Patent ID: 7278351

Claim:
A plate-making method for stencil printing comprising: forming a plurality of minute recesses in one side of a heat-sensitive stencil plate material for stencil printing, the plate material comprising a thermoplastic resin film with a predetermined thickness, wherein forming the minute recesses forms an internal tensile stress in the film and each recess forms a thin portion of the film having a thickness less than the predetermined thickness; and heating an opposite side of the film with a thermal head sufficiently to fuse-penetrate a thin portion of the film, but insufficiently to fuse-perforate the predetermined thickness of the film, so that said openings are formed by the heated fused-penetrated portion communicating with the minute recess; wherein two or more heaters are arranged in a main scanning direction at one sequence or tier on the thermal head, when a main scanning side array pitch of the heater is set to PM, a main scanning side heater length is set to HM, a sub scanning side delivery pitch is set to PS and a sub scanning side heater length is set to HS, the heater size satisfies HM>0.6 PM and HS>0.7 PS so as to distribute two or more minute recesses in such area of the film that is in contact with one heater section of the thermal head.