Patent US5680265A successfully refreshed from Google Patents.
US5680265A
Expired / Lapsed
US
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Circuit for detecting contact of MR head with disk surface
Assignee: Mitsubishi Electric Corp
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Filing: 1996-01-16
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Granted: 1997-10-21
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Expires: 2016-01-16
Abstract
Abstract A circuit for detecting contact of a magneto-resistive (MR) head with a disk surface by properly sensing disturbance signals without being effected by noises using a simple configuration. The circuit for detecting contact of the MR head with the disk surface by sensing a disturbance waveform generated by MR head contact with the disk surface comprises a comparator for comparing a signal read out by MR head with a threshold level V th ; a pulse width limiting circuit for restricting a pulse width x, which is wider than the predetermined pulse width x 1 , to a pulse width x 1 ; and a D flip-flop circuit in which an output signal of the comparator being applied to both D terminal and R terminal, and an output signal from the pulse width limiting circuit being applied to T terminal, and an output signal being obtained from an inverted output terminal QC.
Inventors
- 👤 Kenji Noguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:53
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/09
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
130 words
A circuit for detecting contact of a magneto-resistive (MR) head with a disk surface by sensing a disturbance waveform generated by MR head contact with said disk surface comprising: a comparator for comparing a signal read out by the MR head with a threshold level V th ; a pulse width limiting circuit for restricting a pulse width x to a predetermined pulse width x 1 , said pulse width x being wider than the predetermined pulse width x 1 ; and a D flip-flop circuit in which an output signal of said comparator is applied to both D terminal and R terminal, and an output signal from said pulse width limiting circuit is applied to T terminal, and an output signal is obtained from an inverted output terminal QC.
Claim 2
Dependent Claim
130 words
A circuit for detecting contact of a magneto-resistive (MR) head with a disk surface by sensing a disturbance waveform generated by MR head contact with said disk surface comprising: a comparator for comparing a signal read out by the MR head with a threshold level V th ; a pulse width limiting circuit for restricting a pulse width x to a predetermined pulse width x 1 , said pulse width x being wider than the predetermined pulse width x 1 ; and a D flip-flop circuit in which an output signal of said comparator is applied to both D terminal and R terminal, and an output signal from said pulse width limiting circuit is applied to T terminal, and an output signal is obtained from an inverted output terminal QC.
Claim 3
Dependent Claim
193 words
A circuit for detecting contact of a magneto-resistive (MR) head with a disk surface by sensing a disturbance waveform generated by MR head contact with said disk surface comprising: a comparator for comparing a signal read out by the MR head with a threshold level V th ; a pulse width limiting circuit for restricting a pulse width x to a first predetermined pulse width x 1 , said pulse width x being wider than the first predetermined pulse width x 1 ; a D flip-flop circuit in which an output signal of said comparator is applied to both D terminal and R terminal, and an output signal from said pulse width limiting circuit is applied to T terminal, and an output signal is obtained from an inverted output terminal QC; a second pulse width limiting circuit for generating a pulse having a second predetermined pulse width x 2 ; and a NAND gate for obtaining a signal having a pulse width close to that of disturbance signals from the MR head by applying an output signal of said D-FF and an output of said second pulse width limiting circuit to input terminals.
Claim 4
Dependent Claim
193 words
A circuit for detecting contact of a magneto-resistive (MR) head with a disk surface by sensing a disturbance waveform generated by MR head contact with said disk surface comprising: a comparator for comparing a signal read out by the MR head with a threshold level V th ; a pulse width limiting circuit for restricting a pulse width x to a first predetermined pulse width x 1 , said pulse width x being wider than the first predetermined pulse width x 1 ; a D flip-flop circuit in which an output signal of said comparator is applied to both D terminal and R terminal, and an output signal from said pulse width limiting circuit is applied to T terminal, and an output signal is obtained from an inverted output terminal QC; a second pulse width limiting circuit for generating a pulse having a second predetermined pulse width x 2 ; and a NAND gate for obtaining a signal having a pulse width close to that of disturbance signals from the MR head by applying an output signal of said D-FF and an output of said second pulse width limiting circuit to input terminals.
Claim 5
Dependent Claim
38 words
A circuit for detecting contact of a magneto-resistive (MR) head with a disk surface of claim 2: wherein said first predetermined pulse width x 1 and said second predetermined pulse width x 2 are selected to be equal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-20 | 2001-04-21 | 2001-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-20 | 2005-04-21 | 2005-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-20 | 2009-04-21 | 2009-10-21 | $7700.00 | Window Closed / Lapsed |