Liquid Discharge Device Flow Regulator Ink Pressure Stability

Solution Overview

Problem

Ink jet printers face issues with ink viscosity leading to clogged discharge heads and fluctuating ink pressure, resulting in image quality defects, particularly when printing small numbers of copies, as existing techniques struggle to maintain consistent ink flow and pressure.

Innovation Solution

A liquid discharge device with a storage tank, discharge head, liquid feeder, supply tank, and flow regulator, which includes a bypass path to maintain a constant ink flow rate and pressure at the discharge head, using a flow regulator to control the ink flow and prevent pressure fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ink is constantly circulated to prevent viscosity increase, then image quality defect is reduced, but device complexity increases

Engineering Contradiction:

Improveimage qualityVSAvoidcirculation system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The circulation system is segmented into two independent paths: a main liquid path from the storage tank through the discharge head, and a branch path that bypasses the discharge head. This segmentation allows the circulation function to be achieved without requiring complex circulation mechanisms at the discharge head, thereby reducing device complexity while maintaining image quality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A flow regulator is introduced as an intermediary component in the branch path to control and balance the ink flow between the main path and branch path. This intermediary device enables precise flow control without requiring complex circulation pumps or valves at the discharge head, resolving the contradiction between reliability and device complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If flow regulator is added to control ink flow rate, then ink pressure stability is improved, but device complexity increases

Engineering Contradiction:

Improveink pressureVSAvoidflow control system

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

A flow regulator is introduced as an intermediary component in the branch path to control and balance the ink flow between the main path and branch path. This intermediary device enables precise flow control without requiring complex circulation pumps or valves at the discharge head, resolving the contradiction between reliability and device complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The flow regulator is strategically placed only in the branch path where flow balancing is needed, rather than controlling flow throughout the entire system. This localized approach achieves pressure stability with minimal additional complexity, as the regulator only needs to manage the branch path flow rather than the entire circulation system.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If bypass path is created for flow regulation, then ink flow consistency is improved, but device complexity increases

Engineering Contradiction:

Improveink flow rateVSAvoidliquid path structure

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The circulation system is segmented into two independent paths: a main liquid path from the storage tank through the discharge head, and a branch path that bypasses the discharge head. This segmentation allows the circulation function to be achieved without requiring complex circulation mechanisms at the discharge head, thereby reducing device complexity while maintaining image quality.

Inventive Principle:

Principle #1Segmentation

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

The solution effectively reduces the influence of external disturbances on ink flow, maintaining consistent image quality and reducing the time required to stabilize ink pressure, thereby improving print quality and efficiency, especially for small print runs.

Implementation Method 1

the flow regulator is disposed downstream of the discharge head in the liquid feed direction and configured to control a flow rate of the liquid flowing into the discharge head

Methodology Applied

Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

The supply tank is disposed upstream of the discharge head in the liquid feed direction and configured to store the liquid fed by the liquid feeder while being in a state open to atmosphere

Methodology Applied

Scientific EffectAtmospheric pressure: Pressure Gradient

Data Source

PatentUS11077671B2Liquid discharge device, image forming apparatus, and fabricating apparatus

Publication Date: 2021.08.03 RICOH CO LTD

AI summary

A liquid discharge device includes a storage tank, a discharge head, a liquid feeder, a supply tank, a liquid path, a branch path, and a flow regulator. The liquid feeder is configured to feed liquid from the storage tank to the discharge head in a liquid feed direction. The supply tank is disposed upstream of the discharge head in the liquid feed direction, to store the liquid fed by the liquid feeder while being in a state open to atmosphere. The liquid path is configured to flow the liquid from the liquid feeder to the supply tank. The branch path is connected to the liquid path and configured to cause part of the liquid to branch from the liquid path. The flow regulator is disposed downstream of the discharge head in the liquid feed direction and configured to control a flow rate of the liquid flowing into the discharge head.