Recording and reproducing apparatus with magnetic head protruded onto sheet of magnetic recording medium

Claim 1

A magnetic recording or reproducing apparatus for recording signals on or reproducing signals from a rotating sheet of magnetic recording medium, comprising: driving means for driving the sheet of magnetic recording medium in stable rotation; speed sensing means for sensing a rotational speed of the sheet of magnetic recording medium; regulator means disposed on a surface of the sheet of magnetic recording medium, which surface is opposite to a recording surface of the magnetic recording medium, for holding the sheet of magnetic recording medium generally at a predetermined level; a magnetic head disposed on the recording surface of the magnetic recording medium and opposing said regulator means for recording signals on or sensing signals from the magnetic recording medium, said magnetic head being protruded in such a fashion that a tip of said magnetic head and a portion of the sheet of magnetic recording medium is beyond the predetermined level toward said regulator means both before and after start up of recording or sensing by said magnetic head; head transporting means for transporting said magnetic head radially across the recording surface of the sheet of magnetic recording medium; and control means operative in response to said speed sensing means for controlling said driving means and said head transporting means for causing said magnetic head to be transported onto desired ones of tracks of the sheet of magnetic recording medium; said control means, when powered on, causing said driving means to rotate the sheet of magnetic recording medium, and inhibiting said head transporting means from transporting said magnetic head until the rotational speed of the sheet of magnetic recording medium sensed by said speed sensing means reaches a predetermined value.