A tape guide post mechanism for guiding running of a tape includes: a post arm,
the post arm including a tape guide post, around which the tape is looped at a
predetermined angular distance, and which guides running of the tape, and a hole;
an arm shaft which engages with the hole and rotatably supports the post arm, wherein
an external side surface of the arm shaft is in contact with the hole at at least
two points in the vicinity of an upper opening of the hole and at at least two
points in the vicinity of a lower opening of the hole.
