Liquid Discharge Head Idle Drop Waveform for Print Speed

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Full-line type image forming devices face challenges in implementing idle discharge methods efficiently, leading to increased processing complexity and costs, as well as reduced printing speed, due to the need for data analysis and drive waveform switching during idle discharge operations.

Innovation Solution

An image forming device employing a simple and cost-effective mechanism for idle discharge, where the liquid discharge head discharges smaller liquid drops over the entire image formable region using a second drive waveform with modified voltage and time changes, allowing for efficient idle discharge without degrading image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If idle discharge operation is performed in a position separated from the recording medium during print scanning, then nozzle clogging is prevented, but printing speed is reduced

Engineering Contradiction:
Improvenozzle discharge reliabilityVSAvoidprinting speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines the idle discharge function with the normal printing operation by performing idle discharge within the image formation region during the same scanning process. The liquid discharge head switches between idle discharge and image formation modes without leaving the recording region, thereby maintaining high printing speed while preventing nozzle clogging through continuous liquid discharge.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If data analysis and drive waveform switching are performed during idle discharge, then idle discharge is achieved, but processing complexity and cost increase

Engineering Contradiction:
Improvenozzle discharge reliabilityVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent prepares idle discharge data in advance together with image formation data, and pre-defines specific drive waveforms for idle discharge. During operation, the system simply switches between pre-prepared data and waveforms based on position information, avoiding complex real-time analysis and reducing processing complexity while maintaining reliable idle discharge functionality.

Inventive Principle:
Principle #10Preliminary action

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 efficient idle discharge operations with reduced complexity and cost, maintaining high printing speed and quality by using a second drive waveform to manage liquid drop discharge effectively across the entire image formable region.

Implementation Method 1

a piezoelectric element 121; a liquid chamber 106 communicating with the nozzle 104, in which the piezoelectric element 121 is provided

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP2038121B1Image forming device and printed matter
Publication Date: 2016.02.24 RICOH CO LTD
  • EP2038121B1 patent drawingFigure 1
  • EP2038121B1 patent drawingFigure 2
  • EP2038121B1 patent drawingFigure 3

AI summary

In an image forming device including a liquid discharge head in which nozzles for discharging liquid drops are arranged side by side, a drive waveform generating unit generates, within a single drive cycle, a first drive waveform containing a drive signal to discharge an amount of liquid drop used for image formation, and a second drive waveform containing a drive signal to discharge an amount of liquid drop smaller than a minimum discharge drop amount used for image formation. A head control unit causes the liquid discharge head to discharge the amount of liquid drop used for image formation in accordance with the first drive waveform for a region where an image is formed, and to discharge the amount of liquid drop smaller than the minimum discharge drop amount in accordance with the second drive waveform for a region where any image is not formed.