Patent ID: 7140712

Claim:
A liquid cartridge comprising: a container having a liquid supply port connectable to a flowing path communicating with a recording head of liquid jet printer, said container being a bottomed-box type container having said liquid supply port, and a lid member sealing an opening portion of said container; a memory unit including a memory section storing therein data about a liquid housed in the container and an electric power generating section; and an antenna portion provided on a wall opposed to a wall in which said liquid supply port is formed, and including a rectangular conductive pattern electrically connected to said memory unit, which communicates the data in said memory section to a recording apparatus by radio, and said antenna portion can receive a carrier wave, which is converted into DC electric power by said electric power generating section to become working electric power, wherein the carrier wave is transmitted from the recording apparatus, and after stopping transmission of the carrier wave, the memory unit calculates an amount of said liquid housed in the container based on a signal from a sensor, and the amount of said liquid and said data about said liquid stored in the memory section are transmitted from said antenna portion to the recording apparatus.