Printer Cartridge Memory Matching After Subscription Cancellation

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Solution Overview

Problem

Existing technologies require rewriting identification information in toner memories of subscription cartridges to allow their use after a service contract is cancelled, which is inconvenient and may lead to unauthorized use.

Innovation Solution

An image forming apparatus with a main memory that stores history information about previously used subscription cartridges, allowing them to be used without rewriting identification information in the cartridges, by matching current identification information with stored history information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If identification information in toner memory is rewritten to allow use after service contract cancellation, then cartridges can be used in normal state, but this requires complex rewriting processes and may lead to unauthorized use

Engineering Contradiction:

Improvecartridge usability after contract cancellationVSAvoididentification information rewriting process

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system separates the identification information storage into two distinct locations: the cartridge's own memory (cartridge memory) and the image forming apparatus's memory (main memory). The main memory stores history information including identification information from previously attached subscription cartridges. This segmentation eliminates the need to rewrite cartridge memory while maintaining the ability to control cartridge usage after contract cancellation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The main memory acts as an intermediary that stores history information about previously used cartridges. When a cartridge is attached, the controller reads its identification information and compares it with the history information stored in the main memory. This intermediary approach allows the system to verify cartridge legitimacy without modifying the cartridge's own memory, thus avoiding the complexity and security risks of rewriting operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If identification information is rewritten in subscription cartridges, then cartridges can be used after contract cancellation, but this raises security concerns about unauthorized use

Engineering Contradiction:

Improvecartridge usability after contract cancellationVSAvoidprevention of unauthorized use

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary action by storing the identification information of subscription cartridges in the main memory's history information during the subscribed state, before contract cancellation occurs. This pre-stored information is then used for verification after cancellation, eliminating the need to rewrite cartridge memory and preventing unauthorized use through comparative verification rather than modification.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If the system stores history information about previous subscription cartridges, then cartridges can be used without rewriting, but this requires additional memory storage capacity

Engineering Contradiction:

Improvecartridge usage processVSAvoidmemory storage capacity

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

The history information stored in the main memory serves as a disposable, temporary record that is specific to each image forming apparatus. This information is not permanently embedded in the cartridge but rather stored locally in the apparatus's memory, allowing easy management and deletion when needed without affecting the cartridge itself. The storage requirement is minimal compared to rewriting operations.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS12566405B2Image forming apparatus including main casing to which cartridge is attachable and main memory and method of controlling image forming apparatus

Publication Date: 2026.03.03 BROTHER KOGYO KK

AI summary

An image forming apparatus includes: a main casing; a main memory; and a controller. A cartridge is detachably attachable to the main casing. The cartridge includes a cartridge memory storing therein identification information identifying the cartridge. The main memory is configured to store therein history information including history identification information. The history identification information is identification information for a previous subscription cartridge previously attached to the main casing. The controller is configured to perform: in response to a cartridge being attached to the main casing, (a) reading identification information from a cartridge memory of the attached cartridge as current identification information; (b) determining whether the current identification information read in (a) matches the history identification information included in the history information stored in the main memory; and in response to determining in (b) that the current identification information matches the history identification information, (c) permitting use of the attached cartridge.