Autofocusing Optical System Using Image Spectral Analysis

Solution Overview

Problem

Existing autofocus methods based on statistical analysis are computationally intensive and time-consuming, requiring substantial resources and manual intervention to maintain focus on an object of interest in optical systems.

Innovation Solution

An autofocusing system that utilizes spectral analysis by applying transforms to images to determine the best focused position of an optical system's imaging plane, employing a movable platform controlled by a processor and utilizing look-up tables to speed the autofocusing process, which calculates the difference in blur spread values to adjust the focal distance or image plane position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If statistical analysis methods are used for autofocus, then focus determination can be achieved, but computational resources and processing time increase substantially

Engineering Contradiction:

Improvefocus determination accuracyVSAvoidcomputational resource requirement

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential information needed for focus determination by analyzing the frequency spectrum of the image rather than processing the entire image data. By transforming the image to the frequency domain and examining spectral characteristics, the system identifies focus status without requiring complex multi-step statistical analyses of the complete image, thus reducing computational resource requirements while maintaining focus determination accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex statistical analysis procedures with spectral analysis methods. Instead of using multi-step statistical computations on image histograms, the system applies transforms (such as Fourier transforms) to convert image data into the frequency domain, where focus determination can be achieved through simpler spectral characteristic analysis, thereby reducing computational complexity and processing time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If statistical analysis methods are used for autofocus, then focus determination can be achieved, but processing time increases substantially

Engineering Contradiction:

Improvefocus determination accuracyVSAvoidautofocus processing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the essential information needed for focus determination by analyzing the frequency spectrum of the image rather than processing the entire image data. By transforming the image to the frequency domain and examining spectral characteristics, the system identifies focus status without requiring complex multi-step statistical analyses of the complete image, thus reducing computational resource requirements while maintaining focus determination accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex statistical analysis procedures with spectral analysis methods. Instead of using multi-step statistical computations on image histograms, the system applies transforms (such as Fourier transforms) to convert image data into the frequency domain, where focus determination can be achieved through simpler spectral characteristic analysis, thereby reducing computational complexity and processing time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If manual intervention is used for autofocus, then focus control can be maintained, but system automation and efficiency decrease

Engineering Contradiction:

Improvefocus maintenance capabilityVSAvoidautofocus automation level

Core Design Contradiction:

ReliabilityVSExtent of automation

Solution Approach 1:

The patent implements self-service autofocus by enabling the optical system to automatically determine its own focus status through spectral analysis of captured images. The system processes image data, analyzes frequency spectrum characteristics, and autonomously determines when refocusing is needed, eliminating the requirement for manual intervention while maintaining reliable focus control throughout the imaging process.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent employs feedback mechanisms where the system continuously monitors the frequency spectrum characteristics of captured images and uses this information to automatically adjust focus when deviations are detected. This closed-loop feedback system maintains reliable focus control while achieving full automation, as the system responds autonomously to changes in image quality without requiring manual input.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8507834B2System and method for autofocusing an optical system through image spectral analysis

Publication Date: 2013.08.13 INTERMEC IP CORP

AI summary

A system and method of autofocusing an optical system uses transforms of images or portions of images formed by the optical system. A detector is used to capture images at different positions relative to the optical system. Transforms and blur spread parameters are calculated for the images for use in determining a position to which the detector should be moved to autofocus the system.