Richard J Gahan, 61Holland, MI

6427349, Aug 6, 2002

Jan 11, 2001

09/758518

Rodney K. Blank - Holland MI
Richard J. Gahan - Holland MI
Kenneth L. Schierbeek - Zeeland MI
Kenneth Schofield - Holland MI

Donnelly Corporation

G01C 1728

33356, 33361, 33333, 324252

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. The system automatically exits the initial calibration mode when certain criteria have been met.

5632092, May 27, 1997

Jun 1, 1995

8/457621

Rodney K. Blank - Holland MI
Richard J. Gahan - Holland MI
Howard J. Haselhuhn - Holland MI
Kenneth L. Schierbeek - Zeeland MI
Kenneth Schofield - Holland MI

Donnelly Corporation - Holland MI

G01C 1728
G01R 3306

33361

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. The system automatically exits the initial calibration mode when certain criteria have been met.

5253109, Oct 12, 1993

Apr 27, 1992

7/874635

Desmond J. O'Farrell - Holland MI
Richard J. Gahan - Holland MI

Donnelly Corporation - Holland MI

G02B 508

359604

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. A photoelectric cell/sensor or display is disposed behind the rear surface of the second element and may be aligned with the window formed in the reflective coating so as to receive or transmit light through the first element, the transparent interlayer, and the transparent second element.

5802727, Sep 8, 1998

Mar 24, 1997

8/823469

Rodney K. Blank - Holland MI
Richard J. Gahan - Holland MI
Howard J. Haselhuhn - Holland MI
Kenneth L. Schierbeek - Zeeland MI
Kenneth Schofield - Holland MI

Donnelly Corporation - Holland MI

G01C 1728

33361

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. The system automatically exits the initial calibration mode when certain criteria have been met.

5193029, Mar 9, 1993

Nov 19, 1991

7/794441

Kenneth Schofield - Holland MI
Richard J. Gahan - Holland MI
Kenneth L. Schierbeek - Zeeland MI
Mark L. Larson - Grand Haven MI

Donnelly Corporation - Holland MI

G02B 1700

359604

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.

5644851, Jul 8, 1997

Oct 25, 1993

8/142509

Rodney K. Blank - Holland MI
Richard J. Gahan - Holland MI
Howard J. Haselhuhn - Holland MI
Kenneth L. Schierbeek - Zeeland MI
Kenneth Schofield - Holland MI

G01C 1728

33361

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. The system automatically exits the initial calibration mode when certain criteria have been met.

5406414, Apr 11, 1995

Sep 2, 1993

8/115998

Desmond J. O'Farrell - Holland MI
Richard J. Gahan - Holland MI

Donnelly Corporation - Holland MI

G02B 508
G02B 1700

359604

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. A photoelectric cell/sensor or display is disposed behind the rear surface of the second element and may be aligned with the window formed in the reflective coating so as to receive or transmit light through the first element, the transparent interlayer, and the transparent second element.

6173501, Jan 16, 2001

Sep 8, 1998

9/149227

Rodney K. Blank - Holland MI
Richard J. Gahan - Holland MI
Howard J. Haselhuhn - Holland MI
Kenneth L. Schierbeek - Zeeland MI
Kenneth Schofield - Holland MI

Donnelly Corporation

G01C 1728
G01R 3306

33356

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. The system automatically exits the initial calibration mode when certain criteria have been met.