Imaging Device Using Fibre Optic Faceplates for Wide Field of View
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current miniature near-infrared imaging devices are bulky, costly, and suffer from chromatic aberrations and astigmatism due to the use of prisms, and holograms are complex and expensive to segment for wide field-of-view applications, while conventional planar sensors require beam deflection optics that are inefficient.
Innovation Solution
A miniature imaging device using a planar sensor with fibre optic faceplates that modify angled surfaces to reduce beam deviation, allowing for a wide field of view with varying angular resolution across the field, achieved through a configuration of converging lenses and fibre optic faceplates with facets that receive light from associated lenses, and optionally using scattering or prismatic surfaces to enhance coupling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If prisms are used to deflect beams prior to entering the lens, then beam deflection is achieved, but the device becomes bulky and chromatic aberrations occur
Solution Approach 1:
The patent replaces the mechanical prism-based beam deflection system with a holographic optical element that uses diffraction theory to achieve beam deflection. This substitution eliminates the need for bulky prism structures while maintaining the beam deflection function and reducing chromatic aberrations through holographic beam steering.
Solution Approach 2:
The patent changes the optical parameter approach by using holographic phase modulation instead of geometric prism refraction. The hologram encodes beam deflection information in its phase structure, allowing angular selection and beam steering without physical beam blocking or refraction, thus reducing device volume.
2Ease of operation
If prisms are provided at the sensor surface, then beam deflection is achieved, but additional coma and astigmatism are generated
Solution Approach 1:
The patent replaces the prism-based beam deflection mechanism with a holographic element that uses diffraction to steer beams. This substitution eliminates the geometric optical path changes that cause coma and astigmatism, while maintaining beam deflection capability and improving image quality across the field of view.
3Productivity
If holograms are segmented to obtain high deflection efficiencies over a wide field of view, then beam deflection efficiency is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies segmentation by dividing the holographic element into multiple regions, each responsible for a specific field of view. This allows the wide field of view requirement to be met while maintaining manageable manufacturing complexity through modular design and standard holographic fabrication processes.
4Ease of manufacture
If a planar sensor with conventional optics is used, then manufacturing simplicity is maintained, but beam deflection efficiency is reduced
Solution Approach 1:
The patent replaces conventional mechanical beam deflection optics with a holographic element that achieves beam deflection through diffraction. This maintains the simplicity of a planar sensor configuration while dramatically improving beam deflection efficiency and enabling wide field of view operation.
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 enables a compact, cost-effective near-infrared imaging device with a 120° field of view and improved angular resolution near the center, reducing manufacturing complexity and chromatic aberrations, while maintaining high image quality across the field of view.
Implementation Method 1
light guiding means comprising a plurality of light guides for directing light received via said at least one lens toward said sensor
Implementation Method 2
any surface of the faceplate with an angled surface which is not orthogonal to the longitudinal axis of the optical fibres is modified in order to facilitate guiding of incoming light in order to overcome the fact that beam deviation due to refraction at the angled surface will be reduced
Data Source
Figure 1A~2C
Figure 3
Figure 4A~4C
AI summary
This invention relates to an imaging device, particularly but not exclusively for use in a targeting sensor for missile seekers. The invention provides an imaging device comprising: at least one lens; a substantially planar sensor having a plurality of pixels; light guiding means for directing light received via said lenses toward said sensor; in which said light guiding means comprises a plurality of light guides.