Dynamic Multi-feed Detection Threshold Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Medium conveying apparatuses often incorrectly determine multi-feed conditions when a medium with an adhered object is conveyed, leading to unnecessary stopping of the conveyance process, which impairs user convenience and increases processing time.
Innovation Solution
The apparatus uses a processor to detect ultrasonic wave transmission information or thickness information at multiple positions within the medium, calculates the size of the area where this information falls within a predetermined range, and adjusts a threshold value to accurately determine multi-feed conditions, thereby reducing erroneous stops and improving user convenience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the multi-feed detection function is activated to detect overlapping media, then multi-feed detection capability is improved, but false detection occurs when photograph-adhered media is conveyed, requiring the function to be turned OFF and impairing user convenience
Solution Approach 1:
The patent changes the detection parameters by introducing a time-based criterion: it detects whether the driven roller displacement amount increases for a time shorter than a predetermined threshold. This temporal parameter differentiation allows the system to distinguish between genuine multi-feed events (sudden thick overlap) and photograph-adhered media (smaller, transient displacement), resolving the false detection issue while maintaining multi-feed detection capability
Solution Approach 2:
The patent makes the detection system dynamic by continuously monitoring the driven roller displacement over time and comparing it against temporal thresholds. Instead of using a static displacement threshold that causes false positives, the system evaluates the rate and duration of displacement changes, enabling adaptive detection that maintains reliability while avoiding false alarms that would require users to disable the function
2Device complexity
If a fixed threshold is used for multi-feed determination, then the detection process is simple, but detection accuracy deteriorates when photograph-adhered media is conveyed, causing unnecessary stops
Solution Approach 1:
The patent transforms the static threshold into a dynamic evaluation process by incorporating time as a variable. The system monitors whether displacement amount increases occur within a predetermined time window, creating an adaptive detection mechanism that maintains simplicity while improving accuracy for photograph-adhered media
Solution Approach 2:
The patent introduces a temporal parameter (time threshold) to the detection process, changing from a single-dimensional displacement threshold to a two-dimensional evaluation (displacement amount + time duration). This parameter expansion enables the system to distinguish between genuine multi-feed and photograph-adhered media without significantly increasing system complexity
3Reliability
If the multi-feed detection function stops conveyance upon detection, then multi-feed errors are prevented, but processing time increases due to unnecessary stops during photograph-adhered media conveyance
Solution Approach 1:
The patent implements dynamic decision-making by continuously evaluating both displacement amount and time duration. The system only triggers conveyance stop when the displacement increase occurs within the predetermined short time window, allowing photograph-adhered media to pass through without unnecessary stops while still preventing genuine multi-feed errors
Solution Approach 2:
By adding the time parameter to the detection criteria, the patent enables more precise control over when conveyance should be stopped. The dual-parameter evaluation (displacement + time) reduces false positives that cause unnecessary stops, thereby decreasing processing time while maintaining conveyance accuracy for genuine multi-feed detection
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 enhances the accuracy of multi-feed detection, minimizes incorrect stops during conveyance, and improves user convenience by allowing continuous processing of media with adhered objects without requiring manual intervention.
Implementation Method 1
detect transmission information of an ultrasonic wave transmitted through the medium
Data Source
AI summary
A medium conveying apparatus includes a conveying roller to convey a medium, and a processor to detect transmission information of an ultrasonic wave transmitted through the medium or thickness information of the medium at a plurality of positions in the conveyed medium, calculate a size of an area in which the transmission information or the thickness information is within a predetermined range in the conveyed medium, determine whether a multi-feed of the medium has occurred, by comparing a value based on the transmission information or the thickness information with a threshold, and execute an abnormality processing when it is determined that the multi-feed of the medium has occurred. The processor changes the threshold according to the size.