An ink cartridge comprises a container main body 2 storing ink and having a through hole 67 communicating with the atmosphere as the ink cartridge is placed in a record apparatus, and a liquid level sensor 61 being disposed in the vicinity of a corner in the container main body 2 for detecting the ink...http://www.google.com.au/patents/US6802602?utm_source=gb-gplus-sharePatent US6802602 - Ink cartridge and ink jet record apparatus using ink cartridge
