JPH0596709A - Color tone stabilizing apparatus and stabilizing method for printer - Google Patents

Abstract

PURPOSE:To make it possible to feed an ink distributing roller group, prior to printing, with an accurate quantity of ink under steady printing state by quantitatively grasping the quantity of ink being held by the ink distributing roller group under steady printing state. CONSTITUTION:The color tone stabilizing apparatus comprises an ink film thickness meter 1 for measuring the quantity of ink on the surface of an arbitrary roller in ink distributing roller groups 12-28, an ink film thickness meter 3 for previously storing the reference film thicknesses of the ink distributing roller groups 12-28, an ink supply controller 2 for comparing the reference film thickness of the memory 3 with a thickness measured by the in film thickness meter 1, and an ink ductor rolling regulator 4, an ink original roller rotational speed regulator 5 and an ink key opening regulator 6 being controlled, respectively, through the ink supply controller 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stabilizing device for a color tone at the start of printing, which is applied to an ink supplying device of a printing machine, and a stabilizing method thereof.

[0002]

2. Description of the Related Art As shown in FIG. 4, a proper amount of ink is wound around a plurality of ink brick roller groups 11 to 28 from an ink source roller 10 on an ink key 7 via an ink feeding roller 11 and the roller groups 11 to 28 are arranged. Ink roller 9
When printing on the plate cylinder 8 together with the dampening rollers 29 and 30 through the ink jet printer, it is necessary to wind an appropriate amount of ink around the ink roller group in order to perform printing stably. Therefore, when printing is performed from the state where the ink is not wound on the ink brick roller after washing the ink, if the printing is started without winding the ink on the ink brick roller group as it is, as shown by a curve 33 in FIG.
The color tone is not stable until a fixed amount of ink is collected in the ink roller group.

In such a case, the operator is currently required to set an appropriate amount of ink before printing is started in the ink brick roller groups 12 to 28.
In addition, the ink is directly applied with a spatula or the like, or the ink feeding roller 11 is manually moved to supply the ink, printing is performed once to judge whether the supply amount is good or not, and this work is performed until the density on the paper surface becomes almost a target value. Again, the amount of ink to be supplied at this time is determined by experience and intuition, and lacks accuracy and reproducibility. If the amount is larger than the appropriate amount, the color tone will not be stable for a long time as shown by the curve 35 in FIG.

Therefore, in the printing after cleaning the ink of the roller group, the color tone is slow to stabilize, which adversely affects the number of damaged sheets and the production time.

[0005]

SUMMARY OF THE INVENTION In order to automatically set the amount of ink accumulated in an ink brick roller after ink cleaning, which can be adjusted only by the experience and intuition of an operator, the following problems have been solved. is there. Quantitatively grasp the amount of ink held by the ink brick roller group in the steady printing state.

[0006] The amount of ink in the steady printing state is accurately supplied to the ink-brake roller group before printing. The present invention aims to solve such problems.

[0007]

The structure of the present invention for achieving the above object will be described with reference to FIG. 1 corresponding to an embodiment of the present invention. Ink film thickness measuring device 1 for measuring ink amount
And an ink film thickness storage device 3 for storing the reference film thicknesses of the ink roller groups 11 to 28 in advance, and an ink for comparing the reference film thickness of the storage device 3 with the measured value of the ink film thickness measuring device 1. It is provided with a supply amount control device 2, an invoking roller swing adjusting device 4, an ink source roller rotation speed adjusting device 5, and an ink key opening adjusting device 6 which are respectively controlled via the ink supply amount controlling device 2. Characterize.

Further, according to the present invention, the uniform ink film thickness of the ink brick roller group in the steady printing state is measured and set as the reference ink film thickness, and at the time of printing start-up, an arbitrary ink is formed with the plate cylinder and the inking roller opened. The ink film thickness on the surface of the brick roller is
It is characterized in that the printing is started until the reference ink film thickness is reached, and then the plate cylinder and the inking roller are brought into contact with each other to start printing.

[0009]

According to the present invention, since the amount of ink to be called can be controlled while measuring the ink film thickness by the above means, the time for supplying the required amount of ink to the ink roller group is short and accurate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1. In the figure, reference numerals 7 to 30 designate the same parts as those in the conventional example shown in FIG.
After the printing is performed steadily in the sheet-fed printing press, the printing is ended and the printing is suspended, that is, the ink-brake roller group, 11-2.
Although 8 and all other rollers are rotating, printing is not performed, the calling roller 11 is always in contact with the roller 12 on the most upstream side of the ink roller group, and the inking roller 9 and the plate cylinder 8 are always separated. Continue to stay for about 2 minutes. At this time, the ink film thickness on each ink roller of the ink brick roller group changes from the state of the curve 31 of FIG. 2 to the uniform state of the curve 32.

Then, the ink film thickness on the roller at that time is measured by the ink film thickness meter 1. The reason for measuring the ink film thickness in the print interrupted state is that the state when the ink is accumulated in the roller group is the print interrupted state and the target in that state is obtained. Here, the roller for measuring the ink film thickness may be any roller in the ink brick roller group, but in this embodiment, 20 is a measuring roller.

Data of the measured ink film thickness is stored in the storage device 3.
It is taken in and memorized. A method of collecting a constant amount of ink after cleaning the ink is performed by reciprocating the calling roller 11 between the ink source roller 10 and the ink roller 12 in the printing interrupted state to supply the ink onto the ink roller group. The ink supply amount is determined by three factors: the number of reciprocations of the ink feeding roller 11, the number of revolutions of the ink source roller 10, and the opening degree of the ink key 7.

Therefore, an appropriate amount of ink is supplied to the ink-brake roller group faster, that is, the ink film thickness on the roller 20 which measures the ink film thickness becomes the stored ink film thickness. The device 4 for adjusting the number of times the calling roller reciprocates, the device 5 for adjusting the rotation of the ink source roller, and the device 6 for adjusting the ink key opening are controlled while measuring the ink film thickness of the roller 20. The control example is shown below.

First, three threshold values are determined as follows based on the stored ink film thickness. A value obtained by subtracting 0.3 μm from the finally stored ink film thickness is a threshold value a, a value obtained by subtracting 1.0 μm is a threshold value b, and a value obtained by subtracting 2.0 μm is a threshold value c. When the ink film thickness of the roller 20 is less than or equal to the threshold value c, the ink key 7 is opened to the maximum, the rotation of the ink source roller 10 is also maximized, and the calling roller 11 is rotated once every two rotations of the plate cylinder as in normal printing. Reciprocate at a rate of. When the ink film thickness of the roller 20 exceeds the threshold value c, the ink source roller 10
Change the number of rotations of to the preset value calculated from the drawing rate of the pattern. Then, when the ink film thickness of the roller 20 exceeds the threshold value b, the opening degree of the ink key 7 is changed to a preset value obtained from the drawing rate of the pattern. Finally, when the ink film thickness of the roller 20 exceeds the threshold value a, the reciprocating motion of the calling roller 11 is not interlocked with the plate cylinder 8, and once the ink calling roller 11 is attached to the ink brick roller 12, the roller 20
Do not move to the ink source roller 10 side until the ink film thickness is constant. Ink is stored in the ink roller group up to the ink film thickness thus stored.

[0015]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned constitution, when printing is performed from a state where ink is not present on the surface of the ink roller after washing the ink, the present invention allows the ink to be printed on the group of ink roller without printing. The required amount of ink can be supplied quickly and accurately in the steady printing state. As a result, as shown by the curve 34 in FIG. 3, the stability of the color tone after printing is improved, which is effective in reducing wasted paper and improving operating time.

[Brief description of drawings]

FIG. 1 is a schematic view of a color tone stabilizing device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an ink film thickness distribution on a roller.

FIG. 3 is a diagram showing improvement in stability of color tone.

FIG. 4 is a schematic diagram showing a conventional ink supply system.

[Explanation of symbols]

 1 Ink film thickness measurement device 2 Ink supply amount control device 3 Ink film thickness storage device 4 Ink feeding roller swing adjustment device 5 Ink source roller rotation speed adjustment device 6 Ink key opening adjustment device 8 Plate cylinder 9 Ink application roller 11-28 Inking roller group

Claims (2)

[Claims] 1. An ink film thickness measuring device for measuring an ink amount on an arbitrary roller surface of an ink brick roller group, an ink film thickness storage device for preliminarily storing a reference film thickness of the ink brick roller group, and a storage device of the memory device. An ink supply amount control device that compares and calculates the reference film thickness with the measured value of the ink film thickness measuring device, an ink feeding roller swing adjusting device and an ink source roller rotation that are respectively controlled via the ink supply amount control device. A color stabilizing device for a printing press, comprising a number adjusting device and an ink key opening adjusting device. 2. The uniform ink film thickness of the ink brick roller group in the steady printing state is measured to obtain a reference ink film thickness,
At the time of printing start-up, the plate cylinder and the ink form roller are opened until the ink film thickness on the surface of any ink brick roller reaches the reference ink film thickness, and then the plate cylinder and the ink form roller are contacted. A method for stabilizing color tone of a printing press, which comprises starting printing as a state.