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Publication numberUS3553957 A
Publication typeGrant
Publication dateJan 12, 1971
Filing dateFeb 12, 1969
Priority dateFeb 10, 1966
Also published asDE1673774A1, DE1673774B2
Publication numberUS 3553957 A, US 3553957A, US-A-3553957, US3553957 A, US3553957A
InventorsDome Peter, Luscher Jakob
Original AssigneeLuscher Jakob, Dome Peter
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electronic timepiece
US 3553957 A
Abstract  available in
Images(5)
Previous page
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Claims  available in
Description  (OCR text may contain errors)

ELECTRONIC TIMEPIECE Jan 32, in

5 Sheets-Sheet 1 Filed Feb. 12, 1969 8 Sec ELECTRONIC TIMEPIE'CE 5 Sheets-Sheet a Filed Feb; 12, 1969 UUUUUUUU VD 2O Jan. 1 2, 1971 R DQEETAL ELECTRONIC TIMEPIECE 5 Sheets-Sheet 5 Filed Feb. 12, 1969 ONQ United States Patent O T Int. ci. G04c 3/00 US. Cl. 58-23 4 Claims ABSTRACT OF THE DISCLOSURE An electronic timepiece comprises a time base delivering high frequency electric signals and electronic means for dividing this high frequency, and time-representing members, wherein a device is provided for correcting the time given by the time-representing members when the time does not correspond to that which it should actually be on the basis of a count of the signals of divided frequency issuing from the dividing means.

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part of our application Ser. No. 614,937, filed Feb. 9, 1967, which is now abandoned.

BACKGROUND OF THE INVENTION There are in existence electronic timepieces, e.g. clocks, pocket watches and even wrist watches, having an accuracy which is far greater than that achieved with time pieces which are purely mechanically operated or which are even electromechanically operated.

In some of these electronic timepieces, in particular clocks comprising a time base delivering time signals of well-defined frequency, and further comprising electronic means for dividing this frequency and time-indi eating means controlled by the signals of divided fre quency issuing from the frequency dividing means, accuracy is achieved with the help of a master-clock periodically connected up to the timepiece per se and of a zero resetting device driven by the master-clock and serving to modify the time given by the time-indicating means to agree with that given by the master-clock.

In other electronic timepieces, in particular light-weight transportable ones, such as pocket watches and wrist watches, accuracy is wholly dependent on the time base that is resorted to. There are in existence some exceptionally accurate time bases, e.g. quartz oscillators and tuning fork oscillators, which can readily be set to a desired constant frequency and whose steadiness of operation can be kept up notwithstanding quite substantial variations in temperature. In such timepieces, the greatest source of error is thus caused by defects associated with their time-indicating device.

In particular, when this time-indicating device includes an electromechanical converter controlled by the impulses issuing from the dividing means, the above defects are closely tied to the relative insensitiveness of the converter to the parasitic influences to which it can be subjected, e.g. acceleration and outside magretic fields.

Consequently, in an electronically operating timepiece having a time base delivering high frequency periodic signals, means for dividing this frequency and a time indicating device including such a converter, an improvement of its accuray is possible only if particular care is given to the construction of the time-indicating Patented Jan. 12, 1971 device and this cannot be achieved without resorting to highly skilled labour and to costly constructional techniques that are diflicult to put into eifect.

SUMMARY OF THE INVENTION The present invention seeks to obviate the various drawbacks mentioned above and provides an electronic timepiece comprising a time base delivering high frequency electric signals; electronic means for dividing said frequency which includes a succession of dividing stages; a time-indicating device which includes time-representing members and which is controlled by the signals of divided frequency issuing from the dividing means; and a timesetting device; wherein is provided a correcting device which includes means for periodically detecting any positional deflection of said time-representing members in relation to a reference position corresponding to that which these members should be occupying at the instant of detection on the basis of a count of the signals issuing from the dividing means, means for producing a signal indicative of the direction of said deflection, means for momentarily connecting the time-indicating device to an intermediate stage of said dividing means, when said indicative signal indicates a lag on the part of said timerepresenting members, thereby to accelerate the operation of said device to make up said lag, and means for momentarily interrupting all connection between the dividing means and the time-indicating device, when said indicative signal indicates a lead on the part of said time-representing members, thereby to cut out this lead through stoppage of said device.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a block diagram illustrating the principle of operation of an electronic timepiece according to the invention;

FIG. 2 is a plan view of the movement of the timepiece shown in FIG. 1, here assumed to be a wrist-watch;

FIG. 3 is a section along line III-III of FIG. 2;

FIG. 4 is an electric diagram of an electronic frequency divider for the timepiece shown in FIG. 1;

FIGS. 5, 6, and 7 are diagrams of three stages of the frequency divider shown in FIG. 5;

FIG. 8 is a plan view of an electromechanical converter of monostable type for the timepiece shown in FIG. 1;

FIG. 9 is an electric diagram of a control circuit for the converter shown in FIG. 8;

FIG. 10 shows a number of oscillograms for explaining the operation of the circuit represented in FIG. 9;

FIG. 11 is a functional diagram of a device for correcting the time indication given by the timepiece of FIGS. 1 to 3; and

FIG. 12 shows a number of oscillograms for explaining the operation of the device represented in FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENT The electronic watch, whose constructional features are visible in FIGS. 2 and 3, diagrammatically is as shown in FIG. 1. It comprises a quartz oscillator O which delivers a high frequency periodic signal V0 to an electronic divider DM Whose constructional details will be described later. This divider DM divides the relatively high frequency of the signals V0 which it converts into impulses of relatively low frequency, e.g. 1 c./s., to form signals V0 that are fed to a time-indicating device IT comprising an electromagnetic converter Rb, together with a control circuit ER therefor, and further comprising a train of three wheels s, m and h for driving hands As, Am and Ah for the seconds, minutes, and hours, respectively (FIG. 2). The illustrated watch comprises moreover a device GP for correcting the position of the train of wheels s, m, h. This device is connected to the divider DM, from which it periodically receives a checking Signal Sc, and to a detector cooperating with a wheel which is kinematically associated with the train s, m, h and supplying a signal SI indicative of the position of this wheel at the instant signal Sc is received. Moreover, device CP delivers a correction signal Scc to the converter Rb via its control circuit ER. The exact correction procedure, which consists in periodically moving the train s, m, h from its actual position to that it should have been occupying on the basis of a count of the periodic signals produced by oscillator since the previous correction operation, will be described in detail further on.

The oscillator O, the divider DM and the device IT are supplied with electric power of a source P (FIG. 1) consisting of two cells P1 and P2 connected in series (FIG. 2).

The electronic circuit OA of oscillator O, the electronic circuits EA, EB and EC of divider DM, the electronic circuit CC of correction arrangement CP, and the electronic circuit ER of converter Rb, were here all integrated and mounted on a common base Su, these circuits being suitably connected to one another and being further connected to cells P1 and P2, by electrical connections not shown.

:The quartz crystal Q of the oscillator is encapsulated, together with its electrodes, in a block of insulating material and is positioned beneath a winding Lo (FIGS. 2 and 3) forming an integral part of the oscillator. The oscillator circuit 0A may, for instance, be similar to that described in Canadian Pat. No. 791,946.

The electromagnetic converter Rb, the details of which will be described later, serves to drive, by alternate ratcheting engagement, a toothed wheel 1 (FIG. 2) on whose pin is keyed a pinion 2. meshing with a toothed disc 3. Disc 3 meshes with the second wheels and drives a pinion 4 meshing with the minutes wheel m.

This wheel m is solid with a tube 5 (FIG. 3) which is rotatably mounted on the pin 6 of wheel s and whose lower end broadens out to form a pinion 7 meshing with the hours wheel h, through the intermediary of a toothed disc 8, a pin 9 and a pinion 10.

Time setting of the illustrated watch by the user can be done by means of a device MH which acts on the disc 8 and which can be operated from the outside of the watch by suitable actuating means not shown.

As already mentioned, the illustrated watch comprises moreover a device CP for correcting the position of the train of wheels s, m, h, and this device is wholly independent of the above referred to time setting device MH. FIGS. 2 and 3 show, in addition to the electronic circuit CC, the electromechanical components of device CP, i.e. a checking disc k mounted on a pivotal pin 11 and rotated, via a transmission not shown, off the watch wheel train so as to carry out one revolution every sixtyfour seconds. On its periphery, disc k defines a pair of lugs v1 and v2 forming two mobile electrodes which alternately pass, twice every sixty-four seconds, opposite two stationary electrodes sel and se2 which are connected to circuit CC in a manner to be described later. Another electrode q, intended to form a capacitive coupling with disc k, is secured to the support Su, at a small distance from this disc, so as permanently to overlap a portion thereof.

The oscillator 0 comprises a resonator having a particularly high quality factor, here an At cut quartz. This quartz has a particularly high frequency, here a frequency of 5 mc./s. By way of modification, the oscillator could of course include a resonator of a dilferent type, such as an acoustic vibrator of the tuning-fork kind.

The frequency divider shown in FIG. 4 comprises twenty-one stages of three different types, EA (FIG. 5), EB (FIG. 6), and EC (FIG. 7), in particular a first stage EA1 for dividing high frequency signals, ten stages BB2 to EB11 for dividing high and medium frequency signals, and ten stages EC12 to EC21 for dividing low frequency signals.

As is apparent from FIG. 4, stage EA1 comprises two inputs el and f1 which are respectively connected to the negative pole of source P, via a resistor R, and to the output s of the oscillator 0. Stage EA1 further comprises two outputs b1 and 01 which are respectively connected to the gates of two transistors Td1 and Td2 which are connected in series to the poles of source P and which form a decoupling circuit. The output of this decoupling circuit is connected, on the one hand, to the input, f2, of the following stage BB2 and, on the other hand, to a supply line LA. The ten stages EBZ to EB11, which are all of the type shown in FIG. 6, comprise each an output, respectively d2 to dll, and are separated by a decoupling circuit consisting of three transistors Td3, Td4 and Td5, and of a capacitor Cd3. As will be observed in FIG. 4, Td3 and Cd3 are connected in series to the supply line LA and Td4 and Td5 are connected in series to source P. The outputs d2 to d11 of stages BB2 to EB11 are moreover connected to the gates of transistors Td3 and Td5 of the decoupling circuit associated with the following EB stage. A second supply line LA is connected to the input of stage EB11.

The ten stages EC12 to EC21, which are all of the type shown in FIG. 7, comprise each a first input, respectively g12 to g21, connected to supply line LA and a second input, respectively -]12 to 21, connected to the output of a decoupling circuit separating each EC stage from the preceding stage. Each of the decoupling circuits preceding stages EC13 to EC21, as well as an identical decoupling circuit following stage EC21 comprises two transistors Tdfi and Td7 each connected, in series with a capacitor Cd6 and Cd7, respectively, to the line LA, the gate of Td7 being connected to the output of Td6 and the gate of Td6 being connected to the output, a12 to (121, respectively of the preceding EC stages. As for the decoupled circuit separating stage EB11 from stage EC12, it only comprises a capacitor Q16 and a transistor Td6.

The operation of each type of dividing stage EA, EB and EC, illustrated in FIGS. 5 to 7, is already described in detail in the specification of Canadian Pat. No. 791,946 and in the specification of US. Pat. No. 3,383,570 and will not therefore be repeated here. Suflice it simply to say that with stage EA1 (FIG. 5) the frequency of the voltage impulses delivered at the output terminal c1 is one fourth the frequency of the input signals Vo received from the oscillator O at input 7'1; with the EB and EC stages the frequency of their input signal is divided by two.

The operation of the FIG. 4 divider as a whole is practically identical to that of the divider described in the above mentioned patent specification to which reference should be made for further particulars. Be it simply stated that the FIG. 4 divider delivers at its output one signal per second (F =1 c./s.) and that this signal is used, as described, to control the electromechanical converter of the timepiece, which converter serves to drive the gear train s, m, h and the hands associated therewith. This converter is represented in FIG. 8 in the form of a monostable relay driving one of the gears of the train; by way of variant it can also consist of a bistable relay or even of a stepping motor.

The FIG. 8 relay, which is of the monostable type, comprises a mobile armature consisting of an anchor 12 which is carried by a pin 13 pivotally mounted in the base of the movement (FIG. 3) and which alternately engages, by means of bladees 13a and 13b, the teeth of wheel 1. The shank of anchor 12 carries two small plates 14s and Mn consisting of permanent magnets so oriented as to form a single magnetic circuit. This relay also comprises an energizing winding R6, forming a thin, fiat member, and a magnetic stop 15 defining the only stable position for anchor 12 when current flow of the winding R6 is interrupted, this position being attained under the action of the pull exerted by the magnetic leakage flux and tending to reduce the air gap between stop and magnet 1412 to a minimum.

The described relay is conctrolled by the FIG. 9 circuit which includes the above mentioned winding R6 and which is connected to the FIG. 4 divider at the output a21 of stage EC21 and at point b" of stage EC, this latter point being indicated in FIG. 7 and being identified as 1120 in'FIG. 9.

The relay control circuit comprises, in addition to the winding R6, two transistors Te1'6 and Te17 which are series connected to source -P and a third transistor Tel8 which is connected to this same source P in series with the winding R6 and whose gate is connected to the point of interconnection between Tel6 and Te17. A capacitor Cell is connected in parallel with Te16.

The operation of the FIG. 9 circuit will now be described with reference to the FIG. 10 oscillograms respectively showing the evolution of the following voltages:

Vg'the voltage in the general supply line LA for the EC stages of the divider shown in FIG. 4;

Vfl9--the voltage at the input terminal 1 of the divider stage E'Cl9;

V1119, V1120 and Va2l-the voltages at the output of the first transistor (Tel, point a", FIG. 7) of the divider stages EC19, EC20 and EC21 respectively;

Vb20-the voltage at point b (FIG. 7) of the divider stage EC20;

Vm-the voltage at point In of the FIG. 9 circuit; and

Vi-the voltage at point z of the FIG 9 circuit.

In the case illustrated in FIG. 10, it was assumed that the voltage impulses required to actuate the relay, i.e. Vi, had to have the same frequency as signal Va21 at the output of the divider, but had to be eight times longer in duration than the impulses of the general supply voltage Vg'. That is why the gate of transistor Te17 is connected to point b" of stage EC20, and that of transistor Te16 is connected to the output terminal a2l of stage EC21.

The impulses of signal Vb20 render Tel7 conductive and thus enable capacitor Cell to be charged by source P. The control voltage of Tel8 is thus practically nil and Tel8 consequently remains blocked. When the impulses of signal Va2l appear there are no signal V1220 impulses (see FIG. 10) at the gate of Tel7 which ceases to be conductive; capacitor Cell then discharges through Te16 since the latter is conductive. Provided the duration of the control impulse for Tel6 (signal Va21) is sufficiently long for Cell discharge Within the desired time limits, Tel8 will become conductive and current will thus be able to flow through the relay actuating winding R6. Cell will remain discharged until the appearance of the next signal Vb20 impulse, which impulse causes Cell to be charged again and hence Tel8 to be blocked; no current can then flow through winding R6;

As mentioned earlier, the described watch includes a device CP for correcting the position of the train of wheels (FIG. 1) and the electromechanical features of this device have already been described with reference to FIGS. 2 and 3.

This device operates as follows: the position of the wheel train is periodically detected by means of a signal produced by additional dividing stages connected to the output terminals of the FIG. 4 divider and a check is then made to determine whether or not the detection signal coincides with a reference signal corresponding to the position that the wheel train should in fact be occupying were the relay driving the wheel train correctly. Should a positional error be detected, a correction circuit comes to act on the time indicating device to correct its position and thus avoid any accumulation, over a long period of time, of counting errors. These positional errors of the wheel train may be due, for instance, to parasitic accelerations or to the influence of outside magnetic fields, causing incorrect actuation of the relay armature.

A suitable correcting device is shown in FIG. 11. In this figure is to be found again the checking disc k which is so driven by the wheel train of the watch as to carry out one revolution every 64 seconds. As stated previously, disc k is provided at its periphery with two diametrically opposite radially-projecting lugs v1 and v2 which form two mobile elesctrodes intended to cooperate with two stationary electrodes sel and se2.

These stationary electrodes sel and se2 extend over an angular distance which corresponds at least to two successive intermittent displacement of disc k and are each connected to a capacitor and to a transistor mounted in series, i.e. C12 and T19, and C13 and T20, respectively.

Between each stationary electrode, respectively sel and' se2, and the associated capacitor, respectively C12 and C13, the circuit comprises an ohmic contact, respectively j1 and 2, which is formed on a p-type zone diffused into an n-type base and which determines the potential of the corresponding circuit section. As may be seen from FIG. 11, the gate of transistor T19 is connected to contact '2 and the gate of transistor T20 is connected to contact jl.

FIG. 11 also shows several frequency dividing stages, to wit EC20 to EC26, of which stages EC20 and EC21 are, here, the last two stages of the divider shown in FIG. 4. The five additional stages EC22 to EC26 serve to divide the repetition frequency of l c./s. at the output a21 of stage EC21 to a frequency of A c./s. at the output a26 of stage EC26. Stages EC22 to EC26 are also each provided with a decoupling circuit of the type shown in FIG. 4, but these circuits have been omitted from FIG. 11 in order to simplify the drawing.

The correcting circuit further comprises two transistors T21 and T22 respectively connected, in series with capacitors C14 and C15 respectively, to the output terminals a20 and a21 of the last two stages (EC20 and EC21) for the divider. The gates of T21 and T22 are respectively connected to the outputs of T20 and T19. This circuit moreover includes an actuating circuit R6, T26, C16, T24, T23 for the monostable relay Rb, which actuating circuit corresponds to that shown in FIG. 9. The gate of T23 is connected to the output [220 of stage EC20 whereas the gate of T24 is connected to the output of T22. A transistor T25 is connected, in parallel with C16, between the negative pole of source P and the input of T26. The circuit furthermore comprises a transistor T27 connected, in series with a capacitor C17, to the output of stage EC20, the gate of T27 being connected to the output of T21 and the output of T27 being connected to the gate of T25. In addition, the circuit comprises a transistor T29 connected, in series with a capacitor C18, to the source P, the output of T29 (point 0) being connected to the electrode q (FIGS. 2 and 11). A transistor T28 is connected between the negative pole of source P and point 0, the gate of T28 being connected to the output a26 of additional dividing stage EC26. As is apparent from FIG. 11, a capacitor C19 is connected between the negative pole of source P and the gate (point n) of T29. Further, two transistors T30 and T31 are connected, in series, to source P, the output of T31 being connected to the gate of T29. The circuit finally comprises a transistor T32 connected, in series with a capacitor C20, to the output a21 of divider stage EC21, the output of T32 being connected to the gate of T30, whereas the gates of T31 and T32 are connected to the output a26 of stage EC26.

Positional checking of the wheel train is carried out at time intervals of thirty-two seconds through the intermediary of a signal Vq supplying the coupling electrode q, and the duration of this signal determines the detection and correction period.

It will now be explained how this signal Vq is obtained. For this, it will be assumed that, upon impulses of signals Va21 and Va26 being simultaneously emitted by the respective dividing stages (FIG. 12), capacitor C18 is charged, capacitor C19 is discharged, transistor T29 is open, so that electrode q is at zero potential (Vq=), and transistors T28,T30, T31 and T32 are blocked.

When an impulse of signal Va26 appears in synchronism with an impulse of signal Va21, transistors T28, T31 and T32 become conductive so that:

(1) Capacitor C18 discharges thus causing point 0 and electrode q to drop to the same negative potential as source P (formation stage of the front of an impulse Vq, FIG. 12);

(2) The signal Va21 impulse is earthed via transistor T32, transistor T30 remains blocked and capacitor C19 can be charged by the current flowing through transistor T31; and

(3) Once capacitor C19 is charged, point n acquires zero potential and transistor T29 becomes blocked.

As soon as this impulse of signal Va26 ends, transistors T28, T31 and T32 become blocked again and the circuit for forming signal Vq remains in this condition, with capacitor C18 discharged and capacitor 019 charged, until the arrival of the next impulse of signal Va21, one second after the first, to which there will obviously be no corresponding impulse of signal Va26 since the latter has a lesser frequency in fact thirty-two times less.

This means that:

(1) Capacitor C19 discharges; and

(2) Transistor T29 becomes blocked again, the potential at point 0 becomes zero and capacitor C18 becomes charged so that electrode q, which had been kept at the negative potential of source P, is now raised to zero potential.

The alternate charging and discharging of capacitors C18 and C19 thus enables the production of a voltage impulse to form signal Vq, which impu se has a duration corresponding to the repetition period of the impulses of signal Va21, in this instance one second, the repetition period of the signal Vq impulses corresponding to that of the signal Va26 impulses, i.e. thirty-two seconds in the described embodiment.

During assembly of the watch, disc k is positioned in an angular position such that the mobile electrodes v1 and v2 will overlap the stationary electrodes sel and se2 when electrode q receives a signal Vq impulse (axis Z1Z1). If the wheel train is correctly driven by the re lay, i.e. if disc k does in fact carry out one revolution every sixty-four seconds electrode q will be receiving two signal Vq impulses per revolution of the disc, to wit one when the mobile electrodes of disc k come to occupy the illustrated position and a second when these electrodes will have moved on through 180.

If disc k is assumed to be rotating in an anti-clockwise direction, and if its electrodes v1 and v2 should happen to be lying on axis Z2Z2 when electrode q receives a signal Vq impulse, this would mean that the wheel train is leading in relation to reference position Z1Z1, i.e. the position the wheel train should be occupying on the basis of a count of impulses Vm received \by relay Rb.

But it the electrodes v1 and v2 of disc k should happen to by lying on axis Z3-Z3 when electrod q receives a signal Vq impulse, this would mean that the wheel train is lagging in relation to reference position Z1Z1.

It will now be explained how the position of disc k can be detected when a checking impulse Vq reaches electrode q and how the correcting device of the watch reacts to this detection.

(A) CORRECT WORKING OF THE WATCH Disc k is assumed to be occupying the position shown in FIG. 11. Thus, when a signal Vq impulse is capacitively received from electrode q, it will be retransmitted, capacitively also, to the stationary electrodes se1 and se2. The gates of transistors T19 and T20, respectively connected to contacts 12 and jl, thus receive a negative potential and these transistors then become conductive. Consequently, capacitors C12 and C13 become charged and the potential of gates of transistors T21 and T22 becomes zero so that these transistors remain blocked.

Since T21 is blocked, the impulses of signal Va20, coming from output of stage EC20, can reach the gate of T27 and the latter, through having become conductive, prevents these self-same impulses from reaching the gate of T25 so that this latter transistor remains blocked.

The impulses of signal Va21 and those of signal Vb20 can thus freely supply the control circuit of relay Rb which produces signal Vmv and which is made up of tran sistors T23, T24 and T 26 and of capacitor C16 as already described. The monostable relay is thus driven in the required manner.

(B) THE WHEEL TRAIN OF THE WATCH COMES TO BE LEADING Should the wheel train of the watch comes to be leading, disc k would come to lie for example, in a position such that its electrodes v1 and v2 are in alignment with axis Z2Z2. In fact, any position in which stationary electrodes se2 is no longer overlapped by one or other of electrodes v1 and v2 indicates a lead. This lead is, however, only detectable when one of these mobile electrodes lies opposite stationary electrode sel. In such a position of disc k, a signal Vq impulse of negative potential is then capacitively transmitted only to stationary electrode sel and hence to contact jl.

During the time intervals between the signal Vq impulses, capacitors C12 and C13 discharge through the p-n junctions of contacts jl and i2 and can become charged again when the associated transistors T19 and T20 are conductive.

Since mobile electrode v2 lies remote from stationary electrode se2, signal Vq impulse can reach neither junction j2 nor the gate of transistor T19 so that this latter transistor remains blocked and capacitor C12 remains in a discharged condition. This means that this signal Vq impulse can reach the gate of transistor T22 to unblock the latter whereas transistor T21 remains blocked because of the absence of any voltage at its gate owing to transistor T20 being unblocked by the signal Vq impulse.

Since transistor T22 is open, the signal Va21 impulses cannot reach transistor T24 which remain blocked.

The impulses of signal Va20 cannot reach transistor T25 via capacitor C17 becomes at that instant transistor T27 is open, this open state of T27 being due to the fact that its gate is receiving these same signal Va20 impulses via capacitor C14, transistor T21 being blocked.

This means that capacitor C16 remains discharged and that the control circuit of relay Rb cannot operate since the gate of transistor T26 remains at zero potential thereby not enabling this transistor to be unblocked for current to flow through to the winding R6 of the relay.

In this way a relay actuating impulse Vm can be cut out to enable the accidental lead that has been taken by the wheel train and that has been detected to be wiped out.

(C) THE WHEEL TRAIN OF THE WATCH COMES TO BE LAGGING Should the wheel train of the watch come to be laging, disc k would come to lie, for example, in a position such that its electrodes v1 and v2 are in alignment with axis Z3Z3. In fact, any position in which stationary electrode sel is no long overlapped by one or other of electrodes v1 and v2 indicates a lag. This lag is, however, only detachable when one of these mobile electrodes lies opposite electrode se2. In such a position of disc k, a signal Vq impulse of negative potential is then capacitively transmitted only to stationary electrodes se2 and hence only to contact j2.

As before, capacitor C12 and C13 discharge through the p-n junctions to points '1 and 12 during the time intervals between the signal Vq impulses, these capacitors only being rechargeable when their associated transistors T19 and T20 are conductive.

Since mobile electrode v1 lies remote from stationary electrode sel. Vq impulse can reach neither junction '1 nor the gate of transistor T20 so that this latter transistor remains blocked and capacitor C13 remains in a discharged condition. This means that this signal Vq impulse can reach the gate of transistor T21 to unblock the latter whereas transistor T22 remains blocked because of the absence of any voltage at its gate owing to transistor T19 being unblocked by the signal Vq impulse.

Since transistor T22 is blocked, the signal Va21 impulses can reach transistor T24 which then becomes conductive in phase with these impulses.

Since, moreover, transistor T21 is conductive throughout the duration of the signal Vq impulse, the signal Va20 impulses cannot reach transistor T27 as long as electrode q is receiving signal Va impulses so that this transistor T27 remain blocked. This means that these same signal Va20 impulses can then reach the gate of transistor T25, via capacitor C17, which transistor is thusalternate- 1y opened and closed at the frequency of the signal Va20 impulses.

As may be seen from the FIG. 11 diagram, transistor T25 is placed in a position equivalent to that of transistor T24, i.e. in parallel with capacitor C16, so that it can, upon being opened, cause the discharge of the latter in the same way that transistor T24 can upon becoming conductive.

Since the impulses of signal Va20 have a frequency twice that of the impulses of signal Va21 and since this latter signal is derived from the first, the two signals are consequently in phase (FIG. 12).

When the impulses of these two signals Va20 and Va21 appear simultaneously, transistors T24 and T25 become conductive at the same time also and cause capacitor C16 to discharge under conditions practically identical to those that prevail when only one of these transistors is conductive. The relay is actuated quite normally by a signal Vm" impulse having characteristics very similar to those of the signal Vm impulses being produced at a frequency of 1 c./s. when the watch is working correctly.

When the other signal Va20 impulses appear, stage EC21 produces no signal V1121 impulses so that only transistor T25 becomes conductive. This results in the production of an additional relay-actuating signal Vm impulse, which impulse is thus fitted in between two normal relayactuating signal Vm impulses.

One impulse has thus been added to the 1 c./s. impulse train and this extra impulse makes it possible to correct the position of the wheel train by an amount corresponding to the pitch thereof.

The device for correcting the position of the wheel train, whose characteristic features have just been described, thus enables a relay-actuating impulse to be cut out or to be added in order to make up for a lead or a lag detected by the Wheel train coincidence discriminator in the course of each checking period, which period corresponds to the length of time a signal Vq impulse is applied to electrode q.

According to a modified constructional form which has not been illustrated, the disc k that is visible in FIG. 11 could be provided with only one mobile electrode v and the stationary electrodes sel and se2 could then be arranged on opposite sides of a common axis at a distance therefrom corresponding substantially to half the width of electrode v. This axis constitutes the reference position in which electrode v should come to be located periodically, i.e. at the frequency of the signal Va26 impulses, if the time given by the watch is accurate, i.e. if this indication effectively corresponds to the count made by relay Rb of the signal Va21 impulses that have issued from the divider.

In such an event, a signal Vq impulse that has capacitively been transmitted to the mobile electrode v could be passed on neither to the stationary electrode sel, nor to the stationary electrode se2. This means that the relayactuating circuit Rb is being normally supplied with signal V1121 impulses.

1f mobile electrode v receives a signal Vq impulse before reaching this reference position or when it has al ready moved past it, this indicates that the wheel train is lagging or leading, as the case may be, in relation to the exact position it should be occupying at that instant. In the first case, mobile electrode v lies opposite only stationary electrode se2 and in the second case it lies opposite only stationary electrode sel. Consequently, a correction signal Vq impulse is capacitively transmitted to only one of these electrodes as was the case in the FIG. 11 construction. A lead or a lag that has been detected in this way can be corrected by means of an electronic arrangement similar to that illustrated in this figure and in a similar manner.

It may further be added that, in order for the control voltages for transistors T21 and T22 to be maintained for relatively long checking periods, it would be possible to modulate signal Vq by means of a high frequency signal which is for instance taken from the output of one of the divider stages EB2 to EB11 (FIG. 4), and to use this modulated signal to perform periodic recharging of the input capacitance of these transistors by means of a suitable circuit, e.g. similar to that formed by the transistors Tc3 and T05 and by the capacitor C03 in the EC stage illustrated in FIG. 7.

Although, in the foregoing description, reference has only been made to the possibility of checking and correcting, in an electronic watch, the way in which a wheel train driven by a monostable relay is working, the above described principles are clearly also applicable to watches having a bistable relay or even an electromechanical converter of any other kind provided that the electronic circuits of the watch, which enable, in particular, control of the converter and correction of its operation, are adapted to suit the particular manner of operation of the converter that is resorted to.

What is claimed is:

1. An electronic timepiece comprising a time base delivering high frequency electric signals; electronic means for dividing said frequency which include a succession of dividing stages; a time-indicating device which includes time-representing members and which is controlled by the signals of divided frequency issuing from the dividing means; and a time-setting device; wherein is provided a correcting device which includes means for periodically detecting any positional deflection of said time-representing members in relation to a reference position corresponding to that which these members should be occupying at the instant of detection on the basis of a count of the signals issuing from the dividing means for producing a signal indicative of the direction of said deflection, means for momentarily connecting the timeindicatiug device to an intermediate stage of the dividing means, when said indicative signal indicates a lag on the part of said time-representing members, thereby to accelerate the operation of said device to make up said lag, and means for momentarily interrupting all connection between the dividing means and the time-indicating device, when said indicative signal indicates a lead on the part of said time-representing members, thereby to cut out this lead through stoppage of said device.

2. A timepiece as claimed in claim 1, wherein said correcting device further includes a first information channel for receiving said indicative signal when it indicates a lead on the part of said time-representing members, and a second information channel for receiving said indicative signal when it indicaties a lag on the part of said timerepresenting members, wherein said connecting means include a first electronic switch associated with said first channel and adapted to be controlled by the signal travelling along said first channel, and wherein said interrupting means include a second electronic switch associated with said second channel and adapted to be controlled by the signal travelling along said second channel.

3. A timepiece as claimed in claim 2, wherein said detecting means include a source delivering checking signals having a frequency less than that of the signals issuing from said dividing means, first and second stationary electrodes respectively connected to said first and second information channels and disposed on opposite sides of a geometrical axis defining said reference position, said stationary electrodes serving to detect the possible presence of at least one mobile electrode kinematically associated with said time-representing members and arranged to travel along a circular path past said stationary electrodes and to receive said checking signals from said source, the initial angular position of said mobile electrode and the speed at which it moves being so selected that, each time said source delivers a checking signal, said mobile electrode comes to be located in said reference position when the time shown by said timerepresenting members is the same as that it should actually be on the basis of said count of the signals of divided frequency issuing from said dividing means, and comes to be located ahead of, respectively behind, said reference position, opposite a corresponding one of said stationary electrodes, when the time shown by said time-representing members is fast, respectively slow, in relation to the time corresponding to said count of the signals issuing from said dividing means.

4. A timepiece as claimed in claim 2, wherein said detecting means include a source delivering checking signals having a frequency less than that of the signals issuing from said dividing means, said source being connected with a pair of diametrically opposite electrodes carried by a rotary support which is kinematically associated with said time-representing members and which is arranged to rotate through 180 during the time interval between two successive checking signals when the time shown by said time-representing members is the same as that it should actually be on the basis of said count of the signals of divided frequency issuing from said dividing means, and to rotate though more, respectively less, than when said time-representing members indicate a lead, respectively a lag, in relation to the time corresponding to said count of the signals issuing from said dividing means, said detecting means further including, for detecting the position of said mobile electrodes, first and second stationary electrodes which are respectively connected to said first and second information channels and which extend, along the circular path followed by said mobile electrodes, each over a length corresponding to at least two successive intermittent displacements on the part of said mobile electrodes and in a relative position such that the leading end of said first stationary electrode, in relation to the direction of rotation of said support, lies diametrically opposite the trailing end of said second stationary electrode, and wherein said rotary support is initially angularly so positioned that, during rotation, said mobile electrodes carried thereby come to face each a corresponding one of said stationary electrodes upon receiving said checking signal, when the time shown by said time-representing members is the same as that it should be on the basis of said count of the signals of divided frequency issuing from said dividing means, this relative position of said mobile and stationary electrodes corresponding to said reference postion, and that only one of said mobile electrodes comes to face a particular one of said stationary electrodes, ahead of or behind said reference position, when said checking signal reaches said mobile electrodes, depending on whether said time-representing members show a lead or lag in relation to the correct time.

References Cited UNITED STATES PATENTS 3,479,812 11/1969 Kramer 58-25 RICHARD B. WILKINSON, Primary Examiner E. C. SIMMONS, Assistant Examiner US. Cl. X.R. 5 8-24

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3742697 *Jul 27, 1971Jul 3, 1973Suwa Seikosha KkDriving arrangement for an electric watch
US3756014 *May 18, 1971Sep 4, 1973Timex CorpSynchronized quartz crystal watch
US3757510 *Jul 3, 1972Sep 11, 1973Hughes Aircraft CoHigh frequency electronic watch with low power dissipation
US3778999 *Dec 13, 1972Dec 18, 1973Girard Perregaux SaElectronic wristwatch
US3783600 *Jul 27, 1972Jan 8, 1974Junghans Gmbh GebElectromechanic driving mechanism for the hands of a timepiece
US3787715 *Aug 30, 1972Jan 22, 1974Rca CorpControl circuit employing digital techniques for loads such as balance wheel motors
US3789599 *Oct 20, 1972Feb 5, 1974Suisse Pour L Ind Horlogere SaCorrection of errors occurring in electronic timepieces
US3800523 *Jul 27, 1971Apr 2, 1974Suwa Seikosha KkQuartz crystal wrist watch
US3855781 *Dec 21, 1973Dec 24, 1974Suwa Seikosha KkStep motor mechanism for electronic timepiece
US3922844 *Apr 25, 1974Dec 2, 1975Suwa Seikosha KkElectronic timepiece
US3948036 *Dec 13, 1974Apr 6, 1976Citizen Watch Co., Ltd.Electronic timepiece
US3967442 *Jul 14, 1975Jul 6, 1976Berney Jean ClaudeElectric watch having an electromechanical movement including a correction mechanism for small errors
US3998043 *Nov 25, 1974Dec 21, 1976Citizen Watch Co., Ltd.Electric timepiece for displaying the operating condition thereof
US4178520 *Jun 7, 1978Dec 11, 1979Ebauches S.A.Binary frequency divider stages
US4300223 *Dec 13, 1978Nov 10, 1981Ebauches Electroniques SaSystem for making-up steps lost by the motor of a time-piece
US4348752 *Jun 10, 1980Sep 7, 1982Eta A.G. Ebauches-FabrikElectronic watch with movable detecting member
USRE30588 *Dec 14, 1978Apr 21, 1981Citizen Watch Co. Ltd.Electric timepiece for displaying the operating condition thereof
Classifications
U.S. Classification368/187, 968/491, 377/121, 377/105, 968/446, 968/564, 968/902, 368/201
International ClassificationG04G3/02, G04C17/00, G04C3/14, G04C3/00, G04G3/00
Cooperative ClassificationG04C3/143, G04C3/00, G04G3/02, G04C17/00
European ClassificationG04C3/00, G04G3/02, G04C3/14B, G04C17/00