Covert Reticle Illumination via Wavelength Conversion
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Solution Overview
Problem
Existing optical sights face challenges in providing uniform and reliable reticle illumination without interfering with the observation of the scene, and they often reveal their presence due to light leakage, which can be detected by adversaries.
Innovation Solution
An optical sight design featuring a reticle with a substrate, a relief pattern, and a barrier material opaque to visible light, combined with a wavelength-converting material excited by non-visible light to emit visible light, preventing light leakage and maintaining covert operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If visible light is used to illuminate the reticle, then the reticle is visible to the user, but light leaks out of the optical sight revealing its presence to adversaries
Solution Approach 1:
The patent changes the wavelength parameter of the illumination light from visible to non-visible (ultraviolet or infrared). The reticle is illuminated by non-visible light that cannot be detected by the human eye or conventional detectors, thereby maintaining reticle visibility for the user while preventing detection by adversaries. The reticle material is selected to be transparent or reflective at this non-visible wavelength.
Solution Approach 2:
The patent employs wavelength-converting materials that absorb non-visible excitation light and emit visible light. This allows the reticle to be illuminated by non-visible light (which doesn't leak out and reveal the sight) while the reticle itself appears brightly illuminated in visible light for the user. The wavelength conversion occurs within the reticle structure, converting harmful visible illumination into covert non-visible excitation.
2Object-affected harmful factors
If non-visible light is used to illuminate the reticle, then light leakage is prevented, but the reticle may not be visible to the user
Solution Approach 1:
The patent uses wavelength-converting materials (phosphors, fluorescent materials, or quantum dots) that absorb non-visible excitation light and emit visible light. The reticle is excited by non-visible light that doesn't leak out, while the wavelength-converting material emits visible light that makes the reticle clearly visible to the user. This dual-wavelength approach resolves the contradiction between covert illumination and visible reticle display.
Solution Approach 2:
The wavelength-converting material acts as an intermediary between the non-visible excitation light source and the user's visible light perception. It absorbs the covert non-visible energy and transforms it into visible light that illuminates the reticle markings, allowing the user to see the reticle without the illumination source being detectable by adversaries.
3Use of energy by moving object
If ambient light is used to illuminate the reticle, then energy consumption is reduced, but the illumination is uneven and undependable
Solution Approach 1:
The patent employs a light-pipe or waveguide structure that passively guides ambient light to illuminate the reticle without requiring active illumination components. The light pipe captures ambient light and distributes it uniformly across the reticle through total internal reflection, providing reliable and even illumination without consuming battery power, thus achieving both low energy consumption and high illumination reliability.
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 solution provides a controllably illuminated reticle visible under various conditions without revealing the optical sight's presence to adversaries, ensuring effective aiming while minimizing energy consumption and maintaining performance.
Implementation Method 1
a wavelength-converting material is within the reticle relief pattern such that the layer of the barrier material lies between the wavelength-converting material and the relief surface of the reticle relief pattern. The wavelength-converting material is excitable by a non-visible excitation wavelength of light to emit a visible wavelength of light.
Implementation Method 2
a layer of a barrier material that is opaque to visible light deposited upon the relief surface
Data Source
AI summary
An optical sight includes an optical train with a reticle having a reticle substrate, and a reticle relief pattern in the reticle substrate having a relief surface oriented so that the relief surface faces an output end of the optical sight. A layer of a barrier material that is opaque to visible light is deposited upon the relief surface. There is a wavelength-converting material within the reticle relief pattern that converts a non-visible excitation wavelength to visible light. A light source of the non-visible excitation wavelength controllably illuminates the wavelength-converting material. The optical train prevents the non-visible wavelength from propagating out of the input end of the optical train.