Printing Path Guide Unit for Image Forming Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatuses, the rear end of a printing medium can become raised and polluted by fine developer powder from the developing unit, leading to image deformation and pollution when it contacts the lower end of the housing before the image is fully fused.
Innovation Solution
The apparatus is designed with a horizontally arranged transfer nip and fusing nip, where the fusing nip is positioned lower than the transfer nip, and the printing path includes a downward and upward slope to guide the medium, ensuring the fusing nip is closer to the intersection point of the tangents, with specific tangent length ratios to prevent rear end contact with the developing unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fusing unit is positioned to process the printing medium efficiently, then the image forming speed is improved, but the rear end of the printing medium may be raised and contact with the developing unit causes pollution
Solution Approach 1:
The patent positions the fusing unit in a different spatial dimension (lower than the transfer unit in the vertical direction) to create a three-dimensional arrangement that prevents the raised rear end of the printing medium from contacting the developing unit, while maintaining efficient image forming speed
Solution Approach 2:
The patent introduces a non-fusing region as an intermediary space between the developing unit and fusing unit, and positions guide ribs as intermediary elements to redirect the printing medium path, preventing direct contact between the raised rear end and the developing unit
2Loss of time
If the printing path is shortened to improve efficiency, then the processing time is reduced, but the rear end of the printing medium may contact the developing unit
Solution Approach 1:
The patent creates different local characteristics in the printing path by introducing slopes with specific angles in different regions, and positions guide ribs at specific locations to redirect the printing medium, allowing efficient processing while preventing pollution
3Object-affected harmful factors
If additional anti-pollution elements like guide ribs are added, then the pollution prevention is improved, but the device complexity increases
Solution Approach 1:
The patent merges the pollution prevention function with the existing printing path structure by integrating guide ribs into the slope configuration and using the natural geometry of the printing path to redirect the medium, reducing the need for separate complex anti-pollution mechanisms
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 effectively prevents pollution by ensuring the rear end of the printing medium does not contact the developing unit's lower surface, maintaining image integrity and eliminating the need for additional anti-pollution elements like guide ribs.
Implementation Method 1
a fusing unit to heat and fuse the transferred developer image on the printing medium
Implementation Method 2
a press roller adapted to press the printing medium toward the heating member
Implementation Method 3
a transfer roller used to transfer a visible image formed on the photosensitive body to a printing medium
Data Source
AI summary
An image forming apparatus, having a developing unit and a fusing unit are arranged to horizontally face the developing unit. A printing path between the developing unit and the fusing unit includes a guide unit having a downward slope to guide a printing medium immediately having passed through the transfer nip and an upward slope to guide the printing medium approaching the fusing nip. The fusing nip is located lower than the transfer nip.