Abstract: A system for the remote reading of a gas meter includes an interface unit within a domestic residence but situated such that an input/output terminal for the interface unit is accessable from the exterior of the residence, and a hand-held meter reading unit for connection to the terminal in order to read and record the value of the gas consumption indicated by the meter. The meter reading unit has two LED sources, whose outputs are combined a Y-coupler, for passage into the interface unit when an optical fibre is connected thereto. At a multiplexer, the combined beam is dispersed according to wavelength and separately passes along a fibre array to respective roller digits of the tumbler for reflection or not according to the displayed reading. Reflected light passes back through the system, is divided at a Y-coupler and passes to a de-multiplexer such that the light returning in respect of the roller digits can be measured and displayed at a light detector and liquid crystal display.

Abstract: An optical scanning system (10) is disclosed for scanning a wide incoming field of view of at least 60 degrees. The system (10) incorporates two flat mirrors (12,26) which rotate about two axes (20,28). The motion of the two mirrors is synchronized. The resulting scanned image is directed onto a sensor (54) with minimal rotation and distortion of the image.

Abstract: A monitoring arrangement monitors the power of a light beam which travels in a predetermined path between a laser and a destination location and is reflected at a predetermined location of the path from a reflecting surface of a deflecting mirror, with attendant inherent light scattering into a space portion. The monitoring arrangement includes at least one sensor situated in a space portion having the reflecting surface and imaginary extensions thereof for its boundary and including the predetermined path. The sensor is located between a reflected portion of the light beam and the boundary, preferably close to the boundary, to intercept and sense scattered light reaching it, especially forward-scattered light of the original laser beam, and generates a signal representative of the intensity of such intercepted scattered light. This signal is then evaluated.

Abstract: An optical strain gauge has a first birefringent optical module secured to a specimen bar in a manner transferring tensile strain from the bar to the module and has a similar second birefringent module secured to the bar in a manner transferring shear strain from the bar to the module. The two modules are disposed in series in a light path along which polarized light is directed. A polarization rotator is situated in that path between the two modules and causes the phase shift between two polarized components of the light to optically subtract. The optical subtraction arrangement conduces to making the gauge insensitive to environmental effects because stresses imposed by those environmetal effects equally upon both modules result in optical cancellation of the effects of those stresses on the modules. Those two polarized components, after passing through both modules, are separated to obtain a measure of the difference between the transferred tensile strength and the transferred shear strain.

Abstract: The invention relates to a circuit arrangement for a position sensitive radiation detector which produces a current or voltage signal (U.sub.Y) that depends exclusively on the coordinates x and y of the point of incidence of electromagnetic radiation on the EMR sensitive surface of a lateral diode (1). For this purpose, the circuit arrangement has integrators (4, 5), in which the voltages (U.sub.1, U.sub.2) are formed, which are proportional to the integral over time of the output currents (I.sub.1, I.sub.2) of the lateral diode (1). The difference between the voltages (U.sub.1, U.sub.2) is used as a signal, which depends exclusively on the coordinates at that particular time, at which the arithmetic mean of these voltages (U.sub.1, U.sub.2) has reached a preselected, constant value.

Abstract: In a photoelectric apparatus for tracing a scanning head (8) along a pattern track (13), a constant arrangement (17) of tightly spaced light-sensitive elements (16) is provided in the scanning head forming together with an addressing device (25) scanning patterns (14) which can be sampled. On the arrangement of the light-sensitive elements, a section of a pattern plane for scanning including an essential transversal component of the scanning pattern is imaged. From illumination state signals of the sampled light-sensitive elements, control signals are generated by means of an evaluation device (28, 31, 32), controlling the tracing movement of the scanning head in two movement directions (4, 5) rectangularly oriented relative to each other.

Abstract: In order to initiate the operation of an incremental-correction measurement system, which measures such guidance errors as instantaneous lateral offset of a movable machine part with respect to its guidance direction (Y), a reference mark is provided by two cylindrical lenses (4, 5) which are arranged at an angle to each other and to the guidance direction. Since the distance intercepts for Y-direction scanning of and between the two cylindrical lenses is dependent on the instantaneous lateral offset (.DELTA.X) of the guided part, it is possible to determine the absolute offset values (.DELTA.X.sub.1, .DELTA.X.sub.2) of two spaced incremental-correction measurement systems (K1, K2), using pairs of pulses (A.sub.1/2, B.sub.1/2) generated by two signal transmitters (KNIP1, KNIP2) upon their scanning traverse of the respective cylindrical lenses in the course of a single calibration run.

Abstract: In a light beam scanning recording apparatus, a light beam is modulated by a modulator according to image signals and is caused to scan a photosensitive recording material, and the recording material is developed.

Abstract: There is disclosed an image reader in which the reading magnification can be changed optically to a value designated. The image reader provides a device for adjusting the reading magnitude by moving a lens in the direction of the optical axis thereof and adjusting the focusing by shifting the image sensor relative to the lens. Further, the image reader provides a device for measuring the magnification and calculates amounts of movements for the lens and image sensor respectively based upon the measured magnification and the designated magnification. The lens and image sensor are moved respectively by the amount calculated to give the designated magnification in the focused state.

Abstract: The diameter of a wheel or wheels, such as railroad wheels, is measured while the wheel rolls through a measuring station or while a measuring station is moved past a wheel. Electromagnetic beams, such as light or laser beams, provide respective barriers or sensors. The spacing between the beams is fixed and the time needed to traverse the spacing is measured. The spacing has a definite relationship to the wheel diameter. A computer calculates the diameter based on the measured time and on the given wheel diameter related spacing. Even where only a portion of a wheel is available for sensing or scanning the present method may be used.

Abstract: An apparatus for the highly accurate measurement of measuring surfaces (14) has a lens (68) pre-tensioned by spring members (84, 86), which lens is connected to a magnetic adjusting sleeve (74). The latter cooperates with an annular coil (140) surrounding it. A light source (60) directs a narrow light beam (62) towards the measuring surface (14). The beam reflected by the latter is deflected by a combination prism (90) and split into two partial beams, which reach photoelectric transducers (116, 118). The output signal thereof serves for adjusting the supply current for the annular coil (140). Provided behind the lens (68) is a glass plate (78) which is mirrored with the exception of a central circular region (82), so that light beams reflected by the measuring surface with a considerable inclination with respect to the axis of the apparatus are thrown back again onto the measuring surface and are supplied to the detection system along the axis of the apparatus.

Abstract: A surface displacement sensor is so designed that a stop or aperture for controlling an angle of opening is disposed at the position of a pupil of a detection optical system in which a slit image is focused on the surface to be detected and the light rays reflected from the surface to be detected are collected to re-focus the slit image on the light receiving surface of the sensor. When the height position of the surface to be detected is detected by such stop for controlling the angle of opening, the deviation of the distribution of intensity of light which tends to occur in the widthwise direction of the slit through which passes the light beam which in turn focuses a slit image, can be positively decreased by limiting the angle of opening N.A. in the widthwise direction of the slit for passing the light beam to focus a slit image to be narrow and consequently the degree of detection accuracy can be improved.

Abstract: Method and apparatus for optically detecting information from a recording medium in which pits are formed by thermal energy of a light spot to record the information. A reproduction spot is irradiated onto the recording medium to produce a detection signal. From a differential signal of the detection signal, a signal indicative of zero points of the differential signal and a signal indicative of the presence of the pits are detected, and both the signals are used to detect positions of the pits. For stable and accurate detection of the pit position, the relation between pit size W and reproduction spot size W.sub.s is prescribed and the pit size and reproduction spot size are so set as to satisfy 0.45.ltoreq.W/W.sub.s .ltoreq.0.75.

Abstract: The invention relates to a selective detector arrangement for the detecting of approximately point-like collected light in a predetermined wavelength region and angle of the field of vision, with an optical collector system which is made from a material passing the light at a predetermined wavelength range and with a light sensitive sensor element.

Abstract: In order to focus light beams which are projected onto an optical recording medium, the focusing optical system is moved in a vertical direction to the surface of the recording medium. A focus error signal produced by receiving the light returning from the recording medium is compared in turn with a predetermined plurality of reference levels. A focus servo-means is operated when this signal reaches the reference level within the focus pull-in region after passing through a predetermined order of reference levels.

Abstract: A light pulse detecting device having a photo-transistor whose output is compared with a level to detect incidence of a light pulse thereon. In this device, the photo-transistor is provided with other transistors cascode-connected thereto. For this reason, the capacitance of the emitter-collector path of the photo-transistor becomes equivalently smaller, improving the response characteristic of the light pulse detecting device.

Abstract: An image sensor comprising at least one first light emitting element for irradiating an original with light, at least one photoconductive element for sensing the light via the original and at least one second light emitting element for irradiating the photoconductive element with light. The second light emitting element emits light of photoenergy smaller than the optical band gap of the photoconductive element.

Abstract: An optical motion sensor comprises first and second light emitting diodes that emit complementary pulsed beams of infrared energy within a sensing region. A photodiode sums the energies to produce a proportional sensing signal. An amplifier AC coupled to the photodiode blocks the constant portion of the sensing signal and passes a time varying signal portion produced by motion of an object to a sampling circuit. The sampling circuit samples the sensing signal synchronous with emission of the first pulsed beam and converts the time varying signal to a proportional detection signal. An integrator coupled to the sampling circuit responds to a detection signal by modulating the intensity of the second pulsed beam to null the earlier time varying portion of the sensing signal. The motion sensor can be configured as a presence sensor by changing the time constant of the integrator.

Abstract: In a light barrier, especially for outside application and long distances monitored, insensitivity to interfering light and scattering through fumes or fog and an increased range and sensitivity to objects passing through the light barrier are achieved by subdividing radiation from a source into two radiation branches which are offset relative to each other and differently polarized, e.g., by means of a polarization filter divided into two parts, with different linear or oppositely circular polarization of the filter part surfaces. By means of an analogously subdivided polarization filter, the radiation of each of the two radiation branches is focused on a different individual sensor element. The two sensor elements are connected in a differential circuit which triggers an alarm signal in response to signals arriving from both radiation branches in short succession but does not trigger an alarm signal if both sensor elements are equally irradiated.

Abstract: Dual light beams directed onto adjacent surface elements defining a seam therebetween produce reflected light images which contact an electro-optic linear array sensor which in turn generates light spot position information for determining seam location via triangulation calculations.