Inkjet Head Drive Waveform Control for Noise Reduction

The pulse train is segmented into multiple individual pulses with different widths, where each pulse corresponds to a specific gray level. By selectively applying pulses of different widths (e.g., first pulse with width T1, second pulse with width T2), the system can eject liquid drops of different sizes to achieve gray scale recording while controlling noise through precise pulse timing and width variation.

The pulse width is dynamically adjusted based on the desired gray level. The drive waveform includes pulses with varying widths where the pulse width is changed according to the ejection amount requirement. This dynamic pulse width modulation allows the system to eject liquid drops of different sizes from the same nozzle while maintaining control over noise generation through optimized pulse timing.

The system employs periodic pulse trains with optimized intervals to eject liquid drops at controlled rates. By designing the pulse interval to account for liquid drop flight time and combining drops in the air, the system achieves high printing speed while maintaining landing accuracy. The periodic action allows multiple pulses to be applied within one printing cycle, with the interval carefully calibrated to prevent misregistration.

The pulse widths are pre-calculated and designed based on the desired liquid drop ejection amounts and flight characteristics. The drive waveform is preliminarily optimized with specific pulse width relationships (e.g., T1 > T2 > T3) to ensure that liquid drops ejected at different times will land at the correct positions, preventing misregistration while enabling high-speed operation.

The system achieves liquid drop size variation by changing the pulse width parameter within a standardized voltage waveform, rather than using multiple different voltage levels. The drive waveform maintains a consistent voltage amplitude but varies the pulse duration (width) to control ejection amount. This approach simplifies the waveform generating unit while preserving the ability to eject different sized drops through precise timing control.

A single standardized voltage waveform template is used for all gray levels, with only the pulse width parameter being modified. This universal waveform design allows the same basic drive circuit to generate multiple pulse types (different widths) by simple timing control, reducing device complexity while maintaining full gray scale recording capability through parameter variation.