SCEN103 -- Xerography
SCEN103 -- Xerography
The following steps are representative of the process used for photocopying
and laser printing.
Details of formation of the optical image of the original have been ignored.
- Clean platen, ready for service
- Produce image for replication
- Charge platen with corona wire
-- charge leaks off wire because of corona discharge,
with associated "ozone smell" in some cases
- Expose platen to image
-- illuminated part of platen allows charge to leak away
because of photoconduction
- Dark areas stay charged
- "Charge image" of original
- Expose platen to toner
-- toner is carried electrostatically by
carrier particle,
released onto the relatively stronger charge of the platen
- "Toner image" of original
- Introduce paper for copy
- Charge paper with corona wire
-- with larger charge density that on platen
- Paper ready to receive toner
- Toner adheres to paper
- Toner image on paper
- Toner fused to paper
-- accomplished by heated rollers and a bit of pressure,
hence the warm, sometimes "curled", paper
- Cleaning and back to Step 1.
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Comments, suggestions, or requests to ghw@udel.edu.
"http://www.physics.udel.edu/~watson/scen103/xerox"
Last updated Dec. 12, 1996.
Copyright George Watson, Univ. of Delaware, 1996.