Multi-feed Sensor Placement in Sheet Conveyance
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Solution Overview
Problem
Existing sheet conveyance devices in image forming apparatuses face challenges in accurately detecting and preventing multi-feed conditions, where multiple sheets are fed simultaneously, leading to inefficiencies and potential jamming issues.
Innovation Solution
A sheet conveyance device equipped with a multi-feed sensor and a sheet conveyance controller that suspends the driving of conveyance rollers when a multi-feed condition is detected, ensuring sheets are fed individually and preventing overlap by adjusting the operation based on sensor output signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separation roller is used to prevent multi-feed, then sheet separation is improved, but detection accuracy of multi-feed conditions deteriorates
Solution Approach 1:
A multi-feed sensor is introduced as an intermediary detection device between the paper feed roller and the separation roller. This sensor independently detects the presence of multiple sheets before they reach the separation point, providing accurate multi-feed detection without interfering with the mechanical separation function of the separation roller.
Solution Approach 2:
The detection function is segmented from the separation function. Instead of relying on the separation roller's mechanical action to indicate multi-feed conditions, a dedicated multi-feed sensor separately performs detection, while the separation roller continues its sheet separation task independently.
2Productivity
If continuous conveyance is maintained to improve productivity, then output increases, but multi-feed occurrences worsen
Solution Approach 1:
The sheet conveyance controller receives real-time feedback from the multi-feed sensor and automatically adjusts the conveyance operation. When multiple sheets are detected, the controller suspends the driving of conveyance rollers to prevent multi-feed, and resumes normal operation when single-sheet feeding is restored, thereby maintaining high productivity while preventing multi-feed errors.
Solution Approach 2:
The conveyance system dynamically adjusts its operation based on real-time detection conditions. The driving of conveyance rollers is suspended only when multi-feed is detected, and normal conveyance is resumed when single-sheet feeding is confirmed, creating a dynamic response that balances productivity and reliability.
3Measurement precision
If multi-feed detection is performed continuously to improve detection accuracy, then detection reliability increases, but energy consumption increases
Solution Approach 1:
The multi-feed detection is performed periodically at specific intervals during the conveyance process rather than continuously. The sheet conveyance controller suspends conveyance rollers when multi-feed is detected and resumes normal operation when single-sheet feeding is confirmed, creating a periodic detection pattern that reduces energy consumption while maintaining detection reliability.
Data Source
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AI summary
A sheet conveyance device (200) includes a paper feed section (24), a separation roller (30), a registration roller pair (25) arranged downstream of the paper feed section (24), a conveyance roller pair (26) arranged downstream of the registration roller pair (25), a multi feed sensor (MS) arranged between the paper feed section (24) and the registration roller pair (25), and a document conveyance controller (210). When an original document (D) arrives at the conveyance roller pair (26), the document conveyance controller (210) suspends driving of the paper feed section (24) and starts multi feed determination.