Backlash-Free Focusing Unit for Automated Slide Scanning

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Solution Overview

Problem

Traditional slide scanning systems are bulky, expensive, unreliable, and complex, with issues such as backlash in focusing units, poor visibility of slide labels, and difficulties in manual retrieval due to vertical storage.

Innovation Solution

A compact, automated slide scanning system with a motorized scanning track and focusing unit that moves in the Z-direction, featuring a rigid arm and lever mechanism for backlash-free vertical movement, integrated with a motorized scanning stage and illumination system, allowing horizontal slide storage for clear label visibility and easy retrieval.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional screw or rack-and-pinion focus adjustment is used, then the focusing unit can be simple in structure, but it causes backlash and hysteresis reducing reliability

Engineering Contradiction:
Improvefocusing accuracyVSAvoidfocusing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical focusing mechanisms (screw or rack-and-pinion) with a voice coil motor system that uses electromagnetic fields to move the objective lens. This substitution eliminates mechanical backlash and hysteresis, providing precise and reliable focusing control without the mechanical contact issues inherent in traditional systems.

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

Solution Approach 2:

The patent employs a voice coil motor, which operates on electromagnetic principles similar to pneumatic and hydraulic systems in that it uses a field (electromagnetic rather than fluid) to produce motion. The voice coil motor creates a magnetic field that interacts with a permanent magnet to move the objective lens, providing smooth, backlash-free focusing action.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Area of stationary object

If slides are stored vertically to save space, then the storage density increases, but the visibility of slide labels deteriorates

Engineering Contradiction:
Improvestorage spaceVSAvoidlabel visibility
Core Design Contradiction:
Area of stationary objectVSEase of operation

Solution Approach 1:

The patent transitions from vertical slide storage to horizontal storage arrangement. By changing the storage dimension from vertical stacking to horizontal positioning on a motorized stage, the system maintains space efficiency while enabling clear visibility of slide labels during automated scanning operations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If a traditional loader/microscope setup is used, then the system can be modular, but it becomes bulky and requires considerable space

Engineering Contradiction:
Improvesystem modularityVSAvoidsystem footprint
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent integrates the slide holder, focusing mechanism, and microscope objective into a single compact unit. The objective lens is mounted directly on the focusing mechanism which is integrated with the slide holder assembly, eliminating the need for separate loader and microscope components, thereby reducing the overall system footprint while maintaining functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The motorized stage serves multiple functions: it positions slides for scanning, enables label visibility during operation, and integrates with the focusing mechanism. This multi-functional design reduces the need for separate dedicated components, contributing to a more compact overall system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Device complexity

If manual retrieval of slides is required, then the system can be simple, but it reduces productivity

Engineering Contradiction:
Improveautomation levelVSAvoidslide scanning efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system implements automated slide scanning where the motorized stage automatically positions slides and the integrated focusing mechanism automatically adjusts focus, eliminating the need for manual slide retrieval and positioning. This self-service automation significantly improves productivity while maintaining system simplicity through integrated design.

Inventive Principle:
Principle #25Self-service

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 system provides a reliable, cost-effective, and efficient scanning solution with clear slide label visibility, reducing mechanical failures and simplifying slide handling, while maintaining precise focus control and image capture at various depths.

Implementation Method 1

The focusing mechanism includes a voice coil motor configured to generate an electromagnetic field to move the objective lens in the Z-direction

Methodology Applied
Scientific EffectElectromagnetic field: Electromagnetic Induction

Implementation Method 2

The lever is substantially parallel and spaced apart from the at least one arm. The drive mechanism engages the lever flexing it downwardly which subsequently engages the at least one arm, producing substantially vertical movement of the at least one arm

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP2630537B1Focusing unit and automated slide scanning system using the same
Publication Date: 2018.12.12 MOTIC CHINA GROUP CO LTD
  • EP2630537B1 patent drawingFigure 1
  • EP2630537B1 patent drawingFigure 2
  • EP2630537B1 patent drawingFigure 3~3a

AI summary

An automated slide scanning system is described. The system comprises an automated focusing unit that is simple and that provides a fine adjustment of a focusing tube without any backlash. The focusing unit comprises a block that is cut or fabricated in a pattern forming a head to support a focusing tube and at least one elongated and rigid arm projecting perpendicularly from the head. One end of the at least one arm is integrally joined to the head. The focusing unit further comprises an elongated, rigid, lever which is substantially parallel and spaced apart from the at least one arm. The lever is pivotally mounted to a hinge and has a first end that is linked to the head of the focusing unit and a second free end. The focusing unit further includes a drive mechanism with a roller coupled to a motor. The roller is eccentric roller and is in constant contact to the lever's second end. When the roller rotates it engages the lever which subsequently engages the at least one arm and thus produces a substantially vertical movement in both direction to the head of the focusing unit. The scanning system further comprises a scanning stage that supports the focusing unit and which provides a continuous movement in Y-direction (back and forward) of the scanning stage, and a scanning track that moves the slide holder continuously in one direction along the x-axis until the last slide in the slide holder is scanned. The scanning system of the present invention is suitable for automated screening or prescreening of samples.