| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid droplet discharging head which can take countermeasures against a viscosity increase of ink at a low lost, and to provide a liquid droplet discharging apparatus and its driving method. SOLUTION: A solvent of the ink near nozzles evaporates between dischargings of ink droplets and an ink concentration becomes high, which sometimes causes the viscosity increase and affects ink discharge characteristics. Therefore, such a pulse that generates near the nozzles a flow velocity of a level whereby ink droplets are not discharged is applied as a spare waveform to piezoelectric elements, thereby stirring the ink near the nozzles. Thus the viscosity increase is suppressed. The axis of abscissa is a pulse width of the spare waveform when a natural period of a pressure chamber is made 1. The pulse width of the spare waveform is made not larger than 20% of the natural period or is made 80-125%. In other words, the ink can be stirred without discharging the ink droplets by the spare waveform if it is a pulse width of the range indicated by oblique lines. COPYRIGHT: (C)2005,JPO&NCIPI |
