Conveying Device Sheet End Position Detection
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Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately correcting the posture of sheets with varying reflectance, leading to inaccuracies in skew and lateral displacement corrections during the conveyance process.
Innovation Solution
A conveying device equipped with a first pair of nipping rollers, a second pair of nipping rollers, a position corrector, and an end position detector, along with circuitry to adjust the output of the detector, allowing for precise correction of sheet posture and position by detecting the end position and adjusting the conveying mechanism accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a detector is used to detect the end of a sheet by receiving reflected light, then the sheet position can be detected, but the detection accuracy varies with sheet reflectance (color and transparency)
Solution Approach 1:
The system performs preliminary adjustment of the detector's output level using a reference sheet (white sheet) before actual sheet detection. This preliminary calibration establishes a baseline detection level that can then be adapted for different sheet types, improving detection accuracy across various reflectances.
Solution Approach 2:
The system dynamically adjusts the output level parameter of the detector based on the detected sheet reflectance. By changing the detector's output parameter according to the sheet's optical properties, the system maintains accurate detection across different sheet colors and transparencies.
2Measurement precision
If the detector output level is adjusted using a white reference sheet, then detection accuracy is improved for that sheet, but additional adjustment is needed for different sheet types
Solution Approach 1:
The system uses feedback from the initial detection attempt to automatically adjust the detector output level for subsequent sheets. By monitoring detection results and automatically modifying the output parameter, the system eliminates manual re-adjustment for different sheet types, saving time while maintaining accuracy.
3Measurement precision
If the end position detector is positioned within the conveyance passage, then sheet end position can be detected, but the detector may not be covered by all sheet types extending outward
Solution Approach 1:
The end position detector is positioned extending outward from the conveyance passage in the width direction rather than solely within it. This dimensional relocation allows the detector to be covered by sheets of various sizes as they pass through, improving universal detection capability while maintaining detection precision.
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
The solution enables accurate skew and main scanning registration corrections, enhancing the precision and efficiency of image formation across different types of sheets, reducing the likelihood of malfunctions and jamming.
Implementation Method 1
The detector detects the end of the sheet by receiving reflected light that is emitted by a light source and reflected on the sheet
Data Source
AI summary
A conveying device includes a first pair of nipping rollers, a second pair of nipping rollers, a position corrector configured to correct a position of a recording medium in a width direction of the recording medium, an end position detector configured to detect an end position of the recording medium in the width direction, and circuitry configured to, in adjustment of the end position detector, stop conveying the recording medium in response to arrival of a leading end of the recording medium at the end position detector, cause the position corrector to move the recording medium toward an outside of the conveyance passage in the width direction to a position at which the end position detector is covered by the recording medium, adjust the output of the end position detector, and cause the end position detector to detect the recording medium.