公开(公告)号：JPH08212579A

公开(公告)日：1996-08-20

申请号：JP1518595

申请日：1995-02-01

Applicant: SONY CORP

Inventor： ICHIMURA ISAO ,  MAEDA FUMISADA ,  WATANABE TOSHIO ,  OSATO KIYOSHI ,  YAMAMOTO KENJI

IPC: G11B11/10 ,  G11B7/09 ,  G11B7/135 ,  G11B11/105

Abstract: PURPOSE: To suppress the occurrence of spherical aberration due to dispersion in thickness of a solid immersion lens and a magneto-optical disk. CONSTITUTION: The magneto-optical disk 1 is irradiated with light converged by an objective lens 41 through a plate 42 and a solid immersion lens 43. A holder 44 holding the objective lens 41 and the plate 42 is focus-controlled and tracking-controlled respectively by a focus actuator 45 and a tracking actuator 46. Further, an SIL actuator 48 is driven corresponding to the change in capacity of a capacitor formed between the holder 44 and the holder 47, and it is controlled so that an interval between the holders 47 and 44 becomes a fixed value.

公开(公告)号：JPH0438633A

公开(公告)日：1992-02-07

申请号：JP14252290

申请日：1990-05-31

Applicant: SONY CORP

Inventor： FUKUMOTO ATSUSHI ,  OSATO KIYOSHI

IPC: G11B7/007 ,  G11B7/09 ,  G11B7/24

Abstract: PURPOSE:To allow tracking control by using an optical system of the same space cut-off frequency as heretofore while having the recording tracks of the density equivalently twice larger than the conventional density by forming the tracks by shifting the beginning end of the prepattern which follows the terminal of the preceding prepattern by 1/2 the track pitch. CONSTITUTION:Spiral guide grooves G are parted at every one round on the same radius of the disk, by which plural pieces of the guide grooves Gi, Gj are formed. These grooves are formed by shifting the beginning end Gjs of the guide groove by 1/2 the track pitch p from the terminal Gif of the preceding guide groove. The groove parts and 'partition' parts or the 'partition' parts and the groove parts are, therefore, respectively continued in the track direction in the parted regions. The recording tracks of the density equivalently twice larger than heretofore are formed in this way. The tracking control by using the optical system of the same space cut-off frequency as heretofore is thus possible.

公开(公告)号：JPH03100922A

公开(公告)日：1991-04-25

申请号：JP23560789

申请日：1989-09-13

Applicant: SONY CORP

Inventor： NAKAO TAKASHI ,  OSUE TADASHI ,  KUMAI SATOSHI ,  OSATO KIYOSHI ,  MIYOSHI HIROSHI

IPC: G11B7/00 ,  G11B7/003

Abstract: PURPOSE:To prevent crosstalks by widening the spacing between a track group by multispot scanning and a track group by the next multispot scanning, thereby preventing the adjacency of the tracks recorded with different heads. CONSTITUTION:Recording is so executed that the spacing between the track group TA formed by one time of scanning of an optical head A and the track group TB formed by one time of scanning of an optical head B attains pitch PN wider than the track pitch Pt with an optical tape recorder having two pieces of the heads A, B which output 5 beam spots. The pitch PN is set at about the width at which the sufficient pitch spacing remains between the adjacent tracks even if, for example, the meandering of the tracks arises. The crosstalks are thereby prevented and the accuracy requirement between the two heads A and B is relieved.

公开(公告)号：JPH0354737A

公开(公告)日：1991-03-08

申请号：JP19088189

申请日：1989-07-24

Applicant: SONY CORP

Inventor： OSATO KIYOSHI ,  UDAGAWA TOSHIKI ,  OKADA HITOSHI

IPC: G11B7/095 ,  G11B7/09

Abstract: PURPOSE:To expand the pull-in range and the valid control range of tracking servo control by providing a signal forming circuit part where a signal obtained from a first signal which shows a tracking state and a second signal which substantially has the phase difference of 90 deg. from the first signal is obtained as a tracking error signal. CONSTITUTION:An optical recording and/or reproducing device is constituted of the signal forming circuit 40 where the first signal S1 showing the tracking state of a recording track part on the disk-like recording medium of a light beam and the second signal S2 substantially having the phase difference of 90 deg. from the signal S1 are obtained based on a detection output obtained from a light detection part 14 and a signal S3 obtained according to a formula I, provided as (K>=1), is obtained as the tracking error signal. Thus, the pull-in range to a servo control state and the following valid control range is set by an inclined part in a waveform which is nearly a saw-tooth-wave and the tracking servo control is expanded.

公开(公告)号：JPH02282930A

公开(公告)日：1990-11-20

申请号：JP10420189

申请日：1989-04-24

Applicant: SONY CORP

Inventor： OSATO KIYOSHI

IPC: G11B7/09 ,  G11B7/095 ,  G11B7/14

Abstract: PURPOSE:To form a good quality error signal by forming a tracking error signal based on a difference detected by photodetecting element between main- and sub-beams forming two beam spots at a specified interval on a recording medium. CONSTITUTION:The two light beams emitted from a semiconductor laser part 10 is split into the main beam and at least one subbeam respectively by a grating 22. The split beams are incident upon a disk D via a beam splitter 24 and an objective lens 12 or the like and reflected receiving modulation by a recording track or the like and then changed in the axial direction by the beam splitter 24 to be entered into the photodetector part 14 via a light receiving lens 28. In the detector part 14, the main- and sub-beams are detected respectively by real bisected photodetecting elements, and their outputs are added and deducted by a signal forming circuit 40, where a difference output signal becomes as the tracking error signal St. By this method, even when the recording medium is inclined to an optical axis, the good quality error signal excluding a DC offset component is obtained.

公开(公告)号：JPS63237269A

公开(公告)日：1988-10-03

申请号：JP7283187

申请日：1987-03-25

Applicant: SONY CORP

Inventor： KOBAYASHI SEIJI ,  OSATO KIYOSHI

IPC: G11B7/08 ,  G11B7/085 ,  G11B21/08

Abstract: PURPOSE:To securely count the number of traversed tracks by operating a following signal generation circuit by track across information which can periodically be obtained and counting the number of traversed tracks through the use of the following signals. CONSTITUTION:A two phase detection signal forming circuit 11 receives tracking traverse information STRK, and transmits a first phase detection signal vP and a second phase detection signal vQ to multiplication circuits 12 and 13 as track traverse informa tion, whereby the multiplication outputs vA and vB are subtracted in a subtraction circuit 13. The subtraction output vC is converted into the control signal VCON of a DC voltage by an error signal forming circuit 15, and is given to a two phase follow ing signal generation circuit 16. Said circuit 16 generates a first phase following signal vOP and a second phase following signal vOQ whose phases mutually differ by 90 deg., and gives them to the circuits 12 and 13. Consequently, the value of the output vC has the phase of a difference DELTAphi between the phases of the signals vP and vQ and those of the signals vOP and vOQ. The circuit 15 controls the oscillation frequency of the circuit 16 so that the difference DELTAphi becomes 0. The signals vOP and vOQ are given to the traversed track counting circuit 17 and the number of traversed tracks is obtained.

公开(公告)号：JPS6247849A

公开(公告)日：1987-03-02

申请号：JP18788885

申请日：1985-08-27

Applicant: SONY CORP

Inventor： HENMI FUMIAKI ,  YAMAGAMI TAMOTSU ,  OSATO KIYOSHI

IPC: G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To improve the continuousness of signals by performing the erasion and recording to the same track within a track reproduction period and at the same time starting the next recording from an area that is already recorded and performing the rerecording, erasion and recording in the same time as reproduction. CONSTITUTION:The information signal recorded through an input terminal 1 is processed by a digital processing circuit 15. Then the digital signal containing a prescribed number of bits per frame is supplied to a buffer memory 16. The signal is written to the memory with the clock (f) obtained by giving 1/2 division 18 to the clock 2f of an oscillator 17 and then read out with the clock 2f. Then the time base is compressed down to half. The signal read out of the memory 16 is applied to a laser drive circuit 19 and an optical head device 20 is driven to irradiate a photomagnetic disk 1. Then each circuit is controlled by a system controller 30 and the erasion and the recording are carried out to the same track within a reproduction period. The next recording is started from an area that is already recorded and the rerecording is carried out in the same time as the reproduction. Thus the continuousness of signals is improved.

公开(公告)号：JPS61250845A

公开(公告)日：1986-11-07

申请号：JP9281585

申请日：1985-04-30

Applicant: SONY CORP

Inventor： OSATO KIYOSHI ,  TERAYAMA YASUNARI ,  FUKUMOTO ATSUSHI

IPC: G11B7/09 ,  G11B7/095

Abstract: PURPOSE:To eliminate a DC fluctuation component of a tracking error signal by applying nonreflection coating to a beam incident part of a header so that a side beam made incident to the header other than a laser chip of a semiconductor laser device is not reflected and made incident in a recording medium again. CONSTITUTION:The nonreflecting coating 12 is applied to a face of the header 11 in which the side beam 2 is made incident via a collimator lens 2. Thus, even when the side beam is made incident to a part applied with the nonreflection coating 12 of the header 11, the reflection is suppressed and not almost made incident in the collimator lens 2. In this case, it is not required to apply the nonreflection coating 12 over the entirely lateral area of the opposed face of the header 11 with the collimator lens 2 or the coating can be provided only to a part at the lower part of the laser chip 10 in which the side beam is made incident.

公开(公告)号：JPS6124033A

公开(公告)日：1986-02-01

申请号：JP14576884

申请日：1984-07-13

Applicant: Sony Corp

Inventor： FUKUMOTO ATSUSHI ,  OSATO KIYOSHI ,  OKA MICHIO

IPC: G11B7/09 ,  G11B7/095 ,  G11B7/135

CPC classification number: G11B7/0956 ,  G11B7/0903 ,  G11B7/1353 ,  G11B7/1381

Abstract: PURPOSE: To obtain a tracking error signal of a zero-order beam unchanged by a change in a tangential skew angle to a recording medium by providing a light shield for a reflected beam of a recording medium to both side beams between a semiconductor laser element and a diffractive grating.
CONSTITUTION: The light shield 11 passing a center beam La and shutting both side beams Lb, Lc, in the reflected beam passing through a diffractive grating 3 toward a semiconductor laser element 1 from a recording medium 6 is provided between two pairs of positive lenses 9, 10 and 9, 10 between a collimator lens 2 and the diffractive grating 3. That is, the light absorbing property or the light irregular reflecting property are given to a face of the light shield plate 11 toward the diffractive grating 3 so that the center beam La passes through the center hole 11a and both the side beams Lb, Lc are shut by the light shield plate. Thus, a tracking error signal of the zero-order beam of a head OH unchanged by a change in a tangential skew angle to the recording medium is obtained.
COPYRIGHT: (C)1986,JPO&Japio

Abstract translation: 目的：通过为记录介质的反射光束提供一个用于记录介质的反射光束的光屏蔽，在半导体激光元件与半导体激光器元件之间的两侧光束上，通过与记录介质的切向偏斜角度的变化来获得零级光束的跟踪误差信号， 衍射光栅。 构成：在两对正透镜9之间设置有通过中心光束La并且将通过衍射光栅3的反射光束中的两侧光束Lb，Lc从记录介质6朝向半导体激光元件1关闭的遮光罩11 在准直透镜2和衍射光栅3之间具有10和9,10。也就是说，将光吸收特性或光不规则反射特性赋予遮光​​板11的朝向衍射光栅3的面，使得中心 光束La穿过中心孔11a，并且两个侧光束Lb，Lc被遮光板关闭。 因此，通过与记录介质的切线偏斜角度的变化，头部OH的零级波束的跟踪误差信号被获得。

公开(公告)号：JPS6124032A

公开(公告)日：1986-02-01

申请号：JP14576784

申请日：1984-07-13

Applicant: Sony Corp

Inventor： FUKUMOTO ATSUSHI ,  OSATO KIYOSHI ,  OKA MICHIO

IPC: G11B7/09 ,  G11B7/135

Abstract: PURPOSE:To obtain a tracking error signal of a zero-order beam unchanged by a change in a tangential skew angle to a recording medium by specifying an optical path difference between a center beam and both side beams of a reflected beam of a recording medium. CONSTITUTION:When a straight line connecting the center beam La and the side beams Lb, Lc toward a semicondutor laser beam is nearly orthogonal to an active layer 1a of thd semiconductor laser element 1, the optical path length between the Lb of both the side beams Lb, Lc and the center beam La is selected to lambda/4,(2n+1), where n=0, 1, 2, 3,.... Then the light intensity 1A at a point A is expressed as 1A=const, no interference takes place between the center beam La and one beam Lb of both the side beams and the level of the tracking error signal is unchanged in the conversion of the tangential skew angle. Further, since the beam Lc is reflected irregularly at a heat sink 8, there is no possibility of interference with the center beam La.

Abstract translation: 目的：通过指定记录介质的反射光束的中心光束和两侧光束之间的光程差，通过与记录介质的切线偏斜角度的变化来获得零级光束的跟踪误差信号。 构成：当将中心光束La和侧光束Lb，Lc连接到半导体激光束的直线几乎与半导体激光元件1的有源层1a正交时，两个侧光束的Lb之间的光路长度 Lb，Lc和中心光束La被选择为λ/ 4，（2n + 1），其中n = 0,1,2,3 ...，然后点A处的光强度1A表示为1A = const，在两束侧光束的中心光束La和一个光束Lb之间不发生干涉，并且跟踪误差信号的电平在切向偏斜角的转换中不变。 此外，由于光束Lc不规则地反射在散热器8处，所以不可能干涉中心光束La。