Paper Type Determination via Transmitted Light Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing paper type determination devices in printers and copying machines are not precise and are affected by the surface condition of the paper, leading to detection errors and increased costs due to complex device configurations and the use of CMOS sensors or multiple light receiving elements.
Innovation Solution
A paper type determination device that detects the light diffusing characteristics of paper by using a light emitting device with multiple light emitting points at varying distances and a photodetection device on the other side to measure light intensity, allowing for precise paper type identification without being affected by surface conditions, and is configured to be cost-effective and simple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If reflected light measurement is used to determine paper type, then the device can identify paper glossiness, but detection errors occur due to variance in light receiving sensitivity and surface condition variations
Solution Approach 1:
The patent inverts the measurement approach by measuring transmitted light instead of reflected light. The light emitting device irradiates light to one surface of the paper, and the photodetection device measures light that has passed through the paper from the opposite surface. This inversion eliminates the influence of surface conditions (glossiness, roughness) on the measurement, as the light interacts with the bulk properties of the paper rather than its surface characteristics.
Solution Approach 2:
The patent introduces a diffusing characteristic as an intermediary parameter that mediates between the light transmission measurement and paper type identification. The diffusing characteristic detection device calculates this parameter from the measured light intensity, which serves as a stable intermediate representation of paper properties that is less sensitive to measurement variations than direct reflected light intensity.
2Measurement precision
If CMOS sensors or multiple light receiving elements are used to improve measurement accuracy, then detection precision improves, but device complexity increases and cost increases
Solution Approach 1:
The patent replaces expensive, complex CMOS sensors with simpler, more cost-effective photodetection elements. The photodetection device uses basic light-receiving elements that are cheaper and simpler in structure, achieving adequate measurement precision without the need for sophisticated sensor arrays or image processing capabilities required by CMOS sensors.
Solution Approach 2:
The patent extracts only the essential function of light intensity measurement from the complex CMOS sensor system. By using simple photodetection elements that perform only the basic function of converting light intensity to electrical signals, the patent eliminates unnecessary complexity while retaining the core measurement capability needed for paper type determination.
3Reliability
If multiple light receiving elements are used to compensate for sensitivity variance, then measurement reliability improves, but device complexity and cost increase
Solution Approach 1:
The patent segments the measurement function by using multiple light emitting points with sequentially increasing distances from a reference point. This segmentation allows the system to probe different regions of the paper and obtain a more comprehensive measurement of its diffusing characteristics, compensating for local variations without requiring multiple complex light receiving elements.
Solution Approach 2:
The patent changes the measurement parameter from direct light intensity (which varies with surface conditions and sensitivity) to diffusing characteristic (calculated from light intensity at multiple distances). This parameter transformation makes the measurement more reliable by focusing on the inherent optical properties of the paper bulk rather than surface effects or sensor sensitivity variations.
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 device accurately determines paper type by measuring diffusing characteristics, eliminating the need for complex sensors and reducing costs, while providing precise identification without surface condition interference.
Implementation Method 1
a light emitting device that drives plural light emitting points different from one another and having sequentially increasing distances from a reference point to emit light in such a manner that respective light emitting points are identified for irradiating one surface of a sheet of paper subjected to determination by light emission; a photodetection device that is disposed on the other surface side of the sheet of paper, includes a specific detection field of view having a center at the reference point, and receives light having passed through the sheet of paper from the respective light emitting points at positions on inside and outside of the detection field of view to detect intensity of light for each light emitting point
Data Source
AI summary
A paper type determination device of the invention drives plural light emitting points different from one another and having sequentially increasing distances from a reference point to emit light in such a manner that each is identified for irradiating one surface of a sheet of paper subjected to determination. A photodetection device set at a specific detection field of view having the center at the reference point is disposed on the other surface side of the sheet of paper, and it receives light having passed through the sheet of paper from the respective light emitting points at positions on inside and outside of the detection field of view to detect intensity of light for each light emitting point. A diffusing characteristic of the sheet of paper is obtained on the basis of the intensity of light from each light emitting point detected by the photodetection device, and a paper type is determined on the basis of the diffusing characteristic.