Conductive Member for Developing Roller Bias in Image Forming Apparatus

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Solution Overview

Problem

The existing image forming apparatuses face instability in pressing the developing roller against the photosensitive member, leading to deterioration in image quality due to the conductive bearing member's contact with the power supply terminal.

Innovation Solution

A conductive member is used to electrically connect to the developing roller shaft, which is pressed by an electrical connection member to apply developing bias, ensuring stable contact and minimizing rattling, thereby maintaining image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conductive bearing member is used to apply developing bias to the developing roller, then electrical connection is achieved, but the developing roller becomes unstably pressed against the photosensitive drum, deteriorating image quality

Engineering Contradiction:

Improveelectrical connection stabilityVSAvoidimage quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent introduces a conductive member as an intermediary component between the power supply terminal and the developing roller shaft. This conductive member is specifically designed to be pressed by the electrical connection member, creating a stable mechanical and electrical connection path that prevents direct contact issues between the bearing member and power supply terminal, thereby resolving the instability in pressing the developing roller against the photosensitive drum.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the power supply terminal directly contacts the conductive bearing member, then developing bias is applied, but the developing cartridge becomes unstable, causing rattling and poor image quality

Engineering Contradiction:

Improvedeveloping bias applicationVSAvoiddeveloping cartridge stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent segments the electrical connection function by separating the power supply terminal contact from the developing roller support function. The conductive member is divided into a first portion for electrical connection with the power supply terminal and a second portion for connection with the developing roller shaft. This segmentation allows the electrical connection to be stabilized independently from the mechanical support function, preventing cartridge instability and rattling.

Inventive Principle:

Principle #1Segmentation

3Productivity

If the developing roller is pressed against the photosensitive drum, then image formation occurs, but unstable pressing leads to deterioration of image quality

Engineering Contradiction:

Improveimage formationVSAvoidimage quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements preliminary action by ensuring the conductive member is properly positioned and connected before the developing roller begins its image formation operation. The electrical connection member is designed to contact and stabilize the conductive member's first portion prior to the developing process, preventing instability during image formation and ensuring consistent image quality throughout operation.

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

This solution stabilizes the contact between the developing roller and the photosensitive drum, ensuring high-quality image formation by preventing unstable pressing and maintaining fine image quality.

Implementation Method 1

A conductive member configured to electrically connect to a developing roller shaft is pressed by an electrical connection member for applying developing bias to the developing roller

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS7512363B2Providing electrical potential to a rotatable developer carrier in an image forming apparatus

Publication Date: 2009.03.31 BROTHER KOGYO KK

AI summary

Developing cartridges for use in image forming apparatuses having an image carrier, include: (a) a case; (b) a developer carrier supported by the case (for holding developer thereon); and (c) a conductive member engaged with or provided on the case and being electrically connected to the developer carrier. The case may be configured to allow the developer carrier to be pressed against the image carrier at a designated pressing position in a pressing direction, and the conductive member may be configured to be supplied with electrical potential while being pressed by an electrical connection member in a direction parallel to the pressing direction. Alternatively, in some structures, the conductive member may be configured to be supplied with electrical potential while being pressed by an electrical connection member in a direction parallel to a line extending from the designated pressing position to a developer carrier and image carrier contacting position.