified optical path difference are not equal;

[0067] (2) Obtain a third image, which is an interference fringe image obtained when the edge of the glass to be tested is inserted into the detection opening;

[0068] (3) Identify stripes of corresponding order in the first, second, and third images, and determine the X-axis positions of points with the same Y-axis position on the stripes in the first, second, and third images; and

[0069] (4) Based on the X-axis position of the stripes with corresponding order in the first image, second image and third image, calculate the stress value of the edge of the glass to be detected corresponding to the Y-axis position.

[0070] In processing (1), the first specified optical path difference and the second specified optical path difference can be achieved, for example, by not inserting any optical element into the detection opening 30 (i.e., the introduced optical path difference is zero) or by inserting a waveplate with a known and determined optical path difference. For example, a first image can be acquired without inserting any optical element, and a second image can be acquired with a waveplate inserted; or a first image can be acquired with a waveplate inserted, and a second image can be acquired with a different waveplate inserted.

[0071] Furthermore, it should be understood that the execution order of processing (1) and processing (2) can be interchanged and is not limited to a specific order.

[0072] For ease of understanding, Figure 6 , Figure 7 and Figure 8 Examples of the first image IM1, the second image IM2, and the third image IM3 described above are shown respectively. In the figures, the reference numeral "S0" represents a zero-order bright fringe, and x1, x2, and x3 are the X-axis positions of points on the zero-order bright fringe with the same Y-axis coordinate y in the first image IM1, the second image IM2, and the third image IM3.

[0073] Figure 9An example of a glass edge stress value curve obtained using a glass edge stress detector according to an embodiment of the present invention is shown, wherein... Figure 9 The horizontal axis corresponds to the Y-axis coordinate, and the vertical axis is the stress value coordinate.

[0074] It should be understood that the glass edge stress detector according to the embodiments of the present invention is not limited to having an integrated computing unit; the image acquired by the image acquisition unit (observation device) 50 of the detector can be sent to an external computing device (e.g., a computer) for processing and calculation to obtain the glass edge stress detection result.

[0075] Accordingly, according to other aspects of the present invention, a method for calculating glass edge stress for the glass edge stress detector described above is also provided, comprising:

[0076] (1) Acquire a first image and a second image, wherein the first image and the second image are interference fringe images acquired when a first specified optical path difference and a second specified optical path difference are introduced into the detection opening, respectively, and the first specified optical path difference and the second specified optical path difference are not equal;

[0077] (2) Obtain a third image, which is an interference fringe image obtained when the edge of the glass to be tested is inserted into the detection opening;

[0078] (3) Identify stripes of corresponding order in the first, second, and third images, and determine the X-axis positions of points with the same Y-axis position on the stripes in the first, second, and third images; and

[0079] (4) Based on the X-axis position of the stripes with corresponding order in the first image, second image and third image, calculate the stress value of the edge of the glass to be detected corresponding to the Y-axis position.

[0080] According to other aspects of the present invention, a computer storage medium is also provided, which stores a computer program that, when executed by a processor, implements the glass edge stress calculation method described above.

[0081] According to other aspects of the present invention, a computer device is also provided, comprising a processor and a storage medium storing a computer program that, when executed by the processor, implements the glass edge stress calculation method described above.

[0082] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A glass edge stress detector, comprising: An illumination unit includes a light source and a polarizer, the polarizer receiving light from the light source and making it linearly polarized, wherein the polarization direction of the polarizer is at approximately 45 degrees to the mutually orthogonal X-axis and Y-axis perpendicular to the optical axis. o included angle; The detection unit includes an optical wedge and an analyzer arranged sequentially along the optical path. The optical wedge is configured such that the phase difference it introduces varies along the X-axis and remains constant along the Y-axis. The analyzer has the same or orthogonal polarization direction as the polarizer. as well as A detection opening, formed between the illumination unit and the detection unit, is used to receive the edge of the glass to be tested in a direction substantially perpendicular to the optical axis, such that the edge of the glass to be tested is positioned parallel to the X-axis direction, and the linearly polarized light passes through the edge of the glass to be tested. The glass edge stress detector further includes: An observation device, disposed downstream of the detection unit, is used to observe interference fringes formed via the detection unit, wherein the observation device includes an image acquisition device that acquires an image of the interference fringes formed via the detection unit; and A calculation unit calculates the stress at the edge of the glass to be detected based on the image, wherein the calculation unit is configured to perform the following processing to obtain a glass edge stress value curve: (1) The image acquisition device is used to acquire a first image and a second image, wherein the first image and the second image are interference fringe images acquired when a first specified optical path difference and a second specified optical path difference are introduced into the detection opening, respectively; (2) A third image is acquired using the image acquisition device, wherein the third image is an interference fringe image acquired when the edge of the glass to be tested is inserted into the detection opening; (3) Identify stripes of corresponding order in the first, second, and third images, and determine the X-axis positions of points with the same Y-axis position on the stripes in the first, second, and third images, corresponding to each of the multiple Y-axis positions of the glass edge stress value curve; and (4) Based on the X-axis position of the points with the same Y-axis position on the stripes with corresponding order in the first image, second image and third image, the stress value of the edge of the glass to be detected corresponding to each of the plurality of Y-axis positions is calculated by interpolation.

2. The glass edge stress detector as described in claim 1, wherein, The lighting unit also includes a light-diffusing plate, which is disposed between the light source and the polarizer.

3. The glass edge stress detector as described in claim 1, wherein, A positioning block is provided on one side of the detection opening. The positioning block has a positioning surface perpendicular to the Y-axis, which is used for the edge of the glass to be tested to abut against.

4. The glass edge stress detector as described in claim 1 or 3, wherein, The detection opening has a flat shape perpendicular to the optical axis.

5. The glass edge stress detector as claimed in claim 1 further includes a housing, the housing comprising an upper housing and a lower housing disposed opposite to each other, the illumination unit being disposed in the lower housing, the detection unit being disposed in the upper housing, and the detection opening being formed between the upper housing and the lower housing.

6. The glass edge stress detector as described in claim 5, wherein, The upper housing and the lower housing are connected to each other on one side of the detection opening, and a positioning block is provided on the side of the detection opening. The positioning block has a positioning surface perpendicular to the Y-axis for the edge of the glass to be tested to abut against.

7. The glass edge stress detector as described in claim 5 or 6, wherein, At least one of the bottom surface of the upper housing and the top surface of the lower housing is formed as a plane perpendicular to the optical axis.

8. The glass edge stress detector as claimed in claim 1 further includes a filter, the filter being disposed between the light source and the observation device.

9. The glass edge stress detector as described in claim 8 further includes a filter switching device for moving the filter to switch between a first position in the optical path and a second position away from the optical path.

10. A method for calculating glass edge stress to obtain a glass edge stress value curve, comprising: (1) Acquire a first image and a second image using an image acquisition device. The first image and the second image are interference fringe images acquired by the glass edge stress detector as described in any one of claims 1-9, respectively, when a first specified optical path difference and a second specified optical path difference are introduced into the detection opening. The first specified optical path difference and the second specified optical path difference are not equal. (2) A third image is acquired using the image acquisition device. The third image is an interference fringe image acquired using the glass edge stress detector when the edge of the glass to be tested is inserted into the detection opening. (3) Identify stripes with corresponding levels in the first image, the second image and the third image, and each Y-axis position in the multiple Y-axis positions of the glass edge stress value curve, and determine the X-axis position of the points with the same Y-axis position on the stripes in the first image, the second image and the third image; as well as (4) Based on the X-axis position of the points with the same Y-axis position on the stripes of the corresponding order in the first image, the second image and the third image, the stress value of the edge of the glass to be tested corresponding to each of the plurality of Y-axis positions is calculated by interpolation.

11. A computer storage medium storing a computer program that, when executed by a processor, implements the method of claim 10.

12. A computer device comprising a processor and a storage medium storing a computer program that, when executed by the processor, implements the method of claim 10.

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