Semi-Transparent Detector Array With Tunable Filtering for Night Vision

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Solution Overview

Problem

Traditional nightvision systems have a limited dynamic range, causing dimly illuminated objects to be obscured when brightly illuminated objects are present in the same scene, leading to loss of detail and contrast issues.

Innovation Solution

A nightvision system incorporating a transparent optical device with active semiconductor chip regions and a tunable filter array that processes brightness maps to filter input light, allowing for improved contrast and dynamic range by transmitting specific spectra and applying controlled filtering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a nightvision system uses automatic brightness controls to compensate for bright objects, then the bright objects are managed, but dimly illuminated objects lose detail and contrast

Engineering Contradiction:
Improvebrightness managementVSAvoiddetail loss in dim objects
Core Design Contradiction:
Illumination intensityVSLoss of information

Solution Approach 1:

The patent divides the optical path into multiple spectral channels using dichroic mirrors and beam splitters. Different wavelength ranges are separated and processed independently, allowing selective filtering of bright objects in specific spectra while preserving dim objects in other spectral regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different filtering characteristics to different spectral regions. By assigning unique filter profiles to each wavelength channel, the system optimizes contrast and brightness management locally for each spectrum rather than applying a uniform filter across all wavelengths.

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If a nightvision system captures all light in the visible spectrum, then maximum light is available for imaging, but overly bright lights cause damage and halo effects

Engineering Contradiction:
Improvelight capture efficiencyVSAvoiddamage from bright lights and halo effects
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent dynamically adjusts filter characteristics based on detected brightness levels. When bright objects are detected in specific spectral regions, the system modifies filter transmission properties for those wavelengths while maintaining full sensitivity in unaffected spectral ranges.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts potentially harmful bright light into useful information by using it to trigger selective filtering. The brightness of problematic objects serves as a signal to activate spectral filtering that protects the sensor while preserving information from other spectral regions.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If a nightvision system uses a single spectrum for imaging, then the system is simpler, but the dynamic range is limited compared to the human eye

Engineering Contradiction:
Improvesystem simplicityVSAvoiddynamic range
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent makes a single imaging system capable of operating across multiple spectral functions simultaneously. Each spectral channel can be independently optimized for different lighting conditions, allowing the system to adapt to various environments while maintaining a unified device architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 scene dynamic range, prevents damage from overly bright lights, reduces halo effects, and optimizes image quality by filtering out excessive brightness, thereby improving object detection and identification capabilities.

Implementation Method 1

The transparent optical device includes transparent regions formed in the active area which are transparent to light in the first spectrum to allow light in the first spectrum to pass through from the underlying device to a user

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

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 performed by the image processor

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentEP4261590A1Semi-transparent detector array and spatially tunable filter array
Publication Date: 2023.10.18 L3HARRIS TECH INC
  • EP4261590A1 patent drawingFigure 1
  • EP4261590A1 patent drawingFigure 2~3A
  • EP4261590A1 patent drawingFigure 3B

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.