Adaptive Illumination Optical System for High-Contrast Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional high-dynamic range (HDR) photography techniques struggle with capturing scenes with high brightness differences, leading to over-exposure or under-exposure issues, especially in dynamic scenes, and are impractical for video mode, while alternative HDR image sensors face limitations in depth and efficiency.
Innovation Solution
An optical system with an active light-controlling element, comprising multiple sub-elements that adjust light levels in specific zones of the image sensor, using electro-chromic windows, liquid crystals, or nanocrystals, controlled by a hardware controller to optimize light transmission and reduce brightness differences across the image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If traditional HDR photography captures multiple images with different exposures, then dynamic range is improved, but device complexity and processing complexity increase
Solution Approach 1:
The patent applies dynamics by making the optical system adjustable through variable aperture stops that can change size dynamically. This allows the system to adapt to different lighting conditions in real-time, capturing high dynamic range scenes with a single exposure by physically controlling light transmission rather than requiring multiple static images to be processed later.
Solution Approach 2:
The patent implements preliminary action by pre-positioning multiple variable aperture stops at different locations in the optical path before light reaches the sensor. These stops are configured in advance to create specific illumination patterns, allowing the system to capture balanced exposure across high-contrast scenes in a single shot without requiring post-capture processing of multiple images.
2Illumination intensity
If exposure time is adjusted for HDR, then dynamic range is improved, but motion blur increases affecting moving objects
Solution Approach 1:
The patent uses dynamic aperture control to adjust light transmission in real-time during a single exposure, rather than using long exposure times. The variable aperture stops can rapidly adjust their opening size to control illumination levels, allowing the sensor to capture high dynamic range scenes with short exposure times that freeze motion and maintain image sharpness.
3Illumination intensity
If aperture size is adjusted for HDR, then dynamic range is improved, but depth of focus changes making processing complicated
Solution Approach 1:
The patent segments the aperture control function by placing multiple independent variable aperture stops at different locations in the optical path. Each stop can be controlled independently to manage light transmission for different spatial zones or wavelength ranges, allowing precise control over the illumination pattern reaching the sensor while maintaining consistent depth of focus across the entire image.
Solution Approach 2:
The patent applies local quality by enabling different aperture stops to have different transmission characteristics tailored to specific needs. For example, certain stops can be optimized for specific wavelength ranges or spatial regions, allowing each part of the optical system to contribute differently to the overall image quality while maintaining consistent focusing properties across the entire field of view.
4Illumination intensity
If photochromic glass is used for light control, then light transmission control is improved, but application in complex optical systems is limited
Solution Approach 1:
The patent replaces static photochromic glass with dynamic variable aperture stops that can be actively controlled through electronic mechanisms. This allows real-time adjustment of aperture size and position, providing superior adaptability to different optical configurations and imaging scenarios compared to passive photochromic materials, while enabling integration into complex multi-element optical systems.
Solution Approach 2:
The patent segments the light control function across multiple independent aperture stops rather than relying on a single photochromic element. This segmentation allows each stop to be optimized for specific functions (e.g., different wavelength ranges, spatial zones) and enables flexible configuration within complex optical systems, greatly enhancing versatility and compatibility.
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 active light-controlling element allows for improved dynamic range in single-capture photography, reducing over-exposure and under-exposure issues, enabling higher depth images and more efficient HDR imaging without the drawbacks of traditional methods, and can be applied to both still images and video.
Implementation Method 1
Photochromic glass, also known as smart glass or dynamic glass, is one way to control the amount of light through an optical surface, changing the transmission and reflection percentage of incoming rays of light depending on an applied voltage on its electrodes.
Implementation Method 2
The active light-controlling element generally includes multiple sub-elements allowing to adjust the light level in sub-zones of the image that reach the image sensor of the camera
Data Source
AI summary
A method for controlling an optical system including at least one active light-controlling element to better control the illumination of a scene when imaged on an image sensor is presented. This active light-controlling element is used to control the amount of light in an image zone depending on an electric signal from a controller. This allows imaging scenes with bright objects without over-exposure or scenes with dark objects without under-exposure on the image sensor. After image processing to reverse the effect of the active light-controlling element, the resulting processed images have an enhanced depth without the drawbacks associated to traditional HDR imaging. The method can use any shape of sub-elements in the active light-controlling element depending on the application. The method can also be used with multiple active light-controlling surfaces to further control the light on the image sensor, including separating the colors in the image.