Patents by Inventor Roberto Viscardi

Roberto Viscardi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4916371
    Abstract: The circuit, particularly suitable for high-definition monitors, wherein a power amplifier is fed by a supply voltage source to generate a deflection current in a yoke, furthermore comprises switching means which are activatable to connect another source of a supply voltage higher than the source to the amplifier, and flyback detector means to activate said switching means at the beginning of the flyback.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: April 10, 1990
    Assignee: SGS Thomson Microelectronics spa
    Inventors: Silvano Coccetti, Mauro Merlo, Roberto Viscardi
  • Patent number: 4837464
    Abstract: This circuit comprises a phase-lock stage receiving at the input a reference signal and the synchronism signal EN and generating at the output a triangular signal in phase correlation with the synchronism signal, a rectangular waveform generator receiving at the input the triangular signal and supplying at the output a rectangular signal, a drive element receiving the rectangular signal and generating a periodic control signal, as well as a phase comparator receiving at the input the triangular signal and the control signal, as well as a further reference signal and generating at the output an error signal correlated with the phase shift of the drive element and fed to the rectangular waveform generator. The reference signal fed to the phase-lock stage or to the phase comparator can be suitably varied within preset limits by an external potentiometer.
    Type: Grant
    Filed: June 1, 1987
    Date of Patent: June 6, 1989
    Assignee: SGS Microelettronica S.p.A.
    Inventors: Roberto Viscardi, Silvano Gornati, Silvano Coccetti
  • Patent number: 4803381
    Abstract: This circuit comprises a current source stage connectable to a capacitor which is controlled so as to alternately and periodically charge with the current fed by the source stage and discharge through a switch element, so as to generate a saw-tooth wave voltage. A buffer circuit, with low-impedance output is connected to the capacitor, for feeding a saw-tooth shaped low-impedance voltage signal to a load. In order to prevent the bias current of the buffer stage from introducing an error in the capacitor charge current and in the frequency of the saw-tooth voltage, a current sensor is provided connected between the buffer stage and the current source stage so as to vary the current generated by the source stage in an equal but opposite manner with respect to the error current due to the buffer stage.
    Type: Grant
    Filed: June 1, 1987
    Date of Patent: February 7, 1989
    Assignee: SGS Microelettronica S.p.A.
    Inventors: Silvano Gornati, Roberto Viscardi, Silvano Coccetti
  • Patent number: 4739228
    Abstract: A variable-gain rectifier-amplifier with regulated voltage converts the output ramp of a ramp generator with regulating resistance of ramp amplitude into a triangular wave form with adjustable linearity which a feedback circuit brings back to said regulating resistance in the form of alternating current superimposing it on the direct current regulated through said resistance. This provides an S correction of the output ramp which depends on the gain regulation voltage of the rectifier-amplifier circuit.
    Type: Grant
    Filed: May 16, 1986
    Date of Patent: April 19, 1988
    Assignee: SGS Microelettronica S.p.A.
    Inventors: Roberto Viscardi, Silvano Coccetti, Silvano Gornati
  • Patent number: 4672332
    Abstract: This high accuracy, RC oscillator, particularly for monitors, has different switch-over thresholds independent from such variable parameters as the saturating voltage of transistors, and has a high operating frequency. The oscillator comprises a capacitor having an output terminal, a capacitor power current source, and a control section. The control section is composed of a plurality of differential stages sharing a common input and each having an input connected to a different switch-over threshold. The control section further comprises a switch-over drive stage connected to the oscillator output terminal and to an input terminal thereof for controlling activation and deactivation of the different differential stages (and hence, of the respective associated thresholds) according to the signal present at the output and input terminals of the oscillator.
    Type: Grant
    Filed: April 21, 1986
    Date of Patent: June 9, 1987
    Assignee: SGS Microelettronica S.p.A.
    Inventors: Silvano Coccetti, Roberto Viscardi, Silvano Gornati