Image Forming Apparatus Dynamic Sheet Fixing Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image forming apparatuses face fixing defects due to inadequate toner image fixation on sheets with varying grammage, as they require specific fixing conditions that are not consistently met, leading to inefficiencies and increased processing load in controlling the photosensitive drum and sheet conveyance rollers.
Innovation Solution
The apparatus incorporates a detection unit to assess sheet properties, adjusting the conveyance speed and fixing conditions dynamically by employing a first mode for standard grammage sheets and a second mode for thicker sheets, where the toner image is formed on the second pass through the image formation position, ensuring adequate heat and pressure for proper fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the sheet conveyance speed is decelerated for large grammage sheets to ensure adequate heat provision, then the toner image fixation quality is improved, but the image formation time is extended
Solution Approach 1:
The patent applies dynamics by making the sheet conveyance speed adjustable based on sheet properties. The control unit dynamically changes the conveyance speed of the sheet conveyance unit according to the detected grammage, allowing optimal speed selection for each sheet type to balance fixation quality and processing time
Solution Approach 2:
The patent changes the conveyance speed parameter based on sheet grammage detection. For large grammage sheets, the system adjusts the conveyance speed parameter to a lower value to ensure adequate heat provision, while for small grammage sheets, it uses a higher speed, thus optimizing both fixation quality and efficiency
2Manufacturing precision
If the photosensitive drum and sheet conveyance rollers are controlled independently to adjust conveyance speed, then the fixing conditions are optimized, but the processing load of the control unit increases
Solution Approach 1:
The patent merges the control of the photosensitive drum and sheet conveyance rollers into a unified control approach. By coordinating their operations, the system achieves optimized fixing conditions without requiring complex independent control mechanisms, thereby reducing the processing load on the control unit
3Productivity
If the toner image is formed on the first pass for all sheets, then the image formation speed is maintained, but the fixation quality deteriorates for large grammage sheets
Solution Approach 1:
The patent makes the image formation process dynamic by allowing toner image formation to occur on either the first pass or second pass based on sheet grammage detection. For large grammage sheets, the system delays toner image formation to the second pass to ensure adequate fixation, while maintaining first-pass formation for smaller sheets to preserve speed
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 reduces fixing defects, optimizes power consumption, and shortens the image formation time while minimizing the processing load on the control unit by simplifying the control of conveyance and heating processes.
Implementation Method 1
a fixing unit configured to fix the toner image on the sheet by heating and pressing the sheet
Data Source
AI summary
An image forming apparatus includes a control unit configured to execute a first mode and a second mode. The first mode is a mode in which a toner image is formed on a sheet at a time when a sheet passes through an image formation position for a first time after detecting a property of the sheet by a detection unit. Wherein the second mode is a mode in which a toner image is not formed on a sheet at the time when the sheet passes through the image formation position for the first time after detecting the property of the sheet by the detection unit and is formed on the sheet at a time when the sheet is conveyed via the second conveyance path and passes through the image formation position for a second time.