Canon MF4690 - ImageCLASS B/W Laser Service Manual page 78

Chapter 7
The pickup/feed operation of the machine is explained below.
1) Right after the DCONT board receives a print command from the SCNT board, it rotates the main motor (M1). By doing so, other rollers, except the pickup
roller, start to rotate.
2) When it becomes initial rotation ready state, the pickup solenoid (SL1) turns ON for about 0.2 sec. As a result of that, the rotation of the main motor is transferred
and the pickup roller starts to rotate.
Initial Rotation Ready
It indicates the following state: the main motor drives, and after a certain period of time, the temperature of the fixing assembly reaches to the specified value and
the scanner motor reaches to the specified number of rotation.
3) The pickup cam rotates along with the rotation of the pickup roller, and by following the shape of the pickup cam, the lifting plate is pushed up with the force
of the spring. A paper pushed up with the lifting plate is picked up by the rotation of the pickup roller and fed to inside of the machine.
4) After a certain period of time that the leading edge sensor (PS801) detects the leading edge of picked up paper, the DCNT board transmits the laser beam detection
signal (/BD) to the SCNT board.
5) Based on the /BD signal, the SCNT board transmits the video signal to the laser/scanner assembly and an image is formed on the photosensitive drum. Because
of that, it is controlled to match the leading edges of an image and a paper.
6) A paper is delivered to the delivery tray with the rotation of the photosensitive drum, pressure roller, and face-down delivery roller.
SCNT
[2]
[4]
[1] Face-down delivery roller
[2] Pressure roller
[3] Fixing film unit
[4] Transfer charging roller
[5] Photosensitive drum
[6] Pickup roller
[7] Separation pad
[8] Manual feed tray
[9] Pickup tray
M1: Main motor
SL1: Pickup solenoid
PS801: Leading edge sensor
PS802: Paper width sensor
PS803: Delivery sensor
PS804: Delivery paper width sensor
7-2
[1]
PS804
PS803
[3]
[5]
PS801
PS802
[6]
SL1
[7]
M1
[8]
F-7-2
[9]