Electromagnetic Variable Focus Lens for Sensorless Fast Positioning

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Solution Overview

Problem

Existing focusing lens assemblies lack mechanisms to determine the exact position of the lens, leading to inaccuracies due to component aging, temperature changes, gravity, friction, and slow response times in determining lens position, which is critical for industrial imaging applications.

Innovation Solution

A variable focusing lens apparatus utilizing double coil elements with electromagnetic actuators that move a barrel lens assembly precisely based on the drive current ratio, eliminating the need for spring mechanisms and providing fast, accurate positioning through an open-loop system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If feedback loops are used to determine lens position, then positioning accuracy is improved, but response time increases and manufacturing cost increases

Engineering Contradiction:
Improvelens position determination accuracyVSAvoidresponse time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts and eliminates the feedback loop mechanism from the system. Instead of using sensors and control loops to determine lens position, the invention uses a direct mathematical relationship between drive signal parameters and lens position, removing the need for position sensing and feedback processing, thereby achieving sub-millisecond response times without sacrificing positioning accuracy

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/feedback-based position sensing system with an electromagnetic control system. By using electromagnetic actuators where the lens position is directly determined by the drive signal characteristics rather than mechanical feedback, the system achieves faster response and reduced complexity while maintaining accurate positioning

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If feedback loops are used to determine lens position, then positioning accuracy is improved, but manufacturing cost increases

Engineering Contradiction:
Improvelens position determination accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent removes feedback loop components (position sensors, feedback circuitry, and associated processing hardware) from the system. This extraction eliminates the need for complex manufacturing and assembly of sensing components, reducing overall system cost while maintaining positioning accuracy through the direct electromagnetic control relationship

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a simpler, more cost-effective electromagnetic actuator design that eliminates expensive feedback components. By using a direct control approach where lens position is determined by drive signal parameters rather than expensive position sensors and feedback loops, the system achieves accurate positioning at lower manufacturing cost

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If spring mechanisms are used for lens actuation, then positioning is achieved, but power consumption increases

Engineering Contradiction:
Improvelens actuation capabilityVSAvoidpower consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent replaces mechanical spring mechanisms with electromagnetic actuators. By using electromagnetic fields to directly position the lens rather than mechanical springs, the system eliminates the continuous energy consumption associated with maintaining mechanical tension and overcoming friction, achieving lens actuation with significantly reduced power consumption

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If component aging and environmental factors are considered, then long-term reliability is improved, but system complexity increases

Engineering Contradiction:
Improvepositioning accuracy under aging and temperatureVSAvoidcompensation mechanisms
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a self-service approach where the electromagnetic actuator inherently maintains positioning accuracy without requiring external compensation mechanisms. By using a direct relationship between drive signal parameters and lens position that is insensitive to temperature and aging, the system automatically compensates for environmental factors without adding complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent utilizes parameter changes in the electromagnetic drive signal to directly control lens position. By adjusting electrical parameters (current, voltage, or frequency) of the drive signal rather than using mechanical adjustments or compensation mechanisms, the system maintains accurate positioning under varying temperature and aging conditions without increasing device complexity

Inventive Principle:
Principle #35Parameter changes

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 apparatus achieves sub-millisecond response times and highly reliable positioning accuracy by directly determining lens positions based on current ratios, minimizing the impact of environmental factors and eliminating processing delays.

Implementation Method 1

a rear pair of coil elements powered by a rear coil current; a front pair of coil elements positioned in front of the rear pair of coil elements and powered by a front coil current

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4242715B1Variable focusing lens apparatus
Publication Date: 2026.04.08 HAND HELD PRODS INC
  • EP4242715B1 patent drawingFigure 1A~1B
  • EP4242715B1 patent drawingFigure 1C
  • EP4242715B1 patent drawingFigure 1D

AI summary

An example variable focusing lens apparatus, as well as example methods for assembling and operating the example variable focusing lens apparatus, is provided. The example variable focusing lens apparatus includes a rear pair of coil elements powered by a rear coil current, a front pair of coil elements positioned in front of the rear pair of coil elements and powered by a front coil current, and a barrel lens assembly comprising a top magnetic element secured on a top portion of the barrel lens assembly and a bottom magnetic element secured on a bottom portion of the barrel lens assembly. In some examples, the barrel lens assembly is moveable to a plurality of barrel lens assembly positions corresponding to a plurality of current differential ratios associated with the rear coil current and the front coil current.