High Quality Content by WIKIPEDIA articles! Helical scan is a method of recording high bandwidth signals onto magnetic tape. It is used in video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives. In a fixed head system, tape is drawn past the head at a constant speed. The head creates a fluctuating magnetic field in response to the signal to be recorded, and the magnetic particles on the tape are forced to line up with the field at the head. As the tape moves away, the magnetic particles carry an imprint of the signal in their magnetic orientation. If the tape moves too slowly, a high frequency signal will not be imprinted — the particles' polarity will simply oscillate in the vicinity of the head, to be left in a random position. Thus the bandwidth capacity of the recorded signal can be seen to be related to tape speed — the faster the speed, the higher the frequency that can be recorded.

Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.