Image Processing Apparatus Toner Control via Spot Color Replacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrophotographic full-color printing, the use of more than four colors leads to excessive toner amounts and image quality degradation due to the inability to effectively manage toner consumption, especially when processing image data in special formats like DeviceN color space or unique multi-color separations.
Innovation Solution
An image processing apparatus and method that calculates the sum of signal values for each pixel and compares them to a limit value, replacing signal values of base or process colors with a spot color using a replacement table when the sum exceeds the limit, thereby controlling toner usage and maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If signal processing using spot colors in inkjet printing is applied to electrophotographic full-color printing, then color reproduction performance is improved, but total toner amount increases excessively
Solution Approach 1:
The patent changes the parameter of toner amount by comparing the sum of signal values against a limit value and selectively replacing base color signals with spot color signals when the limit is exceeded, thereby controlling total toner consumption while maintaining color reproduction quality
Solution Approach 2:
The patent dynamically adjusts color signal allocation by using a replacement table that is selected based on the calculated sum of signal values, allowing flexible switching between different color reproduction strategies depending on the toner consumption level
2Manufacturing precision
If image data in special formats like DeviceN color space or unique multi-color separations is processed, then color reproduction is enhanced, but toner management becomes ineffective and total toner amount exceeds limits
Solution Approach 1:
The patent performs preliminary calculation of the sum of signal values for each pixel before toner application, allowing proactive control of toner consumption by identifying pixels that would exceed the limit value and pre-planning their color signal replacement
Solution Approach 2:
The patent implements a feedback mechanism by comparing the calculated sum of signal values against a predetermined limit value and using this comparison result to dynamically select appropriate replacement tables, creating a closed-loop control system for toner management
3Manufacturing precision
If more than four colors are used in electrophotographic printing, then color reproduction capability is improved, but image quality degrades due to toner scattering and winding
Solution Approach 1:
The patent controls the physical parameter of toner amount by enforcing a limit value on the sum of signal values, preventing excessive toner deposition that would cause scattering and winding, thereby maintaining image quality while using multiple colors
Data Source
AI summary
When color materials of more than four colors are used, a signal for the amount of toner used within a range appropriate for the apparatus and toner characteristic is generated using a color separation table. However, a printer receives print data of various formats, such as image data separated into signal values of more than four colors, or image data of a special format to which a six-color separation table cannot be applied. Hence, an image signal representing a combination of colors is input. The sum of the signal values of colors in each pixel of the image signal is calculated and compared with a limit value. When the sum exceeds the limit value, the signal values of base colors are replaced with that of a spot color based on a replacement table for replacing the signal values of the base colors with that of the spot color.