Transparent part stress detection system and detection method

Abstract

The invention provides a transparent part stress detection system and method, the system comprises a first light splitting structure and a second light splitting structure, a polarization detection position is arranged between the first light splitting structure and the second light splitting structure, and the polarization detection position is used for placing a transparent part. One side of the first light-splitting structure away from the second light-splitting structure is provided with a light source, and one side of the second light-splitting structure away from the first light-splitting structure is provided with an imaging device. The imaging device is used for converting the visible light filtered by the second light splitting structure into a part image and detecting stress borne by the transparent part according to the part image. The transparent part is placed at the polarization detection position, the light source is turned on, the light source emits visible light, and the visible light sequentially passes through the first light splitting structure, the transparent part and the second light splitting structure and irradiates the imaging device. The imaging device converts the received visible light into the part image, the stress borne by the transparent part is automatically detected according to the part image, and the accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of stress detection, and in particular to a transparent part stress detection system and detection method. Background Art

[0002] Transparent lenses are widely used in display screens of products such as remote controls and computers. In the process of assembling display screens, it is necessary to detect the three-dimensional dimensions and defects of transparent lenses. If the deformation of the transparent lens is too large, it will be unqualified. After the defects of the transparent lens are detected, manual repairs are performed for different defects such as black spots, scratches, bubbles, deformation and air marks.

[0003] The three-dimensional dimensions and defects of transparent lenses are all inspected manually. Manual inspection has poor consistency and long-term repetitive work can easily cause visual fatigue, resulting in quality accidents. The stress on the transparent lens can be determined based on the defect type of the transparent lens. When there is a deviation in the defect type detected manually, the determination of the stress on the transparent lens will also be biased.

[0004] Therefore, a transparent parts stress detection system is needed that can automatically detect the stress on the transparent lens with high accuracy. Summary of the invention

[0005] In order to overcome the problems existing in the related art, the purpose of the present invention is to provide a transparent part stress detection system and detection method, wherein the transparent part stress detection system can automatically detect the stress exerted on the transparent lens with high accuracy.

[0006] A transparent part stress detection system includes a first beam splitting structure and a second beam splitting structure, wherein a polarization detection position is arranged between the first beam splitting structure and the second beam splitting structure, and the polarization detection position is used to place a transparent part; a light source is arranged on a side of the first beam splitting structure away from the second beam splitting structure, and an imaging device is arranged on a side of the second beam splitting structure away from the first beam splitting structure; the imaging device is used to convert visible light filtered by the second beam splitting structure into a part image, and detect the stress exerted on the transparent part according to the part image.

[0007] In a preferred technical solution of the present invention, the first light splitting structure is a first polarizer, and the second light splitting structure is a second polarizer.

[0008] In a preferred technical solution of the present invention, the light source is a white light source.

[0009] In a preferred technical solution of the present invention, the transparent part stress detection system further includes a deformation detection device, wherein the deformation detection device is located below the imaging device, and the deformation detection device is used to detect the deformation of the transparent part.

[0010] In a preferred technical solution of the present invention, the deformation detection device includes an X-ray source, and a deformation detection position is arranged near the X-ray source, and the deformation detection position is used to detect the deformation of the transparent part.

[0011] In a preferred technical solution of the present invention, the deformation detection position is provided with a fixed mold, and the fixed mold is used to place the transparent part; the fixed mold is placed in a light box, and a strip light is provided in the light box, and the strip light is used to emit visible light to the fixed mold to position the transparent part on the fixed mold.

[0012] In a preferred technical solution of the present invention, the imaging device comprises a photoelectric receiving part, a side of the photoelectric receiving part facing the second light splitting structure is provided with a photoelectric surface, and the photoelectric surface is used to receive visible light filtered by the second light splitting structure.

[0013] In a preferred technical solution of the present invention, a CCD camera is provided on a side of the photoelectric receiving part away from the photoelectric surface, and the CCD camera is used to photograph the photoelectric receiving part to obtain the part image.

[0014] In a preferred technical solution of the present invention, the imaging device also includes a PLC processor, which is electrically connected to the CCD camera. The PLC processor is used to process and analyze the part image taken by the CCD camera to determine whether the transparent part has defects.

[0015] In a preferred technical solution of the present invention, the imaging device further comprises a light shielding device, wherein the light shielding device is located between the photoelectric surface and the second polarizer to form a channel for propagation of only the light passing through the second polarizer.

[0016] The present invention further provides a transparent part stress detection method, based on any of the transparent part stress detection systems described above, the method comprising:

[0017] placing the transparent part at the polarization detection position;

[0018] Turning on the light source so that the light source emits visible light to the first light splitting structure;

[0019] Acquire the part image converted by the imaging device;

[0020] Determining whether the transparent part has a defect according to the gray value distribution of the part image;

[0021] If the transparent part has a defect, the range of stress to which the transparent part is subjected is determined according to the type of the defect.

[0022] In a preferred technical solution of the present invention, judging whether the transparent part has defects according to the gray value distribution of the part image includes:

[0023] Detect whether the number of black dots is greater than 2, and whether the distance between the black dots is less than the black dot distance threshold. If so, it is determined that the transparent part has a black dot defect; wherein a black dot is a pixel point in the part image whose pixel value is less than the pixel value threshold;

[0024] Detecting whether there is a straight line containing a plurality of the black dots in the part image, and if so, determining that the transparent part has a line defect;

[0025] Detect whether there is a surface containing multiple black spots in the part image, and if so, determine that the transparent part has a surface defect.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a stress detection system for transparent parts, including a first spectroscopic structure and a second spectroscopic structure, a polarization detection position is arranged between the first spectroscopic structure and the second spectroscopic structure, and the polarization detection position is used to place the transparent parts; a light source is arranged on the side of the first spectroscopic structure away from the second spectroscopic structure, and an imaging device is arranged on the side of the second spectroscopic structure away from the first spectroscopic structure; the imaging device is used to convert the visible light filtered by the second spectroscopic structure into a part image, and detect the stress of the transparent part according to the part image. The transparent part is placed in the polarization detection position, the light source is turned on, and the light source emits visible light to the first spectroscopic structure, and the visible light passes through the first spectroscopic structure, the transparent part and the second spectroscopic structure in sequence, and the visible light filtered by the second spectroscopic structure is irradiated on the imaging device, and the imaging device converts the received visible light into a part image, and detects the stress of the transparent part according to the part image. Transparent parts, such as transparent lenses, have anisotropy, and the optical axis direction coincides with the stress direction. When light propagates in an anisotropic medium, birefringence occurs. When a transparent part is placed between the first beam splitting structure and the second beam splitting structure, the visible light passing through the first beam splitting structure is reflected and refracted on the surfaces on both sides of the transparent part, causing colored stripes to appear on the transparent part. The greater the stress on the transparent part, the greater the deformation, resulting in a stronger anisotropy of the transparent part and denser colored stripes. The part image converted by the imaging device is a grayscale image. The defect type of the transparent part can be determined based on the grayscale value distribution of the part image. Combining the grayscale value distribution of the part image and the defect type, the stress on the transparent part can be automatically detected with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a transparent part stress detection system of the present invention;

[0029] Figure 2 It is a schematic diagram of the composition of the polarization detection device and the light source of the present invention;

[0030] Figure 3 It is a schematic diagram of the composition of the transparent part stress detection system of the present invention;

[0031] Figure 4 It is a flow chart of the transparent part stress detection method of the present invention.

[0032] Figure numerals: 1. first polarizer; 2. second polarizer; 3. polarization detection position; 4. light source; 5. imaging device; 6. deformation detection device; 7. X-ray source; 8. fixed mold; 9. light box; 10. photoelectric receiving part; 11. photoelectric surface; 12. CCD camera; 13. PLC processor; 14. light shielding device; 15. polarization detection device; 16. transparent parts. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0034] Example 1

[0035] like Figure 1-Figure 3 As shown, this embodiment provides a transparent part stress detection system, including a first spectroscopic structure and a second spectroscopic structure, a polarization detection position 3 is arranged between the first spectroscopic structure and the second spectroscopic structure, and the polarization detection position 3 is used to place a transparent part 16; a light source 4 is arranged on the side of the first spectroscopic structure away from the second spectroscopic structure, and an imaging device 5 is arranged on the side of the second spectroscopic structure away from the first spectroscopic structure; the imaging device 5 is used to convert visible light filtered by the second spectroscopic structure into a part image, and detect the stress on the transparent part 16 according to the part image.

[0036] The first light splitting structure and the second light splitting structure both use polarizers, the first light splitting structure is the first polarizer 1, and the second light splitting structure is the second polarizer 2. A polarizer is a film that can select polarized light of a specific frequency. The working principle of the polarizer is to utilize the structure of the polarizer to absorb the vibration component of light in a specific direction, so that the light passing through the polarizer only contains the vibration component in the specific direction.

[0037] By adopting the first light splitting structure, the natural light emitted by the light source 4 can be converted into polarized light, the reflection of light can be reduced, and the color contrast on the transparent part 16 can be enhanced. In this embodiment, the transparent part 16 is a transparent lens, and the transparent lens is made of polycarbonate as an example. The transparent lens is made of an isotropic amorphous material, but during the injection molding process of the transparent lens, it is cooled and molded before the external pressure is removed, forming residual stress, so that the transparent lens has anisotropy, and the direction of the optical axis coincides with the direction of stress. When light propagates in an anisotropic medium, birefringence occurs. The transparent lens is placed between the first light splitting structure and the second light splitting structure. The polarized light after being split by the first light splitting structure is irradiated on the transparent lens to form color stripes. The greater the stress on the transparent lens, the greater the deformation, resulting in stronger anisotropy and denser color stripes.

[0038] The second light splitting structure filters the light passing through the transparent lens, allowing polarized light in a specific direction to pass through, and the imaging device 5 converts the polarized light passing through the second light splitting structure into a part image. The imaging device 5 analyzes the grayscale value distribution of the part image, and the grayscale value is between 0-255, where 0 is black and 255 is white. The defect type of the transparent lens can be determined based on the grayscale value distribution of the part image. Combining the grayscale distribution of the part image and the defect type of the transparent lens, the stress on the transparent lens can be determined, and whether the quality of the transparent lens is qualified can be determined.

[0039] The present embodiment provides a stress detection system for transparent parts, including a first light splitting structure and a second light splitting structure, a polarization detection position 3 is arranged between the first light splitting structure and the second light splitting structure, and the polarization detection position 3 is used to place a transparent part 16; a light source 4 is arranged on the side of the first light splitting structure away from the second light splitting structure, and an imaging device 5 is arranged on the side of the second light splitting structure away from the first light splitting structure; the imaging device 5 is used to convert the visible light filtered by the second light splitting structure into a part image, and detect the stress of the transparent part 16 according to the part image. The transparent part 16 is placed at the polarization detection position 3, and the light source 4 is turned on. The light source 4 emits visible light to the first light splitting structure. The visible light passes through the first light splitting structure, the transparent part 16, and the second light splitting structure in sequence. The visible light filtered by the second light splitting structure is irradiated on the imaging device 5, and the imaging device 5 converts the received visible light into a part image, and detects the stress of the transparent part 16 according to the part image. The transparent part 16, such as a transparent lens, has anisotropy, and the optical axis direction coincides with the stress direction. When light propagates in an anisotropic medium, birefringence occurs. When the transparent part 16 is placed between the first light splitting structure and the second light splitting structure, the visible light passing through the first light splitting structure is reflected and refracted on the surfaces on both sides of the transparent part 16, so that color stripes appear on the transparent part 16. The greater the stress on the transparent part 16, the greater the deformation, resulting in a stronger anisotropy of the transparent part 16 and denser color stripes. The part image converted by the imaging device 5 is a grayscale image. The defect type of the transparent part 16 can be determined based on the grayscale value distribution of the part image. Combined with the grayscale value distribution and defect type of the part image, the stress on the transparent part 16 can be automatically detected with high accuracy.

[0040] Example 2

[0041] like Figure 1-Figure 3 As shown, this embodiment provides a transparent part stress detection system, including a first spectroscopic structure and a second spectroscopic structure, a polarization detection position 3 is arranged between the first spectroscopic structure and the second spectroscopic structure, and the polarization detection position 3 is used to place a transparent part 16; a light source 4 is arranged on the side of the first spectroscopic structure away from the second spectroscopic structure, and an imaging device 5 is arranged on the side of the second spectroscopic structure away from the first spectroscopic structure; the imaging device 5 is used to convert visible light filtered by the second spectroscopic structure into a part image, and detect the stress on the transparent part 16 according to the part image.

[0042] The first light splitting structure is a first polarizer 1 , the second light splitting structure is a second polarizer 2 , and the light source 4 is a white light source.

[0043] The polarization detection position 3 is arranged between the first polarizer 1 and the second polarizer 2, and the transparent part 16 is placed on the polarization detection position 3. In this embodiment, the transparent part 16 is a transparent lens as an example. The transparent lens is made of polycarbonate as an example. The transparent lens is made of an isotropic amorphous material, but in the injection molding process of the transparent lens, the molding is cooled before the external pressure is removed, forming residual stress, so that the transparent lens has anisotropy, and the optical axis direction coincides with the stress direction.

[0044] The first polarizer 1 and the second polarizer 2 allow light with a specific vibration frequency and vibration direction to pass through. The first polarizer 1 and the second polarizer 2 are of the same type. The first polarizer 1 is a linear polarizer or a circular polarizer.

[0045] White light is composite light, including light of multiple colors. The transparent lens receives the white light passing through the first polarizer 1. Light of different colors has different refractive indices, so colored stripes appear on the transparent lens.

[0046] In this embodiment, the first light splitting structure is a first polarizer 1, the second light splitting structure is a second polarizer 2, and the light source 4 is a white light source. The first polarizer 1 and the second polarizer 2 allow light of a specific vibration frequency and vibration direction to pass through, and the first polarizer 1 and the second polarizer 2 are of the same type, and the first polarizer 1 is a linear polarizer or a circular polarizer.

[0047] Example 3

[0048] like Figure 1-Figure 3 As shown, this embodiment provides a transparent part stress detection system, including a first spectroscopic structure and a second spectroscopic structure, a polarization detection position 3 is arranged between the first spectroscopic structure and the second spectroscopic structure, and the polarization detection position 3 is used to place a transparent part 16; a light source 4 is arranged on the side of the first spectroscopic structure away from the second spectroscopic structure, and an imaging device 5 is arranged on the side of the second spectroscopic structure away from the first spectroscopic structure; the imaging device 5 is used to convert visible light filtered by the second spectroscopic structure into a part image, and detect the stress on the transparent part 16 according to the part image.

[0049] The transparent part stress detection system further includes a deformation detection device 6 , which is located below the imaging device 5 . The deformation detection device 6 is used to detect the deformation of the transparent part 16 .

[0050] The deformation detection device 6 includes an X-ray source 7 , and a deformation detection position is arranged near the X-ray source 7 , and the deformation detection position is used to detect the deformation of the transparent part 16 .

[0051] The deformation detection position is provided with a fixed mold 8, and the fixed mold 8 is used to place the transparent part 16; the fixed mold 8 is placed in a light box 9, and a strip light is provided in the light box 9, and the strip light is used to emit visible light to the fixed mold 8 to position the transparent part 16 on the fixed mold 8.

[0052] The first light splitting structure, the second light splitting structure and the polarization detection position 3 constitute a polarization detection device 15. The polarization detection device 15 and the deformation detection device 6 are both arranged in the detection box, and the deformation detection device 6 is arranged below the polarization detection device 15. After the deformation detection device 6 is used to perform deformation detection on the transparent part 16, such as a transparent lens, the polarization detection device 15 is used to detect the stress on the transparent lens.

[0053] The transparent lens is placed on the fixed mold 8 to prevent the transparent lens from moving. After the position of the transparent lens is fixed, the X-ray source 7 is started, and the X-ray source 7 emits X-rays to the transparent lens on the fixed mold 8. The X-rays penetrate the transparent lens, thereby obtaining the size of the transparent lens. By comparing the size of the transparent lens with the standard size, it can be determined whether the size of the transparent lens is qualified.

[0054] The deformation of the transparent lens needs to meet the following standards: the deformation amplitude of the visible surface of the transparent lens cannot be greater than 0.8mm, and the deformation amplitude of the invisible surface cannot be greater than 1.2mm. If the deformation amplitude of the visible surface and / or the invisible surface of the transparent lens is greater than the corresponding threshold, an alarm will be issued and the transparent lens will be processed to reduce the deformation of the transparent lens so that the transparent lens meets the size standard.

[0055] Before deformation detection, the transparent lens is placed on the fixed mold 8, and the strip light in the light box 9 is turned on. The strip light emits visible light so that the operator can determine the position of the transparent lens. The strip light can be set on the inner wall of the light box 9, or can be set in the light box 9 near the fixed mold 8, which is not limited here.

[0056] The deformation detection device 6 of this embodiment includes an X-ray source 7, and a deformation detection position is arranged near the X-ray source 7, and the deformation detection position is used to detect the deformation of the transparent part 16. The deformation detection position is provided with a fixed mold 8, and the fixed mold 8 is used to place the transparent part 16; the fixed mold 8 is placed in a light box 9, and a strip light is arranged in the light box 9, and the strip light is used to emit visible light to the fixed mold 8 to position the transparent part 16 on the fixed mold 8. A transparent lens is placed on the fixed mold 8 to prevent the transparent lens from being displaced. After fixing the position of the transparent lens, the X-ray source 7 is started, and the X-ray source 7 emits X-rays to the transparent lens on the fixed mold 8. The X-rays penetrate the transparent lens, so as to obtain the size of the transparent lens. By comparing the size of the transparent lens with the standard size, it can be judged whether the size of the transparent lens is qualified.

[0057] Example 4

[0058] like Figure 1-Figure 3 As shown, this embodiment provides a transparent part stress detection system, including a first spectroscopic structure and a second spectroscopic structure, a polarization detection position 3 is arranged between the first spectroscopic structure and the second spectroscopic structure, and the polarization detection position 3 is used to place a transparent part 16; a light source 4 is arranged on the side of the first spectroscopic structure away from the second spectroscopic structure, and an imaging device 5 is arranged on the side of the second spectroscopic structure away from the first spectroscopic structure; the imaging device 5 is used to convert visible light filtered by the second spectroscopic structure into a part image, and detect the stress on the transparent part 16 according to the part image.

[0059] The transparent part stress detection system further includes a deformation detection device 6 , which is located below the imaging device 5 . The deformation detection device 6 is used to detect the deformation of the transparent part 16 .

[0060] The deformation detection device 6 includes an X-ray source 7 , and a deformation detection position is arranged near the X-ray source 7 , and the deformation detection position is used to detect the deformation of the transparent part 16 .

[0061] The imaging device 5 comprises a photoelectric receiving part 10 . A photoelectric surface 11 is arranged on a side of the photoelectric receiving part 10 facing the second light splitting structure. The photoelectric surface 11 is used to receive the visible light filtered by the second light splitting structure.

[0062] A CCD camera 12 is disposed on a side of the photoelectric receiving part 10 away from the photoelectric surface 11 . The CCD camera 12 is used to photograph the color stripes on the photoelectric receiving part 10 .

[0063] The imaging device 5 further includes a PLC processor 13 , which is electrically connected to the CCD camera 12 . The PLC processor 13 is used to process and analyze the part image taken by the CCD camera 12 to determine whether the transparent part 16 has defects.

[0064] The photoelectric surface 11 is an arc-shaped surface, and the photoelectric surface 11 bulges toward the direction close to the second polarizer 2, so that the photoelectric surface 11 can better receive the visible light passing through the second polarizer 2. The photoelectric surface 11 sends the light signal to the photoelectric receiving part 10, and the photoelectric receiving part 10 is excited by the light signal and emits photoelectrons to form an image. The number of photoelectrons is positively correlated with the intensity of visible light, that is, the greater the intensity of visible light, the greater the number of photoelectrons, and the greater the average grayscale value of the corresponding part image.

[0065] The CCD camera 12 is a digital camera with a charge-coupled device, which has the advantages of high sensitivity, strong light resistance, small distortion, small size, long life and vibration resistance. The image of the object being photographed is focused on the CCD chip through the lens. The CCD accumulates a corresponding proportion of charge according to the intensity of the light. The charge accumulated in each pixel is moved outward point by point under the control of the video timing, and after filtering and amplification, it forms an image signal output.

[0066] The part image captured by the CCD camera 12 is a grayscale image. Different regions in the part image have different grayscale values. The defect type of the part image can be determined based on the grayscale value distribution of the part image.

[0067] The CCD camera 12 is electrically connected to the PLC processor 13. The CCD camera 12 transmits the captured part image to the PLC processor 13. The PLC processor 13 counts the grayscale value of each pixel in the part image. The grayscale value ranges from 0 to 255. 0 is black and 255 is white. The defect types of transparent lenses include black spots, scratches, bubbles, deformations and air marks. The specific inspection and judgment standards are as follows: (1) Black spots are controlled according to the standard of 0.5mm. When the number of black spots exceeds 2, the distance between the two black spots must exceed 150mm. (2) Scratches are controlled according to the width ≤0.2㎜ and the depth ≤0.2㎜; the scratch length ≤5mm; and the single workpiece surface ≤2. (3) Bubbles are not allowed. (4) Deformation is qualified if it does not affect assembly, appearance and function and does not have quality risks. (5) Air marks are not allowed on the appearance surface and other parts.

[0068] The upper 1mm and lower 1mm of the transparent mirror display area are divided into 10 small blocks, and the grayscale value of the qualified screen printing area is stored in the computer processor as teaching data. The grayscale values ​​of the 10 small blocks after screen printing are compared with the teaching data to determine whether they are qualified. If the grayscale value of the defective area analyzed is consistent with the grayscale value of the qualified teaching, the transparent part 16 is determined to be a qualified part. The qualified transparent part 16 enters the next process. If the transparent part 16 is unqualified, it is manually repaired according to different defect types.

[0069] Preferably, the imaging device 5 also includes a light blocking device 14, which is located between the photoelectric surface 11 and the second polarizer 2 to form a channel for the propagation of only the light passing through the second polarizer 2, thereby isolating the influence of external light, so that the photoelectric surface 11 only receives the light passing through the second polarizer 2, so as to better reflect the deformation and stress of the transparent part 16.

[0070] The imaging device 5 of this embodiment includes a photoelectric receiving part 10, and a photoelectric surface 11 is arranged on the side of the photoelectric receiving part 10 facing the second light splitting structure, and the photoelectric surface 11 is used to receive the visible light filtered by the second light splitting structure. A CCD camera 12 is arranged on the side of the photoelectric receiving part 10 away from the photoelectric surface 11, and the CCD camera 12 is used to shoot the photoelectric receiving part 10 to obtain the part image. The photoelectric surface 11 is an arc-shaped surface, and the photoelectric surface 11 bulges toward the direction close to the second polarizer 2, so that the photoelectric surface 11 can better receive the visible light passing through the second polarizer 2. The photoelectric surface 11 sends the light signal to the photoelectric receiving part 10, and the photoelectric receiving part 10 is excited by the light signal and emits photoelectrons to form an image. The number of photoelectrons is positively correlated with the intensity of visible light, that is, the greater the intensity of visible light, the greater the number of photoelectrons, and the greater the average grayscale value of the corresponding part image.

[0071] Example 5

[0072] like Figure 4 As shown, this embodiment provides a transparent part stress detection method, based on the transparent part stress detection system described in any one of Embodiments 1 to 4, the method includes:

[0073] S1: placing the transparent component at the polarization detection position.

[0074] S2: Turn on the light source to enable the light source to emit visible light to the first light splitting structure.

[0075] S3: Acquire the part image converted by the imaging device.

[0076] S4: Determine whether the transparent part has defects according to the gray value distribution of the part image.

[0077] S5: If the transparent component has a defect, determine the range of stress to which the transparent component is subjected according to the type of the defect.

[0078] After the transparent part 16 is fixed on the polarization detection position 3, the light source 4 is turned on, and the light source 4 emits white light to the transparent part 16. The white light passes through the first polarizer 1, the transparent part 16 and the second polarizer 2 in sequence, propagates to the photoelectric surface 11, and forms an image on the photoelectric receiving part 10. The CCD camera 12 captures the image formed by the photoelectric receiving part 10 to obtain the part image. The CCD camera 12 is electrically connected to the PLC processor 13, and the CCD camera 12 sends the part image to the PLC processor 13. The PLC processor 13 processes and analyzes the part image to determine whether the transparent part 16 has defects. The PLC processor 13 is electrically connected to the light source 4 to control the opening and closing of the light source 4. If the transparent part 16 has defects, the defect type is further determined. The defect types include black spots, scratches, bubbles, deformations and gas lines. Different defect types have different corresponding stress ranges. The defect types can also be divided into point defects, line defects and surface defects. The stress of surface defects is greater than that of line defects, and the stress of line defects is greater than that of point defects.

[0079] The determining whether the transparent part has a defect according to the gray value distribution of the part image includes:

[0080] S41: Detect whether the number of black dots is greater than 2, and whether the distance between the black dots is less than the black dot distance threshold. If so, determine that the transparent part has a black dot defect; wherein the black dot is a pixel point in the part image whose pixel value is less than the pixel value threshold.

[0081] S42: Detect whether there is a straight line containing a plurality of black dots in the part image, and if so, determine that the transparent part has a line defect.

[0082] S43: Detect whether there is a surface containing multiple black spots in the part image, and if so, determine that the transparent part has a surface defect.

[0083] If there are multiple black dots and the multiple black dots form a straight line, it is determined that the transparent part 16 has a line defect; if there are multiple black dots and the multiple black dots form a surface, it is determined that the transparent part 16 has a surface defect.

[0084] Before step S1 , the method further includes placing the transparent part 16 on the fixed mold 8 in the light box 9 and performing deformation detection on the transparent part 16 using the X-ray source 7 .

[0085] This embodiment provides a method for detecting stress of a transparent part, comprising placing the transparent part 16 at the polarization detection position 3, turning on the light source 4, so that the light source 4 emits visible light to the first light splitting structure. The part image converted by the imaging device 5 is obtained, and whether the transparent part 16 has a defect is determined according to the gray value distribution of the part image. If the transparent part 16 has a defect, the range of stress to which the transparent part 16 is subjected is determined according to the type of the defect. With the above method, the defect type and stress of the transparent part 16 can be automatically detected.

[0086] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a restriction. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in the subsequent accompanying drawings.

[0087] It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would then be positioned "below" or "below" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0088] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A transparent parts stress detection system, characterized in that: It includes a first spectroscopic structure and a second spectroscopic structure, a polarization detection position is arranged between the first spectroscopic structure and the second spectroscopic structure, and the polarization detection position is used to place a transparent part; a light source is arranged on the side of the first spectroscopic structure away from the second spectroscopic structure, and an imaging device is arranged on the side of the second spectroscopic structure away from the first spectroscopic structure; the imaging device is used to convert visible light filtered by the second spectroscopic structure into a part image, and detect the stress on the transparent part according to the part image.

2. The transparent part stress detection system according to claim 1, characterized in that: The first light splitting structure is a first polarizer, and the second light splitting structure is a second polarizer.

3. The transparent part stress detection system according to claim 1, characterized in that: The light source is a white light source.

4. The transparent part stress detection system according to claim 2, characterized in that: It also includes a deformation detection device, which is located below the imaging device and is used to detect the deformation of the transparent part.

5. The transparent part stress detection system according to claim 4, characterized in that: The deformation detection device comprises an X-ray source, and a deformation detection position is arranged near the X-ray source, and the deformation detection position is used to detect the deformation of the transparent part.

6. The transparent part stress detection system according to claim 5, characterized in that: The deformation detection position is provided with a fixed mold, and the fixed mold is used to place the transparent part; the fixed mold is placed in a light box, and a strip light is provided in the light box, and the strip light is used to emit visible light to the fixed mold to position the transparent part on the fixed mold.

7. The transparent part stress detection system according to claim 5, characterized in that: The imaging device comprises a photoelectric receiving part, a side of the photoelectric receiving part facing the second light splitting structure is provided with a photoelectric surface, and the photoelectric surface is used to receive the visible light filtered by the second light splitting structure.

8. The transparent part stress detection system according to claim 7, characterized in that: A CCD camera is arranged on a side of the photoelectric receiving part away from the photoelectric surface, and the CCD camera is used to photograph the photoelectric receiving part to obtain the part image.

9. The transparent part stress detection system according to claim 8, characterized in that: The imaging device also includes a PLC processor, which is electrically connected to the CCD camera. The PLC processor is used to process and analyze the part image taken by the CCD camera to determine whether the transparent part has defects.

10. The transparent part stress detection system according to claim 7, characterized in that: The imaging device further comprises a light shielding device, wherein the light shielding device is located between the photoelectric surface and the second polarizer to form a channel for propagation of only the light passing through the second polarizer.

11. A method for detecting stress of a transparent part, characterized in that: Based on the transparent part stress detection system according to any one of claims 1 to 10, the method comprises: placing the transparent part at the polarization detection position; Turning on the light source so that the light source emits visible light to the first light splitting structure; Acquire the part image converted by the imaging device; Determining whether the transparent part has a defect according to the gray value distribution of the part image; If the transparent part has a defect, the range of stress to which the transparent part is subjected is determined according to the type of the defect.

12. The transparent part stress detection method according to claim 11, characterized in that: The determining whether the transparent part has a defect according to the gray value distribution of the part image includes: Detect whether the number of black dots is greater than 2, and whether the distance between the black dots is less than the black dot distance threshold. If so, it is determined that the transparent part has a black dot defect; wherein a black dot is a pixel point in the part image whose pixel value is less than the pixel value threshold; Detecting whether there is a straight line containing a plurality of the black dots in the part image, and if so, determining that the transparent part has a line defect; Detect whether there is a surface containing multiple black spots in the part image, and if so, determine that the transparent part has a surface defect.

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