公开(公告)号：JPH0628790A

公开(公告)日：1994-02-04

申请号：JP17984392

申请日：1992-07-07

Applicant: SONY CORP

Inventor： NISHIDA NORIO ,  SUZUKI YASUAKI

IPC: G11B21/08

Abstract: PURPOSE:To provide a head position controller capable of operating a seek control having less accoustic noise without deteriorating the servo characteristic of an on-track control. CONSTITUTION:At the time of a seek mode for moving a magnetic head 3 to the target track of a magnetic disk 2, a switch 10 is opened by a switch controlling section 12 and the supplying of a pulse width modulation signal from a second pulse width modulation circuit 9 to an adder 11 is terminated. Then, a voice coil motor driving circuit 13 is driven only by the pulse width modulation signal of a sampling frequency higher than an audible frequency from a first pulse width modulation circuit 8 and a head arm 15 is moved to a target track position.

公开(公告)号：JPH0612798A

公开(公告)日：1994-01-21

申请号：JP19130892

申请日：1992-06-26

Applicant: SONY CORP

Inventor： NISHIDA NORIO ,  HIROSE TOSHIHIKO

IPC: G11B5/596 ,  G11B21/10

Abstract: PURPOSE:To detect head position with high accuracy by digital arithmetic processing. CONSTITUTION:In accordance with a timing signal generated by a timing generating part 11 based on the regenerative signal of a servo pattern at a magnetic disk 1 by a head 3, the signal level of a servo signal at tracking control is detected by a signal level detecting part 12 and digitized by an A/D converter 13 of parallel comparing type, then average is calculated for every four samples by an averaging circuit 14. Then, head position data is calculated by a CPU based on average data obtained by the averaging circuit 14.

公开(公告)号：JPH05114242A

公开(公告)日：1993-05-07

申请号：JP30232891

申请日：1991-10-22

Applicant: SONY CORP

Inventor： HIROSE TOSHIHIKO ,  NISHIDA NORIO ,  SUZUKI YASUAKI

IPC: G11B20/12 ,  G11B21/10

Abstract: PURPOSE:To prevent a servo address from being detected erroneously in a seek operation or the like in which a head is passed through the boundary of an adjacent servo address by a method wherein a gray code on which a gray code at two bits each has been changed to three bits is used and a dummy bit is added to a gray-like code and recorded. CONSTITUTION:A method wherein a dummy bit is added to a gray-like code in a piece of servo address information in a sector servo pattern and the dummy bit is recorded is used. For example, each code word is a code which has been coded additionally while a alternating binary code (a gray code) in which the Hamming distance between two adjacent quantization levels is set to 1 is used as a piece of source data. For example, continuous gray codes of two bits, i.e., (00), (01), (11), (10) are converted from 2 to 3; after that, gray codes which have been converted into 3-channel bits (001), (010), (100), (111) are used; a dummy bit Db is added to the gray codes and recorded.

公开(公告)号：JPH0434778A

公开(公告)日：1992-02-05

申请号：JP14055590

申请日：1990-05-30

Applicant: SONY CORP

Inventor： NISHIDA NORIO ,  NAKANO KATSUHIRO

IPC: G11B21/10 ,  G11B5/596 ,  G11B7/09 ,  G11B19/00 ,  G11B19/02 ,  G11B19/28 ,  G11B21/08

Abstract: PURPOSE:To reduce the energy consumption of a servo signal processing circuit by stopping the supply of a clock signal during a signal processing to the servo signal processing circuit is not performed or supplying the clock signal with decreased frequency. CONSTITUTION:To a servo signal processing circuit 10 processing the signal for servo reproduced intermittently form a disk-shaped recording medium 5, the supply of a clock signal CLK is stopped or the clock signal with decreased frequency is supplied during the signal processing is not performed. When the supply of the clock signal CLK is stopped or a clock signal CLD with decreased frequency is supplied, the servo signal processing circuit 10 maintains data as the result of the signal processing, but stops signal processing operation. Thus, the energy consumption of the servo signal processing circuit 10 can be reduced.

公开(公告)号：JPH10228722A

公开(公告)日：1998-08-25

申请号：JP3353297

申请日：1997-02-18

Applicant: SONY CORP

Inventor： NISHIDA NORIO

IPC: G11B19/28

Abstract: PROBLEM TO BE SOLVED: To perform rotational servo control of the CAV(constant angular velocity) system at low cost and with high accuracy. SOLUTION: A fine clock mark signal formed at fixed intervals in a wobbling groove of a disk D is extracted, and a period of a timing signal corresponding to this fine clock mark signal is counted. Then, the rotation of a spindle motor 6 is controlled with a difference value between this count value and a target value corresponding to a target revolving speed of the spindle motor 6 as a spindle motor error signal.

公开(公告)号：JPH0877733A

公开(公告)日：1996-03-22

申请号：JP20783794

申请日：1994-08-31

Applicant: SONY CORP

Inventor： NISHIDA NORIO

IPC: G11B11/10 ,  G11B7/085 ,  G11B11/105 ,  G11B21/08

Abstract: PURPOSE: To obtain a seek control device and a seek control method capable of reducing the seek time. CONSTITUTION: A speed detecting part 43 calculates the speed of a carriage and a speed/locus calculating part 44 calculates a target speed by a positional error from a positional error detecting part 41. An operation part 46 outputs a servo signal by calculating the difference between the target speed and the speed. A D/A converter 22 executes the D/A conversion of a servo signal to drive a linear motor 27. When the carriage reaches the vicinity of a target track, an operation part 45 calculates the difference between the positional error and the speed to supply it to a D/A converter 22. Consequently, the moving speed of the carriage is deccelerated. When the carriage reaches the target track, a tracking error detecting part 31 calculates a tracking error and a phase is compensated by a phase compensating part 32 to be outputted. A D/A converter 20 drives a galvano actuator 26 based on the tracking error and then a tracking servo is performed.

公开(公告)号：JPH06282863A

公开(公告)日：1994-10-07

申请号：JP9537093

申请日：1993-03-29

Applicant: SONY CORP

Inventor： NISHIDA NORIO

IPC: G11B7/095 ,  G11B20/12 ,  G11B20/18

Abstract: PURPOSE:To control tracking positively even if a large defect exists by compensating a tracking error signal which is formed by reproducing a servo pattern based on a defect signal. CONSTITUTION:An optical disk device 30 reproduces an optical disk 1 where servo patterns a, b, and c in sample format are formed. It Is provided with an optical block 4 for outputting a reproduction signal RF whose signal level changes according to reflection light by receiving the reflection light by applying optical beams L1 to the optical disk 1 and reproduction signal processing circuits 15-18 for outputting reproduction data PDT by binary-coding the sicjnal level of the reproduction signal RF in reference to a reference clock CLK with a shorter period than that for forming the pits of the servo patterns a, b, and c, thus obtaining the comparison result between the reproduction data PDT and the reference pit pattern while reproducing the servo patterns a-c. When both patterns do not match, it is judged that a defect exists at the region for forming the servo patterns a-c, a defect signal FL is output by detection circuits 31 and 33, and then a tracking error signal is compensated based on the defect signal FL.

公开(公告)号：JPH06259794A

公开(公告)日：1994-09-16

申请号：JP6612193

申请日：1993-03-02

Applicant: SONY CORP

Inventor： NISHIDA NORIO ,  OKAWA YOSHIHIRO

IPC: G11B7/095 ,  G11B20/12 ,  G11B21/10 ,  G11B27/10

Abstract: PURPOSE:To surely attain a tracking control and focus control by preferentially processing an interruption signal having a frequency synchronized with a segment over an interruption signal having a frequency synchronized with a sector. CONSTITUTION:In the disk device 1, a discoid recording medium 2 is formed with sectors SC by dividing radially a recording area, and moreover, segments SG are formed by dividing radially each individual sector. Servo information in a unit of the segments SG is detected from a light receiving result RF in response to a generating means 14 for generating the interruption signal i1 in synchronization with the segments SG and generating the interruption signal i2 in synchronization with the sectors SG and the signal i1, and servo information in a unit of the sectors SC is detected from the reult RF in response to the signal i2, and based on both of the servo information, objects 6, 7 and 8 are controlled by a control circuit 17. The signal i1 is received preferentially to the signal i2 by the circuit 17 to control the object 8 with the 1st servo information. Thus, the tracking control and focus control can surely be performed.

公开(公告)号：JPH0636307A

公开(公告)日：1994-02-10

申请号：JP21339992

申请日：1992-07-17

Applicant: SONY CORP

Inventor： NISHIDA NORIO ,  KOBAYASHI SHOEI ,  SHIMIZU YASUNARI

IPC: G11B7/09

Abstract: PURPOSE:To easily cancel the tracking offset of an optical disk driving device. CONSTITUTION:A timing generating circuit 48 generates a sampling signal S based on reflected light from a part having no pits of a frame synchronizing pattern on an optical disk, and a sampling and holding circuit 42 samples and holds a tracking error signal TE1 by the sampling signal S, and this sampled and held signal is used to cancel the tracking offset.

公开(公告)号：JPS63253540A

公开(公告)日：1988-10-20

申请号：JP8756487

申请日：1987-04-09

Applicant: SONY CORP

Inventor： HORIGOME HIDEYOSHI ,  NISHIDA NORIO ,  KAWAKUBO SHIN

IPC: G11B7/085

Abstract: PURPOSE:To stabilize the track shifting of an optical disk in a short time, by detecting the zero crossing point when an optical beam crosses each address signal recording area of plural adjacent tracks by means of a tracking error detecting means. CONSTITUTION:When track shifting is started, the output B of a system controlling circuit 30 becomes 'H' and a switch 43 is connected to S side. In addition, tracking error signals are supplied to a zero crossing detecting circuit 34 from a subtractor 25. When the scanning locus Lop of an optical beam passes the final servo byte (3n) of a sector and the time of the quantity of several bytes has passed, the signal B of the system controlling circuit 30 becomes '0' and the switch 43 is switched to its central contact. Analog push-pull tracking signals supplied to the zero crossing detecting circuit 34 from a subtractor 41 and an original zero crossing point is accurately detected at the intermediate point between two adjacent tracks 1i and 1j.