JP2003182021A - Method and device for judging increase/decrease of ink and dampening water of press, and apparatus for adjusting/controlling ink and dampening water of press using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To judge the change of ink and water in black ink and the change of an ink of a color other than black and water in consideration that the ratio between reflection intensity at the absorption wavelength of water and reflection intensity at the non-absorption wavelength of water (and ink) changes when water changes and to provide an apparatus for keeping the balance between ink and water by using the judgment method. <P>SOLUTION: Dampening water on the surface of the ink feed roll of an offset press, an emulsified ink film, is irradiated with infrared light N (or M) as reference light of the non-absorption wavelength of water and ink and infrared light W of the absorption wavelength of water, and the reflection signal intensity N<SB>1</SB>of the infrared light N (or M) and the reflection signal intensity W<SB>1</SB>of the infrared light W are measured by a photoelectric element. The present value N<SB>1</SB>by the infrared light N and the infrared light which are being measured is compared with a standard value D<SB>1</SB>to judge the increase/decrease of ink and water on the surface of the ink feed roll of the press. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in offset printing, measures the ink thin film on the ink supply roll surface to measure the variation in the ink amount and dampening water amount on the ink supply roll surface of the printing press, BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink and dampening water increase / decrease judging method and a judging device for judging increase / decrease of ink and dampening water of a printing machine, and an ink and dampening water adjusting controller of a printing machine using the same.

[0002]

2. Description of the Related Art Conventionally, in offset printing, printing is performed while supplying ink and dampening water. In order to stabilize the quality of the printed matter of this offset printing, it is important to maintain the balance between the ink and the dampening water. In the case of color printing, offset printing is usually performed with four color inks called process inks, namely, indigo (cyan), crimson (magenta), yellow (yellow), and black (black), except for special colors.

As a water content measuring device for these inks,
Optical sensors using infrared rays have been developed. Briefly explaining the measurement principle of this sensor, using infrared spectral absorption characteristics, wavelengths where ink absorption is large,
Using the wavelength at which water absorption is large, and the reference wavelength that is not affected by both ink and water, the calculation process is performed to calculate the ink film thickness and water film thickness. The water content is calculated from the film thickness. Then, by using this water content, control can be performed so as to balance the ink and the dampening water.

[0004]

The water content of indigo, red, and yellow inks can be measured with the above-described water content measuring device. However, with black ink, since absorption of infrared rays by carbon black is large, it is particularly difficult to measure the ink film thickness, the water content cannot be calculated, and the ink and dampening water cannot be balanced. There was a problem.

The present invention has been made in view of such problems, and the ratio of the reflection intensity at the absorption wavelength of water to the reflection intensity at the non-absorption wavelength of water (and ink) is changed when the water changes. Focusing on the difference, it is possible to determine the change of ink and water in black ink, and the change of ink and water other than black ink, and use that determination method to keep the balance of ink and water constant. It is intended to provide a device for keeping.

[0006]

In order to achieve the above object, the invention according to claim 1 of the present invention provides an ink film emulsified in a fountain solution on the surface of an ink supply roll of an offset printing machine with water and ink. Infrared light N as reference light of non-absorption wavelength
(Or M) and infrared light W having an absorption wavelength of water, respectively, are irradiated, and the reflected signal intensity N1 (or M1) of the infrared light N (or M) and the infrared light W are emitted by the photoelectric element. Of the reflection signal intensity W1 of the same or at a slight time difference, and the reflection signal intensity N1 (or M1) and the reflection signal intensity W1 in a good printing state are set as reference values D1 and D2 in advance, respectively. When the reflected signal intensities of the infrared light N (or M) and the infrared light W are set as the current values N1 (or M1) and W1, respectively, and the current value N1 exceeds the threshold value with respect to the reference value D1, R = W1 / N1-D2 / D1 If the variation value R is larger than the predetermined lower limit threshold value Trl and equal to or less than the upper limit threshold value Trh, the ink amount has changed. Trl <R ≦ Trh On the contrary, the fluctuation value R is less than or equal to the lower limit threshold Trl or the upper limit threshold If it is larger than Trh, then Trl ≧ R or Trh <R It is judged that the amount of dampening water has changed, and the increase / decrease in the amount of ink and water on the ink supply roll surface of the printing press is determined. This is a method for determining water increase / decrease.

The invention according to claim 2 of the present invention uses the discrimination method according to claim 1 to discriminate between increase and decrease of ink and water, and an apparatus for determining increase and decrease of ink and dampening water in a printing press. Is.

The invention according to claim 3 of the present invention uses the determination method according to claim 1 or the determination device according to claim 2, and uses an ink key or / and an ink transfer roll of an ink supply device of a printing press, and An ink and dampening water adjustment control device for a printing press, which controls a dampening water calling roll. An invention according to claim 4 of the present invention is an offset printing machine comprising the ink according to claim 3 and a dampening water adjustment control device.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention is shown in FIG. 1, which is an overall side view of an ink of a printing press, a dampening water supply device, and an ink and dampening water increase / decrease judging device of the printing press. The details will be described below with reference to the schematic block diagram of the method for determining the increase / decrease in the amount of ink and dampening water of the printing machine.

FIG. 1 is a side view of a dampening water and ink supply device in an offset printing machine. 1 is a plate cylinder having an offset printing plate 1a, and 2 is a blanket cylinder having a blanket 2a (transfer blanket cylinder). ) 3 is an impression cylinder, and the plate cylinder 1 is provided with a dampening water supply roll group 10 and an ink supply roll group 20.

The dampening water supply roll group 10 is, for example, a water tank 11 for storing dampening water 12, a fountain roll 13 immersed in the dampening water 12, a dampening water duct (conveying) roll 15, and a roll 13. A dampening water roll 14 that is alternately attached to and detached from a dampening water roll 15 and a dampening water roll that attaches dampening water of a dampening water duct roll 15 to the printing plate surface mounted on the peripheral surface of the plate cylinder 1. By controlling the contact time of the dampening water calling roll 14 with the duct roll 15, the amount of the dampening water 12 supplied to the dampening water depositing roll 16 and the printing plate 1a can be adjusted. There is.
There is also a method of controlling the amount of dampening water by controlling the rotation amount of the roll 13 while the roll 14 is in contact with the rolls 13 and 15.

The ink supply roll group 20 includes, for example, an ink fountain 21 that stores an ink 22 and an ink fountain roll 23 that rotates in contact with the ink 22 to take out the ink.
, An ink key K capable of opening and closing the gap k between the ink fountain 21 and the fountain roll 23, an ink duct roll 25, an ink transfer (swing) roll 24 which is alternately attached to and detached from the rolls 23 and 25, and an ink duct. A duct roll 26 that receives the ink conveyed from the roll 25 via an intermediate roll, and duct rolls 26a and 26b that convey the ink from the duct roll 26 toward the plate cylinder,
26c, 26d and each of the inking rolls 28a, 28b, 28c, 2 for receiving ink from the duct rolls 26a, 26d and adhering the ink to the surface of the printing plate 1a of the plate cylinder 1.
8d and an intermediate roll 27 provided between the inking rolls 28b and 28c, controlling the gap k (opening) by the ink key K and / or contacting the ink transfer roll 24 with the ink duct roll 25. The amount of ink supply can be adjusted by controlling the rotation time. It should be noted that the present invention is not limited to the configuration and arrangement of the rolls.

The printing plate 1 to which the dampening water is supplied (attached or applied) by the dampening water application roll 16 of the dampening water supply roll group 10.
The a-side is formed by the rotation of the plate cylinder 1 in the direction of the arrow, and the inking rolls 28a, 28b, 28c of the ink supply roll group 20,
When the ink reaches 28d, the ink adheres to the lipophilic image area of the printing plate 1a, and subsequently the ink of the image area transfers from the surface of the printing plate 1a to the surface of the blanket cylinder 2,
Then, the ink transferred to the surface of the blanket cylinder 2 is transferred and printed on the printing paper 40 introduced between the blanket cylinder 2 and the impression cylinder 3.

The dampening water supplied from the dampening water supply roll group 10 to the printing plate 1a is supplied to the inking rolls 28a, 28b, 28c and 28d of the ink supply roll group 20 and the inks adjacent to each of the forming rolls. When mixed with the ink adhering to the roll group, emulsification of the ink occurs on the roll surface, and the appropriate emulsified state of this emulsification phenomenon is obtained when the ink is adhered to the printing plate 1a surface by the inking roll. It also has the role of preventing ink from adhering to the hydrophilic non-image areas.

In the present invention, the ink supply roll group 2
0, metal ink duct rolls 26, 26a, 26b, 26c, 26d, 27 that are close to the surface of rubber inking rolls 28a, 28b, 28c, 28d having appropriate hardness. An ink film that is emulsified in dampening water that is generated by mixing dampening water with the ink film that adheres to the surface of the ink (for example, black ink used for printing, each ink of the printing three primary colors, or other various printing inks) It is performed by irradiating infrared light to measure the amount of reflected light reflected from the black ink coating on the surface of the roll, but the amount of transmitted light may be measured by making the roll transparent.

An embodiment of an ink and dampening water increase / decrease determination method of a printing machine according to the present invention will be described in detail below with reference to a side view of the dampening water and ink supply device of FIG. 1 and a block diagram of FIG. For example, the metal duct rolls 26, 26 shown in FIG.
Of the a, 26b, 26c, 26d, and 27, for example, one metal roll 26 on the downstream side in the rotation direction of the printing plate cylinder 1
d or rubber inking roll 28a, 28b, 28
Of the c and 28d, for example, an infrared light source unit 31 (for irradiating infrared rays on the surface of one of the rubber inking rolls 28d on the downstream side in the rotational direction of the printing plate cylinder 1 for irradiating the roll surface with infrared rays ( A light emitting unit) and a photosensor 32 (light receiving unit) that receives the infrared reflected light from the roll surface and detects the light amount thereof are provided.

For example, as shown in FIG. 1, infrared light is projected onto an ink film adhering to the surface of a duct roll 26d made of a metal, and a reflection signal of an infrared wavelength reflected from the ink film is measured. Sensor head (a light source unit 31 that emits infrared light and a photo sensor 3 that receives infrared reflected light)
Install 2).

Then, the measured value obtained by the sensor head is input to a computer 33 such as a personal computer, and the measured value is determined by a central processing unit in the computer 33 for judging the increase / decrease of ink and water and controlling the ink key and the water source roller. And the ink key based on the calculation result,
From the control instruction means 34 of the water source roller (opening and closing control instruction means for opening and closing the ink key by the electric motor and rotating peripheral speed instruction means of the fountain roll 23) to the ink fountain 21 and the fountain roll 23 on the ink dampening water supply device side of the printing machine. By transmitting an instruction signal, the ink supply amount and the dampening water supply amount are controlled by adjusting the opening degree of the ink key (gap k), the rotational peripheral speed of the fountain roll 23, and the contact rotation operation of the dampening water calling roll 14. To do. In FIG. 1, 35 is an ink key opening instruction signal transmission system, 36 is a rotational peripheral speed instruction transmission system of the fountain roll 23, and 37 is the dampening water amount of the dampening water supply roll group 10 (fountain solution calling roll 14). It is a control instruction transmission system.

Specifically, in an offset printing machine,
On the surface of the metal roller (reciprocating roller) of the unit that prints black ink, the wavelength W at which water absorption (absorbance) is large and the absorption at water and ink (light absorption) are small by using a sensor that measures the signal intensity of infrared rays. The infrared light reflection signal intensities W1 and N1 (or M1) due to the irradiation of infrared light of two kinds of wavelengths of the reference wavelength N (or M) are measured simultaneously (or with a slight time difference).

As the infrared light W (known) in the infrared wavelength region showing an absorption peak for water (pure water), infrared light having a wavelength of about 3000 nm is used. As the wavelength of the infrared light N exhibiting a small absorbance, for example, a wavelength of about 3300 nm on the longer wavelength side of the infrared light W (near 3000 nm), or a smaller absorbance for water and ink on the longer wavelength side. As the infrared light M shown, for example, infrared light having a wavelength of 3800 nm is used.

At a certain point of time, for example, during the printing operation, a reference wavelength which shows a small absorbance for water and ink, which is obtained in advance in a state where the printability and print reproducibility of the printed matter printed on the printing paper 40 is good. When the reflected signal intensity due to the irradiation of infrared light is used as a reference value and the change in the reflected signal intensity currently being measured exceeds the reference value by a threshold value, it is determined whether ink or water has changed, and the result Control based on.

The determination and control flow will be described below with reference to the flow chart of the method of the present invention shown in FIG.

First, the printing machine is rotated, and the dampening water 12 and the ink 22 are supplied to the surface of the printing plate 1a by the dampening water supply roll group 10 and the ink supply roll group 20 to start the printing operation. At the same time, of the ink supply roll group 20,
On the roll surface to be measured with the sensor head in close proximity,
Measurement of the amount of reflected light is started using infrared light N (or M) having a reference wavelength that exhibits low absorbance for water and ink S1: Reflection signal intensity N1 (by infrared light N (or M) having a reference wavelength) Or M1) (reflected light quantity) as a reference value D1
Further, the reflected signal intensity W1 (reflected light amount) by the infrared light W (known absorption wavelength of water) in the infrared wavelength region showing the absorbance peak for water (pure water) is taken in as the reference value D2. S2: Next, the current reflection signal intensity N1 (or M1) by the infrared light N (or M) that is the reference wavelength and the current reflection by the infrared light W that shows an absorption peak for water (pure water) Take in the signal strength W1. S3: Next, the current value N1 and the reference value D1 are compared,
Determine if the ink and water balance is out of balance. The current value N1 is larger than the value obtained by subtracting the lower limit threshold value Tdl (actual value is 0.003) from the reference value D1, and the reference value D1
If D1−Tdl <N1 ≦ D1 + Tdh is less than the value obtained by adding 1 to the upper limit threshold value Tdh (actual value is 0.003), it is determined that there is no particular change in water and ink, and the process proceeds to the next step S11. On the other hand, the current value W1 is the reference value D
If it is less than or equal to the value obtained by subtracting the lower limit threshold value Tdl from 1 or larger than the value obtained by adding the upper limit threshold value Tdh to the reference value D1, it is judged that the balance between water and ink is destroyed, and step S4 is performed.
Proceed to. S4: Next, it is determined which of ink and water is changing. From the current absorption wavelength W1 of water divided by the current reference wavelength N1 to the reference wavelength D1 of water absorption divided by the reference wavelength reference value D2, subtract that value as the fluctuation value R. To do. R = W1 / N1-D2 / D1 If the fluctuation value R is larger than the lower limit threshold value Trl (actual value is 0.02) and is less than or equal to the upper limit threshold value Trh (actual value is 0.02), then Trl <R≤ It is determined that the Trh ink has changed, and the process proceeds to step S5. On the contrary, if the fluctuation value R is less than or equal to the lower limit threshold value Trl or greater than the upper limit threshold value Trh, it is determined that Trl ≧ R or Trh <R water has changed, and the process proceeds to step S6. S5: In S5, the increase / decrease of ink is judged. The reference value D1 is subtracted from the current value N1 of the reference wavelength. If it is positive, the process proceeds to N1-D1> 0 S7, and if it is negative, the process proceeds to N1-D1 <0 S8. S6: In S6, the increase / decrease of water is determined. The reference value D1 is subtracted from the current value N1 of the reference wavelength, and if positive, the process proceeds to N1-D1> 0 S9, and if negative, proceeds to N1-D1 <0 S10. S7: In S7, in response to the signal in S5, the opening degree of the ink key in the ink fountain 21 of the ink supply device (gap k)
Is controlled automatically or manually by -1/10 in the closing direction to reduce the ink supply amount. S8: In S8, in response to the signal in S5, the ink supply amount is increased by automatically or manually controlling the opening (gap k) of the ink key by +1/10 in the opening direction. S9: In S9, in response to the signal in S6, the dampening water supply amount of the dampening water calling roll 14 of the dampening water supply roll group 10 is set to −.
The amount of dampening water supplied is reduced by automatic control or manual control in the decreasing direction by 1/10. S10: In S10, in response to the signal in S6, the dampening water supply amount of the dampening water calling rolls 14 of the dampening water supply roll group 10 is automatically or manually controlled in the increasing direction by +1/10 to dampen. Increase water supply. S11: In S11, if control is continued, return to S2,
The measurement is repeated as it is, and if not, the determination and control by the method of the present invention is terminated.

Although the present invention has been described with reference to the example of the black ink, it can be used for the printing ink other than the black ink. Further, the reference wavelength is not limited to one, and other infrared light may be used as long as the infrared light has low absorbance for water and ink.

[0025]

By using the present invention, ink and water can be balanced in black, and all four colors of indigo (cyan), red (magenta), yellow (yellow), and black (black) can be controlled. It is also possible to realize further stabilization of the printing quality, and it is possible to greatly reduce the load on the operator of the printing press. Further, by using the offset printing machine of the present invention, once the adjustment is performed at the beginning of printing, a printed matter having a stable color tone can be obtained until the end of printing.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a method and an apparatus of the present invention.

FIG. 2 is a schematic block diagram illustrating a method and apparatus of the present invention.

FIG. 3 is a flowchart showing a flow of judgment and control by the method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printing plate cylinder 2 ... Blanket cylinder 3 ... Impression cylinder 10 ... Damping water supply roll group 20 ... Ink supply roll group 31 ... Infrared light source part 32 ... Photo sensor 33 ... Computer 34 ... Ink and dampening water supply amount control Instruction means

Continued front page    F-term (reference) 2C034 BB23                 2C250 EA29

Claims (4)

[Claims] 1. An infrared light N (or M) as a reference light of a non-absorption wavelength of water and ink and an absorption wavelength of water on an ink film emulsified in a fountain solution on an ink supply roll surface of an offset printing machine. Infrared light of infrared light W is radiated, and the reflected signal intensity N1 (or M1) of infrared light N (or M) is emitted by the photoelectric element.
And the reflection signal intensity W1 of the infrared light W are measured simultaneously or with a slight time difference, and the reflection signal intensity N in a good printing state is measured.
1 (or M1) and the reflected signal intensity W1 are set as reference values D1 and D2 in advance, respectively, and the infrared light N (or M) currently being measured.
And the reflected signal intensity by the infrared light W are respectively the current value N
1 (or M1) and W1, the current value N1 is the reference value D1
When the threshold value is exceeded, the value obtained by the following equation is used as the fluctuation value R, and R = W1 / N1-D2 / D1 When the fluctuation value R is larger than the predetermined lower threshold value Trl and equal to or less than the upper threshold value Trh, Trl <R ≦ Trh It is judged that the ink amount has changed, and conversely, the fluctuation value R is less than or equal to the lower threshold Trl or the upper threshold T.
If it is larger than rh, Trl ≧ R or Trh <R It is judged that the amount of dampening water has changed, and the increase / decrease in the ink and water on the surface of the ink supply roll of the printing machine is discriminated. Water increase / decrease determination method. 2. An ink / fountain solution increase / decrease determination device for a printing press, wherein increase / decrease of ink and water is determined by using the determination method according to claim 1. 3. Use of the determination method according to claim 1 or the determination device according to claim 2 to control an ink key or / and an ink transfer roll and / or a dampening water feeding roll of an ink supply device of a printing press. Ink and dampening water adjustment control device for printing press, which is characterized by performing. 4. An offset printing machine comprising the ink according to claim 3 and a dampening water adjustment control device.