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    Data encrypting/decrypting conversion methods and apparatuses and data communication system adopting the same
    4.
    发明公开
    Data encrypting/decrypting conversion methods and apparatuses and data communication system adopting the same 审中-公开
    用于执行该方法用于数据加密/Entschlüsselungsumwaldlung和设备和数据通信系统中的方法

    公开(公告)号：EP0896452A2

    公开(公告)日：1999-02-10

    申请号：EP98114719.2

    申请日：1998-08-05

    Applicant: Hitachi, Ltd.

    Inventor： Aikawa, Makoto ,  Takaragi, Kazuo ,  Koreeda, Hiroyuki ,  Sasamoto, Manabu ,  Okamoto, Hiroo ,  Noguchi, Takaharu ,  Furuya, Soichi ,  Hirahata, Shigeru

    IPC: H04L9/06

    CPC classification number: H04L9/0625 ,  G10H2230/015 ,  H04L2209/08 ,  H04L2209/12 ,  H04L2209/601

    Abstract: Encrypting/decrypting conversion method and apparatus capable of controlling dynamically cyclic shift independent of data to undergo encrypting/decrypting conversion includes two or more different fixed circulating shift processing means (201, 202, 203) for shifting cyclically the data by a fixed bit number leftward or rightward, a cyclic shift processing selecting means (606) for selecting fixed cyclic shift processing means (201, 202, 203). The selecting sequence determined by the cyclic shift processing means is determined on the basis of data (G1, G2, G3) for determining the shift number selecting sequence.

    Abstract translation: 加密/解密转换方法和能够控制动态循环移位的独立数据的装置经过加密/解密转换包括用于通过向左固定位数循环移位数据的两个或更多个不同的固定的循环移位处理装置（201，202，203） 或向右，循环移位处理选择装置（606），用于选择固定循环移位处理装置（201，202，203）。 序列选择由循环移位处理装置确定性开采是确定性的所挖掘的数据的基础上（G1，G2，G3），用于确定性采矿移位数目选择序列上。

    Method and system for transsion/reception of encrypted digital signal
    5.
    发明公开
    Method and system for transsion/reception of encrypted digital signal 失效
    用于发送/接收加密的数字信号的方法和装置。

    公开(公告)号：EP0675655A3

    公开(公告)日：1997-09-24

    申请号：EP95104480.9

    申请日：1995-03-27

    Applicant: HITACHI, LTD.

    Inventor： Amada, Nobutaka ,  Yamazaki, Shigeru ,  Noguchi, Takaharu ,  Nishijima,Hideo ,  Ono, Hiroaki ,  Okamoto, Hiroo ,  Owashi, Hitoaki ,  Arai, Takao ,  Hatanaka, Yuji ,  Saito, Seiichi

    IPC: H04N7/52

    CPC classification number: H04N7/52 ,  H04N5/9261 ,  H04N5/937

    Abstract: A digital information signal transmitting/receiving method and system having a transmitter (100) for transmitting an encrypted digital information signal and a plurality of receivers (200) for receiving the encrypted digital information signal from the transmitter (100). The transmitter (100) simultaneously distributes a plurality of identification codes associated with the receivers (200) ahead of the digital information signal. Then, the digital information signal is distributed to the receivers. The receivers (200) detect particular, or their own, identification codes from the plurality of identification signals assigned to the receivers (200). The received encrypted digital information signal is decrypted into the original information on the basis of the particular identification codes associated with the corresponding receivers or the recorders (300). Either the receivers (200) or the recorders (300) generate an information request signal. The transmitter (100) is responsive to this information request signal to add to the digital information signal identification signals for identifying the receivers (200) or the recorders (300) which generated the information request signal. The recorders (300) control the received information signal to be recorded in response to the identification signals received by the receivers (200).

    Digital signal recording method and apparatus
    6.
    发明公开
    Digital signal recording method and apparatus 失效
    Verfahren undGerätzur Aufnahme von Digitalsignalen

    公开(公告)号：EP0735536A2

    公开(公告)日：1996-10-02

    申请号：EP96104729.7

    申请日：1996-03-25

    Applicant: HITACHI, LTD.

    Inventor： Okamoto, Hiroo ,  Hosokawa, Kyoichi ,  Owashi, Hitoaki ,  Noguchi, Takaharu

    IPC: G11B20/10 ,  G11B20/18 ,  H04N9/804

    CPC classification number: H04N5/9261 ,  G11B20/10009 ,  G11B20/1833

    Abstract: A digital signal recording method and apparatus for recording a digital signal on a recording medium (111) by dividing the digital signal at intervals of a certain byte number, adding to each of the divided signals a synchronizing signal, a control signal including block address information, and an error detection and correction code to form signal blocks, and precoding each of the signal blocks in order to detect a partial response. Before the precode processing, the digital signal and the error detection and correction code are scrambled (303) on the basis of the control signal, and the control signal is inverted (301).

    Abstract translation: 一种数字信号记录方法和装置，用于通过以某个字节数的间隔划分数字信号将数字信号记录在记录介质上，将每个分割信号加到同步信号，包括块地址信息的控制信号 以及用于形成信号块的错误检测和校正码，并且对每个信号块进行预编码以便检测部分响应。 在预编码处理之前，数字信号和错误检测和校正码根据控制信号进行加扰（303），控制信号反转（301）。

    Rotary head type PCM recording and reproduction method and system
    8.
    发明公开
    Rotary head type PCM recording and reproduction method and system 失效
    旋转头类型PCM记录和再现方法和系统

    公开(公告)号：EP0155664A3

    公开(公告)日：1986-05-28

    申请号：EP85103110

    申请日：1985-03-18

    Applicant: HITACHI, LTD.

    Inventor： Takahashi, Hiroaki ,  Kobayashi, Masaharu ,  Noguchi, Takaharu ,  Shibuya, Toshifumi ,  Arai, Takao

    IPC: G11B20/18

    CPC classification number: G11B20/1809 ,  G11B20/10527

    Abstract: A data recording/reproducing method and apparatus for' carrying out the method in a rotary head type PCM recording/reproducing apparatus including at least two magnetic heads (10, 11), a rotatable cylinder (9) having mounted thereon the magnetic heads in diametrical opposition at an angle of 180°, an A/D converter (6) for sampling an analog signal such as audio signal and converting it to a digital signal, and a signal processing circuit (7, 14) for adding the digital signal with an error detecting and correcting code, synchronizing signal and control signal, wherein the output of the signal processing circuit is recorded on a magnetic tape (12) or the signal recorded on the magnetic tape is reproduced. In recording operation, the odd-numbered sample data and the even-numbered sample data are discriminatively extracted and stored. The stored data corresponding to an amount of data outputted from the A/D converter (6) and completed within a predetermined time is selectively read out and supplied to the two heads to thereby record the data in such a manner that the odd-numbered data and the even-numbered data are recorded separately on the track basis (24, 25) or alternatively recorded separately on a preceding half (R-ODD, L-ODD) and a succeeding half (L-EVEN, R-EVEN) of each track. The error detecting and correcting code is prepared on the basis of the data to be recorded in each track. In reproduction, upon detection of drop-out of data from one of the two heads, the drop-out data is corrected through interpolation procedure to thereby reconstitute the original analog signal.

    Rotary head type magnetic recording and reproducing apparatus and method of producing tracking control signals therefor
    9.
    发明公开
    Rotary head type magnetic recording and reproducing apparatus and method of producing tracking control signals therefor 失效
    旋转头型磁记录和再现装置及其生成跟踪控制信号的方法

    公开(公告)号：EP0138210A3

    公开(公告)日：1986-02-05

    申请号：EP84112272

    申请日：1984-10-12

    Applicant: HITACHI, LTD.

    Inventor： Furuhata, Takashi ,  Yumde, Yasufumi ,  Okamura, Fujio ,  Noguchi, Takaharu ,  Shibuya, Toshifumi ,  Mohri, Katsuo ,  Arai, Takao ,  Terada, Toshimichi

    IPC: G11B05/584 ,  H04N05/782 ,  G11B15/467 ,  G11B15/473

    CPC classification number: G11B15/4672 ,  G11B15/4678 ,  G11B15/4738

    Abstract: A method of producing a tracking control signal in a ro- ary head type magnetic recording and reproducing apparatus and a rotary head type magnetic recording and reproducing tpparatus capable of a proper tracking by the use of the track- ng control signal. First and second tracking signals (f o , f 1 ) are ecorded on local portions of each odd-numbered track (A) md the first tracking signal (f o ) and a third tracking signal (f 2 ) are recorded on local portions of each even-numbered track B) in such a manner that the second tracking signals on two )dd-numbered track adjacent to any one even-numbered rack are not overlapped with each other and the third tracking signals on two even-numbered tracks adjacent to any one add-numbered track are not overlapped with each other when viewed in a direction perpendicular to the longitudinal direction )f the tracks; upon scanning of a track crosstalk signals are letected from two adjacent tracks simultaneously with repro- luction of the first and second or third tracking signals; and he detected crosstalk signals are compared by the use of tim- ig of the reproduction of the first tracking signal for each rack thereby producing a tracking control signal. The second racking signal may have a frequency equal to that of the third racking frequency. The recording and reproducing apparatus comprises a signal source (e.g., 19) generating at least two dif- erent frequencies, circuit sections (e.g., 9, 10a, 10b, 17) for generating three gate pulse signals (e.g., d, h, i in Fig. 6), a selector (e.g., 18) associated with the signal source and gate pulse signal generating circuit sections for serially and cyclically delivering signals of at least two different frequencies in accordance with the gate pulse signals so that first, second and third tracking signals are recorded on local portions of tracks of the magnetic tape as described above, and a tracking control circuit including filters (e.g., 32, 38) for extracting from reproduction outputs of the heads tracking signal components representative of the first tracking signal for each track and crosstalk signals from two adjacent tracks, a circuit (e.g., 38-41) for generating a sampling pulse signal from the extracted tracking signal component representative of the first tracking signal for each track and a comparator (36) for comparing the extracted tracking signal components representative of the crosstalk signals from two adjacent tracks by the use of the sampling pulse signal.

    PCM data recording system
    10.
    发明公开
    PCM data recording system 失效
    PCM数据记录系统。

    公开(公告)号：EP0149245A2

    公开(公告)日：1985-07-24

    申请号：EP84116409.8

    申请日：1984-12-27

    Applicant: HITACHI, LTD.

    Inventor： Okamoto, Hiroo ,  Kobayashi, Masaharu ,  Noguchi, Takaharu ,  Arai, Takao

    IPC: G11B20/18 ,  G11B20/10 ,  G11B20/12 ,  H03M13/00

    CPC classification number: G11B20/1208 ,  G11B20/10527 ,  G11B20/1211 ,  G11B20/1803 ,  G11B20/1813 ,  G11B27/3027 ,  G11B27/3063 ,  G11B2020/10546 ,  G11B2020/10592 ,  G11B2220/90 ,  G11B2220/913

    Abstract: A rotary-head PCM data recorder in which PCM signals of m in number, synchronizing signal (1), control signals (5-10) related to the PCM signals, and a parity signal (4) for error detection and correction are formed into data blocks (0-127), and data blocks of n in number are recorded on one track of a magnetic tape. Among the control signals, bits of signals common to n data blocks (i.e., information needed once for each track) are formed in distributed data allocated in multiple blocks or multiple tracks, and multiple block distributive control data are recorded on one track multiple number of times, or multiple track distributive control data are recorded along n block strings multiple number of times. In reproduction, block or track distributive data are composed to reproduce the control signals. The recorder in this arrangement reduces the bits count needed for the control signals. and is capable of compensating the dropout of reproduced data due to scars on the tape and the like.

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