Band Detection Sensor Dynamic Rise Criterion
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Solution Overview
Problem
Conventional band detection sensors are prone to false detection of bands on wrinkled or deformed webs due to a fixed threshold value, leading to inaccurate band detection.
Innovation Solution
A band detection sensor utilizing a light emitter and receiver with a band discriminator that generates a band signal based on a rise discriminating criterion, which assesses the rate of change in the detection signal, ensuring accurate detection regardless of web surface conditions, and optionally includes a fall discriminating criterion and a band lack discriminator for precise band identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed threshold value is used for band detection, then the detection method is simple, but false detection occurs on wrinkled or deformed webs
Solution Approach 1:
The patent applies the dynamics principle by transitioning from a fixed threshold value to a dynamic threshold that adapts to web surface conditions. The discrimination unit calculates a dynamic threshold based on the detection signal characteristics, allowing the system to adjust to wrinkles and deformations automatically. This resolves the contradiction by maintaining operational simplicity while improving detection reliability through adaptive thresholding.
Solution Approach 2:
The patent employs parameter changes by modifying the threshold parameter from a fixed value to a dynamically calculated value based on detection signal characteristics. The discrimination unit changes the threshold parameter adaptively according to the actual web conditions, enabling accurate band detection regardless of web surface variations while keeping the overall detection method straightforward.
2Measurement precision
If the detection threshold is set to detect all potential bands, then detection sensitivity increases, but false detection from web wrinkles increases
Solution Approach 1:
The patent applies feedback by using the detection signal itself to dynamically adjust the threshold. The discrimination unit continuously monitors the detection signal characteristics and adjusts the threshold accordingly, creating a feedback loop that distinguishes between actual bands and wrinkles. This allows high detection sensitivity while automatically filtering out false detections from web surface variations.
Solution Approach 2:
The patent employs preliminary action by calculating the dynamic threshold in advance based on the detection signal characteristics before making the band detection decision. The discrimination unit prepares the adaptive threshold based on observed signal patterns, enabling the system to accurately distinguish bands from wrinkles when the actual detection is made, thus preventing false detections while maintaining sensitivity.
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 solution effectively prevents false detection of bands on wrinkled or deformed webs, ensuring high accuracy in band detection and the ability to detect band absence, even under varying web conditions.
Implementation Method 1
a light emitter for radiating detection light onto a traveling web, a light receiver for receiving the detection light reflected by the web
Data Source
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AI summary
A band detection sensor includes LEDs (20) configured to radiate detection light onto one side of a web (W), photodiodes (22) configured to receive the detection light reflected by the web (W) and output a detection signal corresponding to the detection light, and a discrimination section (46) configured to discriminate bands (B) on the web (W) on the basis of the detection signal from the photodiodes (22), wherein the discrimination section (46) includes a rise discriminating criterion (TN, L1) indicating a rate of rise of the detection signal and generates a band signal (SB) indicative of the presence of a band (B) when change of the detection signal fulfills the rise discriminating criterion (TN, L1).