US4944028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-contact type pattern sensor with variable clearance compensation
Assignee: Nippon Gakki Co Ltd
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Filing: 1988-11-10
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Granted: 1990-07-24
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Expires: 2008-11-10
Abstract
Abstract An improved non-contact type pattern sensor includes a magnetic resistor element arranged facing a pattern track on a recoridng medium having a magnetized pattern in the pattern track. A clearance sensor is arranged to face the pattern track on the recording medium and generates a detection signal as a function of the distance between the clearance sensor and the pattern track. The control unit connected to the clearance sensor generates an output signal which varies as a function of the detection signal. A magnetic field generator connected to the control unit is arranged near the magnetic sensor element and generates a bias magnetic field whose intensity varies as a function of the output signal.
Inventors
- 👤 Kenzaburou Iijima
- 👤 Yoshinori Hayashi
- 👤 Kazuo Kurahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:43
CPC Classifications
G; G11; G11B; G11B9/00; G11B9/04; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/142; G01D5/145
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
134 words
An improved non-contact type pattern sensor, comprising: a magnetic resistor element arranged facing a pattern track on a recording medium having a magnetized pattern in said pattern track and having a resistance which varies as a function of a magnetic field of a facing portion of said pattern track; a clearance sensor arranged near said recording medium and generating a detection signal indicative of the distance between said clearance sensor and said recording medium; a control unit connected to said clearance sensor and generating an output signal in response to said detection signal; and a piezo-electric element connected to said control unit and holding said magnetic resistor element, said piezo-electric element moving said magnetic resistor element towards and away from said magnetized pattern on said recording medium as a function of said output voltage.
Claim 2
Dependent Claim
134 words
An improved non-contact type pattern sensor, comprising: a magnetic resistor element arranged facing a pattern track on a recording medium having a magnetized pattern in said pattern track and having a resistance which varies as a function of a magnetic field of a facing portion of said pattern track; a clearance sensor arranged near said recording medium and generating a detection signal indicative of the distance between said clearance sensor and said recording medium; a control unit connected to said clearance sensor and generating an output signal in response to said detection signal; and a piezo-electric element connected to said control unit and holding said magnetic resistor element, said piezo-electric element moving said magnetic resistor element towards and away from said magnetized pattern on said recording medium as a function of said output voltage.
Claim 3
Dependent Claim
61 words
An improved non-contact type pattern sensor as claimed in claim 1 in which: said clearance sensor includes a first electrode spaced from and facing the top surface of said recording medium, and a second electrode arranged in contact with a center rotary shaft of said recording medium, and said control means measures the electrostatic capacity between said first and second electrodes.
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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) | 1993-07-23 | 1994-01-22 | 1994-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-23 | 1998-01-22 | 1998-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-23 | 2002-01-22 | 2002-07-24 | $7700.00 | Window Closed / Lapsed |