Printer

1. A printer which prints on a roll paper transported toward a discharge port and cuts the roll paper, the discharge port provided at a side surface of the printer so that a vertical direction thereof corresponds to a thickness direction of the roll paper, the printer comprising:

a brush provided on a periphery of an upper edge of the discharge port and projecting into the discharge port;

a first lower cover and a second lower cover; and

the first lower cover and second lower cover selectively and exchangeably attached to the printer to define a lower edge of the discharge port,

wherein the first lower cover is in contact with the brush when the first lower cover is selectively attached to the printer, and

the second lower cover is away from the brush when the second lower cover is selectively attached to the printer, and

wherein a change of length in the vertical direction of the discharge port is allowed by selectively exchanging the the first lower cover and the second lower cover.

2. A printer as claimed in claim 1 ,

wherein the first lower cover has a surface which faces the brush to be at a first angle with the brush when the first lower cover is attached to the printer,

and wherein the second lower cover has a surface which faces the brush to be at a second angle with the brush when the first lower cover is attached to the printer, the second angle being smaller than the first angle.

3. A printer as claimed in claim 2 ,

wherein the first lower cover is configured to hold a cut roll paper while the second lower cover is configured to allow the cut roll paper to fall freely.

4. A printer as claimed in claim 1 ,

wherein the first lower cover is configured to hold a cut roll paper while the second lower cover is configured to allow the cut roll paper to fall freely.

5. A printer as claimed in claim 1 ,

wherein the exchangeable lower cover is provided with a first hook or a first receiving portion while a frame to which the exchangeable lower cover is attached is provided with a second receiving portion or a second hook which are corresponding to the first hook and the first receiving portion, respectively, and

wherein the exchangeable lower cover is attachable to and detachable from the frame by elastic deformation of at least one of the exchangeable lower cover and the frame.

6. A specification changing method of a printer which prints on a roll paper transported toward a discharge port and which cuts the roll paper, comprising the step of:

previously providing the discharge port at a side surface of the printer so that a vertical direction thereof corresponds to a thickness direction of the roll paper;

previously providing a brush on a periphery of an upper edge of the discharge port to project into the discharge port;

providing a first lower cover and a second lower cover;

attaching an exchangeable lower cover to the printer to define a lower edge of the discharge port, the exchangeable lower cover selected from the first lower cover and the second lower cover, the first lower cover being in contact with the brush when the first lower cover is selectively attached to the printer, the second lower cover being away from the brush when the first lower cover is selectively attached to the printer, and

exchanging the exchangeable lower cover between the first lower cover and the second lower cover allowing a change of length in the vertical direction of the discharge port, and thereby changing specifications of the printer between one for holding a cut roll paper with the first lower cover and the brush and the other for allowing the cut roll paper to fall freely through a space between the second lower cover and the brush.