(19)
(11) EP 0 042 050 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
13.01.1982 Bulletin 1982/02

(43) Date of publication A2:
23.12.1981 Bulletin 1981/51

(21) Application number: 81102749

(22) Date of filing: 10.04.1981
(84) Designated Contracting States:
DE FR GB

(30) Priority: 12.06.1980 US 158844

(71) Applicant: International Business Machines Corporation
 ()

(72) Inventors:
  • Pries, Robert Wayne
     ()
  • Simpson, Henry Wellington
     ()

   


(54) Electrophotographic copier including copy sheet detach detector


(57) A detach detector for detecting whether or not a copy sheet has been stripped from a photoconductor (19) after transfer comprises a discharge lamp (40) and an electrostatic probe (41). In operation, the lamp discharges the photoconductor during correct operations of the machine to provide a low voltage level at the probe. If, however, a copy sheet remains attached to the photoconductor, the rear side remains at a high voltage level which is detected by the probe.






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