Image Forming Apparatus Intermittent Printing Temperature Control

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Solution Overview

Problem

Image forming apparatuses face challenges in suppressing temperature rise during printing, leading to potential image defects due to excessive heat affecting toner adhesion and doctor blade issues, with existing solutions like cooling structures and intermittent printing being inefficient or causing performance drops.

Innovation Solution

An image forming apparatus with a control unit that adjusts the ratio of printing execution time to stop time based on a stop control number, switching between intermittent modes with different stop times to manage temperature effectively, using temperature sensors to determine optimal operation modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling air is applied to the developing device and doctor blade to reduce temperature, then temperature control is improved, but device complexity increases due to required cooling structure

Engineering Contradiction:
Improvetemperature of developing device and doctor bladeVSAvoidcooling structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent extracts the temperature control function from a dedicated cooling structure and implements it through software-based intermittent printing control. By removing the need for physical cooling components and using control logic to manage printing cycles, the system achieves temperature control without adding complex hardware.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical cooling system with a control-based approach. Instead of using physical cooling air flow, the system uses software control to interrupt printing operations at strategic intervals, allowing natural cooling while maintaining productivity. This substitution eliminates the need for cooling fans, ducts, and associated hardware.

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

2Temperature

If intermittent printing is implemented to suppress temperature rise, then temperature control is improved, but productivity decreases due to repeated printing stoppages

Engineering Contradiction:
Improvetemperature in image forming apparatusVSAvoidprinting throughput
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent implements dynamic intermittent printing control where the printing stoppage intervals are not fixed but adapt based on real-time temperature monitoring and stop control numbers. The control unit dynamically adjusts when to stop and resume printing, optimizing the balance between temperature control and productivity based on current operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback control by monitoring temperature and using this information to determine when to implement printing stoppages. The control unit receives temperature data, compares it against thresholds, and adjusts printing operations accordingly. This feedback mechanism ensures temperature control while minimizing productivity impact by only stopping when necessary.

Inventive Principle:
Principle #23Feedback

3Temperature

If printing stops for extended periods to cool the apparatus, then temperature control is improved, but image quality deteriorates due to toner fixation issues

Engineering Contradiction:
Improvetemperature controlVSAvoidimage quality
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by implementing brief cooling intervals between printing sequences before temperature reaches critical levels that would cause toner fixation. The control unit proactively introduces short stoppages to prevent excessive heat accumulation, ensuring temperature remains within a range that maintains image quality while still providing necessary cooling.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes operational parameters by adjusting printing speed, paper feed rate, and heating element power levels to optimize the balance between productivity and temperature control. By dynamically modifying these parameters during printing operations, the system maintains image quality while controlling temperature rise, avoiding the need for extended stoppages that would compromise image formation.

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 approach effectively suppresses temperature rise during printing, preventing image defects while maintaining performance by dynamically adjusting the printing and stop times based on temperature and stop control number conditions.

Implementation Method 1

using temperature sensors to determine optimal operation modes

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

The control unit changes a ratio between an execution time for executing printing and a stop time for stopping the printing according to a stop control number

Methodology Applied
Scientific EffectIntermittent operation control:

Implementation Method 3

This approach effectively suppresses temperature rise during printing, preventing image defects

Methodology Applied
Scientific EffectThermal management through intermittent operation:

Data Source

PatentEP3702842B1Image forming apparatus and method of operating an image forming apparatus
Publication Date: 2022.10.12 TOSHIBA TEC KK
  • EP3702842B1 patent drawingFigure 1
  • EP3702842B1 patent drawingFigure 2
  • EP3702842B1 patent drawingFigure 3

AI summary

An image forming apparatus includes a control unit that changes a ratio between an execution time for executing printing and a stop time for stopping the printing according to any one of a stop control number that is the number of times that an operation of the printing is stopped, a stop control time that is the time during which the operation of the printing is stopped, a printing execution time that is the time during which the printing is executed, and a printing execution control number that is the number of times that the printing is executed, in an intermittent mode that operates by switching between executing the printing and stopping the printing.