JP2001001500A - Ink supply presetting method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of data to be stored to a large extent and to enhance the presetting accuracy of the opening of an ink key. SOLUTION: Printing image ratio data 3 is converted to ink open degree data on the basis of a conversion function and the open degree of an ink key is preset on the basis of the ink key open degree data 6. In this case, a printing condition (e.g.; material condition data) incapable of being continuously estimated related to a printing material such as the kind of ink or paper and a printing condition capable of being continuously estimated related to a printing speed or a target density are separated and the printing condition capable of being continuously estimated is stored as a function and the conversion function is set on the basis of the data input of the printing condition incapable of being continuously estimated and the printing condition incapable of being continuously estimated stored as the function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for presetting ink supply in an offset printing press. More specifically, the present invention relates to a method of converting image ratio data into ink key opening data using a conversion function, and based on the ink key opening data. The present invention relates to a method and an apparatus for presetting ink supply in which an ink key opening is preset.

[0002]

2. Description of the Related Art An offset printing press is provided with a mechanism for adjusting an ink supply amount in order to adjust the color of a picture.
In a typical ink supply amount adjustment mechanism, the gap between the ink source roller and the ink key is adjusted, and the color of the printed matter (picture) is adjusted by controlling the thickness of the ink draw-out film. I have. In addition, this ink key is divided and arranged in a large number in the width direction of the paper,
It can be adjusted individually according to the picture amount (ink consumption amount) at each key width position.

In the current printing press, the ink key opening is preset based on the picture information in order to properly adjust the opening of each ink key to the amount of the picture more quickly. FIG. 6 is a workflow showing a conventional ink key opening degree presetting method (ink supply presetting method).

Conventionally, first, an image portion (a portion on a pattern on which ink is applied) of a printing plate 1 is measured by using a plate image ratio measuring device 2.
The image ratio data 3 is calculated in advance, and the image ratio data 3 is calculated. Then, using the conversion function f (x) [x: image ratio] for each printing condition previously stored in the storage device 5 as shown in FIG. 6 and drive the ink key controller 7 based on the ink key opening data 6 to preset the ink key opening (see FIG. 6).

[0005]

However, the conventional ink supply presetting method as described above and the conventional ink supply presetting apparatus for implementing the method have the following problems. That is, the optimal conversion function corresponding to the printing conditions is not one, but the optimal conversion function depends on the type of printing material (ink or paper), the target density (target density), and the printing speed (printing speed). Each function will be different. Therefore, it is necessary to collect data under frequently used printing conditions in advance, and to prepare an optimum conversion function for each printing condition in advance.

In the conventional case, as shown in FIG. 8, one conversion function is assigned for each printing condition, and the conversion function is stored in the storage device 5, and when printing is performed, the printing condition and It is necessary to select the conversion function under the same condition and convert the image ratio data 3 to the ink key opening degree data 6.

As described above, since one conversion function is conventionally assigned to one printing condition (see FIG. 8), the printing material, the target density, and the printing conditions mainly affect the conversion function. There is a problem that an enormous amount of conversion functions need to be stored in the storage device 5 (of course, a complicated test is required to collect the data) only by combining the speed conditions. . Further, when selecting a conversion function, one optimal conversion function must be selected from a large number of conversion functions prepared in advance, which causes a problem that the efficiency becomes extremely low. For example, if there are 10 combinations of inks and papers to be printed, 10 target densities, and 10 printing speeds, the printing conditions are 1000 in total. Therefore, in this case, it is necessary to prepare 1000 types of conversion functions and store an enormous amount of data in the storage device 5 in advance.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to significantly reduce the number of data to be stored (data amount) and to improve the preset accuracy of the ink key opening. It is an object of the present invention to provide a method and apparatus for presetting ink supply that can be performed.

[0009]

In order to achieve the above-mentioned object, in the present invention, image ratio data is converted into ink key opening data by a conversion function, and the ink key opening is calculated based on the ink key opening data. In the ink supply presetting method of a printing press that is preset, printing conditions that cannot be continuously predicted for printing materials such as ink and paper type, and printing conditions that can be continuously predicted for printing speed and target density are divided. Storing the continuously predictable printing conditions as a function and setting the conversion function based on the data input of the continuously unpredictable printing conditions and the functionalized continuously predictable printing conditions. I am trying to do it. According to the present invention, there is provided an ink supply presetting method for a printing press, wherein image ratio data is converted into ink key opening data by a conversion function, and the ink key opening is preset based on the ink key opening data. , The target density and the printing speed are used as parameters, and the target density and the printing speed are functioned and stored, and a basic conversion function is selected according to the data input regarding the printing material, while the data input of the target density and the printing speed is performed A correction coefficient is calculated from a function of the correction coefficient for the target density and a function of the correction coefficient for the printing speed based on the correction coefficient, and the ink key is opened according to the correction conversion function obtained by correcting the basic conversion function according to the correction coefficients. I try to preset the degree.

Further, according to the present invention, there is provided an ink supply presetting device for a printing press, wherein image ratio data is converted into ink key opening data by a conversion function, and the ink key opening is preset based on the ink key opening data. (A) a plate image ratio measuring device for measuring the image ratio in the image portion of the plate, (b) an input device for inputting target density data and printing speed data, and (c) each printing material. Basic conversion functions corresponding to each condition are stored,
A storage device for selecting a basic conversion function corresponding to the printing material condition as the printing material data is input,
(D) storage means for respectively storing a function of a correction coefficient for density and a function of a correction coefficient for printing speed, wherein the basic conversion function selected in the storage device is stored in the input device as target density data and printing speed. A correction circuit for performing correction using a correction coefficient calculated based on the function as data is input, and (e) an ink key based on ink key opening degree data obtained from a correction conversion function output from the correction circuit. And an ink key control device for controlling the opening degree.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In these drawings, the same parts as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows a configuration of an ink supply presetting device for presetting an ink key opening (ink supply amount) by implementing an ink supply presetting method according to an embodiment of the present invention, and presetting an ink key opening by this device. FIG. 2 shows a flow (conversion function setting process) for correcting a conversion function used for converting image ratio data to ink key opening degree data.

The ink supply preset device according to the present embodiment is obtained by adding an input device 8 and a correction circuit 10 to a conventional device. Specifically, as shown in FIG. 1, an input device 8 for inputting target density data and printing speed data 9 is provided in the ink supply preset device of the present embodiment.
And a correction circuit 1 for optimally correcting the conversion function according to the target density and printing speed data 9 input from the input device 8.
0 is attached. Further, in the above-described correction circuit 10, a function F1 (d) of a correction coefficient for a previously determined target density (d) and a function F2 (s) of a correction coefficient for a printing speed (s) (FIG. 3A) , (B)) are provided.

The operation of correcting the conversion function in the correction circuit 10 is performed according to the flow shown in FIG. That is, the material condition data (Ai) 1 selected from the storage device
For 1, the basic conversion function Fi (x) is first selected. This basic conversion function Fi (x) is calculated as shown in FIG.
A correction conversion function corrected by the correction circuit 10 in accordance with the correction functions 16 and 17 defined as (b) and the target density (d) 13 and the printing speed (s) 14 input by the input device 8. G (x) is created (FIG. 2)
reference).

Next, a method for selecting a conversion function for converting the image coverage into the ink key opening using the ink supply preset device having the configuration shown in FIGS. 1 and 2 will be described.
It is as follows.

First, the operator of the printing press selects material condition data (Ai) 11 that matches the condition of the material to be printed. Accordingly, the material condition data (Ai) 1 is selected from the conversion functions stored in advance.
The basic conversion function Fi (x) corresponding to 1 is selected.

Next, the target density (d) to be printed and the printing speed (s) (see FIG. 2) are input to the input device 8.
Accordingly, the function F1 (d) of the correction coefficient for the density stored in the memory device in the correction circuit 10 and the function F2 (s) of the correction coefficient for the printing speed are applied to the value input to the input device 8. A correction coefficient is calculated from each of the correction coefficients (see FIGS. 3 (a) and 3 (b)), and the basic conversion function Fi (x) is corrected based on the correction coefficients thus obtained, and a correction conversion function G (x) (here, Then, G (x) = Fi (x)
× F1 (d) × F2 (s)) is set. Then, the corrected conversion function G (x) finally corrected optimally is input to the conversion table. Thus, this correction conversion function G
According to (x), the ink key opening that is optimal for the printing conditions and the image coverage to be printed is calculated, and the ink key opening is preset to a value that matches this calculation result.

Here, one specific example of a data storage method for causing a set conversion function to follow a change in the target density will be described as follows.

In order to select a conversion function according to the target density, a data storage table as shown in Table 1 below is created.

[0020]

[Table 1]

The following data is input to the above Table 1 through <10>. In (1), a target density (for example, a numerical value of 1.9) is input. Since the target density varies depending on the type of paper, a relationship between the type of paper and the target density may be created in another database in advance, and the relationship may be automatically determined according to the setting of the paper type. It is possible. In (2), enter the type of paper. Link to the job setting screen. The name and the number are recorded in another database, and the name is replaced with the number so that the name and the number can be input. In (3), enter the type of ink. This is also used as a number record similarly to paper. In (4), enter the number of rotations of the ink source roller.
This field is fixed. In (5), the image ratio is input. Basically, it is a fixed value. The parameter setting picture is changed so that it finally reaches this streak ratio stage. In (6), enter the ink key opening used in the parameter setting test. Basically, there is no change from the initial value. As the last input value of each image ratio, when a parameter setting test is performed, a smaller one is selected if the target density is exceeded in the second set value, and a larger one is selected if the target density is not exceeded. In (7), when the parameter setting test was performed,
The solid density of the sample printed under the condition of (1) is stored. In (8), the coefficients a and b of the linear approximation (Y = aX + b) when the solid density is defined on the X axis and the ink key opening is defined on the Y axis are input. FIG. 4 shows a first-order approximation formula F (D) = a × D + b (where the image ratios in this case are 10%, 20%, 40%, 60%, and 80%). D:
Where a first-order coefficient term a and a constant term b are applied. (9) In <10>, a set value (ink key opening degree with respect to the image ratio) for each image ratio is input. When the parameter setting test is performed, this setting value is [<10>: setting value] = [: target concentration] × [: coefficient a]
+ [: Constant b]. When the parameter setting test is not performed, a numerical value is input as before.

The upper left graph in FIG.
The relationship between the opening degree of the ink key and the solid density when the pattern (the ratio of the portion where the ink arrives) printed on one control zone is 10% was obtained by an actual machine test. Further, the other graphs in FIG. 5 are obtained when the image streaks are 20, 42, 58, and 83%. From these graphs, it can be seen that the relationship between the ink key opening degree and the solid density is substantially linear for each image ratio. Therefore, the straight line drawn in each graph in FIG. 5 is a straight line approximating the relationship between the ink key opening degree and the solid density by a linear expression, and the primary coefficient term of the linear expression is α,
The constant term is defined as β, and these α and β are summarized for each image ratio as shown in Table 2 below.

[0023]

[Table 2]

In Table 2 above, the ink key opening in the rightmost column of the table on the left is the ink key opening (corresponding to the target density of 1.9) obtained from a straight line approximated by the linear expression of FIG. In the table on the right, the image ratio is 10
%, 20%, 40%, 60%, and 100%.

When the target density for printing is determined, the ink key opening suitable for the target density is automatically calculated from the data shown in Table 2 in accordance with this. Note that the image ratio to be printed varies (the image ratio is not limited to the five-stage image ratio described above), and thus the image ratio is finally determined as described above so as to support all the image ratios. Each point is linearly complemented from the relationship between the five-step image ratio and the ink key opening degree so as to correspond to the entire image ratio.

Conventionally, one conversion function for converting the image coverage into the ink key opening is assigned to one of the printing conditions (see FIG. 8), so that a great number of conversion functions need to be prepared. When selecting a conversion function according to various printing conditions, one optimal conversion function had to be selected from a very large number of conversion functions. According to the method and apparatus,
By formulating printing conditions (that is, parameters that can be converted into functions) that can be continuously predicted with respect to printing speed, target density, and the like (see FIGS. 2 and 3), the number of tests for obtaining a conversion function can be significantly reduced, and As the conditions for selection (the number of conversion functions) are reduced, the time for selecting the conversion function can be reduced. In addition, the printing conditions that can be continuously predicted with respect to printing speed, target density, and the like are converted into a function,
Based on this, the basic conversion function Fi (x) is corrected by the correction circuit 10.
By correcting to the correction conversion function G (x), it is also possible to improve the preset accuracy of the ink key opening.

Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment.
Various modifications and changes are possible based on the technical concept of the present invention. For example, in the above-described embodiment, the memory device in which the correction coefficient function F1 (d) for the previously determined target density and the correction coefficient function F2 (S) for the printing speed are stored in the correction circuit 10. Although the storage device 5 is provided, the storage device 5 can be used as the memory device.

[0028]

According to the first aspect of the present invention, there are provided printing conditions that cannot be continuously predicted for printing materials such as ink and paper type, and printing conditions that can be continuously predicted for printing speed and target density. Separately, printable continuously predictable printing conditions are stored as a function, and a conversion function is set based on data input of printing conditions that cannot be continuously predicted and printing conditions that can be continuously predicted that are functioned. This eliminates the need to store a huge amount of data by allocating one conversion function for each printing condition, as in the past.
The number of data to be stored can be significantly reduced by making the printing conditions function that can be predicted continuously. Also, the amount of work required for the test for collecting the data is significantly reduced. Furthermore, by appropriately performing functionization,
It is also possible to improve the preset accuracy of the ink key opening.

According to a second aspect of the present invention, a printing material, a target density and a printing speed are used as parameters, and the target density and the printing speed are stored as a function. While selecting a conversion function, a correction coefficient is calculated from a function of the correction coefficient for the target density and a function of the correction coefficient for the printing speed based on the data input of the target density and the printing speed, and the basic conversion is performed according to the correction coefficients. Since the ink key opening is preset according to the correction conversion function obtained by correcting the function, the number of data to be stored can be greatly reduced by making the printing conditions of the target density and the printing speed into a function. Above, a correction conversion function corrected (optimized) according to the target density and the printing speed can be obtained, and the set target density and It can be preset to the most suitable ink zone opening on the printing speed.

According to a third aspect of the present invention, there is provided a printing plate image ratio measuring device for measuring an image ratio in an image portion of a printing plate, and an input device for inputting target density data and printing speed data. And a storage device for storing a basic conversion function corresponding to each printing material condition, and selecting a basic conversion function corresponding to the printing material condition as printing material data is input, and a correction coefficient for the density. A storage unit in which a function and a function of a correction coefficient for the printing speed are stored, and the basic conversion function selected in the storage device is converted into a function as target density data and printing speed data are input from the input device. And a correction circuit that performs correction with a correction coefficient calculated based on the ink key opening data obtained from a correction conversion function output from the correction circuit. And the ink key control device for controlling the ink supply, the ink supply preset method according to the present invention described above can be implemented, the number of data to be stored can be reduced, and the ink key opening degree can be preset. Can be provided with a practical ink supply preset device that can perform the above-described steps with high accuracy.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a workflow when an ink supply preset method is performed using an ink supply preset device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a workflow when the conversion circuit used to convert the image ratio data into ink key opening data is corrected by a correction circuit.

3A is a graph showing a function F1 (x) used for calculating a correction coefficient for a target density, and FIG. 3B is used for calculating a correction coefficient for a printing speed. 6 is a graph showing a function F2 (x).

FIG. 4 is a graph showing the relationship between solid density and ink key opening at each image ratio.

FIG. 5 is a graph showing a specific example of the relationship between the ink key opening and the solid density at each image ratio.

FIG. 6 is a flowchart illustrating a workflow when a method of presetting an ink key opening degree using a conventional ink supply preset device is performed.

FIG. 7 is a characteristic curve diagram of a conversion function f (x) conventionally used.

FIG. 8 shows a conversion function fi assigned to each printing condition.
It is explanatory drawing which shows (x).

[Explanation of symbols]

 Reference Signs List 1 printing plate 2 printing plate image ratio measuring device 3 image data 5 storage device 6 ink key opening data 7 ink key control device 8 input device 9 target density data and printing speed data Ai material condition data Fi (x) basic conversion function G ( x) Correction conversion function d Target density s Printing speed x Image coverage

Claims (3)

[Claims] 1. An ink supply presetting method in which image ratio data is converted into ink key opening data by a conversion function, and the ink key opening is preset based on the ink key opening data. Continuous and unpredictable printing conditions for printing materials
It is divided into printing conditions that can be continuously predicted with respect to printing speed and target density, and the printing conditions that can be continuously predicted are functioned and stored. Wherein the conversion function is set based on continuously predictable printing conditions. 2. An ink supply preset method for converting image ratio data into ink key opening data by a conversion function and presetting an ink key opening based on the ink key opening data. The print speed is used as a parameter, the target density and the print speed are functioned and stored, and a basic conversion function is selected in accordance with the data input regarding the printing material, while the target is set based on the data input of the target density and the print speed. A correction coefficient is calculated from a function of a correction coefficient for density and a function of a correction coefficient for printing speed, and the ink key opening is preset according to a correction conversion function obtained by correcting the basic conversion function according to these correction coefficients. A method for presetting ink supply, characterized in that: 3. An ink supply presetting device which converts image ratio data into ink key opening data by a conversion function and presets the ink key opening based on the ink key opening data. A printing plate streak ratio measuring device for measuring a streak ratio in the streak portion,
(B) an input device for inputting target density data and printing speed data, and (c) a basic conversion function corresponding to each printing material condition is stored, and the printing is performed as the printing material data is input. A storage device for selecting a basic conversion function corresponding to a material condition; and (d) storage means for storing a function of a correction coefficient for density and a function of a correction coefficient for printing speed, respectively. A correction circuit that corrects the basic conversion function with a correction coefficient calculated based on the target density data and the printing speed data from the input device based on the function; And an ink key control device for controlling the ink key opening based on the ink key opening data obtained from the output correction conversion function. Ink supply presetting device.