Fixing Unit Insertion Direction and IH Heater Retraction
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Solution Overview
Problem
Conventional image forming apparatuses have limited flexibility in arranging other machinery around the fixing unit due to the fixed insertion and removal direction, which restricts the placement of components like drive gears and interferes with the nip pressure.
Innovation Solution
The image forming apparatus is designed to allow the fixing unit to be inserted and removed in a direction orthogonal to the axial direction of the pressure roller, with a drive mechanism that moves the IH heating unit to a retracted position during insertion and removal, enabling more flexible arrangement of components and preventing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the fixing unit is inserted and removed in a direction facing the inner surface of the concave portion of the holder (orthogonal to the axial direction of the fixing roller), then the heating function is maintained, but the degree of freedom of disposition of other devices is significantly limited
Solution Approach 1:
The holder is designed to be movable relative to the fixing unit, transitioning between a retracted position (allowing fixing unit insertion/removal) and a protruding position (enabling heating). This dynamic configuration resolves the contradiction by making the system adaptable: the holder dynamically changes its position based on operational requirements, providing both heating capability and arrangement freedom without compromise
2Use of energy by moving object
If the holder protrudes towards the fixing unit, then heating efficiency is improved, but it interferes with the insertion and removal of the fixing unit
Solution Approach 1:
The holder's position is made dynamic rather than fixed. It protrudes toward the fixing unit only when heating is required, and retracts when the fixing unit needs to be inserted or removed. This dynamic positioning enables the system to achieve high heating efficiency when needed while maintaining ease of operation during maintenance, resolving the contradiction between these two parameters
3Volume of moving object
If other devices are disposed on the heating unit side with respect to the fixing unit, then the heating structure is compact, but the degree of freedom of disposition is significantly limited
Solution Approach 1:
By making the holder movable between retracted and protruding positions, the invention enables flexible arrangement of other devices. When the holder is retracted, devices can be disposed on the heating unit side without interference. When protruding, the holder maintains compact heating structure. This dynamic design resolves the contradiction between compactness and arrangement freedom
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 the freedom of arrangement for other components, maintains nip pressure, and simplifies maintenance by allowing the fixing unit and IH heating unit to operate without interference, reducing labor and improving maintenance accessibility.
Implementation Method 1
An IH heating unit as an example of the heating unit includes a holder and a plurality of IH coils supported by the holder. The holder has a cylindrical recess into which a surface portion of the fixing roller on a side opposite to the nip portion enters. The IH heating unit heats the outer surface of the fixing roller from the outside in the radial direction via the concave portion.
Data Source
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AI summary
A fixing unit (8) fixes the toner image on a sheet by causing the sheet carrying a toner image to pass through a nip portion formed by bringing a rotary fixing member and a rotary pressing member into pressure contact with each other. The image forming apparatus includes an image forming apparatus main body having a fixing unit accommodating portion (2e) for accommodating the fixing unit (8) in an insertable and removable manner, and a heating unit (50) provided in the image forming apparatus main body and heating a rotary fixing member of the fixing unit (8) mounted on the fixing unit accommodating portion (2e) from outside in a radial direction. The direction in which the fixing unit (8) is inserted into and removed from the fixing unit accommodating portion (2e) coincides with the axial direction of the rotary pressing member.