JP2002196503A - Method for controlling development activity of developer and automatic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling development activity of developer and an automatic control device which easily estimates the development activity at real time without consuming the developer and always keeps the optimum development conditions. SOLUTION: A graph of conductivity versus absorbance corresponding to concentration value is prepared by measuring the concentration value using a concentration scale and the conductivity and absorbance for an arbitrary developer, and the effective region of the conductivity and absorbance corresponding to the development activity is determined. The conductivity and absorbance before a development operation or during the same is measured and, on the basis of the measurement result, the developer or water is supplied in such a manner that a plot of the conductivity versus absorbance is positioned within the effective region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for controlling the developing activity of a developer and an automatic controller.

[0002]

2. Description of the Related Art In the field of graphic arts, a developing process using an alkali developing solution is performed as one of the steps for forming an image. The plate for offset printing is generally of the type in which an image area / non-image area is formed by an alkali developing solution and finished in a printable state. Since the quality of an image formed by developing solution processing depends on the developing activity, it is indispensable to accurately grasp the developing activity in real time in order to maintain a stable developing state. However, at present, it is impossible to measure development activity in real time as described below.

In general, the developing activity of an alkali developing solution strongly depends on the alkali concentration. However, it is not possible to measure the pH of a strong alkaline solution such as a developer with a pH meter with sufficient accuracy. Further, in the case of the neutralization titration, the developer is consumed every time the measurement is performed, so that it is not suitable for repeated measurement or real-time measurement. Therefore, the measured value of conductivity by a conductivity meter is used as an index to grasp the development activity, or the concentration scale is developed with a developer, and the extent to which development is completed is visually measured, and based on the result, The development activity was ascertained. And
The development activity was predicted from the measurement results, and the developer or water was manually replenished to adjust the development activity.

[0004]

With respect to estimating the alkali concentration only by measuring the conductivity with a conductivity meter, the conductivity is strongly affected by the developing object and the like dissolved in the developing solution by performing the developing process. Therefore, the developing activity cannot be accurately grasped with respect to the developer after the development. On the other hand, when processing the density scale with the developer and making a decision based on the result, it is necessary to perform the density scale processing with the developer each time and try it. Can not grasp the state of. In either case, the replenishment of the developer or water is performed manually, which is troublesome, and intermittent adjustment cannot be performed during the development work on the developing machine. After the change of the liquid occurs, it becomes the later work.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing method capable of easily and in real time estimating a developing activity on a developing machine without depleting a developing solution, and capable of always maintaining optimum developing conditions. A method for controlling the developing activity of a solution and the developing activity is easily and real-time estimated on a developing machine without depleting the developing solution, and the developer or water is automatically replenished based on the result of the estimation of the developing activity. It is to provide an automatic control device.

[0006]

According to the first aspect of the present invention, there is provided an apparatus for solving the above-mentioned problems relating to the control method.
"For a large number of developers, a density scale is immersed in the developer, and the density at a predetermined point on the density scale is measured with a densitometer, and the conductivity and absorbance of the developer are measured, and the conductivity corresponding to the density value is measured. Make a graph of the degree of absorbance versus absorbance, determine the range of effective conductivity and absorbance corresponding to the development activity,
Measuring the conductivity and absorbance of the developing solution before or during the developing operation, and replenishing the developing solution or water based on the measurement result such that a plot of the conductivity versus the absorbance is located within the effective area. A method for controlling the developing activity of a developer. ”.

According to a second aspect of the present invention, there is provided an automatic control apparatus comprising: a conductivity measuring means for measuring the conductivity of a developer in real time; An absorbance measuring means for measuring, a computer electrically connected to the conductivity measuring means and the absorbance measuring means, and a replenishing means for a developer or water electrically connected to the computer, The computer has a function of determining the strength of the developing activity of the developer from the measured values of the conductivity and the absorbance, and determining a replenishing amount of the developer or water, and the replenishing means is the developer or the developer sent from the computer. An automatic control apparatus for developing activity of a developing solution, wherein the developing solution or the developing activity is automatically controlled by a control signal based on a replenishing amount of water. The the gist.

According to the method for controlling the developing activity of a developer according to the present invention, the developer can be easily processed on a developing machine without depleting the developer.
In addition, the development activity can be estimated in real time, and the optimum development conditions can be always maintained. In addition, it is not necessary to replenish the developing solution or water by immersing the density scale in the developing solution during the developing operation and measuring the density value to judge the strength of the developing activity, thereby reducing the time and labor cost. Becomes possible.

Further, according to the automatic developing activity control apparatus of the present invention, the developing activity is estimated in real time, and the developing solution or water is automatically replenished based on the estimation result to always provide the optimum developing activity. Conditions can be kept.

[0010]

Next, the method for adjusting the developing activity of the developer according to the present invention will be specifically described.

First, as shown in FIG. 1, a density scale is immersed in a large number of developing solutions, and the density at one point on the density scale is measured with a densitometer. The conductivity and absorbance of the developer are measured for the developer having this concentration value, and the measured conductivity vs. absorbance points are plotted on a graph of conductivity vs. absorbance as shown in FIG. Then, a range of effective conductivity and absorbance corresponding to the development activity is determined. In the example shown in FIG.
B and C are density values obtained as a result of the measurement of a developer having a developing activity, and the effective range is a region between a curve 1 connecting the plots of density A and a curve 2 connecting the plots of density C. After determining the effective range in this way, the conductivity and absorbance of the developer used or in use are measured and plotted on the graph, and the plot of absorbance versus conductivity is within the effective area. It is checked whether it is out of the effective range, and if it is out of the effective range, a new developer or water is added to adjust the plot of absorbance vs. conductivity so as to be within the effective area. Also, when it is expected to go out of the effective range in the near future, a new developer or water is similarly added and the plot of absorbance vs. conductivity is adjusted so as to be located within the effective range.

Next, an apparatus for automatically controlling the developing activity of a developing solution according to the present invention, to which the above-described method for controlling the developing activity of the developing solution is applied, will be described. FIG. 3 is a schematic diagram of the automatic control device of the present invention. The automatic control device includes a conductivity measuring device 3 for measuring the conductivity of the developer in real time, an absorbance measuring device 4 for measuring the absorbance of the developer in real time, the conductivity measuring device 3 and the absorbance measurement. A personal computer 5 electrically connected to the device 4 and a developer or water replenishing device 6 electrically connected to the personal computer 5 are provided. The personal computer 5
It has a function of determining the level of development activity of the developer from the measured values of the conductivity and the absorbance, and determining the replenishment amount of the developer or water. The developer or water replenishing device 6 is configured to automatically replenish the developer or water based on information on the amount of replenishment of the developer or water sent from the personal computer 5. In the drawing, reference numeral 7 denotes an automatic developing device, and 8 denotes a preheater.

The function of the automatic control device according to the present invention will be described. During the developing operation, the conductivity and the absorbance are measured in real time by the conductivity measuring device 3 and the absorbance measuring device 4, and the measurement result is sent to the personal computer 5. The effective conductivity and absorbance range (effective range) corresponding to the development activity is stored in the memory of the personal computer 5, and the strength of the development activity of the developer is determined based on the measured values of the conductivity and the absorbance and the effective range. Is determined, and the replenishing amount of the developer or water is determined. A control signal based on the replenishing amount of the developing solution or water determined by the personal computer is sent to the developing solution or water replenishing device 6,
The developer or water replenisher 6 is controlled by the control signal to supply a necessary amount of the developer or water to the automatic developing device, so that optimum developing conditions are always maintained.

[0014]

As described above in detail, according to the method for controlling the developing activity of the developing solution of the present invention, the developing activity can be easily and real-time estimated on a developing machine without depleting the developing solution. It is possible to always maintain the optimum developing conditions. In addition, it is not necessary to replenish the developing solution or water by immersing the density scale in the developing solution during the developing operation and measuring the density value to judge the strength of the developing activity, thereby reducing the time and labor cost. Becomes possible.

According to the automatic control device for developing activity of the developing solution of the present invention, the developing activity is estimated in real time, and the developing solution or water is automatically replenished based on the estimation result, so that the optimum developing activity is always obtained. Conditions can be kept.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a process of measuring development activity on a density scale.

FIG. 2 is a graph of conductivity versus absorbance.

FIG. 3 is a schematic view of an automatic control device for developing activity of a developer according to the present invention.

[Explanation of symbols]

 1 Curve connecting plot of conductivity vs. absorbance of concentration A 2 Curve connecting plot of conductivity vs. absorbance of concentration B 3 Conductivity measuring device 4 Absorbance measuring device 5 Personal computer 6 Replenisher for developing solution or water 7 Automatic development Equipment 8 Preheater

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) // G01N 21/27 G01N 21/27 F (72) Inventor Yoshio Sagawa 1-chome, Ichigaya-Kagacho, Shinjuku-ku, Tokyo No. 1-1 Inside Dai Nippon Printing Co., Ltd. (72) Inventor Shuji Kayama 1-1-1 Ichigaya Kagacho, Shinjuku-ku, Tokyo F-term inside Dai Nippon Printing Co., Ltd. 2G059 AA01 BB04 EE01 MM12 2H096 AA06 GA02 GA60 LA30 2H098 BA14 DA16 DA23 DA28 EA03

Claims (2)

[Claims] 1. A method for immersing a density scale in a large number of developing solutions, measuring the density at a predetermined point on the density scale with a densitometer, and measuring the conductivity and the absorbance of the developing solution. Prepare a graph of conductivity versus absorbance corresponding to, determine the effective conductivity and absorbance range corresponding to the development activity, measure the conductivity and absorbance of the developer before or during the development work, A method for controlling the developing activity of a developer, comprising replenishing a developer or water such that a plot of conductivity versus absorbance is located within the effective area based on the measurement result. 2. An electric conductivity measuring means for measuring the conductivity of the developer in real time, an absorbance measuring means for measuring the absorbance of the developer in real time, and an electric power supply for the conductivity measuring means and the absorbance measuring means. And a replenishing means for the developer or water electrically connected to the computer. The computer determines the strength of the developing activity of the developer from the measured values of the conductivity and the absorbance. Has a function of determining the replenishing amount of the developing solution or water, and the replenishing means is controlled by a control signal based on the replenishing amount of the developing solution or water sent from the computer and automatically replenishes the developing solution or water. An automatic control device for developing activity of a developer.