COPYRIGHT © 2000 CANON INC. 2000 2000 2000 2000 CANON iR5000/iR6000 REV.0 JULY 2000CHAPTER 4 IMAGE FORMATION SYSTEM4-23 P3.4 Controlling the Pre-Transfer Charging3.4.1 OutlineThe system used for pre-transfer charging serves the following functions:1. Controlling the DC bias to a specific level of current.2. Controlling the AC bias to a specific level of voltage.3. Controlling the output to suit the environment (fuzzy control).The system used to control the pre-transfer charging is constructed as follows:F04-304-01The following signals are used:[1] pre-transfer/separation charging leakage detection signal: ‘0’ when an excessively highor low level of current is detected.[2] pre-transfer charging control signal; the output of pre-transfer current turns ON whenthe voltage is about 3 V or more and less than 11 V; it turns OFF when the voltage isabout 12 V or more.[3] pre-transfer/separating charging remote signal; turns on/off the output of the pre-trans-fer/separation current.DC controller PCBJ510A J4502J450512345678910111213141516 12345678910111213141516PT/SP-REMOTE [3]PT/SP-LEAK-DETECT [1]High-voltage PCBPre-transfer charging wire123-300μAThe level of current of thepre-transfer bias varies as followsin keeping with the potential ofPT-SP-CNT.3V 11V12VPT/SP-CNTPT/SP-CNT [2]High-voltage ACtransformerT4501AC+DCDownload Free Service Manual at http://printer1.blogspot.com
