公开(公告)号：JPH06275034A

公开(公告)日：1994-09-30

申请号：JP8278593

申请日：1993-03-17

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO

IPC: G11B21/10 ,  H03M13/23 ,  H03M13/12

Abstract: PURPOSE:To improve the positioning accuracy of a head by always controlling an off-track amount to an optimum amount by efficiently calculating an optimum shift amount. CONSTITUTION:A corrected value generating circuit 12 performs correction control so that a reproducing head at a target track position can be off-tracked from a track center oppositely just for the shift amount in the disk radius direction of a recording head to this reproducing head, and an error measuring circuit 17 measures the bit error rate of a regenerating signal in a data zone while changing the off-track amount. Tracking is performed with the off-track amount, for which this bit error rate is made best, as the optimum value of the shift amount. Thus, the positioning accuracy of the head is improved by always controlling the off-track amount to the optimum amount by efficiently binding the optimum shift amount.

公开(公告)号：JP2002152193A

公开(公告)日：2002-05-24

申请号：JP2000348450

申请日：2000-11-15

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO ,  FUKUYAMA MUNEKATSU ,  SATO HIDEO

IPC: H04N7/08 ,  G09C1/00 ,  H04L9/26 ,  H04N7/081

Abstract: PROBLEM TO BE SOLVED: To enable an information reproducing device to make a safe cipher communication even when a standard interface is used. SOLUTION: A random number is generated on the basis of a noise signal generated in the information reproducing device 3 and a ciphering key is generated on the basis of the generated random number. Consequently, the random number of high quality having no reproducibility can be generated at a high speed without adding any circuit for generating the random number. Thereby the safe cipher communication can be made even when the standard interface is used.

公开(公告)号：JP2001053870A

公开(公告)日：2001-02-23

申请号：JP22666899

申请日：1999-08-10

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO

IPC: H04M1/673

Abstract: PROBLEM TO BE SOLVED: To provide a portable telephone set for making it unnecessary to execute an inputting operation at the time of releasing the dial lock and a method for releasing the dial lock of the portable telephone set. SOLUTION: In this method for releasing the dial lock of a portable telephone set, at the time of initialization, a designated telephone number or signal for controlling automatic dial lock release and a non-operational time (a time until the automatic dial lock function is turned on) and a password for changing automatic dial lock setting are inputted by the owner of a portable telephone set 9 based on a key 1, and stored through an inputting means 2 and a control means 3 in a storage means 5. At the time of releasing the automatic dial lock of the portable telephone set 9, the control means 3 judges whether or not an incoming designated telephone number or incoming signal from an entrepreneur side is made coincident with the designation telephone number for controlling automatic dial lock release stored in the storage means 5, and releases autonomic dial lock.

公开(公告)号：JPH1131978A

公开(公告)日：1999-02-02

申请号：JP18261997

申请日：1997-07-08

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO

IPC: G11B20/10 ,  G11B20/14 ,  G11B20/18 ,  H03M13/23 ,  H03M13/12

Abstract: PROBLEM TO BE SOLVED: To maintain performance and to reduce power consumption in PRML (partial response maximum likelihood). SOLUTION: In a magnetic disk drive 1, data to be recorded are inputted from a hard disk controller, modulated by a channel encoding part 11 into a channel code, which are recorded on a magnetic disk medium 80 through a recording amplifier 12. A signal reproduced from the magnetic disk medium 80 is amplified by a playback amplifier 13 and converted by an A/D conversion part 14 into a digital signal, which is equalized by an equalizer 15 into a signal with PR4 characteristics. On the basis of this equalized signal, a PLL circuit 16 generates a clock. The equalized signal after being rounded to a discrete value by a nonlinear quantizer 17 is decoded by a Viterbi decoder 18 and restored by a channel decoding part 19 to the original signal, so that the signal is outputted through an a hard disk controller (not shown).

公开(公告)号：JPH10199145A

公开(公告)日：1998-07-31

申请号：JP35034296

申请日：1996-12-27

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO ,  YAMAGOSHI TAKAMICHI

IPC: G11B20/10 ,  G11B20/12

Abstract: PROBLEM TO BE SOLVED: To quickly perform an initial synchronism establishment in a synchronizing servo type disk device. SOLUTION: In an initial synchronism establishment, a waveform of a reproduced signal is blunted by controlling a cut-off frequency of a band pass limiting filter 26 so that the waveform is made a low value. Quantity of an error for a peak value of a detected sampling value is suppressed to a small value by blunting a waveform of a reproduced signal when a sampling phase is out of a phase of a reproduced signal. Thus, in the initial synchronism establishment, probability with which an unique pattern and a segment ID pattern are detected is improved. Therefore, probability with which operation detecting the unique pattern and the segment ID pattern is repeatedly performed can be a low level, and initial synchronism establishment can be quickly performed. Also, probability with which the unique pattern and the segment ID pattern are detected can be improved and initial synchronism establishment can be quickly performed by also controlling a reference amplitude value required for operation of a viterbi decoder in a unique pattern detecting circuit 20 so as to be a low level.

公开(公告)号：JPH09139672A

公开(公告)日：1997-05-27

申请号：JP31963895

申请日：1995-11-14

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO ,  GENDAI YUUJI

IPC: H03M1/12 ,  H03M1/36 ,  H03M13/23 ,  H03M13/12

Abstract: PROBLEM TO BE SOLVED: To reduce the effect due to mis-conversion of an A/D converter. SOLUTION: Each of comparators 11 to 17 compares a reference voltage generated from a resistance voltage division circuit with each input signal in terms of levels, and provides an output of a high level when the input signal is higher than the reference voltage and provides an output of a low level when the input signal is lower than the reference voltage. In the case that outputs of two latches 21, 23 are at a low level and outputs of three latches 24 to 27 are at a high level, and an output of a latch 23 is unstable, outputs of AND gates 31 to 36 might be all at a low level. An output code of 2's complement of latches 51 to 53 is (000). In the case of A/D-converting regenerated data in the partial response system, the effect of mis-conversion is reduced by providing an output of a median in this way.

公开(公告)号：JPH08221728A

公开(公告)日：1996-08-30

申请号：JP2803495

申请日：1995-02-16

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO

IPC: G11B5/596 ,  G11B20/10 ,  G11B20/12 ,  G11B27/10

Abstract: PURPOSE: To surely reproduce an address information even at the time of seeking to traverse a track by using only a required number of bits without adding the redundancy to the address information specifying the track. CONSTITUTION: On a magnetic disk 1, for instance, when the bit magnetized in the running direction of a magnetic head is defined as 1 and the bit magnetized in the opposed direction is defined as 0, 1 is recorded on the track address such as the magnetized direction becomes a gray code and on an air gap of the track address. A servo detecting circuit 14 is provided with a Viterbi decoder, and the track address is reproduced by Viterbi-decoding the reproducing signals of the track address and the air gap. By this arrangement, the decoding is surely attained from the track address while keeping the performance as the gray code, without adding the redundancy against the number of bits of the information amount required as the track address.

公开(公告)号：JPH08194904A

公开(公告)日：1996-07-30

申请号：JP707095

申请日：1995-01-20

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO

IPC: G11B5/09 ,  G11B20/10 ,  G11B20/12 ,  G11B20/18 ,  G11B21/08

Abstract: PURPOSE: To provid a magnetic recording medium and a data reproducer by which a track address can be securely reproduced even at the time of seeking across a track without adding a redundancy to the track address. CONSTITUTION: If, for instance, a bit which is magnetized in the travelling direction of a magnetic head is defined as '1' and a bit which is magnetized in the opposite direction is defined as '0', a track address 7 is recorded so as to make the direction of magnetization a Gray code. A servo detection circuit 14 has a Viterbi decoder and the reproduction signal of the track signal 7 is subjected to the Viterbi decoding to reproduce the track address 7. With this constitution, the track address can be securely decoded while the properties of the Gray code are maintained without adding a redundancy to the number of bits of the information necessary for the track address 7.

公开(公告)号：JPH06282808A

公开(公告)日：1994-10-07

申请号：JP9364993

申请日：1993-03-29

Applicant: SONY CORP

Inventor： HAYASHI NOBUHIRO

IPC: G11B5/09

Abstract: PURPOSE:To prevent inter-code interference by a method wherein such a gap as to correspond to at least half of the number of taps of a filter is provided in the leading or ending part of a data area of a magnetic disk and information is recorded in a part other than the gap. CONSTITUTION:In a data area of a magnetic disk, a gap is provided from the forefront thereof to a position located at such a distance N from the forefront as to correspond to at least half n/2 of the number (n) of taps of an FIR filter, and data are recorded behind the position. In the case when reproduction signals corresponding to the data recorded first in the leading part of the data area are subjected to waveform equalization by the FIR filter, therefore, an unnecessary reproduction pulse generated in the forefront of the data area is not used. A similar gap to the one in the leading part of the data area is provided also in the ending part thereof. Without being affected by inter-code interference caused by the unnecessary reproduction pulse generated in the part of the end of data area, accordingly, correct reproduced data can always be obtained.

公开(公告)号：JPH06259709A

公开(公告)日：1994-09-16

申请号：JP6921893

申请日：1993-03-04

Applicant: SONY CORP

Inventor： WATANABE KENJIRO ,  TAKEDA RITSU ,  SEKO SATORU ,  KAWAZOE KAZUSHIGE ,  MUTO TAKAYASU ,  MORITA OSAMI ,  HAYASHI NOBUHIRO ,  ISHIDA TAKEHISA ,  ISHIOKA HIDEAKI ,  YAMAGOSHI TAKAMICHI

IPC: G11B5/09 ,  G11B5/008 ,  G11B5/012 ,  G11B5/55 ,  G11B5/596 ,  G11B5/64 ,  G11B5/73 ,  G11B5/82 ,  G11B5/84 ,  G11B20/10 ,  G11B20/12 ,  G11B20/18 ,  G11B21/10 ,  G11B25/04 ,  G11B27/19 ,  G11B27/30 ,  G11B33/14

Abstract: PURPOSE:To increase a recording capacity of a magnetic disk. CONSTITUTION:Guard bands 20-20 are formed as recessed parts, and tracks 20-10 are formed as projected parts. A clock mark 20-11 is formed not only on the tracks but also continuously between each track. This clock mark 20-11 is formed along a rotational locus of a reproducing head 20-30.