Various Control Mechanisms; Controlling The Speed Of The Fixing Roller - Canon iR C6800 Series Service Manual

9.3 Various Control Mechanisms

9.3.1 Controlling the Speed of the Fixing Roller

9.3.1.1 Controlling the Speed According to Paper Type
The machine controls the fixing roller to any of 3 speeds according to paper yep.
Mono color print
Color print
9.3.1.2 Controlling the Speed for Large Volume Printing (down sequence)
If the main thermistor (THM1) of the machine's fixing roller identifies the surface temperature of the fixing roller as
being any of the following, the machine starts down sequence, in which distance between sheets is increased to
decrease the speed of printing, thereby preventing poor fixing otherwise caused by drops in the roller temperature
when continuous printing is under way.
The speed of printing is relatively low in color mode and, therefore, the temperature of the fixing roller rarely drops,
thus not calling for down sequence.
The following is a table of control mechanisms used for down sequence prepared according to site environments and
paper types; the notations within the table indicate the following:
LV: down sequence level
deg C: temperature of the fixing roller triggering down sequence
PPM: printing speed
Toner fixing starts to fail when the temperature of the fixing roller drops to level 4 or below. The machine, therefore,
stops (suspends) printing when it detects a level 4 condition; it then starts (resumes) printing using the speed it used
at the start when the temperature of the fixing roller returns to the recovery level.
If the room temperature is less than 20 deg C and heavy paper or a transparency is used, the machine reduces its print
speed (except when heavy paper 1 is used for the 120V or 230V model).
T-9-4
Paper type
plain paper
heavy paper, transparency, postcard
plain paper (64 to 105 g/m2)
heavy paper (106 to 163 g/m2), postcard
heavy paper 2 (164 to 209 g/m2), heavy paper 3
(210 to 250 g/m2), transparency
Fixing speed
normal speed (276 mm/sec)
normal speed (276 mm/sec)
normal speed (276 mm/sec)
2/3 speed (184 mm/sec)
1/3 speed (92 mm/sec)
Chapter 9
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