Laminated FeTaN heads for Hi-Vision digital VTRS have been developed. The FeTaN film is suited to a head core material for high coercivity media. because of its high saturation flux density, soft magnetic properties, high Vickers hardness and corrosion resistance. The head showed smaller pulse width, higher reproduced output and C/N, superior recording/reproducing characteristics in the high frequency range over 20MHz, compared with Sendust head in the same design. The laminated FeTaN heads are expected to be suitable heads for high data transfer rate digital recording, such as Hi-Vision digital VTRs.

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This paper describes the new deck mechanism for high density recording and playback home-use digital VCRs. To obtain high recording density, narrowing track, shortening wave length and thinning tape are needed. And we have developed the tape transport mechanism having low friction, the rotary cylinder mechanism containing moving head actuator and tape tension control mechanism Which realizes low tension and Wide controlled band. Experiments performed by using these mechanisms and thin tape (8/10μm thickness) in an experimental digital VCR deck yielded the following conclusions. 1) The track Width is 6μm, the areal recording density is 2μm^2/bit. 2) The tape transport mechanism realizes low friction and the tape tension ratio (capstan/cassette-out) of 4.7. 3) The rotary cylinder containing a 4) The tape tension moving head actuator is developed and the controlled band is 300Hz. control mechanism With a moving guide is developed and the controlled band is over 15Hz.

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In addition to the picture quality, the important capability as an editing VTR is the access capability. For the improvement of the access capability, the tape running at high speed access is required. In order to realize the high speed access without damaging the tape, the tape transport system, in which the frictional resistance is low, is required. Our new unique tape guide is developed to lower tape running resistance by adding ultrasonic vibration of piezoelectric actuator to the stationary guide pipe. This guide has both advantages of lower running resistance like that of rotating type guide and high stability of tape running like that of fixed type tape guide.

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An architecture of the high speed Reed-Solomon decoder developed for the digital VCR is described. The maximum data-rate of 16Mbyte/sec and the error correction capability of 4-error- or 8-erasure-correction are realized with 4-stage pipelines, such as the syndrome generator, the polynomial coefficient generator, the polynomial evaluator and error corrector. The polynomial coefficients are generated by the superscalar processor on Galois field, which is controlled by the instructions stored in the ROM.

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Feasibility of 1.2Gb/s digital cassette recorder for HDTV using an 8-12 conversion channel code is examined. The density ratio of the channel code is 1.33. A time compression technique is applied in the channel coded signals and then, the number of recording heads can be same as the current available HDTV digital recorder with 1-inch open reel. An experiment using a D2 drum rotated at 150rps shows an error rate of 7×10^<-5> at a recording rate of 297Mb/s, which is essential for the new recorder.

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A digital VCR for consumer use has been experimentally developed with a high efficiency picture coding method. We maintain a constant data volume per frame or field. This method is by the rate-adaptive DCT coding, using a coding bits allocation according to the image activity. And a modulator block with a new block-coding technique and error correction block have realized high density recording. This paper explains the system construction for the experimental equipment and features of individual blocks composing the system. Besides, we describe the method of preventing picture quality deterioration caused by duplication, and the study of the function of DVCR through simulation.

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