Variable IR Illumination Beam Profile via Dual Emitter Power Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional IR illuminators with varifocal lenses produce a fixed illumination pattern, leading to suboptimal IR images due to non-uniform illumination at varying focal lengths, resulting in wasted illumination power or sensor saturation.
Innovation Solution
A method and apparatus using at least two IR emitters with different beam profiles (wide and narrow) that combine to produce an IR beam with a variable linear profile, allowing for selection of a power ratio to optimize irradiance and standard deviation at specific focal lengths, ensuring maximum power delivery within the field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed illumination pattern is used for all focal lengths, then the device complexity is reduced, but the illumination uniformity and image quality deteriorate
Solution Approach 1:
The illumination system is segmented into multiple IR emitters, each producing beam components with different linear profiles (wide beam and narrow beam). By combining these segmented beam components through additive superposition, the system achieves variable illumination patterns that adapt to different focal lengths without requiring complex mechanical adjustment mechanisms.
Solution Approach 2:
Multiple beam components from different IR emitters are merged through optical superposition to create a combined illumination pattern. The wide beam component provides broad coverage while the narrow beam component concentrates energy, and their merger produces an optimized illumination pattern that maintains uniformity across varying focal lengths.
2Illumination intensity
If the illumination pattern is optimized for a specific field of view, then the illumination intensity for that specific view is maximized, but the adaptability to other field of views deteriorates
Solution Approach 1:
The illumination system dynamically adapts its pattern by adjusting the relative power distribution between multiple IR emitters based on the current focal length. The control system modifies the illumination characteristics in real-time, allowing the same hardware configuration to optimize performance across a range of field of views rather than being fixed for a single view.
Solution Approach 2:
The illumination system achieves multi-functionality by using multiple IR emitters that can be selectively activated or adjusted in power. This universal design allows the system to serve multiple field of view requirements with a single configuration, eliminating the need for separate optimized illuminators for each focal length.
3Illumination intensity
If a narrow beam component is used to concentrate illumination power, then the irradiance is increased, but the standard deviation and non-uniformity increase
Solution Approach 1:
Different regions of the illumination beam are assigned different qualities through the use of multiple emitters with distinct linear profiles. The wide beam emitter provides uniform broad coverage in peripheral regions, while the narrow beam emitter concentrates energy in the central region. This local differentiation of beam qualities allows the system to achieve high central irradiance while maintaining overall uniformity through the combined pattern.
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 provides improved uniformity and irradiance of the IR beam across varying focal lengths, maximizing signal-to-noise ratio and preventing wasted illumination power, thereby capturing higher quality IR images.
Implementation Method 1
a first IR emitter operable to emit a wide beam component of the IR beam, and a second IR emitter operable to emit a narrow beam component of the IR beam
Implementation Method 2
combining the generated wide and narrow beam components
Data Source
AI summary
A method for generating an infrared (IR) beam for illuminating a scene to be imaged comprises providing at least two IR emitters, including a first IR emitter operable to emit a wide beam component of the IR beam, and a second IR emitter operable to emit a narrow beam component of the IR beam, wherein the wide beam component has a linear profile that has a lower standard deviation than a linear profile of the narrow beam component. The method also comprises selecting a desired linear profile for the IR beam, and selecting a power ratio of power directed to the first IR emitter and power directed to the second IR emitter that produces the IR beam with the desired linear profile when the narrow beam component and wide beam component are combined.