Fixing Unit Shutter Mechanism for Wear-Free Roller Protection
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Solution Overview
Problem
Existing image forming apparatuses face issues with excessive shutter actuator mechanism wear due to unnecessary shutter openings, increased apparatus size from shutter protrusion, and imprecise fixing device positioning.
Innovation Solution
The image forming apparatus features a fixing device with a shutter mechanism that opens and closes only during attachment and detachment, utilizing a spring and moving member to control shutter movement, and includes a contact portion and shaft for precise positioning, reducing wear and size protrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the shutter is caused to open and close in synchronization with the main cover, then the heating roller is protected when the cover is closed, but the shutter actuator mechanism wears out faster due to unnecessary repeated operations
Solution Approach 1:
The shutter is pre-positioned in the open state when the fixing device is installed, eliminating the need for repeated opening/closing operations. The main cover closing no longer triggers shutter movement, as the shutter remains permanently open during normal operation, thus protecting the actuator mechanism while still allowing the cover to protect the heating roller.
2Reliability
If the shutter is provided to cover the heating roller, then the heating roller is protected, but the shutter protrudes greatly from the fixing device housing increasing the apparatus size
Solution Approach 1:
The shutter function is extracted from the fixing device and relocated to the main cover. The main cover is designed to directly cover and protect the heating roller when closed, eliminating the need for a separate protruding shutter structure within the fixing device, thus reducing the overall apparatus size.
3Ease of manufacture
If a pin is simply dropped into the groove to position the fixing device, then the fixing device can be installed, but the positioning is imprecise because the pin is not pressed against the reference surface with necessary force
Solution Approach 1:
The pin is pre-loaded with a spring that applies preliminary force to press the pin against the reference surface of the groove. This ensures that when the fixing device is installed, the pin automatically engages with sufficient force to achieve precise positioning, combining simplicity of installation with high positioning accuracy.
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 design minimizes shutter actuator wear, reduces apparatus size, and ensures precise fixing device positioning, enhancing the apparatus's durability and efficiency.
Implementation Method 1
The spring is configured to bias the shutter in a direction in which the shutter closes the opening
Implementation Method 2
When the moving member is located in the first position, the shutter is caused to be in the closed positon. When the moving member is located in the second positon, the shutter is caused to be in the open position
Data Source
AI summary
An image forming apparatus includes a fixing device and a main housing. The main housing includes a contact portion that contacts the fixing device. The fixing device includes a fixing device housing having an opening, a shutter configured to move between an open position in which the shutter opens the opening and a close position in which the shutter closes the opening, a spring, and a moving member interlocking with the shutter that moves between a first position and a second positon. In a process of attaching the fixing device to the main housing, the moving member moves from the first positon to the second positon, thereby causing the shutter to move to the open position against the biasing force of the spring. In a process of detaching the fixing device from the main housing, the biasing force of the spring causes the shutter to move to the close position.