Abstract: A control system is described for converting the output current of a photosensitive image detector to an image location voltage of predetermined first and second levels in response to the image detector receiving high and low levels of light, respectively. The image location voltage is developed by passing the output current from the image detector, as well as a selectively variable control current, through an impedance such that increases and decreases in the amplitude of the control current result in corresponding decreases and increases, respectively, in the level of the image location voltage. To change the level of the image location voltage, the amplitude of the control current is caused to be proportional to the charge on a charge storing element and the latter is rapidly and alternately charged and discharged within predetermined limits to vary the amplitude of the control current, and thus the level of the image location voltage.

Abstract: A photo multiplier tube is connected through a wave shaping and coupling cuit to an evaluation circuit; to provide for simple evaluation, for example, in an integrator, the coupling and wave shaping circuit includes an amplifier and a limiter, preferably a Zener diode connected through suitable coupling resistors to the integrator. Switches are provided to close the circuit from the photomultiplier tube (PMT) to the integrator, connected with a photon emission event trigger circuit so that, under non-event producing conditions, the integrator is disconnected from the PMT to prevent evaluating and possibly indicating spurious dark current noise pulses.

Abstract: Electrical appliances, particularly A.C. operated appliances, are turned on and off from remote locations by shining a beam of light, using a flashlight or the like on a photoelectric transducer/semiconductor switching device interconnected between a power line and the appliance, the switching device being bi-stable, activatable for either switch-on or switch-off operations by a signal from a single photoelectric transducer, and further comprises delay means responsive to the occurrence of a switch-on or switch-off operation to prevent a subsequent switching operation until a number of seconds have elapsed to allow for variations of human response in handling of the activating light beam, thereby preventing on and off chattering.

Abstract: Disclosed is a control circuit used to conserve power in a portable optical recognition system. When the system is not being used or between actual scans of the reading electronics, power is supplied only to those circuits required to control power to the system and to permit sequence reading of items. An infrared signal is emitted from the reading device and when a document or other item to be read is scanned the infrared signal is reflected back into the scan unit and is detected, thereby sensing that a document is being read and turning the system on.

Abstract: A limit switch utilizing static components and an infrared light emitting diode in conjunction with a photosensitive transistor. A mechanical shutter is provided for insertion between the diode and transistor to interrupt the infrared link therebetween, this will occur when a predetermined limit is reached by an object which is controlled by the limit switch. The limit switch is of the two terminal type, that is it requires no separate source of power for operation than the power in the line being controlled by the switch. It is adapted for high temperature operation.

Abstract: A device is provided for controlling the sensitivity of a receiver of the type comprising a photosensitive element operative to convert radiant energy into electric signals and having an amplifier connected to the output of the photosensitive element and signal processing members for separating a useful signal from interfering background radiation. A sensor device is connected to the photosensitive element to sense the direct current which the element emits in response to radiation from the sun or other strong sources of disturbance, the sensor device being operative to emit a signal when the direct current exceeds a predetermined value, and a switching device responsive to said signal operates to switch the amplifier from a given fixed sensitivity level to a lower fixed level of sensitivity.

Abstract: A radiant energy integrating meter having one or more parallel connected reversed biased radiant energy sensor cells connected to an integrating circuit having an integrating capacitor. A trigger circuit having a differential amplifier, connected to the integrating capacitor, which drives a further amplifier, is adapted to close a first switch such as a silicon controlled rectifier in response to a predetermined integrated sensor current. A counter circuit is coupled to the first switch and advances by one each time the first switch is closed. A second switch such as a relay is coupled to the first switch to provide a discharge path for the integrating capacitor. Finally, a delay circuit is coupled across the first switch to open the first switch after a predetermined time delay.

Abstract: A combination timer and photoelectrically activated control circuit to selectively repeat a timed electromechanical operation at dawn and/or dusk in response to sunrise and/or sunset conditions. Said photoelectric control timer being provided with a deactivating circuit which turns off the output to the load after a preselected time. The circuit remains off even though the initiating light conditions prevail, or reverse. For example, if set to operate with illumination, the device operates in the morning at about sunrise, and after the preset interval a deactivating circuit switches off the output which remains off the remainder of the day while daylight prevails. When daylight ebbs, the photoelectric initiating circuit resets and the entire circuit is reset to repeat the operation when light returns the following morning. An equivalent photoelectric initiating circuit is provided to trigger the timer when light conditions change from light to darkness, such as at sundown.

Abstract: A device for measuring the irradiation energy impinged upon a target within a fixed period, having a photo-electric receiver impacted by irradiation. Such devices have become known by the designation "Lux hour meter". They are used, e.g. for tests, by which the influence of irradiation energy on the properties of materials, e.g. textiles, shall be determined.

Abstract: A pulse discriminator circuit for use in a closed loop scanning and positioning system for finding and positioning white blood cells. The surface of a slide is scanned to produce an optical signal which is converted by a sensor into an electrical signal. This signal is applied to the pulse discriminator circuit which provides an output pulse only when a white blood cell is being scanned. The output of the pulse discriminator is coupled to a logic circuit which produces signals that are used to drive the microscope stage to cause the white blood cell to be positioned within a small aperture in the optical system.

Abstract: A circuit for preventing laser receiver overload caused by sunlight wherein feedback network provides a d.c. current to cancel the d.c. level of the diode current; and, a receiver design alternative to conventional designs wherein higher sensitivity is provided by maximizing the signal to noise ratio and processing by dual equalization to reshape the frequency response to achieve a flat response over the frequency range of interest.

Abstract: A system sensitive to light pulses which are substantially synchronous with a selected pulsed light source containing frequency components within the pulse which are above a predetermined frequency. A signal for exciting the selected pulsed light source is frequency modulated and connected to an AND gate as well as to the pulsed light source device. The pulsed light is received and conditioned producing a received signal which is also connected to the AND gate. Gate output occurs only during the period of time the received signal is in time coincidence with the frequency modulated pulsed light source excitation signal. Additional light pulses transmitted in the immediate area of the receiver by additional light pulse transmitting devices having frequency components within the light pulse above the predetermined frequency may be sensed by the receiver, but will not produce output at the AND gate unless in time coincidence with the frequency modulated signal.

Abstract: A light-responsive electric switch is composed on the one hand by an electronic circuit constituted, in the case of direct-current supply, by a voltage divider comprising a fixed resistor and a variable resistor forming the photo-conductive cell, by four transistors which are blocked or rendered conductive according to the illumination of the photo-conductive cell, by a change-over switch transmitting the voltage to another transistor into the collector circuit of which a motor is connected, and on the other hand by an electro-mechanical device constituted by a bistable trigger circuit controlling the motor, by a step-down gearing meshing with a pinion fixed on the shaft of this motor, by cams fast with the shaft of the final pinion of the step-down gearing and by one or more contacts which close or interrupt one or more lighting circuits.

Abstract: A light beam target for light beam shooting and apparatus employing it are disclosed. The light beam target has a light transparent target plate, stripe-like first and second X- and Y-axis photoelectric conversion elements and a compensating photoelectric conversion element disposed on the back of the target plate. When a light beam is projected onto the target plate, the first and second X- and Y-axis photoelectric conversion elements provide first and second X- and Y-axis electric signals corresponding to the position of the center of the light beam on the target plate. The apparatus using such light beam target has a circuit for producing X- and Y-axis light beam center indicating signals indicative of the position of the center of the light beam on the target plate based on the first and second X- and Y-axis electric signals and a device for displaying on an indicator plate the position of the center of the light beam on the target plate.

Abstract: An electrical signal ratioing circuit for a source delivering an electric analog pulse signal sequence having compensating means for removing the effects of background influences, such as amplifier signal offsets and extraneous illumination, and integrating means eliminating the effect of line voltage variations and changes in optical and electrical system gains on the ratios so produced.

Abstract: The photometer circuit is operative to receive and store a reference voltage which is generated in a photosensor by light which passes through a blank solution in a cuvette and is received at the photosensor. The photometer circuit includes reference voltage input control circuitry for placing the photometer circuit in a receiving and storage mode of operation for a predetermined period of time while the reference voltage is being generated in the photosensor. The photometer circuit includes a comparator having two inputs, a first electronic switch for coupling the output of the comparator to a voltage storage circuit and a second electronic switch for coupling the output of the voltage storage circuit to a voltage run-down circuit.

Abstract: The method consists in causing objects to pass in front of a background having a distinctly different brightness, in aligning a collimator by means of a sighting telescope in a direction of observation such that the path of the objects intersects a line defining the direction of observation of the collimator, in eliminating light from all directions other than the direction of observation, in detecting the variation of light intensity corresponding to the passage of the object by means of an electrical signal which is delivered by a photoreceiver and is a function of the luminous flux picked up by the photo-receiver and in differentiating the signal with respect to time by means of an electronic circuit so as to obtain an output signal which is a function of the variations of luminous flux on the photoreceiver.

Abstract: A detector of the type utilizing photo-electric detection of reflected light which is almost completely immune to false alarms from changing ambient light and random electrical noise, with a sensitivity that is independent of ambient light, with a power consumption low enough to permit battery operation for a period of over 12 months. The light source is a light emitting diode which is pulsed at a low repetition rate, such as one pulse every two seconds, by an extremely short pulse, such as 20 microseconds. Voltage pulses generated when the reflected pulsed light is received by the photo-generative cell is amplified and applied to a level detector, the output of which is applied to the "set" terminal of a flip-flop circuit. The amplifier is on continuously, however the level detector is pulsed to the on condition simultaneously with the on pulse to the light emitting diode, and for the same period of time.

Abstract: A produce grader that includes first and second signal paths for producing first and second signals corresponding to respective detected characteristics of an article of produce being graded. Each signal path includes chopper means for converting d.c. signals to a.c. signals, a.c. amplifier means, and means including synchronous detector means for reconverting amplified a.c. signals to d.c. signals. The reconverted signals are compared and/or evaluated to establish a basis for grading. Means are provided for adjusting the duty cycle of the gating signal controlling at least one synchronous detector thereby adjusting the gain of the corresponding signal path and adjusting the calibration of the grader.

Abstract: A voltage proportional to the APEX indication quantity for exposure time is coupled to one terminal of a meter through a buffer stage transistor. Circuit means produce a reference potential which is applied to the other terminal of the meter. The buffer stage transistor is biased by circuitry including a feedback stage transistor with the biasing being such that substantially constant collector current operation is ensured.

Abstract: The apparatus is used primarily to monitor the occurrence of lightning diarges in the vicinity of a known objective such, for example, as a large rocket launch tower or other object which might be detrimentally affected by the lightning. A continuous, linear single-axis, position-sensing photodiode is deployed a predetermined distance from the objective and an optical objective lens focuses a relatively narrow field of view, such as a 40.degree. field on the photodiode. The arrangement is such that the image of a lightning discharge occurring within the field of view is in the form of a focussed narrow-line channel bisecting the length of the photodiode at varying locations dependent upon the actual location of the lightning discharges itself. In a conventional manner, the photodiode produces two signal outputs each corresponding in magnitude to the particular location of the bisecting channel image of the lightning. Using the fractional distribution of these signal outputs, the angle to discharge (.psi.

Abstract: A frequency synthesizer for scanning a number of predetermined frequencies using radiated electromagnetic energy detected at an array of electromagnetic energy transducers for providing a frequency determinative code. The frequency code is obtained by insertion of a programmed data mask between a source of electromagnetic energy and the array of electromagnetic energy transducers. The frequency code is connected to the input of a programmable divider which also receives the output from a voltage controlled oscillator. The programmable divider provides an output frequency which is a quotient of the voltage controlled oscillator output frequency. The quotient output frequency is compared with a reference frequency for producing a control voltage for the voltage controlled oscillator. The voltage controlled oscillator is thereby driven to produce an output frequency determined by the coded input to the programmable divider.

Abstract: Circuitry providing a scanning threshold for a scanning apparatus in response to the output of a photomultiplier of the apparatus produced during a threshold determining scan of the field uses a first memory circuit to store a signal level indicative of the maximum light intensity sensed by the photomultiplier with a second memory circuit provided to store a signal level indicative of the minimum light intensity sensed. A threshold circuit connects with the stored signals to provide a threshold signal intermediate the two stored signal levels. An inhibiting circuit may be provided to prevent the second memory circuit from responding to signals below a predetermined level. Inhibiting circuitry and memory deletion circuitry are used to condition the memories prior to and immediately following a threshold determining scan.