Variable Speed Pump Inkjet Circulation for Fast First Print
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing apparatuses with ink circulation systems face longer First Print Out Time (FPOT) due to the need for buffer chambers to absorb air volume changes, which can cause additional time for ink circulation to stabilize pressure within the pressure chamber, especially when starting ink circulation after a stop.
Innovation Solution
The apparatus includes a pump that operates at two different speeds within the ink circulation path, initially at a faster speed to quickly stabilize the buffer chamber and then transitions to a normal speed for efficient ink circulation during printing operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a buffer chamber is provided in the circulation path to absorb air volume changes, then reliability is improved (preventing atmosphere intake and ink leakage), but First Print Out Time increases (additional time required for ink circulation to stabilize pressure)
Solution Approach 1:
The pump operates with variable speed: a first rotation speed during initial ink circulation to quickly contract the buffer chamber, and a second (lower) rotation speed during normal print operation. This dynamic speed adjustment allows the system to rapidly stabilize pressure when starting (reducing FPOT) while maintaining reliable ink circulation during printing.
2Productivity
If ink circulation is started in response to printing instruction from stopped state, then productivity is improved (ready-to-print on demand), but First Print Out Time increases (time required for ink circulation to stabilize)
Solution Approach 1:
When a printing instruction is received, the pump is immediately driven at the first (higher) rotation speed to rapidly contract the buffer chamber and stabilize ink pressure before printing begins. This preliminary high-speed operation ensures the ink circulation system is quickly ready, minimizing the delay between receiving the print instruction and actual printing.
3Loss of time
If pump operates at higher speed to quickly stabilize buffer chamber, then First Print Out Time is reduced, but energy consumption increases
Solution Approach 1:
The pump operates at the first (higher) rotation speed only during the initial period when ink circulation is started or resumed, specifically until the buffer chamber is contracted and pressure is stabilized. After this initial period, the pump switches to the second (lower) rotation speed for normal operation. This periodic high-speed operation minimizes energy consumption while still achieving rapid FPOT reduction when needed.
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 reduces the FPOT by rapidly contracting the buffer chamber, ensuring stable ink flow and pressure within the print head, thereby shortening the time required for the inkjet printing apparatus to start printing after a stop.
Implementation Method 1
a pump provided in the supply flow path or the collection flow path, wherein the pump is driven, during print operation, at a first speed to circulate ink within a circulation path including the tank, the supply flow path, the print head, and the collection flow path
Data Source
AI summary
An inkjet printing apparatus includes a tank in which ink is contained; a print head for ejecting ink supplied from the tank to perform print operation; a supply flow path for supplying ink from the tank to the print head; a collection flow path for collecting ink from the print head to the tank; and a pump provided in the supply flow path or the collection flow path. The pump is driven, during print operation, at a first speed to circulate ink within a circulation path including the tank, the supply flow path, the print head, and the collection flow path, and the pump is driven, from a start of the ink circulation until a lapse of predetermined time period, at a second speed which is faster than the first speed.