Ink Cartridge Optical Detection for Abnormality Verification

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Solution Overview

Problem

Existing liquid ejecting apparatuses, such as inkjet printers, face challenges in accurately determining the remaining ink level in cartridges due to issues like bubble formation during handling, manufacturing defects, and type compatibility, leading to incorrect determinations and inefficient purge operations.

Innovation Solution

The apparatus employs a movable member within the liquid chamber that changes position relative to an optical detector as the liquid surface moves, allowing for real-time determination of the liquid cartridge's normalcy by monitoring the state of a light receiver, which changes based on the movable member's position, distinguishing between normal and abnormal cartridges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a movable member and optical detector are used to detect ink level, then ink level can be monitored, but incorrect determination occurs due to bubbles or manufacturing defects

Engineering Contradiction:
Improveink level detection accuracyVSAvoiddetermination accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent performs a preliminary determination of cartridge normalcy by moving the mounting portion to a specific position and checking if the movable member moves to the expected position. This preliminary check identifies abnormal cartridges (those with bubbles or defects) before ink level measurement, preventing incorrect measurements on defective cartridges.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the movable member's position detection to determine whether the cartridge is normal before proceeding with ink level measurement. The optical detector provides feedback on the movable member's position, and this feedback is used to validate the cartridge's operational status.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If a movable member is used to detect ink level, then real-time monitoring is enabled, but device complexity increases

Engineering Contradiction:
Improvereal-time ink level monitoringVSAvoidcartridge structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The movable member is designed to move automatically based on ink level changes without requiring external actuation. The float rises and falls with the ink level, and the pivotable member responds passively to buoyancy forces, eliminating the need for motors or complex actuation mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex electronic sensors with a simple optical detection system. The optical detector uses light reflection or transmission changes caused by the movable member's position to determine ink level, substituting mechanical position sensing with optical sensing for simpler implementation.

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

3Reliability

If the mounting portion is moved to detect cartridge normalcy, then early detection of abnormal cartridges is enabled, but loss of time occurs during the detection process

Engineering Contradiction:
Improveearly detection of abnormal cartridgesVSAvoiddetection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs the normalcy determination by moving the mounting portion to a specific position before the main ink level measurement. This preliminary positioning and detection step identifies abnormal cartridges early, preventing wasted time on incorrect measurements from defective cartridges.

Inventive Principle:
Principle #10Preliminary 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 solution enables early detection of abnormal cartridges, reducing the likelihood of incorrect ink level assessments and minimizing ink wastage by determining cartridge normalcy during the initial mounting process, thus allowing for timely action.

Implementation Method 1

a float at the other end. The float has a specific gravity which is less than that of ink... Because the specific gravity of the float is less than that of ink, the float attempts to float on the ink surface.

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

The pivotable member includes a light blocking member at one end... the light blocking member moves upward. The case of the ink cartridge is formed with a protruding portion on a side. The case is made of a material through which light can pass.

Methodology Applied
Scientific EffectLight blocking: Absorption (EM radiation)

Implementation Method 3

the inkjet printer includes a movable member configured to move in response to a change in the amount of ink in the ink cartridge, and a detector configured to detect whether the movable member is in a specified position.

Methodology Applied
Scientific EffectOptical detection: Photoelectric Effect

Data Source

PatentEP2165837B1Liquid ejecting apparatus and liquid ejecting system
Publication Date: 2014.04.30 BROTHER KOGYO KK
  • EP2165837B1 patent drawingFigure 1
  • EP2165837B1 patent drawingFigure 2(A)~2(B)
  • EP2165837B1 patent drawingFigure 3(A)~3(B)

AI summary

A liquid ejecting apparatus (100) includes a mounting portion (300) configured to move and a liquid cartridge (10) including a liquid chamber (11) and a movable member (90), an optical detector fixed to the mounting portion (300) and having a light emitter (342B) and a light receiver (342C), and a state determiner (400) configured to determine a change in a state of the light receiver (342C). The movable member (90) is configured to move according to a position of a surface of liquid stored in the liquid chamber (11). The light receiver (342C) is configured to assume two predetermined states according to a position of a portion of the movable member (90) in the liquid chamber (11). The state determiner (400) determines that the liquid cartridge (10) is normal or abnormal according to the change in the state of the light receiver (342C).