Canon    LBP3310, Руководство по обслуживанию

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Chapter 2
2-7
F-2-6
2.3.4.2 Scanner motor speed control
0018-3101
LBP3370 / LBP3310
The scanner motor is 3-phase DC brushless motor unified with the hole effect device and it is unified with the drive circuit.
When the printer is turned ON, the CPU (IC201) divides the oscillated frequency of the crystal oscillator (X201) and generates the reference clock.
The CPU puts the SCANNER MOTOR ACCELERATION signal (/ACC) into "L" and the DECELERATION signal (/DEC) into "H", when the print command is
sent from the video controller.
Then the scanner driver IC rotates the scanner motor when the /ACC signal puts into "L". The scanner motor increases the rotational count only during the /ACC
signal is "L".
The CPU allows the laser to emit light with APC during the scanner motor is rotating. Accordingly, the BD INPUT signal (/BDI) is sent to the CPU from the BD
sensor via the video controller. The CPU compares the intervals between the /BDI signal and the reference clock with the frequency comparator in the CPU, and
controls the rotational count of the scanner motor by controlling the /ACC signal until the rotational count reaches its prescribed count.
The CPU decreases the rotational count of the scanner motor by putting the SCANNER MOTOR DECRELATION signal (/DEC) into "L" and the ACCELERA-
TION signal (/ACC) into "H" to stop the scanner motor.
2.3.4.3 Scanner motor failure detection
0018-3103
LBP3370 / LBP3310
The CPU monitors the /BDI signal from the BD sensor via the video controller, and determines if the scanner motor rotates at its prescribed rotational count or not.
The CPU determines the failure or the error and notifies it to the video controller under the following conditions.
1) Scanner failure
When the /BDI signal is not detected within 0.9 sec. after the forced acceleration of the scanner motor is completed, it is detected for another 60 sec, and if the
interval of the /BDI signal cannot be detected at specified amount during this period.
2) BD failure
If the /BDI signal is not detected within 100msec. after the forced acceleration of the scanner motor. Or if the interval of the /BDI signal is not detected at a
specified value for longer than 2 sec. continuously, after the scanner motor reaches its prescribed rotational count.
3) BD error
If the /BDI signal is not detected in the prescribed interval during the CPU is outputting the /BD signal to the video controller.
Exceptional cases:
If the door open is detected within 200 msec. after the BD error is detected, the CPU does not notify the BD error to the video controller.
Also if the scanner failure or the BD failure is detected after the BD error is detected, the CPU releases the BD error.
2.4 IMAGE FORMATION SYSTEM
2.4.1 Overview/Configuration
2.4.1.1 Outline
0018-3104
LBP3370 / LBP3310
The image formation system serves as the nerve center of the printer. It consists of the cartridge, the transfer charging roller, and the fixing unit etc.
Video controller PCB Engine controller PCB
BD sensor
Divider
Reference
clock
Frequency
comparator
Laser/scanner unit
Integrated
circuit
M
Scanner driver IC
Scanner motor
J801
-13
X201
IC201
CPU
J3
-13
J2
-1 J812
-1
-2
-3
-2
-3
-4
-4
J201
-17 J7
-12
-2
-8
-7
-13
-27
- 21
-22
-16
/ACC
/DEC
/BDI
Drive
circuit
+24VA +24VA