JPS5712382A - Analog electronic timepiece - Google Patents

Abstract

PURPOSE:To prevent an electronic timepiece from malfunctioning owing to an intense magnetic field by circuitry, by stopping advances of hands through a step motor by controlling gates according to magnetism detection and by making a correction by a stopping time when the advances of hands are restarted. CONSTITUTION:When an external magnetic field having a prescribed value or above is detected by a magnetic detecting element 8, such as a Hall element, a detection part 9, etc., a gate 5 is closed and a gate 6 is opened. Consequently, a hand-advancing step motor 4 is stopped and at the same time, the frequency division output of a frequency division part 2 is passed through the gate 6 and then counted by a counter 10 while the motor 4 is stopped. As the magnetic field weakens, the gates 5 and 6 are opened and closed respectively and a gate 7 is also opened, so that the prescribed frequency-division output of the frequency division part 2 is counted by a counter 11 via the gate 7. Until its count value reaches that of the counter 10, the motor 4 is driven at a high speed to compensate for advances of hnds equivalent to the stopping period of the motor 4. Therefore, the malfunction of an analog electronic timepiece dut to an intense magnetic field is prevented easily and securely through circuitry without using a shield, etc.