WO2018128059A1

WO2018128059A1 - Method for inspecting glass plate, method for manufacturing same, and device for inspecting glass plate

Info

Publication number: WO2018128059A1
Application number: PCT/JP2017/044689
Authority: WO
Inventors: 正福久良木; 山本　浩一; 正善山本; 友和南; 敬一吉野; 孝英藤居
Original assignee: Nippon Electric Glass Co Ltd
Current assignee: Nippon Electric Glass Co Ltd
Priority date: 2017-01-06
Filing date: 2017-12-13
Publication date: 2018-07-12
Anticipated expiration: 2019-07-06
Also published as: CN110036281B; JP2018112411A; KR102388575B1; CN110036281A; JP6788837B2; KR20190104324A

Abstract

The present invention has disposed therein: a first imaging system 2 having a first light source 5, a first imaging unit 6 that captures a first transmitted light L1 that is emitted from the first light source 5 and passes through a glass plate G, and a shielding plate 7 that shields a portion of the first transmitted light L1 to form a bright portion and a dark portion in the field of view of the first imaging unit 6; and a second imaging system 3 that has a second light source 8 and a third light source 9, and a second imaging unit 10 that, while capturing, in a bright field, a second transmission light L2 that is emitted from the second light source 8 and passes through the glass plate G, captures, in a dark field, a third transmission light L3 that is emitted from the third light source 9 and passes through the glass plate G. The present invention sorts the types of defects of the glass plate G on the basis of images obtained by the first imaging system 2 and images obtained by the second imaging system 3.

Description

Glass plate inspection method and manufacturing method thereof, and glass plate inspection apparatus

　本発明は、ガラス板の検査方法及びその製造方法並びにガラス板の検査装置に関する。 The present invention relates to a glass plate inspection method, a manufacturing method thereof, and a glass plate inspection apparatus.

　従来、ガラス板の製造工程には、ガラス板に含まれる欠陥の有無を検査する検査工程が含まれるのが通例である。 Conventionally, a glass plate manufacturing process usually includes an inspection step for inspecting the presence or absence of defects contained in the glass plate.

　この種の検査工程としては、例えば、特許文献１に開示のものが挙げられる。同文献に開示の検査工程では、ガラス板の一方の主面側に光源を配置すると共に、光源とは反対のガラス板の他方の主面側に配置されたカメラによってガラス板を透過した光源からの光を受光し、カメラで撮像された光量の変化に基づいてガラス板に含まれる欠陥の有無を検査する。また、同文献には、ガラス板の一方の主面側に光源を配置すると共に、光源と同じガラス板の一方の主面側に配置されたカメラによってガラス板で反射した光源からの光を受光し、カメラで撮像された光量の変化に基づいてガラス板に含まれる欠陥の有無を検査することも開示されている。 Examples of this type of inspection process include those disclosed in Patent Document 1. In the inspection process disclosed in this document, a light source is arranged on one main surface side of the glass plate, and a light source transmitted through the glass plate by a camera arranged on the other main surface side of the glass plate opposite to the light source. And inspecting the presence or absence of defects contained in the glass plate based on the change in the amount of light imaged by the camera. In the same document, a light source is arranged on one main surface side of a glass plate, and light from the light source reflected by the glass plate is received by a camera arranged on one main surface side of the same glass plate as the light source. In addition, it is also disclosed that the presence or absence of a defect included in the glass plate is inspected based on a change in the amount of light captured by the camera.

特開２０１４－２１１４１５号公報JP 2014-2111415 A

　しかしながら、特許文献１には、ガラス板の欠陥として、ガラス板中の泡や異物が例示されているが、これら欠陥の種類を識別することは開示されていない。泡欠陥と異物欠陥（例えば、耐火物等からの剥離物など）ではガラス板の品質に与える影響が異なる。そのため、泡欠陥の許容サイズと異物欠陥の許容サイズとが異なり、同一サイズの欠陥であっても欠陥の種類によって合否基準が異なる。したがって、泡欠陥と異物欠陥を識別する必要がある。 However, Patent Document 1 exemplifies bubbles and foreign substances in the glass plate as defects of the glass plate, but does not disclose identifying the types of these defects. Foam defects and foreign object defects (for example, exfoliation from refractory etc.) have different effects on the quality of the glass plate. Therefore, the allowable size of the bubble defect and the allowable size of the foreign object defect are different, and the pass / fail criterion is different depending on the type of the defect even if the defect has the same size. Therefore, it is necessary to distinguish between bubble defects and foreign object defects.

　また、カメラで撮像された光量の変化に基づいて欠陥の有無を単純に検査しようとすると、ガラス板の表面に付着した埃を誤検出してしまう場合がある。埃はガラス板の洗浄等で除去できる場合が多い。欠陥が検出されたガラス板は廃棄されるのが通例であるため、埃を欠陥として誤検出すると、品質上問題のないガラス板まで廃棄されるおそれがある。したがって、ガラス板の欠陥の誤検出を防止する必要もある。 Also, if an attempt is made to simply inspect the presence or absence of a defect based on a change in the amount of light imaged by the camera, there is a case where dust adhering to the surface of the glass plate is erroneously detected. In many cases, dust can be removed by cleaning the glass plate. A glass plate in which a defect is detected is usually discarded. Therefore, if dust is erroneously detected as a defect, a glass plate having no quality problem may be discarded. Therefore, it is necessary to prevent erroneous detection of defects in the glass plate.

　本発明は、ガラス板の欠陥の誤検出を防止しつつ、ガラス板の欠陥の種類の識別を正確に行うことを技術的課題とする。 This invention makes it a technical subject to identify correctly the kind of defect of a glass plate, preventing the misdetection of the defect of a glass plate.

　上記の課題を解決するために創案された本発明は、ガラス板の検査方法において、第一光源と、第一光源から照射されてガラス板を透過した第一透過光を撮像する第一撮像部と、第一透過光の一部を遮蔽して第一撮像部の視野内に明部と暗部を形成する遮蔽部材とを有する第一撮像系と、第二光源及び第三光源と、第二光源から照射されてガラス板を透過した第二透過光を明視野で撮像しながら、第三光源から照射されてガラス板を透過した第三透過光を暗視野で撮像する第二撮像部とを有する第二撮像系とを配置し、第一撮像系で得られる像と、第二撮像系で得られる像とに基づいて、ガラス板の欠陥の種類を識別することを特徴とする。このような構成によれば、泡欠陥や異物欠陥など欠陥の種類によって、第一撮像系で得られる像及び／又は第二撮像系で得られる像から抽出される特徴量（例えば、形状や色など）が特有の変化を示す。また同様に、欠陥と誤検出されやすいガラス板の表面に付着した埃の場合も、これら二つの像から抽出される特徴量が特有の変化を示す。したがって、第一撮像系で得られる像と第二撮像系で得られる像とに基づいて、ガラス板の欠陥の種類の識別を正確に行うことができる。そして、欠陥の種類の識別を正確に行うことができれば、欠陥の誤検出も必然的に防止することができる。 In order to solve the above-mentioned problems, the present invention provides a glass plate inspection method in which a first light source and a first imaging unit that images the first transmitted light irradiated from the first light source and transmitted through the glass plate A first imaging system having a shielding member that shields part of the first transmitted light and forms a bright part and a dark part in the field of view of the first imaging part, a second light source and a third light source, and a second A second imaging unit that images the second transmitted light irradiated from the light source and transmitted through the glass plate in a bright field while imaging the third transmitted light irradiated from the third light source and transmitted through the glass plate in a dark field; The second imaging system is arranged, and the type of defect of the glass plate is identified based on the image obtained by the first imaging system and the image obtained by the second imaging system. According to such a configuration, a feature amount (for example, shape or color) extracted from an image obtained by the first imaging system and / or an image obtained by the second imaging system, depending on the type of defect such as a bubble defect or a foreign matter defect. Etc.) are characteristic changes. Similarly, in the case of dust adhering to the surface of a glass plate that is likely to be erroneously detected as a defect, the feature amount extracted from these two images shows a specific change. Therefore, it is possible to accurately identify the type of defect in the glass plate based on the image obtained by the first imaging system and the image obtained by the second imaging system. If the defect type can be identified accurately, it is possible to inevitably prevent erroneous detection of the defect.

　上記の構成において、第一光源、第二光源及び第三光源を一つの光源ユニットとし、光源ユニットから照射されてガラス板を透過した透過光を、ビームスプリッタによって、第一透過光を含む第一成分と、第二透過光及び第三透過光を含む第二成分との二つに分離し、第一成分を遮蔽部材を介して第一撮像部で撮像し、第二成分を第二撮像部で撮像することが好ましい。このようにすれば、第一撮像部と第二撮像部によって、ガラス板の同じ位置を同時に撮像することができるため、より緻密なガラス板の検査を実現できる。 In the above configuration, the first light source, the second light source, and the third light source are used as one light source unit, and the transmitted light that has been irradiated from the light source unit and transmitted through the glass plate is included in the first light including the first transmitted light by the beam splitter. The component and the second component including the second transmitted light and the third transmitted light are separated into two, the first component is imaged by the first imaging unit via the shielding member, and the second component is captured by the second imaging unit. It is preferable to take an image. In this way, since the same position of the glass plate can be simultaneously imaged by the first imaging unit and the second imaging unit, a more precise inspection of the glass plate can be realized.

　上記の構成において、第一撮像系で得られる像の有無と、第二撮像系で得られる像の有無とに基づいて、ガラス板中の異物欠陥を識別してもよい。すなわち、異物欠陥の場合、第一撮像系で像が得られ、第二撮像系で像が得られない場合がある。したがって、第一撮像系で得られた像の有無と、第二撮像系で得られた像の有無とに基づいて、ガラス板中の異物欠陥と、それ以外を識別することができる。 In the above configuration, the foreign object defect in the glass plate may be identified based on the presence / absence of the image obtained by the first imaging system and the presence / absence of the image obtained by the second imaging system. That is, in the case of a foreign substance defect, an image may be obtained with the first imaging system and an image may not be obtained with the second imaging system. Therefore, the foreign object defect in the glass plate can be identified based on the presence / absence of the image obtained by the first imaging system and the presence / absence of the image obtained by the second imaging system.

　上記の構成において、第一撮像系で得られる像の面積と、第二撮像系で得られる像の面積とに基づいて、ガラス板中の異物欠陥と泡欠陥とを識別してもよい。すなわち、異物欠陥の場合、第一撮像系で得られる像の面積が、第二撮像系で得られる像の面積に比べて大きくなる傾向がある。換言すれば、（第一撮像系で得られる像の面積）／（第二撮像系で得られる像の面積）の値が大きくなる傾向がある。これに対し、泡欠陥の場合、第一撮像系で得られる像の面積が、第二撮像系で得られる像の面積に比べてそれほど大きくならない傾向がある。換言すれば、（第一撮像系で得られる像の面積）／（第二撮像系で得られる像の面積）の値が小さくなる傾向がある。したがって、第一撮像系で得られる像の面積と第二撮像系で得られる像の面積とに基づいて、泡欠陥と異物欠陥とを識別することができる。 In the above-described configuration, the foreign matter defect and the bubble defect in the glass plate may be identified based on the area of the image obtained by the first imaging system and the area of the image obtained by the second imaging system. That is, in the case of a foreign substance defect, the area of the image obtained by the first imaging system tends to be larger than the area of the image obtained by the second imaging system. In other words, the value of (the area of the image obtained by the first imaging system) / (the area of the image obtained by the second imaging system) tends to increase. On the other hand, in the case of a bubble defect, the area of the image obtained by the first imaging system tends not to be so large as compared to the area of the image obtained by the second imaging system. In other words, the value of (area of the image obtained by the first imaging system) / (area of the image obtained by the second imaging system) tends to be small. Therefore, it is possible to identify the bubble defect and the foreign object defect based on the area of the image obtained by the first imaging system and the area of the image obtained by the second imaging system.

　上記の構成において、第二撮像系で得られる像の色に基づいて、ガラス板中の泡欠陥とガラス板の表面に付着した埃とを識別するようにしてもよい。すなわち、泡欠陥の場合、第二撮像系で得られる像の色が黒く（暗く）なる傾向がある。これに対し、埃の場合、第二撮像系で得られる像の色が白く（明るく）なる傾向がある。したがって、第二撮像系で得られる像の色によって、泡欠陥と埃とを識別することができる。 In the above configuration, the bubble defect in the glass plate and the dust attached to the surface of the glass plate may be identified based on the color of the image obtained by the second imaging system. That is, in the case of a bubble defect, the color of the image obtained by the second imaging system tends to be black (dark). On the other hand, in the case of dust, the color of the image obtained by the second imaging system tends to be white (bright). Therefore, bubble defects and dust can be identified by the color of the image obtained by the second imaging system.

　上記の構成において、第二撮像系で得られる像のガラス板の延伸方向に沿った第一方向の寸法と、第二撮像系で得られる像の第一方向と直交する第二方向の寸法とに基づいて、ガラス板中の泡欠陥とガラス板の表面に付着した埃とを識別するようにしてもよい。すなわち、泡欠陥の場合、ガラス板の延伸方向に引き伸ばされて細長くなっていることが多い。そのため、第二撮像系で得られる像の第一方向の寸法が、第一方向と直交する第二方向の寸法よりも大きくなる傾向にある。換言すれば、（第一方向の寸法）／（第二方向の寸法）の値が大きくなる傾向にある。これに対し、埃の場合、ガラス板の延伸方向とは無関係であるため、第二撮像系で得られる像の第一方向の寸法が、その像の第二方向の寸法と同程度になる傾向にある。換言すれば、（第一方向の寸法）／（第二方向の寸法）の値が小さくなる傾向にある。したがって、第二撮像系で得られる像の第一方向の寸法とその像の第二方向の寸法とに基づいて、泡欠陥と埃とを識別することができる。 In the above configuration, the dimension in the first direction along the stretching direction of the glass plate of the image obtained by the second imaging system, and the dimension in the second direction orthogonal to the first direction of the image obtained by the second imaging system, Based on the above, the bubble defect in the glass plate and the dust attached to the surface of the glass plate may be identified. That is, in the case of a bubble defect, it is often elongated in the drawing direction of the glass plate. Therefore, the dimension in the first direction of the image obtained by the second imaging system tends to be larger than the dimension in the second direction orthogonal to the first direction. In other words, the value of (dimension in the first direction) / (dimension in the second direction) tends to increase. On the other hand, in the case of dust, since it is irrelevant to the extending direction of the glass plate, the dimension in the first direction of the image obtained by the second imaging system tends to be comparable to the dimension in the second direction of the image. It is in. In other words, the value of (dimension in the first direction) / (dimension in the second direction) tends to be small. Therefore, bubble defects and dust can be identified based on the first dimension of the image obtained by the second imaging system and the second dimension of the image.

　上記の構成において、第二撮像系で得られる像の面積と、ガラス板の延伸方向に沿った第一方向と平行な辺および第一方向と直交する第二方向と平行な辺からなり、かつ、第二撮像系で得られる像が内接する矩形の面積とに基づいて、ガラス板中の泡欠陥とガラス板の表面に付着した埃とを識別するようにしてもよい。すなわち、泡欠陥の場合、ガラス板の延伸方向に真っ直ぐ延びていることが多い。そのため、第二撮像系で得られる像の面積が、その像が内接する矩形の面積と同程度になる傾向にある。換言すれば、（第二撮像系で得られる像の面積）／（第二撮像系で得られる像が内接する矩形の面積）の値が大きくなる傾向にある（１に近づく）。これに対し、埃の場合、ガラス板の延伸方向とは無関係であるため、第二撮像系で得られる像の面積が、その像が内接する矩形の面積よりもかなり小さくなる傾向にある。換言すれば、（第二撮像系で得られる像の面積）／（第二撮像系で得られる像が内接する矩形の面積）の値が小さくなる傾向にある（０に近づく）。したがって、第二撮像系で得られる像の面積とその像が内接する矩形の面積とに基づいて、泡欠陥と埃とを識別することができる。 In the above configuration, the area of the image obtained by the second imaging system, the side parallel to the first direction along the extending direction of the glass plate, and the side parallel to the second direction orthogonal to the first direction, and The bubble defect in the glass plate and the dust attached to the surface of the glass plate may be identified based on the rectangular area inscribed by the image obtained by the second imaging system. That is, in the case of a bubble defect, it often extends straight in the extending direction of the glass plate. Therefore, the area of the image obtained by the second imaging system tends to be approximately the same as the area of the rectangle inscribed by the image. In other words, the value of (area of the image obtained by the second imaging system) / (area of the rectangle inscribed by the image obtained by the second imaging system) tends to increase (approaches 1). On the other hand, in the case of dust, since it is irrelevant to the extending direction of the glass plate, the area of the image obtained by the second imaging system tends to be considerably smaller than the rectangular area in which the image is inscribed. In other words, the value of (area of the image obtained by the second imaging system) / (area of the rectangle inscribed by the image obtained by the second imaging system) tends to be small (approaching 0). Therefore, bubble defects and dust can be identified based on the area of the image obtained by the second imaging system and the area of the rectangle inscribed by the image.

　上記の構成において、ガラス板の延伸方向に沿った第一方向と平行な対称軸に対する、第二撮像系で得られる像の対称性に基づいて、ガラス板中の泡欠陥とガラス板の表面に付着した埃とを識別するようにしてもよい。すなわち、泡欠陥の場合、ガラス板の延伸方向に真っ直ぐ延びていることが多いため、第二撮像系で得られる像は、第一方向と平行な対称軸に対する対称性（線対称性）が高くなる傾向にある。これに対し、埃の場合、ガラス板の延伸方向とは無関係であるため、第二撮像系で得られる像は、第一方向と平行な対称軸に対する対称性（線対称性）が低くなる傾向にある。したがって、第一方向と平行な対称軸に対する、第二撮像系で得られる像の対称性に基づいて、泡欠陥と埃とを識別することができる。 In the above configuration, on the surface of the glass plate with bubble defects in the glass plate based on the symmetry of the image obtained by the second imaging system with respect to the symmetry axis parallel to the first direction along the stretching direction of the glass plate. You may make it identify from the dust which adhered. That is, in the case of a bubble defect, since it often extends straight in the drawing direction of the glass plate, the image obtained by the second imaging system has high symmetry (line symmetry) with respect to the symmetry axis parallel to the first direction. Tend to be. On the other hand, in the case of dust, since it is irrelevant to the extending direction of the glass plate, the image obtained by the second imaging system tends to have lower symmetry (linear symmetry) with respect to the symmetry axis parallel to the first direction. It is in. Therefore, bubble defects and dust can be identified based on the symmetry of the image obtained by the second imaging system with respect to the symmetry axis parallel to the first direction.

　上記の構成において、第二撮像系で得られる像のガラス板の延伸方向に沿った第一方向に対する傾きに基づいて、ガラス板中の泡欠陥とガラス板の表面に付着した埃とを識別するようにしてもよい。すなわち、泡欠陥の場合、ガラス板の延伸方向に真っ直ぐ延びていることが多いため、第二撮像系で得られる像は、第一方向に対する傾きが小さくなる傾向にある。これに対し、埃の場合、ガラス板の延伸方向とは無関係であるため、第二撮像系で得られる像は、第一方向に対する傾きが大きくなる傾向にある。したがって、第二撮像系で得られる像の第一方向に対する傾きに基づいて、泡欠陥と埃とを識別することができる。 In the above configuration, the bubble defect in the glass plate and the dust attached to the surface of the glass plate are identified based on the inclination of the image obtained by the second imaging system with respect to the first direction along the extending direction of the glass plate. You may do it. That is, in the case of a bubble defect, since it often extends straight in the extending direction of the glass plate, the image obtained by the second imaging system tends to be less inclined with respect to the first direction. On the other hand, in the case of dust, since it is irrelevant to the extending direction of the glass plate, the image obtained by the second imaging system tends to increase in inclination with respect to the first direction. Therefore, bubble defects and dust can be identified based on the inclination of the image obtained by the second imaging system with respect to the first direction.

　上記の構成において、第二撮像系でガラス板の端辺を撮像し、端辺の形状不良の有無を検査するようにしてもよい。このようにすれば、ガラス板の欠陥の検査と同時に、切断不良などを原因とする端辺の形状不良も検査することができる。 In the above configuration, the edge of the glass plate may be imaged by the second imaging system, and the presence / absence of the edge shape may be inspected. If it does in this way, the shape defect of the edge caused by cutting defect etc. can be inspected simultaneously with the inspection of the defect of the glass plate.

　上記の課題を解決するために創案された本発明は、ガラス板の製造方法において、溶融ガラスを所定方向に延伸して板状のガラスリボンを成形する成形工程と、成形工程で成形されたガラスリボンを徐冷する徐冷工程と、徐冷工程で徐冷されたガラスリボンを所定の大きさに切断してガラス板を得る切断工程と、切断工程で得たガラス板を、既に述べたガラス板の検査方法の構成を適宜備えた方法で検査する検査工程とを備えていることを特徴とする。 The present invention, which was created to solve the above problems, is a glass plate manufacturing method in which a molten glass is stretched in a predetermined direction to form a plate-like glass ribbon, and the glass formed in the molding step. An annealing process for gradually cooling the ribbon, a cutting process for obtaining a glass plate by cutting the glass ribbon that has been cooled in the annealing process into a predetermined size, and the glass plate obtained in the cutting process are described above. And an inspection step of inspecting by a method appropriately equipped with the configuration of the plate inspection method.

　上記の課題を解決するために創案された本発明は、ガラス板の検査装置において、第一光源と、第一光源から照射されてガラス板を透過した第一透過光を撮像する第一撮像部と、第一透過光の一部を遮蔽して第一撮像部の視野内に明部と暗部を形成する遮蔽部材とを有する第一撮像系と、第二光源及び第三光源と、第二光源から照射されてガラス板を透過した第二透過光を明視野で撮像すると共に、第三光源から照射されてガラス板を透過した第三透過光を暗視野で撮像する第二撮像部とを有する第二撮像系と、第一撮像系で得られる像と、第二撮像系で得られる像とに基づいて、ガラス板の欠陥の種類を識別する識別手段とを備えることを特徴とする。 In order to solve the above-described problems, the present invention provides a glass plate inspection apparatus that includes a first light source and a first imaging unit that images the first transmitted light that is irradiated from the first light source and transmitted through the glass plate. A first imaging system having a shielding member that shields part of the first transmitted light and forms a bright part and a dark part in the field of view of the first imaging part, a second light source and a third light source, and a second A second imaging unit that images the second transmitted light irradiated from the light source and transmitted through the glass plate in a bright field, and that captures the third transmitted light irradiated from the third light source and transmitted through the glass plate in a dark field; And an identification means for identifying the type of defect of the glass plate based on the second imaging system, the image obtained by the first imaging system, and the image obtained by the second imaging system.

　上記の構成において、第一光源、第二光源及び第三光源が一つの光源ユニットとされ、光源ユニットから照射されてガラス板を透過した透過光を、第一透過光を含む第一成分と、第二透過光及び第三透過光を含む第二成分との二つに分離するビームスプリッタを備え、第一撮像部とビームスプリッタの間に遮蔽部材が配置され、第一撮像部が第一成分を遮蔽部材を介して撮像すると共に、第二撮像部が第二成分を撮像するように構成されていることが好ましい。 In the above configuration, the first light source, the second light source, and the third light source are a single light source unit, and the transmitted light that has been irradiated from the light source unit and transmitted through the glass plate, the first component that includes the first transmitted light, A beam splitter that separates the second transmitted light and the second component including the third transmitted light into two parts, a shielding member is disposed between the first imaging unit and the beam splitter, and the first imaging unit is the first component; It is preferable that the second imaging unit is configured to image the second component while imaging the image via the shielding member.

　以上のような本発明によれば、ガラス板の欠陥の誤検出を防止しつつ、ガラス板の欠陥の種類の識別を正確に行うことができる。 According to the present invention as described above, it is possible to accurately identify the types of defects in the glass plate while preventing erroneous detection of defects in the glass plate.

本発明の実施形態に係るガラス板の検査装置を示す平面図である。It is a top view which shows the inspection apparatus of the glass plate which concerns on embodiment of this invention. 図１の光源ユニットの正面図である。It is a front view of the light source unit of FIG. 異物欠陥、泡欠陥及び埃を有するガラス板を模式的に示した断面図である。It is sectional drawing which showed typically the glass plate which has a foreign material defect, a bubble defect, and dust. 異物欠陥、泡欠陥及び埃のそれぞれについての図１の検査装置で得られる像の代表例を示す図である。It is a figure which shows the typical example of the image obtained with the inspection apparatus of FIG. 1 about each of a foreign material defect, a bubble defect, and dust. 本発明の実施形態に係るガラス板の検査方法に含まれる欠陥検査工程で実行される処理の一例を示すフローチャートである。It is a flowchart which shows an example of the process performed at the defect inspection process included in the inspection method of the glass plate which concerns on embodiment of this invention. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第一撮像系で得られる異物欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the foreign material defect obtained by a 1st imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる異物欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the foreign material defect obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第一撮像系で得られる泡欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the bubble defect obtained by a 1st imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる泡欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the bubble defect obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる泡欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the bubble defect obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる埃の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the dust obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる泡欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the bubble defect obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる埃の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the dust obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる泡欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the bubble defect obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる埃の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the dust obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる泡欠陥の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the bubble defect obtained by a 2nd imaging system. 欠陥検査工程で実行される処理の変形例を説明するための図であって、第二撮像系で得られる埃の像の一例である。It is a figure for demonstrating the modification of the process performed at a defect inspection process, Comprising: It is an example of the image of the dust obtained by a 2nd imaging system. 本発明の実施形態に係るガラス板の検査方法に含まれる端縁検査工程を説明するための図である。It is a figure for demonstrating the edge test process included in the test | inspection method of the glass plate which concerns on embodiment of this invention. 本発明の実施形態に係るガラス板の検査装置の変形例を示す平面図である。It is a top view which shows the modification of the inspection apparatus of the glass plate which concerns on embodiment of this invention.

　本発明に係るガラス板の検査方法、製造方法及び検査装置の一実施形態について説明する。なお、以下では、ガラス板の製造方法を説明する過程で、ガラス板の検査装置及び検査方法を併せて説明するが、ガラス板の検査装置及び検査方法はガラス板の製造方法から独立して単独実施することもできる。 Embodiments of a glass plate inspection method, manufacturing method, and inspection apparatus according to the present invention will be described. In the following, in the course of explaining the glass plate manufacturing method, the glass plate inspection device and the inspection method will be described together. However, the glass plate inspection device and the inspection method are independent from the glass plate manufacturing method. It can also be implemented.

　本実施形態に係るガラス板の製造方法は、溶融ガラスを所定方向に延伸して板状のガラスリボンを成形する成形工程と、成形工程で成形されたガラスリボンを徐冷する徐冷工程と、徐冷工程で徐冷されたガラスリボンを所定の大きさに切断してガラス板を得る切断工程と、切断工程で得たガラス板を検査する検査工程とを備える。 The method for producing a glass plate according to the present embodiment includes a forming step of forming molten glass in a predetermined direction to form a plate-like glass ribbon, a slow cooling step of gradually cooling the glass ribbon formed in the forming step, A cutting step of cutting the glass ribbon slowly cooled in the slow cooling step into a predetermined size to obtain a glass plate; and an inspection step of inspecting the glass plate obtained in the cutting step.

　成形工程では、オーバーフローダウンドロー法を用いて溶融ガラスからガラスリボンを成形する。詳細には、断面楔形の成形体の頂部から両側に溢れ出たそれぞれの溶融ガラスを成形体の外側面部に沿って流下させながら成形体の下端部で融合一体化させることで、ガラスリボンを成形する。この場合、溶融ガラス（又はガラスリボン）は下方に延伸される。なお、成形工程は、オーバーフローダウンドロー法を用いたものに限定されない。例えば、スロットダウンドロー法やリドロー法などの他のダウンドロー法や、フロート法を用いてもよい。 In the molding process, a glass ribbon is molded from molten glass using the overflow downdraw method. Specifically, the glass ribbon is formed by fusing and integrating the molten glass overflowing on both sides from the top of the shaped wedge-shaped shaped body along the outer surface of the shaped body while fusing and integrating at the lower end of the shaped body. To do. In this case, the molten glass (or glass ribbon) is drawn downward. In addition, a shaping | molding process is not limited to what uses the overflow downdraw method. For example, another downdraw method such as a slot downdraw method or a redraw method, or a float method may be used.

　徐冷工程では、徐冷炉の内部空間に下方に向かって所定の温度勾配を設ける。成形体に連続するガラスリボンは、徐冷炉の内部空間を下方に向かって移動するに連れて、温度が低くなるように徐冷される。これに伴い、ガラスリボンの内部歪が除去（低減）される。 In the slow cooling step, a predetermined temperature gradient is provided downward in the internal space of the slow cooling furnace. The glass ribbon continuous with the formed body is gradually cooled so that the temperature decreases as it moves downward in the internal space of the annealing furnace. Along with this, internal distortion of the glass ribbon is removed (reduced).

　切断工程は、ガラスリボンを所定長さに切断する第一切断工程と、ガラスリボンの幅方向両端部を切断する第二切断工程とを備える。ガラスリボンの幅方向両端部は、幅方向中央部よりも相対的に厚みが大きくなる場合がある。この実施形態では、第二切断工程は、第一切断工程の後に第一切断工程とは別の場所で行われる。第一切断工程及び第二切断工程では、ガラスリボンの一方の主面の切断予定線に沿ってスクライブ線を形成した後、スクライブ線に沿って曲げ応力を作用させることで、ガラスリボンをスクライブ線に沿って切断（割断）する。これにより、ガラスリボンから所定サイズのガラス板が得られる。この実施形態では、第一切断工程及び第二切断工程において、ガラスリボンを縦姿勢（例えば、鉛直姿勢）のまま切断し、得られたガラス板を縦姿勢のまま検査工程に送る。なお、ガラスリボンの切断方法や切断姿勢はこれに限定されない。また、ガラス板は横姿勢（例えば、水平姿勢）で検査工程に送ってもよい。さらに、検査工程の前にガラス板を洗浄する洗浄工程を設けてもよい。 The cutting step includes a first cutting step for cutting the glass ribbon into a predetermined length and a second cutting step for cutting both ends in the width direction of the glass ribbon. The width direction both ends of the glass ribbon may be relatively thicker than the width direction center. In this embodiment, the second cutting step is performed at a place different from the first cutting step after the first cutting step. In the first cutting step and the second cutting step, the scribe line is formed along the planned cutting line of one main surface of the glass ribbon, and then the glass ribbon is scribed by applying a bending stress along the scribe line. Cut along (cut). Thereby, a glass plate of a predetermined size is obtained from the glass ribbon. In this embodiment, in a 1st cutting process and a 2nd cutting process, a glass ribbon is cut | disconnected with a vertical attitude | position (for example, vertical attitude | position), and the obtained glass plate is sent to an inspection process with a vertical attitude | position. In addition, the cutting method and cutting | disconnection attitude | position of a glass ribbon are not limited to this. Further, the glass plate may be sent to the inspection process in a horizontal posture (for example, a horizontal posture). Furthermore, you may provide the washing | cleaning process which wash | cleans a glass plate before an inspection process.

　検査工程は、ガラス板の欠陥を検査する欠陥検査工程と、ガラス板の端縁を検査する端縁検査工程とを備える。ここで、検査工程は、ガラス板の検査方法に相当する。 The inspection step includes a defect inspection step for inspecting a glass plate for a defect and an edge inspection step for inspecting the edge of the glass plate. Here, the inspection step corresponds to a glass plate inspection method.

　図１に示すように、欠陥検査工程ではガラス板の検査装置１が用いられる。検査装置１は、第一撮像系２と、第二撮像系３と、識別手段４とを備える。ここで、図中のＸＹＺは直交座標系であり、Ｘ方向及びＹ方向は水平方向であり、Ｚ方向が鉛直方向である。 As shown in FIG. 1, a glass plate inspection apparatus 1 is used in the defect inspection process. The inspection apparatus 1 includes a first imaging system 2, a second imaging system 3, and identification means 4. Here, XYZ in the figure is an orthogonal coordinate system, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction.

　ガラス板Ｇは、上辺、又は上辺及び下辺が支持された縦姿勢（好ましくは鉛直姿勢）の状態でＸ方向に沿って送られる。第一主面Ｇ１と第二主面Ｇ２が対向するガラス板Ｇの厚み方向はＹ方向に沿っている。成形時のガラス板Ｇの延伸方向はＺ方向に沿っている。ここで、「特定方向（例えばＸ方向）に沿う」という用語は、その特定方向（例えばＸ方向）と平行又は略平行な状態を意味する（以下、同様）。なお、ガラス板Ｇの送り方向は特に限定されるものではない。 The glass plate G is sent along the X direction in a vertical posture (preferably a vertical posture) in which the upper side or the upper side and the lower side are supported. The thickness direction of the glass plate G where the first main surface G1 and the second main surface G2 face each other is along the Y direction. The extending direction of the glass plate G at the time of forming is along the Z direction. Here, the term “along a specific direction (for example, X direction)” means a state parallel or substantially parallel to the specific direction (for example, X direction) (hereinafter the same). The feeding direction of the glass plate G is not particularly limited.

　第一撮像系２は、第一光源５と、第一光源５から照射されてガラス板Ｇを透過した第一透過光Ｌ１を撮像する第一撮像部６と、第一透過光Ｌ１の一部（例えば、半分）を遮蔽して第一撮像部６の視野内に明部と暗部を形成する遮蔽部材としての遮蔽板７とを有する。ここで、撮像部で撮像する測定光として透過光を用いる場合には、「透過光」という用語には散乱光も含まれるものとする（以下、同様）。 The first imaging system 2 includes a first light source 5, a first imaging unit 6 that images the first transmitted light L <b> 1 irradiated from the first light source 5 and transmitted through the glass plate G, and a part of the first transmitted light L <b> 1. It has a shielding plate 7 as a shielding member that shields (for example, half) and forms a bright part and a dark part in the field of view of the first imaging unit 6. Here, when transmitted light is used as measurement light imaged by the imaging unit, the term “transmitted light” includes scattered light (hereinafter the same).

　第一光源５はガラス板Ｇの第一主面Ｇ１側に配置され、第一撮像部６はガラス板Ｇの第二主面Ｇ２側に配置されている。第一光源５の光軸は、ガラス板Ｇの第一主面Ｇ１に略垂直に光が入射する向きとされている。第一撮像部６の光軸は、第一撮像部６で基本的に第一透過光Ｌ１を補足できるように、第一光源５の光軸の直線上に配置されている。これにより、第一撮像部６は、遮蔽板７がなければ第一透過光Ｌ１を明視野で撮像する状態となるが、実際は遮蔽板７によって第一透過光Ｌ１の一部が遮断されるため、第一透過光Ｌ１を半明視野で撮像する状態となる。 The first light source 5 is arranged on the first main surface G1 side of the glass plate G, and the first imaging unit 6 is arranged on the second main surface G2 side of the glass plate G. The optical axis of the first light source 5 is set so that light enters the first main surface G1 of the glass plate G substantially perpendicularly. The optical axis of the first imaging unit 6 is arranged on a straight line of the optical axis of the first light source 5 so that the first imaging unit 6 can basically supplement the first transmitted light L1. As a result, the first imaging unit 6 is in a state of capturing the first transmitted light L1 in a bright field without the shielding plate 7, but actually the shielding plate 7 blocks a part of the first transmitted light L1. Then, the first transmitted light L1 is imaged in a semi-bright field.

　一方、第二撮像系３は、第二光源８及び第三光源９と、第二光源８から照射されてガラス板Ｇを透過した第二透過光Ｌ２を明視野で撮像すると共に、第三光源９から照射されてガラス板Ｇを透過した第三透過光Ｌ３を暗視野で撮像する第二撮像部１０とを有する。 On the other hand, the second imaging system 3 images the second light source 8 and the third light source 9, and the second transmitted light L2 irradiated from the second light source 8 and transmitted through the glass plate G in a bright field, and also uses the third light source. 9 and the second image pickup unit 10 that picks up an image of the third transmitted light L3 irradiated through the glass plate G in a dark field.

　第二光源８はガラス板Ｇの第一主面Ｇ１側に配置され、第二撮像部１０はガラス板Ｇの第二主面Ｇ２側に配置されている。第二光源８の光軸は、ガラス板Ｇの第一主面Ｇ１に略垂直に光が入射する向きとされている。第二撮像部１０の光軸は、第二撮像部１０で基本的に第二透過光Ｌ２を補足できるように、後述するビームスプリッタ１１によって分離された第二光源８の光軸の直線上に配置されている。これにより、第二撮像部１０は、第二透過光Ｌ２を明視野で撮像する状態となる。 The second light source 8 is arranged on the first main surface G1 side of the glass plate G, and the second imaging unit 10 is arranged on the second main surface G2 side of the glass plate G. The optical axis of the second light source 8 is set to a direction in which light enters substantially perpendicularly to the first main surface G1 of the glass plate G. The optical axis of the second imaging unit 10 is on a straight line of the optical axis of the second light source 8 separated by the beam splitter 11 described later so that the second imaging unit 10 can basically supplement the second transmitted light L2. Has been placed. Thereby, the 2nd imaging part 10 will be in the state which images the 2nd transmitted light L2 in a bright field.

　第三光源９はガラス板Ｇの第一主面Ｇ１側に配置されている。第三光源９の光軸は、ガラス板Ｇの第一主面Ｇ１に斜めに光が入射する向きとされている。この実施形態では、第三光源９は一対設けられている。第二撮像部１０の光軸は、第二撮像部１０に基本的に第三透過光Ｌ３が入らないように、第三光源９の光軸の直線上から外れた位置に配置されている。これにより、第二撮像部１０は、第三透過光Ｌ３を暗視野で撮像する状態となる。第三透過光Ｌ３は、ガラス板Ｇで散乱が生じたときなどの特定の場合にのみ、第二撮像部１０で受光される。なお、図１では第三透過光Ｌ３の傾斜角が誇張されているが、第三透過光Ｌ３も後述するビームスプリッタ１１には基本的に入射する。 The third light source 9 is disposed on the first main surface G1 side of the glass plate G. The optical axis of the third light source 9 is set so that light enters the first main surface G1 of the glass plate G obliquely. In this embodiment, a pair of third light sources 9 are provided. The optical axis of the second imaging unit 10 is disposed at a position off the straight line of the optical axis of the third light source 9 so that the third transmitted light L3 basically does not enter the second imaging unit 10. Thereby, the 2nd imaging part 10 will be in the state which images the 3rd transmitted light L3 in a dark field. The third transmitted light L3 is received by the second imaging unit 10 only in specific cases such as when scattering occurs on the glass plate G. Although the inclination angle of the third transmitted light L3 is exaggerated in FIG. 1, the third transmitted light L3 basically enters the beam splitter 11 described later.

　第二撮像部１０では、第二透過光Ｌ２と第三透過光Ｌ３が合成された光が撮像される。 The second imaging unit 10 captures an image of light obtained by combining the second transmitted light L2 and the third transmitted light L3.

　この実施形態では、図１及び図２に示すように、第一光源５、第二光源８及び第三光源９が、一つの光源ユニット１２に組み込まれている。これにより、第一光源５、第二光源８及び第三光源９が近接配置され、第一透過光Ｌ１、第二透過光Ｌ２及び第三透過光Ｌ３がガラス板Ｇの実質的に同じ場所を通過するようになっている。この実施形態では、光源ユニット１２は、第一光源５、第二光源８及び第三光源９を同時に点灯する。なお、光源ユニット１２は、第一光源５、第二光源８及び第三光源９を異なるタイミングで点滅させてもよい。 In this embodiment, as shown in FIGS. 1 and 2, the first light source 5, the second light source 8, and the third light source 9 are incorporated in one light source unit 12. Thereby, the 1st light source 5, the 2nd light source 8, and the 3rd light source 9 are arrange | positioned closely, and the 1st transmitted light L1, the 2nd transmitted light L2, and the 3rd transmitted light L3 pass the substantially same place of the glass plate G. It has come to pass. In this embodiment, the light source unit 12 turns on the first light source 5, the second light source 8, and the third light source 9 simultaneously. The light source unit 12 may blink the first light source 5, the second light source 8, and the third light source 9 at different timings.

　また、図１に戻ると、第一撮像部６の光軸上及び第二撮像部１０の光軸上に、ビームスプリッタ１１が配置されている。遮蔽板７は、ビームスプリッタ１１と第一撮像部６との間に配置される。ビームスプリッタ１１は、光源ユニット１２から照射されてガラス板Ｇを透過した透過光を、第一透過光Ｌ１を含む第一成分と、第二透過光Ｌ２及び第三透過光Ｌ３を含む第二成分との二つに分離する。詳細には、ビームスプリッタ１１として、特定の波長を透過し、それ以外の波長を反射するものを用いる。そして、第一光源５として、例えば青色のＬＥＤを用い、第二光源８及び第三光源９として、第一光源５とは色の異なる、例えば赤色のＬＥＤを用いる。これにより、ビームスプリッタ１１で、第一光源５に由来する第一透過光Ｌ１と、第二光源８及び第三光源９に由来する第二透過光Ｌ２及び第三透過光Ｌ３とに二色分離する。図示例では、第一透過光Ｌ１を含む第一成分がビームスプリッタ１１を透過して第一撮像部６で撮像され、第二透過光Ｌ２及び第三透過光Ｌ３を含む第二成分がビームスプリッタ１１で反射して第二撮像部１０で撮像される。なお、第一光源５、第二光源８及び第三光源９は、ＬＥＤに限定されるものではなく、例えば、メタルハライドランプやレーザ光源などであってもよい。 Returning to FIG. 1, the beam splitter 11 is disposed on the optical axis of the first imaging unit 6 and on the optical axis of the second imaging unit 10. The shielding plate 7 is disposed between the beam splitter 11 and the first imaging unit 6. The beam splitter 11 converts the transmitted light irradiated from the light source unit 12 and transmitted through the glass plate G into a first component including the first transmitted light L1, and a second component including the second transmitted light L2 and the third transmitted light L3. And split into two. Specifically, a beam splitter 11 that transmits a specific wavelength and reflects other wavelengths is used. Then, for example, a blue LED is used as the first light source 5, and, for example, a red LED having a color different from that of the first light source 5 is used as the second light source 8 and the third light source 9. Thus, the beam splitter 11 separates the first transmitted light L1 derived from the first light source 5 and the second transmitted light L2 and third transmitted light L3 derived from the second light source 8 and the third light source 9 into two colors. To do. In the illustrated example, the first component including the first transmitted light L1 passes through the beam splitter 11 and is imaged by the first imaging unit 6, and the second component including the second transmitted light L2 and the third transmitted light L3 is the beam splitter. 11 is reflected and imaged by the second imaging unit 10. In addition, the 1st light source 5, the 2nd light source 8, and the 3rd light source 9 are not limited to LED, For example, a metal halide lamp, a laser light source, etc. may be sufficient.

　さらに、図示は省略するが、光源ユニット１２はＺ方向に沿って複数配置されており、ライン光源を構成している。また同様に、第一撮像部６及び第二撮像部１０もＺ方向に沿って複数配置されており、ラインカメラを構成している。これにより、ガラス板ＧをＸ方向に沿って送ると、ガラス板Ｇの略全面に対して検査が行われるようになっている。 Furthermore, although not shown in the figure, a plurality of light source units 12 are arranged along the Z direction to constitute a line light source. Similarly, a plurality of first imaging units 6 and second imaging units 10 are also arranged along the Z direction, and constitute a line camera. Thereby, when the glass plate G is sent along the X direction, an inspection is performed on substantially the entire surface of the glass plate G.

　識別手段４は、第一撮像部６及び第二撮像部１０に有線又は無線で接続されており、これら撮像部６，１０による撮像結果が入力される。撮像部６，１０は、明るい部分を白、暗い部分を黒としたモノクロ情報からなる像を出力する。ここでいう像はガラス板Ｇの欠陥候補を意味する。識別手段４は、例えば、ＰＣのＣＰＵで構成される。識別手段４は、第一撮像系２で得られた像と、第二撮像系３で得られた像とに基づいて、ガラス板Ｇの欠陥の種類を識別する。図示は省略するが、識別手段４は、識別されたガラス板Ｇの欠陥の種類と位置を記憶手段（例えば、ＰＣのメモリ）に記憶させると共に、ディスプレイにこれらの情報を表示させる。 The identification unit 4 is connected to the first imaging unit 6 and the second imaging unit 10 by wire or wirelessly, and the imaging results by the imaging units 6 and 10 are input. The imaging units 6 and 10 output an image composed of monochrome information in which a bright part is white and a dark part is black. The image here means a defect candidate of the glass plate G. The identification means 4 is constituted by a CPU of a PC, for example. The identification unit 4 identifies the type of defect of the glass sheet G based on the image obtained by the first imaging system 2 and the image obtained by the second imaging system 3. Although illustration is omitted, the identification unit 4 stores the type and position of the defect of the identified glass sheet G in a storage unit (for example, a memory of a PC) and displays the information on the display.

　図３に示すように、ガラス板Ｇの内部に含まれる欠陥としては、異物欠陥Ｘｍと泡欠陥Ｘｂがある。異物欠陥Ｘｍは、ガラス原料に由来する未溶解物などであり、ガラス板Ｇの表面の歪みを伴う場合が多い。泡欠陥Ｘｂは、製造過程で混入した空気などである。また、ガラス板Ｇの表面には、欠陥と誤検出されやすい埃Ｘｄが付着する場合もある。埃Ｘｄは洗浄等で除去できる。 As shown in FIG. 3, the defects contained in the glass plate G include a foreign substance defect Xm and a bubble defect Xb. The foreign substance defect Xm is an undissolved material derived from the glass raw material, and is often accompanied by distortion of the surface of the glass plate G. The bubble defect Xb is air mixed in the manufacturing process. Further, dust Xd that is easily detected as a defect may adhere to the surface of the glass plate G. The dust Xd can be removed by washing or the like.

　異物欠陥、泡欠陥、埃などを有するガラス板Ｇを検査装置１で検査した場合に得られる像の代表的な一例を図４に示す。これらの像は、透過光Ｌ１，Ｌ２，Ｌ３が異物欠陥、泡欠陥、埃で屈折や散乱等することによって得られる。 FIG. 4 shows a typical example of an image obtained when the inspection apparatus 1 inspects the glass plate G having foreign matter defects, bubble defects, dust, and the like. These images are obtained when the transmitted lights L1, L2, and L3 are refracted or scattered by foreign matter defects, bubble defects, and dust.

　同図に示すように、異物欠陥の場合、第一撮像系２では像Ｉ１が得られ、第二撮像系３では像が得られないときが多い。第一撮像系２の像Ｉ１は、例えば、真円に近い白丸と黒丸が連なった形状になる。 As shown in the figure, in the case of a foreign substance defect, an image I1 is often obtained with the first imaging system 2 and an image cannot be obtained with the second imaging system 3. The image I1 of the first imaging system 2 has, for example, a shape in which white circles and black circles close to a perfect circle are connected.

　泡欠陥の場合、第一撮像系２では、像Ｉ２が得られたり、像自体が得られなかったりする。像Ｉ２が得られる場合、例えば、長円に近い白丸と黒丸が連なった形状になる。一方、第二撮像系３では、黒色の像Ｉ３が得られるときが多い。像Ｉ３は、例えば、長円に近い形状となる。 In the case of a bubble defect, in the first imaging system 2, the image I2 may be obtained or the image itself may not be obtained. When the image I2 is obtained, for example, a shape in which white circles and black circles close to an ellipse are connected is formed. On the other hand, in the second imaging system 3, a black image I3 is often obtained. The image I3 has a shape close to an ellipse, for example.

　埃の場合、第一撮像系２では、像Ｉ４が得られたり、像自体が得られなかったりする。像Ｉ４が得られる場合、例えば、波打った形状になる。一方、第二撮像系３では、白色の像Ｉ５が得られるときが多い。像Ｉ５は、例えば、波打った形状となる。 In the case of dust, the first imaging system 2 may obtain the image I4 or may not obtain the image itself. When the image I4 is obtained, for example, it has a wavy shape. On the other hand, in the second imaging system 3, a white image I5 is often obtained. The image I5 has, for example, a wavy shape.

　欠陥検査工程では、これらの傾向を用いて、第一撮像系２で得られた像と第二撮像系３で得られた像とからガラス板Ｇの欠陥の種類を識別する。ガラス板Ｇの欠陥の種類を識別する際に、欠陥検査工程で行われる処理の一例を、図５に示すフローチャートを用いて以下に説明する。 In the defect inspection process, using these tendencies, the type of defect of the glass plate G is identified from the image obtained by the first imaging system 2 and the image obtained by the second imaging system 3. An example of processing performed in the defect inspection process when identifying the type of defect in the glass plate G will be described below with reference to the flowchart shown in FIG.

　同図に示すように、まず、第一撮像系２の像が存在するか否かを判断する（ステップＳ１）。その結果、第一撮像系２の像が存在すると判断された場合、第二撮像系３の像が存在するか否かを判断し（ステップＳ２）、第一撮像系２の像が存在しないと判断された場合には、第二撮像系３の像が存在するか否かを判断する（ステップＳ３）。 As shown in the figure, first, it is determined whether or not an image of the first imaging system 2 exists (step S1). As a result, when it is determined that the image of the first imaging system 2 exists, it is determined whether or not the image of the second imaging system 3 exists (step S2). If it is determined, it is determined whether an image of the second imaging system 3 exists (step S3).

　ステップＳ２で第二撮像系３の像が存在しないと判断された場合、検査対象位置においてガラス板Ｇに異物欠陥があると判断する（ステップＳ４）。 When it is determined in step S2 that the image of the second imaging system 3 does not exist, it is determined that there is a foreign object defect in the glass plate G at the inspection target position (step S4).

　ステップＳ２又はＳ３で、第二撮像系３の像が存在すると判断された場合、第二撮像系３の像の色が白色か否かを判断する（ステップＳ５）。その結果、第二撮像系３の像が白色でないと判断された場合、検査対象位置においてガラス板Ｇに泡欠陥があると判断する（ステップＳ６）。 When it is determined in step S2 or S3 that the image of the second imaging system 3 exists, it is determined whether or not the color of the image of the second imaging system 3 is white (step S5). As a result, when it is determined that the image of the second imaging system 3 is not white, it is determined that the glass plate G has a bubble defect at the inspection target position (step S6).

　一方、ステップＳ５で、第二撮像系３の像が白色であると判断された場合、検査対象位置においてガラス板Ｇに埃があると判断する（ステップＳ７）。 On the other hand, when it is determined in step S5 that the image of the second imaging system 3 is white, it is determined that there is dust on the glass plate G at the inspection target position (step S7).

　また、ステップＳ３で、第二撮像系３の像が存在しないと判断された場合、検査対象位置においてガラス板Ｇに欠陥及び埃がないと判断する（ステップＳ８）。 If it is determined in step S3 that the image of the second imaging system 3 does not exist, it is determined that there is no defect or dust in the glass plate G at the inspection target position (step S8).

　ステップＳ１～Ｓ８の処理は、識別手段４において全自動で行うことができる。 The processing of steps S1 to S8 can be performed fully automatically by the identification means 4.

　そして、これらの最終的な識別結果情報は、検査対象位置の位置情報と紐付けられた状態で、記憶手段に記憶されると共にディスプレイに表示される。また、識別結果情報は、上流側の工程（例えば、成形工程や切断工程）にフィードバックされ、上流側の工程における製造条件などが必要に応じて調整される。なお、異物欠陥及び／又は泡欠陥が存在すると判断されたガラス板Ｇは、その欠陥の大きさ等に応じて廃棄の有無が決定される。 The final identification result information is stored in the storage means and displayed on the display in a state linked to the position information of the inspection target position. Further, the identification result information is fed back to an upstream process (for example, a molding process or a cutting process), and manufacturing conditions and the like in the upstream process are adjusted as necessary. In addition, the presence or absence of disposal of the glass plate G determined to have a foreign object defect and / or a bubble defect is determined according to the size of the defect.

　以上のような欠陥検査工程によれば、埃をガラス板Ｇの欠陥として誤検出するのを防止しつつ、ガラス板Ｇの欠陥（異物欠陥、泡欠陥）の種類を正確に識別することができる。 According to the above defect inspection process, it is possible to accurately identify the types of defects (foreign matter defects, bubble defects) of the glass plate G while preventing dust from being erroneously detected as defects of the glass plate G. .

　ここで、欠陥の識別精度を向上させるために、欠陥検査工程で次のような処理を追加してもよい。 Here, in order to improve the defect identification accuracy, the following processing may be added in the defect inspection process.

　異物欠陥の場合であっても、第二撮像系３で像が得られ、異物欠陥と泡欠陥を識別しにくいときがある。そこで、上記の欠陥検査工程において、図６Ａ及び図７Ｂに示すように第一撮像系２で得られた像Ｉ６，Ｉ８の面積Ａと、図６Ｂ及び図７Ｂに示すように第二撮像系３で得られた像Ｉ７，Ｉ９の面積Ｂとを求め、これら２つの面積の比Ａ／Ｂに基づいて、ガラス板Ｇ中の泡欠陥と異物欠陥とを識別するようにしてもよい。すなわち、図６Ａ及び図６Ｂに示すように、異物欠陥の場合、第一撮像系２で得られた像Ｉ６の面積Ａが、第二撮像系３で得られた像Ｉ７の面積Ｂに比べて大きくなり、面積比Ａ／Ｂの値が大きくなる傾向がある。これに対し、図７Ａ及び図７Ｂに示すように、泡欠陥の場合、第一撮像系２で得られた像Ｉ８の面積Ａが、第二撮像系３で得られた像Ｉ９の面積Ｂに比べてそれほど大きくならず、面積比Ａ／Ｂの値が小さくなる傾向がある（１に近づく）。したがって、面積比Ａ／Ｂの値が所定のしきい値以上の場合を異物欠陥又は異物欠陥候補と判断し、しきい値未満の場合を泡欠陥又は泡欠陥候補と判断してもよい。ここで、異物欠陥候補や泡欠陥候補は、最終的な識別結果を意味するものではなく、その後に別の識別処理を加えることを予定したものである。後述する埃候補も同様の意味である。なお、面積比Ａ／Ｂのしきい値は、異物欠陥を識別するための第一しきい値と、泡欠陥を識別するための第二しきい値（第二しきい値＜第一しきい値）とに分けてもよい。しきい値の大きさは、検査の要求精度に応じて変更できる。 Even in the case of a foreign object defect, an image is obtained by the second imaging system 3, and it may be difficult to distinguish the foreign object defect from the bubble defect. Therefore, in the defect inspection step described above, the area A of the images I6 and I8 obtained by the first imaging system 2 as shown in FIGS. 6A and 7B, and the second imaging system 3 as shown in FIGS. 6B and 7B. The area B of the images I7 and I9 obtained in the above may be obtained, and the bubble defect and the foreign object defect in the glass plate G may be identified based on the ratio A / B of these two areas. That is, as shown in FIGS. 6A and 6B, in the case of a foreign substance defect, the area A of the image I6 obtained by the first imaging system 2 is compared with the area B of the image I7 obtained by the second imaging system 3. The area ratio A / B tends to increase. In contrast, as shown in FIGS. 7A and 7B, in the case of a bubble defect, the area A of the image I8 obtained by the first imaging system 2 is changed to the area B of the image I9 obtained by the second imaging system 3. There is a tendency that the value of the area ratio A / B is small (approaching 1). Therefore, a case where the value of the area ratio A / B is equal to or greater than a predetermined threshold value may be determined as a foreign substance defect or a foreign substance defect candidate, and a case where the value is less than the threshold value may be determined as a bubble defect or a bubble defect candidate. Here, the foreign substance defect candidate and the bubble defect candidate do not mean a final identification result, but are intended to add another identification process thereafter. The dust candidates described later have the same meaning. Note that the threshold value of the area ratio A / B includes a first threshold value for identifying foreign matter defects and a second threshold value for identifying bubble defects (second threshold value <first threshold value). Value). The magnitude of the threshold can be changed according to the required accuracy of inspection.

　埃の場合であっても、第二撮像系３で像が白色にならず、泡欠陥と埃の識別がしにくいときがある。そこで、上記の欠陥検査工程において、図８Ａ及び図８Ｂに示すように、第二撮像系３で得られた像Ｉ１０，Ｉ１１のガラス板Ｇの延伸方向に沿ったＺ方向（第一方向に相当）の寸法Ｃと、その像Ｉ１０，Ｉ１１のＺ方向と直交するＸ方向（第二方向に相当）の寸法Ｄとを求め、これら２つの寸法比Ｃ／Ｄに基づいて、泡欠陥と埃とを識別するようにしてもよい。すなわち、図８Ａに示すように、泡欠陥の場合、第二撮像系３で得られた像Ｉ１０がＺ方向に細長くなっていることが多いため、寸法比Ｃ／Ｄの値が大きくなる傾向にある。これに対し、図８Ｂに示すように、埃の場合、第二撮像系３で得られた像Ｉ１１が延伸成形の影響を受けずにＺ方向とは無関係であるため、寸法比Ｃ／Ｄの値が小さくなる傾向にある。したがって、寸法比Ｃ／Ｄの値が所定のしきい値以上の場合を泡欠陥又は泡欠陥候補と判断し、しきい値未満の場合を埃又は埃候補と判断してもよい。なお、寸法比Ｃ／Ｄのしきい値は、泡欠陥を識別するための第一しきい値と、埃を識別するための第二しきい値（第二しきい値＜第一しきい値）とに分けてもよい。また、しきい値の大きさは検査の要求精度に応じて変更できる。 Even in the case of dust, the image does not become white in the second imaging system 3, and it may be difficult to distinguish between bubble defects and dust. Therefore, in the defect inspection process, as shown in FIGS. 8A and 8B, the Z direction (corresponding to the first direction) along the extending direction of the glass plate G of the images I10 and I11 obtained by the second imaging system 3 is shown. ) And a dimension D in the X direction (corresponding to the second direction) orthogonal to the Z direction of the images I10 and I11, and based on these two dimensional ratios C / D, May be identified. That is, as shown in FIG. 8A, in the case of a bubble defect, since the image I10 obtained by the second imaging system 3 is often elongated in the Z direction, the value of the dimension ratio C / D tends to increase. is there. On the other hand, as shown in FIG. 8B, in the case of dust, the image I11 obtained by the second imaging system 3 is not affected by the stretch molding and is irrelevant to the Z direction. The value tends to decrease. Therefore, a case where the value of the dimensional ratio C / D is equal to or greater than a predetermined threshold value may be determined as a bubble defect or a bubble defect candidate, and a case where the value is less than the threshold value may be determined as dust or a dust candidate. In addition, the threshold value of the size ratio C / D includes a first threshold value for identifying bubble defects and a second threshold value for identifying dust (second threshold value <first threshold value). ). The size of the threshold can be changed according to the required accuracy of inspection.

　また、泡欠陥と埃の識別がしにくい場合には、上記の欠陥検査工程において、図９Ａ及び図９Ｂに示すように、第二撮像系３で得られた像Ｉ１２，Ｉ１３の面積Ｅと、その像Ｉ１２，Ｉ１３が内接するようにＺ方向と平行な辺およびＸ方向と平行な辺からなる矩形Ｓを形成したときの矩形Ｓの面積Ｆとを求め、これら２つの面積比Ｅ／Ｆに基づいて、泡欠陥と埃とを識別するようにしてもよい。すなわち、図９Ａに示すように、泡欠陥の場合、第二撮像系３で得られた像Ｉ１２がＺ方向に真っ直ぐ延びていることが多いため、像Ｉ１２の面積Ｅが矩形Ｓの面積Ｆと同程度になり、面積比Ｅ／Ｆの値が大きくなる傾向にある（１に近づく）。これに対し、図９Ｂに示すように、埃の場合、第二撮像系３で得られた像Ｉ１３が延伸成形の影響を受けずにＺ方向とは無関係であるため、像Ｉ１３の面積Ｅが矩形Ｓの面積Ｆよりもかなり小さくなり、面積比Ｅ／Ｆの値が小さくなる傾向にある（０に近づく）。したがって、面積比Ｅ／Ｆの値が所定のしきい値以上の場合を泡欠陥又は泡欠陥候補と判断し、しきい値未満の場合を埃又は埃候補と判断してもよい。なお、面積比Ｅ／Ｆのしきい値は、泡欠陥を識別するための第一しきい値と、埃を識別するための第二しきい値（第二しきい値＜第一しきい値）とに分けてもよい。また、しきい値の大きさは、検査の要求精度に応じて変更できる。 If it is difficult to distinguish between bubble defects and dust, in the defect inspection process, as shown in FIGS. 9A and 9B, the area E of the images I12 and I13 obtained by the second imaging system 3, and An area F of the rectangle S when a rectangle S composed of a side parallel to the Z direction and a side parallel to the X direction is formed so that the images I12 and I13 are inscribed, and the ratio of these two areas E / F is obtained. Based on this, it is possible to distinguish between bubble defects and dust. That is, as shown in FIG. 9A, in the case of a bubble defect, the image I12 obtained by the second imaging system 3 often extends straight in the Z direction, so that the area E of the image I12 is equal to the area F of the rectangle S. The area ratio E / F tends to increase (approach 1). On the other hand, as shown in FIG. 9B, in the case of dust, the image I13 obtained by the second imaging system 3 is not affected by the stretch molding and is irrelevant to the Z direction. It is much smaller than the area F of the rectangle S, and the value of the area ratio E / F tends to be small (approaching 0). Therefore, a case where the value of the area ratio E / F is equal to or greater than a predetermined threshold value may be determined as a bubble defect or a bubble defect candidate, and a case where the value is less than the threshold value may be determined as dust or a dust candidate. The threshold value of the area ratio E / F includes a first threshold value for identifying bubble defects and a second threshold value for identifying dust (second threshold value <first threshold value). ). The size of the threshold value can be changed according to the required accuracy of inspection.

　さらに、泡欠陥と埃の識別がしにくい場合には、上記の欠陥検査工程において、図１０Ａ及び図１０Ｂに示すように、第二撮像系３で得られた像Ｉ１４，Ｉ１５のＺ方向と平行な対称軸Ｈに対する対称性に基づいて、泡欠陥と埃とを識別するようにしてもよい。すなわち、図１０Ａに示すように、泡欠陥の場合、第二撮像系３で得られた像Ｉ１４がＺ方向に真っ直ぐ延びていることが多いため、像Ｉ１４の対称軸Ｈに対する対称性（線対称性）が高くなる傾向にある。これに対し、図１０Ｂに示すように、埃の場合、第二撮像系３で得られた像Ｉ１５は延伸成形の影響を受けずにＺ方向とは無関係であるため、像Ｉ１５の対称軸Ｈに対する対称性（線対称性）が低くなる傾向にある。したがって、対称軸Ｈに対する対称性を数値化した値（対称性が高いときに値が大きくなる）が所定のしきい値以上である場合を泡欠陥又は泡欠陥候補と判断し、しきい値未満の場合を埃又は埃候補と判断してもよい。なお、対称性のしきい値は、泡欠陥を識別するための第一しきい値と、埃を識別するための第二しきい値（第二しきい値＜第一しきい値）とに分けてもよい。また、しきい値の大きさは、検査の要求精度に応じて変更できる。 Further, when it is difficult to distinguish between bubble defects and dust, in the defect inspection process, as shown in FIGS. 10A and 10B, the images I14 and I15 obtained by the second imaging system 3 are parallel to the Z direction. On the basis of symmetry with respect to the symmetry axis H, bubble defects and dust may be identified. That is, as shown in FIG. 10A, in the case of a bubble defect, the image I14 obtained by the second imaging system 3 often extends straight in the Z direction, so that the symmetry of the image I14 with respect to the symmetry axis H (line symmetry). Tend to be higher. On the other hand, as shown in FIG. 10B, in the case of dust, the image I15 obtained by the second imaging system 3 is not affected by the stretch molding and is irrelevant to the Z direction. There is a tendency for the symmetry (line symmetry) to be low. Therefore, when the value obtained by quantifying the symmetry with respect to the symmetry axis H (the value increases when the symmetry is high) is equal to or greater than a predetermined threshold value, it is determined as a bubble defect or a bubble defect candidate, and is less than the threshold value. This case may be determined as dust or a dust candidate. The symmetry threshold is divided into a first threshold for identifying bubble defects and a second threshold for identifying dust (second threshold <first threshold). It may be divided. The size of the threshold value can be changed according to the required accuracy of inspection.

　また、泡欠陥と埃の識別がしにくい場合には、上記の欠陥検査工程において、図１１Ａ及び図１１Ｂに示すように、第二撮像系３で得られた像Ｉ１６，Ｉ１７のＺ方向に対する傾き角θを求め、この傾き角θに基づいて、泡欠陥と埃とを識別するようにしてもよい。すなわち、図１１Ａに示すように、泡欠陥の場合、第二撮像系３で得られた像Ｉ１６がＺ方向に真っ直ぐ延びていることが多いため、像Ｉ１６の傾き角θが小さくなる傾向にある。これに対し、図１１Ｂに示すように、埃の場合、第二撮像系３で得られた像Ｉ１７は延伸成形の影響を受けずにＺ方向とは無関係であるため、像Ｉ１７の傾き角θが大きくなる傾向にある。したがって、傾き角θが所定のしきい値以下である場合を泡欠陥又は泡欠陥候補と判断し、しきい値超の場合を埃又は埃候補と判断してもよい。なお、傾き角θのしきい値は、泡欠陥を識別するための第一しきい値と、埃を識別するための第二しきい値（第二しきい値＞第一しきい値）とに分けてもよい。また、しきい値の大きさは、検査精度に応じて変更できる。 If it is difficult to distinguish between bubble defects and dust, as shown in FIGS. 11A and 11B in the defect inspection step, the inclinations of the images I16 and I17 obtained by the second imaging system 3 with respect to the Z direction. An angle θ may be obtained, and bubble defects and dust may be identified based on the inclination angle θ. That is, as shown in FIG. 11A, in the case of a bubble defect, since the image I16 obtained by the second imaging system 3 often extends straight in the Z direction, the inclination angle θ of the image I16 tends to be small. . On the other hand, as shown in FIG. 11B, in the case of dust, the image I17 obtained by the second imaging system 3 is not affected by the stretch molding and is irrelevant to the Z direction. Tend to be larger. Therefore, the case where the inclination angle θ is equal to or smaller than the predetermined threshold value may be determined as a bubble defect or a bubble defect candidate, and the case where the inclination angle θ is greater than the threshold value may be determined as dust or a dust candidate. The threshold value of the inclination angle θ includes a first threshold value for identifying bubble defects, a second threshold value for identifying dust (second threshold value> first threshold value), and It may be divided into The magnitude of the threshold can be changed according to the inspection accuracy.

　ここで、以上に例示した泡欠陥と埃の識別方法は、ガラス板Ｇの延伸方向を考慮したものである。そのため、第二撮像系３で得られた像からガラス板Ｇの延伸方向に関連する特徴量を抽出し、この特徴量に基づいて泡欠陥と埃とを識別しているともいえる。 Here, the bubble defect and dust identification method exemplified above takes the stretching direction of the glass plate G into consideration. Therefore, it can be said that the feature quantity related to the extending direction of the glass plate G is extracted from the image obtained by the second imaging system 3, and the bubble defect and dust are identified based on this feature quantity.

　図１２に示すように、端縁検査工程は、第二撮像系３でガラス板Ｇの端辺Ｇｆ，Ｇｂを含む検査エリアＡ１，Ａ２を撮像し、端辺Ｇｆ，Ｇｂの形状不良の有無を検査する。その結果、図１２に拡大して示すように、第二撮像系３の撮像結果に基づいて、端辺Ｇｆ，Ｇｂに切残しＤ１や欠けＤ２があると判断された場合に、ガラス板Ｇの形状不良と判断する。端縁検査工程は省略してもよいし、別の検査装置によって行ってもよい。 As shown in FIG. 12, in the edge inspection step, the second imaging system 3 images the inspection areas A1 and A2 including the edges Gf and Gb of the glass plate G, and determines whether there is a shape defect in the edges Gf and Gb. inspect. As a result, as shown in an enlarged view in FIG. 12, when it is determined that there are uncut D1 and chipping D2 at the edges Gf and Gb based on the imaging result of the second imaging system 3, the glass plate G Judged as a shape defect. The edge inspection step may be omitted or may be performed by another inspection apparatus.

　なお、本発明は、上記の実施形態の構成に限定されるものではなく、上記した作用効果に限定されるものでもない。本発明は、本発明の要旨を逸脱しない範囲で種々の変更が可能である。 In addition, this invention is not limited to the structure of said embodiment, It is not limited to the above-mentioned effect. The present invention can be variously modified without departing from the gist of the present invention.

　上記の実施形態では、第一光源５、第二光源８及び第三光源９を一つにまとめた光源ユニット１２と、ビームスプリッタ１１とを用いて、第一撮像系２と第二撮像系３の光路の一部を重複させる場合を説明したが、これに限定されない。例えば、図１３に示すように、第一撮像系２と第二撮像系３とをガラス板Ｇの送り方向に沿って間隔を置いて配置し、第一撮像系２の光路と第二撮像系３の光路とを完全に独立させてもよい。 In the above embodiment, the first imaging system 2 and the second imaging system 3 are used by using the light source unit 12 that combines the first light source 5, the second light source 8, and the third light source 9, and the beam splitter 11. Although the case where a part of the optical path is overlapped has been described, the present invention is not limited to this. For example, as shown in FIG. 13, the first imaging system 2 and the second imaging system 3 are arranged at intervals along the feeding direction of the glass plate G, and the optical path of the first imaging system 2 and the second imaging system are arranged. The three optical paths may be completely independent.

　上記の実施形態では、ガラス板Ｇを縦姿勢で送りながら欠陥の種類を識別する場合を説明したが、ガラス板Ｇの姿勢は特に限定されるものではない。例えば、ガラス板Ｇを横姿勢（好ましくは水平姿勢）で送りながら欠陥の種類を識別するようにしてもよい。 In the above-described embodiment, the case where the type of defect is identified while feeding the glass plate G in a vertical posture has been described, but the posture of the glass plate G is not particularly limited. For example, the type of defect may be identified while feeding the glass plate G in a horizontal posture (preferably a horizontal posture).

　上記の実施形態では、所定位置に配置された検査装置１に対して、ガラス板Ｇを移動させながら欠陥の種類を識別する場合を説明したが、検査装置１とガラス板Ｇとの間に相対的な移動があればよい。すなわち、ガラス板Ｇを所定位置に配置した状態で、ガラス板Ｇに対して検査装置１を移動させてもよいし、ガラス板Ｇと検査装置１の両方を移動させてもよい。 In the above embodiment, the case has been described in which the type of defect is identified while moving the glass plate G with respect to the inspection device 1 arranged at a predetermined position, but the relative relationship between the inspection device 1 and the glass plate G is described. If there is a like movement. That is, the inspection apparatus 1 may be moved with respect to the glass plate G while the glass plate G is disposed at a predetermined position, or both the glass plate G and the inspection apparatus 1 may be moved.

　上記の実施形態において、検査工程の後に洗浄工程を設けてもよい。この場合、検査工程で特定された埃の位置を記憶手段から呼び出し、その呼び出した位置に対応する部分を選択的ないし重点的に洗浄するようにしてもよい。 In the above embodiment, a cleaning process may be provided after the inspection process. In this case, the position of the dust specified in the inspection process may be called from the storage means, and the portion corresponding to the called position may be selectively or intensively cleaned.

１　　　検査装置
２　　　第一撮像系
３　　　第二撮像系
４　　　識別手段
５　　　第一光源
６　　　第一撮像部
７　　　遮蔽板
８　　　第二光源
９　　　第三光源
１０　　第二撮像部
１１　　ビームスプリッタ
１２　　光源ユニット
Ｇ　　　ガラス板
Ｇ１　　第一主面
Ｇ２　　第二主面
Ｌ１　　第一透過光
Ｌ２　　第二透過光
Ｌ３　　第三透過光 DESCRIPTION OF SYMBOLS 1 Inspection apparatus 2 1st imaging system 3 2nd imaging system 4 Identification means 5 1st light source 6 1st imaging part 7 Shielding plate 8 Second light source 9 3rd light source 10 2nd imaging part 11 Beam splitter 12 Light source unit G Glass plate G1 First main surface G2 Second main surface L1 First transmitted light L2 Second transmitted light L3 Third transmitted light

Claims

In the inspection method of glass plate,
A first light source, a first imaging unit that images the first transmitted light that has been irradiated from the first light source and transmitted through the glass plate, and a part of the first transmitted light is shielded from the first imaging unit. A first imaging system having a shielding member that forms a bright part and a dark part in the field of view;
The second light source and the third light source, and the second transmitted light that has been irradiated from the second light source and transmitted through the glass plate is imaged in a bright field, while the second light source that has been irradiated from the third light source and transmitted through the glass plate. A second imaging system having a second imaging unit that images the three transmitted light in a dark field;
A method for inspecting a glass plate, comprising: identifying a type of defect of the glass plate based on an image obtained by the first imaging system and an image obtained by the second imaging system.

The first light source, the second light source and the third light source as one light source unit,
The transmitted light that has been irradiated from the light source unit and transmitted through the glass plate is, by a beam splitter, a first component that includes the first transmitted light, and a second component that includes the second transmitted light and the third transmitted light. The first component is imaged by the first imaging unit through the shielding member, and the second component is imaged by the second imaging unit. Glass plate inspection method.

The foreign object defect in the glass plate is identified based on the presence or absence of an image obtained by the first imaging system and the presence or absence of an image obtained by the second imaging system. Inspection method of the glass plate of description.

The foreign matter defect and the bubble defect in the glass plate are identified based on the area of the image obtained by the first imaging system and the area of the image obtained by the second imaging system. 4. The method for inspecting a glass plate according to any one of 1 to 3.

The bubble defect in the glass plate and the dust adhering to the surface of the glass plate are identified based on the color of the image obtained by the second imaging system. Inspection method of the glass plate of description.

The dimension of the first direction of the image obtained by the second imaging system along the extending direction of the glass plate and the dimension of the second direction orthogonal to the first direction of the image obtained by the second imaging system. 6. The method for inspecting a glass plate according to claim 1, wherein a bubble defect in the glass plate is discriminated from dust adhering to the surface of the glass plate.

An area of an image obtained by the second imaging system, a side parallel to a first direction along the extending direction of the glass plate, and a side parallel to a second direction orthogonal to the first direction, and The bubble defect in the glass plate and the dust adhering to the surface of the glass plate are identified based on the rectangular area inscribed by the image obtained by the second imaging system. The inspection method of the glass plate of any one of these.

Based on the symmetry of the image obtained by the second imaging system with respect to the symmetry axis parallel to the first direction along the stretching direction of the glass plate, it adheres to bubble defects in the glass plate and the surface of the glass plate The method for inspecting a glass plate according to any one of claims 1 to 7, wherein the dust is identified.

Identifying bubble defects in the glass plate and dust adhering to the surface of the glass plate based on the inclination of the image obtained by the second imaging system with respect to the first direction along the extending direction of the glass plate. The method for inspecting a glass plate according to any one of claims 1 to 8, wherein:

The glass plate inspection method according to any one of claims 1 to 9, wherein an image of an edge of the glass plate is imaged by the second imaging system, and the presence or absence of a shape defect of the edge is inspected. .

A molding step of forming a glass ribbon by stretching molten glass in a predetermined direction;
A slow cooling step of slow cooling the glass ribbon molded in the molding step;
A cutting step of obtaining a glass plate by cutting the glass ribbon slowly cooled in the slow cooling step into a predetermined size;
A method for producing a glass plate, comprising: an inspection step for inspecting the glass plate obtained in the cutting step by the method according to any one of claims 1 to 10.

In glass plate inspection equipment,
A first light source, a first imaging unit that images the first transmitted light that has been irradiated from the first light source and transmitted through the glass plate, and a part of the first transmitted light is shielded from the first imaging unit. A first imaging system having a shielding member that forms a bright part and a dark part in the field of view;
The second light source and the third light source, and the second transmitted light irradiated from the second light source and transmitted through the glass plate are imaged in a bright field, and the second light source irradiated from the third light source and transmitted through the glass plate A second imaging system having a second imaging unit that images three transmitted light in a dark field;
An identification means for identifying the type of defect of the glass plate based on an image obtained by the first imaging system and an image obtained by the second imaging system. Inspection device.

The first light source, the second light source and the third light source are one light source unit,
Transmitted light irradiated from the light source unit and transmitted through the glass plate is divided into two parts, a first component including the first transmitted light and a second component including the second transmitted light and the third transmitted light. With a beam splitter to separate,
The shielding member is disposed between the first imaging unit and the beam splitter,
The first imaging unit images the first component through the shielding member,
The glass plate inspection apparatus according to claim 12, wherein the second imaging unit is configured to image the second component.