Lens-less Optical Position Sensor Using Aperture and Photodiodes
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Solution Overview
Problem
Traditional optical position sensitive detectors require external lenses, which occupy space and increase costs, limiting their miniaturization and efficiency in detecting and tracking light sources.
Innovation Solution
A lens-less optical detector design featuring an integrated circuit with an aperture and electrically isolated photodetectors, where the aperture and photodetectors are monolithically manufactured to accurately measure the angular position of light sources without the need for external lenses, using photocurrents to quantify light and calculate the angle of incidence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional optical lenses are used to focus light on the detector surface, then accurate angular location measurement is achieved, but the device size increases due to the required separation between lens and detector
Solution Approach 1:
The patent extracts and removes the external optical lens from the system entirely. Instead of using a separate lens component positioned at focal length distance, the invention integrates the focusing function directly into the detector structure through microlenses formed on the detector surface, eliminating the need for the space-consuming external lens assembly while maintaining measurement accuracy
Solution Approach 2:
The patent nests the optical focusing function within the detector itself by forming microlenses directly on the detector surface. This nesting approach allows the focusing function to be embedded within the detector structure rather than requiring external space, effectively reducing device volume while preserving angular location measurement capability
2Reliability
If external optical lenses are used in the detector, then light focusing capability is provided, but the manufacturing cost increases
Solution Approach 1:
The patent merges the light focusing function with the detector structure by integrating microlenses directly onto the detector surface. This consolidation eliminates the need for separate external lens components and their associated mounting, alignment, and assembly processes, thereby reducing manufacturing complexity and cost while maintaining reliable light focusing capability
Solution Approach 2:
The detector structure is designed to perform multiple functions: it serves as both the light detection element and the optical focusing element through the integrated microlenses. This multi-functionality eliminates the need for separate dedicated lens components, reducing overall system complexity and manufacturing cost while ensuring reliable optical performance
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 design allows for compact, cost-effective detection and tracking of light sources, improving accuracy and reducing space and cost constraints while enabling efficient light collection and precise angle calculation.
Implementation Method 1
at least two electrically isolated photodetectors, which may be aligned with respect to the aperture so that a quantity of the incident light from a light source detected at each of the photodetectors changes as an angle of the incident light changes
Data Source
AI summary
An optical detector may include an aperture, at least two photodetectors, and a measuring arrangement to quantify light detected at the photodetectors after passing through the aperture without the need for a lens. The aperture may be positioned between a light source and the two photodetectors to allow light from a light source to pass through the aperture to the photodetectors. The photodetectors may include PIN junction photodiodes and may be electrically isolated from each other, positioned next to each other in a side-by-side configuration, and then aligned with the aperture so that a proportion of the quantified light detected at the photodetectors changes as an angle of light from the light source incident to the aperture changes. Optical detectors and methods are provided.