公开(公告)号：JPH06318348A

公开(公告)日：1994-11-15

申请号：JP4738893

申请日：1993-02-12

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO ,  SAITO TAKEHIKO

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/125 ,  G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To form a recording pit in an optimum shape by varying the irradiation output of a laser beam according to the interval from the time when the preceding formation of the recording pit by an optical head just ended to the time when the formation of the next recording pit started. CONSTITUTION:An LD control circuit 4 is provided with a divider circuit 41 dividing a reference voltage V0 at a prescribed voltage division ratio, an amplifier 43 amplifying the obtained divided potential and generating a prescribed first recording voltage V1 and the amplifier 42 amplifying the second divided potential obtained in the divider circuit 41 and generating a second recording voltage V2. Further, the circuit 4 is provided with a switch 45 switching the first recording voltage V1 by a second pulse line 27 and the switch 44 switching the second recording voltage V2 by a first pulse line 25. A recording signal 47 is obtained by the outpus of the switches 44, 45 to be supplied to the optical head. Since a disk is preheated by the second pulse line of the first recording voltage V1 for a preheat interval before the recording of the second recording voltage V2 by the first pulse line, the temperature of the disk at the time of starting the recording is adjusted to a required temperature, and the recording by the first pulse line is performed under a stable condition.

公开(公告)号：JPH06169581A

公开(公告)日：1994-06-14

申请号：JP32102792

申请日：1992-11-30

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO ,  NAKAGAWA TOMIHIRO

IPC: H02N2/00

Abstract: PURPOSE:To provide a small-sized rotation driving device capable of shifting in the radial direction perpendicular to the rotational shaft with a small number of components. CONSTITUTION:A stator 1 is fixed to a fixing base 9 through a bearing housing 7, and a rotational shaft 4 is set freely in the bearing housing 7 so as to be rotatable and shiftable in radial direction, and a rotor 2 is fixed to this rotational shaft so that it may pressure-weld on the stator 1.

公开(公告)号：JPH06150364A

公开(公告)日：1994-05-31

申请号：JP31663992

申请日：1992-10-30

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO

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

Abstract: PURPOSE:To record data with a high density, to suppress the crosstalk and to exactly reproduce the data. CONSTITUTION:At the time of a recording mode, an optical device 64 is arranged between a collimator lens 63 and a beam splitter 65 and a two-dimensional super-high resolution beam is generated. A spot small in diameter is formed on a magneto-optical disk 67 by means of the super-high resolution beam and data are recorded with a high density. At the time of a reproducing mode, the optical device 64 is detached out of the optical path, a spot large in diameter is formed on the magneto-optical disk 67 by means of an ordinary light beam and the data are reproduced. Consequently, the crosstalk due to a side lobe when the super-high resolution beam is used, is prevented.

公开(公告)号：JPH06138418A

公开(公告)日：1994-05-20

申请号：JP30951192

申请日：1992-10-23

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO

IPC: G02B27/58 ,  G11B7/135 ,  G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To realize an optical element whose production and adjustment of assembly are facilitated. CONSTITUTION:A recessed part having a triangular cross section is formed on a plane parallel plate 31. A projected part having triangular cross section is formed on the plane 50 of a plane parallel plate 32. Since a light beam transmitted through the vicinity of the ridgeline 43 of the plate 31, out of laser beams emitted from a laser diode 21, is refracted to the outside, a zone where the light beam does not exist in substance is formed in a zone A.

公开(公告)号：JPH05101599A

公开(公告)日：1993-04-23

申请号：JP28920191

申请日：1991-10-08

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO ,  FUJII HIROSHI

IPC: G11B23/28

Abstract: PURPOSE:To eliminate prevent the other recording area from being erroneously erased when a rewriting of optional information recording area is performed in a tape cassette wherein a magnetic tape having the plural recording areas corresponding to a required format is housed. CONSTITUTION:Plural discriminating holes 4, 5 corresponding to the plural recording areas of the tape are made on a cassette casing 3. A discriminating member 6 to open/close these discriminating holes 4, 5 is arranged inside the cassette casing 3. Combinations of the recording and erasing of each recording area of the tape are selected by this discriminating member 6 in accordance with the combination of the closed discriminating holes 4, 5.

公开(公告)号：JPH04167782A

公开(公告)日：1992-06-15

申请号：JP29213390

申请日：1990-10-31

Applicant: SONY CORP

Inventor： NISHIKATA YUTAKA ,  YAMASHITA KEITARO

IPC: H04N5/7826 ,  G11B5/008 ,  H04N5/782 ,  H04N9/80 ,  H04N9/81

Abstract: PURPOSE:To use the identical rotary drum to record and reproduce a signal for an HDTV system proposed by Japan and the European countries by turning an effective recording area length to be 134OH. CONSTITUTION:Two channels by rotary magnetic heads 36 and 46 (36' and 46') are simultaneously recorded, and the two channels by this pair of heads are turned to be one segment, and a video signal by one frame is recorded to four segments (=eight tracks). At this point the sum of the effective recording area on a magnetic tape 38 where the video signal by one frame and a PCM audio signal are recorded is turned to be 134OH by the horizontal scanning cycle conversion. Thus, the identical rotary drum 37 can be used in both Japanese and European system video tape recorders.

公开(公告)号：JPH0479071A

公开(公告)日：1992-03-12

申请号：JP19419190

申请日：1990-07-23

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO ,  OKAMOTO ICHIRO

IPC: H04N5/60 ,  G11B20/00 ,  G11B20/10 ,  G11B20/12 ,  H04N5/91

Abstract: PURPOSE:To discriminate a sound signal recorded in an objective sound channel by providing a recording means for sound signals of N channels, a control means for performing after-recording and an information adding means for recording information for showing the after-recording. CONSTITUTION:At the usual recording time, in areas corresponding to 1ch-4ch of a video tape 10, their respective after-recording information AF is recorded by setting, for instance, a value X of a bit 0 of one symbol as 0 as the after- recording information AF by a system controller 18. Then, at the time of recording two channel stereo sounds by after-recording them respectively in sound channels of 3ch and 4ch of the tape recorded with sounds of 3-1 system, the after-recording sound signals are written in corresponding areas in a RAM 3 by the system controller 18, and at the same time, the after-recording information AF is recorded in the area corresponding to 3ch and 4ch of the video tape 10. By this method, a channel recorded with an usual sound signal of the recording medium and a channel recorded with a sound signal by after- recording are discriminated.

公开(公告)号：JPH043355A

公开(公告)日：1992-01-08

申请号：JP10376290

申请日：1990-04-19

Applicant: SONY CORP

Inventor： SAITO TAKEHIKO ,  YAMASHITA KEITARO

IPC: G11B15/61

Abstract: PURPOSE:To optimize the tape deformation form in the vicinity of a recording and reproducing head by providing a rotating body, which is rotated to a pair of upper and lower fixed drums, with spiral groups and providing a discharge part, through which air in the internal space is discharged to the outside, on the face opposite to the face, to which the recording and reproducing head is attached, of the rotating body. CONSTITUTION:Pump-out spiral groups 11 and 12 are formed in outer peripheral upper and lower face parts 4a and 4b of a rotating body 4, and the group 12 of the lower face part 4b is cut away in a partial face 4b1 to which a magnetic head 7 is fixed, and the number of groove parts 11a of the group 11 formed on a partial face 4a1 of the upper face part 4a corresponding to the opposite side is made larger than that in the other partial faces. The groove depth may be reduced without increasing the number of groove parts. By this constitution, air in the internal space generated by fixed drums 1 and 2 is discharged to the outside and the tape is run in the floating state when the rotating body 4 attached to the head 7 is rotated at a high speed by a direct drive motor.

公开(公告)号：JPH03122861A

公开(公告)日：1991-05-24

申请号：JP26168689

申请日：1989-10-06

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO ,  SHINDO NORIO ,  SAITO TAKEHIKO

IPC: G11B15/61

Abstract: PURPOSE:To realize such a phase relation that a head abutment, etc. become optimum by all of heads by arranging spiral grooves at equal intervals and deciding the number of grooves so that the positional relation of the plural heads and grooves is arranged in an equal phase state without exception. CONSTITUTION:Spiral grooves are arranged at equal intervals, plural heads 6 are provided on a drum 1 as well and the number of grooves is decided so that the positional relation of these each head and groove is arranged in an equal phase state without exception. All of heads 6 are held in the same phase relation as that of the groove by deciding the number of grooves so as to become the multiples of 4, such as N=4, 8, 12..., in the case of the head 6 being fitted in four pieces at the interval of 90 deg., for example. Thus a head abutment, etc., can be made optimum.

公开(公告)号：JPH03113771A

公开(公告)日：1991-05-15

申请号：JP24718589

申请日：1989-09-22

Applicant: SONY CORP

Inventor： YAMASHITA KEITARO ,  SHINDO NORIO ,  SAITO TAKEHIKO

IPC: G11B15/61

Abstract: PURPOSE:To reduce the variation of blowoff pressure corresponding to the number of grooves with a simple working method by forming a boundary between a spiral-shaped groove and a part other than the groove by nearly linear boundary lines with a first and a second angles, and determining each angle as it is prescribed. CONSTITUTION:The spiral-shaped groove is formed on the bottom surface of a rotary drum 11, and the spiral-shaped groove is constituted of a land 12 and the groove 13. Then, the values of the groove angles beta1, beta2 of two logarithmic spiral curves 14, 15 forming the boundary of the groove 13 to the land 12 at both sides are set up so as to be in the relation of beta1