Segmented Heating Elements for Fuser Temperature Control
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Solution Overview
Problem
Existing fixing devices in image forming apparatuses face challenges in maximizing thermal efficiency due to wide heat distribution, leading to uneven heating and reduced fixing quality, especially in color printing, and inefficient energy use.
Innovation Solution
A fixing device with inclined, divided heat-generating members that selectively heat only the paper passing area, using a switching unit to control heat conduction based on paper size and position, optimizing heating efficiency and reducing unnecessary heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating is performed with Joule's heating by using electromagnetic induction, then heating is focused on a heating area, but the width of a heating area is wide and thus it is difficult to apply heat energy which is dispersed in a wide range to only a nip portion intensively
Solution Approach 1:
The heating device is divided into multiple independent heating units arranged along the paper transport direction. Each heating unit can be independently controlled to heat only the specific region where paper passes through, preventing energy waste in non-passing areas while maintaining focused heating at the nip portion.
Solution Approach 2:
The heating units are dynamically controlled based on paper detection. When paper is detected, the corresponding heating units are activated; when no paper is present, they are deactivated. This dynamic control ensures heat energy is applied intensively only when and where needed, optimizing thermal efficiency.
2Loss of energy
If the heat capacity of components is reduced as much as possible, then thermal efficiency is maximized, but the temperature at a portion through which paper does not pass is extremely increased
Solution Approach 1:
The heating system is segmented into multiple independently controllable heating units. This allows selective activation of only those units corresponding to the paper passing area, preventing temperature increase in non-passing areas while maintaining low heat capacity for optimal thermal efficiency.
Solution Approach 2:
The heating units operate periodically based on paper detection signals. Heating is activated only during the period when paper passes through and deactivated when no paper is present, preventing excessive temperature rise in areas where paper does not pass while maintaining efficient heat capacity.
3Area of stationary object
If heating is performed in a wide area, then heating coverage is improved, but heating unevenness occurs in a perpendicular direction to a paper transporting direction
Solution Approach 1:
The heating device is divided into multiple heating units positioned at different locations along the paper transport path. Each unit covers a specific vertical section, ensuring uniform heat distribution across the entire paper width while maintaining adequate heating coverage. This segmentation prevents heating unevenness by distributing heat sources strategically.
Solution Approach 2:
Different heating units are positioned to provide localized heating to specific regions of the paper. The heating characteristics are optimized for each local area, ensuring uniform temperature distribution across the entire paper surface while maintaining overall heating coverage.
4Loss of energy
If heat-generating members are selectively controlled based on paper size, then energy efficiency is improved, but device complexity increases
Solution Approach 1:
The heating device is segmented into multiple independently controllable heating units. Each unit can be selectively activated based on detected paper size, allowing energy-efficient operation while using a relatively simple control system that only needs to manage individual unit activation rather than complex continuous control.
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 solution enables stable, concentrated heating of the paper passing area, improving fixing quality and energy efficiency by minimizing thermal energy consumption and preventing abnormal heat generation in non-passing areas.
Implementation Method 1
A lamp which is representatively a halogen lamp and generates infrared rays, or a method of performing heating with Joule's heating by using electromagnetic induction is put into practical use as a heat source of a fixing device
Implementation Method 2
The plurality of heat-generating members are formed in a perpendicular direction to a transporting direction of the medium, inclined from the transporting direction to a direction of a predetermined angle, and divided by a predetermined length, and are disposed so as to come into contact with an inner side of the rotating body
Data Source
AI summary
According to one embodiment, a fixing device includes determination means for determining the size of an image forming area of a medium, heating means for including an endless rotating body, plural heat-generating members which are formed in a perpendicular direction to a transporting direction, inclined by a predetermined angle, and divided by a predetermined length, and are disposed so as to come into contact with an inner side of the rotating body, and a switching unit which switches individual conduction, and heats the medium, pressing means for forming a nip by performing pressing and contact at a position of the plural heat-generating members, and nipping and carrying the medium in the transporting direction along with the heating means, and heating control means for controlling the switching unit to select and conduct heat-generating members and controlling the heating means to heat the medium.