Abstract: In a printer of the kind which uses a continuous form print sheet having a plural pages each defined by perforated score lines formed in the widthwise direction of the sheet, a sheet feed control device is provided for controlling a sheet feed means for feeding the sheet. The control device includes a central processing unit which upon measuring a first line distance on the sheet, controls a sheet feeding means so that the perforated score line in the bottom of a printed page is brought in coincidence with a sheet cutting position. The print sheet can thus be separated at the line of perforations even if the first line distance is differently than that of the previous sheet.

Abstract: A guide shaft guides a print head, which moves along a print line of a platen to perform a printing operation. A rotating member and an eccentric cam member, having a toothed sector portion on its periphery, are mounted on the guide shaft. The guide shaft is guided on a frame by a bearing slot, so as to be movable toward and away from the platen. The eccentric cam member rotates as it is always spring-urged to engage a fixed engaging pin. As a result, the guide shaft moves in a direction transverse to its axis, thus changing a gap between the print head and the platen. As the eccentric cam member rotates in one direction, the print head moves away from the platen, in a retreat stroke. In a rear half of the retreat stroke, the toothed sector portion of the rotating member engages a toothed arm, which is connected to a paper bail member for holding a printing medium down on the platen.

Abstract: A printing device wherein a cut-form printing sheet and a serial-form printing sheet is selectively in use is disclosed.

Abstract: A pair of pulleys are rotatably provided between a pair of long frames in the neighborhood of both ends thereof. An endless belt is put over the pulleys, wherein the teeth which mesh with the pulleys are provided on the inner surface of the endless belt. A row of pins which fit into the perforations in a document is provided in the outer feeding surface of the endless belt. A groove extending in the longitudinal direction of the belt is formed in the central portion of the teeth trains of the belt. A rib projecting from the upper surface on which the belt slides and extending in the feeding direction of the document is formed in one of the frames. Since the belt moves in a state in which the rib is fitted into the groove of the belt, the belt runs without deviating from the line which connects between the pulleys.