Drive Signal Circuit Cooling for Liquid Ejecting Heads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The drive signal generation circuit in liquid ejecting apparatuses generates significant heat due to high-amplitude drive signals, leading to potential instability in operation.
Innovation Solution
Incorporation of a metal first substrate with a transistor pair comprising two bipolar transistors to generate drive signals, coupled with efficient heat dissipation mechanisms using aluminum heat sinks and fans.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a transistor pair generates a drive signal with large amplitude, then the liquid ejecting head can be driven effectively, but the drive signal generation circuit generates significant heat leading to unstable operation
Solution Approach 1:
The patent converts the harmful heat generated by the transistor pair into a beneficial effect by using it to drive a liquid cooling mechanism. The cooling liquid flows through a channel formed in the substrate, absorbing heat from the transistor pair and carrying it away, thus transforming the problematic heat generation into an effective cooling solution that maintains operational stability.
Solution Approach 2:
The patent introduces a cooling liquid as an intermediary substance between the heat source (transistor pair) and the surrounding environment. The cooling liquid absorbs heat through thermal conduction in the channel and dissipates it through convection, acting as a mediator that transfers heat away from the critical components without requiring direct contact between the transistor and the cooling system.
2Productivity
If the drive signal generation circuit operates at high power, then the liquid ejecting apparatus functions properly, but the temperature of the circuit increases causing potential instability
Solution Approach 1:
The patent segments the substrate to form a dedicated cooling channel that passes through or near the transistor pair. This segmentation allows the cooling liquid to flow directly through the heat-generating region, creating efficient thermal management pathways that separate the high-power operation zone from the temperature-sensitive components.
Solution Approach 2:
The patent employs a hydraulic cooling system where cooling liquid is pumped through channels formed in the substrate. This hydraulic approach enables continuous flow of coolant through the transistor pair region, utilizing fluid dynamics to efficiently remove heat generated during high-power operation and maintain stable circuit temperatures.
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
Stabilizes the operation of the drive signal generation circuit by effectively managing heat generation, ensuring reliable performance of the liquid ejecting apparatus.
Implementation Method 1
a channel through which a cooling liquid flows is formed in the substrate... the cooling liquid absorbs heat from the transistor pair
Implementation Method 2
the cooling liquid absorbs heat from the transistor pair and removes the heat from the transistor pair by convection
Data Source
AI summary
A liquid ejecting apparatus includes a liquid ejecting head that is driven by a drive signal to eject a liquid, a first substrate made of metal, and a transistor pair that is provided on the first substrate and includes two bipolar transistors generating the drive signal.