Liquid Discharge Apparatus Bubble Exhaust Path Control
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Solution Overview
Problem
Existing liquid discharge apparatuses face issues with bubble accumulation in the circulation path, leading to unstable meniscus pressure and deteriorated image quality due to uncontrolled gas volume in the sub tank, which disrupts the feedback control of the liquid feed pump.
Innovation Solution
A liquid discharge apparatus with an exhaust path connected to the liquid circulation path, where circuitry controls the opening and closing of the connection between the paths to exhaust bubbles outside, maintaining a constant gas volume in the sub tank and stabilizing the meniscus pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a liquid circulation path is used to circulate liquid to multiple liquid discharge heads, then liquid can be supplied efficiently to multiple heads, but bubbles accumulate in the circulation path causing flow blockage and unstable meniscus pressure
Solution Approach 1:
The patent extracts bubbles from the liquid circulation path by providing a separate exhaust path that allows bubbles to be removed from the system. The exhaust path includes a vent hole that opens to the atmosphere, enabling bubbles to escape without interfering with the liquid circulation to multiple discharge heads.
Solution Approach 2:
The patent segments the circulation system into a liquid circulation path and a separate exhaust path. This segmentation allows the liquid flow and bubble removal to occur independently, with the exhaust path specifically designed to handle gas phase separation and removal from the liquid circulation loop.
2Ease of operation
If the gas volume in the sub tank is not controlled, then the liquid circulation path can operate freely, but meniscus pressure becomes unstable and feedback control of the liquid feed pump is disrupted
Solution Approach 1:
The patent incorporates feedback control where the liquid pressure sensor continuously monitors the pressure in the liquid circulation path and provides signals to the liquid feed pump controller. This closed-loop feedback system automatically adjusts pump operation to maintain stable meniscus pressure, compensating for variations caused by gas volume changes in the sub tank.
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 effectively removes bubbles from the liquid circulation path, preventing image quality deterioration by maintaining stable meniscus pressure and ensuring consistent feedback control of the liquid feed pump.
Implementation Method 1
a bubble removal technique is used to prevent a flow of liquid by the liquid feed pump in the liquid circulation path from being blocked by bubbles
Data Source
AI summary
A liquid discharge apparatus includes a liquid discharge head to discharge liquid, a liquid circulation path including the liquid discharge head, an exhaust path connected to the liquid circulation path on a downstream side of the liquid discharge head in a circulation direction of the liquid, and circuitry. The liquid circulation path circulates the liquid via the liquid discharge head. The circuitry opens and closes between the liquid circulation path and the exhaust path to exhaust bubbles in the liquid circulation path to an outside of the liquid circulation path through the exhaust path when the liquid is circulated in the liquid circulation path.