Sheet Detection Accuracy in Condensing Image Forming Apparatus
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Solution Overview
Problem
Conventional sheet sensors in image forming apparatuses face accuracy issues due to decreased reflectance caused by condensation on the reflecting member, leading to incorrect detection of sheets.
Innovation Solution
The image forming apparatus incorporates a light-emitting unit, a reflecting member, a light-receiving unit, a cooling unit, and a determination unit that adjusts the light emission amount and receiving gain based on the temperature and reflectance of the reflecting member to maintain accurate sheet detection despite condensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the light-emitting unit operates in a hot environment near the fixing apparatus, then the sheet detection function can be maintained, but condensation occurs on the reflecting member causing decreased reflectance and detection accuracy
Solution Approach 1:
The cooling unit is activated before the light-emitting unit to preemptively cool the reflecting member and prevent condensation from forming. This preliminary cooling action ensures that when the light-emitting unit operates in the hot environment near the fixing apparatus, the reflecting member remains below the dew point temperature, preventing condensation and maintaining detection accuracy.
Solution Approach 2:
The system dynamically adjusts the operation of the cooling unit based on the operating state of the light-emitting unit. When the light-emitting unit is activated, the cooling unit is automatically turned on to maintain appropriate temperature conditions. This dynamic coordination allows the system to adapt to changing thermal conditions and prevent condensation only when necessary, maintaining reliability while managing energy consumption.
2Measurement precision
If the light emission amount is increased to compensate for decreased reflectance, then detection accuracy can be maintained, but the lifespan of the light-emitting unit decreases
Solution Approach 1:
The cooling unit is activated before the light-emitting unit to preemptively cool the reflecting member and prevent condensation from forming. This preliminary cooling action ensures that when the light-emitting unit operates in the hot environment near the fixing apparatus, the reflecting member remains below the dew point temperature, preventing condensation and maintaining detection accuracy.
Solution Approach 2:
The system dynamically adjusts the operation of the cooling unit based on the operating state of the light-emitting unit. When the light-emitting unit is activated, the cooling unit is automatically turned on to maintain appropriate temperature conditions. This dynamic coordination allows the system to adapt to changing thermal conditions and prevent condensation only when necessary, maintaining reliability while managing energy consumption.
3Reliability
If the cooling unit is continuously operated to prevent condensation, then detection accuracy is maintained, but energy consumption increases
Solution Approach 1:
The cooling unit is activated before the light-emitting unit to preemptively cool the reflecting member and prevent condensation from forming. This preliminary cooling action ensures that when the light-emitting unit operates in the hot environment near the fixing apparatus, the reflecting member remains below the dew point temperature, preventing condensation and maintaining detection accuracy.
Solution Approach 2:
The system dynamically adjusts the operation of the cooling unit based on the operating state of the light-emitting unit. When the light-emitting unit is activated, the cooling unit is automatically turned on to maintain appropriate temperature conditions. This dynamic coordination allows the system to adapt to changing thermal conditions and prevent condensation only when necessary, maintaining reliability while managing energy consumption.
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 ensures accurate detection of sheets even in environments with condensation, reducing errors and extending the lifespan of the light-emitting unit by dynamically adjusting light emission and receiving gain.
Implementation Method 1
a cooling unit that cools the light-emitting unit by supplying air to the light-emitting unit
Implementation Method 2
a reflecting member, provided opposite the light-emitting unit, that reflects the light
Implementation Method 3
a light-receiving unit that receives reflected light from the reflecting member
Data Source
AI summary
An emitter emits light such that the light crosses a conveyance path. A reflector reflects the light. A receiver receives reflected light. A determiner determines that a sheet is present on the basis of an amount of reflected light. A controller may increase a light amount of the light-emitting unit from a first light amount to a second light amount on the basis of a temperature of the light-emitting unit and a reflectance of the reflecting member. The controller may increase a receiving gain of the receiver from a first gain to a second gain on the basis of a reflectance of the reflecting member.