Registration Roller Displacement Correction for Print Alignment

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Solution Overview

Problem

Conventional image forming apparatuses struggle to accurately correct sheet displacement in the width direction during the printing process, leading to potential misalignment of print positions.

Innovation Solution

The image forming apparatus incorporates a pair of registration rollers that can be moved in the width direction, a detection unit to monitor sheet position, and a control unit that performs displacement corrections by adjusting the rollers' position and the writing start position of the electrostatic latent image based on detected displacement information and tendency analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the registration rollers are fixed in position, then the device structure is simple, but the sheet displacement cannot be corrected leading to print position misalignment

Engineering Contradiction:

Improveprint position accuracyVSAvoidroller movement mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The registration rollers are made movable in the width direction through a roller movement mechanism, allowing the system to dynamically adjust roller positions to compensate for sheet displacement and achieve accurate print positioning

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

A detection unit detects the actual position of sheets in the width direction, and this detection information is fed back to the control unit, which then adjusts the roller positions accordingly to correct displacement and ensure accurate print positioning

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If individual displacement correction is performed for each sheet, then print position accuracy is improved, but the processing time increases

Engineering Contradiction:

Improvesheet position accuracyVSAvoidsheet processing speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The system performs displacement correction before the sheet reaches the transfer position, determining the correction amount in advance based on detection information, which allows for efficient processing without delaying the printing workflow

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Real-time detection of sheet positions provides feedback that enables immediate individual correction, allowing the system to maintain high processing speed while achieving accurate positioning for each sheet

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If the home position is displaced based on tendency information, then the overall print alignment is improved, but the complexity of control processing increases

Engineering Contradiction:

Improveoverall print alignmentVSAvoidcontrol processing complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control unit determines tendency information from previously detected sheet positions and displaces the home position in advance based on this tendency, preventing systematic alignment errors before they occur

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of correcting each sheet's position individually based on its specific displacement, the system inverts the approach by adjusting the reference home position itself based on observed tendencies, thereby correcting multiple sheets with a single reference adjustment

Inventive Principle:

Principle #13The other way round (Inversion)

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 solution effectively corrects sheet displacement in real-time, ensuring precise alignment of print positions and improving the overall printing quality and accuracy.

Implementation Method 1

a detection unit to monitor sheet position

Methodology Applied

Scientific EffectOptical detection: Optical Fibre

Implementation Method 2

performs scanning exposure on a member to be exposed to form an electrostatic latent image on the member to be exposed

Methodology Applied

Scientific EffectElectrostatic latent image formation: Electrostatic Induction

Implementation Method 3

develops the electrostatic latent image into a toner image

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 4

transfers the toner image to the sheet in a transfer position

Methodology Applied

Scientific EffectElectrostatic transfer: Electrostatic Induction

Data Source

PatentUS12313997B2Image forming apparatus

Publication Date: 2025.05.27 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

An image forming apparatus includes a pair of registration rollers, an image formation unit, a roller movement mechanism, a detection unit and a control unit which performs a displacement correction for moving the pair of registration rollers from a home position. The control unit determines tendency information indicating the tendency of a displacement direction and a displacement amount of a sheet, the control unit displaces the home position in a direction opposite to the displacement direction indicated by the tendency information only by the displacement amount indicated by the tendency information and the control unit displaces the writing start position of an electrostatic latent image in a main scanning direction in the displacement direction indicated by the tendency information only by the displacement amount indicated by the tendency information.