Image Forming Apparatus Charging Abnormality Detection

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Solution Overview

Problem

In electrophotographic image forming apparatuses, the deterioration of photoconductors and chargers is not effectively monitored, leading to undetected defects and unknown causes of charging abnormalities, which can impact image quality.

Innovation Solution

Incorporating a detection unit to measure the actual charging potential of the photoconductor and a determination unit to identify the cause of charging abnormalities based on the relationship between the standard charging potential and the detected potential, using a coefficient table to determine the degree of deterioration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If photoconductor and charger deterioration is monitored based on number of images formed, then replacement timing can be estimated, but actual defects cannot be detected and causes cannot be determined

Engineering Contradiction:

Improvedefect detection accuracyVSAvoidcause identification information

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent replaces the mechanical/counting-based monitoring system (number of images formed) with an electrical measurement system that detects charging potential. The detection unit measures the actual charging potential electrically, and the determination unit analyzes this electrical data to identify defects and causes, substituting physical counting with electrical field measurement for more accurate and informative monitoring.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces charging potential as an intermediary parameter between the photoconductor/charger components and the defect detection system. By measuring the charging potential that exists between these components during operation, the system obtains indirect but accurate information about their condition, enabling defect detection and cause identification without directly observing the components themselves.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If photoconductor and charger are replaced based on estimated deterioration, then image quality can be maintained, but replacement may occur too early or too late

Engineering Contradiction:

Improveimage quality consistencyVSAvoidreplacement timing accuracy

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent implements a feedback mechanism where the detection unit continuously monitors charging potential and provides real-time information about photoconductor and charger condition. The determination unit processes this feedback to assess deterioration level, enabling dynamic adjustment of replacement timing based on actual component state rather than fixed schedules, thus optimizing both image quality and resource utilization.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent uses charging potential as a changing parameter that reflects the deterioration state of photoconductor and charger. By tracking changes in this electrical parameter over time, the system determines the optimal replacement moment based on actual performance degradation rather than arbitrary time or count thresholds, achieving precise timing for maintenance activities.

Inventive Principle:

Principle #35Parameter changes

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 accurate identification of charging abnormalities, allowing for timely replacement of photoconductors and chargers, thereby maintaining image quality and extending their lifespan.

Implementation Method 1

a charger for charging the photoconductor to a predetermined potential

Methodology Applied

Scientific EffectElectrostatic charging: Electrostatic Induction

Implementation Method 2

a detection unit for detecting an actual charging potential of the photoconductor after being charged by the charger

Methodology Applied

Scientific EffectElectrical potential detection: Electric Field

Data Source

PatentUS11988985B2Image forming apparatus and method for determining a cause on an abnormality

Publication Date: 2024.05.21 TOSHIBA TEC KK

AI summary

An image forming apparatus includes a photoconductor, a charger, a detection unit, and a determination unit. The charger charges the photoconductor. The detection unit detects an actual charging potential of the photoconductor after the photoconductor is charged by the charger. The determination unit determines one of a plurality of causes related to a charging abnormality of the photoconductor based on a relationship between a standard charging potential of the photoconductor to be obtained by charging by the charger and a charging potential detected by the detection unit.