Ink ribbon cassette, ink ribbon cartridge, printing device and control method for printing device

1. A printing device comprising:

an ink ribbon cartridge having a supply roll around which an ink ribbon is wound and a winding roll by which the ink ribbon supplied from the supply roll is wound; and

a main body part to which the ink ribbon cartridge is detachably attached;

wherein when a direction in which the ink ribbon is wound by the winding roll is defined as a ribbon winding direction and a direction in which the ink ribbon is wound by the supply roll is defined as a ribbon rewinding direction, the ink ribbon cartridge comprises:

a winding side rotating part for rotating the winding roll;

a supply side rotating part for rotating the supply roll;

a case body having a cover part which covers a substantially entire ink ribbon wound around the winding roll; and

a rotation prevention mechanism which prevents at least rotation of the winding roll in the ribbon rewinding direction;

wherein the rotation prevention mechanism comprises:

a first engaging part which is provided on a winding side rotating part side; and

a second engaging part which is engaged with the first engaging part to prevent at least rotation of the winding roll in the ribbon rewinding direction;

wherein the main body part comprises:

a mounted part on which the ink ribbon cartridge is mounted from an upper side; and

a cover part which covers the ink ribbon cartridge mounted on the mounted part from the upper side;

wherein when the ink ribbon cartridge has been detached from the main body part, the first engaging part and the second engaging part are engaged with each other, and

wherein at least one of the mounted part and the cover part is formed with an engagement release part which is contacted with the second engaging part when the ink ribbon cartridge is attached to the main body part and thereby engagement of the first engaging part with the second engaging part is released.

2. The printing device according to claim 1 , wherein the engagement release part is formed in the cover part.

3. The printing device according to claim 1 , wherein the rotation prevention mechanism comprises one piece of the first engaging part and a plurality of the second engaging parts.

4. The printing device according to claim 3 , wherein

the rotation prevention mechanism comprises two pieces of the second engaging part,

the engagement release part is formed in each of the mounted part and the cover part,

the engagement release part formed in the mounted part is contacted with one of two pieces of the second engaging part to release engagement of the one of two pieces of the second engaging part with the first engaging part, and

the engagement release part formed in the cover part is contacted with the other of the two pieces of the second engaging part to release engagement of the other second engaging part with the first engaging part.

5. The printing device according to claim 1 , wherein

the rotation prevention mechanism is a ratchet mechanism, and

when the first engaging part and the second engaging part are engaged with each other, the winding roll is capable of rotating in the ribbon winding direction.

6. The printing device according to claim 1 , wherein

the first engaging part is a gear,

the second engaging part is a pawl member which is engaged with the gear,

the rotation prevention mechanism comprises a fixed shaft which turnably supports the pawl member and an urging member which urges the pawl member to one side in a turning direction with the fixed shaft as a center,

the pawl member is engaged with the gear by an urging force of the urging member and, when the engagement release part is contacted with the pawl member, the pawl member is turned to the other side in the turning direction with the fixed shaft as the center and an engaging state of the gear with the pawl member is released.