Cross Roll Registration with Pre-Registration Skew Control

Solution Overview

Problem

Cross roll registration systems are prone to sheet damage, particularly with lightweight media, due to uncontrolled skew and lateral positioning, leading to buckling and curled corners when sheets impact a solid registration edge.

Innovation Solution

A cross roll registration system with an upstream pre-registration system that controls the input skew and lateral movement of sheets to optimize downstream performance by positioning them at a specific approach angle and cross process offset before contact with the alignment stop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a cross roll registration system is used to achieve high registration accuracy at increased speeds, then registration precision is improved, but sheet damage occurs due to uncontrolled skew and lateral positioning causing impact against the alignment stop

Engineering Contradiction:

Improveregistration accuracyVSAvoidsheet damage

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The pre-registration device performs preliminary positioning of the sheet before it enters the cross roll registration system. It adjusts the sheet's skew angle and lateral position in advance, ensuring that when the sheet contacts the alignment stop, it does so in a controlled manner that prevents corner impact and buckling, while still allowing the cross roll system to achieve high registration accuracy

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The pre-registration device acts as an intermediary between the sheet feed and the cross roll registration system. It mediates the sheet's entry by controlling its approach angle and lateral position, thereby protecting the sheet from direct uncontrolled impact against the alignment stop while enabling the downstream system to function effectively

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If cross roll registration systems register sheets against a solid registration wall, then theoretical registration error is minimized, but lightweight media sheets buckle due to insufficient beam strength to resist impact forces

Engineering Contradiction:

Improveregistration errorVSAvoidsheet buckling resistance

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The pre-registration device performs preliminary positioning of the sheet before it enters the cross roll registration system. It adjusts the sheet's skew angle and lateral position in advance, ensuring that when the sheet contacts the alignment stop, it does so in a controlled manner that prevents corner impact and buckling, while still allowing the cross roll system to achieve high registration accuracy

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the parameters of sheet approach (angle and lateral position) to optimize the interaction between the sheet and the solid registration wall. By controlling the approach angle and lateral position, the sheet's effective beam strength at the contact point is enhanced, preventing buckling while maintaining registration precision

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If the forces on cross rolls are controlled for various paper weights, then sheet damage is reduced, but skew control and initial positioning are still insufficient to prevent corner impact at the alignment stop

Engineering Contradiction:

Improvesheet damageVSAvoidskew and positioning control

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The pre-registration device performs preliminary positioning of the sheet before it enters the cross roll registration system. It adjusts the sheet's skew angle and lateral position in advance, ensuring that when the sheet contacts the alignment stop, it does so in a controlled manner that prevents corner impact and buckling, while still allowing the cross roll system to achieve high registration accuracy

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system incorporates sensors and control mechanisms that monitor sheet position and skew, providing feedback to the pre-registration device to continuously optimize the approach angle and lateral positioning, ensuring minimal sheet damage while maintaining ease of operation across various media types

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10160237B2Cross roll registration system with controlled input positioning

Publication Date: 2018.12.25 XEROX CORP

AI summary

A media handling system for contacting a sheet of media against an alignment stop. The system including a pre-registration device and a cross roll registration device. The pre-registration device is configured to position the sheet of media at an approach angle and a cross process offset relative to the alignment stop. The cross roll registration device is configured to move the sheet of media positioned at the approach angle and the cross process offset into contact with the alignment stop.