Liquid Circulation Device with Adjustable Bypass Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In image forming apparatuses with liquid jetting heads, the circulation amount of liquid varies due to changes in the number of jetting heads and flow passage resistance, making it difficult to detect small changes in circulation and requiring adjustments to pump types and pressure control parameters, which existing technologies like JP2018-099858A fail to address effectively.

Innovation Solution

A liquid circulation device with a supply side manifold, a collection side manifold, and a bypass flow passage that adjusts resistance based on the number of liquid jetting heads and pump output, allowing for differential pressure to control the circulation amount, and includes a flowmeter to measure and adjust the flow rate within ±5% of a set value.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of liquid jetting heads is changed, then the adaptability of the device is improved, but the flow rate of the entire device changes requiring pump type changes or pressure control parameter adjustments

Engineering Contradiction:

Improvenumber of liquid jetting headsVSAvoidpump type adjustment

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent introduces a bypass flow passage with adjustable resistance that allows the system to compensate for changes in the number of liquid jetting heads by modifying flow distribution parameters. The bypass passage resistance can be adjusted to maintain constant total flow rate despite variations in the number of active jetting heads, eliminating the need to change pump types or pressure control parameters.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the flow passage resistance varies due to individual differences of liquid jetting heads, then the adaptability is improved, but the measurement precision of circulation amount changes is worsened

Engineering Contradiction:

Improveflow passage resistance variationVSAvoidcirculation amount detection

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The bypass flow passage acts as an intermediary element that provides a reference path for flow measurement. By comparing the flow through the bypass passage with the flow through the liquid jetting heads, the system can accurately detect changes in circulation amount despite variations in flow passage resistance caused by individual head differences.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the threshold value of abnormality detection is widened to accommodate flow passage resistance variations, then the reliability of detection is improved, but the measurement precision of small circulation changes is worsened

Engineering Contradiction:

Improveabnormality detectionVSAvoidsmall circulation amount change detection

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the actual circulation amount is continuously monitored and compared with the target value. The system adjusts the bypass flow passage resistance based on the detected deviations, enabling precise detection of small circulation changes while maintaining reliability in abnormality detection through continuous closed-loop control.

Inventive Principle:

Principle #23Feedback

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 enables precise adjustment of the liquid circulation amount, improving detection of small changes and reducing the need for frequent pump and pressure control parameter changes, enhancing the stability and efficiency of the liquid supply system.

Implementation Method 1

the liquid circulates in the liquid jetting head due to a differential pressure between the supply side manifold and the collection side manifold

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a bypass flow passage that causes the supply side manifold to communicate with the collection side manifold without going via the print bar and that is capable of changing a resistance with respect to the liquid

Methodology Applied

Scientific EffectFlow resistance control: Drag

Data Source

PatentUS20250091359A1Liquid circulation device, adjusting method of liquid circulation device, and manufacturing method of image forming apparatus

Publication Date: 2025.03.20 FUJIFILM CORP

AI summary

Provided are a liquid circulation device, an adjusting method of a liquid circulation device, and a manufacturing method of an image forming apparatus that can appropriately adjust a circulation amount of a liquid. The liquid circulation device includes a supply side manifold that supplies a liquid to a print bar on which one or more liquid jetting heads jetting the liquid are mounted, a collection side manifold that collects the liquid from the print bar, and a bypass flow passage that causes the supply side manifold to communicate with the collection side manifold without going via the print bar, in which the liquid circulates in the liquid jetting head due to a differential pressure between the supply side manifold and the collection side manifold, and the bypass flow passage is capable of changing a resistance with respect to the liquid.