Infrared Sheet Boundary Sensing Through a Transparent Carrier Plate
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Solution Overview
Problem
Existing technologies for sensing the size and boundaries of paper in scanners, copiers, and multifunction machines need to sense the sizes and boundaries of papers, but they face issues such as high cost, space requirements, incorrect determinations due to paper material and color, and inefficient scanning processes.
Innovation Solution
A sheet-sensing system using a microcontroller, infrared-emitting and -receiving apparatus, and a transparent carrier plate to determine paper boundaries by emitting and receiving infrared rays, reducing the need for multiple sensors and minimizing scanning distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple reflective infrared sensors are used to sense paper boundaries, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines multiple sensing functions into a single reflective infrared sensor by utilizing the moving contact image sensor scanning circuit to sequentially scan different positions. This merging approach maintains measurement precision while reducing device complexity and cost.
Solution Approach 2:
The patent employs a dynamic scanning mechanism where the contact image sensor moves across the paper surface to detect boundaries at different positions. This dynamic approach replaces the need for multiple fixed sensors, achieving the same measurement precision with fewer components.
2Measurement precision
If multiple reflective infrared sensors are arranged at specific positions, then measurement precision is improved, but the area required in the electronic apparatus increases
Solution Approach 1:
The patent uses a movable contact image sensor scanning circuit that travels across the glass surface to detect paper boundaries at multiple positions sequentially. This dynamic scanning approach achieves comprehensive measurement precision while requiring minimal static space compared to multiple fixed sensors.
Solution Approach 2:
The patent introduces the time dimension through sequential scanning, allowing a single sensor to cover multiple spatial positions. This transforms a spatial problem (needing multiple sensors simultaneously) into a temporal solution (one sensor scanning over time), reducing the area required.
3Measurement precision
If the focal length of reflective infrared sensors is increased to sense paper existence, then measurement capability is improved, but cost increases
Solution Approach 1:
The patent introduces a reflective member (the paper itself or a separate reflector) as an intermediary to redirect infrared rays back to the sensor. This allows the use of sensors with shorter focal lengths while maintaining detection capability, thereby reducing cost.
Solution Approach 2:
The patent divides the detection process into segments using the scanning mechanism, where the sensor detects paper existence and boundaries at different positions sequentially. This segmentation allows the use of lower-cost sensors with shorter focal lengths compared to requiring a single high-performance long-focal-length sensor.
4Measurement precision
If reflective infrared sensors are used, then paper boundary sensing is achieved, but incorrect determination occurs due to infrared ray absorption by paper material and color
Solution Approach 1:
The patent uses the contact image sensor to create an optical copy or image of the paper boundary by detecting reflected infrared rays. This imaging approach provides more reliable boundary detection compared to simple presence/absence sensing, as it captures spatial information that is less susceptible to material and color variations.
Solution Approach 2:
The patent employs a contact image sensor that can detect both the presence and boundaries of paper through infrared reflection. This multi-functional sensor provides more robust detection across different paper materials and colors compared to dedicated simple presence sensors, improving reliability.
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 avoids incorrect determinations due to paper material and color, reduces scanning time and power consumption, and minimizes sensor usage, providing accurate and efficient paper size and boundary detection.
Implementation Method 1
The microcontroller controls the infrared-emitting apparatus to emit an infrared ray toward the sheet and the transparent carrier plate. The microcontroller uses the infrared-receiving apparatus to receive the infrared ray passing through the transparent carrier plate to determine a boundary of the sheet.
Data Source
AI summary
A sheet-sensing system is applied to a sheet and a transparent carrier plate. The sheet is placed on the transparent carrier plate. The sheet-sensing system includes a microcontroller, an infrared-emitting apparatus, and an infrared-receiving apparatus. The sheet and the transparent carrier plate are disposed between the infrared-emitting apparatus and the infrared-receiving apparatus. The microcontroller controls the infrared-emitting apparatus to emit an infrared ray toward the sheet and the transparent carrier plate. The microcontroller uses the infrared-receiving apparatus to receive the infrared ray passing through the transparent carrier plate to determine a boundary of the sheet.