Abstract: Flyback power supplies require three chip integrated circuits to control the switching cycles on the primary of a transformer including a chip that detects when a voltage threshold and optionally when a current threshold has been crossed on the secondary side of the transformer, an opto-coupler to isolate the secondary to primary feedback from the first chip, and a switch control circuit that receives the feedback information from the opto-coupler and uses the information to modulate the primary pulses in order to regulate the secondary voltage and to optionally set a current compliance limit on the secondary current. This invention shows how these three integrated circuits can be combined into one package using silicon based LEDs. Furthermore, circuit techniques are presented that allow the detection of low level light produced by silicon based LEDs.

Abstract: A method of and apparatus for determining a concentration of nitrogen dioxide that is contained as a trace constituent in atmospheric air utilizes a single-wavelength laser induced fluorescence technique whereby a nitrogen dioxide concentration as lows as at a pptv level can be determined conveniently and accurately.

Abstract: The present invention relates to proximity sensors. It also relates to proximity sensors in electronic devices using lightguides. More specifically the invention relates to a simple self monitoring of optical proximity sensors. This can be achieved according to one embodiment of the present invention by a system of lightguides for the use in proximity sensor. The lightguide system comprises a transceiver lightguide to direct-transmitter to a predefined direction, and a receiver lightguide to direct transmitter light reflected from an object towards a receiver, where the transceiver and receiver lightguides comprise diffracting surfaces to direct a part of-the light from the transmitter as a self monitoring beam in a direction towards a receiver.

Abstract: Using arrays of optical fibers connected to specially configured electronics, e.g., a phototransistor, an LED, an amplifier, a detector, and display, software and PCMCIA A/D board available on a personal computer, continuous real-time acquisition, processing, and visualization of change in a monitored medium is provided. Many of the individual circuit elements above may be replaced with a power meter in an alternative embodiment. In a specific application, scour data are collected on the depth of sediment below a body of water. As the sediment is eroded by an event, the ends of the optical fibers in the array display a different reflection or transmission coefficient indicating that water has replaced sediment. By knowing which of the optical fiber ends in the array is indicating the changed reflection or transmission coefficient, an estimate of how much scour has occurred is provided. A method of employment of the system is also provided.

Abstract: The invention relates to the detection of parameters that are representative of a state associated with an automobile windscreen (1), by optical means. The inventive device comprises a module (20) that is sensitive to at least one of the aforementioned parameters and which is at least partially embedded in a layer (11) of the windscreen. Said windscreen comprises two glass panels (10a, 10b), which are separated by a spacer comprising the part of the module (20) that is embedded.

Abstract: A fiber optic conversion method is provided that includes receiving a first electrical signal. A second electrical signal is received. The first and second electrical signals are compared. A float signal is generated when the first and second electrical signals comprise substantially a same electrical signal. A determination is made regarding whether optical signals are being received. A light signal is generated while optical signals are being received. A driver mode is entered in response to the float signal and the light signal being generated simultaneously. The driver mode is remained in while the light signal is being generated.

Abstract: A light detection equipment in a component with at least one optical access includes a light conveyor having a first terminal part faced inside the component through an optical access. The first terminal part is formed by a spherical cap collecting the light arriving from any angle inside the component. The light conveyor has a second terminal part with a surface faced and substantially in contact with a sensitive element of an optical transducer.

Abstract: A detector of stains on a transparent plate surface is arranged on an internal surface of the plate and includes an emitter for emitting a modulated light signal towards the inside of the plate and a receiver for receiving the signal after it has been reflected on an external surface of the plate. An optical unit made with a material having an index substantially higher than the plate, is arranged on the internal surface of the plate. The optical unit is made up of at least three faces returning the light signal and an interface with the internal surface of the plate through an optical coupler. A deflector deflects the signal from the emitter toward the plate and from the optical unit towards the receiver. At least two reflections on the external surface of the plate are produced through the optical coupler without reflection on the internal surface of the plate.

Abstract: An emitter lens is provided between the radiation source and the work surface to be illuminated. The emitter lens collects radiation and reshapes the illumination pattern to increase intensity and uniformity. The radiation source and emitter lens have associated housings which act to properly orient and align the emitter lens and radiation source. The emitter lens also acts to space the radiation source from an aperture in a housing of the computer input device to provide protection against damage due to electrostatic discharge (ESD). An imaging lens is provided between the work surface and the image sensor to focus light reflected from the work surface onto the image sensor. An imaging lens housing or holder is provided to properly orient and align the imaging lens with the image sensor. The imaging lens housing provides an apron which increases ESD discharge path length.

Abstract: A remote amplifier of the present invention includes an optical splitter and an optical combiner respectively connected to an input and an output thereof. One end of the split output of the splitter is used as an input port while one end of the combiner is used as an output port. When a fault occurs at a certain point on an optical transmission path, an ODOR (Optical Time Domain Reflect meter) is connected to either one of the input port and output port for evaluating the faulty point.

Abstract: An isolation system is provided for generating a control voltage in a low voltage control system that is representative of the input voltage in a high voltage power system of an excitation system, such as in a rotating electrical apparatus. The control voltage isolation system includes a voltage-controlled oscillator for converting the input voltage into a first frequency signal corresponding to the input voltage. Fiber optic conversion and receiving devices are employed in conjunction with a fiber optic cable to transmit the first frequency signal from the high voltage power system to the low voltage control system. Utilizing a fiber optic device provides voltage isolation between the power system and the control system. The use of a fiber optic device for voltage isolation also resists the damaging effects of relatively high transient currents and voltages from affecting sensitive semiconductor components and the like in the control system.

Abstract: Isolation circuits are shown which can be implemented using low efficiency LEDs such as those that can be made directly on silicon. Using silicon based LEDs results in reduced cost and facilitates the incorporation of many optically isolated channels using silicon chips separated with a transparent insulator. These circuits include a linear isolation device for analog signals, an isolated A to D converter, an isolated D to A converter, isolated buffer/driver circuits, isolated multiplexers, and isolated switches. Also, a microprocessor is shown with optically isolated I/O ports, A to D and D to A converters, a multiplexer, and solid state switches.

Abstract: A system for determining wear of an article including an optical fiber for transmitting light from a light source. The optical fiber is embedded in the article, and operatively coupled to an interferometric system. The interferometric system is operatively coupled to a processor. The interferometric system provides the processor with information relating to wear of the optical fiber, and the processor determines wear of the article rate of wear and remaining useful life of the article based on the information relating to wear of the optical fiber.

Abstract: A method and apparatus for generating a control signal which corresponds to movement of an object in contact with a first surface are described. The apparatus includes a platen having the first surface. The platen is characterized by a critical angle beyond which light incident upon the first surface is not transmitted. A source of electromagnetic radiation emits electromagnetic radiation through the platen thereby illuminating the object. A detector having a plurality of sectors receives a portion of the electromagnetic radiation diffused by the object and transmitted through the platen beyond the critical angle. The sectors of the detector accumulate charge in response to the incident electromagnetic radiation. Conversion circuitry then converts the charge accumulated in the detector to the control signal, which in a specific embodiment is for controlling the movement of a pointer on a display.

Abstract: An article and method including an optical fiber coupled to a microstructure which is easily manufactured. The microstructure is comprised of a plurality of layers including a receptacle layer and a movable layer. The optical fiber has a high reflectivity terminal end forming the non-movable layer. The receptacle layer has an opening aligned with the movable layer for receiving the terminal end of the optical fiber. The optical fiber is inserted into the opening and the receptacle layer and fixed in relation to the microstructure, so as to form cavity between the terminal end of the fiber and the movable layer of the microstructure. The movable layer is physically adapted for moving relative to the non-movable layer under the influence of an actuating force.

Abstract: A method for calibrating an optoelectronic component having a light emitter/receiver unit and a connection unit includes the steps of setting an initial relative position of a first part and a second part of the connection unit. After that, the first part is displaced in a reference plane relative to the light emitter/receiver unit. Next, the first part is affixed to the light emitter/receiver unit. Then the second part is displaced relative to the first part and is also affixed to the light emitter/receiver unit. An optoelectronic component is also provided.

Abstract: An optical probe includes a rod-shaped microlens provided with a refractive index distribution in a radial direction, and an evanescent light generating portion formed on a first end face of said microlens. The refractive index distribution and the length of said microlens are such that parallel light that enters said microlens through the second end face converges while being transmitted through said microlens, and substantially focuses on the first end face. The evanescent light generating portion comprises a light-blocking film, which is provided with a micro-aperture formed substantially on an optical axis of the microlens. An aperture diameter of the micro-aperture is dimensioned such that the light transmitted through the microlens is leaked from the microlens as evanescent light only. Outside the micro-aperture, the light transmitted through the microlens is reflected or absorbed by the light-blocking film. It is also possible to use a planar microlens instead of the rod-shaped microlens.

Abstract: A fiber optic control device comprises a joystick having fixed thereon a pivot ball to enable the stick to have universal pivotal movement. The control has a base provided with a socket in which said pivot ball is held captive while permitting the joystick to have said universal movement. The invention provides a pair of swivel members, and pivotally mountings for said swivel members on the base for movement about non-coincidental axes. Slide driving connections are provided between said joystick and swivel members, for causing reversible movements of the members in response to universal movements of the joystick. Mirrors are carried by the swivel members, and a fiber optic light transmission device is provided, which is cooperable with said mirrors and which includes a source of light that is adapted to direct a light beam against the mirrors, thereby to provide output light signals which are a function of the virtual position of said joy stick at any time.

Abstract: A methodology and concomitant circuitry wherein an optical attenuator, having a range of settings including a minimum attenuation, is set to a pre-selected value less than the minimum attenuation whenever a loss of incoming signal power is detected in an optical path coupled to the attenuator.