Optical Sensor Light Distribution Control for Biometric Detection
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Solution Overview
Problem
Existing detection devices face challenges in measuring light intensity due to photodiodes being illuminated at excessively high or low levels, preventing accurate data collection when a planar optical sensor and light source are arranged close to each other.
Innovation Solution
A detection device with a control circuit that adjusts the light emission of the light source to ensure photodiodes receive light within their measurement range by varying the lighting time or current value based on their distance from the source, allowing for effective use of the entire detection area even when the optical sensor and light source are close.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the light source and optical sensor are arranged close to each other, then the device size is reduced and detection speed is improved, but the photodiodes closer to the light source are illuminated at excessively high brightness levels that exceed the measurement range
Solution Approach 1:
The patent applies local quality by making different regions of the optical sensor have different light-receiving characteristics. Specifically, the optical sensor includes a light-receiving section closer to the light source with lower light-receiving sensitivity and a light-receiving section farther from the light source with higher light-receiving sensitivity. This allows each region to operate within its optimal measurement range despite the varying light intensity distribution.
Solution Approach 2:
The patent changes the light-receiving sensitivity parameter of different regions of the optical sensor. By adjusting the sensitivity characteristics of photodiodes in different locations, the system can accurately detect light intensity across the entire sensor array even when the light source is positioned close to the sensor, thereby resolving the measurement range issue.
2Device complexity
If the light source and optical sensor are arranged close to each other, then the device structure is simplified, but the photodiodes farther from the light source are illuminated at excessively low brightness levels that do not reach the measurement range
Solution Approach 1:
The patent applies local quality by making different regions of the optical sensor have different light-receiving characteristics. Specifically, the optical sensor includes a light-receiving section closer to the light source with lower light-receiving sensitivity and a light-receiving section farther from the light source with higher light-receiving sensitivity. This allows each region to operate within its optimal measurement range despite the varying light intensity distribution.
Solution Approach 2:
The patent changes the light-receiving sensitivity parameter of different regions of the optical sensor. By adjusting the sensitivity characteristics of photodiodes in different locations, the system can accurately detect light intensity across the entire sensor array even when the light source is positioned close to the sensor, thereby resolving the measurement range issue.
3Ease of manufacture
If photodiodes are illuminated at excessively high or low brightness levels, then the device can be simpler to manufacture, but measurement accuracy is lost
Solution Approach 1:
The patent applies local quality by making different regions of the optical sensor have different light-receiving characteristics. Specifically, the optical sensor includes a light-receiving section closer to the light source with lower light-receiving sensitivity and a light-receiving section farther from the light source with higher light-receiving sensitivity. This allows each region to operate within its optimal measurement range despite the varying light intensity distribution.
Solution Approach 2:
The patent changes the light-receiving sensitivity parameter of different regions of the optical sensor. By adjusting the sensitivity characteristics of photodiodes in different locations, the system can accurately detect light intensity across the entire sensor array even when the light source is positioned close to the sensor, thereby resolving the measurement range issue.
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
Enables accurate detection of biometric information such as pulse waves and blood oxygen saturation levels by ensuring photodiodes receive suitable light intensities, overcoming the limitations of high or low brightness levels.
Implementation Method 1
an optical sensor that includes a plurality of photodiodes provided in a matrix having a row-column configuration
Data Source
AI summary
According to an aspect, a detection device includes: a housing; an optical sensor including photodiodes; a light source disposed in the housing so as to be close to an end of the optical sensor; and a control circuit configured to control light emission of the light source. The optical sensor includes gate lines arranged in a first direction away from the light source and electrically coupled to the photodiodes. The control circuit is configured to control the light emission of the light source such that, when the photodiodes are sequentially driven on a gate line basis, a total amount of light of the light source when detected by the photodiodes driven by the gate line closest to the light source is smaller than the total amount of light of the light source when detected by the photodiodes driven by the gate line farthest from the light source.