Patent ID: 7023460

Claim:
A thermal head printer for printing a substantially light-insensitive thermographic material, said thermal printer comprising: (a) a transport system having a transport direction, (b) n thermal heads, where n is an integer greater than zero, each of said thermal heads comprising an array of substantially rectangular energizable heating elements, said heating elements having a length L n in said transport direction and a pitch P n between adjacent heating elements, and (c) a means for supplying electrical energy to each of said substantially rectangular energizable heating elements in at least one of said thermal heads, wherein said transport system is capable of transporting said light-insensitive thermographic material in contact or proximity with at least one of said thermal heads, wherein at least one of said thermal heads comprises heating elements for which L n P n is between 0.25 and 0.88, wherein said printer is capable of image-wise printing said substantially light-insensitive thermographic material, and wherein said substantially light-insensitive thermographic material is not perforated by said printer.