Abstract: In a magnetic recording and/or reproducing apparatus, when the reproduced audio data is processed in the reproduction system and the record system and is re-recorded in every cycle of N times the cycle during which the reproducing magnetic head scans a pair of recording tracks, the recording magnetic head is positioned behind the reproducing magnetic head for 8.5+4N track pitch so that the reproduced audio data can be re-recorded on the original recording track, therefor a write-after-read processing can be realized. In the recording magnetic head positioned behind the reproducing magnetic head for the specific track pitch, the audio data is stored in a memory circuit for time base compression and expansion with a multichannel mode such as to record the reproduced audio data at the same part on the magnetic tape, so that a magnetic recording and/or reproducing apparatus which enables to perform the write-after-read processing can be obtained with simple construction if the number of channel is switched.

Abstract: A disc memory apparatus allows its magnetic head to reach a target track in a short period of time, wherein address data is recorded on each two-track width corresponding to each of the even-numbered and the odd-numbered tracks; either of two kinds of burst signals is recorded on each one-track width corresponding to each of the even-numbered and the odd-numbered tracks; the address of the record track is detected, based on the result of a comparison of two kinds of burst signals and the first address data, or in addition to this, the detected address data is further offset by the second address data; since the lengths of the servo sector areas required to detect the address data are shortened, the address data of the magnetic head are detected to a higher accuracy using a smaller number of reference signals; and the magnetic head can be moved at a fast speed, thus in a short period of time, resulting in a short seek time.

Abstract: A magnetic disc apparatus having at least one magnetic disc having a plurality of track groups thereon at different distances from the center of the disc each of which groups comprises plural data tracks having plural data sectors, each of the track groups having a different number of the data sectors therein in such a manner that the outer track group has more data sectors, a transducer head for reading and writing data signals from and on the data tracks, an actuator for positioning the transducer head over a desired one of the data tracks, a position sensor for sensing the position of the transducer head relative to the magnetic disc, and for generating at least two periodic position signals each of which is out of phase with each other, and a controller for controlling the actuator according to the periodic position signals so that the transducer head is positioned over the desired one of the data tracks.

Abstract: A disc memory apparatus comprises: transducer means for reading and writing information on a disc; at least one disc medium having a plurality of concentric tracks each of which is divided into plural data sectors and plural servo sectors therebetween, the data signal being recorded and read by the transducer means on and from the data sectors, the servo sectors having first address region for odd one of the concentric tracks and second address region for even one of the concentric tracks, wherein first and second address signals are prerecorded in the first and second address regions respectively, the width of the address regions in a radial direction of the disc medium being substantially larger than track pitch of said concentric tracks, the first and second address regions being located at different positions in a direction perpendicular to the radial direction, and the servo sectors further having first and second marker regions the centers of which are corresponding to the centers of the odd and even on

Abstract: A magnetic head is disclosed which is formed by magnetic core halves constituted of an oxide magnetic material and soft magnetic thin films, wherein the boundary surfaces between the thin films and the oxide magnetic material runs substantially parallel to the gap surface in the vicinity of the magnetic gap. The soft magnetic thin films are soft magnetic thin films of the Fe-Ga-Si system consisting essentially of Fe, Ga and Si.