The machine uses its image stabilization control mechanism to prevent lowering of image quality (e.g., in the form of a faulty image) otherwise caused by changes

in the environment or deterioration of the photosensitive drum or toner.

The machine's image stabilization control mechanism may be any of 3 types: Image density corrective control (D-max control), Image halftone corrective control

(D-half control), Color Misregistration Corrective Control.

2.4.3.2 Image density correction control (D-max control)

This control is to stabilize the image density of the printer engine.

If the prescribed condition is met, DC controller PCB performs D-max control in the following procedure.

1. Measure the each density detection pattern made on the ITB.

2. According to the measured density of each pattern, controls the primary charge bias and developing bias to get the appropriate density.

The following is the conditions that trigger the image density correction control

- When the power is ON

At power ON, Out-of-Register Colors Correction is suspended until the initial print process is completed and the machine is ready or until 15 min passes after

the power ON. The time setting can be changed from Option > Device Settings > Startup Settings in printer status window.

Startup Settings

Execute Later

2-8

Developing bias

circuit

Cartridge

Secondary transfer

external roller

ITB cleaning roller

bias circuit

Calibration