In an ink cartridge, a negative pressure generating mechanism is disposed between an ink storage region and an ink supply port, and has a wall surface having two through-holes for ink flow, and a valve member contacted with and separated from the through-hole by receiving a pressure in an ink supply port side. 2 dB; and curing adhesive to initially secure the aligned optical element assembly. The method further comprises sensing the airflow disruption to indicate detection of the document trailing edge at the fixed location. The plurality of sensors are configured to detect a water level relative to the opening in the fitting body based on the number of sensors in the array that provide an output indicative of contact with water.