To form an ink ribbon cassette that can cause no printing failures during low temperature printing and solve the problem of a winding bulge.
The cassette includes a pair of winding out and winding in cores housed therein, a recess part 19 for the insertion of a printing head, a winding driving roller 23 being supplementary in traveling of an ink ribbon between the ink ribbon insertion recess part 19 and the winding in core in the pass line of an ink ribbon 12, and a winding out stopping roller 16 between the winding out core 13 and the printing head insertion recess part 19. A dynamic frictional coefficient (μ1) is made in the range of 0.4-0.8 between the winding in winding driving roller 23 and the nonprinting face of the ink ribbon 12, and dynamic frictional coefficient (μ2) is made in the range of 0.2-0.7 between the winding out stopping roller and the nonprinting face of the ink ribbon, thereby satisfying a relation of μ1>μ2 in the dynamic fricational coefficient. Preferably, μ1 is made larger than μ2 by 0.1 or more.
AMEMORI KAZUHIKO
WATANABE NAGATAKE
HORI YOSHIYUKI
