Dust Detection System for Digital Cameras

Solution Overview

Problem

Existing dust detection systems in digital cameras struggle to differentiate between manufacturing flaws and actual dust, leading to false detection and inability to remove minute flaws and dust, which affects image quality and camera inspection.

Innovation Solution

A dust detection system comprising a receiver, dust extraction block, memory, and image correction block that generates a corrected dust-image signal by deleting sub-images of intrinsic-flaw dust from normal dust images, using adjustable parameters to enhance visibility of removable dust while reducing visibility of intrinsic-flaw dust.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If edge-enhancement signal processing is applied to detect dust in photographed images, then dust visibility is improved, but intrinsic flaws and minute dust become falsely detected and cannot be removed

Engineering Contradiction:

Improvedust detection precisionVSAvoidfalse detection rate

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system performs preliminary action by capturing a reference image during manufacturing before any dust can adhere to the imaging device. This reference image is stored and later used to subtract intrinsic flaws from dust detection images, preventing false detection of manufacturing flaws as removable dust.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts and separates intrinsic flaws from the dust detection process by using reference image subtraction. The reference image containing only manufacturing flaws is extracted and removed from subsequent dust detection images, allowing only actual dust to be detected.

Inventive Principle:

Principle #2Taking out (Extraction)

2Measurement precision

If dust detection is performed on all detected particles, then detection sensitivity is improved, but the ability to distinguish removable dust from intrinsic flaws deteriorates

Engineering Contradiction:

Improvedust detection sensitivityVSAvoiddust classification accuracy

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The system performs preliminary action by capturing a reference image during manufacturing before any dust can adhere to the imaging device. This reference image is stored and later used to subtract intrinsic flaws from dust detection images, preventing false detection of manufacturing flaws as removable dust.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system creates a copy of the intrinsic flaws through the reference image captured during manufacturing. This copy is then subtracted from dust detection images, allowing the system to distinguish between removable dust and non-removable manufacturing flaws with high accuracy.

Inventive Principle:

Principle #26Copying

3Measurement precision

If minute flaws and dust are made visible through processing, then detection capability is improved, but the ability to remove them deteriorates since they cannot be removed after manufacturing

Engineering Contradiction:

Improveflaw visibilityVSAvoiddust removal capability

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The system performs preliminary action by capturing a reference image during manufacturing before any dust can adhere to the imaging device. This reference image is stored and later used to subtract intrinsic flaws from dust detection images, preventing false detection of manufacturing flaws as removable dust.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts and separates intrinsic flaws from the dust detection process by using reference image subtraction. The reference image containing only manufacturing flaws is extracted and removed from subsequent dust detection images, allowing only actual dust to be detected and flagged for removal.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS8873881B2Dust detection system and digital camera

Publication Date: 2014.10.28 RICOH IMAGING COMPANY

AI summary

A dust detection system, comprising a receiver, a dust extraction block, a memory and an image correction block, is provided. The receiver receives an image signal. The dust extraction block generates a dust image signal on the basis of the image signal. The memory stores an intrinsic-flaw image signal corresponding to an intrinsic-flaw image including sub-images of dust that the dust extraction block extracts in initializing. The image correction block generates a corrected dust-image signal on the basis of the intrinsic-flaw image signal and a normal dust-image signal. The normal dust-image signal corresponds to a normal dust image including sub-image of dust that the dust extraction block extracts after initializing. The corrected dust image is the normal dust image that sub-images of dust in the intrinsic-flaw image are deleted from.