Fixing Heater Power Estimation via Non-Heating Duration

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Solution Overview

Problem

Existing image forming apparatuses face challenges in accurately estimating power consumption levels, particularly due to the impact of inrush currents in the fixing unit's heater, which are not effectively addressed by current methods that rely on uniform power consumption calculations, leading to inaccuracies in energy measurement.

Innovation Solution

An image forming apparatus that includes a storage unit for the basic power consumption level of the heater, an estimation unit to calculate the increase in power consumption based on the duration of the non-heating state preceding heating, and an output unit to provide an estimated power consumption level, without the need for actual measurement of inrush current using a wattmeter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a wattmeter or measurement equipment is provided to actually measure the increase in power consumption level brought about by the inrush current, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvepower consumption level measurement accuracyVSAvoiddevice cost

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/electrical measurement system (wattmeter) with an information processing system that calculates power consumption based on stored basic power consumption levels and inrush current characteristics. The estimation unit computes the actual power consumption level by adding the inrush current impact to the basic power consumption level, eliminating the need for physical measurement equipment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a virtual model of the power consumption characteristics by storing basic power consumption levels in advance. Instead of directly measuring the actual power consumption, the system uses pre-stored characteristic data and calculation formulas to replicate and estimate the power consumption level, including the impact of inrush current.

Inventive Principle:

Principle #26Copying

2Ease of operation

If a uniform value indicating the increase in power consumption level is added each time the heater is activated, then ease of operation is improved, but measurement precision deteriorates because it does not account for variations in inrush current based on duration of non-heating state

Engineering Contradiction:

Improveease of power consumption estimationVSAvoidpower consumption level estimation accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transitions from a static, uniform addition method to a dynamic estimation method that varies the inrush current impact based on the duration of the non-heating state. The estimation unit determines the actual power consumption level by considering the specific duration of non-heating state preceding heater activation, making the power consumption estimation adaptive to different operational conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter used for inrush current estimation from a fixed uniform value to a variable parameter based on the duration of non-heating state. The estimation unit uses the specific duration of non-heating state as a parameter to determine the appropriate inrush current impact, allowing for more accurate power consumption level estimation across different operational scenarios.

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 allows for accurate estimation of the heater's power consumption level, improving energy measurement accuracy without increasing device costs by accounting for variations in inrush current based on preceding non-heating durations.

Implementation Method 1

a heater (131a) built in the fixing roller (131)

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a pressurizing member (132), and a heater (131a) built in the fixing roller (131)... by the pressurizing member pressing against the heating rotational body

Methodology Applied

Scientific EffectPressure: Pressure Increase

Data Source

PatentUS9207607B2Image forming apparatus capable of accurately estimating power consumption level

Publication Date: 2015.12.08 KONICA MINOLTA INC

AI summary

An image forming apparatus that heat-fixes a toner image onto a recording sheet passing through a fixing nip formed by pressing a pressurizing member against a heating rotational body heated by a heater, comprising: a storage unit storing a basic power consumption level of the heater determined in advance in a situation where inflow of inrush current to the heater is not occurring; an estimation unit calculating an estimated power consumption level of the heater by estimating an increase in the power consumption level, with respect to the basic power consumption level, brought about by inflow of inrush current to the heater; and an output unit outputting the estimated power consumption level. The heater switches between a heating state of receiving power supply and a non-heating state of not receiving power supply. The increase is estimated according to a duration of a non-heating state immediately preceding the heating state.