Hiroo Okamoto

Digital Signal Processing Technology For R-DAT

As one of consumer audio equipment, the CD (Compact Disc) player has come into wide use since its commercialization of 1982 for its high quality sound, easy operation and low price. The Direct Broadcasting Satellite (DBS) service has started in Japan in 1984. On the other hand, the Digital Audio Tape recorder (DAT) which has both recording and reproducing function and easy recording from these digitalized audio sources, is expected to be a next-generation audio product.

A consumer digital VCR for advanced television

A prototype of a digital VCR for ATV (advanced television) has been developed. This VCR records the compressed digital HDTV (high-definition television) signal of the ATV system. The total recording bit rate is 36.8 Mb/s (18.4 Mb/s per channel), and the maximum recording time is 4 h with oxide tape. Thus, it is confirmed that it is possible to produce a low-cost consumer digital VCR for ATV with current VCR technology. >

16-BIT A/D Converter and D/A Converter for Digital Audio

The Compact Disc Player has made a rapid popularization of so called digital audio using a PCM technique. And this fall, Digital Audio Tape-recorder (DAT) is expected to be commercialized. The A/D and D/A converters are two of key devices for DAT, so it is required to realize high performance, low cost and low power consumption.

A Study On The Method on Double The Data Rate For Recording/reproducing And Search Speed For DAT

A method to double the search speed and the data transmission rate for recording/reproducing has been studied for a DAT (digital audio tape recorder). A high speed search up to 400 times the normal playback speed was realized. Using this DAT, the search time for programs from the beginning to the end of a 2-hour long tape was reduced to 26 sec from 44 sec, the latter value being that for a conventional DAT. With this technology, a high-speed search system has been developed for a DAT using magnetic tape as the recording medium. >