Image Carrier Drive Control for Vibration Compensation

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Solution Overview

Problem

Image forming apparatuses face issues with sudden speed variations in the conveyance speed of recording sheets or image carriers due to impulsive vibrations during entry and separation, leading to image deterioration, which existing solutions like adjusting belt tension or using impact-absorbable rollers fail to adequately address without compromising transfer efficiency or mechanical rigidity.

Innovation Solution

An image forming apparatus with a control section that generates a reverse phase variation in the drive signal to offset speed variations caused by vibrations, using a CPU and memory to store and apply a variation cancel waveform to the motor drive signals, thereby minimizing speed fluctuations without requiring belt slack or enhanced mechanical rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the tension of the transfer belt is adjusted to give slack to absorb vibration, then the influence of impulsive vibration is reduced, but slip is produced which deteriorates transfer efficiency

Engineering Contradiction:
Improvevibration influenceVSAvoidtransfer efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The control section generates a reverse phase variation in the drive signal before the impulsive vibration occurs, creating a counteracting force that offsets the vibration's effect on the image carrier speed, thereby preventing speed variation without requiring belt slack that would cause slip

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The invention changes the drive signal parameters dynamically by adding a variation component with reverse phase to the basic drive signal, allowing the motor speed to be adjusted in real-time to compensate for vibration-induced speed variations while maintaining proper belt tension for efficient transfer

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the mechanical rigidity of the apparatus is enhanced to prevent vibration, then speed variation is reduced, but the size of the apparatus and overall costs increase

Engineering Contradiction:
Improvespeed variationVSAvoidapparatus size and cost
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention replaces mechanical solutions (enhancing mechanical rigidity, adding flywheels, increasing apparatus size) with a control system solution that uses electronic signal processing to generate reverse phase variation, thereby reducing speed variation without increasing physical apparatus size or complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control section automatically detects and compensates for speed variations caused by vibration through reverse phase variation in the drive signal, making the system self-correcting without requiring additional mechanical components or external interventions

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If impact-absorbable flexible rollers are used to absorb impact, then vibration is reduced, but transfer efficiency and image quality deteriorate

Engineering Contradiction:
Improveimpact vibrationVSAvoidtransfer efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The invention replaces mechanical impact absorption (flexible rollers) with an electronic control approach that uses reverse phase variation in the drive signal to counteract vibration effects, thereby maintaining the rigidity needed for efficient transfer while still eliminating speed variation through active control

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2136257B1Image forming apparatus
Publication Date: 2015.11.11 KONICA MINOLTA BUSINESS TECH INC
  • EP2136257B1 patent drawingFigure 1
  • EP2136257B1 patent drawingFigure 2~3
  • EP2136257B1 patent drawingFigure 4

AI summary

An image forming apparatus includes an image carrier for carrying a toner image, a drive device for driving the image carrier at a predetermined speed, a control device for giving instruction to the drive device to perform predetermined operation, and a transfer device for nipping a recording sheet with a rotary member at the position opposed to the image carrier and for transferring the toner image on the image carrier onto the recording sheet, wherein the control device gives instruction to the drive device to generate a variation having a phase which is reverse to a phase of a variation given to the predetermined speed of the image carrier by a vibration produced at the time of passage of the recording sheet between the image carrier and the transfer device.