Position Sensor Assembly with Protrusion Magnet for Optical Devices

Solution Overview

Problem

Existing position sensor assemblies in optical devices face challenges in achieving precise position change sensing due to a large gap between the magnet and the sensing unit, which affects the linearity of the signal output, especially in compact designs where the space between them is minimized.

Innovation Solution

The use of a magnet with protrusion units of opposite polarities protruding from each end, forming a concave or inclined surface, and a sensing unit positioned outside the virtual line connecting these protrusions, enhances the linearity of the signal output by ensuring a more uniform magnetic flux density, allowing for precise position change sensing even in compact configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the gap between the magnet and sensing unit is reduced to achieve compact design, then the device size is reduced, but the linearity of signal output deteriorates

Engineering Contradiction:

Improvedevice sizeVSAvoidsignal linearity

Core Design Contradiction:

Volume of moving objectVSMeasurement precision

Solution Approach 1:

The magnet surface is designed with different local geometries (concave curved surface or concave inclined surface) at different positions to create uniform magnetic flux density distribution. The protrusion units at opposite ends have different polarities and the concave surfaces are positioned to ensure that the sensing unit receives uniform magnetic flux, thereby maintaining signal linearity even when the gap is reduced for compact design.

Inventive Principle:

Principle #3Local quality

2Volume of moving object

If the gap between the magnet and sensing unit is reduced to achieve compact design, then the device size is reduced, but the sensing accuracy is compromised

Engineering Contradiction:

Improvedevice sizeVSAvoidposition sensing accuracy

Core Design Contradiction:

Volume of moving objectVSMeasurement precision

Solution Approach 1:

The magnet surface is designed with different local geometries (concave curved surface or concave inclined surface) at different positions to create uniform magnetic flux density distribution. The protrusion units at opposite ends have different polarities and the concave surfaces are positioned to ensure that the sensing unit receives uniform magnetic flux, thereby maintaining signal linearity even when the gap is reduced for compact design.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The magnet incorporates concave curved surfaces or concave inclined surfaces instead of flat surfaces. These curved geometries are specifically designed to shape the magnetic flux distribution, creating more uniform flux density across the sensing area. This curvature-based design allows the magnet to maintain effective magnetic coupling with the sensing unit at smaller gaps while preserving signal linearity and sensing accuracy.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Ease of manufacture

If a flat magnet surface is used, then the manufacturing is simple, but the magnetic flux density distribution is non-uniform affecting signal linearity

Engineering Contradiction:

Improvemagnet manufacturing simplicityVSAvoidsignal linearity

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The magnet incorporates concave curved surfaces or concave inclined surfaces instead of flat surfaces. These curved geometries are specifically designed to shape the magnetic flux distribution, creating more uniform flux density across the sensing area. This curvature-based design allows the magnet to maintain effective magnetic coupling with the sensing unit at smaller gaps while preserving signal linearity and sensing accuracy.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The magnet surface is designed with different local geometries (concave curved surface or concave inclined surface) at different positions to create uniform magnetic flux density distribution. The protrusion units at opposite ends have different polarities and the concave surfaces are positioned to ensure that the sensing unit receives uniform magnetic flux, thereby maintaining signal linearity even when the gap is reduced for compact design.

Inventive Principle:

Principle #3Local quality

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 improves the linearity of the signal output, enabling precise position change sensing while allowing for a smaller gap between the magnet and the sensing unit, thus facilitating a more compact design without compromising sensing accuracy.

Implementation Method 1

a magnet spaced apart from the sensing unit and movably disposed with respect to the sensing unit... which senses a change of magnetic force according to a relative position change

Methodology Applied

Scientific EffectMagnetic force: Magnetic Field

Data Source

PatentUS8842382B2Position sensor assembly and optical device including the same

Publication Date: 2014.09.23 SAMSUNG ELECTRONICS CO LTD

AI summary

Position sensor assemblies having compact structures and capable of precisely sensing a position change, and optical devices including the same are disclosed. A position sensor assembly is provided that includes: a sensing unit that outputs a signal varying as a magnetic force varies; and a magnet spaced apart from the sensing unit and i movably disposed with respect to the sensing unit, and comprising protrusion units of opposite polarities that protrude from each end portion of the magnet in one surface of the magnet toward the sensing unit.