JPH0311900B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects registration errors between each color before printing starts in a multicolor printing press, automatically corrects the registration errors, and detects and displays twisting of the printing plate. This invention relates to an automatic register adjustment device.

In multicolor printing machines, it is necessary to perform register adjustment on the assumption that the printing on the paper by each color printing plate perfectly matches. Conventionally, register marks called register marks are printed for each color and the "misalignment" of these is checked. ”
The situation is visually judged, or the situation of the pattern printed for each color is visually judged, and the register is adjusted while performing a considerable amount of trial printing. This method requires a large amount of paper, takes a long time to adjust the register, and requires skill.

Recently, as a countermeasure for this drawback, a "registration adjustment device" (Special Publication No. 55-25062) has been developed to provide a "F"-shaped register mark on the surface of each color printing plate, to detect this photoelectrically, and to adjust the registration mark by the rotation of each color printing plate. Although methods have been proposed for calculating the relative relationship and adjusting the register before starting printing, it is not necessary due to the irregular rotational fluctuations unique to printing machines, electrical noise, and other external factors. However, this method does not reach the level of accuracy and high stability in register adjustment, and has the drawback that it is still insufficient for practical use.

On the other hand, even if the registration is perfectly adjusted, twisting may occur when the printing plate is attached to the plate cylinder.This twisting can be accurately detected and displayed, making it convenient to correct the twisting situation. There is a demand.

The present invention has an object of fundamentally solving the above-mentioned drawbacks and demands of the conventional art, and provides a triangular shape having sides in the left-right direction and sides inclined from the top-bottom direction to the left-right direction as a register mark provided on each color printing plate surface. Using a first register mark in the shape of a shape, the rotation status of the first register mark is detected by a reflective light emitting/receiving sensor, and
Based on the reference pulse obtained from the rotary encoder that rotates in synchronization with each plate cylinder on which each color printing plate is mounted, and the rotation pulse with a shorter period than this, the left and right side pulse signals obtained from the detection output of the light emitting and receiving sensor and the By obtaining the left-right side time difference signal and the first slope-side time difference signal using the 1-slope side pulse signal, and adjusting the vertical direction and the lateral direction for each plate cylinder according to the output after integrating these, In addition to stable and highly accurate register adjustment,
A second register mark having at least an inclined side from the vertical direction to the left and right is provided on the same vertical axis as the first register mark and at a part separated from the vertical direction, and the projected and received light is obtained accordingly. Process the detection output of the sensor in almost the same way as above,
The present invention provides an extremely effective register automatic adjustment device for a multicolor printing press that detects twist and also displays the twist status.

Hereinafter, details of the present invention will be explained with reference to figures showing examples.

FIG. 1 is a schematic diagram of a multicolor printing machine, in which paper 2 is fed from a paper feed section 1, and a blanket cylinder 3a among blanket cylinders 3a to 3d and impression cylinders 4a to 4d provided for each color is and impression cylinder 4a, passes between each blanket cylinder 3b-3d and impression cylinder 4a-4d via transfer cylinders 5a-5e, and is finally discharged by discharge cylinder 6. and each rubber cylinder 3a
~3d is a plate cylinder 7a~ equipped with printing plates for each color.
7d are in pressure contact, and the ink supplied to each printing plate of the printing cylinders 7a to 7d is transferred to the blanket cylinders 3a to 3d by the ink roller group 8 provided for each printing cylinder 7a to 7d,
This is further transferred to paper to perform multicolor printing.

However, each plate cylinder 7a to 7d is equipped with a motor for adjusting the phase in the vertical direction, that is, in the rotational direction.
M ₁ a to M ₁ d, and motors M ₂ a to M ₂ d for adjusting the positions of these in the left-right direction, that is, the axial direction, are provided, and due to the relationship described below, each plate cylinder 7 a to 7 d is Opposing reflective light emitting/receiving sensor 9
Further, a rotary encoder RE is connected to a transfer cylinder 5c which rotates in synchronization with each plate cylinder 7a to 7d.

FIG. 2 is a diagram showing the relationship between the plate cylinder 7 and the light emitting/receiving sensor 9. A triangular first register mark 22 is provided around the margin of the printing plate 21 mounted on the plate cylinder 7. The register mark 22 is formed to have a side 22a in the left-right direction and a side 22b inclined from the top to the bottom in the left-right direction. Fixed and adjustable in position.

In addition, a second register mark 23, which is triangular in this example, is also provided on the same vertical axis as the register mark 22 and at a portion spaced apart in the vertical direction, and is inclined at least from the vertical direction to the left-right direction. It is formed to have a curved side 23a.

FIG. 3 is a diagram showing details of the register marks 22 and 23 and the light emitting/receiving sensor 9. The lens 31
A light source from a light source 32 is projected as a spot, and changes in the amount of reflected light corresponding to the rotation of register marks 22 and 23 are detected by a light receiving element 3 such as a phototube.
3, the signal is converted into an electrical signal, amplified by an amplifier 34, and then sent out as a detection output.

FIG. 4 is a developed view showing a situation where the printing plate 21 is twisted and installed. If the printing plate 21 is twisted and installed, the register mark 23 will be deviated from the normal position indicated by the dotted line. , the time point at which the signal corresponding to the side 23a obtained from the detection output of the light emitting/receiving sensor 9 is generated changes, causing a delay compared to when the side 23a is in the normal position, and twisting is thereby detected. It has become a thing.

Furthermore, if a deviation occurs in the vertical register of the printing plate 21, the signal generation time from the light emitting/receiving sensor 9 corresponding to the side 22a of the register mark 22 will be different, while if a deviation occurs in the horizontal register, the register mark 2
The time point at which the signal is generated from the light emitting/receiving sensor 9 corresponding to the side 22b of 2 is different, and the register deviation in the vertical and horizontal directions is thereby detected.

FIG. 5 is a block diagram showing the entire configuration, and while the rotary encoder RE is commonly provided as shown in FIG. 1, the other parts are provided for each color plate cylinder 7a to 7d. It's getting old,
Details of the input section IND in FIG. 5 are shown in FIG. 6, details of the reference signal generation section FSG are shown in FIG. 7, details of the time difference detection sections TED ₁ to TED ₃ are shown in FIG. 8, and integration sections INT ₁ to
The details of INT ₃ are as shown in Figure 10.

In addition, the waveforms of each part in FIGS. 5 to 8 are as shown in the timing chart of FIG. 11, and the rotary encoder RE generates one reference pulse (a) per rotation, and
A rotation pulse (b) is generated in synchronization with this and with a shorter period than this, and in this example, the rotation pulse
(b) is generated 1000 times per rotation.

Therefore, the detection output (c) from the light emitting/receiving sensor 9
As shown in Fig. 6, is amplified by a pulse amplifier PA consisting of a variable gain amplifier circuit VGA and a differentiator circuit DF, and the leading edge and rear green of the detection output are differentiated to become a differentiated pulse (d). Reference signal generator
It is extracted via the gate circuit GC, which turns on in response to gate pulses (e ₁ ) to (e ₃ ) from the FSG, and becomes the extraction pulse (f), which is then subjected to waveform shaping and detection by the waveform shaper WF. done, register mark 2
Leading edge pulse signal (left and right side pulse signals) based on 2
and trailing edge pulse signal (first slope pulse signal)
Additionally, it is sent out as a pulse signal (second slope pulse signal) (g) based on the register mark 23.

However, the peak value of the extracted pulse (f) is given to the variable gain amplifier circuit VGA via the gain control circuit GCT, and the variable gain amplifier circuit VGA Since the gain of the detection output (c) is controlled, the detection output (c) is always at a constant peak value and then differentiated. Depending on the timing, a differential pulse (d) is obtained, and the differential pulse (d), which initially has non-uniform peak values, becomes an extracted pulse (f) with the same peak value through automatic gain control.

On the other hand, the reference signal generator FSG counts rotational pulses (b) using a counter CT that is reset by the reference pulse (a) from the rotary encoder RE as shown in Fig. 7, and the count output is decoded by the decoder DEC. Furthermore, pulse generation circuits PG ₁ and PG ₂ such as monostable multivibrators are driven, and gate pulses (e ₁ ) to (e ₃ ) and reference timing pulse (h ₁ ) are generated using the reference pulse (a) as a reference point.
~(h ₃ ), and in this example, the n-th and n+m-th and n+m-th pulses from the reference pulse (a) are generated.
In response to the +p-th rotation pulse (b), the reference timing pulses (h ₁ ), (h ₂ ), and (h ₃ ) are generated, and the n-l _1st , n+m-l _2nd , and n+m+p- l Gate pulses (e ₁ ), (e ₂ ), and (e ₃ ) are generated in response to _{the third} rotation pulse (b).

By gate pulses (e ₁ ) to (e ₃ ), only the required timing is extracted, and the leading edge and trailing edge pulse signals based on the register mark 22 and the register mark 2 from which noise components etc. have been removed are extracted.
The pulse signal (g) based on 3 is given to each of the time difference detection units TED ₁ and TED ₂ for register adjustment and the time difference detection unit TED ₃ for twist detection, and is sent to the reference signal generation unit.
Reference timing pulse from FSG ( _h1 ) to ( _h3 )
The leading edge and trailing edge time difference signals (i ₁ ) and (i ₂ ) and the time difference signal (i 3 ) of the pulse width corresponding to the time difference between the pulse width and the leading edge and trailing edge time difference signals (i ₃ ) are provided to the integrating circuits INT ₁ to INT ₃ respectively.

Note that the time difference detection units TED ₁ to TED ₃ are pulse generators PG using a monostable multivibrator or the like that generate pulses of the same time width according to the input, as shown in FIG. 8 as an example of the time _difference detection unit TED 1. ₃ ,
It is composed of PG ₄ and inhibit gates G ₁ and G ₂ , and operates as shown in FIG. 9, which shows the waveforms of each part in FIG. 8.

That is, in FIGS. 8 and 9, the time difference between the leading edge pulse signal in the leading edge and trailing edge pulse signals (1) based on the register mark 22 and the reference timing pulse (2) is detected, and the time difference between the leading edge pulse signal and the reference timing pulse (2) is detected. Pulses (4) to (7) are generated in response to the edge pulse signal and reference timing pulse (2), and pulses (4) and (7) and gate pulse (3) are applied to the input of inhibit gate _G1. , pulses (5) and (6), and gate pulse (3) are given to the input of inhibit gate G ₂ , so the output (8) of inhibit gate G ₁ is:
The time difference when the leading edge pulse signal (1) occurs later than the reference pulse (2) is extracted, and the output of the inhibit gate _G2 is the leading edge pulse signal (1) with respect to the reference pulse (2). The time difference when the progress occurs is extracted, and the output (8) is the time difference signal i
The output (9) is sent out as a time difference signal i.

In addition, in the time difference detection unit TED ₂ , since (h ₂ ) is given as the reference timing pulse (1) and (e ₂ ) is given as the gate pulse (3), the trailing edge pulse based on the register mark 22 is The time difference from the signal is extracted, and in the time difference detection unit TED ₃ , (h ₃ ) is given as the reference timing pulse (1) and (e ₃ ) is given as the gate pulse (3), so the register mark The time difference with the pulse signal based on the trailing edge of 23 is extracted.

The time difference signals (i ₁ ) to (i ₃ ) repeatedly generated in response to the rotation of the printing plate 7 are respectively applied to differential type integration units INT ₁ to _{INT 3} shown in FIG. , is applied to capacitors C ₁ and C ₂ via resistors R ₁ and R ₂ depending on the positive or negative polarity, and receives an integral action from these, and is also applied from operational amplifier OP, capacitor C ₃ , and resistor R ₃ . The signals are smoothed by an integrator and sent out as outputs corresponding to leading and trailing edge time difference signals (i ₁ ), (i ₂ ) and time difference signal (i ₃ ).

However, a bias voltage from the power supply Vcc is applied between both inputs of the operational amplifier OP by resistors R ₄ , R ₅ , R ₆ and potentiometer RV, and according to the adjustment of potentiometer RV, Output can be forced to zero, and detection output can be
The leading edge and trailing edge of (c) and each time difference signal (i ₁ ) ~
The relative relationship with (i ₃ ) can be set in detail.

The respective outputs of the time difference detection units TED ₁ , TED ₂ and the corresponding integration units INT ₁ , INT ₂ for register adjustment are connected to a 3-phase AC power supply 3φAC intermittently according to the input voltage, and
Since the polarity corresponding to the input polarity is given to the output parts OTD ₁ and OTD _{2 which are sent to the motors M 1 and M 2 respectively ,} the voltage and polarity from each output part OTD ₁ and OTD ₂ are applied to the motors M ₁ and OTD 2. _M2 rotates to perform vertical phase adjustment and horizontal position adjustment with respect to the plate cylinder 7.

That is, as is clear from FIGS. 2, 3, and 11, the leading edge of the detection output (c) by the register mark 22 changes in time depending on the rotational phase of the plate cylinder 7, and this Leading edge pulse signal
Since the time point at which (g) occurs changes, if the pulse width of the leading edge time difference signal (i ₁ ) changes accordingly, the output voltage of the integrating section INT ₁ will also change, and this change will decrease. By controlling the motor M ₁ in the direction, vertical register adjustment is automatically performed, and equilibrium is achieved in a state where the leading edge time difference signal (i ₁ ) is no longer generated.

Further, the register adjustment in the left and right direction is similarly performed based on the trailing edge of the detection output (c) by the register mark 22, and equilibrium is achieved in a state where the trailing edge time difference signal (i ₂ ) is no longer generated.

However, the optimal state can also be artificially set by adjusting the potentiometer RV shown in FIG. 10 as described above.

Note that the output units OTD ₁ and OTD ₂ may be configured by a comparator, a pulse generation circuit, a thyristor, a relay, or the like.

On the other hand, the output of the time difference detection section TED ₃ for twist detection and the corresponding integration section INT ₃ is given to an analog-to-digital converter (hereinafter referred to as ADC) A/D, where it is converted into a digital signal and then transferred to the memory MM. After the contents are read out sequentially, they are sent to the printer PT as a display unit via the output unit OTD ₃ , and the detected amount of twist is printed out and displayed to the operator. .

However, it _is necessary to display the twist after register adjustment _is completely completed.
When the output of the output section OTD 3 becomes zero, the output of the output section OTD ₃ is sent out.

Note that the output unit OTD ₃ is composed of a decoder, a drive circuit, a gate circuit, and the like.

Therefore, registration adjustment in the vertical and horizontal directions is automatically performed, and the twist that occurs when the printing plate 21 is attached to the plate cylinder 7 is accurately displayed, making it extremely easy to correct the twist.

However, the register mark 22 may be formed to have a side 22a in the left-right direction and an inclined side 22b, and the register mark 23 may also be formed to have an inclined side 23a, and the printer PT The same effect can be obtained by using a character display or the like instead of the memory MM.If an analog memory is used as the memory MM, the ADC/A/D can be inserted into the output side of the memory MM, and the configuration of each part is the same. The present invention can be modified in various ways, such as any selection as long as it has a function.

As is clear from the above explanation, according to the present invention, since the input section has an automatic gain function, each pulse signal can be obtained accurately according to the horizontal side and the inclined side of the detection output, and the register mark The detection status is reliable even when there is dirt, etc. Furthermore, by inserting an integral section between the detection section and the output section, highly accurate and stable register adjustment is possible despite the unique rotational characteristics of the printing machine. This is done before the start of printing, and since the twist of the printing plate mounting situation is accurately displayed, it has a remarkable effect on multi-color printing presses for various purposes.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, Fig. 1 is a schematic configuration diagram of a multicolor printing press, Fig. 2 is a diagram showing the relationship between the plate cylinder and the light emitting/receiving sensor, and Fig. 3 is a register mark and the emitting/receiving light sensor. 4 is a developed view showing the situation in which the printing plate is twisted and installed, FIG. 5 is a block diagram of the entire configuration, and FIG. 6 is a block diagram of the input section.
FIG. 7 is a block diagram of the reference signal generation section, FIG. 8 is a block diagram of the time difference detection section, FIG. 9 is a timing chart showing waveforms of each part in FIG.
FIG. 0 is a circuit diagram of the integrating section, and FIG. 11 is a timing chart showing waveforms of each section in FIGS. 5 to 8. 7, 7a to 7d... plate cylinder, 9, 9a to 9d...
Light emitting/receiving sensor, 21... printing plate, 22, 23... register mark, 22a, 22b, 23a... side,
RE...Rotary encoder, IND...Input section,
TED ₁ ~ TED ₃ ... Time difference detection section, INT ₁ ~ _{INT 3}
...Integrator section, OTD ₁ to OTD ₃ ...Output section, M ₁ ,
_M1a ~ _M1d , _M2 , _M2a ~ _M2d ...Motor, GCT...
...gain control circuit, OP...operational amplifier, PT...printer.

Claims (1)

[Scope of Claims] 1. A first register mark provided on each printing plate surface mounted on each plate cylinder of a multicolor printing machine, and having sides in the left-right direction and sides inclined from the vertical direction toward the left-right direction. and a second register mark provided on the same axis in the vertical direction as the first register mark and at a part separated in the vertical direction and having at least a side inclined from the vertical direction to the left-right direction; and each of the plates. The first member rotates in the vertical direction together with the body.
and a reflective light emitting/receiving sensor provided for each of said respective register marks to detect a second register mark, and a reference pulse shorter than said reference pulse rotating in synchronization with said each plate cylinder a rotary encoder that generates a periodic rotational pulse; and a rotary encoder that differentiates the detection output of the light emitting/receiving sensor as a constant peak value by automatic gain control, and uses the reference pulse as a reference time to differentiate the detection output based on the first register mark. outputting a left and right side pulse signal corresponding to the side in the left and right direction and a first slope side pulse signal corresponding to the sloped side, and outputting a first slope side pulse signal corresponding to the sloped side of the detection output based on the second register mark; an input section provided corresponding to the light emitting/receiving sensor that outputs a second inclined side pulse signal; and a predetermined number of rotation pulses from the left and right side pulse signals, the first inclined side pulse signal, and a reference pulse of the rotary encoder. a time difference detection unit for register adjustment that generates a left and right side time difference signal and a first slope side time difference signal according to a time difference with a reference timing pulse output at the counted timing; and the second slope side pulse signal and the rotary encoder. a time difference detection section for detecting torsion that generates a second slope side time difference signal according to a time difference with a reference timing pulse output at a timing when a predetermined number of rotation pulses are counted from the reference pulse; an integrating section provided for each of the time difference detecting sections that integrates the output individually; and an integrating section provided for each of the time difference detecting sections that integrates the output of each of the plate cylinders according to the output corresponding to the left and right side time difference signals of the integrating section corresponding to the time difference detecting section for register adjustment. In addition to adjusting the vertical phase,
an output section provided for each integrating section corresponding to the time difference detection section for register adjustment, which adjusts the horizontal position of each plate cylinder according to the output corresponding to the first inclined side time difference signal; an output section that sends out a signal for display according to the output of the integration section corresponding to the time difference detection section for detecting twist after the vertical direction adjustment and the left and right direction adjustment are performed by the section; and an output section driven by the output section. An automatic register adjustment device for a multicolor printing press, characterized by comprising a display section.