Abstract: A method for refilling an ink cartridge which contains an elastic bladder within the ink reservoir cavity that is connected to outside pressure. The methodology of the invention teaches how to seal and unseal the bladder and ink regions in sequential steps and how to inject ink into the ink reservoir cavity so it may be re-used and not discarded.

Abstract: This invention is directed to improved aqueous pigment-based ink compositions for use in ink jets and methods of enhancing and/or controlling the optical density and print sharpness of both pigment-based and dye-based inks. The improved ink compositions include a class or organic quaternary ammonium compounds which improve the optical density and print sharpness of the inks. Other improvements include the use of a polyalkylene oxide to impedence match the ink with the drop formation rate to provide drop formation rates as high as 8,000 drops per second. These high drop rates permit higher writing speeds and enhanced printer resolution. Yet another improvement to ink jet ink composition is the addition of urea, urea derivatives and thiol compounds. These compounds prevent the ink jet from accumulating dried ink thus preventing clogging of the ink jet.

Abstract: A method of refilling an ink jet cartridge with ink. The cartridge has a housing which encloses an internal ink reservoir extending between top and bottom ends thereof, an ink fill aperture extending through the housing near its top end, and a means for sealing the ink fill aperture. The cartridge further includes a bladder in the reservoir, an air port affixed to the top of the housing, and a spring means which biases the bladder toward a minimum volume state. According to the method, the cartridge is positioned with its top end above its bottom end, the ink fill aperture is unsealed, and the air port is sealed. The bladder is inflated to establish an internal volume in a predetermined range. Ink is then injected into the reservoir through the ink fill aperture. The ink fill aperture is then sealed, and the air port unsealed.

Abstract: A method and apparatus for refilling an ink cartridge include a device for clearing a hole in the cartridge to facilitate the dispensing of ink thereto. The device comprises a handle to which a bit is rigidly affixed so that torque applied to the handle is transmitted to the bit. The bit is arranged to extend along the handle's longitudinal axis. A kit for refilling an ink cartridge includes the aforementioned hole clearing device and a container containing a charge of ink and having a nozzle. The nozzle is formed so that it can pass through the hole cleared by the hole clearing device. In a preferred embodiment, the container is bellows shaped and compressible so that a user can compress the container and increase the rate at which the fresh ink charge is dispensed to the cartridge.