Abstract: A detection device with pixels arranged in N rows and M columns where N and M are each an integer of one or more, each of the pixels including: a detector configured to detect an electromagnetic wave; a first capacitor connected to the detector; a first switch and a second switch each connected to a terminal of the first capacitor opposite to the detector; and a second capacitor connected to a terminal of the second switch opposite to the first capacitor, wherein each of a terminal of the first switch opposite to the first capacitor and a terminal of the second capacitor opposite to the second switch is connected to a reference potential, and wherein an integration operation of turning ON/OFF the first switch and then turning ON/OFF the second switch while maintaining the first switch in an OFF state is repeatedly performed a plurality of times.

Abstract: A sensing circuit includes: a current source that outputs a direct current; an integrator that integrates a sensing current and the direct current, which is higher than the sensing current, to output an integrated value composed of the sum of a sensing voltage and a direct current voltage; and a subtractor that takes the sensing voltage from the integrated value outputted from the integrator, but not the direct current voltage.

Abstract: An exposure control apparatus which is capable of making a backlight judgment with accuracy using image data on a main subject and image data on a photographer and controlling exposure according to the judgment result. First image data is generated according to a main subject image formed by light from the main subject via a first shooting optical system, and second image data is generated according to a photographer image formed by light from a photographer via a second shooting optical system. First luminance information is obtained based on the first image data, and second luminance information is obtained based on the second image data. According to the first luminance information and the second luminance information, whether or not the main subject is in backlight scene is judged, and based on a result of the judgment, exposure for the main subject is controlled.

Abstract: An optical modulator includes: laser diodes disposed in parallel with each other, each laser diode having a different lasing wavelength; optical waveguides disposed in parallel with each other with first ends facing the laser diodes; an optical isolator inserted between the laser diodes and the optical waveguides and attenuating return light reflected from the optical waveguides toward the laser diodes; a lens focusing light emitted from the laser diodes onto the optical waveguides through the optical isolator; an optical switch selecting one of the light beams exiting from the optical waveguides; and an optical modulator modulating the light beam selected by and output from the optical switch.

Abstract: An analyzer of the spatial intensity distribution of a laser beam focused or transmitted by an optical fiber comprises: a shaping lens; a device for taking a partial sample of the beam; a heat sink; a photodiode; an imaging lens to form images of the plane on an image sensor; a motorization of the shaping lens to translate along the optical axis; a motorization of the imaging lens to translate in a plane perpendicular to the optical axis; a motorization of the image sensor to translate along the optical axis; an electronic unit controlling each motorization; an electronic unit synchronizing the image sensor, connected to the photodiode to synchronize image capture with the laser pulses or in the pulses; an electronic unit adjusting the aperture and/or gain of the image sensor; and a software interface parameterizing and piloting the electronic control units, equipped with an image processing unit.

Abstract: A spectroscopic instrument for conducting multi-wavelength, multi-azimuth, multi-angle-of-incidence readings on a substrate, the instrument having a broadband light source for producing an illumination beam, an objective for directing the illumination onto the substrate at multiple azimuth angles and multiple angels-of-incidence simultaneously, thereby producing a reflection beam, an aperture plate having an illumination aperture and a plurality of collection apertures formed therein for selectively passing portions of the reflection beam having desired discreet combinations of azimuth angle and angle-of-incident, a detector for receiving the discreet combinations of azimuth angle and angle-of-incident and producing readings, and a processor for interpreting the readings.

Abstract: A processing circuit coupled to a controlling circuit and including a first capacitor module, a second capacitor, a detection module, a first processing module, and a second processing module is disclosed. The first and the second capacitor modules are charged. The detection module generates a detection signal according to intensity of a light to charge the first and the second capacitor modules. The first processing module asserts a first output signal according to the time of charging the first capacitor module. The second processing module asserts a second output signal according to the time of charging the second capacitor module. The controlling circuit controls a backlight according to the asserted output signal.

Abstract: Disclosed is a system to measure the energy level of a radiation pulse. The system includes a sample-and-hold module to measure the radiation pulse and to generate a signal representative of an energy level of the radiation pulse, and a processing module to determine an energy value of the radiation pulse based on the signal generated by the sample-and-hold module.

Abstract: Testing is performed on an amplifier wafer housing a transimpedance amplifier prior to packaging the transimpedance amplifier with an external photodetector, wherein the transimpedance amplifier includes a small, auxiliary, integrated silicon photodetector provided at the input of the transimpedance, in parallel with external photodetector attachment points. To test the transimpedance amplifier, the transimpedance amplifier is stimulated by optically exciting the small auxiliary photodetector, wherein the small auxiliary photodetector is excited using short wavelength light, whereby advantages such as higher efficiency may be obtained. The testing method includes placing the amplifier wafer in a testing system, probing the power and ground connections on the amplifier wafer, illuminating the small auxiliary photodetector on the amplifier wafer, and detecting the output of the transimpedance amplifier housed on the amplifier wafer.

Abstract: An exemplary measuring apparatus includes a base, a table, a light blocking piece, a sensor, a luminance meter, a drive assembly, and a controller. The table defines a first elongated slot. A light guide plate is arranged on the table with a central portion of a bottom surface thereof exposed to the first elongated slot. The light blocking piece is attached to the central portion of the bottom surface and exposed to the first elongated slot. The sensor is configured for sensing light and generating a sensing signal. The luminance meter is configured for measuring luminance of the back-light source module. The drive assembly is configured for moving the table to align the light blocking piece with the sensor. The controller is configured for switching off the drive assembly when the light is blocked by the light blocking piece from reaching the sensor.

Abstract: In a light sensor test unit, a test circuit is built in a display panel and connected to an output node of a light sensor which senses an intensity of an external light. When external light having a predetermined intensity is provided to the light sensor, the test circuit outputs a driving signal in response to a sensing signal output from the output node. A test pixel part includes pixels selected from a plurality of pixels arranged in the display panel and receives the driving signal from the test circuit to display a gray-scale corresponding to the driving signal. A brightness measurer measures a brightness corresponding to the gray-scale displayed in the test pixel part to compare the measured brightness with a predetermined brightness, thereby testing whether the light sensor built in the display panel is normally operated.

Abstract: Object: To provide an automatic door sensor which is inexpensive and still capable of freely setting a detection area. Solution: Light-emitters (14a-14d) cyclically emit and project light, and lenses (16a-16d) deflect emitted light in the direction perpendicular to a door opening. Light-receivers (22a1-22a9, 22b1-22b9) receive the projected light through segmented lenses (24a, 24b). For each of the light-emitters, a setting unit (44) sets therein whether each light-emitter should emit light. A control unit (30) judges whether a human or an object is present in a surveillance area based on the way how the light-receivers receive light.

Abstract: An exemplary liquid crystal display (LCD) panel includes scan lines, data lines, a scan driver connected to the scan lines, a data driver connected to the data lines, a controller connected to the scan driver and the data driver, and pixels formed by the scan lines and the data lines. The LCD panel is divided into five detecting regions, and the first detecting region is in a center of the LCD panel, and others surround the center portion of the LCD panel. Each detecting region includes a photo sensor. The controller is used to control the five detecting regions to have substantially the same flicker level.

Abstract: Testing is performed on an amplifier wafer housing a transimpedance amplifier prior to packaging the transimpedance amplifier with an external photodetector, wherein the transimpedance amplifier includes a small, auxiliary, integrated silicon photodetector provided at the input of the transimpedance, in parallel with external photodetector attachment points. Totest the transimpedance amplifier, the transimpedance amplifier is stimulated by optically exciting the small auxiliary photodetector, wherein the small auxiliary photodetector is excited using short wavelength light, whereby advantages such as higher efficiency may be obtained. The testing method includes placing the amplifier wafer in a testing system, probing the power and ground connections on the amplifier wafer, illuminating the small auxiliary photodetector on the amplifier wafer, and detecting the output of the transimpedance amplifier housed on the amplifier wafer.

Abstract: In one embodiment, a sensed dataset includes data produced by a plurality of light sensors that have been exposed to a light environment. The data of the sensed dataset corresponds to different ranges of light, and at least a portion of one of the ranges of light is outside the visible (VIS) light spectrum. The sensed dataset is compared to a plurality of known datasets representative of known light environments, and at least one known dataset that is similar to the sensed dataset is identified. In response thereto, an indication of the sensed light environment is provided. Apparatus for implementing this and related methods is also disclosed. In some embodiments, the light sensors are ultraviolet, visible and infrared sensors, and the indication of the sensed light environment is used to control the color of data acquired by an image sensor, or the color of a display backlight.

Abstract: A method is provided of compensating for stray light in a light sensor having a detection photosensor (7) and a reference photosensor (20), the reference photosensor (7) being for use in compensating for stray light falling on the detection photosensor (20). The method comprises using the reference photosensor (20) at least in part to determine a bias voltage applied to the detection photosensor (7). Based on this method, a display device is provided comprising a backlight and a light sensor for determining an ambient light level with the effects of stray light from the backlight substantially removed, with means provided for controlling the intensity of the backlight in dependence upon the determined ambient light level.

Abstract: Disclosed is a system to measure the energy level of a radiation pulse. The system includes a sample-and-hold module to measure the radiation pulse and to generate a signal representative of an energy level of the radiation pulse, and a processing module to determine an energy value of the radiation pulse based on the signal generated by the sample-and-hold module.

Abstract: The present invention relates to a light wavelength and intensity measuring device. The device automatically measures a center wavelength of the light source and an intensity of the light corresponding to the center wavelength by using a main photodetector, at least one optical filter, and at least one sub photodetector when the light source is connected to the device. The main photodetector detects the intensity of the light applied by the light source, the optical filter transmits the light corresponding to a prediscriminated transmission wavelength, and the sub photodetector detects the intensity of the light transmitted through the optical filter. Therefore, the light intensity is more accurately measured by calibrating the intensity according to the wavelength.

Abstract: A pig-tailed optical component used in a powerful fiber laser system is configured with a power monitor unit. The monitor unit has a plate-shaped beam splitter operative to reflect portions of at least one of respective forward and backreflected light signals, and multiple photo-detectors.

Abstract: A photometer that tracks a path of a moving light source with little or no motion of the photometer components. The system includes a non-moving, truncated paraboloid of revolution, having a paraboloid axis, a paraboloid axis, a small entrance aperture, a larger exit aperture and a light-reflecting inner surface, that receives and reflects light in a direction substantially parallel to the paraboloid axis. The system also includes a light processing filter to receive and process the redirected light, and to issue the processed, redirected light as processed light, and an array of light receiving elements, at least one of which receives and measures an associated intensity of a portion of the processed light. The system tracks a light source moving along a path and produces a corresponding curvilinear image of the light source path on the array of light receiving elements.

Abstract: The measurement head is equipped with the ray selection unit, which is entered by the rays emitted by the light unit under test. These rays enter the passages and are detected by the ray detection unit when they exit the ray selection unit. Said ray detection unit provides signals corresponding to the detected image, which are sent on for further processing. A precise measurement of the light unit is possible using the inventive light tester.

Abstract: A photometric device of liquid crystal display and a liquid crystal display in which photometry can be performed without relying upon manpower and the liquid crystal plane is shielded only at the time of photometry. The photometric device comprises a liquid crystal display part, a bezel surrounding the four sides of the liquid crystal display, a shaft part provided at the corner part of the bezel and fixed rotatably thereto, a movable part having the end part thereof connected to the shaft part, and a sensor part provided in the liquid crystal display part at the other end part of the movable part.

Abstract: An exposure control system and method for an image sensor, which includes an image sensor, an illuminator, a controller and a light separator. The image sensor has plural photosensitive pixels in a two-dimensional matrix arrangement. When an exposure is operated in a sub-region of the plural photosensitive pixels, the illuminator produces a flashlight as a light source for exposure. The light separator eliminates light except the flashlight. The controller sequentially activates each row of pixels in the sub-region, and when each row of pixels is in an exposure state, the controller drives the illuminator to produce the flashlight.

Abstract: A photosensitive button structure includes a button body and a photosensitive layer. The photosensitive layer is disposed on a bottom side of the button body, and has a plurality of words and pictures formed thereon. Whereby, the photosensitive layer produces a first color change by absorbing light from one angle, and then produces a second color change or more than two color changes by absorbing light from another angle, in order to produce a dual mode visual effect. The present invention solves problems and the defects of the traditional button having only one fixed color, and that the color of the traditional button can only be changed once, because the photosensitive layer can absorb light from different angles. Hence, the present invention not only improves the appearance of the button body, but can also show more than two color changes of any words or pictures on the button structure.

Abstract: A system which detects droplets on a translucent surface having a camera which, upon activation, acquires an image of a portion of the surface. A radiation source, upon activation, illuminates the portion of the translucent surface while a control circuit selectively activates both the camera and the radiation source. A processor receives a captured image from the camera and, through image processing, generates an output signal representative of the number of droplets on the portion of the translucent surface.

Abstract: A level transmitter can generate a level measurement signal according to the position of a float that follows fluid level in a tank. The transmitter can comprise an optical encoder with a patterned disk that is linked to the float so that fluid level change produces disk rotation. An array of optical sensors positioned on one side of the disk can read reflective and absorptive patches attached to the disk's surface to identify disk position and disk rotation. One or more of the sensors can collect a signal from a reference area of the disk. Circuitry can compare the signals output by each data sensor to the reference signal to enhance binary classification of each acquired data signal. The transmitter can operate in multiple encoding modes, each of which can provide a level of redundancy.

Abstract: An electric signal current corresponding to the intensity of the incident light is output by a photodiode PD, electric charge is integrated in an integrating circuit 10 according to this electric signal current, and a signal voltage corresponding to this quantity of electric charge thus integrated is output. In a CDS circuit 20, the signal voltage output by the integrating circuit 10 is input to the capacitor C21, and an electric charge corresponding to the amount of change in the input signal voltage is integrated in the capacitor C22 or C23 selected by switches SW21-SW23. In the differential calculating circuit 30, the differential in the electric charges integrated respectively by the capacitors C22 and C23 or the CDS circuit 20 is determined, and a signal voltage corresponding to this differential is output.

Abstract: A device for measuring light from a source includes a photometer and a collector. The photometer may include a detector, circuitry for processing output signals from the detector, and an output such as an LCD display. The collector engages with the photometer such that light from the source is incident on the detector and ambient light is prevented from entering. The collector may be configured to be releasably engageable with the photometer. A plurality of interchangeable collectors may be provided so that a single photometer is enabled to measure light from a plurality of sources. The collector may include a hood for engaging the source to block ambient light. The collector may also include optics disposed within the hood for directing light from the source onto the detector. The optics may include an optical diffuser disposed within the hood such that light from the source first passes through the diffuser to be incident on the detector.

Abstract: A signal current I1 that is output from output terminal of semiconductor position detection element is converted to a signal voltage V1 by a current/voltage conversion unit and a signal current I2 that is output from output terminal is converted to a signal voltage V2 by a current/voltage conversion unit. Signal voltages V1 and V2 are compared in magnitude by a comparison circuit and a comparison signal is output so that maximum signal Vmax and minimum signal Vmin are selected. In A/D conversion circuit, the A/D conversion range is set using maximum signal Vmax, and minimum signal Vmin is converted to a digital signal and output. The position of beam incidence on semiconductor position detection element is found by incidence position calculating unit using the comparison signal and digital signal.

Abstract: The present invention provides an optical signal generator for use in calibrating and testing optical components. The optical signal generator utilizes a tunable laser in conjunction with a novel modulation circuit to output an analog/digital optical signal. The modulator circuit combines a low-frequency, closed loop power control with a separate digital modulator. The output beam of the tunable laser may be modulated over a wide range of frequencies, duty cycles and amplitudes. Circuitry is also provided for modulation of an analog signal onto the output.

Abstract: A reflexive light source detector produces different light source value when a printing matter or something receives light so that a reader may receive different stimulus on his/her eyes and then adjust the light source to get proper light for reading or seeing. The detector includes a housing, and a photosensitive element contained in the housing and to be positioned to form an angle &thgr; toward the printing matter so as to let the light source light the printing matter or something and to measure the reflected light by the printing mater or something receiving the light from the light source. Then the detector can decide whether the reflected light is proper for reading or not, based on a preset value, protecting reader's eyes from becoming myopia.

Abstract: A light sensing device for sensing the light output of a bulb in a lamp comprises a fiber-optic light guide having first and second ends and a photodetector. The first end is optically coupled to a projection of a bulb in the lamp and is adapted to pick up light transmitted through the projection from within the bulb. The second is optically coupled to the photodetector such that light exiting from the second end impinges on the photodetector to generate an output indicative of the light output of the bulb.

Abstract: There is provided a photosensor having a photoelectric converter for converting incident light into a photoelectric current, and a function of removing noise light from imaging light including noise light and reflected from an object to be photographed. A plurality of photosensors each having the arrangement are used as an image sensor. A single photosensor having the arrangement or a plurality of photosensors each having the arrangement are used as a distance sensor. There is provided a photosensor in which a storage unit stores electric quantity corresponding to fixed light, and electric quantity corresponding to reflected light in the state wherein electric quantity stored in the storage unit is reproduced by a reproduction unit is introduced, and the difference therebetween is reproduced as an electric signal. A single photosensor having the arrangement or a plurality of photosensors each having the arrangement are used as a distance sensor.

Abstract: A system for receiving electromagnetic energy with reduced signal aliasing in the cross-scan direction. The system is adapted to be mounted on a spacecraft or an aircraft for movement over a surface in the cross-scan direction and has a sensor for receiving electromagnetic energy. The invention (10) includes an arrangement for directing energy to the sensor which has an astigmatic blur in the cross-scan direction which is effective to reduce aliasing of a signal transmitted or received by the system in the cross-scan direction of movement. In the illustrative embodiment, the invention (10) includes an array (20) of radiometric detectors. A reflective optical arrangement directs energy from a surface to the detector array. The optical arrangement includes at least one mirror (16) which has a small controlled cylindrical surface perturbation which introduces an astigmatic blur into the received image which reduces aliasing of the signal in the cross-scan direction.

Abstract: An illuminant discriminator distinguishes a range of separate illuminants, including high efficiency fluorescent lighting, by modifying the frequency response of a signal output from a photodetector. A switchable high pass filter coupled to the photodetector has a first filter section with a first cutoff characteristic selected to pass signal components due to various types of lighting including high efficiency lighting, and a second section with second cutoff characteristic that separates out the high efficiency components. The high pass output is processed by a log amplifier to develop flicker frequency harmonics that are distinguished as to source illuminant by comparator stages. Undersampling artifacts due to high efficiency lighting are present in the mixed illuminant spectrum when the first filter section is operative, and positively identified as high efficiency lighting when the second section is operative.

Abstract: A photo monitoring apparatus including a photoresistor, a series of shunt resistors, and a comparator IC, wherein the comparator IC provides an output signal to a LED and a diaphragm speaker, when the voltage from the shunt resistors drops below a pre-set reference voltage, causing the LED to give light and the diaphragm speaker to produce a warning sound. The shell of the photo monitoring apparatus is installed with a digital time display controlled by a time circuit to indicate time.

Abstract: In a handheld incident light meter instrument, a custom LCD panel provides both a digital readout and a bar graph array which simulates an analog meter but uses no moving mechanical parts and which may be operated in a choice of modes: bar, floating zone or dedicated. Unusual accuracy and stability over a wide dynamic range, from 0.1 to over 50,000 footcandles, are achieved in a novel analog photo-amplifier portion having a linear autoranging preamplifier, an averaging integrator and a temperature-compensated log converter, driving an IC analog-to-digital converter connected to a microprocessor programmed to operate in a choice of modes to operate the LCD via a driver to display light readings according to commands entered via a set of ergonomic user controls. Battery condition is displayed continuously. The digital readout may be backlit for low ambient light level.

Abstract: In a method of analyzing a lighting environment, the lighting environment is initially divided into a plurality of blocks so that all surfaces defining said lighting environment may be divided into a plurality of surface patches. The surface patch that radiates the most light energy is then searched. If the quantity of light radiated from this surface patch exceeds a given value, the quantity of light radiated from this surface patch which arrives at each of said plurality of surface patches is computed. Thereafter, the surface patch that radiates the next most light energy is searched, and the quantity of light radiated from this surface patch which arrives at each surface patch is computed. In this way, the total quantity of light received by each surface patch is obtained. In this method, mirror reflection is taken into account.

Abstract: A printer has a light source and an objective which direct a light beam along a predetermined path, and a unit in the path for measuring the density of a master to be reproduced. The measuring unit includes a filter combination of at least two filters downstream of the objective and a light sensor downstream of the filter combination. The filter combination has a transmission pattern which shifts as the angle of incidence of the light beam on one or more of the filters changes. At least one of the filters is pivotable in order to vary the angle of incidence of the light beam on the same. This allows the transmission pattern to be shifted so as to adjust the measuring unit to the spectral sensitivity of the copy material used for reproduction of the master.

Abstract: This invention relates to an aquarium light meter including a light sensing device, a pivotal assembly connecting the light sensing device to a pair of telescopic tubes, a controller, and a signal wire connected to the light sensing device and passing through the pivotal assembly and telescopic tubes for connection to the controller. The aquarium light meter is adjustable in length and direction of light detection in accordance with the shape of the aquarium and the location of ornaments therein so that the light intensity at any predetermined portions of the aquarium can be precisely detected.

Abstract: A method of measuring light levels, particularly the measurement of exterior light levels in the zone of approach to a tunnel in which vehicles are moving, and from which exterior light levels the minimum light level to be programed inside the tunnel can be calculated, by means of a photo-sensitive cell installed in a recessed tube in order to sense light levels contained within a cone defined by the center of the cell, which constitutes the apex of the cone, and by at least the open end of the tube. The method includes limiting the quantity of light rays entering into tube via the cone, and a device is provided for implementing the method.

Abstract: A photoluminescence sensor for detecting a photoluminescent light from a toluminescent material is disclosed. In a preferred embodiment the photoluminescence sensor comprises: a source of light; a concave mirror having at least one perforation for passing the source light through the at least one perforation; an optical waveguide having proximal and distal ends with the photoluminescent material being disposed at the distal end; an objective for directing the source light into the proximal end of the waveguide; an objective for receiving photoluminescent light and for focusing the photoluminescent light onto the perforated concave mirror; a liquid filter for passing the photoluminescent light reflected from the perforated concave mirror to a detector to detect the photoluminescent light.

Abstract: A method for analyzing antigen or antibody contained in a sample by introducing a first end surface of at least one measuring light guide member and a second end surface of at least one reference light guide member in the sample. Each of said measuring and reference light guide members being coated with a protection layer except for said first and second end surfaces and an other end surface of respect light guides. Only on said first end surface of the measuring light guide member being fixed an antigen or antibody which is specifically reactive with the antigen or antibody contained in the sample to effect an antigen-antibody reaction. Photoelectrically detecting optical properties of said first and second end surfaces of the measuring and reference light guide members, respectively, by transmitting light through the meauring and reference light guide members to derive detection signals as a measure of antigen or antibody in the sample.

Abstract: A device for detecting a backlighting condition comprising a light meter of which the image receiving surface is divided into a central area, an intermediate area and a marginal area, and a circuit for discriminating between true and false backlighting conditions in such a way that when the luminance of the marginal area is greater than that of the intermediate area by more than a predetermined value and when the luminance of the intermediate area is greater than that of the central area, the backlighting condition in question is taken as a true one.

Abstract: A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control

Abstract: A contralight compensation exposure control system which determines as a contralight condition and fires a strobe when there is a difference between the output of a partial light measuring means for measuring the brightness of a portion of a scene to be photographed i.e. the brightness of the main object such as a person, and the output of an average light measuring means for measuring the brightness of comparatively large area of the scene i.e. the brightness of the subordinate object such as the background of the main object. The control circuit of the system inhibits the strobe firing and actuates an exposure compensation means to shift the controlled exposure to the overexposure side when a detecting means detect uncompletion of charging of the main capacitor for firing the strobe even if the contralight condition is detected.

Abstract: A method and apparatus for calibrating an electro-optical mouse during the detection of light reflected from a surface with optically contrasting indicia. The voltage output from the light detector is compared with stepped ramped sequences of reference voltage signals representing a count, the ramped sequence being stopped in response to each transition of the comparator between a first state where the amplitude of one of the input signals is less than that of the other and a second state where the amplitude of the one of the input signals is equal to or greater than the other. A processor determines the highest and lowest numbers at which any of the ramped sequences are stopped; and calculates at least one threshold value in dependence on the difference between the highest and lowest numbers.

Abstract: Apparatus is provided for optically measuring scalar irradiance or incident flux of radiant energy and for optically measuring naturally occurring chlorophyll fluorescence or upwelling radiance in a parcel of water in a natural setting. From a comparison of the two measurements, rate of primary photosynthetic production is calculated by appropriately programmed computer means. Readout means are provided to indicate the rate of primary production. Further, concentrations of chlorophyll that generate the primary production are also determined by means of the apparatus of this invention. The method of this invention, employing measurement instruments of the type disclosed, enables the determination of concentrations of chlorophyll and primary production in parcels of water.

Abstract: A rear light condition detecting device for a camera is arranged to measure distances to a plurality of parts appearing within a taking picture plane on the assumption that an object located nearby is the main object to be photographed or that a light source such as the sun is among faraway objects. The device determines the object to be in a rear-light or counter-light condition in cases where the luminance of the nearby object is extremely lower than other objects or that of a faraway object is extremely higher than other objects.

Abstract: The average video level of a video camera is corrected for film-to-video conversion by having a film aperture plate with a light-passing opening that is slightly enlarged with respect to the image area of the film. Non-image light passes through a peripheral region of the film, as defined by the enlarged opening, and strikes a part of the camera sensor not receiving image-wise illumination. By enlarging the aperture plate opening just enough that the video signal from the non-imaged part of the sensor approximates a desired average video level, the automatic video level correction performed by the camera will pertain only to the image. The aperture plate is part of a film gate that is rotatably mounted so that the film may be supported in either a "horizontal" or "vertical" orientation, depending on how the film image was initially exposed.