Olivetti d-Color MF4003 Service Manual page 620

d-Color MF4003/MF3303
[3] Fusing lever
[5] Fusing heater lamp (HL1)
[7] Heating roller thermostat (TS1)
[9] Pressure roller thermistor/Ctr (TH2)
[11] Fusing motor (M3)
1.13.2 Drive
[1] Fusing motor (M3)
1.13.3 Operation
(1) Fusing speed correction
(a) Fusing loop control
• To prevent double transferred images and brush effects that occur due to a difference in speed between paper transport during image
transfer and fusing, a loop is formed in the paper between the 2nd transfer and fusing sections.
• The fusing loop sensor detects the length of the loop formed in the paper between the 2nd transfer section and the fusing roller.
• The fusing motor increases or decreases the fusing speed according to the length of loop in the paper, thereby ensuring that the length
of loop falls within a predetermined range.
Fusing loop sensor
Blocking
Unblocking
Operation timing
• It starts controlling when the front-edge of the paper reaches to the predetermined position before the fusing roller.
• The fusing speed is decelerated so that a loop is formed in the paper between the 2nd transfer roller and the fusing roller.
• When the paper loop amount is large, the fusing loop sensor is unblocked, and the fusing speed is increased.
• When the paper loop amount is small, the fusing loop sensor is blocked, and the fusing speed is decreased.
• The fusing speed is increased or decreased as necessary to make sure that the paper loop amount falls within a predetermined range,
thereby absorbing a difference between the fusing speed and image transfer speed.
• The fusing loop control will finish after the trailing of the paper passes the 2nd transfer roller.
Fusing speed adjustment
• If double transferred images or brush effects occur due to inadequate paper loop before fusing, adjust the fusing speed using [Service
Mode] -> [Machine] -> [Fusing Transport Speed].
(2) Fusing belt deformation prevention control
• The fusing belt is rotated to prevent the fusing belt from remaining placed on the same side for long periods of time, preventing
deformation.
• Prevents uneven gloss due to fusing belt deformation.
(a) Specific controls
• Select Mode 2 in the Service Mode settings to enable the fusing belt deformation prevention control.
• Configured from [Service Mode] -> [System 2] -> [Fuser roll deform].
Mode
OFF
Service Manual
[1]
[2]
Loop amount
Specific controls
No control
P THEORY OF OPERATION > 1. d-Color MF4003/MF3303
[4] Fusing pad
[6] Heating roller
[8] Pressure roller temperature sensor (TWMS)
[10] Pressure roller thermistor/Edg (TH1)
-
[2] Pressure roller
Large
Small
P-46
Fusing speed
Speed-up
Slowdown
Y119930-3