Fluid-Density Auto-Duplexing Printer Control

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Solution Overview

Problem

Traditional printers face challenges in achieving full duplexing capabilities at lower price points and smaller form factors due to limitations in print media routing, often resulting in higher error rates and reduced print quality.

Innovation Solution

A fluid-density modulated printer control system that uses densitometer readings to estimate media dry time and adjust the printer mechanism sequencing, allowing for a smaller duplexer with a smaller turn radius, which reduces hard failures like media jams while accepting a slight increase in soft failures like smudging or smearing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional print media routing methods are used, then printers can achieve full duplexing capabilities, but the printers will have larger form factors and higher costs

Engineering Contradiction:
Improveduplexing capabilityVSAvoidprinter form factor
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent implements dynamic media routing by adjusting roller speeds and directions in real-time based on media dry time and duplexing requirements. The media path is dynamically reconfigured during operation rather than being fixed, allowing the same hardware to serve multiple functions and reduce overall form factor.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The print media routing system is designed to perform multiple functions: single-sided printing, duplex printing, and media drying. By making the routing path multi-functional and adaptable to different printing modes, the printer achieves full duplexing capability without requiring separate dedicated paths for each function, thereby reducing form factor.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If traditional print media routing methods are used, then printers can achieve full duplexing capabilities, but the printers will have higher price points

Engineering Contradiction:
Improveduplexing capabilityVSAvoidprinter cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The routing system is designed as a universal platform that handles single-sided printing, duplex printing, and media drying through the same physical path. This multi-functionality eliminates the need for additional dedicated components, reducing manufacturing complexity and cost while maintaining full duplexing capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the duplexing function with the existing single-sided printing path by integrating controllable rollers and dynamic routing logic into the same media transport system. This consolidation reduces component count and manufacturing cost compared to having separate dedicated paths for single-sided and duplex printing.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the media is fed quickly through the duplexer, then the printer can maintain higher productivity, but the media may still be wet causing jams or errors

Engineering Contradiction:
Improveprinting speedVSAvoidmedia jam error rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system uses densitometer readings to continuously monitor media ink density and estimates media dry time based on this feedback. The media routing and roller speeds are dynamically adjusted according to this real-time information, allowing the system to maintain high productivity while preventing media jams by ensuring proper drying before duplexing.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary assessment of media dry time using densitometer readings before the media enters the duplexing path. Based on this preliminary evaluation, the routing is pre-adjusted to allow sufficient drying time or to modify roller speeds, preventing media jams before they occur and maintaining reliable operation at high productivity.

Inventive Principle:
Principle #10Preliminary action

4Volume of moving object

If a smaller duplexer with smaller turn radius is used, then the printer can achieve compact form factor, but the media routing becomes more complex and error-prone

Engineering Contradiction:
Improveprinter form factorVSAvoidmedia routing complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent implements dynamic control of roller speeds and directions to compensate for the smaller turn radius and compact routing path. By continuously adjusting the media flow dynamics based on densitometer feedback and estimated dry time, the system manages the increased routing complexity and reduces errors despite the compact form factor.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables the production of lower-cost, compact printers with improved duplexing capabilities by minimizing media jam errors and maintaining print quality, meeting market requirements for cost and form factor.

Implementation Method 1

uses densitometer readings to estimate media dry time

Methodology Applied
Scientific EffectDensitometer measurement:

Data Source

PatentEP3475091B1Density modulated auto-duplexing
Publication Date: 2021.05.05 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3475091B1 patent drawingFigure 1~2
  • EP3475091B1 patent drawingFigure 3A~3B
  • EP3475091B1 patent drawingFigure 3C~3D

AI summary

A method for fluid-density modulated auto-duplexing is disclosed. This method determines when a final swath of a printing operation on a surface of a media occurs within a predefined distal end portion of the media. An estimated media dry time after the final swath in the predefined distal end portion is determined to be greater than a predetermined time. The estimated dry time is capped to a predetermined minimum media dry time and a course of action for a feed mechanism is selected to reduce curling and cockling of the media. Furthermore, a non-transitory computer readable medium and a printer having fluid-density modulated auto-duplexing are also disclosed.