A valve has a valve needle for feeding a medium into a receptacle, a valve chamber, and a valve seat. An internal plunger is used to expand the wall segments in a radial direction, thereby retaining a CD onto the outer perimeter of the pick. The pressure differential causes the liquid precursor to travel uniformly through the through-channels, depositing the membrane-forming materials on the walls of the through-channels and forming the membrane on the walls of the through-channels. The controller maintains in RAM a plurality of track-level damage count values, each associated with one of the plurality of data tracks and representing estimated damage to one of the plurality of data tracks. A first intake passage of the water separator communicates with the ambient air opening. Part of the source light is configured to be taken to an outside of the light emitting device without passing through at least one of the first wavelength conversion portion and the second wavelength conversion portion.