A pressure balancing cartridge for mixing hot and cold water includes a casing having a sleeve therein which further includes a reciprocating balancing spool therein. The MFP adds a department ID of the general affairs department which is authentication information at this operation, as billing destination information, to the document data. A lens array is formed on the light transmission substrate, and the lens array has the same pitch as that of the pixel array. A light trap feature is incorporated into andor around the cold element.