Fixing Member Temperature Control for Narrow Media

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Solution Overview

Problem

In image forming apparatuses using the electrophotographic process, the temperature of the fixing member's ends can exceed the allowable limit when narrower recording media are continuously fed, leading to a decrease in fixing apparatus life due to uneven heat distribution and absorption.

Innovation Solution

The image forming apparatus controls the gap between conveyed recording media to be longer than the default gap for wider media, and adjusts the intermission period between feeding to prevent excessive temperature rise at the fixing member's ends by prolonging the heat release period during non-feeding times, ensuring the temperature remains within the allowable limit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If narrower recording media are continuously fed, then productivity is improved, but the temperature of the fixing member's ends exceeds the allowable limit

Engineering Contradiction:

Improvecontinuous feeding capabilityVSAvoidfixing member end temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The control unit detects the width of the recording medium before feeding and preliminarily determines the feeding interval based on the detected width. When a narrow recording medium is detected, the control unit sets a longer feeding interval in advance, preventing excessive temperature rise at the fixing member ends before it occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces mechanical adjustment of feeding intervals with an automated control system that uses width detection and control unit processing. The control unit automatically adjusts the feeding interval based on detected recording medium width, substituting manual or fixed mechanical timing with intelligent adaptive control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If the feeding interval is extended to control temperature, then fixing member temperature is maintained, but productivity decreases

Engineering Contradiction:

Improvefixing member temperature controlVSAvoidfeeding speed

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The feeding interval is made dynamic rather than fixed. The control unit continuously monitors recording medium width and adjusts the feeding interval in real-time based on the detected width. This dynamic adjustment allows the system to maintain optimal temperature control for narrow media while preserving high-speed feeding for wider media.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the feeding interval parameter based on the recording medium width parameter. When the width parameter indicates a narrow medium, the control unit modifies the feeding interval parameter to a longer value, thereby controlling temperature while adapting to different media conditions.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If a fixed feeding interval is used, then operation is simple, but temperature control precision is insufficient

Engineering Contradiction:

Improvefeeding control simplicityVSAvoidtemperature control precision

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The control unit receives feedback from the width detection unit about the recording medium width and uses this feedback to automatically adjust the feeding interval. This closed-loop feedback system maintains simple operation for the user while achieving precise temperature control through automatic parameter adjustment based on actual conditions.

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 method effectively maintains the fixing member's temperature within safe limits, extending the life of the fixing apparatus and ensuring consistent image quality by optimizing heat distribution and absorption for varying paper widths and environmental conditions.

Implementation Method 1

A rotating fixing member 1 includes a heater 2 inside

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

A temperature sensor 3 is provided on the surface of the rotating fixing member 1

Methodology Applied

Scientific EffectTemperature detection: Thermography

Implementation Method 3

A rotating pressing member 4 presses the rotating fixing member 1 to form a fixing nip press region n

Methodology Applied

Scientific EffectPressure: Pressure Increase

Data Source

PatentUS7742714B2Image fixing apparatus, image forming apparatus, and image fixing method capable of effectively controlling an image fixing temperature

Publication Date: 2010.06.22 RICOH CO LTD

AI summary

An image forming apparatus, an image fixing apparatus, and an image fixing method that fix a toner image onto an recording medium in an electrophotographic process capable of effectively controlling an image fixing temperature. In one example, when a narrower recording medium, narrower than a maximum allowable size, is continuously fed at an image fixing temperature, a gap between the conveyed recording mediums is controlled to be longer than a default gap corresponding to a wider recording medium in a feeding direction to avoid an increase of the temperature of the ends of the fixing member in the longitudinal direction, to thereby maintain an allowable temperature limit.