Correction of errors occurring in electronic timepieces

Claim 2

A timepiece indicator gear train having a rotatable element and means for sensing the angular position of said element, said means comprising: relatively movable electrode surfaces which have a first relative position in which a movable one of said surfaces lies against another of said surfaces; a dielectric layer provided on one of said electrode surfaces; biasing means which urge said electrode surfaces to said first relative position; a coupling portion of said gear train; and a coupling portion of said one of said electrode surfaces for co-operation with said coupling portion of said gear train to cause said electrode surfaces to be periodically moved apart against the action of said biasing means during rotation of said element of said gear train.

Claim 3

A gear train as claimed in claim 1, wherein said biasing means are resilient biasing means.

Claim 4

A gear train as claimed in claim 1, wherein said coupling portion of said one of said electrode surfaces is an entrainment finger, said another of said electrode surfaces being fixed and said one electrode surface being movable relative to said another electrode surface by actuation of said entrainment finger.

Claim 5

A gear train as claimed in claim 1, wherein said rotatable element comprises at least one projection which is disposed eccentrically with respect to the axis of rotation of the rotatable element, said rotatable element being rotatable to periodically abut said coupling portion of said one electrode surface thereby periodicAlly to move said electrode surfaces apart against the action of said biasing means during rotation of said element.

Claim 6

A gear train as claimed in claim 1, wherein said another of said electrode surfaces is provided by a fixed member comprising a first plurality of vanes extending radially about an axis and said one of said electrode surfaces is provided by a pivotable member which is pivotable about said axis and which comprises a second plurality of vanes which extend between said first plurality of vanes such that said biasing means urge said second plurality of vanes into contact with said first plurality of vanes with interposition of said dielectric layer between said first and second pluralities of vanes.

Claim 7

A gear train as claimed in claim 1, wherein said surface upon which is provided said dielectric layer is of aluminium, and said dielectric layer itself comprises an oxide of aluminium.

Claim 8

An electronic timepiece comprising: a. a timepiece indicator gear train having a rotatable element and means for sensing the angular position of said element, said means comprising: relatively movable electrode surfaces which have a first relative position in which a movable one of said surfaces lies against another of said surfaces; a dielectric layer provided on one of said surfaces; biasing means which urge said electrode surfaces to said first relative position; a coupling portion of said gear train; and a coupling portion of said one of said electrode surfaces for co-operation with said coupling portion of said gear train to cause said electrode surfaces to be periodically moved apart against the action of said biasing mean during rotation of said element of said gear train; b. electrically operable drive means coupled to said gear train; c. a time base coupled to said drive means to operate said drive means in dependence upon periodic signals issued by said time base at a predetermined frequency; and d. an error detector circuit coupled to said means for sensing the angular position of said element and also to said time base, said error detector circuit being operable to detect error in the angular position of said element in dependence upon a comparison between signals dependent upon said timebase and signals from said means for sensing the angular position of said element.

Claim 9

An electronic timepiece comprising: a. a timepiece indicator gear train having a rotatable element and means for sensing the angular position of said element, said means comprising: relatively movable electrode surfaces which have a first relative position in which a movable one of said surfaces lies against another of said surfaces; a dielectric layer provided on one of said surfaces; biasing means which urge said electrode surfaces to said first relative position; a coupling portion of said gear train; and a coupling portion of said one of said electrode surfaces for co-operation with said coupling portion of said gear train to cause said electrode surfaces to be periodically moved apart against the action of said biasing mean during rotation of said element of said gear train; b. electrically operable drive means coupled to said gear train; c. a time base coupled to said drive means to operate said drive means in dependence upon periodic signals issued by said time base at a predetermined frequency; and d. an error detector circuit coupled to said means for sensing the angular position of said element and also to said time base, said error detector circuit being operable to detect error in the angular position of said element in dependence upon a comparison between signals dependent upon said timebase and signals from said means for sensing the angular position of said element.

Claim 10

An electronic time piece as claimed in claim 7, including a source for issuing periodic signals at a sub-multiple of the frequency of, and in synchronism with, said time base; said source coupling the said time base to said drive means and to said error detector circuit.

Claim 11

An electronic time piece as claimed in claim 8, wherein said source is constituted by at least one frequency demultiplier stage.

Claim 12

An electronic time piece as claimed in claim 7, wherein said biasing means are resilient biasing means.

Claim 13

An electronic time piece as claimed in claim 7, wherein said coupling portion of said one of said electrode surfaces is an entrainment finger, said another of said electrode surfaces being fixed and said one electrode surface being movable relative to said another electrode surface by actuation of said entrainment finger.

Claim 14

An electronic time piece as claimed in claim 7, wherein said rotatable element comprises at least one projection which is disposed eccentrically with respect to the axis of rotation of the rotatable element, said rotatable element being rotatable to periodically abut said coupling portion of said one electrode surface thereby periodically to move said electrode surfaces apart against the action of said biasing means during rotation of said element.

Claim 15

An electronic time piece as claimed in claim 7, wherein said another of said electrode surfaces is provided by a fixed member comprising a first plurality of vanes extending radially about an axis and said one of said electrode surfaces is provided by a pivotable member which is pivotable about said axis and which comprises a second plurality of vanes whIch extend between said first plurality of vanes such that said biasing means urge said second plurality of vanes into contact with said first plurality of vanes with interposition of said dielectric layer between said first and second pluralities of vanes.

Claim 16

An electronic time piece as claimed in claim 7, including correcting means for correcting any error detected by said error detector circuit.

Claim 17

An electronic time piece as claimed in claim 14, wherein said correcting means includes means for preventing periodic drive signals being fed to said drive means in the event that said error is an advance.

Claim 18

An electronic timepiece as claimed in claim 14, wherein said correcting means includes means for feeding additional periodic drive signals to said drive means in the event that said error is a lag.

Claim 19

An electronic time piece as claimed in claim 7, wherein said surface upon which is provided said dielectric layer is of aluminium, and said dielectric layer itself comprises an oxide of aluminium.