Abstract: A night vision system 10 is provided for detecting objects at relatively low visible light levels. The system 10 includes an infrared light source 14. The system 10 further includes a thin sheet optical element 16 extending along a first axis 27 receiving light from the infrared light source 14 and reflecting the light generally in a first direction. Finally, the system 10 includes an infrared camera for receiving the light reflected off objects in the environment and generating a video signal responsive to the received light.

Abstract: An IR camera comprises an IR Focal Plane Array having a number of detector elements as sensor devices, an optical system focusing an object onto the Focal Plane Array, and a signal processing system connected to the Focal Plane Array. The camera also has a modular structure comprising a camera housing provided with the Focal Plane Array and the signal processing system, an absorbent/emitting shielding device connected to the camera housing, and an optical focusing system removably mounted to the shielding device.

Abstract: A detector with wide detecting range comprises a module of electrical circuit boards including an infrared radiation detector element; a stacked-up multifaceted arc lens assembly installed in front of the detector element which being located at the focus of the arc lens assembly to receive said focused infrared rays; and a single deflector plate being conjoined to the detector element and mounted on the electrical circuit board, the signal deflector plate having a symmetrically constructed reflecting units. Each reflecting unit is composed of at least two reflection planes. The invention is capable of covering detection blind zone exceeding 60 degrees both in right and left directions of the central axis of the detector element, hereby achieving a wide detecting range of over 200 degrees. A method of extending the detecting range is also taught.

Abstract: A concentration detection system with a radiation source device which outputs a collimated beam of radiation across a sample path having an unknown concentration of fluid of interest and a detector device including a sample sensor, a reference sensor, and an integrating lens positioned to integrate the collimated radiation passing through the sample path evenly over the sample sensor and the reference sensor so that the instantaneous fields of view of the sample sensor and the reference sensor are the same to equalize any obscurations effects thereof.

Abstract: A developability sensing system with an optical sensor for measuring the density of imaging material samples on an imaging surface of a printer, with an illumination source and photosensor system for measuring the amount of reflected illumination from the imaging materials. A first lens system and its first photosensor may receive both specularly and diffusely reflected illumination from certain imaging materials. A separate lenslet system is positioned outside of the first lens system. It may comprise one to four spaced apart generally cylindrical lenslets with a central axis generally perpendicular to the imaging material sample and an end surface facing the imaging material sample defined by a segment of a hyperbolic curved surface to form a rotationally symmetrical lens with a hyperbolic cross-section.

Abstract: Infrared radiation receivers (40, 72) of this invention include non-imaging optical concentrators (18, 70) having light exit surfaces (52, 86); a light sensor (46) having a light entrance surface that is separated from the light exit surface by a small air gap (53); and a soft, pliable, light transmissive medium (100, 110) inserted in the gap to reduce the light transmission loss across the gap. The soft, pliable medium is held in place by either a recess (116) in the concentrator or by a surrounding annular ring (104).

Abstract: The present invention is a device for detecting modulated or active infrared light comprises a photodiode mounted on the base aperture of a wave guide for focusing infrared light onto the photodiode. The wave guide is preferably pyramid shaped and has a reflective surface on the inner surface. The apex of the wave guide comprises an acute angle from about 5 degrees to about 10 degrees. Units to process the signal and amplify the signal are attached thereto. The device may also include a Fresnel lens and a means to adjust the voltage of the active infrared signal processing means to improve detection capabilities.

Abstract: An infra-red camera apparatus having a primary mirror assembly formed in a first molded plastic housing; and, a secondary mirror assembly formed in a second molded plastic housing and disposed in front of and in optical alignment with the primary mirror assembly for collecting an image. The first and second housings snap together for assembly of the camera. A focal plane array is disposed in optical alignment with the primary and secondary mirrors for receiving an image focused thereon by the secondary mirror. A substrate is added for supporting the focal plane array and system electronics, which are responsive to images formed on the focal plane array.

Abstract: A night vision system 10 is provided for detecting objects at relatively low visible light levels. The system 10 includes an infrared light source 14. The system 10 further includes a thin sheet optical element 16 extending along a first axis 27 receiving light from the infrared light source 14 and reflecting the light generally in a first direction. Finally, the system 10 includes an infrared camera for receiving the light reflected off objects in the environment and generating a video signal responsive to the received light.

Abstract: The present invention is a device for detecting modulated or active infrared light comprises a photodiode mounted on the base aperture of a wave guide for focusing infrared light onto the photodiode. The wave guide is preferably pyramid shaped and has a reflective surface on the inner surface. The apex of the wave guide comprises an acute angle from about 5 degrees to about 10 degrees. Units to process the signal and amplify the signal are attached thereto. The device may also include a Fresnel lens and a means to adjust the voltage of the active infrared signal processing means to improve detection capabilities.

Abstract: A passive-type infrared detector 1 includes an infrared sensor 3, a pair of lens elements (optical elements) 4R and 4L, a pair of mirrors 5R and 5L and a casing 2. The lens elements 4R and 4L are used to define detection areas a+ and a− opposed substantially 180° to each other for the infrared sensor 3. The mirrors 5R and 5L are used to direct infrared rays of light from the detection areas towards the infrared sensor 3. When this passive-type infrared detector 1 is installed at a position intermediate of an alert region, a combination of the infrared sensor 3, one of the lens elements 4R and one of the mirrors 5R is effective to monitor a range from one end of the alert region to the intermediate position whereas a combination of the infrared sensor 3, the other of the lens elements 4L and the other of the mirrors 5L is effective to monitor a range from the opposite end of the alert region to the intermediate position. Therefore, one half of the alert region may be a detection distance.

Abstract: A system for providing recognition of an approaching object located in a distant no-light environment includes an illumination source for transmitting light to the distant object and an imaging device for detecting the light radiation reflected from the distant object to generate an image of the distant object corresponding thereto. The system also includes an independent digital signal processor for calculating a desired optical magnification of a lens of the imaging device as a function of a distance between the imaging device and the distant object and generates a voltage corresponding thereto. The digital signal processor applies the voltage to the digital zoom circuitry of the imaging device to adjust the magnification of the lens so that the image of the distant object is held in a fixed dimension.

Abstract: A method and apparatus for improving the sensitivity, angular resolution and range of motion detectors, occupancy sensors and similar systems are described. Specifically, an improved infrared input and detection section is described which utilizes two dual-detectors configured to optimally operate equivalent to a single quad-detector.

Abstract: Apparatus for measuring the temperature of an electrically heated pot which uses the Planck formula and employs an infrared reflective hemisphere; first and second infrared wave guides, and first and second infrared filters and infrared detectors as well as a calculating device.

Abstract: A lens array for directing infrared light or radiation to a passive infrared detector having at least two Fresnel lenses mounted on or incorporated into the lens array. Each of the lenses has a different infrared detection pattern and the lenses on the array are adapted to be selectively indexed so that the infrared detection pattern of the array is altered by the indexing. The indexing may be accomplished by rotating the lens array or by the linear movement of the lens array.

Abstract: A motion detector based on mirrored optics for use in decorative lighting fixtures. The motion detector includes a mirror assembly that may be disposed within decorative elements such as saucers and chimneys that are common elements of lighting fixtures. Apertures are defined in the decorative element to admit infra-red radiation, which impinges on the mirror assembly. The mirror assembly comprises a plurality of opaque elongate members that are azimuthally spaced about a central longitudinal axis in such a way as to define an alternating sequence of open elongate slots and opaque elongate members. Each elongate member is formed with a mirror face on its inner surface which is generally facing the central longitudinal axis, and a PIR sensor is also disposed at the longitudinal axis.

Abstract: A motion detector assembly for a decorative lighting fixture that conceals the presence of the motion detector in a decorative element integrated into the design of the lighting fixture and that uses only mirrored optics instead of Fresnel lenses. The motion detector assembly includes a housing having a decorative external appearance harmonious with the style of the lighting fixture and forming an integral part of the lighting fixture. Included within the housing are a mirror assembly and PIR sensor. The mirror assembly includes a number of mirror faces that define a number of monitored zones in the field of view. Each respective mirror face defines an optical path in which radiation admitted through an aperture in the housing from an associated zone is directed to the sensor solely by the respective mirror face without the need for secondary mirrors or auxiliary lenses to complete the optical path.

Abstract: A movement detector includes a lens and a kaleidoscopic mirror. The movement detector is very sensitive and has a very small diameter.

Abstract: An infrared motion sensing apparatus mounted within the canopy of a decorative lighting fixture where the apparatus may be vertically adjusted. The apparatus comprises a pyroelectric infrared sensor located in a stationary base. Mounted over the sensor and movable in a vertical direction is a Fresnel lens array. The array is mounted to a frame that is constrained to ride on the base in a vertical direction in response to the rotation of a screw. The canopy has an opening to allow radiation to be received by the sensor and a second opening for a stem of the screw so that manipulation of the stem may take place without disassembly of any part of the lighting fixture.

Abstract: A universal multifunction sensor having multiple optical designs and providing a plurality of parameter sensors in one sensor module which can interface with and control operation of one or more processor control systems in an occupied space networked environment. The universal multifunction sensor comprises a passive infrared occupancy sensor and an ambient light sensor. A common network communications and control processor coupled to a common communication transceiver are shared in common by the occupancy sensor and the ambient light sensor, such that the multifunction sensor can interface with and control operation of one or more processor control systems in an occupied space networked environment.

Abstract: A method for use on a satellite that automatically inhibits scanning of an Earth sensor to handle sensor intrusions by the sun, moon, or other celestial bodies. In implementing the method, a predicted state vector for the satellite, derived from an orbit propagator, is generated. An attitude profile for the satellite is generated. Then, the satellite state (predicted state vector) and attitude profile are processed to determine Earth, sun, and moon vectors in a satellite body frame of reference at any instant. The Earth, sun, and moon vectors are compared to the Earth sensor field of view and sensor field of view limit boxes to determine if scan inhibiting or Earth sensor switching should occur. The affected Earth sensor is inhibited or switched if an intrusion of the sun and/or moon into the field of view of the Earth sensor is predicted.

Abstract: An infrared photosensitive area is constituted by an infrared ray absorbing part that is heated by infrared rays, a thermal detector that detects the temperature change of the infrared ray absorbing part, and electrodes that are electrically connected to the thermal detector. The infrared photosensitive area is held up above one surface of a substrate by supports. The electrodes of the infrared photosensitive area are electrically connected to contact pads on the substrate by wiring material that constitutes the support. A shield projects from portions of the infrared ray absorbing part other than portions that correspond to the electrodes. The contact pads of the substrate and the surfaces of the electrodes and the supports that are directed away from the substrate are covered by the shield with an interposed space. This configuration enables an increase in the fill factor of the picture elements of the thermal infrared detector and enables greater absorption of infrared light.

Abstract: A passive infrared sensor uses a modified lens or mirror to vertically elongate the detection zones in regions close to the sensor. This vertical elongation reduces the signal produced by a small pet, such as a cat, while the greater height of a human intruder produces a larger signal.

Abstract: The infrared detector contains an entrance window for infrared radiation, an infrared sensor with an evaluation circuit and an anti-masking device having an optical transmitter and an optical receiver for detecting phenomena or optical changes immediately in front of the detector and/or changes in the optical properties of the entrance window. The signals of the anti-masking device are evaluated in two channels, wherein one channel responds to temporally limited phenomena or changes and the other channel responds to temporally stable phenomena or changes. A combined evaluation of the signals in the two channels takes place. In the combined evaluation, the channel processing the signals of the infrared sensor is preferably also included. As a result, the infrared detector acquires an increased immunity to false alarms and a higher sensitivity.

Abstract: The invention relates to detection performed over millimeter and submillimeter wavelengths, especially to imaging solutions functioning over a submillimeter-wavelength range. The system of the invention uses detectors, comprising antenna coupled bolometers together with wavelength selective optics. The detector matrix is preferably curved for reducing the number of imaging errors. In order to provide a curved detector matrix, the detector matrix is constituted by flat submatrices, each being provided with one or more integrated antenna coupled bolometers. The detectable frequency range is preferably limited in two stages, first by means of wavelength selective optics and secondly by means of the operating band of the antenna of an antenna coupled bolometer. In order to focus the incoming radiation on bolometers, the bolometer substrate is fitted or the surface or interior of the bolometer substrate is provided with a bolometer lens or a corresponding optical element in alignment with each bolometer.

Abstract: A passive infrared detection system which has a wide angular field of view and a flat or nearly flat front surface. Input optical elements direct and/or focus incident peripheral infrared radiation onto one or more internal Fresnel lens arrays and/or a sensitive area of a detector, including radiation having incident angles of less than about 30°. Because of the absence of protruding elements improved performance and greater functionality can be obtained by employing larger or multiple infrared input windows and/or opto-electronic sections without degrading the aesthetic appearance of the unit.

Abstract: A sensor device includes a mounting frame having open front and rear ends, and right and left inner side walls opposite to each other in a longitudinal direction and extending between the front and rear ends so as to define a passage. The mounting frame is adapted to be mounted such that the body of a user of the sanitary apparatus will be sighted by the passage. A sensor body is inserted into the passage, and has a front side proximate to the front end to emit and receive a light signal, and right and left lateral walls that face respectively and spacedly the right and left inner side walls. A pair. of pivotally mounting members are respectively disposed between the right lateral and inner side walls, and between the left lateral and inner side walls such that the pivotally mounting members effect pivotal mountings which are pivotable between angular positions about an axis parallel to the longitudinal direction.

Abstract: A multiple sensing technology-based occupancy sensor including a unique sensor case assembly and sensor mounting scheme. The result is an occupancy sensor that is adjustable to provide broader ultrasonic pattern coverage and an ability to focus infrared energy from a variety of directions. In addition, the unique mounting scheme permits simple and efficient installation of the occupancy sensor.

Abstract: A sensor element includes a light detecting section (2), a wiring section and a microlens section (7, 8). The light detecting section (2) is formed to be spaced from a substrate (1) to detect an incident light. The wiring section is composed of leg sections (3, 4) and outputting sections (11, 12) formed to be spaced from the substrate in a peripheral portion of the light detecting section. The wiring section connects the detecting result of the light detecting section to patterns on the substrate. The microlens section is formed to be spaced from the light detecting section to collect and output the incident light to the light detecting section. An area of the light detecting section is equal to or smaller than ¼ of an area of the sensor element. The sensor element may further include a reflecting film formed under the light detecting section to reflect the incident light which passes through the light detecting section.

Abstract: An improved infra-red lens array for use in a passive infra-red intrusion sensor, which maintains high detection capability for intruders moving in the middle and near field, and yet discriminates well between the movement of intruders and of pets in the near field. The upper part of the lens array is composed of at least one row containing convex lenses, operative to focus the far and middle field radiation of the area to be protected onto the detector of the sensor. The lower part of the array has at least one row containing cylindrical lenses, with their axes of symmetry aligned vertically, operative to focus infra-red radiation from the middle and near fields onto the detector. Each cylindrical lens focuses a vertical curtain of the protected area onto the infra-red detector.

Abstract: A device for detecting thermal radiation having a detector and a reflector type concentrator. The detector is arranged to have one or more portions exposed to thermal radiation and one or more portions protected from thermal radiation, wherein the detector delivers detection signals on the basis of a temperature difference between the exposed portions and the protected portions. The detector supports pairs of planar thermocouple elements having a cold junction in contact with the protected portion of the detector and a hot junction in thermal contact with the exposed portion of the detector. The reflector type concentrator concentrates thermal radiation coming from a three-dimensional zone. The detector and the reflector type concentrator are combined to define a zone under surveillance and detect any change in the state of thermal unbalance in the zone under surveillance.

Abstract: A non-imaging optical concentrator (18, 70) includes an optically transparent body having a substantially dome-shaped convex surface (42, 74) of revolution formed about an optical axis (24) and at least one conical concave surface of revolution (44, 76, 78) protruding into the convex surface in a direction along the optical axis toward a light sensor (46). The convex surface receives light rays (54, 90) propagating from low to medium elevational angles and causes them to propagate through the optically transparent body, reflect off the concave surface, and propagate generally along the optical axis toward the light sensor. The concave surface further receives light rays (58) propagating from high elevational angles and refracts them through the optically transparent body toward the light sensor. This invention is advantageous because only one light sensor is required to receive light rays, such as IR controller data, propagating from a wide range of elevational and azimuthal angles.

Abstract: A portable, infrared, multiple gas analyzer for measuring the concentration of a plurality of infrared absorbent gases with a simple optical arrangement for transmitting an infrared beam along an optical path along with gas mixtures to be analyzed. Light transmitting tubes arranged in a U-like configuration transmit infrared energy and the gases applied thereto over a small path to an infrared detector from an infrared source and provide electrical analog output signals representative of the detected gases. The detector output signals are processed by D.C. processing circuits including an analog to digital converter and microprocessing circuits for providing digital, binary coded, output signals representative of the detected gas concentration of the infrared absorbent gases. The analyzer can be readily calibrated by applying a non-infrared absorbent gas to the gas analyzer to provide a maximum output signal level with the infrared beam on and the background level or dark level signal with the beam off.

Abstract: The invention is directed to a disposable airway adapter which includes two optical windows and a reflector, positioned such that radiation transmitted through the first optical window into the airway passage will be reflected by the reflector and be transmitted through the second optical window and out of the airway passage. the disposable airway adapter is for use in connection with a carbon dioxide detector for determining the concentration of carbon dioxide present in the mixture of gases present in the airway passage.

Abstract: A housing assembly includes a combination lens and window retainer, an inner optical lens, an outer optical window and a front cover. The retainer includes a middle body structure, a pair of side wing structures, an inner seat and an outer seat. The middle body structure has opposite lateral sides, interior portions and exterior portions. The side wing structures are attached to and extend in opposite lateral directions from the opposite lateral sides of the middle body structure. Each side wing structure has exterior portions. The inner seat is defined on the interior portions of the middle body structure. The outer seat is defined forwardly of the inner seat on the exterior portions of the middle body structure and of the side wing structures. The inner optical lens is mounted to the inner seat of the retainer. The middle body structure and side wing structures together define an opening aligned with the inner optical lens and provides an unobstructed forward panoramic field of view through the retainer.

Abstract: The present invention concerns a motion sensor for use with a light. The device includes a housing having an outer edge and an interior space in which a plurality of sensors are located. The sensors convert infrared into an electronic signal that is processed to detect motion. A lens located is also used which is located on an outer edge of the housing for directing infrared to the sensors which may be generally arranged in a U-shaped pattern to promote a 270 degree motion detection zone. The ends of the lens are recessed into and held in the interior of the housing a spaced distance from the outer edge of said housing so as to detect motion occurring rearward of the sensors.

Abstract: A detection system including motion detectors, which are built up and connected in such a manner that movement of an object through successive surveillance areas in one direction will result in the delivery of a first detector signal, which is different from a second detector signal, which will be delivered upon movement of said object through the surveillance areas in at least partially opposite direction. The trend of the detector signals furthermore includes a measure for the distance at which the object passes the detection system. When the structures for the motion detectors are provided on the substrate in a specific manner, it becomes possible to manufacture such motion detectors in a simple manner.

Abstract: An infrared video camera system comprises an uncooled infrared sensor mounted and a thermally conductive thin walled radiation shield for shielding radiation from reaching an active surface of the uncooled infrared sensor. A TEC maintains the sensor active surface and the radiation shield at a substantially constant temperature. The uncooled infrared sensor and radiation shield are further housed in a hollow thermally conductive vacuum cover which is vacuum sealed with a base assembly and includes a vacuum sealed infrared transparent window in an aperture at a top end of the vacuum cover for allowing infrared radiation to reach the active surface and for forming a vacuum chamber enclosing the infrared sensor and radiation shield. A relay optical cell mounted to a camera body comprises at least one optical element for relaying an image formed at its entrance onto the active surface.

Abstract: A compound-eye crime prevention sensor system is constructed which reliably distinguishes between a human being and a small animal irrespective of the distance from the detector. This system has a zone spacing changer, and when the detection zones A and B of the detector 1 are at the farthest point L in the trespassing subject detecting range, the spacing between the detection zones A and B is .theta.L and when the optical unit in the detector 1 is rotated to bring the detection zones to the position of a point S, the spacing .theta.S between the detection zones A and B is greater than the spacing .theta.L which results from adjusting the detection zones to the farthest point L.

Abstract: An infrared intrusion sensing system comprises a compound lens having a plurality of lines of focus for focusing infrared radiation that enters the system onto a detector, and a window to allow infrared radiation to enter the system and then be focused onto the detector by a set of curvilinear-shaped mirrors. The detector is located near the focal point of the compound lens elements and curvilinear-shaped mirror elements. An enclosure surrounding the detector provides isolation from insect entry and constitutes an insect exclusion enclosure envelope. The enclosure envelope is a protective volume of space for the optical paths between the lens or window and the detector that prevents the entry of objects about 1 mm in diameter or larger which could interfere with the optical paths.

Abstract: An intrusion detection assembly including an intrusion detector including an inner housing, a detector disposed within the inner housing and a lens for focusing light from outside the inner housing onto the detector, and an outer housing which is generally sealed from the outside and defines a window which is generally transparent to light which is detected by the detector, wherein the intrusion detector is spaced from the window so as to define a region of high sensitivity between the lens and the window which is sealed from the outside environment.

Abstract: An infrared collector employs a concentrator formed of a plurality of spatially related gradient-indexed (GRIN) lenses and a photodetector, interconnected by optical fibers. Since the GRIN lenses are arranged on a hemispherical shell, the concentrator is relatively insensitive to the direction of the incoming infrared radiation. Optical fibers are used to connect the GRIN lenses to a photodetector, whereby assembly is simplified. The infrared detector in the collector of the present invention has a size that is significantly smaller than those used in conventional collectors. The concentrator has high optical gain, and therefore, is particularly well adapted for use in low-power portable systems. The arrangement is useful as a node in an infrared data network.

Abstract: A multi-lens system provides a plurality of sensitive areas of even size over a wide panoramic field of view and reduces an exposure height of the system above an installation plane, yet assuring successful motion detection. The system has a dome-shaped shell with a plurality of convex lenses for collecting infrared radiation from the panoramic field of view to an optical detector positioned in a focal region. The lenses are distributed over a wide solid angular range to give the discrete sensitive areas. The focal region is offset towards a vertex of the shell from a point where optical axes of the outermost lenses at a maximum solid angle about the center axis intersect with each other. Thus, the outer lens at a greater angular disposition has a greater distance to the detector so that it could define its own sensitive area closer in size to the adjacent sensitive area defined by the adjacent lens at a less angular disposition, enabling to equalizing the discrete sensitive areas.

Abstract: Infrared sensor that can make a temperature compensation by itself, and method for compensating a temperature thereof, are disclosed. The infrared sensor preferably includes a substrate, a diaphragm formed on the substrate, and a first thermopile sensor formed on a region of the diaphragm for sensing an infrared radiation emitted from a measured object and infrared radiations emitted from regions other than the measured object. A second thermopile sensor is formed on a region of the diaphragm and connected to the first thermopile sensor for sensing the infrared radiations emitted from the regions other than the measured object. A housing protects a front face of the substrate including the first, and second thermopile sensors includes an infrared filter in the housing over the first and second thermopile sensors for transmission of infrared radiations, and a reflector reflects the infrared radiation emitted from the measured object toward the first thermopile sensor.

Abstract: A catoptric optical system enhances the ability of a radiation sensor to detect motion of a radiant source within a region of a three-dimensional space without need for a polyethylene lens array. A preferred embodiment of the system includes first and second pairs of spaced-apart concave reflector elements arranged to form a chamber having a radiation reflective interior with a rectangular opening at each of input and output ends. The reflective elements of each of the first and second pairs are positioned in opposed relationship and separated by respective first and second distances. A two-element radiation sensor having a top surface is positioned proximal to the output end of the chamber.

Abstract: A passive infrared motion detector that creates a detection pattern with non-diverging insensitive zones. The sensing elements are of alternating polarity and each has a width w. An optical collection system directs infrared radiation onto the sensing elements. The sensing elements are separated by a distance equal to an integer multiple of width w, with the integer being at least two. The optical centers of the optical collection system are separated by an integer multiple of width w, with the integer being at least two. The arrangement of the optical centers and the sensing elements results in a detection pattern with non-diverging insensitive zones, with the insensitive zones having a negligible width.

Abstract: Two pairs of pyroelectric devices are each mounted on a cone-shaped substrate to precisely control their alignment. Each cone-shaped substrate is a part of a sensor module which also supports an attenuator, along with a transistor and a resistor chip associated with each pyroelectric device of the pair. The sensor module is provided with a silicon filter through which infrared radiation is transmitted to the pair of pyroelectric devices. Each module is mounted in an inner space formed by two hemispherical lenses which serve to direct light to the module. Two such hemispherical lens-sensor modules are provided in a precise optical arrangement designed to operate in conjunction with associated circuitry in order to detect infrared radiation from any of six distinguishable zones. Applications of such a device include for example cameras and air conditioning systems.

Abstract: An electronic apparatus having an optical communication capability of the present invention has a casing 10 and optical filters 12 and 13 for screening an infrared beam emitting/receiving device 25. The optical filters 12 and 13 each has a particular screening characteristic. The filters 12 and 13 are selectively removably fitted in a beam input/output window 11 formed in the casing 10. With these filters 12 and 13, it is possible to use one of the filters 12 and 13 matching the varying environment, and therefore to intercept optical noise lying in a broad wavelength range.

Abstract: A gas monitor includes an infra-red source enclosed within a housing having inner surfaces which are reflective. Radiation emitted from the source reflects off ellipsoidal surfaces and intermediate planar surfaces to be focussed at a sensor, being reflected five times. Radiation is absorbed by gas within the housing and a comparison of the source intensity and detected intensity gives a measure of the gas concentration. Use of ellipsoidal reflective surfaces directs emitted radiation along a plurality of routes having substantially the same path length, hence giving an accurate measure of the gas concentration with a compact device. In another embodiment, off axis parabolas are used to direct the radiation through the gas.

Abstract: A fluorescence detection apparatus is provided which has a partial reflection mirror 8 for transmitting a part of fluorescence light emitted from a fluorescent substance by projecting excitation light and reflecting the rest of the fluorescence light, and a pair of a first and a second photodiode 2,3 for measuring the light transmitted through or reflected by partial reflection mirror 8 respectively at a selected wavelength, and the pair of the first and the second diodes are arranged to be optically equivalent relative to the partial reflection mirror 8. This fluorescence detection apparatus is affected less by positional deviation of the measurement cell relative to the optical measurement system.