Recording Characteristics of Main Pole Drive Head at Short Wavelength

An MPD head for video signal recording was constructed, and the recording/ reproduction characteristics of the secondary peaks were compared with the performance of APD (auxiliary pole driven) heads. While the recording sensitivity of the MPD head was superior to that of the APD head, the reproduced output of secondary peaks was weaker. Further experiments indicated that the difference originated in the magnetic properties of the main pole films. By improvinig the main pole film, it should be possible to realize MPD heads with improved secondary peak ratios.