Generally, as a printing apparatus that prints barcode and the like onto a recording medium (label paper) using an ink ribbon, there is known a thermal printer such as a label printer or a barcode printer and the like. The thermal printer includes a thermal head arranging multiple heat generating elements in a direction (horizontal scanning direction) perpendicular to a conveyance direction of the label paper.
The thermal head, arranged opposite to a platen roller, conveys the label paper fed from a paper roll along a conveyance path, and sandwiches the label paper and the ink ribbon in between the thermal head and the platen roller, and then pressurizes. Then, the platen roller is driven to rotate by a drive motor to convey label paper, and heat generating elements of the thermal head are contacted with the ink ribbon to thermally transfer the ink from the ink ribbon to the label paper. The conveyance of the ink ribbon is carried out by a ribbon motor, and the ink ribbon moves along the conveyance path while rewinds to a ribbon winding roller (See Japanese Unexamined Patent Application Publication No. Hei 10-157244).
Also, the conventional printing apparatus has a ribbon save function reducing the use amount of the ink ribbon. The ribbon save function operates the following actions: raising the thermal head and stopping the rotation of the ribbon motor for a non-printing area of the printing pattern, and declining the thermal head to print if the paper is conveyed to a printing area. Hereinafter, raising the thermal head is called head up, and declining the thermal head is called head down.
However, the time from a firmware demands the head down to the thermal head is actually fixed onto the paper is determined by a variation of ambient temperature or the mechanism. Therefore, there exists an issue such as the printing is started while the thermal head remains not fixed onto the paper, and the printing is not correctly carried out, and white blank occurs.