Abstract: A light source (10) coupled to a first fiber optic waveguide (14) which is coupled by a first directional coupler (22) and a second directional coupler (24) to a second waveguide (20). The first waveguide (14) has a phase modulator (60), a delay loop (62) and a polarization controller (68) therein to cause a differential delay time T on counterpropagating coherent light waves phase modulated at a frequency 1.sub.M. The first directional coupler (22) has one part connected to a photodector (28) and the second directional coupler (24) has a probe (20D) coupled to the first fiber (14) and the second fiber (20). The probe directs light toward a surface (18) whereupon the counterpropagating waves are shifted in phase by an amount proportional to the amplitude of displacement of the surface 18.

Abstract: A flying spot scanner system uses a beam splitting mirror to produce adjacent flying spot images on a material to be analyzed, typically a moving web. The images from the flying spots are split by this beam mirror and sensed by separate photodetectors. The outputs from the photodetectors are algebraically combined on a real time basis, the resultant output signal indicative of web conditions, such as web edges, dirt spots, streaks, scratches and holes. The algebraic output signal amplitude is immune from rapid changes in the web illumination such as caused by changes in external ambient light levels. This signal is also highly immune to variations in the illumination level of the web along the path of the flying spots. The algebraic output signal, by not utilizing differentiation of the received information, has an amplitude independent of the flying spot speeds. The shape of the flying spots can be varied to enhance detection of particular types of defects.

Abstract: The device comprises a transducer (3) with photoelectric elements (31) and a coupling member (5) which comprises an entrance face (9) which is to be aimed at the document and an exit face (11) which is optically coupled to the transducer. The coupling member (5) comprises a number of light conductors (7) having first ends (13) which are arranged in at least one straight line in the entrance face (9) and second ends (21) which are situated in arbitrary positions in the exit face (11). The relation between the positions of the first ends (13) in the entrance face (9) and the positions of the second ends (21) in the exit face (11) is stored in a memory (29). The photosensitive surface of the transducer (3) may have an arbitrary length/width ratio and the light conductors (7) may extend rather arbitrarily through the coupling member (5) so that the cost of the device may be comparatively low.

Abstract: A robotic vehicle is guided along a predetermined path which is to be traversed autonomously by the vehicle. As the vehicle is guided along the path, the area before the vehicle is scanned and discontinuities in the scan scene are reduced to a series of time separated pulses. The pulse series at selected locations along the path are stored such that the vehicle can autonomously retrace the predetermined path by matching pulse series generated by current scanning with stored pulse series. A scanner mirror receives and directs a laser beam through an area before the vehicle along the path to be traversed and receives reflected return signals from the scanned area. Optical detection means receive the return signals from the scanner mirror and generate raw scene signals which are doubly differentiated to generate pulse series representative of the discontinuities of the scanned area.

Abstract: A centrifugal analyzer comprising a container adapted for holding a sample, a centrifuge having a rotor which holds the container, a source of electromagnetic energy and an array of photodiode means. The source is positioned such that at least a portion of the electromagnetic energy provided thereby impinges on the container, and the array of photodiode means is positioned such that at least a portion of the electromagnetic energy that impinges on the container is sensed by the array.

Abstract: A laser beam impacts an object through a focusing lens. The beam spot produced on the object is reproduced by means of an optical assembly of three measuring diaphragms in the form of a stripe of a width varying as a function of the state of focusing, with the measuring diaphragms being mutually offset with respect to the ideal focusing point. The light passed by the measuring diaphragms impacts three photoreceivers and the measuring signals produced by them are processed in an evaluating stage to produce a correction signal which then is used for the automatic setting of the focus by means of a control device. The system requires no mechanically oscillating parts, is simple in its configuration and suitable for pulsed laser systems.

Abstract: A transresistance amplifier particularly adapted for use in a radiation detection system. The amplifier includes a feedback gain stage with a switched capacitor load. The amplifier is arranged to provide an average detector voltage approximating zero thus substantially reducing detector noise and also providing a low equivalent input impedance for increasing injection efficiency. A switched capacitor output load is also provided which allows the total transresistance to be determined by simply selecting an appropriate capacitance value.

Abstract: A photosensor comprises a first conductive layer formed on a given substrate, a one-dimensional array of a plurality of unit picture elements formed on the first conductive layer to extend in the longitudinal direction thereof, each unit picture element having a photodiode and a blocking diode connected in series with the photodiode in a relationship of reversed rectifying direction therewith, a second conductive layer for connecting together, at one end, respective unit picture elements belonging to each of at least two unit picture element groups having each at least two of adjacent unit picture elements, and a third conductive layer for connecting together, at the other end, corresponding unit picture elements in the respective groups, the set of the photodiode and blocking diode in the respective groups being made of the same semiconductor material. Dispersion of outputs from the respective unit picture elements can be minimized.

Abstract: To achieve a greater accuracy, an optoelectronic measuring method and an apparatus for measuring with optoelectronic instruments provides that one or two light rays of one or two light transmitters, such as lasers, are directed at an acute angle onto a surface to be shaped and that the distance covered from the starting position to the end position in the shaping operations is measured by means of a photodetector, e.g., a diode camera, which is set up perpendicular to the light spot or spots.

Abstract: A detector for the detection of, for example, Cerenkov radiation includes an entrance screen (5) which may cover more than half of an envelope (1); the majority of the envelope is preferably spherical. A photo-electron detecting exit screen (11) is proportioned and arranged inside the envelope (1) so that a small decay time and a high sensitivity are achieved. A scintillant exit screen (11), which is mounted on an indentation (15) in the envelope (1), can thus produce, in conjunction with a photomultiplier tube (17) mounted inside the indentation (15), a photoelectric intensification by a factor 100.

Abstract: Disclosed is a laser recording arrangement including a mirror for redirecting the laser beam in a controlled scan mode plus an associated electro-optical position monitor for monitoring mirror orientation, these being housed in a unitary casting.

Abstract: A method and apparatus for detecting focus conditions of a photographic optical system is disclosed. The invention comprises a member for dividing the wavefront of a light beam from a photographic optical system in an image space thereof, a first light receiving device including two photocell arrays provided in the front and the rear of a surface conjugated to a predetermined focal plane of the optical system, and a second light receiving device including at least one photocell array provided at a surface conjugated to one of the photocell arrays in the first light receiving device. A first signal representing horizontal shift of an optical image is detected based on outputs of at least one photocell array in the second light receiving device and one photocell array in the first light receiving device having a relation conjugated to the photocell array in the second light receiving device.

Abstract: The invention relates to a device for measuring a magnetic field, comprising a source of rectilinearly polarized light. A magnetooptical medium is situated in the path of the beam, this medium being followed by a mirror refecting this beam. This medium is a medium of which the intrinsic propagation modes are polarized in right-hand and left-hand directions, and which retains the circular polarization. An element acting as a separator by polarization is situated between the source and the medium, a detector device being coupled to the same.

Abstract: A method of measuring of backlash arising in a drive mechanism comprising a screw and a nut device co-operating with the screw, the nut device being connected to a movable unit which is displaceable in opposite directions along the screw. The drive mechanism comprises a pulse generating system of which the number of pulses emitted for each displacement corresponds to the distance traveled in accordance with the method the movable unit is operated to move away from an end position adjacent one end of the screw, and when a predetermined position has been reached the pulse counter is reset while the movement continues. The movement is maintained a distance beyond the position in which the pulse counter was reset, the distance being greater than the possible maximum backlash. The drive mechanism is then stopped and operated to move the movable unit back to the end position, during which movement the pulse counter is counting backwards.

Abstract: Disclosed is an improved transmission illumination device for use in a picture scanning device such as an electronic picture scanner which can illuminate an annular region around an illuminated spot. This annular illuminated spot is produced by using an annular convex lens as part of an optical system. Since the area surrounding the illuminated spot is also illuminated, finding a desired spot on an original picture is greatly facilitated. Having an illuminated annular region does not create any problem which may arise from flare light if an iris diaphragm is provided in a light receiving head for the exclusion of the light emitted from the illuminated annular area.

Abstract: Light from an external source is collimated, polarized, passed through a voltage dependent quarterwave plate and onto an elasto-optic sensor which serves to retard the light passing therethrough as a function of the external stress being measured. Light emanating from the sensor is divided into components at .+-.45.degree. to the applied stress axis. These components are coupled through optical fibers to photodetectors and the resulting electrical signals are applied to difference amplifier. The amplifier output is used to control a second light source whose output via an optical fiber is converted to a voltage suitable to drive the voltage dependent quarterwave plate in a negative feedback fashion such that the wave retardations resulting from the applied stress and nulled out. The power necessary to drive the voltage dependent quarterwave plate is used as a measure of the applied stress.

Abstract: An illumination detector is positioned adjacent one surface of a wedge-shaped light pipe which is optically coupled to a mirror in a scanning system. The light coupled into the light pipe is representative of the illumination reflected from a document scanning plane, yet is totally internally reflected from the angled surface of the light pipe to produce a uniform, integrated illumination level at the photosensor. This photosensor output represents an exposure level used to adjust the output of a document illumination power supply.

Abstract: A pre-amplifier located "at the focal plane" of a detector array is disclosed which uses MOSFET transistors operated in the "weak inversion" region to provide operational amplifier performance. The dimensions of certain of the transistors are designed to minimize noise amplification. Feedback resistance for the operational amplifier is provided by switched capacitance using MOSFET transistors as switches, thereby permitting adjustment of the amplifier gain. Implanted and non-implanted MOSFET transistors are used in the differential amplifier in such a way as to avoid the need for a biasing network.

Abstract: A radiation shield in a light detector and/or sensor assembly generally comprises a horizontally oriented buffer on which the detector is disposed, a vertically oriented radiation shield surrounding the detector, and a horizontally oriented collimating buffer disposed on the vertically oriented radiation shield above the detector. Advantages of the invention include minimization of the effect of radiation emitted from the hot junctions of a thermoelectric cooler employed in the detection assembly, and the provision of an electromagnetic shield when the arrangement is connected to the low-impedance side of the amplifying circuitry associated with the detector. The buffer preferably comprises a highly emissive material, while the collimating buffer is preferably of an electrically conductive material. Electromagnetic shielding can be provided by the use of high permeability material.

Abstract: A multi-element spectral filter with curved interior surfaces which provides uniform angular response and is particularly well-suited for use in wide field of view optical detection systems.