Multiple actuator disk drive

• US 5,223,993 A
• Filed: 11/03/1989
• Issued: 06/29/1993
• Est. Priority Date: 11/03/1989
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Conner Peripherals Incorporated (Whitehouse Group Ltd.)
• Inventors: Sander, Charles M., Bagnell, Glade N., Squires, John P., Anderson, Kurt M.
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Garland, Steven R.
• Application Number:
  US07/431,575
• Time in Patent Office: 1,334 Days
• Field of Search: 360/48, 360/77.02-77.11, 360/78.04-78.15, 360/97.01-97.03, 360/98.01, 360/98.02, 360/98.07, 360/105, 360/106, 360/75, 360/61, 360/63
• US Class Current: 360/77.08
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G11B 5/4813 Mounting or aligning of arm assemblies, e.g. actuator arm supported by bearings, multiple arm assemblies, arm stacks or multiple heads on single arm G11B5/484 takes precedence
• CPC Class Codes: G11B 5/5578 Multiple actuators addressing the same disk, e.g. to improve data rate or access rate
• CPC Class Codes: Y10S 360/902 Storage density, e.g. bpi, tpi
• CPC Class Codes: Y10S 360/903 Physical parameter, e.g. form factor

Abstract

A multiple actuator disk drive utilizes multiple heads, associated with respective ones of multiple actuators, to read data from and write data to all tracks on the surface of a disk. The positioning of each head by the respective actuators is controlled by embedded servo-information recorded in the data tracks. The data tracks have a density of greater than 2000 tracks per inch. Utilizing two actuators provides access times which are reduced with respect to the access times provided by disk drives having a single actuator and an increased data transfer rate.

Claims

1. A disk drive, comprising:

a housing;

a disk having first and second surfaces, each surface having a plurality of concentric tracks for storing data and embedded servo information;

means for mounting said disk in said housing and for rotating said disk;

four transducers for interacting with said disk to read data and servo information from and to record data on said tracks;

first means for supporting and positioning a first one of said transducers adjacent to said first surface of said disk and for supporting and positioning a second one of said transducers adjacent to said second surface of said disk;

second means for supporting and positioning a third one of said transducers adjacent to said first surface of said disk and for supporting and positioning a fourth one of said transducers adjacent to said second surface of said disk; and

third means, responsive to said servo information, for controlling said first means to position said first one or said second one of said transducers over a selected one of said tracks on a corresponding one of said first and second surfaces, for controlling said second means to position said third one or said fourth one of said transducers over a selected one of said tracks on a corresponding one of said first and second surfaces, and for controlling the recording of data so that data is stored on the concentric tracks of said first surface until all of the concentric tracks on the first surface are filled with data and then stored on said second surface.

2. A disk drive according to claim 1, wherein said tracks have a density of at least 1500 tracks per inch.

3. A disk drive according to claim 1, wherein said housing provides a controlled environment isolated from ambient atmospheric conditions and said disk is provided in said controlled environment.

4. A disk drive, comprising:

a housing;

a plurality of disks, each disk having first and second surfaces for storing a plurality of data files in a plurality of concentric data storage tracks on said first and second surfaces, said data storage tracks having embedded servo fields and a track density of at least 1500 tracks per inch;

means for mounting said disks in said housing and for rotating said disks;

a plurality of transducers for interacting with said disks to read data and the servo fields from and to record data on said concentric tracks, said plurality of transducers comprising first and second groups of transducers, one transducer from said first group and one transducer from aid second group being associated with corresponding ones of said first and second surfaces of each of said plurality of disks;

a first actuator for supporting and positioning said first group of transducers;

a second actuator for supporting and positioning said second group of transducers; and

control means, responsive to said embedded servo fields, for (i) controlling said first and second actuators to independently position said first and second groups of transducers so that both said first and second groups of transducers read data from and record data on selected ones for all of said concentric data storage tracks on corresponding ones of said first and second surfaces, and (ii) controlling the recording of data so that for each of said disks data files are stored on the concentric tracks on said first surface until all of the concentric tracks on said first surface are filled with data and then stored on the concentric tracks of said second surface.

5. A disk drive responsive to a host computer, comprising:

a housing;

at least two hard disks, each said hard disk including a surface having a plurality of concentric tracks for storing data and servo information, said tracks having a density of at least 1500 tracks per inch;

means for mounting said hard disks in said housing and for rotating said hard disks;

first and second groups of transducers for interacting with said hard disks to read data and servo information from and to record data on said tracks, each said group of transducers including one transducer associated with each surface of each of said hard disks;

first means for supporting and positioning said first group of transducers adjacent to said surfaces of said hard disks;

second means for supporting and positioning said second group of transducers adjacent to said surfaces of said hard disks;

third means, responsive to the servo information read by said first and second groups of transducers, for

(i) controlling said first and second means to independently position said first and second transducers so that both said first and second transducers read data from and record data on selected ones of all of said concentric tracks on corresponding, respective ones of said surfaces of said disks,

(ii) controlling the reading and recording of data so that said first and second transducers are able to perform simultaneous read or write operations, and

(iii) controlling the recording of data so that, for each said disk, data is stored by filling said tracks on said first surface of the disk and then filling said tracks on said second surface of the disk; and

fourth means for electrically interfacing said third means and the host computer.

6. A disk drive, comprising:

a housing;

a plurality of hard disks D₀ through D_n, each hard disk including first and second surfaces, each said surface having a plurality of concentric data storage tracks for storing data, said data storage tracks having embedded servo information and a density of at least 2000 tracks per inch;

a spin motor mounted in said housing for rotating said hard disks;

2n transducers for interacting with said disks to read data and servo information from and to record data on said data storage tracks, said transducers comprising first and second groups of n transducers, one transducer from said first group and one transducer from said second group being associated with corresponding ones of said first and second surfaces of each of said plurality of disks;

a first actuator for supporting and positioning said first group of transducers;

a second actuator for supporting and positioning said second group of transducers; and

third means, responsive to said embedded servo information, for

(i) controlling said first and second actuators to independently position respective ones of said first and second groups of transducers so that both said first and second groups of transducers read data from and record data on selected ones of all of said concentric data storage tracks,

(ii) controlling the reading and recording of data so that one transducer in said first group of transducers and one transducer in said second group of transducers are able to simultaneously read data,

(iii) controlling the reading and recording of data so that the timing of the reading and recording of data is based on the servo information read from said disks by said transducers, and

(iv) controlling the recording of data so that data is stored by recording data on said first surface of each disk until all of the concentric tracks on said first surface of the disk are filled with data and then recording data on the said second surface of the disk until all of the data storage tracks on said second surface of the disk are filled.