Interference Image Compensation in Optical Displacement Sensors

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Solution Overview

Problem

Existing optical displacement estimating apparatuses face inaccuracies in displacement estimation due to interference images caused by objects like scraping traces, fingerprints, or dust on the detecting surface, requiring additional hardware or complex algorithms to resolve.

Innovation Solution

A method and apparatus that utilize image characteristics from current frames to determine and update interference images without additional hardware or complex algorithms, using a processing unit to illuminate objects, capture frames, and store interference images, allowing for simple computation and compensation of interference effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If extra hardware or complicated algorithms are used to solve interference images, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedisplacement estimation accuracyVSAvoidhardware and algorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the sensor's own captured frames to identify and compensate for interference images. By analyzing image characteristics from the current frame and comparing with the defined interference image, the system performs self-diagnosis and self-correction without requiring external assistance or additional hardware components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The interference image is pre-defined and stored in the storage apparatus before actual displacement measurement begins. This preliminary characterization of interference patterns allows the system to quickly compare and compensate for interference during operation, avoiding the need for complex real-time analysis or additional hardware.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If simple computation is used to determine interference images, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improvecomputation complexityVSAvoiddisplacement estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system creates a copy or model of the interference image pattern by storing it in the storage apparatus. This copied interference model can be repeatedly used for comparison and compensation without requiring complex real-time computation, thus maintaining both simplicity and accuracy.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The interference image characteristics are pre-computed and stored before actual measurement. This preliminary action transfers the computational burden to an offline stage, allowing simple comparison operations during real-time displacement estimation while maintaining high precision.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If interference images are not compensated, then device complexity is reduced, but measurement precision deteriorates due to inaccurate displacement estimation

Engineering Contradiction:
Improvealgorithm simplicityVSAvoiddisplacement estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system extracts the interference image component from the captured frame by comparing it with the defined interference image stored in the storage apparatus. This extracted interference information is then compensated for, allowing the remaining valid image data to be used for accurate displacement estimation without requiring complex overall processing.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach enables accurate displacement estimation by removing interference images through image compensation, reducing hardware costs and computational complexity, and maintaining precision without the need for extra hardware or intricate algorithms.

Implementation Method 1

controlling a light source to illuminate an object on a detecting surface to generate an image

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

controlling a sensor to catch a current frame of the image

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentUS9335841B2Computer readable media can perform interference image determining method and interference image determining apparatus
Publication Date: 2016.05.10 PIXART IMAGING INC
  • US9335841B2 patent drawing
  • US9335841B2 patent drawing
  • US9335841B2 patent drawing

AI summary

A computer readable media having at least one program code recorded thereon. An interference image determining method can be performed when the program code is read and executed. The interference image determining method comprises: (a) controlling a light source to illuminate an object on a detecting surface to generate an image; (b) controlling a sensor to catch a current frame of the image; (c) utilizing an image characteristic included in the current frame to determine a interference image part of the current frame; and (d) updating a defined interference image according to the determined interference image part.