ELECTRO-PHOTO TYPE PRINTING MACHINE FOR PERFORMING PRINT PROCESS WITH CONSTANT IMAGE CONCENTRATION

摘要

PURPOSE: An electro-photo type printing machine is provided to perform a print process with a constant image concentration in spite of the change in humidity and temperature. CONSTITUTION: Four developing devices are mounted on inside of a case. A transfer device feeds a recording paper in order to be transferred toner images developed to the developing devices. The transfer device comprises two drive rollers, and a transfer belt wound by the drive rollers and for feeding the recording paper layed thereon. The developing device comprises a drum unit(100) and a developing unit(200). A thin layer roller(220) is mounted adjacent on a rotating developing roller(210). During the printing operation, temperature and humidity of the printing machine are measured by a temperature sensor and a humidity sensor. The measured data are transmitted to a central processing member and stored to a memory. The central processing member reduces the rotating speed of the thin layer roller by a motor controller when the measured concentration value is lower than the reference concentration value.