Patent ID: 7165823

Claim:
A method for driving a recording head having a plurality of heating elements as driving elements for ejecting ink droplets from a plurality of nozzles, the plurality of heating elements being arranged in a direction substantially perpendicular to the direction of carrying a carried recording medium, the method comprising: a time-division driving step of dividing the plurality of heating elements into a plurality of blocks, each block consisting of a predetermined number of spatially and sequentially arranged heating elements of the plurality of heating elements corresponding to the plurality of nozzles, respective ones of the heating elements and the corresponding nozzles in each block positioned similarly to form respective positional sets and sequentially driving each set of heating elements and corresponding nozzles simultaneously driven over the respective blocks, in a time-divisional manner in a driving order in which none of the next-driven heating elements is adjacent to any of the immediately previously-driven heating elements; and a recording step of ejecting ink droplets from the nozzles corresponding to the driven heating elements and impacting the ink droplets on the recording medium, thus recording dots made of the ink droplets, wherein the time-divisional manner includes a number of time divisions and the number of time divisions is related to a number of simultaneously driven nozzles as follows: t max =T/P (1) A=t/τ (2) n=N/A (3) and m×n≦A (4) where t max is a maximum ink ejection frequency; T is a time period for printing a head width in one row by a line head for one color capable of color printing; P is a pulse number of a conventional pulse number modulation system; t is less than t max ; τ is an ejection pulse width; N is a total number of nozzles; A is a maximum number of time divisions; n is the number of simultaneously driven nozzles rounded out to a whole number; and m is a number of time divisions.