JPH05118997A - Appearance inspecting device for long material - Google Patents

Abstract

PURPOSE:To precisely detect an abnormality even in the case of a long material having a complicated form by irradiating the long material with line fibers provided at a determined distance in the longitudinal direction of the continuously transferred lengthy material. CONSTITUTION:Along the longitudinal direction of a lengthy material 1 continuously transferred in the longitudinal direction, line fibers 2a, 2b, 2c are provided at a determined distance. The image of the lengthy material 1 irradiated with the line fibers 2a, 2b, 2c is taken by image pickup means 4a, 4b, 4c. The image informations detected by the image pickup means 4a, 4b, 4c are synthesized by an image synthesizing means consisting of a horizontal synchronous signal generating circuit 6, a timing circuit, and a multiplexer 8. An abnormality of the lengthy material 1 within a determined area is detected every image by an abnormality detecting means consisting of a synchronous separating circuit, a judging circuit and others, and stored in a shift resistor. The moved distance of the lengthy material 1 is detected by an encoder 20, whereby the shift resistor corrects the detecting time slippage of the abnormal position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection apparatus for a long object for detecting a partial abnormality such as a scratch on the long object.
It can be used to detect defects such as scratches when installing the product on a production line to control the appearance of long objects, and after eliminating the defect by distinguishing it from other products. is there.

[0002]

2. Description of the Related Art As a conventional visual inspection apparatus for a long object for detecting a partial abnormality such as a scratch on this long object, an optical fiber for supplying light from four directions around the long object is used. The guided light sources are arranged at two positions in the transport direction of the length direction, the surroundings of the long object are illuminated by the light sources, and the illuminated long object is specified by another optical fiber in a specific frame body. There is a commercially available optical fiber which is guided to the end portion of the optical fiber arranged vertically with respect to and is imaged by one imaging means.

Further, as an improved version of the above, Japanese Patent Application Laid-Open No. 1-112143 (Japanese Patent Application No. 62-2698) filed by the present applicant.
No. 48) has the technology of appearance inspection equipment for long objects,
According to this, two or more image pickup means arranged around a long object continuously transferred in the length direction and image information detected by the image pickup means are vertically combined to form one screen. An image synthesizing unit that makes two or more images in units, an abnormality detecting unit that detects a partial abnormality of the long object from the output signal of the image synthesizing unit, and an abnormality is detected by the output of the abnormality detecting unit. An abnormal point detecting means for specifying an abnormal point of the long object is provided.

According to this type of appearance inspection apparatus for long objects,
An image in a unit of a plurality of screens is input to the anomaly detection unit as an image input in a unit of a screen, and a partial anomaly of the long object is detected therein, and the anomaly location detection unit detects the anomaly location of the long object Can be specified.

[0005]

However, in the above-described conventional appearance inspection apparatus for a long object, two or more image pickup means arranged around the long object continuously transferred in the length direction are provided. Since the long objects are located on the same plane perpendicular to the longitudinal direction, when the long object is a glass run or the like, the appearance inspection aspect of the urethane surface and the appearance inspection aspect of the design surface are different. However, in order to perform an inspection with high accuracy, it is necessary to change the incident angle of illumination light, and it may not be possible to detect clearly at a specific incident angle.

For example, as shown in the explanatory view of the arrangement of the light source and the CCD camera when observing the appearance of the urethane surface in FIG. 4, when observing the appearance of the urethane surface 100 of the work, When the light source 101 is provided obliquely at an angle of about 15 degrees and the light is irradiated and observed by the CCD camera 102 from the direction perpendicular to the urethane surface 100, the shadow of the fine irregularities becomes large and can be detected reliably. On the other hand, in the design surface 200 formed by the smooth surface of the work, as shown in FIG.
As shown in the explanatory view of the arrangement of the light source and the CCD camera when observing the appearance of the design surface of the
1 is provided and the light from the light source 201 is irradiated at about 80 to 90 degrees so that the CCD camera 202 always captures the regular reflection (total reflection) of the illumination. It has the characteristic of being able to In addition, when the long object has a complicated shape such as a glass run, even if the specific surface is illuminated at a predetermined incident angle, the accuracy may not be improved due to the reflection on the other surface.

[0007] Therefore, an object of the present invention is to provide a visual inspection apparatus for a long object which can detect a long object having a complicated shape with high accuracy.

[0008]

A visual inspection apparatus for a long object according to the present invention comprises a plurality of line fibers arranged at a predetermined distance in the lengthwise direction of a continuously transferred long object, and A predetermined area of the long object based on the output signal of the image synthesizing means for synthesizing the image information of the long object illuminated by the line fiber and the image information detected by the image synthesizing means to form a plurality of images on one screen. Abnormality detecting means for detecting an abnormality in each image, an encoder for detecting a moving distance of a long object continuously transferred, and an output of the abnormality detecting means for detecting each image are written, and the written signal is written. A storage means for correcting the detection time shift of the abnormal portion, which is shifted by the output of the encoder, is used to perform visual inspection of a long object by irradiation light of a line fiber arranged along the flow of the long object.

[0009]

In the present invention, a plurality of line fibers are arranged at a predetermined distance in the lengthwise direction of a continuously transported long object, and the line fibers are set at a position according to the object to be detected. A long object is irradiated with the line fiber whose position has been set, and the irradiated long object is imaged by an imaging means which is paired with the line fiber. Then, the abnormality in the predetermined area of the long object is detected for each image by the abnormality detecting means, and the abnormal portion of the long object where the abnormality is detected is stored in the shift register. The image information detected by the imaging means is separated by a predetermined distance in the length direction of the long object continuously transferred, so that the distance is replaced by the number of pulses generated by the movement of the long object by the encoder, The shift register is shifted by the output pulse of the encoder, and the moving position of the long object is specified even if there is a position shift in the abnormal part of the images combined as a plurality of images by the image combining means.

[0010]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 is a block diagram showing a configuration of a visual inspection apparatus for a long object according to an embodiment of the present invention until a monitor image is created. FIG. 2 is a block diagram showing a configuration of obtaining an abnormality detection output from a monitor image of the appearance inspection apparatus for a long object according to an embodiment of the present invention. FIG. 3 is a layout explanatory diagram centering on the long object 1 showing an arrangement state of the image pickup means 4a, 4b, 4c used in the appearance inspection apparatus for the long object of one embodiment of the present invention.

In the figure, a long object 1 which is continuously transferred in the longitudinal direction is a tube material such as a glass run, a weather strip, a molding or a bar material. The single or plural line fibers 2a, 2b, 2c are optical fibers 3a,
The ends of 3b and 3c are held, and the light guided by the optical fiber 3 is evenly applied to the outer peripheral surface of the long object 1. The length, shape, and The number is set. The image pickup means 4a, 4b, 4c are CCD image sensors, MOS image sensors, image orthicons, vidicons and the like used in video cameras, industrial television cameras, industrial photographing devices, etc., and a vertical / horizontal synchronizing signal generating circuit 6 Driven by.

Particularly, in this embodiment, FIG. 2 and FIG.
As shown in FIG. 1, the imaging means 4a, 4b, 4c are arranged along the length direction of the long object 1 at a predetermined distance.
Further, the line fibers 2a, 2b, 2c have an irradiation angle that matches the properties of the detection target surface, and as shown in FIGS. 4a, 4b, 4c and line fibers 2a, 2
The positions of b and 2c are set. Further, the lights of the respective line fibers 2a, 2b, 2c are positioned so as not to interfere with each other, or a shield plate is provided between the two so as not to interfere with each other. In this embodiment, the line fiber 2 whose irradiation angle is set to about 15 degrees with respect to the abnormality detection surface
By disposing a at the end portion, the influence of the irradiation light does not interfere with the image pickup means 4b and the image pickup means 4c on the side of the other line fibers 2b and 2c.

The outputs of the three image pickup means 4a, 4b, 4c driven by the vertical / horizontal synchronizing signal generation circuit 6 are images of a predetermined number of scanning lines in the image signal circuits 5a, 5b, 5c, that is, It is output as image information. At this time, the outputs of the three image pickup means 4a, 4b, and 4c are such that the image pickup means 4a has an area of one-third of the top of the screen unit and the image pickup means 4b outputs 1 area.
Image unit 4 in the upper one-third to two-thirds of the screen unit
The three image pickup means 4a, 4b, 4c are installed so that the long object images 1a, 1b, 1c are located in the upper two-thirds to three-thirds region of b per screen.

The multiplexer 8 includes image pickup means 4a, 4b,
4c is input, the number of horizontal synchronizing signals starting from the vertical synchronizing signal is counted from the vertical / horizontal synchronizing signal generating circuit 6, and the image of the long object 1 is captured by the image pickup means 4a from the top of the screen by 3 units. 1/3 of the area, the image pickup means 4b is in the upper 1/3 to 2/3 area of the screen unit, and the image pickup means 4c is in the upper 2/3 to 3/3 area of the screen unit. Then, the timing circuit 7 counts the horizontal synchronizing signal to create the switching timing of the image information, and switches the outputs of the image pickup means 4a, 4b, 4c. The image information output from the image pickup means 4a, 4b, 4c is output by the image signal output circuit 9 as image information for each screen. Therefore, as shown in the figure, the long object images 1a, 1b, 1c obtained by imaging the long object 1 on the monitor 10 by the imaging means 4a, 4b, 4c are displayed by the imaging means 4a in a unit of 3 minutes from the top. 1 area, the image pickup means 4b is located in the upper one-third to two-thirds area of one screen unit, and the imaging means 4c is located in the upper two-third to three-third area of one screen unit. Become.

The image of the long object 1 of the three image pickup means 4a, 4b, 4c is positioned at the center position by setting the timing of the horizontal synchronizing signal from the vertical / horizontal synchronizing signal generating circuit 6 starting from the vertical synchronizing signal. It is also possible to synthesize what is captured in.

The same image as the image visualized on the monitor 10 is input to the sync separation circuit 13. The sync separation circuit 13 separates the vertical sync signal and the horizontal sync signal from the imaged signal of one screen unit, and the timing generation circuit 12 opens and closes the analog gate 14 according to the image position of the imaging means 4a, 4b, 4c. Obtain timing signals to control. That is, the timing generation circuit 12 extracts the image information in the predetermined area starting from the start of the vertical synchronizing signal and the horizontal synchronizing signal.

The predetermined area W from which this image information is extracted is
The area setting circuit 11 presets and inputs the predetermined range length to be extracted. Thereby, which range of one screen is to be extracted is determined. The timing generation circuit 12 of the predetermined area W to be extracted controls the opening / closing of the analog gate 14, and only the essential signal of the long object images 1a, 1b, 1c imaged by the predetermined imaging means 4a, 4b, 4c is differentiated. To enter. The differentiating circuit 15 differentiates the incoming signal.
At this time, if there is a discontinuous portion such as a flaw in the signal of the main part of the long object images 1a, 1b, 1c, the discontinuous portion is differentiated.
The output of No. 5 becomes large, and the output becomes small for a monotonous flat signal. The output of the differentiation circuit 15 is input to the determination circuit 17 via the sensitivity adjustment circuit 16. The determination circuit 17 compares the output of the differentiating circuit 15 at a predetermined signal level with a predetermined threshold value and when it is equal to or higher than a predetermined threshold value,
The output is set to "H" or "L".

As for the output of the judgment circuit 17, the output of the signal is the long object image 1 picked up by the image pickup means 4a, 4b, 4c.
The output of the timing generation circuit 12 determines which of a, 1b, and 1c the AND gates 19a, 19b, and 1 correspond to.
9c is opened and closed, and the output of the determination circuit 17 is written in a predetermined address of the shift register 18. This shift register 1
The predetermined address of 8 is stored in the memory corresponding to the distance of the imaging means 4a, 4b, 4c arranged along the length direction of the long object 1. That is, the shift register 18 is shifted by the output of the encoder 20 which detects the moving distance of the long object 1 which is continuously transported in the length direction, and the image pickup means 4a.
The specific position of the long object 1 photographed in
If the address of the shift register 18 stored in a is used, the output of the encoder 20 is shifted according to the movement of the long object 1, and the specific position of the long object 1 is imaged by the imaging means 4b. Then, the specific position photographed by the image pickup means 4a of the long object 1 corresponds to the address stored in the AND gate 19b. Therefore, the position shift of the image pickup means 4a, 4b, 4c is corrected by the difference in the address of the shift register 18, and the abnormality detection output is the output obtained by correcting the position shift of the image pickup means 4a, 4b, 4c, that is, , Output corresponding to the position of the long object 1. The appearance inspection apparatus for the long object 1 of the above-described embodiment configured as described above is used as an inspection apparatus before cutting the long object 1 into a predetermined length.

As described above, in the appearance inspection apparatus for a long object of this embodiment, a plurality of long objects 1 which are continuously transported in the length direction are arranged at a predetermined distance along the length direction. Line fibers 2a, 2b, 2c and the line fibers 2a, 2
imaging means 4a, 4b, which forms a pair with the line fibers 2a, 2b, 2c for imaging the long object 1 irradiated with b, 2c,
4c and the image information detected by the image pickup means 4a, 4b, 4c are combined to form the image pickup means 4a, 4b, 4c in one screen.
Within a predetermined area W of the long object 1 from an image synthesizing means including a vertical / horizontal synchronizing signal generating circuit 6 and a timing circuit 7, a multiplexer 8 and the like for forming a plurality of images corresponding to A vertical sync signal and a horizontal sync signal are separated by a sync separation circuit 13 which detects the abnormality of each image, and the timing generation circuit 12 picks up image pickup means 4a, 4a.
The analog gate 14 is opened / closed in accordance with the image positions of b and 4c, and anomaly detecting means including a differentiating circuit 15, a sensitivity adjusting circuit 16, and a judging circuit 17 for differentiating the signal, and continuous transfer in the length direction. An encoder 20 for detecting the moving distance of the long object 1, a timing generation circuit 12, a sync separation circuit 13, an analog gate 14 detected for each image.
A shift register 18 for writing the output of the abnormality detecting means composed of the differentiating circuit 15, the sensitivity adjusting circuit 16, and the judging circuit 17, shifting the written signal by the output of the encoder 20, and correcting the detection time shift of the abnormal portion. It is equipped with.

Accordingly, the form of the long object 1 is used as image information by the three image pickup means 4a, 4b, 4c, and is converted into 3 image information for each screen by the image synthesizing means such as the multiplexer 8. When detecting a morphological abnormality such as a scratch on the long object 1, although the morphology of the long object 1 is used as image information by the three imaging means 4a, 4b, 4c, the abnormality of one screen is detected. Since a circuit for judging, that is, the output of the three image pickup means 4a, 4b, 4c is used as the output of one screen, it is sufficient to have a circuit for detecting the output of one image pickup means. The configuration of the device can be inexpensive. Of course, the number of image pickup means in the case of implementing the present invention is not limited to three, but may be plural.

The line fibers 2a, 2b, 2c for imaging the long object 1 illuminated by the line fibers 2a, 2b, 2c
The imaging means 4a, 4b, 4c forming a pair with 2b, 2c can set the surface illuminance according to the form of the object to be inspected for cancer of the long object 1, and in particular, the line fiber 2 according to the property of the long object 1.
Since a, 2b, 2c and the image pickup means 4a, 4b, 4c may be selected, a plurality of image pickup means 4a, 4b, 4c may be positioned with respect to one elongated object 1 in the longitudinal direction of the elongated object 1. The line fibers 2a, 2b, 2c can be arranged so as to be offset from each other so that the irradiation lights of the line fibers 2a, 2b, 2c do not interfere with each other.
Since the shapes and sizes and the numbers of 2b and 2c can be arbitrarily set according to the shape of the long object 1, it is possible to improve the detection accuracy of the appearance abnormality.

Then, as an abnormal point detecting means for specifying the abnormal point of the long object in which the abnormality is detected by the output of the abnormality detecting means, the output of the abnormality detecting means is shifted to match the transfer distance of the long object 1. Since it is stored in the register 20, the timing with respect to the working position such as marking and cutting can be easily obtained.

By the way, the three image pickup means 4a, 4b, 4c arranged around the long object 1 of the above-mentioned embodiment form a surface when judging the entire circumference of the long object 1. It is desirable to set it so that it can shoot vertically only. Therefore, when implementing the present invention, the line fibers 2a, 2
It is desirable to set the irradiation angle on the sides b and 2c.

In addition, the image pickup means 4a, 4b, and
The image synthesizing means such as the multiplexer 8 which synthesizes the image information detected by 4c in the vertical direction into three image information for each screen is a long image obtained by previously capturing the long object 1 with the image capturing means 4a, 4b, 4c. In the scale images 1a, 1b, and 1c, the image pickup means 4a has an area that is one-third of the top of the screen unit, and the image pickup means 4b has one area.
Image unit 4 in the upper one-third to two-thirds of the screen unit
Although c is located in the upper two-thirds to three-thirds region of one screen unit, when the present invention is carried out, the image information of the image pickup means may be vertically combined. From the above, the image pickup means may be set so that the long object image picked up by the image pickup means is positioned at the center of one screen unit, and the image information detected by the image pickup means may be vertically combined through the delay means. ..

Then, from the output signal of the image synthesizing means of the above embodiment, only the image information is input to the differentiating circuit at the output of the sync separating circuit 13 which detects an abnormality in the predetermined area of the long object 1, and the differentiating circuit 15 is provided. Although the abnormality detecting means composed of the determination circuit 17 for comparing the output of the above with the predetermined threshold is the detecting means of the discontinuous portion such as a scratch, in the case of implementing the present invention, the long object image of one screen unit It is also possible to compare the approximate states of each other. Further, when the scratch or the like generated due to the property of the long object 1 becomes large, the differential circuit 15 detects the edge of the scratch, but the range of the scratch is detected by detecting both ends of the flip flop or the like. Can be detected.

Further, the line fiber 2a of the above embodiment,
The image pickup means 4a, 4b, 4c forming a pair with 2b, 2c may be a plurality of ones or a plurality of a plurality of pairs, rather than simply corresponding one to one.

[0028]

As described above, the appearance inspection apparatus for a long object according to the present invention is provided with a plurality of long objects which are continuously transported in the length direction and are separated from each other by a predetermined distance. A line fiber and an image pickup means paired with the line fiber for picking up an image of a long object illuminated by the line fiber, and the image information detected by the image pickup means is synthesized by the image synthesizing means to form one screen. A plurality of images corresponding to the image pickup means are formed, an abnormality in the predetermined area of the long object is detected for each image from the output signal of the image synthesizing means, and the detected abnormal position is set in the shift register image pickup means. The data is written in the corresponding location, and the data written in the shift register is shifted by the output of the encoder that detects the moving distance of the long object to correct the detection position shift of the abnormal location.

Therefore, a plurality of line fibers arranged at a predetermined distance along the length direction of the long object continuously conveyed in the length direction and the imaging means paired with the line fiber are the long objects. Since it is not necessary to set it on a plane perpendicular to the vertical direction, the installation conditions of the line fiber and the imaging means necessary for visual inspection of long objects are not restricted, and even long objects with complicated shapes A line fiber and an image pickup means can be installed according to the property of the object, and the abnormality detection accuracy can be increased, so that the appearance abnormality detection can be performed with high reliability.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a visual inspection apparatus for a long object according to an embodiment of the present invention until a monitor image is created.

FIG. 2 is a block diagram showing a configuration for obtaining an abnormality detection output from a monitor image of the appearance inspection apparatus for a long object according to an embodiment of the present invention.

FIG. 3 is a layout explanatory diagram centering on a long object showing an arrangement state of image pickup means used in the appearance inspection apparatus for a long object according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a state of arrangement of a light source and a CCD camera when observing the appearance of a urethane surface.

FIG. 5 is an explanatory diagram of an arrangement state of a light source and a CCD camera when observing an appearance of a design surface.

[Explanation of symbols]

 1 long object 2a, 2b, 2c line fiber 4a, 4b, 4c image pickup means 6 vertical / horizontal synchronizing signal generating circuit 7 timing circuit 8 multiplexer 12 timing generating circuit 13 synchronization separating circuit 14 analog gate 15 differentiating circuit 16 sensitivity adjusting circuit 17 Judgment circuit 18 Shift register 20 Encoder

Claims (1)

[Claims] 1. A plurality of line fibers arranged at a predetermined distance along a length direction of a long object continuously transferred in the length direction, and an image of the long object irradiated by the line fiber. An image pickup means forming a pair with the line fiber; an image synthesizing means for synthesizing the image information detected by the image pickup means to form a plurality of images corresponding to the image pickup means in one screen; and an output of the image synthesizing means. Abnormality detecting means for detecting an abnormality in a predetermined area of the long object from a signal for each image, an encoder for detecting a moving distance of the long object continuously transferred in the length direction, and an abnormality detected for each image A visual inspection apparatus for a long object, comprising: a shift register for writing the output of the detecting means, shifting the written signal by the encoder output, and correcting the detection time shift of the abnormal portion.