Dynamic Temperature Threshold Control for Fixing Device Sheet Feeding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face challenges in promptly starting the supply of recording sheets when the fixing device reaches a fixable state while maintaining fixing quality, as the time required for the fixing device to heat up varies based on the heater output, leading to inconsistent sheet feeding times.
Innovation Solution
An image forming apparatus with a heater and temperature sensor, where a controller determines the optimal timing for sheet feeding based on temperature thresholds and adjusts these thresholds dynamically upon receiving a printing command, ensuring the sheet is supplied promptly when the fixing device reaches a fixable state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the output of the heater is increased to heat the fixing device faster, then the time to reach fixable state is shortened, but the temperature gradient becomes less consistent and fixing quality may deteriorate
Solution Approach 1:
The patent applies dynamics by making the heater output adjustable rather than fixed. The control device dynamically changes the heater output based on the current state of the fixing device (cold state vs. warm state), allowing optimal heating speed when needed while maintaining temperature consistency when required, thus resolving the contradiction between heating time and fixing quality
Solution Approach 2:
The patent changes the parameter of heater output according to different operational conditions. When the fixing device is in a cold state, the heater output is set to a first level for rapid heating. When the fixing device is in a warm state, the heater output is set to a second level (lower than the first) to maintain temperature consistency, thereby resolving the contradiction between heating speed and temperature uniformity
2Device complexity
If a fixed threshold value is used for determining sheet supply timing, then the control logic is simple, but the timing cannot adapt to varying heater output and temperature conditions
Solution Approach 1:
The patent makes the threshold value dynamic rather than fixed. The control device determines the threshold value based on the heater output level and the state of the fixing device. This dynamic adjustment allows the control logic to adapt to varying temperature conditions while maintaining reasonable complexity through systematic decision-making based on heater state
3Productivity
If the sheet supply timing is set earlier to improve productivity, then more sheets can be processed, but the fixing device may not be at the required temperature
Solution Approach 1:
The patent implements feedback control by continuously monitoring the temperature of the fixing device and using this information to determine the appropriate sheet supply timing. The control device waits for the fixing device to reach the required temperature threshold before supplying sheets, ensuring both timely processing and reliable fixing, thus resolving the contradiction between productivity and reliability
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 allows for timely and consistent sheet feeding while maintaining the quality of the fixing process by dynamically adjusting the temperature thresholds and sheet feeding times according to the heating device's temperature and output state.
Implementation Method 1
a fixing device including a heater... configured to heat-fix developer on a recording sheet
Implementation Method 2
a temperature sensor... configured to detect temperature of the fixing device
Implementation Method 3
configured to heat-fix developer on a recording sheet at a fixing region
Data Source
AI summary
An image forming apparatus includes a fixing device including a heater and a temperature sensor; a feeding roller configured to feed a recording sheet to the fixing device; and a controller. The controller is configured to: turn on the heater when the controller receives a printing command; cause the feeding roller to feed the recording sheet at a first timing, in a case where the controller determines that a temperature detected by the temperature sensor is equal to or greater than a first threshold temperature; cause the feeding roller to feed the recording sheet at a second timing later than the first timing, in a case where the controller determines that the detected temperature is smaller than the first threshold temperature; and selectively set the first threshold temperature to a first value or a second value smaller than the first value when the controller receives the printing command.