Bispectral Device Optical Path Folding
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Solution Overview
Problem
Current airborne infrared missile firing systems lack the capability to formally identify targets, such as light armored vehicles, at maximum range without causing friendly fire, due to limitations in resolution and stabilization, which require expensive and fragile mechanical components and large pupil sizes, and passive infrared imaging technologies impose bulk constraints that hinder range requirements.
Innovation Solution
A bispectral device with a primary and secondary mirror, dichroic semi-reflecting plates, and a double bending system that allows for simultaneous active imaging and infrared recognition without moving parts, enabling identification and recognition functions across different wavelength bands without altering the optical field, thus integrating into airborne systems with improved performance and reduced size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If passive infrared imaging technologies are used to increase the range, then the range is improved, but the device size and bulk increase significantly
Solution Approach 1:
The optical system is segmented into multiple reflective surfaces (primary mirror, secondary mirror, tertiary mirror) that work together to achieve the desired optical path folding. This segmentation allows the system to maintain a compact form factor while achieving the necessary optical path length for long-range imaging.
Solution Approach 2:
The patent employs a folded optical path that utilizes three-dimensional space efficiently. By reflecting light between multiple mirrors at different orientations, the system achieves a long effective optical path within a compact physical footprint, transitioning from a linear arrangement to a multi-dimensional folded configuration.
2Measurement precision
If the pupillary diameter is increased to improve resolution, then the resolution is improved, but the device size increases
Solution Approach 1:
The folded optical design allows the optical path to extend in multiple directions rather than requiring a large linear aperture. This enables the system to achieve high resolution through an extended folded path length rather than simply increasing the pupillary diameter, thereby maintaining a compact device size.
3Adaptability or versatility
If field changers with moving parts are integrated to change the field, then the field adjustment capability is improved, but the reliability decreases due to fragility and vibration sensitivity
Solution Approach 1:
The patent replaces mechanical field-changing components with a fixed multi-mirror optical system. The field adjustment capability is achieved through the geometric arrangement of mirrors rather than mechanical movement, eliminating fragile moving parts and improving reliability in vibratory airborne environments.
4Measurement precision
If expensive optronic and mechanical devices are added to improve resolution and stabilization, then the resolution and stabilization are improved, but the device complexity and cost increase
Solution Approach 1:
The patent achieves improved resolution and stabilization through a purely optical reflective system rather than requiring expensive mechanical stabilization devices or complex optronic components. The fixed mirror arrangement provides inherent stability while maintaining high resolution capability.
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 device achieves target identification and recognition at long distances with improved performance in complex backgrounds and adverse weather, offering better size-to-performance ratios and ocular safety, while maintaining a compact footprint, thus overcoming the limitations of prior systems.
Implementation Method 1
a primary mirror (M1), a secondary mirror (M2)... the primary mirror being adapted to receive the incident light flux and reflect it towards the secondary mirror
Implementation Method 2
the secondary mirror being adapted to receive the luminous flux from the primary mirror and to reflect it towards the first semi-reflecting plate
Implementation Method 3
a first dichroic semi-reflecting plate (21)... the first semi-reflecting plate being adapted to transmit the first band of wavelengths towards an objective through the second semi-reflecting plate, and for reflecting the second band of wavelengths towards the double bending system
Implementation Method 4
a second dichroic semi-reflecting plate (22)... the second semi-reflecting plate being further adapted to receive the second band of wavelengths from the double bending system, and to reflect the second band of wavelengths towards the objective
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The device has a system for double bending a band of wavelengths, and a dichroic semi-reflective blade (21) adapted to transmit another band (lambda 1) of wavelengths toward a bispectral lens (3) through another dichroic semi-reflective blade (22) and to reflect the former band of wavelengths toward the system. The latter semi-reflective blade is adapted to receive the latter band of wavelengths from the system and to reflect the latter band of wavelengths toward the lens, where the two bands of wavelengths are distinct from each other.