Ink jet printers and methods of operating such printers.

摘要

During the start-up and shut-down operations of an inkjet printer, a movable ink catching device (12) comprising a tubular probe is moved from a position remote from the nozzle plate (14) of the printer along the flight path of undeflected ink droplets to a position in which it is closely adjacent to the nozzle plate (14) with the result that all ink ejected from the nozzle plate is caught by the probe. In normal operation of the printer, ink droplets not required for printing are deflected into a fixed gutter (26). Such deflection of unwanted ink droplets may be effected by a conventional charge electrode (20) and a pair of deflection plates (22, 24). At shut-down of the printer, the charge electrode is moved away from the flight path of the ink droplet streams and the undeflected droplets are caught by the probe. The probe is then inserted between the deflection plates to a position adjacent to the nozzle plate. The printer may then be turned off, all ink being caught in the probe. At start-up the probe is moved back along the flight path (32) of undeflected ink droplets to a position remote from the nozzle plate. The charge electrode is then moved into the vicinity of the nozzles in the nozzle plate and energised to cause the ink droplets to be deflected into the ink gutter. The ink catching device (12) is then moved to a home position which may be behind a medium on which printing is to be effected.