Ultrasonic Paper Jam Detection via Frequency Band Analysis
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Solution Overview
Problem
Existing paper conveying apparatuses face increased costs due to the need for dedicated microphones to detect jams based on sound, which is not efficient for determining jam occurrences during paper conveyance.
Innovation Solution
Incorporating an ultrasonic detector near the conveyance path to detect ultrasonic waves and using bandpass filters to differentiate between components of the ultrasonic signal for multifeed and jam detection, allowing for cost-effective jam detection without dedicated microphones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dedicated microphone is used to detect sound for jam detection, then the accuracy of jam detection is improved, but the cost of the paper conveying apparatus increases
Solution Approach 1:
The patent replaces the acoustic detection system (microphone) with an optical detection system. The light receiver detects changes in light intensity caused by paper jams in the conveyance path, converting a mechanical/acoustic detection problem into an optical measurement problem. This substitution eliminates the need for dedicated microphones while maintaining detection accuracy.
Solution Approach 2:
The patent uses an existing light receiver (designed for other purposes in the imaging apparatus) to perform jam detection functionality. Instead of adding a dedicated microphone, the system copies the detection capability to an existing optical component, allowing one element to serve multiple functions including jam detection.
2Device complexity
If the light receiver is used for both image reading and jam detection, then the device complexity is reduced, but the measurement precision for jam detection may be affected
Solution Approach 1:
The patent segments the detection signals by using different characteristics of light reception. The light receiver generates multiple types of signals (first light reception signal for image reading, second light reception signal for jam detection) from the same physical component. This segmentation allows the single light receiver to perform distinct detection functions with appropriate signal processing for each purpose.
Solution Approach 2:
The patent applies different processing methods to different aspects of the light receiver's output. The image reading function processes visual information from the paper, while the jam detection function monitors light intensity changes caused by paper position variations. Each function receives optimized signal processing tailored to its specific measurement needs, maintaining precision despite using a shared component.
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 accurate and cost-effective detection of jams and multifeed occurrences by analyzing ultrasonic signals, reducing erroneous detections and operational costs.
Implementation Method 1
an ultrasonic detector, provided near a conveyance path of paper, for detecting an ultrasonic wave which passes through paper and outputting an ultrasonic signal
Data Source
AI summary
There are provided a paper conveying apparatus, a jam detection method and a computer-readable, non-transitory medium which can determine whether a jam has occurred based on the sound which is generated by a paper during conveyance at a low cost. The paper conveying apparatus includes an ultrasonic detector, provided near a conveyance path of a paper, for detecting an ultrasonic wave which passes through paper and outputting an ultrasonic signal, a multifeed detector for determining whether multifeed of papers has occurred based on a component of a first frequency band in the ultrasonic signal, and a sound jam detector for determining whether a jam has occurred based on a component of a second frequency band lower than the first frequency band in the ultrasonic signal.