Slow Photoreceptor Rotation in Image Forming Apparatus for Image Quality

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Abnormal images such as blurred or scratchy images occur due to volatile components from waste toner and discharge products adhering to the photoreceptor surface, leading to changes in residual potential and electrical resistance.

Innovation Solution

The image forming apparatus includes a mechanism to change the positional relationship between the photoreceptor and other components like the charger and cleaning unit after a predetermined time, rotating the photoreceptor at a slower speed to prevent these changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the photoreceptor remains in a stopped state with fixed positional relationship with the charger and cleaning unit, then power consumption is reduced and mechanical wear is minimized, but abnormal images occur due to volatile components and discharge products adhering to the photoreceptor surface

Engineering Contradiction:
Improveimage qualityVSAvoidpositional adjustment mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the photoreceptor's positional relationship with the charger and cleaning unit changeable rather than fixed. The photoreceptor is rotated at a slow speed (different from printing speed) to dynamically adjust its position relative to these components, preventing adhesion of volatile components and discharge products while maintaining operational reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements periodic action by rotating the photoreceptor at slow speeds during idle periods when no printing is performed. This periodic movement changes the positional relationship between the photoreceptor and the charger/cleaning unit over time, preventing the accumulation of harmful substances on the photoreceptor surface without requiring continuous high-speed operation.

Inventive Principle:
Principle #19Periodic action

2Reliability

If the photoreceptor rotates at slow speed to change positional relationship, then abnormal images are suppressed, but printing productivity is reduced

Engineering Contradiction:
Improveimage qualityVSAvoidprinting speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies periodic action by implementing slow-speed rotation only during idle periods when no printing is being performed. During actual printing operations, the photoreceptor operates at normal printing speed. This time-based differentiation ensures image quality maintenance without compromising printing productivity when needed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the photoreceptor's rotation speed based on operational state: slow speed during idle periods to prevent abnormal images, and normal printing speed during active printing. This dynamic adaptation resolves the contradiction between image quality and productivity by applying different operational modes at different times.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the positional relationship between photoreceptor and charger is fixed, then device complexity is reduced, but discharge products stick to photoreceptor and decrease electrical resistance causing abnormal images

Engineering Contradiction:
Improveelectrical resistance stabilityVSAvoidpositional control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the positional relationship between the photoreceptor and charger dynamic rather than fixed. By rotating the photoreceptor at slow speeds, the system continuously changes the relative position, preventing discharge products from permanently adhering to the same location on the photoreceptor surface, thereby maintaining stable electrical resistance.

Inventive Principle:
Principle #15Dynamics

4Reliability

If the photoreceptor and cleaning unit maintain fixed positional relationship, then mechanical structure is simplified, but volatile components from waste toner are absorbed into photoreceptor surface increasing residual potential

Engineering Contradiction:
Improveresidual potential controlVSAvoidpositional adjustment mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by enabling the photoreceptor to rotate at slow speeds, creating a dynamic positional relationship with the cleaning unit. This movement prevents volatile components from waste toner from being continuously absorbed into the same area of the photoreceptor surface, thereby controlling residual potential levels while using a relatively simple rotational mechanism.

Inventive Principle:
Principle #15Dynamics

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 effectively suppresses the occurrence of abnormal images by maintaining optimal electrical conditions and reducing friction, while also conserving power.

Implementation Method 1

a component volatilized from waste toner of the cleaning unit may be absorbed into the surface of the photoreceptor

Methodology Applied
Scientific EffectVolatilization: Evaporation

Implementation Method 2

a component volatilized from waste toner of the cleaning unit may be absorbed into the surface of the photoreceptor

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

a discharge product of the charger sticks to the surface of the photoreceptor

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 4

a discharge product of the charger sticks to the surface of the photoreceptor, and the discharge product dissolves in water adsorbed on the surface at high humidity to decrease electrical resistance

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4579352A1Image forming apparatus
Publication Date: 2025.07.02 FUJIFILM BUSINESS INNOVATION CORP
  • EP4579352A1 patent drawingFigure 1
  • EP4579352A1 patent drawingFigure 2
  • EP4579352A1 patent drawingFigure 3

AI summary

An image forming apparatus (1) includes a photoreceptor (31) that holds a toner image to be transferred to a paper sheet (P), a charger (32) that charges a surface of the photoreceptor, a developer (33) that supplies toner to the surface of the photoreceptor, a cleaning unit (34) that collects toner stuck to the photoreceptor, and a unit that changes a positional relationship between the photoreceptor and the charger and/or a positional relationship between the photoreceptor and the cleaning unit under a predetermined condition after the photoreceptor stops.