KR101977243B1 - Apparatus for Inspecting Glass Substrate, Method of Inspecting Glass Substrate and Deposition Apparatus - Google Patents

Abstract

An embodiment of the present invention, the stage on which the loaded glass substrate is seated; A light source unit irradiating light to the inside of the glass substrate to guide the light; A camera for obtaining an image of light emitted through one surface of the glass substrate as an image; And an inspection unit for analyzing an image transmitted from the camera and inspecting the glass substrate for cracks or foreign substances.

Description

Inspection apparatus of glass substrate, inspection method and deposition apparatus using the same {Apparatus for Inspecting Glass Substrate, Method of Inspecting Glass Substrate and Deposition Apparatus}

Embodiment of the present invention relates to an inspection apparatus for a glass substrate, an inspection method and a deposition apparatus using the same.

With the development of information technology, the market for a display device, which is a connection medium between a user and information, is growing. Accordingly, organic light emitting display (OLED), electrophoretic display (EPD), liquid crystal display (LCD) and plasma display panel (PDP) The use of display devices such as these is increasing.

Some of the aforementioned display devices, for example, an organic light emitting display device, an electrophoretic display device, and a liquid crystal display device, form a device by depositing a thin film on a substrate by heating a source disposed in the deposition device.

A glass substrate is generally used as a material of the substrate used in manufacturing the aforementioned display device. In the case of the glass substrate, cracks (scratches, stamps, etc.) or foreign matters are formed on the inside and outside due to various causes. Therefore, the manufacturing process of the display device includes a fine defect inspection process for inspecting the state of the upper surface (such as scratches or imprints on the surface, presence or absence of foreign substances, etc.) before and after the etching process of the glass substrate.

In the related art, a fine defect inspection was performed on a glass substrate using a line scan camera. By the way, the scratches formed on the surface of the glass substrate had a shallow depth before etching, and the stamping had a shallow depth after etching. Scratches have different depths of defect before and after etching, and stamping causes diffuse reflection of light. Therefore, it is difficult to detect cracks or foreign substances, etc. formed on the upper surface of the glass substrate in the conventional micro-failure inspection apparatus and method, so improvement thereof is required.

An embodiment of the present invention for solving the above-described problems of the background art is to detect cracks or foreign substances, etc. formed on the inside and outside of the glass substrate at low resolution to improve the process yield through shortening the tact time.

Embodiments of the present invention by the above-described problem solving means, the stage on which the loaded glass substrate is seated; A light source unit irradiating light to the inside of the glass substrate to guide the light; An inspection camera positioned on an upper portion of the glass substrate and obtaining an image of light emitted through the upper surface of the glass substrate; And an inspection unit for analyzing an image transmitted from the inspection camera and inspecting the glass substrate for cracks or foreign substances.

The light source unit may be at least one of a plasma light emitting illumination device and a light emitting diode illumination device.

The light source unit may further include an optical waveguide that guides the emitted light into the glass substrate.

The light source unit may be disposed on at least one of the short axis side and the long axis side of the glass substrate.

The optical sheet unit may further include an optical sheet disposed below the glass substrate and configured to diffuse or reflect light incident on the glass substrate to the upper portion of the glass substrate.

The inspection camera may be an area scan camera.

In another aspect, an embodiment of the present invention, the step of loading a glass substrate on the stage; Irradiating light into the glass substrate to guide the light; Obtaining light emitted through the upper surface of the glass substrate as an image using an inspection camera; And analyzing the image transmitted from the inspection camera and inspecting the glass substrate for cracks or foreign substances.

In the inspecting step, the first image photographed after the glass substrate is loaded and the second image photographed after irradiating light to the inside of the glass substrate may be analyzed to examine whether the glass substrate is cracked or foreign.

In another aspect, an embodiment of the present invention, the glass substrate inspection unit consisting of a glass substrate inspection apparatus manufactured by any one of claims 1 to 6; A loader unit for loading a glass substrate into the inspection unit of the glass substrate; And a deposition unit for forming a thin film on the glass substrate.

The display device may further include a substrate selection unit disposed between the inspection unit and the deposition unit of the glass substrate, and configured to import a good glass substrate into the deposition unit or to export a defective glass substrate to the outside in response to the inspection result of the glass substrate transferred from the inspection unit of the glass substrate. have.

The present invention has the effect of detecting the fine defect inspection for the presence or absence of cracks (scratches or stamps) or foreign matter according to the depth before and after the etching process of the glass substrate at a low resolution. In addition, the present invention is capable of detecting the presence or absence of measurement and defects by a vision system composed of an area camera and an inspection unit immediately upon loading of the glass substrate, thereby improving the process yield through shortening the tact time.

1 and 2 are diagrams illustrating the configuration of an inspection apparatus for a glass substrate according to an embodiment of the present invention.
3 and 4 are views for explaining an example of the inspection method using the inspection apparatus of the glass substrate.
Fig. 5 is a diagram for explaining the correction of the cessation of the light source unit before inspection;
6 is a flowchart for explaining a method for inspecting a glass substrate.
7 to 9 illustrate various modified embodiments of the light source unit.
10 shows an embodiment when using a bare glass substrate.
11 is a configuration diagram for explaining a deposition apparatus according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, the specific content for the practice of the present invention will be described.

1 and 2 are exemplary views illustrating a configuration of an inspection apparatus for a glass substrate according to an exemplary embodiment of the present invention.

1 and 2, the inspection apparatus of the glass substrate according to an embodiment of the present invention, the stage 120, the glass substrate seating portion 125, the light source 130, 140, the inspection camera 150 The review camera 155 and the inspection unit 160 are included.

The stage 120 is a mechanism for transferring the loaded glass substrate 110 to the glass substrate mounting portion 125. The stage 120 may hold the glass substrate 110 by an air pressure method (or a vacuum method), and may transfer it by an air flotation transport method, but is not limited thereto. The glass substrate 110 loaded on the stage 120 is aligned. The glass substrate 110 may be aligned by an alignment unit that interworks with the review camera 155.

When the glass substrate 110 is loaded on the stage 120, the stage 120 transfers the glass substrate 110 to the glass substrate seating part 125 positioned in the inspection region and retreats to the standby region.

The glass substrate seating part 125 may be implemented in the form of a pair of rails spaced apart from each other to correspond to the width of the glass substrate 110 in the short axis direction. As the glass substrate seating part 125 is implemented as described above, the lower surface of the glass substrate 110 (in other words, the outer surface or the non-display surface) has a state facing the inspection camera 150 or the review camera 155. do.

The light source units 130 and 140 irradiate and guide light into the glass substrate 110 loaded on the stage 120. The light source units 130 and 140 are installed to travel between the standby area and the inspection area. That is, the light source units 130 and 140 take a standby state in the standby region, but when the stage 120 enters the inspection region, the light source unit 130 or 140 moves to the inspection region and then emits light to irradiate light into the glass substrate 110. Can be taken.

The light source units 130 and 140 are selected from at least one of a plasma light emitting illumination device and a light emitting diode illumination device that emit light by changing a gas in the lamp into a plasma state. In the drawings, the light source units 130 and 140 are provided on the short axis side and the long axis side of the glass substrate 110 as an example. However, the light source units 130 and 140 may be disposed on at least one of the short axis side and the long axis side of the glass substrate 110.

The inspection camera 150 is installed in the inspection area. The inspection camera 150 obtains light emitted through the lower surface of the glass substrate 110 as an image. For this purpose, the inspection camera 150 may be installed in a fixed manner under the glass substrate 110. The inspection camera 150 is selected as an area scan camera capable of obtaining all the light emitted through the lower surface of the glass substrate 110 in one shot. In the case of the inspection camera 150, a line scan camera may be used, but since it is necessary to obtain an image for each line, the loss of inspection time compared to the area scan camera is expected.

The review camera 155 is installed in the review area located after the inspection area or the inspection area. The review camera 155 is a separate camera for monitoring the status of various devices before or after the inspection process. The review camera 155 may be installed at a lower portion of the glass substrate 110 in a fixed manner or a movable manner. The review camera 155 obtains an image together with the inspection camera 150 to improve the accuracy of the inspection, and serves to transfer the obtained image to the inspection unit 160. In addition, the review camera 155 may monitor the state of the inspection camera 150, the light source 130, etc. forming the vision system.

The inspection unit 160 analyzes the image transmitted from the inspection camera 150 and inspects whether the glass substrate 110 is cracked (scratched or stamped) or foreign matter. The inspection unit 160 may be constructed as a vision system that obtains light emitted through the lower surface of the glass substrate 110 together with the inspection camera 150 as an image and analyzes, determines, and displays the obtained image. . The inspection unit 160 analyzes the image transmitted from the inspection camera 150 and the review camera 155 to improve the accuracy of the inspection, and inspects whether the glass substrate 110 is cracked (scratched or stamped) or foreign matter. It may be.

Hereinafter, an example of an inspection method using the inspection apparatus of the glass substrate according to the embodiment will be described.

3 and 4 are views for explaining an example of the inspection method using the inspection apparatus of the glass substrate, Figure 5 is a view for explaining the correction correction of the light source unit before inspection, Figure 6 is a inspection method of the glass substrate It is a flowchart for explanation.

As illustrated in FIGS. 1 to 6, the glass substrate 110 may be loaded into the inspection apparatus of the glass substrate in a state in which the thin film transistor 115 is formed or in a bare state in which the thin film transistor 115 is not formed. (S110)

When the glass substrate 110 enters the inspection region, the light source unit 130 irradiates and guides the light L into the glass substrate 110. (S120) The light L emitted from the light source unit 130 is a glass substrate ( The film is guided into the glass substrate 110 by a thin film such as the thin film transistor 115 formed on the bottom surface of the 110.

The inspection camera 150 installed below the glass substrate 110 obtains the light L emitted through the lower surface of the glass substrate 110 as an image and transmits the obtained image to the inspection unit 160. S130)

The inspection unit 160 inspects the presence or absence of foreign matters or cracks in the glass substrate 110 through an analysis process of the image transmitted from the inspection camera 150 to derive a fine defect inspection result.

In the inspection apparatus and inspection method of the glass substrate according to the embodiment, the state of the inside and outside of the glass substrate 110 using the light source unit 130, the inspection camera 150, and the inspection unit 160 (whether the surface is scratched or stamped, foreign matter). Micro defect inspection process that inspects the presence or absence of

The inside / outside of the glass substrate 110 is formed with a crack (scratch or stamp) SC or a foreign material PT due to various causes. Therefore, during the manufacturing process of the display device, the state of the inside and outside of the glass substrate 110 before and after the etching process may be inspected.

For example, in the case of the foreign material PT formed on the lower surface of the glass substrate 110, the light L emitted from the lower surface of the glass substrate 110 is blocked according to the medium of the foreign material PT. Accordingly, the foreign material PT formed on the lower surface of the glass substrate 110 may have the inspection unit 160 as shown in FIG. 4 by using the first image IMG1 or the second image IMG1 obtained by the inspection camera 150. It can be easily detected by a simple analysis process.

As another example, in the case of the crack SC formed on the lower surface of the glass substrate 110, the light L that is guided into the glass substrate 110 is diffusely reflected or leaked out. Therefore, the crack SC formed on the lower surface of the glass substrate 110 is the inspection unit 160 as shown in FIG. 4 to the first image IMG1 or the second image IMG1 obtained by the inspection camera 150. It can be easily detected by the analysis process. However, unlike the foreign material PT, the crack SC formed on the lower surface of the glass substrate 110 may not be easily detected by only a process of analyzing the image.

The reason is that the scratches formed on the lower surface of the glass substrate 110 have a shallow depth before etching, and the stamping has a shallow depth after etching. The scratch depth is different before and after etching, and the stamping causes diffuse reflection of light.

Therefore, the inspection apparatus and the inspection method of the glass substrate of the embodiment is the first image IMG1 photographed after the glass substrate 110 is loaded and the second image IMG2 photographed after irradiating light into the glass substrate 110. ) Can be inspected for the presence or absence of cracks in the glass substrate 110. That is, the inspection apparatus and the inspection method of the glass substrate of the embodiment captures the form of diffuse reflection, scattering, etc. of the light (L) flowing out from the inside of the glass substrate 110 forming the waveguide of the light (L) to the outside The presence or absence of the crack SC is detected. The inspection apparatus and inspection method of the glass substrate of the embodiment may perform analysis on the area, the center coordinates, the width and the height of the SC for the image obtained for accurate defect detection.

On the other hand, since the inspection apparatus and the inspection method of the glass substrate of the embodiment guides the light inside the glass substrate 110, there is a defect in the method of analyzing the change in the light according to the bubbles or foreign matter formed inside the glass substrate 110 It can also be detected.

Meanwhile, as shown in FIG. 2, when the light source units 130 and 140 are formed on the short axis side and the long axis side of the glass substrate 110, an image that is segmented for each exposure time of light may be obtained. The reason for the saturation is that the intensity of the light varies depending on the distance from the light sources 130 and 140. Therefore, when the appropriate amount of illumination is delivered to the position farthest from the light source units 130 and 140, the shunt is generated in the proximal region and the obtained image is also obtained.

According to the embodiment, in order to prevent the phenomenon that occurs when the light source units 130 and 140 are arranged as shown in FIG. 2, the longer the exposure time to the light irradiation area is, the longer the light source unit 130 or 140 is not separated from the light source units 130 and 140. Images of the area can be extracted and combined. Therefore, the inspection camera 150 splits and captures the image LI by the exposure time of the light irradiation area as shown in FIG. 5, and the inspection unit 160 corrects the images by combining them to generate an image that is not segmented. Based on this, analysis can be performed.

On the other hand, the embodiment has an example that the inspection camera 150 and the review camera 155 is installed under the glass substrate 110. However, the inspection camera 150 and the review camera 155 may be installed on the glass substrate 110.

Hereinafter, modified embodiments of the present invention will be described.

7 to 9 are views showing various modified embodiments of the light source unit, Figure 10 is a view showing an embodiment when using a bare glass substrate.

As shown in FIG. 7, according to the first modified embodiment of the present invention, the light source unit 130 includes a single type lighting device 131, an optical waveguide 132, and a reflector 133.

The lighting device 131 is installed in a single type. The lighting device 131 installed as a single type primarily irradiates light to the optical waveguide 132. The single type lighting device 131 may be selected as a plasma light emitting lighting device.

The optical waveguide 132 secondaryly changes the direction of light irradiated from the single type lighting device 131 and guides the inside of the glass substrate 110. The optical waveguide 132 amplifies the width of the light emitted from the single type lighting device 131 serving as the point light source.

The reflector 133 reflects the light into the glass substrate 110 to reduce the loss of light and efficiently amplify the light when the optical waveguide 132 secondaryly changes the direction of the light irradiated from the illumination device 131. Play a role.

As shown in FIG. 8, according to the second modified embodiment of the present invention, the light source unit 130 includes a multi-type lighting device 131 and an optical waveguide 132.

The lighting device 131 is installed in a multi-type including first to fourth lighting devices 131a to 131d. The lighting device 131 installed in a multi-type primarily irradiates light to the optical waveguide 132. The multi-type lighting device 131 may be selected as a plasma light emitting lighting device.

The optical waveguide 132 secondaryly converts the light emitted from the multi-type lighting device 131 to guide the inside of the glass substrate 110. The optical waveguide 132 may include a waveguide groove 132H to amplify the width of the light emitted from the multi-type lighting device 131 serving as the point light source. The waveguide groove 132H may be formed of micro patterns such as triangles, circles, and polygons to amplify the width of light, but is not limited thereto.

As shown in FIG. 9, according to the third modified embodiment of the present invention, the light source unit 130 includes a multi-type lighting device 131 and an optical waveguide 132.

The lighting device 131 is installed in a multi-type including first to fourth lighting devices 131a to 131e. The lighting device 131 installed in a multi-type primarily irradiates light to the optical waveguide 132. The multi-type lighting device 131 may be selected as a light emitting diode lighting device.

The optical waveguide 132 secondaryly converts the light emitted from the multi-type lighting device 131 to guide the inside of the glass substrate 110. The optical waveguide 132 may include a waveguide groove 132H to amplify the width of the light emitted from the multi-type lighting device 131 serving as the point light source. The waveguide groove 132H may be formed of micro patterns such as triangles, circles, and polygons to amplify the width of light, but is not limited thereto.

In the modified embodiments of FIGS. 7 to 9, the lighting device 131 is selected as one of the plasma light emitting device and the LED lighting device. However, the lighting device 131 may be selected by a combination of a plasma light emitting lighting device and a light emitting diode lighting device.

In FIG. 3, the glass substrate on which the thin film transistor is formed is taken as an example. However, when using the bare glass substrate 110 in which the thin film transistor is not formed as shown in FIG. 10, the optical sheet part 127 is attached to the upper surface of the bare glass substrate 110.

The optical sheet unit 127 diffuses or reflects light incident into the bare glass substrate 110 to the lower portion of the bare glass substrate 110. The optical sheet unit 127 which performs this role may be installed in a manner of being attached to the upper surface of the bare glass substrate 110 and then detached during the inspection process.

On the other hand, in the above embodiments it is assumed that the inspection apparatus of the glass substrate is provided alone. However, the inspection apparatus of the glass substrate may be equipped with the deposition apparatus as follows.

11 is a configuration diagram illustrating a deposition apparatus according to another embodiment of the present invention.

As shown in FIG. 11, the deposition apparatus according to another embodiment of the present invention includes a loader unit 210, a glass substrate inspector 220, a substrate sorter 230, a first deposition unit 240, and a second deposition process. Part 250 is included.

The loader 210, the glass substrate inspecting unit 220, the substrate sorting unit 230, the first deposition unit 240, and the second deposition unit 250 are connected through the gate G, respectively. The deposition apparatus according to another embodiment is not limited thereto, but is simply configured to describe an inspection system using the glass substrate inspection unit 220.

The loader 210 loads a glass substrate. The loader 210 loads the loaded glass substrate into the inspection unit 220 of the glass substrate.

The glass substrate inspecting unit 220 performs a fine defect inspection process for inspecting a state of the inside and the outside of the glass substrate (such as scratches or marks on the surface, presence or absence of foreign matter, etc.). The glass substrate inspecting unit 220 may include a stage 120, a stage transfer unit 125, a light source unit 130 and 140, an inspection camera 150, and an inspection unit 160 as shown in FIGS. 1 to 3.

The glass substrate inspection unit 220 obtains light emitted through the lower surface of the glass substrate as an image and analyzes the obtained image to detect the state of the inside and the outside of the glass substrate (such as scratches or marks on the surface, presence or absence of foreign substances, etc.). Can be checked

Meanwhile, the light source units 130 and 140 of the glass substrate inspecting unit 220 may be modified in the form as shown in FIGS. 7 to 9. When the glass substrate carried in the glass substrate inspecting unit 220 is a bare glass substrate, the optical sheet unit 127 may be further attached to the upper portion of the glass substrate 110 as shown in FIG. 10.

The glass substrate inspection unit 220 inspects the state of the inside and the outside of the glass substrate (such as scratches or imprints on the surface, presence of foreign substances, etc.), and carries the completed glass substrate into the substrate sorting unit 230 and inspects the glass substrate. The result is transferred to the substrate sorting unit 230.

The substrate sorting unit 230 imports a good glass substrate into the first deposition unit 240 or exports a poor glass substrate to the outside in response to an inspection result of the glass substrate transmitted from the inspection unit 220 of the glass substrate. The substrate sorting unit 230 may carry out the defective glass substrate to the defective glass substrate carrying unit 235.

The first deposition unit 240 performs a deposition process or the like on a good glass substrate loaded from the substrate selection unit 230. The first deposition unit 240 may be composed of a plurality of process chambers 242, 243, 244 and one laboratory 245, but is not limited thereto. The good glass substrate loaded into the first deposition unit 240 is moved between the plurality of process chambers 242, 243, 244 and one test chamber 245 by the first transport robot 241 to follow the deposition process and the inspection process. do.

When the deposition process or the like is completed on the good glass substrate, the first deposition unit 240 carries out the good glass substrate having completed the process to the first carry-in / out chamber 248. The first carry-in / out chamber 248 carries in a favorable glass substrate to the 2nd depositing part 250.

The second deposition unit 250 performs a deposition process or the like on a good glass substrate carried in from the first carry-in / out chamber 248. The second deposition unit 250 may be composed of a plurality of process chambers 252, 253, 254 and one laboratory 255, but is not limited thereto. The good glass substrate carried in the second deposition unit 250 is moved between the plurality of process chambers 252, 253, 254 and one test chamber 255 by the second transport robot 242 to follow the deposition process and the inspection process. do.

When the deposition process or the like is completed on the good glass substrate, the second deposition unit 250 carries out the good glass substrate having completed the process to the second carry-in / out chamber 258. The second carry-in / out chamber 258 brings in a good glass substrate into another process chamber which can carry out a good glass substrate to the outside, or when further processing is needed.

Using the above-described deposition apparatus, a selective process may be performed according to fine defects in which cracks or foreign substances are formed on the glass substrate when manufacturing a display device such as an organic light emitting display device, an electrophoretic display device, and a liquid crystal display device. .

As described above, the present invention has the effect of detecting a fine defect inspection for the presence or absence of a crack (scratch or scratch) or foreign matter according to the depth before and after the etching process of the glass substrate at low resolution. In addition, the present invention is capable of detecting the presence or absence of measurement and defects by a vision system composed of an area camera and an inspection unit immediately upon loading of the glass substrate, thereby improving the process yield through shortening the tact time.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

110: glass substrate 120: stage
125: stage transfer unit 130, 140: light source unit
150: camera 160: inspection unit
131: lighting device 132: optical waveguide
133: reflecting portion 127: optical sheet portion
SC: crack PT: foreign body

Claims (12)

A stage on which the loaded glass substrate is seated;
A light source unit corresponding to the short axis side and the long axis side of the glass substrate to irradiate and guide light into the glass substrate;
A camera for obtaining light emitted through one surface of the glass substrate as an image; And
An inspection unit for analyzing an image transmitted from the camera and inspecting the glass substrate for cracks or foreign substances;
The camera splits an image for each exposure time of the light irradiation area of the light source unit,
The inspection unit corrects an image by combining images divided by the camera to generate an image that is not segmented for each exposure time of light, and an inspection apparatus for a glass substrate that performs an analysis based on the image that is not segmented. . The method of claim 1,
The light source unit
An apparatus for inspecting a glass substrate comprising at least one of a plasma light emitting illumination device and a light emitting diode illumination device. The method of claim 1,
The light source unit
Lighting device for irradiating light,
An optical waveguide for guiding and guiding the light irradiated from the illumination device into the glass substrate;
And a reflector for reflecting light irradiated from the illumination device into the glass substrate. delete The method of claim 1,
And an optical sheet unit attached to a lower portion of the glass substrate so as to diffuse or reflect the light incident into the glass substrate to the lower portion of the glass substrate. The method of claim 1,
The camera
And an area scan camera provided on the bottom surface of the glass substrate. Loading the glass substrate onto the stage;
Irradiating and guiding light through the short axis side and the long axis side of the glass substrate;
Obtaining light emitted through one surface of the glass substrate as an image using a camera, and dividing the image by the exposure time of the light irradiation area of the light source unit; And
The image is received from the camera, and the image is corrected by combining images divided by the camera to generate an image that is not segmented for each exposure time of light, and analyzes the glass based on the image that is not segmented. Glass substrate inspection method comprising the step of inspecting the presence of cracks or foreign matter. The method of claim 7, wherein
The inspection step
The first image photographed after the glass substrate is loaded and the second image photographed after irradiating light to the inside of the glass substrate are analyzed to examine the presence or absence of cracks or foreign substances on the glass substrate. method of inspection. Claims 1 to 3, claim 5 and claim 6, wherein the glass substrate inspection unit composed of a glass substrate inspection apparatus made by any one of claims;
A loader unit for loading the glass substrate into the inspection unit of the glass substrate; And
Deposition apparatus including a deposition unit for forming a thin film on the glass substrate. The method of claim 9,
Is disposed between the inspection unit and the deposition unit of the glass substrate,
And a substrate sorting unit for bringing a good glass substrate into the deposition unit or a poor glass substrate to the outside in response to an inspection result of the glass substrate transferred from the inspection unit of the glass substrate. The method of claim 1,
The camera
An inspection camera for obtaining an image of light emitted through one surface of the glass substrate;
And a review camera for monitoring a state of the device including the inspection camera and the light source unit. The method of claim 3,
The optical waveguide is
And a wave guide groove for amplifying the width of the light emitted from the illumination device.

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