Detection Of Front Cover Open/Closed - Canon BJ-W3000 Service Manual

b. Direction control
The output timing of the motor drive pulses (YMA, YMAN, YMB, YMBN) from the carriage
motor driver is changed by the carriage motor driver control signals (MTP12-15) output from the
CPU, to control the direction of the carriage motor (M2).
c. Speed control
The speed of the carriage motor (M2) is controlled by changing the frequency of the carriage
motor current control signals (MTP9-11) and the carriage motor driver control signals (MTP12-
15) issued by the CPU.
d. Supply current control
The 2 signals (Vref1, Vref2) output from the current control circuit are controlled by the
carriage motor drive control signal (D/A1) output by the CPU, to control the current supplied to
the carriage motor (M2) by the carriage motor driver for stopping, holding, low-speed operation
and high-speed operation. By changing the carriage motor supply current according to the
current condition of the carriage motor (M2), the carriage motor (M2) is smoothly controlled.
e. Detection of problems
If a heavy load is placed on the carriage for any reason, the pulse signal output from the linear
encoder will not be detected within a specified time. The engine controller interprets this as a
problem with the carriage motor and stops it.

3. Detection of front cover open/closed

As a safety precaution against the front cover being opened while the carriage is operating, a
front cover switch (SW2) is provided.
When the front cover is opened, the front cover switch is turned OFF, the carriage motor (M2)
drive voltage (+26V) is cut off after printing 1 band, and the carriage motor stops.
CHAPTER 2. BASIC OPERATION
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