(19)
(11) EP 0 680 829 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
27.12.1995 Bulletin 1995/52

(43) Date of publication A2:
08.11.1995 Bulletin 1995/45

(21) Application number: 95302418.9

(22) Date of filing: 12.04.1995
(51) International Patent Classification (IPC)6: B41J 13/00, B41J 15/00, B41J 11/44, G05B 19/39
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 03.05.1994 US 238079

(71) Applicant: Hewlett-Packard Company
Palo Alto, California 94304 (US)

(72) Inventors:
  • Rice, Huston W.
    Vancouver, WA 98680 (US)
  • Beretta, Robert K.
    Vancouver, WA 98661 (US)

(74) Representative: Colgan, Stephen James et al
CARPMAELS & RANSFORD 43 Bloomsbury Square
London WC1A 2RA
London WC1A 2RA (GB)


(56) References cited: : 
   
       


    (54) Optical control system for media handling assemblies in printers


    (57) A media motion controller (46) for a printer (10) uses a low cost, low resolution optical encoder (such as an LED encoder) (60) which outputs an analog signal with a repeatable cycle indicative of media movement through the printer. An A/D converter (44) is connected to the optical encoder (60) to convert the analog signal into multiple discrete digital levels, where an increment of movement of the recording media (14) is defined as the movement during an interval between a selected discrete digital level in one cycle to the same selected discrete digital level in the next cycle. A controller (46) is coupled to the A/D converter (44) to receive the discrete digital levels and controllably move the media (14) a selected number of movement increments as derived from recurrence of the selected discrete digital level during individual cycles.






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