Olivetti d-Color MF4003 Service Manual page 615

d-Color MF4003/MF3303
• Determining that the tray 1 upper limit sensor is blocked, the machine stops the tray 1 lift-up motor to complete the up operation of the
paper lift-up plate.
• Control is provided to make sure that only one tray performs the up operation at one time.
• If the tray is slid out during the up operation of the paper lift-up plate and accordingly the tray 1 set switch is unblocked, the up
operation of the paper lift-up plate is terminated.
During a print cycle
• When the amount of paper decreases as the unit keeps printing, the pick-up roller will gradually come down to unblock the tray 1 upper
limit sensor. The tray 1 lift-up motor will rotate again to lift up the paper lift-up plate.
• When the tray 1 upper limit sensor is blocked, the tray 1 lift-up motor will stop to stop lift-up the paper lift-up plate.
• The sequence of these operations is repeated to keep constant the pressure between the pick-up roller and paper stack (paper take-
up pressure) regardless of the amount of paper still available for use.
(2) Pick-up roller retract mechanism
• A mechanism to retract the pick-up roller is provided, in order to avoid damaging stacked paper when the paper feed tray is inserted.
• When the paper feed tray is open, the retraction lever in the back of the machine presses the pick-up roller up to the retract position.
• When the pick-up roller is in the retract position, paper cannot be damaged as the pick-up roller does not make contact with the stacked
paper.
• Closing the paper feed tray presses the retraction lever to move the pick-up roller to the a position such that it can supply paper.
[1]
[1] Retraction lever
(3) Separation roller retract mechanism
• When a paper jam occurs and paper is caught between rollers where the feed roller is pressing the separation roller, paper will be left
inside the machine through pulling out the paper feed tray. If you insert the paper feed tray in that state, the paper may get torn in pieces
which may fall off and scatter inside the machine. It prevents paper from being torn or falling off through retracting the separation roller.
• The separation roller is pressed against the feed roller by spring pressure when the paper feed tray is closed. (Paper feed position)
• Release the paper tray lock, the roller pushdown lever is also released and the separation roller retract lever is pushed down to the
retracting position. It releases the paper from the rollers even if it is jammed between the rollers.
[1] Feed roller
(4) Paper feed control
• Rotation of the main motor is transmitted through the paper feed clutch to drive the feed roller to take up and feed the paper.
• The paper taken up and fed in is conveyed onto the registration roller.
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P THEORY OF OPERATION > 1. d-Color MF4003/MF3303
[2]
[2] Pick-up roller
[1]
[2]
[2] Separation roller
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Service Manual