H. Error Detection Circuit1. OutlineFigure 6-109 is a block diagram showing the control circuit for the error detectioncircuit, and the circuit has the following functions:a. Monitoring the activation of the scanning lamp (LA1).b. Monitoring the activation of the fixing heater (main, H1; sub, H2).c. Monitoring the rotation of each motor in normal mode and in stream reading mode.Each function concentrates at the gate array on the DC controller PCB.The gate array detects the state of each appropriate load used for the detection ofan error, checks for the presence/absence of an error, and communicates the result tothe master CPU.Figure 6-1092. Scanning Lamp Error Activation Detection CircuitThe gate array receives the scanning lamp ON signal (CVRON) and the scanninglamp ON detection signal (CVR ACTIVE). If the scanning lamp is on in the absence ofthe scanning lamp ON signal, the gate array will identify an error.At this time, the gate array will communicate to the master CPU the wrong detectionand, at the same time, generates the power supply OFF signal.LA1H2H1RFPS4M3 M3LampregulatorPCBACdriverPCBMotorerrordetectionPCBGatearrayMasterCPUDC controller PCBCOPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 6 FIXING SYSTEM6-15
