Scanner Motor; Outline; Operations - Canon CLC5000 Service Manual

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1.4 Scanner Motor

The following figure shows the circuit used to control the scanner motor, and the circuit

has the following functions:

1. Controlling the direction of rotation of the scanner motor

2. Controlling the speed of rotation of the scanner motor

The scanner motor changes its direction of rotation to move the scanner forward or in re-

verse, and the speed of its rotation when the scanner is moved forward changes to suit the

selected reproduction ratio.

When the scanner is moved in reverse, the speed of rotation is the same regardless of the

selected reproduction ratio, which is ten times as high as the speed at which the scanner is

moved forward in Direct.

The CPU (IC8) on the scanner motor driver PCB receives instructions from the reader

controller PCB on the mode, distance, and reproduction ratio selected for scanning. Then, in

response to the start command, the CPU sends drive pulses to the scanner motor base on

these instructions.

The scanner motor is a 5-phase stepping motor, and its direction (scanning direction) and

speed are switched by changing the sequence of drive pulses (A through E) and frequency.

When the scanner is moved in reverse, the motor must be rotated at high speed, requiring

the drive voltage switching circuit to switch from 8 V (forward) to 40 V (reverse).

The constant current control circuit is used to control the current flowing to the motor to a

specific level according to the rotation of the motor. When the motor is kept at rest (as in

standby), the current to the motor is cut off by means of the HOLD-OFF signal.

Voltage change

Scanner driver PCB

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CANON CLC5000 REV.0 JAN. 2001

CHAPTER 2 NEW FUNCTIONS

Drive voltage

Scanner motor

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