Image Scanning Apparatus On-the-Fly Focus Adjustment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing image scanning apparatus methods, such as those using focus maps generated by pre-scans, are time-consuming and lack accuracy in regions with non-uniform tissue detail, leading to incorrect focus measurements and reduced productivity.

Innovation Solution

A method that monitors in-focus positions at seed and end locations, conducts a pre-scan along a calculated path, and adjusts the focal position during an imaging scan based on focus parameter comparisons between pre-scan and imaging scan locations, allowing for 'on-the-fly' focusing without relying on extensive pre-scan measurements or interpolation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a pre-scan is conducted with many measurement points to generate an accurate focus map, then focus measurement precision is improved, but scanning time increases and productivity decreases

Engineering Contradiction:
Improvefocus measurement precisionVSAvoidscanning productivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent divides the scanning process into two distinct phases: a rapid pre-scan phase that identifies key focus points, and a subsequent imaging phase that uses those points to guide focus adjustments. This segmentation allows the system to obtain sufficient focus information without requiring exhaustive measurement at every possible location, thereby maintaining precision while improving productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pre-scan phase performs preliminary focus measurements at strategically selected points before the main imaging scan. These preliminary actions establish a focus map that guides subsequent focus adjustments during imaging, eliminating the need for extensive real-time focus measurements and significantly reducing total scanning time while maintaining accuracy.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If a pre-scan is conducted with too few measurement points to save time, then productivity is improved, but focus measurement precision deteriorates and interpolated regions become inaccurate

Engineering Contradiction:
Improvescanning productivityVSAvoidfocus measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary focus map generated from limited pre-scan measurements that serves as a guide for focus adjustments during the main imaging scan. This intermediary structure allows the system to bridge the gap between sparse measurement points and continuous focus requirements, maintaining precision even with fewer measurement points by using the focus map to predict and adjust focus positions dynamically.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback by continuously comparing actual focus measurements during the imaging scan with predictions from the pre-scan focus map. This feedback mechanism allows real-time correction of focus positions, ensuring that even though fewer points are measured in the pre-scan, the final imaging achieves high precision through dynamic adjustment based on actual observations.

Inventive Principle:
Principle #23Feedback

3Productivity

If the ribbon-focus technique is used to generate a focus map quickly, then scanning time is reduced, but accuracy deteriorates in regions with non-uniform tissue detail

Engineering Contradiction:
Improvescanning productivityVSAvoidfocus measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by treating different regions of the sample differently based on their characteristics. In regions with non-uniform tissue detail, the system performs additional localized focus measurements and adjustments rather than relying solely on the ribbon-focus technique. This allows the system to maintain high productivity overall while ensuring accurate focus measurement in challenging regions where uniformity cannot be assumed.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2884326B1Method and apparatus for estimating an in-focus position
Publication Date: 2019.04.17 FFEI LTD
  • EP2884326B1 patent drawingFigure 1
  • EP2884326B1 patent drawingFigure 2
  • EP2884326B1 patent drawingFigure 3~4A

AI summary

A method for estimating an in-focus position of a target using an image scanning apparatus is provided. The in-focus position is monitored at a seed location and an end location on the target and a pre-scan path is calculated between these locations. A pre-scan is then performed and a focus parameter is monitored for a plurality of locations along the pre-scan path. An imaging scan is next performed wherein the target is imaged along an image scan path and a focus parameter is monitored for a plurality of locations along said path. The focal height of the apparatus is adjusted during the imaging scan by comparing the focal parameter monitored for a current location on the image scan path with the focal parameter monitored for a similar location on the pre-scan path. The focal parameter monitored for different locations on the image scan path may also be compared.