Method and apparatus for helical scan type magnetic recording and reproducing with a rotary magnetic head

摘要

A VTR of helical scan type includes a rotary magnetic head fixed on an electro-mechanical converter made of a piezoelectric element and adapted to be displaced along the width of a recording track. In this type of VTR, the rotary head can follow the curving of the recording track, and therefore a superior reproduction output is always produced. Also, a noiseless reproduction image is provided at the time of special reproduction with a tape feed rate different from the recording speed. When the electro-mechanical converter is driven, the average DC component of the drive voltage is desirably reduced to zero to secure a dynamic range effectively. Especially this consideration is necessary to maintain the service life of the piezoelectric element which may make up the electro-mechanical converter. The average DC component of the drive voltage of the electro-mechanical converter is reduced to zero, or specifically, a weighted average of the drive voltage for head scanning is produced, and the drive voltage is appropriately processed during the period when the head is not in contact with the tape.