B. Controlling the Intensity of the Scanning Lamp1. OutlineFigure 4-105 shows the circuit used to control the intensity of the scanning lamp, andthe circuit has the following functions:q Turning on and off the scanning lamp.w Controlling the intensity of the scanning lamp.• Keeps the intensity to a specific level in spite of changes in the power supplyvoltage.• Controls the intensity to suit changes in the sensitivity of the drum.• Controls the intensity to suit the setting of the Copy Density key.• Controls the intensity (AE control) to suit the density of the original.e Checking the activation of the scanning lamp.Figure 4-105Q156Micro-processor(master)D/AconverterQ159Errordetectioncircuit12VPWOFFJ111B-6J111B-7J111B-8CVRONLINTLAONJ503-4J503-2J503-2Lamp activationcircuitPower switchSW1ThermalfuseTP2ScanninglampJ501-1Arc circuitLamp regulator PCBDC controller PCBHIM1Differentialamplification/phase controlpower voltagecircuitJ501-3COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 4 IMAGE FORMATION SYSTEM4-6Download service manual and resetter printer at http://printer1.blogspot.com
