Elongate hand-held printer device with an optical encoder wheel

An elongate hand-held printer device for printing on a medium when a user moves said device over the medium, the device comprising:

• an upper and a lower moulding configured to receive each other in a complementary fashion to define a housing, said housing defining an ink ejection slot;
• a printhead module housed in the housing, the module having a plurality of micro-electromechanical ejection devices configured to eject ink via the ink ejection slot;
• an ink supply cartridge housed in the housing, the cartridge configured to supply the printhead module with ink;
• an optical encoder wheel to engage the medium and facilitate regulation of a printing rate of the printhead module as the device is moved along the medium;
• and
• a capping device coupled externally to a major face of the upper molding, the capping device having an actuation arm substantially parallel to the major face and a capping arm extending normal to the major face and across a print face of the printhead module, wherein
• the capping device further includes a finger pad provided on the actuation arm, the finger pad configured to pivot the capping arm away from the print face of the printhead module.