Fixing Roller Lifetime Judgment via Brake Force and Rotation Speed
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Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately judging the lifetime of fixing members, such as rollers and belts, due to varying usage conditions and paper types, leading to inconsistent image quality and difficulty in detecting surface roughness degradation, especially at high temperatures without specialized mechanisms.
Innovation Solution
An image forming apparatus equipped with a first and second roller configuration, a pressing unit, an actuating motor, a brake unit, and a judgment unit that detects the rotation speed of the second roller under controlled pressing and brake forces to assess surface roughness degradation, allowing for accurate judgment and reporting of degradation progress without requiring additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensors are used to detect surface roughness of the fixing member, then measurement precision is improved, but device complexity increases and durability decreases due to high temperature exposure
Solution Approach 1:
The patent replaces optical sensors with a mechanical detection method using the brake unit and rotation speed measurement. The brake unit applies a known brake force to the second roller, and the resulting rotation speed is measured to calculate surface roughness. This mechanical approach eliminates the need for optical sensors, reducing device complexity and improving durability in high-temperature environments.
Solution Approach 2:
The fixing member itself is used as the detection tool. By applying a brake force to the second roller and measuring its rotation speed, the system leverages the existing mechanical components (rollers, brake unit, motor) to perform the surface roughness detection function, eliminating the need for separate sensing mechanisms.
2Ease of operation
If conventional standards based on operation time and number of paper sheets are used to judge lifetime, then ease of operation is improved, but measurement precision deteriorates due to varying usage conditions and paper types
Solution Approach 1:
The patent replaces conventional operational metrics (time, sheet count) with a direct physical measurement of surface roughness degradation. By measuring the actual surface condition of the fixing member through brake force and rotation speed, the system obtains precise lifetime judgment data that reflects real wear conditions rather than relying on generalized operational statistics.
Solution Approach 2:
The patent changes the judgment parameter from indirect operational metrics (operation time, number of sheets) to a direct physical parameter (surface roughness). This parameter change enables accurate lifetime assessment that adapts to varying usage conditions and paper types, as it measures the actual physical state of the fixing member rather than inferring from operational history.
3Device complexity
If the fixing member surface is detected at only the edge position, then device complexity is reduced, but measurement precision deteriorates because overall surface degradation cannot be assessed
Solution Approach 1:
The detection method uses the entire second roller as the measurement target. By applying brake force to the whole roller and measuring its overall rotation speed, the system assesses the average surface condition across the entire width of the fixing member, providing comprehensive degradation evaluation without requiring multiple sensors or scanning mechanisms.
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 accurate detection of surface roughness degradation and timely notification of replacement needs, maintaining image quality by adjusting fixing control parameters based on the assessed degradation, thus extending the lifespan of fixing members and ensuring consistent output.
Implementation Method 1
a brake unit configured to apply a brake force to the second roller
Implementation Method 2
judgment unit configured to judge a degradation of surface roughness of each of the first roller and the second roller in accordance with a rotation speed of the second roller, which is detected when the first roller is actuated at a predetermined rotation speed in a situation in which the first roller and the second roller are pressed against each other by the predetermined pressing force and when the brake unit applies a predetermined brake force to the second roller
Data Source
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AI summary
Disclosed is image forming apparatus, including a first roller and a second roller that conveys the recording sheet by sandwiching the recording sheet in a fixing process of an image forming; a pressing actuator that presses the first roller and the second roller against each other; an actuating motor that actuates the first roller; a brake that applies a brake force to the second roller; a rotation speed detector that detects a rotation speed of the second roller; and a hardware processor that judges a degradation of each surface roughness of the first roller and the second roller in accordance with the rotation speed of the second roller, which is detected when the first roller is actuated in a situation in which the first roller and the second roller are pressed against each other and when the brake applies a predetermined brake force to the second roller.