JP5761499B2 - Sheet-fed printed matter inspection device - Google Patents

Description

  The present invention relates to an apparatus for in-line inspection of printed matter printed on a sheet-fed printing machine such as an offset sheet-fed printing machine.

  The sheet-fed printing machine is provided with an inspection device for inspecting the print quality of the sheet-fed printed matter before the sheet-fed printed matter reaches the delivery unit. As shown in FIG. 5, the inspection by the inspection device is performed by irradiating illumination light from the illumination device 2 to the printing surface of the sheet-fed printed material a traveling in contact with the circumferential surface of the impression cylinder 1 of the final printing unit, and reflecting the light. The light is received as an image by the camera 3, and this image is subjected to pattern matching by the image processing unit.

  Further, if the printed sheet a during the inspection floats or flutters on the impression cylinder 1, the image taken by the camera 3 is distorted, and an accurate inspection cannot be performed. Air is blown onto the sheet printed material a so that the sheet printed material a is brought into close contact with the peripheral surface of the impression cylinder 1 (see, for example, Patent Documents 1 and 2).

JP 2010-137385 A JP 2004-136585 A

  As shown in FIG. 5, a step 6 is provided between the impression cylinder 1 and the delivery unit 5 of the final printing unit for the operator b of the printing press to perform various operations. The leaf printed material a is visible from the step 6 side. Therefore, conventionally, the camera 3 is attached to the cover 5 a of the delivery unit 5, and the optical path c of the reflected light from the sheet printed material a on the impression cylinder 1 toward the camera 3 is set so as to cross step 6. Step 6 is formed with a slit through which reflected light passes. However, when the optical path c is set in this way, for example, when the operator b goes up to step 6 to perform ink replenishment work, the reflected light is blocked by the body of the operator b, and during that time the sheet printed material a is not inspected. It is discharged to the delivery part 5 as it is. Alternatively, the inspection apparatus may determine that the printing is defective, and the good product may be determined as a defective product.

  Moreover, in the delivery part 5, powder is sprayed on the printing surface of the sheet printed matter a before stacking so that it may not show through when the discharged sheet printed matter a is stacked. There is also a problem that this powder adheres to an optical system such as the camera 3 and impairs an appropriate inspection.

  Accordingly, an object of the present invention is to provide a sheet-fed printed matter inspection apparatus that can solve the above-described problems.

  In order to solve the above problems, the present invention employs the following configuration.

  In addition, although the code | symbol with a parenthesis is attached | subjected in order to make an understanding of this invention easy, this invention is not limited to this.

That is, the invention according to claim 1 includes an air spraying means (16) for pressing the printed sheet (a) against the peripheral surface of the impression cylinder (11) adjacent to the delivery section (8) of the sheet-fed printing machine, and air spraying. Illuminating means (21) for irradiating the sheet printed matter (a) pressed against the peripheral surface of the impression cylinder (11) by the means (16), and the sheet printed matter (a) illuminated by the illuminating means (21) In the sheet-fed printed matter inspection apparatus, comprising: a camera (27) for picking up a picture of the image; and a print quality judgment unit (19) for judging the quality of printing from an image photographed by the camera (27). The reflected light from the printed sheet (a) on the impression cylinder (11) passes under the step (15) installed between the delivery part (8) and the impression cylinder (11). The above step (15) and the above delivery A reflecting mirror (22) for directing the reflected light to the back side of the cover (8a) of the delivery section (8) is disposed in the vicinity of the boundary between the cover (8a) of the section (8) and the camera ( 27) is arranged so as to receive the reflected light passing through the back side of the cover (8a) of the delivery part (8), and at least passes through the back side of the cover (8a) of the delivery part (8). The optical path (e) of the reflected light reaching (27) is covered with an optical duct (25), and the optical path (d) of the reflected light under the step (15) is covered with an optical duct (26). Adopt leaf print inspection device.

  As described in claim 2, in the printed sheet inspection apparatus according to claim 1, the reflecting mirror (22) may be covered with a protective member (23).

  As described in claim 3, in the sheet printed matter inspection apparatus according to claim 1 or 2, the reflecting mirror (22) can be a surface mirror.

  According to the present invention, the illumination means (21) is a step in which the reflected light from the printed sheet (a) on the impression cylinder (11) is installed between the delivery section (8) and the impression cylinder (11). (15) is arranged so as to pass under, and in the vicinity of the boundary between the step (15) and the cover (8a) of the delivery part (8), the reflected light is reflected behind the cover (8a) of the delivery part (8). Since the reflecting mirror (22) for directing to the camera is arranged, and the camera (27) is arranged to receive the reflected light passing through the back side of the cover (8a) of the delivery part (8), The optical path (d, e) is not blocked or disturbed by the operator (b) or the like riding on the step (15). Therefore, it is possible to inspect the print quality for the total number of printed sheets (a). Further, since the optical path (e) of the reflected light that passes through at least the back side of the cover (8a) of the delivery part (8) and reaches the camera (27) is covered with the optical duct (25), powder for preventing show-through or the like Crossing the optical path or adhering to the lens of the camera (27) can be prevented, and therefore the print quality can be accurately inspected.

It is the schematic of the rear part of the offset sheet-fed printing press provided with the sheet printed matter inspection apparatus which concerns on this invention. (A) is a front view of an air spraying device, and (B) is a sectional view taken along line BB in FIG. It is a front view which shows the location from a reflective mirror to a camera. It is a perspective view of the protection member in which the reflecting mirror was accommodated. It is the schematic of the rear part of the offset sheet-fed printing press provided with the conventional sheet-fed printed matter inspection apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a delivery unit 8 that discharges a printed sheet a that has been printed is installed next to the final printing unit 7 of the offset sheet-fed printing press.

  The final printing unit 7 is provided with a set of a plate cylinder 9, a blanket cylinder 10 and an impression cylinder 11 for printing with a predetermined color ink.

  The delivery unit 8 has a receiving cylinder 12 disposed so as to contact the impression cylinder 11. The endless chain 13 extends from the receiving cylinder 12 to a stacking portion (not shown) of the printed sheet a. When the printed sheet a passes between the blanket cylinder 10 and the impression cylinder 11, it is gripped on the receiving cylinder 12 by a gripping claw (not shown) attached to the endless chain 13 and conveyed to the stacking section.

  A powder spraying device 14 is provided in the middle of the endless chain 13 from the receiving drum 12 to the stacked portion. By spraying the powder from the powder spraying device 14 onto the printing surface of the sheet printed matter a, the ink show-through is prevented when the sheet printed matter a is stacked in the stacking portion.

  Further, covers 7a and 8a are vertically attached to the final printing unit 7 and the delivery unit 8, respectively, and a step 15 in which an operator b of the printing press rides is placed between the covers 7a and 8a. Step 15 is arranged horizontally near the impression cylinder 11 of the final printing unit 7 and just above the receiving cylinder 12 of the delivery unit 8. The operator b can get on the step 15 to replenish ink, or open the cover 7a to check the impression cylinder 11 and the like.

  As shown in FIG. 1, an inspection device for inspecting the print quality of the sheet printed material a discharged from the final printing unit 7 is disposed between the final printing unit 7 and the delivery unit 8.

  This sheet-fed printed matter inspection apparatus includes a nozzle device 16 that is an air blowing unit that presses a sheet-fed printed matter a against the peripheral surface of the impression cylinder 11 adjacent to the delivery unit 8 of the sheet-fed printing machine, and air pressure from the nozzle device 16. A lighting device 21 that is an illuminating unit that irradiates light onto the sheet printed material a pressed against the peripheral surface of the cylinder 11, a camera 27 that captures an image of the sheet printed material a illuminated by the lighting device 21, and a camera 27. And a printing quality determination device 19 that determines printing quality from the photographed image. Further, a reflecting mirror 22 is provided in the optical path where the reflected light from the printed sheet a reaches the camera 27.

  The nozzle device 16 is for bringing the printed sheet a into close contact with the peripheral surface of the impression cylinder 11 by blowing air toward the surface of the impression cylinder 11. Specifically, as shown in FIGS. 2A and 2B, the nozzle device 16 has a double cylinder structure in which a cylinder 18 is inserted on an axis in the square cylinder 17, and one of the square cylinders 17. A slit-like air discharge hole 17a is provided at the ridge. The cylinder 18 is provided with a number of air ejection holes 18 a on the bus bar opposite to the ridge of the square tube 17. A blower 20 is connected to the cylinder 18. When air is supplied from the blower 20 into the cylinder 18, the air flows into the rectangular tube 17 from the air ejection hole 18 a and flows uniformly toward the ridge along the inner wall surface of the rectangular tube 17. The air flows out from all the air discharge holes 17a to a substantially uniform flow rate.

  As shown in FIG. 1, the nozzle device 16 is installed so that the air discharge holes 17 a are aligned with one bus bar of the impression cylinder 11. As a result, the air blown out from the air discharge holes 17 a hits the printing surface of the sheet printed material a, thereby bringing the sheet printed material a into close contact with the peripheral surface of the impression cylinder 11.

  In addition, although the row | line | column of the said air discharge hole 17a of the nozzle apparatus 16 is a slit-shaped opening part, it can replace with this and can also be made into the row | line | column of a spot-like opening part.

  As shown in FIG. 1, the illuminating device 17 is arranged such that the reflected light from the sheet printed matter a on the impression cylinder 11 passes under the step 15 installed between the delivery unit 8 and the impression cylinder 11. Is done. The sheet printed matter a is pressed against the peripheral surface of the impression cylinder 11 by the air blown out from the nozzle device 16 and is arranged so that the illumination light strikes a position where it is brought into close contact. Since the printed image is stationary with respect to the impression cylinder 11 where the sheet printed material a is in close contact with the peripheral surface of the impression cylinder 11, the printed image is photographed by the camera 27 without distortion.

  Illumination device 21 is specifically composed of a light source such as an LED or a fluorescent lamp, and is provided so as to extend along the generatrix of impression cylinder 11. Illumination light from the illuminating device 21 is reflected by the printing surface of the sheet printed matter a on the impression cylinder 11, and this reflected light passes under the step 15 and reaches the reflecting mirror 22.

  On the back side of the boundary between the step 15 and the cover 8a of the delivery unit 8, a reflecting mirror 22 that directs the reflected light to the back side of the cover 8a of the delivery unit 8 is disposed. The reflecting mirror 22 is configured as a plate mirror that is elongated in parallel with the axial direction of the impression cylinder 11, similarly to the lighting device 21.

  As the reflecting mirror 22, a surface mirror formed by vapor-depositing metal on the surface of a glass plate is preferably used in order to increase inspection accuracy. When the glass plate is thin, a back mirror can be used.

  As shown in FIG. 4, the reflecting mirror 22 is preferably covered with a protective member 23. The protective member 23 is configured as a box-shaped case, and a portion where reflected light passing under the step 15 enters and a portion reflected by the reflecting mirror 22 and exiting to the camera 27 are made of transparent glass 23a made of transparent glass or the like. , 23b, respectively. By covering the reflecting mirror 22 with the protective member 23 in this way, it is possible to prevent the powder sprayed by the powder spraying device 14 and floating in the vicinity of the delivery unit 8 from adhering to the reflecting mirror 22.

  As shown in FIG. 1, a slit 24 through which reflected light passes is formed at a position in step 15 that contacts the cover 8a of the delivery unit 8. However, the slit 24 is closed so that the reflecting mirror 22 and the protective mirror 22 are protected. It is also possible to arrange the member 23 under the step so that the optical path of the reflected light does not pass over the step 15 at all.

  The camera 27 is disposed above the cover 8a of the delivery unit 8 so as to receive the reflected light passing through the back side of the cover 8a of the delivery unit 8. The camera 27 is specifically a line sensor camera. A plurality of line sensor cameras may be arranged in the width direction of the sheet printed material a (direction perpendicular to the conveying direction of the sheet printed material) according to the resolution required for the inspection of the print quality.

  The optical path of the reflected light from the reflecting mirror 22 through the back side of the cover 8a of the delivery section 8 to the camera 27 is covered with an optical duct 25 as shown in FIG. The start end side of the optical duct 25 covers the transparent plate 23 b of the protection member 23, and the end end side extends while converging toward the lens side of the camera 27. This prevents a decrease in inspection accuracy due to the powder sprayed and scattered from the powder spraying device 14 traversing the optical path from the reflecting mirror 22 to the camera 27.

  In order to avoid the scattered powder and ink mist crossing the optical path of the reflected light and appearing in the image, the optical path below the step 15 may be covered with the optical duct 26.

  The print quality determination device 19 is for transferring a print image of the sheet printed matter a imaged by the camera 27 to an inspection processing unit (not shown) and performing quality determination by pattern matching. Since this apparatus is a known apparatus, a detailed description thereof will be omitted.

  Next, the operation of the sheet-fed printed matter inspection apparatus having the above configuration will be described.

  (1) A sheet printed matter a such as a sheet printed on one or more colors by a sheet-fed printing machine is inspected for quality on the impression cylinder 11 of the final printing unit 7 as shown in FIG. The

  (2) The printed sheet a is in close contact with the peripheral surface of the impression cylinder 11 by being pressed against the impression cylinder 11 by air discharged from the nozzle device 16 at a predetermined location on the impression cylinder 11.

  (3) Light is emitted from the illumination device 21 to the portion where the sheet-fed printed material a is in close contact with the peripheral surface of the impression cylinder 11, and the reflected light travels under the step 15 toward the reflecting mirror 22.

  Thus, since the reflected light passes under step 15 instead of on step 15, even if operator b gets on step 15, the reflected light is not blocked by operator b. Accordingly, erroneous recognition of the print quality determination device 19 is eliminated, and an appropriate total inspection of the sheet printed matter a is possible.

  (4) After the reflected light is reflected by the reflecting mirror 22, it passes through the optical duct 25 and reaches the camera 27. The camera 27 receives the reflected light, captures a print image of the sheet printed material a, and transfers the image to the print quality determination device 19.

  Since the optical path from the reflected mirror 22 to the camera 27 is covered by the optical duct 25, the powder ejected from the powder spraying device 14 is prevented from entering the optical path. For this reason, an appropriate image is picked up by the camera 27, and erroneous recognition of the print quality determination device 19 is prevented.

  (5) The print quality determination device 19 inspects image information sent from the camera 27 by pattern matching and determines whether print quality is appropriate.

  When it is determined as a defective product by the printing quality determination device, for example, it is displayed by attaching a tape to a corresponding sheet printed material in the stacking portion of the sheet printed material a of the delivery unit 8 by a tape applicator.

  In addition, this invention is not limited to the said embodiment, A various change is possible. For example, in the above embodiment, only one reflecting mirror is provided, but a plurality of reflecting mirrors may be arranged.

DESCRIPTION OF SYMBOLS 8 ... Delivery part 8a ... Cover 11 ... Impression cylinder 15 ... Step 16 ... Nozzle device 27 ... Camera 19 ... Printing quality determination device 21 ... Illumination device 22 ... Reflector 23 ... Protection member 25, 26 ... Optical duct a ... Sheet-fed printed matter d, e ... optical path

Claims (3)

An air spraying means for pressing the printed sheet onto the circumferential surface of the impression cylinder adjacent to the delivery section of the sheet-fed printing press; In the sheet printed matter inspection apparatus comprising a camera that captures an image of a sheet printed matter illuminated by the illuminating means, and a printing quality judging means that judges the quality of printing from an image photographed by the camera, the illuminating means includes: The reflected light from the printed sheet on the impression cylinder is disposed so as to pass under a step installed between the delivery section and the impression cylinder, and the boundary between the step and the cover of the delivery section. In the vicinity of, a reflecting mirror for directing the reflected light to the back side of the cover of the delivery unit is arranged, and the camera receives the reflected light passing through the back side of the cover of the delivery unit. Are arranged, the optical path of the reflected light reaching to the camera is covered by the light duct through the back side of the cover at least the delivery unit,
The sheet printed matter inspection apparatus, wherein an optical path of the reflected light under the step is covered with an optical duct .   The sheet printed matter inspection apparatus according to claim 1, wherein the reflecting mirror is covered with a protective member.   3. The sheet printed matter inspection apparatus according to claim 1 or 2, wherein the reflecting mirror is a surface mirror.

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