INK JET RECORDER AND RESIDUAL INK DETECTING METHOD

PURPOSE: To provide an ink jet recorder which has excellent reliability and maintainability capable of detecting the lack of ink, and a method for detecting the residual ink. CONSTITUTION: The ink jet recorder comprises a recording head 38 having a discharge port for discharging ink, an ink vessel 21 for containing the ink to be supplied to the head, and a carriage mounting the head and the vessel 21 to linearly move. The recorder further comprises a member 32 to be detected with ink and having a shielding member 33 having light shielding properties and a floating member 34 disposed at the upper part of the member 33 in the vessel 22 and freely floated on the ink, a detecting ink reservoir 31 mounted in a protrusion with the transparent lower part of the vessel 21, and an optical detecting member 35 having a light emitting element 36 and a light receiving element 37 for detecting the light from the element 36. The member 32 shields between the element 36 and the element 37.