Abstract: An electronic circuit (50) for receiving and discriminating modulated light of a specific modulation frequency or within a specific modulation frequency range includes a photodiode detector (52) responsive to light incident thereto for generating an electric current signal. A controllable shunt (54) is connected in parallel with the photodiode detector (52) and is controllable between a first operational mode in which the current is shunted, and a second operational mode in which the current is not shunted. A control circuit (56) is connected to the photodiode detector (52) and the shunt (54) for controlling the controllable shunt (54) into (a) the first operational mode, provided that the current signal does not include a signal of the specific modulation frequency or within the specific modulation frequency range, or (b) the second operational mode, provided that the current signal includes a signal of the specific modulation frequency or within the specific modulation frequency range.

Abstract: Remote sensing method and apparatus wherein sparse optical events are distinguished from false events. "Ghost" images of actual optical phenomena are generated using an optical beam splitter and optics configured to direct split beams to a single sensor or segmented sensor. True optical signals are distinguished from false signals or noise based on whether the ghost image is presence or absent. The invention obviates the need for dual sensor systems to effect a false target detection capability, thus significantly reducing system complexity and cost.

Abstract: In order to provide a photo detector in which the generation of spontaneous noise is suppressed and external noise is effectively reduced, a p-type diffusion layer is provided on the obverse side of an n-type semiconductor substrate, a p-type low-resistance layer is provided on the obverse side of the p-type diffusion layer, a lead frame is provided on the reverse side of the n-type semiconductor substrate with an insulative resin film in between, and the p-type low-resistance layer is electrically connected to the lead frame. With this structure, the obverse surface of the photo detector is held at the ground potential and the intrusion of electromagnetic noise from outside, that is, external noise can be prevented, so that the reception distance can be increased. In addition, since the junction between the p-type diffusion layer and the p-type low-resistance layer is not a pn junction, the generation of spontaneous noise is sufficiently suppressed.

Abstract: An active regulator that reduces the noise occurring on an image intensif tube particularly suited for use in night vision system is disclosed. The active regulator reduces the noise thereof and increases the sensitivity of the night vision system.

Abstract: Circuitry capable of controlling a bias voltage for an avalanche photodiode (APD) in accordance with the temperature slope of the breakdown voltage of the APD is disclosed. A reference voltage generating circuit sets a voltage implementing an optimal amplification ratio on an output terminal, and generates a reference voltage by taking account of the temperature slope of the breakdown voltage of the APD. The reference voltage is applied to one input of a voltage comparator. A setting circuit feeds to an adding circuit a preselected voltage for controlling the voltage on the output terminal to a value capable of implementing the optimal multiplication ratio. A temperature compensating circuit feeds to the adding circuit a voltage corresponding to the temperature slope of the above breakdown voltage. The temperature slope is representative of the variation of the breakdown voltage with respect to temperature.

Abstract: A read out circuit for an active pixel sensor array is provided. The read out circuit includes a first circuit, coupled to a pixel of the array, to receive from the pixel information indicative of an intensity of light detected by the pixel and to drive the information to a read out device when the pixel is accessed. The read out circuit further includes a second circuit, coupled to the first circuit, to reset the read out device prior to access to the pixel.

Abstract: In a photointerrupter comprising a light emitting diode and a photo transistor which are opposed to each other, the photo transistor has an emitter which is grounded through a resistor while the light emitting diode has a cathode which is connected to an input terminal of a one IC chip for controlling a flexible disk drive. The one IC chip incorporates a constant current source which is connected to the input terminal through an npn-type bipolar transistor. The one IC chip incorporates a logic circuit having an output terminal which is connected to a base of the npn-type bipolar transistor.

Abstract: A background suppression technique uses well-controlled and repeatable charge skimming operations to increase the charge capacities of the integration capacitors of integrated focal plane readout unit cells. A MOSFET (Q1) is connected to an integration capacitor (C.sub.int) from which the quantity of stored charge is to be reduced. During each photocurrent integration period, the MOSFET is driven with a "skimming pulse" (V.sub.sk) to draw charge from the capacitor. The skimming pulse is substantially shorter than an integration period, reducing the amount of noise contributed by the MOSFET's noise mechanisms, and has an amplitude great enough to drive the MOSFET into its strong inversion mode, making the quantity of the removed charge relatively insensitive to variations in MOSFET threshold voltage. The charge skimming pulse is arranged to reduce the charge on the capacitor almost, but not quite, to zero, so that the entire integration period remains utilized.

Abstract: An image sensor circuit which employs a photodiode in conjunction with a charge transfer mechanism. By employing the photodiode, at least a portion of the light sensed does not pass through a layer of polysilicon, and so is not prevented from reaching the sensing area by the polysilicon. The image sensor circuit of the invention is made up of device structures readily available in standard CMOS process technologies Advantageously, image sensors embodying the invention show substantially improved quantum efficiency for short wavelength light over the prior art sensors. In addition, image sensors embodying the invention display improved dark current uniformity, thus improving yield.

Abstract: A first object of the present invention is to provide a photosensor for use in an apparatus such as a copying machine, a printer etc. employing an electrophotographic technology which can prevent an image anomaly such as a blurring from generation even if it is exposed to a high-humidity ambient for a long period and subjected to multiple repetitions of numerous printing characters.A second object of the invention is to provide a photosensor for use in electrophotography which is excellent in surface abrasion durability, humidity resistivity etc.To satisfy the first purpose mentioned above, a photoconductive layer 2 formed of an amorphous layer including silicon atoms as a major element is deposited on a conductive substrate 1 formed of aluminium etc.

Abstract: A test circuit incorporated as part of an image sensor array having a plurality of image sensors and associated transfer circuits includes a test line associated with each photosensor. In a test mode, a signal output from a photosensor can be substituted with a predetermined voltage from an external source. By providing a predetermined test voltage to the transfer circuits and then reading out signals from the transfer circuits, faults in the transfer circuits can be isolated from faults in the photosensors.

Abstract: A method for providing an improved active pixel sensor cell having a soft-saturation circuit. The method includes providing a pixel node and a photodiode coupled to the pixel node. The photodiode receives light and converts the light into an electrical signal representative of light. A soft-saturation circuit for selectively affecting the electrical signal at the pixel node based on the electrical signal at the pixel node based on the electrical signal at the pixel node is also provided.

Abstract: Probes previously used only in polar systems are used to detect the presence of foam in nonpolar systems, such as hydrocarbon systems. The probes are used to detect the present of foam in high pressure separating equipment and to notify the operator of such equipment that a foaming condition exists. In response, the operator can either increase or decrease the amount of defoaming chemicals being added to the separator or the flowrate of the defoaming chemical is automatically changed to a predetermined flow rate. The probes may also be used to determine the amount of gas that is trapped or entrained in the crude oil.

Abstract: An optical preamplifier device for a light receiver, the device including a first optical amplifier. The first optical amplifier is coupled to an input of an optical filter centered around a fixed wavelength .lambda..sub.o via a wavelength conversion device for converting wavelength to the fixed wavelength .lambda..sub.o of the filter, thereby enabling the device to be made independent of the wavelength .lambda..sub.i of the signal.

Abstract: A solid-state radiation detecting device comprises an insulation layer having a pair of opposed surfaces. First and second single crystal silicon semiconductors are disposed on respective ones of the opposed surfaces of the insulating layer. A photoelectric conversion element is disposed on the first single crystal silicon semiconductor. A signal processing circuit having a charge transfer device is disposed on the second single crystal silicon semiconductor.

Abstract: A photosensor includes a light emitting device, a light receiving device for receiving a side beam from said light emitting device, and a light diffusing member disposed between a side surface of said light emitting device and said light receiving device.

Abstract: Circuitry provides an electronic shutter capability to photo-receiving circuitry for the purpose of disabling integration of a photo-generating charge on an integration capacitor until a reading device reads the integrated signal from the integrating capacitor. With an input from a shutter control line of a high logic voltage, the shutter discontinues charging of the integrating capacitor until the integration capacitor is selectively connected to a read line. Upon receipt of a low logic voltage signal from the shutter control line, the shutter allows the integration capacitor to integrate a photo-receiving charge. The electronic shutter therefore provides well controlled integration time via shutter control. Another advantage is that the integration time is completely independent of the cell reading rate.

Abstract: A night vision device with an image intensifier tube includes an improved power supply which operates the image intensifier tube of the device according to a variable duty cycle either at a design voltage level for the tube or at a voltage level simulating a dark-field. This duty cycle variation is effected as a function of the current flow in the image intensifier tube in order to provide automatic brightness control and bright source protection. An improved service life for the image intensifier tube is achieved. Also, a microchannel plate of the image intensifier tube need not carry an ion barrier film, resulting in an improved light amplification for the image intensifier tube.

Abstract: A transducer sensitive to electromagnetic radiation has a substrate with printed conductor runs arranged on both sides, a sensor that is sensitive to radiation glued over a large surface at the front side of the substrate, and of a thermal expansion-compensating "dummy" component connected to the back side of the substrate. The printed conductor runs have connections to one another only in the middle region of the substrate, and otherwise are free of intersections. The basic orientation of the conductor runs can be stellate or right-angled. The absence of conductor run intersections allows gas to escape during the gluing process, so that gas pockets do not form in the adhesive, which can degrade the quality of the adhesive connection.

Abstract: An apparatus and method for improving dynamic rays and motion representation in digital imaging. A light sensitive element such as a photo diode is employed to sense a light level at a surface during a period of time. A plurality of storage elements are associated with the light sensitive element but electrically segregated therefrom by a plurality of sampling transistors by enabling the sampling transistors between the particular storage element and the light sensitive element in a predetermined way. Its dynamic range can be extended and since readout between exposures is not required, exposure may be taken in closer temporal proximity thereby improving motion representation.

Abstract: A plurality of light-receiving devices dispersed over the area of an IC chip operate in response to the opening of an IC device such that switching transistors are turned on or off to prohibit the normal operation of logic circuits or logic elements, thereby securing protection against normal reading of the internal data of the opened IC device, particularly against the analysis of the IC's internal logic with an electron beam tester.

Abstract: A cathode switch particularly suited for an image intensifier tube (IIT) is disclosed. The cathode switch provides cathode pulses to turn "on" and n "off" the IIT tube and does so with reduced power consumption and with reduced noise generated by associated high voltage switching.

Abstract: A photoelectric measurement is made by charging (or discharging) a capacitor at a charge rate dependent on the intensity of the light received by a sensor. The time taken for the charge level to change by a predetermined amount is measured, and the operation is repeated, with the time intervals being accumulated, for a number of times, the number being dependent on the charge rate, so as to enhance resolution of high-intensity measurements. A single comparator is used to detect when the charge level passes through a first level, to initiate the timing, and through a second level, to stop the timing, by altering the threshold level so as to avoid errors due to varying propagation delays.

Abstract: Disclosed is a radiation detector which includes a photoconductive detector and a modulator which modulates radiation passing to the photoconductive detector from a radiation source. An AC bias source is connected to the photoconductive detector and provides at least two levels of bias thereto. The modulator supplies synchronization signals to the AC bias source such that the level of bias supplied to the photoconductive detector is synchronized to the modulation of the radiation by the modulator. An integrator is connected to and receives an output signal generated by the photoconductive detector.

Abstract: The COPA accelerometer utilizes a sensing body having a non-zero product of inertia to sense acceleration when spun or oscillated about the y'-axis of an x'-y'-z' Cartesian coordinate system. The sensing body is pivotally attached to a platform and pivots about an axis parallel to the z-axis of an x-y-z coordinate system fixed in the sensing body, the z-axis being in the x'-z' plane. An orientation sensor provides a measure of the average angle between the y-axis and the y'-axis. The orientation sensor contains a laser diode which illuminates a plurality of regions of a photodetector thereby causing photodetector regional currents to flow out of the photodetector.

Abstract: A storage pixel sensor comprises a photosensor selectively connectable to a reset potential; a switched buffer amplifier having a control terminal coupled to said photosensor, a first terminal connected to a source of a transfer signal, and a second terminal; a storage capacitor coupled to said second terminal of said switched buffer amplifier; and an amplifier coupled to said storage capacitor.

Abstract: An integrated circuit 100 emits light corresponding to a defect in the integrated circuit 100. The light is transformed to electrical signals by a photomultiplier 206. The spectral content of the electrical signals is compared with predetermined or known noise signatures to identify the defects in the integrated circuit 100.

Abstract: A pixel circuit construction for image sensing includes a photosensor, an amplifier, a selector switch and, and a reset switch. The amplifier may be a single polycrystalline silicon (channel) transistor for high gain. The selector switch may also be a single polycrystalline silicon (channel) transistor for high conductivity. The reset switch may a single amorphous crystalline silicon (channel) transistor for low leakage current. The photosensor and amplifier may be connected to a shared bias line or may be connected to separate bias and drive lines, respectively. The selector and reset switches may be connected to a shared data line or may be connected to separate data and reset lines, respectively. Laser crystallization and rehydrogenation techniques are well suited to obtaining devices described herein. Threshold response is provided.

Abstract: A high S/N ratio, stable, and high read rate photoelectric conversion device is formed by the same process as that for a TFT in a photoelectric conversion apparatus, and includes a photoelectric conversion device having a first electrode layer, a semiconductor layer, and a second electrode layer, first and second switch devices each having first and second main electrodes, first and second power sources, and a reading circuit, where the first electrode layer is electrically connected to the first main electrode, the second electrode layer is electrically connected to a power source, and the second main electrode is electrically connected to the reading circuit. The switch device is turned on in refresh driving for applying an electric field from the power source to the second electrode layer in a direction for guiding carriers from the semiconductor layer to the second electrode layer, thereby fixing a potential on a first electrode layer side of the photoelectric conversion device.

Abstract: An active pixel sensor with a shared readout structure controls the switching of its transistors in a time-divided manner in conjunction with the appropriate switching of the voltage of a variable voltage source, whereby two pixels in a sensor can share a common readout structure and a selecting transistor commonly used in conventional art is not required.

Abstract: A circuit and apparatus for generating a light pulse from an inexpensive light-emitting diode (LED) for an accurate distance measurement and ranging instrument comprises an LED and a firing circuit. An optional pre-biasing circuit provides a reverse-bias signal to the LED to ensure the LED does not begin to emit light before a firing circuit can provide a sufficiently high current pulse of short duration as a forward current through the LED. The LED is driven by the firing circuit with a pulse of high peak power and short duration. The resulting light pulse from the LED can be inexpensively used to derive distance and ranging information for use in a distance measurement and ranging device.

Abstract: Photosensor comprising a network (R) of cells ( . . . , Cn-1, Cn, Cn+1, Cn+2, . . . ) each comprising a photosensitive component (PH) and an exploitation circuit (CE) for allowing the transfer of a measurement signal coming from the cell ( . . . , Cn-1, Cn, Cn+1, Cn+2, . . . ) and due to the illumination of this cell, to a common output (SC) of the photosensor. An addressing signal allows to sequentially connect all the cells to said common output. According to the invention, each cell also comprises an integrated conductive region (RC) forming together with said photosensitive component (PH) a test capacitor (CPT) which is coupled to the parasite capacitor (CP).

Abstract: This invention provides a solution to the problem of determining how long the peak value detected for the first pulse be kept, and when should it be updated. In infrared communication, the communication distance may vary over time during the transmission. For instance in a mobile infrared telephone the users generally are moving with respect to each other. The signal amplitude changes within a very large range over time and the receiver expected to operate in this environment must also handle a large number of different communication protocols. It uses the instant signal as a basis for adjusting the threshold. The present invention is capable of accepting a wide input dynamic range of signals up to and beyond five orders of magnitude (50 dB). This is accomplished while overcoming the difficulties presented by many communications protocols, by providing a technique in which the output pulse width of an amplified photo detector input is not strongly dependent upon the input signal amplitude.

Abstract: A bias voltage supply circuit for an optical receiver includes a high-voltage generation circuit, a current detection circuit, a reference voltage generation circuit, and an operational amplifier. The high-voltage generation circuit supplies a variable bias voltage to an APD having an amplification function. The current detection circuit converts an output current, which is based on the bias voltage supplied from the high-voltage generation circuit, into a voltage signal. The reference voltage generation circuit outputs a constant reference voltage. The operational amplifier outputs a voltage control signal, corresponding to a difference between an output voltage from the current detection circuit and the reference voltage from the reference voltage generation circuit, to the high-voltage generation circuit, thereby variably controlling the bias voltage to be supplied to the photoelectric converting element.

Abstract: A method for generating quasi-sinusoidal signals includes illuminating an object capable of reflecting light, focusing a portion of the reflected light on a multi-element detector to form an image, and matching the image size to the size of the detector elements. A first weighted sum of signals generated by a first set of elements produces an in-phase signal, and a second weighted sum of signals generated by a second set of elements produces a quadrature signal. Weights are signed quantities selected to exhibit a band-pass behavior in the spatial frequency domain, thereby attenuating noise generated by, for example, non-uniform surface reflectance and non-uniform illumination.

Abstract: An optical transmission apparatus includes a feedback amplification circuit having flat and wideband frequency characteristics in which the linearity within a band is excellent. As a result, frequency characteristics of the optical transmission apparatus are improved. A feedback amplification circuit is structured with an amplifier including a transistor receiving an input signal at the base thereof, a first feedback path including a feedback resistance provided between the input terminal and the output terminal of the amplifier, i.e.

Abstract: A method is disclosed for obtaining a read-out signal of a MOS-based pixel structure having at least a photosensitive element with an output node and a memory element with a first switch therebetween. The method comprises the steps of while acquiring charge carriers on said output node of said photosensitive element, said charge carriers being converted from electromagnetic radiation on the photosensitive element, after a first time period creating a first signal, and after a second time period, creating a second signal, said read-out signal being a combination of at least said first and said second signals.According to the present invention, there is no limitation to the amount of collected charges in none of the integrated periods. The signal collected during the first period is memorized by a switch which shortly opens and closes between the period. The switch is thus in the same state in both period of time. After a second period, there are thus two charge packets, each obtained during a different time.

Abstract: A method and apparatus for measuring very low light signals including integrating a signal from a photo diode, avalanche photo diode, photomultiplier tube or the like, digitally sampling the integrator output more than two times during each integration period, fitting a curve to the multiple digitized readings to calculate the integration slope for each integration period and determining the original signal from the calculated integration slope.

Abstract: A triggered optical receiver includes a single-ended or double-ended detector for detecting the optical signal and responsively transmitting a corresponding electrical signal to a first stage amplifier. The first stage amplifier output is transmitted to a triggered circuit having an input/output voltage hysteresis characteristic for identifying whether the amplified signal is a logic low or high. The hysteresis characteristic minimizes the effect of input noise and supply noise on the output. The width of the hysteresis loop may be selectively controlled to balance the sensitivity of the circuit against its noise tolerance characteristics.

Abstract: Methods for wavelength determination of a monochromatic light beam are described. The methods involve a detector unit containing at least one pair of photo detectors. One of the detectors in each detector pair is covered with a variable attenuator and the other is not covered by the variable attenuator. The optical transmission coefficient of the variable attenuator is a monotonic function of wavelength. Under illumination of a monochromatic light, the photocurrents produced in the detectors with and without the variable attenuator are compared. The relative values of the photocurrents are used to determine the wavelength of the monochromatic light.

Abstract: A light level sensor for use in controlling the switching of artificial lighting. The sensor comprises a photoelectric transducer which provides an output signal at a level which is significant of the illumination level of incident light. An A-D converter and a microprocessor are located in circuit with the transducer for detecting the level of the transducer output signal and for any cyclic variation of the transducer output signal resulting from cyclic variation of the level of incident light. Further circuit means are provided for generating a sensor output signal if either (a) the level of the transducer output signal is below a predetermined level or (b) the level of the output signal is above the predetermined level and, at the same time, cyclic variations occur in the level of the transducer output signal.

Abstract: A photoelectric cell which detects a distance of an object, including: a first detection component configured to produce a first current which is a function of the distance of the object; a second detection component configured to produce a second current which is a function of the distance of the object; and, a processing circuit configured to shape a first voltage signal and a second voltage signal that correspond to the first current and second current, respectively.

Abstract: This invention is to provide a photovoltaic element capable of improving the production yield in the manufacturing process and the reliability such as the weather resistance and the durability, while also improving the photoelectric conversion efficiency by the light enclosing effect. For attaining such object, the photovoltaic element is featured by a fact that the transparent conductive layer, positioned between the substrate and the semiconductor layers, is provided, at a face in contact with the semiconductor layers, with a fractal structure of a fractal dimension D within a range of 1.01.ltoreq.D.ltoreq.1.20 at least within a dimensional range from 40 to 400 nm.

Abstract: Disclosed is a method and associated apparatus for compensating for kTC noise in individual pixels of an MOS imaging array. The kTC noise at issue forms when a pixel is disconnected from a reset voltage by turning off an MOS transistor which controls access to the pixel photodiode. Compensation is accomplished by first exposing the photodiode to the reset voltage and then disconnecting the well region from V.sub.dd to cause it to float. By allowing the well to float, the kTC charge subsequently introduced (at the conclusion of the reset process) redistributes so that most of it accumulates on the capacitor between the well and the substrate. Later, the well is reclamped to V.sub.dd, and the noise contribution stored in the well-substrate capacitor is canceled. A disclosed apparatus includes an array of pixels, each having a separate well. In addition, access of the well to a source of power (V.sub.dd) must be switchable. Therefore, a transistor is included at each pixel's connection to a V.sub.dd.

Abstract: A photo diode is connected to an input terminal of an amplifier to which a feedback resistor is connected. An output current of this photo diode flows from the output terminal side of the amplifier through the feedback resistor. The output of the photo diode converted into a voltage is given to the output terminal side of the amplifier. The feedback resistor is formed by a P-type resistor region provided in an N-type resistor land of a semiconductor substrate. In order to apply an inverse bias to the PN junction between the resistor land and resistor region, the resistor land is connected to the output terminal of the amplifier.

Abstract: A radiation sensor means for detecting a radiation comprises a radiation sensor element outputting a current which is generated by the incident radiation power, a detection circuit detecting the current generated by the radiation sensor element, and a reset circuit connected to the radiation sensor element in such a way that, when said reset circuit is driven by a reset signal, the charge carriers produced by the incident radiation power recombine at a rate which is higher than the rate without the reset signal, the reset signal being adapted to be applied to said reset circuit by means of the detection circuit.

Abstract: A light-received position detecting circuit includes a light receiving portion 10 formed by plural photodiodes arranged side by side for detecting light to generate a photoelectric current, and a resistor group RR formed by plural resistors RR1 to RRn-1 connected in series and the photodiodes are correspondingly connected to the respective resistors to divide the photoelectric current from a light emitting portion 31 into photoelectric current parts according to the position of generation of the photoelectric current. First and second current detecting amplifiers 12 and 16 for generating detection signals corresponding to the photoelectric current parts are connected to the opposite ends of the resistor group RR, respectively. A third current detecting amplifier 14 for dividing the light receiving portion 10 into light receiving sections and detecting the photoelectric current part is connected to selected one of the resistors located in the intermediate portion of the resistor group RR.

Abstract: A recording apparatus capable of determining malfunction of an ink detection device such that a light emitting device of an ink detection sensor provided for the recording apparatus to detect ink depending upon whether ink traversing a detection optical axis exists is periodically operated to emit light. Malfunction of the ink detection sensor is determined in accordance with the quantity of light received by a light receiving device in a state where ink traversing the detection optical axis is not discharged.

Abstract: An adhesive agent 116 is coated to a peripheral flat portion 115 of an optical glass 113. A center flat portion 114 is mounted to an opening portion 108 of a TAB tape 105 from the reverse side of which copper leads 107 are formed. Thus, the optical glass 113 and the TAB tape 105 are adhered. At this point, the center flat portion 114 and the TAB tape 105 are arranged almost on the same plane. Thus, protrusion of the adhesive agent 116 and foreign matter stuck on the optical glass 113 can be easily and securely removed.

Abstract: A drive circuit for a photoelectric sensor which automatically adjusts the sensor response time with adjustments in the drive current to the light source based on a desired sensing distance. The drive circuit includes an oscillator for establishing an output signal having an output frequency. An output of the oscillator is provided as an input to an adjustable current source. The current source is connected to the light source for providing the drive current to the light source at the output frequency. A peak detector is connected to a lead of the light source for detecting a feedback voltage proportional to the drive current through the light source. The feedback voltage is provided as an input to the oscillator, and the output frequency of the oscillator is variable depending on the feedback voltage so that variations in the drive current result in corresponding variations in the output frequency and, therefore, the frequency of the drive current.