(19)
(11) EP 0 147 068 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.01.1986 Bulletin 1986/05

(43) Date of publication A2:
03.07.1985 Bulletin 1985/27

(21) Application number: 84308201

(22) Date of filing: 27.11.1984
(84) Designated Contracting States:
BE CH DE FR IT LI NL SE

(30) Priority: 21.12.1983 GB 8334038

(71) Applicant: THE POST OFFICE
 ()

(72) Inventors:
  • Evans, David
     ()
  • Klee, Terrence John
     ()
  • Paris, Raymond
     ()

   


(54) Time of flight measurement for ink jet printers


(57) Apparatus for giving an indication of the time of flight of the ink stream of an ink jet printer comprises detector means (16) towards which one or more selected droplets of the ink stream may be directed by a deflection system comprising charging electrode (5) and deflecting electrodes (8). The detector means detects the presence of the selected droplets to give an indication of the time of flight of the said droplets.
The time of flight may be calculated and displayed, or employed to control printing paramaters such as ink supply pressure, deflecting charge or the rate at which items to be printed are conveyed past the printer. The time of flight also acts as a useful "state of health" monitor, to detect blockages or other malfunctions of the printer.






Search report