Image Defect Detection via Development Current Comparison

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Solution Overview

Problem

Existing image forming apparatuses face challenges in identifying the cause of image defects without increasing machinery installation area, as they rely on post-processing apparatuses and struggle to differentiate defects originating from different image forming processes.

Innovation Solution

Incorporating a developer bearing member, an image bearing member, a development current detector, and a development current calculator to determine image defects by comparing actual and calculated development currents, allowing for accurate identification of defect causes without additional machinery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a post-processing apparatus with an image reading device is provided to detect image defects, then image defect detection capability is improved, but the machinery installation area increases

Engineering Contradiction:
Improveimage defect detection capabilityVSAvoidmachinery installation area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent extracts the image defect detection function from a separate post-processing apparatus and integrates it into the image forming apparatus itself. The image reading device is incorporated within the image forming apparatus, allowing defect detection to be performed at the formation location without requiring additional standalone equipment, thereby reducing machinery installation area while maintaining detection capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the image defect detection function with the image forming apparatus by integrating an image reading device within the same system. This combination allows the apparatus to both form images and detect defects in those images using the same machinery footprint, eliminating the need for separate post-processing equipment and reducing overall installation space.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If image defects are detected based on output images on sheets, then defect detection is achieved, but the ability to identify specific cause origins from different image forming processes is lost

Engineering Contradiction:
Improvedefect detectionVSAvoidcause identification information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent performs preliminary detection of image defects at the point of image formation, before the image is fully processed and output. By detecting defects during or immediately after formation using the integrated image reading device, the system can identify which specific image forming process caused the defect, preserving cause identification information that would be lost if detection occurred only at the final output stage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where detection results from the image reading device are fed back to identify the specific cause of image defects. The system correlates detected defects with the corresponding image forming processes, providing feedback information that enables identification of the origin of defects, thereby preventing loss of cause identification information.

Inventive Principle:
Principle #23Feedback

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

Enables easy division of defect causes and provides accurate feedback to image forming processes, preventing defects by controlling development current within threshold limits, thus reducing machinery requirements.

Implementation Method 1

a development current detector that detects an actual measurement value of a development current which flows between the image bearing member and the developer bearing member

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3309621B1An image forming apparatus and a recording medium
Publication Date: 2020.03.11 KONICA MINOLTA INC
  • EP3309621B1 patent drawingFigure 1
  • EP3309621B1 patent drawingFigure 2
  • EP3309621B1 patent drawingFigure 3~5

AI summary

An image forming apparatus includes a development current detector that detects an actual measurement value of a development current, a development current calculator that calculates a provisional calculation value of a development current based on an image formation condition, and an image-defect determiner that determines whether or not an image defect occurs, based on the actual measurement value of the development current detected by the development current detector and the provisional calculation value of the development current calculated by the development current calculator.