Samsung ML 1710 - B/W Laser Printer Service Manual page 37

S U M M A RY OF PRO D U C T
4.6 Engine F/W
4.6.1 Feeding
If feeding from a cassette, the drive of the pickup roller is controlled by controlling the solenoid. The on/off
of the solenoid is controlled by controlling the general output port or the external output port. If feeding
from a manual feeder, decide to insert the paper according to the operation of the manual sensor, and by
driving the main motor, insert the paper in front of the feed sensor. While paper moves, occurrence of jam
is judged as below. (Refer to the [6.2 Paper Transfer rout])
4.6.1.1 Jam 0
• After picking up, paper cannot entered due to paper didn't feed.
• After picking up, paper entered but it cannot reach to the feed sensor in certain time due to slip, etc.
• After picking up, if the feed sensor is not on, repack up. After repacking up, if the feed sensor is not on
after certain time, it is Jam 0.
- It is a status that the leading edge of the paper doesn't pass the feed sensor.
• Even though the paper reaches to the feed sensor, the feed sensor doesn't be on.
- It is a status that the leading edge of the paper already passes the feed sensor.
4.6.1.2 Jam 1
• After the leading edge of the paper passes the feed sensor, the tailing edge of the paper cannot pass the
feed sensor after certain time. (The feed sensor cannot be Off)
• After the leading edge of the paper passes the feed sensor, the paper cannot reach the exit sensor after
certain time. (The exit sensor cannot be On)
- The paper exists between the feed sensor and the exit sensor.
4.6.1.3 Jam 2
• After the tailing edge of the paper passes the feed sensor, the paper cannot pass the exit sensor after
certain time.
4.6.2 Drive
By gearing, the main motor drives the rollers such as feeding roller, developing roller, fuser roller, and dis-
tributing roller. The step motor is controlled for the sections, acceleration section and fixed speed section.
In the initial stage of the motor run, appoint the acceleration section to prevent the isolation of the motor. It
is controlled by the A3977 motor driver IC. The step signal and the enable signal are sent to make the
phase for driving the motor in CPU.
4.6.3 Transfer
The charging voltage, developing voltage and the transfer voltage are controller by PWM (Pulse Width
Modulation). The each output voltage is changeable due to the PWM duty. The transfer voltage admitted
when the paper passes the transfer roller is decided by environment recognition. The resistance value of
the transfer roller is changed due to the surrounding environment or the environment of the set, and the
voltage value, which changes due to the environments, is changed through AD converter. The voltage
value for impressing to the transfer roller is decided by the changed value.
Service Manual
4-20
Samsung Electronics