Fuse Segmentation in Liquid Discharge Head Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid discharge heads, conduction between heat resistors and protection layers can lead to electrochemical reactions, degrading the protection layer's durability and potentially spreading this degradation across the entire head, especially when the number of discharge ports increases, making it challenging to securely disconnect the fuse portion due to high line resistance.
Innovation Solution
A liquid discharge head substrate design with multiple heat resistor arrays, conductive covering portions, and strategically placed fuse portions that connect common lines to reduce line resistance and ensure secure disconnection of the fuse portions, even in heads with long heat resistor arrays, thereby preventing the spread of durability degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of discharge ports is increased, then the productivity is improved, but the line resistance increases making it difficult to securely disconnect the fuse portion
Solution Approach 1:
The patent divides the single long common line into multiple shorter common lines by introducing intermediate connection points with fuse portions. This segmentation reduces the line resistance of each individual common line, ensuring that fuse portions can be securely disconnected even when a large number of discharge ports are present.
Solution Approach 2:
The patent introduces intermediate connection points as mediators between the power supply and multiple discharge ports. These intermediaries break the long current path into shorter segments, reducing overall line resistance and enabling reliable fuse disconnection while maintaining high productivity.
2Ease of operation
If the protection layers are electrically connected to each other, then the ease of operation is improved for applying voltage during cleaning, but the harmful factors spread across the entire head when conduction occurs
Solution Approach 1:
The patent divides the protection layers into electrically isolated segments using fuse portions. During normal operation, multiple protection layers are connected through common lines for efficient voltage application during cleaning. When conduction occurs between a heat resistor and protection layer, the fuse portion disconnects the affected segment, preventing durability degradation from spreading to other protection layers.
Solution Approach 2:
The patent implements different electrical connection states for different regions: protection layers are electrically connected in regions where cleaning is performed, but are electrically isolated in regions where conduction may occur, as determined by the fuse portion disconnection status. This allows localized quality control across the head.
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 design effectively suppresses the influence of durability degradation across the liquid discharge head by ensuring secure disconnection of fuse portions, maintaining the protection layer's integrity and reducing the frequency of head replacements, thus lowering operational costs.
Implementation Method 1
a fuse portion which connects an end portion of the first common line in the direction of the first heat resistor array to the third common line, and a second fuse portion which connects an end portion of the second common line in the direction of the second heat resistor array to the third common line
Implementation Method 2
the fuse portion is disconnected by the current
Implementation Method 3
electric power is supplied to the protection layer, electrochemical reaction occurs between the protection layer and the liquid and a function of the protection layer may be lost
Data Source
AI summary
Influence of transform of quality to an entire liquid discharge head is suppressed when a heat resistor and a covering portion are electrically connected to each other. To address this problem, a liquid discharge head substrate includes fuse portions for respective heat resistor arrays.