| 摘要 |
PURPOSE:To make it possible to always obtain constant printing pressure, by a method wherein the rotary radius of a platen or a printing head is reduced as the increment in the elasticity of an electric member and the position for attaching the elastic member is set so as to maximize rotary moment by the elastic force thereof. CONSTITUTION:One end of a coil spring 5 is fixed to the side opposed to the printing head 1 of a platen 7 pivotally supported with respect to a shaft 8 in a freely revolvable manner and the other end thereof is fixed to a support base table 4. A revolving habit toward a counterclockwise direction is imparted to the platen 7 by the coil spring 5 to press the printing head 1. The attaching position of the coil spring 5 is set in such a manner that the rotary radius of the platen 7 or the printing head 1 with respect to elastic force is made small and the rotary moment of the platen 7 or the printing head 1 due to elastic force is made max. as the elastic force of the coil spring 5 is increased to make it possible to obtain constant printing pressure within a minute range. |
