Backward-Propagating Autoalignment System for Wide Field of View

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Solution Overview

Problem

Multi-function sensor systems face limitations in auto-alignment systems that operate over a limited field of view and introduce additional error sources due to the use of multiple auto-alignment beams and auxiliary optical paths, leading to reduced accuracy and undesired aperture obscurations.

Innovation Solution

The implementation of a backward propagating auto-alignment system with a shared aperture component and a single auto-alignment beam that utilizes common all-reflective optical paths to provide alignment over a wide field of view, minimizing error sources by reflecting the auto-alignment beam through a passive imager and position sensing detector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a forward propagating auto-alignment system is used, then alignment can be established, but the field of view is limited and aperture obscurations occur

Engineering Contradiction:

Improvealignment accuracyVSAvoidfield of view

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent inverts the traditional forward-propagating auto-alignment approach by implementing a backward-propagating system. The auto-alignment beam travels through the passive imager in the opposite direction of the transmit beam, allowing the system to utilize the full aperture and wide field of view of the passive imager while maintaining alignment accuracy. This inversion resolves the contradiction by enabling wide FOV operation without the limitations of forward-propagating systems.

Inventive Principle:

Principle #13The other way round (Inversion)

2Measurement precision

If multiple auto-alignment beams and auxiliary optical paths are used, then alignment can be established, but device complexity and error sources increase

Engineering Contradiction:

Improvealignment accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the auto-alignment function with the existing passive imager and shared aperture component. By combining these functions into a single integrated system where the auto-alignment beam shares the same optical path as the passive imaging, the system eliminates the need for separate auxiliary optical paths and multiple alignment beams. This merging reduces device complexity while maintaining alignment accuracy through the unified optical architecture.

Inventive Principle:

Principle #5Merging (Combining)

3Area of stationary object

If a shared aperture component is used, then aperture utilization is improved, but beam path separation becomes challenging

Engineering Contradiction:

Improveaperture utilizationVSAvoidbeam path separation

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent employs wavelength division to separate different beam paths within the shared aperture. The transmit beam, receive beam, and auto-alignment beam operate at different wavelengths, allowing them to coexist in the same physical aperture without interference. This wavelength-based separation method enables full aperture utilization while maintaining clear distinction between different optical paths, resolving the challenge of beam path separation.

Inventive Principle:

Principle #32Color changes

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

This configuration allows for accurate sampling of the shared aperture over a wide field of view, reducing errors and improving alignment accuracy by tracing errors to specific channels, enabling quick and precise corrections.

Implementation Method 1

the shared aperture component is a dichroic beam splitter

Methodology Applied

Scientific EffectDichroic beam splitting: Dichroic Filter

Implementation Method 2

the auto-alignment beam is transmitted through the shared aperture component, reflected by the corner cube, and reflected off a back side of the shared aperture component towards the third channel

Methodology Applied

Scientific EffectRetroreflection: Retroreflector

Implementation Method 3

a position sensing detector (PSD) configured to receive the auto-alignment beam from the passive imager

Methodology Applied

Scientific EffectOptical detection: Photoelectric Effect

Data Source

PatentUS11841217B2WFOV backward-propagating active-to-passive autoalignment system

Publication Date: 2023.12.12 RAYTHEON CO

AI summary

A multi-function sensor system including an auto-alignment system. The multi-function sensor system includes a laser module configured to provide a transmit beam and an auto-alignment beam, a shared aperture component, a first channel configured to direct the transmit beam and the auto-alignment beam to the shared aperture component, a second channel configured to receive the transmit beam from the shared aperture component and provide a receive beam to the shared aperture component, and a third channel including a passive imager configured to receive the auto-alignment beam and a first portion of the receive beam from the shared aperture component, wherein the auto-alignment beam propagates through the passive imager to provide an indication of a line of sight (LOS) of the transmit beam relative to a field of view (FOV) of the passive imager.