Image Processing Apparatus Toner Control Density
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Solution Overview
Problem
Image processing apparatuses face instability in outputting images due to ambient temperature and humidity changes, leading to issues like excessive toner usage, jaggies, and discontinuities, especially when trying to maintain target maximum density while controlling toner amount per unit area.
Innovation Solution
An image processing apparatus that calculates a maximum density value and determines a limit value for recording material based on the difference between the calculated and target densities, controlling the toner amount to ensure it does not exceed the limit, thereby preventing excessive toner usage and maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the upper-limit density is restrained using a look-up table to prevent exceeding target maximum density, then image density control is improved, but jaggies or discontinuities occur in texts and thin lines
Solution Approach 1:
The patent applies dynamics by making the upper-limit density value adjustable and adaptive rather than fixed. The system dynamically determines the upper-limit density based on the relationship between target maximum density and actual maximum density, allowing the limit to flex according to apparatus state while still preventing excessive toner application that causes jaggies
Solution Approach 2:
The patent changes the parameter of upper-limit density from a static restrained value to a dynamically calculated value based on the ratio of target maximum density to actual maximum density. This parameter adjustment allows the system to maintain image continuity while controlling density within acceptable ranges
2Reliability
If the total recording material amount per unit area is controlled to fall below a preset fixed amount, then inferior fixing and scattering are prevented, but image density and color depth are reduced
Solution Approach 1:
The patent applies partial action by allowing the recording material amount to occasionally exceed the preset fixed amount when the calculated upper-limit density permits, rather than strictly enforcing a fixed limit. This partial exemption maintains fixing quality while preserving image density and color depth in conditions where excess material is acceptable
3Manufacturing precision
If black toner amount is increased instead of reducing cyan, magenta, and yellow toner to control total toner amount, then tint and gradation are maintained, but the complexity of toner combination control increases
Solution Approach 1:
The patent applies local quality by differentiating the control strategy for black toner versus cyan, magenta, and yellow toners. Instead of uniformly reducing all toners, the system selectively adjusts black toner amount while maintaining other colors, applying different control qualities to different toner types to preserve gradation while simplifying the overall control logic
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 allows for appropriate setting of the recording material limit value according to the apparatus state, preventing excessive toner reduction and ensuring stable image output without causing inferior fixing or scattering, thus maintaining image quality and preventing damage to the apparatus.
Implementation Method 1
The electrophotographic method forms a latent image on a photosensitive drum by using a laser beam and develops the latent image by a charged color material (hereinafter referred to as toner) to form a toner image
Implementation Method 2
fixes the transferred image
Data Source
AI summary
A limit value of a recording material is determined based on a difference between a maximum density value of an image formed by an image forming unit and a maximum density value to be targeted by an image processing apparatus, and the amount of the recording material corresponding to the image data is controlled so as to be the determined limit value or below.