Alignment Plate Angle Adjustment for Duplex Print Registration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing image forming apparatuses face challenges in accurately aligning images on both faces of a recording sheet during duplex printing, particularly when the printed materials are bound into a book, due to issues like transverse shift and skew with respect to the transport direction.

Innovation Solution

The apparatus incorporates a skew correction mechanism with an alignment plate and an inclination angle adjustment mechanism, along with a detection device and control system to calculate and adjust the alignment angle, ensuring precise image placement on both sides of the sheet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If duplex printing is performed without skew correction, then the printing process is simple and fast, but the image alignment between front and back faces deteriorates

Engineering Contradiction:
Improveimage alignment accuracyVSAvoidskew correction mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The skew correction mechanism performs preliminary correction of the recording sheet's skew angle before the sheet enters the image forming device. The alignment plate is positioned upstream to preemptively align the sheet, ensuring that subsequent printing operations occur on properly oriented material, thus preventing misalignment between front and back faces.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The alignment plate serves as an intermediary component between the sheet feeding device and the image forming device. It mediates the skew correction process by providing a reference surface that the recording sheet contacts, thereby passively correcting the sheet's orientation without requiring complex active control mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the inclination angle of the alignment plate is adjusted to correct skew, then the transverse shift is reduced, but the detection and calculation complexity increases

Engineering Contradiction:
Improvetransverse shift correctionVSAvoidcorner detection and deviation calculation
Core Design Contradiction:
Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The detection device captures the position of corners on the recording sheet, and the control device calculates the deviation from the ideal position. This feedback information is used to determine the appropriate inclination angle adjustment for the alignment plate, creating a closed-loop system that continuously optimizes sheet alignment based on actual measured conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical skew correction mechanisms with a detection-and-calculation-based system. Instead of using multiple sensors and complex mechanical adjustments, the system uses corner detection combined with mathematical calculation to determine the required alignment plate inclination angle, simplifying the overall system while maintaining precision.

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

3Productivity

If manual adjustment of the alignment plate is required, then the device complexity is reduced, but the operation time and productivity decrease

Engineering Contradiction:
Improveduplex printing efficiencyVSAvoidautomatic inclination angle adjustment
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The system performs self-service by automatically detecting the skew of the recording sheet and calculating the required inclination angle adjustment. The control device autonomously determines the correction parameters without requiring manual intervention, enabling the system to adapt to varying sheet conditions while maintaining high productivity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4647263A1Image forming apparatus
Publication Date: 2025.11.12 KYOCERA DOCUMENT SOLUTIONS INC
  • EP4647263A1 patent drawingFigure 1
  • EP4647263A1 patent drawingFigure 2
  • EP4647263A1 patent drawingFigure 3

AI summary

An image forming apparatus (1) includes a skew correction mechanism (15A,15B) having an alignment plate (151) extending parallel to a transport direction of a recording sheet, and configured to correct a skew of the recording sheet with respect to the transport direction, by pressing a side of the recording sheet extending along the transport direction, against the alignment plate (151), an inclination angle adjustment mechanism (21) that enables manual adjustment of the inclination angle of the alignment plate (151) with respect to the transport direction, a calculator (101) that calculates a distance between the leading edge corner and the trailing edge corner in the width direction orthogonal to the transport direction, detected by the detection device (16), as a deviation amount of the recording sheet, and calculates an adjustment amount of the inclination angle that reduces the deviation amount, and a controller (100) that notifies the adjustment amount of the inclination angle calculated by the calculator (101), to a user.