Printed matter examination apparatus

Abstract

The invention aims to provide a printed matter checking device for preventing the single sheet from jiggling while photographing for checking the printed matter. In the device of the invention, a photographing unit is equipped for photographing the checked surface of the printed matter, a first blowing unit 4 for blowing air from the upper front direction of the conveying and a second blowing unit 5 for blowing air from the upper rear direction of the conveying are disposed on the photographed position, and an air absorbing unit 6 is disposed upon the checking position between the two blowing units for absorbing at least the air from the first unit 4 and the second unit 5.

Description

technical field [0001] The present invention relates to a printed matter inspection device that captures an image of a printed matter printed on a single sheet by an imaging unit, and performs the printed matter inspection on-line. Background technique [0002] Conventionally, images of printed matter printed in the final device of single-sheet printing have been taken, and it has been judged whether or not it has been printed normally without smudging or lack. In order to judge whether it is good or bad, the image of the printed matter is taken when the printed matter is conveyed to the impression cylinder of the final printing device, or when the printed matter is conveyed from the impression cylinder of the final printing device to the chain conveying equipped between the discharge parts Shoot while on the road. [0003] As mentioned above, in the case of inspection based on the image of the printed matter to be inspected, the image of the printed matter must be correctl...

AI Technical Summary

Problems solved by technology

[0007] However, when air is blown from the front of the conveying direction to the sheet conveyed on the impression cylinder, when the thickness of the paper is thick, even if the air is blown strongly, it may not be completely adhered to the impression cylinder.

On the other hand, in the case of using paper with a thinner thickness, a lifting force is generated on the paper due to the flow of air blown towards the paper, or due to the air passing through the paper hitting the rubber roller. , the air flowing in from the rubber cylinder enters between the paper and the impression cylinder, etc., sometimes the shaking of the rear end of the paper cannot be suppressed, especially the correct image of the rear end cannot be taken.

[0008] In the case of photographing a single sheet of paper on a horizontal transport path, the cost of the inspection device, etc. increases compared to the case of photographing the paper on the impression cylinder

In addition, in the case of high-speed printing, since the moving speed of the sheet is also increased, when moving on the horizontal conveying path, the trailing end part also shakes, and accurate images cannot be taken.

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