Printhead Nozzle Segmentation for Nip Jump Artifacts

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Solution Overview

Problem

Print artifacts occur at the bottom of pages due to media movement errors, particularly 'nip jumps,' during the transition from feedroll to exit roller in printers, especially in high-quality edge-to-edge printing on glossy media.

Innovation Solution

Implementing a system with a printhead that uses two sets of nozzles: one set applies ink before the nip jump and another set after, with a processor controlling the movement of the media and adjusting nozzle usage to minimize misalignment and artifacts by detecting the nip jump and adjusting the ink application accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a single set of nozzles is used for printing across the entire page, then the device complexity is reduced, but print artifacts occur at the bottom of the page due to media movement errors during feedroll-to-exit-roller transfer

Engineering Contradiction:

Improveprint qualityVSAvoidnozzle configuration

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The printhead is divided into two separate sets of nozzles: a first set of nozzles for printing on the upper portion of the page and a second set of nozzles for printing on the lower portion of the page. This segmentation allows each nozzle set to be optimized for its specific printing zone, eliminating artifacts at the bottom of the page while maintaining overall system manageability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different nozzle sets are assigned to different regions of the page based on their specific printing requirements. The first set of nozzles handles the upper portion where standard printing applies, while the second set handles the lower portion where media movement errors occur during feedroll-to-exit-roller transfer, providing locally optimized print quality

Inventive Principle:

Principle #3Local quality

2Productivity

If the feedroll transports media through the printing apparatus, then productivity is improved, but media movement errors occur during feedroll-to-exit-roller transfer causing print artifacts

Engineering Contradiction:

Improveprinting speedVSAvoidprint quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system detects when the trailing edge of the media is approaching the feedroll-to-exit-roller transfer zone and preemptively switches from the first set of nozzles to the second set of nozzles before the media enters the problematic transfer region. This preliminary action prevents artifacts from occurring while maintaining continuous high-speed printing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The printing apparatus includes a detection mechanism that monitors media position and feedroll operation, providing feedback to the controller to determine when to switch between nozzle sets. This feedback loop ensures accurate timing of nozzle switching to prevent artifacts during feedroll-to-exit-roller transfer while maintaining printing productivity

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS7862137B2Method and system for avoiding bottom of page printing artifacts

Publication Date: 2011.01.04 BRADY WORLDWIDE INC

AI summary

Method and devices for reducing printing artifacts. In one embodiment, a method includes directing ink onto a medium, the medium having a trailing edge; tracking the position of the medium in relation to a nip roller; adjusting the direction of ink onto the medium a first time when the trailing edge of the medium is in close proximity to the nip roller; and adjusting the direction of ink onto the medium a second time.