Printhead Temperature Sensing Resistor Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing printheads face challenges in uniform temperature measurement and heating across their regions, which can affect fluid ejection performance, especially in larger devices where temperature equalization between regions takes longer.
Innovation Solution
A temperature sensing resistor (TSR) is designed to extend around the edge and between adjacent fluid slots, acting as both a temperature sensor and heating element, allowing for more representative temperature measurements and uniform heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensing resistor is placed in a single location in existing printheads, then the device structure is simple, but the temperature measurement is not representative of the entire printhead and heating is non-uniform
Solution Approach 1:
The temperature sensing resistor is divided into multiple discrete sensing elements positioned at different locations (edge region and inner region) of the printhead. Each segment independently measures temperature at its specific location, enabling comprehensive temperature mapping across the printhead structure rather than relying on a single measurement point.
Solution Approach 2:
The temperature measurement transitions from a single-point measurement to a distributed spatial measurement across multiple dimensions of the printhead. By placing sensing elements at both the edge and inner regions, the system captures temperature variations across the spatial dimension, providing a more representative overall temperature profile.
2Productivity
If the printhead is made larger to increase productivity, then more fluid slots can be served, but the temperature equalization time increases
Solution Approach 1:
The temperature sensing resistor is positioned to detect temperatures in both edge and inner regions simultaneously, enabling preliminary temperature assessment before fluid ejection begins. This allows the system to pre-compensate for temperature variations and initiate heating or cooling actions in advance, reducing the overall temperature equalization time.
Solution Approach 2:
The distributed temperature sensing provides real-time feedback from multiple locations within the printhead. This feedback mechanism enables the control system to monitor temperature equalization progress and adjust heating elements accordingly, accelerating the temperature equalization process in larger printheads by actively responding to measured temperature conditions.
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 configuration enables more accurate temperature monitoring and efficient heating of the printhead, improving fluid ejection performance and reducing temperature equalization time across different regions, particularly beneficial for larger printheads.
Implementation Method 1
Some printheads include a temperature sensing resistor which is used to detect a temperature of the printhead
Implementation Method 2
A temperature sensing member or heating element, which extends around at least a part of an edge of the fluid slot area... In one example a temperature sensing resistor acts as both a temperature sensor and a heating element
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A printhead including a fluid slot area in which a plurality of fluid slots are formed and a temperature sensing member, heating element or temperature sensing resistor including an edge portion and an inner portion. The edge portion extends along at least a part of an edge of the fluid slot area and the inner portion is connected to the edge portion and extends in-between two adjacent fluid slots.