Toner Level Sensing Using Magnetic Pulse Width Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for an effective method to measure the remaining toner level in replaceable units of image forming devices to prevent damage and notify users when the toner is low or empty, as existing systems lack reliable sensing mechanisms.
Innovation Solution
A method involving a rotatable shaft with a paddle that falls due to its own weight, a magnet, and magnetic sensors to detect changes in the pattern of digital pulses generated by the magnet's presence, allowing for estimation of toner levels by monitoring the paddle's motion and adjusting the toner level estimate based on sensed pulse widths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic sensor is used to detect toner levels, then measurement precision is improved, but device complexity increases due to additional sensing components and signal processing requirements
Solution Approach 1:
A magnetic element is introduced as an intermediary carrier on the paddle to enable indirect measurement of toner levels. The magnetic sensor does not directly measure toner but rather detects the position and motion of the magnetic element, which in turn reflects toner level conditions. This intermediary approach improves measurement precision while managing system complexity by using a simple magnetic field detection mechanism rather than direct toner sensing.
Solution Approach 2:
The paddle with magnetic element serves multiple functions: it acts as a mechanical indicator of toner level, a carrier for the magnetic sensor target, and a component that interacts with toner to provide self-diagnostic information. The system uses the natural motion and position changes of this self-service component to generate measurement data without requiring additional active sensing elements.
2Loss of information
If a paddle mechanism is added to rotate with the shaft, then toner level detection capability is improved, but device complexity increases due to additional moving parts
Solution Approach 1:
The paddle with magnetic element is merged with the existing shaft rotation mechanism. The paddle rotates together with the shaft as an integrated assembly, combining the shaft's rotational function with the paddle's information-carrying function. This merging approach prevents information loss about toner levels while avoiding the complexity of separate independent mechanisms.
Solution Approach 2:
The paddle-shaft assembly serves multiple functions: it transfers rotational motion for toner agitation, carries the magnetic element for sensing, and provides a mechanical indicator of operational status. This multi-functionality ensures that toner level information is preserved and captured without requiring dedicated separate components for each function.
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 solution accurately estimates toner levels by correlating paddle motion and magnetic sensor data, enabling timely notification of low toner conditions and preventing device damage by ensuring proper toner replenishment.
Implementation Method 1
A magnetic field of a magnet connected to the paddle is sensed by a first magnetic sensor when the paddle is near a lowest center of gravity of the paddle
Implementation Method 2
A paddle mounted on the shaft and free to fall ahead of the rotation of the shaft
Data Source
AI summary
A method for estimating an amount of toner remaining in a reservoir of a replaceable unit for an image forming device according to one example embodiment includes measuring an amount of revolution of a shaft in the reservoir of the replaceable unit, decreasing an estimate of the amount of toner remaining in the reservoir based on the measured amount of revolution of the shaft, monitoring whether a pattern of widths of digital pulses generated from a magnetic sensor when the magnetic sensor senses a magnetic field of a magnet connected to a paddle mounted on the shaft in the reservoir when the paddle is near a lowest center of gravity of the paddle changes, and adjusting the estimate of the amount of toner remaining in the reservoir when the pattern of widths of digital pulses generated from the magnetic sensor changes.