Inkjet Head Density Correction via Pre-computed Coefficients

Solution Overview

Problem

Inkjet recording methods face inefficiencies due to density non-uniformity caused by misfiring nozzles, which require time-consuming calculations for correction coefficients, leading to delayed image recording and reduced efficiency.

Innovation Solution

An image recording device and method that acquires non-uniformity information, calculates correction coefficients, detects misfiring nozzles, and adjusts pixel density data in real-time to correct for density variations, enabling quick response and efficient image recording.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If misfiring correction coefficient is calculated for each image density to reduce misfiring nozzle effect, then image quality is improved, but calculation time increases significantly

Engineering Contradiction:

Improveimage qualityVSAvoidcalculation time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores misfiring correction coefficients for all possible image density values before actual image recording. This preliminary action allows the system to simply retrieve pre-computed coefficients during recording without performing time-consuming calculations, thus maintaining high image quality while significantly reducing real-time calculation time.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent pre-calculates and stores misfiring correction coefficients for all possible image density values before actual image recording. This preliminary action allows the system to simply retrieve pre-computed coefficients during recording without performing time-consuming calculations, thus maintaining high image quality while significantly reducing real-time calculation time.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If density correction is performed for each recording element, then density non-uniformity is corrected, but device complexity increases

Engineering Contradiction:

Improvedensity uniformityVSAvoidcorrection system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by adjusting the misfiring correction coefficient based on image density values. Instead of complex physical modifications to the inkjet head, the system simply changes the correction parameters (coefficients) retrieved from pre-computed tables, thereby correcting density non-uniformity while keeping the device structure simple.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses pre-computed correction coefficient tables that are stored and retrieved during recording. Rather than performing complex real-time calculations or physical modifications, the system copies appropriate correction coefficients from pre-prepared tables based on the current image density, simplifying the correction mechanism while maintaining effectiveness.

Inventive Principle:

Principle #26Copying

3Measurement precision

If misfiring correction coefficient is calculated in real-time, then correction accuracy is improved, but image recording efficiency decreases

Engineering Contradiction:

Improvecorrection accuracyVSAvoidimage recording efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent pre-calculates and stores misfiring correction coefficients for all possible image density values before actual image recording. This preliminary action allows the system to simply retrieve pre-computed coefficients during recording without performing time-consuming calculations, thus maintaining high image quality while significantly reducing real-time calculation time.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses pre-computed correction coefficient tables that are stored and retrieved during recording. Rather than performing complex real-time calculations or physical modifications, the system copies appropriate correction coefficients from pre-prepared tables based on the current image density, simplifying the correction mechanism while maintaining effectiveness.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS8118389B2Image recording device and image recording method

Publication Date: 2012.02.21 FUJIFILM CORP

AI summary

An image recording device comprises: a recording head that has a plurality of recording elements; non-uniformity information acquiring unit that acquires non-uniformity information of each recording element by using a test pattern; non-uniformity correction coefficient calculating unit that calculates a non-uniformity correction coefficient value for each density as recording characteristics of the recording element; misfiring correction coefficient calculating unit that calculates a misfiring correction coefficient value for each density in a case where a nearby recording element is misfiring as the recording characteristics of the recording element; selecting unit that selects one of the recording characteristics for each recording element based on pixel density data of image data and the misfiring information detected by misfiring information detecting unit; and correction processing unit that corrects the pixel density data using the recording characteristics selected by the selecting unit.