US 4,400,093 AGranted

Method for inspecting the running of a timepiece and timepiece adapted for such method

AssigneeOMEGA Louis Brandt & Frere S.A.

InventorJean-Pierre Jaunin

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Abstract

In order to determine the adjustment precision .DELTA.T of a timepiece provided with an oscillator (1) and an adjustable frequency divider chain (3-18; 18-20) on which an adjustment unit (15) acts, initially the real period TQ of the oscillator is measured with the adjustment unit disconnected following a first actuation of a time setting circuit (21). A second actuation of said circuit then effects running of the display at a rate n times above the normal and the adjustment unit is connected. Following a time T/n representing the adjustment cycle the period TQ is measured as corrected by the amount n.DELTA.T, thus TQ+n.DELTA.T. The first measured value obtained is subtracted from the second thus giving n.DELTA.T which when divided by n gives the adjustment precision .DELTA.T.

Claims8

Dependent claims

Method for determining the adjustment precision .DELTA.T of an electronic timepiece having an oscillator, a frequency divider chain and an adjustment rate unit adapted to to vary the division rate of the divider chain comprising the steps of:

initially running the display at a rate n times higher than the normal rate with the adjustment unit disconnected;
measuring the real period TQ furnished by the oscillator at the output of the divider chain following a predetermined period T/n defining an adjustment cycle;
running the display a second time at a rate n times higher than the normal rate with the adjustment unit connected;
measuring the real period TQ furnished by the oscillator at the output of the divider chain following the same predetermined period T/n and corrected by the amount n.DELTA.T furnished by the adjustment unit to give a result TQ+n.DELTA.T;
calculating the difference in value of the two measurements to obtain n.DELTA.T;
and
dividing said difference n.DELTA.T by the factor n thereby to obtain the adjustment precision .DELTA.T.

4 more elements

Dependencies are inferred from the claim text.