Dynamic Toner Density Control for Image Forming Apparatus

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image forming apparatuses face issues with toner density control, leading to weak or uneven images due to delayed toner supply during high coverage rate printing and unnecessary print stops, as well as potential fogging when coverage rates change, due to inflexible toner density control standards.

Innovation Solution

An image forming apparatus with a toner density detecting unit, mode setting unit, and adjustable standard values that dynamically set supply modes based on detected toner density and consumption speed, allowing for continuous printing without unnecessary stops and preventing excessive toner buildup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed toner density control standard value is used, then toner supply can be controlled simply, but print action is unnecessarily stopped when coverage rate changes, reducing productivity

Engineering Contradiction:

Improvetoner density controlVSAvoidcontinuous printing capability

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent applies dynamics by making the toner density control standard value variable rather than fixed. The control standard value is dynamically adjusted based on the coverage rate of the image being printed. When high coverage rate images are detected, the control standard value is raised to prevent unnecessary toner supply interruptions, thereby maintaining continuous printing capability while still ensuring adequate toner density control.

Inventive Principle:

Principle #15Dynamics

2Productivity

If toner density control standard value is raised for high coverage rate printing, then unnecessary print stops are prevented, but fogging may occur when switching to low coverage rate printing

Engineering Contradiction:

Improvecontinuous printing capabilityVSAvoidfogging on white background

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by adjusting the toner density control standard value based on the detected coverage rate of the image. When high coverage rate images are printed, the control standard value is raised to prevent unnecessary interruptions. When switching to low coverage rate images, the control standard value is lowered to prevent fogging. This dynamic parameter adjustment resolves the contradiction between maintaining continuous printing and preventing harmful fogging effects.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by using a coverage rate detecting unit to monitor the type of image being printed and providing this information back to the control unit. The control unit then adjusts the toner density control standard value based on this feedback, creating a closed-loop system that prevents both unnecessary print stops and fogging by continuously adapting to changing printing conditions.

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If toner is supplied frequently to maintain density, then image quality remains consistent, but toner consumption increases and supply delays occur during high coverage rate printing

Engineering Contradiction:

Improveimage quality consistencyVSAvoidtoner consumption

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent applies parameter changes by adjusting the toner density control standard value according to the coverage rate of the printed image. During high coverage rate printing, the control standard value is raised, allowing the system to tolerate lower toner density levels without interrupting printing. This reduces the frequency of toner supply operations and decreases overall toner consumption while maintaining acceptable image quality consistency.

Inventive Principle:

Principle #35Parameter changes

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 ensures consistent toner supply, prevents unnecessary print stops, and reduces fogging by adjusting toner density control standards based on actual consumption rates, maintaining image quality across varying coverage rates.

Implementation Method 1

an electrostatic latent image forming unit; a developer accommodating unit; a developing unit... The electrostatic latent image forming unit forms an electrostatic latent image on the surface of the image bearing member

Methodology Applied

Scientific EffectElectrophotographic process: Electrostatics

Implementation Method 2

The developing unit supplies toner to the image bearing member and develops the electrostatic latent image as toner image

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentUS8942579B2Image forming apparatus including developing unit

Publication Date: 2015.01.27 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

The present disclosure relates to an image forming apparatus including: a developing unit; a developer supply unit; a toner density detecting unit; a mode setting unit; a first supply control unit; a second supply control unit; and a second standard value setting unit. The toner density detecting unit detects toner density. The mode setting unit, when toner density detected by the toner density detecting unit is less than a first standard value and a second standard value that is lower than the first standard value or more, sets a first developer supply mode as a mode for supplying developer to the developing unit and when the toner density detected by the toner density detecting unit is less than the second standard value, sets a second developer supply mode as a mode for supplying developer to the developing unit.