Changes in the laser output cause changes in the surface potential. To maintain a specific level of surface potential, the machine corrects the laser output control

value. The following shows the type and the particulars of laser output control value correction:

Main power

switch ON

(1) Between-Sheet APC Control

Purpose: to maintain a specific level of surface potential without lowering the productivity during a continuous job; the machine measures the potential after

laser output between sheets, and corrects the laser output control value.

Timing: over the 1st interval between sheets every 1 min after the start of a continuous print job.

Potential measurement: the drum potential varies in drum peripheral direction; thus, the machine computes the average drum surface potential in drum

peripheral direction. It uses the result of computation to determine the laser output correction value. If measurement is not possible because of conditions

imposed by the need for measurement between sheets, the machine will continue measurement for an additional 1 min.

(2) Initial Rotation APC Control

Purpose: to make up for the changes in the VL potential of the laser output occurring after an appreciable time, the machine measures the drum potential and

corrects the laser output control value.

Timing: during initial rotation of the 1st job 60 min after the end of a job.

Potential measurement: the drum potential varies in peripheral direction, and the machine computes the average drum potential in peripheral direction. The

machine uses the result of computation to obtain the appropriate laser output correction value.

(3) Last Rotation APC Control

Purpose: when intermittent printing is repeated at short intervals, the absence of potential control can cause changes in the VL potential of the laser output.

To make up for the changes, the machine computes a correction value for the laser output control value and uses the result for the next job.

Timing: during last rotation for the 1st job 30 min after the most recent laser output correction.

Potential measurement: the drum potential varies in peripheral direction. The machine computes the average drum potential in peripheral direction, and

obtains the appropriate laser output correction value using the result of computation.

SERVICE MODE:

COPIER>OPTION>BODY>LAPS-SW (switching laser correction)

0: ON (left alone for 10 min -> initial rotation APC)

1: ON (left alone for 60 min -> initial rotation APC; default)

2: ON (left alone for 120 min -> initial rotation APC)

3: OFF only for initial rotation APC

4: OFF

7.4.7 Adjusting the Density in Various Modes

iR5065 / iR 5055 / iR5075 / iR5075N / iR5065N / iR5055N

The machine corrects the development bias determined as a result of potential control for the following operating modes, and uses the result as the target value for

the individual modes:

Fixing assembly temperature 195 C

WMUP

Potential sensor

Laser

Secondary

charging

Resulting

potential

Printer

Copier

potential