Patents by Inventor Clifford B. Lau

Clifford B. Lau 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).

  • Optical pointer input device
    Patent number: 5347275
    Abstract: A computer input device uses an ordinary sheet material such as a card, letter or envelope to select and point to a symbol. A remote portion of the sheet material covers adjacent light emitters and sensors which sense reflected light from the emitters. A single sensor is associated with multiple symbols and is associated with symbols in at least two specific groups of symbols. A processor is connected to a demultiplexer and a multiplexer, and the demultiplexer and multiplexer are connected to individual sensors. Biasing resistors are connected to individual sensors. The processor selects a pair of connectors from the demultiplexer and multiplexer, thus sampling a particular sensor. The output of that sensor is converted a digital signal, which is sent to the processor and stored in a random access memory.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: September 13, 1994
    Inventor: Clifford B. Lau
  • Object pointer computer input apparatus
    Patent number: 5302948
    Abstract: A computer input device uses an ordinary sheet material such as a card, letter or envelope to select and point to a symbol. A remote portion of the sheet material covers sensors which sense available ambient light. Uncovered sensors provide background light information. A single sensor is associated with multiple symbols and is associated with symbols in at least two specific groups of symbols. A processor is connected to a demultiplexer and a multiplexer, and the demultiplexer and multiplexer are connected to individual sensors. Biasing resistors are connected to individual sensors. The processor selects a pair of connectors from the demultiplexer and multiplexer, thus sampling a particular sensor. The output of that sensor is converted a digital signal, which is sent to the processor and stored in a random access memory.
    Type: Grant
    Filed: October 3, 1991
    Date of Patent: April 12, 1994
    Inventors: Clifford B. Lau, Marian S. Gould
  • Touch plate for providing a computer response
    Patent number: D347002
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: May 17, 1994
    Inventor: Clifford B. Lau