专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

21. 发明专利

JP2002015530A DATA RECORDING AND REPRODUCING DEVICE 失效
公开(公告)号：JP2002015530A
公开(公告)日：2002-01-18
申请号：JP2000193370
申请日：2000-06-27
申请人： FUJITSU LTD
发明人： TAGUCHI MASAKAZU , ITAKURA AKIHIRO , UCHIDA AKIYOSHI
IPC分类号： G11B5/008 , G11B5/012 , G11B20/10 , G11B20/18 , H03M13/39 , H03M13/41
摘要： PROBLEM TO BE SOLVED: To provide a data recording and reproducing device which can improve data reproduction rate by reducing reproduced data errors due to the defect of a recording medium, interferences between data of reproduced signals or the like. SOLUTION: The data recording and reproducing device for recording data on a recording medium, for sampling a reproduced signal from the recording data of the recording medium, and for reproducing the recording data on the basis of sampled data, has a recording means to repeatedly record data on the recording medium a prescribed number of times, a sampled data storage means for storing the sampled data in which a reproduced signal from the recording data repeatedly recorded by the recording means was sampled sequentially, and a likelihood information conversion means for converting a passmetric calculation result, calculated by a passmetric calculation means into likelihood information showing the probability of the calculation result. On the basis of likelihood information converted by the likelihood information conversion means, the passmetric calculation means performs a passmetric calculation, to decode the recording data.

22. 发明专利

JPH10124950A INFORMATION RECORDING METHOD OF OPTICAL RECORDING MEDIUM 失效
公开(公告)号：JPH10124950A
公开(公告)日：1998-05-15
申请号：JP27667496
申请日：1996-10-18
申请人： FUJITSU LTD
发明人： TANAKA TSUTOMU , IKETANI TOMONORI , ITAKURA AKIHIRO
IPC分类号： G11B11/10 , G11B7/00 , G11B7/0045 , G11B7/006 , G11B7/125 , G11B7/126 , G11B11/105
摘要： PROBLEM TO BE SOLVED: To obtain the information recording method of optical recording medium reducing an edge shift and the jitter of a recording mark in a high frequency band. SOLUTION: A signal for controlling power of laser beam is outputted to an optical head 12 by an APC 1 in accordance with a data to be recorded. At the time of forming the recording mark, a power value is modulated into four values of Pw1, Pw2, Paw and Pb, and at the time of forming a space, the power value is modulated into two values of Pae and Pb by the optical head part 12, and an optical disk is irradiated with the laser beam of the power value of the above total five values to form the recording marks and the spaces.

23. 发明专利

JPH10112030A DATA REPRODUCING DEVICE 失效
公开(公告)号：JPH10112030A
公开(公告)日：1998-04-28
申请号：JP26334696
申请日：1996-10-03
申请人： FUJITSU LTD
发明人： TAGUCHI MASAKAZU , MATSUURA MICHIO , FUJITA YOSHIHIDE , ITAKURA AKIHIRO
IPC分类号： G11B7/00 , G11B7/0037 , G11B7/005 , G11B20/10
摘要： PROBLEM TO BE SOLVED: To provide the data reproducing device in which the interchangeability for optical disks is secured, pit position recorded data and edge position recorded data of an optical disk are reproduced while conducting the digital operations empolyingthe digital values obtained by sampling the reproduced signals. SOLUTION: The reproduced signals obtained by an optical head 2 are converted into digital values in an A/D converter 15a. Based on the converted digital values, pit position recorded data are detected by a pit position detector 30. Moreover, the reproduced signals obtained by the head 2 are converted into digital values by A/D converters 15a and 15b. Based on the converted digital values, front edge and back edge maximum likelihood decoded data, which are edge position recorded, are detected by maximum likelihood detectors 16a and 16b and a synthesizer 14 synthesizes both maximum likelihood decoded data.

24. 发明专利

JPH1091965A DATA REPRODUCING DEVICE 失效
公开(公告)号：JPH1091965A
公开(公告)日：1998-04-10
申请号：JP24528896
申请日：1996-09-17
申请人： FUJITSU LTD
发明人： TAGUCHI MASAKAZU , MATSUURA MICHIO , FUJITA YOSHIHIDE , ITAKURA AKIHIRO
IPC分类号： G11B7/00 , G11B7/005 , G11B20/10 , G11B20/14 , G11B20/18 , H04L7/033 , H04L25/493
摘要： PROBLEM TO BE SOLVED: To provide a data reproducing device for an optical disk having the maximum likelihood detecting system compensating a stead edge shift and edge shift depending on a recording pattern at the time of reproduction. SOLUTION: Edge shift being not compensated fully at the time of recording of an optical disk is compensated by controlling a expected value in branch metric calculation (11) of the maximum likelihood detection recognizing a recording data pattern at the time of reproduction. Quantity of edge shift is measured based on a reproducing signal for a VFO region of an optical disk 1 (17), a expected value compensating table indicating the optimum expected value in the branch metric calculation is previously selected in accordance with the measured value (16). And a recording data pattern of a data region of the optical disk is recognized (15), the optimum expected value is decided in accordance with the recognized recording data pattern referring to the selected expected value compensating table (16), and the branch metric calculation is performed by using the optimum expected value (11).

25. 发明专利

JPH0963137A MAGNETO-OPTICAL RECORDING MEDIUM 失效
公开(公告)号：JPH0963137A
公开(公告)日：1997-03-07
申请号：JP20981395
申请日：1995-08-17
申请人： FUJITSU LTD
发明人： IZUMI HARUHIKO , TAGUCHI MASAKAZU , MATSUURA MICHIO , FUJITA YOSHIHIDE , ITAKURA AKIHIRO
IPC分类号： G11B20/12 , G11B7/003 , G11B7/007 , G11B11/10 , G11B11/105 , G11B27/30
摘要： PROBLEM TO BE SOLVED: To prevent the influence of crosstalks at the time of reproducing the ID signals of header parts. SOLUTION: The formats of the sectors in recording tracks 1 and 2, 2 and 3 adjacent to each other are changed in such a manner that the regions of the ID signals of the header parts within the one recording track and the regions (VFO parts) exclusive of the ID signals of the header parts in the other recording track are adjacent to each other and that the regions of the ID signals are not adjacent to each other. The crosstalk components from the VFO parts which are the closed patterns are small and hardly influence the ID signals at the time of the reproduction thereof. The exact reproduction of the ID signals is thus made possible.

26. 发明专利

JP2003203435A DATA REPRODUCING DEVICE 审中-公开
公开(公告)号：JP2003203435A
公开(公告)日：2003-07-18
申请号：JP2002002264
申请日：2002-01-09
申请人： FUJITSU LTD
发明人： TAGUCHI MASAKAZU , ITAKURA AKIHIRO
IPC分类号： G11B20/10 , G11B20/18 , H03M13/15 , H03M13/29 , H03M13/41 , H03M13/45
摘要： PROBLEM TO BE SOLVED: To provide a data reproducing device in which deterioration in a transfer rate is prevented as much as possible while conducting a correct data decoding. SOLUTION: The data reproducing device generates likelihood information in accordance with a repeated decoding method corresponding to a turbo coding method from sampling values obtained by sampling reproduced signals from a recording medium (110) using a prescribed period and generates decoded data based on the data bits obtained by conducting hard discrimination for the likelihood information. The data reproducing device is provided with reliability discriminating means (4772, 4773 and 4774) which are used to determine whether the data bits are obtained from the likelihood information in a prescribed range, where the reliability of the hard discrimination is not sufficient, or not and an error correction decoding means (50) which conducts an error correcting decoding for the data bits in accordance with a prescribed rule while considering the discrimination result of the corresponding reliability discriminating means and generates the decoded data. COPYRIGHT: (C)2003,JPO

27. 发明专利

JP2001176071A OPTICAL RECORDING AND REPRODUCING METHOD AND ITS DEVICE 失效
公开(公告)号：JP2001176071A
公开(公告)日：2001-06-29
申请号：JP35828699
申请日：1999-12-17
申请人： FUJITSU LTD
发明人： ITAKURA AKIHIRO
IPC分类号： G11B20/10 , G11B7/004 , G11B7/007
摘要： PROBLEM TO BE SOLVED: To provide an optical recording and reproducing method and its device by which a multi-level recording with high precision can be attained with a simple configuration. SOLUTION: Wobble grooves 11 are formed in an optical disk recording medium as a guide groove. A reference clock is generated from a wobble signal which is obtained from a light reflection signal by the wobble groove and the light emission timing of a laser is controlled to change the shift amount of each recording mark position concerning the leading edge of the reference clock in accordance with multi-level recording data. At the reproduction of data recorded by a multi-level, the peak level position of an MO signal obtained by reproducing a recording mark is detected and multi-level data are discriminated on the basis of the phase difference between the leading edge of the reference clock and the peak level position of the MO signal.

28. 发明专利

JP2000353347A MAGNETO-OPTICAL RECORDING MEDIUM, ITS RECORDING/ REPRODUCING METHOD, AND MAGNETO-OPTICAL RECORDING DEVICE 失效
公开(公告)号：JP2000353347A
公开(公告)日：2000-12-19
申请号：JP16468299
申请日：1999-06-11
申请人： FUJITSU LTD
发明人： UCHIDA AKIYOSHI , TAGUCHI MASAKAZU , ITAKURA AKIHIRO
IPC分类号： G11B11/10 , G11B11/00 , G11B11/105
摘要： PROBLEM TO BE SOLVED: To obtain an accurate reproducing signal by suppressing the adverse effect of a leaked magnetic field from an adjacent track, in the case of reproducing a recorded signal with an optical head while impressing the magnetic field. SOLUTION: The magneto-optical recording medium is constituted such that it is provided with a recording layer, a intermediate layer and a reproducing layer and that, in the case of reproducing a signal magnetically recorded on the recording layer by the irradiation of an optical beam and a magnetic field impressed from the outside, the signal so recorded is transferred to the reproducing layer through the intermediate layer. The front edge and the rear edge of a recording mark M are situated near the center of the recording mark M or the space S of the adjacent track, the mark M is recorded in the manner that the magnetizing directions of the adjacent track on both sides are different from each other. In the reproduction, the signal containing the recording mark M is reproduced in a state where the effect of the leaked magnetic field from the adjacent track on both sides of the track to be reproduced is cancelled.

29. 发明专利

JP2000242989A MAGNETO-OPTICAL RECORDING MEDIUM AND RECORDING METHOD THEREFOR 失效
公开(公告)号：JP2000242989A
公开(公告)日：2000-09-08
申请号：JP3989699
申请日：1999-02-18
申请人： FUJITSU LTD
发明人： SUGIMOTO TOSHIO , ITAKURA AKIHIRO
IPC分类号： G11B11/10 , G11B11/105
摘要： PROBLEM TO BE SOLVED: To provide a magneto-optical recording medium capable of enhancing a crosstalk characteristic and a crosswrite characteristic and, moreover, capable of a high density recording and reproducing and to provide a recording system therefor. SOLUTION: This medium is a magneto-optical recording medium 10 which is provided with multilayered films including a non-magnetic substrate 20, single- layer or multi-layer magnetic films 21 to 23 on which information are to be recorded and a dielectric protective film 32 and which is capable of a magnetic super-high resolution reproduction and this medium has a characteristic that a recording power needed for carrier saturation in the case a recording mark is long becomes higher than a recording power needed for the carrier saturation in the case the recording mark is short.

30. 发明专利

JP2000215537A METHOD AND DEVICE FOR REPRODUCING MAGNETO-OPTICAL RECORDING MEDIUM 失效
公开(公告)号：JP2000215537A
公开(公告)日：2000-08-04
申请号：JP850499
申请日：1999-01-14
申请人： FUJITSU LTD
发明人： ITAKURA AKIHIRO , TAGUCHI MASAKAZU
IPC分类号： G11B7/125 , G11B11/10 , G11B11/105
摘要： PROBLEM TO BE SOLVED: To provide a method for reproducing a magneto-optical recording medium, capable of carrying out accurate reproduction, without breakdown of balance between laser power and an applied magnetic field. SOLUTION: Information recorded in the track of a magneto-optical recording medium is read from the reflected light of the light of irradiation by having the track irradiated with the light and applying a magnetic field. One or plural prescribed sections are provided in the track, detecting information for detecting a prescribed section and pulse information prescribed in number are contained in information to be read within the specified section, a magneto-optical recording medium reproducing device stores a specified numerical value, and from the read information, detects the specified section based on detecting information (S2), counts the number of pulses contained in the information read within the detected specified section (S6), compares the counted number of pulses with the prescribed numerical value (S8), and adjusts the power of the light or the strength of the magnetic field based on the result of the comparison (S12, and S14).

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式