Printhead Priming Cap with Separate Venting Port
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Solution Overview
Problem
Air accumulation in printheads can damage or degrade their performance, and existing priming methods often leave ink and froth in the priming cap and vacuum line, interfering with subsequent priming operations.
Innovation Solution
The implementation of separate priming and venting ports on the priming cap, connected to a vacuum pump and a vent respectively, with a camshaft-driven vent-arm that controls the timing of priming and venting operations to clear air and ink without drawing additional ink from the printhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single priming port is used for both priming and venting, then the device structure is simpler, but ink and froth contaminate the venting system and interfere with subsequent priming operations
Solution Approach 1:
The single priming port is divided into two separate ports: a priming port for drawing ink and a venting port for releasing air. This segmentation prevents ink and froth from contaminating the venting system, ensuring reliable subsequent priming operations while maintaining structural simplicity through the use of a single cap assembly.
Solution Approach 2:
The venting function is extracted from the priming port by providing a separate venting port. This allows the venting operation to be performed independently without drawing additional ink from the printhead, eliminating the contamination problem while keeping the overall device structure relatively simple.
2Reliability
If the vent remains closed during vacuum operation, then air can be removed from the printhead, but additional ink is drawn from the printhead through the vacuum line
Solution Approach 1:
By separating the priming and venting functions into different ports, the system can control the venting port to remain closed during vacuum operation for air removal, then open it subsequently to prevent additional ink drawing. This segmentation allows independent control of each function to optimize both air removal effectiveness and ink loss prevention.
Solution Approach 2:
The vent is closed before vacuum operation to enable effective air removal from the printhead. After air removal is complete, the vent is opened as a preliminary action to prevent additional ink from being drawn through the vacuum line, thereby reducing ink loss while maintaining effective air removal.
3Productivity
If ink and froth remain in the priming cap after priming, then the priming operation is complete, but they interfere with subsequent priming operations
Solution Approach 1:
The separation of priming and venting ports allows ink and froth to be contained in the priming port area while the venting port remains clear. This segmentation enables subsequent priming operations to proceed reliably without interference from residual ink and froth, maintaining both productivity and reliability.
Solution Approach 2:
The venting function is extracted to a separate port, allowing froth and excess ink to be vented away from the priming path. This extraction prevents contamination of the priming system, ensuring reliable subsequent priming operations while maintaining efficient productivity.
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 air and ink from the printhead, preventing damage and ensuring reliable printing performance by maintaining a clear venting path and preventing ink contamination in the venting system.
Implementation Method 1
a vacuum pump in fluid communication with the priming port
Implementation Method 2
allows the vacuum pump to form a vacuum condition within the printhead
Data Source
AI summary
An example apparatus includes a cap to seal a printhead in a printhead assembly, where the cap includes a priming port and a venting port. A vent connected to the venting port is sealed by a cam controlled vent-arm while a vacuum pump connected to the priming port applies a vacuum to prime the printhead. The vent is unsealed by the cam controlled vent-arm and the vacuum pump clears ink from the priming cap.