Abstract: This invention provides a method for creating/writing defect management information of an information recording medium and an apparatus and optical disc based on the method. In the present invention, it depends on the type of data to be reproduced whether or not defective sectors which are detected during reproduction operation are replaced with non-defective sectors. If read-out errors are detected in reproducing non-audio/video data, linear replacement algorithm is applied to the corresponding defective sectors. On the other hand, in case of audio/video data, location information of the corresponding defective sectors is just kept without any sector replacement. Therefore, this invention enables to reproduce audio/video data in real-time regardless of the presence of defective sectors and to avoid writing data to the defective sectors when new data is overwritten to the information recording medium.

Abstract: This invention provides a method for creating/writing defect management information of an information recording medium and an apparatus and optical disc based on the method. In the present invention, it depends on the type of data to be reproduced whether or not defective sectors which are detected during reproduction operation are replaced with non-defective sectors. If read-out errors are detected in reproducing non-audio/video data, linear replacement algorithm is applied to the corresponding defective sectors. On the other hand, in case of audio/video data, location information of the corresponding defective sectors is just kept without any sector replacement. Therefore, this invention enables to reproduce audio/video data in real-time regardless of the presence of defective sectors and to avoid writing data to the defective sectors when new data is overwritten to the information recording medium.

Abstract: A process and system for creating and recording still picture management data in a rewritable storage media making it possible to reduce the amount of navigation information and index information necessary by grouping a plurality of still pictures according to their attributes, thus sharing navigation information and recording index information of still pictures with common attributes linked by the shared navigation information. In the method of the present invention, instead of creating navigation information and index information of each still picture, a plurality of still pictures share navigation information according to their attributes or those of audio signals linked to the still pictures and index information of the still pictures are recorded based on the shared navigation information, thereby effectively reducing the amount of navigation information and index information required for reproduction of still pictures recorded on a rewritable storage media.

Abstract: A process and system for creating and recording still picture management data in a rewritable storage media making it possible to reduce the amount of navigation information and index information necessary by grouping a plurality of still pictures according to their attributes, thus sharing navigation information and recording index information of still pictures with common attributes linked by the shared navigation information. In the method of the present invention, instead of creating navigation information and index information of each still picture, a plurality of still pictures share navigation information according to their attributes or those of audio signals linked to the still pictures and index information of the still pictures are recorded based on the shared navigation information, thereby effectively reducing the amount of navigation information and index information required for reproduction of still pictures recorded on a rewritable storage media.

Abstract: A method and apparatus for recording digital data streams on a recording medium are provided. The method includes checking the existence of entry point information in a received digital transport stream, and creating map information regarding the entry point information. The map information includes time information and location information regarding the entry point information.

Abstract: A rewritable recording medium and a system for creating or recording presentation order information for the recording medium are disclosed. The rewritable recording medium includes (a) a data area in which a data file is recorded, and (b) a navigation information area in which a navigation information file is recorded. The navigation information file includes a plurality of presentation order information units for defining a data presentation sequence and a plurality of presentation order information groups each of which including at least one of the presentation order information units. Recording of new data is permitted only when the total number of the presentation order information units for all the presentation order information groups is less than a predetermined value.

Abstract: A method and apparatus for recording received digital data streams on a recording medium such as a digital video disk and creating and recording management information pertaining to the recorded digital data streams. Random access information contained in the received digital data streams is detected and stream object units are created based upon the detected random access information, which enables reproduction of recorded data to start from the transport stream packet having the random access information and prevents imperfect data reproduction after track seek or time seek operations.

Abstract: A method of creating and recording presentation order management information for a rewritable recording medium, which enables effective control of the amount of the presentation order management information needed when a user edits preferred play lists of recorded data. In the present invention, each time a new play list is made by a user, a user-defined program chain is created, wherein presentation order information units for defining presentation order of user-chosen data are contained. The maximum number of user-defined program chains and the total number of presentation order information units are limited. When editing of a new play list is requested, the number of user-defined program chains created so far and the total number of presentation order information units contained in all the user-defined program chains are checked.

Abstract: This invention provides a method of managing the navigation data for a rewritable recording medium which are referred to for control of recording, editing, and reproduction. It enables to access to each information table in the navigation data directly by referring to the start address, which is kept in the first information table in the navigation data. When data are recorded to the rewritable recording medium, the management data which are relevant to the data to be recorded are created and written to the relevant information tables, which are accessed directly based on the start addresses. When data on the recording medium are reproduced, the information tables which contain management data required for reproduction of the requested data are located directly by the start addresses. Then, the data are read out from the rewritable recording medium and reproduced in reference to the management data.

Abstract: This invention provides a method of managing the navigation data for a rewritable recording medium which are referred to for control of recording, editing, and reproduction. It enables to access to each information table in the navigation data directly by referring to the start address, which is kept in the first information table in the navigation data. When data are recorded to the rewritable recording medium, the management data which are relevant to the data to be recorded are created and written to the relevant information tables, which are accessed directly based on the start addresses. When data on the recording medium are reproduced, the information tables which contain management data required for reproduction of the requested data are located directly by the start addresses. Then, the data are read out from the rewritable recording medium and reproduced in reference to the management data.

Abstract: Disclosed is a method of manufacturing large-grained uranium dioxide pellets through the use of U3O8 single crystals. The method consists of two main steps; producing U3O8 single crystals and manufacturing large-grained UO2 pellets. The U3O8 single crystals are produced by annealing U3O8 powder to make U3O8 polycrystalline aggregates having a large crystal size, and by dividing the U3O8 polycrystalline aggregate into its constituent U3O8 single crystals. Large-grained UO2 pellets are produced by forming a mixture comprising UO2 powder and the U3O8 single crystals, making granules of the mixture, pressing the granules into green pellets, and sintering the green pellets above 1600° C. for more than one hour in a reducing gas. The U3O8 powder is produced preferably by heating defective UO2 pellets in air to oxidize UO2 to U3O8. The invention provides a method of manufacturing a large-grained UO2 pellet with defective pellets reused.

Abstract: A method of judging a sector synchronous signal for a disk reproducing apparatus, includes a first step for decoding and storing a synchronous signal, a second step for comparing the decoded synchronous signal with a reference sector synchronous signal, a third step for assuming the detected synchronous signal to be a sector synchronous signal when the decoded synchronous signal and the reference sector synchronous signal are identical based on a result of the second step, a fourth step for judging whether the synchronous signal stored before the decoded synchronous signal indicates a desired state, and a fifth step for finally judging that the assumed sector synchronous signal is a sector synchronous signal based on a result of the fourth step.

Abstract: In a disk storage system using an RLL coding and an NRZ1 recording method and applying a (1+D) PR channel, a viterbi detector of the present invention includes an inverter for multiplying a present input by "-1"; a delay for delaying the output of the inverter for a predetermined time period; and a comparator for comparing the present input with a previous input supplied via the delay and outputting a specific value which varies its sign according to the result.