Thermal printer unit

1. A thermal printer unit, comprising:

a main body module;

a platen module including a supporting structure and a platen; and

a thermal head module including a supporting structure and a thermal head;

wherein the main body module, the platen module and the thermal head module are separable from each other,

the platen module and the thermal head module are configured to be individually detachably connectable to the main body module,

the platen module is configured to be detachably connectable to the main body module to which the thermal head module is connected, and

the thermal head module is configured to be detachably connectable to the main body module to which the platen module is connected.

2. The thermal printer unit as claimed in claim 1 , wherein the thermal head module further includes clamping mechanisms configured to clamp bearings provided one for each end of a shaft of the platen of the platen module connected to the main body module.

3. The thermal printer unit as claimed in claim 1 ,

wherein the thermal head module further includes clamping mechanisms configured to clamp bearings provided one for each end of a shaft of the platen of the platen module connected to the main body module, and hook sections each configured to engage a part of the main body module, and

the thermal head module is connected to the main body module by the clamping mechanisms and the hook sections, after the platen module is connected to the main body module.

4. The thermal printer unit as claimed in claim 1 ,

wherein the thermal head module further includes bearing receivers configured to receive bearings provided one for each end of a shaft of the platen of the platen module, hook sections each configured to engage a part of the main body module, and hook levers respectively disposed between the corresponding bearing receivers and the corresponding hook sections to engage the main body module, and

the thermal head module is connected to the main body module by the hook sections each engaging a part of the main body module, the bearing receivers receiving the bearings and the hook levers engaging the main body, after the platen module is connected to the main body module.

5. The thermal printer unit as claimed in claim 1 ,

wherein the platen module is arranged on an upper side of the main body module, and the thermal head module is arranged on a lateral side of the platen module and the main body module,

the main body module and the thermal head module respectively have hook levers configured to engage bearings provided one for each end of a shaft of the platen of the platen module,

the hook levers of the main body module are configured to approach the corresponding bearings from the thermal head module side to engage therewith, and

the hook levers of the thermal head module are configured to approach the corresponding bearings from the main body module side to engage therewith.

6. The thermal printer unit as claimed in claim 5 , wherein the thermal head module includes biasing force generating mechanisms configured to press the thermal head against the platen while the hook levers of the thermal head module engage the bearings provided one for each end of the shaft of the platen.

7. The thermal printer unit as claimed in claim 6 ,

wherein each one of the biasing force generating mechanisms is configured to rotatably support corresponding one of the hook levers of the thermal head module while allowing a displacement of a rotation center of said one of the hook levers, including a spring member between said one of the hook levers and a back side of the thermal head, and

each one the biasing force generating mechanisms generates a biasing force when the rotation center of said corresponding one of the hook levers is displaced to deform the spring member.

8. The thermal printer unit as claimed in claim 1 ,

wherein the platen module further includes a stationary blade,

the thermal head module further includes a movable blade and a movable blade unit that moves the movable blade, and

the stationary blade and the movable blade unit serve as a cutter for cutting a sheet when the main body module, the platen module and the thermal head module are detachably connected to each other.