Polarized Pulse Light Imaging for Rain
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Solution Overview
Problem
Conventional imaging devices struggle to capture clear images in environments with precipitation due to the limitations of existing methods, which require high-resolution, high-accuracy, and expensive camera systems to account for falling objects and water droplets, and are restricted to short distances with reduced irradiation intensity and inability to remove reflection signals from water droplets.
Innovation Solution
An imaging device utilizing a light source that emits pulse light, a radiation unit that scans and polarizes the light perpendicular to the scanning direction, and an imaging unit with a polarization filter that transmits light parallel to the scanning direction for synchronized exposure, allowing for effective image capture over longer distances by reducing the impact of raindrops and fog.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-resolution and high-accuracy camera systems are used to photograph the target visual field and analyze images to extract raindrop positions, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The invention extracts only the necessary information (raindrop positions) using a simpler polarized light imaging system rather than requiring full high-resolution camera systems and complex image analysis, thereby reducing device complexity while maintaining measurement precision
Solution Approach 2:
The patent uses inexpensive polarized filters and simple imaging components instead of expensive high-definition camera systems, achieving the same functional goal with much lower cost and simpler hardware
2Area of stationary object
If the entire visual field is irradiated with laser light, then illumination coverage is improved, but irradiation intensity is significantly lowered in distant places, restricting measurement range to short distance
Solution Approach 1:
The patent uses pulsed laser illumination instead of continuous illumination, allowing for higher peak intensities at distant locations while maintaining safe average power levels, thereby extending the measurement range without sacrificing illumination coverage
Solution Approach 2:
The invention changes the temporal parameters of light emission from continuous to pulsed mode, and adjusts the polarization state to optimize both illumination intensity at distance and effective detection, resolving the contradiction between coverage area and intensity
3Reliability
If polarized light with the same direction as the light source is received to suppress blooming, then image quality is improved, but direct reflection light from water droplets cannot be removed, leaving noise components
Solution Approach 1:
The patent applies different polarization filtering strategies to different parts of the optical path: the illumination uses one polarization state while the detection uses an orthogonal polarization state, allowing selective suppression of water droplet reflections while maintaining object signal quality
Solution Approach 2:
The invention creates asymmetry in the polarization configuration between illumination and detection paths, with the light source emitting polarized light in one direction and the imaging unit detecting polarized light in the orthogonal direction, enabling discrimination between direct water droplet reflections and object reflections
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 solution enables clear image capture over a relatively long distance in precipitation environments by enhancing irradiation intensity and reducing multireflection interference, thus improving the imaging device's performance and usability in rainy conditions.
Implementation Method 1
a light source that emits pulse light
Implementation Method 2
spreads, in a direction perpendicular to the scanning direction, the pulse light for the scanning when the scanning is performed, and radiates the pulse light, which is in a state of being polarized in the direction perpendicular to the scanning direction
Implementation Method 3
an imaging unit that receives reflection light from the object
Implementation Method 4
a polarization filter that transmits light that is included in the reflection light received by the imaging unit and polarized to be parallel to the scanning direction
Data Source
AI summary
Provided is an imaging device that is able to obtain a clear image in a relatively long distance in an environment of precipitation. A rainy weather camera includes: a light source that emits pulse light; a fan-shaped pulse light radiation unit that performs scanning in one direction with the pulse light emitted by the light source, spreads, in a direction perpendicular to the scanning direction, the pulse light for the scanning when the scanning is performed, and radiates the pulse light, which is in a state of being polarized in the direction perpendicular to the scanning direction, to an object; an imaging unit that receives reflection light from the object and performs exposure to a pixel; and a polarization filter that transmits light that is included in the reflection light received by the imaging unit and polarized to be parallel to the scanning direction. The imaging unit performs exposure only to a pixel which is synchronized with the scanning with the pulse light.