Keigo Majima

Investigation of particulate media with an ultra-thin magnetic layer suitable for MR heads on a rotating drum

To improve recording density and data transfer rate, we investigated the electromagnetic characteristics of the combination of the MP with an ultra-thin magnetic layer (U-MP) and MR head on a rotating drum. The magnetic layer thickness was reduced to 40-90 nm, and the magnetic particles volume was one-third of conventional ones. Reproduced output of the U-MP/MR combination was at least ten times higher than that of the combination of a conventional MP and MIG head. The areal recording density was estimated to be 6 times as large as that of the conventional MP/MIG combination.

A Study on Bit Rate Reduction for a Broadcast-use HDTV-VTR

Abstract In order to lower costs and to improve the mobility of HDTV program production, a small format digital VTR using a compact cassette is needed. We have been studying bit rate reduction (BRR) techniques with the objective of recording high quality HDTV images over a long recording time. In this paper, we present a concept for broadcast-use cassette HDTV-VTR, show the characteristics of multiple copies, and propose new architectures of compression, rate control and code arrangement.

High-density reproduction characteristics with MR head for rotary drum in helical-scan tape system

A magneto-resistive (MR) head for a rotary drum in a helical-scan tape system has been developed to realize a high-capacity tape storage system with a high data transfer rate that uses a small cassette. Also, various experimental ME (Metal Evaporated) tapes whose magnetic layer thickness is 0.1 /spl mu/m or less (thin-magnetic-layer ME tapes) for the MR head has been fabricated. Reproduction characteristics of the MR head with the ME tapes was evaluated. The output voltage of the MR head was 20 times that of a conventional inductive head. An areal recording density of 1.2 Gbit/inch/sup 2/ was found to be possible combining the MR head with the thin-magnetic-layer ME tapes whose magnetic layer thickness was 0.09 /spl mu/m.

High-Density Reproduction Characteristics of an MR Head for a Rotary Drum in a Helical-Scan Tape System.

We have evaluated the reproduction characteristics of a magnetoresistive (MR) head for a rotary drum in a helical-scan tape system. This MR head was developed for use in a high-capacity tape storage system that has a high data transfer rate and uses a small cassette. Various experimental thin-magnetic-layer metal evaporated (ME) tapes suitable for the MR head, whose magnetic layer thickness is 0.1 μm or less, have been made, and our evaluation was done using such tapes. We found the output voltage of the MR head was 20 times that of an inductive head, and an areal recording density of 1.2 Gbit/ inch2 was feasible with the combination of the MR head and the thin-magnetic-layer ME tapes. Moreover, the pulse width and CN ratio showed that the optimum value of Brδ, the product of remanent flux density and magnetic layer thickness of the tape, for the trial MR head was from 140 to 220 G·μm.