Intermediate Transfer Belt Toner Detection for Malfunction Prevention

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Solution Overview

Problem

Existing image forming apparatuses face issues with detecting malfunctions that result in full-page solid images, leading to toner and paper waste, and require precise density detection methods, which are costly and inefficient, especially when multiple photoconductors are involved.

Innovation Solution

An image forming apparatus with a configuration that includes density detectors to identify toner density on an intermediate transfer belt, using a reflective optical sensor system to differentiate between image and non-image areas, and a control system to detect malfunctions by determining the presence of toner in non-image ranges, allowing for timely intervention and reducing the need for multiple detectors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple density detectors are provided for each photoconductor to detect toner density, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvetoner density detection accuracyVSAvoidnumber of density detectors
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the density detector serve multiple functions: it detects both the toner density in the image formation area and the presence of toner in the non-image area for malfunction detection. This multi-functional use of a single detector eliminates the need for separate detectors for each photoconductor, reducing device complexity while maintaining measurement precision

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the malfunction detection function with the existing density detection system. Instead of adding separate detection mechanisms, it merges the malfunction detection capability into the density detector by having it monitor both image and non-image areas, thereby reducing the total number of detectors required

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If precise density detection is performed to identify full-page solid images, then reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvemalfunction detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses the non-image area on the intermediate transfer belt as an intermediary indicator for detecting malfunctions. Instead of directly monitoring each photoconductor's toner density with high precision, it detects the presence of toner in the non-image area, which serves as a mediator to indicate charger breakdown or other malfunctions causing full-page solid images

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a simplified copy of the detection approach by monitoring the non-image area as a representative sample. Instead of precisely measuring toner density across the entire image area, it uses the non-image area as a representative zone that reflects the overall system status, thereby reducing detection complexity while maintaining reliability

Inventive Principle:
Principle #26Copying

3Productivity

If image formation continues after charger breakdown, then productivity is maintained, but loss of substance increases due to toner and paper waste

Engineering Contradiction:
Improvecontinuous image formationVSAvoidtoner and paper waste
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent implements a feedback mechanism where the density detector continuously monitors the non-image area for toner presence. When toner is detected in the non-image area, it provides feedback indicating a charger breakdown or malfunction, triggering the control unit to stop image formation and prevent further waste of toner and paper

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary detection of malfunctions by monitoring the non-image area before significant waste occurs. The system proactively detects charger breakdown through toner presence in the non-image area and stops image formation in advance, preventing the accumulation of wasted toner and paper that would occur if detection happened after full-page solid images began forming

Inventive Principle:
Principle #10Preliminary action

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

The solution enables accurate detection of malfunctions, preventing wasteful image formation, reducing toner and paper waste, and lowering costs by using existing density detection infrastructure for both image quality control and malfunction detection.

Implementation Method 1

using a reflective optical sensor system to differentiate between image and non-image areas

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2284618B1Image forming apparatus
Publication Date: 2019.09.04 RICOH CO LTD
  • EP2284618B1 patent drawingFigure 1
  • EP2284618B1 patent drawingFigure 2~3
  • EP2284618B1 patent drawingFigure 4

AI summary

An image forming apparatus (100) including at least one latent image carrier (2), an image forming unit to form a toner image on the at least one latent image carrier (2) based on image data, a transfer body (8) onto which the toner image formed on the at least one latent image carrier (2) is transferred in one or more valid image ranges, a non-image range determiner (31) to determine a non-image range on a surface of the transfer body (8) onto which the toner image is not transferred, a surface detector (23) to detect the surface of the transfer body (8) in the non-image range, and a toner determiner (33) to determine whether or not toner is present in the non-image range based on a result detected by the surface detector (23).