Semi-Transparent Detector Array for Nightvision Dynamic Range
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Solution Overview
Problem
Nightvision systems have a limited dynamic range, obscuring dimly illuminated objects when bright objects are present, leading to loss of scene detail.
Innovation Solution
A transparent optical device is integrated with nightvision systems, capable of detecting brightness maps and performing controlled filtering to enhance contrast and improve dynamic range, using a tunable filter array and image processor to optimize image output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If automatic brightness controls are used to compensate for bright objects, then bright objects are visible, but dimly illuminated objects lose detail and are obscured
Solution Approach 1:
The patent divides the optical path into multiple spectral channels using a dispersive element, separating light into different wavelength ranges. This allows independent processing of bright and dim objects in different spectral bands, preventing the bright object from overwhelming the entire image and preserving detail in dimly illuminated areas.
Solution Approach 2:
The system dynamically adjusts the transmission characteristics of the transparent optical device based on detected brightness levels. By changing optical parameters such as transmission efficiency and filtering characteristics in response to scene conditions, the system can simultaneously preserve details in both bright and dim regions without losing information.
2Use of energy by moving object
If the transparent optical device has high transparency to transmit phosphor screen light, then image transmission is efficient, but detection capability is reduced
Solution Approach 1:
The transparent optical device is segmented into transparent regions for light transmission and active detector regions for light detection. This spatial segmentation allows the device to simultaneously transmit phosphor screen light efficiently while maintaining detection capability in specific areas, resolving the contradiction between transparency and detection.
Solution Approach 2:
The patent merges the transparent optical device with the detector array, combining light transmission and detection functions into a single integrated component. This allows the device to perform both functions simultaneously without compromising either transmission efficiency or detection accuracy.
3Loss of information
If a tunable filter array is added to enhance contrast and dynamic range, then image quality improves, but device complexity increases
Solution Approach 1:
The tunable filter array is integrated with the transparent optical device, merging filtering functionality into the existing optical path. This reduces overall system complexity compared to adding a separate filtering subsystem, while still achieving enhanced contrast and dynamic range through spectral filtering.
Solution Approach 2:
The transparent optical device serves multiple functions: light transmission, light detection, and spectral filtering. By making the device multi-functional, the patent avoids adding separate components for each function, thereby improving image quality without proportionally increasing device complexity.
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
Enhances contrast and dynamic range, protecting the system from bright sources, reducing halos, and improving detection, recognition, and identification capabilities.
Implementation Method 1
The image intensifier has a photocathode. When photons strike the photocathode, electrons are emitted into a vacuum tube
Implementation Method 2
directed towards a microchannel plate to amplify the electrons
Implementation Method 3
The amplified electrons strike a phosphor screen. The phosphor screen is typically chosen such that it emits human visible light when the amplified electrons strike the phosphor screen
Data Source
AI summary
A nightvision system includes an underlying device that provides output light in a first spectrum. A transparent optical device transmits light in the first spectrum from the underlying device through the transparent optical device. The transparent optical device includes an active area of a semiconductor chip. The active area includes active elements that cause the underlying device to detect light from the underlying device and transparent regions formed in the active area which are transparent to the light in the first spectrum to allow light in the first spectrum to pass through from the underlying device to a user. An image processor processes brightness maps produced using light detected by the first plurality of active elements. A tunable filter array coupled to the image processor filters at least a portion of the input light into the underlying device the underlying device based on brightness map processing.