Toner Cartridge Life

This product detects the life of the toner cartridges using the following two methods:

• Detection by counting the dots of each colour that are necessary to create an image
• Detection by counting the rotations of the developer roller

The print operation will stop when either of the upper limits is reached. The upper limit is set above the number of dots or rotations that would be required for the cartridge to perform consistently with its advertised page yield. This function is intended to reduce the risk of poor print quality and damage to the machine.

There are two messages that indicate when the toner is low or needs replacing: Toner Low and Replace Toner.

Toner Low is displayed on the LCD when the number of dots or rotations of the developer roller nears its maximum count. Replace Toner is displayed on the LCD when the number of dots or rotations of the developer roller reaches its maximum count.

Colour Correction

The number of developer roller rotations that is counted may not only be for normal operations, such as printing and copying, but also for machine adjustments, such as Colour Calibration and Colour Registration.

Colour Calibration (Adjustment of Colour Density)

To obtain stable print quality, the density of each toner cartridge needs to be maintained at a fixed value. If the density balance between the colours cannot be kept, the tint becomes unstable, and accurate colour reproduction becomes impossible. The toner density can change due to chemical changes to the toner that affect its electrical charge, deterioration of the developer unit, and temperature and humidity levels in the machine. During calibration, the density level adjustment test patterns are printed on the belt unit.

Calibration is mainly performed at the following times:

• When you start the Colour Correction from the control panel or the printer driver to improve the colour density.
• When you replace a used toner cartridge or drum unit with a new one.
• When the machine detects that the ambient temperature and humidity have changed.
• When a specified number of printed pages is reached.

Colour Registration (Correction of Colour Position)

In this machine, the drum unit and developer unit are prepared for black (K), yellow (Y), magenta (M), and cyan (C), respectively. Four colour images are combined into one image, and therefore colour registration errors (for example, how the four colour images align) may occur. When registration errors occur, registration correction test patterns are printed on the belt unit.

Registration is mainly performed at the following times:

• When you start the Colour Correction to clear the colour registration error.
• When a specified number of printed pages is reached.