JPH04125455A - Apparatus for inspecting surface - Google Patents

Abstract

PURPOSE:To perform accurate inspection even when an object to be inspected meanders by scanning the edge parts of the object to be inspected from the outside to the inside by two scanning type flaw detectors. CONSTITUTION:Scanning type flaw detectors 11, 12 are arranged in the lateral direction of a web 14 being an object to be inspected. The detectors 11, 12 consist of floodlight projectors 18, 19 irradiating the surface of the web 14 with scanning lights 15, 16 and photodetectors 21, 22 receiving the scanning lights transmitted through a flaw part to detect a flaw. The web 14 is allowed to run in an A-direction and scanned from the edge parts thereof toward the inside thereof by scanning lights 15, 16. Light shielding plates 24, 25 having pulleys 26, 27 rotating in contact with both edge parts 14a, 14b of the web 14 moves with the meandering of the web 14 and the scanning lights 15, 16 respectively rise on the basis of the edges of the light shielding plates 24, 25. By this constitution, accurate inspection can be performed.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a surface inspection device for photoelectrically detecting and evaluating defective portions existing on the surface of an object to be inspected, such as a continuously running web. It is.

[Conventional technology]

Various surface inspection devices are known for detecting defects on the surface of continuously running sheet materials such as films, paper, thin plates, etc., and these devices are used to control the quality of products and semi-finished products. It is being said.

Among these surface inspection devices, the surface of the object to be inspected is irradiated with scanning light by a laser, and the reflected light and transmitted light are photoelectrically detected by a light receiver, and the presence or absence of surface defects is evaluated based on the photoelectric detection output. It is widely used in manufacturing lines because it can inspect objects without contact and at high speed.

As such a photoelectric surface inspection device, there is one known, for example, from Japanese Patent Publication No. 56-31737. The surface inspection device shown here has a plurality of scanning defect detectors arranged in the width direction of the object to be inspected so that the inspection area is not limited by the width size of the object to be inspected, and the scanning defect detectors at both ends are scanned. By performing this from the inside of the object to the outside, the dead zone in the rising portion is eliminated and the dead zone is reduced overall.

[Problem to be solved by the invention]

However, the conventional surface inspection apparatus as disclosed in the above-mentioned publication has the disadvantage that when the object to be inspected meanderes, the detection position of the defective part of the object to be inspected shifts, so that accurate inspection cannot be performed. there were.

[Purpose of the invention]

The present invention has been made in view of the drawbacks of the prior art, and it is an object of the present invention to provide a surface inspection apparatus that can perform accurate inspection even when an object to be inspected meanderes.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured such that two scanning defect detectors each inspecting an edge of an object to be inspected perform each scan in a direction from the outside to the inside of the object to be inspected. .

In addition, each of the two scanning defect detectors that respectively inspect the edges of the object to be inspected scans from the outside to the inside of the object to be inspected, and one of the two scanning defect detectors A data order changing means is provided for rearranging the scan data so that the scan start side of one scanning defect detector becomes the first scan data of one scan, and the scan start side of the other scanning defect detector becomes the final scan data. It is something that

In addition, the two scanning defect detectors each inspect the edge of the object to be inspected, each scanning from the outside to the inside of the object to be inspected, and the width direction of the object to be inspected is subdivided into lanes for inspection output. As a reference for the lane division signal used to locate the position of the pulse in the width direction of the object to be inspected, it is installed between the object to be inspected and the projector, and is used to follow the meandering of the object to be inspected. This uses an output signal that detects the edge of the light shielding member that is moved in the width direction or the edge of the object to be inspected itself.

In addition, the two scanning defect detectors each inspecting the edges of the object to be inspected scan in the direction from the outside to the inside of the object to be inspected, and as a reference for the inspection area,
This uses an output signal that detects the edge of a light shielding member that is installed between the object to be inspected and the projector and is moved in the width direction following the meandering of the object to be inspected, or the edge of the object to be inspected itself. .

[Effect]

According to the above configuration, the object to be inspected is scanned from the outside to the inside at both edges, and the inspection area is determined by following the movement of the edge on the scanning start side, so the meandering of the object as a whole is scanned following.

Further, since the data order changing means changes the order of the scan data in the direction opposite to the direction in which the lane number increases, the obtained scan data is regarded as one scan data as a whole.

Embodiments of the present invention will be described below with reference to the drawings.

〔Example〕

In FIG. 1 showing the basic configuration of the surface inspection apparatus of the present invention, the surface inspection apparatus includes two scanning defect detectors 11 and 12.
are arranged in the width direction of the web 14 which is the object to be inspected. Each scanning defect detector 11.12 includes a light projector 18.19 that reflects the light with a rotating mirror and irradiates the surface of the web 14 with scanning light 15.16, and a scanning light 15 that has passed through the defective portion of the web 14. .16 to detect defective portions of the web 14.

The web 14 is run in the direction of arrow A, and the scanning light 15 is scanned on this surface from left to right in the figure, and the scanning light 16 is scanned in the opposite direction to the scanning light 15 from right to left.

A light shielding plate 24.25 is provided near both edges 14a, 14b of the web 14 so as to be movable in the width direction of the web 14, and prevents the scanning light 15.16 from directly entering the light receiver 21.22. are doing. The light shielding plates 24 and 25 are located at both edges 14a of the web 14.

It is provided with pulleys 26 and 27 that are rotated in contact with the web 14b, and are moved forward and backward in the width direction of the web 14, following the meandering of the web 14. Therefore, when the web 14 meanders to the left or right, the light shielding plate 24.25 is moved accordingly, and the scanning light 15.16 is incident on the light receiver 2122.
stand up with each edge of the light shielding plate 24°25 as a reference.

In FIG. 2, which schematically shows the configuration of the signal processing circuit, and FIG. 3, which shows the schematic waveforms of each output signal, the light receiver 21 that has received the scanning light 15 outputs a photoelectric conversion signal (1) proportional to the intensity of the inspection light. output, filter circuit 31 and edge detection circuit 3
Supply to 2. The edge detection circuit 32 applies the slice level TH to the photoelectric conversion signal (2) to detect the edge of the light shielding plate 24, and inputs this edge detection signal (2) to the inspection width setting circuit 33 and the lane division signal generation circuit 34.

The length Wll of both unnecessary edges determined by the width of the web 14 and the length W1 □ from the edge to the center are input in advance to the inspection width film constant circuit 33, and it receives the edge detection signal ■. At the same time, an inspection width signal ■ based on W, . On the other hand, when the lane division signal generation circuit 34 receives the edge detection signal ■, it supplies the lane division signal ■ to the memory interface 36. That is,
Since the inspection width signal (2) and the lane division signal (2) are output based on the edge detection signal (2), they follow the meandering of the web 14 as a result.

Further, the filter circuit 31 that receives the photoelectric conversion signal (2) removes noise components contained in the photoelectric conversion signal (2), and supplies this filter circuit output signal (2) to the binarization circuit 35. The binarization circuit 35 receives the inspection width signal ■ from the inspection width setting circuit 33, and at the same time converts the filter circuit output signal ■ into a binary value according to a preset threshold level TH3, and detects defects within one scanning period. When detected, a pulsed test output [phase] is input to the memory interface 36.

Similarly, the photoelectric conversion signal ■ output from the light receiver 22
is supplied to a filter circuit 41 and an edge detection circuit 42, and the edge detection circuit 42 applies a slice level TH to detect the edge of the light shielding plate 25, and sends this edge detection signal ■ to an inspection width setting circuit 43 and a lane division signal generation circuit. Supplied to circuit 44. The inspection width setting circuit 43 has W inputted in advance.
2. , W22, a binarization circuit 45 converts the inspection width signal ■ to
The lane division sub-signal generation circuit 44 inputs the lane division signal (2) to the memory interface 46 . In this way, the inspection width signal (2) and the lane division signal (2) are output based on the edge detection signal (2), so that they follow the meandering of the web 14 as a result.

On the other hand, when the 2(l!! converting circuit 45 receives the test width signal ■), it binarizes the filter circuit output signal ■ and inputs the test output @ to the memory interface 46.

On the other hand, the line length measurement signal of the web 14 outputted from the encoder 48 is frequency-divided by a frequency dividing circuit 49, and a print interval signal for setting the printing interval to the printer is outputted to the computer 51.

The computer 51 has a memory interface 36.4.
The inspection output [phase] and @ are read from 6 as a defect signal of each lane at each print interval.

At this time, for the data read from the memory interface 46, the computer 51 changes the order of the lanes so that the scan start side is the 10th lane and sequentially decreases the number. However, the inspection data is output to the printer 52 as if it were continuous inspection data scanned continuously from one end of the web 14 to the other by a single scanning defect detector.

In the embodiment described above, there are two scanning defect detectors, but there may be three or more scanning defect detectors. For example, in the case of three scanning defect detectors, three scanning defect detectors 55,
The scanning direction of the central scanning defect detector 56 among the scanning defect detectors 56 and 57 is from left to right in the figure in the same manner as the scanning defect detector 55, and the light shielding plate 59 for the light receiver 58 of the scanning defect detector 56 is It is provided on the scanning start side integrally with the light shielding plate 62 for the light receiver 61 of the scanning defect detector 55. The scanning direction of the scanning defect detector 57 is the scanning direction of the scanning defect detector 55.
56, do it from right to left in the figure. With such a configuration, the scan start positions of all the scanning defect detectors follow the meandering of the web 61 even when there are three or more defect detectors.

Furthermore, although the embodiments described above are of a transmission type, the present invention may be applied to a surface inspection apparatus of a reflection type. In the case of this reflection method, when the reflectance between the inspection roller and the object to be inspected is significantly different, or when the edges of the web can be detected by photoelectric conversion signals without using the inspection roller, the light shielding plate may be omitted. You can.

Note that the above embodiments have been explained on the assumption that the width of the web is constant, but if the width of the web varies depending on the type of web, the inspection area can be changed by changing the settings of the inspection area and lane division. It is possible to prevent duplication and uninspected areas from occurring. Therefore, the present invention is effective for lines where there are many different widths even for lines where meandering hardly occurs.

〔Effect of the invention〕

As explained above, according to the surface inspection apparatus of the present invention, the scanning defect detector that inspects the edge of the object to be inspected scans from the outside to the inside of the object to be inspected. Even when the object to be inspected is meandering, the surface of the object to be inspected can be accurately inspected for defects. In addition, there is no need to anticipate the meandering portion as a dead zone (uninspected area') in advance.
The scannable area of the scanning defect detector can be used effectively.

Also, the scan start side of one of the scanning defect detectors becomes the first scan data of one scan, and the scan start side of the other scanning defect detector becomes the final scan data. Therefore, the obtained scan data is regarded as one scan data as a whole, and it is possible to obtain test data that is easy to see as if it were inspected with one detector.

In addition, as the reference for the lane division signal, we used the output signal that detected the edge of the light shielding member that is moved in the width direction following the meandering of the object to be inspected or the edge of the object to be inspected itself.
Lane division is always performed consistently for the objects to be inspected, and the correspondence between the objects to be inspected and the inspection data becomes accurate, so that the objects to be inspected can be managed effectively.

In addition, since we used the output signal 4° that detected the edge of the light shielding member that is moved in the width direction following the meandering of the inspected object or the edge of the inspected object itself as a reference for the inspection area, we The settings are always made constant for the object to be inspected, and the object to be inspected can be managed more effectively.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention. FIG. 2 is a block diagram showing the signal processing circuit of the embodiment shown in FIG. 1. FIG. 3 is a chart showing an outline of signal waveforms at each part of the embodiment shown in FIG. 1. FIG. 4 is a perspective view showing another embodiment of the present invention. 11, 12. 55. 56. 57...Scanning defect detector 18.19... Emitter 21.22, 58.61... Light receiver 24.25, 59.62... Light shielding plate 51... ·······Computer.

Claims (4)

[Claims] (1) A scanning defect detector consists of a light projector that irradiates a continuously traveling object to be inspected with scanning light, and a receiver that detects defects in the object by receiving the reflected or transmitted light. In a surface inspection device configured by arranging a plurality of defect detectors in the width direction, each scan of the two scanning defect detectors, each of which inspects the edge of the object to be inspected, is carried out in the direction from the outside to the inside of the object to be inspected. Features of surface inspection equipment. (2) A scanning defect detector consists of a light projector that irradiates a continuously traveling object to be inspected with scanning light, and a receiver that detects defects in the object by receiving the reflected or transmitted light. In a surface inspection apparatus configured by arranging a plurality of defect detectors in the width direction, two scanning defect detectors each inspecting an edge of an object to be inspected scan in a direction from the outside to the inside of the object to be inspected, and The scan start side of one of the two scanning defect detectors is 1.
A surface inspection device comprising a data order changing means for rearranging the scan data so that the first scan data of the scan is the scan data and the scan start side of the other scanning defect detector is the final scan data. (3) A scanning defect detector consists of a light projector that irradiates a continuously traveling object with scanning light, and a light receiver that receives the reflected or transmitted light to detect defects on the object. In a surface inspection device configured by arranging multiple defect detectors in the width direction, two scanning defect detectors each inspecting the edge of the object to be inspected scan in a direction from the outside to the inside of the object to be inspected. It is installed between the object to be inspected and the projector as a reference for the lane division signal used to subdivide the width direction of the object into lanes and position the pulse of the inspection output in the width direction of the object to be inspected. 1. A surface inspection device that uses an output signal that detects an end of a light shielding member that is moved in the width direction following the meandering of the object to be inspected or an edge of the object to be inspected itself. (4) A scanning defect detector consists of a light projector that irradiates a continuously traveling object to be inspected with scanning light, and a receiver that detects defects in the object by receiving the reflected or transmitted light. In a surface inspection device configured by arranging a plurality of defect detectors in the width direction, two scanning defect detectors each inspecting the edge of the object to be inspected scan in a direction from the outside to the inside of the object to be inspected. As a reference, the output signal that detects the edge of the light shielding member that is installed between the object to be inspected and the projector and is moved in the width direction following the meandering of the object to be inspected or the edge of the object to be inspected itself is used as a reference. A surface inspection device characterized in that it is used.