Temperature Control Device for Image Formers Using Duty-Based Estimation

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Solution Overview

Problem

Existing temperature control systems for image forming apparatuses face challenges in preventing temperature ripples while maintaining accurate temperature control, often requiring high-cost temperature sensors with good responsiveness.

Innovation Solution

A temperature control device comprising a temperature estimation component, a duty generation component, and a signal generation component, which estimates the temperature of a heat roller based on a duty value, generates the duty value from temperature estimation and detection results, and outputs an energization pulse to control the heater power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a temperature sensor with good responsiveness is used to prevent temperature ripple, then temperature control accuracy is improved, but the cost increases

Engineering Contradiction:
Improvetemperature detection accuracyVSAvoidcost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent uses a low-cost temperature sensor with slower response characteristics instead of an expensive high-responsiveness sensor. By combining this affordable sensor with software-based temperature ripple correction algorithms, the system achieves accurate temperature control without requiring costly hardware upgrades, thereby resolving the contradiction between measurement precision and manufacturing cost

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent introduces an intermediary processing layer (temperature ripple correction unit) that mediates between the low-cost temperature sensor and the control system. This intermediary component processes the temperature detection signals to eliminate ripples, allowing the use of cheaper sensors while maintaining control accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If high-speed sampling is used to detect energization pulse changes, then temporal accuracy is improved, but processing load increases

Engineering Contradiction:
Improvetemporal accuracyVSAvoidprocessing load
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs periodic sampling at optimized intervals rather than continuous high-speed sampling. By sampling the temperature and energization pulse data at strategically chosen periodic intervals, the system achieves sufficient temporal accuracy while significantly reducing the processing load on the CPU, thus resolving the contradiction between measurement precision and device complexity

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent performs preliminary processing of energization pulse signals by using pre-stored pulse width information and duty cycle data. This preliminary action allows the system to calculate temperature corrections without requiring real-time high-speed analysis of every pulse change, thereby reducing processing load while maintaining temporal accuracy

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

The solution effectively prevents temperature ripples and reduces processing load, allowing for accurate temperature control without the need for high-speed sampling, thus lowering costs and improving system efficiency.

Implementation Method 1

a heater configured to heat the fixing rotator

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a temperature sensor configured to detect a surface temperature of the heat roller

Methodology Applied
Scientific EffectThermal detection:

Data Source

PatentEP4310596B1Temperature control device and image forming apparatus
Publication Date: 2025.04.30 TOSHIBA TEC KK
  • EP4310596B1 patent drawingFigure 1
  • EP4310596B1 patent drawingFigure 2
  • EP4310596B1 patent drawingFigure 3

AI summary

A temperature control device (14) comprising a temperature estimation component (81) configured to estimate the temperature of a temperature controlled target to which heat is propagated by supplying power to a heater (73); a duty generation component (87) configured to generate a duty value based on a temperature estimation result by the temperature estimation component, a temperature detection result of the temperature controlled target by a temperature sensor (74), and a target temperature; and a signal generation component (89) configured to output an energization pulse to control the power supplied to the heater based on the duty value, wherein the temperature estimation component is further configured to estimate the temperature of the temperature controlled target based on the duty value.