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US 3,937,049 AGranted
Monitoring system for digital electronic timepiece
AssigneeCitizen Watch Co., Ltd.
InventorsTomomi Murakami, Hideyuki Kawashima
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AssigneeCitizen Watch Co., Ltd.
InventorsTomomi Murakami, Hideyuki Kawashima
Estimating the term…
An electronic timepiece provided with a liquid-crystal cell in a grounded casing, a common electrode on one side thereof and a segmented pattern electrode on the other side has a transparent shield electrode which is grounded to the casing and overlies the major part of the cell, with the exception of at least one window registering with a detecting electrode positioned on the glass cover of the casing. An ungrounded electrode underneath the window is pulsed by the electronic clockwork, the pulses being picked up by the detecting electrode and delivered to an evaluating device for measuring the operating rate of the timepiece. In one embodiment, two such windows associated with respective detecting electrodes are provided, one window registering with the common electrode at a location remote from all the segments of the pattern electrode, the other window being aligned with a coplanar extension of one of the segments of a digital array which is intermittently energized in the course of a pattern-forming cycle; the evaluator distinguishes between periods when the pulses picked up by the detecting electrodes are in phase and in phase opposition.
In an electronic timepiece provided with a metallic casing, display means including electrode segments arrayed in digital patterns to be displayed in a recurrent cycle, and an electronic clockwork for selectively exciting said segments to establish said patterns, the combination therewith of a transparent cover on said casing overlying said display means and enabling said patterns to be observed, a transparent shield electrode within said casing electrically connected thereto and extending over the major part of said display means while leaving free at least one window offset from said segments, at least one monitoring conductor in said casing electronically disconnected therefrom and aligned with said window, circuit means linking said monitoring conductor with said electronic clockwork for periodic pulsing thereby, at least one detecting electrode on said cover aligned with said window for picking up pulses from said monitoring conductor, and evaluation means connected to said detecting electrode for measuring the recurrence rate of said pulses.
Dependencies are inferred from the claim text.