Droplet Discharging Apparatus Recirculation Path
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Solution Overview
Problem
Existing droplet discharging apparatuses, such as ink jet printers, face high liquid consumption during maintenance due to the need for frequent flushing operations to prevent viscosity increase and clogging, which is inefficient and wasteful.
Innovation Solution
A droplet discharging apparatus with a return flow path that allows liquid from the pressure chambers to be circulated back into the supply flow path when no droplets are being discharged, reducing the need for flushing and minimizing liquid consumption by maintaining meniscuses on gas-liquid interfaces within the nozzles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If regular flushing operations are performed to suppress viscosity increase, then liquid discharge reliability is improved, but liquid consumption increases
Solution Approach 1:
The patent introduces a pre-flush operation that performs a preliminary discharge of liquid from the pressure chamber before the main recording operation. This preliminary action prevents viscosity increase by moving liquid from the pressure chamber through the nozzle and into the discharge flow path, where it is then recirculated back to the liquid supply source. This resolves the contradiction by maintaining discharge reliability through the pre-flush while minimizing liquid consumption through recirculation.
Solution Approach 2:
The patent implements a recirculation system that recovers liquid discharged during the pre-flush operation. The discharge flow path is coupled to form a circulation path that returns the discharged liquid to the liquid supply source. This allows the system to discard the liquid from the pressure chamber (preventing viscosity increase) while recovering it for reuse, thereby maintaining reliability without increasing net liquid consumption.
2Reliability
If flushing operations are performed frequently, then nozzle clogging is prevented, but maintenance time increases
Solution Approach 1:
The patent implements periodic pre-flush operations that are automatically performed at predetermined intervals during the recording operation. The controller is configured to execute the pre-flush at specific timing without requiring separate maintenance intervention. This periodic action prevents nozzle clogging by regularly moving liquid through the system while minimizing maintenance time by integrating the flushing into the normal operation cycle.
Solution Approach 2:
The patent ensures continuous liquid circulation through the system by coupling the discharge flow path to form a closed loop that returns liquid to the supply source. This continuous circulation maintains liquid movement through the nozzles and pressure chambers during recording operations, preventing clogging without requiring interruption for maintenance. The useful action of liquid discharge continues uninterrupted while preventing harmful stagnation.
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 suppresses liquid viscosity increase without discharging droplets, thereby reducing maintenance liquid consumption and improving operational efficiency.
Implementation Method 1
a return flow path coupled to the discharge flow path and forming a circulation path for circulation of the liquid together with the liquid supply flow path
Data Source
AI summary
A droplet discharging apparatus includes: a droplet discharger including a pressure chamber, an actuator and a nozzle provided corresponding to the pressure chamber, and a discharge flow path coupled to the pressure chamber, the droplet discharger performing a recording process by discharging liquid in the pressure chamber from the nozzle in the form of droplets; and a return flow path coupled to the discharge flow path and forming a circulation path. The droplet discharging apparatus performs as a maintenance operation for the droplet discharger, a first discharge operation of causing the liquid in the pressure chamber to be discharged toward the return flow path via the discharge flow path when no droplets are discharged from the nozzle during the recording process.