Abstract: An opto-electronic end-of-tape sensor has a pulsed light source for producing high intensity, short duration light pulses and a photodetector controlling a clock driven digital counter. In a normal condition with tape blocking the light pulses, the counter is kept in a reset state. If a clear light path of sufficient time duration is detected the photodetector output enables the counter to reach a predetermined count to obtain an end-of-tape signal output. The sensor circuit discriminates against pinholes in the tape by requiring detection of an uninterrupted predetermined number of light pulses to generate the end-of-tape signal.
Abstract: The invention proposes an electro-optical measurement system to be used to measure the width and possibly also the thickness of a strip 14 being rolled. The strip is imaged onto an electro-optical transducer each of which views the whole width of the strip. To compensate for inaccuracies resulting from the imaging system, a calibration of the imaging system is effected by means of a grid of known dimensions. The calibration results are recorded during a setting up process and used by a digital or analogue computer to correct any measurements taken by the imaging system during operation. There is also disclosed an improved technique for edge detection and for processing video data in real time.
Abstract: To eliminate or suppress amplifier noise in amplifiers (6, 7) connected to a semiconductor light sensor, for example of a charge coupled type, in which the noise introduced by the amplifiers has a frequency spectrum which is low with respect to the clock frequency of operation of the sensor, the minimum value signal from the light sensor, as amplified, is determined; the maximum value of the signal, as amplified, is determined; and a reference is derived based on the minimum value, for example by clamping the minimum value, or utilizing the minimum value as a dynamic reference for subtraction from the maximum value, to thereby eliminate the effect of low-frequency shift of signals due to low-frequency noise of the amplifiers; various circuits may be used, such as clamping circuits (FIG. 3), threshold or non-additive mixing circuits (FIGS. 4, 5) coupled to a subtraction stage (24), band-pass filtering and envelope demodulation (FIG. 6: 28, 29, 30) or synchronous demodulation (FIG.
December 8, 1981
Date of Patent:
December 11, 1984
Robert Bosch GmbH
Hans-W. Zappen, Dieter Poetsch, Klaus Lehmann, Friedrich Zimmermann, Klaus D. M/u/ ller
Abstract: An optical proximity sensor for optically detecting an object within a predetermined detection volume. More specifically, an optical proximity sensor is disclosed having an illuminator assembly including an illuminator lens (55) and a plurality of light-emitting diodes (53) located at first predetermined positions along the focal plane (54) of the illuminator lens (55). A detector assembly including a detector lens (65) and a plurality of photodiodes (60) located at second predetermined positions along the focal plane of the detector lens (65) is also provided. The two lenses are spaced apart a predetermined distance in accordance with the configuration of the light-emitting diodes (53) and the photodiodes (60) in order to define a predetermined detection volume. Each light-emitting diode has a corresponding photodiode, and their relative positions on their respective focal planes determine the detection volume defined by their overlapping fields of view.
March 11, 1981
Date of Patent:
October 23, 1984
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: An automatically focussed optical system in which two arrays of photosensitive detectors have different optical spacings respectively in front of and behind the image plane of the system, and sense different portions of the image. Differences in electrical signals generated by adjacent detectors (C,D and E,F) in each set, and indicative of differences in intensity of the corresponding portions, are processed to generate a focus drive signal (Fd) of a value related to an error in the focus of the image. This signal is used to adjust the focus. Two discrete arrays of detectors (FIG. 2B) can be used or alternatively a single array (FIG. 2D) tilted relative to the image plane can be used. In another example (FIG. 2C) a transparent block is inserted adjacent to a part only of a single detector array to thereby lengthen the optical path length of that part relative to the remainder of the array.
Abstract: A transducer utilizes a laser source, photoelastic waveguides, two optical beam paths and detectors 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 either combined or compared with a reference signal to obtain the stress intelligence.
Abstract: An automatic focusing device in a stereoscopic microscope having a pair of left and right stereoscopic observation optical systems disposed rearwardly of a common objective lens includes automatic focusing means for converting an amount of focus deviation into an electrical signal and automatically controlling the stereoscopic microscope to its in-focus position on the basis of the electrical signal, and selector means for selecting the operation and non-operation of the automatic focusing means.
Abstract: An automatic focus adjusting apparatus is provided with a light sensor producing a photoelectric output corresponding to the optical image of an imaged object, an operation device generating control information indicative of the in-focus position of a phototaking lens with respect to the object in response to the photoelectric output, a servo circuit for driving the phototaking lens in response to the control information, and filter means for transmitting the control information of the operation device to the servo circuit and controlling the responsiveness of the servo circuit to the control information.
Abstract: In a solid-state image sensor of the type comprising an image pickup region comprising photosensor element arrays and charge transfer arrays, a charge storage region and a read-out region, two or more charge storage arrays are provided for each of the charge transfer arrays. The number of transfer electrodes in each of the charge storage arrays can be reduced to 1/n, where n is the number of charge storage arrays for each charge transfer array, as compared with the case in which one charge storage array is provided for each charge transfer array. As a consequence, the area of the charge storage region on a chip can be considerably reduced and the reduction of the transfer charge signal can be improved; that is, the error rate can be reduced.
December 17, 1981
Date of Patent:
May 8, 1984
Matsushita Electric Industrial Co., Ltd.
Abstract: Control apparatus for controlling the quantity of light includes a light emitting device for emitting light in response to a driving signal applied thereto, a photodetector for receiving the light to produce a detection signal representative of the quantity of the light received, a comparator for comparing the detection signal with a reference signal, a circuit for applying a recording signal to the light emitting device, a start control responsive to an instruction signal which causes the control apparatus to start controlling the quantity of light during the time period when no recording signal is applied, an incrementing device for incrementing the driving signal to be applied to the light emitting device in response to the instruction signal received, and a stopping circuit for stopping the incrementing in response to the comparator to hold a count which is contained in the incrementing device when stopping, until the instruction signal is subsequently applied.
Abstract: A sensor for measuring stress, temperature, pressure, sound, etc. comprising an optical waveguide, preferably an optical fiber waveguide, a light source which injects light into one end of the waveguide, a deformer contacting and deforming the waveguide to cause light to couple from originally excited modes to other modes, and an optical detector to detect the change in light coupling caused by deformation of the waveguide.
May 13, 1982
Date of Patent:
April 17, 1984
Pedro B. Macedo, Theodore A. Litovitz
Pedro B. Macedo, Theodore A. Litovitz, Nicholas Lagakos, Robert K. Mohr, Robert Meister
Abstract: An optical beam intensity control system having a light controller which allows a beam of electromagnetic energy of varying intensity to pass therethrough. A beam splitter directs a portion of the output beam to a detector which provides a signal indicative of the intensity of this beam to a threshold control signal generator. The control signal generator compares the intensity signal with a preselected intensity range and provides a signal indicative of whether or not the intensity of the beam falls within the preselected intensity range. The light controller operates in accordance with the signal from the control signal generator in order to maintain the output beam of the variable beam of electromagnetic energy within the preselected intensity range.
Abstract: Means and method is disclosed for achieving a low profile optical coupling to a module comprising an optoelectronic device together with other circuitry. Maintaining the optoelectronic device parallel to the substrate on which it and the associated circuitry are mounted enables the use of standard, well known manufacturing assembly techniques while providing electrical connection to the electric ports of said optoelectronic device. Subsequent to the electrical interconnection operation, the optoelectronic device is moved, together with its connections, to a position substantially orthogonal with the mounting substrate. Optical fiber, light coupling is utilized. The low profile of the overall module package is achieved by introducing the optical fiber in a direction generally parallel with the substrate and perpendicular to the light active surface of the optic port of the optoelectronic device.
Abstract: A circuit (10) that prevents a photo diode (12) from reaching its saturation output voltage thus ensuring the sensitivity of the photo diode to small changes in radiance at high radiance levels is disclosed. The circuit utilizes a transistor (30) that is allowed to conduct after the output voltage of the photo diode (12) has reached a predetermined level thus shunt loading the photo diode preventing it from reaching its saturation level. A resistor (28)-capacitor (32) time constant circuit is provided preventing the transistor (30) from conducting until the output voltage of the photo diode (12) has reached a predetermined level for a predetermined period of time thus preventing premature conduction of the transistor (30) in response to transient or spurious voltages.
Abstract: A scanning method for scanning a scanned surface simultaneously by a plurality of beam spots in which each beam spot passing through light beam detecting means provided outside the requisite scanned area of the scanned surface, to detect the time when each beam spot begins the scanning of the requisite scanned area, is focused with respect to the scanning direction of the beam spot and defocused with respect to a direction orthogonal to the scanning direction.
Abstract: An apparatus useful for positioning a light filter includes an incrementally stepped motor having the light filter affixed thereto. The apparatus also includes means for detecting a light signal and incrementing the motor in response thereto.
Abstract: A defocus compensation linkage arrangement automatically corrects for the defocussing of the converging viewing lens onto a photodetector in a rotational optical scanning system wherein the distance between the photodetector and the source of the image varies during the rotational scan. This is achieved by a mechanical feed forward arrangement that effectively tracks the rotational movement of the scanner and continuously adjusts the distance between the lens system and the photodetector array as rotational movement proceeds. The defocus compensation linkage comprises a rotational-to-linear translator arrangement that responds to the rotation of the scanning optics about a fixed axis of rotation and moves the lens by an amount proportional to the changing distance between the image source and the photodetector array.
Abstract: This specification discloses an apparatus disposed in the light beam from an object passed through an imaging lens for producing an output variable with movement of the image of the object by the imaging lens in the direction of the optical axis. The apparatus produces, when the image of the object is formed on a predetermined imaging plane, an output corresponding to a critical value representative of the in-focus of the imaging lens to the object and produces, when the image of the object is formed at a position deviated from the predetermined imaging plane, an output corresponding to the amount of said deviation.
Abstract: An optical shaft angle encoder which provides sensor output voltages having waveform characteristics modified for use with "multiplication type" tachometer converter circuits to provide improved servo control system performance by reducing step changes in the tachometer output voltage due to phase error and reducing tachometer output voltage ripple. The geometry of the encoder mask combination provides a non-sinusoidal sensor output voltage comprised of linear and parabolic segments having a trapezoidal derivative.
Abstract: A plurality of lights are mounted relative to one another to direct light beams toward a glass sheet along continuous scan portions. The sheet moves through the scan portions to reflect light beams toward a linear array of diodes. The linear array of diodes is activated and deactivated to simulate a discrete scan path and to generate points of intersection between the edge portions of the glass sheet and the scan path. The signals of the photodetectors are acted on to determine peripheral characteristics of the sheet such as squareness of the corners, linearity of the sheet sides and length of each sheet side.