Parallel-Guided Focus Adjustment for Heavy-Lens Optoelectronic Sensors

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Solution Overview

Problem

Existing focus adjustment mechanisms for optoelectronic sensors, such as cameras, face limitations in supporting a wide range of objective lenses, particularly larger and heavier ones, due to mechanical wear and complex structural requirements, leading to limited versatility and increased development costs.

Innovation Solution

A focus adjustment unit with a parallel guide and at least one flexible retaining element moves the light receiver in a constant orientation on the optical axis, allowing for refocusing without tilting or changing the optical axis piercing point, thereby minimizing wear and enabling use with various objective lenses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a motor-driven cam disk and parallel guide are used for focus adjustment, then the focus position can be adjusted, but mechanical wear increases with the weight of the objective lens

Engineering Contradiction:

Improveservice life of focus adjustment mechanismVSAvoidweight of objective lens

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces the motor-driven cam disk mechanical transmission system with a voice coil actuator that uses electromagnetic force to move the objective lens directly along the optical axis. This eliminates the cam disk and its mechanical transmission elements, thereby eliminating the wear associated with those components while still achieving precise focus adjustment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the actuation mechanism from mechanical rotation and transmission to electromagnetic linear actuation. By using a voice coil that generates direct linear motion through electromagnetic fields, the system eliminates the need for mechanical transmission elements like cam disks, thereby eliminating wear while maintaining the ability to adjust focus position.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If a larger objective lens is used to improve image quality, then more wear occurs and mechanical adjustment requires complex variants

Engineering Contradiction:

Improveimage qualityVSAvoidcomplexity of mechanical adjustment

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex motor-driven cam disk mechanism with a simpler voice coil actuator that provides direct linear motion. This simplification eliminates the need for complex mechanical transmission elements and reduces the number of moving parts, thereby reducing device complexity while supporting larger objective lenses.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The voice coil actuator design creates a universal focus adjustment mechanism that can accommodate different objective lens sizes and weights without requiring complex mechanical adjustments or variants. The same basic structure works for various lens configurations, simplifying the overall device design.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If a swivel arm with plunge coil actuator is used for focus adjustment, then wear is reduced, but circular movement causes offset between transmitting optics and light transmitter

Engineering Contradiction:

Improveservice life of focus adjustment mechanismVSAvoidoptical alignment

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

Instead of moving the transmitting optics on a swivel arm in a circular path, the patent inverts the approach by using a voice coil actuator to move the objective lens or light receiver in a straight line along the optical axis. This linear motion path eliminates the circular offset problem while maintaining reduced wear characteristics.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the swivel arm mechanical system with a voice coil electromagnetic actuator that provides precise linear motion control. This substitution eliminates the circular movement path that causes optical misalignment while maintaining the low-wear benefits of non-contact actuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach extends the service life of the focus adjustment system, reduces development and manufacturing costs, and allows for the use of a wide variety of objective lenses, including high-quality or cost-effective options, while avoiding the limitations of liquid lenses and complex temperature compensations.

Implementation Method 1

To reduce wear, a voice coil can be used as an actuator

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

A focus adjustment unit with a parallel guide and at least one flexible retaining element moves the light receiver

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12010424B2Optoelectronic sensor and method for focus adjustment

Publication Date: 2024.06.11 SICK AG

AI summary

An optoelectronic sensor comprising a light receiver, receiving optics in front of the light receiver, and a focus adjustment unit having an actuator and configured to move the light receiver, wherein the focus adjustment unit comprises a parallel guide having at least one flexible retaining element and moving the light receiver in a constant orientation on the optical axis of the receiving optics.