| Patent Number |
Title Of Patent |
Date Issued |
| RE38643 |
Optical disk having specified track pitch, and optical disk apparatus |
November 2, 2004 |
| An optical disk with sectional trapezoidal pits comprising a substrate having information recorded by a plurality of pit trains formed thereon at a specified track pitch, and a reflective layer formed on the substrate, wherein the information is reproduced by being irradiated with light |
| 5021898 |
Head positioning control method and apparatus |
June 4, 1991 |
| A head positioning control system has a speed control mode in which a head is moved by controlling a speed of said head and a position control mode in which the head is positioned onto a target track in accordance with position data of the head attained from servo data. The head position |
| 5012372 |
Head access mechanism for moving heads |
April 30, 1991 |
| An access mechanism includes a fixed generating section for generating a first magnetic field, and a carriage, having at least one head, for generating a second magnetic field so as to be moved together with the head in accordance with a propulsive force generated by interaction betw |
| 4896240 |
Magnetic disk having an index area and a limited number of radially extending servo sections |
January 23, 1990 |
| A magnetic disk, which is used for recording and reproducing data with a read/write head. The magnetic disk has an index area with an index signal recorded therein and a plurality of servo sectors formed between a plurality of data areas subsequent to the index area. Each servo sector |
| 4851933 |
Magnetic disk apparatus having magnetic head with pre-erase gap |
July 25, 1989 |
| A magnetic disk adapted for use in a magnetic disk apparatus, which has a magnetic head with a pre-erase gap and a read/write gap with a predetermined spacing therebetween, and which uses a sector servo system to position the magnetic head onto a target track of the disk, is divided |
| 4745503 |
Linear actuator for moving a recording/reading head in an access direction relative to a recordi |
May 17, 1988 |
| A linear actuator has a flat box-like carriage movable along an access direction of a disk as a recording medium, a motor coil housed and fixed in the carriage, and a permanent magnet arrangement housed and fixed in the carriage to apply a magnetic field to the motor coil. The permanent |
| 4737869 |
Magnetic disk having data area and index servo area and servo system for positioning read/write |
April 12, 1988 |
| A magnetic disk comprises a data area and a single index servo sector area embedded in the data area. The servo sector has three or more servo information pattern sections formed side by side in the direction of data tracks in the data area. The servo information pattern sections each ha |
| 4636885 |
Servo system for a magnetic disk memory having spiral tracks |
January 13, 1987 |
| Disclosed is a disk memory having a plurality of data sectors and servo sectors each provided between adjacent data sectors, spiral tracks being formed in each data sector and each servo sector. Servo information patterns are formed in each servo sector. To cause a read/write head to |
| 4631606 |
System for detecting the position of a read-write head on a disk recording medium having servo s |
December 23, 1986 |
| In order to perform a high-speed seek of a target track while the increase of area of servo sectors is minimized, each servo sector of a disk recording medium has K (an integer of 3 or more) servo patterns. The K servo patterns consist of a first servo pattern consisting of two-phase |
| 4499511 |
System for detecting position of a read-write head in seek operation on a disk memory having dat |
February 12, 1985 |
| A system for detecting a head position for use in a tracking servo system to accurately and quickly place a read-write head on a selected data track of a magnetic disk memory. The magnetic disk comprises data sectors and servo sectors embedded between the data sectors. A two-phase servo |
