Fixer Nip Width Control via Temperature Adjustment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image forming apparatuses face challenges in accurately controlling the nip width without temperature adjusters or automatic pressure-contact and release mechanisms, leading to issues like crinkles and curls on sheets.

Innovation Solution

An image forming apparatus that includes a heat source, a temperature sensing unit, and a controller to calculate the nip width based on the rotation and rest periods of a heated rotary member, adjusting the target temperature accordingly to maintain optimal nip width.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a temperature adjuster or automatic pressure-contact and release mechanism is used to control the nip width, then the nip width control precision is improved, but the device complexity increases

Engineering Contradiction:

Improvenip width control precisionVSAvoiddevice complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical temperature adjuster and automatic pressure-contact mechanism with a control system that calculates nip width based on rotation period and rest period measurements. The controller uses these temporal parameters to determine and adjust the target temperature, eliminating the need for complex mechanical adjustment devices while maintaining nip width control precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameters from direct mechanical adjustment of nip width to indirect control through temperature adjustment based on rotation period and rest period. By measuring these temporal parameters and calculating the corresponding target temperature, the system achieves nip width control without mechanical complexity.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If a temperature adjuster or automatic pressure-contact and release mechanism is used to control the nip width, then the nip width control precision is improved, but the cost increases

Engineering Contradiction:

Improvenip width control precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive mechanical adjustment mechanisms with a cost-effective control system that uses sensors and calculations to determine nip width and adjust temperature accordingly. This substitution significantly reduces manufacturing costs while maintaining control precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs self-diagnosis and self-adjustment by measuring its own rotation period and rest period, then automatically calculating the appropriate target temperature. This self-service capability eliminates the need for expensive external adjustment mechanisms and reduces manufacturing costs.

Inventive Principle:

Principle #25Self-service

3Device complexity

If the rotation period and rest period are measured and target temperature is adjusted to control nip width, then the device complexity is reduced, but the measurement precision requirement increases

Engineering Contradiction:

Improvedevice complexityVSAvoidrotation period and rest period measurement precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback control system where the controller continuously measures the rotation period and rest period, calculates the current nip width, compares it with the target value, and adjusts the target temperature accordingly. This closed-loop feedback mechanism ensures that high measurement precision requirements are met through continuous monitoring and adjustment.

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

Enables precise control of the nip width without the need for temperature adjusters or automatic pressure-contact mechanisms, ensuring proper fixation of toner images onto sheets.

Implementation Method 1

a fixer that fixes a toner image onto a sheet by heat and pressure, and includes: a heat source; a first rotary member that is heated by the heat source

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a temperature sensing unit that senses a temperature of the first rotary member

Methodology Applied

Scientific EffectTemperature sensing: Thermistor

Data Source

PatentUS9760045B2Image forming apparatus and image forming method

Publication Date: 2017.09.12 KONICA MINOLTA INC

AI summary

An image formation apparatus includes: a fixer that fixes a toner image onto a sheet by heat and pressure, and includes: a heat source; a first rotary member that is heated by the heat source; a temperature sensing unit that senses a temperature of the first rotary member; and a second rotary member that forms a nip with the first rotary member for applying heat and pressure to the sheet; and a controller that calculates a nip width of the nip in a passing direction of the sheet with use of a rotation period and a rest period of the first rotary member during which the heat source operates, and changes a target temperature of the first rotary member in accordance with the calculated nip width.