Optical Detector Annular Reflector Field of Regard
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Solution Overview
Problem
Semi-active laser and similar optical sensor systems have limited field of regard (FOR) and field of view (FOV) due to the size of the photoactive area and system f/number, restricting their operational capabilities.
Innovation Solution
Incorporating a reflector with an annular reflective surface positioned in proximity to the detector array, creating a 'virtual detector' that increases the field of regard by reflecting light beyond the detector's perimeter onto the array, allowing for a larger focal length and aperture without increasing the detector diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the detector diameter is increased to expand the field of regard, then the field of regard and field of view are improved, but the device complexity and cost increase
Solution Approach 1:
A reflector is introduced as an intermediary optical element between the condenser lens and detector array. The reflector redirects light paths to expand the field of regard without requiring a larger detector, effectively mediating between the optical system and the fixed-size detector to achieve enhanced angular coverage
Solution Approach 2:
The patent utilizes the spatial dimension by positioning the reflector at an offset from the optical axis and orienting it at a specific angle. This dimensional arrangement creates additional light paths that fold into the detector's active area, expanding the field of regard without increasing the detector's physical diameter
2Measurement precision
If the focal length is increased to improve resolution, then the aperture area can be increased proportionally, but the device complexity and size increase
Solution Approach 1:
The system achieves variable effective focal length through the reflector's geometric configuration. By adjusting the reflector's position and orientation, the optical path length can be dynamically modified, allowing the system to achieve high resolution equivalent to long focal length without the corresponding increase in physical system size
Solution Approach 2:
The reflector is positioned within the existing optical system footprint, nesting an additional optical path within the original configuration. This allows the effective optical path length to be extended without proportionally increasing the overall device size, maintaining compact form factor while achieving improved resolution
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 enhances the field of regard and field of view, enabling the detection of distant objects outside the original detector area, thereby improving the sensor system's ability to detect and determine the angle of incidence of radiation, and potentially increasing the focal length and aperture area proportionally.
Implementation Method 1
Incorporating a reflector with an annular reflective surface positioned in proximity to the detector array, creating a 'virtual detector' that increases the field of regard by reflecting light beyond the detector's perimeter onto the array
Data Source
AI summary
There is provided in a first form, a detector. The detector includes a photosensitive detector element; and a reflecting surface disposed about and proximal to the photosensitive detector element, wherein the reflecting surface is configured to reflect radiation impinging on the reflecting surface onto the photosensitive detector element; and wherein the reflecting surface is further configured to determine a field of regard greater than a predetermined field of view.