Abstract: Apparatus for detecting the presence of a single banknote or a double banknote (5) comprises a cylindrical roller (1) biased by way of a pivot arm (2) against a moving surface (6) which conveys banknotes under the roller (1). The other end of the pivot arm is connected to the core of a linear variable differential transformer (4) which is activated by an oscillator (7). The output of the L.V.D.T. (4) is proportional to the displacement of the roller (1) normal to the surface (6) and is thus indicative of the thickness of any banknotes passing under the roller. In order to compensate of mechanical and electrical drift in the thickness level corresponding to the absence of a banknote, the auto-reference circuit (9) derives first and second threshold values for single and double notes respectively by adding predetermined potentials to the reference potentials. These predetermined differentials may be controlled manually by a variable resistor (11) within a thickness control circuit (10).

Abstract: A fiber optic sensor for determining the position of a shaft 10 that is supported by a bearing 12 includes a sensor circuit 14 and at least one fiber 16 that extends from the sensor circuit to a point proximate but slightly separated from the shaft surface, with a portion of the optical fiber extending through and being carried by the bearing. Target areas 18, 20 and 22 are located on shaft 10 so as to correspond to the positions to be determined. Each target area consists of an angled recess that is constructed and arranged, relative to the numerical aperture and orientation of the optical fiber, so as to substantially nonreflective insofar as the optical fiber is concerned, thus providing a sharp contrast to the highly reflective background of the shaft surface.

Abstract: The reading head of an optical reading system for determining the presence or absence of marks on the surface of a document consists of an array of the single ends of a plurality of bifurcated light fibers. The first and second branches of the bifurcated ends of each light fiber are arranged in serial arrays. A single light source and a single light detector sequentially interface with the first and second branches respectively of the light fibers with the light source transmitting light through the first branch and the light detector generating a signal indicative of the light level reflected from the document surface through the second branch. The sequential signals generated by the light detector are processed to determine the information content of the document.

Abstract: The use of pulse width modulation rather than analog excitation to control the resistance of a light emitting diode--photoresistor pair is described. In particular, for two LED/LDR opto-isolators in a totem pole configuration, the duty cycle of the first opto-isolator is arranged to equal 1 minus the duty cycle of the second opto-isolator. Thus, both opto-isolators are always active resulting in the ratiometric output being proportional to the duty cycle, and the output impedance being constant.

Abstract: A reflection light barrier for recognizing also strongly reflecting articles has at one side of a monitored region a light transmitter (13) which is combined with a light receiver (12) and, at the other end of the monitored region, a reflecting device (11). The reflecting device (11) has optical filter characteristics so that the spectral distribution of the light beam is changed on reflection. An electronic processing circuit only produces a signal following the incidence of reflected light on the receiver when the spectral distribution does not correspond with the spectral distribution of light reflected from the reflecting device.

Abstract: A device having a light emitter coupled to direct light to a portion of a photodetector to provide Built-In Test Equipment (BITE) capability for an optical sensor. A light emitting diode and a photodiode are mounted side by side on the upper surface of a conventional header with suitable electrical connections bonded thereto. A prismatic light bridge member overlies the light emitting diode and extends to cover a portion of one corner of the photodetector. This member serves as a light conduit, directing virtually all of the light from the emitter to the detector by virtue of the near total internal reflection of the surfaces of the light conduit member. An outer enclosure having a transparent glass window serves to seal and protect the respective elements while permitting external radiation to reach the photodetector.Alternative embodiments provide for coupling of light from a single emitter or a plurality of emitters to a single associated photodetector.

Abstract: A module for a fiber optic link has a case housing a circuit module plate. An optoelectric element mounted at a predetermined position of lead frames is molded from a transparent transfer molding material. The case has a socket for mounting a fiber cable connector which is molded from a nontransparent injection molding material. A hole in which is inserted a plug of the connector is formed in the socket and the case. The optoelectric element is arranged to oppose the hole of the case through a convex lens segment of the case.

Abstract: A method and apparatus for adjusting the reference system of a pre-programmable laser device relative to the position of an inscription field of a part to be processed such as a silicon wafer characterized by a laser beam from a laser operating in a continuous wave mode being programmed to travel in various search motions with each motion traversing and passing over an edge of the part. The light which is unblocked by the part is received by a photoelectric element to trigger a position signal for each time the light passes across the edge of the wafer. The precise position of the wafer or part relative to the reference system is calculated from the position signals with the assistance of a computer and subsequently the coordinates of the reference system are corrected to match the precise position of the part.

Abstract: The focusing detecting device determines whether or not the optical image of an object to be photographed is in a focusing state in which the image is clearly formed on a predetermined image forming surface through a photographing or image forming optical system. The device can be used with a dark optical system.

Abstract: Optical wand for automatic character recognition including a scanner unit designed to be a manually movable along a line of print of a data carrier in order to recognize optical characters and incorporating a light source for illuminating a scanning window and a sensing device. A second scanner unit includes a second sensing device and is designed for recognizing bar code marks. A gun shaped housing forms a common case for both scanner units.

Abstract: An optical transducer for detecting the angular position of a rotary member with respect to a fixed structure, which comprises a shutter disc of transparent material, having two faces which are parallel to each other. The disc is provided with a plurality of radial shutter elements, spaced by elements which transmit the light. The shutter elements are formed by V-shaped elements provided on one face of the disc and capable of totally deflecting the light incident thereon.

Abstract: A solid state a.c. relay has two separate and indentical power thyristors connected in anti-parallel arrangement. The power thyristors are optically switched, lateral conduction devices with anode and cathode electrodes on the same surface. Both are switched by illuminating their surface by reflected illumination from an LED. Each thyristor is provided with a respective control circuit which includes a MOSFET transistor for clamping its respective thyristor gate wherever the voltage across the thryistor exceeds a given absolute value or whenever there is a high dV/dt transient across the thyristor. The control circuit for the control transistor includes a capacitance divider, one element of which is the distributed capacitance of the control transistor. The control circuit components can be integrated into the same semiconductor chip which contains the respective power thyristor. Each of the two identical power chips and the LED chip are spaced from one another and mounted on an alumina substrate.

Abstract: An optical electromagnetic radiation detector having a probe for receiving nearby electromagnetic radiation. The probe includes a loop antenna connected to a pair of transparent electrodes deposited on the end surfaces of an electro-optic Fabry-Perot interferometer. When the loop antenna picks up the presence of electromagnetic radiation, a voltage will be developed across the crystal of the electro-optic Fabry-Perot interferometer thereby changing the optical length of the interferometer. A beam of light from a remote location is transmitted through an optical fiber onto the Fabry-Perot interferometer. The change in optical length of the Fabry-Perot interferometer alters the intensity of the beam of light as it is reflected from the Fabry-Perot interferometer back through the optical fiber to the remote location. A beamsplitter directs this reflected beam of light onto an intensity detector in order to provide an output indicative of the variations in intensity.

Abstract: Described is a counting apparatus for counting paper sheets settable when effecting a batch counting to a clear mode in which the count data obtained in the counting operation of each preceding batch of paper sheets are cleared for counting a new batch or to an add mode in which the count data for the current batch is added to the count data for the preceding batch or batches and the resulting sum of the count obtained until the current time is displayed.

Abstract: A light beam splitter for splitting a light beam from a focusing lens to obtain two split light beams incident on respective light receiving elements, as a pair, wherein a total reflection film is formed to one side of a substantial boundary surface constituted by a plane containing the optical axis of said focusing lens so that said light beam is split into two by said total reflection film, and said pair light receiving elements are disposed such that the split light beam transmitted through a region free from said total reflection film is received by one of the light receiving elements while the split light beam reflected in a region where said total reflection film is situated is received by the other light receiving element.

Abstract: A transducer utilizes a laser source, photoelastic waveguides, two optical beam paths and a detector for processing optical energy from the laser through a stress transfer medium and thereby detects stress forces present on the transducer. This allows forces such as pressure, strain, voltage, or current to be detected and converted from one form to another for measurement of the force and response thereto. Input forces are detected as optical frequency shifts and converted to electrical signal outputs for indicating circuitry. In an integrated optic format, the transducer package volume is small, allowing ready use in guidance or navigation systems. Light generated by the laser travels along two paths, is optically stressed by the force transfer member and is combined with a reference signal to obtain the stress intelligence.

Abstract: An electrostatic shutter tube comprises a photocathode adapted to emit electrons along a path as an electron image in response to a radiant image incident upon the photocathode. A phosphor screen is spaced from the photocathode and is adapted to emit a light image in response to the impingement of the electron image thereon. A shuttering grid is disposed in the electron path between the photocathode and the phosphor screen to control the emission of the electron image. An anode member adjacent to the screen has therein a pair of primary deflection plates disposed along the electron path for deflecting the electron image in a first direction across the screen. A pair of secondary deflection plates are disposed within the anode member, along the electron path, in a cross-over region of the electron image.

Abstract: In a method for inspecting a pattern produced by using pattern data of a predetermined reference pattern, comparison is carried out between the pattern reproduced from the scanning signal of the pattern and the pattern produced from the signal of a modified form of the predetermined reference pattern.

Abstract: An improvement to computer control robot arm assemblies having a work head on the free end thereof for allowing the work head to be positioned and held within closer tolerance limits to a desired coordinate position. The work head is attached to the robot arm by a vernier control assembly allowing vernier movement in the X, Y, and Z directions. A moveable support member is provided on the robot arm adjacent the work head. A detector is mounted to the work head for sensing a light beam. A collimated light beam is passed through a point associated with the desired coordinate position under computer control. The work head is positioned within first tolerance limits by the robot arm under computer control. The logic of the computer then contacts the work piece with the support member to hold the free end of the robot arm in position. Under closed-loop computer control, the vernier drives are used to position the detector at a point where the work piece is in the desired coordinate position.

Abstract: A pressure and temperature compensated acoustic transducer utilizing a pressure sensitive birefringent element coupled between a flexible diaphragm sealing the transducer and an internal variable rigid diaphragm that forms two internal chambers. Relatively rapid variation in pressure applied to the birefrigent element cause fluctuations in the phase difference between orthogonal components of a polarized light beam traversing the photo-elastic material. Detections of this phase difference variation provides signals representative of incident acoustic signals. Provision for the transfer of liquid filling the chambers permits the equalization between the two chambers of slowly varying internal pressures caused by changes in external ambient pressure and temperature.