Patent ID: 7475978

Claim:
A liquid cartridge comprising: a liquid container section for containing a recording liquid; and a liquid supply section for supplying the recording liquid contained in the liquid container section to an ejection device, wherein, the liquid cartridge functions as a supply source of the recording liquid to the ejection device, is detachably installed in a liquid ejection apparatus and includes (1) a liquid chamber for containing the recording liquid, (2) a pressure-generating element which generates a pressure to place the recording liquid contained in the liquid chamber under increased pressure, and (3) the ejection device which includes an ejection port for ejecting the recording liquid pressure-in the form of droplets when placed under increased pressure by the pressure-generating element, (4) which drives the pressure- generating element with a pulsed current at a frequency of 5 kHz or more, and (5) which causes each droplet to eject with a volume of 10 pl or less, the recording liquid comprises (a) a coloring matter which imparts color to the recording liquid, (b) a solvent for dissolving or dispersing the coloring matter, and (c) a nonionic surfactant, and the recording liquid has a foaming power of 0 mm to 50 mm and a foam stability of 0 mm to 50 mm, the foaming power and the foam stability being determined by substantially the same test method as that used to determine the foaming power and foam stability according to a Japanese Industrial Standard, JIS-K3362.