Tektronix Phaser 600, Руководство по обслуживанию

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Service Manual 5-13
Theory of Operation
5
Print process in operation
Media positioning
The print process is preceded by the printer positioning and measuring the roll
or sheet of media currently installed. When the paper input sensor detects a
sheet of media inserted up to the upper feed rollers, the clamp-close solenoid are
energized to close the spring-loaded clamp against the drum. The clamp-rotate
solenoids then energized to engage the clamp to the drum. Next, the Y-axis
motor drives the drum in the reverse direction to position the clamp (engaged to
the drum) in the ready-to-clamp position. The clamp-ready sensor detects when
the clamp is in this position. Then the clamp-close solenoids are de-energized to
open the clamp and the clamp-rotate solenoid are de-energized to release the
clamp from the drum.
With the clamp in the ready position, the drum rotates forward to pull the media
through the upper-feed rollers and paper guides to insert the leading edge of the
paper in the open clamp. The three paper skew sensors, mounted on the paper
guides, determine if the paper feeds into the paper path squarely. After waiting
long enough for this to occur, the clamp-close solenoid are energized to close the
clamp against the drum, clamping the leading edge of the paper. Again, the
clamp-rotate solenoids energized to engage the clamp to the drum and the
Y-motor rotates the drum to position the paper in the print position.
Figure 5-8 Loading and positioning media to be printed
9482-104
Paper-input
sensor
Upper-feed
roller Paper-skew
sensor
The drum rotates
forward to pull
paper into clamp
Head-to-media
set
Back-tension
blade
Clamp-close solenoid
energizes to close
clamp to drum
Clamp in
ready position
Clamp in clamp-home position.
The drum rotates backward to
move the closed clamp to the
ready position
Clamp-rotate solenoid
energizes to engage
clamp to drum so the
clamp moves with
the drum