Takaaki Maegawa

Optimum magnetic-head shape design for high-density recording

The optimum magnetic head shape suitable for high-density recording is determined by observing the head-to-tape contact for various head shapes and tapes by using transparent heads and an optical interference fringe method. The experiment proved that the use of heads with smaller r/R values and smaller head area at the trailing edge is highly effective for achieving contact and longer head life, where R is a radius of the head along its longitudinal direction and r is the radius along its transverse direction. >

An analysis of tape-to-head spacing by three-dimensional computer simulation

Experimental and theoretical studies of tape-to-head spacing loss in magnetic recording are reported. A computer simulation on a 3D model representing tape-to-head spacing clarified the relationship between tape surface roughness, tape-to-head spacing loss, and the output voltage level. The results showed that the spacing theoretically derived from the model can be separated into the corresponding spacing-loss and modulation noise near the carrier frequency by separating the spacing into AC and DC components. It is also found that the spacing produced in VHS-VCR is about 500 AA. It was also shown that an increase of 50 AA in spacing would produce a decrease of 1 dB in output level at a recording wavelength of 0.5 micron. >