Abstract: A micro-Winchester disk drive system particularly suited to meet the demands of a portable computer system. The micro-Winchester disk is a Winchester disk of 85-100 mm in diameter. This disk drive system by virtue of its small size and vibration isolation is ideally suited for use in portable computer systems. The micro-Winchester disk drive system was developed to store data at a density of 600 tracks per inch utilizing open-loop positioning mechanism. This disk drive system provides fast access data storage for use with small business computers, terminals and microprocessor based systems, portable or otherwise, and many other areas where compact, rugged light-weight hard-disk storage is required. The disk drive system of the present invention normally utilizes either one or two hard disks such as Winchester disks and provides data storage on each disk in excess of 5 Megabytes, once the disks are formatted.
Type:
Grant
Filed:
November 19, 1985
Date of Patent:
January 20, 1987
Inventors:
James G. McGinlay, Roderick M. Urguhart
Abstract: A tapped surface acoustic wave (SAW) delay line with time-resolved outputs sing piezoelectric leaky wave coupling and bulk wave amplification, and having low loss characteristics. A solid piezoelectric semiconductor is placed adjacent to a solid piezoelectric substrate. A pulsed rf input signal is applied to interdigital transducers (IDT) on the substrate. The applied signal launches a SAW in the substrate in a direction parallel to the interface between the substrate and the piezoelectric semiconductor solid. Upon reaching the interface, the SAW is piezoelectrically leaky-wave coupled across an air gap to a bulk acoustic wave in the piezoelectric semiconductor. Reflections of the bulk wave occur at both surfaces of the piezoelectric semiconductor, and piezoelectrically couples back across the air gap to excite a SAW on the piezoelectric substrate. The resultant rf output includes the normal delayed SAW pulse and additional delayed and time-resolved pulses.
Type:
Grant
Filed:
April 19, 1977
Date of Patent:
May 9, 1978
Assignee:
The United States of America as represented by the Secretary of the Navy
Inventors:
James D. Crowley, Joseph F. Weller, Thomas G. Giallorenzi