Rolling Pin Focus Adjustment Mechanism for Compact Lens Systems

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Solution Overview

Problem

Existing focus adjustment devices for image acquisition systems, such as code readers, face challenges in achieving a compact and long-lasting design with minimal aberrations and sliding friction, which affects their service life and efficiency.

Innovation Solution

A focus adjustment device utilizing a cylindrical pin that rolls along a threaded spindle without sliding friction, integrated with a motor unit, allowing for precise focus adjustment with minimal rolling friction and a compact design, using standard components and a bearing unit that includes a ball, pin, or cylinder bearing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a traditional threaded rod and nut mechanism is used for focus adjustment, then the device can be manufactured inexpensively, but sliding friction occurs which reduces service life

Engineering Contradiction:
Improvemanufacturing costVSAvoidservice life
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the traditional sliding friction mechanism (threaded rod and nut) with a rolling friction mechanism (cylindrical pin rolling on thread turns). This substitution reduces friction from sliding to rolling, significantly increasing service life while maintaining the threaded structure for cost-effective manufacturing

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

Solution Approach 2:

The patent changes the friction parameter by introducing a cylindrical pin with specific diameter that rolls along the thread turns. The pin diameter is optimized to be smaller than the thread pitch, enabling rolling motion and transforming the friction characteristic from sliding to rolling, thereby improving reliability

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the cylindrical pin diameter is reduced to fit in smaller thread turns, then rolling friction is minimized, but the structural integrity may be compromised

Engineering Contradiction:
Improverolling frictionVSAvoidstructural integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent optimizes the cylindrical pin diameter parameter to be smaller than the thread pitch, enabling effective rolling motion. This parameter optimization minimizes rolling friction while maintaining sufficient structural integrity through proper material selection and dimensional design

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the focus adjustment device is designed to be compact, then space is saved, but the bearing unit may experience increased stress

Engineering Contradiction:
Improvedevice sizeVSAvoidbearing stress
Core Design Contradiction:
Volume of moving objectVSStress or pressure

Solution Approach 1:

The patent integrates the cylindrical pin bearing unit within the compact focus adjustment mechanism, nesting the bearing function inside the existing structural components. This nesting approach achieves compact device size while the rolling friction mechanism distributes stress more effectively than sliding friction

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution enhances the service life and efficiency of the focus adjustment device by reducing friction and enabling precise focus adjustments without tilting the lens, while maintaining a compact and cost-effective design.

Implementation Method 1

the cylindrical pin can roll along the thread of the thread unit without sliding friction

Methodology Applied
Scientific EffectRolling friction: Friction

Data Source

PatentEP3006973B1Focus adjustment device for an image acquisition system
Publication Date: 2018.02.21 SICK AG
  • EP3006973B1 patent drawingFigure 1~2
  • EP3006973B1 patent drawingFigure 3
  • EP3006973B1 patent drawingFigure 4~4a

AI summary

To achieve a compact design with a long service life for a focus adjustment device, a focus adjustment device is provided for an image acquisition system, comprising a lens with at least one lens and a motor unit for adjusting the position of the lens, wherein the lens is provided on a movable lens holder, wherein the movable lens holder is connected to a threaded unit of the motor unit via a bearing unit provided in the movable lens holder such that the bearing unit with the lens holder can roll along a principal axis of the threaded unit in accordance with a rotation of the threaded unit, and an axis of rotation of the bearing unit is directed perpendicular to the principal axis of the threaded unit.