Patents by Inventor Takezo Nagamitsu

Takezo Nagamitsu 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: 8482182
    Abstract: A driving apparatus includes a piezoelectric element which undergoes expansion/contraction motion by a driving signal; a driving shaft which is mounted on the piezoelectric element, and undergoes reciprocating movement according to the expansion/contraction motion of the piezoelectric element; a first movement member which is friction-engaged with the driving shaft, and moves due to the reciprocating movement of the driving shaft; and a first control portion which applies driving signals to the piezoelectric element; the first control portion applies driving control pulse signals when the first movement member is to be moved, and applies stop control pulse signals when the stopped first movement member is not to be moved to put the first movement member into a vibration-arrested state. By this means, the stopped first movement member can be smoothly moved, and the first movement member in motion can be smoothly stopped.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: July 9, 2013
    Assignees: FUJIFILM Corporation, Sanyo Semiconductor Co., Ltd., Sanyo Electric Co., Ltd.
    Inventors: Hisao Ito, Hideo Yoshida, Takezo Nagamitsu, Tetsuya Tokoro, Yukihiko Sigeoka
  • Patent number: 8237327
    Abstract: Abnormal noise generated while driving a piezoelectric actuator is prevented. A pulse-generation circuit is capable of selectively generating a displacement pulse and a stationary pulse as a drive pulse for application to a piezoelectric element, the displacement pulse having a duty ratio for causing a lens to be displaced by a predetermined step width, and the stationary pulse having a duty ratio for causing the lens to remain stationary in a current position. The pulse-generation circuit controls the production of the drive pulse continuously for a plurality of times within the servo control cycle, causes the displacement pulse to be produced when the remainder of a required amount of displacement is equal to or greater than a threshold value, and causes the stationary pulse to be continuously produced until the initiation of the next servo control cycle when the remainder is less than the threshold value.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: August 7, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd., Fujifilm Corporation
    Inventors: Tetsuya Tokoro, Yukihiko Shigeoka, Hisao Ito, Hideo Yoshida, Takezo Nagamitsu
  • Publication number: 20100270954
    Abstract: A driving apparatus includes a piezoelectric element which undergoes expansion/contraction motion by a driving signal; a driving shaft which is mounted on the piezoelectric element, and undergoes reciprocating movement according to the expansion/contraction motion of the piezoelectric element; a first movement member which is friction-engaged with the driving shaft, and moves due to the reciprocating movement of the driving shaft; and a first control portion which applies driving signals to the piezoelectric element; the first control portion applies driving control pulse signals when the first movement member is to be moved, and applies stop control pulse signals when the stopped first movement member is not to be moved to put the first movement member into a vibration-arrested state. By this means, the stopped first movement member can be smoothly moved, and the first movement member in motion can be smoothly stopped.
    Type: Application
    Filed: April 5, 2010
    Publication date: October 28, 2010
    Inventors: Hisao ITO, Hideo Yoshida, Takezo Nagamitsu, Tetsuya Tokoro, Yukihiko Sigeoka
  • Publication number: 20100271700
    Abstract: Abnormal noise generated while driving a piezoelectric actuator is prevented. A pulse-generation circuit is capable of selectively generating a displacement pulse and a stationary pulse as a drive pulse for application to a piezoelectric element, the displacement pulse having a duty ratio for causing a lens to be displaced by a predetermined step width, and the stationary pulse having a duty ratio for causing the lens to remain stationary in a current position. The pulse-generation circuit controls the production of the drive pulse continuously for a plurality of times within the servo control cycle, causes the displacement pulse to be produced when the remainder of a required amount of displacement is equal to or greater than a threshold value, and causes the stationary pulse to be continuously produced until the initiation of the next servo control cycle when the remainder is less than the threshold value.
    Type: Application
    Filed: April 5, 2010
    Publication date: October 28, 2010
    Applicants: SANYO ELECTRIC CO., LTD., SANYO SEMICONDUCTOR CO., LTD., FUJINON CORPORATION
    Inventors: Tetsuya TOKORO, Yukihiko SHIGEOKA, Hisao ITO, Hideo YOSHIDA, Takezo NAGAMITSU