JPS5811156A - Adjusting system of distorted register in multicolor press - Google Patents

Abstract

PURPOSE:To precisely detect and adjust distorted registering errors in mounting a printing block by a method wherein a pair of register marks are provided on horizontally symmetrical and opposite positions of a printing block and detected by mark sensors and the detected output is processed electrically. CONSTITUTION:A pair of register marks 3a, 3b are provided on horizontally symmetrical and opposite positions on the surface of a printing block 2 mounted on a plate cylinder 1 and mark sensors 4a, 4b are provided facing each register mark 3a, 3b. The detecting output of the mark sensor 4a, 4b is given to a phase differece detector through a gate circuit, an automatic gain control circuit. When the printing block 2 is mounted distortedly phase differences are caused between those detected outputs, the output due to the difference is obtained from the phase difference detector. This output is sent to an operation section and operated there and printed on a printer as a distorted register error. The mounting state of the printing block 2 is adjusted according to this indication.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a 1-/1 sheet-fed printing press that is mounted on each color plate cylinder of a multicolor sheet-fed printing press.
8. This relates to a twist register adjustment method for correctly mounting each printing plate on the plate cylinder without twisting it.

If the printing plate is installed in a one-twist state with respect to the printing cylinder, the printing state of each color will be in a non-overlapping state with respect to the paper, so various proposals have been made regarding means for detecting installation errors in the twisting direction of the printing plate. Although this method has been developed, it has not yet been put into practical use. Conventionally, the printing plate installation status was adjusted by visually judging the printing status, repeating trial printing and stopping the printing press. However, this method requires a large amount of time and a large amount of trial printing paper, and has drawbacks such as requiring a great deal of skill for adjustment.

The purpose of the present invention is to fundamentally eliminate the above drawbacks of the conventional method, and a pair of register marks are provided at symmetrically opposite positions in the left-right direction on the printing plate surface of each color, and these are provided opposite to each register mark. By detecting this as an electrical signal using a mark sensor, and then electrically processing this detection output, the torsional registration error in mounting each color printing plate can be detected for each color.
The installation status of each color printing plate is adjusted accordingly, and an extremely effective twist register adjustment system for a multicolor printing press is provided.

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

The "No." ratio is a diagram showing the relationship between a printing plate and a mark sensor, etc., in which a printing plate 2 is attached to a printing cylinder 1 rotating in the direction of the arrow, and the printing plate 2 is placed at symmetrically opposite positions in the left-right direction on the surface of the printing plate 2. fart,
A pair of register marks 3a arranged in the same direction.
, 3b are provided, and in this example, each is formed in an rfj 0M shape along the left and right direction of force.

The printing plate 2 is wound onto the first printing cylinder 1 by means such as "Plate vise device for sheet-fed printing press" (in the order of utility model registration, dated June 13, 1981), which was separately filed by the applicant. It is installed several times.

A mark sensor 4a, 4b, such as a reflection type light-receiving type, is provided on each of the register marks 3a, 3b to face the register marks 3a, 3b.
A pair of detection outputs corresponding to b are generated, and the plate cylinder 1
A proximal body 5 is fixed to the side surface with bolts or the like,
This is detected by a proximity switch 6 as a total gate signal generator, and a gate signal synchronized with the detection outputs of mark sensors 4a and 4b is generated in accordance with the rotation of plate cylinder 1.

Figure 2 is a block diagram of the electric circuit, and shows the mark sensor 4.
The detection output of a
- ON, only the detection outputs from the mark sensors 4m and 4b are extracted, noise components are removed, and then applied to the automatic gain control circuits AGC1 and AGC2, the peak values of each detection output are made the same, and the phase comparator A phase difference detector PDD such as the above detects the phase difference between each detection output.

Therefore, if the printing plate 2 is installed in a "twisted" manner and the straight line 7 connecting the register marks 3m, 3b is not parallel to the rotation axis 8 of the plate cylinder 1, there will be a phase difference between the detection outputs of the mark sensors 4m, 4b. occurs, and an error signal S0 corresponding to this is obtained from the phase difference detector PDD.

However, as shown in Figures 1 and 2, one is provided for each plate cylinder of each color, and in multi-color printing of the first to fourth colors, the phase difference detector for each color detects the first to fourth colors. Error signals se1 to So4 are obtained depending on the color.

FIG. 3 is a block diagram of a circuit that performs arithmetic processing and display based on the error signals sol~Se4Inl7 of each color. (hereinafter referred to as ADC) The signal n is sequentially and repeatedly applied to the A/D, becomes a digital signal to each trtA, and is then sent to an arithmetic unit OP mainly composed of a microprocessor or the like.

In the calculation unit OP, the error signal Sol~8.4 has a polarity depending on which one is deviated upward or downward in the vertical direction due to the relative relationship between the register marks 3a and 3b. , based on this polarity and absolute value, find the correction direction for each color, convert the absolute value into a specific error amount, and further determine that the relative error between each color is less than a predetermined value among the error amounts for each color. Determine whether there is a combination of

As a result of the judgment, if there is a combination that corresponds to a relative error less than a predetermined value, calculate the average value of each color error amount, use this as the front (FRONT) correction amount, and calculate the relative error less than a predetermined value. The amount of correction corresponding to is considered to be zero, and the amount of correction of other items is calculated based on the difference between the other error amounts and the average value. ' Also, as a result of the judgment, if there is no combination that corresponds to a relative error less than a predetermined value, the average value of each color error amount is determined, and the error amount closest to this is determined as the front correction amount, and This 7'Lf correction amount is regarded as zero, and correction amounts for other items are calculated based on the difference between this and other error amounts.

These calculation results are sent to the printer PT as the correction direction and correction amount for each color, and are printed by the printer PTK.

Figure 4 is a printing example when there is a combination corresponding to a relative error VC of less than this n when a predetermined value is set and 0.05, and it shows the amount of error from the mechanical reference position. Front "FRONT" and first color "A I '~WJ
4 colors @A4” ink “STJMI”, indigo “AI”, red “
The direction and amount of correction are shown for Island A'' and Yellow KI''.

However, in this example, the first color is "161" and the third color is "3".
”, the relative error is 0.05 mm or less, and the amount of correction for these is zero.

Fig. 5 is a printing example when the predetermined values are the same as in Fig. 4, but there is no combination with a relative error of 0.0511g or less. In this example, the third color "A3" is Since it is closest to the average value, the positive quantity is set to zero in A1.

Therefore, based on the printed display of the printer PT,
If you adjust the torsional register of each printing plate, you can easily and quickly adjust the torsional register without performing trial printing. T
Naeru.

In addition, the above-mentioned [plate vise device J K t, I, l! +
, 'J adjustment scale is attached, and after adopting this,
If adjustment is made according to the correlation between this scale and the detected torsional register error, the adjustment work will be made easier.

However, instead of the proximity switch 6, a rotary encoder connected to the rotating shaft 8 may be used, and the ADC-A/D
The same effect can be obtained by inserting .

As is clear from the above description, according to the present invention, the torsional registration error in mounting each color printing plate is reliably and specifically detected and displayed, and the mounting status of each color printing plate is adjusted based on this. Since the twist register adjustment can be easily and quickly completed without trial printing, it is extremely effective in multicolor printing machines for various purposes.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Fig. 1 shows the relationship between the printing plate and the mark sensor, etc., Figs. 2 and 3 are block diagrams of the electric circuit, and Fig. 4 and #! FIG. 5 is a diagram showing an example of printing by a printer. 1... Plate cylinder, 2... Printing plate, 38-3b...
Register matrix, 4m + 4b...Mark sensor, 5...Proximity object, 6...Proximity switch (gate signal generator), GCl, GC2...Gate circuit, PDD...・Phase difference detector, op... #Φ calculation unit,
PT--war printer. Patent applicant Komori Printing Machinery Co., Ltd. Agent Masaki Yamakawa (and one other person) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A pair of register marks are provided at symmetrically opposite positions in the left and right direction on each printing plate surface attached to the plate cylinder for each color,
Each of the register marks is detected individually by a mark sensor facing each of the register marks, and each detection output is detected by a gate signal generated in synchronization with a pair of detection outputs generated for each color and in accordance with the rotation of each plate cylinder. After extracting, the phase difference between each pair of extracted detection outputs is determined for each color, the phase difference is converted to the amount of error between the register marks of each pair of words, and the average value of the amount of error for each color is calculated. The torsional register adjustment of a multicolor printing press is characterized in that the difference between the error amount of each color is determined based on the average value, and then the difference is displayed, and the torsional register adjustment of each printing plate is performed based on the display. method.