Abstract: A device, e.g., a luminaire, that includes a plurality of LEDs connected in series, and an active shunt arrangement for sensing a failure of one or more of the LEDs and for shunting current that would have otherwise flowed through a failed LED, to thereby maintain a flow of current through remaining ones of the plurality of LEDs. In one exemplary embodiment, the active shunt arrangement includes a plurality of active shunts connected in parallel across respective ones of the LEDs, and remote sense and digital control logic for detecting an open-circuit condition of the normally closed circuit, and for sequentially activating the active shunts until the normally closed circuit has been restored to a closed-circuit condition.

Abstract: A semiconductor light emitting device incorporates therein with (a) a light emitting portion formed by semiconductor overlying layers including a first conductivity layer and a second conductivity layer in order to a light emitting layer, and (b) a protecting element portion provided in electrical connection between said first conductivity type layer and said second conductivity type layer so that said light emitting portion is protected against at least a reverse voltage applied to said light emitting portion. The light emitting portion and the protecting element portion can be formed by separate chips or in one chip having the both. They are formed into a lamp-type or chip-type light emitting device. The incorporation of the protecting element increase the reverse-voltage resistance for a compound semiconductor, such as galium-itride or the like, that is less resistive to reverse voltages applied.

Abstract: In a distance measuring apparatus for measuring the distance to an object on the basis of reflected light obtained as a result of projecting light toward the object, in the case of an active distance measurement operation, the flickering frequency of a light beam projected from a light projection unit (B) toward the object (A) is prolonged within the range in which charges obtained by a signal charge supply unit (C) are not saturated in a circulating shift register (E). When the flickering period is longer than a predetermined period, a distance measurement operation inhibition unit (L) inhibits transition to a passive distance measurement operation.

Abstract: A scanning apparatus for scanning and reading a luminescent pattern of a sample in a flat-plate shape, having a placing member for placing the sample as an object for reading; a light condensing member for condensing light emitted from the luminescent pattern of the sample; a movement member for moving the light condensing member relative to the placing member; a light receiving member for dividing the light of the luminescent pattern of the sample condensed by the light condensing member into predetermined segments and receiving the light by scanning the light from the segments in a one-dimensional way; a photoelectrical conversion member for converting optical signals of the light received by the light receiving member into electrical signals; a control member for controlling a scan by the light receiving member in accordance with the electrical signals from the photoelectrical conversion member; and a data processing member for converting the electrical signals from the photoelectrical conversion member in

Abstract: The invention relates to a method as well as to apparatus for testing the function of microstructure elements, wherein the microstructure element is driven for testing the emission and/or mechanical properties and the corpuscles emitted or reflected by it are detected and evaluated.

Abstract: Time consuming analyzing of the dressing levels on bowling lanes is eliminated through the use of an apparatus that includes a path of travel (48) for a sample strip, a light source (50) on one side of the path (48) and a photosensitive sensor (46) on the other side of the path. A feed roller (60) is journaled adjacent the path and is driven by a stepper motor (58) in predetermined increments. An analog to digital converter (40) is connected to the sensor (36) for receiving analog signals therefrom and converting the same to digital signals. A random access memory (38) is connected to the converter (40) for receiving signals therefrom and for storing data represented by the signals. A central processing unit (34) is provided for operating the motor (58), the sensor (46) and the random access memory (38).

Abstract: A high-speed driver for LED data communications systems. A differentiator provides a turn-on and a turn-off pulse of current to the LED. The amount of charge delivered during turn-off is adjusted to sweep substantially all of the carriers from the LED without reverse-biasing the LED.

Abstract: A light-emitting diode lamp comprises a cathode wire having a cup lined with a metal foil formed in its head end, an anode wire parallel to the cathode wire and having a flattened head end lined with a metal foil, a light-emitting diode seated in the cup and connected to the anode with a thin connecting wire, the entire assembly being potted in a transparent material. A leadframe for assembly of LED lamps comprises a pair of elongated strips and a plurality of wire pairs attached to the strips, each wire pair having an anode wire having a layer of metal foil welded to its head end and a cathode wire having a metal foil-lined cup in its head end. A method for preparing wires for leadframe assembly is also described.

Abstract: A system and method for transmitting an identification signal include a triggering device for periodically generating an enabling pulse signal at random times, whereby the periodic generation of the enabling pulse signal varies in each period in proportion to light incident on the triggering device and a transmitter for transmitting an identification signal in response to the enabling pulse signal. It is preferred that the triggering device include a timer for generating the enabling pulse signal in a defined time cycle in response to a control signal and a signal generator for variably generating the control signal within the defined cycle, wherein the signal generator includes a light sensitive component for varying in time the generation of the control signal in proportion to light incident on the light sensitive component for a portion of said defined cycle.

Abstract: A technique for the simultaneous measurement, in real time, of the changes in mode size, pulse length, and power of a wavetrain of laser pulses delivered by mode-locked or other pulsed laser systems contemplates directing respective portions of the beam along each of three beam paths. The beam portions along the first and second beam paths are subjected to respective, and different, degrees of focusing, and then passed through respective non-linear elements which generate radiation at the second harmonic. The first harmonic components are removed, and the second harmonic components are passed to respective first and second detectors which generate signals representative of the total second harmonic energy along each of the first and second beam paths. The beam portion along the third beam path is passed to a detector which generates a signal representative of the total energy in the beam pulse. The three signals are combined to give values proportional to peak power, pulse length, and mode size.

Abstract: This invention relates to an optical module for coupling an optically operative device with an optical fiber. Near the optically operative device, the module includes a fiber saddle on which the optical fiber is affixed by soldering to optically connect the operative device and the fiber. The fiber saddle is provided on a heat insulative substrate, which also mounts the optically operative device, so that heat for melting the solder will not be conducted through the fiber saddle when the optical fiber is soldered to the saddle. Thus, the temperature necessary for soldering can be attained rapidly. A mounting surface of the fiber saddle is plated with solder. A pre-formed solder structure is bridged over the optical fiber after it is positioned on the fixation surface. The pre-formed structure is melted and then allowed to solidify whereby the optical fiber is affixed to the fiber saddle to prevent dislocation of the fiber.

Abstract: A low distortion light source comprising a light emitting diode and a compensating diode connected in parallel with respect to a D.C. bias current and in anti-series with respect to an A.C. signal source. The compensating diode is selected to have a forward resistance similar to the forward resistance of the LED. Adjusting the D.C. bias current through the diodes to be approximately equal matches the forward resistance characteristics and substantially reduces the undesired intermodulation products.

Abstract: The present invention is a regulator circuit for combined regulation of the emitted wavelength from a laser diode, and its output. According to the invention, a fraction of the radiation from the laser diode (1) is caused to be transmitted, via a glass fibre (2) to a sensor unit (8). The sensor unit contains a dispersing device (3), possibly separate focussing devices, and a detector unit (4). The detector unit (4) contains one or more detector elements, whose electrical output signals are conducted to a signal decoding unit (5). The signal decoding unit (5) is connected (i) to a temperature generator (6), in turn connected by thermal means to the laser diode, (ii) to a power generator (7) which is electrically connected to the laser diode. By using a concave lattice as the dispersing device, the reflective radiation from the lattice (3) is focussed on to the detector elements in the detector unit.

Abstract: An alignment fixture includes an optical bench 12 mounting a semiconductor laser 21, a monitor 23 of optical emission, a lens 27 focused for transmitting optical emission along an optical axis 43, a holder 26 mounting the lens 27, a pedestal 36 positioning a diaphragm 29 spaced for the lens 27, an optical fiber 45, a tube 49 surrounding the fiber 45 and joined to the fiber 45, a bushing 55 surrounding the tube 49 and joined to the optical bench 12, and a datum surface 16' on the bench 12 for aligning the lens 27 and the fiber 45 with the optical axis 43.

Abstract: A multicolor optical device having at least three optically stable states includes a plurality of pairs of associated light sensors and light sources for emitting light of respectively different colors when activated. Each light source is divided by an opaque wall into a first light emitting portion and a second light emitting portion. The light signals from the first light emitting portions of all light sources are blended to obtain a composite light signal of a variable color. Separate optical feedbacks are established between the second light emitting portions and light sensors in pairs tending to stabilize the light sources in their conditions to thereby maintain the color of the composite light signal.

Abstract: An auxiliary light source for a passive focus detector, such as would be used for automatic focusing. A projection lens is inclined with respect to the imaging lens and projects a patterned image from a surface inclined with respect to the projection lens. Preferably the patterned image is projected to lie along the axis of the imaging lens so that a sharp illumination pattern is formed at all distances along that axis. Preferably the pattern is such that a higher intensity portion is imaged at a far distance and a lower intensity portion is imaged at a near distance.

Abstract: The disclosed distance measuring device for a camera capable of measuring the distances of a plurality of objects within a target area comprises center-weighting means for treating the distance information of the object whose image lies near or at the center of the area of the picture frame with a heavier emphasis than those of the other objects, whereby an optimum focusing adjustment is allowed to be formed automatically.

Abstract: In a semiconductor arrangement including at least one semiconductor element composed of a semiconductor material which generates recombination radiation when current flows through the semiconductor element, and a control element disposed for monitoring the operation of the semiconductor element, the control element has an internal photoelectric effect and is disposed for receiving the recombination radiation generated in the semiconductor material for producing an output parameter representative of the intensity of such radiation.

Abstract: An image sensor comprising at least one first light emitting element for irradiating an original with light, at least one photoconductive element for sensing the light via the original and at least one second light emitting element for irradiating the photoconductive element with light. The second light emitting element emits light of photoenergy smaller than the optical band gap of the photoconductive element.

Abstract: A half-duplex transceiver circuit is disclosed in which a single diode acts as both the light emitter and the light detector. The diode is connected in parallel with a junction in an associated device. The forward voltage drop across the diode exceeds the forward voltage drop across the junction.

Abstract: A multicolor display device having seven illuminated optically stable states includes three triads of associated electro-optical components. In each triad, a light sensor is electrically coupled with a display light emitting diode and auxiliary light emitting diode. An optical feedback is established in each triad between the auxiliary light emitting diode and the light sensor tending to maintain its associated display light emitting diode either in the illuminated or extinguished condition. Light signals of respectively different colors emitted by three display light emitting diodes are blended to obtain a composite light signal of a color in accordance with the conditions of respective display light emitting diodes.

Abstract: Increased light energy is introduced into the end of a fiber in a fiber optic light transmission system by this invention, thus providing further distances between repeater stations along long transmission paths and producing higher signal energy levels along the transmission path. This is achieved by presenting input modulated light from a ring shaped light emission pattern concentrically configured about a fiber near an end for receiving input light signals, and processing the modulated light from the ring pattern with an optical system including a parabolic reflector receiving the modulated light to direct and focus it upon the end of the fiber for transmission along the fiber. Light emitting semiconductors with ring shaped emission junctions about a central duct for passing a fiber provide more energy than conventional shapes in a manner that may be processed in a simple low loss optical system.

Abstract: A light string system is provided having a plurality of mono-color or bi-color light-emitting diodes electrically connected thereto. Each light-emitting diode has a generally elongated, hollow envelope mounted thereover, and the envelope is substantially filled with light-conducting optical spheres or even fragments. The envelope may be additionally filled with light-conducting epoxy, light-conducting liquid or light-conducting gas and sealed for improved light transmission and dispersion characteristics. The light-emitting diodes may include an improved base with light-emitting diode leads disposed approximately perpendicular to the axis of the envelope for bulb stability and for enabling the bulb to stand upright on the branches. Both the envelope and the optical spheres include light-conducting glass or plastic material. The spheres may be either hollow or spherical and may be of a uniform or a mixed size.

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 numerical control system in which data signals are exchanged between a computer processing device MPU and each function block through an address bus ABUS and a data bus DBUS. Parallel electric signals are converted into serial signals by shift registers SHR.sub.1 and SHR.sub.2, and are converted into light signals by transmitters Tx.sub.11 and Tx.sub.12. The light signals are delivered to pulse distributors PDN through optical fiber cables OF.sub.1 and OF.sub.2 and these light signals are converted back to electric signals by receivers Rx.sub.3 and Rx.sub.4 and are further converted into parallel signals by shift registers SHR.sub.3 and SHR.sub.4. The parallel signals are delivered to a pulse distributor PD as position signals in the directions of X, Y and Z axes thereby to driving servomotors.

Abstract: A pulsed light emitting diode used as the light source in a photoelectric scanner is operated from a secondary power source which automatically adjusts the power to the LED approximately inversely proportional to frequency as the modulating frequency of the scanner is adjusted over a range, so that the average power of the LED remains approximately constant, within safe operating limits and close to optimum, over the range of adjustment. In the preferred embodiment this is accomplished by operating the LED from a capacitor used as a secondary power source without a series current limiting resistor for the LED. Peak current is determined by the forward characteristics of the diode and the voltage on the capacitor, and an impedance controls the recharging of the capacitor during the off time such that the desired average power characteristics are achieved as operating frequency varies.

Abstract: The disclosed apparatus is a temperature tracking narrow band optical range finder which includes a prior art GaAs laser diode for emitting a laser energy pulse to a target and an improved GaAs avalanche detector for receiving a reflected pulse from the target. This range finder can be arranged in a single optical axis with the laser diode electrically shielded from the detector and the reflected pulse defocused so as to impinge on the detector area surrounding the laser diode, or it can be arranged by combining the emitted and reflected pulse in an interspersed fiber optical plane.

Abstract: An automatic range finder for measuring the distance to an object on the basis of the triangulation principle, including a light-emitting diode (16) for projecting the emitted light toward an object whose distance is to be measured, and a plurality of light-receiving elements (8a, 8b, 8c, 8d) being so arranged on a base plate (12) that either one of them can receive the reflected light from the object. The light-emitting diode (16) is electrically connected with planar, electrically conductive frames (20), (22) and is so molded by use of transparent material (26) as to be formed unitarily with the electrically conductive frames. The light-emitting diode (16) thus formed into one unit is mounted on the base plate through the electrically conductive frame.

Abstract: The invention relates to a socket for a plug and socket connection for coupling an optical fiber used in optical telecommunication systems. The socket comprises a light detector for converting the light radiated adjacent the optical fiber into an electrical signal for controlling the power dissipation of the light source.

Abstract: A distance measuring device having a light projector and a light receptor, at least one of which is caused to move so that when the intersection of their optical paths is disposed at an object, its coincidence is detected by the signal generated in the light receptor for measuring the distance from the device to the object based on the triangulation. In order to obtain a clear peak signal, according to the invention, for the light source, use is made of a light energy distribution characteristic which is higher at the marginal zone than at the central zone.

Abstract: An aiming post light for artillery and mortar operations at night wherein an ordinary GI flashlight may be used, without modification, as a post light when mounted on a support and wherein its original ordinary lightbulb is replaced with a novel bulb of same base outer configuration in which the bulb has encapsulated solid state circuitry to provide a blinking and/or steady light emitting diode (LED) as the light source. Depending upon the particular LED and circuitry selected, the light may be continuous or intermittent and may be a selected color. In one embodiment several options are available when using a single bulb.

Abstract: An active optical coupler between an optical bus line and subscribers. The optical coupler couples an emitting optical conductor and a receiving optical conductor and includes a diversion device that allows passage of a fraction of the incident light transmitted to the receiving conductor while diverting another fraction of this incident light energy to a photoreceiver which controls the injection of light energy into the optical coupler with a control in the form of a photoemitter for controlling the light energy transmitted to the receiving conductor with restoration of the level. A switch controls the operation of the photoemitter which in turn can be controlled either by the photoreceiver or by an input signal emitted by the subscriber. Digital data can be transmitted to subscribers by means of an optical bus line.

Abstract: A photo-reflective sensor comprising a light-emitting element and a light-detecting element adapted to receive the light from the light-emitting element after the light has been reflected from an article to be detected as modulated by a variation in the reflectance of the article. The sensor is characterized in that it is fabricated by molding a light-blocking wall portion, an outer case portion and a lead wire fixing portion integrally from an insulating base material to form a header, fixing chip lead wires and internal wiring lead wires to the header to form a stem, placing a photo-emitting chip and a photo-detecting chip on the chip lead wires and connecting the chips to the internal wiring lead wires to form the light-emitting and light-detecting elements. The sensor can be manufactured in a small size, by a reduced number of assembly steps and with improved light-blocking characteristics.

Abstract: A light emitting diode (LED) having excellent directivity, which is provided with a light emitting surface formed by a PN-junction of a semiconductor body, and a dome of a transparent material formed on the light emitting surface. The external surface of the dome is made a light emitting window. This external surface is in a semi-spherical shape at least in its one part, and the light emitting surface is on the symmetrical axis of the semi-spherical surface. Further, the light emitting surface is disposed at a position displaced for a finite distance in the direction opposite to the light emitting direction with respect to the center of curvature of the semi-spherical surface. With such construction of the LED, light from the light emitting surface intensifies its directivity at the time of its emission from the external surface of the dome.

Abstract: A laser is coupled to an optical fiber in an hermetic encapsulation by locking a portion of the fiber near the laser in a body of solder. With the laser energized, the position of the optical fiber is adjusted within an aperture through the solder body to optimize the light output at the end of the fiber. The solder body then is heated to cause flow around the fiber and cooled to lock the fiber in position.

Abstract: An optical cable connector includes a fiber connector plug and a mating connector receptacle.The plug, which receives an assembly including sheath and optical fiber, includes a generally cylindrical optical pin, a copression spring, a spring retainer nut, and a pin housing.The mating connector receptacle includes a housing, a circular shim, a photodiode housing assembly, and a retainer cap.

Abstract: A device for coupling a laser beam to an end surface of an optical fiber comprises a beam converging lens, a holder for the fiber, a block of a solid material, and a mass of a binder between the block and the end surface and between the block and the holder. The lens and the holder are fixed to each other so as to make the laser beam focus on the end surface. Use is preferred of an arrangement comprising a first and a second holder in which the holders have axial lines, respectively, and hold a laser element for the laser beam and the lens with a beam axis of the laser beam and an optical axis of the lens rendered coincident with the respective axial lines and in which the holders are fixed to each other with the axial lines aligned. The arrangement is effective also in coupling the laser beam to a general transmission medium. Instead of using the arrangement, a lens holder may be fixed to the fiber holder and then to a laser element holder so as to make the laser beam focus on the optical fiber end surface.

Abstract: An optical device for the simultaneous transmission and reception of optical data on the same optical waveguide. A transmission and receiving means at each end of the fiber optic cable permits simultaneous transmission. Each transmit/receive means comprises a pedestal supporting an emitter and photodetector. The emitter is mounted centrally of the inner surface of the pedestal at the focal point of a circular ellipsoidal reflector. The photodetector is also mounted centrally of the inner surface of the pedestal and placed forward of the emitter. In this manner the emitters and photodetectors at each end of the fiber optic cable can transmit and receive simultaneously or in sequence on the same optical waveguide.

Abstract: A nonlinear signal transducer U, such as a light-emitting diode or a semiconductive laser, is maintained at a suitable operating point by a constant biasing current and receives an electrical input signal by way of a series resistor R from a main amplifier AM of variable gain. The output voltage of the main amplifier is detected and integrated to provide a first reference voltage which is compared with the load voltage of the transducer U in a differential amplifier AE1, forming part of a first feedback loop, to adjust a voltage generator GT controlling the output voltage of the main amplifier AM so as to eliminate any voltage drop across the series resistor R as long as the input signal is absent or has an instantaneous magnitude equal to its mean value.

Abstract: A current isolation circuit converts a pulse width modulated input signal to an isolated DC output current whose magnitude is a function of the duty cycle of the input signal. The isolation circuit includes an optical isolator which receives the pulse width modulated input signal and has an output which changes between a conductive and a non-conductive state in response to the input signal. A voltage regulating diode, such as a Zener diode, is connected to the output of the optical isolator and to an isolated power supply so that the voltage across the Zener diode varies between two known voltage values in response to the switching of the optical isolator output between conductive and non-conductive states. A signal derived from the Zener diode is filtered to produce a reference signal with a magnitude which is a function of the duty cycle of the input signal.

Abstract: A solid state relay having a light-emitting diode, an array of series connected photodiodes and a field effect transistor is described.The light-emitting diode is optically coupled to the array of photodiodes. The conductive state of the transistor is determined entirely by the voltage developed by the array of photodiodes.

Abstract: A connector assembly for efficiently coupling optical data from a fiber optic transmission line terminal to an electro-optic conversion device which may be associated with, for example, a hybrid electronics circuit substrate contained within a hermetically sealed enclosure or hybrid circuit package is disclosed. The connector is characterized by a unitary assembly of a generally tubular connector body adapted to removably receive and align a fiber optic terminal with an aperture therein, a transparent faceplate aligned with the aperture and hermetically sealed in the body, and an electro-optic conversion device mounted on the body in alignment with the aperture. The connector assembly may be tested prior to being hermetically sealed to the hybrid circuit package whereafter the conversion device may be connected to the hybrid circuit substrate and the entire hybrid circuit package hermetically sealed.

Abstract: A sensor for producing an electrical signal parameter responsive to the mean square of an applied alternating voltage has a rectifier element, and has a zener diode element electrically in series with a light-emitting diode element across the direct voltage which the rectifier element produces. The polarity of the direct voltage applies reverse voltage to the zener diode element and applies forward voltage to the light-emitting diode element. A photoconductor is optically coupled to receive electroluminescense which the light-emitting diode element emits.

Abstract: In a system wherein a single input signal is transmitted via a plurality of output signal channels for various signal processing and control functions, optical isolating circuits in combination with current limiting resistors provide operational isolation among the respective output signal transmitting channels such that a component failure in one channel will not adversely affect the operation of the remaining channels.

Abstract: An optical fiber coupler for interfacing with a light active element and means for assembling and connecting said coupler to said element. The coupler comprises a guide assembly having at least three glass rods disposed in a side-by-side array, parallel to one another and with longitudinal peripheral portions of adjacent rods in contact and connected to each other to form a cusp-shaped interstitial channel therebetween. The assembly includes a first and second flat end. The channel at the second end is flared to facilitate the ingress of an optical fiber in said channel. A segment of optical fiber having a first and second flat end is disposed and fused within the channel with its second end located at an intermediate portion along the channel with its first end being co-planar with the first end of the guide assembly.

Abstract: Arrangement for regulating the output power of a semiconductor laser for a data transmission system including a light conductive fiber through which the laser power is transmitted and a photodiode which is responsive to light energy produced by the laser and whose output signal is utilized, possibly after appropriate amplification, to regulate the laser current. The photodiode is a thin-film photodiode which is transparent for the light frequencies to be transmitted via the light conductive fiber and is inserted in the light-conductive fiber used to transmit the signals.

Abstract: Temperature regulation of an avalanche photodiode is obtained by internal heating, by passing a reverse current through the breakdown region of the photodiode. In operation, an empirically-derived, reverse bias potential, equal to the breakdown potential at the desired operating temperature, is applied; and when incident radiation is to be detected the reverse bias potential is temporarily lowered to an empirically-derived operating value.

Abstract: An improved failsafe logic function apparatus is disclosed which includes an input signal section and an output signal section, with a middle gating network section isolated from each of the input signal section and the output signal section. An external control signal determines the logic function operation of the apparatus.

Abstract: The optocoupling between an optical source and an optical sensor is enhanced while retaining a high dielectric strength by providing a homogeneous medium surrounding the source and the sensor having an inner light transmissive region and an outer light reflective region encapsulated within a substantially opaque body. The homogeneous medium is formed by applying an optically transmissive material to the source and sensor and no more than partially curing said material before applying an optically reflective material which, when fully cured along with the optically transmissive material, does not form an isolation degrading boundary therebetween.

Abstract: A laser mounting package includes a ferrule containing an optical fiber held in it by jewels at each end of the fiber, the laser being mounted adjacent one end of the fiber. The laser is enclosed by an outer housing and the ferrule is mateable with a ferrule ended optical fiber transmission line.