JPH058816B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a printing plate processing liquid replenishing device that keeps the activity of a processing liquid for processing printing plates constant.

[Prior Art] As a printing plate processing device, a printing plate is conveyed to a position above a processing liquid tank, and a processing liquid stored in the processing tank is sprayed onto the printing plate via a liquid jetting means. Some types return the processing liquid to the processing liquid tank. As printing plates with exposed images processed by this printing plate processing device, there are, for example, positive-type and negative-type photosensitive printing plates, and the positive-type photosensitive printing plates contain an O-quinonediazide compound on a support. Some are provided with a photosensitive layer containing a composition.

By the way, when the photosensitive layer of a positive-working photosensitive printing plate containing an O-quinonediazide compound is exposed to actinic light through a transparency, the O present in the exposed area is
- Quinonediazide compound changes to carboxylic acid,
The solubility is increased by alkaline processing liquid, and a positive image is formed when developed.

In addition, a negative photosensitive printing plate containing a photosensitive diazo compound on a support may be given solubility in an alkaline processing liquid by, for example, mixing or combining a compound having an acid group such as a carboxylic acid. Many photosensitive layers are used in which areas exposed to light decompose and become insoluble in water, so that those areas remain as an image upon development.

As described above, by developing with an alkaline processing solution, compounds with carboxylic acid groups dissolved in the processing solution and other acid components contained in the photosensitive layer, as well as carbonic acid dissolved from the air, are removed. The gas etc. neutralize and consume the alkaline components in the processing liquid. That is, by developing a photoreceptor having such an alkali-soluble component or a photosensitive material containing a photoreceptor having an alkali-soluble component, the alkaline component in the processing solution is reduced.

If the activity of the processing solution decreases due to a decrease in the alkaline component in the processing solution, and the developing ability becomes insufficient, in addition to preparing a new processing solution and replacing the entire amount, A method has been used to restore the developing activity of the processing solution by replenishing the reduced amount of the components.

An example of replenishing the treatment liquid is to calculate the average size of the amount of printing plates processed over a predetermined period of time and replenish a certain amount every time one printing plate is processed.
In addition, when the power to the printing plate processing device is turned on, time is measured from that point on, and after a certain period of time has elapsed, a fixed time is measured based on a predetermined time, regardless of the printing plate processing time or processing stop time. There is one that replenishes the amount of replenishing fluid.

[Problems to be Solved by the Invention] However, with the conventional system that replenishes a fixed amount of replenisher each time one sheet is processed, it is difficult to process a large number of printing plates that are smaller or larger than the average size. On the other hand, even with a method that measures time and replenishes a fixed amount of replenisher, there are cases where only a small amount of printing plates are processed within a predetermined period of time, and there are cases where a large amount of printing plates are processed.

When printing plates are processed in this way, the amount of alkaline components may increase due to excessive replenishment, or the amount of alkaline components may decrease due to insufficient replenishment, making it impossible to obtain appropriate sensitivity. This causes skipped dots or missing dots, which is one of the causes of poor printing durability and poor inking as a printing plate. For this reason, for example, it was necessary to develop the control piece several times a day and manage the alkaline component.

This invention was made in view of such circumstances,
It is an object of the present invention to provide a printing plate processing liquid replenishing device capable of replenishing the replenishing liquid in accordance with the actual processing of printing plates and performing accurate replenishment.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the printing plate processing liquid replenishing device of the present invention transports the printing plate to a position above the processing liquid tank, and replenishes the printing plate on the printing plate in the processing tank. The printing plate processing apparatus includes a printing plate type detection means for detecting the type of the printing plate, and a printing plate type detection means for detecting the type of the printing plate; non-image area calculating means for calculating the area of the non-image area of the printing plate according to the process; processing time measuring means for measuring the ejection time or stop time of the liquid ejecting means; and the area of the non-image area of the printing plate and the processing time. The present invention is characterized by comprising a replenishment amount calculation means for calculating the replenishment amount of the replenishment liquid based on the replenishment amount, and a replenishment means for replenishing the processing liquid tank with the calculated replenishment amount.

[Function] In this invention, the amount of replenishment liquid is calculated based on the area of the non-image area of the printing plate and the processing time, and the calculated amount of replenishment is replenished into the processing liquid tank, and the amount of replenishment is calculated according to the actual processing of the printing plate. and replenish the replenisher.

[Example] Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

In the figure, reference numeral 1 denotes a printing plate processing device, and this printing plate processing device 1 is equipped with a processing liquid tank 2 . The printing plate 3 is conveyed to a position above the processing liquid tank 2, and the processing liquid stored in the processing tank 2 is sprayed onto the printing plate 3 via the liquid jetting means 100, and the sprayed processing liquid is sent to the processing tank 2. It's starting to go back. A replenishing liquid is supplied to the processing liquid tank 2 from a replenishing means 4.

The replenishment means 4 is driven by a control section 5, and the control section 5 receives detection signals from a sensor 6, which is an area detection means of the printing plate 3, and a printing plate type detection means 7, which detects the type of the printing plate 3. is input. That is, the sensor 6 senses the width and conveyance speed of the printing plate 3, and inputs a signal related to the width and conveyance speed to the conversion circuit 8 of the control section 5. In this embodiment, reflective sensors are used as the sensors 6, and a plurality of sensors are arranged in the insertion section of the printing plate processing device 1 so as to be orthogonal to the conveyance direction of the printing plate 3. The sensor 6 can also be a transmission sensor, a microswitch, a continuous light receiver, etc.

The printing plate type detection means 7 receives a signal from, for example, a manual type set button. Since the film thickness of the photosensitive layer differs depending on the type of printing plate 3, the type is set by manually operating the type set button, and the printing plate type detection means 7 detects the type of printing plate 3 from the set signal. This detection signal is sent to the non-image area ratio circuit 9 of the control section 5. Instead of inputting from the type set button, the printing plate type detection means 7 may be configured to automatically detect a signal obtained from the amount of reflection from the sensor 6 at the insertion end of the printing plate.

The non-image area ratio circuit 9 is the printing plate type detection means 7
Based on the signal from the printing plate 3, a coefficient of the non-image area ratio according to the film thickness is obtained according to the type of the printing plate 3, and this non-image area information is output to the counter 10. This non-image area ratio can be arbitrarily set, for example, from 10% to 100%, and for example, the average non-image area ratio of the printing plate 3 used for two weeks to one month is input as information.

The conversion circuit 8 converts the signal from the sensor 6 into a voltage, calculates the area from the width of the printing plate 3 and the length determined from the conveyance speed, and outputs the area to the counter 10. The counter 10 calculates and integrates the area of the non-image area based on the area information from the conversion circuit 8 and the non-image area ratio information from the non-image area ratio circuit 9.

When a plurality of printing plates 3 are processed, the integrated amount of area of the non-image area until a certain predetermined value is reached and, for example, the amount of replenishment liquid determined according to the area are counted. The integrated amount of area of the non-image portion is counted by a fixed amount and integrated until it reaches a certain predetermined value. For example, the area for replenishment is counted in increments of 0.01 m, and the integrated value can be varied from 1 m to 99.9 m. The non-image area ratio circuit 9, the conversion circuit 8, and the counter 10 constitute a non-image area calculating means 20 for calculating the area of the non-image area of the printing plate 3 according to the type of the printing plate 3.

The timer 11 measures and integrates the ejection operation time of the liquid ejecting means 100 for processing the printing plate 3 based on the detection signal from the sensor 6, and also
The timer 11 measures and adds up the injection operation stop time of 0, and this timer 11 controls the liquid injection means 100.
A processing time measuring means 21 is configured to measure the injection time or injection stop time.

Correction information for fatigue due to air oxidation due to injecting the processing liquid is obtained from the measurement integration of the injection operation time, and on the other hand, fatigue over time due to air oxidation when the processing liquid is stationary is obtained from the measurement integration of the injection operation stop time. We are trying to obtain correction information for fatigue due to

The arithmetic circuit 12 compares and calculates the set value of the replenishment amount from the integrated area value of the non-image area from the counter 10 and the air oxidation fatigue information from the timer 11, and sends a signal to the driver circuit 13 until they match. This calculation circuit 12 constitutes a replenishment amount calculation means 22 that calculates the amount of replenishment liquid based on the area of the non-image area of the printing plate 3 and the processing time. Driver circuit 13
drives the replenishing means 4, and the replenishing means 4 supplies the replenishing liquid to the processing liquid tank 2, and by replenishing the processing liquid tank 2 with the calculated replenishment amount, the alkaline activity of the processing liquid is kept constant. I'm learning to keep it that way.

Next, the operation of this embodiment will be explained.

First, before inserting the printing plate 3 on which the image has been exposed into the printing plate processing device 1, the printing plate type detection means 7 detects a coefficient based on the film thickness according to the type of the printing plate 3 to be developed in the non-image area. The non-image area ratio is input to the ratio circuit 9, and the non-image area ratio is selected and stored.

Next, the printing plate processing device 1 starts developing the printing plate 3, but at the same time as the printing plate 3 is inserted, the sensor 6 obtains a signal regarding the width of the printing plate 3 and the conveyance speed, and converts this signal. The area of the printing plate 3 is calculated by inputting it to the circuit 8.

Then, the counter 10 multiplies the area of the printing plate 3 by the non-image area ratio from the non-image area area ratio circuit 9.
The integrated value of the area of the non-image area and the amount of replenishment liquid corresponding to the integrated value of the area are counted.

On the other hand, the detection signal of the sensor 6 is input to the timer 11, and from this detection signal, the timer 11 measures the injection operation time and the injection operation stop time during which the liquid injection means 100 injects and processes the processing liquid onto the printing plate 3. and is accumulated. From this injection operation time and injection operation stop time, correction information for fatigue due to air oxidation due to injecting the processing liquid and correction information for fatigue due to aging fatigue due to air oxidation when the processing liquid is in a stationary state are obtained.

The information from the counter 10 and timer 11 is input to the arithmetic circuit 12, and the replenishment amount is obtained from the printing plate processing fatigue and the air oxidation fatigue of the processing liquid from the integrated area value of the non-image area, and the replenishment of this replenishment amount is completed. A drive signal is output from the arithmetic circuit 12 to the driver circuit 13 until
A replenisher 4 supplies a replenisher to the processing liquid tank 2 .

In the above embodiment, the timer 11 measures both the injection operation time and the injection operation stop time of the liquid injection means 100, but at least one of them is measured to replenish the air oxidation fatigue of the processing liquid. Good too.

[Effects of the Invention] As described above, the present invention calculates the replenishment amount of replenisher based on the area of the non-image area of the printing plate and the processing time,
Since the processing liquid tank is replenished with this calculated replenishment amount, the replenishment liquid can be replenished in accordance with the actual processing of printing plates, and accurate replenishment can be performed.
Therefore, even when developing a large amount of printing plates with sizes that deviate from the average size, or regardless of the length of the processing time, an appropriate amount of replenishment can be obtained and the alkaline activity of the processing solution can be maintained at an appropriate level. is,
Sensitivity changes are reduced. Therefore, there is no need to manage the alkaline component liquid, and replenishment of the processing liquid is simple and reliable, allowing long-term use.

[Brief explanation of the drawing]

The figure is a schematic diagram of a printing plate processing apparatus of the present invention. 1... Printing plate processing device, 2... Processing liquid tank, 3...
...Printing plate, 4...Replenishment means, 5...Control unit, 6...
...Sensor, 7...Printing plate type detection means, 8...Conversion circuit, 9...Non-image area ratio circuit, 10...Counter, 12...Arithmetic circuit, 13...Driver circuit, 20...Non-image area ratio circuit part calculation means, 21...processing time measurement means, 22...replenishment amount calculation means.

Claims (1)

[Claims] 1. A printing plate in which a printing plate is transported to a position above a processing liquid tank, a processing liquid stored in the processing tank is sprayed onto the printing plate via a liquid jetting means, and the sprayed processing liquid is returned to the processing liquid tank. In the processing device, a printing plate type detection means for detecting the type of the printing plate, a non-image area calculation means for calculating the area of the non-image area of the printing plate according to the type of the printing plate, and an ejection time or the amount of time of the liquid ejection means. processing time measuring means for measuring the ejection stop time; replenishment amount calculation means for calculating the replenishment amount of the replenisher based on the non-image area of the printing plate and the processing time;
A printing plate processing liquid replenishing device comprising a replenishing means for replenishing the processing liquid tank with the calculated replenishment amount.