Liquid Discharge Head Drive Control Waveform Selection
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Solution Overview
Problem
Variations in manufacturing lead to inconsistent discharge speed and amount of liquid among liquid discharge heads or nozzles, resulting in uneven printing quality.
Innovation Solution
A liquid discharge apparatus and head drive control device that generate and output a common drive waveform with selected waveform portions for expansion and holding pressure chamber states, using selection signals to adjust the discharge characteristics of each nozzle, allowing for precise control of droplet size and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common drive waveform is applied to all nozzles, then the device complexity is reduced, but the discharge speed and discharge amount vary among nozzles due to manufacturing variations
Solution Approach 1:
The drive waveform is segmented into multiple waveform portions (first waveform portion for expansion, second waveform portion for holding, third waveform portion for contraction). By selectively applying or deselecting specific segments (particularly the holding waveform portion) based on nozzle characteristics, the patent achieves customized control for each nozzle while maintaining a common base waveform structure, thus resolving the contradiction between device simplicity and discharge consistency.
Solution Approach 2:
The patent introduces dynamic selection capability where the drive waveform can be adaptively adjusted for each nozzle based on its discharge characteristics. The selection signal dynamically determines which waveform portions are applied to each pressure generating element, allowing the system to transition from a static common waveform approach to a dynamic customized approach, thereby improving discharge consistency without excessive complexity increase.
2Manufacturing precision
If waveform portions are selectively applied to each nozzle, then discharge characteristics consistency is improved, but the device complexity increases
Solution Approach 1:
The patent employs a universal common drive waveform that serves all nozzles as a base, while incorporating multi-functionality through the selection signal mechanism. The same common waveform can be selectively applied or modified for different nozzles based on their characteristics, allowing one waveform structure to serve multiple purposes and reducing the need for completely separate waveforms for each nozzle, thus limiting the increase in device complexity.
Solution Approach 2:
The patent changes parameters of the drive waveform (specifically the application timing and duration of the holding waveform portion) based on nozzle characteristics. By adjusting waveform parameters rather than creating entirely different waveforms, the system achieves customized control for each nozzle while maintaining a common waveform framework, thereby improving discharge consistency with minimal complexity increase.
3Quantity of substance
If the holding waveform element is applied, then the discharge amount control is improved, but the droplet speed variation increases
Solution Approach 1:
The patent applies the holding waveform portion selectively and partially - not to all nozzles at all times, but only to specific nozzles that require additional holding time based on their discharge characteristics. This partial application allows sufficient holding time for nozzles that need it (improving discharge amount control) while avoiding excessive holding time for nozzles that would experience speed degradation, thus resolving the contradiction between discharge amount control and droplet speed maintenance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables consistent discharge characteristics across nozzles, reducing variations in droplet speed and improving printing quality by optimizing the timing and duration of waveform application.
Implementation Method 1
a pressure generating element to expand and contract a pressure chamber
Data Source
AI summary
A liquid discharge apparatus includes a liquid discharge head and circuitry. The liquid discharge head includes a nozzle to discharge liquid. The circuitry is configured to: generate and output a common drive waveform including a drive pulse for discharging liquid from the nozzle of the liquid discharge head; select a waveform portion of the drive pulse to be applied to a pressure generating element of the liquid discharge head; and output a selection signal for designating the waveform portion selected. The drive pulse includes at least an expansion waveform element for expanding a pressure chamber of the liquid discharge head and a holding waveform element for holding a state expanded by the expansion waveform element. The selection signal includes a deselection signal for deselecting at least a part of a waveform portion preceding the expansion waveform element having, as a terminal, a state held by the holding waveform element.