Asymmetric Reversing Roller Pair for Sheet Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatuses, the reduction in size leads to increased frictional resistance and difficulty in shifting sheets perpendicular to the conveyance direction, causing positional inaccuracies and jamming issues during double-sided printing.
Innovation Solution
The implementation of a double-sided conveyance path with a guide member and a reversing roller pair, where the second roller has a larger outer diameter than the first roller, allowing for controlled sheet alignment and oblique conveyance to ensure accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the image forming apparatus is reduced in size, then the apparatus becomes more compact, but the frictional resistance increases and sheet shifting becomes difficult
Solution Approach 1:
The reversing roller pair uses asymmetric roller diameters where the second roller has a larger outer diameter than the first roller. This asymmetry creates differential friction forces that enable effective sheet shifting perpendicular to the conveyance direction despite the compact apparatus size and increased overall frictional resistance.
Solution Approach 2:
The invention changes the physical parameter of roller diameter within the reversing roller pair. By making the second roller larger than the first roller, the system creates unequal frictional forces that generate the necessary sheet shifting capability in a compact configuration where uniform roller sizes would fail.
2Length of moving object
If the conveyance distance from the discharge reversing roller to the re-feed roller is decreased, then the apparatus size is reduced, but the sheet cannot be shifted by the required amount
Solution Approach 1:
The asymmetric roller diameters in the reversing roller pair compensate for the reduced conveyance distance. The differential friction forces generated by the unequal roller sizes create sufficient shifting force over the shorter distance to achieve the required sheet positional accuracy for double-sided printing.
Solution Approach 2:
By changing the diameter parameter of the rollers in the reversing roller pair, the system generates enhanced frictional force differential that enables adequate sheet shifting even when the conveyance distance is reduced due to compact apparatus design.
3Volume of moving object
If the degree of bending of the curved conveyance path is increased, then the apparatus size is reduced, but the frictional resistance between the sheet and conveyance guide increases
Solution Approach 1:
The asymmetric roller diameters create a friction force differential that overcomes the increased frictional resistance caused by the tightly curved conveyance path. The larger second roller generates sufficient additional friction force to push the sheet against the conveyance guide despite the high resistance from the bent path.
4Device complexity
If a conventional reversing roller pair with equal diameter rollers is used, then the structure is simple, but the sheet cannot be shifted perpendicular to the conveyance direction
Solution Approach 1:
The invention applies asymmetry by making the second roller's outer diameter larger than the first roller's outer diameter. This asymmetric configuration generates differential friction forces that enable the sheet to shift perpendicular to the conveyance direction, solving the functional requirement while maintaining relatively simple structure.
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 configuration enhances positional accuracy and reduces jamming occurrences by effectively guiding the sheet to contact reference guides, ensuring reliable double-sided printing even in compact apparatuses.
Implementation Method 1
the frictional resistance between the sheet S and a conveyance guide increases
Data Source
AI summary
An image forming apparatus includes an image forming unit, a discharge unit, a double-sided conveyance path, a sheet plate, a skew correction unit, and a frame. The discharge unit discharges a sheet having an image from the image forming unit. The double-sided conveyance path conveys the sheet again to the image forming unit. The sheet plate restricts a position of an end, in a sheet width direction, of the sheet. The skew correction unit obliquely conveys the sheet to abut the sheet end. The frame determines a position of the sheet plate and includes a first positioning portion to position a sheet plate first positioned portion and a second positioning portion to position a sheet plate second positioned portion with the skew correction unit between the first and second positioned portion. The first positioning portion faces the first positioned portion and the second positioning portion faces the second positioned portion.