Ultrasonic Multiple Feed Detection in Sheet Conveying
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Solution Overview
Problem
Conventional sheet conveying apparatuses face challenges in accurately detecting multiple feeds, particularly when the overlapping width of documents is large, leading to delayed detection and potential damage to documents, as existing sensors struggle with directional characteristics and diffraction issues.
Innovation Solution
The apparatus employs an upstream side roller and an ultrasonic wave sensor positioned downstream to detect the presence of sheets and multiple feeds based on the intensity of ultrasonic waves, allowing for precise calculation of document locations and deviation amounts, and adjusts the drive state of rollers to prevent document damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an ultrasonic wave sensor is used to detect multiple feeds, then the detection capability is improved, but directional characteristics and diffraction issues cause detection inaccuracies
Solution Approach 1:
The patent segments the detection function by using multiple ultrasonic wave sensors positioned at different locations and angles in the conveying path. Each sensor detects specific portions of multiple-fed documents, and the control unit integrates information from all sensors to achieve comprehensive and accurate detection, overcoming the limitations of single-sensor directional characteristics and diffraction.
Solution Approach 2:
The patent merges the detection results from multiple ultrasonic wave sensors to form a comprehensive judgment on multiple feed occurrence. By combining signals from sensors positioned at different locations, the system achieves more reliable detection than any single sensor could provide alone, resolving the reliability issue caused by individual sensor limitations.
2Loss of time
If the detection sensor is positioned upstream, then early detection is achieved, but detection precision is reduced due to document curvature and positioning issues
Solution Approach 1:
The patent positions ultrasonic wave sensors at multiple locations and angles along the conveying path, transitioning from a single-point detection approach to a multi-dimensional detection network. This spatial distribution allows early detection while maintaining precision by selecting and combining signals from sensors that provide the most accurate readings at each moment.
Solution Approach 2:
The system performs preliminary detection using upstream sensors to identify potential multiple feed conditions early in the conveying process. When abnormalities are detected, the control unit activates additional sensors and implements corrective actions, ensuring both early detection and maintained precision through progressive verification.
3Object-affected harmful factors
If multiple feeds are detected late, then document damage occurs, but early detection requires sensors positioned upstream where precision is compromised
Solution Approach 1:
The patent divides the conveying path into multiple detection zones with sensors positioned at strategic locations. This segmentation allows the system to perform preliminary detection upstream and confirmatory detection downstream, enabling early intervention while maintaining high precision through the combined information from all zones.
Solution Approach 2:
The control unit continuously receives feedback from multiple sensors positioned at different locations and dynamically adjusts its detection strategy. When upstream sensors indicate potential issues, the system activates additional sensors and implements corrective actions, creating a feedback loop that enables early detection without sacrificing precision.
4Device complexity
If a single sensor type is used, then device complexity is reduced, but detection accuracy for multiple feeds deteriorates
Solution Approach 1:
The patent employs multiple ultrasonic wave sensors that serve universal detection functions across different positions and angles in the conveying path. Each sensor performs the same basic function of detecting document presence and characteristics, but their collective operation achieves high-precision multiple feed detection, maintaining simplicity while improving accuracy.
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 enables quick and accurate detection of multiple feeds, minimizing document damage by precisely controlling the rollers' drive state and ensuring precise document separation.
Implementation Method 1
an ultrasonic wave sensor to detect presence or absence of occurrence of multiple feed, based on intensity of ultrasonic waves received
Data Source
AI summary
An image forming apparatus as a sheet conveying apparatus comprises a paper feeding roller, an upstream side sensor, and an ultrasonic wave sensor. The paper feeding roller provides a plurality of sheets placed on a document tray in series to a conveying path. The upstream side sensor detects presence or absence of a sheet being conveyed along the conveying path, at a location of a downstream side of the paper feeding roller along the conveying path. The ultrasonic wave sensor detects presence or absence of occurrence of multiple feed, based on intensity of ultrasonic waves received at a location of a downstream side of the upstream side sensor along the conveying path.