JPS6128089B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a density control method for gravure printed matter. Conventionally, the density management of printed matter, not just gravure printed matter, has been done by the printer visually comparing the printed matter with a standard, or by using a densitometer or other method to measure solid color marks imprinted in the margins of the printed matter. Other methods include printing the four primary colors (yellow, red, eye, and black) on the margins of a printed matter to create a gray color, and visually comparing it with a standard gray color. However, these methods need to be automated from the perspective of labor saving, and not only cannot numerically control the quality of the product in visual inspection, but also in roll printing, there is a need for automation during printing. Although it is normally difficult to know the inking status of printed matter, the present invention has made this possible. In addition, in the second density control method described above, in the case of gravure printing, if only the solid color mark is measured, only the state of the shadow portion can be measured. The present invention compensates for the drawbacks of the above-mentioned methods by automating measurement, display, and recording, and by color-scaling color marks.

The present invention will be explained in detail with reference to the drawings below. As shown in FIG. 1, color scales 3, 3', 3'', 3 and Start mark 4,
Imprint 4', 4'', 4.

The color scale 3 divides the area from the lowest density part 5 to the highest density part 6 into 10 equal parts as shown in FIG. The value of this equal division is arbitrary, and as an example, the case where it is divided into 10 equal parts will be explained. Also color scale 3',
3'' and 3 are similar to color scale 3, and color scale 3 is usually printed with yellow, color scale 3' with red, color scale 3'' with eyes, and color scale 3 with black. On the other hand, the start mark 4 is printed next to the color scale 3 with a black mark as shown in FIG. Start mark 4', 4'', 4
Also, the color scales 3', 3'', and 3 are printed next to each other in a manner similar to the relationship between the color scales 3 and the start marks 4.

Now, for the sake of simplicity, color scale 3,
Of 3', 3'', 3, only color scale 3 should be noted. Measure the density values of 10 levels of color scale 3 of standard products in any printed matter in advance, memorize these values, and use this memory. This value is compared with the automatically measured value of the density of 10 levels of color scale 3 of printed matter produced one after another, and the difference is recorded and displayed. If the specified upper and lower limits are exceeded, a warning is issued and the data at that time is displayed.This data allows the printer to take measures to ensure proper printing, and if the plate needs to be replaced. The above data can be used as valid data for the new edition.

As an example of controlling the concentration as described above,
A method using a photo frame for the light receiving system and a microcomputer for the processing device is as shown in Figure 3, in order to convert density information of 10 levels of color scale 3, 3', 3'', 3 into electrical signals. A halogen lamp 10 turned on by a stabilized power source 9 illuminates the color scales 3, 3', 3'', 3, and the reflected light from the color scale 3 is filtered through a Ratten filter No. 47 (Eastman Koda). The incident light from the color scale 3' passes through the filter 13' using the Wratten filter No. 59, and enters the photoprint 14.
Similarly, the light reflected from color scale 3' is filtered through filter 13'' and filter 13, which utilizes Wratten filter No. 25, and the light reflected from color scale 3 is filtered through Wratten filter No. 106.
and enters the photomultiplier 14.

In this way, it is necessary to select filters that are compatible with each of the color scales 3, 3, 3, 3, so the filters 13, 13', 13'', 13 are attached to the disk 25 as shown in Figure 4. The disk 25 is rotated by the pulse motor 11,
The color scales 3, 3', 3'', 3 and the filters 13, 13', 13'', 13 are matched.

At this time, the pulse motor 11 is driven by a signal from the microcomputer 19 and a signal obtained through the interface circuit 12, and this signal will be described later. Now, to simplify the explanation, only color scale 3 will be described, but the same applies to color scales 3', 3'', and 3.

The light incident on the photomultiplier 14 as described above is converted into an electrical signal, amplified by the amplifier 15, and converted into a logarithm by the logarithmic amplifier 16. This logarithmic signal is an analog signal, but A/
The data is digitized by the D converter 17, passes through the interface circuit 18, and is input to the RAM in the microcomputer 19.

The start mark 4 is used as a trigger signal when inputting the 10-level density values of the color scale 3 to the RAM in the microcomputer. That is, the start mark 4 is detected by the mark sensor 7, amplified by the amplifier 8, and then input to the microcomputer 19 through the interface circuit 18.

After the signal from the start mark 4 is inputted to the microcomputer 19, the densities of the 10 levels of the color scale 3 are sampled and stored at a speed proportional to the speed of the printed material 1 in the flow direction.

At the time of sampling, the signal from the microcomputer 19 passes through the interface circuit 12 and is sent to the pulse motor 11, which rotates the disk 25 and filters the
It falls between 4 and color scale 3. In addition, the microcomputer 19 uses the 10-level density values of the color scale 3 of the standard printed matter stored in the internal RAM in advance and the color scale 3 of the printed matter 1 sampled and memorized as described above.
The 10 levels of concentration values are compared, and it is determined whether the upper and lower limits previously stored in the RAM in the microcomputer 19 have been exceeded, and the results are stored in the internal RAM along with the difference value from the standard. It is stored in memory, printed out by the digital printer 21 through the interface circuit 20, and the necessary data accumulated in the microcomputer 19 is arbitrarily called up and displayed by the display device 22, so that the upper limit value and the lower limit value are exceeded. If so, sound the buzzer 23. In addition, the density values of the 10 levels of color scale 3 of the above-mentioned standard printed matter are measured using a commercially available reflection densitometer, and the printer sets the thumb rotary switch 24 and stores it in the internal RAM of the microcomputer 19. Alternatively, there is a method in which the values obtained by scanning a standard printed matter with the photoelectric conversion system of the present invention are automatically stored in the internal RAM of the microcomputer 19. Furthermore, since the above-mentioned upper limit value is determined on-site depending on the type, quality, etc. of the printed matter, the printer sets the upper limit value with the thumb rotary switch 24' and the lower limit value with the thumb rotary switch 24''. The internal RAM of the microcomputer 19
A method is used to store it in memory. Further, a program for operating the microcomputer 19 is input into a PROM in the microcomputer 19. The method described above is based on the microcomputer 1.
Although this method uses the microcomputer 19, it is clear that the same effect can be obtained even if a digital IC is used in combination without using the microcomputer 19.

Since the present invention has the above-described configuration, it is possible to finely and automatically measure, record, and display the density of the gradation between the highlight part and the shadow part of the gravure print, which saves labor in quality control of the gravure print. This makes it possible to quantify and accurately quantify the product, making it easier to maintain the high quality of the product.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan view of a printed matter, and FIG. 2 is a plan view of a printed matter.
FIG. 3 is a block diagram of the photoelectric conversion and processing section, and FIG. 4 is a filter disc. 1... Printed matter, 3, 3', 3", 3... Color scale, 4, 4', 4", 4... Start mark, 13, 13', 13", 13... Filter, 19... Micro Computer, 22...
display device.

Claims (1)

[Scope of Claims] 1. Printing a color scale with multiple density changes in the margins of a gravure print using the ink used for the print, and continuously scanning the color scale with a photoelectric conversion device during the printing process. The electrical signal obtained is input to the signal processing device, which is stored in advance, and compared with the value of the electrical signal of the color scale of the standard printed matter to determine the ink transfer status of the printed matter. A method for controlling the density of gravure printed matter, which is characterized by continuously measuring, recording, and displaying. 2. Density of a gravure printed matter according to claim 1, in which a photoelectric conversion device uses a halogen lamp lit by a DC stabilized power source to emit light, and uses red, green, and blue-violet filters and a photomultiplier to receive light. Management method. 3 In the signal processing device, RAM is used to store the density information of the standard printed matter, PROM is used to store the signal processing program, a microcomputer is used to perform signal processing, and the processing is completed. To memorize the ivy signal
A method for controlling density of gravure printed matter according to claim 1 using RAM.