Abstract: An optical disk apparatus for recording and reproducing data corresponding to a track length. The track length is obtained by subtracting a total length of an m (m: natural number) number of sectors from the distance by which a track is moved when a disk is rotated an n (n: natural number) number of times.

Abstract: A copy protecting method for an optical medium includes a writing step of writing watermark data as ECC data in a data storage area of a disk having a certain data stored therein.

Abstract: As pit patterns a pattern A and a pattern B are prepared. The adjacent tracks are made to have different embossed pit patterns.

Abstract: On a recording medium, first information obtained by enciphering data with the first key and second information obtained by enciphering the first key with each of the predetermined second keys are recorded. A deciphering method is characterized by comprising the steps of inputting the first and second information, deciphering the first key using at least one of the second keys, determining by a specific method that the obtained first key is correct, and then deciphering the data using the first key to obtain the data.

Abstract: There is disclosed an apparatus in which a modulation method differs between information of a cryptograph associated information or distinction associated information region, and information of user data regions, and a channel bit length also differs.

Abstract: When an error-correcting code is created for the data stored in a memory and added to the data, even if an error occurs in the data on the memory, the adverse effect of the error will be eliminated. In the present invention, when the data is stored in the memory, an error-correcting code PI is created beforehand using another memory, such as an S-RAM. The error-correcting code PI, together with the data, is written into the memory. After 16 sectors of data and PI have been stored, an error-correcting code PO is created for the data and PI and added to them. When the data is read from the memory, a PI correcting process is carried out each time a PI series is read out. This makes it possible to restore the original data, even if the data is destroyed (or an error occurs) on the memory.

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 along 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 row of the data block which is a set of the data sector is distributed to constitute two blocks. In this case, as a distribution condition, an even-number row block of the even-number sector and the odd-number row block of the even-number sector, the odd-number row block of the even-number sector and an even-number row block of the even-number sector are obtained. Then, the block is aggregated in the transmission order, and an outer parity is scattered to each sector to form an interleaved form.

Abstract: Data on multiple stories or scenes are recorded on a recording medium so as to reduce the physical distance moved by a pickup at playback time and to suppress breaks or disturbances in reproduced video. A multi-scene program having a plurality of optionally selectable branch stories B0, B1, B2, B3, etc., is recorded between a branch point X and a connection point Y. The preceding main story of a video program, made up of video, sound, text and the like, branches off at branch point X to the branch stories, and at connection point Y connects to the succeeding main story in the video program. The recorded state between the branch point X and the connection point Y is such that the branch stories are each divided into multiple cells and the cells of the respective branch stories are recorded time-division multiplexed.

Abstract: A signal recording medium has a plurality of recording layers. Each recording layer has tracks for recording information. The tracks have a wobbling structure in which they are wobbled at different periods for the respective recording layers. Appropriate processing can be performed for a target recording layer by monitoring the wobbling period of the track.

Abstract: An optical disk apparatus for recording data on a track formed on an optical disk and reproducing data recorded on the track includes a rotation means for rotating the optical disk at a predetermined speed, an irradiation means for irradiating the optical disk with a light beam for data recording and data reproduction, a recording means for irradiating the optical disk rotated by the rotation means at the predetermined speed with the light beam provided from the irradiation means to record data from a first point to a second point along the track in units of sectors, a reproduction means for irradiating the optical disk rotated by the rotation means at the predetermined speed with the light beam provided from the irradiation means to reproduce data from the first point to the second point along the track in units of sectors, and a setting means for setting the distance from the first point to the second point along the track to {(track length corresponding to n (n natural number) turns of the disk)&minus

Abstract: A burst error-correcting capability is largely improved. At least the even-number row and at least the odd-number row of the data block which is a set of data sectors are separated. An outer parity is created for each column and an inner parity is created for each row. Then, the outer parity is scattered with respect to each of the sectors of the data block to be interleaved.

Abstract: On a recording medium, first information obtained by enciphering data with the first key and second information obtained by enciphering the first key with each of the predetermined second keys are recorded. A deciphering method is characterized by comprising the steps of inputting the first and second information, deciphering the first key using at least one of the second keys, determining by a specific method that the obtained first key is correct, and then deciphering the data using the first key to obtain the data.

Abstract: In this invention, an information recording/reproducing apparatus has an authentication function and directly transfers information to an MPEG board, sub-picture run-length board, speech coding/decoding board without using a main CPU. Thus, information transfer between the information recording/reproducing apparatus and various processing boards can be performed without using a main controller, the load of the main CPU can be alleviated and the main CPU can perform another process during the information transfer period.

Abstract: Data on multiple stories or scenes are recorded on a recording medium so as to reduce the physical distance moved by a pickup at playback time and to suppress breaks or disturbances in reproduced video. A multi-scene program having a plurality of optionally selectable branch stories B0, B1, B2, B3, etc., is recorded between a branch point X and a connection point Y. The preceding main story of a video program, made up of video, sound, text and the like, branches off at branch point X to the branch stories, and at connection point Y connects to the succeeding main story in the video program. The recorded state between the branch point X and the connection point Y is such that the branch stories are each divided into multiple cells and the cells of the respective branch stories are recorded time-division multiplexed.

Abstract: On a recording medium, first information obtained by enciphering data with the first key and second information obtained by enciphering the first key with each of the predetermined second keys are recorded. A deciphering method is characterized by comprising the steps of inputting the first and second information, deciphering the first key using at least one of the second keys, determining by a specific method that the obtained first key is correct, and then deciphering the data using the first key to obtain the data.

Abstract: Data on multiple stories or scenes are recorded on a recording medium so as to reduce the physical distance moved by a pickup at playback time and to suppress breaks or disturbances in reproduced video. A multi-scene program having a plurality of optionally selectable branch stories B0, B1, B2, B3, etc., is recorded between a branch point X and a connection point Y. The preceding main story of a video program, made up of video, sound, text and the like, branches off at branch point X to the branch stories, and at connection point Y connects to the succeeding main story in the video program. The recorded state between the branch point X and the connection point Y is such that the branch stories are each divided into multiple cells and the cells of the respective branch stories are recorded time-division multiplexed.

Abstract: Data on multiple stories or scenes are recorded on a recording medium so as to reduce the physical distance moved by a pickup at playback time and to suppress breaks or disturbances in reproduced video. A multi-scene program having a plurality of optionally selectable branch stories B0, B1, B2, B3, etc., is recorded between a branch point X and a connection point Y. The preceding main story of a video program, made up of video, sound, text and the like, branches off at branch point X to the branch stories, and at connection point Y connects to the succeeding main story in the video program. The recorded state between the branch point X and the connection point Y is such that the branch stories are each divided into multiple cells and the cells of the respective branch stories are recorded time-division multiplexed.

Abstract: Data on multiple stories or scenes are recorded on a recording medium so as to reduce the physical distance moved by a pickup at playback time and to suppress breaks or disturbances in reproduced video. A multi-scene program having a plurality of optionally selectable branch stories B0, B1, B2, B3, etc., is recorded between a branch point X and a connection point Y. The preceding main story of a video program, made up of video, sound, text and the like, branches off at branch point X to the branch stories, and at connection point Y connects to the succeeding main story in the video program. The recorded state between the branch point X and the connection point Y is such that the branch stories are each divided into multiple cells and the cells of the respective branch stories are recorded time-division multiplexed.

Abstract: There is provided an apparatus for processing data for generating an error correction product code block devised so as to maintain the current level of redundancy after the error correcting ability is modified as a result of advancement of semiconductor and data recording/transmission technologies. Unlike any known technique of configuring a Reed-Solomon error correcting product code block of (M+P0)×(N+PI) bytes for an information data of (M×N) bytes, an error correcting product code block data structure is obtained by configuring a (K×(M+1)×(N+P))-byte Reed-Solomon error correcting product code block for (K×M×N)-byte data, making K variable to consequently make the entire size of the Reed-Solomon error correcting product code block variable. At the same time, the error correcting ability varies in proportion to the value of K without increasing redundancy.