Chapter 88-10If an optimum grid bias cannot be selected after measuring the surface potential of the drum several times, a corrective control sequence is started todetermine the optimum grid bias.F-8-128.3.6 Determining the Optimum Laser Output0006-9604iR105i/iR105+ / iR9070 / iR85+ / iR8070The laser output is determined so that the surface potential (light area potential VL) of the drum at time of laser exposure will be identical to the targetpotential.F-8-138.3.7 Laser Output Corrective Control0006-9606iR105i/iR105+ / iR9070 / iR85+ / iR8070If an optimum laser output cannot be selected after measuring the surface potential of the drum several times, a corrective control sequence is started todetermine the optimum laser output.WMUPRWMUP STBY195˚C 200˚CGrid bias500V 600V 700V Vg Vg1 Vg2 Vg3 Vg8VD1VD-NGVD2VD3VD-NG VD1 VD2 VD3 VD8Target VDMeasurement is continued while varying the level ofthe grid bias so as to attain the target VD. If the measurement is identical to the target VD,control is ended. Measurements are taken as manyas 8 times; at times, an approximate level (to thetarget VD) may be used.Primary chargingbias (DC)Potential controlsequence started Corrective controlsequence startedThe grid bias (vg) needed toattain the target VD isdetermined.PotentialsensorWMUPRWMUP STBY195˚C 200˚CPotentialsensorLaserReference outputReference output -10%-10%-20%-20%Measurement(VL1)Measurement(VL2) Measurement(VL3)PwVL1VL2VL3Laser outputThe relationship between the surface potential of thedrum (VL) and the laser output is determined basedon measurements taken several times.If the target VL is obtained atthis measurement, control isended; otherwise, correctivecontrol is stated.Activation usingthe reference outputdetermined at time ofshipment.Activation at an output 10%lower than the referenceoutput.The laser output (P)needed to attain the targetVL is determined.Developingbias (DC)Measurement(target VL)
