Variable Resistance Absorber for Uniform Ink Discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid droplet jetting apparatuses, idle suction is inefficient in discharging ink from the cap, leading to uneven ink removal and residual ink in the absorber, as air is sucked in from the exposed surface, preventing uniform discharge.
Innovation Solution
A cap with a groove containing an absorber having a first absorbing portion with higher channel resistance near the discharge port and a second absorbing portion with lower channel resistance, ensuring continuous ink discharge without air interference, using materials like sponges or felt with varying hole ratios to manage liquid and air resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an ink absorber with constant hole ratio is used to reduce the space between cap and nozzle formation surface, then purge suction efficiency is improved, but during idle suction air is sucked in from the exposed surface causing non-uniform ink discharge
Solution Approach 1:
The ink absorber is divided into two distinct regions: a first region with a first hole ratio and a second region with a second hole ratio. The first region (closer to discharge port) has smaller holes to prevent air intake, while the second region (exposed surface) has larger holes for efficient ink discharge. This local differentiation of properties resolves the contradiction between maintaining seal integrity and enabling uniform ink discharge.
Solution Approach 2:
The ink absorber is segmented into functionally distinct zones based on their proximity to the discharge port. The segmentation allows each zone to perform its specific function: the first region controls air exclusion during idle suction, while the second region facilitates ink absorption and discharge. This segmentation resolves the contradiction by assigning different structural characteristics to different functional regions.
2Reliability
If a large space is formed between cap and nozzle formation surface, then sealing is easier to achieve, but purge suction takes longer and is less efficient
Solution Approach 1:
The cap is constructed with an elastic body that can deform to conform to the nozzle formation surface, creating an effective seal even with minimal clearance. This flexibility allows the system to achieve reliable sealing without requiring a large space between the cap and nozzle formation surface, thus maintaining both sealing quality and purge suction efficiency.
3Reliability
If the cap contacts directly with the nozzle formation surface, then sealing is improved, but the rib deforms elastically causing potential damage to nozzles
Solution Approach 1:
The ink absorber serves as an intermediary layer between the cap and the nozzle formation surface. It maintains the seal by filling the space created by the elastic rib deformation, while simultaneously protecting the delicate nozzles from direct contact with the rigid cap structure. This intermediary function resolves the contradiction between achieving reliable sealing and preventing mechanical damage.
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
Ensures uniform and complete ink discharge from the cap during idle suction by managing channel resistances and preventing air interference, ensuring all ink is removed without leaving residues.
Implementation Method 1
an absorber which is arranged in the groove, and which absorbs the liquid jetted from the jetting port
Implementation Method 2
a suction mechanism which communicates with the discharge port to suck the liquid
Data Source
AI summary
A liquid droplet jetting apparatus includes: a head having a jetting port surface in which a jetting port is formed; and a maintenance unit having a cap in which a discharge port is formed, an absorber arranged in the cap, and a suction mechanism which communicates with the discharge port. The absorber includes a first absorbing portion covering the discharge port, and a second absorbing portion arranged to be in contact with the first absorbing portion. A channel resistance of the first absorbing portion with respect to a liquid is higher than that of the second absorbing portion. Accordingly, when an idle suction is performed, it is possible to discharge uniformly a liquid absorbed in the first and absorbing portions.