Paper Pick - Tektronix Phaser 340 Service Manual

5
Theory of Operation
5-26 Phaser 340 Color Printer

Paper pick

To pick a sheet of paper, the process motor rotates clockwise, driving the process
drive belt and the one-way clutch compound gear counterclockwise. Rotating
counterclockwise, the one-way clutch turns and, in turn, engages a gear train
that rotates the pick roller clutch gear counterclockwise. The paper pick
solenoid 1 (mounted on I/O board 1) energizes for a moment, engaging the
paper pick clutch and allowing it to rotate one revolution. The pick roller rotates
and pulls a sheet of paper from the paper tray. The sheet of paper trips the paper
pick sensor to assure that the paper was picked from the tray. If the paper is not
sensed, the pick solenoid is energized to rotate the pick roller again to attempt to
recover from the mis-pick and pick the sheet of paper.
With the paper-pick sensed, the paper-feed electric clutch energizes to allow the
upper and lower paper-feed rollers to rotate and carry the sheet of paper to the
paper pre-heater. At this point, the paper stops at the entry to the paper
pre-heater, tripping the paper pre-heater entry sensor on the left end of the
paper preheater. The paper also trips the paper width (A/A4-size) sensors on
the right end of the paper preheater to verify that the width of the paper is
within the printer's specifications. At this point, the process motor is stopped to
wait for more ink deposition on the drum.