公开(公告)号：JPH10208249A

公开(公告)日：1998-08-07

申请号：JP901397

申请日：1997-01-21

Applicant: SONY CORP

Inventor： HIDA MINORU ,  TOSAKA SUSUMU ,  NIWA YOSHIKATSU

IPC: G11B7/24 ,  G11B7/007 ,  G11B11/10 ,  G11B11/105

Abstract: PROBLEM TO BE SOLVED: To reduce the jitters in the time axial direction of a wobble signal corresponding to a joint part of '1' and '0' of address information. SOLUTION: The biphase modulated address information ADM is frequency modulated, and a groove part on a magneto-optical disk is wobbled corresponding to a modulated signal, and the modulated signal is recorded as a groove wobble. The groove wobble is made four waves at the time of the '1' per one bit (biphase one bit) of the address information ADM, and is made three waves at the time of the '0'. The amplitude of this groove wobble is changed according to the frequency of the modulated signal, and the tilt of the groove wobble at a zero cross point corresponding to the joint part of the '1' and '0' of the address information ADM is made not to be changed. The jitters of the wobble signal in the time axial direction corresponding to the joint part of the '1' and '0' of the address information ADM are reduced remarkably, and the address information is obtained excellently.

公开(公告)号：JPH10112078A

公开(公告)日：1998-04-28

申请号：JP28322996

申请日：1996-10-04

Applicant: SONY CORP

Inventor： HORIGOME HIDEYOSHI ,  HIDA MINORU ,  FUJITA GORO ,  TOSAKA SUSUMU

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/085 ,  G11B7/26

Abstract: PROBLEM TO BE SOLVED: To manufacture a recording medium provided with a format suitable for enlargement of capacity, speed-up of transfer rate and minglement of pit/land/groove by installing a recordable/reproducible region and a reproduction-only region of a specified constitution. SOLUTION: The recordable/reproducible region is formed by performing the cutting action for one circular track which conducts pit cutting of the servo area and the groove cutting in the data area in each unit region for one circulating track and the cutting action for one circulating track which conducts pit cutting of the service area in the unit region alternately at each circulating track. And in the reproduction-only region, so as to form a double spiral-shaped track, the moving speed of the cutting position in the radial direction of disk is made to be the moving speed in the recordable/reproducible region and further the movement of the cutting position for one circulating track is performed in the radial direction of disk at each circular track.

公开(公告)号：JPH10112051A

公开(公告)日：1998-04-28

申请号：JP28323796

申请日：1996-10-04

Applicant: SONY CORP

Inventor： HORIGOME HIDEYOSHI ,  HIDA MINORU ,  FUJITA GORO ,  TOSAKA SUSUMU

IPC: G11B7/00 ,  G11B7/004 ,  G11B7/007 ,  G11B7/095

Abstract: PROBLEM TO BE SOLVED: To provide a large-capacity recording in recording scanning for a recording medium in which circulating tracks having data area on the land and the groove are alternately formed at each circulating track by switching alternately tracking control to each center of the land and the groove at each circulating track. SOLUTION: An L/G alternate type RAM disk is constituted by being formed so that the groove GB and the land LD alternately appears every circulation with the progress of the track in the circumferential direction. A solid-line arrow SSPR which proceeds spirally with the laser spot LSP as the starting point shows the locus of the recording/reproducing scan of the laser spot LSP for an L/G alternate type RAM disk. The SSPR proceeds through the center of the groove GB or the land LD and the scan by means of the laser spot LSP proceeds in the just tracking condition for the groove GB or the land LD. By this a recording/reproducing system correspondable to large-capacity recording can be constituted.

公开(公告)号：JPH10112032A

公开(公告)日：1998-04-28

申请号：JP28323596

申请日：1996-10-04

Applicant: SONY CORP

Inventor： HORIGOME HIDEYOSHI ,  HIDA MINORU ,  FUJITA GORO ,  TOSAKA SUSUMU

IPC: G11B20/12 ,  G11B7/00 ,  G11B7/004 ,  G11B7/007 ,  G11B7/095

Abstract: PROBLEM TO BE SOLVED: To provide a recording medium which is large in capacity and high in transfer rate by forming double spiral-shaped circulating tracks having data areas on a groove and a land, setting the center-to-center interval between the land snd the groove at about one-half of the laser spot diameter. SOLUTION: A groove GA and a land LD are formed in a double spiral shape and both as data recording tracks. In the figure, the black portion of the spot corresponding to the servo area ARs is a servopit; the shaded portion of the data area ARd is the data track formed by the groove GB; and the unshaded portion is the data track formed by the land LD. Both the groove GD and the land LD are simultaneously applied with reproducing scanning using a laser spot LSP. By this, compared with the disk in which the data track is formed by either the land LD or the groove GB, the data recording capacity is enlarged more than twice and the data transfer rate is speeded.

公开(公告)号：JPH09265651A

公开(公告)日：1997-10-07

申请号：JP7458696

申请日：1996-03-28

Applicant: SONY CORP

Inventor： TSUKADA HIROSHI ,  FUJITA GORO ,  TOSAKA SUSUMU

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

Abstract: PROBLEM TO BE SOLVED: To attain the high speed access even in the case where a noncontact temperature sensor is used and to bring the effectiveness of the non-contact temperature sensor at most by providing an optical output control system (ALPC system). SOLUTION: By the ALPC system 21 which is constituted of both circuits for an optical output detecting system 22 and an optical output control system 23, the optical output of an optical head 2 is controlled in accordance with the information of estimated temperature of a magneto-optical disk D set based on a temperature time constant of the non-contact temperature sensor 36 within the prescribed time right after the magneto-optical disk D is loaded. Then, the optical output of the optical head 2 is controlled specified time later in accordance with the temperature information from the temperature sensor 36. By this procedure, the control of optical output in the transitional period up to the normal state from the time point the magneto-optical disk D is loaded, also becomes stable similarly to the control of optical output in the normal state, and the access of information data is attained from the time right after the magneto-optical disk D is loaded into the device, thereby the access speed is increased.

公开(公告)号：JPH06251403A

公开(公告)日：1994-09-09

申请号：JP4035993

申请日：1993-03-02

Applicant: SONY CORP

Inventor： TOSAKA SUSUMU

IPC: G11B7/095 ,  G11B21/10

Abstract: PURPOSE:To detect a tracking error by a differential push-pull method without being affected by the influence of the ID part of an adjacent track. CONSTITUTION:A position mutually shifted by an half track pitch is irradigted with a main beam BM and a pair of side beams BS1, BS2 respectively. The push-pull signal of the main beam BM is introduced to an arithmetic circuit 8, the push-pull signal of a pair of the side beams BS1, BS2 is introduced to the arithmetic circuit 8 through a low pass filter 9 and the differential push-pull signal is obtained.

公开(公告)号：JPH0560162B2

公开(公告)日：1993-09-01

申请号：JP9199285

申请日：1985-04-29

Applicant: SONY CORP

Inventor： NAITO MINE ,  TOSAKA SUSUMU

IPC: G11B5/02 ,  G11B11/10 ,  G11B11/105

公开(公告)号：JPH05144250A

公开(公告)日：1993-06-11

申请号：JP30222691

申请日：1991-11-19

Applicant: SONY CORP

Inventor： NAITO MINE ,  TOSAKA SUSUMU

IPC: G08B21/20 ,  G11B33/10 ,  G11B33/14

Abstract: PURPOSE:To detect and display an internal temperature rise due to the abnormality of a cooling fan or a dust filter in a magneto-optical disk drive apparatus provided with the cooling fan to which the dust filter has been attached. CONSTITUTION:When the temperature, inside an apparatus, detected by using a temperature sensor becomes a permissible temperature or higher, the output- signal level of a comparator 2 is set to 'H'. Then, an instruction signal is supplied to a drive part 1b form a judgment part 1a at a drive controller 1. The drive part 1b periodically turns on and off a transistor 3 according to the instruction signal from the judgment part 1a, and a light-emitting diode 4 is turned on and off. Thereby, it is possible to display that the temperature inside the apparatus has been raised due to the abnormality of a cooling fan or a dust filter.

公开(公告)号：JPH0489644A

公开(公告)日：1992-03-23

申请号：JP19630490

申请日：1990-07-26

Applicant: SONY CORP

Inventor： TOSAKA SUSUMU

IPC: G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To make the intensity of a magnetic field on a magneto-optical disk constant by controlling a current amt. to be supplied to a magnetic field generating means based on a heightwise position of an objective lens to be detected by a height detecting means. CONSTITUTION:The magneto-optical disk 1 possesses a signal recording layer 1a capable of vertical magnetization, and an information signal is recorded by a different direction of vertical magnetization of this signal recording layer 1a. In this case, the current amt. to be supplied to the magnetic field generating means 26 disposed opposite to the magneto-optical disk 1 is controlled by a control means for controlling the current amt. based on the heightwise position of the objective lens 8 to be driven and controlled in order to make a distance from the objective lens, which is disposed via the magneto-optical disk 1 to be opposite to the magnetic field generating means 26, to the magneto-optical disk 1 constant, as against an optical system block part 2a of an optical pickup device 2. By this method, the magnetic field intensity on the magneto-optical disk 1 is made to be constant.

公开(公告)号：JPS63316346A

公开(公告)日：1988-12-23

申请号：JP15227187

申请日：1987-06-18

Applicant: SONY CORP

Inventor： WACHI SHIGEAKI ,  YAMAMOTO SHIRO ,  TOSAKA SUSUMU

IPC: G11B5/02 ,  G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To hold a permanent magnet at a prescribed position without always allowing control current to flow after the inverse operation of the permanent magnet by obtaining control current to be applied to a holding coil for holding the permanent magnet based on a magnetic field detecting output consisting of a rotational angle error of the permanent magnet. CONSTITUTION:In a magnetic field impressing device 2 consisting of a magnetic field detecting means 8 for detecting the rotational angle error of the permanent magnet 4 and sending a magnetic field detecting output SH, the holding coil 6 for holding the magnet 4 in a prescribed direction corresponding to recording or erasing operation and kick coil 7 for starting the rotation of the magnet 4, the holding coil 6 is controlled at its drive by a drive controlling means 30A provided with an absolute circuit 34 for sending the absolute output SH1 of a magnetic field detecting output SH, an inverse circuit 36 for inversing the code of the output SH1 in accordance with recording or erasing operation. Control current IV10 to be applied to the coil 6 for holding the permanent magnet 4 is obtained based on the magnetic field detecting output SH consisting of the rotational angle error of the permanent magnet 4.