relates to an ink jet printing head comprising in combination a thermal head having a plurality of thermal dot elements a guide member having a plurality of grooves corresponding to the thermal dot elements respectively and being in contact with the thermal head and an ink supplying passageway for supplying ink to the grooves the rear ends of the grooves are closed and the thermal head and guide member are movable with respect to each other all of the ink in each of the grooves is respectively and completely jetted out of the grooves together with steam caused by the thermal dot elements producing heat ink bubbles do not remain in the grooves thereby avoiding an overheating condition of the thermal head in an ink less condition thereby eliminating blockage application_number US 21129788 A description reference is now made to the accompanying drawings showing certain preferred embodiments of the present invention as shown in fig1 a thermal head 1 has a plurality of thermal dot elements 2 and an ink supplying pipe 3 shown partially in phantom which is connected to an outer ink tank not shown the pipe 3 is mounted on the thermal head 1 another pipe 3a shown partially in phantom may also be used a guide member 5 having a plurality of grooves 4 form a plurality of ink nozzles and.