Fixing Device Throughput Control for Sheet Size Transitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face productivity losses and overheating issues when transitioning from small to large sheets due to rapid temperature increases in fixing devices, leading to high temperature offset and out-of-sheet-path overheating, which existing solutions either prolong processing times or reduce productivity.
Innovation Solution
Implementing a throughput-down control mechanism that reduces the printing speed for a preset number of small sheets when a large sheet is about to be printed, allowing for a controlled cooling process to equalize temperatures between sheet-path and out-of-sheet-path portions of the fixing device, thereby preventing overheating and maintaining productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the printing speed is increased to improve productivity, then the output speed increases, but the out-of-sheet-path portions of the fixing device overheat more quickly
Solution Approach 1:
The controller detects when a large sheet is about to be conveyed and preemptively reduces the throughput for a preset number of small sheets printed immediately before. This preliminary action allows the out-of-sheet-path portions to cool down before the large sheet enters the fixing device, preventing high temperature offset without requiring idle rotation after the fact.
Solution Approach 2:
The system dynamically adjusts the throughput based on the sheet size sequence. When transitioning from small to large sheets, the throughput is temporarily reduced for a preset number of small sheets, then restored to normal. This dynamic adjustment optimizes the balance between productivity and temperature control.
2Temperature
If the throughput is reduced to cool the fixing device, then the temperature equalization is achieved, but the total processing time increases
Solution Approach 1:
Instead of reducing throughput after small sheets are already printed (which would add idle time), the system preemptively reduces throughput during the printing of small sheets that immediately precede the large sheet. This allows temperature equalization to occur during the normal printing process rather than requiring additional idle time afterward.
3Temperature
If a preset number of small sheets are printed at reduced throughput, then the out-of-sheet-path portions cool down, but the time for these specific sheets increases
Solution Approach 1:
The system converts the potentially harmful effect of reduced throughput (increased processing time) into a benefit by strategically applying it only to a preset number of small sheets that immediately precede a large sheet. The time increase for these specific sheets is acceptable because it prevents damage to the fixing device and ensures quality output for the subsequent large sheet, which would otherwise be affected by high temperature offset.
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 approach effectively reduces the time required for temperature equalization and minimizes high temperature offset, ensuring high-quality image output while maintaining productivity by adjusting the throughput during the transition from small to large sheets.
Implementation Method 1
a fixing portion configured to heat and fix the toner image formed on the recording material
Data Source
AI summary
An image forming apparatus includes an image forming portion configured to form a toner image on a recording material, a fixing portion configured to heat and to fix the toner image formed on the recording material, and a controller configured to control the apparatus, which is operable to form an image on a recording material having a first size and a recording material having a second size smaller than the first size in a direction perpendicular to a recording material feeding direction. If a printing instruction for printing on the recording material of the first size is received while continuously printing on the recording material of the second size at a first throughput, the controller controls the apparatus so as to print on the recording material of the second size at a second throughput, lower than the first throughput, before printing on the recording material of the first size.