Fuser Heater Element Power Control via Preliminary Heating

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Solution Overview

Problem

Existing methods for estimating heating power in electrophotographic printer fuser assemblies show inconsistency due to the initial temperature of the heater element, leading to unpredictable power delivery and potential damage from excessive power.

Innovation Solution

A method is introduced where the heater element is set to a consistent starting condition by heating it to a predefined temperature and maintaining it within a specific range for a defined period, ensuring that the initial temperature's energy contribution is factored into the power estimation, thereby enabling consistent power control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the heater element is heated from different starting temperatures to estimate heating power, then the power estimation method can handle various operational conditions, but the heating power estimation becomes inconsistent and unpredictable

Engineering Contradiction:

Improvepower estimation across different temperaturesVSAvoidheating power estimation consistency

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by heating the heater element to a predetermined temperature range (e.g., 40-60°C) before performing power estimation measurements. This preliminary heating ensures that the heater element starts from a consistent thermal state, eliminating the inconsistency caused by varying initial temperatures. The control unit maintains the temperature within the predetermined range for a predetermined time before initiating the power estimation sequence.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If power is applied to heat the heater element quickly after powering up, then image generation can be enabled sooner, but excessive power may be delivered causing catastrophic damage

Engineering Contradiction:

Improveimage generation speedVSAvoidexcessive power delivery

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements feedback control where the control unit continuously monitors the actual temperature of the heater element using temperature sensors and adjusts the power delivery accordingly. The control unit compares the actual temperature with target temperatures and modifies the heating power to maintain optimal temperature profiles, preventing both insufficient heating and excessive power delivery that could cause damage.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies dynamics by implementing variable power delivery based on real-time temperature conditions. The control unit dynamically adjusts the heating power during different phases: initial heating phase, temperature maintenance phase, and power estimation phase. This dynamic control ensures safe power delivery while maintaining productivity by enabling quick image generation when conditions permit.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If the heater element temperature is not standardized before power estimation, then the system can operate with varying initial conditions, but the power ratio calculation becomes inaccurate and varies significantly with temperature

Engineering Contradiction:

Improveoperation under varying conditionsVSAvoidpower ratio calculation accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary 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

This approach significantly reduces inconsistencies in heating power estimation, with the power ratio variation across different temperatures minimized to less than 7%, ensuring safe and efficient power delivery to the fuser assembly.

Implementation Method 1

applying power to a heater element in the fuser assembly for heating the heater element

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS8023851B2Method and printer assembly for consistent power control in fuser assembly of electrophotographic printer

Publication Date: 2011.09.20 LEXMARK INTERNATIONAL INC

AI summary

A method for setting a heater element of a fuser assembly to a consistent starting condition to achieve consistency in heating power measurement is provided. The heater element is heated to a first predefined temperature when the temperature of the heater element is less than the first predefined temperature. The temperature of the heater element is maintained within a predefined range for a predefined period of time. This sets the temperature of the heater element in the fuser assembly to a consistent starting condition. Thereafter, the heating power estimation measurement is made and heating power supplied to the fuser assembly is estimated. This controls the heating power delivered to the fuser assembly in a consistent manner.