Image Forming Apparatus Paper Surface Detection
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Solution Overview
Problem
Conventional recording paper surface detection methods produce varying results due to the relationship between the fiber arrangement direction of the recording sheet and the direction of light illumination, leading to inconsistent paper type determination, especially when the fiber arrangement direction does not align with the standard angular range of 0 to ±15 degrees relative to the recording sheet conveyance direction.
Innovation Solution
The implementation of a recording paper surface detection apparatus that uses two light sources with optical axes oriented at specific angles relative to the recording sheet conveyance direction, one perpendicular and one parallel, to capture surface images from different directions, thereby reducing the dependency on fiber arrangement direction and improving determination accuracy by averaging contrast values from these images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light illumination direction is fixed at 15 to 70 degrees relative to recording sheet conveyance direction, then paper type determination accuracy is improved for papers with fiber arrangement in standard angular range, but determination accuracy deteriorates for papers with fiber arrangement outside this angular range
Solution Approach 1:
The single illumination direction is segmented into multiple illumination directions (first and second light sources at different angles). Each light source illuminates the paper surface from a different direction, and the contrast values from both illuminations are combined to determine paper type, ensuring accurate detection regardless of fiber arrangement direction
Solution Approach 2:
The detection system transitions from one-dimensional (single illumination direction) to two-dimensional (multiple illumination directions in different angular planes). By introducing illumination from multiple dimensional angles relative to the paper surface, the system captures surface unevenness characteristics independent of fiber orientation direction
2Device complexity
If single light source illumination is used, then device complexity is reduced, but detection result variation increases due to fiber arrangement direction dependency
Solution Approach 1:
Multiple contrast measurements from different illumination directions are merged into a single paper type determination. The system combines the contrast value from first light source illumination and the contrast value from second light source illumination, ensuring reliable detection results while maintaining relatively simple device structure
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 significantly reduces variation in detection results and enhances the accuracy of surface unevenness determination for recording sheets with diverse fiber arrangement directions, ensuring consistent paper type identification regardless of the fiber orientation.
Implementation Method 1
capturing surface images by causing shadows to be formed on the recording sheet in different directions
Data Source
Figure 1A
Figure 1B
Figure 2A~2C
AI summary
An image forming apparatus comprising: image forming means for forming an image on a recording sheet; light emitting means for emitting a first light beam in a first direction and a second light beam in a second direction different from the first direction; image capturing means for capturing an image of a first light-illuminated area illuminated with the first light beam on a surface of the recording sheet as a first image, and an image of a second light-illuminated area illuminated with the second light beam and different from the first light-illuminated area as a second image; and control means for controlling an image forming condition for the image forming means based on information to be obtained from the first image and the second image.