Sheet Interval Control for Image Forming Apparatus
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Solution Overview
Problem
Existing image forming apparatuses face issues with ensuring a sufficient sheet interval during continuous printing due to disorderly supplied papers, leading to potential double-feeding, size errors, and jamming, especially when papers are not properly loaded or fed.
Innovation Solution
The apparatus incorporates a sheet interval control system that switches between normal and extended sheet interval modes, using a conveyed sheet detection part and conveyance amount counting to adjust the feeding action, ensuring proper sheet alignment and preventing misfeeding by delaying image formation until the sheet is detected and maintaining an extended interval when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If papers are loaded on the sheet loading section, then the sheet feeding section can perform feeding action, but papers may be positioned not to contact the sheet feed roller causing feeding failure
Solution Approach 1:
The sheet sensor detects the position of the sheet before the feeding action starts, and the control unit adjusts the feeding control based on this preliminary detection. When the sheet is detected to be positioned apart from the sheet feed roller, the system performs a retry feeding action to ensure proper contact and feeding, preventing feeding failure while maintaining productivity.
2Reliability
If feed retry control is performed when sheet feeding failure occurs, then feeding reliability is improved, but sheet interval may become insufficient causing double-feeding
Solution Approach 1:
The sheet sensor provides feedback on sheet position and feeding status. The control unit uses this feedback to determine whether a retry feeding action is necessary. After retry feeding, the sensor continues to monitor sheet arrival at the conveying section, allowing the system to adjust subsequent feeding timing to maintain proper sheet intervals and prevent double-feeding.
Solution Approach 2:
The sheet interval control is made dynamic by adjusting the feeding timing based on actual sheet position feedback. When sheets are fed with extended intervals due to retry actions, the system adapts the next feeding timing accordingly, switching between normal and extended sheet interval modes to maintain precision while accommodating reliability improvements.
3Manufacturing precision
If extended sheet interval mode is used to prevent double-feeding, then sheet interval precision is improved, but continuous printing productivity decreases
Solution Approach 1:
The system dynamically switches between normal sheet interval mode and extended sheet interval mode based on feeding conditions. When feeding proceeds normally without position issues, the system operates in normal mode for high productivity. When retry feeding is performed or position abnormalities are detected, it switches to extended mode to ensure precision, thereby optimizing the balance between productivity and precision in real-time.
4Productivity
If the sheet sensor detects sheet arrival within predetermined time, then feeding efficiency is maintained, but feeding failures may be missed when sheets are positioned apart
Solution Approach 1:
The sheet sensor performs preliminary detection of sheet position before the feeding action commences. This preliminary action identifies sheets that are positioned apart from the sheet feed roller, allowing the control unit to anticipate and correct potential feeding failures before they occur, thereby maintaining both efficiency and reliability.
Solution Approach 2:
The sensor provides continuous feedback on sheet position and feeding progress. When a sheet is detected to be in an abnormal position or when feeding takes longer than expected, the feedback triggers a retry feeding action, ensuring that detection accuracy is maintained even when sheets are initially positioned apart, while minimizing impact on overall efficiency.
Data Source
AI summary
An image forming apparatus performs a continuous printing job in a normal sheet interval mode as an initially setting mode when an arrival waiting control such as a feed retry control is not performed. In the normal sheet interval mode, a feeding action is performed such that a sheet interval between successive two sheets is set at a predetermined normal sheet interval during the continuous printing. When the initially setting mode is not maintained, the continuous printing is performed with switching the sheet interval mode to an extended sheet interval mode for performing the feeding action with an extended sheet interval which is longer than the normal sheet interval.