Liquid Cartridge Viscosity Estimation via Movable Detector

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Solution Overview

Problem

Inkjet recording apparatuses face challenges in accurately calculating the viscosity of ink stored in ink tanks, especially when the ink type and environmental temperature vary, leading to potential clogging and deterioration in image quality.

Innovation Solution

A liquid cartridge design that includes a movable body with resist surfaces and a detector, allowing for direct estimation of viscosity by measuring the time it takes for the detector to move from a restricted to a released position, thereby improving the accuracy of ink viscosity estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the inkjet recording apparatus calculates viscosity based on ink tank remaining amount and elapsed time, then viscosity estimation is performed, but the estimation accuracy deteriorates when ink type or environmental temperature varies

Engineering Contradiction:
Improveviscosity estimation accuracyVSAvoidadaptability to different ink types and environmental conditions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The liquid cartridge performs self-diagnosis by using its own internal components (detector, restriction member, liquid) to measure viscosity directly, without relying on external calculations based on remaining amount and time. The detector measures the time for the restriction member to move from restricted to released position, providing direct viscosity data that adapts to any ink type or environmental condition.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the calculation-based viscosity estimation system with a direct mechanical measurement system. Instead of calculating viscosity from indirect parameters (remaining amount, time), the system uses a detector to directly measure the movement time of a restriction member through liquid, providing accurate viscosity data regardless of ink composition or environmental variations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a movable body with resist surfaces is added to measure detector movement time, then viscosity estimation accuracy is improved, but device complexity increases

Engineering Contradiction:
Improveviscosity estimation accuracyVSAvoidcartridge internal structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The liquid cartridge integrates multiple functions into existing components: the detector serves both as a position sensor and as the moving object whose movement time is measured; the restriction member serves both as a flow controller and as the object whose movement through liquid directly indicates viscosity. This multi-functionality reduces overall device complexity while maintaining measurement accuracy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The liquid itself serves as the measurement medium and the source of measurement data. The time required for the restriction member to move through the liquid is directly proportional to liquid viscosity, eliminating the need for separate measurement systems. The cartridge uses its own liquid and internal components to perform self-diagnosis.

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

The solution enhances the accuracy of ink viscosity estimation, enabling better handling of varying ink types and environmental conditions, reducing clogging and improving image quality.

Implementation Method 1

the body is a float having a lower specific gravity than ink stored in the ink chamber

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

a plurality of resist surfaces formed by the plurality of openings, the resist surfaces being configured to resist movement of the body between the first and second positions

Methodology Applied
Scientific EffectDrag: Drag

Implementation Method 3

a restriction member configured to move between a release position in which the detector is movable to the released position, and an a restrict position to position the detector in the restricted position

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3408103B1Liquid cartridge
Publication Date: 2020.04.01 BROTHER KOGYO KK
  • EP3408103B1 patent drawingFigure 1
  • EP3408103B1 patent drawingFigure 2
  • EP3408103B1 patent drawingFigure 3

AI summary

A liquid cartridge comprises a liquid chamber (36), a liquid outlet (60), and a body positioned in the chamber being movable between a first position wherein movement of the body is restricted, and a second position wherein the body is movable along a movement path between the first and second positions, the body having a plurality of sides. The liquid cartridge further comprises a detector positioned in the chamber movable in response to movement of the body between the first and second positions, a restriction member. Plurality of openings are defined in the body and extending into the body through at least two sides of the body. Plurality of resist surfaces are formed by the plurality of openings, the resist surfaces is configured to resist movement of the body between the first and second positions.