Cooling Roller Control for Image Forming Apparatus
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Solution Overview
Problem
Existing electrophotographic image forming apparatuses face issues with drying marks on the second side of a sheet due to heat-induced water evaporation during double-side printing, leading to suboptimal image quality, and current cooling solutions are not adaptive to varying environmental temperatures.
Innovation Solution
An image forming apparatus with a temperature sensor and controller that switches between two modes based on temperature, controlling the rotation direction of cooling and ejection rollers to optimize sheet cooling and feeding, ensuring effective cooling only when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the cooling roller always cools the sheet after the fixing unit, then the drying mark on the second side is prevented, but the sheet is excessively cooled and uselessly fed in low-temperature environments
Solution Approach 1:
The cooling roller's operational state is dynamically adjusted based on detected temperature conditions. The controller switches between cooling mode (when temperature is high) and non-cooling mode (when temperature is low), making the system adaptive rather than static
Solution Approach 2:
A temperature sensor provides real-time feedback on the image forming apparatus temperature, and the controller uses this feedback to determine whether to activate the cooling roller, creating a closed-loop control system
2Ease of operation
If the cooling roller always feeds the sheet back, then the sheet is consistently positioned for re-printing, but unnecessary feeding occurs in low-temperature environments
Solution Approach 1:
The sheet feeding operation is dynamically controlled based on temperature conditions, switching between active feeding (high temperature) and passive positioning (low temperature) modes
Solution Approach 2:
Temperature sensor feedback controls the feeding mechanism, preventing unnecessary feeding operations when the apparatus is already in a low-temperature state
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 prevents excessive cooling and unnecessary sheet feeding, maintaining image quality by adapting to environmental temperatures and reducing the risk of drying marks and paper jams.
Implementation Method 1
a cooling roller disposed downstream relative to the fixing unit in a sheet feeding direction, the cooling roller being configured to cool the sheet on which the developer image is fixed by the fixing unit
Implementation Method 2
a fixing unit configured to fix the developer image formed on the sheet by the image forming unit
Implementation Method 3
water contained in the sheet is evaporated by heat generated by a fixing unit during image formation on the first side
Data Source
AI summary
An image forming apparatus is provided, which includes a fixing unit, a cooling roller disposed downstream relative to the fixing unit in a sheet feeding direction, an ejection roller disposed downstream relative to the cooling roller in the sheet feeding direction, a driving unit rotating the cooling roller and the ejection roller normally or reversely, and a controller including a determining unit determining whether a detected temperature is higher than a predetermined temperature, the controller switching between a first mode to, after a sheet passes through the cooling roller, control the driving unit to reversely rotate the cooling roller and the ejection roller being rotating normally and a second mode to, in a state where the cooling roller is nipping the sheet, control the driving unit to reversely rotate the cooling roller and the ejection roller being rotating normally, based on the determination of the determining unit.