Image Number 14 for United States Patent #8104880.
A liquid cartridge mountable in a recording device includes a liquid accommodating chamber that accommodates liquid therein, a float movably disposed in the liquid accommodating chamber, and a detection section to be detected by an external light detector for determining remaining amounts of the liquid in the liquid accommodating chamber. The detection section is movably disposed in the liquid accommodating chamber to move along a predetermined path in conjunction with movements of the float. The light detector includes a light emitting section that emits light and a light receiving section that receives the light. The detection section includes a first section and a second section; the first section transmits the light when the first section is in a detection point, while the second section blocks the light, the first section and the second section being arranged alternately. An amount of liquid accommodated in the liquid accommodating chamber when the liquid cartridge is mounted in the recording device is determined based on a number of times the light emitted from the light emitting section traverses the alternately arranged first and second sections during mounting the liquid cartridge in a mounting direction in the recording device.