JP2001305070A - Method and device for marking defect in sheet product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively guarantee that a defect is not included in a partition part in cutting a sheet product to cut out the partition part of specified shape while suppressing a lowering of yield. SOLUTION: The defect 13 can be detected by applying various image processing to the image of the surface of the sheet product photographed by an image pickup means 12. Upon detecting the defect 13, a marking means 14 puts linear marks 15 parallel with a conveying direction 11a, so as to hold a defect position from both sides of a cross direction. A lighting system 17 uniformly lights over the whole cross direction of the sheet product 11, using a tubular emitter such as a fluorescent light or a transmission light.

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 marking defects on a sheet-like product such as a synthetic resin film.

[0002]

2. Description of the Related Art Conventionally, in a process of manufacturing a synthetic resin film or paper, various processes are automatically performed in a state of a long strip having a constant width, and finally a predetermined shape is formed according to product specifications. Has been cut. The detection of a defective portion that does not satisfy the product specifications is also automatically performed in a belt-like state, and marking is performed so that the defective portion can be easily identified in a later process. For example, when manufacturing a polarizing plate used for a liquid crystal display panel, a sheet-like product is in a long strip-like state in processes such as manufacturing as a synthetic resin film and imparting polarization characteristics by stretching in a certain direction. , And cut in the size and direction predetermined by the product specifications. In order to perform the defect inspection automatically, the defect detection and the defect marking must be performed by the sheet-like product 1.
It is necessary to carry out along the transport path.

FIG. 5 shows a general defect marking method performed on paper or the like. FIG. 5A shows a schematic configuration of the apparatus, and FIG. 5B shows a state of a marked product. As shown in FIG. 5A, in the marking device, the surface of a sheet-like product 1 conveyed at a constant speed in a band shape having a constant width is imaged by a camera 2, and the defect 3 is detected by image processing. Do. Markers 4 are arranged at one end or both ends in the width direction on the downstream side in the transport direction of the sheet-like product 1. When the defect 3 is detected by the camera 2, the marker 4 is moved in accordance with the timing at which the portion including the defect 3 in the width direction is transported from the position where the camera 2 is disposed to the position where the marker 4 is disposed. Activated. A linear mark 5 is drawn on one or both side edges of the portion including the defect 3 in the width direction. As shown in FIG. 5B, when the sheet-like product 1 is wound up to form the roll 6, the mark 5 looks spiral from the side. In the case of paper or the like, a portion provided with the mark 5 is excluded and used in the length direction.

FIG. 6 shows the concept of marking by a defect marking apparatus for a sheet-like product disclosed in Japanese Patent Application Laid-Open No. 9-304295. In this prior art, a pen of a marking device arranged downstream of the sheet-like product 1 in the transport direction is movable in the width direction with respect to a detection unit that optically detects a defective portion. The pen of the marking device is moved to the position of the defect in the width direction based on the position information of the defect point detected by the detection means, and the tip of the pen is sheet-shaped at the timing when the vicinity of the defect point is transported to the pen position. Control for bringing the product 1 into contact with the surface is performed. By such control, the mark 7 can be directly marked at the position of the defect 3 on the surface of the sheet-like product 1.

[0005]

In the marking on the end in the width direction as shown in FIG. 5, a defect 3 is located somewhere in the width direction in the length range where the mark 5 is formed on the sheet-like product 1. Only the existence can be obtained as information. Therefore, if a slit or trimming is performed to cut off the side edge, the mark 5 is cut off, and information about the position of the defect 3 is completely lost. Therefore, when the sheet-shaped product 1 is cut finely, it is necessary to first remove the portion where the mark 5 is provided in the length direction.

However, the portion to be removed in the length direction includes the defect 3 and at the same time, there are many good portions where the defect 3 is not detected. Removing a lot of good parts lowers the yield of the product. Further, if the sheet-like product 1 is cut in the longitudinal direction prior to the fine cutting step, the fine cutting step cannot be performed continuously, and the productivity is reduced.

In the case of direct marking on a defective portion as shown in FIG. 6, it is impossible to reflect information on the existing range of the defect 3 in the width direction. In the manufacturing process of the sheet-like product 1 which is continuous in a belt shape, defects 3
May have a certain length in the width direction or may occur at a plurality of positions in the width direction. Japanese Patent Application Laid-Open No. 9-30 / 1990 describes a case where such information in the width direction is also necessary.
As disclosed in Japanese Patent No. 4295, in the concept of directly marking a defective portion by moving a pen, only one location can be marked in the width direction.
For this reason, when the sheet-like product 1 is cut to cut out a section having a predetermined shape, even if the defect 3 exists, the section having the mark 7 and the section not having the mark 7 are formed. There is a possibility that it is not determined that the defect 3 exists in the section where the mark 7 is not provided, and it is determined that the defect 3 does not exist.

SUMMARY OF THE INVENTION An object of the present invention is to ensure that when a sheet-shaped product is cut out to form a section having a predetermined shape, the section does not contain any defect, and that a reduction in yield is suppressed. It is an object of the present invention to provide a method and an apparatus for marking defects in a sheet-like product.

[0009]

According to the present invention, when a partial defect is detected in a sheet-like product having a constant width and conveyed in a length direction perpendicular to the width direction, the defect is detected. And marking the defective portion at a position near a predetermined range on both sides in the width direction with respect to the defective portion.

According to the present invention, since marking is performed at a position near a predetermined range on both sides in the width direction of the defective portion, the defective portion exists between the positions where the marking is performed in the width direction. Can be easily recognized, and it can be assured that no defective portion exists outside the position where the marking is made. Since the marking is applied to a position near a predetermined range with respect to the defective portion, it is possible to prevent a large gap between the marking position and the defective portion, and to cut the sheet-shaped product to a certain degree. When cutting out the section of the shape of the product into a product, if the section where the marking is applied is removed, it is assured that the product does not contain defective parts, and the yield will also decrease. Can be suppressed.

Further, in the present invention, when the positions to be marked on both sides in the width direction are apart from each other by a predetermined distance or more, the marking is also performed in the middle.

According to the present invention, when a detected defective portion occupies a large area in the width direction, even if marking is performed at a position near a predetermined range on both sides, even if the marking is performed on both sides thereof, The spacing increases. By providing the marking in the middle in the width direction, the presence can be clearly specified even in the middle of the defective portion over a wide range.

Further, the present invention detects a partial defect of a sheet-like product having a constant width and conveyed in a length direction perpendicular to the width direction, and specifies the detected defect portion. A marking device, which is disposed on the downstream side in the transport direction of the sheet-like product with respect to the defect detection position,
Marking means operable to apply a mark on the surface of the sheet-like product at a position near a predetermined range in the width direction with respect to the detected defective portion,
Adjust the timing based on the detection point of the defective part,
Control means for operating the marking means in a predetermined range extending before and after the defective portion with respect to the length direction of the sheet-like product, and controlling to apply linear marking on at least both sides in the width direction of the defective portion. A defect marking device for a sheet-like product, characterized in that the marking device includes:

According to the present invention, when a defect is detected in the sheet-shaped product, the width of the detected defective portion in the width direction of the detected defect is determined by the marking means arranged on the downstream side of the detection position in the conveying direction of the sheet-shaped product. Since the marking is applied to a position near a predetermined range on both sides of the mark, it can be easily recognized that a defective portion exists between the positions where the marking is applied in the width direction. Since it is possible to reliably ensure that no defective portion exists outside the position where the marking is applied, and since the marking is applied to a position near a predetermined range with respect to the defective portion, In addition, it is possible to prevent a large gap between the position of the marking and the defective portion. When cutting a sheet-shaped product to cut out a section of a certain shape into a product, if the section where the marking is applied is removed, it is assured that the product does not contain defective parts It is possible to guarantee and suppress a decrease in yield.

In the present invention, the marking means includes a plurality of markers arranged at predetermined intervals in a width direction of the sheet-like product, and the control means determines the defective portion from the plurality of markers. A marker located at a position near a predetermined range in the width direction is selected and activated.

According to the present invention, the marking means includes a plurality of markers arranged at predetermined intervals in the width direction of the sheet-like product, and includes a predetermined range in the width direction of the defective portion among the plurality of markers. A marker arranged at a nearby position is selected by the control means, and marking can be performed on both sides in the width direction of the defective portion. Since it is sufficient to select markers arranged in the width direction, even for a defect that spreads greatly in the width direction or for a plurality of defects,
Marking can be easily and quickly made clear.

In the present invention, the detection of the defective portion is performed by a plurality of detecting means arranged at predetermined intervals in the width direction of the sheet-like product. The marker is associated, the control means, based on a defect detection result from each detection means,
A marker associated with each detection means is selected and activated.

According to the present invention, a plurality of detecting means share the width direction of the sheet-like product to detect a defect, and if a defect is detected, a marker associated with each detecting means is assigned. Marking can be performed by selecting a defect corresponding to a defect detection position by each detection means and activating the selected marker. Since a plurality of detection means are arranged in the width direction, even when a plurality of defects are detected, position detection can be performed on each defect with high accuracy, and marking can be reliably performed in the vicinity of each defect portion.

[0019]

FIG. 1 shows a schematic configuration of a marking device 10 as one embodiment of the present invention. The sheet-shaped product 11 is, for example, a transparent synthetic resin film used as a polarizing plate of a liquid crystal display device. However, it is not preferable that the image is present because the display quality of the image is deteriorated. In addition, even if the defect covers a relatively wide range, it may be difficult to determine it with the naked eye. Even if the defect is difficult to determine with the naked eye, the defect 13 is obtained by performing various image processing on the image of the surface of the sheet-like product 11 captured by the imaging unit 12.
Can be detected as

The sheet-like product 11 is conveyed at a constant speed in the conveying direction 11a, and a marking means 14 is provided downstream of the detecting means in the conveying direction 11a. The marking means 14 applies a linear mark 15 parallel to the transport direction 11a on the surface of the sheet-like product 11 as a marking. The sheet-like product 11 is pulled out from the state wound on the roll 16 and becomes an inspection target. Defect 13 to be inspected
In order to reliably detect from the image captured by the imaging unit 12, illumination by the illumination device 17 is also important. The lighting device 17 extends over the entire width of the sheet-like product 11.
Provide uniform illumination.

As the illumination device 17, a tubular light-emitting body such as a fluorescent lamp or a linear light source such as a transmission light is used.
In the transmission light, a strong light source such as a metal halogen lamp is disposed on an axial end face of a rod-shaped light guide, and light incident on the end face is guided to a side face between both end faces to function as a rod-shaped light source. The laser beam can be spread and irradiated. The light emitted from the illuminating device 17 to the sheet-like product 11 is set to have a wavelength or a polarization characteristic at which the defect 13 can be easily detected.
The combination of the imaging means 12 and the lighting device 17 determines the type of the defect 13 that can be detected efficiently. In order to be able to detect a plurality of types of defects 13, the imaging unit 12 and the illumination device 1
7 may be arranged along the transport direction 11a, and if any type of defect 13 is detected, marking may be performed by the marking means 14.

The transport speed of the sheet-like product 11 is detected by a transport speed detecting device 18. Transport speed detection device 1
The output from 8 is input to the control unit 20 together with the image processing result from the image processing device 19 that performs predetermined image processing on the image captured by the imaging unit 12. Control means 2
0 is realized by, for example, an industrial personal computer or the like, and determines whether there is a defect from the image processing result,
The position when the defect 13 exists is detected. The control means 20 further adjusts the timing based on the output from the transport speed detecting device 18 so that the marking is performed within a predetermined vicinity range in the width direction with respect to the defect existing position. Activate. Imaging means 12
Has a plurality of cameras 21,... In the width direction. Also,
The marking means 14 includes a plurality of markers 31 in the width direction.
….

FIG. 2 shows the concept of marking a defect 13 detected by the imaging means 12 as a detection means by the marking means 14 in this embodiment. Imaging means 1
2, a plurality of cameras 21,... Are arranged at regular intervals in the width direction. Each camera 21,...
A one-dimensional CCD sensor in which pixels are arranged at high density is provided as an image sensor. The work width, which is the width of the sheet-like product 11 to be inspected, is, for example, in the range of 800 to 1300 mm.
The width is 0 mm. Six cameras 21,... Are arranged in this inspection area, and the field of view 2 of each camera 21,.
.. Are 250 mm. The field of view 21a of each of the cameras 21,... Overlaps with the field of view 21a,.

In the marking means 14, a plurality of markers 3
Are arranged in the width direction at regular intervals, for example, at intervals of 20 mm. Each of the markers 31,... Is located on the extension of the field of view 21a,. The control means 20 of FIG.
When a defect 13 is detected in the images from 1,.
3, the closest marker 31 sandwiching both sides in the width direction of 3,
, Is selected, and if there is a marker 31,... Between the selected markers 31,. Each marker 31,... Is a felt-tip pen type,
By bringing the leading end into contact with the surface of the sheet-like product 11, a linear mark 15 can be formed in the transport direction 11a. It is preferable that each of the markers 31,... Be covered with a cap when not in use to prevent a solvent, a diluent, or the like from evaporating to reduce writing taste. In general, when the defect 13 is detected between the positions of the markers 31,..., Marks 15 are formed on both sides of the detected position, and marking is performed. When the polarizing plate is cut out, an oblique cut is performed as indicated by a broken line, and only the cut section having no mark 15 is shipped as a non-defective product. Discard as good.

FIG. 3 shows an outline of the entire process of manufacturing the sheet-like product 11 as a polarizing plate. The production starts from step s1, and the production process as the sheet-like product 11 ends in step s2. In step s3, an automatic inspection for a defect is performed by the detecting means of the present embodiment. As a result of the automatic inspection, if the defect 13 is NG in which the defect 13 is detected, step s4
The marking is performed so as to sandwich the defect 13 from both sides in the width direction. Defect 1 as a result of the automatic inspection in step s3
3 is OK when not detected, or when detected and marked in step s4, step s
It moves to 5 and cutting is performed. When manufacturing a polarizing plate, an oblique cut is made at an oblique angle as shown by a broken line in FIG. Each section separated by the cutting in step s5 is subjected to the marking inspection in step s6 and the visual inspection in step s7.

In the marking inspection at step s6, even if the defect 13 is hard to be identified by the naked eye, the mark 15 is provided so as to sandwich both sides thereof, so that the defect 13 can be easily identified. Even if the mark 15 is not found, a visual inspection is performed in step s7. The visual inspection in step s7 determines other defects such as a cutting defect. As a result, if the mark 15 and other defects are not found, the product is shipped as a product in step s8, and if the mark 15 and other defects are found, it is discarded in step s9.

FIG. 4 shows an example of the concept of control when the control means 20 of FIG. 1 activates the marking means 14 and performs marking in FIG. 4 (b) and 4 (c)
Indicates marks 15b and 15c to be applied to large defects 13b and 13c in the width direction and the length direction according to the concept of FIG.

As shown in FIG. 4A, the sheet-like product 1
The first surface is defined by a virtual block 40. Each block 40 has 20 sides 41, 42, 43, 44 in accordance with the arrangement pitch of the markers 31,.
mm square. The sides 41 and 42 are boundaries on the upstream side and the downstream side in the transport direction 11a, respectively, and the sides 43 and 44 are boundaries on one side and the other side in the width direction, respectively. When the defect 13 exists inside each block 40, markers at the positions of the sides 43 and 44 on both sides in the width direction are selected and marked. Defect 13 is side 4
If any one of the blocks 3 and 44 is applied, marking is performed on the side opposite to the side in the block adjacent to the side. Therefore, FIG.
As shown in (b), marking is performed on the side of the defect 13b that is long in the width direction and extends over a plurality of blocks, at the position sandwiched from both sides in the width direction, and on all sides therebetween. Will be.

In FIG. 4A, when the defect 13 is on one of the sides 41 and 42, marking is performed on both sides in the width direction even in an adjacent block with that side as a boundary. . Therefore, as shown in FIG. 4 (c), for a defect 13c that is long in the length direction and extends over a plurality of blocks, the block 13 is extended to the side at a position sandwiched from both sides in the width direction and continuously. The marking is applied.

Even if a single marker is used, if it is possible to move in the conveying direction 11a and the width direction at a higher speed than the conveying speed of the sheet-like product 11, both sides of the defect 13 may be sandwiched. It is possible to apply markings. However, the control of the movement of the marker becomes complicated, and it is difficult to perform reliable marking when a plurality of defects 13 are detected at close positions. In addition, if a plurality of markers are moved, marking can be performed on many defects 13 at the same time, but the control becomes more complicated.

Although the marking means 14 is of a felt pen type, other types of markers such as an ink jet type can be used. The imaging means 12 as the detection means is optically defective.
The present invention is also applied to the case where the sheet-like product 11 is different from the synthetic resin film used as the material of the polarizing plate, for example, when the detection of electromagnetic defects or the detection of defects using radiation is performed, although the detection of 3 is performed. Since such a defect cannot be discriminated by the naked eye at all, the effectiveness of the marking can be enhanced.

[0032]

As described above, according to the present invention, marking is performed at a position near a predetermined range on both sides in the width direction of the defective portion, and a defect is provided outside the position between the marked portions. It can be assured that no parts are present. Since it is possible to prevent the gap between the position of the marking and the defective portion from being largely separated, when a sheet-shaped product is cut out to cut out a section having a certain shape to be a product, the section where the marking is applied By removing the portion, it is possible to reliably ensure that the product does not include a defective portion, and to suppress a decrease in the yield.

Further, according to the present invention, even when the detected defective portion occupies a large area in the width direction, marking is also performed in the middle of the width direction to ensure the presence of the defective area over a wide area. Existence can be specified.

Further, according to the present invention, the sheet-like product is transported in a direction 1 with respect to the position where the defect of the sheet-like product is detected.
1a, marking is performed on both sides in the width direction of the detected defective portion by the marking means disposed downstream of the detected defective portion, and it is confirmed that the defective portion exists between the positions where the marking is performed in the width direction. It can be easily recognized. Since the marking is applied to a position near the predetermined range with respect to the defective portion, it is possible to prevent the position between the marking and the defective portion from being largely separated.
When cutting a sheet-shaped product to cut out a section of a certain shape into a product, by removing the section where the marking is applied, the section that becomes the product does not contain a defective part Can be reliably assured, and a decrease in the yield can be suppressed.

Further, according to the present invention, of the plurality of markers provided in the marking means, a marker arranged at a position near a predetermined range in the width direction of the defective portion is selected by the control means, and the marking is performed. Apply. Defects that spread significantly in the width direction or a plurality of defects can be easily and quickly marked to clearly indicate the existence.

According to the present invention, a plurality of detecting means detect a defect in the width direction of the sheet-like product, and if a defect is detected, a marker associated with each detecting means is set to a defect detection position. Can be selected and marked. Even when a plurality of defects are detected, the position of each defect can be detected with high accuracy, and marking can be reliably and quickly performed in the vicinity of each defective portion.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view showing a schematic configuration of a marking device 10 as one embodiment of the present invention.

FIG. 2 is a diagram showing a concept of marking in the marking device 10 of FIG.

FIG. 3 is a flowchart showing an outline of an entire process of manufacturing the sheet-like product 11 of FIG. 1 as a polarizing plate.

FIG. 4 is a diagram showing an example of a concept of control when the control unit 20 of FIG. 1 operates the marking unit 14 to perform marking.

FIG. 5 is a simplified perspective view and a side view showing a conventional concept of marking.

FIG. 6 is a simplified plan view showing the concept of marking in the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Marking apparatus 11 Sheet-like product 11a Transport direction 12 Imaging means 13, 13b, 13c Defect 14 Marking means 15 Mark 17 Illumination 18 Transport speed detection apparatus 19 Image processing apparatus 20 Control means 21, ..., Camera 31, ..., Marker 40 Block 41, 42, 43, 44 sides

Claims (5)

[Claims] When a partial defect is detected in a sheet-like product having a fixed width and conveyed in a length direction perpendicular to the width direction, a marking method for specifying the defect portion is provided. A defect marking method for a sheet-like product, characterized in that the defective portion is marked at a position near a predetermined range on both sides in the width direction. 2. The method according to claim 1, wherein when the positions to be marked on both sides in the width direction are apart from each other by a predetermined distance or more, the marking is also performed in the middle. 3. While detecting a partial defect of a sheet-like product having a fixed width and conveyed in a length direction perpendicular to the width direction, a mark for clearly indicating the detected defect portion is formed. An apparatus for applying the sheet-like product, which is located downstream of the detection position of the defect in the conveying direction of the sheet-like product and which is located near a predetermined range in the width direction with respect to the defect portion to be detected. Marking means operable to apply marking to the surface, and performing timing adjustment based on the time of detection of the defective portion;
Control means for operating the marking means in a predetermined range extending before and after the defective portion with respect to the length direction of the sheet-like product, and controlling to apply linear marking on at least both sides in the width direction of the defective portion. A defect marking device for a sheet-like product, characterized in that it comprises: 4. The marking means includes a plurality of markers arranged at predetermined intervals in a width direction of the sheet-like product, and the control means determines a width direction of the defective portion from the plurality of markers. 4. A marker arranged at a position near a predetermined range is selected and activated.
A defect marking device for the sheet-like product described in the above. 5. The detection of a defective portion is performed by a plurality of detecting means arranged at predetermined intervals in a width direction of the sheet-like product, and a predetermined number of the markers are provided for each detecting means. 5. The sheet according to claim 4, wherein the control unit selects and activates a marker associated with each detection unit based on a defect detection result from each detection unit. 6. Marking device for defect products.