Sheet Feeding Path Unjamming Control for Image Forming Apparatus
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Solution Overview
Problem
In electrophotographic image forming apparatuses, especially when dealing with long sheets, unjamming operations often result in sheet breaking or toner scattering due to the limitations of existing sheet conveyance systems, which complicates the removal of jams without increasing the apparatus size or causing toner contamination.
Innovation Solution
The apparatus incorporates a jam detection system and a control section that determines the optimal unjamming procedure based on the sheet's state, allowing for controlled separation at the boundary between sheet feeding and conveyance paths, enabling the first sheet feeding path to be pulled out while cutting the sheet if necessary, to prevent breaking and facilitate unjamming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the sheet conveyance unit is pulled out to perform unjamming, then the guide member is exposed and the sheet can be carefully removed, but the sheet may protrude from the sheet conveyance unit into the sheet feeding path or sheet ejection path causing sheet tearing and breaking
Solution Approach 1:
The control section determines the sheet state and issues unjamming instructions before the user performs unjamming operations. The sheet conveyance unit is pulled out only after determining it is safe to do so, preventing sheet protrusion and breaking before the operation occurs.
Solution Approach 2:
The control section detects the sheet state (whether the sheet is present in the sheet conveyance unit or protruding) and provides feedback through unjamming instructions. This feedback mechanism guides the user to perform unjamming operations at the appropriate time, preventing sheet damage.
2Adaptability or versatility
If a long sheet is used for image formation, then the image forming capability is enhanced, but the sheet cannot be sent into the sheet conveyance unit completely making unjamming difficult and causing breaking
Solution Approach 1:
The control section determines whether a long sheet is being processed before unjamming operations. The sheet conveyance unit is pulled out only after confirming it is safe to do so, preventing long sheets from protruding and breaking during unjamming.
Solution Approach 2:
The system dynamically adjusts unjamming procedures based on sheet type (long sheet vs. standard sheet). The control section issues different unjamming instructions depending on the detected sheet state, enabling appropriate handling for different sheet lengths and configurations.
3Ease of operation
If the sheet is pulled out from the sheet ejection side for unjamming, then the sheet can be removed, but unfixed toner image scatters causing toner contamination
Solution Approach 1:
The control section determines the sheet state and toner fixation status before allowing unjamming operations. The system ensures that unjamming is performed only when it is safe to do so, preventing the scattering of unfixed toner images.
Solution Approach 2:
The control section provides feedback through unjamming instructions based on the detected sheet state. This feedback mechanism prevents users from performing unjamming operations that would cause toner scattering, guiding them to wait until the appropriate time.
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 effectively prevents sheet breaking during unjamming and minimizes toner scattering, simplifying the unjamming process for both long and standard sheets by determining the appropriate unjamming procedure based on the sheet's state and cutting the sheet at strategic points when necessary.
Implementation Method 1
irradiate (expose) a uniformly-charged photoconductor (for example, a photoconductor drum) with (to) laser light based on image data to form an electrostatic latent image on the surface of the photoconductor
Implementation Method 2
The toner image is directly or indirectly transferred to a sheet through an intermediate transfer belt, followed by heating and pressurization for fixing, whereby an image is formed on the sheet
Data Source
AI summary
An image forming apparatus includes: an image forming section that electrophotographically forms an image on a sheet; and a sheet feeding path including a first sheet feeding path that conveys a sheet to the image forming section, and a second sheet feeding path provided continuously with the first sheet feeding path. Unjamming is allowed to be performed by separating the apparatus at a boundary between the first sheet feeding path and the second sheet feeding path, and by pulling out the first sheet feeding path. The apparatus further includes: a jam detection section that detects an occurrence of a jam in the sheet feeding path; and a jam clearing section that determines a procedure for unjamming in accordance with a state of a sheet on the sheet feeding path when a jam occurs, and the jam clearing section makes a request to perform unjamming according to a determined procedure.