Liquid Discharging Apparatus Meniscus Control for Film Deterioration
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Solution Overview
Problem
Liquid discharging apparatuses face issues with liquid repellent film deterioration during maintenance processing, leading to reduced reliability and efficiency in discharging special-type liquids that tend to damage or adhere to the nozzle-formed surface.
Innovation Solution
The apparatus employs a specific activation pulse with components to manage the meniscus within the nozzle, ensuring the liquid is primarily pulled and pushed upstream, reducing the impact of repellent film deterioration, and switches to a different pulse after a predetermined condition is met to maintain reliable discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a liquid repellent film is formed on the nozzle-formed surface to improve liquid repellency and durability, then liquid discharge performance is improved, but the film deteriorates when exposed to special-type liquids containing pigments or inorganic materials
Solution Approach 1:
The patent applies preliminary action by performing maintenance processing (suction of mist and liquid) before the liquid repellent film deteriorates significantly. The control unit monitors discharge characteristics and triggers maintenance when deterioration is detected, restoring the film's liquid repellency before it completely fails, thereby extending the film's effective lifespan while maintaining discharge reliability
Solution Approach 2:
The liquid repellent film provides self-service by inherently preventing liquid adhesion to the nozzle-formed surface during normal operation. This self-protective function reduces the frequency and intensity of maintenance required, allowing the film to serve itself for extended periods between maintenance cycles
2Object-affected harmful factors
If maintenance processing is performed by suction to remove liquid and foreign matter from the nozzle-formed surface, then liquid adhesion is reduced, but mist and liquid may still adhere during the process
Solution Approach 1:
The patent implements feedback control by monitoring the discharge characteristics of the liquid discharging head and using this information to determine when maintenance processing is required. The control unit detects changes in discharge performance caused by liquid repellent film deterioration and triggers maintenance at the optimal time, ensuring reliable liquid discharge while minimizing liquid adhesion during maintenance
Solution Approach 2:
The patent applies parameter changes by modifying the suction pressure and flow rate parameters during maintenance processing. By optimizing these parameters, the system effectively removes adhered liquid and foreign matter while minimizing the risk of additional liquid adhesion during the maintenance process itself
3Productivity
If a sweeping mechanism with a wiper is used to sweep the nozzle-formed surface, then liquid and foreign matter removal efficiency is improved, but the liquid repellent film may be mechanically damaged
Solution Approach 1:
The patent replaces the mechanical sweeping action with a suction-based maintenance system. Instead of using a wiper that mechanically contacts and potentially damages the liquid repellent film, the system uses controlled suction to remove liquid and foreign matter from the nozzle-formed surface, thereby maintaining removal efficiency while preserving film integrity
Solution Approach 2:
The patent introduces an intermediary approach by using a suction mechanism that indirectly removes contaminants without direct mechanical contact between the wiper and the liquid repellent film. The suction field acts as an intermediary force that achieves contaminant removal while the film remains undisturbed, preventing mechanical damage
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 configuration allows for extended reliable liquid discharge by minimizing the impact of repellent film deterioration, even when discharging liquids that are corrosive, contain pigments, or adhere easily, thereby maintaining performance over time.
Implementation Method 1
a pressure chamber (37) that discharges liquid droplets (Id) by generating pressure vibrations in liquid (Ink)
Implementation Method 2
a liquid repellent film (29) formed on a nozzle-formed surface (S1)
Data Source
AI summary
A liquid discharging apparatus includes a liquid discharging head having an actuator, a nozzle-formed surface on which a nozzle opens and discharging liquid from the nozzle by activating the actuator, and an activation pulse generation circuit that generates an activation pulse for activating the actuator. The nozzle-formed surface has a liquid repellent film formed thereon. The activation pulse includes a first pull-in component that pulls a meniscus in the nozzle from an initial position of the meniscus, a first push-out component that pushes the meniscus that has been pulled, a second pull-in component that pulls the meniscus that has been pushed, and a second push-out component that pushes at least a portion of the meniscus that has been pulled again. The nozzle discharges a special-type liquid. The special-type liquid is a type of liquid that relatively tends to cause repellency of the liquid repellent film to deteriorate.