Information storage disc and information recording and reproducing apparatus

An information recording and reproducing apparatus for writing and reading data to and from an information storage disc having tracks divided into a plurality of sectors, each of said sectors being divided into a servo data area for storing servo data and a data storage area for storing written data, said data storage area having an ID storage area previously formed therein in the radial direction of the disc, said ID storage area storing sector numbers and track numbers, said sector numbers designating said sectors, said track numbers designating said tracks, said ID storage area having said sector numbers and said track numbers recorded therein previously and magnetically, said information recording and reproducing apparatus comprising:

• a write head for writing information to said tracks;
• a read head for reading information from said tracks, said read head being separated from said write head by a predetermined distance in the direction of said tracks;
• a rotating arm rotated on a suitable axis;
• an arm driving circuit for driving said rotating arm;
• and
• data detecting means for detecting data using a read signal read by said read head;
• wherein said write head and said read head are attached to said rotating arm so as to be positioned in a substantially aligned manner on the innermost track and on the outermost track of said information storage disc;
• wherein said write head and said read head are mounted so as to be aligned along a head alignment center line which passes through the gap center of said write head and the gap center of said read head and wherein the head alignment center line intersects the center line of said rotating arm at a point distal from both said write head and said read head and intersects the center line of said rotating arm at an angle .theta.;
• wherein, when a tangent to the track substantially in the middle between the innermost and the outermost tracks coincides with the center line connecting the head gaps, said angle .theta. equals the angle formed between said tangent and the center line of said rotating arm;
• and
• wherein said sector numbers are recorded not only along said tracks but also in the radial direction continuously between adjacent tracks on said information storage disc.