Kunihiko Nakagawa

An Experimental Home-use Digital VCR With Three Dimensional DCT And Superimposed Error Correction Coding

An experimental digital VCR system for home use is described. A high-quality moving picture is obtained by a newly developed bit rate reduction technology, which is based on subband and three-dimensional DCT (discrete cosine transform) coding. A high-density magnetic recording method which adopts a 12-to-15 modulation scheme and superimposed error correction coding enable sufficient recording time with a small cassette. Component video signals with a ration of 4:2:2 were compressed to about the ratio of 1/7, keeping a high quality, using the subband and 3-D-DCT coding method. >

A car-use mini disc (MD) changer

The authors have developed a new mini disc (MD) changer for car-use which fits a 1 DIN size chassis. The paper describes the concept design, vibration proof mechanism, and disc transport mechanism. >

A digital VCR deck mechanism using new precision actuators for high density recording

A VCR deck mechanism using high-performance actuators has been developed for high-density recording. ME (metal-evaporated) tape and laminated Sendust heads are used to raise the linear recording density, a moving-head actuator permits narrow track recording and playback, and thin tape media of 8 mu m thickness are employed. The track density is 4200 TPI when the recording wavelength is 0.53 mu m. The tape transport mechanism has realized a tape tension ratio (capstan/cassette-out) of 4.7. A rotary cylinder containing a moving-head actuator has been developed to accurately trace a 6 mu m track pitch, 78 mm track length with a control band of 300 Hz. A newly developed tape transport adjustment method based on measuring tape buckling deformation damage has been proposed which ensures the stability of 8 mu m-tape running for the deck. >

On the development of mini disc players

A very thin portable MD (mini disc) and a four-disc MD auto changer for cars have been developed. The development of a very small optical pickup and small mechanisms in particular, together with the small MD discs, has helped to dramatically reduce the size of portable MDs and the construct a four-disc MD auto changer system of only 1 DIN size. In the auto changer, by developing a new memory control, four discs can be played continuously. It has been confirmed that vibration characteristics of the MD changer are no longer a practical problem. >