Toner Density Control via Dynamic Target Adjustment
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Solution Overview
Problem
Existing toner supply control methods in image forming apparatuses struggle to accurately adjust toner density to both high and low levels within a design phase, leading to unstable image quality due to delays in toner consumption and excessive supply issues.
Innovation Solution
An image forming apparatus with a control device that combines feedforward and feedback control units to determine toner supply amounts based on detected toner density and image information, allowing for precise adjustment of toner density by stopping or reducing toner supply when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If toner supply control is implemented based on detected toner density to maintain optimal density, then image quality is improved, but the system cannot respond to changes requiring low toner density adjustments, causing delays and unstable image quality
Solution Approach 1:
The control system dynamically adjusts the target toner density value based on detected image density. When image density is high, the system lowers the target toner density to prevent excessive toner accumulation. When image density is low, the system raises the target toner density to ensure sufficient toner availability. This dynamic adaptation resolves the contradiction by making the system flexible enough to handle both high and low density requirements while maintaining stable image quality throughout operation.
2Quantity of substance
If toner supply amount is increased to compensate for density reduction, then toner density is maintained, but toner consumption increases and supply timing becomes delayed
Solution Approach 1:
The system performs preliminary action by proactively adjusting the target toner density value before actual toner supply occurs. When image density indicates future toner deficiency, the system preemptively modifies the target density to optimize upcoming toner supply timing and amount. This prevents both excessive toner consumption and delayed supply responses, as the control parameters are optimized in advance based on image density trends.
3Quantity of substance
If toner supply control focuses on preventing density reduction, then toner density is maintained, but the system cannot adapt to optimal conditions requiring low density, resulting in excessive toner supply
Solution Approach 1:
The system employs feedback control by continuously detecting image density and using this information to adjust the target toner density value. When image density is high, the feedback loop lowers the target toner density to reduce unnecessary toner supply. When image density is low, the feedback loop raises the target to prevent density deficiency. This closed-loop feedback mechanism resolves the contradiction by optimizing toner consumption while maintaining appropriate density levels based on actual image formation requirements.
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 solution enables stable toner density control, preventing fluctuations and improving image quality by ensuring accurate toner consumption and supply matching, thus eliminating the need for prolonged waiting periods and reducing toner density oscillations.
Implementation Method 1
a value of toner density is detected by a density sensor
Implementation Method 2
charging the toner with a frictional electrification action generated at the time of stirring the mixture
Data Source
AI summary
An image forming apparatus includes a latent image carrier carrying a latent image, a developing device visualizing the latent image utilizing a two-component developer, a supply device supplying toner according to a change in toner density in the two-component developer inside the developing device, and a control device having an input side connected to a density sensor detecting a value of the toner density and an image information acquisition device acquiring information on an image formed on the latent image carrier, and an output side connected to a driving device driving the supply device. When the detected value is higher than a target value of the toner density stored by the control device, the control device performs control to stop the driving device or drive the driving device to supply toner in an amount less than a combined toner supply amount of first and second toner supply amounts.