Abstract: An information transmission system includes a base station in which a digital information signal is divided into packets of a predetermined amount of information of a same type, a packet identification signal is inserted into each of the packets, the packet identification signal indicating the total number of consecutive packets carrying packet information of the same type and a packet number specifying an associated packet among the consecutive packets, and the packets are transmitted. The system includes a relay station, in which diagnosis data of an erred information signal is stored in a memory, and the diagnosis data is transmitted to the base station in response to a diagnosis return instruction sent from the base station. According to a further aspect of the invention, an error correction code is added to each packet and an error correction code for an identification code including a relay station pointing code is also added in the base station.

Abstract: An information transmission system in which an information signal supplied from a base station is automatically edited at relay stations and retransmitted to terminal stations according to a retransmission schedule assigned to each relay station. The transmission schedule is transmitted together with the information signal from the base station to the relay station which in turn records portions of the information signal directed to the station itself onto a rewritable recording medium (e.g. an optical disk) and retransmits it to its terminal stations according to the retransmission schedule.

Abstract: Method and apparatus of recording and reproducing picture information on a recording medium. In addition to a coded information signal, subcodes together with identification codes for identifying the coding system of the subcodes are recorded in a first recording area of a recording medium and the identification codes and content discrimination codes for indicating contents of information included in the subcode using the coding system indicated by the identification code are recorded in a second recording area of the recording medium. It is further characterized that the identification code and the content discrimination information recorded in the second recording area are displayed at the time of the playback of the recording medium.

Abstract: Method and apparatus of recording and reproducing picture information on a recording medium. In addition to video format signal and a coded information signal, graphic codes including picture information are recorded on the recording medium, by inserting the graphic codes as a subcode of the coded information signal. At the time of reproduction, a signal according to the graphic codes is mixed with the video format signal. When the recording medium is played back, a portion of the video format signal corresponding to a predetermined period of the video format signal read-out from the recording medium is written in a memory, and the signal according to the graphic code is mixed with a still picture video format signal which is produced by repeatedly reading the stored content of the memory.

Abstract: Method and apparatus of recording and reproducing picture information on a recording medium. In addition to a coded information signal, subcodes together with an identification code for identifying the coding system of the subcodes are recorded in a first recording area of a recording medium. The subcodes are preferably graphic codes including picture information and character codes having predetermined bit patterns, and are decoded in accordance with the identification code at the time of the playback of the recording medium.

Abstract: Method of recording and reproducing picture information and a recording medium on which the picture information is recorded by the method, and an apparatus for playing such a recording medium. In addition to video format signal and a coded information signal, graphic codes including picture information are recorded on the recording medium correspondingly to playback sections of the video format signal, the graphic codes being inserted as the subcode of the coded information signal. At the time of playback of the recording medium, a video signal according to the graphic codes corresponding to the playback section of the video format signal is generated each time one playback section of the video format signal is played back. Preferably, presence or absence of the graphic codes is displayed each time one playback section of the video format signal is played back.

Abstract: Playback method for use in an apparatus for playing a recording medium having a lead-in area, a first area in which only a coded information signal is recorded, and a second area in which a video format signal and a coded information signal are recorded by using a multiplexing operation. The method is characterized by the operations of reading information recorded in the lead-in area in response to a command, moving an information reading point of the pickup to the first area of the recording medium when subcode picture presence information, which indicates that a graphic code including picture information is inserted in a subcode of the coded information signal, is detected from information recovered from the lead-in area, and reproducing information of the first area preferentially to other areas of the recording medium.

Abstract: A sync signal detecting device includes a circuit for generating a sync signal pattern corresponding to an expected sync signal pattern contained in a digital signal, a circuit for comparing the digital signal with the sync signal pattern to detect a sync signal in the digital signal, a circuit for detecting errors in the digital signal, and a counter for counting the errors thus detected. A sync detection signal is outputted when, where no error is detected, the sync pattern is detected, and when, where errors are detected, the number of errors detected is a predetermined value or less and the part of the digital signal which is not coincident with the sync signal pattern is the part where the errors have been detected.