Piezoelectric Sensor Embedded in Fuser Roll for Nip Width Measurement
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Solution Overview
Problem
Current methods for measuring nip width between rollers in printing systems are inaccurate, prone to variations due to temperature and moisture, and require manual intervention, leading to image quality defects and excessive wear on fuser rolls.
Innovation Solution
Embedding piezoelectric (PZT) crystals at the inboard and outboard ends of rollers to generate electrical signals indicative of pressure, which are processed to determine nip width and dwell time, allowing for dynamic and continuous measurement and adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual nip width measurement methods (carbon paper, prescale film, foil) are used, then measurement can be performed, but the measurement is inaccurate and susceptible to temperature and moisture variations
Solution Approach 1:
The patent replaces manual mechanical measurement methods (carbon paper impressions, prescale film deformation, foil rupture) with an automated sensor-based system. Load sensors mounted on the pressure roll directly measure the nip width through electrical signals, eliminating the need for manual intervention and chemical/physical indicators that are susceptible to environmental variations.
Solution Approach 2:
The patent introduces load sensors as intermediary devices between the pressure roll and the measurement system. These sensors act as mediators that convert mechanical pressure into electrical signals, providing an indirect but more reliable measurement method that is not affected by temperature and moisture variations that plague direct manual measurement methods.
2Measurement precision
If manual nip width measurement and adjustment is performed, then nip width can be checked, but the process requires operator intervention and is not done consistently, leading to incorrect settings
Solution Approach 1:
The patent implements a self-measuring system where load sensors automatically detect and report nip width without requiring operator intervention. The system serves itself by continuously monitoring the nip width and providing real-time feedback, eliminating the need for manual measurement and adjustment procedures that depend on operator skill and consistency.
Solution Approach 2:
The patent establishes a feedback loop where load sensors continuously measure nip width and provide real-time data to the control system. This feedback mechanism enables automatic adjustment and maintains consistent nip width settings without relying on periodic manual checks by operators, ensuring both precision and operational ease.
3Manufacturing precision
If fuser roll replacement and manual nip width adjustment is performed, then nip width can be set, but the measurement is frequently incorrect due to Durometer variations and aging
Solution Approach 1:
The patent replaces manual measurement methods that are sensitive to material properties (Durometer variations, aging) with an automated load sensor system. The sensors directly measure the actual nip width through electrical signals, bypassing the need for manual estimation based on material characteristics that vary between batches and over time.
Solution Approach 2:
The patent implements continuous monitoring of nip width through permanently mounted load sensors, rather than periodic manual measurements. This continuous action ensures that nip width is consistently tracked and adjusted throughout the fuser roll's lifecycle, maintaining manufacturing precision regardless of roll aging or batch variations.
4Duration of action of stationary object
If uneven nip settings occur, then fuser roll life is reduced due to accelerated edge wear, but manual measurement methods cannot detect the unevenness accurately
Solution Approach 1:
The patent divides the measurement function into multiple load sensors positioned at different locations (inboard and outboard ends) of the pressure roll. This segmentation allows independent measurement of nip width at each location, enabling detection of unevenness that would be missed by single-point manual measurement methods and preventing localized edge wear that reduces fuser roll life.
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
Enables precise and consistent nip width measurement, reducing image quality defects and extending fuser roll life by minimizing edge wear through real-time monitoring and adjustment.
Implementation Method 1
A piezoelectric (PZT) crystal generates a charge when subjected to a load
Implementation Method 2
A piezoelectric (PZT) crystal generates a charge when subjected to a load and when the load is released
Data Source
AI summary
According to aspects of the embodiments, an apparatus and method is proposed to detect nip width by use of at least one piezoelectric (PZT) crystal embedded into a roll at both the inboard and outboard ends. A piezoelectric (PZT) crystal generates a charge when subjected to a load and when the load is released. The PZT generate signal is channeled to the ends of the roller such as with a brush contact to be processed and used within machine control. The duration measure from application and released of the load is indicative of the dwell time and the amplitude PZT generate signal is a function of the pressure. The time and amplitude of the PZT signal can be calibrated to correlate directly to nip width or pressure and tracked in machine control.