| 摘要 |
PROBLEM TO BE SOLVED: To prevent an ink droplet from drying and to fly the droplet with a high efficiency in an ink jet recorder for flying the droplet from a slit-like opening provided on an ink holding chamber by focusing ultrasonic waves from a plurality of piezoelectric elements in a main scanning direction by a predetermined driving means, and focusing it via an acoustic lens in a sub- scanning direction. SOLUTION: When a depth F of an ink liquid 20, a sound velocity V of the liquid 20 and an applying time T of a burst wave applied to a piezoelectric element for flying one droplet of the liquid satisfy V.T 3 and a bean width W of a focused ultrasonic wave in the main scanning direction, a beam width W2 of the wave in the sub-scanning direction and an opening S satisfy, at the time of W1>=W2, S>(W1.W2)<1/2> or at the time of W1<S2, S>W2. |
