Capacitive sensing employing thin film inductors

Patent 4648087 Issued on March 3, 1987. Estimated Expiration Date:

June 28, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3783196

3842194

Pickup circuitry for a video disc player with printed circuit board
Patent #: 4080625
Issued on: 03/21/1978
Inventor: Kawamoto , et al.

Method and apparatus for the determination of signal pickup qualities of a stylus of a capacitive disc video player
Patent #: 4152641
Issued on: 05/01/1979
Inventor: Hughes , et al.

Arrangement for preventing discharge current flow between a rotary recording medium and a reproducing stylus in a rotary recording medium reproducing apparatus
Patent #: 4459691
Issued on: 07/10/1984
Inventor: Yamada

Apparatus for detecting variation of electrostatic capacitance
Patent #: 4528655
Issued on: 07/09/1985
Inventor: Tamura , et al.

Digital signal sampling system with two unrelated sampling timebases Patent #: 4558422
Issued on: 12/10/1985
Inventor: DenBeste , et al.

Inventors

Application

No. 06/625756 filed on 06/28/1984

US Classes:

360/234.7, Head attachment to slider360/110, HEAD360/234.5, Electrical attachment of slider/head369/126, Electrical modification or sensing of storage medium (e.g., capacitive, resistive, electrostatic charge)369/14SIMULTANEOUS DIVERSE TYPES OF STORAGE OR RETRIEVAL

Examiners

Primary: Cardillo, Raymond F. Jr.
Assistant: Garland, Steven R.

Attorney, Agent or Firm

Pollock, Vande Sande & Priddy

International Classes

G11B 9/07 (20060101)
G11B 5/31 (20060101)
G01D 5/24 (20060101)
G01D 5/12 (20060101)
G01H 11/06 (20060101)
G01H 11/00 (20060101)
G11B 5/48 (20060101)
G11B 5/596 (20060101)
G11B 5/58 (20060101)
G11B 9/00 (20060101)

Abstract

A capacitive variation sensor includes one or more elements providing inductive reactance in the form of thin film coils. This enables a capacitive variation sensor to be integrated on a substrate along with a thin film magnetic read/write head. One element of the capacitive variation sensor is a sensing electrode, and in some embodiments of the invention a dedicated sense electrode can be eliminated by employing the pole tips of the thin film magnetic read/write head as the sense electrode.

Other References

Scientific American, "Disk Storage Technology", White, Aug. 1980, pp. 138-148
IBM TDB, vol. 23, No. 3, "Optically Read and Servoed Direct--Access Storage Device", Workman, 8/80, pp. 1201-1203
IBM Disk Storage Technology, "IBM 3370 Film Head Design and Fabrication", Jones, Jr., pp. 6 et seq
IBM TDB, vol. 21, No. 6, "Capacitive Servoing on Topographic Variations", Potter, 11/78, p. 2506
IBM TDB, vol. 21, No. 10, "Floppy Disc Embossing for Servo Applications", Acosta et al., 3/79, pp. 4259-4260
IERE Conference Proceeding, No. 423, "Embossed Servo Techniques for Floppy Discs", Thompson et al., 1979, pp. 321-327