Image Forming Apparatus Halftone Screen Selection for Non-White Media
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Solution Overview
Problem
Conventional image forming apparatuses face challenges in producing high-quality images, especially when printing on non-white recording media, as they struggle to achieve good color development and minimize Moire interference and granular quality.
Innovation Solution
The apparatus employs a dual printing mode system with a determining section and selector to choose between a first and second printing mode, using specific halftone screens for each mode to optimize toner usage and image quality, including the use of white toner for underlayer printing and color toners, and adjusts toner amounts to prevent exceeding the toner limit, thereby ensuring high-quality image formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single halftone screen is used for all printing modes, then the device complexity is reduced, but the image quality deteriorates due to granular quality and Moire interference
Solution Approach 1:
The patent divides the halftone screen into multiple types (first halftone screen for single-color printing, second halftone screen for multi-color printing) and selectively applies them based on the printing mode. This segmentation allows each screen type to be optimized for its specific purpose, reducing granular quality and Moire interference while maintaining manageable device complexity through automated selection.
Solution Approach 2:
The patent implements dynamic selection of halftone screens based on the determined printing mode. The system automatically switches between the first and second halftone screens depending on whether single-color or multi-color printing is required, allowing the image forming apparatus to adapt to different printing conditions and optimize image quality for each mode.
2Manufacturing precision
If white toner is used for underlayer printing on non-white media, then color development is improved, but the toner consumption increases and may exceed the toner limit
Solution Approach 1:
The patent adjusts the white toner amount parameter based on the determined printing mode and image characteristics. By dynamically controlling the white toner application quantity, the system achieves sufficient color development on non-white media while preventing excessive toner consumption that would exceed the toner limit, thus resolving the contradiction between color quality and toner usage.
3Manufacturing precision
If the halftone screen is selected based on printing mode, then the image quality is improved by minimizing granular quality and Moire interference, but the control complexity increases
Solution Approach 1:
The patent determines the printing mode in advance before selecting the halftone screen. This preliminary determination of whether single-color or multi-color printing is required allows the system to pre-select the appropriate halftone screen type, simplifying the control process while maintaining high image quality through optimized screen selection for each printing scenario.
Data Source
AI summary
An image forming apparatus, method, and system are disclosed. The apparatus includes first and second image forming sections; a selector that selects one of a first halftone screen for a first printing mode in which the first image forming section forms a first image on the print medium, and a second halftone screen for a second printing mode in which the first image forming section forms the first image on the print medium and the second image forming section forms a second image on the first image so that the first image and the second image are printed one over the other. The first and second halftone screens include respective first and second numbers of raster lines per unit, the first halftone screen and the second halftone screen being different in the number of raster lines; a controller; and a discharging section.