Printhead Alignment via Web Position Feedback

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Solution Overview

Problem

High-speed production printers face challenges in maintaining precise alignment of printheads due to micron-level fluctuations in the web of print media, leading to reduced print quality as lateral shifts cause misalignment of color pixels.

Innovation Solution

A system with sensors to detect the lateral position of upstream and downstream printheads relative to the web, and a controller to dynamically adjust the position of downstream printheads to match the upstream printhead's position, ensuring accurate alignment and print quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-speed printing is used to meet production demands, then productivity is improved, but manufacturing precision deteriorates due to micron-level web fluctuations causing printhead misalignment

Engineering Contradiction:

Improveprinting speedVSAvoidprinthead alignment precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system uses sensors to continuously detect the lateral position of the web and printheads, feeding this information back to a controller that dynamically adjusts downstream printhead positions to compensate for web fluctuations, maintaining alignment at high printing speeds

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The printhead positioning system transitions from static calibration to dynamic adjustment, where downstream printheads are continuously repositioned based on real-time web position data, allowing the system to adapt to micron-level web variations during high-speed printing

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If multiple printheads are used to form mixed color pixels, then manufacturing precision is improved, but object-affected harmful factors worsen as web position fluctuations cause color misalignment

Engineering Contradiction:

Improvecolor placement precisionVSAvoidweb position fluctuation impact

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

Sensors detect web position fluctuations in real-time and feed this information to the controller, which adjusts downstream printhead positions to maintain accurate color alignment despite web variations, ensuring precise mixed color pixel formation

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary detection of web position before the web reaches the printheads, allowing the controller to pre-adjust downstream printhead positions to compensate for anticipated misalignment, ensuring accurate color placement

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9186885B2Alignment of printheads in printing systems

Publication Date: 2015.11.17 RICOH CO LTD

AI summary

Systems and methods are provided for aligning printheads of a printing system. One embodiment is a system for aligning printheads of a printing system. The system includes a first sensor configured to detect lateral positions of an upstream printhead relative to sections of a web of print media traveling through the printing system, and a second sensor configured to detect lateral positions of a downstream printhead relative to the sections of the web. The downstream printhead is placed after the upstream printhead in the direction of travel of the web. The system also includes a controller configured to align the downstream printhead with the sections of the web based on the lateral positions of the upstream printhead and the lateral positions of the downstream printhead.