JPH0640021A - Folding-accuracy measuring device - Google Patents

Abstract

PURPOSE:To provide an automatic folding-accuracy measuring device, in which individual dispersion by each inspector does not happen. CONSTITUTION:A folding-accuracy measuring device is composed of a means, in which the enlarged picture of the folding section of a print is photographed, a projection processing means 5, to which the picture signal of the enlarged picture is input and which prepares density data in the direction rectangular to a folding, a means 6 differential-processing density data, a binary-coding processing section 7 binary-coding differential processing data, and a means 8 arithmetically operating the quantity of displacement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a folding accuracy measuring device for printed matter.

[0002]

2. Description of the Related Art Folding accuracy is the accuracy of folding when a printed matter is folded by a folding machine of a rotary printing machine, and is represented by the amounts of misalignment at a and b points shown in FIG. “A” is called parallel folding accuracy, which is represented by the distance from the fold to the edge of the reference mark, and “b” is called right angle folding accuracy, which is represented by the amount of deviation between the lower paper and the upper paper. Folding accuracy is one of the important quality factors for rotary printing presses. Conventionally, the amount of deviation is visually measured by an inspector using a loupe with a scale.

[0003]

In the conventional measurement of the folding accuracy by visual inspection, there are individual variations in the measured values due to the skill and fatigue of the inspector. It is an object of the present invention to provide an automatic measuring device for folding accuracy that is free from individual variations by inspectors.

[0004]

An image of a folded portion of a printed matter is input by a microscope and a TV camera, and this image signal is input to an image processing apparatus, and projection processing, difference processing, binarization processing, and shift amount calculation processing are performed. I do.

[0005]

The microscope and the TV camera capture an image of the folding accuracy measurement portion of the printed matter, and input this image signal to the image processing apparatus. In the image processing device, the projection processing unit creates density data (projection data), the difference processing unit creates difference data, the binarization processing unit performs binarization with an appropriate threshold value, and the deviation amount calculation unit determines folding accuracy. Calculate the amount of deviation and display it on the monitor.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. The printed matter 10 is placed on the black base 11, and the folding accuracy measurement part (a in FIG. 2) of the printed matter described in the section (Prior Art) is described.
And b) are illuminated by the light source 1, the microscope 2 and the TV camera 3
Capture the image of the part. Here, the black base 11 is used to make it easy to distinguish the edge portion of the printed matter 10 from the background, and is not particularly particular about black color. The captured image is input to the image processing device 4. Image processing device 4
Processes this image by the following procedure to obtain the folding accuracy.

(1) In the projection processing unit 5, the density information of the image is integrated by a proper length in the direction parallel to the fold line (projection),
Create one-dimensional density data (projection data) in the direction perpendicular to the fold line. See (A2) of FIG. 3 and (B2) of FIG. (2) The difference processing unit 6 takes the difference between the density data and takes the absolute value to create difference data. (A in FIG.
3) and (B3) in FIG.

With this process, there are density steps at both edge portions of the reference mark in the parallel folding and at the edge portions of the upper and lower papers in the right-angle folding, so that there is a density difference in FIG. As shown in (B3) of 4, a large difference value is obtained. (3) Next, the binarization processing unit 7 binarizes the difference data with an appropriate threshold value. 3A4 and 4B
See 4). By appropriately setting the threshold value, it is possible to separate the portion having the above-mentioned concentration step into "1" and the other portion into "0".

(4) Next, the shift amount calculating section 8 calculates the distance between "1" and "1" of the binarized data. This value is the deviation amount of folding accuracy. The amount of deviation thus obtained is displayed on the monitor 9.

[0010]

According to the folding accuracy measuring apparatus of the present invention, a means for photographing an enlarged image of a folded portion of a printed material and a means for performing a projection process for inputting the same image signal and creating density data in a direction perpendicular to the fold line. And the means for performing the difference processing on the same density data and the means for performing the binarization processing on the same difference processing data and calculating the deviation amount have the following effects.

Since the width of the reference mark (in the case of parallel folding) and the amount of misalignment of the upper and lower papers can be calculated accurately, it is possible for the inspector to perform accurate automatic measurement of the folding accuracy without individual variations.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a perspective view showing measurement points for folding accuracy of a printed material.

FIG. 3 is a diagram showing a processing procedure of a portion (parallel folding) of FIG. 2;

FIG. 4 is a diagram showing a processing procedure of a part b (right angle folding) of FIG. 2;

[Explanation of symbols]

 4 image processing device 5 projection processing unit 6 difference processing unit 7 binarization processing unit 8 deviation amount calculation unit 9 monitor 10 printed matter

Claims (1)

[Claims] 1. A means for photographing an enlarged image of a folded portion of a printed matter, a means for inputting the same image signal and a projection processing for producing density data in a direction perpendicular to a fold, and a difference processing for the same density data. A folding accuracy measuring device comprising: a means and a means for binarizing the difference processing data and calculating a deviation amount.