Liquid Container Movable Member Pivot Timing Control

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Solution Overview

Problem

Existing ink cartridges with movable members for indicating ink levels suffer from variability in pivotal movement timing due to capillary forces and surface tension, leading to inconsistent detection of empty ink cartridges and wastage of ink.

Innovation Solution

A liquid container design featuring a movable member with a pivot center, a detection portion, and a float portion, where the contact surface separates smoothly from a regulating member when the ink level decreases, minimizing the impact of surface tension and ensuring consistent pivotal movement timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the signal blocking portion contacts the rib when ink level is sufficient, then the movable member is constrained to prevent false detection, but capillary force in the gap draws remaining ink to the gap, creating surface tension that hinders pivotal movement and causes timing variability

Engineering Contradiction:
Improvedetection accuracyVSAvoidpivotal movement smoothness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A liquid communication path is introduced as an intermediary between the ink chamber and the inner space of the translucent portion. This allows the inner space to remain filled with ink rather than air, eliminating the capillary force and surface tension that occur when air contacts the ink at the signal blocking portion-rib interface. The movable member can then pivot smoothly without being hindered by surface tension forces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the physical state parameter of the inner space from air-filled to ink-filled by establishing liquid communication with the ink chamber. This parameter change eliminates the harmful capillary effect and surface tension, allowing the movable member to pivot consistently and smoothly while maintaining reliable detection accuracy.

Inventive Principle:
Principle #35Parameter changes

2Loss of substance

If the predetermined value for ink droplet counting is set to the ideal value, then ink consumption is maximized, but variability in pivotal movement timing causes the cartridge to be detected as empty before the ideal point is reached, resulting in ink wastage

Engineering Contradiction:
Improveink wastageVSAvoidempty detection timing consistency
Core Design Contradiction:
Loss of substanceVSMeasurement precision

Solution Approach 1:

The liquid communication path acts as an intermediary that ensures consistent ink presence in the inner space, eliminating variability in pivotal movement timing. This consistency allows the predetermined value for ink droplet counting to be accurately set at the ideal point, maximizing ink utilization without wastage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces the air-ink interface mechanism with a liquid-filled communication path, substituting the problematic capillary action and surface tension effects with a consistent liquid environment. This substitution ensures uniform pivotal movement timing, enabling precise measurement and accurate setting of the predetermined ink droplet count.

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

3Difficulty of detecting and measuring

If a movable member with signal blocking portion is used to indicate ink level, then ink level can be monitored, but the contact surface separation from regulating member is hindered by surface tension, causing inconsistent detection timing across cartridges

Engineering Contradiction:
Improveink level detection capabilityVSAvoiddetection timing consistency
Core Design Contradiction:
Difficulty of detecting and measuringVSStability of the object's composition

Solution Approach 1:

The liquid communication path serves as an intermediary that maintains ink presence in the inner space throughout the detection process. This eliminates the air-ink interface that causes variable surface tension forces, ensuring that the separation of the contact surface from the regulating member occurs at consistent timing across all cartridges while maintaining ink level detection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design ensures that the movable member pivots smoothly and consistently, allowing for accurate detection of ink levels, reducing ink wastage by setting the predetermined value closer to the ideal amount, and maintaining efficient ink consumption.

Implementation Method 1

a specific gravity of the float portion is less than a specific gravity of the liquid within the liquid chamber, and the float portion moves based on an amount of liquid within the liquid chamber

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

a gap is formed between the signal blocking portion and the rib, and a capillary force in the gap draws the ink remaining in the inner space of the translucent portion to the gap between the signal blocking portion and the rib

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 3

The surface tension of the ink positioned between the signal blocking portion and the rib pulls the signal blocking portion, which attempts to move away from the rib, toward the rib

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP1944168B1Liquid container
Publication Date: 2009.07.15 BROTHER KOGYO KK
  • EP1944168B1 patent drawingFigure 1(A)~1(B)
  • EP1944168B1 patent drawingFigure 2
  • EP1944168B1 patent drawingFigure 3

AI summary

A liquid container includes a liquid chamber and a movable member pivotally positioned within the liquid chamber. The movable member includes a float portion and a contact surface, and the float portion moves based on an amount of liquid within the liquid chamber, and the movable member pivots based on a movement of the float portion. The liquid container further includes a regulating member configured to contact the contact surface when the amount of liquid within the liquid chamber is equal to or greater than a predetermined amount, and a pivotal movement of the movable member is regulated by the regulating member contacting the contact surface. When the amount of liquid within the liquid chamber decreases, the float portion moves such that the contact surface separates from the regulating member, and when the contact surface initially separates from the regulating member, the contact surface is positioned within the liquid.