KR102619212B1 - Apparatus of inspecting cutting surface of glass substrate using scattered light - Google Patents

Abstract

The present invention discloses an apparatus for inspecting defects on a cut surface of a glass substrate. An inspection device according to the present invention includes a light emitting unit that irradiates light to a cut surface of a glass substrate; A light receiving unit that detects scattered light generated from the cut surface of the glass substrate; An image generator that generates an image using the detection signal of the light receiver; It includes a transfer drive unit that moves the glass substrate, and while the glass substrate is moving, light is irradiated to the cut surface and an image is generated.
According to the present invention, by irradiating light directly to the cut surface of a glass substrate and analyzing the scattered light, it is possible to more accurately identify micro defects present on the cut surface. Additionally, according to the present invention, since multiple glass substrates can be inspected simultaneously, inspection efficiency can be greatly improved.

Description

Apparatus of inspecting cutting surface of glass substrate using scattered light}

The present invention relates to a device for inspecting damage or defects in a glass substrate, and specifically to a device for inspecting a cut surface of a glass substrate using scattered light.

In general, glass substrates used in displays, smartphones, etc. are manufactured through a molding process that molds molten glass into a flat plate, a cutting process according to the product shape, a cut surface healing process, and an inspection process.

Among these, the cut surface healing process is a process that removes potential causes of damage by removing cracks, chipping, etc. on the cut surface generated during the cutting process. A method of polishing the cut surface with a polishing device or etching the cut surface with an etchant. This applies.

In addition, the inspection process is a process of checking whether there are defects that could not be removed in the cut surface healing process. A camera inspection method is mainly used, which photographs the surface of the edge of the glass substrate with a vision camera and then determines the presence and location of the defect through an enlarged image. there is.

However, relatively large defects can be easily detected through images captured by a vision camera, but there is a problem in that it is not easy to accurately detect microscopic defects of several micrometers or less.

To improve this problem, a device that detects microdefects in a glass substrate using scattered light was recently introduced.

As illustrated in FIG. 1, the inspection device using scattered light includes a stand 20 on which a glass substrate 10 is placed, and a light emitting unit 30 and a light receiving unit 40 respectively installed on the upper part of the stand 20. and an image generator 50 that generates an image using the light detected by the light receiving unit 40, and a determination unit 60 that determines whether there is a defect and the location of the defect using the image generated by the image generator 50. ), etc.

However, the inspection device of FIG. 1 has a limitation in that it is difficult to detect fine defects present on the cut surface of the glass substrate 10 because the light emitting unit 30 emits light to the edge of the upper surface 11 of the glass substrate 11. In addition, since light must be shined on the upper surface 11 of the glass substrate 10, it is difficult to inspect multiple glass substrates 10 at the same time, which limits the ability to improve inspection efficiency.

Korean Patent Publication No. 10-2018-0012359 (published on February 6, 2018)

The present invention was conceived against this background, and its purpose is to provide a device capable of inspecting the cut surface of a glass substrate. Additionally, the purpose of the present invention is to increase inspection efficiency by allowing multiple glass substrates to be inspected simultaneously.

In order to achieve this object, one aspect of the present invention includes a light emitting unit that irradiates light to a cut surface of a glass substrate; A light receiving unit that detects scattered light generated from the cut surface of the glass substrate; An image generator that generates an image using the detection signal of the light receiver; An apparatus for inspecting a cut surface of a glass substrate is provided, including a transfer drive unit that moves the glass substrate, and irradiating light to the cut surface while the glass substrate is moving and generating an image.

In the inspection device according to one aspect of the present invention, the transfer drive unit includes a pair of alignment rollers, and the pair of alignment rollers each contact one surface and the other surface of the moving glass substrate to set the cut surface of the glass substrate to a reference position. It serves to align the light emitting unit and can irradiate light to the cut surface of the glass substrate between the pair of alignment rollers.

Additionally, in the inspection device according to one aspect of the present invention, the transfer driving unit includes a plurality of transfer lines that respectively move a plurality of glass substrates, and the light emitting unit includes a cutting surface of a plurality of glass substrates that respectively move along the plurality of transfer lines. It includes a plurality of light emitting units that each emit light, but only one by one is sequentially turned on in a time division manner, and the light receiving unit can detect scattered light generated from a plurality of glass substrates.

Additionally, in the inspection device according to one aspect of the present invention, the light receiving unit may include a plurality of light receiving units each detecting scattered light generated from a plurality of glass substrates.

Additionally, in the inspection device according to one aspect of the present invention, the transfer driving unit includes a plurality of transfer lines that respectively move a plurality of glass substrates, and the light emitting unit includes a cutting surface of a plurality of glass substrates that respectively move along the plurality of transfer lines. It includes a plurality of light emitting units each emitting light, and a light blocking wall may be formed between the plurality of light emitting units to prevent mutual interference.

Another aspect of the invention is a light source; a splitter that splits the light transmitted from the light source into multiple pieces; A plurality of optical systems that respectively irradiate a plurality of lights output from the splitter onto the cut surfaces of a plurality of glass substrates; A plurality of shutters respectively installed between the splitter and the plurality of optical systems to selectively block light; A light receiving unit that detects scattered light generated from a plurality of glass substrates; An image generator that generates an image using the detection signal of the light receiver; It includes a transfer drive unit that moves a plurality of glass substrates, wherein the plurality of optical systems irradiate light to the cut surfaces of the plurality of glass substrates each moving along the plurality of transfer lines, one by one in a time division manner according to the operation of the shutter. Only the light can be irradiated sequentially.

According to the present invention, by irradiating light directly to the cut surface of a glass substrate and analyzing the scattered light, it is possible to more accurately identify micro defects present on the cut surface. Additionally, according to the present invention, since multiple glass substrates can be inspected simultaneously, inspection efficiency can be greatly improved.

1 is a diagram illustrating a conventional inspection device.
Figure 2 is a schematic configuration diagram of an inspection device according to a first embodiment of the present invention.
3 is a perspective view of an inspection device according to a first embodiment of the present invention.
Figure 4 is a perspective view of an inspection device according to a second embodiment of the present invention.
5 is a plan view of an inspection device according to a second embodiment of the present invention.
Figure 6 is a diagram showing a modified example of an inspection device according to a second embodiment of the present invention.
7 is a diagram illustrating the operation sequence of the first to third light emitting units.
Figure 8 is a diagram illustrating the process of inspecting the first to third glass substrates at once
9 is a diagram showing a modified example of the light emitting unit.
Figure 10 is a diagram showing a modified example of the light receiving unit.
11 is a diagram showing an inspection device according to a third embodiment of the present invention.
Figure 12 is a diagram showing a modified example of an inspection device according to a third embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

For reference, in the drawings attached to this specification, there are parts shown in dimensions or proportions that are different from the actual ones, but this is for convenience of explanation and understanding, and it should be noted in advance that the scope of the present invention should not be construed as limited due to this. In addition, in this specification, when one element is connected, combined, or electrically connected to another element, it is not only a case where it is directly connected, combined, or electrically connected to another element, but also when an element is connected to another element in the middle. This also includes cases where they are indirectly connected, combined, or electrically connected. Additionally, when one element is directly connected or combined with another element, it means that it is connected or combined without any other elements in between. In addition, the fact that a part includes a certain component does not mean that other components are excluded, but that it can further include other components, unless specifically stated to the contrary. Additionally, in this specification, expressions such as before, after, left, right, up, and down are relative concepts that can vary depending on the viewing position, so the scope of the present invention should not necessarily be limited to the corresponding expressions.

<First Example>

As shown in the schematic configuration diagram of FIG. 2 and the perspective view of FIG. 3, the inspection device 100 according to the first embodiment of the present invention is a light emitting device that radiates light in an oblique direction to the cut surface 12 of the glass substrate 10. Unit 110, a light receiving unit 120 that detects light reflected or scattered from the cut surface 12, an image generating unit 130 that generates an image using the light detected by the light receiving unit 120, and image generation It includes a determination unit 140 that determines whether there is a defect and the location of the defect using the image generated by the unit 130, and a transfer drive unit 180 that moves the glass substrate 10.

Since light must be accurately irradiated to the cut surface 12 of the glass substrate 10 of the light emitting unit 110, it is desirable to use a laser light source with excellent straight-line propagation, but is not necessarily limited to this. This is because it is also possible to focus light on the cutting surface 12 using a general LED light source and optical system.

In addition, the light emitting unit 110 preferably outputs green light, for example, but is not necessarily limited thereto.

Meanwhile, when the thickness of the glass substrate 10 is very thin, it may be difficult to accurately irradiate light to the cut surface 12 due to the curvature of the glass substrate 10.

In order to prevent this problem, in the embodiment of the present invention, as shown in FIG. 3, the glass substrate is moved between a pair of alignment rollers 190a selected from among the plurality of transfer rollers 190 that transfer the glass substrate 10. It is desirable to irradiate light to the cut surface 12. Specifically, it is desirable to irradiate light while focusing on the midpoint of the pair of alignment rollers 190a.

In this way, the glass substrate 10 is spread while passing between the pair of alignment rollers 190a and the position of the cut surface 12 is maintained constant, so that the light output from the light emitting unit 110 is transmitted to the cut surface 12. You can always illuminate accurately.

The light receiver 120 detects light reflected or scattered from the cut surface 12, and for example, a CCD image sensor or a CMOS image sensor may be used. Additionally, the light receiving unit 120 may include an optical system that condenses light reflected and scattered from the cut surface 12 to an image sensor.

Additionally, an image sensor of a sufficient size must be installed in the light receiving unit 120, taking into account the curves and irregularities of the cut surface 12.

The light emitting unit 110 is preferably installed so that the output direction can be adjusted. Additionally, it is preferable that the light receiving unit 120 is installed so that its direction can be adjusted.

In the drawing, the output direction of the light emitting unit 110 and the direction of the light receiving unit 120 are shown to be symmetrical about a vertical line, but this is only an example and may be installed differently as needed.

For example, in order to receive only the scattered light generated from the defect area and excluding the reflected light generated from the cut surface 12 of the glass substrate, it is desirable to install the light receiving unit 120 in a direction different from the reflection angle. When installed in this way, parts without defects appear dark in the image, and defective parts appear bright in the image due to scattered light.

Meanwhile, the drawing shows that the light emitting unit 110 and the light receiving unit 120 are installed independently of each other, but the light emitting unit 110 and the light receiving unit 120 are not limited to this. Accordingly, the light emitting unit 110 and the light receiving unit 120 may be mounted on one frame, or may be connected to each other using a connecting member.

The image generator 130 generates an image of the cut surface 12 of the glass substrate using the electrical signal generated by the image sensor of the light receiver 120. The image generated by the image generator 130 may be output through a display (not shown in the drawing).

The determination unit 140 determines whether or not there is a defect and its location in the image generated by the image generator 130.

For example, the determination unit 140 may compare the size and brightness of the scattered light displayed in the image with a set standard, and determine it to be a defect if it exceeds the set standard. Additionally, if it is determined that there is a defect, the location of the defect can be determined using the moving distance of the glass substrate 10.

The determination unit 140 may determine whether there is a defect and the location of the joint through a machine learning algorithm or a deep learning algorithm using the image generated by the image generator 130.

It is also possible to omit the determination unit 140 and use the image generated by the image generator 130 to determine whether there is a defect with the naked eye.

The transfer drive unit 180 rotates the transfer roller 190 and may include a motor, a rotating cylinder, etc.

A plurality of transfer rollers 190 are installed to move the glass substrate 10. In particular, a pair of alignment rollers 190a selected from among the plurality of transfer rollers 190 are positioned on the cut surface 12 of the glass substrate 10 at a reference position where the light emitting unit 110 irradiates light even while the glass substrate 10 is moving. ) serves to accurately align the

Therefore, the pair of alignment rollers 190a must be installed to contact one side and the other side of the glass substrate 10, respectively, while being spaced apart by the thickness of the glass substrate 10.

The transfer drive unit 180 rotates at least one of the plurality of transfer rollers 190, and is preferably installed to rotate at least one of the pair of alignment rollers 190a.

In the drawing, it is shown that the glass substrate 10 is transported standing up with the transport roller 190 positioned vertically, but it is not limited to this. Therefore, it is also possible to transfer the glass substrate 10 by laying it down by placing the transfer roller 190 horizontally.

Meanwhile, the inspection device 100 according to an embodiment of the present invention is a device that inspects defects by irradiating light to the narrow cut surface 12 rather than the upper surface of the glass substrate 10, so it can inspect multiple glass substrates 10 at once. It can be easily modified in this way. Below, various embodiments that can inspect multiple glass substrates 10 at once will be described.

<Second Embodiment>

The inspection device 100a according to the second embodiment of the present invention, as illustrated in the perspective view of FIG. 4 and the plan view of FIG. 5, has the first to third glass substrates 10a, 10b, and 10c parallel to each other, respectively. After being emitted from the three transfer lines, the first to third light emitting units 111, 112, and 113 installed at the top of each transfer line, and the first to third light emitting units 111, 112, and 113, respectively, An image is generated using first to third light receiving units 121, 122, and 123 that respectively receive scattered light, and electrical signals generated from each image sensor of the first to third light receiving units 121, 122, and 123. It may include an image generator 130 that determines the presence and location of defects in the image generated by the image generator 130.

Each of the three transfer lines includes a plurality of transfer rollers 190, as shown in FIG. 3, and the transfer drive unit 180 can rotate at least one transfer roller 190 for each transfer line.

Also, as described in the first embodiment, it is desirable to install a pair of alignment rollers 190a in each of the three transfer lines to prevent the cutting surface 12 from deviating from the reference position even while the glass substrate 10 is moving.

That is, a pair of alignment rollers 190a installed in each of the three transfer lines are installed to contact one side and the other side of the glass substrate 10, respectively, while being spaced apart from each other by the thickness of the glass substrate 10, and the first to 3 Preferably, the light emitting units 111, 112, and 113 radiate light to the cut surface 12 of the glass substrate passing between the pair of alignment rollers 190a in the corresponding transfer line.

The first to third light emitting units 111, 112, and 113 may be installed independently of each other as shown in FIG. 4, and the first to third light emitting units 111, 112 may be installed in one frame as shown in FIG. 5. , 113) may be an integrated modular light emitting unit 110a.

Meanwhile, in FIGS. 4 and 5, the light scattered after being emitted from the first to third light emitting units 111, 112, and 113 is shown to be received by the first to third light receiving units 121, 122, and 123, respectively. It is not necessarily limited to this.

For example, as shown in the inspection device 100b of FIG. 6, the light of the first to third glass substrates 10a, 10b, and 10c is emitted from the first to third light emitting units 111, 112, and 113. It may be configured to receive all of the light scattered from each of the cut surfaces 12 by one light receiving unit 120.

However, if the first to third light emitting units 111, 112, and 113 emit light at the same time, the accuracy of inspection may be reduced due to interference, so it is necessary to prevent interference.

As an example, a light blocking member (not shown in the drawing) is installed between the first to third glass substrates 10a, 10b, and 10c, so that the light emitted from each light emitting unit 111, 112, and 113 is transmitted to the corresponding glass substrate. It is possible to prevent light from shining on an adjacent glass substrate or from being reflected and then incident on an adjacent light receiving unit.

As another example, as illustrated in FIG. 7, the first to third light emitting units 111, 112, and 113 may be alternately turned on by controlling the first to third light emitting units 111, 112, and 113 in a time division manner.

In this case, as shown in FIG. 8, it is preferable to move the first to third glass substrates 10a, 10b, and 10c in response to the on/off states of the first to third light emitting units 111, 112, and 113.

That is, when only the first light emitting unit 111 is ON, the light receiving unit 120 and the image generating unit 130 move only the first glass substrate 10a, as shown in (a) of FIG. 8. It is possible to generate an image of the cut surface 12 of the first glass substrate 10a.

In addition, when only the second light emitting unit 112 is ON, as shown in (b) of FIG. 8, the light receiving unit 120 and the image generating unit 130 are moved while only the second glass substrate 10b is moved. Through this, an image of the cut surface 12 of the second glass substrate 10b can be generated.

In addition, when only the third light emitting unit 113 is ON, as shown in (c) of FIG. 8, the light receiving unit 120 and the image generating unit 130 are moved while only the third glass substrate 10c is moved. Through this, an image of the cut surface 12 of the third glass substrate 10c can be generated.

By continuously repeating this process, an image of the cut surface 12 can be obtained for each glass substrate while sequentially moving the first to third glass substrates 10a, 10b, and 10c.

Meanwhile, in the embodiment of the present invention, the entire area of the cut surface 12 must be continuously photographed without any gaps while moving each glass substrate 10a, 10b, and 10c, so the frame rate of the image is adjusted to each glass substrate 10a, 10b, and 10c. ) must be able to be adjusted according to the moving speed.

For example, if a high frame rate is applied when the glass substrate moves at high speed, and a low frame rate is applied when the glass substrate moves at low speed, the shooting interval on the cutting surface 12 can be kept constant.

FIG. 9 shows another method of preventing interference when the first to third light emitting units 111, 112, and 113 simultaneously emit light.

That is, if a light blocking wall 116 protruding downward from both sides of each light emitting part 111, 112, and 113 is formed on the bottom of the integrated light emitting part 110b in which the first to third light emitting parts 111, 112, and 113 are integrated, the adjacent light blocking wall 116 is formed. Interference by the light emitting part can be prevented.

In this case, the space between two adjacent light blocking walls 116 may be provided as a space through which the upper ends of each glass substrate 10a, 10b, and 10c pass. Additionally, if the lower end of each light blocking wall 116 is positioned lower than the upper end of the glass substrates 10a, 10b, and 10c, interference by adjacent light emitting units can be further prevented.

The drawing shows that a light blocking wall 116 is formed on both sides of each light emitting unit 111, 112, and 113, but this is not necessarily limited, so the light blocking wall 116 is formed to protrude only between two adjacent light emitting units 111, 112, 112, and 113. You may.

Meanwhile, when the integrated light emitting unit 110b is applied in this way, as shown in FIG. 10, the first to third light receiving units 121, 122, and 123 are integrated on the bottom of the integrated light receiving unit 120b, where each light receiving unit 121, 122, and 123 is installed. Interference by adjacent light emitting units can be more reliably prevented by forming light blocking walls 126 protruding downward from both sides.

<Third Embodiment>

The inspection device 100c according to the third embodiment of the present invention is similar to the first and second embodiments in that it includes a light source 150, a splitter 160, and an optical system 200, as illustrated in FIG. 11. There is a difference.

That is, while the inspection devices 100, 100a, and 100b according to the first and second embodiments of the present invention include light emitting units 110, 110a, and 110b each having their own light emitting elements such as light emitting diodes, The inspection device 100c according to the third embodiment splits the light transmitted from the single light source 150 into three lights using the splitter 160, and sends the three split lights into first to third optical systems ( Each cut surface 12 of the first to third glass substrates 10a, 10b, and 10c is irradiated through 210, 220, and 230).

The light source 150 is preferably a laser light source, but is not necessarily limited thereto.

The splitter 160 serves to branch the light transmitted from the light source 150 by reflecting and transmitting it, and one or more splitters may be used considering the number of branched lights.

The first to third optical systems 210, 220, and 230 each include one or more lenses, and send three lights diverged through the splitter 160 to the first to third glass substrates 10a, 10b, and 10c, respectively. It serves to irradiate each cut surface (12).

Meanwhile, a shutter 170 capable of selectively blocking light may be installed between the splitter 160 and the first to third optical systems 210, 220, and 230.

Since the shutter 170 can be used to selectively block light incident on the first to third optical systems 210, 220, and 230, the first to third glass substrates ( Inspection of the cut surfaces 12 of 10a, 10b, and 10c) may be performed in a time-sharing manner.

Meanwhile, in Figure 11, the light scattered from the cut surface 12 of the first to third glass substrates 10a, 10b, and 10c after being output from the first to third optical systems 210, 220, and 230 is sent to one light receiving unit ( 120) is shown to receive light, but is not limited to this.

For example, as shown in FIG. 12, the first to third light receiving units 121, 122, and 123 installed to respectively correspond to the first to third optical systems 210, 220, and 230 are connected to the first to third glass substrates. It may also be configured to receive scattered light generated from each of the cut surfaces 12 of (10a, 10b, and 10c).

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and may be implemented with various modifications or modifications.

For example, in the above-described embodiment, one inspection device inspects three glass substrates at once, but the device is not limited to this and may be configured to inspect two or four or more glass substrates at once.

As such, the present invention can be implemented in various forms in the course of specific application, and modified or modified embodiments also fall within the scope of rights of the present invention if they include the technical idea of the present invention disclosed in the patent claims described later. Of course.

10: Glass substrate 11: Top surface 12: Cut surface
100: inspection device 110: light emitting unit
111, 112, 113: first, second, third light emitting parts 116: light blocking wall
120: light receiving unit 121, 122, 123: first, second, third light receiving unit
126: light blocking wall 130: image generator 150: light source
160: Splitter 170: Shutter 180: Transport drive unit
190: Transfer roller 190a: Alignment roller 200: Optical system
210, 220 230: 1st, 2nd, 3rd optical system

Claims (6)

A light emitting unit that radiates light to the cut surface of the glass substrate;
A light receiving unit that detects scattered light generated from the cut surface of the glass substrate;
An image generator that generates an image using the detection signal of the light receiver;
A transfer drive unit that moves a glass substrate and includes a pair of alignment rollers.
Includes,
While the glass substrate is moving, light is radiated to the cut surface and an image is generated.
A pair of alignment rollers contact one side and the other side of the moving glass substrate and serve to align the cut surface to the reference position.
A cut surface inspection device for a glass substrate, wherein the light emitting unit irradiates light to a cut surface aligned between a pair of alignment rollers among the cut surfaces of a moving glass substrate. delete According to paragraph 1,
The transfer drive unit includes a plurality of transfer lines,
Each of the multiple transfer lines includes a pair of alignment rollers that contact one side and the other side of the moving glass substrate to align the cut surface to the reference position,
The light emitting unit includes a plurality of light emitting units each emitting light to cut surfaces of a plurality of glass substrates moving along a plurality of transfer lines, but only one by one is turned on sequentially in a time division manner,
Each of the plurality of light emitting units irradiates light to a cut surface of a moving glass substrate aligned between a pair of alignment rollers,
A cut surface inspection device for a glass substrate, wherein the light receiving unit detects scattered light generated from a plurality of glass substrates. According to paragraph 3,
A cut surface inspection device for a glass substrate, wherein the light receiving unit includes a plurality of light receiving units each detecting scattered light generated from a plurality of glass substrates. According to paragraph 1,
The transfer drive unit includes a plurality of transfer lines,
Each of the multiple transfer lines includes a pair of alignment rollers that contact one side and the other side of the moving glass substrate to align the cut surface to the reference position,
The light emitting unit includes a plurality of light emitting units that respectively irradiate light to cut surfaces of a plurality of glass substrates each moving along a plurality of transfer lines,
Each of the plurality of light emitting units irradiates light to a cut surface of a moving glass substrate aligned between a pair of alignment rollers,
A cut surface inspection device for a glass substrate, characterized in that a light blocking wall is formed between the plurality of light emitting units to prevent mutual interference. light source;
a splitter that splits the light transmitted from the light source into multiple pieces;
A plurality of optical systems that respectively irradiate a plurality of lights output from the splitter onto the cut surfaces of a plurality of glass substrates;
A plurality of shutters respectively installed between the splitter and the plurality of optical systems to selectively block light;
A light receiving unit that detects scattered light generated from a plurality of glass substrates;
An image generator that generates an image using the detection signal of the light receiver;
Multiple transfer lines that each move multiple glass substrates
Includes,
Each of the multiple transfer lines includes a pair of alignment rollers that contact one side and the other side of the moving glass substrate to align the cut surface to the reference position,
A plurality of optical systems irradiate light to the cut surfaces of a plurality of glass substrates each moving along a plurality of transfer lines, but sequentially irradiate light only one by one in a time-division manner according to the operation of the shutter,
A glass substrate cut surface inspection device, wherein a plurality of optical systems each irradiate light to a cut surface aligned between a pair of alignment rollers among the cut surfaces of a moving glass substrate.