COPYRIGHT © 2000 CANON INC. 2000 2000 2000 2000 CANON iR5000/iR6000 REV.0 JULY 2000CHAPTER 4 IMAGE FORMATION SYSTEM4-12 P2.3 Determining the Laser OutputTo measure the light area potential (VL1) after the power switch is turned on, the poten-tial based on the previous laser output (LP0) is let to flow, and the surface potential of thedrum is measured by the potential sensor.The DC controller PCB compares the surface potential of the drum against the target po-tential; if the measured potential is ±6 V or higher, the potential of the laser output is cor-rected, and the potential is corrected once again.The potential is measured as many as eight times, and the laser output is corrected asmany as eight times. In addition, the developing bias for light area (VL2) is measured underthe corrective conditions used to determine the laser output (LP) needed for target potential.F04-203-01WMUPRWMUP STBY200˚CPotential sensorDeveloping bias(DC)LaserLP0 LP0 LP0 LP0 LP0 LPVL1 VL1 VL1 TargetVL1VL1VL1Correction controlsequence startFixing assemblytemperature 195˚CVL1+6V-6VVL1VL1VL1Previous potentialTarget VL1Potential controlsequence startVL2Download Free Service Manual at http://printer1.blogspot.com
