JPH0567229B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used in an automatic developing machine to replenish a developer replenisher according to the degree of fatigue of the developer when developing a large number of photosensitive planographic printing plates. The present invention relates to a developer replenisher replenishing device for a photosensitive lithographic printing plate developing machine.

[Prior art] When processing a photosensitive lithographic printing plate using an automatic processor, the developing ability of the developer generally deteriorates as processing progresses, and if processing continues, non-image areas of the photosensitive layer will be eluted. The ability to do so will be significantly reduced, leading to poor development. The factors that cause this development defect are processing fatigue caused by components eluted from the photosensitive layer consuming the effective components in the developer, and if the developer is alkaline, it absorbs carbon dioxide gas from the air over time. However, the alkalinity decreases due to the neutralization reaction, and when the active ingredient in the developer is alcohol, the alcohol evaporates over time, resulting in fatigue over time.

There are various methods for detecting the degree of fatigue of the developer, for example. A method is known in which the remaining state of the photoresist film in the non-image area of a photosensitive lithographic printing plate is measured as an AC impedance value, and replenishment is performed based on the measured value. That is, this method is based on the principle that as the degree of fatigue of the developer increases, the elution rate of the photoresist film in the non-image area slows down, so that the measured impedance value increases.

For this reason, one method is to dispose a fatigue level detection sensor in the developing section, and detect the leading edge of the photosensitive planographic printing plate with the insertion detection sensor disposed on the insertion side of the developing section. A known method is to detect the degree of fatigue of the developer after a period of time has elapsed using a fatigue level detection sensor, and when this detected value reaches a preset value, replenish the replenisher to recover the fatigue of the developer.

In order to detect the remaining state of the photoresist film, it is preferable to collect data after a predetermined period of time has elapsed after the tip of the photosensitive lithographic printing plate was inserted and the photoresist film has been dissolved to some extent. For this reason, an insertion detection sensor is arranged upstream of the entrance roller to detect the conveyance of the leading end of the photosensitive planographic printing plate (see time chart in FIG. 4).

[Problems to be Solved by the Invention] However, when the photosensitive lithographic printing plate is detected at the leading end in the transport direction, if the transport speed is different, the non-image of the photosensitive lithographic printing plate at a specific position within the development zone may be detected. Because the dissolved state (residual state) differs,
There are cases where measurements cannot be performed in the optimum state (a state in which the photoresist film is dissolved to some extent before it is completely dissolved), and optimum data cannot be obtained. Furthermore, the distance between the insertion roller and the ejection roller differs depending on the model, and it is necessary to change the setting of the time for each model.

Further, when the dimension of the photosensitive planographic printing plate in the conveying direction is short, data may be taken after the rear end of the photosensitive planographic printing plate is separated from the insertion roller. In this case, since the data is obtained in a state where the developer has flowed down from the photosensitive layer of the photosensitive lithographic printing plate, the true impedance value of the developer cannot be measured.

Furthermore, when applied to a model in which the output side conveyance roller is a so-called flower-shaped roller, vibration occurs during conveyance of photosensitive planographic printing, and the impedance varies accordingly, so that an appropriate value may not be obtained.

In consideration of the above facts, the present invention measures the accurate impedance according to the degree of fatigue of the developer using a fatigue level detection sensor, and replenishes the replenisher at the optimal timing even if the replenisher is refilled intermittently. It is an object of the present invention to provide a development replenisher replenishing device for a photosensitive lithographic printing plate developing machine that can eliminate waste of replenisher.

[Means for Solving the Problems] The developer replenisher replenishing device of the photosensitive lithographic printing plate developing machine according to the present invention includes an insertion detection sensor that is disposed on the insertion side of the developing section and detects the presence of the photosensitive lithographic printing plate. ,
a fatigue level detection sensor disposed in the developing section to detect the fatigue level of the developer; a storage means for storing the output of the fatigue level detection sensor; and a point at which the presence of the photosensitive lithographic printing plate is no longer detected. calculating means for calculating the average value of the fatigue level stored in the storage means within a previous predetermined time range; and replenishing the replenisher by comparing the average value calculated by the calculating means with a predetermined value set in advance. and replenishing means for replenishing the developer with a replenisher when it is determined that replenishment is necessary.

[Function] When the insertion detection sensor detects the leading edge of the photosensitive lithographic printing plate being conveyed to the development section on the insertion side of the development section, the fatigue level detection sensor starts detecting the fatigue level of the developer, and this deterioration is detected. The temperature is periodically detected at predetermined time intervals and the data is stored sequentially.

Next, when the trailing edge of the photosensitive lithographic printing plate is detected by the insertion detection sensor, the data acquisition is stopped, and the calculation means calculates the average value based on the data from a predetermined period of time from this point. This average value data is compared with a predetermined value.

The predetermined value is the lowest usable level of the developer, and if the average value data is inferior to this predetermined value, the developer is replenished with a replenisher so that optimal development work can be performed thereafter.

In this way, from among the detected fatigue degrees, accurate fatigue degree data (when the photosensitive lithographic printing plate is no longer detected) is determined based on the state in which the photosensitive film of the photosensitive lithographic printing plate is dissolved to some extent before it is completely dissolved. Since the replenisher is replenished based on the average value within a predetermined time range before the time when the replenisher is ).

In addition, since the replenisher is refilled based on a preset predetermined value in this way, the amount of replenishment fluid at one time is constant, and the replenishment amount is calculated and refilled according to the ever-changing fatigue level. Control is easier than control (for example, control such as replenishing at Xl/min per 1Ω of fatigue level).

[Example] FIG. 1 shows a photosensitive planographic printing plate developing machine 30 according to this example.

A pair of insertion rollers 32 is disposed on the insertion side of the developing section 31 of the photosensitive planographic printing plate developing machine 30.
The photosensitive planographic printing plate 34 is held between the insertion rollers 32 and conveyed in the direction of arrow A in FIG. 1 by the driving force of a driving means (not shown).

A pair of ejection rollers 36 having the same shape as the insertion roller 32 are disposed on the ejection side of the developing section 31, and when the photosensitive planographic printing plate 34 is conveyed by the insertion roller 32 and its leading end reaches the ejection roller 36, This is clamped and sent to the next process.

A plurality of injectors 38 are disposed above the photosensitive lithographic printing plate conveyance path of the developing section 31, and a plurality of injectors 38 are disposed above the photosensitive planographic printing plate conveyance path of the developing section 31.
0 discharge port. This injector 38 is communicated by a circulation pipe 42 to the bottom of a receptacle 44 for developer 40 disposed below the developing section 31 . A pump 46 is interposed in the middle of the circulation pipe 42 and pumps out the developer 40 from the receiving tray 44 and sends it to the injector 38.

Additionally, a replenishment pipe 48 is provided at the opening of the saucer 44.
A discharge port is provided, and the rear end communicates with a replenishment tank 50. A pump 52 is interposed in the middle of the replenishment pipe 48, and when a pump operating relay 56 is actuated and energized by a signal from a microcomputer 54, the replenisher 58 is pumped from the replenisher tank into the saucer 4.
4 is being replenished.

An insertion detection sensor 60 is connected to the microcomputer 54 to detect the insertion state of the photosensitive planographic printing plate 34.
A signal line 62 of the developer 40 is connected to a signal line 66 of a fatigue level detection sensor 64 that measures the fatigue level of the developer 40 as impedance.

The insertion detection sensor 60 is disposed upstream of the insertion roller 32 of the developing section 31, and inputs a high-level signal from the time the leading edge of the photosensitive planographic printing plate 34 is conveyed until the trailing edge passes. Output to output port 68, and other low level signals to input/output port 6
8 (see Figure 2).

Note that at the time when the rear end of the photosensitive planographic printing plate 34 is detected by the insertion detection sensor 60, the intermediate portion of the photosensitive planographic printing plate 34 is at least close to the insertion roller 32.
It is held between.

A pair of electrodes 64A and 64B are provided at the tip of the fatigue level detection sensor 64. Here, when the developer 40 is injected from the injector 38, the developer 40 is retained above the photosensitive layer of the photosensitive lithographic printing plate 34, and the electrodes 64A and 64B are immersed in the developer.
The impedance of the system to be measured (system containing the support of the photosensitive lithographic printing plate, the remaining photosensitive film, and the developer) can be measured.

As shown in FIG. 2, this measured value is input to the input/output port 68 via the A/D converter 70. The measurement of this impedance is
It is performed every 10 msec, and the storage device 72 (RAM)
It's starting to be remembered. Storage device 72
(RAM), when the number of measurements reaches 100, that is, 1 second, the data is sent to the CPU 74, the average value is calculated, and this average value is stored again in the storage device 74.
(RAM). By repeating this, the storage device 72 (RAM)
impedance values are stored in a table format every second.

As shown in FIG. 3, this measurement is performed only when the insertion detection sensor 60 becomes high level. When the rear end of the photosensitive lithographic printing plate 34 is detected by the insertion detection sensor 60, data for a predetermined time (P seconds) going back a predetermined time (N seconds) from this point is input to the CPU 74, and the data is averaged over the P seconds. The value (R) is now calculated. This average value (R) is compared with a replenishment timing level (R ₀ ) stored in advance in the storage device 76 (ROM). Depending on the result of this comparison, if the impedance of the developer 40 exceeds a predetermined value, a signal is sent from the microcomputer 54 to the pump operating relay 56. Here, the predetermined time (N) is 5 seconds, and the predetermined time (P) is 3 seconds.
Preferably, it is seconds.

The operation of this embodiment will be explained below.

The developer 40 is pumped into the saucer 4 by the operation of the pump 46.
4 and sent to the injector 38 via the circulation pipe 42. The developer 40 is injected from the injector 38 and reaches the tray 44 again. In this way, the developer 40 is constantly circulated.

When the photosensitive planographic printing plate 34 is conveyed, its leading end is first detected by the insertion detection sensor 60 before reaching the developing section 31, and a high-level signal is input to the microcomputer 54.

When the plate is held between the insertion rollers 32 and sent to the developing section 31, the developer 40 flows out onto the photosensitive layer of the photosensitive lithographic printing plate 34, and the non-image areas of the photosensitive layer are eluted and developed.

Further, in parallel with this, when the signal of the insertion detection sensor 60 becomes high level, the fatigue level detection sensor 64 starts measuring the impedance of the developer 40.
As shown in the time chart of FIG. 3, when the leading edge of the photosensitive planographic printing plate 34 is detected, the photosensitive planographic printing plate 34 has not reached below the fatigue level detection sensor 64, so the impedance value is constant. shows a high level of Here, as the photosensitive planographic printing plate 34 is gradually conveyed and reaches below the fatigue level detection sensor 64, the developer 40 is retained on the photosensitive layer surface of the photosensitive planographic printing plate 34, so the impedance value becomes smaller. . The microcomputer 54 measures this impedance value every 10 msec from the time when the insertion detection sensor becomes high level, stores it in the storage device 72 (RAM), calculates the average value every 100 measurements, and then calculates the average value again. The values are converted into a table and stored in the storage device 72 (RAM).

Next, when the rear end of the photosensitive lithographic printing plate 34 is detected by the insertion detection sensor 60, the fatigue level detection sensor 64 stops measuring the impedance of the measurement system, and the storage device 72 (RAM) stores data for a predetermined period of time (P = 3 seconds). developer 40
When the plate becomes fatigued, the solubility of the photoresist film in the non-image area decreases and the remaining photoresist film increases, resulting in a high impedance value. However, this impedance value data indicates that the rear end of the photosensitive lithographic printing plate 34 is It is preferable to import data that has gone back a predetermined period of time (N=5 seconds) from the time of detection, and the average value (R) of this 3 second data is applied as the true value of whether or not replenishment is possible.

A replenishment timing level (R ₀ ) is stored in advance in the storage device 76 (ROM), and the average value (R) of data is determined by the CPU as this replenishment timing level (R ₀ ).
If R ₀ <R, a signal is sent to the pump operating relay 56 and power is supplied to the pump 52 via the pump operating relay 56 . When the pump 52 is activated, a certain amount of replenisher is replenished into the saucer 44, and the operation of the pump 52 is stopped.

In this way, it is determined whether or not to replenish the replenisher after confirming that the rear end of the photosensitive planographic printing plate 34 has been detected, so that at least the photosensitive planographic printing plate 34 is placed on the insertion roller 32. This ensures that the fatigue level detection sensor 64 is immersed in the developer 40.

Therefore, there is no need to change the timing of measuring the impedance of the developer 40 depending on the size of the photosensitive planographic printing plate 34 in the conveying direction, making adjustment before work easier. Further, even if the distance between the insertion roller 32 and the ejection roller 36 differs depending on the model, the photosensitive planographic printing plate 34 will not pass the fatigue level detection sensor 64 arrangement area, and the fatigue level detection sensor 64 will detect the impedance in the air. Misdiagnosis such as measuring

Furthermore, even in models in which so-called flower-shaped rollers are applied to the insertion or ejection rollers 32 and 36, the predetermined time P
Since the average value is taken, there will be no misdiagnosis when comparing with the replenishment timing level.

[Effects of the Invention] As explained above, the developer replenisher replenisher for a photosensitive lithographic printing plate developing machine according to the present invention uses a replenisher whose impedance is accurately measured according to the degree of fatigue of the developer using a fatigue level detection sensor. Even if the replenisher is refilled intermittently, the replenisher can be replenished at the optimal timing and has the excellent effect of eliminating waste of replenisher.

[Brief explanation of the drawing]

FIG. 1 is a front view of a photosensitive planographic printing plate developing machine according to this embodiment, FIG. 2 is a block diagram of a replenisher replenishing device applied to the photosensitive planographic printing plate developing machine, and FIG. 3 is a front view of a photosensitive planographic printing plate developing machine according to this embodiment. FIG. 4 is a time chart of the conventional insertion detection sensor and fatigue level detection sensor. 30... Photosensitive planographic printing plate developing machine, 31... Developing section, 40... Developer, 54... Microcomputer, 60... Insertion detection sensor, 64... Fatigue level detection sensor.

Claims (1)

[Scope of Claims] 1. An insertion detection sensor that is arranged on the insertion side of the developing section and detects the presence of a photosensitive lithographic printing plate; A fatigue level detection sensor that is arranged inside the developing section and detects the fatigue level of the developer; a storage means for storing the output of the fatigue level detection sensor; and calculating an average value of the fatigue levels stored in the storage means within a predetermined time range before the time when the presence of the photosensitive lithographic printing plate is no longer detected. and a replenishing means for replenishing the developer with the replenisher when it is determined that replenishment of the replenisher is necessary by comparing the average value calculated by the calculation means with a predetermined value set in advance. A developer replenisher replenishing device for a photosensitive lithographic printing plate developing machine.