Bridge-Circuit Light Sensing Device for Disturbance Rejection
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Solution Overview
Problem
Existing light sensing devices are susceptible to disturbances such as temperature and magnetic fields, which affect the accuracy of light intensity measurements.
Innovation Solution
A light sensing device is designed with a bridge circuit configuration using four optical sensors, where only one sensor is exposed to the light to be measured, while the others are not, and the resistance values of all sensors are balanced to cancel out the effects of disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single optical sensor is used to measure light intensity, then the device complexity is reduced, but the measurement precision deteriorates due to disturbance influences
Solution Approach 1:
The measurement system is segmented into multiple independent optical sensors (first optical sensor and second optical sensor) that separately measure different aspects of light intensity. This segmentation allows the system to distinguish between light intensity variations and disturbance influences by comparing measurements from multiple sensors, thereby improving measurement precision without requiring a single complex sensor design.
Solution Approach 2:
A second optical sensor is introduced as a copy of the first optical sensor to measure light intensity under the same conditions. By having identical sensors measure simultaneously, the system creates redundant data that can be used to eliminate disturbance influences through differential measurement, improving precision while maintaining relatively simple sensor designs.
2Measurement precision
If multiple optical sensors are used to cancel disturbance effects, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
Multiple optical sensors are merged into a unified measurement system where the outputs of the first and second optical sensors are combined through signal processing. The system integrates these sensors to cancel disturbance effects by comparing and differentiating their measurements, achieving improved precision while managing device complexity through coordinated operation rather than independent complex subsystems.
3Device complexity
If all optical sensors are exposed to light, then the light intensity measurement is simplified, but the reliability deteriorates due to disturbance influences
Solution Approach 1:
Different parts of the sensor array are given different functional qualities: the first optical sensor is positioned to measure light intensity, while the second optical sensor is positioned to measure disturbance influences. This local differentiation of measurement functions allows each sensor to be optimized for its specific purpose, improving reliability by separating the measurement of light intensity from the measurement of disturbance effects.
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 minimizes the impact of disturbances, ensuring accurate light intensity measurements by isolating the sensor affected by light from those influenced by environmental factors.
Implementation Method 1
a photosensitive layer that is provided between the first electrode and the second electrode and generates a voltage in a case where light is applied to the photosensitive layer
Implementation Method 2
A magnetic state of a magnetic element changes and a resistance value thereof changes when the magnetic element is irradiated with light
Data Source
AI summary
The light sensing device includes a first terminal, a second terminal, a third terminal, a fourth terminal, a first element, a second element, a third element, and a fourth element. The first terminal, the first element, the second element, and the second terminal form a first path. The first terminal, the third element, the fourth element, and the second terminal form a second path. The third terminal is connected between the first element and the second element. The fourth terminal is connected between the third element and the fourth element. Each of the first element, the second element, the third element, and the fourth element includes a photosensitive layer that. The photosensitive layer of the first element is irradiated with light to be measured. The photosensitive layers of the second element and the third element are not irradiated with the light to be measured.