Abstract: In an optical disk, data are recorded by using a hierarchical file structure in which a frame is composed of digitized data, a packet is composed of at least one frame, and a pack is composed of at least one packet. In this structure, the pack is composed of an integral number of packets, each packet being completed, and each of the packets is composed of an integral number of frames, each frame being completed. Therefore, there is no possibility that one frame is assigned over two or more different packets and one packet is assigned over two or more different packs. Since an integral number of frames are assigned in each packet, when a packet header is detected, reproduction of data can be carried out from the beginning of each packet.

Abstract: An information storing disk including at least one system stream stored thereon. The at least one system stream includes a silent cell for defining a silent period and an audio cell for defining audio data to be reproduced after the silent period. The silent period is a period to be silent, which is from when one system stream to be reproduced among at least one system stream is determined until reproduction of an audio cell included in the one system stream is started.

Abstract: A data scrambling method, defined by data polynomial,D(X)=d.sub.n X.sup.n +d.sub.n-1 X.sup.n-1 +d.sub.n-2 X.sup.n-2 + . . . +d.sub.2 X.sup.2 +d.sub.1 X.sup.1 +d.sub.0 X.sup.0generating polynomial,G(X)=1+g.sub.-1 X.sup.-1 +g.sub.-2 X.sup.-2 + . . . +g.sub.-m+2 X.sup.-m+2 +g.sub.-m+1 X.sup.-m+1 +g.sub.-m X.sup.-mresidual polynomial,R(X)=R.sub.-1 X.sup.-1 +R.sub.-2 X.sup.-2 +R.sub.-3 X.sup.-3 + . . . +R.sub.-m+2 X.sup.-m+2 +R.sub.-m+1 X.sup.-m+1 +R.sub.-m X.sup.-mis characterized by:setting initial values R.sub.-m+k (0)=N.sub.-m+k of the respective coefficients R.sub.-m+k (k=0, 1, . . . , m-1) in the residual polynomial (here, R.sub.-m+k(i) is a value obtained, when the coefficient R.sub.-m+k in the residual polynomial is a value of a latch, by shifting the latch by i times) to 0 or 1, using an initial value setting means;outputting ds(1).about.ds(8), in a lump, as ds7.about.ds0, said ds(1).about.

Abstract: A data transmission system for transmitting information data with a parity of an error correcting code for correcting an error in the information data. A read-out controller controls a transmitter to transmit information data and a parity so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are transmitted at intervals of each sector having a sector address. The sector is defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.

Abstract: A method and apparatus for descrambling data that is characterized by shift registers that realize an operation of generating polynomial and that have a ring-shaped structure that realizes plural and continuous operation. The method and apparatus further includes an initial value setting means for setting initial values in m shift registers; after setting the initial values, shifting the initial values while synchronizing the initial values with input clocks, and outputting the exclusive OR of data which is input while being synchronized with clocks and the lowermost latch outputs. Scrambled data with a byte is treated as a unit by using an exclusive OR circuit block.

Abstract: A method and apparatus for descrambling data that is characterized by shift registers that realize an operation of generating polynomial and that have a ring-shaped structure that realizes plural and continuous operation. The method and apparatus further includes an initial value setting means for setting initial values in m shift registers; after setting the initial values, shifting the initial values while synchronizing the initial values with input clocks, and outputting the exclusive OR of data which is input while being synchronized with clocks and the lowermost latch outputs. Scrambled data with a byte is treated as a unit by using an exclusive OR circuit block.

Abstract: The code error detecting method uses the code error detecting apparatus which comprises a sector buffer memory for storing various kinds of data, an adder circuit for performing exclusive OR addition of data, a CRC generator/checker for producing error check parities by dividing a result of addition performed in the adder circuit by a predetermined generator polynomial, a temporary memory for storing the error check parities, and an error correction circuit for calculating error correction parities which are used to correct an error of the data. At the time of recording, the data incorporating various parities produced in the code error detecting apparatus is recorded on an optical disk, and, at the time of reproducing, the data reproduced and stored in the sector buffer memory is corrected by using the reproduced error correction parities, and the error check parities are obtained by using the CRC generator/checker.

Abstract: A sound reproducing system for reproducing sounds from two loudspeakers located in front of a listener comprises a difference creating network for causing a ratio of sound pressures applied to left and right ears of the listener and causing a time difference between sound waves thereat by a sound radiated from a sound source located at any point around the listener, and a front and back recognizing network provided in common with both ears for cancelling information which causes the listener to feel that said loudspeakers are located in front of the listener and enabling the listener to localize a sound image at any point, whereby the listener can localize the sound image at any point around the listener while he is listening the sounds radiated from the two loudspeakers located in front of him.