| 摘要 |
First and second rotatable edge guide rollers are provided having precision roller positioning means for preventing skewing of sheets of predetermined widths, such rollers being laterally shifted in position to accommodate various widths by means of a roller actuation device which controls a counter which counts the extent of travel of a recording head between a reference position and a position indicative of the guide roller position. The count within the counter is examined by logic circuitry which determines whether the rollers are properly positioned across the width of sheets. The sheet reference platen has a plurality of apertures which receive a fiducial referencing projection mounted upon the roller actuation device and when the actuation device and hence the roller is in one of the predetermined positions the projection device will pass through a particular aperture to permit the sheet referencing platen to be lowered into position. Such projection also produces a visual indication to the operator that the roller is properly positioned with respect to the sheet.
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