Blower Unit Temperature Control for Pressing Roller Condensation
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Solution Overview
Problem
Image forming apparatuses using the electrophotographic method face issues with condensation slipping due to moisture condensation on the pressing roller, leading to conveyance failures and increased curling of recording materials, particularly in high-humidity environments, which affects printing productivity and material handling.
Innovation Solution
The apparatus incorporates a blower unit with controlled fan operation periods and adjustable intervals between recording materials to manage the surface temperature of the pressing roller, preventing condensation slipping and curling by optimizing air flow and temperature management during continuous printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cooling fan is used to reduce humidity around the pressing roller to prevent condensation, then condensation slipping is prevented, but the pressing roller temperature drops and curling of recording materials increases
Solution Approach 1:
The blower unit operates intermittently with alternating operation periods and stop periods instead of continuously. During operation periods, it blows air to prevent condensation slipping. During stop periods, it allows the pressing roller temperature to recover. This periodic operation balances condensation prevention with temperature maintenance, reducing curling while preventing conveyance failures.
Solution Approach 2:
The blower operation is dynamically controlled based on real-time temperature detection. The control unit adjusts the blower's operation schedule according to the pressing roller's actual temperature state, making the system adaptive rather than static. This ensures optimal prevention of condensation slipping while minimizing temperature drop and curling.
2Reliability
If the blower unit operates continuously to prevent condensation slipping, then conveyance reliability improves, but the pressing roller temperature drops and curling increases
Solution Approach 1:
The blower operates in periodic cycles with operation periods followed by stop periods. This intermittent operation prevents condensation slipping during operation phases while allowing temperature recovery during stop phases, maintaining both conveyance reliability and printing productivity without continuous operation.
Solution Approach 2:
The control unit uses temperature detection feedback to dynamically adjust blower operation timing and duration. When the pressing roller temperature approaches optimal levels, the blower operates to prevent condensation. When temperature drops, the blower stops to allow recovery. This feedback-based control optimizes both reliability and productivity.
3Reliability
If the interval between recording materials is widened to warm the pressing roller, then condensation slipping is prevented, but printing productivity decreases
Solution Approach 1:
Instead of permanently widening intervals, the system uses periodic blower operation during normal continuous printing intervals. The blower operates during specific periods to prevent condensation slipping, allowing normal printing intervals to be maintained while still preventing reliability issues.
Solution Approach 2:
The system replaces the mechanical approach of widening material intervals with a thermal approach using the blower unit. Rather than changing the physical timing of material conveyance, the blower actively manages the thermal environment to prevent condensation, allowing normal printing intervals to be maintained.
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 effectively reduces condensation slipping and curling, enhancing printing productivity while maintaining smooth material handling and alignment, even in high-humidity conditions.
Implementation Method 1
a blower unit configured to blow air around the pressing roller
Implementation Method 2
a heater disposed in a space surrounded by the fixing film
Implementation Method 3
water vapor from the recording material at the fixing nip portion is condensed on the surface of the pressing roller
Data Source
AI summary
An image forming apparatus for forming a toner image on a recording material includes a fixing unit and a blower unit to blow air around a roller. The fixing unit includes a tubular shape film, a heating member disposed in a space surrounded by the film, and the roller forming a nip portion with the heating member. The fixing unit heats and fixes the toner image onto the recording material at the nip portion. For printing that forms toner images on continuously conveyed recording materials where a roller surface temperature is lower than a predetermined temperature, fan stop and operation periods are set. During the fan stop period, the blower unit is stopped and an interval between preceding and subsequent recording materials is widened. During the fan operation period, the blower unit is in operation and the interval is narrower than the interval during the fan stop period.