Abstract: Means for digitizing and averaging the signals in an optical time domain reflectometer are disclosed in which a comparator is used to output a 1 or 0 into an arbitrarily large number of successive time-bins. In each comparator choice, the analog voltage signal from the OTDR receiver is compared to a selected analog voltage value. The selected value is chosen randomly from the range of available signals in the interval of interest; and each such valve is used to provide a comparator input into every time-bin during one waveform recovery.Each comparator output signal (1 or 0) is directed to a separate time-bin (counter), representing the desired time interval (resolution). Subsequent comparator output signals are added to each time bin. The waveform recovery runs are repeated until an acceptable signal-to-noise result is achieved. Each waveform run uses a different voltage for comparison to the receiver voltage.

Abstract: A bump bonding process and product are disclosed in which both pressure and heating are used in situations where the temperature should not exceed a predetermined amount, e.g., bonding of a photoconductor array to a module containing electronic processing devices. The bonding process involves eutectic alloying of indium and bismuth, allowing welding of the bumps at a temperature substantially below the two metals' melting points. In one version of the invention, bumps on adjacent substrates are directly aligned. In another version, each bump on one substrate is wedged between a pair of bumps on the other substrate.

Abstract: A spectrometer system is disclosed in which a plurality of computers are linked by cable carrying serial electronic signals. At least one control computer, and at least one optical head computer are linked by a local area network system (LAN), which includes means for parallel-to-serial signal conversion of the outgoing signals at each computer, and means for serial-to-parallel signal conversion of the incoming signals at each computer. The system permits remote control of multiple optical heads, a characteristic which is particularly important in process control and environment monitoring situations.

Abstract: This application discloses a system in which a single optical time domain reflector is used to monitor a plurality of cables. In one embodiment two lasers having different wavelengths are separately fired into different cables, and the returning signals are fed into the appropriate port of a wavelength dependent coupler. In another embodiment, each laser simultaneouly checks two cables having different lengths, the length difference permitting identification of the cable in which a fault has occurred.

Abstract: A solar power plant and still is disclosed in which a heat source for a Rankine Cycle engine is provided by a shallow pond which is covered by a sheet of suitable material, i.e., plastic; and which has a layer of air between the pond and the cover, flowing in accordance with a flue-induced motion, and moving water vapor from the pond through the flue. Because both the ambient air and the water supply enter at the periphery of the pond, at a location remote from the flue, their temperature gradients both rise from the pond periphery toward the flue.

Abstract: A microscopic unit for a multi-station modular FTIR spectrometer system is disclosed. The microscope unit, which has a Cassegrain objective, not only provides the usual optical path for radiation during visual observation, and for infrared radiation in the transmission mode, but also provides a separate optical path for infrared radiation in the reflectance mode and in a macroscopic transmission mode.

Abstract: An infrared microscope is disclosed in which two adjustable field stops are included. One is used to determine the illuminated area at the sample when the microscope is used in the transmission mode. The other is used to determine the illuminated area at the sample when the microscope is used in the reflectance mode. The latter field stop is imaged in the plane of the former; and the radiation in the reflectance mode passes through the former field stop both as it passes to the sample and as it returns from the sample after reflectance.

Abstract: A running/walking machine, or treadmill, is disclosed which has an automatically controlled speed-varying electric motor and an automatically controlled elevation-varying electric motor. The commands are entered in a display panel having a microprocessor which communicates with the motor controlling circuitry. The display panel has feedback information in a pictorial display, controlled by the microprocessor, in which an oval track simulating a running track displays both the current position of the user in moving around the track and the percentage of completion of a pre-established goal. The track has a multiplicity of segments, each represented by an LED, and each constituting a given fraction of the distance represented by the complete track. A lighted LED, which changes as the user progresses, indicates the current position of the user; and a string of LEDs behind the LED indicates the portion of the total program which has been completed.

Abstract: A spectroscopy system is disclosed which obtains analytical information from an internal reflectance element (IRE) deeply immersed in a container. The system is designed to provide adequate radiation throughput under difficult conditions. A plurality of embodiments deal with the optical element(s) at the bottom of the tube and the optical element(s) above the tube which direct post-interference radiation downward in the tube and receive post IRE upward radiation for re-direction to the detector.

Abstract: An optical/electronic real time image motion transfer system is disclosed in which voltage output signals from photodetectors in an array are fed through a switching network. This network includes intermediate buses, electronic switching devices between such buses and addresses of the signals from the photodetectors, and electronic switching devices between such buses and addresses of the signals which are fed to the output lines. The output lines preferably receive their multiplexed signals from filters, or bins, which have stored (and thus integrated) successive voltage signals from individual pixels.

Abstract: A spectrometer system is disclosed in which a single ended internal reflectance element (IRE) is readily insertable into, and removable from, liquid samples being analyzed. The IRE is carried by an articulated housing construction having enclosed radiation passages, through which radiation is directed by a plurality of mirrors. The IRE-supporting enclosure is pivotally mounted by means of aligned rotatable members, which permit the IRE to be moved into and out of samples without disconnecting or re-purging the enclosed radiation passages.

Abstract: A chromatography sample transfer process is disclosed in which fractions on a TLC plate are automatically moved by capillary action from the plate to separate receptacles adapted to retain material for diffuse reflectance measurement. The developed TLC plate is so mounted that its fractions are horizontally spaced, and its lower edge is in a solvent. As the solvent moves upwardly due to capillarity, it dissolves the fraction samples, and transfers them to a plurality of horizontally spaced wicks. The wicks, which are preferably made of sintered stainless steel powder, carry their solvent/sample material upwardly to separate receptacles, each containing transparent powder which retains the sample during diffuse reflectance measurement. The solvent is removed from the receptacles by horizontal airflow (air knife) without requiring significant heating.

Abstract: A spectrmeter radiation transmission system is disclosed which permits concurrent availability of numerous alternative accessory devices by conserving radiation throughput. Parabolic reflectors are used to provide alternating collimated and confocal segments of radiation, thereby largely eliminating the problem of vignetting (i.e., loss of radiation throughput due to beam size expansion). Modular enclosure elements are provided, inside which the radiation path travels between the parabolic reflectors.

Abstract: A machine positioning apparatus and method are disclosed in which motor control values are established by causing intentional overshoot of the destination, and automatically reducing the motor control values each time an overshoot occurs. The system disclosed is a three stage system in which: (1) the first stage is a continuation motion relatively fast stage wherein the motor control values relate to the distance traveled; (2) the second stage is a much slower stage in which a series of interim targets are set, each of which is at a distance from current position which is a fraction of the remaining distance to destination, the motor control values during the second stage being motor duty cycle values; and (3) the third (final) stage is the slowest and involves setting a series of interim targets to be passed, each of which is substantially the current position, the motor control values during the third stage being motor duty cycle values.

Abstract: A spectrometer construction is shown in which the chassis of the spectrometer is fabricated by stamping, punching, and bending sheet metal. The mirror supports and other elements are also formed from sheet metal. Precision locations are assured by tab and slot, or half-shear and recess, matching of the sheet metal parts. The mirrors in the spectrometer (other than those in the interferometer) are secured directly to vertical sheet-metal walls without intervening adjustments. The mirrors have unitary reflection and backing structures formed either by a diamond-cutting lathe, or by precision plastic molding. The same mirror locating means are used both during formation of each curved mirror surface and also in assembling of the mirror body in the spectrometer.

Abstract: A thermal imaging system is disclosed in which infrared radiation from the viewed scene is transmitted to a two-dimensional detector array carried on the focal plane of an optical/electronics module which has embedded in it amplifying, filtering and multiplexing circuitry utilizing MOSFET transistors. The module is located inside the cooling device. Cooling requirements depend on the alternatives (a) of using detectors responsive to wavelengths in the 3.0 to 5.0 micron range, which require less cooling, or (b) of using detectors responsive to wavelengths in the 8.0 to 12.0 micron range, which require liquid nitrogen cooling. The two-dimensional detector array may be combined with a limited scanning, called "nutation", which causes each detector to view a plurality of pixels in the incoming infrared radiation.

Abstract: Circuitry for a focal plane pre-amplifier is disclosed in which the input of the pre-amplifier is switched between the signal from its photo-detector and a connection to ground. During the ground-connected interval, the pre-amplifier transistor is temporarily diode-connected in such a way that the transistor's voltage is stored on a capacitor, which is connected between the incoming photo-detector signal and the input of the pre-amplifier transistor. During the photo-detector connected interval, the voltage stored on the capacitor is subtracted from the voltage signal supplied by the photo-detector.

Abstract: A modular spectrometer system is disclosed which includes various types of standard building blocks which permit: (a) a multiple accessory system in which experiments can be readily switched from one accessory to another; and (b) easy and cost effective revision of the multiple accessory system as desired. Optical switch components are provided which facilitate steering and switching of the radiation paths, and which are capable of being assembled from standard parts. Modular connecting tubes and interface elements are provided to interconnect components in the system. Component substitutions and position adjustments may be readily accomplished without loss of alignment in the system.

Abstract: A focal plane electronic system is disclosed, in which a two-dimensional array of photo-detectors receives pixel information from a scanned scene. Each pixel is observed by a plurality of detectors, and their signals are summed by time delay and integration (TDI) circuitry. The TDI circuitry comprises parallel capacitors which are charged and discharged under the control MOSFET switches. The discharge timing is such that all the detector signals representing a given pixel arrive simultaneously at a summing node. Means are included for automatically reducing the effect of anomalous detector signals on the summed output. The entire TDI system is included in a Z-type three-dimensional focal plane module.

Abstract: An accessory for use in the sample region of a spectrometer is disclosed which combines a matched pair of off-axis paraboloid reflectors having their focii optically imaged on the sample (either imaged at a common point or at two points which are optically imaged on each other) and having relative locations and orientations such that each ray of radiation strikes the two reflectors at points on the reflectors having approximately the same focal lengths. This arrangement involves the use of collimated optical beams into and out of the accessory. The accessory may function as a transmission-type accessory, in which the radiation passes through the sample, or as an internal reflectance accessory, in which the radiation passes through the sample holder but is reflected by the sample. The focal length relationship set forth is accomplished by having the "back-to-back" paraboloid reflectors, i.e., their reflecting surfaces face in substantially different, preferably opposite, directions.