US 7,583,565 B2Granted

Electronic timepiece

AssigneeSeiko Instruments Inc.

InventorsKenji Ogasawara, Yoshihiro Shibuya

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Abstract

To be able to promote oscillation start characteristic while having a simple constitution and maintaining low power consumption. In starting to oscillate an oscillation circuit, a capacitor for protecting from leakage is shortcircuited by bringing a switch of an oscillation stabilizing circuit 11 into a closed state and a constant voltage circuit starts to oscillate the oscillation circuit by supplying a drive voltage of a power source voltage to the oscillation circuit. After an elapse of a predetermined time period, oscillation is prevented from being stopped by leakage by inserting the capacitor into the oscillation circuit loop by bringing the switch into an open state, and an oscillation operation is continued by supplying a voltage lower than the power source voltage to the oscillation circuit by intermittently driving the constant voltage circuit.

Claims4

Dependent claims

An electronic timepiece comprising:

oscillating means having a capacitor for protecting from a current leakage in an oscillation circuit loop for outputting a signal of a predetermined frequency;
dividing means for dividing the output signal from the oscillating means and outputting a timepiece signal constituting a reference of a time counting operation;
driving means for outputting a drive signal based on the timepiece signal outputted from the dividing means;
displaying means driven by the drive signal for displaying current time;
drive power supplying means for supplying a drive power at least to the oscillating means;
and
controlling means for controlling the drive voltage outputted from the drive power supplying means;
wherein the oscillating means includes switching means;
and
wherein the controlling means controls the switching means to short-circuit the capacitor in order to generate noise constituting a trigger in starting to oscillate the oscillating means and electrically insert the capacitor into the oscillation circuit loop after an elapse of a predetermined time period, and the controlling means controls the drive power supplying means to supply a power source voltage to the oscillating means as the drive voltage in starting to oscillate the oscillating means, and to supply a voltage within a predetermined range lower than the power source voltage and a voltage pulsating by a predetermined period from the drive power supplying means to the oscillating means by intermittently controlling to drive the drive power supplying means by the predetermined period after an elapse of a predetermined time period from starting to oscillate the oscillating means.

7 more elements

Dependencies are inferred from the claim text.