Abstract: A method for changing the direction of a cutting edge of a cutting plotter in order to align the cutting edge in the direction in which the initial portion of the desired cut will be made, prior to beginning a cut in the effective plotting area of a sheet mounted on a recording surface. By preliminarily aligning the cutting edge along the cutting direction, the cut can be made accurately along, for example, a straight line from the starting point of the cut. The method is performed with a cutting blade with a main edge directed diagonally upwardly from a cutting point, the cutting blade being rotatably supported in a holder for rotation around its axial center. The edge of the cutter can be aligned in a certain direction by first pressing the blade against a non-used portion of the sheet and moving the cutter therealong in a predetermined direction to cause rotation of the main edge of the cutter in the holder to align it in a first predetermined direction.

Abstract: A sheet feed mechanism for a plotter comprises a main drive roller, and a plurality of sub drive rollers which are serially arranged at predetermined spacings from the main drive roller. A main pinch roller is arranged in opposition to the main drive roller so as to be rotatable and movable over and axially of the main drive roller, and a sub pinch roller is arranged in opposition to the sub drive rollers so as to be rotatable and movable over and axially of the sub drive rollers. The axial length of the main drive roller is made greater than that of the main pinch roller. The side edges of a sheet are respectively held between the main drive roller and the main pinch roller and between one of the sub drive rollers and the sub pinch roller, and the main and drive rollers are synchronously rotated, thereby to feed the sheet in the lengthwise direction thereof.

Abstract: A plotter wherein, while a sheet is being moved on a recording surface, figures, characters etc. are automatically depicted on the surface of the sheet, or the contours of figures, characters etc. are automatically cut in the surface of the sheet. In the plotter, both the side edges of the sheet are respectively held between drive rollers and corresponding pinch rollers mounted at both the sideward parts of the recording surface in opposition to each other, and the drive rollers at both the sideward parts of the recording surface are rotated synchronously to each other, whereby the sheet is moved in the rotating direction of the drive rollers on the recording surface. Each of the drive rollers is formed at its peripheral surface with milling or ruggedness for preventing the sheet from slipping.