Patents by Inventor Fuminobu Ito

Fuminobu Ito 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 attenuator apparatus without steep level variation
    Patent number: 5210657
    Abstract: A first optical attenuation filter is arranged in a predetermined optical path and attenuates light to be attenuated with a first variable attenuation amount. A second optical attenuation filter is arranged in the predetermined optical path and attenuates, with a second variable attenuation amount, the light which has been transmitted through the first optical attenuation filter. The first and second optical attenuation filters can be driven in the forward and reverse directions and each has an attenuation amount characteristic which changes monotonously in both the forward and reverse directions. An attenuation amount setting section sets a desired attenuation amount to the light to be attenuated. First and second drivers are coupled to drive the first and second optical attenuation filters in the forward and reverse directions, respectively.
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: May 11, 1993
    Assignee: Anritsu Corporation
    Inventors: Hiroshi Komazawa, Fuminobu Ito, Kenichiro Umesaki, Yuuichi Watanabe, Yoshiharu Sasaki