Process and apparatus for replenishing developer in photoprinting machines

摘要

A process for replenishing developing medium in a developing chamber of a photoprinting machine and apparatus for performing the process. The process and apparatus for performing it utilizes at least one photocell in combination with various electrical and optical elements for measuring the concentration of developing medium in the developing chamber, comparing the measured value to a nominal value, and controlling the replenishing of the developing medium correspondingly.