Slide Scanner Focus Control Using Slide Slope Estimation

Solution Overview

Problem

Existing slide scanning devices struggle with prolonged scanning times due to tilting of slides, which can occur when the slide is not uniformly thick or is inclined, leading to images that are out of focus despite the use of automatic focus technology.

Innovation Solution

A method for determining the slope of a slide in a slide scanning device by obtaining z-stack images, calculating focus evaluation values, and estimating the slide's slope to adjust the focal location for improved focus and scanning efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If automatic focus technology is applied to scan tilted slides, then focus can be obtained, but scanning time increases significantly

Engineering Contradiction:

Improvefocus qualityVSAvoidscanning time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary slope detection by capturing z-stack images and calculating focus evaluation values at multiple z-axis locations before the main scanning process. This preliminary action determines the slide's tilt angle in advance, allowing the automatic focus system to pre-calculate compensation values and start scanning immediately without time-consuming focus exploration during actual scanning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical trial-and-error focus exploration process with a computational approach. By substituting physical focus adjustment iterations with mathematical calculations based on slope detection and focus evaluation algorithms, the system rapidly determines optimal focus parameters without mechanical delays.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Speed

If the slide is scanned without slope estimation, then scanning speed is maintained, but image focus quality deteriorates

Engineering Contradiction:

Improvescanning speedVSAvoidimage focus quality

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The system performs preliminary slope detection by capturing z-stack images and calculating focus evaluation values at multiple z-axis locations before the main scanning process. This preliminary action determines the slide's tilt angle in advance, allowing the automatic focus system to pre-calculate compensation values and start scanning immediately without time-consuming focus exploration during actual scanning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses focus evaluation values calculated from z-stack images as feedback to determine the optimal z-axis location for each horizontal position. This feedback mechanism allows real-time adjustment of focus parameters based on actual slide topology, ensuring high-quality images while maintaining scanning speed through automated compensation.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12591123B2Method for determining slope of slide in slide scanning device, method for controlling slide scanning device and slide scanning device using the same

Publication Date: 2026.03.31 VIEWORKS CO LTD

AI summary

An embodiment relates to a method for determining a slope of a slide in a slide scanning device, which includes: (a) obtaining, by a scanning control unit of a slide scanning device, z-stack images for at least a partial area of a sample of a slide; (b) extracting, by the scanning control unit, a z-axis location of a slice image in which a focus evaluation value has a top value of a predetermined ranking along a plurality of lines of any one of a plurality of rows or a plurality of columns of the z-stack images as a slope calculation z-axis location; and (c) calculating, by the scanning control unit, a slope by using a distance according to a location of a horizontal plane of the plurality of lines and the slope calculation z-axis location, and estimating the calculated slope as the slope of the slide.