Lens Position Detection Using Magneto-Resistive Sensors
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Solution Overview
Problem
Conventional autofocus systems in cameras consume high power and have limited accuracy in determining lens position, which affects distance measurement and parallax correction in multi-camera setups.
Innovation Solution
A system comprising first and second sensor components, connected to a processor, measures the angle between them to determine the rotating lens position, allowing for accurate calculation of distances and parallax correction between cameras, using magneto-resistive sensors or capacitor plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrical motors are used to move the lens and control signals are used to infer lens position, then the lens position can be determined, but the system consumes high power and has limited accuracy
Solution Approach 1:
The patent replaces the electrical motor system with a passive mechanical sensing system. Magneto-resistive sensors detect the position of a magnet attached to the lens barrel through non-contact magnetic field sensing, eliminating the need for powered motors while achieving high measurement precision through magnetic field detection
Solution Approach 2:
The patent introduces a magnet as an intermediary element attached to the lens barrel. This magnet serves as a passive marker that modulates the magnetic field detected by magneto-resistive sensors, enabling accurate position detection without requiring active power consumption from the lens driving mechanism
2Measurement precision
If conventional sensor systems are used to determine lens position, then basic position detection is achieved, but accuracy and energy efficiency are insufficient
Solution Approach 1:
The patent replaces conventional electrical motor systems with a magnetic field-based sensing system. Magneto-resistive sensors provide high-resolution position detection by measuring changes in magnetic field strength as the lens barrel moves, achieving superior measurement precision and system reliability without mechanical contact or power consumption
Solution Approach 2:
The lens barrel itself serves as part of the sensing system by carrying a magnet that passively indicates its position. The existing mechanical movement of the lens barrel automatically modulates the magnetic field, eliminating the need for separate actuators or powered sensing mechanisms while providing continuous position information
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 method provides precise and energy-efficient determination of lens position, enabling effective parallax correction between cameras, especially in systems like LWIR and SWIR cameras, improving image alignment and composite image quality.
Implementation Method 1
A first magneto-resistive sensor is disposed on the housing. A second magneto-resistive sensor is disposed on the rotating lens component.
Data Source
AI summary
A system for determining lens position includes a first sensor component disposed on a stationary housing of a camera. A second sensor component is disposed on a rotating lens component of the camera. A processor is operatively connected to the first and second sensory components to identify the position of the rotating lens component of the camera based on an angle between the first and second sensor components.