Alternating Current Patents (Class 340/388.2)
  • Patent number: 6373958
    Abstract: An electro-mechanical-audio converter and an electro-mechanical-audio converting device using the same employed in mobile terminals such as mobile phones for generating paging vibration which realizes stable vibration function. The electro-mechanical-audio converter includes a housing (1a), movable part (2), forming a magnetic circuit, mounted on an opening of the housing (1a) through a suspension (3); and a detection coil (11) disposed near the movable part (2) for generating excitation voltage by vibration of the movable part (2). Strong vibration of the movable part (2) during resonance is detected by the detection coil (11) as an excitation voltage, and fed back. Accordingly, the electro-mechanical-audio converter and electro-mechanical-audio converting device using the same having an extremely stable vibration function, even when resonance frequency changes due to environmental changes such as ambient temperature, is made feasible.
    Type: Grant
    Filed: May 31, 2000
    Date of Patent: April 16, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsutaka Enomoto, Masakuni Hirata, Takanori Fukuyama, Mitsukazu Kuze