Patent ID: 7311370
Filing Date: 2007-12-25
Classification: B41J

Abstract:
1. A driving circuit for an inkjet recording head, the inkjet recording head having: a plurality of pressure generation chambers filled with an ink; a nozzle which is provided in each of the pressure generation chambers, and from which ink is discharged; and a vibration generation section which is provided to relate to each of the pressure generation chambers, and the role of which vibration generation section is to cause a pressure change in each of the pressure generation chambers, the driving circuit comprising: a driving waveform generation section that generates a first group of driving waveforms including at least a first driving waveform and a second driving waveform that are different from each other, according to sizes of droplets of the ink, and a second group of driving waveforms including a third waveform which is generated once every driving cycle; a control section that during each driving cycle outputs, on the basis of a recording data, a waveform select signal for selecting a driving waveform, from among the plurality of driving waveforms including the first and second driving waveforms to be supplied to the vibration generation section; and a driving waveform supply section that includes a trigger signal generation section which outputs a trigger signal when a prescribed time period corresponding to the first driving waveform or the second driving waveform has elapsed from the beginning of each driving cycle, and that selects, for each divided period into which the driving cycle is divided, either the first or the second driving waveform on the basis of the trigger signal and the waveform select signal, and supplies the driving waveform selected to the vibration generation section, wherein the driving waveform generation section includes a first driving waveform generation section that generates the first group of driving waveforms and a second driving waveform generation section that generates the second group of driving waveforms, and wherein the waveform select signal is at least one serial signal composed of a plurality of driving waveform select signals provided in accordance with the number of first and second waveform generation sections, and the driving waveform supply section includes: a plurality of switches that is provided to respectively relate to the plurality of driving waveform select signals, and that, in accordance with the respective plurality of driving waveform select signals, turns on and off a supply of the driving waveform to the vibration generation section; a shift register that converts the at least one serial signal into at least one parallel signal; a latch section that latches the at least one parallel signal on the basis of a latch signal; and an inverted signal generation section that, when one of the first through third driving waveforms selected is a driving waveform generated by the first waveform generation section, generates an inverted signal which, on the basis of the at least one parallel signal latched by the latch section, is turned on during divided periods in which the driving waveform is generated, and which is turned off during other periods, and that outputs, instead of one of the plurality of driving waveform select signals related to the first waveform generation section, an inverted signal to at least one of the plurality of switches.