| 摘要 |
PROBLEM TO BE SOLVED: To obtain a liquid droplet ejection head which can improve an image quality at the time when ejection is resumed by controlling a preparatory waveform given for an ejection stand-by time to be optimum, and to obtain an image forming apparatus equipped with this. SOLUTION: When the ejection stand-by time is long as shown in Fig. 1(A), the viscosity of ink near a meniscus greatly increases, and therefore the preparatory waveform is applied for a considerably long time. The meniscus 40 is fully vibrated accordingly, so that an ejection speed of the first droplet at the time of resumption of ejection is recovered to 70% of an ejection speed at the time of continuous ejection. Moreover, when the ejection stand-by time is short as shown in Fig. 1(B), the preparatory waveform is applied for a short time. By controlling a length of an application time of the preparatory waveform on the basis of the liquid droplet ejection stand-by time, the ejection speed of the first droplet at the time of resumption of ejection is secured by 70% of the ejection speed at the time of continuous ejection. At the same time, an ejection speed of the second droplet and thereafter is prevented from decreasing due to diffusion of the viscosity-increased ink in consequence of excessive application of the preparatory waveform. COPYRIGHT: (C)2008,JPO&INPIT
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