Abstract: An electro-optic aperture includes an electrochromic medium at least partially disposed thereon. The electrochromic medium is operable to adjust the transmissivity of light through the aperture in response to an electrical signal applied to the aperture. The aperture preferably is operable to significantly attenuate all wavelengths of energy in an area where the electrochromic medium is energized, thereby allowing the energy to pass through an area of the aperture which either does not include the film or is not being energized. Preferably, the electro-optic aperture is implemented with a silicon imaging array sensor, and functions to improve focusing of images when there is sufficient light available in the scene, while allowing a greater amount of light therethrough when lighting conditions darken.

Abstract: A method and apparatus for traveling-wave photodetection. A plurality of discrete waveguide photodetectors is provided. Each discrete waveguide photodetector has a maximum detectable modulation frequency, and each is serially interconnected with all of the others. Each discrete waveguide photodetector has a length less than a quarter of a microwave wavelength at the maximum detectable modulation frequency. Each discrete waveguide photodetector provides a respective discrete waveguide photodetector output current. Each respective discrete waveguide photodetector output current is coherently summed to provide an RF output current. Respective transmission lines are provided coupling each discrete waveguide photodetector to the summer. Lengths of the respective transmission lines are adjusted to provide for current waves traveling in the respective transmission lines to arrive at the summer in phase and sum constructively.

Abstract: When a diffraction grating having a grating period of d and a diffraction order of m for an incident light having a wavelength interval &Dgr;&lgr;i between i'th and (i+1)'th channels is used, an optical path length between the diffraction grating and the photodetector is represented by L and a mean output angle is represented by &thgr;o, a pitch pi between the i'th and (i+1)'th photodetectors in the photodetector array satisfies the equation of pi=m&Dgr;iL /d cos &thgr;o.

Abstract: A device is proposed, which makes it possible to ascertain the relative position of the reference axis BA of an object relative to a reference beam Rp of an electromagnetic radiation, in particular a laser beam. The device displays a spatially fixed radiation transmitter S and—at the object end—a splitting mirror 22 as well as two position detectors 23 and 25. The splitting mirror branches a partial beam Rp′ off from the reference beam. The reference beam passing rectilinearly through the splitting mirror impinges on the one position detector and the partial beam on the other. The position detectors supply electrical signals, from which the position of the reference axis is ascertainable by means of a computer. The known devices of this species have an appreciable space requirement. This defect is eliminated by a particular structuring of the beam conduction and the additional use of special optical means.

Abstract: A device is proposed, which makes it possible to ascertain the relative position of the reference axis BA of an object relative to a reference beam Rp of an electro-magnetic radiation, in particular a laser beam. The device displays a spatially fixed radiation transmitter S and at the object end a splitting mirror 22 as well as two position detectors 23 and 25. The splitting mirror branches a partial beam Rp′ off from the reference beam. The reference beam passing rectilinearly through the splitting mirror impinges on the one position detector and the partial beam on the other. The position detectors supply electrical signals, from which the position of the reference axis is ascertainable by means of a computer. The known devices of this species have an appreciable space requirement. This defect is eliminated by particular structuring of the beam conduction and the additional use of special optical means.

Abstract: In order to improve the noise performance of a charge balance type photodiode array by reducing error influences, e.g. due to offset voltages, flicker and/or thermal noise, on a desired signal a compensation circuit is inserted in each channel of this array. The basic concept under lying this compensation circuit is to effect a correlated double sampling method without any significant increase in space or power demand for the silicon chip of at least one channel of said photodiode array. Because the wanted signal is primarily an amount of charge, the compensating circuit comprises a switchable compensating capacitor to compensate an error contribution of the desired signal. In a first “calibration period” the compensating capacitor is charged or discharged in dependence on the actual noise contribution. In a second compensation period the compensation capacitor provides a voltage which is used to correct a predetermined reference voltage to insure compensation of the error contribution.

Abstract: A system for modulating light is disclosed. The system comprises a detector (102) that receives input radiation (101) and generates detector data (104) representative of the input radiation (101). An information processor (106) receives the detector data (104) and generates control data (108). A filter (110) associated with the detector (102) receives the control data (108) and filters the radiation input into the detector (102) in response to the control data (108). A system for light modulation is disclosed. The system comprises a sensor (114) that receives input radiation (101) and generates detector data (104) representative of the input radiation (101). An information processor (106) receives and processes the detector data (104) and generates control data (108). A filter (110) receives the control data (108) and filters the radiation in response to the control data (108). A method for modulating light is disclosed.

Abstract: A charge balance type of photodiode array uses parallel A/D conversion in each channel of the photodiode array. The charge caused by the photocurrent of a photodiode in each channel is removed in predetermined charge packets provided by a dumping circuit and the binary encoded number of delivered charge packets corresponds to the actual photocurrent. Charge balance photodiode arrays have a wide variety of applications. It is therefore useful to adapt photodiode arrays to the specific requirements of an individual application. The intention therefore provides a photodiode array having at least one switching circuit to vary signal processing parameters such as a gain factor g or an attenuation factor k. This improvement facilitates a multifunctional photodiode array for a plurality of different applications.

Abstract: An optical device is positioned to receive an image and to deflect it into spatially separate portions onto the mutually spaced photosensitive surfaces of an array of staring array detectors. The optical device, which can be implemented with prisms or mirrors, directs the deflected light portions only onto the photosensitive portions of the array, avoiding non-photosensitive gaps between the photodetectors. The focal surface of the optical device may be nonplanar, and in that case the photosensitive portions of the array are positioned to lie at the nonplanar focal surface. The portions of the image received by the individual photodetectors combine to form the overall image.

Abstract: The invention concerns a method and device to carry out the method to provide quality control for a photosensor, especially a photodiode array, whose output signal depends on the intensity of an input signal formed by electromagnetic waves. The photosensor to be tested receives stimulation signals forming the input signals while the stimulation signal intensity of the stimulation signals is varied. The associated output signals of the photosensor to be tested are measured and recorded for evaluation purposes. The photosensor preferably receives at least two independently controllable, superposed individual stimulation signals with individual intensities. The different stimulation signal intensities of the individual stimulation signals are set with the aid of a controller coupled to stimulation signal source, and the output signals of the photosensor are measured and recorded using a measurement data recorder unit.

Abstract: The directional reception of extremely weak light signals without diverting a portion of the signal light into separate detectors for the purpose of obtaining an alignment signal is caused by the arrangement of several detector means (X, Y) which, when unmodulated light is superimposed on them, generate electrical output variables (x1, x2, y1, y2) which, after they have been added in a network (I), result in an information signal which, when it is linked by multiplication with several difference signals (x, y) formed in the network (I), converts them into narrow-band signals, which reproduce an alignment error.

Abstract: An optical recording/reproducing apparatus and method to determine a type of disk including a photodetector divided into at least two light receiving sections in a radial direction. A radial subtractor generates a radial push-pull signal from a difference between light receiving signals from a disk and received by the at least two light receiving sections, where the disk includes one of a first disk and a second disk. An upper envelope detector detects an upper envelope signal from the radial push-pull signal and a lower envelope detector detects a lower envelope signal from the radial push-pull signal. A phase comparator detects a phase difference between the upper envelope signal and the lower envelope signal. A type of disk determiner distinguishes the first disk from the second disk according to a magnitude of the phase difference and outputting a signal indicative thereof, where the second disk includes a density higher than the first disk.

Abstract: An optical detection system and method detects movement of an optical pointing device in a data processing environment. The system works with any surface than can diffusely scatter a collimated beam from a coherent light source. Specifically, the system comprises a coherent light source and an optical sensing assembly. The optical sensing assembly comprises a plurality of photosensor arrays and a plurality of optical elements. Each photosensor array includes pixels of a particular size and shape. Each optical element has an artificially limited aperture and is associated, through optical matching, with a respective photosensor array. The coherent light source generates a collimated beam that is diffusely reflected off of the surface. The optical sensing assembly receives the diffusely reflected, or scattered, collimated beam and passes it through the artificially limited apertures of the optical elements to the associated corresponding photosensor array.

Abstract: A threshold device or comparator comprises an array of energy emitters, e.g. light emitting diodes (16) or diode arrangements. The bits of a binary string are supplied to respective diodes or diode arrangements, which have the property of emitting energy of a distinguishable different characteristic depending on whether the applied bit is a 0 or 1. Sensors (18, 20) sensitive to the intensities of the respective different characteristics detect the intensities and a comparator 24 provides an output indicating the relative quantities of 0's and 1's in the binary string.

Abstract: A metal-semiconductor-metal photodetector (18) is provided including an optical waveguide (22) disposed on a substrate (28) and an array of metal-semiconductor-metal photodiodes (20) coupled to the optical waveguide (22). An absorber (30) is disposed between the photodiodes (20) and the optical waveguide (22) and a transmission line (26) is coupled to the photodiodes (20). Each of the photodiodes (20) includes an electrode (24) having a plurality of interdigitated electrode fingers (31) wherein a width of each finger (31) and a gap between adjacent fingers (31) tapers from one end of the electrode (24) to the other. Preferably the rate of tapering corresponds to an exponential rate of optical power decay through the photodiode (20). In this way, both the photocurrent density in the fingers (31) and the uniformity of the electric field underneath the electrodes (24) are optimized.

Abstract: The useful beam component of the radiation emitted vertically by an optical transmitter passes via a lens body to the coupling zone of an optical coupling partner. A component of the emitted radiation strikes a reception zone of a monitor unit. The reflected component likewise traverses the lens body, and is reflected toward the reception zone at the boundary surface thereof on the coupling zone side.

Abstract: A vacuum electron device comprises an evacuated envelope containing a cathode for supplying electrons to form an electron beam, an anode spaced from the cathode for receiving the electron beam, and a sensor electrode located between the cathode and the anode.

Abstract: A method for generating quasi-sinusoidal signals includes illuminating an object capable of diffusely scattering light, focusing a portion of the scattered light on a multi-element sensor to form an image, and matching the image size to the size of the sensor elements.

Abstract: A detector array for use in a laser imaging apparatus, comprises a plurality of housings disposed in an arc around an opening in which an object to be scanned is disposed, each housing including an open front end, a rear end and a longitudinal axis; and a detector disposed within each housing at a distance from the front end, thereby to restrict the field of view of each detector. The housings are adapted to be orbited around the object about an orbit axis. Each detector is adapted to simultaneously detect light exiting from the object within the respective field of view of each detector. A method for collecting light exiting from a object being scanned with a light source is also disclosed.

Abstract: A position detection element is provided with a photoelectric conversion unit comprising a plurality of pixels arranged on a straight line, a switch group for switching the output of pixels, the first memory group, the second memory group, the first switch group for selecting a memory from the first memory group, the second switch group for selecting a memory from the second memory group, the first signal line for transmitting a signal from the first memory group, the second signal line for transmitting a signal from the second memory group, and a differential amplifier for detecting the difference between signals inputted respectively from the first signal line and the second signal line, and these components constitute the position detection element.

Abstract: A circuit architecture for computing the outputs of odd and even symmetric spatial filters simultaneously comprises at least two resistive networks interconnected by at least one controlled current source. In one embodiment the nodes of the resistive network are arranged in a two-dimensional array to allow filtering of two-dimensional signals such as images. The resulting filters are orientation selective. The spatial orientation and the scale of the filter can be selected by appropriately tuning the resistive elements forming the resistive networks and the gains of the controlled sources. The controlled sources may be voltage controlled (eg transconductance amplifiers) or current controlled. This circuit architecture may be implemented in VLSI to incorporate both image sensing and orientation selective filtering on the same chip.