JP3068210B2 - Ink supply control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic control device applied to an ink supply device of an offset printing press of a lithographic printing press.

[0002]

2. Description of the Related Art As shown in FIG.
The ink film thickness 7 on the roller 10 corresponds to the image ratio 3 in the width direction of the printing plate 6 when the image area ratio measuring device 20 and the ink presetting device 9 are provided, as shown in FIGS. As shown, there are various ink film thickness distributions in the width direction. On the other hand, as shown in FIG. 5, when a certain period of time is applied by the ink reciprocating roller 21, the distribution of the ink film thickness 7 in the width direction becomes uniform, but if the time is insufficient, the printing operation is started.
From the start of printing until the ink film thickness 7 on the ink roller 10 becomes constant, the solid density in the width direction becomes non-uniform. If the picture area ratio measuring device 20 is not provided, even if the ink supply amount in the width direction is adjusted by the ink presetting device 9 so that the ink film thickness 7 in the width direction becomes constant by visual inspection or the like, the width direction at the start of the printing operation is changed. Although unevenness does not occur much in the solid density, a phenomenon occurs in which the density of the printing plate 6 where the image ratio 3 is large is low and the density of the portion where the image ratio 3 is small increases with the lapse of time. Conversely, after the opening of the ink key-1 in the width direction is adjusted by proof printing or the like before the printing operation is started, when the printing operation is started, the same result as in the case where the above-described pattern area ratio measuring device 20 is provided is obtained. Becomes Therefore, it is necessary for the operator to monitor the ink film thickness 7 on the ink roller 10 before the start of printing and after the operation, and to appropriately adjust the ink supply amount, which requires considerable skill.

The image area ratio measuring device 20 measures an image ratio 3 for each key 2 from the printing plate 6, and obtains an image ratio 3 for each key 2.
Is a device for sending a signal 4 for adjusting the opening degree of the in-key key 1 to the ink presetting device 9 so as to provide an ink supply amount corresponding to the width direction of the printed matter 8 corresponding to the printing unit 8, and the ink presetting device 9 This is a device for presetting the ink key opening.

[0004]

[Problems to be solved by the invention]

1) Before the start of printing, since there is no ink consumption, the distribution of the ink film thickness 7 in the width direction on the ink roller 10 is, as shown in the graph of FIG. (The ink reciprocating roller 21 tends to make the ink film thickness distribution in the width direction uniform over time, but requires a considerable amount of time.) That is, if the ink key 1 is large, the ink roller The upper ink film thickness 7 increases. Therefore, the principle that the ink film thickness 7 on the ink roller 10 must be constant in the width direction when there is ink consumption, that is, at the time of printing (if the ink film thickness 7 distribution is not uniform in the width direction). This causes unevenness in the width direction of the printed matter 8). Therefore, as described above, before printing starts,
Ink key 1 according to signal 4 of picture area ratio measuring instrument 20
When the operation is performed with the opening adjusted, the printed matter 8 until a certain time elapses (until the ink supply amount reaches a steady state) from the start of printing.
Causes uneven density in the width direction.

[0005] 2) When the picture area ratio measuring device 20 is not provided, even if the ink film thickness 7 in the width direction can be made constant by visual adjustment of the operator, the image ratio 3 after a certain time has elapsed from the start of printing.
The solid density is low in a portion where is large, and the solid density is high in a portion where the image ratio 3 is small. Conversely, even if the ink supply amount in the width direction is properly adjusted by the ink presetting device 9 by proof printing or the like, the same result as the above 1) is obtained.

3) As the ink film thickness 7 on the ink roller 10 increases, the ink film thickness 7 (solid density) on the printed matter 8 also increases (FIG. 2).
Thus, the solid density on the printed matter 8 can be maintained almost properly by obtaining the relationship in advance. However, in the evaluation of the ink film thickness visually by the operator, the solid density close to the proof print can be estimated. Impossible.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink supply amount control device capable of controlling a set density without skill and further reducing the time until printing is stabilized.

[0008]

As shown in FIG. 1, 1) an ink film thickness meter 14 for measuring the widthwise ink film thickness on the ink roller 10 is provided. 2) An arithmetic unit 12 for comparing and calculating the target ink film thickness 13 and the width direction ink film thickness 7 on the ink roller 10 is provided.

3) A control device 11 for controlling the opening of the ink key 1 for adjusting the opening of the ink key 1 in the width direction based on the result of the above 2) and controlling the opening and closing of the ink is provided. 4) Before the operation, the ink film thickness 7 on the ink roller 10 is fed back, and the opening of the ink key 1 is controlled so that the target ink film thickness 13 becomes substantially the target density. After the operation is started, the ink preset device 9 is controlled by a signal from the picture area ratio measuring device 20 so that the ink key 1 is opened according to the picture area of the printing plate 6 (basically, the feed back after the operation). Although the control is possible, as shown in FIG. 2, since the relationship between the water-containing ink film thickness on the ink roller 10 and the paper surface density fluctuates due to the influence of the dampening solution, the target ink film thickness 13 must be uniquely determined. Therefore, it is considered that the open-loop control by the picture area ratio measuring device 20 is safer).

[0010]

As shown in FIG. 2, the relationship between the ink film thickness 7 on the ink roller 10 and the solid density on the printed matter 8 is measured in advance, and the target ink film on the ink roller 10 is adjusted to a predetermined density. After the thickness 13 and the actual ink film thickness 7 in the width direction on the ink roller 10 are matched, the ink application roller 17
Is applied to the plate cylinder 19 and printing is started, so that the density on the printed material 8 in the width direction at the start of printing becomes almost a predetermined density. Further, after the start of the operation, the control is entrusted to the pattern area ratio measuring device 20, so that the ink supply amount is controlled so as to be an appropriate ink supply amount in the stamp pattern area. Therefore, the density unevenness in the width direction is hindered even after the operation.

[0011]

An embodiment of the present invention will be described with reference to FIG. 1) When the print start button 26 is pressed, the control device 11
Then, the ink presetting device 9 is interrupted, and the control of the opening of the ink key 1 is controlled by the control device 11.

2) A target ink film thickness 13 which is presumed to have a predetermined density is input to the comparison operation device 12 in advance, and the ink film thickness meter 14 is scanned in the width direction on the ink roller 10 to print. The width-direction ink film thickness 7 on the ink roller 10 is measured and compared with the target ink film thickness 13. 1 is an ink key, 2 is a key, 3 is an image ratio, 4 is a demi signal, 5
Is an ink roller group, 6 is a printing plate, 7 is an ink film thickness, 8 is a printed matter, 9 is an ink presetting device, 10 is an ink roller, 11 is a control device, 12 is a comparison operation device, and 13 is a target ink film. Thickness, 14 is an ink film thickness gauge, 15 is a stop signal,
16 is an opening adjustment signal, 17 is an ink application roller, 18 is a swimsuit roller, 19 is a plate cylinder, 20 is a pattern area ratio measuring device, 21
Is an ink reciprocating roller, 22 is an ink source roller control device,
23 is an ink feeding roller, 24 is an ink source roller,
Reference numeral 25 denotes an ink fountain, 26 denotes an operation start button, and 27 denotes a roller attaching / detaching device.

Next, the operation of the control device will be described. 3) Target ink film thickness 13 and printing press ink roller 10
The deviation from the upper width direction ink film thickness 7 is appropriately calculated by the comparison operation device 12, and a signal that makes the deviation zero is output to the control device 11. 4) The signal calculated by the comparison calculation device 12 is input to the control device 11, and the control device 11 outputs an opening adjustment signal 16 for adjusting the opening of the widthwise ink key 1 to the ink preset device 9. The opening of the ink key 1 in the width direction is controlled by the above operation so that the deviation becomes zero.

5) After the target ink film thickness 13 matches the width direction ink film thickness 7 on the ink roller 10, the control device 11 supplies an ink feed roller stop signal 15 to the ink source roller control device 22 to supply ink. The amount is stopped. 6) The above is the case where the ink is wound around after cleaning the ink roller group 5. In the case where the machine stops or the lot changes due to a trouble, the ink film thickness meter 14 is scanned in the width direction above the ink roller 10. When the ink thickness 7 in the width direction on the ink roller 10 of the printing press is measured, the ink
In some cases, the ink film thickness 7 on the roller 10 is larger than the target ink film thickness 13. In such a case, the ink key 1 is closed and excess ink is returned from the ink feed roller 23 to the ink fountain 25 via the ink source roller 24. When the ink film thickness is smaller than the target ink film thickness 13, the same control as in the case of winding the ink after cleaning the ink roller group 5 is performed.

7) At the same time when all the units have reached the target ink film thickness 13, a command is given from the control device 11 to the roller attaching / detaching device 27, and
3. A signal is given to the ink application roller 17 and the swimsuit roller 18, the ink feeding roller 23 is started, and the ink application roller 17 and the swimsuit roller 18 are attached to the plate cylinder 19, and the printing paper is fed from the paper supply side. Paper is fed and printing starts.

8) However, if the desired density cannot be obtained due to the influence of the dampening solution, the controller 11 accepts the demear signal 4 at the same time when all the units have reached the target ink film thickness 13, and the demear signal 4 outputs the ink. The preset device 9 is controlled. Thereby,
The opening degree of the ink key 1 corresponds to the opening area ratio 3 of the printing plate 6 in the width direction. 9) Immediately thereafter (simultaneously), a command is given from the control device 11 to the roller attaching / detaching device 27, and signals are given from the roller attaching / detaching device 27 to the ink feeding roller 23, the ink feeding roller 17, and the swimsuit roller 18, and the ink feeding roller Reference numeral 23 denotes a start, and the ink is applied to the ink forming roller 17 and the swimsuit roller 18 on the plate cylinder 19, and the printing paper is fed from the paper feeding side to start printing.

[0017]

The ink supply amount control device according to the present invention includes means for measuring the width-direction ink film thickness on the ink roller before starting printing, and the target ink film thickness and the width-direction ink film thickness on the ink roller. Means for performing a comparison operation, means for controlling the ink supply amount in the width direction such that the ink film thickness in the ink roller width direction matches the target ink film thickness based on the result of the comparison operation, The means to start the printing operation when the target ink film thickness is reached, and the pattern after printing starts
Ink key according to the pattern area by the signal of the area device
Means for controlling the ink presetting device so that the opening is attained, and means for controlling the ink supply amount in the width direction so that the film thickness in the width direction coincides with the target film thickness in the same manner as described above. Since the ink film thickness distribution in the width direction can be promptly and uniformly made uniform, the following effects are obtained. 1) The set concentration can be controlled without skill. 2) Print density is stable after printing. 3) The printing quality is stable because the ink supply amount is automatically controlled so that the widthwise ink film thickness is always constant during operation.

[Brief description of the drawings]

FIG. 1 is a schematic layout diagram of an ink supply amount control device according to an embodiment of the present invention.

FIG. 2 is a graph obtained from experimental data of ink film thickness on an ink roller and print density.

FIG. 3 is a schematic diagram showing a conventional ink supply device.

FIG. 4 is a graph showing an ink film thickness distribution in a width direction of an ink key and an ink roller.

FIG. 5 is a schematic structural diagram of a printing machine.

FIG. 6 is a graph showing an ink film thickness distribution before printing corresponding to a printing plate.

FIG. 7 is a graph showing an ink film thickness distribution before printing corresponding to a printing plate.

[Explanation of symbols]

 Reference Signs List 5 Ink roller group 9 Ink presetting device 10 Ink roller 11 Control device 12 Comparison operation device 13 Target ink film thickness 14 Ink film thickness meter 20 Picture area ratio measuring device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Shimoyama 4--22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Inside the Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Hitoshi Isono 4-chome, Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture No. 6-22 Mitsubishi Heavy Industries, Ltd. Hiroshima Laboratory (56) References JP-A-62-170345 (JP, A) JP-A-60-101048 (JP, A) JP-A-2-155648 (JP, A)

Claims (1)

(57) [Claims] 1. A means for measuring a widthwise ink film thickness on an ink roller before starting printing, a means for comparing a target ink film thickness with a widthwise ink film thickness on the ink roller, and a result of the comparison operation Means for controlling the ink supply amount in the width direction so that the ink film thickness in the width direction of the ink roller matches the target ink film thickness, and the printing operation when the ink film thickness in the width direction reaches the target ink film thickness. To start printing
After the start, the signal corresponding to the picture area is obtained by the signal of the picture area device.
Controls the ink presetting device to achieve the ink key opening
And a means for controlling the widthwise ink supply amount so that the widthwise ink film thickness coincides with the target ink film thickness in the same manner as described above.