Liquid Ejection Head Drive Signal Pulse Width Control

The drive signal is made dynamic by selectively applying different pulse configurations based on the number of droplets to be ejected. For single droplet ejection, an auxiliary pulse is added before the expansion pulse to improve ejection speed. For multiple droplet ejection, only the expansion and contraction pulses are applied without the auxiliary pulse. This dynamic adaptation resolves the contradiction by adjusting signal complexity according to operational requirements.

The drive signal parameters (presence/absence of auxiliary pulse, pulse width, amplitude) are changed based on the ejection mode. The control unit adjusts the drive signal configuration: adding an auxiliary pulse with specific timing and amplitude for single droplet ejection, while using a simpler two-pulse configuration for multiple droplet ejection. This parameter adaptation allows optimization of ejection speed when needed while maintaining simplicity when not required.

An auxiliary pulse is applied before the expansion pulse to perform preliminary action on the ink. This auxiliary pulse prepares the ink by creating initial pressure vibration and movement, ensuring more stable and predictable ejection behavior. This preliminary action enhances the effectiveness of the subsequent expansion pulse, providing better control over the ejection process for single droplet operations.

The drive signal uses periodic pulsing with specific timing relationships between the auxiliary pulse, expansion pulse, and contraction pulse. The periodic nature of these pulses creates consistent pressure vibrations in the ink, improving ejection stability. The timing and duration of each pulse are carefully controlled to achieve reliable droplet ejection while maintaining the ability to adapt to different ejection requirements.