Developing Chamber Detection for Accurate Developer Supply

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional developing devices in image forming apparatuses inaccurately calculate the total remaining amount of developer by detecting it only in the accommodating chamber, leading to potential underestimation or overestimation of the actual developer supply.

Innovation Solution

A developing device with a conveying member in the developer accommodating chamber that rotates opposite to the supplying roller, combined with a detecting portion on the inner wall to accurately measure the developer amount in the developing chamber, ensuring precise detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the remaining amount detecting portion is provided in the accommodating chamber to detect developer amount, then the detection function is implemented, but the detection accuracy is insufficient because it cannot accurately reflect the actual developer supply amount in the developing chamber

Engineering Contradiction:

Improvedeveloper remaining amount detection accuracyVSAvoidinaccurate developer amount information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent introduces a conveying member as an intermediary mechanism that physically transports developer from the accommodating chamber to the developing chamber. By placing the detecting portion at the downstream end of this conveying path, the system detects developer amount after it has been actively conveyed, providing more accurate information about the actual supply amount rather than just the stored amount.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The conveying member performs preliminary action by actively transporting developer toward the developing chamber before detection occurs. This preliminary conveyance ensures that the developer being detected has already undergone the supply process, making the detection result more representative of the actual developer amount available for image formation.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If the detecting portion is placed on the inner wall surface of the accommodating chamber, then the detection structure is simplified, but the detection location does not accurately represent the developer amount in the developing chamber

Engineering Contradiction:

Improvedetection structure complexityVSAvoiddeveloper amount measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the spatial dimension of detection by moving the detecting portion from the accommodating chamber (storage dimension) to the developing chamber (supply dimension). Specifically, it places the detector on the inner wall at the downstream end of the opening, which is the location where developer accumulates after being conveyed from the accommodating chamber, thus detecting the actual supply amount rather than storage amount.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Device complexity

If the conveying member rotates in the same direction as the supplying roller, then the mechanical structure is simplified, but the developer flow and detection accuracy are compromised

Engineering Contradiction:

Improvemechanical structure complexityVSAvoiddeveloper remaining amount detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies inversion by making the conveying member rotate in the opposite direction to the supplying roller. This counterintuitive design creates a more effective developer flow pattern where the conveying member can properly transport developer from the accommodating chamber through the opening to the developing chamber, ensuring that the detecting portion accurately measures the developer amount at the correct location in the supply path.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS20250306500A1Developing device

Publication Date: 2025.10.02 CANON KK

AI summary

A developing device includes a developing roller, a supplying roller, and a developing container. The developing container includes a developing chamber, a developer accommodating chamber having an opening and an inner wall surface, a conveying member having a rotational axis, and a detecting portion. In a cross section perpendicular to the rotational axis, the detecting portion is provided in a region of the inner wall surface positioned between a first point and a second point with respect to the rotational direction of the conveying member, the first point being a downstream end of the opening with respect to the rotational direction, and the second point being a point where a virtual line passing through the rotational axis and an upstream end of the opening with respect to the rotational direction crosses the inner wall surface.