Image Forming Apparatus Temperature Control for Toner Aggregation

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Solution Overview

Problem

Image forming apparatuses face temperature-related issues during continuous printing, leading to potential toner aggregation or melting, which can result in decreased print quality or equipment failure, as existing intermittent print modes may not adequately reduce internal temperatures when external factors prevent cooling.

Innovation Solution

The apparatus includes a temperature detector and processing circuitry that switches between continuous and intermittent print modes based on internal temperature thresholds, and stops heating the fixing device when temperatures do not decrease as intended, effectively managing temperature rises by alternating print operations and suspensions to prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If continuous print mode is used to maintain high productivity, then output per unit time increases, but internal temperature rises causing toner aggregation or melting

Engineering Contradiction:

Improveprint output per unit timeVSAvoidinternal temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The system implements periodic action by alternating between continuous print mode and intermittent print mode. When the internal temperature reaches a predetermined threshold during continuous printing, the system automatically switches to intermittent mode, performing a print operation followed by a suspension period. This periodic switching allows the apparatus to maintain high productivity during normal operation while periodically cooling down to prevent toner aggregation and melting, thus resolving the contradiction between continuous high-speed printing and temperature control.

Inventive Principle:

Principle #19Periodic action

2Temperature

If intermittent print mode is activated to reduce temperature, then internal temperature decreases, but print productivity is reduced

Engineering Contradiction:

Improveinternal temperatureVSAvoidprint output per unit time

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The system applies dynamics by making the print mode flexible and adaptive rather than fixed. The control circuitry dynamically switches between continuous print mode and intermittent print mode based on real-time temperature monitoring. When temperature is within safe ranges, the system operates in continuous mode for maximum productivity. When temperature thresholds are exceeded, it automatically transitions to intermittent mode for cooling. This dynamic adaptation allows the system to optimize both temperature control and productivity according to actual operating conditions.

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If heater stops heating in intermittent print mode when temperature does not decrease, then temperature control precision improves, but energy consumption increases

Engineering Contradiction:

Improvetemperature control precisionVSAvoidheater energy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system implements feedback control by continuously monitoring the internal temperature with a temperature detector and using this information to control the heater operation. In intermittent print mode, when the temperature does not decrease to below the cancellation temperature within a predetermined time after mode switching, the control circuitry stops the heater. This feedback mechanism ensures precise temperature control by responding to actual temperature conditions, preventing toner issues while managing energy consumption based on real-time thermal state rather than operating indefinitely.

Inventive Principle:

Principle #23Feedback

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 efficiently reduces temperature rises within the image forming apparatus, preventing toner aggregation and equipment failure by dynamically adjusting print modes and heating control, thereby maintaining print quality and extending equipment lifespan.

Implementation Method 1

a fixing device that fixes a toner image on a surface of a sheet by heating of a heater

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

a temperature detector that detects an internal temperature of the image forming apparatus

Methodology Applied

Scientific EffectTemperature detection:

Data Source

PatentUS12130583B2Image forming apparatus and method for switching a continuous print mode to an intermittent print mode

Publication Date: 2024.10.29 RICOH CO LTD

AI summary

An image forming apparatus includes a fixing device, a temperature detector, and processing circuitry. The fixing device fixes a toner image on a surface of a sheet by heating of a heater. The temperature detector detects an internal temperature of the image forming apparatus. The processing circuitry switches a continuous print mode to an intermittent print mode when the internal temperature is equal to or higher than a first execution temperature during the continuous print mode. The processing circuitry cancels the intermittent print mode and switches to the continuous print mode when the internal temperature is equal to or lower than a first cancellation temperature. The processing circuitry causes the heater to stop heating the fixing device in the intermittent print mode when the internal temperature is higher than the first cancellation temperature even after a predetermined time has elapsed since a start of the intermittent print mode.