Image Forming Apparatus with Selective Sheet Rotation Correction
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Solution Overview
Problem
Existing image forming technologies suffer from reduced adjustment accuracy of image position on a sheet due to coarse rotation corrections, which can increase memory capacity requirements.
Innovation Solution
An image forming apparatus that determines the inclination angle of a sheet and performs rotation correction only when necessary, cutting out and storing specific areas of the image in memory, and forming images on a second sheet to minimize position differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If rotation correction is performed on the read chart image, then the inclination amount is reduced, but the image becomes coarser and adjustment accuracy is lowered
Solution Approach 1:
The patent changes the parameter of rotation correction by introducing a threshold value for the inclination amount. When the inclination amount is less than the threshold, rotation correction is skipped to avoid image coarsening. This parameter-based decision-making resolves the contradiction by selectively applying correction only when necessary, maintaining both measurement precision and manufacturing precision.
2Manufacturing precision
If rotation correction is performed to reduce inclination amount, then image positioning is improved, but memory capacity requirement increases
Solution Approach 1:
The patent applies parameter changes by using a threshold value to determine whether rotation correction is necessary. By skipping correction when the inclination amount is small, the system reduces memory capacity requirements while maintaining sufficient positioning accuracy for most cases.
Solution Approach 2:
The patent implements partial action by applying rotation correction only partially - specifically, only when the inclination amount exceeds the threshold. This selective application avoids the excessive memory capacity requirements that would result from always performing correction, while still providing correction where actually needed.
3Quantity of substance
If the read chart image is used directly without rotation correction, then memory capacity is reduced, but position adjustment accuracy is lowered
Solution Approach 1:
The patent resolves this contradiction through parameter-based decision making. By comparing the inclination amount against a threshold, the system determines whether to perform rotation correction. This allows the system to use memory capacity efficiently while maintaining position adjustment accuracy when correction is actually needed.
Data Source
AI summary
An image forming apparatus includes an image forming circuit that forms a chart image on a first sheet, a reader that reads the formed chart image, and a controller. If an inclination amount of the first sheet is greater than a first amount and is less than a second amount greater than the first amount, the controller performs a rotation correction on the read image to reduce the inclination amount, and stores an image of a first sheet area in the image after the correction, in a memory. If the inclination amount is less than the first amount, the controller stores an image of a predetermined area including the first sheet area, in the memory without the correction. The image forming circuit forms an image on a second sheet so as to reduce a difference in position between the stored image and an image used to form the chart image.