Abstract: An adaptive motor pulsing apparatus for a driven element positioning system is disclosed which divides the available time between recurring motor on periods and motor off periods, and which also varies the duty cycle of the motor during successive on periods in order to provide precise positioning control. The final approach uses a "nudging" technique which increases the duty cycle by increments until forward motion of the driven element is detected.

Abstract: An apparatus, for photo-luminescent analysis of the surface of crystalline silicon, is disclosed, in which the photons emitted from the sample are passed through a two-beam (or two-arm) interferometer, having the usual beamsplitter, fixed mirror, and movable mirror. The interferometer output is directed to a detector which is a germanium photo-diode, cooled in a Dewar, which also cools the initial electronic circuitry to which the detector output is input. Using the disclosed apparatus, methods are available for readily eliminating the negative effect of the electron-hole-droplet phenomenon, and for utilizing the no-photon region of the spectrum to identify otherwise unidentified impurity (or dopant) materials.

Abstract: A spectrometer is disclosed having an interferometer in which: (a) the variable-length arm has a moving retroreflector (copy A to A in summary). The pivoted linkage comprises three or more arms each having its upper end pivotally connected to a supporting structure and its lower end pivotally connected to a carrier for the retroreflector. The stationary folding mirror blocks approximately half of the open face of the retroreflector, causing the radiation which enters the unblocked half of the retroreflector to be reflected back to the retroreflector after it has traveled diagonally across the retroreflector and then been reflected toward the folding mirror.

Abstract: A pre-amplifier located "at the focal plane" of a detector array is disclosed which uses MOSFET transistors operated in the "weak inversion" region to provide operational amplifier performance. The dimensions of certain of the transistors are designed to minimize noise amplification. Feedback resistance for the operational amplifier is provided by switched capacitance using MOSFET transistors as switches, thereby permitting adjustment of the amplifier gain. Implanted and non-implanted MOSFET transistors are used in the differential amplifier in such a way as to avoid the need for a biasing network.

Abstract: A photo detector array module is disclosed which comprises a stack of semiconductor chips having integrated circuitry on each chip. To permit the emplacement of photo-detectors on the focal plane end, and of thin film circuitry on the back plane end, each plane is etched to cut back the semiconductor material, then covered with passivation material, and thereafter lapped to uncover the ends of electrical leads on the chips.

Abstract: The disclosure provides an electronic motor control circuit which switches and amplifies to control a bi-directional electric motor, using a symmetrical circuit, each half of which consists of five transistors. The circuit has a logic level input and motor driving power output using, for control in each direction: an input transistor; a control transistor turned on and off by the input transistor; two matched, complementary motor drive transistors (at opposite terminals of the motor) turned on and off simultaneously by the control transistor; and a lockout transistor, also actuated by the control transistor, which is operatively connected to one of the motor drive transistors in the other half of the system to prevent short circuiting.

Abstract: An interferometer spectrometer aligning apparatus and method are disclosed, in which the laser beam generator, which is in the instrument to provide data controlling clock signals, is also used to accomplish initial (and as needed) alignment of the instrument. The laser beam is directed through a target both on its way from the laser generator to the interferometer, and as it is reflected back from the interferometer, thereby validating the perpendicularity of the reflector to the axis of the interferometer. A semi-transparent mirror, i.e., a small beamsplitter, is used in the path of the laser beam ahead of the interferometer beamsplitter, thereby enabling portions of the laser beam to go into both the interferometer and the sample chamber.

Abstract: A dual beam Fourier-type spectrometer is disclosed in which the collimated output beam of a Michelson type interferometer is divided (post-interferometer) by a reflector which (a) reflects the bulk of said beam to the sample and thereafter a first detector, but (b) transmits part of said beam (preferably through apertures in the reflector) directly to a second detector. The relatively small portion of said beam which is transmitted to the second detector preferably passes through a substantial number of very small apertures in the reflector which are spaced in such a way as to maximize the spatial identity of the beams reaching the first and second detectors.

Abstract: An interferometer, for use in spectrometry, is disclosed in which a more reliable synchronization of the starting points of successive analytical scans is obtained by combining:(a) a moving retro-reflector in the variable-length arm which reflects both the analytical beam and the reference beam;(b) stationary reflecting means in the variable-length arm providing a flat "folding" reflector which causes the path of at least the reference beam from the retro-reflector to be folded on itself and returned to the retro-reflector; and(c) stationary reflecting means for the reference beam in the fixed-length arm so located as to offset the reference interferogram with respect to the analytical interferogram. Two versions of the invention are shown, each having two disclosed embodiments. In one version all three of the beams (clock, reference, and analytical) are "folded" by means of mirrors located adjacent to the moving retro-reflector. In the other version only the reference beam is folded.

Abstract: A high-density electronic package module is disclosed which comprises a stack of semiconductor chips having integrated circuitry on each chip. To permit the emplacement of thin film circuitry on the access ends, each access plane is etched to cut back the semiconductor material then covered with passivation material, and thereafter lapped to uncover the ends of electrical leads on the chips.

Abstract: A multiplexer circuit is disclosed, for use with such signal sources as focal plane detector arrays, which contains a large number of parallel branches, each of which includes a transconductance MOSFET amplifier and a MOSFET switch of opposite channel polarity from the amplifier. The amplifier in each branch receives high impedance voltage signals originating from its individual detector and converts them with high power gain into current signals which feed into the common output line whenever the switch in the same branch is turned on. The multiplexer branches, together with the multiplexer control logic, and other electronic devices, are all included on a signal IC chip which provides CMOS logic.

Abstract: An accessory for optical spectroscopy is disclosed which combines a matched pair of off-axis paraboloid reflecting surfaces having their focal points at a common location on the reflecting surface of a sample. The entering and exiting beams are collimated. Preferably the paraboloid reflecting surfaces have co-linear, anti-parallel axes, and are part of a unitary structure which is rotatable around the collimated optical beam axis to vary the angle of incidence on the sample without altering the optical alignment, thereby allowing the specular reflectance component to be included or excluded, at will.

Abstract: A focal plane detector mosaic array is formed by securing wafers of the detector material to a focal plane having individual conductor leads embedded therein, ion milling to delineate separate detector islands in individual electrical contact with the conductor leads, and using ion implantation to form p-n junctions in the detector islands.

Abstract: A focal plane photo-detector mosaic array is disclosed in which thin stacked substrate layers extending in planes perpendicular to the focal plane provide closely spaced electrical contact points at the focal plane, and photo-detectors on the focal plane which individually communicate with those contact points are arranged in rows extending diagonally with respect to the planes in which the stacked substrate layers extend.

Abstract: An exerciser is disclosed, of the type providing automatically controlled variations of effort levels, wherein "random" variations of effort level are included which are not predictable by the operator. The effort levels [steps] are provided in a sequence of four: the second [step] level is random; the fourth [step] level is different from the second [step value] level by half of the range; and the first and third [steps] levels are averages of the immediately preceding and immediately following [steps] levels.

Abstract: A photo-detector array module is disclosed wherein: (a) the focal plane array of photo-detectors is in electrical contact with thin film conductors supported on thin ceramic layers extending perpendicular to the focal plane, and (b) sub-module structures, each composed of such layers, have complementary shapes (such as "O-shaped" and "I-shaped") to provide "component wells" for electronics within the three dimensional space defined at one end by the two-dimensional area of the focal plane. In order to fabricate such a module satisfactorily, a method is disclosed in which each unimaged layer (i.e., layer whereon the thin film conductors have not yet been photodelineated) is individually laminated to the prior structure, and the photo-delineation process on the unimaged layer includes an optical alignment step to insure alignment of the thin film conductors on each layer with those on preceding layers.

Abstract: A photo-detector array module is disclosed wherein: (a) the focal plane array of photo-detectors is in electrical contact with thin film conductors supported on thin ceramic layers extending perpendicular to the focal plane, and (b) sub-module structures, each composed of such layers, have complementary shapes (such as "O-shaped" and "I-shaped") to provide "component wells" for electronics within the three dimensional space defined at one end by the two-dimensional area of the focal plane. In order to fabricate such a module satisfactorily, a method is disclosed in which each unimaged layer (i.e., layer whereon the thin film conductors have not yet been photo-delineated) is individually laminated to the prior structure, and the photo-delineation process on the unimaged layer includes an optical alignment step to insure alignment of the thin film conductors on each layer with those on preceding layers.

Abstract: A motor control positioning apparatus and method are disclosed wherein variable duration pulses are fed to a DC motor. After the vicinity of the destination has been reached, the final pulsing stage is initiated, in which a short duration pulse is fed to the motor; position is then checked to determine if forward movement of the driven element has occured; and if movement has not occurred, the pulse duration is increased by an increment which is repeated until movement does occur. Thereupon a new series of such pulses is started; and this cycling continues until destination is reached.

Abstract: A digital motor control positioning system, and method, are disclosed in which lead screw position is measured by an encoder, and the error between that position and the destination is measured, either continuously or repetitively, to provide digital, distance-representing control pulses to the motor. In the final, settling-in portion of motor movement, it is successively started and stopped to provide incremental distance movements, which preferably are reduced in size as the destination is approached.

Abstract: A photo-detector array module is disclosed wherein: (a) the focal plane array of photo-detectors is in electrical contact with thin film conductors supported on thin ceramic layers extending perpendicular to the focal plane, and (b) sub-module structures, each composed of such layers, have complementary shapes (such as O-shaped and "I-shaped") to provide "component wells" for electronics within the three dimensional space defined at one end by the two-dimensional area of the focal plane. In order to fabricate such a module satisfactorily, a method is disclosed in which each unimaged layer (i.e., layer whereon the thin film conductors have not yet been photo-delineated) is individually laminated to the prior structure, and the photo-delineation process on the unimaged layer includes an optical alignment step to insure alignment of the thin film conductors on each layer with those on preceding layers.