Abstract: A passive infra-red detection apparatus is described, which comprises an infrared sensor array (16) mounted in a housing (10), and a focusing reflector system (20, 22) and focusing refractor (14) which focus infra-red radiation from different distance ranges onto the sensor array (16). The sensor array (16) comprises at least three sensing elements or groups of elements (16A, 16B, 16C) spaced apart transversely with respect to the lens axis of the focusing refractor (14). Thus in combination with a multiple reflector (20, 22) having at least three reflector surfaces and/or a multiple focusing refractor (14), the sensor array receives several different views spaced apart transversely thereby providing a wider viewing angle than the prior art construction. Thus, the present detector is more suited to use with a closed-circuit television (CCTV) surveillance system.

Abstract: An infrared array sensor system capable of sensing the position and orientation of a human body without using any expensive sensor elements required in conventional infrared array sensors and having functions enabling it to an air conditioner by a relatively simple construction. The infrared array sensor system includes a Fresnel lens for focusing infrared rays, a plurality of guides for guiding the infrared rays focused by the Fresnel lens in predetermined directions, a filter for filtering desired wavelength band ones of the guided infrared rays, a plurality of infrared sensor elements for sensing the filtered infrared rays, the infrared sensor elements corresponding to the directions of the infrared rays guided by the guides, respectively, and a circuit device for processing signals respectively outputted from the infrared sensor elements.

Abstract: A system for infrared sensing has thermally sensitive picture elements within a substrate; bias contact areas within the substrate and around a periphery of the thermally sensitive picture elements; a common electrode on a front side of the thermally sensitive picture elements and the bias contact areas; an optical coating on top of the common electrode; a first electrical contact metal on a backside of the thermally sensitive picture elements; and a second electrical contact metal connected to the bias contact areas on a backside of the bias contact areas and electrically connected to the common electrode. The bias contact areas may include a conductive substrate area. In addition, the device may be connected to an integrated circuit by an ohmic connection to the first and/or the second electrical contact metal.

Abstract: A heat source detector includes an infrared sensor 1 wherein plural infrared ray sensing elements 7 on which an infrared image is formed by an infrared lens 10 are arranged into an array form; and an infrared analyzer 2 which analyzes a detection signal detected by the infrared ray sensing elements 7. The infrared analyzer 2 has: an infrared intensity detecting unit 3 which detects the infrared intensity for each of the infrared ray sensing elements 7; an infrared center of gravity detecting unit 5 which obtains the center of gravity of a heat source emitting infrared rays, from the infrared intensities detected by the infrared intensity detecting unit 3, and a heat source moving direction detecting unit 6 which obtains the moving direction of the heat source, from temporal vector displacement of the center of gravity obtained by the infrared center of gravity detecting unit 5.

Abstract: A non-dispersive infrared analyzer and method for analyzing a concentration in a gas utilizes an infrared light source and a cell configured to have a gas flow therethrough. The cell also has an infrared light passage through which a sample gas stream and an infrared light beam can travel. A sector has at least two filters for filtering infrared light, and is provided with the apparatus. The sector alternately inserts the at least two filters into the infrared beam. A detector detects wavelengths of the infrared light beam which corresponds to an absorption band of the gas to be measured, and a second wavelength which corresponds to an absorption band of the preselected reference gas. The detector receives the infrared light beam after the light beam has traveled through the sample cell.

Abstract: An assembly for mounting a focal plane array. The assembly includes a fixture of thermally conductive material having a first substantially planar surface and a second surface. The fixture is attached to the focal plane array at the first surface and to a frame of a housing at the second surface thereof. In a specific embodiment, the assembly further includes a mechanism for aligning the fixture, with the attached array, to the frame and at least one flexible connector for electrically connecting the focal plane array to a circuit board disposed within the housing. In the illustrative embodiment, the alignment mechanism includes a clocking slot in the second surface of the fixture which is adapted to engage a protrusion on the frame.

Abstract: An infrared sensor apparatus has an infrared array element having infrared detection portions arranged at a plurality of positions in a two-dimensional array, and a plurality of infrared lenses arranged such that infrared images from a detection area divided into a plurality of portions are formed on the corresponding infrared detection portions without any superposition. These infrared lenses are a plurality of cylindrical lenses or Fresnel lenses.

Abstract: Thermal imaging system (10) includes a focal plane array (18) having pixels (20). Signals produced by pixels (20) are addressed by integrated circuit substrate (22) and passed to video processor (24). Video processor (24) includes, among other modules, a detection and substitution module (28) that detects defective pixels (21) and substitutes the signals produced by defective pixels (21). The detection and substitution of signals produced by defective pixels (21) may be performed while viewing the thermal scene (12) or while stimulating pixels (20) with a stimulus. A thermal stimulus may be generated by a thermoelectric cooler (50) thermally coupled to integrated circuit substrate (22) and focal plane array (18). An electrical stimulus to identify defective pixels (21) may also be delivered to pixels (20) of focal plane array (18).

Abstract: A radiation detector employs a thermopile having a potentiometer for calibrating the thermopile output to best suit a particular output meter and sensing application. A thermocouple may be connected in series with the thermopile. The output of the thermopile is calibrated to best match a linear function which intersects the thermopile output function at a temperature in the center of a temperature range of interest. A total output signal of the detector is the sum of the thermopile signal and the thermocouple signal, and is indicative of the temperature of a target emitting radiation sensed by the thermopile. The series connection of the thermopile and the thermocouple allow the thermopile hot junction temperature to be referenced to the cold junction temperature of the thermocouple. Thus, the reference temperature may be remote from the thermopile sensor. A filtering lens may be used to prevent short wavelength radiation from reaching the thermopile sensor, improving the linearity of the thermopile response.

Abstract: A double direct injection dual band focal plane array input circuit provides simultaneous and separate integration of the current from two sensors which share a common node. The sensors are constant voltage and variable current sensors such as HgCdTe infrared photodiodes. The sensor voltage biases are independently adjustable. Multiple integration of the signal from one sensor may be performed within one integration time of the other sensor. The circuit is used in staring infrared dual band focal plane arrays and may be used process information from more than two sensors.

Abstract: An automated interrupt driven system which employs a circular buffer is used to sort materials based on differing electromagnetic radiation absorption and penetration characteristics. The system has a conveyor and a source of electromagnetic radiation which radiates materials travelling along the conveyor. A controller samples detector outputs at various times to evaluate the absorption and penetration characteristics of the materials to be sorted, based on a plurality of samples. Portions of the materials are ignored to obtain accurate readings from the detectors. Based on the detected penetration and absorption characteristics, the controller activates ejection mechanisms causing materials of different compositions to be deposited into different bins. The controller executes interrupts to cause detection, ejection, testing, and system history maintenance at required times.

Abstract: The invention described forms improved ferroelectric (or pyroelectric) layer by adding lead to an original perovskite layer having an original ferroelectric (or pyroelectric) critical grain size, then forming a layer of the lead enhanced perovskite layer having an average grain size less than the original ferroelectric (or pyroelectric) critical grain size whereby the remanent polarization (or pyroelectric figure of merit) of the layer is substantially greater than the remanent polarization (or pyroelectric figure of merit) of the original perovskite layer with an average grain size similar to the average grain size of the layer. The critical ferroelectric (or pyroelectric) grain size, as used herein, means the largest grain size such that the remanent polarization (or pyroelectric figure of merit) starts to rapidly decrease with decreasing grain sizes. Preferably, n-type lead enhanced perovskite layer is doped with one or more acceptor dopants whereby the resistivity is substantially increased.

Abstract: A method and apparatus for mounting pyroelectric crystal elements and arrays on a molded plastic base. The molded plastic base includes a plurality of upwardly tapered plastic flexible legs which engage the pyroelectric crystal element or array at various points. The upwardly tapered plastic legs reduce to a nominal thickness of approximately 0.002 inches where they are fastened by epoxy onto the pyroelectric crystal element or array.

Abstract: An infrared detector, having improved infrared absorptance and operating performance at or near ambient as well as the cryogenic temperature ranges. The infrared detector, in one embodiment includes a multi-filament HgCdTe detector region mounted upon a CdTe substrate, a metallic reflective region placed in front of, or behind, the HgCdTe detection region forming a resonant layer between the reflective region and HgCdTe. Electrical contacts operable to detect the change in resistance of the HgCdTe detector filaments are connected to the detector region. Embodiment for a back surface illuminated detector device is described for use in the 8 micron to 12 micron, longwave infrared (LWIR) range. Improved operation in the LWIR range at higher temperatures results in detector arrays having decreased cooling needs and infrared detector systems produced with a significant decrease in overall system weight.

Abstract: The attitude of a satellite is determined by using an array of IR detectors receiving an image of space and the Earth. The detectors are positioned so that at least one detector monitors the radiance from the Earth's horizon and a second detector monitors a region of the Earth adjacent to said horizon. The output of the first detector is compensated for variations in the radiance of the Earth by using the output of the second detector.

Abstract: A substrate for attaching infrared detector elements to multi-layer modules has a detector interface member to which the infrared detector elements are attachable and which is attachable to the multi-layer module so as to provide electrical communication between the infrared detector elements and the multi-layer module. At least one removable tab is formed upon the detector interface member and a plurality of probing pads are formed upon each tab. Conductive conduits formed upon each tab extend from the detector interface member to the probing pads so as to facilitate electrical communication between dedicated ones of the infrared detector elements and dedicated ones of the probing pads. The probing pads facilitate electrical testing of individual infrared detector elements.

Abstract: A pyroelectric infrared detector used in the intrusion detection system, the detector including a housing having an opening, at least two infrared transmissive pyroelectric layers spaced to be mutually free from thermal influence; and a plurality of electrodes formed on the surfaces of each of the pyroelectric layer, the electrodes electrically connected to each other.

Abstract: A passive-type moving object detection system is disclosed. The system includes an infrared detector, infrared sensors mounted on the infrared detector, a detection field including two columns of detection regions for monitoring a human intruder and two rows of detection regions for detecting a non-human intruder. The columns have a height corresponding to a human height, and an optical system is located between the infrared detector and the detection field. The infrared sensors have infrared accepting areas that include first and second sections. The first section optically corresponds to the columns and the second section optically corresponds to the rows. Each sensor receives infrared radiation from a moving object passing through the detection regions. The detector includes an arithmetic circuit that subtracts the peak values of signals generated by the detector and a decision circuit to compare the result with a reference level.

Abstract: Radiation detectors are mounted in an optic focal plane of an infrared radiation sensor system. The radiation detectors produce output signals indicating detected radiation. The output signals are sampled by a sample-and-hold circuit and passed to a 1-bit comparator. The comparator produces a 1-bit signal at a high voltage level for samples of the output signal that are greater than a reference voltage and at a low voltage level for samples of the output signal that are less than the reference voltage. In this manner, the comparator reduces the effects of any gamma spikes on the measurement of intensity of radiation. The 1-bit signal is less susceptible to effects of interference than analog signals in conventional systems and the 1-bit comparator produces this 1-bit signal without consuming a great deal of electrical power. A multiplexor carries such 1-bit signals from the focal plane to a processor over less wires than in conventional systems.

Abstract: The attitude of a satellite is determined by using an array of IR detectors receiving an image of space and the Earth. The detectors are spaced so that at least in a central zone, the sun will not enter the optical field of more than one detector. The signals from each detector are monitored and if a signal is very high, indicating that the sun's image is falling on the detector, that signal is ignored.

Abstract: A detector apparatus uses two scanners on the right of way for monitoring the wheels of a moving train . The scanners scan the wheels transversely to the tracks along a common axis and generate wheel temperature signals. The signals corresponding to the wheel bearing end caps or housing lids indicative of the wheel bearing temperatures are separated and analyzed so that the apparatus can detect and indicate both hot wheel and hot bearing conditions.

Abstract: An infrared detector array having a plurality of infrared detectors arranged in a matrix of rows and columns in a first semiconductor body; and, a plurality of integration/read circuits arranged in a matrix of rows and columns in a second semiconductor body, each one of the plurality of integration/read circuits being in vertical registration with, and electrically connected to, a corresponding one of the plurality of detectors. Each one of the integration/read circuits includes: a capacitor; a first transistor, electrically coupling the capacitor and the corresponding one of the detectors during an integration mode, for enabling current generated in the detector in response to impinging radiation to pass from the detector to the capacitor for integration; and a second transistor, electrically coupling the charge built-up on the capacitor during the integration mode to an output bus during a subsequent read mode.

Abstract: An infrared detector particularly well suited for the detection of heat sources, specifically from fires in an outdoor environment. The infrared detector comprises an infrared sensor receiving infrared radiation from a focused refractive optical unit. The infrared radiation from the optical unit is appropriately filtered so as to optimize the reception of infrared radiation by the detector in a frequency band of within about 2.5 to 5 microns. The sensor is configured utilizing a linear matrix of individual infrared sensing elements which may be flexibly applied to modify the field of view of the sensor. The detector contains appropriate power and signal amplification circuitry so as to provide an electrical output signal corresponding to infrared radiation received in the desired frequency band.

Abstract: A detection system includes an infrared emitter (2) and an infrared detector (8) having optical axes (6) and (12) extending parallel to one another but being offset from one another. As the detector (8) and the emitter (2) approach one another the distance between them decreases but their angular separation increases. Accordingly, the increase in signal engendered in the detector as it approaches the emitter is countered to some extent by the greater angular separation. Accordingly, the net result is that any change in output of the detector resulting from a change in its spacing from the emitter is substantially reduced. Instead of the detector and emitter moving relative to one another they may be fixed and the light path between them varied by a moving reflector to achieve a similar result.

Abstract: A system for measuring the physical characteristics of a hydrocarbon places a reference hydrocarbon cell in thermal contact with a sample cell containing an unknown hydrocarbon. A near infrared spectrum measurement is taken of both the cells. Measurement data from the sample cell is adjusted by the measurement data from the reference cell, and the adjusted measurement data is evaluated by a model to predict the characteristics of the sample. The model is built from a teaching set of hydrocarbons having known physical characteristics and the reference hydrocarbon. Each of the teaching set hydrocarbons is measured and then adjusted by a measurement of the same reference hydrocarbon, and the adjusted measurements are used to build the model.

Abstract: A gas analysis device for the remote detecting, measuring and recording of NO, CO, CO.sub.2, HC, and H.sub.2 O levels from the exhaust (30) of moving motor vehicles (28) utilizes a source (11) of collimated infrared and ultraviolet radiation (15) and includes a detector unit (16) positioned on the opposite side of the roadway for receiving and measuring the infrared and ultraviolet radiation from the source (11) tranmitted through the vehicle exhaust. The detector unit splits the combined infrared and ultraviolet radiation into separate infrared and ultraviolet beams (42) and (40). The ultraviolet beam is diffracted onto a photodiode array in a spectrometer that generates a signal indicative of NO in the vehicle exhaust. A rotating reflector (27) time-multiplexes the infrared beam to a plurality of infrared sensors that generate electrical signals indicative of, for example, CO, CO.sub.2, HC, and H.sub.2 O in the vehicle exhaust. A computer (17) then computes the relative concentrations of CO, CO.sub.

Abstract: An uncooled IR array, in conjunction with an array of binary optical microlenses, having a large effective fill factor.

Abstract: A horizon sensor orbiting the earth views the earth's horizon in at least two points in the earth's summer and winter hemisphere and calculates pitch and roll information therefrom. The summer pitch and roll information is calculated at intervals long with respect to pitch and roll rates, but short with respect to weather variation. The pitch and roll information is then periodically corrected during a predetermined correction interval using the summer hemisphere pitch and roll information.

Abstract: A proximity detector for motor cars, to aid parking, has 3 infra-red transmitter units 10-1 to 10-3 producing a zone of radiation 36 and two receiver units 20-1 and 20-2 producing a zone 46 of sensitivity to the radiation. Each transmitter unit has 3 transmitter elements housed behind a common aperture, and each receiver unit has 2 receiver elements housed behind a common aperture, giving for each unit a polar diagram with at least two distinct directions of high magnitude, the axes of peak radiation or sensitivity from the elements of a unit being divergent through the aperture and forming the directions of high magnitude. An indicating device indicates the amplitude of the combined signal from the receivers by means of a pulsed tone the pulse frequency of which is varied.

Abstract: A detector for detecting edge cracks in the web in a papermaking machine includes a plurality of light sources for directing light at the web and a plurality of light sensors for receiving the light through the cracks for generating a plurality of signals indicative of the dimensions and shape of the crack. The size and shape of the cracks are determined from the sensor outputs by a processor and preferably displayed on a suitable display. Crack shapes are determined by introducing a delay parameter which relates the output for each detector channel to the time a first detector channel is triggered. In particular, the first detector channel which is triggered is given a delay value of zero, while other channels are given delay values greater than zero depending on the order of activation. The signal acquisition and analysis are designed to be compatible with a personal computer so as to ensure the system's portability.

Abstract: Gases such as pollutants are discerned in the open air, preferably using a laser to emit an infrared light beam along a sight path for illuminating the gases. A telescope is directed along the sight path and collects light from the gases, the combination of the laser and telescope permitting redirection of the sight path to any target, such as fugitive emissions of a stack. An optical tunable filter is coupled to the telescope for selecting a particular optical wavelength or band, and focusing the filtered wavelength on a detector. A processor 72) is coupled to the detector output and pulses the laser. The processor analyzes the light levels as a function of wavelength to discriminate for the presence of selected gases by determining a characteristic pattern of light absorption and light emission by the gases. The tunable filter has an acousto-optical crystal of Tl.sub.3 AsSe.sub.3, in which an RF acoustic wave is generated for varying diffraction of light by the filter, thereby selecting a wavelength.

Abstract: A bolometer for detecting radiation in a spectral range is described herein. The bolometer includes an integrated circuit substrate 122 and a pixel body 120 spaced from the substrate 122 by at least one pillar 124. The pixel body 120 comprises an absorber material 132, such as titanium for example, for absorbing radiation in the spectral range, which may be 7 to 12 microns for example. The absorber material 132 heats the pixel body 120 to a temperature which is proportional to the absorbed radiation. An insulating material 134 is formed over the absorber material 132. In addition, a variable resistor material 136, possible amorphous silicon for example, with an electrical resistance corresponding to the temperature of the pixel body 120 is formed over said insulating layer 134. A current flows through the variable resistor material 136 substantially parallel to the integrated circuit substrate 122 for detection. Other systems and methods are also disclosed.

Abstract: An automated interrupt driven system which employs a circular buffer is used to sort materials based on differing electromagnetic radiation absorption and penetration characteristics. The system has a conveyor and a source of electromagnetic radiation which radiates materials travelling along the conveyor. A controller samples detector outputs at various times to evaluate the absorption and penetration characteristics of the materials to be sorted, based on a plurality of samples. Portions of the materials are ignored to obtain accurate readings from the detectors. Based on the detected penetration and absorption characteristics, the controller activates ejection mechanisms causing materials of different compositions to be deposited into different bins. The controller executes interrupts to cause detection, ejection, testing, and system history maintenance at required times.

Abstract: A detection unit comprises a support element and at least one module connectable to the support element, each module comprising a housing and an infrared detector fitted therein. When connected each module has a defined circumferential position relative to the support element. Preferably, the detection unit is designed for fitting three modules which circumferentially enclose the support element, as well as a further module.

Abstract: A noncontact bench flotation sensor system for use with a flotation bench. The system comprises a plurality of reflectors that are disposed on the body of the bench, typically on the inside of the skirt or overhanging portion of the table surface of the bench. Each reflector is such that it reflects over a narrow region, or angle. Two sensor assemblies, preferably infrared, are disposed adjacent each reflector and are located on each leg of the bench. Each of the sensor assemblies is comprised of an transmitter and an detector. The two sensor assemblies are separated by a distance that corresponds to upper and lower limits of bench flotation. The sensor assemblies transmit infrared energy, for example, at the reflector. In the event that the isolator moves to a point where one of the transmitters is aligned with the reflector, energy is reflected back to the associated detector, and the reflected energy is detected.

Abstract: A proximity detector for motor cars, to aid parking, has 3 infra-red transmitter units 10-1 to 10-3 producing a zone of radiation 36 and two receiver units 20-1 and 20-2 producing a zone 46 of sensitivity to the radiation. Each transmitter unit comprises 3 transmitter elements housed behind a common aperture, and each receiver unit comprises 2 receiver elements housed behind a common aperture, giving for each unit a polar diagram with at least two distinct directions of high magnitude, the axes of peak radiation or sensitivity from the elements of a unit being divergent through the aperture and forming the directions of high magnitude. An indicator indicates the amplitude of the combined signal from the receivers by providing a pulsed tone the pulse frequency of which is varied.

Abstract: A radiation detector employs a thermopile having a potentiometer for calibrating the thermopile output to best suit a particular output meter and sensing application. A thermocouple may be connected in series with the thermopile. The output of the thermopile is calibrated to best match a linear function which intersects the thermopile output function at a temperature in the center of a temperature range of interest. A total output signal of the detector is the sum of the thermopile signal and the thermocouple signal, and is indicative of the temperature of a target emitting radiation sensed by the thermopile. The series connection of the thermopile and the thermocouple allow the thermopile hot junction temperature to be referenced to the cold junction temperature of the thermocouple. Thus, the reference temperature may be remote from the thermopile sensor. A filtering lens may be used to prevent short wavelength radiation from reaching the thermopile sensor, improving the linearity of the thermopile response.

Abstract: A gas analysis device (10) for the remote detecting, measuring and recording of NO.sub.x, CO, CO.sub.2, HC and H.sub.2 O levels from the exhaust (30) of moving motor vehicles (28) utilizes a source (11) of collimated infrared and ultraviolet radiation (15) and includes a detector unit (16) positioned on the opposite side of the roadway for receiving and measuring the infrared and ultraviolet radiation from the source (11) tranmitted through the vehicle exhaust. The detector unit splits the combined infrared and ultraviolet radiation into separate infrared and ultraviolet beams (42) and (40). An ultraviolet sensor (44) receives the separate ultraviolet beam and generates a signal indicative of NO.sub.x. A rotating reflector (27) time-multiplexes the infrared beam to a plurality of infrared sensors that generate electrical signals indicative of, for example, CO, CO.sub.2, HC and H.sub.2 O in the vehicle exhaust. A computer (17) then computes the relative concentrations of CO, CO.sub.2, HC, NO.sub.x, and H.sub.

Abstract: A rapid near-infrared instrument for measuring constituents of nonhomogeneous samples is disclosed which alleviates the need for taking successive measurements of the sample, and repositioning the sample for each successive measurement, by providing a novel illumination system including a light pipe which transmits near-infrared energy to the sample at a plurality of substantially separate and independent location. This arrangement permits a plurality of subsample measurements to be taken simultaneously which enables accurate constituent measurements to be made quickly and easily.

Abstract: A filter inspection apparatus for inspecting filters comprises a support frame for supporting a substantially tubular filter having inner and outer surfaces for rotation about its axis, a source of EMR for directing radiation along one of the inner and outer surfaces of a filter, an EMR sensing unit mounted adjacent to the other of the surfaces for sensing EMR passing through the filter and generating a signal, and an indicator responsive to the signal for indicating passage of EMR through the filter.

Abstract: At least one detector element (1) of cadmium mercury telluride or other infrared-sensitive semiconductor material is sandwiched between a substrate (20) and a lens plate (10) or other optical element. When an adhesive layer (11) is used to secure the lens plate or substrate over the detector element (1), there is found to be an unexpected decrease in cut-off wavelength and increase in junction resistance. In experiments leading to the invention, these changed characteristics were found to result from stress induced in the semiconductor material (1) by contraction of the adhesive (11) which led to a change in the energy bandgap of the semiconductor material (1). The stress is reduced and changes in characteristics minimised by adopting a slotted layer structure 1 and 8, in which the element body (1) is part of a wider layer (1 and 8) of the semiconductor material which occupies a majority of the volume around the element body (1) between the substrate (20) and the optical element (10).

Abstract: A confocal scanning optical microscope in which a specimen under test is simultaneously scanned with two distinct spots or slits of illumination and two output beams emitted from the specimen due to reflection or fluorescence are descanned and passed to separate stationary confocal apertures and detectors.

Abstract: A method for measuring thermal differences in infrared emissions from semiconductors, the method utilizing an image sensor including an array detector having a plurality of detector elements which produce signals corresponding to semiconductor radiation emission focused thereupon by an optical lens system. At least one bandpass filter is utilized to substantially filter that portion of the semiconductor radiation emission having wavelengths greater than 5 micrometers. The detector element signals are processed to identify performance degrading phenomena occurring in the semiconductor device.

Abstract: The invention relates to a multispectral sensor with several filters and sensor elements for different spectral ranges of a radiation to be measured. The object of the invention is to so further develop a multispectral sensor of this type that it can be manufactured as a discrete component with small dimensions and has a high measuring accuracy, whilst obtaining a high output signal. This object is achieved in that the beam is broken down by an optical device into several partial beams and reflected onto filters. Behind the filters are located radiation-sensitive elements, which detect the spectral range corresponding to the transmission range of the in each case upstream filter. The remaining spectral range of the partial beam is reflected by the filter surface towards the other filters. Thus, each filter is supplied with the associated spectral ranges of all the partial beams.

Abstract: Multispectral signature analysis techniques are used to reliably separate a missile electro-optical signal from a background. The system provides higher reliability and reduced complexity when compared to conventional approaches.

Abstract: In order to detect the movement of a heat source over a widened range by using a reduced number of pyroelectric type infrared sensors, a sensor section includes two infrared detecting means X and Y. The area to be observed by the infrared detecting means X is divided into two zones A and B while the area to be observed by the infrared detecting means Y is divided into two single zones a and b. The single zones A and a are overlapped on each other to form an overlap zone (A, a). The movement of the heat source between the single zone B and the single zone b, between the overlap zone (A, a) and the single zone B and between the overlap zone (A, a) and the single zone b is judged to detect the movement of the heat source over the entire area to be observed by the sensor section. In such a manner, two infrared detecting means can cover three zones to be observed.

Abstract: A dual pyroelectric-effect sensor having the sensing elements aligned in a motion plane permits direction determinations to be made for moving IR sources. Dual sensing-element PIR sensors provide different voltage outputs depending upon a relative direction of movement of an object and the sensing elements. By alternating the effective polarizations of the sensing elements in the PIR sensor, clear direction information is available from the PIR sensor. A direction detecting circuit working in cooperation with a switch controller employing a counter and a timer, permits independent tallying of entrances and exits. Upon the counter indicating that the number of objects that exited the area equals the number of objects that entered, the lights are immediately extinguished. The timer ensures that the lights turn off should incorrect values become recorded in the counter.

Abstract: A microstructure design for high IR sensitivity having a two level infrared bolometer microstructure, the lower level having a reflective metal film surface such as Pt, Au, or Al to reflect IR penetrating to that level, the upper level being separated from the lower level by an air gap of about 1-2 microns which allows the reflected IR to interfere with the incident IR and increase the sensitivity to a higher level.

Abstract: A passive intrusion alarm system having an array of infrared sensing elements arranged and sampled so as to provide a two dimensional thermographic image of an intruder.

Abstract: An optical data transducer system is described which comprises a cryogenic dewar for containing an infrared focal plane array at low temperature and an optical spatial light modulator, collimated laser beam and associated optical train and detector for efficient extraction of information from the array.