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Phaser 380 Color Printer
5
Theory of Operation
Paper preheater
The paper preheater warms the sheet of media before ink is transfixed from the
drum to the paper. Warming the sheet of media, improves ink transfer and print
durability. The preheater exit sensor detects the leading and trailing edges of the
media. The leading edge information is used to set the bottom margin. The
trailing edge info is used to determine the media length and completion of the
transfix operation.
Media width sensor unit
The media width sensor unit contains a moveable sensor which performs many
functions.
■
It detects the leading edge of incoming media prior to the
“buckle/deskew” operation which straightens the sheet of media to
the paper path.
■
It locates the left and right edges of the media so the printer can
correctly place the image on the print, or clip the image if it is too large
for the media.
■
The media width sensor detects grossly skewed media. If such
conditions arise, the print job is aborted to prevent any of the latent
image on the drum from being inadvertently transferred onto the
transfix pressure roller.
The media width sensor is located in the paper path just before the paper
preheater. It consists of a photo-reflective sensor which is driven across the
width of the media by a lead screw and carriage. Also attached to the carriage is
a home flag. The lead screw is driven by a stepper motor. The printer
determines the position of the photo sensor by counting motor steps referenced
from to the home sensor.
Paper tray
The paper tray supports all the paper sizes allowed by the printer. Sensors
inside the base of the printer detect the standard paper size loaded in the printer
based on the positions of the tray’s paper length setting. If a standard size
media is loaded in the tray, the printer uses this information to scale the “first”
print job.
Exit unit
The exit unit’s gear train transports the printed copy to the exit tray. The gear
train is driven by a ring gear on the end of the drum.
Summary of Contents for PHASER 380
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Page 346: ...C 4 Phaser 380 Color Printer C Wiring Diagrams Figure C 6 Wire dressing behind the printhead...