US Patent 7354135 Waste liquid collecting method, liquid injecting apparatus and cartridge set

A printer includes a recording head and a maintenance mechanism for sucking an ink in the recording head. A plurality of cartridges to be attached to the printer includes a first housing portion for storing an ink to be supplied to the recording head and a second housing portion for storing a waste ink discharged from the maintenance mechanism. In a first one of the cartridges, the flow path resistance of a cartridge side flow path from a waste ink introducing portion to an air communicating hole for discharging air in a waste ink reservoir portion to an outside through the waste ink reservoir portion is lower than the flow path resistance of each of the cartridge side flow paths of the other cartridges (FIG. 14).