Patent ID: 7431414

Claim:
A printer-control apparatus comprising: a memory for sequentially recording at least either a relative position of a printing medium specified from an accumulated carried amount of the printing medium or a driving speed of a paper-feed motor for driving a printing medium carrying mechanism for carrying the printing medium; a mechanical paper detection sensor which detects at least either a front edge or a rear edge of the printing medium by swinging operation of a swing pin; and a processing unit, when the edge of the printing medium is detected by the mechanical paper detection sensor, for specifying an absolute position of the printing medium by calculating the carried distance of the printing medium since the edge of the printing medium to be detected by the mechanical paper detection sensor actually reached an initial position of the swing pin until the edge of the printing medium was detected by the mechanical paper detection sensor on the basis of the records of the relative position of the printing medium or the driving speed of the paper-feed motor at each one of a plurality of recording timings in a period going back from the detection time point by a time corresponding to a reaction delay time, which is a time difference between a time when the edge of the printing medium, that is to be detected by the mechanical paper detection sensor, reaches the initial position of the swing pin, and a time when the edge of the printing medium is detected by the mechanical paper detection sensor; wherein the recordings in the memory are performed for a period longer than the reaction delay time, each of the recording of the relative position of the printing medium or the driving speed of the paper-feed motor being performed at time intervals shorter than the reaction delay time.