Ink Cartridge Remanufacturing via Shell Modification

The patent applies universality by designing a single empty shell structure that can serve multiple functions - it can be used as a high-capacity ink cartridge shell or modified to serve as a low-capacity ink cartridge shell. This eliminates the need to maintain separate inventories of empty shells for different capacities, thereby reducing manufacturing costs while preserving compatibility with different ink cartridge requirements.

The patent employs parameter changes by modifying the capacity parameter of the same empty shell structure through selective removal of parts. The empty shell maintains its basic structure and engagement parts but has different internal volumes achieved by removing portions of the shell, allowing it to function as either high-capacity or low-capacity cartridge depending on the modification applied.

The patent applies inversion by reversing the conventional remanufacturing approach. Instead of collecting and modifying high-capacity empty shells to create low-capacity cartridges (which is difficult because high-capacity shells are scarce), the invention collects abundant low-capacity empty shells and modifies them to create high-capacity cartridges by adding an external body, thereby solving the collection difficulty problem.

The patent uses copying by creating a new external body that replicates the structure and engagement parts of a high-capacity ink cartridge shell. This external body is attached to the low-capacity empty shell, effectively copying the appearance and functionality of a high-capacity cartridge without requiring actual high-capacity shells for collection and remanufacturing.