Digital signal reproduction apparatus
    6.
    发明公开
    Digital signal reproduction apparatus 失效
    Digitalsignalwiedergabegerät

    公开(公告)号:EP0854483A3

    公开(公告)日:1998-12-16

    申请号:EP98100814.7

    申请日:1998-01-19

    申请人: Hitachi, Ltd.

    IPC分类号: G11B20/18 H04N9/804

    摘要: A quick retry operation is possible by outputting an error flag pertaining to a sector after error correction processing of digital data. When an output of an error detection flag unit for a correction block indicates the existence of an uncorrectable error, the sectors are checked to see if the sectors corresponding to retrieved data include any error or not based on output from a sector error flag register B. When the sectors are judged as error, signals are retrieved again from a storage medium, re-stored in a memory, and an error correction processing is repeated again. The data such as that of P pictures or B pictures of MPEG which can be reproduced even with errors are output even when the error detection flag unit indicates the existence of the uncorrectable error. It enables identification of the sectors with the errors and simplifies the following operations pertaining to the error at a data receiving side by outputting the error flag along with the data.

    Digital signal reproduction devices, integrated circuits for use therewith, and digital signal reproduction methods
    8.
    发明公开
    Digital signal reproduction devices, integrated circuits for use therewith, and digital signal reproduction methods 失效
    装置,用于再现数字信号,集成电路为此,和方法,用于再现数字信号。

    公开(公告)号:EP0597372A3

    公开(公告)日:1996-05-15

    申请号:EP93117802.4

    申请日:1993-11-03

    申请人: HITACHI, LTD.

    摘要: A digital signal reproduction device including a data strobe circuit high in margin against noise and rapid in recovery from dropout of data and a digital signal reproduction method performed in such device. The digital signal reproduction device includes a pair of data strobe circuits (4, 5) and a switching circuit (3) for selecting one of the outputs of the pair of data strobe circuits, and a circuit (1, 2) for generating from the received signal a signal to control the switching circuit (3). The data strobe circuits (4, 5) ensure high reliability of the received signal against noise and a short time from dropout of the received signal to acquisition of a reproduction clock. The data strobe circuit (4 or 5) is selectable which is suitable for the reproduction state of the reproduced signal.

    摘要翻译: 的数字信号再现装置,其包括在对噪声和在从数据的脱落,在这种设备中执行的数字信号再现方法恢复快速高裕度的数据选通电路。 该数字信号再现装置包括一对数据选通电路(4,5)和开关电路(3),用于选择所述一对数据选通电路的输出中的一个,和一个电路(1,2),用于从产生 接收到的信号的信号来控制开关电路(3)。 数据选通电路(4,5)确保防止噪声的接收信号,并从接收到的信号以获取一个再现时钟的脱落短时间内的高可靠性。 数据选通电路(4或5)是可选择的所有其适合于再现信号的再现状态。

    Rotary head type magnetic recording and reproducing apparatus
    9.
    发明公开
    Rotary head type magnetic recording and reproducing apparatus 失效
    装置,用于记录和用旋转磁头鼓再现。

    公开(公告)号:EP0658052A3

    公开(公告)日:1995-10-18

    申请号:EP94119441.7

    申请日:1994-12-08

    申请人: HITACHI, LTD.

    IPC分类号: H04N5/926 H04N5/91

    摘要: A rotary head type magnetic recording and reproducing apparatus for recording and reproducing an analog wide-band video signal, audio signal and compressed digital signal on the same recording medium. The modulated analog wide-band video signal or the narrow-band-converted compressed digital signal is recorded on two video tracks adjacent to each other on a magnetic tape (301) by magnetic heads (301a, 301b and 302a, 302b) on a rotary drum (300). In another arrangement in which the audio signals multiplexed in frequency are recorded on the audio track adjacent to the video tracks on the magnetic tape (310) by the magnetic heads (303a, 303b) and the decision circuit (264), by utilizing the signal reproduced from the audio track, determines whether the signal recorded on the video tracks is analog or digital, the input analog wide-band video signal is divided into signals of two channels by the recording-system analog signal processing circuit (57), those signals are recorded on the magnetic tape (60) in multi-track recording by a pair of magnetic heads (62a, 62b) and another pair of magnetic heads (62, 62d), the input audio signals are modulated by the FM modulator (15) and the QPSK modulator (16), and recorded in a deep-layer portion of another track between the video tracks. A compressed digital digital signal received by the antenna (1) is added with error correction codes by the recording-system digital signal processing circuit (5), and is modulated by the 16QAM modulator (6) so that the spectral components of the compressed digital signal does not enter the audio signal frequency band, and is recorded on said audio track superposed but in a deeper-layer portion of the tape by yet another pair of magnetic heads (64a, 64b).