1
Donald H McMahon: Real time fingerprint recording terminal. Sperry Rand Corporation, Howard P Terry, August 17, 1976: US03975711 (90 worldwide citation)

A fingerprint optical sensor terminal is provided for use in the real time recording of an impression of a fingerprint pattern, the human finger being placed for the purpose at an input window surface of the sensor terminal. The sensor terminal provides precise angular and positional alignment of th ...


2
Richard A Soref, Donald H McMahon: Electro-optical switch for unpolarized optical signals. Sperry Corporation, Howard P Terry, Arnold L Albin, May 14, 1985: US04516837 (84 worldwide citation)

An optical 1.times.N switch uses a polarizing beam splitter cube and a reflector to separate an arbitrarily polarized incident light beam into polarized components which propagate along parallel paths. A polarization rotator is positioned in the path of the reflected component to rotate the plane of ...


3
Donald H McMahon: Spurious signal removal in optical processor fingerprint identification apparatus. Sperry Rand Corporation, Howard P Terry, July 6, 1976: US03968476 (83 worldwide citation)

An improved incoherent optical processor fingerprint identification apparatus employs a rotatable grating for inspecting the ridge orientations in a plurality of preselected finite sample areas of a fingerprint. A detector array including a plurality of detectors each related to a discrete sampled a ...


4
Donald H McMahon, Richard A Soref: Liquid crystal matrices. Sperry Corporation, Howard P Terry, July 14, 1981: US04278327 (65 worldwide citation)

The improved electrooptical devices provide means for switching pluralities of polarized or unpolarized optical signals between input and output multimode single strand light guides. The electrooptical switching elements employ electric field-effect liquid crystal compositions and are adapted to use ...


5
Donald H McMahon: Fiber optic small displacement sensor. Sperry Corporation, Howard P Terry, October 6, 1981: US04293188 (62 worldwide citation)

An opto-electronic transducer is provided for converting small displacements into optical intensity or phase variations which may then be converted into varying electric currents. A first optical fiber guide is disposed with its end face stationary, for example, while a second optical fiber guide is ...


6
Donald H McMahon: Electro optic switch. Sperry Corporation, Howard P Terry, Seymour Levine, July 24, 1984: US04461543 (61 worldwide citation)

An optical switch utilizes a birefringent device to cause orthogonally polarized components of an arbitrarily polarized incident light beam to propagate along separate paths. A polarization rotator is positioned in one path to rotate the polarization of the light beam propagating therealong to that ...


7
Donald H McMahon: Digital processor for extracting data from a binary image. Sperry Rand Corporation, Howard P Terry, Seymour Levine, July 6, 1976: US03968475 (61 worldwide citation)

A digital processor for extracting data from a binary image in which the image is divided into an array of sample areas, each sample area containing an array of binary data spaces. Patterns formed by adjacent data spaces within the sample sample represent local line orientations from which the image ...


8
Donald H McMahon: Bulk optic wavelength division multiplexer. Polaroid Corporation, Francis J Caufield, June 2, 1992: US05119454 (55 worldwide citation)

An optical multiplexing/demultiplexing device combines an etalon and weak diffraction grating along with temperature control to finely tune local resonant stations along the etalon to separate and/or combine a plurality of optical signals that are finely spaced in wavelength.


9
Donald H McMahon, Colin G Whitney: Method of inspecting circuit boards and apparatus therefor. Sperry Rand Corporation, Howard P Terry, Eugene L Flanagan III, May 1, 1979: US04152723 (49 worldwide citation)

A method and apparatus for generating a digital image representation of a printed circuit board. The board has a substrate of insulating material. A pattern of metallic conductors is disposed on a surface of the insulating material. A beam of light energy scans this surface in a predetermined patter ...


10
Amaresh Mahapatra, Donald H McMahon, William C Robinson, Norman A Sanford: Integrated optic resonant structres and fabrication method. Polaroid Corporation, Francis J Caufield, September 22, 1987: US04695121 (49 worldwide citation)

Integrated optic resonant structures for use in optical communications and sensing applications requiring control or detection of electromagnetic radiation in the optical region of the spectrum. Preferably of planar form, the structures comprise a substrate made of a ferroelectric crystalline materi ...