COPYRIGHT © 2000 CANON INC. 2000 2000 2000 2000 CANON iR5000/iR6000 REV.0 JULY 2000CHAPTER 4 IMAGE FORMATION SYSTEM4-19 P3.2 Controlling Primary Charging3.2.1 OutlineThe primary charging control system serves the following functions:1. Turning on/off the primary corona current.2. Controlling the primary corona current to a specific level.3. Controlling the grid bias to a specific level (fixed to 850 V by varistor).The system used to control primary charging is constructed as follows:F04-302-01The following signals are used:[1] primary charging leakage detection signal; ‘0’ upon detection of an excessively high orlow level of current.[2] primary corona current control signal; the output of the primary corona current turnsON when the voltage is about 3 V or higher or lower than 11 V; it turns OFF when thelevel is about 12 V or higher.[3] high-voltage remote signal; turns on/off the output of primary corona current.DC controller PCBHigh-voltage PCBJ102A J450212345678910111213141516 12345678910111213141516PR-LEAK-DETECT [1]PR/TR-REMOTE [3]Primary charging wireGrid wireT4506J45071400μAThe primary charging biaschanges as follows in keepingwith the potential of HV-PR.PR-CNT [2]3V 11V12V600μAHV-PRPrimary coronachargingDownload Free Service Manual at http://printer1.blogspot.com
