Printer capable of detecting status of unutilized ribbon

1. A printer capable of detecting status of unutilized ribbon, the printer comprising:

a ribbon supply end;

a ribbon retrieving end;

a ribbon wherein two ends of the ribbon are installed on the ribbon supply end and the ribbon retrieving end respectively;

a print head for printing dye on the ribbon onto print medium;

a print medium fixture installed on the side of the print head;

a driving module for driving the ribbon supply end and the ribbon retrieving end, and to move the ribbon from the ribbon supply end to the ribbon retrieving end;

a moving shaft for moving from a first position of the ribbon between the print head and the ribbon supply end so as to elongate the ribbon between the print head and the ribbon supply end before the print head transfers the dye on the ribbon onto the print medium and when the print head and the print medium fixture clamp the print medium; and

a control module for controlling the printer according to whether the moving shaft can be moved from the first position to a second position, wherein when the moving shaft reaches the second position, the control module controls the moving shaft to return to the first position and then controls the print head to print dye on the ribbon onto the print medium.

2. The printer of claim 1 wherein the control module controls the print head not to print the dye on the ribbon onto the print medium when the moving shaft cannot move from the first position to the second position.

3. The printer of claim 1 further comprising:

a warning interface coupled to the control module wherein the control module controls the warning interface to display a warning signal when the moving shaft cannot move from the first position to the second position.

4. The printer of claim 3 wherein the warning interface is a warning light.

5. The printer of claim 1 further comprising:

a fixed roller installed between the print head and the moving shaft.

6. The printer of claim 1 wherein the moving shaft is a roller.

7. The printer of claim 1 wherein the print medium fixture is a roller.

8. The printer of claim 1 wherein the printer is a thermal printer.

9. A method of controlling a printer, the method comprising the following steps:

(a) providing a moving shaft and a print medium fixture;

(b) controlling the moving shaft to move from a first position of a ribbon between a print head and a ribbon supply end of the printer so as to elongate the ribbon between the print head and the ribbon supply end of the printer before the print head of the printer prints dye on the ribbon onto the print medium and when the print head and the print medium fixture clamp the print medium; and

(c) controlling the printer according to whether the moving shaft can move from the first position to a second position, wherein when the moving shaft reaches the second position, the moving shaft is controlled to return to the first position and then the print head is controlled to print dye on the ribbon onto the print medium.

10. The method of claim 9 wherein step (c) controls the print head not to print the dye on the ribbon onto the print medium when the moving shaft cannot move from the first position to the second position.

11. The method of claim 9 wherein step (c) comprises controlling the printer to display a warning signal when the moving shaft cannot move from the first position to the second position.