Laser Printer Toner Measurement Using Vibration and Charge Signals
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Solution Overview
Problem
Existing toner level measurement systems in laser printer cartridges are inaccurate and unreliable, often providing only general indications like 'full', 'medium', or 'low' without precise quantification, leading to inefficiencies in toner replacement and potential shortages.
Innovation Solution
A measuring system that utilizes a combination of an acceleration sensor and a charge variation sensor to measure vibrations and electrostatic charge variations generated by the cartridge's rotating elements, employing machine learning techniques to accurately determine the toner level based on feature parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inductive sensors are used to detect toner level, then the measurement can be performed, but the measurement precision and reliability are insufficient
Solution Approach 1:
The patent combines multiple sensing modalities (inductive sensor, acceleration sensor, charge variation sensor) into an integrated measurement system. This merging of different sensor types enables cross-validation of measurements and provides redundant information, thereby improving both precision and reliability of toner level detection beyond what single sensors can achieve.
Solution Approach 2:
The system implements feedback mechanisms where measurement results are continuously monitored and used to adjust sensor operation parameters. The control unit processes signals from multiple sensors and uses feedback loops to optimize measurement conditions, ensuring consistent high-quality measurements while compensating for individual sensor limitations.
2Loss of information
If general toner level indications (full, medium, low) are provided, then the system complexity is reduced, but the information accuracy and usefulness are insufficient
Solution Approach 1:
The system dynamically adjusts the granularity of toner level reporting based on actual measurement quality and cartridge conditions. Rather than static discrete levels, the system can provide continuously varying precision measurements when conditions permit, maximizing information accuracy while adapting complexity to actual needs rather than using fixed complex thresholds.
Solution Approach 2:
The patent changes the parameter representation from discrete categorical levels to continuous quantitative measurements. By measuring physical parameters (inductance, acceleration, charge variation) and converting them to precise toner quantity estimates, the system transforms limited categorical information into rich quantitative data without proportionally increasing system complexity.
3Measurement precision
If multiple sensors are combined to improve measurement accuracy, then the measurement precision increases, but the device complexity increases
Solution Approach 1:
The patent designs sensors that serve multiple functions: inductive sensors detect toner quantity while also providing information about cartridge positioning; acceleration sensors measure vibrations that indicate both toner level and cartridge installation status; charge variation sensors provide toner measurement and electrostatic field characterization. This multi-functionality reduces the need for dedicated sensors for each measurement task, thereby limiting complexity growth.
Solution Approach 2:
The control unit acts as an intermediary that integrates and processes signals from multiple sensors. Rather than requiring complex direct interactions between sensors, the control unit mediates by collecting, synchronizing, and fusing data from all sensors, then presenting unified measurement results. This intermediary approach manages system complexity by centralizing the integration logic.
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
The system provides precise and reliable toner level measurements with an accuracy of up to 94.191%, ensuring timely replacement and minimizing waste and costs by accurately indicating the amount of toner remaining.
Implementation Method 1
measuring vibrations and electrostatic charge variations generated by the cartridge's rotating elements
Implementation Method 2
measuring vibrations and electrostatic charge variations generated by the cartridge's rotating elements
Data Source
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AI summary
Measuring system (50) for a cartridge (10) for laser printer (40), the measuring system (50) being configured to be coupled to an external body (14) of the cartridge (10) and comprising: an acceleration sensor (52) configured to measure vibrations of the cartridge (10) generated by rotating elements (20, 22, 24) of the cartridge (10); and a charge variation sensor (54) configured to measure electrostatic charge variations generated by movements of the toner (12) in the cartridge (10). The measuring system (50) further comprises a control unit (56) configured to: receive from the acceleration sensor (52) an acceleration signal indicative of the measured vibrations, and from the charge variation sensor (54) a charge variation signal indicative of the measured electrostatic charge variations; determine feature parameters as a function of the acceleration signal and the charge variation signal, the feature parameters comprising a peak-to-peak distance (App) of the acceleration signal and a maximum (Cm) of the charge variation signal; and generate, on the basis of the feature parameters, a level signal indicative of the level of the toner (12) in the cartridge (10).