Toner Detection Error Reduction in Image Forming Apparatus

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Solution Overview

Problem

Existing methods for detecting the remaining toner amount in image forming apparatuses, such as electrophotographic printers, often result in errors, especially during initial operations, leading to inaccurate measurements even when the toner is depleted.

Innovation Solution

An image forming apparatus is equipped with a measuring unit to determine the toner amount based on information stored in a memory unit and measurements obtained during initial operations, accounting for potential measurement errors to ensure accurate toner remaining amount detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional toner remaining amount detection method is used during initial operation, then the measurement process is simple and quick, but the measurement precision deteriorates due to error components arising from empty toner bottle conditions

Engineering Contradiction:

Improvetoner remaining amount detection accuracyVSAvoiddetection system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing a toner supplying operation before the toner remaining amount detection during initial operation. This ensures that the developing unit contains sufficient toner at the time of measurement, eliminating detection errors that occur when the toner bottle is empty. The supplying operation is executed in advance to prepare the system for accurate measurement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using detection results from multiple sampling points during the toner supplying operation. The system collects toner remaining amount data at different time points, compares these values, and determines the final remaining amount based on the relationship between successive detection results. This feedback mechanism filters out erroneous measurements and improves overall detection accuracy.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If multiple sampling points are used to reduce detection errors, then the measurement precision improves, but the loss of time increases due to extended measurement duration

Engineering Contradiction:

Improvetoner remaining amount detection accuracyVSAvoidinitial operation time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies continuity of useful action by performing toner remaining amount detection continuously during the toner supplying operation. Instead of pausing the supplying process to take measurements, the system conducts detections at multiple sampling points while the supplying continues uninterrupted. This approach maintains productive action while gathering multiple data points for accurate determination.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent uses partial action by selecting specific sampling points during the toner supplying operation rather than measuring at every possible moment. The system performs detections at strategically chosen intervals (e.g., at predetermined time points or rotation angles of the developing roller) to obtain sufficient data for accurate determination without unnecessarily extending the measurement time.

Inventive Principle:

Principle #16Partial or excessive 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 approach allows for precise measurement of the toner remaining amount, reducing errors and ensuring accurate detection even when the toner is nearly depleted, thus preventing unnecessary toner consumption and extending the service life of the developing unit.

Implementation Method 1

Another method for detecting a toner remaining amount that has been proposed is a method that detects the electrostatic capacitance of toner that is formed between a developing roller and an antenna electrode

Methodology Applied

Scientific EffectElectrostatic capacitance: Capacitance

Implementation Method 2

a developing unit configured to develop an electrostatic latent image formed on the image bearing member, with toner

Methodology Applied

Scientific EffectElectrostatic latent image: Electrostatics

Data Source

PatentUS10698353B2Image forming apparatus

Publication Date: 2020.06.30 CANON KK

AI summary

An image forming apparatus includes an image bearing member, a developing unit to develop an electrostatic latent image formed on the image bearing member with toner, and a detachable toner container in which toner for supplying to the developing unit is contained. A measuring unit measures information relating to an amount of toner in the developing unit, and a determination unit determines an amount of toner in the developing unit based on the measured information. In a case where the determination unit determines that the toner container is empty, a supply operation for supplying toner from the toner container to the developing unit is performed and the measuring unit measures the information relating to an amount of toner in the toner container after the supply operation is performed, and in a case where the information relating to an amount of toner in the toner container measured after the supply operation is performed is within a measurement error range, the determination unit determines that the toner container is empty.