Abstract: An optical rotating recording medium in which a 17-bit codeword is recorded converted from a 16 bit data, wherein (i) a 16-bit data word is coded to a 17-bit codeword set with restrictive conditions on a minimum number (d) of consecutive zeros, a maximum number (k) of consecutive zeros, and a maximum number (r) of consecutive “1”s in the codeword; (ii) a “1” in a codeword is converted to an inversion of “1” and “0” in recording data and a “0” in a codeword to non-inversion by non-return to zero inverse (NRZI), and (iii) a “1” and “0” in the recording data are stored linked with one of the existence of a bit on the optical rotating recording medium and two polarities of magnetization and a data recording method, a recording apparatus, and a reproducing apparatus relating to the same.

Abstract: In a data decoding apparatus of this invention, level of a reproduction RF signal 7a at the time of the binary level judgment of channel bit is temporarily stored into a RF signal level memory section 20. The portions which do not satisfy the conditions of the minimum run length and the maximum run length of the same symbols within the channel bit data train are respectively detected by a (d'-1) detecting section 16 and a (k'+1) detecting section 17. This data decoding apparatus comprises correction bit position detecting sections 18, 19 for outputting correction bit position designation signals on the basis of level of the RF signal at the time of the binary level judgment stored in the RF signal level memory section 20, and a bit data inversion correcting section 15 for inverting logic level of data at bit position designated on the basis of the correction bit position designation signals 18a, 18b, 19a, 19b.

Abstract: A digital signal reproducing circuit which enables precise measurement of a phase difference and jitter components of reproduction signals while realizing miniaturization of the circuit is disclosed. The digital signal reproducing circuit has a phase comparator for detecting a phase difference by using sampled values before and after an edge portion of a reproduction signal from an optical disc outputted from an A/D converter, and a jitter measuring section for detecting a jitter detection signal on the basis of unevenness of the phase difference obtained by the phase comparator.

Abstract: If there is any portion in channel bit data obtained on converting a signal read out from a recording medium into a bi-level signal which fails to satisfy a condition concerning a minimum run length or a maximum run length of the same symbol, the channel bit data is corrected to improve the bit error rate to secure a skew margin. To this end, channel bit data not satisfying a minimum run length d' of the same symbol is detected by a (d'-1) detector 4 using n-tupled clocks obtained on n-tupling channel clocks of playback data by a bit clock generator 2, where n is an integer not less than 2. A correction position of the channel bit data having the run length of the same symbol equal to (d'-1) is designated by a correction bit position designating unit 5. A data correction unit 6 then corrects the channel bit data so that the minimum run length of the same symbol will be equal to d'.

Abstract: An encoder/decoder device for improving the bit error rate, speedily and at low cost without using an A/D converter circuit. A comparator compares the playback signal loaded from the disk with a specified reference level, places the signal in binary notation and sends the binary information to a memory. When the continuous length showing the quantity of zeroes placed between ones in succession is an error length which is shorter than a specified length 3T designated beforehand, an error length detection circuit detects this as a continuous length. A pattern detector circuit detects patterns in which the continuous length in front of error length 2T is 3T and the continuous length behind 2T is 4T or more, and further detects patterns in which the next continuous length after error length 2T is 3T and the continuous length in front of 2T is 4T or more.

Abstract: In the present invention, a partly duplexed conversion table is used as a conversion table for converting an M-bit based data string directly into an N-bit based code string without using margin bits. This conversion table is constituted by first and second sub-tables including plural code groups, respectively. The plural code groups include different codes for the same input data. The second sub-table is a table which is partly duplexed with the first sub-table and is produced by allocating different codes to data from first input data to second input data in the first sub-table. The first and second sub-tables are so designed that code sets of the duplexed portions take variants of digital sum variations which are opposite in sign. Codes are allocated to all the code groups in the duplexed portions of the first and second sub-tables with respect to input data sequentially from a code having a maximum absolute value of variant of the digital sum variation.

Abstract: In the present invention, a partly duplexed conversion table is used as a conversion table for converting an M-bit based data string directly into an N-bit based code string without using margin bits. This conversion table is constituted by first and second sub-tables including plural code groups, respectively. The plural code groups include different codes for the same input data. The second sub-table is a table which is partly duplexed with the first sub-table and is produced by allocating different codes to data from first input data to second input data in the first sub-table. The first and second sub-tables are so designed that code sets of the duplexed portions take variants of digital sum variations which are opposite in sign. Codes are allocated to all the code groups in the duplexed portions of the first and second sub-tables with respect to input data sequentially from a code having a maximum absolute value of variant of the digital sum variation.

Abstract: A device for recording/reproducing a digital pattern as a sound track of a cinefilm is disclosed. The device includes a cinefilm 1 having an image recording area 2 in which an image is recorded, a perforation section 3 for film feed and digital pattern data recording areas 5 and 6 provided in the vicinity of the perforation section 3. Plural channels of audio data are recorded as the digital patterns in the digital pattern data recording areas.

Abstract: A clock signal reproduction circuit including an A/D conversion circuit for converting an input RF analog signal with a restricted upper limit of a frequency band into a digital signal, a digital phase error calculation unit for digitally calculating a phase error of a digital signal converted in the A/D conversion circuit, a control voltage generating unit including a loop filter, a D/A conversion unit for outputting an analog control voltage signal based on the digital phase error calculated, and an analog voltage-controlled type oscillating circuit for outputting a reproduction clock signal having a frequency of at least 2 times the frequency of the input analog signal. The A/D conversion circuit uses the clock signal output from the analog voltage-controlled type oscillating circuit to convert the input analog signal into a digital format and output a reproduction clock signal from the analog voltage-controlled oscillating circuit.

Abstract: In the present invention, a partly duplexed conversion table is used as a conversion table for converting an M-bit based data string directly into an N-bit based code string without using margin bits. This conversion table is constituted by first and second sub-tables including plural code groups, respectively. The plural code groups include different codes for the same input data. The second sub-table is a table which is partly duplexed with the first sub-table and is produced by allocating different codes to data from first input data to second input data in the first sub-table. The first and second sub-tables are so designed that code sets of the duplexed portions take variants of digital sum variations which are opposite in sign. Codes are allocated to all the code groups in the duplexed portions of the first and second sub-tables with respect to input data sequentially from a code having a maximum absolute value of variant of the digital sum variation.

Abstract: A clock signal reproduction circuit including an A/D conversion circuit for converting an input RF analog signal with a restricted upper limit of a frequency band into a digital signal, a digital phase error calculation unit for digitally calculating a phase error of a digital signal converted in the A/D conversion circuit, a control voltage generating unit including a loop filter, a D/A conversion unit for outputting an analog control voltage signal based on the digital phase error calculated, and an analog voltage-controlled type oscillating circuit for outputting a reproduction clock signal having a frequency of at least 2 times the frequency of the input analog signal. The A/D conversion circuit uses the clock signal output from the analog voltage-controlled type oscillating circuit to convert the input analog signal into a digital format and output a reproduction clock signal from the analog voltage-controlled oscillating circuit.

Abstract: An optical disk having a diameter less than 140 mm and, a thickness of 1.2 mm.+-.0.1 mm, with a plurality of record tracks having data recorded thereon as embossed pits representing information and exhibiting a track pitch in the range between 0.646 .mu.m and 1.05 .mu.m; with the tracks being divided into a lead-in area, a program area and a lead-out area. The data includes table of contents (TOC) information recorded in a plurality of sectors in at least one TOC track and user information recorded in a plurality of sectors in user tracks; with the TOC information including addresses of start sectors recorded in the user tracks. The data (both user and TOC information) is encoded in a long distance error correction code having at least eight parity symbols, and is run length limited (RLL) modulated.

Abstract: A signal binary coding circuit and a recording medium reproducing apparatus can binary coding efficiently the input signal sampled by the discrete time, by providing: a subtracting circuit for subtracting direct current components from the sampled value input; a comparator circuit for comparing the output value of said subtracting circuit and a threshold and outputting the binary signal based on said comparison value; an amplitude limiting circuit to amplitude-limit the output value of the subtracting circuit with the fixed value; and a direct current component forming circuit to calculate direct current components from the output value of the amplitude limiting circuit.

Abstract: An optical disk having a diameter less than 140 mm and, a thickness of 1.2 mm.+-.0.1 mm, with a plurality of record tracks having data recorded thereon as embossed pits representing information and exhibiting a track pitch in the range between 0.646 .mu.m and 1.05 .mu.m; with the tracks being divided into a lead-in area, a program area and a lead-out area. The data includes table of contents (TOC) information recorded in a plurality of sectors in at least one TOC track and user information recorded in a plurality of sectors in user tracks. The user information is comprised of MPEG-compressed video data, which may exhibit any one of difference MPEG formats, and compressed audio data, which likewise may exhibit an MPEG format, a PCM format or the like. The TOC information includes addresses of start sectors recorded in the user tracks and also includes application table of contents (ATOC) information which identifies various parameters for accessing and using the user information.

Abstract: An optical disk having a diameter less than 140 mm and, a thickness of 1.2 mm.+-.0.1 mm, with a plurality of record tracks having data recorded thereon as embossed pits representing information and exhibiting a track pitch in the range between 0.646 .mu.m and 1.05 .mu.m; with the tracks being divided into a lead-in area, a program area and a lead-out area. The data includes table of contents (TOC) information recorded in a plurality of sectors in at least one TOC track and user information recorded in a plurality of sectors in user tracks; with the TOC information including addresses of start sectors recorded in the user tracks. The data (both user and TOC information) is encoded in a long distance error correction code having at least eight parity symbols, and is run length limited (RLL) modulated.

Abstract: An optical disk having a diameter less than 140 mm and, a thickness of 1.2 mm.+-.0.1 mm, with a plurality of record tracks having data recorded thereon as embossed pits representing information and exhibiting a track pitch in the range between 0.646 .mu.m and 1.05 .mu.m; with the tracks being divided into a lead-in area, a program area and a lead-out area. The data includes table of contents (TOC) information recorded in a plurality of sectors in at least one TOC track and user information recorded in a plurality of sectors in user tracks; with the TOC information including addresses of start sectors recorded in the user tracks. The data (both user and TOC information) is encoded in a long distance error correction code having at least eight parity symbols, and is run length limited (RLL) modulated.

Abstract: Method and apparatus for recording MPEG-compressed video data and compressed audio data on an optical disk having a diameter less than 140 mm and, a thickness of 1.2 mm.+-.0.1 mm, with a plurality of record tracks having data recorded thereon as embossed pits representing information and exhibiting a track pitch in the range between 0.646 .mu.m and 1.05 .mu.m; with the tracks being divided into a lead-in area, a program area and a lead-out area. The data includes table of contents (TOC) information recorded in a plurality of sectors in at least one TOC track and user information recorded in a plurality of sectors in user tracks. The user information is comprised of MPEG-compressed video data, which may exhibit any one of difference MPEG formats, and compressed audio data, which likewise may exhibit an MPEG format, a PCM format or the like. The TOC information includes addresses of start sectors recorded in the user tracks.

Abstract: Method and apparatus for reproducing MPEG-compressed video data and compressed audio data from an optical disk having a diameter less than 140 mm and, a thickness of 1.2 mm.+-.0.1 mm, with a plurality of record tracks having data recorded thereon as embossed pits representing information and exhibiting a track pitch in the range between 0.646 .mu.m and 1.05 .mu.m; with the tracks being divided into a lead-in area, a program area and a lead-out area. The data includes table of contents (TOC) information recorded in a plurality of sectors in at least one TOC track and user information recorded in a plurality of sectors in user tracks. The user information is comprised of MPEG-compressed video data, which may exhibit any one of difference MPEG formats, and compressed audio data, which likewise may exhibit an MPEG format, a PCM format or the like.

Abstract: An apparatus for recording and/or reproducing a magneto-optical recording medium having a recording layer, a reproducing layer and an intermediate layer for magnetically coupling the recording layer and the reproducing layer in a stationary state, in which the magnetic coupling between the recording layer and the reproducing layer is only able to take place in an area in which a temperature is increased to be higher than a predetermined temperature by the radiation of a light upon reproducing and in which a recorded information held in the recording layer is read out from the reproducing layer in the radiated area. This magneto-optical recording medium is characterized in that a Curie temperature of the intermediate layer is selected to be 150.degree. C. or more. Also, an apparatus which performs the above-mentioned functions and additionally which is capable of recording and/or reproducing conventional magneto-optical discs which reproduce and/or record over the entire area of irradiation.

Abstract: Method and apparatus for reproducing MPEG-compressed video data and compressed audio data from an optical disk having a diameter less than 140 mm and, a thickness of 1.2 mm±0.1 mm, with a plurality of record tracks having data recorded thereon as embossed pits representing information and exhibiting a track pitch in the range between 0.646 &mgr;m and 1.05 &mgr;m; with the tracks being divided into a lead-in area, a program area and a lead-out area. The data includes table of contents (TOC) information recorded in a plurality of sectors in at least one TOC track and user information recorded in a plurality of sectors in user tracks. The user information is comprised of MPEG-compressed video data, which may exhibit any one of difference MPEG formats, and compressed audio data, which likewise may exhibit an MPEG format, a PCM format or the like.