公开(公告)号：JP2001331383A

公开(公告)日：2001-11-30

申请号：JP2000147016

申请日：2000-05-18

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI

IPC: G06F1/26 ,  G06F3/06 ,  G06F12/16 ,  G06F13/00

Abstract: PROBLEM TO BE SOLVED: To improve the reliability of data, while avoiding the possibility of fault occurrence by detecting the disconnection of a power source or I/F during the command execution of a magnetic disk device. SOLUTION: When a command is received from a high-order host prior to command execution, command receiving information is set to a magnetic disk 14 or a nonvolatile memory 32. After command execution, a microcomputer 28 initializes the command receiving information set on the magnetic disk 14 or nonvolatile memory 32. In this case, when the power source is turned on, the microcomputer 28 decides whether the execution of the command is normally completed or not before power source is turned off by reading the set command receiving information. When it is decided that the command has not been finished normally, this is notified to the high-order host, and the file check of the magnetic disk device and the recovery processing operation of a file are executed, if necessary.

公开(公告)号：JPH11213314A

公开(公告)日：1999-08-06

申请号：JP918598

申请日：1998-01-21

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI

IPC: G11B5/09

Abstract: PROBLEM TO BE SOLVED: To improve the reliability of a magnetic disk device by reducing a possibility of data write in an off-track state. SOLUTION: In response to the occurrence of an off-track error during the write operation of a magnetic head to a disk medium, data are written in an area other than a user area, which a user uses, to recover the error. Whether the error disappears or not is confirmed after this recovery operation. In this confirmation, data, are read out in the off-track state (steps 104 and 105), and restoration from the error is decided if the error occurrence rate for this read is lower than a preliminarily determined value (step 106). That is, the off-track error is detected, and whether the error is recovered or not is decided after the execution of the recovery operation. The reliability of the magnetic disk device is improved by this decision.

公开(公告)号：JPH0589412A

公开(公告)日：1993-04-09

申请号：JP27480791

申请日：1991-09-26

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI ,  OKANO YASUSHI

IPC: G11B5/09 ,  G11B7/00 ,  G11B7/005

Abstract: PURPOSE:To always execute the optimum correction of undershoot for different heads and cylinders in a magnetic storage device using a thin film head. CONSTITUTION:In a waveform equalization circuit to be used for the reproduction circuit of the magnetic storage device using the thin film head, a five-tape type cosine equalization circuit to change delay time on based on tape switching signals 105, 106 from the outside and an undershoot detector to detect the undershoot and detect its position are provided. By controlling tap change-over switches 5 by the tape switching signals 105, 106 in accordance with the position of the undershoot, optimum waveform equalization is executed always even if there is the dispersion of the position of the undershoot due to the difference of the head and the cylinder.

公开(公告)号：JPH04157606A

公开(公告)日：1992-05-29

申请号：JP28392690

申请日：1990-10-22

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI

IPC: G11B5/09

Abstract: PURPOSE:To increase the reliability of reproduction of read information by switching over peak pulses obtained from two sets of signal processing circuits when a gap part is read out or when recorded information is read out. CONSTITUTION:A read start signal 113 becomes active at the head of a gap part and a phase sync circuit 9 starts a phase lead-in operation. A peak pulse switching signal 112 switches over simultaneously when the read start signal 113 becomes active, or before it becomes active, and also before data start information (DM), and a cosine equalizing circuit B5 and a peak detecting circuit B7 are selected during a period from the same time when the read start signal 113 becomes active or the time before it becomes active to the time before the DM, while a cosine equalizing circuit A4 and a peak detecting circuit A6 are selected during a period other than the above. According to this constitution, fluctuation in the phase of a peak pulse of the gap part is lessened, improvement is made in a peak shift and fluctuation in amplitude, the lead-in operation of the phase sync circuit is becomes stable, and the reliability of reproduction of readout information is improved.

公开(公告)号：JP2014007687A

公开(公告)日：2014-01-16

申请号：JP2012143745

申请日：2012-06-27

Applicant: Nec Corp ,  日本電気株式会社

Inventor： FUKUDA JUNICHI

IPC: H01Q3/26 ,  H01Q21/08

Abstract: PROBLEM TO BE SOLVED: To provide an antenna having a radiation pattern for suppressing radiation in the sky direction and becoming cosecant square curve in the ground direction, and having an electrical tilt while maintaining a high radiation gain, and to provide a wireless communication device including the same.SOLUTION: An antenna 10 includes a plurality of antenna elements 21, 22, ..., 2n, and feeding means 30 for feeding power having an amplitude decreasing toward both end sides of an array and a phase which advances gradually toward one end side and delays gradually toward the other end side.

Abstract translation: 要解决的问题：提供一种天线，其具有用于抑制在天空方向上的辐射的辐射图案，并且在地面方向上变为辅助平方曲线，并且在保持高辐射增益的同时具有电倾斜，并且提供一种无线通信装置，包括 相同。解决方案：天线10包括多个天线元件21,22，...，2n以及馈送装置30，用于馈送具有朝向阵列的两端侧的振幅减小的功率，并且朝向一个逐渐前进的相位 并且朝向另一端逐渐延伸。

公开(公告)号：JP2001307449A

公开(公告)日：2001-11-02

申请号：JP2000120345

申请日：2000-04-21

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI

IPC: G11B21/12

Abstract: PROBLEM TO BE SOLVED: To provide a magnetic disk device whose life can be predicted by discriminating between retracting operation having been performed in a forcible retraction state and normal retracting operation. SOLUTION: This device is equipped with a disk medium 1, a magnetic head 3, a loading/unloading mechanism 6, and a control part 10. The disk medium 1 is provided with a retraction information storage area in which retraction information on the magnetic head 3 is stored and the control part 10 is equipped with a retraction information writing function of writing specific information to the disk medium 1 when the magnetic head 3 is normally retracted, a retraction information readout function of reading the retraction information out of the disk medium 1 when the power source is turned on, a retraction information initializing function of initializing the information in the retraction information storage area right after the retraction information is read out when the magnetic head is reloaded, and a forcible retraction function of forcibly retracting the magnetic head 3 to a standby area when the power source is forcibly turned off.

公开(公告)号：JPH05210913A

公开(公告)日：1993-08-20

申请号：JP1573292

申请日：1992-01-31

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI

IPC: G11B20/10

Abstract: PURPOSE:To set the reference level of amplitude detection to an optimum value to prevent the error in the data reproducing circuit in the peak detection system using the amplitude detection as well. CONSTITUTION:The reference voltage of a level slicing circuit 7 is set by a level slice control circuit 10. An error detecting circuit 9 detects the error of a data pulse signal 107 demodulated by a data demodulating circuit 8 and outputs an error detection signal 108 to the level slice control circuit 10. This circuit 10 changes a level slice reference voltage 109 as the threshold of the level slicing circuit 7 and obtains the error occurrence rate from the error detection signal 108 and sets the level slice reference voltage 109 to such value that the error occurrence rate is minimum.

公开(公告)号：JPH04222906A

公开(公告)日：1992-08-12

申请号：JP41407690

申请日：1990-12-26

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI ,  NAKAMURA KIYOHITO ,  SHIMAUJI MASAHIRO

IPC: G11B5/09

Abstract: PURPOSE:To effectively reduce the peak shift amount and error rate, to increase the margin to a clock of data, and to improve a reliability by making possible to perform a write compensation for the peak shift generated from a reproducing waveform peculiar to a thin film head, making the compensation with a combined use of this write compensation and the write compensation of peak shift generated from previous data pattern, and facilitating a counter-measure to the characteristics difference of thin film heads. CONSTITUTION:When the data are read out, the peak shift generated by the data pattern is written with correcting in advance the time generating the peak shift at the data writing time.

公开(公告)号：JPH04134601A

公开(公告)日：1992-05-08

申请号：JP25443690

申请日：1990-09-25

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI

IPC: G11B5/09 ,  G11B20/14 ,  H04L7/08

Abstract: PURPOSE:To improve the reliability of a device by switching by a filter changeover signal when reproducing actual data and when reproducing the reference data train of a fixed cycle for executing a phase matching to a referring clock. CONSTITUTION:A peak pulse train 104 is equipped with a data area identifying code 104b and a data part (the actual data) 104c following to it after a phase matching same cycle part (the reference data train) 104a. A data discriminating circuit 5 executes the phase matching to the referring clock by the phase matching same cycle part 104a of the peak pulse train 104. The phase matching same cycle part 104a, being defined as a circuit constant for the phase matching same cycle part by a filter changeover signal, and after finishing the phase matching, switches to the circuit constant for the actual data before reading out the data 104c.

公开(公告)号：JPH03256262A

公开(公告)日：1991-11-14

申请号：JP5569290

申请日：1990-03-07

Applicant: NEC CORP

Inventor： FUKUDA JUNICHI

IPC: G11B21/08 ,  G11B19/12 ,  G11B21/10

Abstract: PURPOSE:To facilitate an increase and a change of kinds of head disk assembly HDA by providing an electronic circuit configuration for discriminating the classification of the kinds of the HDA and processing a signal based on its discriminated result. CONSTITUTION:The classification of the kinds of the HDA 1 is set by a classification setting mechanism 1-1 in the HDA 1, and a discriminating signal 101 is outputted. A control signal 102 corresponding to the classification of the kinds of the HDA 1 is generated and outputted by a classification discriminating circuit 2 based on the signal 101. Then, a regenerative signal 103 from the other output of the HDA 1 is inputted to an amplifier circuit 3, and a post- amplifier regenerative signal 104 is outputted. Filtration processing on the post- amplifier regenerative signal 104 to remove its high frequency component is performed by a filter circuit 4, whereas a filtration condition is changed based on the control signal 102. A peak position of a post-filtration processing regenerative signal 105 is detected by a peak detecting circuit 5, and a peak pulse 106 corresponding to the peak position is outputted. This pulse 106 is processed, and hence a recorded data is reproduced.