Patents by Inventor Toru Hamanaka

Toru Hamanaka 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).

  • Driver circuit for driving a light emitting element by superimposing an analog sub-information signal over a digital main signal
    Patent number: 4864649
    Abstract: A driver circuit for driving a light emitting element with a signal generated by superimposing an analog sub-information signal over the pulse string of a digital main signal. The driver circuit includes an input interception detector for detecting any interception of the digital main signal, and a gain-controlled amplifier for increasing the gain of the analog sub-information signal when the digital signal is intercepted.
    Type: Grant
    Filed: August 26, 1987
    Date of Patent: September 5, 1989
    Assignee: NEC Corporation
    Inventors: Tsutomu Tajima, Toru Hamanaka