Motor Current Sensing for Jam Detection in Print Engines
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Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately detecting paper jams, as they often misinterpret increases in motor current due to paper thickness or motor deterioration rather than actual jams, leading to incorrect jam detection.
Innovation Solution
The apparatus employs a dual-interval current sensing method, where the processor compares current data from a first interval during stable motor operation and a second interval after the paper has passed through the fuser, to differentiate between jam occurrences and other factors like paper thickness or motor load changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If motor current is monitored to detect paper jams, then jam detection capability is improved, but false detection increases due to misinterpretation of current increases from paper thickness or motor deterioration
Solution Approach 1:
The patent divides the current monitoring into two distinct time intervals: a first interval during stable motor operation and a second interval after paper passes through the fuser. By segmenting the detection process temporally, the system can compare current characteristics across different operational phases to distinguish actual jams from false causes like paper thickness variations or motor deterioration.
Solution Approach 2:
The patent changes the monitoring parameters by measuring motor current at different time points (before and after fuser passage) and comparing the magnitude of current increases. This parameter change approach allows the system to identify the characteristic current profile of actual jams versus other conditions, thereby improving detection precision while maintaining reliability.
2Device complexity
If single-interval current monitoring is used, then device complexity is reduced, but detection precision deteriorates due to inability to differentiate jam causes
Solution Approach 1:
The patent applies temporal segmentation by dividing current monitoring into two intervals without adding physical hardware complexity. The processor simply measures current at different time points and compares the increases, achieving enhanced detection precision through intelligent use of existing components rather than additional sensors or mechanisms.
Solution Approach 2:
The system uses the motor's own current consumption pattern as the detection signal, eliminating the need for separate sensors. By analyzing how the motor's current draw changes across different operational intervals, the system achieves precise jam detection using only the existing motor and processor, maintaining low device complexity.
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 approach enables precise jam detection, reducing false alarms and ensuring accurate identification of paper jams, thereby preventing damage from excessive heat and allowing for timely intervention.
Implementation Method 1
a size of current provided to a motor while the motor is driven in a first time interval after the motor starts operating is sensed
Data Source
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AI summary
An image forming apparatus is provided. The image forming apparatus includes a print engine to be used to perform an image forming job, a motor to start the print engine, a driving circuit to supply a power to the motor and to include a sensor to sense a size of current of the power supplied to the motor during an operation to perform the image forming job, and a processor to detect an occurrence of jam based on a size of current sensed by the sensor in a first time interval while the motor is driven and a size of current sensed by the sensor after a determined time from the first time interval.