http://printwiki.org/Helical_ScanRecent Changes of the page "Helical Scan" on PrintWiki.en-us http://printwiki.org/Helical_Scan2007-09-06 12:00:00Encyclopedia of Graphic Communications Import <div id="content" class="wikipage content"> Differences for Helical Scan<p><strong></strong></p><table> <tr> <td> <span> Deletions are marked with - . </span> </td> <td> <span> Additions are marked with +. </span> </td> </tr> <tr> <td> Line 1: </td> <td> Line 1: </td> </tr> <tr> <td> </td> <td> <span>+ The means by which a ["head"] on a videocassette recorder scans the magnetic tape. The playback head on a VCR is not aligned perfectly with the tape transport mechanism, but is rather skewed at a 30º angle. It thus is able to contact and process more of the tape surface. The video head also rotates as the tape moves past it, making one rotation per ["frame"]. The addition of a second play head allows each ["field"] to be read separately.</span> </td> </tr> </table> </div>