JP2010214521A - Device and method for detecting cutting failure in bookbinding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for more exactly detecting a cutting defective of a printed book by using a CCD camera. <P>SOLUTION: This cutting failure detection device 1 includes a translucent conveying belt 3 for delivering the printed book to be inspected, a light source 5 installed on a lower side of the translucent conveying belt 3 and the CCD camera 7 installed on an upper side of the translucent conveying belt 3. The CCD camera 7 photographs the shadow of the printed book formed by light applied from the light source 5 through the translucent conveying belt 3. The photographed image is distinctly divided into two of a part of the shadow of the printed book (a black part) and a part where the surrounding translucent conveying belt 3 is irradiated with light (a white part). By determining a contour of the shadow part, the cutting failure of the printed book can be decided. Two mirrors 9A and 9B are interposed between the light source 5 and the CCD camera 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for detecting a cutting failure of a printing book in a bookbinding machine.

  As an apparatus for detecting a cutting failure of a printing book, an apparatus for conveying a printing book on a conveyor and detecting the cutting defect using a plurality of detection devices including light sources and photoelectric sensors arranged above and below the conveyor is disclosed. (For example, refer to Patent Document 1). The detection device is arranged in series and in parallel in the transport direction at a predetermined position on the transport path, and detects a finishing width of a predetermined portion of the booklet transported by the conveyor. For this reason, when a defect has occurred in a portion where no detection device is installed, detection is impossible.

  It is also conceivable that the printing book is photographed by a photographing device such as a CCD camera and a cutting defect is detected from the image. In this case, the printing book is irradiated with illumination installed above the printing book, and the printing book is similarly photographed by an imaging device installed above the printing book. In this case, when the image is processed, there is a possibility that the outline of the printing book cannot be accurately detected depending on the color or pattern of the printing book. In addition, when the distance between the photographing apparatus and the book is long, the apparatus becomes tall.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus and method for more accurately detecting a cutting failure of a printing book using a CCD camera. It is another object of the present invention to provide a cutting defect detection device that can be configured so that the height of the device is not increased even when the distance between the CCD camera and the printing book is long.

  The cutting defect detection device in the bookbinding machine of the present invention comprises: a translucent transport belt that sends a printed book to be inspected; a light source installed below the translucent transport belt; and above the translucent transport belt. A camera that photographs the shadow of the printing book formed by light irradiated from the light source through the translucent transport belt, and processes the image captured by the camera to improve the quality of the printing book. It is characterized by comprising: a judging means for judging a defect; and a means for separating the booklet judged to be good or bad by the judging means.

  When a printed book to be inspected is projected from a light source and its shadow is photographed by a CCD camera, the captured image has light on the shadow part (black part) that is the object to be inspected and the translucent belt around it. It is clearly divided into two parts: the irradiated part (white part). Then, by determining the contour of the shadow portion, it is possible to determine the cutting failure of the printing book that is the inspection object. In this way, by photographing the shadow of the printing book, the contour can be detected more accurately without being bound by the color or pattern of the printing book. In addition, since the entire outline of the book can be detected as compared with the case where a detection device including a light source and a photoelectric sensor is used, it is possible to more accurately determine a cutting defect.

  In this invention, it is preferable to provide the mirror which folds an optical path between the said light source and a camera.

  When the distance (light path) between the light source and the camera is long, it is necessary to dispose the camera away from the light source, which increases the height of the apparatus. Therefore, by arranging a mirror in the optical path and folding the optical path, the camera can be installed in the vicinity of the light source or the booklet, so that the apparatus does not become tall.

  In this case, as the mirror, a first mirror that reflects light emitted from the light source obliquely downward, and a second mirror that reflects the image reflected by the first mirror and projects it onto the camera. , And can have.

  In the present invention, it is preferable to further include a moving rope for pressing the upper surface of the printing book conveyed by the translucent belt.

  If the thickness of the book is thick, the page at the top of the book may open, or the focal position of the camera may be shifted by the thickness, and an accurate contour may not be captured. Therefore, an accurate contour can be photographed by closing the upper surface of the printing book with a rope.

  In the bookbinding machine according to the present invention, the cutting failure detection method includes placing a printed book to be inspected on a translucent transport belt, and directing the printed book from the light source installed below the translucent transport belt to the print book through the translucent belt. Irradiating light, photographing the shadow of the booklet formed with the light with a camera, processing the shadow image of the booklet photographed with the camera, judging the quality of the booklet, The printing book judged to be good or bad by the means is sorted out.

  As is clear from the above description, according to the present invention, since the printing book is projected from the light source and the shadow is photographed by the CCD camera, the captured image is the shadow part (black part) of the printing book. The light-transmitting belt around it is clearly divided into two parts (white part) irradiated with light. Then, since the outline of the shadow portion is obtained to determine the cutting failure of the printing book, the outline can be detected without being bound by the color or pattern of the cover of the printing book. In addition, since the entire outline of the printing book can be detected, it is possible to determine the cutting failure more accurately. Furthermore, if a plurality of mirrors are interposed between the light source and the camera, the height of the apparatus can be suppressed.

It is a figure which illustrates typically the structure of the cutting defect detection apparatus which concerns on embodiment of this invention, FIG. 1 (A) is a side view, FIG.1 (B) is a top view. It is a figure explaining arrangement | positioning of the camera and mirror of a cutting defect detection apparatus. It is a figure explaining an example of the image processing method in a cutting defect detection apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
With reference to FIG. 1, the structure of the cutting defect detection apparatus according to the embodiment of the present invention will be described.
The cutting failure detection apparatus 1 is installed on the downstream side of a cutting machine that cuts three sides of a printing book. The printed book is sent from the cutting machine to the cutting defect detection device with the back (the outer portion of the fold) first. As shown in FIG. 1A, the cutting defect detection device 1 includes a translucent transport belt 3 for sending a printed book to be inspected, a light source 5 installed below the translucent transport belt 3, and a translucent transport belt. The camera 7 installed above the optical conveyance belt 3 and a plurality (two in this example) of mirrors 9A and 9B disposed between the light source 5 and the camera 7 are provided. Furthermore, a control means 11 for processing an image picked up by the CCD camera 7 and determining the quality of the printed book from the picked up image is provided.

The translucent conveying belt 3 is an endless sheet-like belt, and is arranged between a roller 15 arranged upstream in the conveying direction (indicated by an arrow in FIG. 1A) and a driving roller 16 arranged downstream. It is wound around. The translucent transport belt 3 is made of a material (for example, polyester canvas) that can transmit light emitted from the light source 5 and can hold the printing book without slipping. The driving roller 16 is connected to a motor (not shown), and when the roller 16 is driven by the motor, the belt 3 rotates in the counterclockwise direction of FIG. The track on the upper side of the rotation track of the belt 5 serves as a transport path for the printing book. The rotation speed and rotation angle of the rotation shaft of the drive roller 16 are detected by a rotary encoder (not shown). The output of the rotary encoder is input to the control means 11.
A tension roller 17 is disposed between the rollers 15 and 16 so that the belt 3 is tensioned.

  A sensor 19 is attached to the most upstream portion of the transport path to detect that the book has entered the transport path. A signal detected by the sensor 19 is input to the control means 11.

  The light source 5 can use a plurality of white LED lights that are long in the transport direction and are housed in a light box. As shown in FIG. 1B, the light source 5 has a size that is slightly larger than the printing book S, and irradiates the printing book S uniformly. The light source 5 is disposed inside the conveyance belt 3 wound between the rollers 15 and 16, that is, below the conveyance path through which the printing book is conveyed.

  The CCD camera 7 is disposed on the opposite side of the light source 5 across a transport path for transporting the printing book. Specifically, the CCD camera 7 is arranged at the most upstream portion (above the roller 15) of the transport path with the light receiving surface facing the transport path downstream. As the CCD camera 7, for example, CV-S200C (trade name, manufactured by Keyence Corporation) can be used. The CCD camera 7 releases the shutter when the booklet transported along the transport path enters the field of view. The CCD camera 7 captures an image of the shadow of the printing book irradiated with light transmitted from the light source 5 through the conveyor belt 3.

  The captured image is sent to the control means 11. The control means 11 is provided with means for processing an image and determining a cutting book cutting failure. The captured image is clearly divided into two parts: a shadowed part (black part) of the printing book S and a part around the printing book S irradiated with light (white part). It is done. Then, by determining the outline of the shadow portion, the cutting failure of the printing book as the inspection object is determined (an example of an image processing method will be described later).

Between the light source 5 and the CCD camera 7, two mirrors 9A and 9B are arranged.
As shown in FIG. 2, the first mirror 9A is disposed above the light source 5 and reflects light emitted from the light source 5 obliquely downward toward the downstream side in the transport direction. In this example, the angle θA between the reflecting surface of the mirror 9A and the horizontal plane is 30 °.
The second mirror 9 </ b> B is disposed in the opposite direction (downstream side) to the camera 7, and causes the light reflected by the first mirror 9 </ b> A to enter the light receiving surface of the camera 7. In this example, the angle θB between the reflecting surface of the mirror 9B and the horizontal plane is 105 °.

  When not using a mirror, it is necessary to install the CCD camera above the light source by the length of the optical path. By using two mirrors in the optical path, the light source and the camera can be connected without changing the length of the optical path. It can be placed in a close position and the back of the device can be kept low. In this example, the length of the optical path from the light source 5 to the light receiving surface of the CCD camera 7 is 1130 mm, of which the length of the optical path from the light source 5 to the first mirror 9A is 370 mm, from the first mirror 9A to the first mirror 9A. The length of the optical path to the second mirror 9B is 296 mm, and the length of the optical path from the second mirror 9B to the light receiving surface of the CCD camera 7 is 464 mm. In this example, a printing book having a length T in the transport direction of about 400 mm can be inspected.

  A description will be given with reference to FIG. 1 again. On the exit side of the transport path, a lever 21 for discharging a defective book and a tray 23 for receiving the discharged defective book are arranged. As shown in FIG. 1B, the discharge lever 21 has a plurality of claw members fixed on an axis extending in a direction orthogonal to the transport direction. The lever 21 rotates between a conveyance position where the claw member extends on the conveyance path and a discharge position where the claw member extends upward from the conveyance path. The rotation of this shaft is controlled by the control means 11. The tray 23 is disposed below the defective book exclusion lever 21. When the lever 21 is rotated to the discharge position, the printing book transported on the transport belt 3 hits the claw member, is guided downward by the lower surface of the claw member, and falls onto the tray 23.

  Further, the cutting defect detection device 1 is provided with a presser rope 25 disposed above the conveyance path. The presser rope 25 is composed of a plurality of (for example, two) ropes arranged away from each other in a direction orthogonal to the conveying direction. Each rope is composed of a roller 26 arranged upstream in the conveying direction and a roller arranged downstream. 27 is wound around. The presser rope 25 presses the upper surface of the booklet transported along the transport path. The clearance between the lower track of the presser rope 25 and the upper track of the translucent transport belt 5 can be adjusted according to the thickness of the printing book.

Next, the operation of the cutting failure detection apparatus 1 will be described.
First, the sensor 19 detects that the book to be inspected has entered the transport path, and a signal from the sensor 19 is input to the control means 11. Then, the control means 11 counts the pulses output from the rotary encoder provided on the driving roller 16 of the conveying belt 5 and releases the shutter of the CCD camera 7 at the timing when the printing book enters the field of view of the CCD camera 7. Take a picture of the shadow. Then, the captured image is subjected to image processing to determine whether the book is good or bad.

An example of the image processing means will be described with reference to FIG.
First, the visual field of the CCD camera 7 is converted into pixel coordinates. In this example, 1000000 pixels are arranged in a matrix of 1024 (X1) × 960 (Y1). Then, the shadow image of the printing book is projected onto the coordinates. On the coordinates, a binarized image of a shadow image A of the printing book and an image B of a portion where light is applied to the surrounding translucent belt is projected. Then, the upper left corner coordinates (x1, y1), the upper right corner coordinates (x2, y2), the lower left corner coordinates (x3, y3), and the lower right corner coordinates (x4, y4) of the image A of the shadow of the book are printed. Ask. For example, CV-3000 (trade name, manufactured by Keyence Corporation) can be used as software for image processing / cutting defect determination.

  From these coordinates, the length a of the top and bottom sides of the shadow image A of the booklet, the length b of the top and bottom sides, the length c of the left side of the fore edge, the length d of the right side of the fore side, and the angle between the top side and the left side of the fore edge θ1, the angle θ2 between the ceiling and the right edge of the forehead, the angle θ3 between the ceiling and the left side of the forehead, and the angle θ4 between the ceiling and the right side of the edge of the foreground are obtained. Then, it is determined whether or not these values satisfy a predetermined value.

  If it is determined to be good, the printed book is sent from the cutting defect inspection apparatus 1 to the subsequent process as it is. On the other hand, if it is determined as defective, the discharge lever 21 is rotated to discharge the defective book onto the tray 23.

DESCRIPTION OF SYMBOLS 1 Cutting defect detection apparatus 3 Translucent belt 5 Light source 7 CCD camera 9 Mirror 11 Control means 15 Roller 16 Drive roller 17 Tension roller 19 Sensor 21 Discharge lever 23 Tray 25 Holding rope 26, 27 Roller

JP 2004-322286 A

Claims (5)

A translucent transport belt for sending the book to be inspected;
A light source installed below the translucent transport belt;
A camera that is installed above the translucent transport belt and shoots the shadow of the printing book formed by light irradiated from the light source through the translucent transport belt;
Determination means for processing the image photographed by the camera to determine whether the book is good or bad;
Means for separating the booklet judged to be good or bad by the judging means;
A cutting failure detection apparatus in a bookbinding machine, comprising:   The cutting failure detection apparatus for a bookbinding machine according to claim 1, further comprising a mirror that folds an optical path between the light source and the camera.   The mirror includes a first mirror that reflects light emitted from the light source obliquely downward, and a second mirror that reflects an image reflected by the first mirror and projects the image onto the camera. The cutting defect detection device for a bookbinding machine according to claim 2, wherein:   The cutting failure detection device for a bookbinding machine according to any one of claims 1, 2, and 3, further comprising a moving rope that presses an upper surface of a printing book conveyed by the translucent belt. Place the book to be inspected on the translucent conveyor belt,
From the light source installed under the translucent transport belt, irradiate light toward the printing book through the translucent belt,
The shadow of the booklet formed with the light is photographed with a camera,
Processing the shadow image of the booklet taken with the camera to determine the quality of the booklet;
A method of detecting a cutting failure in a bookbinding machine, wherein the booklet determined to be good or not by the determining means is sorted.

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