Canon FAX-L350, Service Manual

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FAX-L350 Chapter 2: Technical Reference
c) Document scanning section
c-1) System controller (IC10)
The system controller IC include image processing function (UHQ) are as follows:
• Serial-to-parallel conversion
• A/D conversion
Input signals from the contact sensor are A/D converted.
• ABC(Auto Background Control)
Sets the slice level for each scan line.
• Edge enhancement processing
• Binaryzation processing
• Halftone processing
d) Printer control section (SCNT board)
The printer control section is made up of the printer controller IC (IC 501). The printer controller IC is a
microcomputer that incorporates a Fujitsu MBCU34102-105 8kbyte ROM and a 256byte RAM. The
ROM contains printer control software to control LBP operations.
The printer control section receives commands from the system controller IC and controls paper pickup
and loading, and the LASER/scanner unit.
The printer control section transfers the signal received from the printer section to the system controller IC
as printer status.
The printer controller IC has the following other functions:
• Main motor control
• Fixing heater control
• Fixing heater temperature detection
• BD signal detection
• LASER drive control
• APC control
• Scanner motor, fixing ass’y, or BD failure detection
• Control of high-voltage power supply
e) Fixing/high-voltage controller (IC301)
Fixing heater control
The overvoltage prevention function is available to control power supply to the fixing roller heater using
a heater drive signal (FSRD) from the SCNT board, detect resistance value of the thermistor in the fixing
roller heater, prevent fixing roller heater temperature rise using a thermal fuse, protect the print PC board
against overvoltage.
High-voltage power supply
The high-voltage power supply provides the high voltage required for primary charging, development,
and transfer using a control signal from the SCNT board.