Image Carrier Contamination Avoidance in Electrophotographic Apparatus

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Solution Overview

Problem

Existing image forming apparatuses face issues with contamination of the image carrier due to components seeping from the transfer member, leading to irregular images and reduced productivity, as existing solutions either reduce productivity or prolong the first print time.

Innovation Solution

An image forming apparatus equipped with a control section that includes an avoidance judging section and a toner image formation mechanism to detect and manage toner attachment amounts on the image carrier, determining the necessity for avoiding specific regions to prevent contamination, using optical sensors to compare toner attachment amounts between pressed and adjacent regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a non-image region is constantly provided on an image carrier to limit an image region, then contamination is avoided, but productivity is reduced when a large number of images are formed

Engineering Contradiction:
Improveimage qualityVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent makes the non-image region dynamic by adjusting its size and position based on the actual contamination level detected by the toner attachment amount detection mechanism. Instead of a fixed non-image region, the system dynamically modifies the image formation region to maximize usable area while maintaining image quality standards.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback control by detecting toner attachment amounts in real-time and using this information to adjust the non-image region boundaries. The detection results feed back to the control section, which modifies image formation parameters to prevent contamination while maximizing productivity.

Inventive Principle:
Principle #23Feedback

2Reliability

If a contaminated region is removed before image formation by rotating the photosensitive body, then image quality is improved, but first print time is prolonged

Engineering Contradiction:
Improveimage qualityVSAvoidfirst print time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary detection of toner attachment amounts before image formation begins. By detecting contamination levels in advance and preparing the appropriate non-image region configuration beforehand, the system avoids time-consuming rotation operations while still ensuring image quality.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical rotation method with an optical detection and control system. Instead of physically rotating the photosensitive body to remove contaminated regions, the system uses optical sensors to detect contamination and electronically adjusts image formation parameters, eliminating the time loss associated with mechanical rotation.

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

3Reliability

If image formation is avoided for a preset number of sheets in the pressed region, then contamination is reduced, but the avoidance may not match actual contamination levels

Engineering Contradiction:
Improvecontamination preventionVSAvoidadaptability to actual usage
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system uses real-time feedback from toner attachment amount detection to adjust image formation avoidance strategies. Instead of using a fixed preset number of sheets, the control section continuously monitors contamination levels and dynamically adjusts the non-image region configuration based on actual contamination conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameter from a fixed sheet count to a dynamic detection-based threshold. The system monitors toner attachment amounts and adjusts image formation parameters accordingly, allowing the avoidance strategy to adapt to actual contamination levels rather than relying on predetermined sheet numbers.

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

This solution allows for the minimum necessary avoidance of contaminated regions, preventing white spot images and reducing productivity and first print time issues, ensuring reliable and efficient image output.

Implementation Method 1

a detection device for detecting a toner attachment amount of the toner image formed on the image carrier

Methodology Applied
Scientific EffectOptical detection: Absorption Spectroscopy

Data Source

PatentEP2233981B1Image forming apparatus
Publication Date: 2015.01.21 KONICA MINOLTA BUSINESS TECH INC
  • EP2233981B1 patent drawingFigure 1
  • EP2233981B1 patent drawingFigure 2
  • EP2233981B1 patent drawingFigure 3

AI summary

An image forming apparatus includes an image carrier (2), a transfer member (4) provided at a position at which the transfer member can be pressed against the image carrier, a detection device (6) for detecting a toner attachment amount of the toner image formed on the image carrier, an avoidance judging section (7) for judging whether or not avoidance of a pressed region (A) should be performed when a toner image for image formation is formed on the image carrier, the pressed region serving as a region located on the image carrier and being pressed against the transfer member from the end of a previous image forming operation to the start of a present image forming operation, and an avoidance continuation judging section for judging the necessity for continuation of the avoidance by being operated when it is judged as avoidance by the avoidance judging section.