Image Forming Apparatus Fixing Temperature Control

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Solution Overview

Problem

Image forming apparatuses face challenges in suppressing adverse image effects, such as 'hot offset,' which occur when changing the fixing temperature, leading to potential new defects during image forming operations.

Innovation Solution

An image forming apparatus that includes a reader to detect image defects, a media sensor to determine the basis weight of the recording material, and a control system to adjust the fixing temperature by setting a target temperature based on the basis weight and correcting for defects by determining a correction temperature, thereby preventing adverse effects from temperature changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fixing temperature is changed to suppress a determined image defect, then the occurrence of the determined image defect is reduced, but adverse image effects such as hot offset may occur

Engineering Contradiction:
Improveimage defect suppressionVSAvoidadverse image effects
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the fixing temperature based on the basis weight of the recording material. The control value setting unit modifies the fixing temperature parameter according to the measured basis weight, ensuring optimal temperature for each material type to suppress image defects while preventing adverse effects like hot offset.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback through the image reading unit that reads the formed image and provides information about image defects back to the control system. This feedback loop enables the control value setting unit to adjust the fixing temperature based on actual image quality, continuously suppressing defects while preventing adverse effects.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If the fixing temperature is increased to improve image fixation, then image fixation quality is improved, but hot offset and other adverse effects occur

Engineering Contradiction:
Improveimage fixation qualityVSAvoidhot offset
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the fixing temperature parameter dynamically based on the basis weight of the recording material. By adjusting this parameter according to material properties, the system achieves optimal image fixation quality without excessive temperature that would cause hot offset.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by tailoring the fixing temperature to the specific recording material being used. Different basis weights require different temperature conditions, and the system provides localized temperature optimization for each material type rather than using a fixed temperature for all materials.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the fixing temperature is decreased to prevent hot offset, then adverse effects are reduced, but image fixation quality deteriorates

Engineering Contradiction:
Improvehot offset suppressionVSAvoidimage fixation quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent adjusts the fixing temperature parameter based on the basis weight of the recording material. For lighter materials with lower hot offset risk, the system maintains higher temperatures for good fixation quality, while for heavier materials, it adjusts temperatures to prevent hot offset, thus balancing both requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3876038B1Image forming apparatus configured to set control value
Publication Date: 2024.10.16 CANON KK
  • EP3876038B1 patent drawingFigure 1
  • EP3876038B1 patent drawingFigure 2
  • EP3876038B1 patent drawingFigure 3

AI summary

An image forming apparatus includes: image forming means arranged to form an image on a recording material based on first image data; control means (2010) arranged to control an image forming operation by the image forming means; acquisition means (40) arranged to acquire property information related to a property of the recording material; setting means (2043) configured to set a control value to be used in the image forming operation; reading means (2050) arranged to read an image formed on the recording material, and to output second image data; and comparison means (2042) configured to compare the first image data to the second image data. The setting means is further configured to set the control value based on a comparison result from the comparison means and the property information.