Optical Sensor Yellow Wavelength Detection via Red Light Subtraction
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Solution Overview
Problem
Existing optical sensors face challenges in accurately detecting the yellow wavelength band due to interference from red light, and there is a need for improved detection accuracy and reliability, especially in non-uniform light conditions.
Innovation Solution
The optical sensor incorporates a light receiving unit with a yellow filter and a red filter, where the intensity of the yellow wavelength band is calculated based on the difference between output signals from these filters, and the light receiving elements are arranged in a lattice-like manner to reduce variations and enhance detection accuracy. Additionally, a nonvolatile memory adjusts sensitivity and a blocking layer prevents ultraviolet light from affecting stored information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a yellow filter is used to detect yellow wavelength band light, then the detection capability for yellow light is improved, but red light interference is introduced because the yellow filter transmits both yellow and red wavelengths
Solution Approach 1:
The patent extracts the red light component from the total light detected by the yellow filter using a separate red filter and red light receiving element. By measuring red light independently and subtracting it from the yellow filter signal, the system isolates the pure yellow wavelength band intensity, eliminating red light interference from the yellow detection channel.
Solution Approach 2:
The patent introduces a red filter as an intermediary component that selectively transmits red light to a dedicated red light receiving element. This intermediary structure enables the system to separately measure and subsequently remove the red light contribution from the yellow filter's total signal, resolving the spectral overlap issue.
2Manufacturing precision
If light receiving elements are arranged in a lattice-like manner, then manufacturing variations between elements are reduced, but the device complexity increases due to precise positioning requirements
Solution Approach 1:
The patent segments the light receiving unit into multiple discrete light receiving elements arranged in a lattice pattern, with each element covered by a specific color filter (yellow, red, green, blue). This segmentation allows independent optimization of each element's characteristics while maintaining overall system performance through the regular lattice structure, which provides manufacturing tolerance.
3Adaptability or versatility
If multiple color filters are used to detect different wavelength bands, then the versatility of the optical sensor is improved, but the device complexity increases due to multiple components
Solution Approach 1:
The patent implements a universal light receiving unit structure where multiple light receiving elements with different color filters (yellow, red, green, blue) share a common lattice arrangement and similar optical paths. This multi-functional design allows the same basic structure to detect multiple wavelength bands simultaneously, achieving versatility without proportionally increasing device complexity.
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 configuration allows for enhanced detection accuracy of the yellow wavelength band by selectively eliminating red light interference and reduces variations in light reception, improving the overall reliability and precision of the optical sensor.
Implementation Method 1
a yellow filter that covers a light receiving surface of the first light receiving element and a red filter that covers a light receiving surface of the second light receiving element
Implementation Method 2
a first light receiving element and a second light receiving element through which a photocurrent flows when receiving light
Data Source
AI summary
An optical sensor includes a light receiving unit and a calculating unit. The light receiving unit includes a plurality of light receiving elements and a plurality of color filters. The plurality of light receiving elements include a first light receiving element and a second light receiving element through which a photocurrent flows when receiving light. The plurality of color filters include a yellow filter that covers a light receiving surface of the first light receiving element and a red filter that covers a light receiving surface of the second light receiving element. The calculating unit calculates an intensity of a yellow wavelength band based on a difference between a first output signal obtained from the photocurrent of the first light receiving element and a second output signal obtained from the photocurrent of the second light receiving element.