Other

Tufts University

Eikonix Corportation

Robert A Gonsalves

Richard A Menelly

Steven M Ebstein

Mark Cronin-Golomb

Anthony J Devaney

A segmented array, perfectly aligned except for piston wraps, will have perfect imaging at wavelength &#x3bb; but will have degraded imaging at other wavelengths. The present method detects and corrects piston wraps by making image-based measurements at a wavelength &#x3bb; and a second wavelength &#x3bb;. These measurements will produce an image of the piston-wrapped segments and the intensities of these segments in the image at wavelength &#x3bb;are linearly related to the sizes of the piston wraps at wavelength &#x3bb;. The method needs no additional equipment like inter-segment apertures, lenslets, and detectors. It needs only a narrowband filter to change the measurement wavelength from &#x3bb; to &#x3bb;.

Elimination of piston wraps in segmented apertures by image-based measurements at two wavelengths

A national wave event is provided by the application of light and sound in a controlled manner along an extended plane whereby the time duration and application of the light and sound is visually and acoustically recorded and transmitted from a predetermined distance. Automobile headlights and horns are activated for a brief time period along a directed path within a plurality of selected states to provide the wave transfer indication.

Wave transfer teaching aid and national wave transfer device (RAG-1)

A linear array of photoemitters and photodiodes are positioned on opposite sides of currency paper for denomination and verification determination under transmitted light. The photoemitters are arranged for projecting an image of the indicia printed on the security thread embedded within the currency paper. The photodiodes receive the image and connect with a processor circuit which determines the presence or absence of the security feature, reads the denomination indicia and correspondingly provides indication thereof. The processor contains stored information identifying currency denomination and a comparison is made at the time of verification to also determine the denomination of the proffered currency.

Verification device for currency containing an embedded security thread

A linear array of photodiode and phototransistor pairs are positioned on opposite sides of currency paper for denomination determination under reflected light and for verification determination under transmitted light. The focus of one of the photodiodes in each pair is precisely adjusted for the top surface of the currency paper. The focus of the other photodiode in each pair is slightly out of focus at the top surface. A phase diversity algorithm integrates the successive images from both photodiodes to form a clear image. A processor determines the presence or absence of the security feature and correspondingly provides visual or audible indication thereof. The processor contains stored information identifying currency denomination and a comparison is made at the time of verification to also determine the denomination of the proffered currency.

Currency paper verification and denomination device having a clear image

Achromatic volume holograms are attained for broad band phase conjugation and image reconstruction having bandwidths of 250 nanometers. The holograms are generated by means of a diffraction grating having a predetermined angle of tilt. Achromaticity is achieved by tilting the holographic recording medium at the same predetermined angle.

Achromatic volume holography apparatus

Adaptive optics with controllable delay in a matrix of regions focuses the image of an object upon a detector array in an image plane that provides a signal set representative of the radiant energy incident upon a matrix of locations in the image plane. An image signal processor processes this signal set to provide a wavefront error signal representative of the estimated wavefront phase distortion of the radiant energy incident upon the detector array. A control system responds to this wavefront error signal to effect alteration of the phase delay introduced by the adaptive optics to reduce the phase distortion of radiant energy incident upon the detector array.

Growing community of inventors

Woburn, MA, United States of America

Robert A Gonsalves