Patents Examined by Mahammad Edun
  • Patent number: 6249495
    Abstract: In a method of the present invention for controlling stepping motor, the stepping motor driving current is increased or reduced at a fixed inclination in proportion to the time to control the stepping motor effectively, and, a stepping motor driving current pattern is changed by 1/4 cycle or over to synchronize the state of excitation between the stepping motor driving means and the stepping motor to control the pick-up very accurately. In addition, the disk apparatus of the present invention, which uses a stepping motor is provided with a pulse rate pattern variable means, a pulse rate change proportion measuring means, and a driving voltage variable means, and when the pulse rate and the pulse rate change proportion are low, the driving voltage amplitude is lowered to reduce surplus torque generation in the stepping motor.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: June 19, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takanori Okada, Shuichi Yoshida, Masaharu Imura, Kiyoshi Masaki, Kazuhiro Mihara, Tsutomu Kai, Noritaka Akagi, Masanori Harui, Kazuhiko Kouno