Automatic Gain Control Patents (Class 250/214AG)
  • Patent number: 4174177
    Abstract: A system for warning a target designator operator whenever a target less n a predetermined distance from the operator is designated. Actuating the target designator triggers a time interval counter and circuitry to detect reflected pulses. An indicator will warn the operator if a pulse is reflected to the system from an object less than a predetermined distance from the operator.
    Type: Grant
    Filed: August 14, 1978
    Date of Patent: November 13, 1979
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Keith L. Gardner, Goro Fujiwara
  • Patent number: 4142729
    Abstract: A record player has a record track selection system using sensing means to scan a record to identify selected record tracks, the sensing means feeding signal processing circuitry having a gain or threshold adapted to individual record characteristics as determined by a record scan prior to track identification.
    Type: Grant
    Filed: November 29, 1977
    Date of Patent: March 6, 1979
    Assignee: Pico Electronics Limited
    Inventor: Harold M. McLennan
  • Patent number: 4133008
    Abstract: A compensation circuit for use in a document reproduction system for correcting variations in white level occurring between different documents and due to nonuniformity of the scanning process including a variable voltage gain amplifier for compensatingly modifying the output of an image scanner and having a gain control system which drives the white level amplifier gain to a predetermined level so that the scanner output is made independent of certain well known causes of nonuniformity.
    Type: Grant
    Filed: March 14, 1977
    Date of Patent: January 2, 1979
    Assignee: Rapicom Inc.
    Inventor: James G. Tisue
  • Patent number: 4127813
    Abstract: A method is provided for balancing the sensitivity of two channels comprising intermittently-appearing pulse waves, such as the signals generated by respective sensors in a detecting couple which is used in the so-called differential detection of flaws in materials. The balancing of the levels of the pulse signals is accomplished by the use of, essentially, a pair of sample and hold circuits, one or two variable gain amplifiers and the same number of comparison loops as variable gain amplifiers.
    Type: Grant
    Filed: May 17, 1977
    Date of Patent: November 28, 1978
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Tatsuo Hiroshima, Tetsuya Hirota
  • Patent number: 4097731
    Abstract: A beam-of-light (BOL) sensor having means for regulating the intensity of the sensor light source to compensate for extraneous factors in the operating environment, e.g. dust accumulation, that may affect consistent sensor operation. The BOL sensor includes a photosensor whose output signal is compared against a reference signal to determine if the light source intensity is of the proper level. The comparison signal is transformed into a digital pulse that adjusts the stored count of a counter upward or downward in accordance with the comparison of the photosensor signal and reference signal. The adjusted count is converted to analog form and fed back to drive the light source.A trailing edge detector enables the counter to count up or down when an object is in the sensing station defined by the light source and photosensor.
    Type: Grant
    Filed: June 2, 1977
    Date of Patent: June 27, 1978
    Assignee: Burroughs Corporation
    Inventors: Thomas R. Krause, Eugene E. Paananen, John F. Burcz
  • Patent number: 4097732
    Abstract: A beam-of-light (BOL) sensor having means for regulating the intensity of the sensor light source to compensate for extraneous factors in its operating environment, e.g., dust accumulation, component aging, misalignment, etc., that may affect consistent sensor operation. The BOL sensor includes a photosensor whose output signal is compared against a reference signal to determine if the light source intensity is of the proper level. The comparison signal is used to gate clock pulses to a counter to adjust its stored count upward or downward, dependent on whether the light source intensity is low or high, respectively. A filter is provided to override interruptions in the photosensor output signal below a predetermined minimum time duration.
    Type: Grant
    Filed: June 2, 1977
    Date of Patent: June 27, 1978
    Assignee: Burroughs Corporation
    Inventors: Thomas R. Krause, Eugene E. Paananen, John F. Burcz
  • Patent number: 4092069
    Abstract: A spectrophotometer comprising means for producing electrical signals Er and Es corresponding to reference and measuring beams, respectively; means for multiplying the value Es by a factor k to produce an electrical signal corresponding to the value kEs; means for controlling said signal producing means so as to keep the value (Er + kEs) constant; and means for producing an electrical signal corresponding to the value (Er - kEs), whereby minute changes of the absorbance of a sample can be accurately measured without logarithmic conversion.
    Type: Grant
    Filed: July 12, 1976
    Date of Patent: May 30, 1978
    Assignee: Shimadzu Seisakusho Ltd.
    Inventors: Yoshio Fukuda, Jugoro Suzuki, Toshiaki Fukuma, Michinosuke Takada
  • Patent number: 4061925
    Abstract: An apparatus for testing the optical output of light-emitting devices in the presence of ambient light, with means for compensating for said ambient light, is described. The d.c. and periodic components of the ambient light are measured and stored during a time when the apparatus is not being subjected to radiation from the device under test (DUT). When radiation from the DUT is received, the resulting signal is processed with the stored ambient light intensity data, and an output proportional to the intensity of the radiation from the DUT and compensated for the ambient light is provided.
    Type: Grant
    Filed: February 20, 1976
    Date of Patent: December 6, 1977
    Assignee: Versatile Integrated Modules
    Inventors: Leonard C. van der Gaag, Luciano Pacheco
  • Patent number: 4054795
    Abstract: A photoelectric sensing system for detecting the occurrence of interruptions of a light beam is arranged to compensate for non-interrupting short-term variations occurring during transmission of the light beam. A clock controlled memory element enables a light emitting generator to generate a serial train of light pulse signals. Each generated light pulse signal is sensed by a sensor arranged to control the memory element to modulate the emitted light pulse signal to compensate for short-term variations occurring in the light signal transmission path.
    Type: Grant
    Filed: December 16, 1975
    Date of Patent: October 18, 1977
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventor: George William Kinder
  • Patent number: 4048510
    Abstract: In a surface inspection system a detector responds to light received from the surface to give a detector signal including disturbances due to surface faults, and includes an equalizer circuit to control the gain of a photomultiplier, and therefore signal amplitude, in response to a peak level detector, to control the level of the signal in relation to the amplitude of the disturbances and a band-pass filter to compensate for variations in the signals due to changes in the optical gain of the detector. The equalizer circuit is an amplifier and the control is achieved by way of feedback and feedforward control loops. In a modification the system may comprise a row of detectors and the equalizer circuit may be arranged to accommodate changes in the amount of light received at the junctions of detectors.
    Type: Grant
    Filed: February 24, 1976
    Date of Patent: September 13, 1977
    Assignee: Ferranti Limited
    Inventors: Graham Morley Clarke, George Fisher
  • Patent number: 4039844
    Abstract: A flame monitoring system includes a flame sensor for producing a flame signal as a function of flame conditions in a monitored environment and flame signal enhancing circuitry coupled to the flame sensor. The flame signal enhancing circuitry has a first response as a function of a first characteristic of the flame signal and a second response different from the first response as a function of a second characteristic of the flame signal and is arranged to combine the first and second responses to provide an enhanced flame signal representative of the monitored flame.
    Type: Grant
    Filed: March 20, 1975
    Date of Patent: August 2, 1977
    Assignee: Electronics Corporation of America
    Inventor: Malcolm F. MacDonald
  • Patent number: 4027154
    Abstract: The disclosure relates to an electronic document detector particularly adapted for but not limited to use in a document recording system. The document detector comprises a light source, a current source which includes a light sensitive element spaced from the light source and arranged for receiving at least a portion of the light output of the light source for providing a current having a magnitude directly related to the amount of light received by the element, wherein the space between the light source and the light sensitive element defines a path in which documents to be detected traverse. As each document traverses the path, the light sensitive element is shielded from the light source. A current sink coupled to the current source has an input and an output for providing at its output an intermediate control voltage having a magnitude related to the magnitude of the current provided by the current source and within a first range below a given level and within a second range above the given level.
    Type: Grant
    Filed: December 29, 1975
    Date of Patent: May 31, 1977
    Assignee: Bell & Howell Company
    Inventor: John R. Flint
  • Patent number: 4003445
    Abstract: Code circuitry for controlling the operation of a vehicle that is guided along a guide line by means of a vehicle guidance mechanism comprises a plurality of code markers positioned in a code marker path alongside the guide line, a sensor circuit that senses the intensity of radiation received from the guide line and code marker path and generates a code signal whenever the radiation from the code marker path increases to a predetermined proportion of the intensity of the radiation received from the guide line, and a control mechanism that controls the operation of the vehicle in response to code signals generated by the sensor circuit. A gain control feedback mechanism provides gain adjustment for wide variations in guide line and code marker intensity, and modulation circuitry eliminates the effect of static background radiation.
    Type: Grant
    Filed: February 12, 1976
    Date of Patent: January 18, 1977
    Assignee: Lear Siegler, Inc.
    Inventor: Carl De Bruine
  • Patent number: 4001594
    Abstract: An improved method for controlling the quantity of exposure in photographic printing to obtain high-quality prints is disclosed. The method is carried out by photoelectrically detecting a plurality of optical densities from a principal portion of a negative film then discriminating the maximum value and the minimum value of the photoelectrically detected optical densities. The difference between the maximum and minimum values is calculated to achieve a first output, and the first output is non-linearly converted and combined with the maximum or minimum value output to achieve a third output for controlling the quantity of exposure. The method provides satisfactory prints even from those negative films having principal subject density failures or color failures.
    Type: Grant
    Filed: June 20, 1975
    Date of Patent: January 4, 1977
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Taizo Akimoto, Takaaki Terasita, Shigeru Watanabe
  • Patent number: 3999060
    Abstract: A device is provided for controlling the sensitivity of a receiver of the type comprising a photosensitive element operative to convert radiant energy into electric signals and having an amplifier connected to the output of the photosensitive element and signal processing members for separating a useful signal from interfering background radiation. A sensor device is connected to the photosensitive element to sense the direct current which the element emits in response to radiation from the sun or other strong sources of disturbance, the sensor device being operative to emit a signal when the direct current exceeds a predetermined value, and a switching device responsive to said signal operates to switch the amplifier from a given fixed sensitivity level to a lower fixed level of sensitivity.
    Type: Grant
    Filed: February 11, 1975
    Date of Patent: December 21, 1976
    Assignee: AB Bofors
    Inventor: Lars-Erik Skagerlund
  • Patent number: 3988611
    Abstract: A direct current power supply circuit for a photomultiplier tube comprises a step-up transformer with a secondary winding connected to rectifier means feeding output terminals. The primary winding in series with a transistor switch is connected across a d.c. supply source and the switch is controlled by pulses from a pulse generator which is switched on to produce pulses and hence to switch current in the primary winding when a control signal opens a gate in a feedback circuit of the pulse generator. The control signal is derived from the photomultiplier circuit and the circuit operates with the gate opening and closing as necessary to obtain the required voltage. The control signal may be derived from across an anode resistor of the photomultiplier tube or across a resistor in series with the dynode resistor chain according to the characteristics required.
    Type: Grant
    Filed: June 19, 1975
    Date of Patent: October 26, 1976
    Assignee: Medical & Electrical Instrumentation Company Limited
    Inventor: Arthur Gordon Davies
  • Patent number: 3986037
    Abstract: In a yarn inspection system for detecting variations in yarn diameter wherein a plurality of yarns move past a plurality of transducers for generating electrical signal outputs corresponding to yarn diameter and including discriminator circuitry sequentially connected to each of the transducers for processing the signal outputs, a self calibrating circuit arrangement has been devised to compensate for normal variations in the output of individual transducers due to different characteristics among the separate transducers.
    Type: Grant
    Filed: October 3, 1975
    Date of Patent: October 12, 1976
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Mark Edwin Faulhaber
  • Patent number: 3970840
    Abstract: A vehicle guidance mechanism for guiding a vehicle along a guide line comprises a radiation source that causes the guide line to reflect or emit a guidance signal; photocell sensors mounted in the vehicle and adapted to sense the guidance signal and produce an error output signal proportional to the variation of vehicle position from a predetermined lateral position with respect to the guide line; and a control device in the vehicle adapted to steer the vehicle in response to the error signal so as to cause the vehicle to follow the guide line. An automatic contrast or gain control circuit eliminates the effect of background illumination in the output signal received from the guide line. Modulation circuitry and appropriate filters reduce the effects of static background illumination and improve the reliability and line detecting ability of the guide system. Line detection circuitry is employed to prevent operation of the automatic control device unless the vehicle is tracking a valid guide line.
    Type: Grant
    Filed: July 16, 1974
    Date of Patent: July 20, 1976
    Assignee: Lear Siegler, Inc.
    Inventor: Carl De Bruine