Fixing Apparatus Pressure Pad Segmentation for Friction Reduction
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Solution Overview
Problem
Conventional fixing units in image forming apparatuses experience issues with pressure pad instability due to friction resistance, leading to poor print quality, increased load on the fixing motor, and potential unit stoppage, caused by the pressure pad declining, vibrating, or rattling within the holder.
Innovation Solution
A fixing unit design featuring a pressure pad with projections that reduce frictional contact area with the holder, preventing seizure and ensuring consistent urging force against the fixing roller, thereby maintaining image quality and preventing unit stoppage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the pressure pad is disposed to slide on the inner surface of the pressure belt, then the pressure pad can be supported and positioned, but friction resistance develops between the pressure pad and pressure belt causing the pressure pad to decline, vibrate, or rattle
Solution Approach 1:
The pressure pad is divided into multiple independent pressing portions (first pressing portion, second pressing portion, third pressing portion) that can independently contact the pressure belt. This segmentation allows each portion to distribute the sliding contact, reducing overall friction resistance and preventing the pressure pad from declining or vibrating as a single unit.
Solution Approach 2:
Different portions of the pressure pad are designed with different contact characteristics. The first pressing portion contacts the pressure belt at a specific location while the second and third pressing portions contact at different locations. This local differentiation optimizes the distribution of friction forces across the pressure pad surface, preventing concentrated stress and vibration.
2Reliability
If the pressure pad urges the pressure belt against the fixing roller, then image fixation is achieved, but the friction resistance increases the load on the fixing motor
Solution Approach 1:
The pressure application is segmented into multiple pressing portions that contact the pressure belt at different locations. This distributes the friction load across multiple contact points rather than concentrating it at a single point, reducing the peak load on the fixing motor while maintaining effective image fixation pressure.
Solution Approach 2:
The pressure belt serves as an intermediary element between the pressure pad and the fixing roller. The segmented pressing portions transfer pressure through the pressure belt to the fixing roller, allowing the pressure pad to maintain urging force while reducing direct friction contact with the fixing roller, thereby decreasing motor load.
3Ease of operation
If the pressure pad is held in position within the holder, then the pressure pad is stable, but the friction resistance causes the pressure pad to seize within the holder
Solution Approach 1:
The pressure pad is segmented into multiple pressing portions that can independently contact and slide on the pressure belt. This segmentation reduces the overall friction resistance between the pressure pad and the pressure belt, preventing the pressure pad from seizing within the holder while maintaining adequate positioning stability.
Solution Approach 2:
The contact parameters between the pressure pad and pressure belt are changed by distributing contact across multiple pressing portions rather than a single large contact area. This reduces the friction force per unit area and prevents seizure while maintaining sufficient positioning stability through the distributed contact points.
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
The design effectively minimizes frictional resistance and maintains stable pressure, preventing image quality issues and motor load increases, ensuring continuous operation of the fixing unit.
Implementation Method 1
a spring (107) urging the pressure pad (106) against the fixing roller (103) with the pressure belt (105) sandwiched between the pressure pad (106) and the fixing roller (103)
Implementation Method 2
when the pressure belt (105) runs, a friction resistance is developed between the inner surface of the pressure belt (105) and the upper surface of the pressure pad (106)
Implementation Method 3
A heater (109) is disposed inside the fixing roller (103)
Implementation Method 4
When the print paper carrying a toner image thereon passes through the nip N3, the toner image is fused by heat and is pressed by the pressure belt assembly (102), thereby being fixed into the print paper
Data Source
AI summary
A fixing member is rotatably supported. A first pressing member faces the fixing member. A running member runs while being sandwiched between the fixing member and the first pressing member. A first mechanism urges the first pressing member against the fixing member, defining a first nip between the fixing member and the running member. A second pressing member presses the running member against the fixing member. A second mechanism includes a holding member that holds the second pressing member and an urging member therein, and urges the second pressing member against the fixing member with the running member sandwiched therebetween, defining a second nip, adjacent to the first nip, between the fixing member and the running member. The second pressing member and the holding member abut each other through a plurality of projections formed on at least one of the second pressing member and second pressing mechanism.