Fixing Roller Speed Control for Noise and Temperature Management

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Solution Overview

Problem

Conventional electrophotographic printers face challenges in reducing noise and preventing temperature overshoot of the fixing roller, leading to increased noise levels and inefficient energy use, especially after the recording medium has passed through the fixing unit.

Innovation Solution

An image forming apparatus with a controller that adjusts the speed of the drive motor for the fixing unit, reducing the speed after the recording medium has passed through to minimize noise and prevent temperature overshoot, using temperature profiles and sensors to determine the optimal rotation time for the fixing roller.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the fixing roller continues to rotate at high speed after the recording medium has passed through, then the temperature overshoot is minimized, but the noise generated during printing increases

Engineering Contradiction:

Improvefixing roller temperature overshootVSAvoidnoise generated during printing

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the rotation speed of the fixing roller variable rather than constant. The drive motor adjusts the rotation speed based on the presence or absence of recording medium: maintaining high speed during printing to prevent temperature overshoot, and reducing to low speed after printing to minimize noise. This dynamic speed adjustment resolves the contradiction between temperature control and noise reduction.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters (rotation speed) of the fixing roller based on operational conditions. By switching between first rotation speed (high) and second rotation speed (low), the system optimizes both temperature control and noise levels. The controller monitors the state and adjusts the parameter accordingly, resolving the technical contradiction.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If the fixing roller rotates for extended time after medium discharge, then temperature overshoot is prevented, but energy consumption increases

Engineering Contradiction:

Improvefixing roller temperature stabilityVSAvoidmotor energy consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the rotation duration and speed based on operational phase. During active printing, high speed maintains temperature stability. After medium discharge, the system transitions to low speed for a predetermined cooling period, then stops rotation. This dynamic time-speed coordination prevents unnecessary energy consumption while maintaining temperature control.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements periodic action through predetermined time-based control: the fixing roller rotates at high speed during printing, switches to low speed for a specific cooling duration after printing, then stops. This time-structured operation pattern ensures temperature stability during needed periods while minimizing energy consumption during idle periods.

Inventive Principle:

Principle #19Periodic action

3Productivity

If the printing speed is increased, then productivity is improved, but the noise generated during printing increases

Engineering Contradiction:

Improveprinting speedVSAvoidnoise generated during printing

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the operation into distinct phases: active printing phase with high speed for productivity, and post-printing phase with low speed for noise reduction. By separating these temporal segments, the system achieves high productivity during printing while minimizing noise during the transition and idle periods.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system uses periodic action with different speed levels corresponding to different operational phases. High printing speed is maintained only during active printing, then transitions to low speed after medium discharge. This time-based speed variation maintains productivity during printing while reducing noise overall.

Inventive Principle:

Principle #19Periodic action

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

The solution effectively reduces noise levels and prevents temperature overshoot, enhancing the operational efficiency and quietness of the printer by adjusting the motor speed and rotation time based on detected temperatures and profiles.

Implementation Method 1

a heater element... the electric power supplied to a heater element is shut off

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the heat in the fixing roller is transferred to the pressure roller

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS7539430B2Image forming apparatus with self cooling fixing section

Publication Date: 2009.05.26 OKI ELECTRIC INDUSTRY CO LTD

AI summary

An image forming apparatus includes a fixing section that fixes an image formed on a recording medium and a drive section that drives the fixing section in rotation. The drive section is stopped or rotated at a lower speed for reducing noise after fixing an image on the recording medium while preventing the temperature of a fixing roller from increasing.