Image Reader Mode Switching for Sheet Edge Detection
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Solution Overview
Problem
Existing image forming apparatuses struggle to accurately detect the positions of side ends of colored sheets due to insufficient contrast at the sheet ends.
Innovation Solution
An image forming system that includes a sheet feeder, a conveyor, a reader with multiple reading modes, and a hardware processor. The reader can switch between reading modes based on print settings, and the processor adjusts the image formation timing accordingly to ensure accurate detection of sheet size and shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a contact image sensor (CIS) is used to detect sheet positions, then detection speed is improved, but detection accuracy deteriorates for colored sheets due to insufficient contrast
Solution Approach 1:
The patent changes the parameter of light wavelength by using a laser beam with a specific wavelength (e.g., 650nm or 780nm) that provides high contrast against colored sheets. This parameter change enables the light receiving sensor to accurately detect sheet positions and edges regardless of sheet color, resolving the contradiction between detection speed and accuracy for colored sheets.
2Adaptability or versatility
If multiple reading modes are implemented to handle different sheet types, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal light receiving sensor system that can handle both white and colored sheets using the same hardware component. By using a laser beam with appropriate wavelength and controlling the background surface color, the system achieves multi-functionality without requiring separate detection systems for different sheet types, thus improving adaptability while maintaining relatively simple device structure.
3Measurement precision
If image formation timing is adjusted in response to reading mode switches, then detection accuracy is improved, but processing time increases
Solution Approach 1:
The patent performs preliminary actions by pre-setting the background surface color according to the expected sheet type before reading occurs. This allows the light receiving sensor to be immediately ready for accurate detection without requiring time-consuming adjustments during the reading process, thus improving detection accuracy while minimizing processing time delays.
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 system accurately detects sheet size and shape by varying the image formation timing in response to reading mode switches, thereby improving detection accuracy for both white and colored sheets.
Implementation Method 1
a reader including a reading sensor that optically reads the sheet conveyed through the conveyance path
Data Source
AI summary
An image forming system includes: a reader including a reading sensor that optically reads a sheet conveyed through a conveyance path; and a hardware processor that controls the reader, in which the reader is able to execute a plurality of reading modes including at least a first reading mode and a second reading mode different from the first reading mode, and reads the sheet in any one of the reading modes selected according to a print setting, and the hardware processor varies an image formation timing of forming an image on the sheet by an image former between when switching of the reading modes is performed and when the switching of the reading modes is not performed.