Liquid Discharge Drive Waveform Generator Pulse Interval Control

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Solution Overview

Problem

Existing liquid discharge technologies face challenges in achieving consistent discharge speed and efficiency due to resonance and damping states of meniscus vibrations, leading to variations in droplet size and discharge performance.

Innovation Solution

A liquid discharge apparatus with a drive waveform generator that applies a first discharge pulse followed by a second discharge pulse, with a pulse interval set to a damping state where the second pulse is damped by the meniscus vibration generated by the first pulse, to control and stabilize the discharge process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple discharge pulses are applied to form large liquid droplets, then droplet size increases, but discharge speed variations increase due to resonance and damping states

Engineering Contradiction:

Improvedroplet sizeVSAvoiddischarge speed consistency

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies periodic discharge pulses with specifically controlled intervals. The pulse interval is set to align with the damping state of meniscus vibration from previous pulses, creating a periodic action pattern that suppresses resonance and maintains consistent discharge speed while accumulating liquid for larger droplets.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes the temporal parameters of the discharge pulses, specifically the pulse interval timing, to match the damping state of meniscus vibration. By adjusting when pulses are applied relative to the vibration cycle, the system achieves stable discharge speed while forming larger droplets through multiple pulses.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If discharge pulses are applied at resonance state, then liquid discharge efficiency increases, but discharge speed variations increase

Engineering Contradiction:

Improveliquid discharge efficiencyVSAvoiddischarge speed consistency

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent converts the harmful resonance effect into a beneficial damping effect. By timing discharge pulses to occur during the damping state of meniscus vibration rather than the resonance state, the system eliminates discharge speed variations while maintaining efficient liquid discharge through properly spaced pulses.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If pulse interval is shortened to increase discharge frequency, then productivity increases, but discharge stability decreases due to resonance interference

Engineering Contradiction:

Improvedischarge frequencyVSAvoiddischarge stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent establishes a periodic discharge pattern where pulse intervals are specifically set to coincide with the damping phase of meniscus vibration. This periodic timing allows high discharge frequency while maintaining stability, as each pulse occurs when vibration amplitude is minimized, preventing resonance interference.

Inventive Principle:

Principle #19Periodic 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

This approach reduces variations in discharge speed and enables more consistent droplet formation by aligning the second discharge pulse with the damping state of the meniscus vibration, improving overall discharge efficiency and stability.

Implementation Method 1

a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval being equal to a time period in which the liquid is discharged by the second discharge pulse in a damping state in which the second discharge pulse is damped by a meniscus vibration generated by the first discharge pulse

Methodology Applied

Scientific EffectMeniscus vibration: Vibration

Implementation Method 2

the drive pulse applies a contraction waveform element that contracts a pressure chamber at a timing at which liquid discharge operations resonates in accordance with a phase of a period (Helmholtz period) of meniscus vibration generated by an expansion waveform element that expands the pressure chamber

Methodology Applied

Scientific EffectPressure chamber contraction and expansion: Compression

Implementation Method 3

liquid discharge operations resonates in accordance with a phase of a period (Helmholtz period) of meniscus vibration

Methodology Applied

Scientific EffectHelmholtz resonance: Helmholtz Resonance

Data Source

PatentUS12109811B2Liquid discharge apparatus, drive waveform generator, and head drive method

Publication Date: 2024.10.08 RICOH CO LTD

AI summary

A liquid discharge apparatus includes a liquid discharge head configured to discharge a liquid, and a drive waveform generator configured to generate a drive waveform to be applied to the liquid discharge head, the drive waveform including a first discharge pulse to cause the liquid discharge head to discharge the liquid, a second discharge pulse after the first discharge pulse, the second discharge pulse to cause the liquid discharge head to discharge the liquid, and a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval being equal to a time period in which the liquid is discharged by the second discharge pulse in a damping state in which the second discharge pulse is damped by a meniscus vibration generated by the first discharge pulse.