Abstract: A multi-beam photoelectric sensor is disclosed which can be fabricated by selecting the length of a light projection/light-receiving columnar member and the number and pitches of optical axes in accordance with the width of a hazardous area of an object or the diameter of the minimum object to be detected. A projector string or a photo-detector string includes an optical module string having an alignment of a plurality of optical modules with an optical system for one optical axis, a light projection circuit for one optical axis and a plurality of flip-flops corresponding to one stage of a shift register, integrated with each other, and a flat cable. The flip-flops in the adjacent optical modules are connected in cascade by the adjacent module conduction wires thereby to make up a shift register. The optical modules making the optical module string are sequentially activated by the data sequentially sent by the shift register.

Abstract: The present invention provides a method to maintain a multiplication factor of an avalanche photodiode independent on temperatures without additional devices. The light-receiving apparatus of the invention includes an avalanche photodiode (APD), a dividing circuit, and a bias supplying circuit. The APD has a first region, where a significant multiplication factor appears, and a second region without any multiplication factor. The dividing circuit extracts a second signal.

Abstract: An optical sensor is provided corresponding to a scanning line and a reading line. The optical sensor includes a light-receiving element, a current flowing between both terminals thereof being changed according to the amount of incident light and a transistor whose gate is connected to one end of the light-receiving element, one of a source and a drain being connected to the scanning line and the other being connected to the reading line. In an initialization period in which the scanning line is selected, a predetermined initialization voltage is applied to the gate and, after the application of the initialization voltage ends, a result according to the amount of received light is output based on a voltage on the reading line.

Abstract: An automatic power controller includes a photo detector for detecting the output power of the laser light source and generating a detection signal, a comparator for comparing the detection signal with a reference signal and outputting a comparison signal, a signal source for providing the reference signal with different voltages representing different output power levels of the laser light source to be set, and a gain-adjustable amplifier for receiving the comparison signal and generating an output signal. The gain of the gain-adjustable amplifier is adjusted so that the voltage difference between the steady-state voltage of the comparison signal and the voltage of the reference signal is kept substantially unchanged regardless of the output power of the laser light source, the occurrence of charging/discharging the capacitor in the comparator is reduced. Therefore the automatic power controller can rapidly reach its new steady state while changing the laser output power.

Abstract: Among the embodiments of the present invention is an apparatus that includes a transistor, a servo device, and a current source. The servo device is operable to provide a common base mode of operation of the transistor by maintaining an approximately constant voltage level at the transistor base. The current source is operable to provide a bias current to the transistor. A first device provides an input signal to an electrical node positioned between the emitter of the transistor and the current source. A second device receives an output signal from the collector of the transistor.

Abstract: A digital pixel sensor, comprising a first switch coupled between a first voltage and a first node, turned on or off by a rest signal to provide a first voltage to the first node when turned on; a light sensing unit coupled to the first node generating a transformation current responsive to the intensity of an incident light source and thereby discharging the first node, and a decision device coupled with the first node and a reference signal to output an intensity reference signal corresponding to the intensity of the incident light source when the voltage at the first node is discharged to a level below that of the reference signal.

Abstract: An input circuit has a first current-limiting resistor, a second current-limiting resistor, and an AC-input photocoupler. The photocoupler has an input terminal connected to a first external terminal and another input terminal connected to a positive electrode through the first current-limiting resistor and also to a ground electrode through the second current-limiting resistor. The first external terminal is connected to a PNP transistor and NPN transistors.

Abstract: A low-level light detector includes an avalanche photodiode (APD) to which is applied a bias voltage adjusted to produce a multiplication factor of not more than 30, and a capacitor for accumulating carriers produced by light in the APD and multiplied using the APD characteristics, the capacitor being connected to the avalanche photodiode. The detector detects the intensity of light impinging on the avalanche photodiode by periodically reading the capacitor voltage and obtaining time-based differences in the voltage, or by resetting the capacitor voltage to a predetermined voltage each time the capacitor voltage is read.

Abstract: The invention relates to a device for compensating for fluctuations in the light which is emitted by a light source and propogates along a light path. The device has a first light-sensitive sensor. The sensor detects the intensity of the light at a first location along the light path in a spatially resolved manner and generates electrical image signals. Furthermore, a second light-sensitive sensor is provided, which detects the intensity of the light at a second location along the light path and generates electrical output signals.

Abstract: In a programmable power supply used in a semiconductor test apparatus, high-speed switching of a large current in a current rage or an output relay is enabled. In a MOSFET drive circuit 22 of a switch portion 20 provided in a programmable power supply 10 of a semiconductor test apparatus 1, a capacitor portion 22-12 is charged with electric charges by a current from a light receiving portion 22-12 of a light insulating element 22-1. When an SWA is turned on (SWB is turned off) by changeover of the analog switch portion 22-3, a gate of each MOSFET in the MOSFET portion 21 is charged with the electric charges stored in the capacitor portion 22-12, and enters an ON state. On the other hand, when the SWB of the analog switch portion 22-3 is turned on (SWA is turned off), the gate of the MOSFET is discharged.

Abstract: The invention relates to a method and to an apparatus for the processing of a received signal of an optoelectronic sensor, in particular of a light grid having a plurality of reception channels, with a comparison being carried out between the received signal and a signal delayed with respect to the received signal and the signal obtained by the comparison being supplied to a further processing.

Abstract: A photoelectric conversion apparatus includes a photoelectric conversion element and a logarithmic conversion unit for converting a signal from the photoelectric conversion element to a logarithmically compressed voltage by means of a diode characteristic of p-n junction. The p-n junction in the logarithmic conversion unit is composed of any two terminals of the emitter, the base and the collector of the bipolar transistor, and a residual terminal of the transistor is connected to a semiconductor substrate.

Abstract: A semiconductor photosensor device which outputs a detection result when a trigger signal is inputted, comprises: a photodiode current arithmetic circuit which is in an operating state regardless of whether before or after the input of the trigger signal, and which outputs a photocurrent generated by light irradiation; a first amplifier which is in an operating state regardless of whether before or after the input of the trigger signal, and which amplifier and outputs the output of the photodiode current arithmetic circuit; and a second amplifier which is in a non-operating state before the input of the trigger signal, wherein the second amplifier shifts to an operating state upon receiving the trigger signal, and amplifies and outputs the output of the first amplifier.

Abstract: A supply assembly for an LED lighting module includes a control switch for supplying a constant current to the LED lighting module. A dual switching signal composed of low frequency bursts of high frequency pulses is applied to the control switch. By varying the low frequency component of the dual switching signal, the average current through the LED lighting module may be varied in order to vary the light intensity outputted by the LED lighting module.

Abstract: Disclosed is a temperature-compensating device for an APD optical-receiver system using an APD (Avalanche Photo Diode). The device includes a temperature-compensating circuit which employs a digital potentiometer capable of linear compensation through data look-up in compensating the decrease in gain caused by the temperature change of the APD.

Abstract: A current-voltage transforming circuit used with a photo detector integrated circuit includes a photo detector to detect a photo signal (laser beam signal) to generate a photo current, an amplifier to amplify the photo current, which corresponds to the photo signal, an emitter follower to receive an output of the amplifier, an output buffer to receive an output of the emitter follower, a current detecting limiter unit having an input terminal and an output terminal and turned on to generate a limiter current when the detected current outputted from the amplifier is greater than a predetermined current, and a feedback resistor connected between the photo detector and an output terminal of the output buffer.

Abstract: In a photocurrent-to-voltage conversion apparatus for converting a photocurrent flowing through a light receiving element into a detection voltage, an amplifier, a feedback resistor and a clamping MOS transistor are provided. The amplifier has an input connected to the light receiving element and an output for generating the detection voltage, and includes (2n+1) inverter stages connected in series where n is 1, 2 . . . . The feedback resistor and the clamping transistor are connected between the output and input of the amplifier. The clamping MOS transistor is controlled by an output voltage of a non-final inverter one of the inverter stages.

Abstract: A photodetector continuously measure quantity of light ranging from high intensity to low intensity at high speed.

Abstract: A device and method for detecting the relative position of reference light includes a plurality of photodetector arrays arranged in a generally vertical row. Each array includes a plurality of photodetector elements arranged in a generally vertical array row. The photodetector elements in the arrays are arranged in a generally vertically oriented, extended row. Each of the photodetector elements provides an electrical output when illuminated with the light. A plurality of weighting circuits is provided, each weighting circuit being associated with a respective one of the plurality of photodetector arrays.

Abstract: A mirco-controller and boost converter circuit provide constant current to light emitting diode array. A micro-controller operatively coupled with a semiconductor switch and the boost converter circuit measure the ability of a DC power supply to change the inductor. Duty cycles of the semiconductor switch are modified according to the measurement so as to supply substantially constant current to the LED array through an inductor regardless of actual battery voltage.

Abstract: A circuit arrangement (1) for a photodiode (2) has a microprocessor (3) with an output (4) which emits a pulse-width-modulated voltage signal via a low-pass filter (5) to the cathode of the photodiode (2). The voltage which is applied to the cathode of the photodiode (2) is detected by an input (12) of the microprocessor (3) and is regulated at a nominal value by adjusting the voltage signal at the output (4) of the microprocessor (3). The circuit arrangement (1) has a particular wide dynamic measurement range.

Abstract: An optical sensing circuit is provided with a light detector, a voltage to current conversion circuit connected to the light detector, and a comparator. The voltage to current conversion circuit includes an electric resistor and a current mirror circuit connected in parallel to the resistor. The voltage to current conversion circuit increases an electric current flowing through the circuit as a voltage of the output of the light detector decreases. The comparator compares the voltage of the output of the light detector with a reference voltage.

Abstract: A CMOS light-to-current sensor built on silicon substrate is disclosed in this invention. This light-to-current sensor includes a photo-diode and two MOS transistors. The first MOS transistor is connected as the load transistor for the photo-generated current from the photo-diode, and the second MOS transistor is connected as the current-mirror transistor for the first transistor to output a current linearly proportional to the photo-generated current to the external resistor connected to the sensor.

Abstract: A port isolator apparatus includes an optical isolator circuit that electrically isolates an input circuit from a high-speed output circuit. The input circuit uses a transistor to control the current flow of a data signal into the optical isolator. The optical isolator generates, from the data signal, an output signal that controls the high-speed output circuit in the regeneration of the output signal. The output signal is substantially similar to the input data signal. The input circuit and the optical isolator circuit are coupled to one power and ground circuit while the high-speed output circuit is coupled to a second power and ground circuit that is isolated from the first power and ground circuit.

Abstract: A method and apparatus are provided for driving an electro-optic converter assembly with an information signal. The method includes the steps of disposing a resistor having a resistance substantially equal to a resistance of the electro-optic converter adjacent the electro-optic converter, coupling the electro-optic converter and resistor together, in series, to form a current loop, driving the electro-optical converter end of the current loop with the information signal and driving the resistor end of the current loop with an opposite polarity of the information signal.

Abstract: The present invention provides a light-receiving module that realized a reliable wire bonding from a light-receiving device to a die-capacitor on which the light-receiving device is mounted with adhesive. The light-receiving module of the present invention includes a stem and a die-capacitor disposed on the set. The upper electrode of the die-capacitor has a mounting area where the light-receiving device is mounted, a bonding area to which the bonding-wire is to be bonded, and a structure for interrupting the adhesive from spreading from the mounting area to the bonding area. Since the adhesive for die-bonding the light-receiving device in the mounting area does not spread to the bonding area, the wire-bonding to the bonding area can be reliably performed.

Abstract: The present invention provides a bias generation circuit in which the voltage of electrically isolated circuits are stabilized by providing a photovoltaic diode in each circuit, a common light source uniformly positioned to provide equivalent energy to each photovoltaic diode and an operational amplifier, configured with a capacitor as an integration circuit, driving the common light source, wherein one isolated circuit provides feedback to the amplifier, such that variations in the voltage in the isolated circuit causes the amplifier to provide an adjusted signal to the common light source, adjusting the energy output to compensate for voltage variations simultaneously, yet independently occurring in each isolated photovoltaic diode circuit. Such bias voltage circuit may be used with chromatographic ionization detectors as well other devices.

Abstract: A detector is provided for short wave fiber optic communication having compensation to reduce detector jitter. The detector includes a photodetector providing a modulated current. A transimpedance amplifier is coupled to the photodetector receiving the modulated current and providing an output voltage signal. An output buffer is coupled to the transimpedance amplifier receiving the output voltage signal. The output buffer includes a differential transistor pair; a pair of source degeneration resistors connected to the differential transistor pair; and a capacitor coupled between connections of the differential transistor pair and the source degeneration resistors. The value of the capacitor coupled between connections of the differential transistor pair and the source degeneration resistors is selected to reduce jitter. The capacitor passes high slew rate transimpedance amplifier output voltage signals more readily than low slew rate transimpedance amplifier output voltage signals.

Abstract: A night-vision optical device of the invention with controlled life expectancy contains a time measuring device built into the housing of the aforementioned device for measuring the accumulated time of active work of the device. In application to a night scope for a firearm, the device also contains a sensor, which is interlocked with activation of the scope and reacts on the shots produced from the firearm in general and separately on those shots produced during active work of the night-vision optics at nighttime. The aforementioned shots of both types are counted and stored in separate memory units. The night-time shots affects the life expectancy of the night-vision optics because of muzzle flashes which cause such devices as an image intensifier to work with an increased light load. The information obtained from the time measuring device and the shot counter makes it possible to timely receive a warning signal about the fact that the night optics or the entire firearm must be replaced.

Abstract: A compact integrated APD device integrates the bias voltage and temperature compensation functions inside a standard 4-pin PIN package. The active components of the bias and temperature compensation circuits are integrated into a single ASIC using a high-voltage CMOS process and operated at frequencies of at least 1 MHz to greatly reduce the size of the passive components. To mount the relatively large ASIC chip inside the package with the APD chip, TIA chip and passives, the 4-pin package may be modified by either recessing the pins inside the can to facilitate surface mounting the ASIC or adding a spacer inside the can to facilitate three-dimensional packaging. Communication with the bias and temperature circuits is accomplished using a unique bi-directional 1-wire serial interface via the power supply pin. A clock signal is preferably embedded in the control data to synchronize the APD with an external controller.

Abstract: An optical receiver includes a photodiode, a variable current source, and a current mode comparator to detect a difference between current from the photodiode and current from the variable current source.

Abstract: A photodiode array includes a plurality of arrayed individual diode devices. The arrayed diode devices include at least one active photodiode and at least one reference diode. A bias control circuit for the array monitors operation of the reference diode at an applied first bias voltage and adjusts that applied first bias voltage until optimal reference diode operation is reached. A second bias voltage having predetermined relationship to the first bias voltage is applied to the active photodiode to optimally configure array operation. More specifically, an operational characteristic of the reference diode at the first bias voltage is monitored and compared to a reference value. As a result of this comparison, the circuit adjusts the applied first and second bias voltage in order to drive the reference diode measured characteristic to substantially match the reference value.

Abstract: The method and apparatus for compensating a photo-detector allows both regulation and monitoring of the photo-detector to be performed with a common digital controller. The controller accepts input of monitored operational parameters including received signal strength and temperature. The controller provides as an output a bias control signal which regulates a positive the positive or negative side bias voltage power supply for the photo-detector. The controller maintains the bias voltage to the photo-detector at levels which optimize the gain and signal-to-noise ratios for the photo-detector thereby facilitating the decoding of the received signal over a broad range of signal strengths and temperatures. The controller includes a corresponding digital signal strength and temperature compensators the outputs of which summed with a summer to provide the bias control signal.

Abstract: There is described an integrating circuit (20) for use with a photodetector (10) and an optical sensor (1) including such an integrating circuit. The integrating circuit comprises an operational amplifier (30) having a non-inverting input (32) connected to a non-zero bias voltage (VPD-BIAS), an inverting input (31) coupled to the photodetector (10), and at least one output (33). This integrating circuit further includes an integrating voltage storage device (25) having a first terminal coupled to the operational amplifier output and a second terminal coupled to the operational amplifier inverting input, and switching circuitry for controlling timing of the integrating circuit and switching the integrating circuit between a reset phase and an integration phase.

Abstract: A drive circuit for LEDs or other light-emitting elements with which the influence of the changes in temperature or power supply voltage and the element variations can be restrained in order to output a pulse current with a constant level. When n-type MOS transistor 10 is on, power is supplied from switching power supply 60 to the LED, and the current of LED is detected by resistor 20. The error signal Serr between said detection signal Sfb and setpoint signal Sref is generated by error signal generating unit 30 and is averaged by signal holding unit 40. The power supplied to the LED is controlled corresponding to the averaged error signal SerrA. When n-type MOS transistor 10 is turned off from the on state, the power supplied to the LED is stopped, and error signal SerrA is held in signal holding unit 40. When n-type MOS transistor 10 is turned on from the off state, the averaging of error signal Serr is started with the signal level of the held error signal SerrA used as the initial level.

Abstract: The Floating Diffusion charge detection system has incorporated a signal feedback directly into the charge-detection node. The feedback is coupled to the node from the output of the standard buffer amplifier A1 through a feedback amplifier A3, switching transistors S2 and S3, and capacitors Cf and Ch. The feedback significantly reduces kTC noise, has good linearity, and improves DR.

Abstract: The low noise light receiver comprises

Abstract: A transistor photoelectric conversion drive circuit to excite coupled photoelectric conversion device by electric energy driven light emission device or natural light source in the environment to generate electric energy of positive voltage to drive metal-oxide-silicon field effect transistor (MOSFET) or insulated gate bi-carrier transistor (IGBT) or any other high input resistance transistor while electric energy is stored at a slave negative voltage supply circuit device by means of the electric energy of positive voltage so that upon the signal of positive voltage is cut off, negative voltage is inputted to gate and emitter of one or more than one high input resistance transistors to facilitate cutoff.

Abstract: A photovoltaic solid state relay has a light-emitting diode for emitting light in response to an electrical control signal. First and second photovoltaic devices are optically coupled to the light-emitting diode for converting the light to first and second voltages, respectively. First and second unipolar transistors are provided having first and second gate electrodes for respectively receiving the first and second voltages and jointly establishing a first current conducting path between output terminals to which a load circuit will be connected. A bipolar transistor is provided having a base connected to a junction between the first and second unipolar transistors for establishing a second current conducting path in parallel to the first current conducting path in one of opposite directions depending on voltages applied to the output terminals.

Abstract: An automatic power controller includes a photo detector for detecting the output power of the laser light source and generating a detection signal, a comparator for comparing the detection signal with a reference signal and outputting a comparison signal, a signal source for providing the reference signal with different voltages representing different output power levels of the laser light source to be set, and a gain-adjustable amplifier for receiving the comparison signal and generating an output signal. The gain of the gain-adjustable amplifier is adjusted so that the voltage difference between the steady-state voltage of the comparison signal and the voltage of the reference signal is kept substantially unchanged regardless of the output power of the laser light source, the occurrence of charging/discharging the capacitor in the comparator is reduced. Therefore the automatic power controller can rapidly reach its new steady state while changing the laser output power.

Abstract: A method of producing an optoelectronic circuit comprising: forming a first optoelectronic element of the circuit on a first surface of a semiconductor substrate; forming a second optoelectronic element of the circuit on a second surface of the semiconductor substrate; and wherein the first and second optoelectronic elements communicate via current transmitted through the substrate.

Abstract: A sensor has an emitting device for emitting radiation pulses repeatedly and a receiving device for receiving these pulses. The receiving device includes a converter such as a photoelectric converter to convert the received radiation pulses into electrical pulses. On the basis of a known waveform characteristic or characteristics of true electrical pulse it is judged if a pulse which appears on the output line of the converter is a true electrical pulse caused by receiving the radiation pulse emitted from the emitting device or a false electrical pulse caused by noise. The result of this judgment is outputted from an output device. The emitting device may serve to emit the pulses according to a specified bit pattern and the receiving device may serve to compare the pattern of received pulses with a standard bit pattern and to thereby distinguish between true and false electrical pulses.

Abstract: Receiver circuits are provided for detecting a target light source. The circuits include a photocell arranged to detect light impinging thereupon, and a biasing circuit that maintains a constant reverse voltage across, the photocell irrespective of the photocell output. This maintains the capacitance of the photocell at a substantially constant value, and results in faster response times from the photocell. Further, the present invention provides circuits for effectively removing ambient conditions such as daylight from the output. Also, the present invention reduces the amount of signal loss between the photocell output and an amplifier due to loading at the input stage of the amplifier.

Abstract: A selective optical actuation system for a plurality of electrical devices (20) comprises a variable pulse frequency pulsed light source (10) and an optical fibre network (12, 13, 14) distributing the light pulses to actuation gateway for each device, comprising a photovoltaic converter (16) whose correspondingly pulsed electrical output is applied to a ferroelectric transformer (18). Only if the pulse frequency is within the resonant band for a given transformer will the voltage be raised above a threshold value required to actuate that device. Choice of light pulse frequency thereby determines the device(s) to be actuated.

Abstract: A photoelectric sensor transmits pulsed light repetitively, receives light which may include noise and generates a corresponding electrical reception signal. The level of reception signal is compared with a specified threshold value at a timing which is slightly delayed from the timing of light transmission. A sensor output is generated on the basis of the result of this comparison. If periodically changing noise is present and the reception signal has an AC waveform, the level of the reception signal is compared with another threshold value proximal to an AC zero level. The timing of next light transmission is controlled on the basis of the result of the second comparison.

Abstract: A photoelectric sensor has an emitting device for emitting radiation pulses repeatedly and a receiving device for receiving these pulses. The receiving device includes a converter such as a photoelectric converter to convert the received radiation pulses into electrical pulses. On the basis of a known waveform characteristic or characteristics of true electrical pulse it is judged if a pulse which appears on the output line of the converter is a true electrical pulse caused by receiving the radiation pulse emitted from the emitting device or a false electrical pulse caused by noise. The result of this judgment is outputted from an output device. The emitting device may serve to emit the pulses according to a specified bit pattern and the receiving device may serve to compare the pattern of received pulses simultaneously with two or more standard bit patterns and to thereby distinguish between true and false electrical pulses.

Abstract: A Loss Of Signal (LOS) circuit in an opto-electronic receiver circuit. The LOS circuit includes a current to voltage converter and a comparator circuit. The current to voltage circuit receives a current signal including a DC current signal component from a photodetector circuit included in the opto-electronic receiver. The current to voltage receiver generates a voltage signal in response to the DC current signal. The comparator circuit receives the voltage signal from the current to voltage circuit and generates a LOS signal from the voltage signal by comparing the voltage signal to a reference voltage signal.

Abstract: Each of N optical detector parts 801 to 80N has a photodiode PD, a capacitor Cd and a switch SW0. An amplifier A1, an integrator circuit capacitor Cf1, and a switch SW11 , are connected in parallel between the input terminal and the output terminal of an integrator circuit 10. The capacitance of the integrator circuit capacitance C11 is equal to the capacitance of the capacitor Cd in each of the N optical detector parts 801 to 80N. A switch SW01, is equipped between the input terminal of the integrator circuit 10 and the switch SW0 for each of the N optical detector parts 801 to 80N. A switch SW02 is equipped between the output terminal of the integrator circuit 10 and the switch SW0 in each of the N optical detector parts 801, to 80N.

Abstract: Among the embodiments of the present invention is an apparatus that includes a transistor, a servo device, and a current source. The servo device is operable to provide a common base mode of operation of the transistor by maintaining an approximately constant voltage level at the transistor base. The current source is operable to provide a bias current to the transistor. A first device provides an input signal to an electrical node positioned between the emitter of the transistor and the current source. A second device receives an output signal from the collector of the transistor.

Abstract: An LED lamp package for packaging an LED driver with an LED is provided. In one embodiment, the LED lamp package includes an LED driver chip and an LED chip, both of which are mounted on the ground lead of the LED lamp package and both of which are enclosed by the light transparent encapsulant of the LED lamp package. In another embodiment, the LED chip is mounted on top of the LED driver chip in the LED lamp package. In this embodiment, the LED driver chip includes an attachment pad, on which the bottom surface of the LED chip is mounted.