Image Density Control via Multi-Point Detection in Printers
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Solution Overview
Problem
Image density in image forming apparatuses such as copiers and printers fluctuates due to changes in the rotation cycle of developer bearings, leading to inconsistent image quality.
Innovation Solution
An image forming apparatus with an image bearer, toner image forming device, and multiple image density detectors that form and detect toner image patterns across different positions, allowing a controller to adjust the image forming conditions to achieve uniform density and correct cyclic fluctuations in image density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single image density detector is used to detect toner image density, then the device complexity is low, but the manufacturing precision of image density control is insufficient to correct cyclic fluctuations
Solution Approach 1:
The patent divides the detection system into multiple image density detectors positioned at different locations (first detector at first position, second detector at second position) to detect cyclic fluctuations at multiple points simultaneously, enabling more precise correction of density variations across the image bearer
Solution Approach 2:
The patent transitions from single-point detection to multi-point spatial detection by placing detectors at different positions around the image bearer, adding a spatial dimension to the detection system that enables comprehensive measurement of cyclic fluctuations
2Manufacturing precision
If multiple image density detectors are added to detect cyclic fluctuations at different positions, then the manufacturing precision of image density control is improved, but the device complexity increases
Solution Approach 1:
The patent implements a feedback control system where multiple image density detectors continuously monitor toner image density at different positions, and the controller adjusts image forming conditions based on detected cyclic fluctuations to maintain uniform density across the image bearer
Solution Approach 2:
The system uses the detection data from multiple detectors to automatically determine and adjust image forming conditions without external intervention, enabling the system to self-correct cyclic fluctuations and maintain optimal image density
3Reliability
If image forming conditions are adjusted based on single-position detection, then the operation is simple, but the reliability of image density correction is insufficient to eliminate cyclic fluctuations
Solution Approach 1:
The patent performs preliminary detection of cyclic fluctuations using multiple image density detectors before final image formation, allowing the controller to pre-determine appropriate image forming conditions that will compensate for anticipated density variations
4Productivity
If the rotation cycle of the developer bearer changes, then the productivity of the image forming apparatus is maintained, but the manufacturing precision of image density deteriorates due to cyclic fluctuations
Solution Approach 1:
The patent implements dynamic adjustment of image forming conditions based on real-time detection of cyclic fluctuations caused by developer bearer rotation variations, allowing the system to adapt to changing rotational conditions while maintaining consistent image density
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
The solution effectively suppresses cyclic fluctuations in image density, ensuring consistent image quality across the image bearer by determining and adjusting the image forming conditions based on detected toner image patterns, thereby reducing amplitude and phase errors.
Implementation Method 1
The plurality of image density detectors detect a density of the toner image patterns formed on the image bearer
Data Source
AI summary
An image forming apparatus includes an image bearer, a toner image forming device, a plurality of image density detectors, and a controller. The plurality of image density detectors are disposed at predetermined intervals opposite the image bearer in a width direction of the image bearer. The controller causes the toner image forming device to form toner image patterns having an identical density at the plurality of positions on the image bearer and the plurality of image density detectors detects a density of the toner image patterns. Based on the detected density of the toner image patterns, the controller identifies multiple cyclic fluctuations of the density of the toner image patterns and adjusts an image forming condition based on the multiple cyclic fluctuations of the density of the toner image patterns to decrease an amplitude caused by the multiple cyclic fluctuations of the density of the toner image patterns.