Photoreceptor Charging Voltage Correction for Stable Image Quality

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Solution Overview

Problem

Existing image forming systems struggle to set a charging voltage for a photoreceptor to a specified voltage due to fluctuations in sensitivity caused by factors such as cumulative use time, leading to inconsistent image quality.

Innovation Solution

An image forming system that uses information on the layer film thickness and driving frequency of the photoreceptor, along with temperature and humidity data, to correct the charging voltage applied to the photoreceptor, thereby maintaining consistent charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed charging voltage is applied to the photoreceptor, then the system operation is simple, but the charging voltage cannot be maintained at the specified value due to photoreceptor sensitivity fluctuations

Engineering Contradiction:
Improvecharging voltage accuracyVSAvoidvoltage control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system measures the actual charging voltage on the photoreceptor surface and uses this feedback to adjust the charging member voltage dynamically. This closed-loop control ensures the charging voltage remains at the specified value despite photoreceptor sensitivity changes, resolving the contradiction between voltage accuracy and system simplicity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the charging voltage parameter based on detected photoreceptor characteristics and operating conditions. By dynamically adjusting the voltage parameter rather than using a fixed value, the system maintains accurate charging despite variations in photoreceptor sensitivity over time and environmental conditions.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the charging voltage is adjusted to compensate for photoreceptor sensitivity changes, then the charging accuracy improves, but the system complexity increases due to additional sensors and control mechanisms

Engineering Contradiction:
Improveimage quality consistencyVSAvoidcontrol system structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system incorporates voltage detection and feedback control to automatically adjust charging parameters, eliminating the need for complex manual calibration systems while maintaining consistent image quality across different photoreceptor lifecycles and environmental conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of charging voltage based on real-time detection of photoreceptor state and environmental conditions, without requiring external intervention or complex preset configurations, thereby maintaining image quality consistency with minimal added complexity.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If environmental conditions (temperature, humidity) are monitored and used for voltage correction, then the charging stability improves, but the device complexity increases due to additional sensors

Engineering Contradiction:
Improvecharging voltage stabilityVSAvoidsensor system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The system adjusts the charging voltage parameter based on detected environmental parameters (temperature, humidity) and photoreceptor characteristics. This dynamic parameter adjustment compensates for environmental effects on photoreceptor sensitivity, maintaining charging stability without requiring overly complex sensor systems.

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

The system ensures the charging voltage is set accurately regardless of the photoreceptor's use situation, stabilizing image quality and reducing fluctuations in charging voltage.

Implementation Method 1

a charging member configured to electrically charge a surface of the photoreceptor as a voltage is applied

Methodology Applied
Scientific EffectElectrostatic charging: Electrostatics

Implementation Method 2

an exposure device configured to allow the surface of the photoreceptor to be exposed with light to form an electrostatic latent image

Methodology Applied
Scientific EffectPhotoconductivity: Photoconductivity

Data Source

PatentEP4707935A1Image forming system and program
Publication Date: 2026.03.11 FUJIFILM BUSINESS INNOVATION CORP
  • EP4707935A1 patent drawingFigure 1
  • EP4707935A1 patent drawingFigure 2
  • EP4707935A1 patent drawingFigure 3

AI summary

An image forming system includes: a photoreceptor formed with a film including a photosensitive layer on a surface of a base material; a charging member configured to electrically charge a surface of the photoreceptor as a voltage is applied; an exposure device configured to allow the surface of the photoreceptor to be exposed with light to form an electrostatic latent image; a developing device configured to develop the electrostatic latent image formed on the surface of the photoreceptor as a toner image; and a processor configured to use both information of a layer film thickness of an outermost layer of the photoreceptor and information of a driving frequency of the photoreceptor, the information of the driving frequency being derived from driving information of the photoreceptor in a most recently set time width, to correct the voltage to be applied to the charging member.