Toner Density Control Apparatus for Image Forming Systems
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Solution Overview
Problem
In electrophotographic image forming apparatuses, maintaining consistent toner density is challenging, leading to variations in image density, which existing methods fail to adequately address, resulting in inefficiencies and toner wastage.
Innovation Solution
A control apparatus that includes a toner density specifying unit, a toner density controller, a calculator, a correction amount specifying unit, and a correcting unit to adjust and correct toner density target values based on real-time image density measurements, ensuring optimal toner usage and minimizing variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If toner density is adjusted to suppress charged state changes, then image density consistency is improved, but device complexity increases
Solution Approach 1:
The patent implements a feedback control mechanism where the controller receives toner density information from the developing device, compares it with target values, and adjusts developing conditions accordingly. This closed-loop feedback system automatically maintains toner density consistency without requiring complex manual intervention or overly complicated device architecture.
Solution Approach 2:
The system dynamically adjusts developing parameters such as developing bias voltage and developing roller speed based on measured toner density values. By changing these parameters in response to feedback, the system maintains stable toner density and image quality while using relatively simple control mechanisms.
2Stability of the object's composition
If toner density is continuously adjusted, then image quality consistency is improved, but toner wastage increases
Solution Approach 1:
The system performs preliminary measurements of toner density at specific intervals (e.g., after developing device assembly or when density drift is detected) rather than continuous adjustment. This preliminary action approach allows the system to proactively correct density issues before they affect image quality, reducing unnecessary toner consumption while maintaining quality consistency.
Solution Approach 2:
The controller adjusts toner density only when necessary based on measured deviations from target values, rather than continuously adjusting. This partial action approach applies correction only when needed, avoiding excessive toner consumption while still maintaining image quality consistency within acceptable tolerances.
3Stability of the object's composition
If correction amount is reduced when image density change is large, then toner density stability is improved, but image density accuracy may deteriorate
Solution Approach 1:
The correction amount is dynamically adjusted based on the measured image density change. When large density changes are detected, the system applies smaller correction increments to stabilize toner density, while still achieving the target density through multiple smaller adjustments rather than one large correction. This dynamic approach balances stability and accuracy.
Solution Approach 2:
The system performs periodic measurements of image density and toner density at different stages of the developing process. By using these periodic data points, the controller can determine appropriate correction amounts that stabilize toner density while maintaining image density accuracy, avoiding both over-correction and under-correction.
Data Source
AI summary
A control apparatus includes the following elements. A toner density specifying unit specifies a toner density in a developer stored in a developing device. A toner density controller performs control such that the toner density approximates a predetermined toner density target value. A first calculator calculates a first value corresponding to an image density of an image to be output after a first timing. A correction amount specifying unit specifies a correction amount for the toner density target value at the first timing. When the condition that an absolute value of a difference between the first value and a second value is greater than a predetermined threshold is satisfied, the correction amount specifying unit specifies a smaller correction amount for the toner density target value, compared with when the condition is not satisfied. A correcting unit corrects the toner density target value on the basis of the correction amount.