Konica Minolta bizhub C658 Service Manual page 1984

bizhub C658/C558/C458/C368/C308/C258
• When the leading edge of the original moves past the document reading roller/1, the document reading sensor (reflector type) disposed
downstream of the roller detects the original. The length of the original is also detected based on the period of time during which the sensor
remains activated.
[2]
[3]
[4]
[1] Document reading motor (M1)
[3] Document reading roller/1
[5] Document reading roller/2
[7] Document exit roller
3.3.2 Document reading roll pressure/release control
• When the trailing edge of the original moves past document reading roller/1, document reading roller/1 acts to push the original, so that the
document transport speed increases instantaneously. This results in an image being read unevenly. (Fluctuations in the document
transport speed)
To prevent this problem from occurring, the document reading roll is released using the reading roller release motor. When the document
reading roll is released, no thrust force is transmitted to the original.
• After the document reading roll is released, the original is transported only by rollers locating downstream of a reading position.
(1) Pressure/release operation
• When the reading roller release motor is energized, the pressure/release gear is rotated and the cam mounted on the same shaft as the
pressure/release gear is rotated.
• Then, the cam pushes down the rotation shaft of the document reading roll, so that the document reading roll is released from the
document reading roller.
• The pressure/release gear is provided with a semi-circular light blocking plate. When the gear rotates a half turn, the reading roll position
sensor is unblocked and blocked. Then, a condition is detected in which the document reading roll is released. (Blocked: released;
unblocked: pressed)
[2]
[3]
[4]
[5]
[1] Reading roller release motor (M4)
[3] Reading roll position sensor (PS4)
[5] Document reading roll
[1]
[6]
[5]
[1]
[6]
PC THEORY OF OPERATION DF-704 > 3. OPERATION
[7]
[2] Document reading roll
[4] Document reading sensor (PS6)
[6] Document reading roller/3
- -
[2] Pressure/release gear
[4] Document reading roller/1
[6] Document reading sensor (PS6)
PC-10