MULTIPLE TONE PRINTING METHOD

摘要

PURPOSE: To realize printing of a large number of gray scale stages by selecting the channel length and the dimensions and the position of a nozzle to provide a high resonance frequency and imparting ink with a pulse for causing liquid ejection at or in the vicinity of the resonance frequency. CONSTITUTION: The multi-tone printer comprises an array of parallel and constant interval channels associated with liquid ejection nozzles, a common liquid supply member, and an electric action member for imparting an ejection energy pulse to a liquid droplet in a liquid channel. Channel length and the dimensions and the position of nozzles are selected to provide a channel of high resonance frequency in the longitudinal direction and the electric action member imparts an energy pulse of sequence amplitude and frequency to the ink in a number of channels selected to act for respective continuous intervals. Liquid droplets are ejected from channels selected at or in the vicinity of the resonance frequency. Each pulse sequence includes a large number of pulses in order to eject corresponding number of liquid droplets and the number is dependent on the tone of printing.