Adaptive IR LED Array for Balanced Scene Illumination
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Solution Overview
Problem
Conventional camera flashes often overexpose objects close to the camera while underexposing those farther away due to inconsistent illuminance profiles, leading to suboptimal lighting in images.
Innovation Solution
An adaptive lighting system utilizing an array of infrared (IR) light-emitting diodes (LEDs) controlled by a microprocessor that captures images, detects faces, and adjusts illuminance profiles based on 3D scene analysis to deliver precise light distribution, ensuring optimal exposure for all objects in the scene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional camera flash is used, then the lighting is simple and the device is compact, but the illuminance profile is inconsistent causing overexposure of close objects and underexposure of distant objects
Solution Approach 1:
The patent divides the light source into multiple independently controllable LED elements arranged in an array. Each LED or group of LEDs can be controlled separately to create different illuminance profiles, allowing precise control over light distribution to resolve the contradiction between consistent illumination and device complexity.
Solution Approach 2:
The patent implements dynamic control of LED current levels based on detected scene characteristics. The system adjusts the intensity and distribution of light from different LED elements in real-time according to the 3D profile and object positions, transforming a static flash into a dynamic adaptive lighting system that maintains consistency without excessive complexity.
2Illumination intensity
If the flash illuminates the entire scene uniformly, then all areas receive light, but close objects become overexposed while distant objects remain underexposed
Solution Approach 1:
The patent applies different current levels to different LED elements based on their position in the array and the detected scene geometry. LEDs directed at closer objects receive lower current while those aimed at distant objects receive higher current, creating locally optimized illumination that balances exposure across the entire scene without requiring excessive manufacturing precision.
Solution Approach 2:
The system uses a camera to capture the scene, processes the image to generate a 3D profile, and uses this information to feedback control the LED current distribution. This closed-loop feedback mechanism enables precise exposure control by continuously adapting the light distribution based on actual scene characteristics, resolving the contradiction between uniform illumination and balanced exposure.
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 system effectively balances light distribution across the scene, preventing overexposure of close objects and ensuring sufficient illumination of distant ones, resulting in better image quality by dynamically adjusting the IR LED current levels according to the 3D profile of the scene.
Implementation Method 1
The IR light source includes an array of IR light emitting diodes (LEDs)
Data Source
AI summary
A method includes capturing a first image of a scene, detecting a face in a section of the scene from the first image, and activating an infrared (IR) light source to selectively illuminate the section of the scene with IR light. The IR light source includes an array of IR light emitting diodes (LEDs). The method includes capturing a second image of the scene under selective IR lighting from the IR light source, detecting the face in the second image, and identifying a person based on the face in the second image.