Image Bearing Member Life Prediction via Surface Voltage Difference

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing image forming apparatuses struggle to accurately predict the end-of-life of image bearing members due to environmental and usage condition variations, leading to premature replacement and potential defective images, as previous methods fail to account for differences in transfer impact between toner-attached and toner-non-attached areas.

Innovation Solution

An image forming apparatus with a life status determination device that measures and compares surface voltages under different current and voltage conditions to assess the degree of transfer impact, using a voltage detector to identify the difference in post-charging surface voltages between areas with and without toner, thereby determining the image bearing member's life expectancy and preventing residual images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the replacement timing of the image bearing member is fixed based on life expectancy indices, then the replacement process is simplified and standardized, but the image bearing member may break down before replacement due to environmental and usage condition variations

Engineering Contradiction:
Improvereplacement timing determinationVSAvoidimage bearing member durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism by continuously monitoring the surface voltage of the image bearing member during operation. The life status determination device measures surface voltage at different positions (with and without toner attachment) and uses the voltage difference as feedback to dynamically adjust replacement timing, resolving the contradiction between fixed replacement scheduling and actual component durability under varying conditions

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The image bearing member effectively monitors its own health status through the surface voltage measurement system. By measuring the voltage difference between toner-attached and non-attached areas, the system enables the component to self-diagnose its degradation state, eliminating the need for complex external monitoring while improving replacement timing accuracy

Inventive Principle:
Principle #25Self-service

2Reliability

If the replacement timing is set early enough to avoid defective images, then image quality is maintained, but a number of image bearing members are replaced prematurely which is uneconomical and wasteful

Engineering Contradiction:
Improveimage quality consistencyVSAvoidpremature replacement waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent replaces fixed mechanical replacement scheduling with an electrical measurement-based determination system. By substituting the mechanical/time-based replacement approach with electrical surface voltage measurement and analysis, the system achieves precise, condition-based replacement timing that prevents both premature replacement and defective image output

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system monitors changes in surface voltage parameters (specifically the voltage difference between toner-attached and non-attached areas) to determine replacement timing. By tracking parameter degradation rather than using fixed time intervals, the system optimizes replacement timing to coincide with actual component degradation, preventing both waste and quality issues

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the life expectancy is predicted based on charging delay detection, then the prediction method is simple, but it cannot accurately predict end-of-life related to transfer impact differences between toner-attached and non-attached areas

Engineering Contradiction:
Improveprediction system complexityVSAvoidend-of-life prediction accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the surface voltage measurement into two distinct areas: toner-attached regions and non-attached regions. By measuring and comparing the voltage difference between these segmented areas, the system achieves precise detection of transfer impact effects that single-point charging delay measurements cannot capture, significantly improving prediction accuracy

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from one-dimensional charging delay measurement to two-dimensional surface voltage distribution analysis. By measuring voltage across different spatial positions (with and without toner) and analyzing the voltage difference dimension, the system captures transfer impact effects that traditional single-point measurements miss, enhancing prediction precision without excessive complexity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution allows for precise identification of image bearing member degradation, enabling timely replacement and reducing waste by predicting the end-of-life based on surface voltage differences, thus maintaining image quality and optimizing resource usage.

Implementation Method 1

a surface voltage detector to measure a first surface voltage of a surface portion of the image bearing member charged by the charger

Methodology Applied
Scientific EffectElectrostatic charge detection: Electrostatics

Data Source

PatentEP2477074B1Image forming apparatus
Publication Date: 2019.05.15 RICOH CO LTD
  • EP2477074B1 patent drawingFigure 1~3
  • EP2477074B1 patent drawingFigure 4~5
  • EP2477074B1 patent drawingFigure 6~7

AI summary

An image forming apparatus having an image bearing member (1), a charger (2) to charge the surface of the image bearing member, an irradiator (3) to irradiate the image bearing member to form the latent image, a developing device (4) to develop the latent electrostatic image with toner to obtain a visible image, a transfer device (5) to transfer the visible image to a transfer medium by a transfer bias applied to a transfer area between the image bearing member and the transfer member, and a voltage detector (8) to measure a first surface voltage and a second surface voltage under different conditions, and a life status determination device (9) to identify whether or when the expected working life of the image bearing member has come to the end based on a comparison of the first surface voltage and the second surface voltage.