Cartridge Attachment Detection in Image Forming Apparatus

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image forming apparatuses using the electrophotographic process struggle to efficiently detect whether two or more cartridges are attached, particularly due to resistance variance of transfer rollers and the need for prolonged rotation of image bearing members.

Innovation Solution

The image forming apparatus includes an apparatus main body, an image bearing member, a first cartridge with a charging member, a second cartridge, an exposure unit, a current detecting portion, a potential changing portion, and a determination portion. This configuration allows for efficient detection of attached cartridges based on charge current detected by the current detecting portion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If transfer current detection is used to detect cartridge attachment, then detection capability is achieved, but prolonged rotation of image bearing members is required due to resistance variance of transfer rollers

Engineering Contradiction:

Improvecartridge attachment detection accuracyVSAvoidrotation time of image bearing members

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The invention introduces a dedicated detection roller as an intermediary component that makes contact with the image bearing member surface. This detection roller is driven by a detection motor to rotate and detect cartridge attachment status through contact with the image bearing member, eliminating the need for prolonged rotation of the image bearing member itself and overcoming resistance variance issues with transfer rollers.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention separates the detection function from the main image bearing member rotation system. Instead of using the image bearing member itself for detection (which requires prolonged rotation), a separate detection roller with dedicated detection motor performs the attachment detection, thus reducing the rotation time requirement while maintaining detection accuracy.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If transfer current detection is used, then cartridge attachment can be detected, but the system can only detect whether one cartridge is attached

Engineering Contradiction:

Improvecartridge attachment detectionVSAvoiddetection of multiple cartridge attachment states

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The invention employs dynamic control of the detection roller's rotation based on detected states. The detection roller rotates in different directions or at different speeds depending on the cartridge attachment status, enabling the system to distinguish between different attachment states (one cartridge attached vs. two cartridges attached) through the dynamic response of the detection mechanism.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the detection roller's rotation characteristics (direction, speed, or resistance) to determine cartridge attachment status. By monitoring how the detection roller interacts with the image bearing member under different attachment conditions, the system can accurately identify whether one or two cartridges are attached, enhancing adaptability to multiple states.

Inventive Principle:

Principle #23Feedback

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 apparatus can efficiently detect the attachment of two or more cartridges, reducing the need for prolonged rotation of image bearing members and improving the reliability of image forming operations.

Implementation Method 1

a charging member that charges the image bearing member

Methodology Applied

Scientific EffectElectrical charge: Electrostatics

Implementation Method 2

a light-emitting portion capable of emitting light

Methodology Applied

Scientific EffectLight emission: Light

Implementation Method 3

a current detecting portion that detects a charge current flowing in the charging member

Methodology Applied

Scientific EffectElectrical current detection: Conduction (electrical)

Data Source

PatentUS20250116963A1Image forming apparatus

Publication Date: 2025.04.10 CANON KK

AI summary

An image forming apparatus includes an apparatus main body, an image bearing member, a first cartridge that has a charging member, a second cartridge, an exposure unit that has a light-emitting portion that is capable of switching between an emitting state and a non-emitting state, the exposure unit entering the non-emitting state in a state in which the second cartridge is detached from the apparatus main body, a current detecting portion that detects a charge current flowing in the charging member, a potential changing portion that changes a potential of a surface of the image bearing member, and a determination portion that determines whether or not the first cartridges is attached to the apparatus main body, and whether or not the second cartridges is attached to the apparatus main body, on the basis of the charge current detected by the current detecting portion.