Image Forming Apparatus Exposure Correction for Toner Reduction
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Solution Overview
Problem
Image forming apparatuses face challenges in reducing developer consumption while maintaining image quality, particularly due to issues like the edge effect and sweeping, which can lead to degradation in dot reproducibility and image quality, especially for narrow line-shaped images.
Innovation Solution
The implementation of an image forming apparatus that employs a CPU-controlled exposure unit with lookup tables for adjusting exposure amounts and correcting pixel values based on distance from edges, using pulse width modulation to adjust the number of subpixels exposed, thereby reducing toner consumption and suppressing edge effects and sweeping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If exposure amount is adjusted to suppress sweeping and edge effect, then toner consumption is reduced, but dot reproducibility and image quality of narrow line-shaped images degrade
Solution Approach 1:
The patent applies different exposure correction strategies to different regions of the image. Correction regions are determined based on pixel data values and positional relationships, applying exposure adjustment only where needed (at edges and trailing portions) rather than uniformly across the entire image, thus preserving dot reproducibility in non-correction areas while reducing toner consumption in correction areas
Solution Approach 2:
The patent segments the image into correction regions and non-correction regions based on pixel analysis. By identifying specific pixels that require correction (those at edges or trailing portions) and applying exposure adjustment only to these segmented regions, the system achieves toner reduction without degrading overall image quality and dot reproducibility
2Loss of substance
If exposure amount is adjusted to suppress sweeping, then toner consumption is reduced, but image quality of narrow line-shaped images degrades
Solution Approach 1:
The patent applies exposure correction locally to specific regions identified as correction regions rather than uniformly across the image. By determining correction regions based on pixel data values and positional relationships (upstream pixels relative to downstream pixels), the system reduces toner consumption at problematic areas while maintaining image quality in non-correction areas
Solution Approach 2:
The patent segments the image into correction and non-correction regions by analyzing pixel relationships. Pixels are classified into correction regions based on their data values and positional relationships with downstream pixels, allowing selective exposure adjustment that reduces toner consumption without degrading overall image quality
3Loss of substance
If exposure intensity is lowered for large area images, then toner consumption is reduced, but image quality may degrade
Solution Approach 1:
The patent applies different exposure strategies to different regions: correction regions (identified by pixel analysis and positional relationships) receive exposure adjustment to reduce toner consumption, while non-correction regions maintain normal exposure to preserve image quality, thus achieving toner reduction without overall image quality degradation
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 approach effectively reduces toner consumption while minimizing degradation in image quality and dot reproducibility, specifically for narrow line-shaped images, by precisely controlling exposure amounts and avoiding excessive toner adhesion.
Implementation Method 1
an exposure unit that applies exposure to a photosensitive member based on the corrected image data
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
An image forming includes: specifying means for specifying, based on image data, a pixel to be subjected to correction from among pixels of an image to be formed from the image data; and correction means for correcting an exposure amount by exposure means for the pixel to be subjected to correction from an exposure amount indicated by the image data. When exposure amounts for a plurality of pixels to be subjected to correction remain the same after correction, the correction means varies an exposure pattern for at least one of the plurality of pixels to be subjected to correction from exposure patterns for the rest of the plurality of pixels to be subjected to correction.