Image Forming Apparatus White Developer Usage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image forming apparatuses experience poor legibility when using a white developer due to mixing with process color developers, especially noticeable in black printing, resulting in white spots and high contrast issues.
Innovation Solution
An image forming apparatus and method that differentiate between black and non-black pixel values in image data, reducing the usage amount of white developer for black portions to prevent mixing and improve legibility, by identifying white pixel values based on predetermined ranges and adjusting toner amounts through a color conversion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a white developer is used as a base to shield the base color of the print medium, then the color accuracy is improved, but the legibility deteriorates due to white spots appearing when process color developer sinks into the white developer
Solution Approach 1:
The patent applies local quality by differentiating white developer usage between black portions and non-black portions of the image. For black portions, the white developer usage is reduced to prevent mixing with process color developer and maintain legibility. For non-black portions, normal white developer usage is maintained to achieve color accuracy. This spatial differentiation of material properties resolves the contradiction between color accuracy and legibility.
2Manufacturing precision
If white developer is used in black portions to shield the base color, then the color accuracy is improved, but the contrast between black and white deteriorates due to high white developer usage
Solution Approach 1:
The patent implements local quality by applying different white developer quantities to different regions: reduced white developer in black portions to maintain contrast, and normal white developer in non-black portions to ensure color accuracy. This regional differentiation resolves the contradiction between color accuracy and contrast.
Solution Approach 2:
The patent changes the parameter of white developer quantity based on the portion type (black vs. non-black). By adjusting the white developer usage amount as a variable parameter according to image content, the system achieves both color accuracy and contrast preservation.
3Device complexity
If process color developer and white developer are transferred and fused together, then the image formation process is simplified, but the mixing causes white spots and poor legibility
Solution Approach 1:
The patent maintains the simplified simultaneous transfer process but introduces local quality control by reducing white developer usage specifically in black portions. This selective material application prevents mixing issues in critical areas while preserving the overall process simplicity.
Solution Approach 2:
The patent applies preliminary anti-action by proactively reducing white developer usage in black portions before the transfer process occurs. This preventive measure stops the mixing problem from occurring in the first place, rather than attempting to correct it after transfer and fusion.
Data Source
AI summary
An image forming apparatus includes an image process part that creates image data including pixel values of a process color image and pixel values of white which becomes a base of the process color image based on image forming data, and an image forming process part that forms the image on a medium using a process color developer and a white developer based on the image data. Wherein, the image process part that determines a black portion in which a combination of the pixel values of the process color image is regarded as black and a non-black portion in which the combination of the pixel values of the process color image is regarded as a color other than black, and identifies the pixel values of white for the base of the process color image in the image data such that an usage amount of the white developer for the black portion is less than that for the non-black portion.