Inkjet Printhead Ink Tracking via Networked Dot Count Aggregation

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Solution Overview

Problem

Current inkjet printhead cartridges have limited nonvolatile memory, leading to coarse ink level indications, making it difficult to accurately track the remaining ink level when moved between printers, which is unacceptable in applications requiring precise accounting.

Innovation Solution

A network-connected system where each printer maintains a history of used printhead cartridges, allowing it to request and aggregate ink dot count values from other printers with matching serial numbers, updating the count based on the highest recorded value or latest timestamp to determine the precise ink remaining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If nonvolatile memory in printhead cartridges is kept small to reduce manufacturing costs, then manufacturing cost is reduced, but measurement precision of ink level deteriorates

Engineering Contradiction:
Improvemanufacturing costVSAvoidink level indication precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent extends the measurement system from a single-dimension approach (cartridge-only memory) to a multi-dimension networked approach. By distributing memory across multiple printers in a network and aggregating data from all locations where a cartridge has been used, the system achieves high measurement precision while keeping individual cartridge memory small and inexpensive.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a printhead cartridge is moved from one printer to another, then printer versatility is improved, but reliability of ink level tracking deteriorates

Engineering Contradiction:
Improveprinthead mobilityVSAvoidink level tracking accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system implements a feedback mechanism where each printer in the network reports ink level data back to a central server or other printers. When a cartridge is moved between printers, the network aggregates ink level information from all printers that have used the cartridge, providing continuous feedback that maintains reliable tracking despite the cartridge's mobility.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a network server or intermediary system that mediates between multiple printers and the mobile cartridge. This intermediary aggregates ink level data from all printers that have used the cartridge, ensuring reliable tracking without requiring the cartridge itself to maintain detailed records at each location.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If coarse ink levels are encoded in limited nonvolatile memory, then device complexity is reduced, but loss of information increases

Engineering Contradiction:
Improvememory encoding complexityVSAvoidink usage information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent merges the memory systems of multiple printers into a unified networked memory structure. Instead of requiring complex encoding in a single cartridge, the system combines simple memory readings from multiple printers to reconstruct complete ink usage information, thereby reducing individual device complexity while preserving information integrity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3722099B1Method for determining an amount of ink and inkjet printer
Publication Date: 2023.01.11 FUNAI ELECTRIC CO LTD
  • EP3722099B1 patent drawingFigure 1
  • EP3722099B1 patent drawingFigure 2
  • EP3722099B1 patent drawingFigure 3A~3B

AI summary

A system tracks the exact amount of ink remaining in printhead cartridges used in printers connected to a network. Each printer stores a history of cartridges that have been used in the printer. Each cartridge stores a status indicator that indicates whether the cartridge has been used before in any printer. When a printer receives a previously-used cartridge, the printer broadcasts a request for information about that cartridge from the other printers. Each printer having the matching printhead identification number in its history reports over the network the last recorded ink dot count associated with the matching printhead identification number. The requesting printer chooses the most up-to-date response based on the highest dot count or the latest time-stamp. The requesting printer then updates its memory using the dot count from the most up-to-date response and begins counting dots from that updated count for subsequent print jobs performed using the installed cartridge.