| 摘要 |
PROBLEM TO BE SOLVED: To realize the stable flying of one drop of an ink by a method wherein the wave number of burst signals for driving a piezoelectric element is set within a specified range. SOLUTION: In order to determine the range of the optimum wave number N of burst signals the relationship, which satisfies the two following formulae: 4Fr.λ<N<200Fr.λ, 2×10<4> /(10<-a/10> .V<2> )<N<1×10<6> /(10<-a/10> .V<2> ), is set among F numbers in both main scanning direction and sub-scanning direction (the ratio Fs of the focal lemgtj to the aperture in the main scanning direction and the ratio Ff of the focal length to the aperture in the sub-scanning direction), the wavelengthλ[μm] of an ultraosnic wave in an ink liquid, the creset value V [Vpp] of a driving voltage, the damping amount (a) [dB] of the ultrasonic wave between the surface of the ink liquid and the radiating surface of ultrasonic wave under the condition that Fr is the square root of the product of Ff and Fs. Thus, one drop of an ink can be stably flown. |
