Toner Density Correction via Belt Speed Fine-Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatuses, the existing methods for toner pattern density control, especially using an intermediate transfer belt with an elastic surface, face challenges in accurately detecting toner image density due to the belt's low glossiness and varying surface speed, which affects image quality and productivity.
Innovation Solution
The apparatus includes a secondary transfer belt with a toner image sensor and a conveyance speed controller that fine-tunes the speed of the secondary transfer belt based on sheet thickness, allowing for precise detection and correction of toner pattern density during printing, thereby maintaining optimal image density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the conveyance speed of the secondary transfer belt is fine-tuned based on sheet thickness, then image quality is improved, but the detection accuracy of toner pattern density deteriorates due to speed variations
Solution Approach 1:
The patent applies parameter changes by introducing a conveyance speed correction value that compensates for speed variations in the secondary transfer belt. The control unit calculates the actual conveyance speed based on the correction value and uses this corrected speed parameter to accurately determine toner pattern density, thereby maintaining measurement precision even when the belt speed is fine-tuned for image quality
Solution Approach 2:
The patent implements feedback by using the conveyance speed correction value (obtained from sheet thickness detection) to adjust the toner pattern density calculation. The control unit continuously monitors the actual conveyance speed and compensates for deviations, creating a closed-loop system that maintains accurate density detection despite speed variations introduced by fine-tuning
2Manufacturing precision
If the first density control is performed regularly to maintain optimal image density, then image quality is improved, but productivity decreases due to suspension of printing operation
Solution Approach 1:
The patent applies preliminary action by performing density control during blank areas between transfer sheets or at the end of sheets, rather than suspending printing. Toner patterns are formed and detected in advance during these idle periods, allowing density adjustment without interrupting the continuous printing workflow
Solution Approach 2:
The patent implements periodic action by performing second density control regularly during continuous printing at specific intervals (between sheets or at sheet ends). This periodic monitoring and adjustment maintains optimal image density while keeping the printing operation continuous, balancing quality control with productivity
3Productivity
If the second density control is performed in synchrony with printing during continuous printing, then productivity is maintained, but detection accuracy deteriorates due to belt speed variations
Solution Approach 1:
The patent applies parameter changes by introducing a conveyance speed correction value that compensates for speed variations in the secondary transfer belt. The control unit calculates the actual conveyance speed based on the correction value and uses this corrected speed parameter to accurately determine toner pattern density, thereby maintaining measurement precision even when the belt speed is fine-tuned
Solution Approach 2:
The patent implements feedback by using the conveyance speed correction value (obtained from sheet thickness detection) to adjust the toner pattern density calculation. The control unit continuously monitors the actual conveyance speed and compensates for deviations, creating a closed-loop system that maintains accurate density detection despite speed variations
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 enables high-precision detection and adjustment of toner pattern density on the secondary transfer belt, even when the belt speed is fine-tuned, ensuring consistent image quality and reducing productivity losses during continuous printing.
Implementation Method 1
a toner image sensor to detect the toner image transferred onto the transfer medium
Data Source
AI summary
An image forming apparatus includes an endless belt-shaped image bearer that is rotatably supported and entrained around rollers; a transfer member positioned to contact an outer surface of the image bearer; a transfer device to transfer a toner image conveyed while being carried on the outer surface of the image bearer onto a transfer medium conveyed between the image bearer and the transfer member; a toner image sensor to detect the toner image transferred onto the transfer medium; and a conveyance speed controller to fine-tune a conveyance speed of the transfer medium. Based on fine-tuning data of the conveyance speed controller, a detection result of the toner image sensor is corrected and image forming conditions are corrected based on the corrected detection result.