Liquid Pool Portion Prevents Shaft Solidification in Level Detection

Solution Overview

Problem

The existing liquid remaining amount detecting mechanisms in liquid ejection devices face difficulties in accurately detecting the remaining liquid due to solidification of the liquid on the outer and inner surfaces of the shaft and through-hole, which prevents smooth rotation of the rotating member and subsequent detection of the liquid level.

Innovation Solution

A liquid remaining amount detecting mechanism that includes a rotating member with a float and a detection target portion, where a liquid pool portion is located between the outer peripheral surface of the shaft and the inner peripheral surface of the through-hole to hold the liquid, ensuring smooth rotation and accurate detection even when the liquid level decreases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the liquid level in the storage chamber is lowered below the shaft, then the rotating member can detect lower liquid levels, but the liquid adhering to the shaft and through-hole may solidify and fix the surfaces together, preventing smooth rotation

Engineering Contradiction:

Improveliquid level detection accuracyVSAvoidrotating member rotation smoothness

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The liquid pool portion is designed to preliminarily hold liquid between the shaft and through-hole before the liquid level drops below the shaft. This preliminary liquid retention prevents the liquid from solidifying on the contact surfaces, ensuring smooth rotation continues even when the main liquid level is low.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The liquid pool portion acts as an intermediary mechanism that maintains a small amount of liquid between the shaft and through-hole. This intermediary liquid prevents direct contact and solidification between the shaft and through-hole surfaces, allowing the rotating member to continue rotating smoothly at low liquid levels.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the rotating member rotates smoothly at low liquid levels, then detection continues accurately, but the liquid between the shaft and through-hole may solidify and prevent rotation

Engineering Contradiction:

Improveremaining liquid amount detection accuracyVSAvoidrotating member rotation smoothness

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The liquid pool portion is designed to preliminarily hold liquid between the shaft and through-hole before the liquid level drops below the shaft. This preliminary liquid retention prevents the liquid from solidifying on the contact surfaces, ensuring smooth rotation continues even when the main liquid level is low.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The liquid pool portion acts as an intermediary mechanism that maintains a small amount of liquid between the shaft and through-hole. This intermediary liquid prevents direct contact and solidification between the shaft and through-hole surfaces, allowing the rotating member to continue rotating smoothly at low liquid levels.

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 liquid pool portion maintains a sufficient amount of liquid between the shaft and through-hole, preventing solidification and ensuring smooth rotation of the rotating member, thereby enabling accurate detection of the remaining liquid amount and timely notification of cartridge replacement.

Implementation Method 1

a rotating member that is disposed in a storage chamber of a tank that stores a liquid; and a sensor, in which the rotating member is rotatable about a shaft and includes a float that receives buoyancy from the liquid

Methodology Applied

Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentUS11548289B2Liquid remaining amount detecting mechanism

Publication Date: 2023.01.10 CANON KK

AI summary

A liquid remaining amount detecting mechanism includes a rotating member that is disposed in a storage chamber of a tank that stores a liquid, and a sensor. The rotating member is rotatable about a shaft and includes a float that receives buoyancy from the liquid, a detection target portion that is detectable by the sensor, and a through-hole into which the shaft is inserted. The sensor is disposed at a position facing a portion of a locus of the detection target portion when the rotating member is rotated. The liquid remaining amount detecting mechanism further includes a liquid pool portion, at least a portion of which is located between an outer peripheral surface of the shaft and an inner peripheral surface of the through-hole to hold the liquid.