SCEN103 -- Xerography

[logo] 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.

  1. Clean platen, ready for service
  2. Produce image for replication
  3. Charge platen with corona wire
    -- charge leaks off wire because of corona discharge, with associated "ozone smell" in some cases
  4. Expose platen to image
    -- illuminated part of platen allows charge to leak away because of photoconduction
  5. Dark areas stay charged
  6. "Charge image" of original
  7. Expose platen to toner
    -- toner is carried electrostatically by carrier particle, released onto the relatively stronger charge of the platen
  8. "Toner image" of original
  9. Introduce paper for copy
  10. Charge paper with corona wire
    -- with larger charge density that on platen
  11. Paper ready to receive toner
  12. Toner adheres to paper
  13. Toner image on paper
  14. Toner fused to paper
    -- accomplished by heated rollers and a bit of pressure, hence the warm, sometimes "curled", paper
  15. Cleaning and back to Step 1.

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Last updated Dec. 12, 1996.
Copyright George Watson, Univ. of Delaware, 1996.