Steven Michael Bell

US Patent:

45041300, Mar 12, 1985

Filed:

Sep 27, 1982

Appl. No.:

6/424841

Inventors:

Steven A. Bell - Venice CA
Ivan T. Kruglak - Sylmar CA

Assignee:

Coherent Communications, Inc. - Sylmar CA

International Classification:

G03B 1724

US Classification:

352 92

Abstract:

An apparatus and related method for recording a continuous digital time code on motion picture film as it is advanced intermittently by a motion picture camera. The apparatus controllably adjusts the time durations of the successive bits of the signal it records, to compensate for the variable velocity profile of the intermittently advancing film. As a result, the apparatus records the time code signal as a continuous signal with a uniform time base, even though the film is being moved in an intermittent and non-uniform fashion.

US Patent:

58672583, Feb 2, 1999

Filed:

Oct 27, 1997

Appl. No.:

8/958365

Inventors:

Donald A. Frederick - Canoga Park CA
Steven G. Bell - Woodland Hills CA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

G01B 902

US Classification:

356 355

Abstract:

A system for performing high resolution measurement of frequency variations in multimode fiber laser acoustic sensors having an end-pumped active fiber sensor emitting a plurality of lasing modes, wherein precise frequencies of the lasing modes emitted are dependent upon a strain acting on said acoustic sensor. An optical fiber is connected to the active fiber sensor for transmitting the lasing modes. The optical fiber transmits the multiple lasing modes to an optical amplifier fiber where the lasing mode signals are amplified. The amplified lasing modes signals are then fed through a phase modulator connected to the optical fiber for applying a phase generated carrier on the lasing mode signals. The output from the phase modulator is supplied to a receiving interferometer having a predetermined path imbalance for interferometrically analyzing the frequency shifts of each of the lasing mode signals, wherein the predetermined path imbalance is matched with the longitudinal mode spacing between the lasing modes of the active fiber sensor. A demodulation unit is connected to the receiving interferometer for receiving and demodulating the output of the receiving interferometer to determine the frequency shift incurred by the lasing mode signals, wherein the demodulated frequency shift is proportional to the strain acting on the acoustic sensor.

US Patent:

44913990, Jan 1, 1985

Filed:

Jul 7, 1983

Appl. No.:

6/511522

Inventors:

Steven A. Bell - Venice CA

Assignee:

Coherent Communications, Inc. - Sylmar CA

International Classification:

G03B 1724

US Classification:

352 92

Abstract:

A method and apparatus for recording a digital signal such as a modified SMPTE time code on motion picture film as it is being intermittently advanced by a motion picture camera. The recorded time code includes a set of timing bits followed immediately by a set of synchronization bits. In one embodiment, the time code is recorded as a continuous signal with the last bit recorded for each frame having an extended length, to ensure that uncertainties in the specific times at which the camera begins and ends its advancement of the film don't result in the recording of a bit that is shorter than a nominal bit duration. In a second embodiment, an addition set of synchronization bits is recorded at the beginning of each frame, so that a time code reader assumes it corresponds to the previous frame and properly decodes the following sets of timing bits and synchronization bits as corresponding to the current frame.