摘要 |
A drop-on-demand multi-tone printing apparatus has a series of channels arranged to receive ink from a source. Each channel has a respective ink outlet. Each adjacent pair of the channels is separated by a respective dividing wall, and each dividing wall is movable in response to a respective pulsed electrical signal to apply pressure pulses to the respective pair of the channels, whereby ink can be ejected from the outlets and deposited onto a recording medium. A respective pulsed electrical signal is developed for each channel in dependence upon whether ink is to be ejected from that channel, the signals for adjacent pairs of the channels temporally overlapping each other and not being in phase with each other. |