When the throughput down control is ON, print speed is switched step by step depending on the paper type or the temperature on the edge of the fixing sleeve etc.

Following shows the print speed list in case of the minimum throughput.

Plain paper/Plain paper H/Recycled paper/Color paper

Heavy paper 1/Heavy paper 2/Rough paper

Transparency

Postcard/Return postal card

9.2.5 Feeding Speed Control

The machine switches the paper feeding speed depending on the type of paper fed in order to prevent a fixing failure.

The DC controller switches the paper feeding speed over 4 settings (1/1 speed, 4/5 speed, 1/2 speed, 2/5 speed) depending on the paper type specified by the main

controller.

9.2.6 Warp Control

To prevent an image failure, it is necessary to keep the paper warped at an appropriate level between the fixing assembly and the ETB.

When the paper transport speed of the pressure roller is slower than that of the ETB, the paper warp increases, and an image defect or paper crease occurs. Con-

versely, the speed is faster than that of the ETB, the paper is pulled by the pressure roller, and a color displacement occurs in the sub-scanning direction.

The machine controls the rotational speed of the fixing motor (M1), which drives the pressure roller, to keep an appropriate level of paper warp.

When the paper is warped, the paper loop flag is pressed up, and the paper loop sensor (SR6001) is turned ON. In this case, the DC controller increases the rotational

speed of the fixing motor.

When the paper loop sensor is turned OFF, the DC controller determines that the level of paper warp is small and decreases the rotational speed of the fixing motor.

Fixing sleeve

Fixing pressure roller rotational speed is faster

than ETB feeding speed.

MEMO:

If there are appropriate distance between the transfer unit and the fixing assembly in the product, this control is not necessary to make paper warped.

However, since the machine performs vertical feeding and it is necessary to minimize its height, no distance can be secured between the transfer unit and the fixing

assembly. Therefore, it is necessary to perform warp control.

9-8

Paper

Type

Paper

Grammage

Plain paper

60 to 105 g/m2

Thick paper

105 to 120 g/m2

Thick paper

121 to 176 g/m2