Title |
The Effects of Driving Waveform for Piezoelectric Drop On Demand Industrial Inkjet Head |
Authors |
김영재(Kim Young-Jae) ; 유영석(Yoo Young-Seuck) ; 심원철(Sim Won-Chul) ; 박창성(Park Chang-Sung) ; 정재우(Joung Jae-Woo) ; 오용수(Oh Yong-Soo) |
Keywords |
Inkjet ; Piezoelectric ; MEMS ; Waveform ; Droplet |
Abstract |
This paper presents the effect of driving waveform for piezoelectric bend mode inkjet printhead with optimized mechanical design. Experimental and theoretical studies on the applied driving waveform versus jetting characteristics were performed. The inkjet head has been designed to maximize the droplet velocity, minimize voltage response of the actuator and optimize the firing frequency to eject ink droplet. The head design was carried out by using mechanical simulation. The printhead has been fabricated with Si(100) and SOI wafers by MEMS process and silicon direct bonding method. To investigate how performance of the piezoelectric ceramic actuator influences on droplet diameter and droplet velocity, the method of stroboscopy was used. Also we observed the movement characteristics of PZT actuator with LDV(Laser Doppler Vibrometer) system, oscilloscope and dynamic signal analyzer. Missing nozzles caused by bubbles in chamber were monitored by their resonance frequency. Using the water based ink of viscosity of 4.8 cps and surface tension of 0.025 N/m, it is possible to eject stable droplets up to 20 kHz, 4.4 m/s and above 8 pl at the different applied driving waveforms. |