Transfer Device Constant Current Control for Textured Paper

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Solution Overview

Problem

Conventional electrophotographic image forming apparatuses face challenges in transferring toner evenly onto recessed parts of textured recording sheets, leading to issues like white splotches and varying transferability due to environmental changes and different paper types, as existing voltage control methods are complex and limited in range.

Innovation Solution

The system employs a power source configuration that allows for constant current control of both DC and AC voltage components, enabling adjustable output voltages to maintain high transferability on textured surfaces by setting specific current levels for optimal toner transfer, regardless of environmental conditions or paper types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a DC voltage is superimposed on an AC voltage and the resultant voltage is applied to improve transferability to recessed parts, then the transferability to recessed parts is improved, but the acceptable ranges of voltage settings become more limited and the system becomes more complex

Engineering Contradiction:
Improvetransferability to recessed partsVSAvoidvoltage control system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the voltage application movable and adjustable through constant current control. The DC and AC voltage components are dynamically adjusted based on detected current values, allowing the system to adapt to different paper types and environmental conditions while maintaining optimal transferability to recessed parts.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes physical parameters by superimposing AC voltage on DC voltage and controlling the resultant voltage through constant current control. By detecting current values and adjusting voltage components accordingly, the system optimizes transferability parameters for different recording sheets and environmental conditions.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a DC voltage is superimposed on an AC voltage to improve transferability, then the transferability to recessed parts is improved, but the relation between voltages becomes complex and difficult to cope with environmental changes and different paper types

Engineering Contradiction:
Improvetransferability to recessed partsVSAvoidadaptability to environmental changes and paper types
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies feedback by detecting the current value flowing through the transfer member and using this information to control the DC and AC voltage components. This closed-loop control system automatically adapts to environmental changes and different paper types, maintaining optimal transferability without requiring complex manual adjustments.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-service by automatically adjusting voltage parameters based on detected current values. The constant current control mechanism enables the system to self-regulate and maintain optimal performance across different operating conditions without external intervention.

Inventive Principle:
Principle #25Self-service

3Reliability

If constant current control is applied to DC and AC voltage components, then stable toner transfer is achieved across various conditions, but the device complexity increases

Engineering Contradiction:
Improvestability of toner transferVSAvoidpower source control complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the control of DC and AC voltage components into a unified constant current control system. By combining the voltage control functions and using a single current detection mechanism to regulate both components, the system achieves stable toner transfer while minimizing overall control complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 approach ensures stable and high-quality toner transfer onto recessed parts across various paper types and environmental conditions, improving image quality by maintaining consistent transferability and reducing the risk of image abnormalities.

Implementation Method 1

a voltage which has a direct current (DC) component superimposed on an alternating current (AC) component is applied to a transfer member (80)

Methodology Applied
Scientific EffectElectrostatic deposition: Electrostatic Deposition

Implementation Method 2

forms an image by visualizing a charged latent image obtained by imaging optical image information onto an image carrier that has been evenly charged in advance, using toner supplied from a developing unit, and by transferring and fixing the image

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentEP2498135B1Transfer device and image forming apparatus
Publication Date: 2020.07.08 RICOH CO LTD
  • EP2498135B1 patent drawingFigure 1~2
  • EP2498135B1 patent drawingFigure 3~4
  • EP2498135B1 patent drawingFigure 5~6

AI summary

According to an embodiment, a transfer device includes: an image carrier (80) from which an image is transferred onto a transfer medium using electrostatic toner, the image carrier (80) being applied with a direct current voltage superimposed with an alternating current (AC) voltage as a transfer bias. An output voltage of a power source (110) for applying the voltage is controlled so that a current level of a direct current component output from the power source (110) is kept at a specified current level.