Print Media Surface Status Assessment via Optical Luminance Analysis

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Solution Overview

Problem

Existing printing technologies face challenges in determining the appropriateness of print media surfaces for printing, leading to non-uniformity in print density, particularly for gloss sheets used in laser and inkjet printers, as current methods only measure light diffusion properties without assessing surface status for printing suitability.

Innovation Solution

A printing device and method that includes a light input unit, image pickup unit, and measurement-target surface status value calculating unit to assess the surface status by analyzing luminance information and spatial frequencies, using parameters like RMS granularity and human visual spatial frequency characteristics to determine the appropriateness of print media surfaces for printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If light diffusion property measurement is performed using existing technology, then measurement speed is improved, but measurement precision for determining printing appropriateness deteriorates

Engineering Contradiction:

Improvemeasurement speedVSAvoidsurface status assessment precision

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent changes the measurement parameters from simple light diffusion properties to comprehensive surface status parameters including RMS granularity and spatial frequency characteristics. This allows precise assessment of printing appropriateness while maintaining efficient measurement through automated image processing and analysis algorithms.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If comprehensive surface status analysis is performed, then measurement precision for printing appropriateness is improved, but device complexity increases

Engineering Contradiction:

Improveprinting appropriateness assessment precisionVSAvoidmeasurement system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs a digital imaging device that serves multiple functions: capturing surface images, analyzing spatial frequencies, calculating RMS granularity, and determining printing appropriateness. This multi-functional approach achieves comprehensive surface status analysis without requiring separate specialized devices for each measurement type.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces complex mechanical measurement systems with optical imaging and digital image processing. By using a digital camera or imaging sensor combined with software analysis, the system achieves precise surface status measurement without the mechanical complexity of traditional contactless or contact-based surface profilers.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If existing light diffusion measurement is used, then ease of operation is maintained, but manufacturing precision of print output deteriorates

Engineering Contradiction:

Improvemeasurement operation simplicityVSAvoidprint density uniformity

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements an automated measurement and assessment system that performs surface status analysis and printing appropriateness determination without manual intervention. The system automatically captures images, processes spatial frequency data, calculates surface parameters, and provides assessment results, maintaining ease of operation while achieving high manufacturing precision.

Inventive Principle:

Principle #25Self-service

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

Enables precise prediction of print media surface appropriateness for printing, allowing for sorting and ensuring high-quality prints by distinguishing between smooth and rough surfaces, thereby preventing non-uniformity in print density.

Implementation Method 1

an image pickup unit that picks up an image of the measurement-target surface by collecting reflection light fluxes for the light fluxes input by the light input unit which are reflected from the measurement-target surface

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

performing a photoelectric conversion process for the light fluxes received by the plurality of light receiving elements

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS7952715B2Printing device, method of controlling printing device, and recording medium

Publication Date: 2011.05.31 SEIKO EPSON CORP

AI summary

A printing device calculates a status value of a surface of a print medium to determine the appropriateness of the print medium for printing. Light fluxes are inputted to the surface of the print medium at an incidence angle. An image pickup unit picks up reflection light fluxes and a measurement-target surface status value calculating unit calculates a status value relating to the appropriateness of the print medium for printing based on the picked up luminance information.