Steven C Dohmeier

6999663, Feb 14, 2006

Oct 31, 2001

09/999533

Edward C. Gage - Apple Valley MN, US
Steven C. Dohmeier - Apple Valley MN, US
Ronald E. Gerber - Richfield MN, US
Craig A. Parsons - Victoria MN, US
Thomas J. Schmitt - Apple Valley MN, US
Eric K. Lindmark - Shoreview MN, US
John C. Holman - Coon Rapids MN, US
Kevin D. Batko - Bloomington MN, US
Timothy S. Gardner - Eden Prairie MN, US

ADC Telecommunications, Inc. - Eden Prairie MN

G02B 6/26

385 48, 385 39

An improved fiber optic tap monitor has characteristics that are flatter over the wavelength range of interest. The polarization dependence of the characteristics of the tap monitor is reduced, and the package for the tap monitor is smaller. The tap monitor reduces the amount of light reflected back to the source. The tap monitor is also assembled in a manner to improve temperature stability, so that its characteristics over a range of temperatures are more nearly constant.

20040156596, Aug 12, 2004

Sep 5, 2003

10/656920

Craig Parsons - Victoria MN, US
Steven Dohmeier - Apple Valley MN, US
Timothy Gardner - Eden Prairie MN, US
Edward Gage - Mars PA, US
Ye Feng - Santa Clara CA, US

ADC Telecommunications, Inc. - Eden Prairie MN

G02B006/36

385/088000

An improved fiber optic tap monitor has characteristics that are flatter over the wavelength range of interest. The tap monitor includes a filter that reflects a major fraction of the light from a first fiber to a second fiber. A photodetector located behind the filter detects the light transmitted by the filter. The reflectance spectrum of the filter is selected to compensate for nonuniformities in the detection response characteristic of the photodetector over the wavelength range of interest, so that the overall response of the tap monitor is relatively flat.

55373836, Jul 16, 1996

Mar 1, 1995

8/397701

Edward C. Gage - Fairport NY
Steven C. Dohmeier - Rochester NY

Eastman Kodak Company - Rochester NY

G11B 700

369116

An apparatus and method for providing differential detection and source noise subtraction in data signals read from magneto-optic (MO), write-once (WO) or other types of optical storage media using an incident radiation beam. A source monitor signal is generated by detecting radiation from an optical source providing the radiation beam. An error detector generates an error signal corresponding to a difference between the source monitor signal and a reference signal. A power level of the radiation beam is adjusted in response to the error signal. A data signal generator is adapted to receive a return beam resulting from application of the radiation beam to the medium and to generate a WO data signal from the return beam. A signal combiner combines the data signal and the source monitor signal to provide a compensated WO data signal. An MO data signal may be generated using a separate AGC circuit to adjust the gain of each differential detection channel in accordance with low-frequency amplitude differences between the detected signals and a reference signal.

57843481, Jul 21, 1998

Jun 19, 1996

8/666172

Clarke K. Eastman - Rochester NY
Roger A. Hajjar - Fairport NY
Edward C. Gage - Fairport NY
Steven C. Dohmeier - Rochester NY

Eastman Kodak Company - Rochester NY

G11B 700

369 54

An optical recording system for recording data on an optical medium comprising: an optical source capable of providing at least one write pulse incident upon the optical medium; a direct read during write (DRDW) verification and control system within the optical source having a capability of measuring light reflected from the optical medium into a return beam aperture, the DRDW system including a plurality of detectors configured to receive light from different areas of the return aperture; and a comparison circuit for comparing light received in different portions of the return aperture.

55861016, Dec 17, 1996

Mar 1, 1995

8/397293

Edward C. Gage - Fairport NY
Steven C. Dohmeier - Rochester NY

Eastman Kodak Company - Rochester NY

G11B 700

369124

An apparatus and method for detecting a data signal read from a magneto-optic (MO) storage medium. First and second detected signals are generated from first and second portions, respectively, of a radiation beam reflected from the medium. First and second gain control circuits are coupled to the first and second detectors, respectively. Each of the gain control circuits is operative to alter the gain of a signal path of the corresponding detected signal in response to a control signal which varies in accordance with a difference between the corresponding detected signal and a reference signal. The reference signals in each gain control circuit may be a common reference voltage level. A signal difference circuit produces a data signal corresponding to the difference between the detected signals.

58090010, Sep 15, 1998

Nov 7, 1996

8/745038

Edward C. Gage - Fairport NY
Steven C. Dohmeier - Rochester NY
Mark V. Hettel - Penfield NY

Eastman Kodak Company - Rochester NY

G11B 700

369124

Apparatus for reading data from an optical medium having improved settling time characteristics and reduced bandwidth requirements is disclosed. The apparatus includes a front facet detector for producing a front facet monitor signal from a laser light beam; first and second detectors for producing first and second data signals, respectively; and a first gain control circuit responsive to the front facet monitor signal to produce a gain adjusted front facet monitor signal. The apparatus further includes a second gain control circuit responsive to the first data signal and the gain adjusted front facet monitor signal to produce a first gain adjusted data signal; a third gain control circuit responsive to the second data signal and the gain adjusted front facet monitor signal to produce a second gain adjusted data signal; circuitry responsive to the first and second gain adjusted data signals to produce a magneto-optic data signal as a function of the difference between the first and second gain adjusted data signals; or to produce a combined data signal as a function of the sum of the first and second gain adjusted data signals and responsive to the gain adjusted front facet monitor signal and the combined data signal to produce a write-once data signal as a function of the difference between the gain adjusted front facet monitor signal and the combined data signal.

54954665, Feb 27, 1996

Jan 10, 1994

8/179472

Steven C. Dohmeier - Rochester NY
Clarke K. Eastman - Rochester NY
Jeffrey T. Klaus - Rochester NY
Michael E. Meichle - Rochester NY

Eastman Kodak Company - Rochester NY

G11B 700

3692754

An optical recording system and method which provide verification of recorded data, while the data is being written onto an optical recording medium, by detecting the rate of change of a reflected write pulse. The system includes an optical source for supplying a intensity-modulated incident write signal, having at least one write pulse, to an optical recording medium. The write signal records a logic level of the data on the medium as a mark having a distinct reflectivity. An optical detector detects a reflection of the incident write signal from the medium to provide a reflected write signal which includes a reflected write pulse corresponding to the incident write pulse. The reflected write pulse has a rate of change resulting from a change in reflectivity of the optical medium as the mark is formed thereon. A mark formation effectiveness signal generator receives the reflected write signal and generates a mark formation effectiveness signal which estimates a normalized rate of change of the reflected pulse, to provide an indication of the quality of mark formation on the medium. Comparison means may be included for comparing the measured mark formation effectiveness signal with a predetermined range of acceptable rates of change in order to verify proper mark formation.

56129386, Mar 18, 1997

Apr 20, 1995

8/425549

Steven C. Dohmeier - Rochester NY
Michael Meichle - Rochester NY
Michael G. Fairchild - Webster NY

Eastman Kodak Company - Rochester NY

G11B 509

369 48

Method for correcting the length of marks and lands representing information taken from an optical disk is disclosed. The method includes digitizing amplified analog data having marks and lands played back from an optical disk and providing a data synchronization clock by using a phase lock loop (PLL). The method further includes providing an adjustment to a threshold signal level based upon the difference in timing position in mark and land edge marks with reference to the data synchronization clock and changing the data mark and land lengths with reference to the adjusted threshold signal.