Abstract: The invention is directed to a method of operating a laser diode in a measuring system for spectroscopically measuring the concentration of a gaseous component in a gas sample. This method is improved in that the mode jumps of the laser diode are easily recognized when adjusting the temperature-current operating point of the laser diode. An optical filter is placed in the beam path for adjusting the temperature-current operating point of the laser diode and, by changing the temperature T and the operating current I of the laser diode while simultaneously receiving the output signal supplied by an evaluation unit, the spectral positions of the mode jumps of the laser diode are determined which are included in the absorption lines of the gas sample. Thereafter, the temperature-current operating point is adjusted so that the distance of this operating point to the positions of the mode jumps is not less than a fixed spacing.

Abstract: A portable blood glucose monitoring meter that employs an analog circuit in conjunction with a manually rotatable dial that varies the resistance of a potentiometer to locate a null position that balances the measure taken of the blood glucose-induced changes in the chemistries of disposable test strips. The dial supports a replaceable, pre-printed, man-readable calibration disk. The calibration disk displays in man-readable format blood glucose concentrations in milligrams per milliliter calibrated to the specific batch-lot chemistries of the disposable test strips used with the meter. A patient places a replaceable batch-lot calibration disk upon the dial, and inserts a corresponding test strip bearing a drop of capillary blood into the meter. The patient then manually adjusts the dial until prompting arrows indicate a null position. If the dial has rotated past the null position, an opposing arrow will illuminate indicating a need to rotate the dial in the opposite direction.

Abstract: In an optical unit used for a laser beam printer, a laser beam generated by a laser diode is converted by a group of conversion lenses into a laser beam having a predetermined-size cross section. The laser beam is directed toward a photosensitive body by a scanner. A focusing lens allows the rotating angle of the reflecting faces of the scanner to correspond to a desirable point on the surface of the photosensitive body. In other words, the rotating angle is made to correspond to the distance between the optical axis center determined with respect to a main scanning direction and a point to which the laser beam is irradiated for scanning. The conversion lenses includes at least one aspheric glass lens arranged close to the laser diode. The glass lens and the laser diode are integrally held by a lens barrel which linearly expands in a predetermined manner in response to a temperature change.

Abstract: A double wall housing for a camera contains a thermostatic switch which senses elevated temperature within the housing to activate a compressed air powered vortex tube which is capable of producing cool air. The cool air is supplied to a helical path between inner and outer housing members of the housing to cool the housing and its interior space. A second thermoswitch mounted outside the housing senses the ambient temperature and, if the temperature rises to a selected level, activates a compressed air supply for supplying purging air to the lens tube.

Abstract: A detector unit which is capable of outputting electrical signals proportional in magnitude to the intensity of that energy in a beam thereof which lies in two different wavelength bands. A beam splitter directs energy in those bands from the entire compass of the beam to a data detector and a reference detector, and bandpass filters and optical traps in front of those detectors ensure that only energy in the selected bands and from the beam reach them. The detectors are mounted in precisely aligned relationship with each other and the beam splitter on, and are electrically isolated from, a monolithic, conductive, isothermal support which allows them to be maintained at the same, selected temperature by a system including data and reference detector heaters and a temperature responsive controller.

Abstract: In order to eliminate the influence of temperature on the focus of an IR optical imaging system, radiation from an auxiliary heat source is deflected through the IR optical imaging system such that said radiation impinges on an autocollimating reflector from where it is reflected back into said IR optical imaging system and then impinges on detector elements which are arranged in a detector image plane. Electrical signals generated by the affected detectors are analyzed, digitized, and then compared in a computer whose output signals control a motor for adjusting the axial position of at least one of the optical lens elements of the IR system such that the autocollimating condition between the auxiliary heat source and its image in the detector plane is maintained at all times.

Abstract: An image sensor is operable in a read state, a rest state, and a stand-by state. Control signal generating means generate a control signal. The control signal has a first constant preset level during the read state, a second preset level during the rest state, and alternates between the first and second levels at a duty ratio during the stand-by state. Drive circuit means transfer current to the image sensor in response to the control signal. Therefore, current is continuously transferred to the image sensor during the read state, no current is transferred during the rest state, and current is intermittently transferred to the image sensor at the duty ratio during the stand-by state.

Abstract: A line sensor apparatus is adapted to read a character or pattern image on a document. In this apparatus, an illumination device for illuminating the document, a optical lens for focusing the light beam reflected by the document, a CCD line reading sensor for photoelectrically converting the light beam focused by the optical lens into an electric signal, and a holding member for holding the CCD line sensor and the optical lens are assembled as one body in such a manner as to constitute a carriage device. A uniformly radiated heat-radiating plate is in contact with the entire botttom surface of a support for the CCD line sensor, so that the heat generated by the CCD line sensor is radiated from the heat-radiating plate. Further, the CCD line sensor is kept in tight contact with the holding member, so that the heat generated by the CCD line sensor is also radiated from the holding member.

Abstract: A variable focal length lens integrated onto a silicon wafer. A light transmitting material such as gas or liquid is entrapped in a cavity in the wafer. The cavity has a flexible, light transmitting wall. The wall provides one surface of the lens. When the material inside the cavity is heated or cooled, the wall flexes and the focal length of the lens changes. The lens is suitable for use in temperature and pressure sensors, fiber optic communication networks, optical computers, and other applications.

Abstract: A method for temperature compensation of a bipolar transistor through optically-induced carrier density enhancement. In response to the output of a temperature sensor, the optical output power of a photon source directed toward the bipolar transistor to be compensated is varied. Photons incident on the semiconductor surface effect variations in supplemental carrier concentration that maintain junction potential of the bipolar transistor at a predetermined level.

Abstract: The present invention provides an apparatus including a laser scanner wherein the apparatus further includes a scanner temperature detector (3) located in the proximity of a position sensor (2), an environment temperature detector (4) and temperature controlling mechanism adapted to perform controlling operation so as to allow the temperature of the position sensor to be kept constant on the basis of an output from the environment temperature detector and an output from the scanner temperature detector.

Abstract: A photoelectric measurement head (26) for the monitoring of the cross-section of a profiled section between an extruder and a calibrating device of an extrusion press for the manufacture of plastic profiled sections (24) is provided in the region of a free head end of the measurement-head housing (30) with two light-passage openings (38, 42) for a light outlet and light inlet respectively. The light passage openings are arranged on opposite sides of a passage (40) for the profiled section. In each opening (38, 42) a light-transmitting glass cover (64, 66) is inserted. Furthermore, two heating elements (60, 62) are inserted in the measurement-head housing (30) in the region of its free head end in the direct vicinity of the glass covers (64) and (66). The heating elements are connected to a temperature-setting device which maintains the temperature of the free head end of the measurement-head housing at the temperature of the profiled section (24) at the nozzle outlet of the extruder.

Abstract: The photoelectric switch includes a heating unit formed on a light transmitting plate around a beam transmission part of the body of a light receiving part. A received light quantity decision circuit compares an electrical signal corresponding to a quantity of light received with a set level to decide whether or not it is below the set level. A temperature circuit generates an electrical signal corresponding to an ambient temperature in the vicinity of the body. A driving circuit for energizing the heating unit requires that the temperature circuit below a set temperature and that the quantity of received light is also below the set level. If either condition fails, the heating unit remains deenergized.

Abstract: Three means or methods for compensating for thermal noise, also referred to as dark signal, are utilized to enhance the accuracy of a monolithic diode array. A charge-coupled linear photodiode array is used in a camera to detect densities of any image projected or reflected onto the array. After conversion, voltage variations of one/one thousandth (1/1,000) volt in a ten volt range are significant to the measurement of densities. Therefore, extremely accurate control of thermal noise, which is generated in the cell sites and in the shift registers used to obtain the data from the cell sites, is extremely important. The three methods or means of control are as follows. Temperature control maintains the temperature of the photodiode array at approximately ten degrees centigrade to minimize the generation of thermal noise. A thermistor is used to detect any temperature variations within the range controlled by the cooling means and the reading is compensated for those variations in temperature.

Abstract: A new type of infrared reflectance device is disclosed to provide a quantitative evaluation of skin pallor. The instrument is designed to produce a measurement proportional to the percentage of infrared reflectance of the skin. In one embodiment, it consists of a miniature GaAs light emitting diode, which provides a pulsed infrared light source, a silicon photodiode detector, and processing circuitry. The device electronics are temperature compensated and are designed to respond only to the pulsed component of the detector output and to reject components due to stray light from external sources. The wavelength is chosen such that the measurement is relatively insensitive to the level of blood oxygenation and melanin pigment in the skin.

Abstract: In an optical sensor, a heating element is formed on a substrate, and an amorphous semiconductor film is formed on an insulating layer covering the heating element, and is electrically insulated from the heating element. A common electrode and a plurality of electrodes are also formed on the substrate and are extended along the amorphous semiconductor film, to form cells for converting light into electrical signals, in the amorphous semiconductor film. An electric current is supplied to the heating element, to heat the amorphous semiconductor film after the film has been illuminated and photoelectric current has been picked up from the electrodes.

Abstract: An optical power stabilizing device for use in an optical information recording and reproducing apparatus is disclosed. The device comprises a light source for generating a light output power having a non-linear characteristic to a driving current or voltage thereof, a light detection circuit coupled to the light source for detecting a part of the output light to generate an electric signal, a signal treating circuit connected to the light detection circuit for treating the detected electric signal, a compension circuit connected to the signal treating circuit for compensating the current or voltage to be supplied to the light source in accordance with the temperature variation, and a control circuit connected to the signal treating circuit and the compensation circuit for controlling the current or voltage to be supplied to the light source.

Abstract: A light source stabilizer comprises a light emitting device, a heating element for heating the light emitting device, a temperature sensor for sensing a temperature of the light emitting device, a temperature control circuit for controlling the heating element by the output of the temperature sensor, a light intensity detector for detecting a light intensity of the light emitting device and a light intensity control circuit for controlling the light emitting device by the output of the light intensity detector.

Abstract: A preamplifier network or circuit for converting non-linear signal information, such as is produced by a mercury cadmium tellurium (MCT) detector, to a substantially linear voltage signal output corresponding to the incident light levels on the MCT detector. Conceptually speaking, the subject preamplifier functions as a constant-voltage variable-current source to the MCT detector, and incorporates positive feedback for being effective as a negative resistance to nullify the MCT detector resisance introduced signal component of the signal information being monitored.

Abstract: The invention is an adjustable mount for positioning an electro-optic transducer in an evacuated cryogenic environment. Electro-optic transducers are used in this manner as high sensitivity detectors of gas emission lives of spectroscopic analysis. The mount is made-up of an adjusting mechanism 10 and a transducer mount 20. The adjusting mechanism provided five degrees of freedom, 3 linear adjustments and 2 angular adjustments. The mount allows the use of an internal lens 66 to focus energy on the transducer element thereby improving the efficiency of the detection device. Further, the transducer mount 20, although attached to the adjusting mechanism 10, is isolated thermally such that a cryogenic environment can be maintained at the transducer while the adjusting mechanism 10 remains at room temperature. Radiation shields 68 also are incorporated to further reduce heat flow to the transducer location.

Abstract: A laser-doppler-anemometer for measuring the velocities of moving test specimens employing a laser beam source, deflection optics for at least two partial beams, collecting optics for focussing at least one of the partial beams on the test specimen, and a detector for the scattered light radiated from by the moving test specimen. A compact construction and further possible applications can be obtained when the laser beam source is provided by at least one laser diode whose temperature can be adjusted and kept constant with a temperature control circuit.

Abstract: A radiographic image is formed of a workpiece irradiated by neutron or X-ray energy. A radiophosphorescent screen is positioned adjacent the workpiece to form a scintillation pattern. The radiation may consist of thermal neutrons radiation from which gamma radiation has been substantially removed. The image is stored upon the semi-conductor target of a television camera.

Abstract: Apparatus for converting weak light, or light of low intensity, to electrical signals descriptive of such light. The apparatus is capable of sensing differences in photon flux over an area of detection, that is, sensing a pattern of lighter and darker areas. An important application of the apparatus is in spectroscopy and spectroscopic anaylsis, where it is desired to record a spectrum in other than visual form.

Abstract: Light exposure apparatus comprises a light source, a spectral filter perivious to light of a prescribed wavelength range, a glass member whose cut-off frequency in the prescribed wavelength range is variable with temperature, and a temperature control for controlling the temperature of the glass member. Intensity of the light from the light source, passing through the spectral filter and glass member, and impinging upon the surface subject to light-exposure is controlled by the temperature control.

Abstract: A photodiode receiver circuit having self-contained automatic gain control and which is temperature compensated over a wide operating range contains a resistor coupled in series between a bias power supply and one end of an avalanche photodiode. Self-generated AGC action results from the fact that the gain of an avalanche photodiode increases as the bias voltage applied across the diode increases. As the light intensity received by the diode increases, there is a corresponding increase in the current flow through the diode and the series-connected resistor. The consequential increase in IR drop across the resistor decreases the bias voltage across the diode, so that the gain of the diode is reduced. Through this action, the dynamic range of optical input of the photodiode will be increased for a fixed dynamic range of electrical output.Temperature compensation is achieved by coupling a temperature-sensitive voltage divider circuit between the bias voltage supply and the gain-controlling resistor.

Abstract: Apparatus for determining the reflectivity of the surface of a measured object, and, in particular, for determining properties of the measured object which are connected with its reflectivity. A light source emits light along a light path so that a wide-band light beam impinges on the surface of the measured object. The light reflected by the surface of the measured object goes through a pair of narrowband light filters which pass, respectively, light beams of different narrow bands of wave-lengths effective for evaluation by a photo-detection device. The photo-detection device comprises two separate photo-detectors each covered by one of the narrow-band filters. The filters are fixed in their positions relative to the photo-detectors and transmit their different wave-lengths of light to their respective photo-detectors.

Abstract: An apparatus for, and a method for, achieving temperature compensation of an avalanche photodiode. The apparatus and method automatically detect the breakdown voltage of an avalanche photodiode immediately before the photodiode is operated and automatically applies the photodiode with a bias voltage always lower than the breakdown voltage of the photodiode, so that the multiplication factor of the photodiode is maintained constant.

Abstract: Temperature sensitive photodetectors are temperature stabilized by coupling the photocathode of a photodetector in heat exchange relationship to a heated casting which acts as a heat source for the photocathode. The photocathode is coupled to the casting by a metallic Z-shaped bracket positioned on an insulating block with one base of the Z being coupled to the photocathode and the other base being coupled to a metal box through a Mylar insulating spacer, the box being directly mounted on the casting. A printed circuit board associated with the photodetector is also mounted on the insulating block. The direct heat path from the heated casting through the Z-shaped bracket to the photocathode reduces the warm up time of the photodetector thereby more rapidly temperature stabilizing the photodetector.

Abstract: A mounting for a silicon solar cell comprises a layer of molybdenum on the back surface of the cell and a molybdenum wire along the peripheral edge of the radiation receiving surface of the cell. An electrode formed with an aperture aligned with the radiation receiving surface abuts and is secured along the border of the aperture to the wire and a heat sink is in conductive contact with the molybdenum layer. The coefficients of expansion of the molybdenum and silicon are similar and this protects the relatively brittle cell from damage when its temperature is changed.

Abstract: Apparatus for determining the content of moisture or other substance in a material by measuring its relative reflectance at two infrared wavelengths. A chopped radiation beam is produced by arranging a tuning fork such that an oscillating element alternatively moves first and second spaced optical bandpass filters having first and second passband wavelengths into position to intercept a beam of source radiation. The chopped beam is directed on the material being analyzed, and radiation reflected therefrom is applied to a radiation detector. The relative transmittances of the filters at their passband wavelengths are such that the radiation detector generates alternating pulses of equal amplitude for a material having a specified content of the substance. The tuning fork also includes a third filter of zero transmittance which periodically interrupts the beam of source radiation so that the detector provides a background signal which is used to correct the amplitudes of the alternating pulses.

Abstract: Thermal isolation shields consisting of two glass slides separated by insulating standoffs are positioned upon the front radiation receiving surface of a solar cell and/or upon the back surface of the solar cell. One of the two glass plates is made from material selected to absorb and radiate electromagnetic wave energy with a wavelength above 5 microns to prevent overheating of the cell. The space between the two cover plates forms a thermal gap that is, if desired, bridged by a bimetallic strip. The strip is adhered to one of the plates and has a reverse bend to extend along the face surface of the opposed cover plate. The strip distorts under an increased temperature to break the bridge between the two plates and thereby isolates the solar cell from the thermal shield formed by the outer cover plate until there is a sufficient reduction in temperature at which the bimetallic strip reestablishes conductive contact between the cover plates.

Abstract: A highly accurate thermoelectrically controlled radiant energy detector achieving sufficient measurement stability to permit it to monitor the radiant energy output of a calibrated standard instrument, such as a luminance/illuminance source, which is to generate a standard quantity of radiant energy to be used, e.g., in the field testing and calibration of photometric instruments. The radiant energy detector provides a highly stable and drift free photometric measurement using a silicon photovoltaic detector arranged to receive radiant energy upon a sensitive surface thereof and to emit an electrical output signal related to the magnitude of incident radiant energy. A thermally conductive member, such as a mounting block, carries the light detecting element, and temperature sensing means, such as the semiconductor junction of a transistor, is in thermal communication with the conductive member.

Abstract: This invention has particular utility in the field of absorption spectrophotometry or colorimetry, and is particularly applicable, when incorporated in such type of equipment, as a sample detector to enable direct readings to be taken in concentration or absorbance of sample fluids or the like.

Abstract: A wideband heterodyne receiver for a laser communication system is disclosed which includes a front end having a cooled photomixer contained in a hermetically sealed spaced quality housing designed for wide bandwidth transmission. The photomixer is coupled through a wideband preamplifier to the receiver back end which includes a frequency tracking network and demodulating equipment. The receiver is capable of tracking a doppler frequency shift of 750 MHz, positive or negative, and has an instantaneous intermediate frequency information bandwidth of 400 MHz. The receiver system is also capable of operating over a wide temperature range and is designed to be suitable for use in outer space communication.

Abstract: The high density, third dimension geometry solar panels consist of closely placing any type of conventional solar cells in an in depth, oblique attitude to the sun's normal rays.In one panel arrangement, highly polished side reflectors are applied to reflect the sun's rays into the underside groups of solar cells so that a minimum of surface area is required for a higher than normal electrical power yield from the high density cells.The most effective geometric shape for these reflected type of solar panels is the triform, or tri-panel, and modifications of the triform cross-section.Another type of high density solar panel is the V form, or Vee cavity form in which the individual solar cells must have reflective surfaces, for mutual reflection and solar energy concentration.

Abstract: An integrated optical-to-electrical signal transducing system and apparatus therefor which, through the use of a novel combination of fiber optics and microelectronics, permits locating the optical signal detection circuits close to their associated preamplifier circuits and remote from sources of interfering signals without losing the ability to do effective optical tracking or seeking. Specific structure including a hybrid microelectronic device package modified to receive optical input signals through a fiber optics terminal incorporated therein is provided to achieve the desired results.

Abstract: An improved spectrophotometer of the non-dispersive absorption type useful for detecting the presence of SO.sub.2 in a gaseous sample, despite the simultaneous presence of NO.sub.2. Ultraviolet light from a commercially-available source impinges upon a fixed phosphor screen which fluoresces to produce ultraviolet radiation at a first wavelength, at which both SO.sub.2 and NO.sub.2 absorb radiation; and at a second wavelength at which absorption by SO.sub.2 is minimal but NO.sub.2 absorption is approximately the same as at the first wavelength. The radiation is directed through a sample chamber having windows which are transversely slidable to effect cleaning without destroying the integrity of the chamber seal, then introduced into an envelope enclosing filters and a pair of photosensors. One photosensor receives light at the second wavelength and produces a signal which reflects the attenuation by NO.sub.2 at that wavelength.

Abstract: An optical scanning system has a dirigible head of generally spherical shape mounted on a support body for scanning through a substantially hemispherical field of view, and optical lenses, a scanner rotor and drive motor therefor, and a cryogenically-cooled detector element array are all mounted within the confines of the dirigible head. The head has a primary objective lens in its outer shell and further lenses are mounted within the head in an adjustable holder enabling different lenses to be brought into alignment with the objective lens. The scanner rotor is generally annular and rotates about an axis oblique to the optical axis of the objective lens; it comprises a multi-faceted reflector receiving the image beam from the lens system and reflecting it laterally on to the detector array.