Printing Plate Alignment via Optical Detection and Drum Rotation

Solution Overview

Problem

Existing printing plate alignment methods rely on mechanical pins, which are inflexible and pose reliability challenges, especially when handling large format plates, and do not effectively accommodate a wide range of plate formats without interference.

Innovation Solution

A method involving a rotatable imaging drum with leading and trailing edge clamps, where the drum rotates in reverse to align and straighten the printing plate's leading edge with a slot, and then rotates forward to position it correctly over the slot, utilizing digital camera imaging for precise alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mechanical alignment pins are used to align the printing plate, then alignment precision is improved, but device flexibility and reliability deteriorate

Engineering Contradiction:

Improvealignment precisionVSAvoiddevice flexibility

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent replaces the mechanical alignment pin system with an optical detection system. Edge detection sensors and cameras are used to detect the position of the printing plate edges and calculate alignment parameters, eliminating the need for physical contact between pins and plate. This substitution maintains alignment precision while significantly improving flexibility and reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses optical imaging to create a digital copy of the printing plate position. Cameras capture images of the plate edges and registration marks, and software processes these images to determine precise alignment. This optical copying approach replaces mechanical measurement while maintaining or improving measurement precision.

Inventive Principle:

Principle #26Copying

2Measurement precision

If mechanical alignment pins are used to align the printing plate, then alignment precision is improved, but reliability deteriorates

Engineering Contradiction:

Improvealignment precisionVSAvoidloading reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical alignment pin system with an optical detection system. Edge detection sensors and cameras are used to detect the position of the printing plate edges and calculate alignment parameters, eliminating the need for physical contact between pins and plate. This substitution maintains alignment precision while significantly improving flexibility and reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses the printing plate's own features (edges and registration marks) as the alignment references. The plate itself provides the measurement targets through its geometric features, eliminating the need for separate alignment pins. This self-service approach improves reliability by removing the interface between pins and plate that causes loading issues.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If mechanical alignment pins are used, then alignment is achieved, but adaptability to different plate formats deteriorates

Engineering Contradiction:

Improvealignment precisionVSAvoidplate format adaptability

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent replaces the mechanical alignment pin system with an optical detection system. Edge detection sensors and cameras are used to detect the position of the printing plate edges and calculate alignment parameters, eliminating the need for physical contact between pins and plate. This substitution maintains alignment precision while significantly improving flexibility and reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The optical detection system is designed to handle multiple plate formats universally. The camera and image processing software can detect and measure various plate sizes and configurations using the same basic principles of edge detection and feature recognition. This universal approach allows a single system to accommodate different plate formats without requiring format-specific alignment pins.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS7784402B2Method for loading printing plate on imaging device

Publication Date: 2010.08.31 EASTMAN KODAK CO

AI summary

A method for aligning the leading edge of printing plate (110) to an axially disposed slot (70) in a cylindrical surface (30) of an imaging drum (20) comprising at least one printing plate clamp (90) having a clamp surface (100) disposed parallel to the slot, the method comprising straightening (210) the leading edge against the clamp surface and positioning (220) the leading edge to protrude over the slot by rotating the imaging drum under the plate. The straightening comprises resting (200) the leading edge of the plate on the cylindrical surface of the imaging drum and rotating the imaging drum about its cylindrical axis (60) to contact with the clamp surface a point along the leading edge of the plate and to rotate the plate until its leading edge is in alignment with the clamp surface.