Printer

1. A printer, comprising:

a recording head;

a platen roller;

a first case to which the recording head is attached, the first case including a paper-feed port for feeding recording paper;

a second case to which the platen roller is attached, the second case including a paper-ejection port for ejecting the recording paper; and

an operable lock lever that is disposed in the first case and includes a support configured to rotatably support a shaft of the platen roller,

wherein the printer is configured such that

the shaft of the platen roller is placed in the support when the first case and the second case are joined together, and

the shaft of the platen roller is disengaged from the support when the lock lever is operated.

2. The printer as claimed in claim 1 , wherein

the second case includes a sliding part;

the first case includes a groove in which the sliding part is placed; and

the printer is configured such that when the lock lever is operated, the sliding part slides in the groove and the second case moves relative to the first case.

3. The printer as claimed in claim 1 , further comprising:

a spring configured to bias the recording head toward the platen roller, wherein

the printer is configured such that when the lock lever is operated to disengage the shaft of the platen roller from the support, the recording head is caused to press the platen roller by a biasing force of the spring and thereby causes the first case and the second case to be separated from each other; and

a direction in which the spring biases the recording head is different from a direction in which the first case and the second case are separated from each other.

4. The printer as claimed in claim 1 , further comprising:

a bezel that is connected to the second case at a position corresponding to the paper-ejection port.

5. The printer as claimed in claim 1 , further comprising:

an operations panel and an interface port disposed on one of the first case and the second case.

6. A printing device, comprising:

the printer of claim 1 ; and

a housing including a printer holder that houses the printer, a recording paper holder configured to house recording paper, and a paper-ejection port for ejecting the recording paper.

7. A printer, comprising:

a first case including a recording head;

a second case including a platen roller; and

a lock disposed in the first case and configured to support a shaft of the platen roller; and

an operable lock lever connected to the lock,

wherein the printer is configured such that

the first case and the second case are joined together in a state where the shaft is supported by the lock, and

the first case is separable from the second case by disengaging the shaft from the lock by operating the lock lever.

8. The printer as claimed in claim 1 , further comprising:

an opening knob protruding from the first case and connected to the lock lever,

wherein the printer is configured such that the shaft of the platen roller is disengaged from the support when the lock lever is moved by operating the opening knob.

9. The printer as claimed in claim 7 , further comprising:

an opening knob protruding from the first case and connected to the lock lever,

wherein the printer is configured such that the shaft of the platen roller is disengaged from the lock when the lock lever is moved by operating the opening knob.