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51. 发明专利

JPH11273091A Optical disk 审中-公开
标题翻译：光盘
公开(公告)号：JPH11273091A
公开(公告)日：1999-10-08
申请号：JP1396799
申请日：1999-01-22
申请人： Hitachi Ltd , Hitachi Maxell Ltd , 日立マクセル株式会社 , 株式会社日立製作所
发明人： YANAGIHARA HITOSHI , MAEDA TAKESHI , NISHIDA TETSUYA , TSUCHINAGA HIROYUKI , ONUKI HIDEO , WATANABE HITOSHI
IPC分类号： G11B7/24 , G11B7/00 , G11B7/007 , G11B7/30
摘要： PROBLEM TO BE SOLVED: To reduce signals leaking to a reproducing header from its adjacent header, in a high density DVD-RAM using a same optical head as 2.6 GB DVD- RAM disk performing land/groove recording and further narrowing a track pitch about 1.25 times. SOLUTION: In a high density DVD-RAM using both grooves 2 and lands 3 as recording and reproducing regions, the symmetric center axis of the header containing each address information is deviated from the center axis of the tracks (grooves 2 or lands 3) in which an optical head runs. And, a disk is formatted in such a way that an header of either grooves 2 or lands 3 becomes invisible from the optical head.
摘要翻译：要解决的问题：为了减少从其相邻的报头泄漏到再现报头的信号，在使用与执行陆/沟槽记录的2.6GB DVD-RAM盘相同的光头的高密度DVD-RAM中，进一步缩小约1.25的轨道间距倍。解决方案：在使用槽2和焊盘3作为记录和再现区域的高密度DVD-RAM中，包含每个地址信息的标题的对称中心轴偏离轨道（槽2或焊盘3）的中心轴线光头运行。并且，盘被格式化为使得凹槽2或平面3的标题从光学头不可见。

52. 发明专利

JPH1186441A DATA DEMODULATION METHOD AND OPTICAL DISK DEVICE USING THE SAME 失效
公开(公告)号：JPH1186441A
公开(公告)日：1999-03-30
申请号：JP24067997
申请日：1997-09-05
申请人： HITACHI LTD
发明人： TSUCHINAGA HIROYUKI
IPC分类号： G11B20/10 , G11B7/00 , G11B7/005 , G11B20/14 , H03M1/00
摘要： PROBLEM TO BE SOLVED: To provide a method capable of executing the data demodulation processing by digital processing with a relatively less increase in circuit scales and lowering the operation speed necessary for decision by using sample data before and behind edge data. SOLUTION: Reproducing signals 104 are sampled by frequency bisection clock signals and two threshold levels 107, 108 are set for sample data sequence 105. The sample data sequence is decided to three levels and intermediate value data sequence 109 is obtd. Two remainder terms are computed for the intermediate value data sequence 109, by which the data of the sample data sequence 105 is decided. The data of the non-sample data sequence 105 is decided by the state transition of the sample data sequence 1-5, by which the reproduction data 112 is obtd.

53. 发明专利

JPH10269591A DEVICE AND METHOD FOR CORRECTING AF OFFSET VALUE IN OPTICAL DISK DEVICE 失效
公开(公告)号：JPH10269591A
公开(公告)日：1998-10-09
申请号：JP7574997
申请日：1997-03-27
申请人： HITACHI LTD
发明人： TSUCHINAGA HIROYUKI , MAEDA TAKESHI
IPC分类号： G11B19/04 , G11B7/09
摘要： PROBLEM TO BE SOLVED: To obtain an optimum AF(autofocus) offset value from a pre-pit mark regenerative signal even when a disk cartridge is write-protected. SOLUTION: In an optical disk device provided with the disk cartridge capable of on/off setting 103 of write-protecting, this correcting device is provided with first means 107 and second means 109 correcting a target offset value of an AF servo, and the first means 107 is provided with a function recording the correcting pattern of the target offset value and setting the optimum AF offset value from the data of the regenerative output of the recorded pattern, and the second means 109 is provided with the function setting the optimum AF offset value from the data of the regenerative output of a pre-pit pattern. Then, the correcting device detects the off setting of the write-protecting, and switches to the first means 107, and detects the on setting of the write- protecting, and switches to the second means 109 to correct the AF offset value.

54. 发明专利

JPH1031823A WAVEFORM EQUALIZING METHOD FOR OPTICAL DISK RECORDING AND REPRODUCING DEVICE 失效
公开(公告)号：JPH1031823A
公开(公告)日：1998-02-03
申请号：JP18928696
申请日：1996-07-18
申请人： HITACHI LTD
发明人： TSUCHINAGA HIROYUKI , SASAKI TORU , KONISHI YOSHIRO , MAEDA TAKESHI , KAMISADA TOSHIMASA , KAKU TOSHIMITSU
IPC分类号： G11B20/10 , G11B7/00 , G11B7/005
摘要： PROBLEM TO BE SOLVED: To enhance recording density against fluctuation of a target point of focus control even when astigmatism takes place in a laser beam by setting an optimum waveform equalizing quantity. SOLUTION: This waveform equalizing method has the following three main steps. The 1st step is to perform in such a way that the target point of focusing the laser beam is changed, and the target points of making a densest repeating signal and a coarsest repeating signal max. respectively in amplitude are measured, and a middle point between these two target points is decided as the focusing target point. The 2nd step is that under the state of focusing this middle point, the waveform equalizing quantity is changed, and a jitter of regenerative signal after equalizing its waveform is measured, and then the equalizing quantity of making the jitter min. is decided as an optimum setting value for the waveform equalization, and is stored. The 3rd step is that at the time of working the device, the stored optimum setting value for the waveform equalization is read out, and based on the read-out setting value, the waveform equalization is executed.

55. 发明专利

JPH07169055A OPTICAL DISK DEVICE AND OPTICAL DISK 失效
公开(公告)号：JPH07169055A
公开(公告)日：1995-07-04
申请号：JP31470893
申请日：1993-12-15
申请人： HITACHI LTD
发明人： SATO NAOKI , MAEDA TAKESHI , SAITO ATSUSHI , SUGIYAMA HISATAKA , SUKETA YASUSHI , TSUCHINAGA HIROYUKI , OUCHI YASUHIDE
IPC分类号： G11B7/00 , G11B7/004 , G11B7/0045 , G11B7/005 , G11B7/007 , G11B20/10
摘要： PURPOSE:To obtain an optical disk for equalizing with high accuracy and high efficiency the deterioration of a reproduced signal, which is generated due to nonlinearity at the time of recording and reproducing, and an optical disk medium suitable therefor. CONSTITUTION:Nonlinear distortion remaining in a reproduced signal from an optical disk 22 in which the front edge of a waveform is equalized by a transversal type linear equalizer 2, is corrected by a feedback equalizer 8 which utilizes the output of a discriminator 6 to obtain an output 7 of accurate mark discrimination. The tap length of the linear equalizer 2 is determined with a size ratio of a light spot and a mark and the number of tap of the feedback equalizer 8 is determined with the maximum continuous number of a zero bit in a modulation system. In the optical disk 22 are provided a plurality of training tracks for setting the equalization constant of these equalizers for every recording region. Thereby, the deterioration of a reproduced signal, which is generated due to nonlinearity at the time of recording and reproducing, is equalized with high accuracy and high efficiency, so that an optical disk device which excels in interchangeability of disks and an optical disk medium suitable therefor is obtained.

56. 发明专利

JPH06236553A RECORDING AND REPRODUCING METHOD FOR OPTICAL RECORDING MEDIUM 失效
公开(公告)号：JPH06236553A
公开(公告)日：1994-08-23
申请号：JP2239193
申请日：1993-02-10
申请人： HITACHI LTD
发明人： KIRINO FUMIYOSHI , TSUCHINAGA HIROYUKI , TODA TAKESHI , IDE HIROSHI , MAEDA TAKESHI , SAITO ATSUSHI , SUGIYAMA HISATAKA , KUGIYA FUMIO
IPC分类号： G11B7/00 , G11B7/005 , G11B11/10 , G11B11/105
摘要： PURPOSE:To optimize recording conditions by detecting position shifts in the binary signals of reproduced data obtained from evaluation patterns, analyzing the position shifts and detecting fluctuation in binary signals which are generated during a recording and reproducing process. CONSTITUTION:A detection window width Tw is used as a reference for a pulse width. The leading pulse width is 3/2 Tw and in order record 3Tw, a recording waveform in which Tw/2 pulses are successively connected with Tw/2 gaps is used. Moreover, in order to record 3Tw, pulses are set to the power and pulse width which are the values used record previous 2Tw, and a recording power is again irradiated with a Tw/2 width, through a preheat level with a Tw/2 width. Moreover, as a mark length is stretched for every Tw, a gap section and a pulse section are made into one combination and a recording is performed using the waveform to which one combination is added as Tw increases. Thus, how the amount of the maximum edge position shift varies against the change in fluctuation parameters which are generated during a recording and reproducing process is evaluated.

57. 发明专利

JPH02172026A ROTARY HEAD SYSTEM OPTICAL TAPE DEVICE 失效
公开(公告)号：JPH02172026A
公开(公告)日：1990-07-03
申请号：JP32579388
申请日：1988-12-26
申请人： HITACHI LTD
发明人： TSUCHINAGA HIROYUKI , MITA SEIICHI , IZUMIDA MORIJI
IPC分类号： G11B7/09 , G11B7/135
摘要： PURPOSE:To attain focus control by stopped-down aperture lens drive without being affected by a centrifugal force by fixing a stopped-down aperture lens to a lens support, making the entire gravity center to the rotating center of a drum and driving the lens support. CONSTITUTION:A radiated light from semiconductor lasers 5a, 5b is collimated by collimate lenses 6a, 6b, bent at a right angle by a full mirror 7 and stopped onto a tape 1 by stopped-down aperture lenses 8a, 8b provided in the vicinity of the drum outer circumference. The reflected light from the tape 1 is led to half prisms 11a, 11b by 1/4 wavelength plates 9a, 9b and polarized beam splitters 10a, 10b. Then the focus of the supports 14a, 14b and the lenses 8a, 8b is adjusted in advance onto the tape 1 and the gravity center including the supports 14a, 14b is made coincident with the turning center, the centrifugal force exerted to the lenses 8a, 8b is cancelled. Thus, the support is driven in the focus direction to drive easily the lenses 8a, 8b toward the focal direction thereby correcting out of focus.

58. 发明专利

JPH02121123A TAPE DEVICE 失效
公开(公告)号：JPH02121123A
公开(公告)日：1990-05-09
申请号：JP27296988
申请日：1988-10-31
申请人： HITACHI LTD
发明人： HARA FUMIO , MITA SEIICHI , IZUMIDA MORIJI , TSUCHINAGA HIROYUKI
IPC分类号： G11B7/00 , G11B7/003 , G11B7/0055 , G11B7/09
摘要： PURPOSE:To stably position a head on a target signal track even at a part where no tape exist on a cylinder by applying the sample servo technique. CONSTITUTION:A signal track is discontinuous at the position of a slit 8 while a cylinder 3 is revolving, and therefore the focus and tracking control operations are interrupted. Thus a sampling/holding circuit 6 issues a command to a control circuit 11 to perform the sampling/holding jobs when the spot of an optical head 2 reaches the slit 8. The circuit 11 performs the focus and tracking control jobs for the time T corresponding to the width points A and B of the slit 8 based on an index pulse 10 which is produced through the slit of an encoder set in a motor 7 which revolves a cylinder 3, for example, for each rotation of the motor 7. Thus no error signal is detected during the sample-hold operation and therefore, no tape exists. Therefore, a positioning control system is not affected despite the increase of the error signal value.

59. 发明专利

JPH0224862A TAPE POSITION CONTROL SYSTEM 失效
公开(公告)号：JPH0224862A
公开(公告)日：1990-01-26
申请号：JP17270588
申请日：1988-07-13
申请人： HITACHI LTD
发明人： TSUCHINAGA HIROYUKI , HARA FUMIO , IZUMIDA MORIJI , MITA SEIICHI , ETO YOSHIZUMI
IPC分类号： G11B15/60 , G11B7/00 , G11B7/003 , G11B7/0055 , G11B15/61
摘要： PURPOSE:To reduce burden applied to a tracking servo mechanism so that the tracking can be more stabilized by controlling the position of a magneto-optical tape by optically checking the movement of the tape in a lateral direction while the tape is run. CONSTITUTION:Optical tapes 1a and 1b are wound around a cylinder composed of an upper and lower stators 3a and 3b by means of guide rollers 2a and 2b and guided by a guide belt so that the tapes 1a and 1b can be run through normal positions. Bisected photodetectors 5a and 5b are provided on the stator 3b above the belt 4 and irradiated by light from light sources 6a and 6b. Light-transmissive section 7a and 7b are provided on the optical tapes 1 at the same interval as that between the detectors 5a and 5b. Therefore, when it is discriminated that the tapes 1 are dislocated from the normal positions from the light-transmissive sections 7a and 7b when the sections pass over the detectors 5a and 5b, the detectors 5a and 5b output a differential signal which is proportional to the dislocated quantity of the tapes 1. When the differential signal is outputted, the tapes 1 are returned to the normal positions by expanding or contracting piezo-electric elements 10a and 10b. Therefore, the burden applied to a tracking servo mechanism can be reduced and the tracking is more stabilized.

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