JP4114351B2 - Color target setting method, color management method, color target setting device, color management device, and offset printing machine equipped with them - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to offset printing using inks of at least four colors of black, indigo, red, and yellow, and is suitable for managing the color on the paper surface of a printed material, and a color management setting method and color management suitable for the printed material The present invention relates to a method, a color target setting device, a color management device, and an offset printing machine including them.
[0002]
[Prior art]
Conventionally, the ink key control device controls the density as a target when all the colors are predicted before printing, and the density obtained as a result of color matching performed by the printing press operator during printing for all colors. The case was proposed.
[0003]
At this time, it is difficult for the former to predict the density of each color that can guarantee the quality of the pattern before printing. Further, since the appropriate density differs depending on the paper, the desired print quality cannot be obtained. It was.
[0004]
In the latter case, color matching is completed quickly by highly skilled operators. However, in reality, there are few operators with such high skills, so time and paper are consumed until color matching is completed. Since the print quality depends on the operator, there is a problem that density variation occurs between lots or in the surface of a single printed matter.
[0005]
In particular, when performing color matching of ink, human vision is less sensitive to high-density ink, so time and paper are more likely to be consumed before color matching is completed. There is a problem in that the shadow portion of the black ink is crushed or the black ink density is lowered due to insufficient black ink, so that a desired print quality cannot be obtained, for example, the gradation of the black ink shadow portion is lost.
This problem is often seen in items such as publications in which black with a high halftone dot area ratio is frequently used, for example, publications in which characters and background are solid black.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems of the prior art. For all colors, when managing the density of printed matter based on the density target of each color predicted before printing, all colors are printed. Problems that occurred when humans (typically the operator of the printing press) performed the color matching of each color as a density target for each color and managed the density of the printed material based on them. It is an object of the present invention to provide a novel invention relating to a color target setting method, a color management method, a color target setting device, a color management device, and an offset printing press equipped with them.
[0007]
[Means for Solving the Problems]
First, as shown in claim 1, black, cyan, magenta, and used in offset printing using at least four colors of inks of yellow, a method of setting a color target to manage the color of the paper surface of prints, color Using the Lab color system, for black, the color predicted before the start of printing is set as the color target, and for at least three colors of indigo, red, and yellow, the results of color matching after the start of printing The color target setting method for printed matter is characterized in that each color is set as a color target based on the above. Color may use a color system as appropriate, but Lab is a representative example. Prior to the start of printing, a color target predicted by the operator for which it is difficult to perform color matching is set, and after the start of printing, a target may be set and controlled for colors other than black. Therefore, it is possible to achieve in a short time a printed matter with little color balance and lot-to-lot variation.
[0008]
According to a second aspect of the present invention, there is provided the color target setting method for a printed matter according to the first aspect, wherein the solid target color of each color is used as the color target.
In this way, by using the solid color, it is possible to reliably set the density target value in particular.
[0009]
The invention of claim 3 is characterized in that the ink key of each color is adjusted based on the color target of each color obtained by the color target setting method of the printed matter according to claim 1 or 2. This is a color management method for printed matter.
In this way, the setting of the target values for the colors other than black is changed, so that a well-balanced color management becomes possible in a short time.
[0010]
The invention of claim 4 is used for offset printing using ink of at least four colors of black, indigo, red, and yellow, and sets a color target for managing the color on the paper surface of the printed material. In this apparatus, the color uses the Lab color system, and the black color target input means for inputting the black color target, indigo, red and yellow on the paper surface of the printed material for at least three colors of indigo, red and yellow. Measuring means for measuring color, and indigo, red, yellow, equal color target input means for inputting a color target of each color based on color data of at least three colors obtained by using the measuring means, and the like This is a color target setting device for printed matter.
[0011]
According to a fifth aspect of the present invention, there is provided a color target setting device for printed matter according to claim 4, and an ink key adjustment control means for controlling the adjustment of the ink key for each color based on the color target for each color set by the setting device. A color management device for printed matter characterized by comprising the above.
[0012]
According to a sixth aspect of the present invention, there is provided an offset printing machine comprising the color management device for printed matter according to the fifth aspect.
[0013]
The color target referred to in the present invention may be a constant value or any target having a certain width.
[0014]
According to the present invention, printing quality and productivity are improved, and this effect is particularly noticeable in items such as publications in which characters having a high halftone dot area ratio are frequently used, for example, letters and backgrounds made of solid black. Appear in That is,
(I) Productivity is improved because the time and paper required for ink color matching are reduced.
(B) Since the ink density does not depend on the operator, variation in the ink density is not seen between lots or within the surface of a single printed matter, so that the print quality is improved.
(C) Since the appropriate black ink is supplied onto the black plate, the black ink will not be crushed due to too much black ink, or the black ink concentration will not decrease due to insufficient black ink. The gradation in the shadow area is richer and print quality is improved.
(D) Since the color matching operation for black ink is eliminated, the operator can concentrate on the color matching of indigo, red, and yellow, and the balance of indigo, red, and yellow is improved, and the printing quality is improved.
There are the effects as described above.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a part of a BT full-size BB offset rotary printing press provided with an ink key control device for controlling the density on the paper surface with an arbitrary value as a target value.
[0016]
FIG. 1 shows an offset rotary printing press 10 that can use four colors of ink by having a black unit 11, an indigo unit 12, a red unit 13, and a yellow unit 14. First, an arbitrary value is set as a target value. There is provided an ink key control device 20 that measures the color on the printing paper 15 using the measurement camera 22, calculates it with the control arithmetic device 21, and controls the ink key via the cable 23. FIG. 2 shows a conventional color target setting method and a procedure according to an embodiment of the present invention.
[0017]
In FIG. 2, 30 is the conventional method 1 which is one of the methods conventionally proposed, 31 indicates the color of the control object, 32 indicates ink, indigo, The operation of predicting the color target of each color of red and yellow is shown. 33 indicates the operation of inputting the color target predicted in 32 to the color target of ink, indigo, red and yellow, and 34 is input. This is an operation to start control of black, indigo, red, and yellow using an ink key based on a color target.
[0018]
In FIG. 2, reference numeral 40 is a conventional method 2 indicating one of the conventionally proposed methods, 41 indicates a color to be controlled, and 42 indicates colors of ink, indigo, red, and yellow during printing. A color matching operation is performed. 43 is an operation in which the operator determines the color of ink, indigo, red, yellow as a color target as a result of the operator performing color matching of ink, indigo, red, yellow during printing. 44 indicates an operation of inputting ink, indigo, red, and yellow color targets to the ink key control device based on the color target determination, and 45 indicates ink, indigo using the ink key based on the input color target. The work to start the control of red, yellow.
[0019]
In FIG. 2, 50 indicates one embodiment of the present invention, 51 selects a color for predicting a color target from past data before printing, and 52 selects the black for the selected black from past data. , 53 indicates the operation of inputting the black color target to the control device, and 54 indicates the operation of starting the black control using the ink key based on the input black color target. . 55 selects the color to be controlled with the color as a result of color matching performed by the operator during printing for colors other than black, and 56 performs color matching of indigo, red and yellow selected by the operator. 57 indicates an operation for determining the density of indigo, red and yellow obtained as a result of the color matching of indigo, red and yellow by the operator during printing, and 58 indicates the color target. An operation for inputting indigo, red, and yellow color targets to the ink key control device based on the determination is shown. 59 is an operation for starting indigo, red, and yellow control based on the input color target. In the appropriate setting of the color, it is preferable that the setting is performed in a state where the solid portion of each color is printed.
[0020]
As described above, by adjusting the ink key of the printing press based on the color target setting of each color, an appropriate color management method for the printed matter has become possible.
As an apparatus for realizing such a color target setting method, as shown in FIG. 1, when used for offset printing using four colors of ink, a black color target input means for inputting a black color target; Measuring means for measuring each color on the paper surface of the printed material for at least three colors of indigo, red, and yellow, and a color for inputting a color target of each color based on the color data of each color obtained using this measuring means A color target setting device including target input means is provided.
The color management device is a color management device provided with an ink key adjustment control means for controlling the adjustment of the ink key in the color target setting device.
Further, the offset printing machine includes the color management device.
[0021]
【Example】
(1) Comparative Example 1
Here, the results of the conventional method 1 of the procedure shown by 30 to 34 in FIG. 2 are shown. As an execution procedure, first, for each color of black, indigo, red, and yellow 31, a solid density target of each color was predicted by an operation 32 of predicting an appropriate solid density of each color from past data. Specifically, we predicted that black was 1.6, indigo was 1.2, red was 1.2, and yellow was 1.1. Next, an operation 33 for inputting the value as a target value to the ink key control device is performed, and an operation 34 for starting the control of black, indigo, red, and yellow from the start of printing is performed.
[0022]
As a result, although there was almost no variation in the density of each color between lots or within one printed sheet, the balance of indigo, red and yellow was poor, and the desired print quality could not be obtained.
[0023]
(2) Comparative Example 2
Here, the result of having performed the conventional method 2 in the procedure shown by 40 to 45 of FIG. 2 is shown. As an execution procedure, first, in the ink, indigo, red, and yellow 41, after the operator of the printing press finishes the color matching operation 42 for the proof, the density of ink, indigo, red, and yellow obtained from the result is obtained. The operation 43 for determining as a target concentration was performed. Next, an operation 44 for inputting the determined target values of black, indigo, red, and yellow to the ink key control device is performed, and then an operation 46 for starting control of black, indigo, red, and yellow is performed.
[0024]
As a result, printed materials with a good balance of indigo, red, and yellow were obtained, but variations in the density of each color were observed between lots and within the surface of one printed material. Due to this variation, for example, the density of characters composed of solid black ink became non-uniform, and there were cases where the print quality was significantly reduced. In some cases, an operator takes more time than necessary to complete color matching, and the operator consumes 2000 or more printing sheets.
[0025]
(3) Example 1
Here, the present invention was carried out according to the procedure indicated by 50 to 59 in FIG. The result is shown. As an execution procedure, for black 51 at first, L = −60, a = 1, b = −2 for Lab using the operation 52 for predicting an appropriate black color from past data before printing. , And predicted the color target respectively.
Next, an operation 53 for inputting the black target value to the control device was performed, and an operation 54 for starting the black control based on the target value was performed. Next, with respect to indigo, red and yellow 55, after the operator finishes the indigo, red and yellow color matching operation 56 for the proof, the resulting indigo, red and yellow colors are used as color targets. A decision 57 was made.
Here, the operation 58 for inputting the target values of indigo, red and yellow to the ink key control device is performed, and then the operation 59 for starting the control of indigo, red and yellow based on the target color values is performed.
[0026]
Here, for black, a color target is predicted, this color target is input, and control is performed based on this color target. So I can hardly see the ink color variation. In addition, black ink based on the color target is supplied on the black plate, so that the black ink shadow does not collapse due to overprinting of the black ink, and the black color is lowered due to insufficient black ink. As a result, the shaded area of the ink becomes richer, and the quality of the characters composed of the solid ink and the white characters in the solid ink area are improved.
In addition, since the work of color matching of ink has been eliminated, the time and paper required for color matching of ink have been reduced, so productivity has been improved, and the operator has been able to concentrate on color matching of indigo, red and yellow. Productivity and quality improved dramatically, with the balance of indigo, red, and yellow in about 800 sheets after the start of printing.
[0027]
In Comparative Example 1, although there is almost no variation in the density of each color between lots or within the surface of a printed material, the color balance of indigo, red and yellow is poor, and the desired print quality cannot be obtained. There was a problem.
[0028]
In Comparative Example 2, a printed material with a good balance of indigo, red, and yellow was obtained, but variations in the density of each color were observed between lots and within the surface of one printed material. In some cases, the density of characters, etc., was uneven and the print quality was significantly reduced. In addition, there are cases where it takes more time than necessary to complete color matching including black, and there is a problem that the operator has consumed more than 2000 print sheets.
[0029]
【The invention's effect】
According to the present invention, a predicted color target value is input for black, while a color target based on an operator's proof color match color is input for colors other than black, and each color (density is set). In the case of controlling the density that was predicted before printing for all colors as a density target, or the operator of the printing press performed color matching during printing for all colors. It is possible to propose a new color target setting method, color target setting device, and ink key control device that solves the problems that have occurred when controlling the resulting density as a color target.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of an ink key control device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating an implementation procedure and print quality results between a conventional technique and the present invention.
[Explanation of symbols]
10. ・ Printing unit 11 ・ ・ Ink unit 12 ・ ・ Indigo unit 13 ・ ・ Red unit 14 ・ ・ Yellow unit 15 ・ ・ Printing paper 20 ・ ・ Ink key control device 21 ・ ・ Calculation device 22 ・ ・ Measurement camera 23 ・ ・Cable 30 ... Procedure 31 of conventional method 1 ... Color 32 to be controlled ... Work to predict target color 33 ... Work to input target value 34 ... Work to start control.
40 ·· Implementation procedure 41 of Conventional Method 2 · · Control target color 42 · · Color matching operation 43 · · The obtained color is determined as the target color 44 · · Target value input 45 · · Work to start control 50 .. Implementation procedure 51 of the present invention .. Color selection 52 to be controlled .. Work to predict a color target 53..Work to input target value 54..Work to start black control 55. · · Color selection 56 to be controlled · · Color matching 57 · · Color 58 to determine the obtained color as a target · · Target input 59 · · Control start

Claims (6)

In a method of setting a color target used for offset printing using ink of at least four colors of black, indigo, red, and yellow, and managing the color on the paper surface of the printed matter,
The color uses the Lab color system,
For black, set the color target predicted before the start of printing as the color target,
A method of setting a color target for a printed material, wherein for at least three colors of indigo, red and yellow, each color is set as a color target based on a result of color matching after the start of printing.   The color target setting method for a printed matter according to claim 1, wherein a solid color of each color is used as the color target.   A color management method for a printed matter, wherein the ink key of each color is adjusted based on the color target for each color obtained by the color target setting method for a printed matter according to claim 1. In an apparatus for setting a color target for printed matter, which is used for offset printing using at least four inks of black, indigo, red, and yellow, and sets a color target for managing the color on the paper surface of the printed matter,
The color uses the Lab color system,
A black color target input means for inputting a black color target, a measurement means for measuring indigo, red, and yellow colors on a printed paper for at least three colors of indigo, red, and yellow, and obtained using the measurement means An apparatus for setting a color target of a printed matter, comprising: indigo, red, yellow, and so on target input means for inputting color targets based on color data of at least three colors, and the like.   5. A color target setting device for printed matter according to claim 4, and an ink key adjustment control means for controlling the adjustment of the ink key for each color based on the color target for each color set by the setting device. A color management device for printed materials.   An offset printing machine comprising the color management device for printed matter according to claim 5.

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