Patent ID: 7097265

Claim:
A driving device of an ink-jet print head that discharges liquid drops through a plurality of nozzles, comprising: a data storage unit, which stores a data block having a plurality of data items for liquid drop discharge, each data item indicating one of discharge data for which liquid drops are to be discharged and non-discharge data for which liquid drops are not to be discharged; a data determination unit, which determines the stored data block; a driving device shift register, which outputs the determined data block to an ink-jet print head shift register; and a clock signal generation unit, which generates first clock signals for driving the driving device shift register and second clock signals for driving the ink-jet print head shift register; wherein: when the data items of the plurality are identical, the data determination unit generates a first signal indicating that the data items are identical and a second signal indicating one of that the data items indicate discharge data and that the data items indicate non-discharge data; when the first signal is generated, the clock signal generation unit continues generating the second clock signals and stops generating the first clock signals for a number of cycles corresponding to a number of data items in the plurality; and when the first signal is generated, the data determination unit outputs the second signal to the ink-jet print head shift register.