US 5,901,010 A · Magnetic disc recording system employing two stage actuators for simultaneous accesses through multiple recording heads

Abstract

A magnetic disc storage system employing two stage actuators for simultaneously positioning recording heads over the top and bottom surfaces of the disc is disclosed. The recording heads are fastened to a distal end of respective top and bottom load beams. A base end of the load beams is connected to a voice coil motor (VCM) rotary actuator which simultaneously positions both recording heads over the disc. A silicon microactuator is also fastened to the distal end of at least one of the load beams for positioning the recording heads independent of one another, thereby allowing simultaneous tracking of embedded servo data. Various data formats are provided, including interleaving logical sector numbers, symbols of a logical sector, and segments of a logical sector, between the top and bottom physical sectors of a track. Complexity and cost of the servo controllers is reduced through the use of sliding mode control: a simple, robust and fast control system implemented using simple switching circuitry, small lookup tables, and simplified binary multipliers (shift registers). A dual path read channel implemented in a single integrated circuit is provided for parallel processing the read signals from the top and bottom recording heads.

Claims7

Dependent claims

A disc storage device, comprising:

(a) a disc storage medium comprising a top surface and a bottom surface where data is recorded on each surface in the format of a plurality of data tracks and embedded servo wedges;
(b) a first actuator for simultaneously positioning a top recording head over the top surface of the disc and a bottom recording head over the bottom surface of the disc;
(c) a top load beam comprising a base end connected to the first actuator and a distal end extending out over the top surface of the disc, wherein the top recording head is connected to the distal end of the top load beam;
(d) a bottom load beam comprising a base end connected to the first actuator and a distal end extending out over the bottom surface of the disc, wherein the bottom recording head is connected to the distal end of the bottom load beam;
(e) a second actuator connected to the distal end of one of the load beams for positioning one of the recording heads independent of the other recording head,
wherein:
(a) a top data track on the top surface of the disc comprises a first plurality of physical data sectors, and a bottom data track on the bottom surface of the disc comprises a second plurality of physical data sectors;
and
(b) a logical sector number sequence is assigned to the physical data sectors in the top and bottom data tracks in an interleaved manner.

6 more elements

A disc storage device, comprising:

(a) a disc storage medium comprising a top surface and a bottom surface where data is recorded on each surface in the format of a plurality of data tracks and embedded servo wedges;
(b) a first actuator for simultaneously positioning a top recording head over the top surface of the disc and a bottom recording head over the bottom surface of the disc;
(c) a topload beam comprising a base end connected to the first actuator and a distal end extending out over the top surface of the disc, wherein the top recording head is connected to the distal end of the top load beam;
(d) a bottom load beam comprising a base end connected to the first actuator and a distal end extending out over the bottom surface of the disc, wherein the bottom recording head is connected to the distal end of the bottom load beam;
(e) a second actuator connected to the distal end of one of the load beams for positioning one of the recording heads independent of the other recording head;
(f) a frequency synthesizer for generating a sampling clock at a predetermined frequency;
(g) a first sampled amplitude read channel for detecting data from a first analog read signal emanating from the top recording head, comprising;
(i) a first sampling device, responsive to the sampling clock, for asynchronously sampling the first analog read signal to generate a sequence of first asynchronous sample values;
(ii) a first interpolated timing recovery circuit, responsive to the sampling clock and the first sequence of asynchronous sample values, for generating first interpolated sample values substantially synchronized to a baud rate of the recorded data;
and
(iii) a first sequence detector for detecting a first estimated data sequence from the first interpolated sample values;
and
(h) a second sampled amplitude read channel for detecting data from a second analog read signal emanating from the bottom recording head, comprising;
(i) a second sampling device, responsive to the sampling clock, for asynchronously sampling the second analog read signal to generate a second sequence of asynchronous sample values;
(ii) a second interpolated timing recovery circuit, responsive to the sampling clock and the second sequence of asynchronous sample values, for generating second interpolated sample values substantially synchronized to a baud rate of the recorded data;
and
(iii) a second sequence detector for detecting a second estimated data sequence from the second interpolated sample values.

14 more elements

Dependencies are inferred from the claim text.

Magnetic disc recording system employing two stage actuators for simultaneous accesses through multiple recording heads

Life of this patent

Magnetic disc recording system employing two stage actuators for simultaneous accesses through multiple recording heads

Life of this patent

Abstract

Claims7