JP2002214157A - Flaw detecting method and device for plate-like body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flaw detecting method and its device for a plate-like body capable of detecting a flaw having a fracture surface perpendicular to a principal plane without affected by a protective film stuck to the principal plane. SOLUTION: A light beam 6 irradiates the plate-like body 3 while an irradiation position by the light beam 6 is moved, and the flaw is detected based on a change of the light quantity transmitting the plate-like body 3 of the irradiated light beam 6 by this flaw detecting method and the device. The light beam 6 irradiates the plate-like body 3 so that the optical axis 101 lies nonperpendicularly to a principal plane 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting flaws on a plate-like body, and more particularly, to a method for detecting a flaw whose surface is perpendicular to the main surface without being affected by the state of the main surface (protective film, dirt, etc.). With respect to which can be detected.

[0002]

2. Description of the Related Art For example, in a manufacturing process of a glass plate, a glass plate of a product size can be obtained by scoring and scratching a glass base plate, breaking the glass plate and dividing it. At the time of the division, a flaw such as a crack or a chip may be generated at an end portion (hereinafter, referred to as an edge) of the glass plate. Therefore, such a flaw is detected to prevent a defective product from flowing to the next process. There is a need.

FIG. 23 is a perspective view showing an example of such a method for detecting a flaw on a glass plate, and FIG. 24 is a side view thereof.

In FIG. 23 and FIG. 24, this method for detecting flaws on a glass plate is performed by irradiating a laser beam 6 from above onto an edge portion of a main surface 3a of a glass plate 3 by a light projector 4, and The light transmitted through the glass plate 3 is received by a light receiver 5 installed below the glass plate 3. Then, the glass plate 3 and the projector 4 are moved so that a portion (hereinafter referred to as a spot) 7 irradiated by the laser beam 6 on the glass plate 3 moves along the edge 3 c of the glass plate 3.
In addition, the light receiver 5 is relatively moved, and a flaw is detected by a change in the amount of light received by the light receiver 5 due to the movement.

Next, the operation and effect of this flaw detection method will be described. FIG. 25 is a plan view showing the relationship between the optical path of the laser beam 6 and a detectable scratch on the glass plate 3.

In FIGS. 23 to 25, a glass plate 3
For example, assume that a crack 301 exists and that the spot 7 of the laser beam 6 moves in the direction of arrow 201 shown in FIG. Then, the optical path 51 of the laser beam 6 moves along the edge 3c of the glass plate 3 so as to follow the positions indicated by reference numerals a to f in FIG. At this time, when the optical path 51 of the laser beam 6 is located at the position indicated by the symbol d, the laser beam 6 is diffusely reflected by the fracture surface 301a of the crack 301, and the transmitted light amount decreases. As a result, the amount of light received by the light receiver 5 decreases as compared with the case where the optical path 51 of the laser beam 6 is located at another position. Therefore, by appropriately setting a threshold value for the decrease in the amount of received light, the presence of the crack 301 can be detected. Thereby, the glass plate 3
Can be automatically detected in a non-contact manner.

[0007]

By the way, in the above-mentioned method for detecting a flaw on a glass plate, as shown in FIG. 24, the laser beam 6 is applied so that the optical axis 101 is perpendicular to the main surface 3a of the glass plate 3 (in other words, The glass plate 3 is transmitted so as to be parallel to the normal line 102 of the main surface 3a), and a flaw is detected by a change in the amount of transmitted light. Therefore, when the fracture surface 301a is not perpendicular to the main surface 3a of the glass plate 3 as in a crack 301 shown in FIG. 25, the light beam constituting the laser beam 6 is incident non-parallel to the fracture surface 301a. Since the light is diffusely reflected on the broken surface 301a, the flaw 301 can be detected. On the other hand, when the broken surface is substantially perpendicular to the main surface 3a of the glass plate 3 as in the notch 302 shown in FIGS. 23 and 26, the light beam constituting the laser beam 6 is incident substantially parallel to the broken surface. Therefore, the light is hardly diffusely reflected on the fracture surface, and therefore, the amount of transmitted light does not change much. For example, as shown in FIG. 26, when the optical path 51 of the laser beam 6 moves so as to follow the positions indicated by reference numerals a to f, even if the optical path 51 of the laser beam 6 is located at the positions indicated by reference numerals c and d, The amount of light received by the light receiver 5 is
There is almost no change as compared with the case where the optical path 51 of the laser beam 6 is at another position. Therefore, in such a case, the flaw of the glass plate 3 cannot be detected.

In general, a transparent protective film is adhered to the main surface 3a of the glass plate 3. In such a case, the laser beam 6 is reflected by the protective film and the amount of transmitted light is reduced. However, it becomes a disturbance factor of the measurement, so that it becomes difficult to detect the flaw.

As another conventional method for detecting flaws on a plate-like body, there is, for example, a flaw detection method for a glass plate described in Japanese Patent Application Laid-Open No. 54-24081. The method is the same as the above-described method for detecting a glass plate, except that light from a fluorescent lamp is used instead of a laser beam as light for detection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides a method and an apparatus for detecting a flaw in a plate-like body capable of detecting a flaw having a fracture surface perpendicular to the main surface. Is the first object.

It is a second object of the present invention to provide a method and an apparatus for detecting flaws on a plate-like body, which can detect flaws without being affected by a protective film attached to a main surface.

[0012]

In order to solve the above-mentioned problems, a method and an apparatus for detecting flaws on a plate-like body according to the present invention apply a light beam to a plate-like body while moving an irradiation position by a light beam. A flaw detection method and apparatus for detecting flaws based on a change in the amount of light of the irradiated light beam transmitted through the plate-like body, wherein the light is emitted so that an optical axis is not perpendicular to the main surface of the plate-like body. A beam is irradiated (claims 1 and 10).
With such a configuration, the light beam passes through the plate-shaped body so as not to be perpendicular to the main surface of the plate-shaped body. Even in the case of a flaw that is substantially perpendicular to the surface, the light beam that constitutes the light beam is incident non-parallel to the fractured surface, so that the diffused reflection of the light beam occurs on the fractured surface and the amount of transmitted light changes. Therefore, such a flaw can be detected.

In this case, the light beam may be irradiated so that the optical axis is not parallel to the end face of the plate-like body. With such a configuration, a flaw whose fracture surface is substantially perpendicular to the main surface of the plate-like body is occupied in the field of view of the light receiving means because the light beam enters the fracture surface from the end face side as well. Since the ratio is increased, the detection sensitivity is improved. As a result, even when the protective film is stuck to the main surface of the plate-like body and becomes a cause of disturbance, the influence of the disturbance can be suppressed, and the flaw can be easily detected.

In this case, the method for detecting flaws on the plate-like body is a method in which the plate-like body is obtained by breaking a plate-like base material, and wherein the irradiation spot is formed by dividing the plate-like body. The light beam may be applied to the end while moving in the direction in which the end extends. With such a configuration, since many flaws are present at the end of the plate-like body obtained by breaking the plate-like base material, the effect of flaw detection becomes more remarkable.

Further, according to the method for detecting a flaw of a plate-like body according to the present invention, the plate-like body is irradiated with a light beam while moving the irradiation position of the light beam, and the irradiated light beam is reflected by the plate-like body. A flaw detection method for detecting flaws based on a change in the amount of light, wherein the light beam may be applied to an end face of the plate-like body. With this configuration,
The end face of the plate is irradiated with a light beam and the reflected light beam is received to detect flaws, so even if a protective film is adhered to the main surface of the plate, the effect is not affected. A flaw can be detected without receiving it. Further, it is possible to detect a flaw without being affected by disturbance light such as illumination and the color and transmittance of the glass plate, and it is possible to configure the apparatus at low cost.

Further, according to the method and the apparatus for detecting a flaw of a plate-like body according to the present invention, the plate-like body is irradiated with a light beam while moving the irradiation position by the light beam, and the plate-like body of the irradiated light beam is used. A flaw detection method and apparatus for detecting flaws based on a change in the amount of reflected light, wherein the two light beams are substantially the same at two locations separated in a direction in which the irradiation location of the plate-like body should be moved. Irradiation is performed under irradiation conditions, and a flaw is detected based on a change in a difference between light amounts of the two irradiated light beams reflected by the plate-like body (claims 5 and 12). With this configuration, the difference between the reflected light amounts of the two light beams is obtained. By setting a threshold value for the difference between the reflected light amounts, the detection target and the light beam projecting and light receiving means are set. Even if the distance to the fluctuates, the flaw can be reliably detected with a simple configuration.

In this case, in the method for detecting a flaw in the plate-like body, the plate-like body is obtained by breaking a plate-like base material, and the irradiation spot is formed by breaking the plate-like body. The light beam may be applied to the end face while moving the end face in the extending direction of the end face. Since there are many flaws at the edge of the plate-like body obtained by breaking the plate-like base material, the effect of flaw detection becomes more remarkable.

Further, in the method and the apparatus for detecting a flaw of a plate-like body according to the present invention, the end of the plate-like body is moved in the direction in which the end of the main surface of the plate-like body extends, and the end of the plate-like body is imaged using an image sensor. Then, actual contour information representing the actual contour of the plate is extracted from the image information of the end portion output from the image sensor, and the extracted actual contour information and the scratches of the plate are extracted. A flaw is detected by comparing virtual contour information obtained by virtualizing a contour in a non-existent state (claims 7 and 13). With such a configuration, the flaw is detected based on the actual contour of the plate-like body imaged, so that the flaw can be detected without being affected by the color or transmittance of the plate-like body. In addition, since a flaw is detected by comparing actual contour information representing an actual contour with virtual contour information imagining a contour in a state where there is no flaw, a plate such as a chipped end or a protrusion is detected. It is possible to appropriately detect a flaw in which the contour of the shape changes.

In this case, as the virtual contour information, information such as a straight line or a straight line representing a curve obtained by simplifying the actual contour is derived from the real contour information, and the derived simplified straight line information is derived. And the actual contour information may be compared to detect a flaw.
4). With such a configuration, a flaw is detected by comparing information directly or indirectly derived from image information captured by the image sensor, so that the flaw can be detected with a simple configuration.

In this case, in the method for detecting a flaw in the plate-like body, the plate-like body is obtained by breaking a plate-like base material, and the imaging location is formed by breaking the plate-like body. The end may be imaged while being moved in the direction in which the end extends (claim 9). With such a configuration, since many flaws are present at the end of the plate-like body obtained by breaking the plate-like base material, the effect of flaw detection becomes more remarkable.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 Embodiment 1 of the present invention uses a transmission-type optical sensor for detecting flaws on a plate-like body.

FIG. 1 is a perspective view schematically showing a hardware configuration of a plate-like body flaw detection apparatus according to the present embodiment, FIG. 2 is a side view thereof, and FIG. 3 is a plate according to the present embodiment. FIG. 3 is a functional block diagram showing a functional configuration of the device for detecting a flaw in a shape. In the present embodiment, the plate-like body to be detected as a flaw is the glass plate described in the related art.

1 and 2, a plate-like body flaw detection device (hereinafter simply referred to as a flaw detection device) 1 includes a light emitter (light emitting means) 4, a light receiver (light receiving means) 5, and a sensor moving mechanism (irradiation). A location moving means: not shown), a sensor amplifier 8, and a data processing device (scratch detecting means) 9 are configured as main components.

The glass plate 3 is a transparent rectangular plate, and its end surface 3b is perpendicular to its main surface 3a. And
The glass plate 3 is horizontally held by a holding member (not shown). The light projector 4 has a flat rectangular cross section and is configured to emit a laser beam 6 as a light beam, and is disposed above the glass plate 3. Receiver 5
Is for receiving the laser beam 6 emitted from the light projector 4, and is disposed below the glass plate 3 so as to face the light projector 4. Therefore, when the laser beam 6 is emitted from the light projector 4, the laser beam 6 is formed between the light projector 4 and the light receiver 5 so as to extend in a thin plate shape. The light projector 4 and the light receiver 5 are integrally held by a holder (not shown), and together with the holder, constitute a laser sensor 16 as an optical sensor. The laser sensor 16 is held by a sensor moving mechanism 18 (see FIG. 3) so as to be movable in a three-dimensional direction. In addition, the laser sensor 16
Is the optical axis 101 of the laser beam 6 emitted from the projector 4.
Of the laser beam 6 and the optical axis 10
It is held by the sensor moving mechanism 18 so as to be rotatable around 1.

In the present embodiment, the laser sensor 16 is arranged such that the optical axis 101 of the laser beam 6 is not perpendicular to the main surface 3a of the glass plate 3, that is, forms a predetermined angle θ1 with the normal 102 of the main surface 3a. Is set to Further, the optical axis of the laser beam 6
101 is set so as to be parallel to the end face (hereinafter simply referred to as an end face) 3b to be inspected. The angle θ1 is
It is sufficient that the angle is not less than a certain angle determined by the thickness of the glass plate 3 and the width of the laser beam 6. If so, the detection sensitivity of the flaw does not change. However, from the viewpoint of the stability of flaw detection, as long as the laser sensor 16 does not interfere with the glass plate 3,
It is desirable that the angle be close to 90 degrees. Also, the laser sensor 16 has a laser beam 6 extending from the main surface 3 of the glass plate 3.
It is set so as not to incline in the width direction (direction perpendicular to the optical axis 101) with respect to a. At this time, as shown in FIG. 1, the laser beam 6 is set so that a portion in the width direction passes through the glass plate 3 and another portion passes outside the glass plate 3. In this specification, irradiating the glass plate 3, that is, the plate-shaped body with the laser beam 6, means that the laser beam 6
Not only the case where the whole is irradiated on the plate-shaped body but also the case where a part of the laser beam 6 is irradiated on the plate-shaped body as described above. Then, the laser sensor 16 is scanned by the sensor moving mechanism 18 in the extending direction of the edge 3c of the glass plate 3 (indicated by an arrow 201). Thereby, the laser beam 6
Spot 7 moves along the edge of the glass plate 3 along the edge 3c.

In FIG. 3, the laser sensor 16 includes the light emitter 4, the light receiver 5, and the holder (not shown) as described above.
It is comprised including. The floodlight 4 is a laser light generator
11 and an optical system 12. The laser light generator 11 is composed of, for example, a semiconductor laser, and has a wavelength of 78 in the present embodiment.
Generates and emits a laser beam consisting of 0 nm laser light. The optical system 12 includes a collimator, an aperture, and the like, and converts the laser beam emitted from the laser light generator 11 into a laser beam 6 having a flat rectangular cross section and emits the laser beam. The light receiver 5 includes a photoelectric conversion element such as a photodiode, receives the laser beam 6 emitted from the light projector 4, converts the amount of received light into an electric signal, and outputs the electric signal. The sensor amplifier 8 amplifies the electric signal of the amount of light received from the light receiver 5. The data processing device 9 includes a control unit 13, a data processing unit 14, and a data output unit 15. The data processing unit 14 is composed of an arithmetic unit such as a CPU together with the control unit 13. The data processing unit 14 differentiates the electric signal of the received light amount output from the sensor amplifier 8 to obtain a change in the received light amount. Compare with the set threshold. This threshold value is set to a value that can reliably detect a flaw that is not desired to be passed to the next step through experiments or the like. If the change in the amount of received light exceeds the threshold value, it is determined as “scratch”. This determination result is output to the data output unit 15 together with the change in the amount of received light. The data output unit 15 is configured by a display, a printer, and the like, and performs display, printout, and the like of the determination result and the change in the amount of received light output from the data processing unit 14. The control unit 13 is connected to an operation unit (not shown), and performs operations such as ON / OFF of the laser light generator 11, the data processing unit 14, and the data output unit 15 of the projector 4 in accordance with an operation input from the operation unit. Control.

The sensor moving mechanism 18 includes a mechanism for changing the position and the attitude of the laser sensor 16 and a control unit for controlling the position and the attitude of the laser sensor 16 through the mechanism. Of the arithmetic unit. The control unit controls the position and orientation of the laser sensor 16 according to teaching (teaching) or a program input from the outside.

Next, the operation of the flaw detection device configured as described above (method for detecting flaws on a plate-like body: hereinafter simply referred to as flaw detection method) will be described with reference to FIGS.

FIG. 4 is a view seen from the optical axis direction of the laser beam in FIG. 1, that is, a view taken in the direction of the arrow A, showing a case where a crack existing portion of the glass plate is scanned, and FIG. FIG. 6 is a diagram showing a case where a missing scratch existing portion is scanned.

1 to 5, the glass plate 3 is set at a predetermined position, the attitude and the moving direction of the laser sensor 16 are set to predetermined conditions by teaching, programming, etc., and then the sensor moving mechanism 18 and the data processing device are set. 9 is started. Then, the laser sensor 16 moves to the edge 3c of the glass plate 3.
The laser beam 6 is emitted from the light projector 4 while moving in the extending direction 201 of the laser beam, and the emitted laser beam 6 is received by the light receiver 5. The received light amount is input as an electric signal to the data processing unit 14 of the data processing device 9 via the sensor amplifier 8, the data is processed by the data processing unit 14, and the flaw detection result is output from the data output unit 15. You. In this state, when the laser sensor 16 scans the portion of the glass plate 3 where the crack 301 is present as shown in FIG. 4, the optical path 51 of the laser beam 6 moves along the edge 3c of the glass plate 3 as shown in FIG.
Are moved so as to follow the positions indicated by symbols a to f. At this time, when the optical path 51 of the laser beam 6 is located at the position indicated by the symbol d, the laser beam 6
And the amount of transmitted light is greatly reduced. As a result, the amount of light received by the photodetector 5 is greatly reduced as compared with the case where the optical path 51 of the laser beam 6 is located at another position, and the change in the amount of received light in the data processing unit 14 of the data processing device 9 sets the threshold value. Exceed. Therefore, the change is determined as “scratch”,
The result of the determination is output from the data output unit 15 of the data processing device 9.

When the laser sensor 16 scans the portion of the glass plate 3 where the notch 302 shown in FIG. 5 is present, the optical path 51 of the laser beam 6 moves along the edge 3c of the glass plate 3 as shown in FIG. Move so as to follow the positions indicated by a to f. At this time, when the optical path 51 of the laser beam 6 is located at the positions indicated by the reference numerals c and d, the light beam constituting the laser beam 6 is incident non-parallel to the broken surface 302a of the chipped scratch 302 and diffuses at the broken surface 302a. The reflected light reduces the amount of transmitted light. In particular, when the optical path 51 of the laser beam 6 is located at the position indicated by the symbol d, the number greatly decreases. As a result, when the optical path 51 of the laser beam 6 is located at the location where the chipped defect 302 exists, the amount of light received by the light receiver 5 is greatly reduced as compared with the case where the optical path 51 of the laser beam 6 is located at another position. However, in the data processing unit 14 of the data processing device 9, the change in the amount of received light exceeds the threshold. Therefore, the change is determined to be “scratch”, and the determination result is output from the data output unit 15 of the data processing device 9. The laser beam 6 is applied to the glass plate 3 as in this embodiment.
When the laser beam 6 is irradiated obliquely to the main surface, the irradiated laser beam 6 is regularly reflected at a constant rate on the main surface 3a.
However, since the reflectance is constant irrespective of the scanning position of the laser sensor 16 on the glass plate, the reflection on the main surface of the glass plate 3 is the amount of light received by the scanning position of the laser sensor 16 on the glass plate. It does not affect the result of flaw detection performed based on the relative change.

FIG. 6 shows the data output unit 15 of the data processing device 9.
FIG. 7 is a diagram showing an example of a flaw detection result output from the finder.
In FIG. 6, the horizontal axis represents time and the vertical axis represents a change in the amount of received light. Reference numeral 311 denotes a line representing a temporal change of the received light amount change. In the change line 311 of the received light amount change, a small change portion 304 is a disturbance portion due to the protective film of the glass plate 3 and greatly changes. The portion 303 indicated is a flaw detection portion. Then, an arrow marker 305 indicating “scratch” is displayed so as to indicate the scratch detection portion 303. The detection result of this flaw is output to the data output unit 15.
It is displayed on a display as shown in FIG. 6 and printed out in response to an operation input from the operator to the control unit 13.

As described above, in this embodiment, since the laser beam 6 is transmitted through the glass plate 3 so as not to be perpendicular to the main surface 3a of the glass plate 3, the chipped edge 302 of the edge of the glass plate 3 is formed. As described above, even if the broken surface is a flaw substantially perpendicular to the main surface 3a of the glass plate 3, the light beam constituting the laser beam 6 is incident non-parallel to the broken surface. Diffuse reflection of the beam 6 occurs, and the amount of transmitted light changes. Therefore, such a flaw can be detected.

Next, a modified example of the laser beam irradiation mode will be described.

FIG. 7 is a perspective view showing another irradiation mode of the laser beam, FIG. 8 is a view as viewed from an arrow C in FIG. 7, FIG. 9 is a view as viewed from an arrow D in FIG. 7, and FIG. FIG.

7 and 8, in this modification, the laser sensor 16 is arranged such that the optical axis 101 of the laser beam 6 is
Not only is not perpendicular to the main surface 3a, but is not parallel to the end surface 3b. That is, the laser sensor
16 indicates that not only does the optical axis 101 of the laser beam 6 form a predetermined angle θ1 with the normal 102 of the main surface 3a of the glass plate 3 when viewed from the side (viewed from the arrow D in FIG. 7), but also when viewed from the front (see FIG. (In the direction of arrow C), the angle is set to form a predetermined angle θ2 with the normal line 102 of the main surface 3a of the glass plate 3. In order to obtain such a state, for example, the attitude of the laser sensor 16 is changed from the state of FIG. 1 so as to rotate around an axis 103 parallel to the extending direction of the edge 3c of the glass plate 3, or The posture may be changed from the state of 1 so as to rotate around the normal 102 of the main surface 3a of the glass plate 3 (however, the value of θ1 in FIG. 1 changes). In the present embodiment, the former is adopted.

In this manner, as is apparent from FIG. 10, a flaw whose broken surface is substantially perpendicular to the main surface 3a of the glass plate 3, such as a chipped flaw 302 at the edge of the glass plate 3, is removed. Since the laser beam 6 is also incident on the surface from the end face side, the occupation ratio of the broken surface in the field of view of the light receiver 5 is shown in FIG.
In this case, the detection sensitivity is improved. Here, the surface of the main surface of the glass plate 3 is usually
The protective film is stuck, which may be a factor of disturbance, making it difficult to detect scratches. However, according to the present modified example, the detection sensitivity of the flaw is improved. Therefore, even in such a case, the influence of the disturbance can be suppressed and the flaw can be easily detected. Embodiment 2 In Embodiment 2 of the present invention, a reflection-type optical sensor is used to detect a flaw in a plate-like body.

FIG. 11 is a perspective view schematically showing a hardware configuration of the flaw detection apparatus according to the present embodiment, FIG. 12 is a plan view thereof, and FIG. 13 is a function of the flaw detection apparatus according to the present embodiment. It is a functional block diagram showing the above configuration.

In FIGS. 11 to 13, FIG.
3 indicate the same or corresponding parts.

In this embodiment, a laser sensor is used as the optical sensor.

The flaw detection device 20 according to the present embodiment mainly includes first and second laser sensors 31 and 32 as optical sensors, a data processing device 9, and a belt conveyor 2 as a laser beam irradiation point moving means. It is configured as a simple component.

The belt conveyor 2 has a glass plate 3 thereon.
Is placed, and moves in the direction of arrow 202 here. The glass plate 3 is placed so that one end face 3 b thereof is parallel to the moving direction 202 of the belt conveyor 2.

The first and second laser sensors 31 and 32 are
A light projector and a light receiver are arranged in front of each other, and are configured to emit a laser beam 6 from the light projector and receive the laser beam 6 reflected by the object with the light receiver. The first and second laser sensors 31 and 32 are arranged so that each laser beam 6 irradiates the end face 3 b of the glass plate 3, and is arranged close to the moving direction of the belt conveyor 2. I have. As a result, the spots 33 and 34 of the first and second laser sensors 31 and 32 point to the end face 3b of the glass plate 3 by arrows 2
Move in 01 direction. The irradiation conditions of the laser beams of the two laser sensors 31 and 32, that is, the distance to the end face 3b of the glass plate 3, the output of the laser beam 6, the spot diameter, etc. And the conditions are substantially the same.

As shown in FIG. 13, each of the first and second laser sensors 31 and 32 has a light emitter 4, a light receiver 5, and a sensor amplifier 8, respectively. These light emitter 4, light receiver 5,
The sensor amplifier 8 is the same as that shown in FIG. However,
The optical system 12 of the light projector 4 converts the laser beam from the laser light generator 11 into a laser beam 6 having a circular cross section and emits it. The data processing device 9 has the same configuration as that of FIG. However, the data processing unit 14 is different from the one shown in FIG.
50 and a comparison circuit 52. That is, in the first embodiment, data processing for determining the presence or absence of a flaw from the amount of received light is performed by software, whereas in the present embodiment, the data processing is performed by hardware.

Next, the flaw detection device configured as described above
20 operation (scratch detection method) will be described. 11 to 13
, The belt conveyor 2 and the data processing device 9 are started. Then, the laser beams 6 are respectively emitted from the light projectors 4 of the first and second laser sensors 31 and 32 to the end face 3b of the glass plate 3, and those reflected on the end face 3b are received by the light receiver 5 respectively. . Here, it is assumed that the end surface 3b of the glass plate 3 is slightly oblique to the rearward direction from the laser sensors 31 and 32 with respect to the moving direction of the belt conveyor 2 due to an error or the like at the time of mounting. The first and second
The amount of light received by each light receiver 5 of the laser sensors 31 and 32 is subtracted by the subtraction circuit 50 of the data processing device 9.

The process of the subtraction process will be described with reference to FIG. FIGS. 14A and 14B are diagrams showing the processing steps in the subtraction circuit 50, where FIG. 14A is a graph showing the change over time of the amount of light received from the two laser sensors, and FIG. In the graph, the difference between the amounts of received light is plotted on the vertical axis, and time is plotted on the horizontal axis. In FIG. 14A, reference numerals 312 and 313
These indicate the amounts of light received from the respective projectors of the first and second laser sensors.

Referring to FIG. 11 to FIG. 13 and FIG.
The amount of light 312,313 received from each of the projectors 5 of the first and second laser sensors 31,32 decreases linearly because the end face 3b of the glass plate 3 moves away with time, and the chipped portion 302 of the glass plate 3 In the portions 312a and 313a corresponding to the above, the irradiated laser beam 6 is diffusely reflected by the fractured surface of the chipped scratch 302, so that the value is greatly reduced. The amount of light 313 received from the light projector 5 of the second laser sensor 32 is larger than the amount of light 312 received from the light projector 5 of the first laser sensor 31 by the two laser sensors 31, 32.
And changes by a time corresponding to the interval between the spots 33 and 34 of FIG. When the two received light amounts 312 and 313 are subtracted by the subtraction circuit 50, the difference between the two received light amounts 312 and 313 is, as shown by reference numeral 314 in FIG. Only 314a changes greatly, and the other portions have constant values close to substantially zero.

The difference 314 between the two received light amounts is input to the comparison circuit 52 of the data processing device 9, where it is compared with a threshold value. Since this threshold value is set in the same manner as in the first embodiment, the portion 314a corresponding to the missing scratch 302 is determined to be "scratch". Thereby, a flaw is detected.

As described above, in this embodiment, the end face 3b of the glass plate 3 is irradiated with the laser beam 6 and the reflected laser beam 6 is received to detect a flaw. Even if a protective film is stuck on the main surface of the above, a flaw can be detected without being affected by the protection film. In addition, the flaw can be detected without being affected by disturbance light such as illumination, the color of the glass plate, the transmittance, and the like, and the apparatus can be configured at low cost.

Further, for example, when one laser sensor 30 is used as shown in FIG.
When the end face 3b gradually moves away from the laser sensor 30, the amount of received light 312 decreases linearly as shown in FIG. Not only the change 312a in the received light amount but also a change in the received light amount caused by a change in the distance between the end face 3b of the glass plate 3 and the laser sensor 30 is determined to be "scratch" and malfunctions. Therefore, in order to prevent such a malfunction, it is necessary to obtain a change in the received light amount by differentiating the received light amount and to set a threshold value for the change in the received light amount. Is complicated. However, according to the present embodiment, the difference between the amounts of received light is obtained by using the two laser sensors 31 and 32. Therefore, by setting a threshold value for the difference between the amounts of received light, 3b and laser sensor 31,
Even if the distance from the flap 32 changes, the flaw can be reliably detected with a simple configuration. Third Embodiment A third embodiment of the present invention uses image processing for detecting flaws on a plate-like body.

FIG. 17 is a perspective view schematically showing the hardware configuration of the flaw detection device according to the present embodiment, and FIG. 18 is a functional block showing the functional configuration of the flaw detection device according to the present embodiment. FIG.

In FIGS. 17 and 18, respectively, FIG.
3 indicate the same or corresponding parts.

The flaw detection device 40 according to the present embodiment includes first and second image pickup devices 41 and 42, a data processing device (flaw detection means) 45, an image pickup device moving mechanism (not shown) (imaging point moving means), And illuminations 43 and 44 as main components.

The glass plate 3 is horizontally held by a holding member (not shown). First and second imaging elements 41 and 42
Is constituted by a CCD camera in the present embodiment. The first and second image pickup devices 41 and 42 are arranged above the glass plate 3, and the edge portions 3 d and 3 e of the glass plate 3 are independently scanned by the image pickup device moving mechanism. , 3e. Lighting 43,44
Illuminates the edge portions 3d, 3e of the glass plate 3 while moving together with the first and second imaging elements 41, 42, respectively.

The first and second imaging elements 41 and 42 output the captured images as image signals. The data processing device 9 includes a control unit 13, an image processing unit 46, and a data output unit 15. The image processing unit 46 is configured by a computing unit such as a CPU, and separately performs image processing on image signals input from the first and second imaging elements 41 and 42 to determine the presence or absence of a flaw. Control unit
Reference numeral 13 is connected to an operation unit (not shown), and controls ON / OFF of the first and second imaging elements 41 and 42, the image processing unit 46, and the data output unit 15 according to an operation input from the operation unit. Control behavior. The data output unit 15 is the same as that of FIG.

Next, the flaw detection device configured as described above
The operation 40 (flaw detection method) will be described with reference to FIGS. FIG. 19 is a flowchart showing the contents of the operation program of the image processing unit 46 of FIG. 18, and FIG. 20 is a diagram schematically showing the contents of the image processing of the image processing unit 46 of FIG.

17 and 18, the lights 43 and 44 are turned on to activate the data processing device 45 and the image pickup device moving mechanism. Then, the first and second imaging elements 41 and 42 respectively image the edge portions 3d and 3e while scanning the different edge portions 3d and 3e of the glass plate 3, and output image signals.

When an image signal is input from the first and second image pickup devices 41 and 42, the image processing section 46 of the data processing device 45
The following processing is performed for each of them in a time sharing manner.

19 and 20, first, an image of an input image signal is taken in (step S1). Here, it is assumed that the captured image is as shown in FIG.

Next, as shown in FIG. 20 (b), the captured image is differentiated to extract a contour candidate (actual contour information) 315 of the glass plate 3 (step S2).

Next, as shown in FIG. 20C, a straight line component (information such as a simplified straight line) 316 of the edge 3c of the glass plate 3 is derived from the extracted contour line candidates by using the Hough transform (step S3). ). When the scanning position of the image sensor is at a corner of the glass plate, a linear component of two edges sandwiching the corner is derived (see FIG. 22B).

Next, as shown in FIG. 20D, a distance 317 between the derived linear component 316 and the contour candidate 315 is derived, and the presence or absence of a flaw is determined based on the distance 317 (step S4). ). The determination of the presence / absence of the flaw is performed by, for example, comparing the distance 317 with a threshold that is appropriately set. When the scanning position of the image sensor is at a corner of the glass plate, the distance between the straight line component of the two edges sandwiching the corner and the contour candidate is derived.

Next, the determination result is output to a data output unit together with the captured image (step S).
5).

The data output unit combines the input judgment result and the captured image with the screens shown in FIGS. 21 and 22 and displays them on the display, and responds to an operation input to the data processing device 45. Print out.

FIG. 21 is a diagram showing an example of a result of detection of a flaw at the edge portion of the glass plate, and FIG. 22 is a diagram showing an example of a result of detection of a flaw at the corner portion of the glass plate. FIG. FIG. 3B is a diagram showing a determination result.

In FIG. 21, on the flaw detection result screen, a captured image of the glass plate 3 is displayed together with a linear component 316 of the edge portion and a marker 318 indicating that the flaw is a flaw. In addition, the projection damage 308 is detected on the damage detection result screen.

In FIG. 22, a straight line component 316 of two edge portions sandwiching the corner portion and a character 319 indicating a scratch are displayed on the scratch detection result screen together with the captured image of the glass plate 3. In this flaw detection result screen, the chipped flaw 310 in the corner is detected.

As described above, in the present embodiment,
Since the flaw is detected based on the actual contour of the glass plate 3 that has been imaged, the flaw can be detected without being affected by the color or transmittance of the glass plate 3. In addition, since a flaw is detected by comparing a contour candidate representing an actual contour of the glass plate 3 with a linear component of an edge imagining the contour of the glass plate 3 in a state where there is no flaw, the edge portion is detected. It is possible to appropriately detect a flaw, such as a chipped portion or a projection, which changes the contour of the glass plate 3. Further, since a flaw is detected by comparing information directly or indirectly derived from image information captured by the imaging elements 41 and 42, the flaw can be detected with a simple configuration.

In the first to third embodiments, the case where the present invention is applied to a glass plate has been described. However, the present invention can be similarly applied to a plate-like body.

In the first and second embodiments, a laser beam and a laser sensor are used as the light beam and the optical sensor. However, for example, a light beam other than the laser light such as an LED or a fluorescent lamp and the light beam are projected. Light and light receiving optical sensors may be used.

In Embodiments 1 and 3,
Although the laser sensor and the image sensor are moved, the glass plate may be moved. Embodiment 2
In the above, the glass plate is moved, but the laser sensor may be moved.

Further, in the first embodiment, the angle of the optical axis of the laser sensor with respect to the glass plate can be changed, but this may be fixed.

In the first and second embodiments, a photodiode is used as the light receiver. Alternatively, a photoelectric conversion element such as a phototransistor, a photoconductive cell, a phototube, or a photomultiplier may be used.

In the first embodiment, the laser sensor is
The processing for detecting the scratch from the received light amount was performed by software using a unit, but the processing for detecting the scratch from the received light amount was performed by hardware using two laser sensors as in the second embodiment. May go.

In the third embodiment, the Hough transform is used to derive a straight line component from a contour candidate.
Other techniques such as multiplication may be used.

Further, in the third embodiment, the case where the present invention is applied to a glass plate having a rectangular shape, that is, a glass plate having an external shape composed of straight lines, has been described. Can also be applied. In this case, for example, a scratch-free outer shape (virtual contour line) of the glass plate is previously input as teaching data (virtual contour line information) by teaching, and the teaching data is compared with a contour line candidate to thereby obtain a scratch mark. The presence or absence may be determined.

In the third embodiment, a CCD camera is used as an image pickup device.
Other imaging devices such as an address type solid-state imaging device, an imaging tube, and an image tube may be used.

[0078]

The present invention is embodied in the form described above and has the following effects. (1) A flaw whose fracture surface is substantially perpendicular to the main surface of the plate-like body can be detected. (2) Assuming that the light beam is irradiated so that the optical axis is not parallel to the end surface of the plate-like body, even if a protective film is adhered to the main surface of the plate-like body, the influence of disturbance due to the protective film. Can be suppressed, and a flaw can be easily detected. (3) The plate-like body is obtained by breaking the plate-like base material,
In addition, if the light beam is irradiated to the end while moving the irradiation position in the extending direction of the end formed by splitting the plate-like body, the effect of flaw detection becomes more remarkable. (4) The end face of the plate is irradiated with the light beam while moving the irradiation position by the light beam, and the flaw is detected based on a change in the amount of light of the irradiated light beam reflected by the plate. Then, even if the protective film is adhered to the main surface of the plate-like body, the scratch can be detected without being affected by the protection film. In addition, the flaw can be detected without being affected by disturbance light such as illumination, the color of the glass plate, the transmittance, and the like, and the apparatus can be configured at low cost. (4) A flaw detection method for irradiating a plate-like body with a light beam while moving an irradiation position by a light beam, and detecting a flaw based on a change in the amount of light of the irradiated light beam reflected by the plate-like body; An apparatus for irradiating the two light beams on two places separated from each other in a direction in which the irradiation position of the plate-like body is to be moved under substantially the same irradiation conditions, and If the flaw is detected based on the change in the difference between the amounts of light reflected by the body, even if the distance between the object to be detected and the light emitting and receiving means of the light beam changes, a simple configuration can be used to ensure the reliability. Flaws can be detected. (5) While moving the imaging location in the direction in which the end of the main surface of the plate-like body extends, the end is imaged using an image sensor, and the image information of the end output from the image sensor is used to obtain the image. Real contour information representing the actual contour of the plate is extracted, and the extracted real contour information is compared with virtual contour information which virtually represents the contour of the plate in a state where there is no flaw. By doing so, it is possible to detect the flaws without being affected by the color and transmittance of the plate-like body, and to detect the contour of the plate-like body such as a chipped end or a projection. A flaw that changes can be appropriately detected. (6) Simplified straight line information or the like representing a straight line or a curve obtained by simplifying the actual outline is derived from the actual outline information as the virtual outline information. If the flaw is detected by comparing the flaws, the flaw can be detected with a simple configuration. (7) The plate-like body is obtained by breaking the plate-like base material,
And it is assumed that the imaging part is imaged while moving the imaging part in the extending direction of the end formed by dividing the plate-like body,
The effect of flaw detection becomes more remarkable.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a hardware configuration of a plate-like body flaw detection device according to Embodiment 1 of the present invention.

FIG. 2 is a side view schematically illustrating a hardware configuration of the plate-like body flaw detection device according to the first embodiment of the present invention.

FIG. 3 is a functional block diagram showing a functional configuration of the plate-like body flaw detection device according to the first embodiment of the present invention.

FIG. 4 is a view taken in the direction of arrow A in FIG. 1 and shows a case where a crack existing portion of the glass plate is scanned.

FIG. 5 is a view taken in the direction of arrow A in FIG. 1 and shows a case where a chipped portion of a glass plate is scanned.

FIG. 6 is a diagram illustrating an example of a flaw detection result output from a data output unit of the data processing device of FIG. 1;

FIG. 7 is a perspective view showing another irradiation mode of the laser beam of the flaw detection device of FIG. 1;

8 is a view as viewed in the direction of arrow C in FIG. 7;

FIG. 9 is a view as viewed in the direction of arrow D in FIG. 7;

FIG. 10 is a view taken in the direction of arrow B in FIG. 7;

FIG. 11 is a perspective view schematically showing a hardware configuration of a plate-like body flaw detection device according to Embodiment 2 of the present invention.

FIG. 12 is a plan view schematically showing a hardware configuration of a plate-like body flaw detection device according to Embodiment 2 of the present invention.

FIG. 13 is a functional block diagram showing a functional configuration of a plate-like body flaw detection device according to Embodiment 2 of the present invention.

14A and 14B are diagrams illustrating a processing process in a subtraction circuit of the data processing device in FIG. 13, wherein FIG. 14A is a graph illustrating a change over time in the amount of light received from two laser sensors, and FIG. It is a graph which shows the subtraction result of the light reception amount.

FIG. 15 is a plan view illustrating a configuration of a flaw detection device using one laser sensor.

FIG. 16 is a graph showing a change with time in the amount of light received by a light receiver when one laser sensor is used.

FIG. 17 is a perspective view schematically showing a hardware configuration of a flaw detection device according to Embodiment 3 of the present invention.

FIG. 18 is a functional block diagram showing a functional configuration of a flaw detection device according to Embodiment 3 of the present invention.

FIG. 19 is a flowchart showing the contents of an operation program of the image processing section 46 in FIG. 18;

20 is a diagram schematically showing the content of image processing of the image processing unit in FIG. 18;

FIG. 21 is a diagram illustrating an example of a result of detecting a flaw at an edge of a glass plate.

22A and 22B are diagrams illustrating an example of a result of detection of a flaw at a corner of a glass plate, wherein FIG. 22A illustrates a captured image, and FIG. 22B illustrates a determination result.

FIG. 23 is a perspective view showing an example of a conventional method for detecting a flaw on a glass plate.

FIG. 24 is a side view showing an example of a conventional method for detecting a scratch on a glass plate.

FIG. 25 is a plan view showing a relationship between an optical path of a laser beam and a detectable flaw of a glass plate in a conventional method for detecting a flaw on a glass plate.

FIG. 26 is a plan view showing the relationship between the optical path of a laser beam and chipping of a glass plate in a conventional method for detecting a glass plate flaw.

[Explanation of symbols]

 Reference Signs List 1,20,40 Plate-like scratch detection device 2 Belt conveyor 3 Glass plate 3a Main surface 3b End surface 3c Edge 3d, 3e Edge 4 Projector 5 Receiver 6 Laser beam 7 Spot 8 Sensor amplifier 9 Data processing device 11 Laser light Generator 12 Optical system 13 Control unit 14 Data processing unit 15 Data output unit 16 Laser sensor 18 Sensor moving mechanism 31 First laser sensor 32 Second laser sensor 33, 34 Spot 41 First image sensor 42 Second image Element 43,44 Illumination 45 Data processing unit 46 Image processing unit 50 Subtraction circuit 51 Optical path 52 Comparison circuit 101 Optical axis of laser beam 102 Normal line of main surface of glass plate 103 Axis 201 parallel to edge extending direction 201 Movement of spot Direction (scanning direction) 202 Belt conveyor moving direction 205 Scanning direction 301 Crack 301a Fracture 302 Missing 302a Fracture 303 Flaw detection part 304 Disturbance part 305 Flaw display marker 308 Protrusion flaw 310 Missing flaw 311 Change line of received light amount 312 Change line of received light amount 312a Flaw corresponding part 313 Change line of received light amount 313a Flaw corresponding part 314 Change line of received light difference 314a Flaw corresponding part 315 Contour candidate 316 Linear component 317 Contour candidate Difference from linear component 319 Scratch display character θ1, θ2 Predetermined angle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Sumihiro Ueda 1-1, Kawasaki-cho, Akashi-shi, Hyogo Prefecture Kawasaki Heavy Industries, Ltd. Inside Akashi Plant (72) Inventor Sadao Kubo 1-1-1, Kawasaki-cho, Akashi-shi, Hyogo Prefecture Kawasaki Heavy Industries, Ltd.Akashi Factory (72) Inventor, Koji Tsujida 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawageshi Plant Co., Ltd. 3-1-1, Kawage Plant Co., Ltd. Kobe Head Office F-term (reference) 2G051 AA42 AB03 AB07 BA01 BA10 BA20 BC07 CA03 CA04 CB01 CB02 CD03 DA01 DA06 EA08 EA30 EB01

Claims (14)

[Claims] 1. A flaw detection method for irradiating a plate-like body with a light beam while moving an irradiation position by a light beam, and detecting a flaw based on a change in the amount of light of the irradiated light beam transmitted through the plate-like body. A method for detecting flaws on a plate-like body, wherein the plate-like body is irradiated with the light beam so that an optical axis is not perpendicular to a main surface of the plate-like body. 2. The method according to claim 1, wherein the light beam is irradiated such that an optical axis is not parallel to an end face of the plate. 3. The plate-shaped body is obtained by breaking a plate-shaped base material, and the irradiation position is moved in an extending direction of an end formed by breaking the plate-shaped body. 3. The method according to claim 1, wherein a light beam is applied to the end. 4. A flaw detection device that irradiates a plate-like body with a light beam while moving an irradiation position by a light beam, and detects a flaw based on a change in the amount of light of the irradiated light beam reflected by the plate-like body. A method for detecting flaws on a plate-like body, wherein the light beam is applied to an end face of the plate-like body. 5. A flaw detection device that irradiates a plate-like body with a light beam while moving an irradiation position of the light beam, and detects a flaw based on a change in the amount of light of the irradiated light beam reflected by the plate-like body. A method of irradiating the two light beams to two places separated in a direction in which the irradiation position of the plate-like body is to be moved under substantially the same irradiation conditions, and applying the two light beams to the plate-shaped body. A flaw detection method for a plate-like body that detects flaws based on a change in the difference between the amounts of light reflected by the body. 6. The plate-like body is obtained by breaking a plate-like base material, and the light is moved while moving the irradiation position in an extending direction of an end face formed by dividing the plate-like body. 6. The method according to claim 4, wherein a beam is applied to the end face. 7. An image pickup part is imaged using an image pickup element while moving an image pickup part in an extending direction of an end part of a main surface of the plate-like body,
Extracting actual contour line information representing the actual contour line of the plate-like body from the image information of the end portion output from the image sensor, and the extracted actual contour line information and a state where the plate-like body is not damaged A flaw detection method for a plate-like body, wherein flaws are detected by comparing virtual contour information obtained by virtualizing a contour line in (1). 8. Deriving, as the virtual contour information, simplified line information representing a straight line or a curve obtained by simplifying the actual contour line from the real contour line information, and the derived simplified straight line information and the like. 8. The method for detecting flaws on a plate-like body according to claim 7, wherein flaws are detected by comparing the actual contour information. 9. The plate-like body is obtained by breaking a plate-like base material, and moving the imaging location in the extending direction of an end formed by breaking the plate-like body. 9. The method for detecting flaws on a plate-like body according to claim 7, wherein an image of an end is taken. 10. A light projecting means for irradiating a plate-shaped object with a light beam; an irradiation position moving means for moving an irradiation position of the plate-shaped object by the light beam; A flaw detection device comprising: a light receiving unit that detects a transmitted light amount; and a flaw detection unit that detects a flaw based on a change in the detected light amount, wherein an optical axis is not perpendicular to a main surface of the plate-like body. Thus, a plate-like body flaw detection device capable of irradiating the light beam. 11. The apparatus according to claim 10, wherein the light beam can be irradiated such that an optical axis is not parallel to an end face of the plate. 12. A light projecting means for irradiating the plate-shaped object with a light beam, an irradiation position moving means for moving an irradiation position of the plate-shaped object by the light beam, and A flaw detection device comprising: a light receiving unit that detects a reflected light amount; and a flaw detection unit that detects a flaw based on a change in the detected light amount. And two light projecting means capable of irradiating two places separated in a direction to be moved under substantially the same irradiation conditions, wherein the detecting means is reflected by the plate-like body of the two irradiated light beams. And a plate-like body flaw detection device for detecting flaws based on a change in the difference in the amount of received light. 13. An image pickup device for picking up an end of a main surface of a plate-like body, and an image-pickup point movement for moving an image-pickup point by the image pickup element in an extending direction of the end of the main surface of the plate-like body. Means for extracting real contour line information representing the actual contour line of the plate from the image information of the end portion outputted from the image sensor, and the extracted real contour line information And a flaw detection means having a comparison means for detecting flaws by comparing virtual contour line information obtained by imagining a contour line of the flawless body with no flaws. . 14. A simplified straight line representing a straight line or a curve obtained by simplifying the actual contour line from the actual contour line information extracted by the actual contour line information extracting means as the virtual contour line information. The apparatus further comprises a simplified straight line information deriving means for deriving the equal information, wherein the comparing means detects the flaw by comparing the derived simplified straight line information and the real contour line information. Item 14. The plate-like body flaw detection device according to Item 13.