JP2552450B2 - Error correction method for automatic register adjustment device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an error correction method in an apparatus that automatically adjusts a registration error between colors of a multicolor printing machine.

[Conventional technology]

In a double-sided multi-color printing machine such as a rotary printing machine, the register between each color varies depending on the printing material such as printing paper, blanket and ink, and the change of printing conditions such as tension applied to the paper and ink tack. Therefore, for the purpose of automatically detecting this and correcting the register error between the colors on each side of the paper and on both the front and back sides, the method disclosed in Japanese Patent Application Laid-Open No. 58-14751 filed by the applicant of the present invention. Etc. are gradually spreading.

That is, register marks are printed on the front surface and the back surface of the paper for each color, and these are optoelectrically detected by a front surface sensor and a back surface sensor that are arranged to face the front surface and the back surface of the paper and are spaced apart in the paper transport direction. However, the register adjustment for each surface and the register adjustment between the front and back sides are automatically performed based on these detection outputs.

[Problems to be Solved by the Invention]

However, each sensor on both the front and back sides has a predetermined mutual distance for mounting and mounting, etc., and the mounting distance of each sensor must be precisely set when manufacturing or adjusting the printing machine. A large amount of printing paper is consumed, which causes an uneconomical problem.

The same applies when replacing the sensor, etc.
There is also the problem of making adjustments troublesome.

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention comprises the following means.

That is, in the device for automatically performing the register adjustment described above, after mounting each sensor, and after manually registering the front and back register positions of register marks of the same color printed on the front surface and the back surface of the paper, the The mounting distance between each sensor is calculated based on the detection output of each sensor by the register mark of the same color, and the calculated mounting distance is registered as a reference distance. The difference between the calculated distance based on the detection output and the reference distance is obtained as the amount of registration error between the front and back sides of the color,
The registration of the front surface and the back surface of the color is adjusted based on the calculated registration error amount between the front and back sides.

[Action]

Therefore, according to the present invention, each sensor is mounted,
After matching the front and back register positions of, for example, the first-color register marks printed on the front surface and the back surface of the paper by manual operation, the mounting distance between the sensors is detected based on the detection output of each sensor by the first-color register mark. (D _S ) is calculated,
If this calculated mounting distance is registered as the reference distance, the difference between the calculated distance (D _R ) based on the detection output of each sensor by the register mark of the same color and the reference distance (D _S ) causes the color The front and back registration error amount (Ec) is calculated, and the front and back registration of the color is adjusted based on this front and back registration error amount.

〔Example〕

Hereinafter, the details of the present invention will be described with reference to the drawings showing examples.

Figure 2 is a register adjustment is a block diagram of an electrical circuit for performing a surface photoelectric sensor for detecting the surface and the surface registers marks and the back register marks are printed for each color to the rear surface of the paper (hereinafter, LES) 20 ₁ And each output of the LES20 ₂ for the back side is converted into a square wave by a waveform shaping circuit (hereinafter, WFC) 21 ₁ and WFC 21 ₂ , and a multiplexer (hereinafter, MPX) 2
These are given to the gate circuit (hereinafter, GAT) 23 via 2 and GAT is generated by the gate pulse from the gate pulse generation circuit (hereinafter, GPG) 24 generated based on the operation of the printing machine.
23 and controls the clock pulse generator (CL,
The counter (hereinafter, CUT) 26 that counts clock pulses from G) 25 is reset, and the GPG 24 generates a gate pulse from the detection start point corresponding to the detection reference point for each color, and the register mark for each color. Since the gate pulse continues to be generated until the end of detection, the detection output by LES 20 ₁ and 20 ₂ of each register mark is GAT for each color.
It passes through 23 and is fed to the fine powder circuit (hereinafter, DEF) 27.

Then, the DEF 27 sends out a differentiated pulse corresponding to the leading edge or the trailing edge of the register mark for each color and gives it to the latch circuit (hereinafter referred to as LAT) 28, which holds the count value of the CUT 26, so that the gate pulse of the GPG 24 is generated. The count value of CUT26 that was reset at the same time as the start and restarted the counting of the clock pulse given from CLG25 is held by LAT28, and if the rotation speed of the printing machine is constant, this is the distance between the detection reference point for each color and the register mark. Will be shown.

The GPG 24 sends a clear pulse for each color to clear the LAT 28 immediately before starting the detection of each register mark. Therefore, in LAT28, first, the distance between the detection reference point of the first color and the front side register mark is held, then the same distance by the back side register mark of the first color is held, and thereafter the second color is sequentially held a similar distance beyond, these arithmetic circuits (hereinafter, OPC) becomes that given sequentially to 29, OPC29 is performs operations described below, the output signal SD (SD _F, SD _R) indicating the corrected target value It is supposed to be sent out.

Further, for the OPC29, registration switch for registering command (hereinafter, RGS) Yes 30 are provided, OPC29 to operations and response, performs the registration operation will be described later in LES20 _1, 20 ₂ calculates The mounting distance D _S is registered as a reference distance, and the OPC 29 performs a correction calculation using this reference distance D _S.

In addition, the LES 20 ₁ and 20 ₂ are generally arranged such that the LES 20 ₁ precedes on the paper transport path, and the front and back sides of the unit used are the same and the front register of the same color. Regarding the mark and the multi-sided register mark, first, the front side register mark is detected by LES20 ₁ , and the back side register mark is detected by LES _{20 2} .
By obtaining a difference between the detected timing to the timing and the back register mark detected by LES20 ₁ surface register marks of the same color by LES20 _2, it is possible to calculate the mounting distance between LES20 ₁ and LES20 _2.

In this case, if there is no registration error between the front and back sides, the calculated mounting distance matches the actual distance. If there is a registration error between the front and back sides, the calculated mounting distance does not match the actual distance. That is, when there is no registration error between the front and back sides, the printing positions of the front surface register mark and the back surface register mark of the same color are the same between the front and back surfaces (see FIG. 3 (a)). When there is a registration error between the front and back sides, the printing positions of the front surface register mark and the back surface register mark of the same color are misaligned between the front and back surfaces (Fig. 3 (b)).
reference). In the third diagram, M _F surface register mark, M _R denotes the rear surface register mark. Therefore, if there is no registration error between the front and back sides, LES20 ₁ and LES20 calculated from the difference between the timing when the front surface register mark M _F of the same color is detected by LES20 ₁ and the timing when the back surface register mark M _R is detected by LES _{20 2.} The mounting distance with ₂ matches the actual distance.

On the other hand, the OPC 29 is composed of a processor (hereinafter, CPU), memory, etc., and stores instructions stored in the memory in the CPU.
Is executed and the arithmetic processing is performed while accessing the required data to the memory, and the arithmetic processing is performed according to the flowchart shown in FIG.

That is, LES20 ₁ and 20 ₂ are mounted, and any same color,
For example, if the RGS30 is operated after the front and back register positions of the first color are made to match manually, "Registration operation?" 101 is displayed as Y.
(YES), the “front and back mark positions / retrieve” 102 is performed according to the detection timing of the front side register mark of the first color and the detection timing of the back side register mark, and between LES20 ₁ and 20 ₂ based on these values. The mounting distance “D _S ” calculation 103 is performed, and the calculated mounting distance D _S is stored in the reference distance “D _S memory storage” 104. In this case, since the front and back register positions of the first-color front-side register mark and the back-side register mark match, the calculated mounting distance D _S, that is, the reference distance.
D _S matches the actual distance.

After each of the above processes, when the practical operation is started, step 102
Same as nth color "Front / back mark position / uptake" 11
1, and, after performing a similar distance "D _R calculation" 112 and step 103, corresponds to the step 104 "D _S read" 1
13 is performed, and the difference between the calculated distance D _R and the reference distance D _S is calculated as the front / back surface registration error amount Ec of the color by the “error amount calculation” 114, and the calculated front / back surface registration error amount Ec is calculated. Based on the current position of the plate cylinder register on the front and back sides of the color concerned, the correction value is obtained, and the output signal SD _F and SD _R
Is performed to adjust the registration of the front surface and the back surface of the nth color, and then step 101 and subsequent steps are repeated via “RET” to perform the same processing for each color.

Therefore, according to the present embodiment, if the RGS30 is operated after the front and back register positions of any same color are matched,
Even if the mounting distances of the ES20 ₁ and 20 ₂ are not set accurately, the reference distance D _S is automatically registered, and after that, the register adjustment is performed accurately based on this, and the LES 20 ₁ and 20 ₂ are mounted. It is extremely easy to implement and reduces the trial print volume.
Saves test printing paper.

The same applies when replacing or re-adjusting the LES 20 ₁ and 20 ₂ .

However, depending on the shape of the register mark, LES20 ₁ , 20 ₂
By selecting the detection site by, it is possible to perform the register adjustment not only in the vertical direction but also in the horizontal direction.

Also, in FIG. 2, MPX22, GAT23, CUT26 to LAT
The 28 functions may be accommodated in the OPC 29 and realized by the CPU, or the OPC 29 may be configured by combining various logic circuits, and the like, and the like, and various modifications are possible.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, it becomes easy to mount and replace each sensor for the front surface and the back surface, and particularly, it is not necessary to adjust the separation distance with high accuracy.
A remarkable effect can be obtained in various double-sided multicolor rotary printing presses.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a flow chart of a calculation processing situation, FIG. 2 is a block diagram of an electric circuit, and FIG. 3 is the same color in the case where there is no register error between front and back sides. It is a figure which shows the positional relationship between a front surface register mark and a back surface register mark. 20 ₁ , 20 ₂ ...... LES (photoelectric sensor), 22 …… MPX (multiplexer), 26 …… CUT (counter), 27 …… DEF (differential circuit), 28 …… LAT (latch circuit), 29 …… OPC (arithmetic circuit), 30 ... RGS (registration switch).

Claims (1)

(57) [Claims] 1. A front surface sensor and a rear surface sensor of a plurality of respective colors are respectively detected by a front surface sensor and a rear surface sensor provided separately from each other to detect the register marks. In the device for automatically performing the register adjustment, each sensor is mounted, and the register positions of the register marks of the same color printed on the front surface and the back surface of the paper are matched by a manual operation, and then the The mounting distance between the respective sensors is calculated based on the detection output of each sensor by the register mark of the same color, and the calculated mounting distance is registered as a reference distance. The difference between the calculated distance based on the detection output of the sensor and the reference distance is obtained as the front / back surface registration error amount of the color, and based on the obtained front / back surface registration error amount. Error correction method for an automatic register adjustment device characterized by performing the front surface and the back surface of register adjustment of the color.