US4668100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic equipment with geomagnetic direction sensor
Assignee: Citizen Watch Co Ltd
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Filing: 1986-09-02
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Granted: 1987-05-26
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Expires: 2006-09-02
Abstract
Abstract Electronic equipment has, in its case, a flux gate magnetic sensor with an excitation coil and a sensing coil wound around an annular magnetic core made of high permeability material, an integrated circuit including a magnetic field detector, cooperating with the magnetic sensor for detecting an external magnetic field and an operation circuit for operating the geomagnetic direction, a display device for displaying at least the geomagnetic direction, and a power source battery. The flux gate magnetic sensor is arranged along the inner surface of the case and the battery is arranged within the annular magnetic core of the magnetic sensor.
Inventors
- 👤 Tomomi Murakami
- 👤 Hiroyuki Kihara
- 👤 Kazuya Mitaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:54
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/02; G01C17/28; G01C17/30; G04; G04B; G04B47/00; G04B47/06; G04B47/065
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
110 words
Electronic equipment comprising a case, a flux gate magnetic sensor with an excitation coil and a sensing coil wound around an annular magnetic core made of high permeability material, an integrated circuit including a magnetic field detector operably connected with said magnetic sensor for detecting an external magnetic field and an operation circuit operably connecting said magnetic sensor and said integrated circuit for determining geomagnetic direction, a display device for displaying at least the geomagnetic direction, and a power source battery; wherein said flux gate magnetic sensor is arranged along an inner surface of said case and said battery is arranged within said annular magnetic core of said magnetic sensor.
Claim 2
Dependent Claim
110 words
Electronic equipment comprising a case, a flux gate magnetic sensor with an excitation coil and a sensing coil wound around an annular magnetic core made of high permeability material, an integrated circuit including a magnetic field detector operably connected with said magnetic sensor for detecting an external magnetic field and an operation circuit operably connecting said magnetic sensor and said integrated circuit for determining geomagnetic direction, a display device for displaying at least the geomagnetic direction, and a power source battery; wherein said flux gate magnetic sensor is arranged along an inner surface of said case and said battery is arranged within said annular magnetic core of said magnetic sensor.
Claim 3
Dependent Claim
22 words
Electronic equipment according to claim 1, wherein a magnetic shielding plate is arranged between said flux gate magnetic sensor and said battery.
Claim 4
Dependent Claim
30 words
Electronic equipment according to claim 1, wherein a module including said integrated circuit and said display device is arranged within said annular magnetic core of said flux gate magnetic sensor.
Claim 5
Dependent Claim
37 words
Electronic equipment according to claim 1, wherein an operation member is provided at a display surface side or a rear cover side of said case except a side portion where said flux gate magnetic sensor is disposed.
Claim 6
Dependent Claim
73 words
Electronic equipment according to claim 1, wherein said integrated circuit includes a direction indicator having an excitation signal generator for generating an excitation signal which is supplied to an excitation coil of said flux gate magnetic sensor, a pair of magnetic field detectors for detecting external magnetic field signals generated at two sensing coils, and an operation circuit for calculating direction data based on the signal from said pair of magnetic field detectors.
Claim 7
Dependent Claim
56 words
Electronic equipment according to claim 5, wherein said excitation signal generator is a rectangular pulse generator for generating a rectangular pulse, and said magnetic field detector comprises a timer circuit arranged to operate with said rectangular pulse as a synchronizing signal and a sample/hold circuit arranged to operate with an output signal of said timer circuit.
Claim 8
Dependent Claim
44 words
Electronic equipment according to claim 5, wherein said excitation signal generator is a rectangular pulse generator for generating a rectangular pulse, and said magnetic field detector is a peak hold circuit for performing a detection operation using said rectangular pulse as a synchronizing signal.
Claim 9
Dependent Claim
44 words
Electronic equipment according to claim 5, further comprising a direction error discriminator for comparing a signal level from said magnetic field detector with a predetermined level to output a direction error signal and providing a direction error alarm according to said direction error signal.
Claim 10
Dependent Claim
39 words
Electronic equipment according to claim 8, wherein said direction error discriminator has a first direction level discriminator for discriminating that an external magnetic field signal generated at said sensing coil is larger than the geomagnetic level as normally detected.
Claim 11
Dependent Claim
39 words
Electronic equipment according to claim 8, wherein said direction error discriminator has a second direction level discriminator for discriminating that external magnetic field signals generated at said two sensing coils are smaller than the geomagnetic level as normally detected.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |