Patent ID: 7165903

Claim:
A platen roller retaining structure comprising: a platen roller capable of rotating; a regulating member having a connecting portion mounted to the platen roller and an engagement portion kept at a predetermined distance from the connecting portion and which is capable of relative rotation coaxially with and with relative to the platen roller; and a stationary frame having a first recess for retaining the platen roller at a predetermined position opposed to a recording head performing recording on a recording medium, and a second recess for retaining the engagement portion of the regulating member at a predetermined position, wherein: a part of an inner peripheral edge of the first recess is located in a position where the part of the inner peripheral edge of the first recess regulates movement of the platen roller in a particular direction, with the platen roller being retained in the first recess and the engagement portion of the regulating member being retained in the second recess; a part of an inner peripheral edge of the second recess forming an arc whose center is the platen roller is located in a position where the part of the inner peripheral edge of the second recess regulates movement of the engagement portion in a particular direction, with the platen roller being retained in the first recess and the engagement portion of the regulating member being retained in the second recess; and with the platen roller being retained in the first recess and the engagement portion of the regulating member being retained in the second recess, the regulating member rotates coaxially with and relative to the platen roller while the platen roller remains retained in the first recess without moving, and the engagement portion moves along the inner peripheral edge of the second recess to escape from the second recess to thereby enable the platen roller to move in a direction in which the platen roller can escape from the first recess.