Optical Sensor Light Scatterers Reduce Interference
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Solution Overview
Problem
Existing detection devices face challenges in achieving high accuracy due to light interference from front lights, which reduces contrast and affects detection precision.
Innovation Solution
A detection device is designed with an optical sensor, a light guide plate, a light source, and light scatterers. The light scatterers are arranged between the optical sensor and the light guide plate to scatter light propagating in the light guide plate, reducing light interference and enhancing detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a front light is provided between the object and photodiodes, then illumination intensity is improved, but measurement precision deteriorates due to direct light entering photodiodes reducing contrast
Solution Approach 1:
A light guide plate is introduced as an intermediary component between the front light and the photodiodes. The light guide plate guides light from the front light to the object while preventing direct light from entering the photodiodes, thus resolving the contradiction between providing sufficient illumination and avoiding direct light interference.
Solution Approach 2:
The harmful direct light path is extracted and separated from the useful light path. By using the light guide plate's optical properties, the direct light that would reduce contrast is diverted away from the photodiodes, while still maintaining illumination of the object.
2Illumination intensity
If a light diffusion structure with triangular section is provided on the light guide plate, then light distribution is improved, but measurement precision deteriorates due to refracted light entering photodiodes
Solution Approach 1:
The refracted light that would enter the photodiodes and reduce detection accuracy is extracted and removed from the optical path. The light diffusion structure is designed to distribute light uniformly across the object surface while preventing refracted light from reaching the photodiodes.
3Area of stationary object
If light sources are positioned on the lateral side of the light guide plate, then illumination coverage is improved, but device complexity increases due to additional light scatterer structures
Solution Approach 1:
The light source positioning is shifted from a vertical arrangement (directly above the photodiodes) to a lateral arrangement (side direction). This dimensional change allows light to illuminate the object from the side, improving coverage while the light guide plate manages the light paths to prevent interference with the photodiodes.
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 proposed configuration effectively reduces light interference, improving the accuracy of detection by ensuring that less refracted light enters the photodiodes, thereby enhancing the overall detection precision.
Implementation Method 1
a light guide plate that is disposed on one side in a first direction of the optical sensor so as to overlap the optical sensor and has a light-transmitting property
Implementation Method 2
a plurality of light scatterers that are arranged between the optical sensor and the light guide plate so as not to overlap the photodetection elements as viewed in the first direction and are configured to scatter the light propagating in the light guide plate
Data Source
AI summary
According to an aspect, a detection device includes: an optical sensor including a plurality of photodetection elements arranged in a planar configuration; a light guide plate that is disposed on one side in a first direction of the optical sensor so as to overlap the optical sensor and has a light-transmitting property; a light source that is disposed adjacent to the light guide plate in a second direction intersecting the first direction and is configured to emit light to a side surface of the light guide plate; and a plurality of light scatterers that are arranged between the optical sensor and the light guide plate so as not to overlap the photodetection elements as viewed in the first direction and are configured to scatter the light propagating in the light guide plate.