JP2000348174A - Card examination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a card examination device which automatically examine whether alignment between a punched side and a pattern is proper or not. SOLUTION: This device is provided with a carrying means which carries a card, an arrival detection means which outputs a leading side detection signal when detecting that the leading side in the direction orthogonal to the carrying direction of the card arrives at a prescribed position, a position detection means which takes the leading side detection signal as a reference signal for detection start to detect the interval between the side in the direction parallel with the carrying direction of the card and a reference line, an image pickup means which picks up the image of the card with the leading side detection signal as a reference signal for detection start to generate a pickup picture, a picture positional deviation extent calculation means 4 which stores the pickup picture of the card to be an examination object as an examination object picture, inputs the pickup picture of the card to be the examination object as the examination object picture to calculate the extent of positional deviation between the pattern of the card in the reference picture and that in the examination object picture, and a discrimination means 5 which discriminates whether the pattern in the cased is in a proper position or not on the basis of the interval and the extent of positional deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the technical field of automatic visual inspection. In particular, the present invention relates to a card inspection apparatus for inspecting whether or not the alignment between a punched side and a picture is proper in a small-sized plastic card obtained by punching a large-size sheet.

[0002]

2. Description of the Related Art A visual inspection is performed to check whether the alignment between a punched side of a plastic card and a picture is proper.

[0003]

The visual inspection involves fatigue and the work load is extremely large. In addition, since it is a work performed by a human, it is inevitable that a defective product is mixed into a product due to a change in inspection standard or an oversight.

The present invention has been made to solve the above problems. The goal is to automate the inspection of whether the alignment between the punched side and the pattern is appropriate so that defective products can be prevented from entering the product due to fluctuations or oversight of inspection standards. To provide a card inspection device that performs

[0005]

The above object is achieved by the present invention described below. That is, a card inspection device according to a first aspect of the present invention provides a card inspection device including a transport unit, an arrival detection unit, a position detection unit, an imaging unit, an image position deviation amount calculation unit, and a pass / fail determination unit. An apparatus, wherein the transporting means transports a card, the arrival detecting means detects that a leading edge in a direction perpendicular to the transport direction of the card has reached a predetermined position, and outputs a leading edge detection signal, The position detecting means detects the interval between a reference side and a side parallel to the transport direction of the card using the leading edge detection signal as a reference signal for starting detection, and the imaging means starts detecting the leading edge detection signal. The card as a reference signal to generate a captured image, the image position shift amount calculating means stores the captured image of the reference card as a reference image, and compares the captured image of the card to be inspected with the inspection target. Input as an image, calculate the amount of misalignment between the pattern of the card in the reference image and the pattern of the card in the image to be inspected, and the pass / fail judgment means determines whether or not the card is defective based on the interval and the amount of misalignment. This is to determine whether or not the picture is at an appropriate position.

According to the present invention, the card is carried by the carrying means, the arrival detecting means detects that the leading side in the direction perpendicular to the carrying direction of the card has reached a predetermined position, and a leading side detection signal is output. The position detection unit detects the leading edge detection signal as a reference signal for starting detection, detects the interval between the side in the direction parallel to the card conveyance direction and the reference line, and uses the imaging unit to detect the leading edge detection signal as the detection start reference signal. Is captured to generate a captured image, the captured image of the reference card is stored as the reference image by the image position shift amount calculating means, the captured image of the card to be inspected is input as the inspection target image, and the card in the reference image is input. The amount of misregistration between the pattern of the card and the pattern of the card in the inspection target image is calculated, Whether kicking pattern is in the proper position is determined.

That is, since the leading edge detection signal is used as the reference signal for starting the detection, the position of the leading edge of the card completely matches the reference image and the image to be inspected. With this in mind,
The positions (a1, 0) and (a2, 0) of the punched sides of the card in the reference image and the inspection target image can be determined from the distance between the side of the card and the reference line detected by the position detection means. On the other hand, with respect to the picture of the card, the positional deviation amount (A2-A1, B2-B1) between the reference image and the inspection target image can be determined from the positional deviation amount detected by the image positional deviation amount calculating means. From this, the amount of displacement (A2-A1-a2 + a1, B2-B1) between the punched side of the card and the picture is obtained. Therefore, there is provided a card inspection apparatus for automatically inspecting whether or not the alignment between the punched side and the picture is proper.

According to a second aspect of the present invention, there is provided the card inspection apparatus according to the first aspect, wherein the image position shift amount calculating means includes a pattern portion of the card in the reference image and the inspection object image. The relative position is changed with respect to the detected position, and the evaluation value of the degree of coincidence is calculated, and the difference between the detected position and the relative position in the evaluation value giving the maximum degree of coincidence is calculated as a positional deviation amount. It was made. According to the present invention, the displacement amount can be calculated as a relative position at which the evaluation value (for example, the correlation coefficient, the sum of the absolute values of the differences, the sum of the squares of the differences, and the like) gives the maximum coincidence. .

According to a third aspect of the present invention, there is provided a card inspection apparatus according to the first or second aspect, further comprising a line sensor camera as the image pickup means, and a conveyance amount detection means. The amount detecting means detects the carry amount of the carrying means, and the line sensor camera uses the leading edge detection signal as a reference signal for starting detection, and synchronizes with the carry amount in a direction perpendicular to the carrying direction of the card. The card is imaged by a main scan by the image pickup means itself and a sub-scan by transport to generate a picked-up image. According to the present invention, an image of a card being conveyed can be captured by the line sensor camera.

According to a fourth aspect of the present invention, there is provided a card inspection apparatus according to any one of the first to third aspects, wherein the image position shift amount calculating means is configured to determine a position between the reference image and the inspection target image. This is a printed pattern inspection apparatus that calculates a position shift, corrects the position shift, and compares the reference image and the inspection target image in pixel units to inspect a pattern. According to the present invention, the misregistration correction function of the printed picture inspection device can be used as the misregistration amount calculating means in the card inspection device of the present invention.

[0011]

Next, the present invention will be described with reference to embodiments. FIG. 1 shows the configuration of the card inspection apparatus of the present invention.
Shown in In FIG. 1, 1 is a photoelectric switch, 2 is a two-dimensional displacement sensor, 3 is a line sensor camera, 4 is an image position deviation amount calculating unit, 5 is a pass / fail determination unit, 11 is a belt conveyor, 12 is an arrow indicating a conveying direction, 13 is a rotary encoder, 21a is a reference line A, 21b is a reference line B, 21c
Is a reference line C, 100 is a reference card, 111a, 111
b and 111c are cards to be inspected.

The photoelectric switch 1 is an example of arrival detecting means. The photoelectric switch 1 detects that the leading side in the direction perpendicular to the card transport direction has reached a predetermined position, and outputs a leading side detection signal. For example, the photoelectric switch 1 includes a light projecting unit and a light receiving unit. The light projecting unit emits a light beam (or a laser beam), and the light receiving unit is arranged at a position to receive the beam. When the beam has arrived, the photoelectric switch 1 is "OFF" (or "ON"), and when the beam has not arrived, it is "ON" (or "OFF"). In FIG. 1, a belt conveyor 1
When the first side of the reference card 100 and the cards 111a, 111b, and 111c to be inspected reach the beam and block the beam, the beam does not reach the light receiving unit and the photoelectric switch 1 is turned off. The state changes to “ON” (or “ON” to “OFF”). This “ON” /
The signal indicating “OFF” is the leading edge detection signal.

The two-dimensional displacement sensor 2 is an example of a position detecting means. The two-dimensional displacement sensor 2 uses the leading edge detection signal as a reference signal for starting detection and detects an interval between a reference line and a side in a direction parallel to the card conveyance direction. The two-dimensional displacement sensor 2 is a scanning displacement sensor, and the displacement sensor is an object surface (xy
The two-dimensional displacement sensor 2 detects the displacement (z-axis direction) of a point on a straight line on the object plane (xy plane) while detecting the displacement (z-axis direction) of one point on the object plane (z-axis direction). Output as a profile. A line profile is output not only for an object surface displaced in time series but also for an object surface having irregularities. That is, since the surface of the belt conveyor 11 and the surface of the card conveyed there have a difference in height, the side of the card appears as a step in the line profile. The position of the side in the direction parallel to the transport direction of the card is detected from the step. As shown in FIG. 1, the two-dimensional displacement sensor 2 uses this position as the distance X from the reference line A21a.
Output as 1.

The above distance X1 by the two-dimensional displacement sensor 2
Is detected using the leading edge detection signal output from the photoelectric switch 1 as a reference signal for starting detection. Whether the detection is performed immediately after the leading edge detection signal is output or the detection is performed at a time interval depends on the relative arrangement of the photoelectric switch 1 and the two-dimensional displacement sensor 2. That is, a necessary condition is that the card is being conveyed to a position where the two-dimensional displacement sensor 2 detects the side of the card after the output of the leading side detection signal. At the timing that satisfies this requirement, 2
The distance X1 is detected by the dimensional displacement sensor 2.

The line sensor camera 3 is an example of an image pickup means. The line sensor camera 3 captures an image of the card using the leading edge detection signal as a reference signal for starting detection, and generates a captured image. Whether the imaging is performed immediately after the leading edge detection signal is output or the imaging is performed at a time interval is determined by the relative arrangement of the photoelectric switch 1 and the line sensor camera 3. That is, it is a necessary condition that the card is conveyed to an appropriate position where the line sensor camera 3 captures an image of the card and its peripheral area after the output of the leading edge detection signal. The imaging by the line sensor camera 3 is performed at a timing satisfying the necessary conditions.

The rotary encoder 13 is an example of a conveyance amount detecting means. As shown in FIG. 1, the rotary encoder 13 is provided on a shaft of a roller around which the belt of the belt conveyor 11 is wound, and detects the amount of conveyance of the belt conveyor 11 by detecting the rotation of the shaft. The line sensor camera 3 uses the above-described leading edge detection signal as a reference signal for starting detection, and performs electronic main scanning by the line sensor camera 3 in a direction perpendicular to the transport direction of the card in synchronization with the transport amount. This electronic main scanning and the belt conveyor 1
The two-dimensional region can be imaged by the mechanical sub-scanning by 1, and a captured image is generated.

The image position shift amount calculating means 4 stores a captured image of the card 100 as a reference as a reference image, and inputs captured images of the cards 111a, 111b, 111c to be inspected as images to be inspected. Further, the amount of displacement between the card pattern in the reference image and the card pattern in the inspection target image is calculated. For example, the image position shift amount calculating means 4 changes the relative position of the picture portion of the card between the reference image and the image to be inspected with reference to the detected position, calculates an evaluation value of the degree of coincidence, and evaluates the maximum degree of coincidence. An arithmetic operation is performed using the difference between the detected position and the relative position in the numerical value as the amount of positional deviation.

As the evaluation value, it is possible to apply a correlation coefficient, a sum of absolute values of differences, a sum of squares of differences, etc., calculated for pixels corresponding to the position of the reference image and the image to be inspected. it can. In the case of a correlation coefficient, the closer the evaluation value is to 1, the greater the degree of coincidence. In the case of the sum of the absolute values of the differences and the sum of the squares of the differences, the closer the evaluation value is to 0, the greater the degree of coincidence. The difference between the detected position and the relative position in the evaluation numerical value giving the maximum coincidence, that is, the amount of positional deviation is a vector, which is an x direction perpendicular to the card transport direction and a direction parallel to the card transport direction. It has two components, the y direction.

In the example shown in FIG. 1, the component in the x direction is X2 and the component in the y direction is (Y2-Y1). X2 of the component in the x direction is a reference line B21b which is the position of the pattern of the reference card 100 in the vertical direction (the upper limit of the character string DNP);
The distance from the reference line C21c, which is the position of the pattern of the card 111a to be inspected in the vertical direction (the upper limit of the character string DNP), is shown. The component (Y2−Y1) in the y direction is a distance Y from the first side in the horizontal direction of the pattern of the reference card 100.
1 (the right end of the character string DNP) and the card 111 to be inspected
The distance Y2 from the first side in the left-right direction of the pattern a (character string D
NP (right end of NP).

The image displacement calculating means 4 does not need to be a dedicated device for the card inspection device. The image misregistration amount calculating means 4 calculates the misregistration between the reference image and the inspection target image, corrects the misregistration, compares the reference image with the inspection target image on a pixel-by-pixel basis, and performs a picture inspection. It is possible to apply a printing pattern inspection apparatus for performing. That is, it is possible to use the output of the image position shift amount calculated for correcting the position shift in the printed picture inspection apparatus. With such a configuration, a defect on the surface of the card can be detected by the printed picture inspection apparatus, and at the same time, by the card inspection apparatus of the present invention,
An inspection can be performed to determine whether the alignment between the punched side and the pattern is appropriate. Further, the equipment cost can be reduced as compared with the case where the apparatus is configured alone.

An example of such a printed picture inspection apparatus and the calculation of the image position shift amount is disclosed in Japanese Patent Application Laid-Open No. Hei 9-330410, which is a prior invention by the present inventors. In addition, the present invention is not particularly limited by the method of calculating the evaluation value, and a detailed description thereof will be omitted.

The pass / fail judgment means 5 includes the above-mentioned interval X1 detected by the two-dimensional displacement sensor 2 and the image position shift amount calculating means 4
Is calculated based on the above-described X2 and (Y2-Y1), and whether or not the pattern on the card is at an appropriate position is determined. That is, the amount of displacement between the punched side of the card and the picture is (X2-X1) in the x direction and (Y2-Y1) in the y direction. The pass / fail determination means 5 compares the values of (X2-X1) and (Y2-Y1) with an allowable value, and if the value is within the allowable value range, the picture on the card is at an appropriate position. It is determined that the product is good. If the value exceeds the allowable value range, it is determined that the picture on the card is not at an appropriate position, that is, the card is defective.

When the conditions of the expression 1 are satisfied, assuming that the allowable values are Εx and Εy, the card is determined to be good and the other cards are determined to be defective.

| X2-X1 | ≦ Εx | Y2-Y1 | ≦ Εy

Next, in the above configuration, the process of the card inspection process will be summarized and described. FIG. 2 is a flowchart showing the process of the card inspection process according to the present invention.
First, in step S1 of FIG.
(Arrival detection means) keeps monitoring that the card is conveyed by the belt conveyor 11 and reaches the detection range.
When the card is conveyed, the photoelectric switch 1 outputs a signal indicating that the leading side in the direction perpendicular to the card conveyance direction has reached a predetermined position.

Next, in step S2, the two-dimensional displacement sensor 2 (position detecting means) uses the leading edge detection signal as a reference signal for starting detection, and sets the distance X1 between the side parallel to the card transport direction and the reference line. Is detected. Next, in step S3, the line sensor camera 3 (imaging unit) images the card using the leading edge detection signal as a detection start reference signal to generate a captured image. Next, in step S4, if the captured image is a captured image obtained by capturing the reference card 100, the process proceeds to step S5. In step S5, the image displacement amount calculating unit 4 determines the interval X1 and the reference image. Is stored in the memory of the card inspection device. On the other hand, if the captured image is a card to be inspected, the process proceeds to step S6.

Next, in step S6, the image misregistration amount calculating means 4 calculates the difference between the card pattern in the inspection target image, which is a captured image of the input card to be inspected, and the card pattern in the aforementioned reference image. Is calculated. Next, in step S7, the pass / fail determination means 5 determines whether the interval X1 and the displacement X2 (Y2-Y
Based on 1), it is determined whether or not the pattern on the card to be inspected is at an appropriate position with respect to the punched side.
Next, in step S8, it is determined whether to continue or end the card inspection, and if so, step S1 is performed.
And the above processing is repeated. If the process is to be terminated, the process is terminated.

[0027]

As described above, according to the card inspection apparatus according to the first aspect of the present invention, there is provided a card inspection apparatus for automatically inspecting whether or not the alignment between a punched side and a picture is proper. Is done. According to the card inspection apparatus of the second aspect of the present invention, the displacement amount is calculated as a relative position at which the evaluation value (for example, the correlation coefficient, the sum of the squares of the differences, and the like) gives the maximum matching degree. be able to. Further, according to the card inspection apparatus according to the third aspect of the present invention, the card being transported can be imaged and inspected by the line sensor camera.
Further, according to the card inspection device according to claim 4 of the present invention,
The misregistration correction function of the printed picture inspection device can be used as the misregistration amount calculating means in the card inspection device of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a card inspection device of the present invention.

FIG. 2 is a flowchart showing a process of a card inspection process according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoelectric switch 2 two-dimensional displacement sensor 3 line sensor camera 4 image position shift amount calculation means 5 pass / fail determination means 11 belt conveyor 12 arrow indicating transport direction 13 rotary encoder 21 a reference line A 21 b reference line B 21 c reference line C 100 reference card 111a, 111b, 111c Cards to be inspected

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasutaka Fujii 1-1-1 Ichigaya-Kagacho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 2C005 HA30 LA09 LB34 LB44 5B057 AA02 BA12 CH20 DA03 DA07 DA08 DB02 DB09 DC34 5B064 AA05 AB02 BA01 CA07 DA02 DA19 DB07 DC10 DC25 DC35

Claims (4)

[Claims] 1. A card inspection apparatus comprising a transporting unit, an arrival detecting unit, a position detecting unit, an image capturing unit, an image position shift amount calculating unit, and a pass / fail determining unit, wherein the transporting unit removes a card. The arrival detecting means detects that the leading side in the direction perpendicular to the carrying direction of the card has reached a predetermined position and outputs a leading side detection signal, and the position detecting means outputs the leading side detecting signal. As a detection start reference signal, an interval between a side line in a direction parallel to the transport direction of the card and a reference line is detected, and the imaging unit images the card by using the leading edge detection signal as a detection start reference signal. The image misregistration amount calculation means stores the captured image of the reference card as a reference image, inputs the captured image of the card to be inspected as an inspection target image, and Calculating the amount of misalignment between the picture of the card to be inspected and the picture of the card in the image to be inspected, and the pass / fail determination means determines that the picture on the card is at an appropriate position based on the distance and the misalignment. A card inspection device for determining whether or not the card is present. 2. The card inspection device according to claim 1, wherein
The image position shift amount calculating means changes the relative position of the picture portion of the card in the reference image and the inspection target image with reference to the detection position, calculates an evaluation value of the degree of coincidence, and gives the maximum degree of coincidence. A card inspection apparatus for performing a calculation using a difference between the detected position and the relative position in an evaluation value as a positional deviation amount. 3. The card inspection device according to claim 1, wherein a line sensor camera as said imaging means,
A conveyance amount detection unit, wherein the conveyance amount detection unit detects the conveyance amount of the conveyance unit, and the line sensor camera uses the leading edge detection signal as a detection start reference signal and synchronizes with the conveyance amount. do it,
A card inspection apparatus, wherein the card is imaged by a main scan by the imaging means itself and a sub-scan by conveyance in a direction perpendicular to the conveying direction of the card to generate a picked-up image. 4. The card inspection apparatus according to claim 1, wherein said image position shift amount calculating means calculates a position shift between a reference image and an inspection target image.
A card inspection apparatus, wherein the card inspection apparatus is a printed pattern inspection apparatus that corrects the positional deviation, compares the reference image and the inspection target image on a pixel basis, and inspects a pattern.