Thermal printer head

Claim 1

A thermal printer head for printing on heat sensitive paper under the condition in which there is relative motion between the printer head and the paper, said printer head comprising a cylindrical insulator base having a plurality of shallow linear recesses in the cylindrical surface thereof along a single line parallel to the cylinder axis, heat generator film resistors within said recesses and filling said recesses to a level just below the surface of the base surrounding the recesses, the areas of the surface of the base between said recesses contacting the heat sensitive paper during a printing operation and frictional contact occurring only between the base and the paper, and the heat generator film resistors being protected from abrasion due to friction between the resistors and the paper, said heat generator film resistors having first film conductor terminals extending therefrom around said cylindrical insulator base, the first film conductor terminals from alternate heater elements extending in opposite directions around the cylindrical insulator base, and said heat generator film resistors having second lead wire terminals extending therefrom around the cylindrical insulator base in the opposite directions from the first film conductor terminals in the spaces on the surface of the cylindrical insulator base between the first film conductor terminals and for a distance less than the length of said first terminals, whereby the arrangement of the heat generator film resistors is compact due to the fact that the pitch therebetween is half the pitch between adjacent first film conductor terminals and adjacent second lead wire terminals and the printer head is suitable for a line-dot type printer head.