Liquid Discharge Head Control for Stable Nozzle Output
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Solution Overview
Problem
Existing liquid discharge apparatuses experience a decrease in discharge amount immediately after starting discharge or when the number of nozzle holes changes, leading to deteriorated liquid application quality.
Innovation Solution
A liquid discharge apparatus with a valve that is driven to open and close the nozzle hole for a variable valve opening time based on the head pressure, controlled by circuitry to maintain consistent discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a needle valve is used to open and close the nozzle hole, then the liquid discharge apparatus can control the discharge timing, but the discharge amount decreases immediately after start or when nozzle hole count changes
Solution Approach 1:
The system performs preliminary action by detecting head pressure before discharge and using this information to pre-calculate the appropriate valve opening time. This ensures that the correct discharge amount is achieved from the very first discharge operation, eliminating the transient period where discharge amount is unstable.
Solution Approach 2:
The system implements feedback by continuously monitoring the head pressure in the liquid discharge head and using this feedback to adjust the valve opening time. The controller modifies the valve opening duration based on the detected pressure, ensuring consistent discharge amount even when nozzle hole count changes or during initial operation.
2Manufacturing precision
If the valve opening time is fixed, then the control system is simple, but the liquid application quality deteriorates when head pressure changes
Solution Approach 1:
The system applies dynamics by making the valve opening time variable rather than fixed. The valve opening duration is dynamically adjusted based on the detected head pressure, allowing the system to maintain optimal liquid application quality under varying pressure conditions while responding to real-time system state.
Solution Approach 2:
The system changes the parameter of valve opening time based on head pressure detection. By varying this critical parameter in response to pressure changes, the system maintains consistent discharge characteristics and liquid application quality without requiring complex hardware modifications.
Data Source
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AI summary
A liquid discharge apparatus (200) includes a liquid discharge head (10) and circuitry (500). The liquid discharge head (10) has a nozzle hole (N) from which a liquid (3) is discharged and includes a valve (12) to open and close the nozzle hole (N) and a valve driver (13) to drive the valve (12). The circuitry (500) causes the valve driver (13) to drive the valve (12) to open the nozzle hole (N) for a valve opening time to discharge the liquid (3) onto an object (3000), and changes the valve opening time based on a head pressure applied to the liquid (3) in the liquid discharge head (10).