Movable Light-Blocking Portion for Optical Sensor Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional inkjet-recording apparatuses face issues with the irradiated portion of the ink cartridge being susceptible to damage from external impacts, which can affect the accuracy of the optical sensor's signal for detecting the cartridge's attachment state.

Innovation Solution

A liquid cartridge design featuring a light-blocking portion that moves between two positions in response to impacts and is supported by resilient members, minimizing damage and ensuring proper alignment with the optical sensor, even during insertion and removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the irradiated portion protrudes outward from the outer surface of the casing to enable optical sensor detection, then the detection function is achieved, but the irradiated portion becomes susceptible to external impacts and damage

Engineering Contradiction:
Improveoptical sensor detection reliabilityVSAvoidexternal impact damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The light-blocking plate is designed as a movable member that can dynamically change its position between a first position (protruding from the casing) and a second position (retracted into the casing). This dynamic positioning allows the system to adapt to different conditions: protruding for optical detection and retracted for impact protection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The urging member (spring) is pre-loaded to provide an urging force that pushes the light-blocking plate toward the retracted position. This beforehand cushioning mechanism ensures that the light-blocking plate is automatically protected from external impacts by being pushed into the casing before impact occurs, while still allowing it to protrude when needed for detection.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Measurement precision

If the light-blocking plate is positioned to protrude from the casing for optical detection, then the optical sensor can detect the cartridge attachment state, but the light-blocking plate is vulnerable to damage from drops and impacts

Engineering Contradiction:
Improvecartridge attachment state detection accuracyVSAvoidlight-blocking plate damage resistance
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The light-blocking plate transitions between static states (protruding and retracted) dynamically based on operational needs. When the cartridge is properly attached, the plate protrudes to block light for accurate detection. When the cartridge is removed or subjected to impact, the plate retracts to protect itself, maintaining detection capability while reducing vulnerability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The urging member acts as an intermediary between the light-blocking plate and external forces. It provides a controlled restoring force that allows the plate to protrude for detection while automatically retracting when external forces (such as impacts) are applied, thus mediating between the need for detection accuracy and damage resistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the light-blocking plate is made movable to absorb impacts, then damage resistance is improved, but the structure becomes more complex with additional components

Engineering Contradiction:
Improveimpact absorption capabilityVSAvoidcartridge structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The light-blocking plate is designed to move along the optical axis within a simple linear guide structure provided by the casing. This linear movement capability provides impact absorption functionality without requiring complex mechanisms, maintaining structural simplicity while achieving the desired dynamic behavior.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The light-blocking plate utilizes the elastic potential energy stored in the pre-compressed urging member (spring) to automatically return to its protruding position after being pushed back by external forces. This self-service mechanism eliminates the need for additional actuators or control systems, reducing overall structural complexity while providing impact absorption.

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

This configuration reduces the risk of damage to the light-blocking portion and maintains effective optical sensor detection, ensuring reliable attachment and removal of the ink cartridge.

Implementation Method 1

an urging member that urges the movable member toward the deformable member

Methodology Applied
Scientific EffectElastic force: Spring

Implementation Method 2

a light-blocking plate that blocks light from a light source

Methodology Applied
Scientific EffectLight blocking: Absorption (EM radiation)

Implementation Method 3

if the light blocking portion incurs an impact from an external source when the liquid cartridge is dropped with the top surface facing downward, the light blocking portion moves from the first position to the second position against the urging force of the urging member, thereby absorbing the impact

Methodology Applied
Scientific EffectImpact force: Impact Force

Data Source

PatentEP3546224B1Liquid cartridge including movable member and system using the same
Publication Date: 2021.08.11 BROTHER KOGYO KK
  • EP3546224B1 patent drawingFigure 1
  • EP3546224B1 patent drawingFigure 2
  • EP3546224B1 patent drawingFigure 3

AI summary

A liquid cartridge is configured to be inserted into a cartridge-attachment section including a casing, a top surface, a movable member, and an urging member. The casing includes a liquid chamber storing liquid therein; and a liquid passage extending in a first direction in an upright posture. The top surface faces upward in the upright posture and formed with a recess. The movable member has a light blocking portion. The light blocking portion in the upright posture is configured to move between a first position and a second position. At least a part of the light blocking portion in the first position is positioned above the top surface in the upright posture. The urging member is configured to urge the movable member toward the first position.