Liquid Ejection Apparatus Meniscus Vibration Control
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Solution Overview
Problem
Liquid ejection apparatuses, such as ink jet printers, face issues with nozzle clogging due to liquid stagnation when not in use, leading to ejection failures from prolonged non-use periods.
Innovation Solution
The apparatus incorporates a drive signal generation unit and controller that manage ejection and non-ejection pulses to create pressure fluctuations in the pressure chamber, ensuring the meniscus of the liquid is vibrated during non-ejection periods to prevent stagnation, with the controller determining pulse supply based on elapsed time since the last ejection and natural vibration cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the nozzle branches off from the second flow path and extends in a different direction, then the liquid circulation is improved, but the liquid in the nozzle tends to stay during non-ejection periods causing thickening
Solution Approach 1:
The patent applies mechanical vibration by causing the meniscus of liquid in the nozzle to vibrate at its natural frequency during non-ejection periods. This vibration prevents the liquid from stagnating and thickening, thereby maintaining ejection reliability while addressing the harmful effect of liquid stagnation in the branched nozzle configuration.
Solution Approach 2:
The patent implements periodic action by applying pressure fluctuations to the liquid in the pressure chamber at regular intervals during non-ejection periods. These periodic pressure fluctuations cause the meniscus to oscillate, preventing liquid stagnation in the nozzle while maintaining the beneficial branched flow path configuration.
2Loss of energy
If drive signal is not supplied to the drive element during non-ejection periods, then energy consumption is reduced, but liquid stagnation occurs in the nozzle
Solution Approach 1:
The patent applies partial action by supplying drive signals only during specific intervals of non-ejection periods when liquid stagnation is detected or anticipated. This partial signaling approach prevents complete liquid stagnation and maintains ejection reliability while minimizing energy consumption compared to continuous signaling during all non-ejection periods.
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 approach effectively reduces ink thickening and ejection failures by maintaining liquid agitation during non-use periods, enhancing printing reliability and image quality.
Implementation Method 1
a drive element that gives pressure fluctuations to a liquid in the pressure chamber according to a drive signal
Implementation Method 2
a time length that is q times or more 1/2 of a natural vibration cycle of a meniscus of a liquid in the nozzle
Data Source
AI summary
A liquid ejection apparatus is configured to control a supply of a drive signal to a drive element by a controller so that a target period is either an ejection period or a non-ejection period based on print data. The drive signal includes an ejection pulse and a non-ejection pulse. The controller: does not supply the non-ejection pulse to the drive element when the target period is the non-ejection period and an elapsed time length from the last ejection period is less than the predetermined time length, and supplies the non-ejection pulse to the drive element when the target period is the non-ejection period and the elapsed time length is equal to or longer than the predetermined time length. The predetermined time length is an integral multiple or more of ½ of a natural vibration cycle of a meniscus of a liquid in the nozzle.