JP2006001079A - Printed matter inspecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed matter inspecting device which suppresses fluttering of a sheet on the occasion when the image of the printed matter is photographed for inspection of the printed matter. <P>SOLUTION: A photographing means for photographing the image of the surface to be inspected of the printed matter is provided. Besides, a first blowing means 4 which blows air against the position of inspection to be photographed, obliquely from above the front in the direction of conveyance, a second blowing means 5 which blows the air against the position obliquely from above the rear in the direction of conveyance and an air intake means 6 which takes in at least the air discharged from the first blowing means 4 and the second blowing means 5, from above the position of inspection between the two blowing means, are disposed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printed matter inspection apparatus that takes an image of a printed matter printed on a sheet by a photographing means and inspects the printed matter in-line.

  Conventionally, an image of a printed material that has been printed in the final unit of sheet-fed printing is taken and it is determined whether or not the image is printed normally without being smudged or chipped. When shooting images of printed matter, take pictures of the printed matter transported on the thick cylinder of the final printing unit or on the chain conveyance path provided between the thick cylinder of the final printing unit and the paper discharge unit. There are times when you want to.

  As described above, when performing an inspection based on an image of a printed material to be inspected, it is necessary to accurately photograph the image of the printed material. However, when photographing a printed material on a thick cylinder, the sheet is a thick cylinder and rubber. When the sheet is sandwiched between the cylinders, the sheet is in close contact with the thick cylinder. The part became free and fluttered, and it was not possible to take an accurate image away from the thick drum.

  Therefore, air is blown from the front to the back in the transport direction on the sheet on the thick cylinder so that the sheet is brought into close contact with the thick cylinder.

In addition, when taking a sheet image on the chain conveyance path between the thick cylinder of the final printing unit and the paper discharge unit, a straight line that is substantially horizontal and longer than the length of the sheet conveyance direction is formed. The sheet was photographed at the position (see, for example, Patent Document 1).
JP-A-10-166557

  However, when air is blown from the front in the transport direction onto a sheet transported on the thick cylinder, when the paper is thick, the air may not be completely adhered to the thick cylinder even if the air is blown strongly. Further, in the case of a paper having a relatively thin paper thickness, lift of the paper is generated by the flow of air blown on the paper, or the air passing through the upper surface of the paper hits the rubber cylinder, and this rubber For example, the air flowing in from the cylinder may enter between the paper and the thick cylinder, and it may not be possible to suppress the fluttering of the trailing edge of the paper, and in particular, an accurate image of the trailing edge may not be taken. It was.

  Further, when photographing a sheet on a horizontal conveyance path, the cost of an inspection apparatus or the like is higher than when photographing a sheet on a thick cylinder. In addition, when printing at high speed, the moving speed of the sheet is also increased, so that even when moving on a horizontal conveyance path, the back end portion may flutter, and an accurate image is taken. There was a case that could not be done.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a printed matter inspection apparatus that suppresses fluttering of a sheet when photographing an image in order to inspect the printed matter.

The printed matter inspection apparatus according to the present invention is a printed matter inspection device that inspects a printed matter printed on a single sheet in-line, and includes an imaging unit that captures an image of a surface to be inspected of the printed matter, and for an inspection position to be captured. The first spraying means for blowing air from the front diagonally upward in the transport direction, the second spraying means for spraying air from the diagonally upward rearward in the transport direction, at least the first spraying means and the second spraying An air intake means for taking in air discharged from the means from above the inspection position sandwiched between both blowing means is provided.
Therefore, the printed matter can be pressed downward by the air blown from both the first spraying means and the second spraying means. Further, since the air blown from both of the blowing means is sucked from the intake means provided between the two blowing means, there is no flow of air in portions other than the inspection position. Fluttering caused by the blown air can be suppressed.

  The first spraying unit and the second spraying unit may each include a plurality of nozzles in the width direction of the printed matter, and spray uniform air in the width direction of the printed matter.

  In addition, the control means comprises control means for controlling the start and end of air blowing by the first blowing means and the start and end of air blowing by the second blowing means, respectively. The spraying may be terminated when a predetermined portion before the end of the printed material is conveyed to the inspection position so that air does not enter the lower surface of the printed material from the end of the printed material.

  In addition, a camera that constitutes the imaging unit is provided above the inspection position, an intake port that constitutes the intake unit is provided at a position between the inspection position and the camera, and between the inspection position and the camera. A photographing slit for securing an optical path may be provided in the intake port.

  Further, the photographing unit may photograph a printed material being conveyed on a cylinder for offset printing.

  Further, the photographing means has at least an illumination composed of a reflecting mirror whose cross-sectional shape viewed from the side surface in the width direction of the printed material has a shape lacking a part of an ellipse and a light source provided at one focus of the ellipse. The size of the inspection apparatus can be reduced by providing the part.

  The printed matter inspection apparatus according to the present invention as described above is capable of pressing the printed matter downward by the air blown from both the first spraying means and the second spraying means, suppressing the fluttering of the printed matter, and accurately You can shoot a good image. Further, since the air blown from both of the blowing means is sucked from the intake means provided between the two blowing means, air flow is not generated in portions other than the inspection position. It is possible to take an accurate image while suppressing the flutter caused by the blown air.

  In addition, since the first spraying means and the second spraying means are provided with a plurality of nozzles in the width direction of the printed matter, air can be blown almost uniformly in the width direction of the printed matter, and the printed matter It will be possible to ensure close contact.

  Further, the control means starts spraying when the printed material is conveyed, and ends spraying when a predetermined portion before the rear end of the printed material is conveyed to the inspection position. Since the spraying ends at a predetermined portion before the rear end portion, air does not enter the lower surface from the rear end of the printed matter, and the printed matter is kept in a state where fluttering is suppressed. An accurate image can be taken.

  In addition, by providing a camera above the inspection position in the transport direction, an accurate image of the printed matter can be taken, and an imaging slit for securing an optical path between the camera and the inspection position is provided at the intake port. Since it is provided, air can be sucked from almost right above the inspection position, and the installation space can be reduced.

  In addition, in the case of offset printing, since the printed material being transported on a cylinder such as a thick cylinder is photographed, the printed material inspection apparatus is less expensive than when photographing the printed material being transported on a horizontal transport path. Can be equipped with a printing press.

  In addition, an illumination unit is provided that includes a reflecting mirror whose cross-sectional shape as viewed from the side surface in the width direction of the printed material lacks a part of an ellipse, and a light source provided at one focal point of the ellipse. Therefore, the illumination effect in the vicinity of the inspection position can be enhanced by setting the vicinity of the focal point where the light source is not provided as the inspection position.

  An embodiment of a printed matter inspection apparatus according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the printed matter inspection apparatus is an apparatus that is provided in the printing machine 1 for sheet-fed printing and inspects the printed matter printed by the final printing unit 2 in the printing machine 1. This printed matter inspection apparatus includes a camera 3 constituting an imaging unit, a first spraying unit 4 that blows air from the front in the transport direction, and a rear back in the transport direction opposite to the first spraying unit 4. A second blowing means 5 for blowing air, an intake means 6 for sucking air discharged from the two blowing means 4 and 5, an illumination unit 7 (see FIG. 2) constituting the photographing means, and the two blowing means It is mainly configured by control means (not shown) for controlling the attaching means 4 and 5, and determination means (not shown) for determining the printing state based on the image taken by the camera 3.

As shown in FIG. 1, the printing machine 1 is an offset printing machine for a sheet, and prints a sheet fed from a sheet feeding unit (not shown) by a printing unit 2, and a chain transport unit 8. The ink transferred onto the sheet by the dryer 12 is dried and discharged from the paper discharge unit 9. In FIG. 1, only one printing unit 2 is provided. However, when printing is performed many times such as multicolor printing or double-sided printing, printing is performed by providing a plurality of printing units 2. The printing unit 2 is a printing unit that is generally used in offset printing. A rubber cylinder (also referred to as an offset cylinder or a rubber blanket) 10 that transfers ink to a sheet of paper, and a sheet of paper on the rubber cylinder 10. A thick cylinder 11, a plate cylinder (not shown), and the like are provided for conveying the paper and feeding the sheet onto which the ink has been transferred to the chain conveyance unit 8.
The chain transport unit 8 includes a dryer 12 that dries the ink printed by the printing unit 2. When the ink is an ultraviolet curable ink, the dryer 12 irradiates the printing surface with ultraviolet rays to fix the ink on the sheet.

In this embodiment, as shown in FIG. 1, an image of a sheet (printed material) 13 (see FIG. 3) transported on the thick cylinder 11 of the final printing unit 2 is taken with the camera 3 and accurately. Although it is determined whether or not printing has been performed, the position for photographing the sheet (printed material) 13 is not limited to the thick cylinder 11 of the final printing unit 2, but from the thick cylinder 11. For example, an image of a sheet 13 conveyed through the chain conveyance unit 8 may be taken to determine whether or not there is an abnormality in printing. May be. Further, the inspection may be performed by a printing unit other than the final printing unit 2. Especially in the case of double-sided printing, the unit 2 that prints one side (for example, the front side) of the printed material and the unit 2 that prints the other side (for example, the back side) can be inspected by two units. An inspection device is installed in each unit, and when it is transported to the paper discharge unit 9, both sides are inspected. In addition, as shown in FIG. 1, the position where the sheet (printed material) is photographed is not limited to the thick cylinder 11, but is on a cylinder (cylinder) such as a bran cylinder, a private cylinder, or an inverted cylinder. Also good. Note that it is desirable that the image to be taken be taken after the printing on the printing surface has been completed. However, when the surface of the printed material is coated, the image before the coating treatment is taken. The inspection may be performed based on the image.
In the present embodiment, paper is described as an example of printed matter. However, the present invention is not limited to this, and printing is performed with a sheet-fed printing machine such as a synthetic resin sheet or a metal plate. It covers everything you can.

As shown in FIG. 2, the printed matter inspection apparatus includes a camera 3 constituting the photographing unit above the inspection position A provided on the thick cylinder 11 and an illumination unit 7 that illuminates the vicinity of the inspection position A. I have.
Note that the upper side of the inspection position in the claims and the specification does not mean the upper side based on the vertical direction of the printing press 1, but the direction of the printed surface at the inspection position (from the surface to be inspected). (Outward direction). More specifically, as shown in FIG. 2, the direction is the camera 3 side from the inspected surface 13 a of the sheet (printed material) 13. For example, as shown in FIG. 2, when the inspection position A is on a cylinder such as the thick cylinder 11, the radially outward direction from the axis of the cylinder is above the inspection position. 1 has an inspection position, when the printed material is conveyed to the inspection position of the chain conveyance unit 8, the printed material is removed from the surface of the inspection position of the chain conveyance unit 8. The direction toward the camera 3 to be photographed is above the inspection position.

The camera 3 may shoot the entire inspection position A with one camera according to the length of the printed material in the width direction, but a plurality of cameras 3, ..., 3 are predetermined in the width direction. An interval may be provided so that the plurality of cameras 3 capture images for each fixed region, and the entire image in the width direction of the inspection position A may be captured. Then, based on the image data output from the camera 3, it is determined whether there is an abnormality in printing by a determination unit (not shown). In addition, since the said determination means uses the existing technique, it does not elaborate on in this specification.
The illumination unit 7 includes a light source such as a fluorescent lamp or a light emitting diode, and illuminates at least the inspection position A.
In addition, the conveyance direction in this claim and a specification shows the direction in which printed matter is conveyed, as shown in FIG.2 and FIG.3 etc. FIG. Further, the front in the transport direction (forward in the transport direction) indicates a direction in which the transport is performed from now on, and the rear in the transport direction (rear in the transport direction) indicates the direction in which the transport has already been performed. Further, the width direction of the printed material indicates a direction perpendicular to the transport direction.

As shown in FIGS. 2 and 3, the first spraying means 4 is a means for blowing air from the front (transport direction) obliquely upward in the transport direction of the sheet 13 to the vicinity of the inspection position B. A plurality of first blowing nozzles 4 a are provided at substantially equal intervals in the width direction of the paper 13. And the compressed air is blown out from this 1st blowing nozzle 4a.
By controlling the flow rate of air blown from each first blowing nozzle 4a to almost the same flow rate in all nozzles 4a, air is blown almost uniformly in the width direction of the sheet 13, and the sheet 13 is The thick cylinder 11 can be brought into close contact. Depending on the type of the sheet 13, the flow rate of air blown near the center in the width direction may be increased, or the flow rate of air blown near the width direction end of the sheet 13 may be increased. . Further, as shown in FIG. 3, the first blowing nozzles 4a,..., 4a may be provided so as to have substantially the same length as the width direction of the sheet 13, but the length of the sheet 13 in the width direction. You may provide the 1st blowing nozzle 4a longer than this.

As shown in FIGS. 2 and 3, the second spraying means 5 is a means for spraying air from the rear side in the transport direction of the sheet 13 (the transport source direction) obliquely upward to the vicinity of the inspection position C. A plurality of second blowing nozzles 5 a are provided at substantially equal intervals in the width direction of the leaf paper 13. And the compressed air is blown out from this 2nd blowing nozzle 5a.
By controlling the flow rate of air blown from each second blowing nozzle 5a to almost the same flow rate in all the nozzles 5a, air is blown almost uniformly in the width direction of the sheet 13, and the sheet 13 is The thick cylinder 11 can be brought into close contact. Depending on the type of the sheet 13, the flow rate of air blown near the center in the width direction may be increased, or the flow rate of air blown near the width direction end of the sheet 13 may be increased. . As shown in FIG. 3, the second blowout nozzles 5a,..., 5a may be provided so as to have substantially the same length as the width direction of the sheet 13, but the length of the sheet 13 in the width direction. You may provide many 2nd blowing nozzles 5a so that it may become longer than this.

  The intake means 6 is means for sucking air blown from the first spray means 4 and the second spray means 5, and as shown in FIG. 2, the first spray means 4 and the first spray means 4. The two spraying means 5 are sandwiched and arranged. Further, the air sucked by the air intake means 6 is passed through an air filter (not shown) to remove dust and the like, and is moved from the first blowing means 4 and the second blowing means 5 to the vicinity of the inspection positions B and C. You may spray. When the intake means 6 is disposed at a position between the inspection position A and the camera 3, an optical path between the inspection position A and the camera 3 is ensured at the intake port 6 a constituting the intake means 6. A photographing slit 15 is provided. That is, the camera 3 can take an image of the inspection position A through the photographing slit 15 and can be provided with the intake means 6 at a position sandwiched between the first blowing means 4 and the second blowing means 5. The air blown from the blowing means can be efficiently sucked. Further, the intake means 6 and the camera 3 can be provided above the inspection position A, and these devices (means) can be installed even in a small space.

  Further, when the printing press 1 is provided with a control means (not shown) for controlling the start and end of the spraying from the first spraying means 4 and the second spraying means 5, the control signal of the control means Based on the above, both spraying means 4 and 5 are controlled. The control means includes a rotation speed of the thick cylinder 11 serving as an inspection position, a position of a gripper (not shown) provided on the thick cylinder 11 and sandwiching the front end (front end in the transport direction) of the sheet 13, and the sheet 13 Based on information such as the length in the transport direction, a calculation process is performed to control the start and end of spraying. As shown in FIG. 2, the control means is configured to move a predetermined portion from the front end of the conveyed sheet 13 to the inspection position A before the position where the spraying of the sheet 13 is finished. The spraying is started, and the spraying is terminated when the predetermined part before the rear end (the rear end in the transport direction) of the sheet 13 moves to the inspection position A from the predetermined part where the spraying is started.

  FIG. 4 (a) is a graph showing the relationship between the amount of air blown from the first blowing nozzle 4a of the first blowing means 4 and the time, and point D is the front end of the sheet 13. The time taken for the inspection position A is shown. The point E indicates the time when the substantially central portion of the sheet 13 in the conveying direction is conveyed to the inspection position A, and the point G indicates the time when the rear end of the sheet 13 is conveyed to the inspection position A. H point indicates the time when the front end of the sheet 13 to be inspected next to the sheet 13 is conveyed to the inspection position A. That is, the first blowing means 4 (first blowing nozzle 4a) does not blow air between the front end and the central portion of the sheet 13 in this way (does not blow), and from the central portion to the rear end. No air is blown out (blow) between the rear end and the front end of the next sheet 13 from the rear end.

  FIG. 4B is a graph showing the relationship between the amount of air blown from the second blowing nozzle 5a of the second blowing means 5 and the time, and the point D is the front end of the sheet 13. The time taken for the inspection position A is shown. Point E indicates the time when the substantially central portion of the sheet 13 in the transport direction is transported to the inspection position A, and point F indicates a predetermined portion (for example, the rear side) before the rear end of the sheet 13. The position 40 mm before the edge) indicates the time when the sheet 13 is conveyed to the inspection position A, and the point H indicates the time when the front edge of the sheet 13 to be inspected next to the sheet 13 is conveyed to the inspection position A. Show. That is, the second blowing means 5 (second blowing nozzle 5a) does not blow air between the front end and the central portion of the sheet 13 in this way (does not blow), and from the central portion to the rear end. No air is blown out (blow) between the rear end and the front end of the next sheet 13 from the rear end.

In the graphs shown in FIGS. 4A and 4B, control is performed to start blowing (spraying) when a substantially central portion in the transport direction of the sheet 13 is transported to the inspection position A. , It may be controlled to start blowing (spraying) when the front end side (gripper side) portion of the sheet is conveyed to the inspection position A from the central portion, or the sheet You may control to start blowing (spraying), when the part of the rear end side (opposite side of a gripper) is conveyed to the test position A.
Further, the first spraying means 4 is controlled so as to end the blowing (spraying) when the rear end portion of the sheet 13 is conveyed to the inspection position A, but before the rear end portion. It may be controlled to end the blowing (blowing) at a predetermined position on the side (front end side). On the other hand, the second spraying means 5 may be controlled so as to finish the blowing (blowing) earlier than the blowing (blowing) of the first spraying means 4 is finished.

Depending on the installation position of the intake port 6a, the flow rate of the air blown (blown) from the first blowing means 4 and the angle (direction) of the blowing to the inspection position B, from the second blowing means 5 The flow rate of the blown out (blowing) air and the angle (direction) of the blowing to the inspection position C are set as appropriate. In addition, the flow rate of the blown (sprayed) air, the spray start position, the spray end position, and the like are set according to the type (thickness, size, material, etc.) of the sheet 13 (printed material).
The intake means 6 always inhales without controlling the start and end of the blowing (blowing) as in the first blowing means 4 and the second blowing means 5, but by the control means The start and end of intake may be controlled. The air intake amount of the intake means 6 may be substantially the same as the total amount of air blown by the two blowing means 4 and 5, or may be smaller than that, and the printed matter (sheets) It is set appropriately depending on the type (thickness, size, material, etc.) of the paper 13).

  As shown in FIG. 2, the two spraying means 4 and 5 and the intake means 6 are arranged, and as shown in FIGS. 4 (a) and 4 (b), by controlling the air blowing (blowing), As shown in FIG. 3, the sheet 13 in the region shown from the inspection position B to the inspection position C is pressed from above and is in close contact with the thick cylinder 11. Further, since the two spraying means 4 and 5 spray air from the front and the rear in the transport direction, most of the air hitting the sheet 13 is above the inspection position (normal line 14 of the inspection position A). The air flowing in the width direction of the sheet 13 and flowing upward in the normal line 14 is sucked from the intake port 6a. Therefore, the air hitting the rubber cylinder 10 does not enter between the sheet 13 and the thick cylinder 11, and the back end of the sheet 13 can be prevented from fluttering. Further, the timing at which the second spraying means 5 finishes the spraying ends earlier than the timing at which the first spraying means 4 finishes the spraying. No air is blown between the rear end of 13 and the thick drum 11, and fluttering can be suppressed.

  Next, as shown in FIG. 5 and FIG. 6, the reflecting mirror in which the cross-sectional shape viewed from the side surface in the width direction of the printed material (sheet) 13 conveyed on the thick cylinder 11 lacks a part of an ellipse. The photographing means provided with an illuminating section composed of at least 16 and an internal light source 17 provided at one of the elliptical focal points 16a will be described.

  The reflecting mirror 16 is a concave mirror having a cross-sectional shape viewed from the side in the conveying direction and lacking a part of an ellipse, and is a glass concave mirror whose outer surface is subjected to silver plating. The concave mirror made of synthetic resin may be used, or a metal whose reflecting surface is mirror-polished may be used. As shown in FIGS. 5 and 6, the reflecting mirror 16 has an open lower end surface (lower end side) facing the surface 13 a to be inspected of the sheet 13. Although the ellipse has two focal points, the first focal point 16b existing on the side close to the thick cylinder 11 of the reflecting mirror 16, which is one of the focal points, is a sheet 13 conveyed on the thick cylinder 11. The reflecting mirror 16 is disposed so as to be located on the surface 13a to be inspected, and the internal light source 17 is disposed at the second focal point 16a that is the other focal point. The internal light source 17 is a linear or rod-shaped light source, and for example, a white diode arranged in a line, a halogen bulb, a fluorescent lamp, or the like can be used. A white diode arranged in a row is convenient as a point light source, and a fluorescent lamp is low-cost, has a wide spectral distribution of the light source, and is suitable for inspection of a multicolor print. In this embodiment, a fluorescent lamp is used as the internal light source 17. The internal light source 17 extends in the width direction of the sheet 13 and is disposed so as to be parallel to the surface to be inspected 13 a of the sheet 13. In the reflecting mirror 16 having the structure as described above, as shown in FIGS. 5 and 6, all the light emitted from the internal light source 17 and reflected by the reflecting mirror 16 is on the surface to be inspected 13 a of the sheet 13. The first focal point 16b can be focused and the inspection position can be efficiently illuminated.

As shown in FIG. 5, the photographing slit 18 for securing the optical path between the surface to be inspected 13 a (inspection position A) and the camera 3 extends in the width direction of the sheet 13 like the internal light source 17. , An opening provided in the reflecting mirror 16 so as to be parallel to the internal light source 17. In addition, a transparent member 21 for securing an optical path between the surface 13a to be inspected and the camera 3 is also provided in the intake portion 6c along the width direction of the sheet 13 like the photographing slit. The photographing slit 18 has an opening in the reflecting mirror 16, and as will be described later, the air blown to the sheet 13 by the first spraying means 4 and the second spraying means 5 causes the photographing slit 18 to pass through. The air is sucked into the intake nozzle 6b. The transparent member 21 is a transparent member made of glass, synthetic resin or the like.
Further, as shown in FIG. 5, a portion from the lower portion of the photographing slit 18 to the top of the reflecting mirror 16 is provided in the intake portion 6c so that air can be sucked from the photographing slit 18.

  The intake means 6 shown in FIG. 5 sucks air blown from both the first blowing means 4 and the second blowing means 5 inside the reflecting mirror 16 and passes the air through the photographing slit 18. Since the air intake nozzle 6b is passed from the air intake portion 6c, the sheet 13 can be pressed onto the thick drum 11 by the air blown from both the blowing means 4 and 5. . Further, the air that pressed the sheet 13 collides in the vicinity of the inspection position A, and the bumped air is sucked up almost in the vicinity of the inspection position A and passes through the photographing slit 18 from the inside of the reflecting mirror 16. It is possible to suppress the flutter caused by the blown air without generating an air flow other than the portion at the inspection position. Further, the inspection position efficiently illuminates the inspection position by collecting light emitted from the internal light source 17. The printed matter at the illuminated inspection position can be photographed through the photographing slit 18 and the transparent member 21. In addition, since the reflecting mirror 16 constituting the illumination unit is also a part of the intake means 6, the inspection apparatus can be made compact.

  Further, in the inspection apparatus as shown in FIG. 6, the reflecting mirror 16 includes a flat transparent member 19 at the opening on the lower end surface (lower end side) facing the surface 13 a to be inspected of the sheet 13. The transparent member 19 prevents air from entering the reflecting mirror 16. Further, in order to ensure an optical path between the inspection position A and the camera 3, the optical path securing portion 20 of the reflecting mirror 16 positioned on the optical path is configured to be transparent. The optical path securing unit 20 may be configured by integrating a transparent member with the reflecting mirror 16 lacking the optical path securing unit 20 by bonding or the like. Further, when the reflecting mirror 16 is provided with a reflective material such as silver plating on the surface of transparent glass or synthetic resin, the optical path securing unit 20 is not provided with a reflective material such as silver plating on the optical path securing unit 20. May be configured to be transparent. The transparent member 19 and the optical path securing unit 20 are transparent members made of glass, synthetic resin, or the like, and prevent air from entering the reflecting mirror 16. In addition, an outside of the reflecting mirror 16 is provided with an intake portion 6c for sucking air blown from the first blowing means 4 and the second blowing means 5, and the air flows along the outside of the reflecting mirror 16. The entire reflecting mirror 16 is provided inside the air intake portion 6c so that it can be sucked. Further, in order to secure an optical path between the inspection position A and the camera 3, a transparent member 21 is provided in the intake section 6c located on the optical path. That is, when the camera 3 captures an image at the inspection position A, light from the inspection position A (near the inspection position A) passes through the transparent member 19, the optical path securing unit 20, and the transparent member 21 and reaches the camera 3. , Images can be taken.

  Further, as described above, the reflecting mirror 16 shown in FIG. 6 includes the internal light source 17 at the second focal point 16a existing on the side far from the thick cylinder 11, and the second focal point 16a at which the internal light source 17 is located. A straight line connecting the first focal point 16b and the other first focal point 16b conveys the sheet 13 with respect to a normal line (hereinafter simply referred to as a normal line) 14 with respect to the surface 13a to be inspected at the first focal point 16b (inspection position A). Tilt forward in the direction. That is, the second focal point 16 a of the reflecting mirror 16 where the internal light source 17 is located is located closer to the front in the transport direction than the normal line 14. An optical path securing unit 20 extending in the width direction of the sheet 13 and parallel to the internal light source 17 is provided near the top of the reflecting mirror 16 and behind the normal line 14 in the transport direction. In addition, a camera 3 is provided above the outside of the reflecting mirror 16 and behind the normal line 14 in the transport direction. The camera 3 is provided on the transparent member 21 and the reflecting mirror 16 provided in the intake portion 6c. The first focal point 16b on the surface 13a to be inspected of the sheet 13 can be seen through the optical path securing part 20 and the transparent member 19 provided in the opening at the lower end of the reflecting mirror 16. The camera 3 also has an angle (J in FIG. 6) between the normal 14 and the straight line from the second focal point 16a where the internal light source 17 located in front of the normal line 14 is located to the first focal point 16b. And the angle (K in FIG. 6) formed by the normal line 14 and the line of sight of the camera 3 that is located behind the normal line 14 and that looks through the first focal point 16b. Yes. Therefore, as shown in FIG. 6, the camera 3 reflects regular radiated light from the internal light source 17 toward the first focal point 16b so that the incident angle and the reflection angle with respect to the normal line 14 are equal. Can be captured. Further, the camera 3 can also capture irregularly reflected light at the first focal point 16b on the surface 13a to be inspected of the sheet 13.

  As shown in FIG. 6, when air is sucked in from the outside without sucking air through the inside of the reflecting mirror, the sheet 13 sprayed by the two spraying means 4 and 5 is used. The transparent member 19 prevents dust such as dust and ink from entering the reflecting mirror 16. When dust such as dust or ink adheres to the transparent member 19, a clear image can be taken by wiping them off.

It is the schematic of the printing machine provided with the printed matter inspection apparatus. It is the schematic which looked at the printed matter inspection apparatus from the side. It is explanatory drawing which looked at the printed matter inspection apparatus from the upper part. (A) is the graph which showed the relationship between the blowing amount of the air which a 1st blowing nozzle blows, and its time, (b) showed the blowing amount of the air which a 2nd blowing nozzle blows, and the relationship between that time. It is a graph. It is sectional drawing of the printed matter inspection apparatus provided with the reflective mirror which makes the shape which lacks a part of ellipse. It is sectional drawing of the printed matter inspection apparatus provided with the reflective mirror which makes the shape which lacks a part of ellipse.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing machine 2 Printing unit 3 Camera 4 1st spraying means 4a 1st blowing nozzle 5 2nd blowing means 5
5a Second blowout nozzle 6 Air intake means 6a Air intake port 6b Air intake nozzle 6c Air intake part 7 Illumination part 8 Chain transport part 9 Paper discharge part 10 Rubber cylinder 11 Thick cylinder 12 Dryer 13 Sheet 13a Test surface 14 Normal 15 Photographing Slit 16 Reflector 16a Focus 16b Focus 17 Internal light source 18 Shooting slit 19 Transparent member 20 Optical path securing portion 21 Transparent member A Inspection position B Inspection position C Inspection position

Claims (6)

In a printed material inspection apparatus that inspects printed materials printed in sheets, in-line,
While providing a photographing means for photographing an image of the surface to be inspected of the printed matter,
A first spraying means for blowing air from an obliquely upper front in the conveying direction to the inspection position to be photographed;
A second spraying means for blowing air from a rear upper side in the transport direction;
A printed matter inspection apparatus comprising: at least air suction means for sucking air discharged from the first spraying means and the second spraying means from above the inspection position between the spraying means.   The printed matter inspection apparatus according to claim 1, wherein each of the first spraying unit and the second spraying unit includes a plurality of nozzles in a width direction of the printed matter. Control means for controlling the start and end of air blowing by the first blowing means and the start and end of air blowing by the second blowing means, respectively.
The printed matter inspection apparatus according to claim 1, wherein the control unit finishes the spraying when a predetermined portion before the end of the printed matter is conveyed to the inspection position.   A camera constituting the photographing means is provided above the inspection position, an air inlet constituting the air intake means is provided at a position between the inspection position and the camera, and an optical path between the inspection position and the camera is provided. The printed matter inspection apparatus according to claim 1, wherein a photographing slit for securing is provided in the intake port.   5. The printed matter inspection apparatus according to claim 1, wherein the photographing unit photographs a printed matter conveyed on a cylinder for offset printing. The photographing unit includes an illuminating unit including at least a reflecting mirror having a shape in which a cross-sectional shape viewed from the side surface in the width direction of the printed material lacks a part of an ellipse, and a light source provided at one focal point of the ellipse. The printed matter inspection apparatus according to claim 1, further comprising:

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