Image Density Localization Across Transfer Stages in Printers
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Solution Overview
Problem
Image forming apparatuses with multiple rollers experience non-uniform density variations in the main scanning direction, making it difficult to identify the cause of these variations on recording media.
Innovation Solution
The apparatus is equipped with intermediate-transfer-member density sensors and a processor that analyze density variations to determine if they occur before or after the second-transfer process, using sensors to identify the specific components causing the variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple rollers are used for image forming units and fixing device, then image formation capability is improved, but the ability to identify the location of density variations deteriorates
Solution Approach 1:
The patent divides the density detection function into multiple segments by placing density sensors at different locations (intermediate transfer member and recording medium). This segmentation allows the system to isolate and identify which specific roller or process stage is causing density variations, resolving the difficulty of locating problems in multi-roller systems.
2Device complexity
If density sensors are placed only on recording medium, then detection simplicity is maintained, but measurement precision of density variation location deteriorates
Solution Approach 1:
The patent introduces an intermediate transfer member as a mediator in the detection system. By placing density sensors on both the intermediate transfer member and the recording medium, the system creates an intermediary detection point that enables precise localization of density variations without significantly increasing overall system complexity.
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
Accurately locates the cause of density variations, enabling targeted maintenance actions to correct issues in the image forming process.
Implementation Method 1
intermediate-transfer-member density sensors that are disposed in an axial direction of an intermediate transfer member and that detect corresponding densities of a developer image
Data Source
AI summary
An image forming apparatus includes: multiple intermediate-transfer-member density sensors that are disposed in the axial direction of an intermediate transfer member and that detect corresponding densities of a developer image having been subjected to first transfer onto the intermediate transfer member; and a processor configured to: in response to occurrence of a variation of density on a recording medium, if a relationship between the highest density value and the lowest density value among the density values detected by the respective intermediate-transfer-member density sensors indicates a first density state, output information indicating that the variation of density is caused in a process of or after a second-transfer process in which the developer image having been subjected to first transfer onto the intermediate transfer member is transferred onto the recording medium; and if the relationship indicates a second density state opposite to the first density state, output information indicating that the variation of density is caused in a process before the second-transfer process.