Image Shift Correction in Image Forming Apparatus Using Test Image Data Segmentation
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Solution Overview
Problem
Existing image forming apparatuses face issues with image shift in the main scanning direction, which can lead to enlarged or reduced images, and correcting this shift using test images can introduce step parts that worsen the image shift detection accuracy.
Innovation Solution
The apparatus includes a photosensitive member rotated by a light-emitting unit array and a controller that generates image data with bit control for lighting and extinguishing, using a test image to determine image shift without inserting or removing bit data in the test image region, thereby avoiding step parts and improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pixels are added or removed from test image data to correct image shift, then image shift in the main scanning direction is reduced, but step parts are produced in the test image that worsen detection accuracy
Solution Approach 1:
The image data is divided into two distinct regions: a test image region used for detecting shift amount and a main image region for actual image formation. Pixel insertion/removal operations are applied only to the main image region, leaving the test image region unchanged. This segmentation allows independent optimization of detection accuracy and shift correction without mutual interference.
Solution Approach 2:
The test image region is extracted and isolated from the main image data processing pipeline. By separating the test image data from the main image data, the system can perform pixel insertion/removal operations on the main image region without affecting the test image region, thereby eliminating step parts in the test image while still achieving image shift correction.
2Manufacturing precision
If pixel insertion/removal is applied uniformly across all image data, then image shift is corrected, but the test image quality deteriorates due to step parts
Solution Approach 1:
Different processing strategies are applied to different regions of the image data. The test image region maintains its original pixel structure without insertion or removal operations to preserve continuity and quality. The main image region undergoes pixel insertion/removal operations to correct image shift. This local differentiation ensures that each region receives the appropriate treatment for its specific function.
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 effectively corrects image shift in the main scanning direction without introducing step parts, enhancing the accuracy of image detection and correction, thus improving the overall image forming process.
Implementation Method 1
an exposure light source including a plurality of light-emitting units that are arranged parallel to a rotation axis of the photosensitive member and that emit light that exposes the photosensitive member
Data Source
AI summary
An apparatus comprises a photosensitive member, an exposure light source including a plurality of light-emitting units that are arranged parallel to a rotation axis of the photosensitive member and that emit light that exposes the photosensitive member, and a controller configured to generate image data that is a group of bit data controlling lighting and extinguishing of the plurality of light-emitting units and that corresponds to an image, and to insert and/or remove the bit data in the image data. The image includes a test image for obtaining a shift amount in an image formation position relative to a reference position. The image data includes test image data corresponding to the test image. The controller does not insert and/or remove the bit data in a region of the image data that corresponds to the test image data.