An ink cartridge is used mounted in a recording device with a hollow needle, a lever, a protruding wall, and an optical sensor. The lever and the optical sensor are located on either side of the hollow needle, but closer to the opening through which the ink cartridge is mounted. The ink cartridge is...http://www.google.com.au/patents/US7152966?utm_source=gb-gplus-sharePatent US7152966 - Ink cartridge and recording device
