Patents by Inventor Richard J. Gahan
Richard J. Gahan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6427349Abstract: An electronic compass is described for use in vehicles. The compass employs a magnetoresistive sensor for sensing the earth magnetic field and the sensor is operated in alternate set/reset bias modes. In a first embodiment, the compass is provided with deviation compensation by a closed loop system including measurement of the sensor output signals and an offset current strap for nullifying the vehicle deviation field. In a second embodiment, deviation compensation is provided by operation in an initial calibration mode and by operation in a normal compensation mode to adjust compensation, as needed, on a long term basis during normal operation of the compass. In the initial calibration mode, while the vehicle is being driven, the signal peak values are adjusted to a nominal earth field level by changing the offset current. Then, compensating signal reference values for each axis are determined as each peak for that axis is determined.Type: GrantFiled: January 11, 2001Date of Patent: August 6, 2002Assignee: Donnelly CorporationInventors: Rodney K. Blank, Richard J. Gahan, Howard J. Haselhuhn, Jr., Kenneth L. Schierbeek, Kenneth Schofield
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Publication number: 20020083605Abstract: An electronic compass is described for use in vehicles. The compass employs a magnetoresistive sensor for sensing the earth magnetic field and the sensor is operated in alternate set/reset bias modes. In a first embodiment, the compass is provided with deviation compensation by a closed loop system including measurement of the sensor output signals and an offset current strap for nullifying the vehicle deviation field. In a second embodiment, deviation compensation is provided by operation in an initial calibration mode and by operation in a normal compensation mode to adjust compensation, as needed, on a long term basis during normal operation of the compass. In the initial calibration mode, while the vehicle is being driven, the signal peak values are adjusted to a nominal earth field level by changing the offset current. Then, compensating signal reference values for each axis are determined as each peak for that axis is determined.Type: ApplicationFiled: January 11, 2001Publication date: July 4, 2002Inventors: Rodney K. Blank, Richard J. Gahan, Howard J. Haselhuhn, Kenneth L. Schierbeek, Kenneth Schofield
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Patent number: 6173501Abstract: An electronic compass is described for use in vehicles. The compass employs a magnetoresistive sensor for sensing the earth magnetic field and the sensor is operated in alternate set/reset bias modes. In a first embodiment, the compass is provided with deviation compensation by a closed loop system including measurement of the sensor output signals and an offset current strap for nullifying the vehicle deviation field. In a second embodiment, deviation compensation is provided by operation in an initial calibration mode and by operation in a normal compensation mode to adjust compensation, as needed, on a long term basis during normal operation of the compass. In the initial calibration mode, while the vehicle is being driven, the signal peak values are adjusted to a nominal earth field level by changing the offset current. Then, compensating signal reference values for each axis are determined as each peak for that axis is determined.Type: GrantFiled: September 8, 1998Date of Patent: January 16, 2001Assignee: Donnelly CorporationInventors: Rodney K. Blank, Richard J. Gahan, Howard J. Haselhuhn, Jr., Kenneth L. Schierbeek, Kenneth Schofield
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Patent number: 5802727Abstract: An electronic compass is described for use in vehicles. The compass employs a magnetoresistive sensor for sensing the earth magnetic field and the sensor is operated in alternate set/reset bias modes. In a first embodiment, the compass is provided with deviation compensation by a closed loop system including measurement of the sensor output signals and an offset current strap for nullifying the vehicle deviation field. In a second embodiment, deviation compensation is provided by operation in an initial calibration mode and by operation in a normal calibration mode to adjust compensation, as needed, on a long term basis during normal operation of the compass. In the initial calibration mode, while the vehicle is being driven, the signal peak values are adjusted to a nominal earth field level by changing the offset current. Then, compensating signal reference values for each axis are determined as each peak for that axis is determined.Type: GrantFiled: March 24, 1997Date of Patent: September 8, 1998Assignee: Donnelly CorporationInventors: Rodney K. Blank, Richard J. Gahan, Howard J. Haselhuhn, Jr., Kenneth L. Schierbeek, Kenneth Schofield
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Patent number: 5644851Abstract: An electronic compass is described for use in vehicles. The compass employs a magnetoresistive sensor for sensing the earth magnetic field and the sensor is operated in alternate set/reset bias modes. In a first embodiment, the compass is provided with deviation compensation by a closed loop system including measurement of the sensor output signals and an offset current strap for nullifying the vehicle deviation field. In a second embodiment, deviation compensation is provided by operation in an initial calibration mode and by operation in a normal calibration mode to adjust compensation, as needed, on a long term basis during normal operation of the compass. In the initial calibration mode, while the vehicle is being driven, the signal peak values are adjusted to a nominal earth field level by changing the offset current. Then, compensating signal reference values for each axis are determined as each peak for that axis is determined.Type: GrantFiled: October 25, 1993Date of Patent: July 8, 1997Inventors: Rodney K. Blank, Richard J. Gahan, Howard J. Haselhuhn, Jr., Kenneth L. Schierbeek, Kenneth Schofield
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Patent number: 5632092Abstract: An electronic compass is described for use in vehicles. The compass employs a magnetoresistive sensor for sensing the earth magnetic field and the sensor is operated in alternate set/reset bias modes. In a first embodiment, the compass is provided with deviation compensation by a closed loop system including measurement of the sensor output signals and an offset current strap for nullifying the vehicle deviation field. In a second embodiment, deviation compensation is provided by operation in an initial calibration mode and by operation in a normal calibration mode to adjust compensation, as needed, on a long term basis during normal operation of the compass. In the initial calibration mode, while the vehicle is being driven, the signal peak values are adjusted to a nominal earth field level by changing the offset current. Then, compensating signal reference values for each axis are determined as each peak for that axis is determined.Type: GrantFiled: June 1, 1995Date of Patent: May 27, 1997Assignee: Donnelly CorporationInventors: Rodney K. Blank, Richard J. Gahan, Howard J. Haselhuhn, Jr., Kenneth L. Schierbeek, Kenneth Schofield
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Patent number: 5406414Abstract: An electro-optic device including first and second optically transparent elements mounted in spaced relationship to each other to define a gap and each having a front and rear surface. At least one optically transparent interlayer element is sandwiched between the first and second elements and joining a predetermined area of the rear surface of the first element and the front surface of the second element. A liquid, semi-liquid, gel, or semi-solid electro-optic medium, whose light transmittance is variable, is added to the gap between the first and second element. One surface of the second element may include a reflective coating except in those areas aligned with the transparent interlayer element sandwiched between the first and second element.Type: GrantFiled: September 2, 1993Date of Patent: April 11, 1995Assignee: Donnelly CorporationInventors: Desmond J. O'Farrell, Richard J. Gahan
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Patent number: 5253109Abstract: An electro-optic device including first and second optically transparent elements mounted in spaced relationship to each other to define a gap and each having a front and rear surface. At least one optically transparent interlayer element is sandwiched between the first and second elements and joining a predetermined area of the rear surface of the first element and the front surface of the second element. A liquid, semi-liquid, gel, or semi-solid electro-optic medium, whose light transmittance is variable, is added to the gap between the first and second element. One surface of the second element may include a reflective coating except in those areas aligned with the transparent interlayer element sandwiched between the first and second element.Type: GrantFiled: April 27, 1992Date of Patent: October 12, 1993Assignee: Donnelly CorporationInventors: Desmond J. O'Farrell, Richard J. Gahan
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Patent number: 5193029Abstract: An automatic rearview mirror system having a reflective element that is actuatable between at least two different reflective conditions by a control that discriminates between glare-causing and nonglare-causing light simultaneously sensed by a single light sensor. The control includes a processor that is more responsive to decreasing levels of light than to increasing levels of light to produce a signal that is indicative of the slow-transient characteristic of the light sensed by the single light sensor. The processor may include a very slow signal processor that is always operative and a somewhat faster-slow signal processor, which may be selectively inhibited when the mirror is fully colored, or when a differential circuit indicates that the difference between the glare and the non-glare light sensed by the light sensor exceeds a predetermined level. The differential circuit may additionally limit the differential between the glare and the nonglare lights sensed by the light sensor.Type: GrantFiled: November 19, 1991Date of Patent: March 9, 1993Assignee: Donnelly CorporationInventors: Kenneth Schofield, Richard J. Gahan, Kenneth L. Schierbeek, Mark L. Larson
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Patent number: 5066112Abstract: An electro-optic mirror of the type having an electro-optic cell or medium with a transmittance which is variable upon the application of an electric field includes a perimeter coating applied to a front or rear surface of a substrate element for concealing any seal and/or electrical connections for the elctro-optic cell or meidum. The perimeter coating may be reflective to increase the field of view in the mirror and allow use of smaller cases or retaining bezels. Alternately, the perimeter coating may be opaque and nonreflective such as black frit, paint or lacquer. In either case, the coating may also be electrically conductive to substantially encircle an electrically conductive layer on the substrate and evenly distribute electric current to the electro-optic cell or medium for enhanced coloration response.Type: GrantFiled: December 21, 1989Date of Patent: November 19, 1991Assignee: Donnelly CorporationInventors: Niall R. Lynam, Richard J. Gahan