Method for replenishing development replenisher in automatic developing machine for photosensitive lithographic printing plate precursor and automatic photosensitive lithographic printing plate precursor developing machine

A development replenisher replenishment method in an automatic developing machine for a photosensitive lithographic printing plate precursor, the method comprising:

• developing a plurality of sheets of exposed photosensitive lithographic printing plate precursors with a developer containing an electrolyte while replenishing a development replenisher to keep a developer activity constant,
• wherein an electric conductivity of the developer is measured every constant period,
• a set value of a time lapse replenishment rate is integrated to an integrated value of the time lapse replenishment rate every constant time;
• a set value of a processing replenishment rate is integrated to an integrated value of the processing replenishment rate every processing of a constant area of a photosensitive lithographic printing plate precursor(s);
• a percent replenisher replacement which is a ratio of a developer replenishment to a developer in a developing tank is calculated;
• a percent time lapse replenishment which is a ratio of a time lapse replenisher to a developer in a developing tank is calculated;
• and
• thereafter, when a sum of the integrated value of the time lapse replenishment rate and the integrated value of the processing replenishment rate exceeds a value of the lowest replenishment amount, and
• a set value of a replenishment system indicates an electric conductivity system, steps (A-1), (A-2), (A-3), (A-4), (A-5) and (A-6) are executed, or a set value of a replenishment system does not indicate an electric conductivity system, steps (B-1) and (B-2) are executed:
• (A-1) a time elapsed between the last time of replenishment and a present time is measured, and a first calculated value of an electric conductivity is calculated from the elapsed time and the percent replenisher replacement;
• (A-2) the set value of the time lapse replenishment rate and the set value of the processing replenishment rate are changed according to a result of a comparison of the first calculated value of the electric conductivity with the measured value of the electric conductivity of the developer;
• (A-3) a second calculated value of an electric conductivity is calculated by utilizing the percent replenisher replacement and the percent time replenishment;
• (A-4) the set value of the time lapse replenishment rate and the set value of the processing replenishment rate are changed according to a result of a comparison of the second calculated value of the electric conductivity with the measured value of the electric conductivity of the developer;
• (A-5) a developer in a developing tank is replenished with a replenisher in an amount corresponding to a sum of the integrated value of the time lapse replenishment rate and the integrated value of the processing replenishment rate;
• and
• (A-6) the integrated value of the time lapse replenishment rate and the integrated value of the processing replenishment rate are initialized,
• (B-1) a developer in a developing tank is replenished with a replenisher in an amount corresponding to a sum of the integrated value of the time lapse replenishment rate and the integrated value of the processing replenishment rate;
• and
• (B-2) the integrated value of the time lapse replenishment rate and the integrated value of the processing replenishment rate are initialized.