Fixing Device Separation Claw Placement for Uniform Heating
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Solution Overview
Problem
The uneven temperature distribution along the axial direction of the fixing device, caused by gaps in the heating elements and contact with a separation member, results in improper toner fixation on the paper.
Innovation Solution
A fixing device with a cylindrical fixing belt, a pressing member, a heater with resistance heating elements arranged in gaps, and a separation member with claws positioned to avoid these gaps, ensuring uniform temperature distribution and effective toner fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the separation member is in contact with the pressing roller at the position corresponding to the gaps, then the separation member can effectively peel off the medium, but the surface temperature of the pressing roller decreases at the contact position, causing uneven temperature distribution in the nip
Solution Approach 1:
The separation member is deliberately positioned asymmetrically relative to the heating element gaps. Specifically, the separation member contacts the pressing roller at a position that is axially displaced from the gaps between heating elements. This asymmetric positioning ensures that the separation member removes stuck medium without contacting the heated surfaces, thereby preventing localized temperature decreases while maintaining effective peeling function.
2Device complexity
If the heating elements are arranged with gaps in the axial direction, then the heating structure is simplified and cost-reduced, but the surface temperature of the endless belt becomes uneven in the axial direction
Solution Approach 1:
The heating elements are strategically positioned at specific axial locations corresponding to the pressing roller heating zones. By concentrating heating capacity at these critical locations rather than distributing it uniformly, the system achieves adequate temperature distribution with fewer heating elements, simplifying the overall structure while maintaining functional effectiveness.
3Ease of operation
If the separation member absorbs heat from the pressing roller surface, then the separation member can effectively separate the medium, but the temperature at the nip becomes uneven and toner cannot be properly fixed
Solution Approach 1:
The invention introduces an intermediary positioning approach where the separation member is axially displaced from the heating element gaps. This intermediary positioning allows the separation member to perform its function of removing stuck medium without directly contacting the heated pressing roller surfaces, thereby preventing excessive heat absorption that would cause temperature unevenness and compromise toner fixation quality.
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 solution maintains uniform temperature across the axial direction, ensuring proper toner fixation on papers of varying sizes, reducing warm-up time, and preventing excessive temperature rise.
Implementation Method 1
The resistance heating elements are arranged on one surface of the base board, where faces an inner surface of the fixing belt, with gaps in the axial direction, and generates heat by being energized
Implementation Method 2
The heater comes into contact with an inner surface of the fixing belt facing the pressure region, and heats the fixing belt
Implementation Method 3
The fixing belt is formed in a cylindrical shape and rotates around an axis to heat toner on a medium
Implementation Method 4
The pressing member forms a pressure region with the fixing belt and pressurizes the toner on the medium passing through the pressure region while rotating around an axis
Data Source
AI summary
A fixing device includes a fixing belt, a pressing member, a heater, and a separation member. The separation member comes into contact with a surface of the pressing member and peels off the medium passed through the pressure region, from the surface of the pressing member. The heater includes a base board, and a plurality of resistance heating elements. The base board is made of insulator and extends the in axial direction corresponding to the fixing belt. The resistance heating elements are arranged on one surface of the base board, where faces an inner surface of the fixing belt, with gaps in the axial direction, and generates heat by being energized. The separation member has at least one separation claw which is in contact with the surface of the pressing member at a position displaced in the axial direction relative to the gaps.