USA As Represented by Secretary of the Navy

Thx Ltd.

Bolt Beranek and Newman Inc.

Michael J Rudd

Donald E Nelsen

A video test tool for diagnosing video processing for interlacing is disclosed along with a video test tool for quantifying 'jaggies' in a video display.

Video test tools

Optical interferometric apparatus for detecting and measuring discontinuis in structural materials from ultrasonic stress waves at their surfaces. The apparatus includes an acousto-optic (a/o) modulator which shifts a portion of a laser beam in frequency, producing a modulated beam of light. This modulated light beam is deflected and passes through an adjustable lens to the surface being measured. The light scattered by the surface is focused by the lens on an end mirror of the laser which produced the original beam, and is divergingly reflected therefrom. The reflected, scattered light is heterodyned with the unshifted portion of the laser beam in a photodiode to produce a phase modulated signal at the acoustic frequency of the a/o modulator. Surface displacement can be measured as a function of instantaneous phase shift, and surface velocity as a function of rate of change of phase shift.

Laser vibrometer

In the frequency measuring system disclosed herein, a control signal is generated which is related to the value of function of the input signal for a selectable delay time. The average value of the control signal is employed to control the clock rate of a shift register which is used to obtain a delayed version of the input signal, the input signal being digitized and fed into the shift register. This feedback path forms a servo-loop which adjusts the clocking rate of the shift register in correspondence with the frequency of any coherent component in the input signal, even though the input signal may be a composite comprising many random components.

Growing community of inventors

Concord, MA, United States of America

Michael J Rudd