Inkjet Drive Waveform Correction for Nozzle Count Variations

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Solution Overview

Problem

Conventional image recording apparatuses face challenges in maintaining consistent image quality due to variations in ejection characteristics among recording heads, which are affected by manufacturing errors and nozzle size differences, leading to degraded image quality when using multiple recording heads.

Innovation Solution

An image recording apparatus that includes a data storage system to retain parameter sets specific to each recording head, a simultaneously driven nozzle count detector, a correction parameter selector, and a drive waveform data generator, which corrects the drive waveform for each recording head based on detected nozzle counts and temperature, ensuring uniform ejection characteristics across all heads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a common drive waveform is applied to all recording heads, then the device complexity is reduced, but the ejection characteristics become unsteady due to manufacturing variations

Engineering Contradiction:

Improvedrive waveform controlVSAvoidejection characteristics

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by storing and applying individual correction parameters for each recording head. Each recording head has its own correction parameter that compensates for manufacturing variations, allowing each head to be optimized independently while maintaining overall system simplicity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the drive waveform parameters dynamically based on the simultaneously driven nozzle count. Correction parameters are applied to adjust the drive waveform characteristics, transforming a static common waveform into an adaptive per-head optimized waveform without requiring complete waveform redesign.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If individual correction parameters are stored for each recording head, then the ejection characteristics are stabilized, but the data storage requirements and device complexity increase

Engineering Contradiction:

Improveejection characteristicsVSAvoiddata storage and parameter management

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by pre-calculating and storing correction parameters for each recording head before actual operation. These correction parameters are determined in advance based on individual head characteristics, eliminating the need for real-time complex calculations during image recording.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by creating a parameter set that includes correction values for each recording head. Instead of managing complex individual configurations, the system copies and applies appropriate correction parameters from a predefined set, simplifying parameter management while maintaining individual head optimization.

Inventive Principle:

Principle #26Copying

3Manufacturing precision

If the drive waveform is corrected for each recording head individually, then image quality uniformity is improved, but the processing time and complexity increase

Engineering Contradiction:

Improveimage density uniformityVSAvoidwaveform correction processing

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-calculating correction parameters during manufacturing or initial setup. These parameters are stored in the system memory, allowing rapid retrieval and application during actual image recording without requiring time-consuming real-time calculations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system applies self-service by automatically selecting and applying the appropriate correction parameter for each recording head based on its identification. The system autonomously manages the parameter selection process, eliminating the need for manual configuration or complex external processing.

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

This solution effectively stabilizes ejection characteristics and prevents uneven image densities, resulting in improved image quality by accounting for unique variations in each recording head's performance.

Implementation Method 1

A known method for driving the recording head that includes the piezoelectric element as the pressure generator

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9738092B2Image recording apparatus and recording head driving method

Publication Date: 2017.08.22 RICOH CO LTD

AI summary

An image recording apparatus includes: a plurality of recording heads driven on a basis of drive waveform data; a data storage that retains parameter sets corresponding to the respective recording heads; a simultaneously driven nozzle count detector that detects, for each of the recording heads, a simultaneously driven nozzle count that represents a count of nozzles to be driven at an identical drive timing based on image data to be recorded on a recording medium; a correction parameter selector that selects, for each of the recording heads, a correction parameter corresponding to the detected simultaneously driven nozzle count from among a plurality of correction parameters included in the parameter set corresponding to the recording head; and a drive waveform data generator that corrects reference waveform data using the correction parameter selected for each of the recording heads and generates the drive waveform data for each of the recording heads.