Drive system for a thermal label printer

摘要

A label printing apparatus receives a cassette holding printing tape on which an image is to be printed. The apparatus also has a printing mechanism which includes a thermal printhead having a group of printing elements to which pixel data defining the image to be printed is passed sequentially on a group-by-group basis. The groups are printed adjacent one another in the direction of movement of the printing tape. A drive system is provided for driving the printing tape through the printing mechanism end includes a dc motor which is provided with a shaft encoder for monitoring the speed of rotation of the motor. Sequential printing of the groups of pixel data is controlled in dependence on the monitors speed of rotation of the motor. There is also described a label printing apparatus which uses monitoring of the speed of rotation of the motor to detect an end of tape condition.