Alternating Current Ink Level Detection Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printers face issues with ink detection due to electrolysis when using direct current, leading to bubble formation and clogging, and existing solutions do not effectively address the positioning and connection of circuit elements for reliable liquid surface level detection.
Innovation Solution
A liquid consumption apparatus using a circuit substrate with an alternating current generation circuit, elastic contacts, and a substrate holder to ensure proper positional alignment and electrical connections between terminals and conductive members, preventing electrolysis and improving detection reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct current is passed through the ink to detect the amount of remaining ink, then the liquid detection unit can measure ink levels, but electrolysis occurs causing bubbles and ink component deposition on electrodes
Solution Approach 1:
The patent changes the electrical parameter from direct current to alternating current with a frequency of 1 kHz or higher. This parameter change prevents electrolysis while maintaining the ability to detect ink levels through electrical resistance measurements, thereby eliminating bubble formation and ink component deposition on electrodes.
Solution Approach 2:
The patent employs periodic alternating current instead of continuous direct current. The periodic reversal of current direction prevents the accumulation of reaction products at electrodes, avoiding electrolysis-related issues while enabling continuous ink level detection through resistance measurements.
2Reliability
If circuit elements on the circuit substrate are not appropriately positioned, then the liquid detection unit cannot reliably detect liquid surface levels, but proper positioning requires additional positioning structures
Solution Approach 1:
The patent merges the positioning function with the connection structure by integrating positioning protrusions and recesses directly into the substrate holder and circuit substrate. This combination eliminates the need for separate positioning structures while ensuring reliable positioning of the circuit substrate relative to the ink tank.
Solution Approach 2:
The patent introduces a substrate holder as an intermediary component between the ink tank and the circuit substrate. The substrate holder provides both positioning protrusions and connection functions, mediating the relationship between the ink tank and circuit substrate to achieve reliable positioning without direct complex coupling.
3Reliability
If elastic contacts are not provided, then the electrical connection between terminals and electrically-conductive members may be unreliable due to displacement, but adding elastic contacts increases device complexity
Solution Approach 1:
The patent introduces elastic contacts that can dynamically adjust to displacement between the circuit substrate and ink tank. These elastic contacts maintain reliable electrical connection by flexing to accommodate positional variations, providing a dynamic solution to the displacement problem.
Solution Approach 2:
The patent employs elastic contacts made from flexible materials that can deform to maintain contact pressure and electrical connection reliability. The flexibility of these contacts allows them to accommodate displacement while maintaining stable electrical connection between terminals and electrically-conductive members.
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 apparatus effectively detects liquid surface levels without electrolysis-induced issues, ensuring reliable ink ejection by maintaining stable electrical connections and preventing ink component deposition on electrodes.
Implementation Method 1
the liquid detection unit passes an electric current through the ink inside the ink tank in order to detect the amount of remaining ink
Implementation Method 2
The substrate holder is provided with an elastic contact for connecting the pair of electrically-conductive members and the pair of terminals with each other. The elastic contact is a contact that is elastic in a first direction
Data Source
AI summary
A liquid consumption apparatus that detects a liquid surface level of a liquid inside a liquid container (ink tank), including: a circuit substrate; a substrate holder that holds the circuit substrate; and a control unit that detects the liquid surface level. A pair of electrically-conductive members consisting of a first electrically-conductive member and a second electrically-conductive member are provided for the liquid container. The circuit substrate is provided with a pair of terminals corresponding to the pair of electrically-conductive members. The substrate holder is provided with an elastic contact for connecting the pair of electrically-conductive members and the pair of terminals with each other. The elastic contact is a contact that is elastic in a first direction, where the first direction is a longitudinal direction of the pair of electrically-conductive members.