Patents by Inventor William S. H. Cheung

William S. H. Cheung 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).

  • Publication number: 20030095371
    Abstract: The gas dielectric capacitor for high frequency applications. The capacitor has first and second planner electrodes separated by an adhesive having solid particles, which establish the distance between electrodes. An adhesive is formed along peripheral edges of the planner electrodes. The capacitor may include air, vacuum, or any number of other dielectric gases, which may be under pressure. A method is disclosed for manufacturing an array of capacitors having a pressurized gas dielectric.
    Type: Application
    Filed: November 21, 2002
    Publication date: May 22, 2003
    Inventor: William S.H. Cheung
  • Patent number: 6476685
    Abstract: A circuit and method for creating an all pass network for equalizing the group delay of a filter. The all pass filter provides an equalization network including a transformer having a primary and secondary winding magnetically coupled together. One end of each primary and secondary winding is connected together to form a connection, the remaining ends of the primary and secondary winding constitute input and output terminals to the equalization network. Control over the group delay response is effected by a bias conductor serially connected to the common ends of the primary and secondary winding and a capacitor connected to the common terminal. The bias conductor modifies the mutual inductance, therefore modifying the coupling factor for the transformer. By shifting control of the coupling to the bias conductor, group delay response may be controlled without further modifications of the transformer coupling.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: November 5, 2002
    Inventor: William S. H. Cheung
  • Patent number: 4620226
    Abstract: A television signal generator for producing a composite RF signal without high level intermodulation products. A signal network is provided to linearly combine a first video modulated carrier signal and a second carrier frequency of the same frequency modulated with an audio modulated subcarrier. An audio subcarrier generator is disclosed having a ceramic resonator for a frequency determining circuit element. The resonator is parallel connected with a voltage sensitive reactance element to provide a frequency modulated subcarrier in response to a modulating voltage.
    Type: Grant
    Filed: May 17, 1984
    Date of Patent: October 28, 1986
    Inventor: William S. H. Cheung
  • Patent number: 4527195
    Abstract: Apparatus for encoding and decoding information. Multiple scrambling techniques are provided to prevent unauthorized reception of a television picture signal. A first mode of scrambling provides for shifting randomly occurring horizontal synchronization pulses within each field of video signal producing horizontal as well as vertical instability. Video line inversion of selected lines within a field comprises a second mode of scrambling of the signal. A third mode of scrambling provides for amplitude shifting the television signal during selected portions of the signal which contains luminance and chrominance information following a line synchronization pulse.
    Type: Grant
    Filed: June 11, 1982
    Date of Patent: July 2, 1985
    Assignee: Payview Limited
    Inventor: William S. H. Cheung
  • Patent number: 4438752
    Abstract: A vehicle ignition system comprises a transformer having a primary winding and a secondary winding for providing the desired high voltage to the spark plug of the vehicle engine and a circuit including a further winding for said transformer connected across a switch and a load. The switch is operable only by a security device and when it is closed, the load absorbs energy from the transformer so that insufficient voltage is generated at the spark plug and the vehicle is immobilized. The load can be replaced by a reverse flux generator, the reverse flux opposing that generated by the primary winding. The security device may comprise a conventional key and keyhole, or more sophisticated devices such as code readers which read a code inputted from a magnetic card or from a keyboard. Further security may be provided by a further switch in series with the primary winding and battery, the further switch being operable in synchronism with and in the opposite sense to the first mentioned switch.
    Type: Grant
    Filed: September 4, 1981
    Date of Patent: March 27, 1984
    Inventor: William S. H. Cheung
  • Patent number: 4430669
    Abstract: During non-program hours, a subscription broadcast television station broadcasts in place of programming the time of a future special broadcast as well as other information to enable decoding circuitry of subscribers. The receiver at the subscriber's residence tunes during non-broadcast hours all subscription television broadcast frequencies, and compares the subscriber's identification number with information being broadcast. When a coincidence between the received identification number being broadcast, and a stored identification number is obtained, the time of the future special broadcast is stored in a memory. At the time of a subscription broadcast identified in the memory, tuning data is recalled from a memory for tuning the receiver to receive the special broadcast. The subscriber's decoding apparatus is also activated permitting descrambling of the special program broadcast.
    Type: Grant
    Filed: May 29, 1981
    Date of Patent: February 7, 1984
    Assignee: Payview Limited
    Inventor: William S. H. Cheung
  • Patent number: 4396947
    Abstract: A composite video signal containing an information portion and a synchronization pulse is encoded by shifting the level of the synchronization pulse and also by inverting the information portion. The encoding is switched on and off at a randomly chosen frequency, under the control of random number generator enabled at regular intervals. The encoded signal is transmitted with a data signal representing the random number so that a receiver can decode the received signal. The transmitted data can include details of undesired recipients, to disable their decoders. Applied to a pay TV system, the transmitted data can include the rate to be charged for the program and a billing mechanism at the receiver will meter the appropriate charge.
    Type: Grant
    Filed: March 26, 1980
    Date of Patent: August 2, 1983
    Assignee: Payview Limited
    Inventor: William S. H. Cheung
  • Patent number: 4329711
    Abstract: Information encoding apparatus comprises at least two modulators, each operating on a different channel, means for combining the outputs of the modulators, means for applying an information signal to the modulators for modulating the carrier waves in their channels according to the information signal, a random data terminal and means responsive to the random data signal to enable the combining means to receive a carrier wave modulated with said information from individual modulators in turn. The invention also includes transmitting apparatus for transmitting the encoded information together with a signal from the random data terminal and the invention also includes receiving apparatus for receiving and decoding the information under the control of the random data signal extracted from the received signal.
    Type: Grant
    Filed: November 6, 1979
    Date of Patent: May 11, 1982
    Assignee: Payview Limited
    Inventor: William S. H. Cheung