阅读说明：本技术 用于检测玻璃片的设备和方法 (Apparatus and method for inspecting glass sheets ) 是由 韩兌熏 于 2019-02-08 设计创作，主要内容包括：本文公开一种用于检查玻璃片的边缘的设备和方法。所述设备包括：光学系统,所述光学系统包括：光源,所述光源被布置成沿着相对于玻璃片倾斜的方向照射所述玻璃片的边缘部分,以及相机,所述相机被布置成拍摄所述边缘部分图像；以及图像处理装置,所述图像处理装置被配置成处理从所述相机接收的所述玻璃片的图像以检测所述玻璃片的边缘缺陷。所述方法包括以下步骤：获取玻璃片的图像；从所述图像检测所述玻璃片的边缘线；从所述边缘线检测参考线；以及通过将所述边缘线与所述参考线比较来检测所述玻璃片的边缘缺陷。(An apparatus and method for inspecting an edge of a glass sheet is disclosed herein. The apparatus comprises: an optical system, the optical system comprising: a light source arranged to illuminate an edge portion of a glass sheet in a direction oblique to the glass sheet, and a camera arranged to capture the edge portion image; and an image processing device configured to process the image of the glass sheet received from the camera to detect an edge defect of the glass sheet. The method comprises the following steps: acquiring an image of a glass sheet; detecting an edge line of the glass sheet from the image; detecting a reference line from the edge line; and detecting an edge defect of the glass sheet by comparing the edge line to the reference line.)

1. An apparatus for inspecting an edge of a glass sheet, the apparatus comprising:

an optical system, the optical system comprising: a light source arranged to illuminate an edge portion of a glass sheet in a direction oblique to the glass sheet, and a camera arranged to acquire an image of the edge portion; and

an image processing device configured to receive the image from the camera and process the image to detect an edge defect of the glass sheet.

2. The apparatus of claim 1, further comprising: a transport apparatus configured to convey the glass sheet, the optical system being disposed on a side of the transport apparatus.

3. The apparatus of claim 1, wherein the camera comprises: a tilt portion configured to adjust a direction of a focal plane of the camera such that the focal plane of the camera is parallel to the glass sheet.

4. The apparatus of claim 1, wherein the optical system further comprises: a first mirror, the first mirror and the camera oriented such that a focal plane of the camera is parallel to the glass sheet.

5. The apparatus of claim 4, wherein the optical system further comprises: a second mirror, the second mirror and the light source oriented such that light emitted from the light source is reflected by the second mirror and is incident on the glass sheet along the direction oblique to the glass sheet.

6. The apparatus of claim 1, wherein the camera comprises a telecentric lens and the light source comprises a telecentric light source.

7. A method of inspecting an edge of a glass sheet, the method comprising:

acquiring an image of a glass sheet;

detecting an edge line of the glass sheet from the image;

detecting a reference line from the edge line; and

detecting an edge defect of the glass sheet by comparing the edge line to the reference line.

8. The method of claim 7, wherein acquiring the image of the glass sheet comprises acquiring a plurality of partial images of portions of the glass sheet.

9. The method of claim 8, wherein detecting the edge lines comprises detecting each of partial edge lines from each of the partial images.

10. The method of claim 9, wherein detecting the edge line further comprises combining the partial edge lines into one edge line.

11. The method of claim 7, wherein detecting the reference line comprises applying a line fit to the edge line.

12. The method of claim 11, wherein the line fitting employs a random sample consensus method.

13. The method of claim 7, wherein the edge line corresponds to one of a plurality of edges of the glass sheet.

14. The method of claim 7, wherein detecting the edge defect comprises detecting at least one of a type of the edge defect, a size of the edge defect, and a location of the edge defect.

15. A method of inspecting an edge of a glass sheet, the method comprising:

acquiring an image of a glass sheet conveyed by a conveyance device;

detecting an edge line of the glass sheet from the image;

detecting a reference line from the edge line;

detecting an edge defect in the glass sheet by comparing the edge line to the reference line; and

determining that the glass sheet is defective when the size of the edge defect is greater than a predetermined value.

16. The method of claim 15, wherein acquiring the image comprises sequentially acquiring partial images of the glass sheet conveyed by the conveyance device with a stationary camera at predetermined time intervals.

17. The method of claim 15, further comprising stopping conveyance of the glass sheet when the glass sheet is determined to be defective.

18. The method of claim 15, wherein the predetermined value depends on a location of the edge defect.

19. The method of claim 18, wherein the glass sheet is comprised of a plurality of regions and the predetermined value is dependent upon the region in which the edge defect is present.

20. The method of claim 15, wherein the predetermined value depends on a type of the edge defect.

Technical Field

The present disclosure relates to apparatus and methods for inspecting glass sheets, and more particularly to apparatus and methods for inspecting edge portions of glass sheets.

Background

Glass sheets can be made by melting raw materials to form molten glass, forming the molten glass into a glass ribbon, and cutting the glass ribbon into glass sheets of appropriate size. In some cases, the glass sheet cut from the glass ribbon may be further processed, for example, by cutting the glass sheet into smaller predetermined sizes again depending on the intended use, polishing the edges of the cut glass sheet, washing the cut glass sheet, and the like. These processes often require the transportation of glass sheets from one location to another. Unfortunately, during the cutting process, defects may form at the edges of the glass sheet. When the glass sheet includes defects at its edges, the glass sheet may break into many fragments during subsequent handling, including during transportation. To remove the fragments of glass from the transportation device, the transportation device may need to be stopped, and the processing may be delayed.

Disclosure of Invention

The present disclosure describes an apparatus and method for inspecting an edge of a glass sheet for defects.

In accordance with an aspect of the present disclosure, an apparatus for inspecting an edge of a glass sheet is disclosed, the apparatus comprising: an optical system, the optical system comprising: a light source arranged to illuminate an edge portion of a glass sheet, for example, in a direction oblique to the glass sheet, and a camera arranged to acquire an image of the edge portion. The apparatus further comprises: an image processing device configured to process images of the glass sheet received from the camera to detect edge defects of the glass sheet.

According to one or more embodiments, the apparatus may further comprise: a transport device configured to convey the glass sheet, and the optical system is disposed on a side of the transport device.

According to one or more embodiments, the camera may have a tilt portion configured to adjust a direction of a focal plane of the camera such that the focal plane of the camera is parallel to the glass sheet.

According to one or more embodiments, the camera may be oriented such that a focal plane of the camera is parallel to the glass sheet.

According to one or more embodiments, the optical system may further include: a first mirror, the first mirror and the camera oriented such that a focal plane of the camera is parallel to the glass sheet.

According to one or more embodiments, the optical system may further include: a second mirror, the second mirror and the light source being oriented such that light emitted from the light source is reflected by the second mirror and is incident on the glass sheet, for example, in a direction oblique to the glass sheet.

According to one or more embodiments, the camera may comprise: a telecentric lens, and the light source may include: a telecentric light source.

According to another aspect of the present disclosure, a method of inspecting an edge of a glass sheet is described, the method comprising: the method includes acquiring an image of a glass sheet, detecting an edge line of the glass sheet from the acquired image, detecting a reference line from the edge line, and detecting an edge defect of the glass sheet by comparing the edge line with the reference line.

In accordance with one or more embodiments, acquiring the image of the glass sheet may comprise: a plurality of partial images of portions (e.g., edge portions) of the glass sheet are acquired.

According to one or more embodiments, detecting edge lines may include: each of a piece of partial edge lines is detected from each of the partial images.

According to one or more embodiments, detecting edge lines may further include: combining a plurality of partial edge lines into one edge line.

According to one or more embodiments, detecting a reference line may include: a line fit is applied to the edge lines.

In accordance with one or more embodiments, the line fitting may utilize random sample consensus.

According to one or more embodiments, the edge line may correspond to one of a plurality of edges of the glass sheet.

According to one or more embodiments, detecting an edge defect may include: at least one of a type of the edge defect, a size of the edge defect, and a location of the edge defect is detected.

In accordance with another aspect of the present disclosure, a method of inspecting an edge of a glass sheet is disclosed, the method comprising the steps of: an image of a glass sheet conveyed by a conveyance device is acquired, an edge line of the glass sheet is detected from the image, and a reference line is detected from the edge line. The method further comprises: an edge defect in the glass sheet is detected by comparing the edge line to a reference line, and the glass sheet is determined to be defective when the size of the edge defect is greater than a predetermined value.

According to one or more embodiments, acquiring the image may include: sequentially acquiring, with a stationary camera, partial images of the glass sheet conveyed by the conveyance device at time intervals.

According to one or more embodiments, the method may further comprise: stopping conveyance of the glass sheet when the glass sheet is determined to be defective.

According to one or more embodiments, the predetermined value may depend on the location of the edge defect.

According to one or more embodiments, the glass sheet may be comprised of a plurality of regions, and the predetermined value may depend on the region where the edge defect is present.

According to one or more embodiments, the predetermined value may vary depending on the type of edge defect.

Drawings

Embodiments of the present disclosure will be more clearly understood from the following description taken in conjunction with the accompanying drawings, in which

In the figure:

fig. 1 is a diagram illustrating an apparatus for inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Fig. 2A is a diagram illustrating an optical system included in an apparatus for inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Fig. 2B is a diagram illustrating an optical system included in an apparatus for inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Fig. 3 is a block diagram of an apparatus for inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Fig. 4 is a flow chart illustrating a method of inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Fig. 5A to 5D are diagrams illustrating each step of the method of inspecting an edge of a glass sheet in fig. 4.

Fig. 6 is a flow chart illustrating a method of inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Fig. 7A and 7B are diagrams illustrating some steps of the method of inspecting an edge of a glass sheet in fig. 6.

Fig. 8 is a flow chart illustrating a method of inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Fig. 9A and 9B are diagrams illustrating some steps of the method of inspecting an edge of a glass sheet in fig. 8.

FIG. 10 is a flow chart illustrating a method of inspecting an edge of a glass sheet according to an embodiment of the present disclosure; and

FIG. 11 is a diagram illustrating the step of determining a defect of the glass sheet in FIG. 10.

Detailed Description

Fig. 1 is a diagram illustrating an apparatus for inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Referring to fig. 1, an apparatus 100 for inspecting an edge of a glass sheet may comprise: a transport device 110, at least one optical system 120, and an image processing apparatus 130.

The transport apparatus 110 may convey the glass sheet GS that has undergone the forming and cutting process in direction D1. The transport apparatus 110 may be a conveyor (e.g., a belt conveyor, a chain conveyor, a drum conveyor, or a wheel conveyor). In some embodiments, the glass sheets GS may be loaded on the end of the transport apparatus 110. The conveyance device 110 can convey the glass sheet GS to the other end of the conveyance device 110. For example, the conveyance device 110 may convey the glass sheet GS to the finishing process section.

The optical system 120 is arranged to acquire an image of the glass sheet GS. For example, the optical system 120 may be disposed at a side of the transportation apparatus 110, and may be operated to acquire an edge portion image of the glass sheet GS moved by the transportation apparatus 110. According to some embodiments, glass sheet GS may have a rectangular shape with 4 edges (although other shapes may be used in further embodiments). However, it should be noted that: the apparatus and method are generally utilized to detect defects on an edge of a glass sheet that includes two opposing and parallel edges that extend parallel to the conveyance direction D1. Thus, in some embodiments, the apparatus 100 may comprise: two optical systems 120, wherein the two optical systems 120 may be arranged on each of the two sides of the transport device 110 and are arranged to acquire an image of each of the two opposite edges E1 and E2 of the glass sheet GS parallel to the conveying direction D1. For example, in an embodiment, the optical system 120 may have a configuration that will be described later with reference to fig. 2A and 2B. The optical system 120 is configured to transmit the acquired image to the image processing device 130.

The image processing device 130 processes the image received from the optical system 120 to detect edge defects. For example, the image processing apparatus 130 may detect an edge defect according to a method of inspecting an edge of a glass sheet, which will be described later with reference to fig. 4 to 9B. The image processing device 130 may be, for example: any suitable processing device (e.g., computer). In some embodiments, the image processing device 130 may further include: a display device that displays a real-time image of the glass sheet GS and an edge inspection result of the glass sheet GS. For example, in some embodiments, the displayed inspection results may be "fail" results (e.g., when edge defects exceeding a predetermined size are detected). In some embodiments, a pass result may be indicated if no edge defects are detected that exceed a predetermined size.

In some embodiments, the image processing device 130 may further include: a storage device (e.g., a digital memory device) that stores the acquired images and edge defect detection results.

Fig. 2A is a diagram illustrating an exemplary optical system 120, according to an embodiment of the present disclosure.

The optical system 120 includes: a camera 123 and a light source 124. The light source 124 is arranged to illuminate an edge portion of the glass sheet GS adjacent to the longitudinal edge of the glass sheet. The light source 124 is oriented such that light a emitted from the light source is incident on the glass sheet GS from an oblique direction relative to the glass sheet GS (rather than the Z direction or parallel Y direction). In other words, the light source 124 may be oriented in an oblique direction with respect to the Z direction or parallel to the Y direction of the glass sheet GS. Camera 123 may face light source 124 with glass sheet GS therebetween. The camera 123 may be arranged to capture an edge portion image. The camera 123 may also be oriented in an oblique direction relative to the Z direction perpendicular to the glass sheet GS.

The glass sheet GS includes: two parallel and opposing major surfaces S1 and S2. Further, the edge of the glass sheet GS includes: a surface extending between the two major surfaces S1 and S2. The defective portion of the edge of glass sheet GS in which a defect exists tends to have a surface extending in a direction perpendicular to both main surfaces S1 and S2. For example, the defective portion of the edge of the glass sheet GS may have a surface parallel to the Z direction. Therefore, in the image acquired using the light source 124 and the camera 123 arranged in the oblique direction with respect to the glass sheet GS, the surface of the defective portion of the edge of the glass sheet GS may appear to be thicker (compared to the surface of the defective portion of the edge of the glass sheet GS in the image acquired using the light source 124 and the camera 123 arranged in the Z direction perpendicular to the glass sheet GS). When the edge of the glass sheet GS appears thick enough in the image, an edge line is easily detected from the image of the glass sheet GS. Here, the edge line indicates a line corresponding to the edge of the glass sheet GS on the image of the glass sheet GS. Thus, edge defects can be more accurately detected by imaging the glass sheet at an oblique angle.

As shown in fig. 2A, camera 123 and light source 124 may be located on opposite sides of glass sheet GS. For example, camera 123 may be located above glass sheet GS and light source 124 may be located below glass sheet GS, but conversely camera 123 may be located below glass sheet GS and light source 124 may be located above glass sheet GS.

The camera 123 may be a monochrome digital camera or a color digital camera. The camera 123 may include: a lens 123L and a sensor portion 123S. The light passing through the lens 123L reaches the sensor 123S, and is converted into a digital signal by the image sensor of the sensor portion 123S. In some embodiments, lens 123L may be a compound lens composed of a plurality of sub-lenses. In some embodiments, the camera 123 may further include: the inclined portion 123T. The inclined portion 123T may be used to adjust the direction of the focal plane POF of the camera 123. For example, the inclined portion 123T may be used to adjust the direction of the focal plane POF by changing the angle between the lens 123L and the sensor portion 123S. For example, the inclined portion 123T may rotate about the X axis. More particularly, the inclined portion 123T may be used to adjust the direction of the focal plane POF by adjusting the angle between the lens plane LP of the camera 123 and the image plane IP of the camera 123 (wherein according to the Scheimpflug principle). Here, the lens plane LP is defined as an imaginary plane passing through the optical center of the lens and perpendicular to the optical axis of the lens 123L. The image plane IP is defined as an imaginary plane on which the surface of the image sensor of the sensor section 123S is located. The focal plane POF is defined as an imaginary plane, which is the group focus. In other words, any object located on the focal plane POF is sharply imaged. In some embodiments, the inclined portion 123T may be used to adjust the lens plane LP and the image plane IP to be non-parallel to each other. Also, the inclined portion 123T may be used to adjust the focal plane POF to be parallel to the glass sheet GS. When the focal plane POF is oriented parallel to the glass sheet GS, a clear image can be acquired over the entire area.

According to some embodiments, lens 123L may be a telecentric lens. Telecentric lens representation: a lens with entrance or exit pupils at infinity can reduce errors due to the location of defects in the image or due to the size of defects in the image. Thus, a telecentric lens can be used to obtain an image that accurately shows the size of the edge defect. According to some embodiments, light source 124 may be a telecentric light source. A telecentric light source emitting parallel rays can be used to obtain sharp images with precisely sized edges.

Fig. 2B is a diagram illustrating an optical system included in an apparatus for inspecting an edge of a glass sheet according to an embodiment of the present disclosure. Will be described hereinafter: the difference between the embodiment shown in fig. 2A and this embodiment.

Referring to fig. 2B, in some embodiments, the optical system 120a may further include: a first mirror 121 and a second mirror 122. In other embodiments, the optical system 120a may further include: a first mirror 121, or a second mirror 122. The first mirror 121 and the camera 123 may be oriented such that the focal plane POF becomes parallel to the glass sheet GS. For example, the optical axis of the lens 123L of the camera 123 is fixed in the direction Y parallel to the glass sheet GS, and the direction in which light is incident on the camera 123 can be adjusted by adjusting the direction of the first mirror 121. The second mirror 122 and the light source 124 may be oriented such that light emitted from the light source 124 is reflected by the second mirror 122 and is incident on the glass sheet GS in an oblique direction. For example, the direction of light emitted from the light source 124 is fixed in the direction Y parallel to the glass sheet GS, and the direction of light incident on the glass sheet GS can be adjusted by adjusting the direction of the second mirror 122. Further, the adjustment of the direction of the second mirror 122 may also adjust the direction in which light is incident on the camera 123. For example, instead of adjusting the direction of the camera 123, the direction of the second mirror 122 may be adjusted when the optical axis of the camera 123 is fixed in the direction Y parallel to the glass sheet GS.

The first mirror 121 and/or the second mirror 122 make the following possible: the size of the optical system 120a is reduced by arranging the camera 123 and the light source 124 in a small space, and adjustment of the traveling direction of light is facilitated.

When the optical system 120 or 120a described with reference to fig. 2A or 2B is applied to the apparatus 100 for inspecting an edge of a glass sheet in fig. 1, a small edge defect can be detected, and the size of the edge defect can be measured. For example, the apparatus 100 for inspecting an edge of a glass sheet may detect edge defects having a length of less than about 1mm in each direction.

Fig. 3 is a block diagram of an apparatus for inspecting an edge of a glass sheet according to an embodiment of the present disclosure.

Referring to fig. 3, an apparatus 300 for inspecting an edge of a glass sheet may comprise: a transport apparatus 110, two optical systems 120, an image processing device 130, and a controller 340.

An optical system 120 transmits an image of the edge of the glass sheet to an image processing device 130. Another optical system 120 transmits images of the opposite edges of the glass sheet to an image processing device 130. The image processing device 130 analyzes the received image to detect edge defects of the glass sheet. In some embodiments, the display device of the image processing apparatus 130 may display the acquired image of the glass sheet and the edge inspection results. In some embodiments, the storage device of the image processing device 130 may store the acquired image and the edge defect detection result.

In some embodiments, the image processing device 130 may determine whether the glass sheet to be inspected is defective based on the edge defect detection results. For example, it may be determined from a method 1000 of inspecting an edge of a glass sheet, which will be described later with reference to fig. 10 and 11: whether the glass sheet is defective or not. The image processing apparatus 130 transmits the determination result to the controller 340.

The controller 340 may be: for example, a Programmable Logic Controller (PLC), and may be configured to control the operation of the transport apparatus 110. For example, the controller 340 may stop the operation of the transportation device 110 when a determination result indicating that the glass sheet is defective is received from the image processing apparatus 130. When a determination result indicating that the glass sheet is not defective is received from the image processing apparatus 130, the controller 340 does not stop the operation of the transportation device 110.

In some embodiments, the controller 340 may be connected to an alarm device 350. When a determination result indicating that the glass sheet is defective is received from the image processing apparatus 130, the controller 340 operates the alarm apparatus 350 to notify the user of: defective glass sheets have been found.

In some embodiments, the controller 340 may also be connected to an input device 360. The user may select and enter one of several options via input device 360. When the user determines that there is a low likelihood that the glass sheet will be damaged in a subsequent process as a result of inspecting the glass sheet that has been determined to be defective, the user may select a pass option to pass the glass sheet. When the user determines that there is a high likelihood that the glass sheet will be damaged in a subsequent process as a result of inspecting the glass sheet that has been determined to be defective, the user may determine to immediately remove the glass sheet or to later remove the glass sheet. When it is determined that the glass sheet is immediately removed, the user may remove the glass sheet and then select a removal complete option. When it is determined to later remove the glass sheet, the user may select a later removal option without removing the glass sheet. When the following is determined: as a result of inspecting the glass sheet that has been determined to be defective, the determination by the image processing apparatus 130 is erroneous, and the user may select a non-defective option.

The input device 360 may transmit input information to the controller 340. The controller 340 receives the input information and then replies to the operation of the transportation device 110. In addition, the controller 340 may transmit the defect determination result and the input information to the upper server.

Fig. 4 is a flow chart illustrating a method of inspecting an edge of a glass sheet according to an embodiment of the present disclosure. Fig. 5A to 5D are diagrams illustrating each operation of the method of inspecting an edge of a glass sheet illustrated in fig. 4.

Referring to fig. 4, a method 400 of inspecting an edge of a glass sheet according to an embodiment of the present disclosure includes the steps of: acquiring an image S410, detecting an edge line S420, detecting a reference line S430 and detecting an edge defect S440.

Referring to fig. 4 and 5A, in the image acquisition step S410, an image IMG of the glass sheet GS is acquired. The optical system may be used to take an image of the glass sheet GS. For example, the optical system 120 or 120a shown in fig. 2A or fig. 2B may be used to capture an image IMG of the glass sheet GS. The image IMG may show at least a portion of the edge of the glass sheet GS. Some glass sheets GS may include: an edge defect. Here, the edge defect indicates a defect existing at the edge of the glass sheet GS. Edge defects may include (for example): a protruding defect a and a recessed defect B. Here, the projected defect a denotes a portion projected from an edge, which is not defective elsewhere. Here, the recessed defect B denotes a portion extending inward from an edge, wherein the edge is free of defects elsewhere.

Referring to fig. 4 and 5B, in the edge line detecting step S420, an edge line EL of the glass sheet GS is detected from the image IMG. Detecting the edge line EL may include the steps of: an edge filter is applied to the image IMG. For example, in the direction shown in fig. 5B, a vertical edge filter may be applied to detect an edge line EL of an edge extending in the horizontal direction Y. The edge line EL may correspond to one of a plurality of edges of the glass sheet.

Referring to fig. 4 and 5C, in the step S430 of detecting the reference line, the reference line RL may be detected from the edge line EL of fig. 5B. For example, the reference line RL may be detected by applying line fitting to the edge line EL. In some embodiments, the line fitting may utilize random sample consensus (RANSAC). Using RANSAC, distortion of the reference line RL caused by the presence of the edge defects a and B or the shaking of the moving glass sheet GS can be reduced. In this way, the reference line RL approximating the edge having neither the edge defect a nor the edge defect B can be obtained.

Referring to fig. 4 and 5D, in the step S440 of detecting an edge defect, the edge line EL and the reference line RL may be compared. A projected defect a as a part of the edge line EL projected from the reference line RL along the outward direction X of the glass sheet GS or a recessed defect B as a part of the edge line EL extended inward from the reference line RL along the direction X of the glass sheet GS can be detected. In the step S440 of detecting the edge defect, at least one of a type, a size, and a position of the defect may be detected. Here, the type of the defect may be a protruding defect a or a recessed defect B. The size of the defect may be represented by a length L1 of the defect in the direction X and a length L2 of the defect in the orthogonal direction Y. The location of the defect may be a distance D from an end of the glass sheet GS to a location where the defect begins along the direction of extension Y of the glass sheet GS.

Fig. 6 is a flow chart illustrating a method of inspecting an edge of a glass sheet according to an embodiment of the present disclosure. Fig. 7A and 7B are diagrams illustrating steps of the method of inspecting an edge of a glass sheet in fig. 6. Differences from the embodiment illustrated in fig. 4 to 5D will be described hereinafter.

Referring to fig. 6 and 7A, a method 600 of inspecting an edge of a glass sheet includes: a step S410 of acquiring an image of the edge, said step S410 further comprising: a step S411 of acquiring partial images and a step S412 of combining partial images. In the step S411 of acquiring partial images, a plurality of images IMG1 to IMG3 of each portion of the glass sheet GS may be acquired. For example, as shown in fig. 1, partial images IMG1 to IMG3 of the moving glass sheet GS are sequentially photographed at predetermined time intervals using the fixed optical system 120. Each of the partial images IMG1 to IMG3 may show only a part of the edge of the glass sheet GS. In the drawings, 3 partial images IMG1 to IMG3 are captured. However, the number of partial images is not limited to 3, and may vary depending on the size of the glass sheet GS.

In the step S412 of combining the partial images, the partial images IMG1 to IMG3 may be combined into one image IMG. Each of the partial images IMG1 through IMG3 may show a portion of the edge of the glass sheet GS. The combined image IMG may show all portions of the edge of the glass sheet GS. To combine the partial images IMG 1-3 into a single image IMG, the partial images IMG 1-3 may be connected side-by-side. In some embodiments, when the optical system 120 shown in fig. 1 is misaligned with the moving direction D1 of the glass sheet GS, the partial images IMG1 to IMG3 may be joined as shown in fig. 7A in consideration of the rotation angle RA caused by the misalignment.

Referring to fig. 6 and 7B, in the step S420 of detecting edge lines, one edge line EL may be detected from the combined image IMG.

Since the method 600 of inspecting the edge of the glass sheet according to the embodiment of the present disclosure makes it possible to detect defects by combining partial images IMG1 to IMG3, a large glass sheet GS can also be inspected (regardless of the size of the glass sheet GS).

Fig. 8 is a flow chart illustrating a method of inspecting an edge of a glass sheet according to an embodiment of the present disclosure. Fig. 9A and 9B are diagrams illustrating some steps of the method of inspecting an edge of a glass sheet in fig. 8. Differences from the embodiment illustrated in fig. 4 to 5D will be described later.

Referring to fig. 8, the step S410 of acquiring an image includes: a partial image is acquired in step S411. The step S411 of acquiring the partial image is the same as the step described with reference to fig. 6.

Referring to fig. 8 and 9A, the step S420 of detecting an edge line includes: a step S421 of detecting partial edge lines and a step S422 of combining partial edge lines. In the step S421 of detecting partial edge lines, partial edge lines EL1 to EL3 may be detected from the partial images IMG1 to IMG3, respectively. Each of the partial edge lines EL 1-EL 3 may correspond to a respective portion of the edge of the glass sheet GS.

In the step S422 of combining partial edge lines, the partial edge lines EL1 to EL3 may be combined into one edge line EL. In some embodiments, the edge line EL may correspond to one of the plurality of edges of the glass sheet GS.

Referring to fig. 8 and 9B, in the step S430 of detecting a reference line, a reference line RL may be detected from an edge line EL (see fig. 9A). Since the reference lines are not separately detected from the partial edge lines EL1 to EL3, and the single reference line RL is detected from the combined single edge line EL, the reference line RL can be detected which is preferably approximated to an edge having no defect. Thus, small edge defects can be detected more accurately.

Since the method 800 of inspecting the edge of the glass sheet according to the embodiment of the present disclosure makes it possible to detect defects by combining partial images IMG1 to IMG3, the glass sheet GS can also be inspected (regardless of the size of the glass sheet GS). Further, since the reference line RL is detected from the single edge line EL obtained by combining the partial edge lines EL1 to EL3, small edge defects can be detected more accurately.

Fig. 10 is a flow diagram illustrating a method of inspecting an edge of a glass sheet according to further embodiments of the present disclosure. FIG. 11 is a diagram illustrating the steps of determining defects of the glass sheet in FIG. 10.

Referring to fig. 10, in the input glass sheet step S1010, the glass sheet GS may be input to an apparatus for inspecting an edge of the glass sheet. For example, as shown in fig. 1, the transport apparatus 110 may be used to input the glass sheet GS into the portion where the optical system 120 is mounted.

Subsequently, the step S410 of acquiring an image, the step S420 of detecting an edge line, the step S430 of detecting a reference line, and the step S440 of detecting an edge defect may be performed. The steps from step S410 of acquiring an image to step S440 of detecting an edge defect may be the same as those in any one of the methods 400, 600, and 800 of inspecting an edge of a glass sheet described with reference to fig. 4, 6, and 8.

Referring to fig. 10 and 11, in the step S1020 of determining the defects of the glass sheet, it may be determined based on the size of the edge defects measured in the step S440 of detecting the edge defects: whether or not the glass sheet GS is defective. For example, when the glass sheet GS includes at least one edge defect having a size greater than a predetermined value, the glass sheet GS may be determined to be defective. For example, when the glass sheet GS includes at least one edge defect having a length greater than 5mm in the X direction or greater than 3mm in the Y direction, the glass sheet GS may be determined to be defective. However, it should be noted that: these length values are merely exemplary and the predetermined dimension values used to determine whether a glass sheet is defective may vary.

In some embodiments, the predetermined value may vary depending on the type of edge defect. For example, when glass sheet GS includes at least one of protruding defect a1 or a2 having a length greater than 5mm in the X-direction or greater than 5mm in the Y-direction or recessed defect B1 or B2 having a length greater than 4mm in the X-direction or greater than 4mm in the Y-direction, glass sheet GS may be determined to be defective.

In some embodiments, the predetermined value may vary depending on the location of the edge defect. For example, glass sheet GS may include: a plurality of regions R1 to R4, and the predetermined value may be changed according to the region. For example, glass sheet GS may be determined to be defective when glass sheet GS includes at least one defect a1 having a length greater than 4mm in the X-direction or greater than 4mm in the Y-direction (and the defect is present in first region R1) or defect a2 having a length greater than 5mm in the X-direction or greater than 5mm in the Y-direction (and wherein the defect is present in second region R2).

The likelihood of cracking in subsequent processes may depend not only on the size of the defect, but also on the location and type of the defect. Using the information about the location and/or type of the defect and the size of the defect, the glass sheet GS with a high probability of breakage in subsequent processes can be determined more accurately.

When the glass sheet GS is determined to be defect-free, the glass sheet GS may pass through the inspection apparatus during the performance of step S1031. When the glass sheet GS is determined to be defective, the movement of the glass sheet GS may be stopped at step S1032. The user of the inspection apparatus can inspect the state of the glass sheet GS that has been determined to be defective and then determine whether to convey the glass sheet GS or remove the glass sheet GS from the transportation apparatus. When it is determined by the user that the glass sheet GS that has been determined to be defective has a low possibility of breakage in the subsequent process, the user can resume the movement of the glass sheet GS, and the glass sheet GS can pass through the inspection apparatus. When it is determined by the user that the glass sheet GS that has been determined to be defective has a high possibility of breakage in the subsequent process, the glass sheet GS may be removed from the transportation apparatus. The glass sheet GS may be removed from the transportation apparatus at a point of time when the movement of the glass sheet GS is stopped or immediately after the movement of the glass sheet GS is resumed. When it is determined by the user that the glass sheet GS that has been determined to have the defect is not defective, the user can resume the movement of the glass sheet GS, and the glass sheet GS can pass through the inspection apparatus.

The method 1000 of inspecting the edges of glass sheets according to embodiments of the present disclosure makes it possible to determine that glass sheets have a high likelihood of damage in subsequent processes and remove these glass sheets from the transportation apparatus. Thus, the down time of the conveyor can be reduced to clear sheets of glass from the conveyor due to damage to the glass sheets in subsequent processes (e.g., finishing processes).

As will be apparent to those skilled in the art: various modifications and variations may be made to the disclosed embodiments without departing from the spirit and scope of the disclosure. Therefore, what is desired is: this disclosure is intended to cover such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.