Optical Toner Level Detection in Electrophotographic Development Chamber

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Solution Overview

Problem

In electrophotographic image forming apparatuses, maintaining a stable toner level in the development chamber is challenging, leading to toner stress and degradation, as excessive toner supply increases pressure and affects image quality.

Innovation Solution

The implementation of a toner level detecting unit using an optical detection method with multiple sensors to monitor toner levels and adjust supply accordingly, preventing excessive toner accumulation and ensuring consistent image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If toner is supplied from a toner containing unit to a development chamber, then the photoreceptor can be developed to form visible toner images, but excessive toner supply increases pressure in the development chamber causing toner stress and degradation

Engineering Contradiction:
Improvetoner supply amountVSAvoidtoner property stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent implements a feedback control system where a toner level detecting unit continuously monitors the toner level in the development chamber and provides signals to a controller. The controller adjusts the toner supply from the toner containing unit based on this feedback, maintaining the toner level within an optimal range. This prevents both toner deficiency and excessive toner accumulation, thereby avoiding toner stress and degradation while ensuring reliable toner property stability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system enables self-regulation of toner supply through the automatic detection and control mechanism. The toner level detecting unit and controller work together to automatically adjust toner supply without manual intervention, allowing the system to maintain optimal toner levels and prevent toner degradation through self-service monitoring and adjustment.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If toner level in development chamber is not properly maintained, then image quality degrades, but implementing monitoring and control systems increases device complexity

Engineering Contradiction:
Improveimage quality consistencyVSAvoidcontrol system structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs a feedback control mechanism where a toner level detecting unit monitors toner levels and communicates with a controller that automatically adjusts toner supply. This feedback system ensures consistent image quality by maintaining optimal toner levels in the development chamber, while the automated nature of the control minimizes the need for complex manual intervention systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual mechanical monitoring and adjustment methods with an automated optical detection and electronic control system. The toner level detecting unit uses optical or electromagnetic fields to detect toner levels, and the controller uses electronic signals to regulate toner supply, substituting complex mechanical measurement and adjustment mechanisms with more streamlined sensor-based systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 stabilizes toner levels, reduces toner stress, and maintains image quality by ensuring the right amount of toner is supplied, thereby extending the lifespan of consumable components and reducing replacement costs.

Implementation Method 1

a toner level detecting unit which detects the toner level in the development chamber

Methodology Applied
Scientific EffectOptical detection: Absorption (EM radiation)

Data Source

PatentEP3196706B1Electrophotographic image forming apparatus, toner cartridge for the same, imaging cartridge for the same, and method of controlling toner level in developing chamber of the same
Publication Date: 2020.08.05 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3196706B1 patent drawingFigure 1
  • EP3196706B1 patent drawingFigure 2
  • EP3196706B1 patent drawingFigure 3A~3B

AI summary

An electrophotographic image forming apparatus may include an imaging cartridge and a toner cartridge that are detachably attached to a main body, a first optical sensor that is mounted in the imaging cartridge and detects a toner level in a development chamber, and a second optical sensor that is mounted in the toner cartridge and detects a toner level in the development chamber.