Other Control; Skew Correction Function; Feed Speed Control; Detecting The Machine Inside Temperature - Canon MF8100 Series Service Manual

Chapter 2
3. controls the speed at which paper is moved to suit the temperature inside the machine

2.4.2 Other Control

2.4.2.1 Skew Correction Function

This function is utilized to correct the skew of the paper to be fed, using the registration shutter method.
The operations of this function are discussed below.
When paper is fed to the registration roller, the leading edge of paper is pushed against the registration shutter to correct a skew (1). Paper is warped as the feed
roller keeps pushing it when it is pushed against the shutter (2). The shutter is lifted up by the stiffness of paper as paper warps, and paper passes through the shutter
(3). It allows the skew of paper to be corrected.

2.4.2.2 Feed Speed Control

In this control, a feed speed is changed based on the types of the fed paper in order to prevent fixing defects.
The DCNT Board changes a feed speed in two levels based on a paper type specification command sent from the SCNT Borad.
Types of paper and their feed speeds are indicated below.
Media type
Plain paper
Heavy paper
OHP sheet
Thick paper
Special paper
Envelope
Label

2.4.2.3 Detecting the Machine Inside Temperature

As a means to prevent overheating inside the machine, the machine is equipped with a thermistor (TH3) used to detect the temperature inside the machine (found
near the toner cartridge motor).
If the STNT board finds that the machine inside temperature has exceeded an upper limit (Td) at time of continuous printing/copying, it will increase the distance
between sheets to prevent overheating. If the temperature falls below a specific level (Tu), on the other hand, it changes the sheet-to-sheet distance to normal.
2-32
Paper
Registration shutter
[1]
Registration shutter
Registration roller
[2]
[3]
F-2-47
T-2-6
Print type
Full-color
Mono-color
Full-color
Mono-color
------------
Mono-color
Full-color
Mono-color
Full-color
Mono-color
Full-color
Mono-color
Full-color
Mono-color
Paper
Feed speed
Normal speed
Half speed
0008-1720
0008-1721
0008-1723