Patents Assigned to Cititzen Watch Co., Ltd.
  • Patent number: 6349075
    Abstract: A small electronic equipment with a vibration alarm has, as a drive source, a flat stator type bipolar stepping motor, which has a rotor having high durability, can be assembled easily, requires low power consumption, is started constantly stably, and can be rotated at a high speed. In this electronic equipment with the vibration alarm, a rotor (1) is rotated by a rotary drive system including a drive pulse generating means (112, 113, 114), a drive circuit (110), a flat stator (6), a counter electromotive voltage detection coil (306), and a magnetic pole position detection means (107, 115, 116), so that an eccentric weight (2) fixed to the rotor is rotated, thereby generating vibration. The drive pulse generating means outputs a pulse signal for driving the stepping motor on the basis of an alarm signal output at alarm time. The drive circuit supplies a drive current to a drive coil (305) on the basis of the pulse signal from the drive pulse generating means.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: February 19, 2002
    Assignee: Cititzen Watch Co., Ltd.
    Inventors: Norio Miyauchi, Tatsuo Nitta, Tomomi Murakami