公开(公告)号：DE2331803A1

公开(公告)日：1974-01-17

申请号：DE2331803

申请日：1973-06-22

Applicant: IBM

Inventor： HILL JAMES DAVID ,  NAYLOR HUGH EDWARD ,  WEST DONALD LEE

IPC: B41J2/115 ,  B41J2/12 ,  B41J2/185 ,  G06K15/10 ,  H04N1/23 ,  B41J3/14

Abstract: 1405197 Ink drop printers INTERNATIONAL BUSINESS MACHINES CORP 14 May 1973 [27 June 1972] 22760/73 Heading G4H An ink-drop printer 1-30 comprises means 37-57 for detecting failure in synchronisation between drop charging and drop formation. Test signals 41-43, 81 or 65 (ramp or pulse signals, Fig. 3, not shown) are applied to the charge electrode 18 so as to cause otherwise uncharged drops to be deflected into a gutter 35 or 36; the synchronization may be effected line-by-line (e.g. in the home position for each line), between characters or within the matrix boundaries of individual characters. Each gutter contains a sensor which translates charge into current level; the use of gutter 35 produces current levels smaller than those normally encountered during printing, whereas the levels obtainable from gutter 36 are higher since a greater potential is required to deflect the drops thereto (this can also detect lack of potential 25 on deflecting plate 22). The resulting signal A or B is changed to a voltage level and fed with a reference 55 to a comparator 57, the resulting difference signal being used to adjust the timing of drop separation in a piezo-electric crystal driver 15 relative to the signals applied to charge electrode 18. Another embodiment similar to that of Fig. 1 is described with reference to Fig 2 (not shown). Co-pending Application No. 41107/73 describes a similar system for a plurality of ink streams.