JPS62257852A - Sensor mounting error correcting method for automatic registration adjuster - Google Patents

Abstract

PURPOSE:To facilitate the mounting of front and rear face sensors and to unnecessitate highly accurate adjustment of distance by correcting a registration error based on a positional difference between register marks obtained from at least one detection outputs of respective sensors with reference to an actual mounting error then adjusting the registration according to said corrected registration error. CONSTITUTION:After a referential distance is registered by means of a register switch 30, an actual distance between sensors is operated from detected distances of first color register marks on the front and rear faces to produce an actual mounting error Ec which is compared with an allowable error and if the error is within an allowable range, it is stored in a memory. Then the operation transfers to the adjustment of registration on the same face and the operation 'storage of rear face mark position into a memory' is executed according to a rear face register mark, for example, thereafter a distance between rear face marks is operated based upon the positional difference between respective colors and an error En between rear face colors is operated for an n-th color. Then En corrected by Ec to provide a corrected registration error and a corrected target value is operated in accordance with the current position of the n-th color rear face registration thus feeding an output signal SD.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a device for automatically adjusting registration errors between each color of a multicolor printing machine, which corrects installation errors in register mark detection sensors. It is about the method.

[Conventional technology]

In double-sided multicolor printing machines such as rotary printing machines, printing paper,
The registration between each color changes depending on the printing material materials such as blankets and ink, and the printing conditions such as the tension applied to the paper and the ink tack. This is automatically detected, and the registration is automatically detected for each side of the paper and for both the front and back sides. For the purpose of correcting the registration error between each color in
The method disclosed in No. 14751 is becoming increasingly popular.

That is, register marks are printed on each side of the paper and in each color, and these are placed opposite the front and back sides of the paper.
In addition, the paper is photoelectrically detected by a front sensor and a back sensor installed spaced apart from each other in the transport direction of the paper, and based on these detection outputs, registration adjustment for each side and registration adjustment between the front and back surfaces is automatically performed. It is to be carried out in a specific manner.

[Problem that the invention seeks to solve]

However, each sensor on both the front and back surfaces has a predetermined distance from each other when mounted, and the mounting distance of each sensor must be precisely set when manufacturing or adjusting the printing press. Since the registration error between the front and back surfaces may be slightly larger than the registration error for each same side, the registration adjustment between the front and back sides is first performed as a standard, and then the registration adjustment for the same side is performed as a standard. In addition, it takes time and effort to set the mounting distance of each sensor, and the test printing paper is wasted, resulting in an uneconomical problem.

[Means for deciding issues]

In order to solve the above-mentioned problem, the present invention is constructed by the following means.

In other words, in the device that automatically performs the register adjustment described above, the reference distance between each sensor is registered, the amount of mounting error is calculated from the difference from the actual distance between each sensor, and at least one of the sensors is For detection output! The amount of registration error based on the positional difference between the register marks determined by the method is corrected by the amount of mounting error, and the registration is adjusted according to the corrected amount of registration error.

[Effect]

Therefore, by registering a predetermined reference distance between each sensor, the amount of mounting error can be determined from the actual measured distance, and the amount of mounting error can be corrected and the registration U can be automatically performed.

〔Example〕

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

Figure 2 is a block diagram of the electric circuit that performs register adjustment, and shows the outputs of the front side photoelectric sensor (hereinafter referred to as LES) 201 and the back side LH820B that detect the register marks printed in each color on both sides of the paper. The waveform shaping circuit (below,
WFC) 211 and WFC 21m generate square waves individually, and provide these to a gate circuit (hereinafter referred to as GAT) 23 via a multiplexer (hereinafter referred to as MPX) 22, while a gate pulse generation circuit generates based on the operation of the printing press. (hereinafter referred to as GPG) 24 controls the GAT 23, and the clock pulse generator C
After resetting the CUT 2B that counts clock pulses from the CLG 25, the GPG 24 generates a gate pulse from the detection start point corresponding to the detection reference point for each color. In order to continue generating gate pulses until register mark detection is completed, the LES20L, 2 of each register mark is
The detection output at 0m passes through K()AT23 for each color,
It is given to a differentiation circuit (hereinafter referred to as DEF) 27.

Then, the DEF 27 sends out a differential pulse corresponding to the leading edge or trailing edge of the register mark for each color and applies it to the latch circuit (hereinafter referred to as I, AT) 28, which causes the count value of the CUT 26 to be held. CUT26 is reset at the same time as the gate pulse generation starts, and starts counting clock pulses given from CLG25 by p4.
The count value is held by the LAT 28 and indicates the distance between the detection reference point and the register mark for each color.

1. Since the GPG 24 sends out a clear pulse for each color immediately before starting detection of each register mark to clear the LAT 28, first, the distance between the detection reference point of the first color and the front register mark is maintained in the LAT 28. , Next, similar distances are maintained by the backside register mark of the first color, and thereafter similar distances of the second and subsequent colors are maintained sequentially, and these are sequentially given to the arithmetic circuit (hereinafter referred to as 0PC) 29. The 0PC 29 performs calculations to be described later, and sends out an output signal SD indicating the corrected target value.

In addition, a registration switch (hereinafter referred to as RG8) 30 using a digital switch or the like is provided for 0PC29, and this sets a predetermined reference distance between LES201 and LES20 m. , 0PC29, 0PC2 is registered using this reference distance.
9 performs correction calculations.

In addition, the LES 201 and 202 are generally placed in front of each other on the paper transport path,
The front register mark and the back register mark of the same color printed by the same printing unit are as follows: First, the front register mark is detected by LES201, and then the back register mark is detected by LES20! The surface register mark of the same color is detected by LES201.
The distance detected by LES 2 and the register mark on the back side
If we calculate the difference from the distance detected by LES20
The actual distance between 1 and 202 can be measured.

On the other hand, the 0PC29 is composed of a processor (hereinafter referred to as CPU) and memory, etc., and the CPU executes instructions stored in the memory and performs arithmetic processing without accessing the required data to the memory. Now,
Arithmetic processing is performed according to the flowchart shown in FIG.

In other words, the reference distance “D registration ↑” 1 according to RGS 30
If 01 is Y (YES), after performing this reference distance "D mesori storage" 102, for example, the actual distance between the sensors [d Calculation] 111 is performed, and “E
The mounting error iEc is determined by calculating c=d−D J 112.

At TS I/1, r IEcI>X? J121 is used to compare the allowable error - Jix, and if this is Y, then "E
"C memory storage" 122 is performed, whereas when the result is N (NO), Ec is cleared by "EC4-O" 123 because it is likely to cause trouble even if the mounting error amount is ignored.

Next, the process moves to register adjustment for the same side, and for example, according to the back side register mark, "back side mark position/memory storage" 131
The distance between the marks on the back side is determined by the position difference between each color.
After performing the calculation 132, the back side color error amount ``En calculation'' 133 is performed for the nth color, and r Enr = E
n-)-Ec J By the calculation in 141, En is corrected using Ec to obtain a corrected register error 1Enr, and "correction target value calculation" 142 is performed according to the current position of the rear plate cylinder register of the nth color.
is performed, the output signal sD is sent by the "Send correction value" 143, and after the back side register adjustment of the nth color is performed, the "RET" is sent.
'', steps 101 and subsequent steps are repeated, and similar processing is performed for each color.

Therefore, if you register the reference distance and match the front and back register positions of the same color, especially LE8201.202
The amount of mounting error is automatically determined without having to set the mounting distance accurately, and the corrected register adjustment is performed on the same surface. The amount of printing is reduced, resulting in savings in test printing paper.

Further, the judgment in step 121 eliminates unnecessary corrections, and increases the response speed of register adjustment.

However, depending on the shape of the register mark, LES201.
By selecting the detection location according to 201, register adjustment can be performed not only in the vertical direction but also in the horizontal direction.

In addition, in Fig. 2, MPX22, GAT23
.

The functions of CUT26 to LAT28 may be accommodated in 0PC29 and realized by the CPU.
Various modifications are possible, such as configuring 9 by a combination of various logic circuits.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, it is easy to mount each sensor for the front side and the back side, and there is no need for particularly high-precision separation distance adjustment. A remarkable effect can be obtained on the machine.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, with FIG. 1 being a flowchart of the arithmetic processing situation, and FIG. 2 being a block diagram of the electric circuit. 201120! ...LES (photoelectric sensor), 22
...MPX (multiplexer), 26...CU
T (counter), 27...DEF (differential circuit)
, 28...LAT (latch circuit), 29...0
PC (arithmetic circuit), 30...RGS (registration switch).

Claims (1)

[Claims] Register marks printed individually on the front and back sides of paper for each of multiple colors are detected by a front sensor and a back sensor installed at a distance from each other, and registration adjustment between the colors is automatically performed based on the respective detection outputs. In a device that performs the above-mentioned system, the reference distance between each of the sensors is registered, and the amount of mounting error is determined from the difference from the actual measured distance between the sensors, and the amount of mounting error is determined from the detection output of at least one of the sensors. A sensor mounting error correction method for an automatic register adjustment device, characterized in that the amount of registration error based on the positional difference between the register marks is corrected by the amount of mounting error, and the registration adjustment is performed according to the corrected amount of registration error. .