Magnetic properties of obliquely evaporated Co-Cr films prepared at low substrate temperature were investigated. It was found that, even at room temperature, Co-Cr films having a coercivity more than 1000 Oe and an anisotropy field more than 6000 Oe could be obtained. Auger electron spectroscopy and X-ray photoelectron analysis revealed that a large amount of oxigen was incorporated in the films and the oxigen preferentially combined with Cr. These results suggest that the compositional segregation consist of nonmagnetic Cr oxide region and ferromagnetic Co-enriched region occurs in the films. The high coercivity and anisotropy field of the films were considered to originate from the compositional segregation in addition to physical separation by the self-shadowing effect.

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Obliquely deposited Co/CoO magnetic thin film is known as ME tape. Corrosion resistance is one of the most important problem for metal magnetic tape. ME tape with DLC film was investigated to improve archivability in the real field. Archivability in acceralated test is slightly different from that of in the real field. We analized corrosion of ME tape without DLC film in the real field, and found the mechanism of corrosion process. Corrosion resistance of ME tape with DLC film in the field test found fine compared with ME tape without DEC film.

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The magnetic characteristics and the corrosion resistance of Fe-Al-Ta-C thin film of 1.3T of Bs is studied. The corrosion resistance depends on the [Ta]/[C] ratio. A [Ta]/[C] ratio between 0.52 and 0.68 with 9.8at% added Al produces the highest corrosion resistance in 0.5N NaClaq. The passive film is found on the surface of this magnetic film. As shown by the crystal structure analysis using the X-ray diffraction pattern and the electron microscope, the grain size of TaC is fine. A SiO_2 layer is used as a underlayer to produce this magnetic thin film on the Mn-Zn ferrite substrate to cotrol the orientation of Fe.

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It is important for the new multi-media system to achieve the digital VTR, and to carry out this, it is necessary to develop the high performance magnetic heads. We tried to make the metal-in-gap heads with high saturation flux density magnetic film which is formed parallel to the head gap and found that it had both the high productivity and the good magnetic recording characteristics. Strong points of this head are firstly its structure which is suitable for the narrow track pitch recording and reproducing, and secondary its excellent recording ability to the highly coercive ME tape, and thirdly its high reproducing sensitivity achieved by the good selection of the glass material which is optimized by using the three dimensional simulation program of the head efficiency.

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A digital interface for consumer digital VCR is developed. Video and Audio data is transmitted on IEEE 1394 High speed serial bus using isochronous transmission. The compressed video and audio signal in DVCR format is packetized by 480 bytes and transmitted with a header. A link layer LSI for IEEE 1394 link layer process and DVCR signal packetization is developed for this interface. A small 4-pin connector and thin and flexible cable are also developed.

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For news gathering, camcorders and video editing equipment using analog 1/2-inch tapes are mainly utilized. However, more compact, cost-efficient, digital news systems with easy-to-edit features and high picture quality are now in demand. To meet this demand, we developed a professional-use VCR format, "DVCPRO", and VCRs conformed to the format. The DVCPRO format, using 1/4-inch metal particle tape., can records 123 minutes high quality digital video compressed 5 : 1 and 2 channels of high quality audio. The DVCPRO VCRs feature newly developed technologies for a variety of functions and high reliability as professional-use system.

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