GB2027235A - Improvements in or relating to electronic analog timepieces - Google Patents

Abstract

An electronic analog timepiece has displayed time correction means comprising manually operable means for correcting the hour and minute hand positions and stopping the advance of the second hand during such correction, means for memorising the time taken for such correction, manually operable means, operable after such correction, for causing the second hand to advance again and means for automatically causing the last mentioned advance of the second hand to be at a rate which is high relative to the normal timekeeping rate for a time corresponding with the memorised time and thereafter to advance at the normal timekeeping rate. In Fig. 4(1) is a crystal controlled time standard oscillator followed by a multistage divider (2) providing signals for a drive circuit (3) driving a stepping motor (4) driving a time display (6) with hour minute and second hands through a gear train (5). (7) is a stem operated switch the signals from which are passed to a timing counter (8) and (9) is an up/down counter counting up signals produced while the second hand is stopped for correction of the hour and minute signals and counting down signals of a higher frequency after such correction is finished. <IMAGE>

Description

SPECIFICATION Improvements in or relating to electronic analog timepieces This invention relates to electronic analog timepieces and more particularly, though not exclusively, to so-called quartz crystal motor driven analog watches. The invention is concerned with the provision of the means for effecting displayed timesetting or correction in an electronic analog timepiece and seeks to provide a satisfactory solution of a problem which arises with such means, namely the problem of ensuring that the position of the second hand is not disordered by a displayed time correcting or setting operation but is automatically made correct after such an operation is performed.

In a conventional quartz crystal analog watch having a time standard quartz cyrstal oscillator, a frequency divider fed with output from said oscillator and a driving circuit providing driving signals to an electro-mechanical transducer (usually a stepping electric motor) driving time display members including an hour hand, a minute hand and a second hand through a gear wheel train, correction of the time displayed is effected by means of an externally operable member such as a stem with a knurled knob on the end. A common arrangement is shown in Fig. 1. Here the stem 7 has three longitudinal positions indicated by the references 7 a, 7b and 7c. In the most inward position, 7a, rotation of the stem performs no function-this is a neutral position.When the stem is pulled out to the intermediate or second position 7bthe date or day of the week can be changed, the date by rotating the stem in one direction and the day by rotating the stem in the opposite direction, the watch still continuing or run normally.

When the stem is pulled out to its outermost position, 7 c, the second hand is stopped and rotation of the knob moves the hour and minute hands to correct the time, rotation in one direction advancing these hands and rotation in the other moving them back. The usual arrangement is such that, when the stem 7 is pulled out to its third position 7c, a second setting lever cooperating with the stem so controls the gear wheel train and the second hand as to slip or effectively disconnect part of the gear wheel train and put said train into a condition for allowing it to be used for time setting, said second setting lever at the same time contacting with a pin in conductive connection with a point in the circuitry so as to reset a required part of the electronic circuity.

When after this, the stem is pushed right in from position 7cto position 7a, the gear wheel train is released for normal time keeping operation, the electronic circuit is released from the reset condition and the second hand starts again. The watch thereafter runs normally.

It is not easy to obtain an exact correction of displayed timee.g. by means of a radio time signal-with a conventional watch with provision for time display correction as above described for it takes time to correct the position of the hour and minute hands and, if the watch has to be corrected or set it is very difficult to cause the second hand to restart at the correct time with all its hands, including the second hand, in their correct positions.

In a method of displayed time correct which has been proposed for an ordinary mechanical (clockwork) watch with a date display (see Japanese Patent No. 2798/72 as laid open to inspection) the stem again has three positions. The first (most inward) position, is a neutral position as regards time setting; the second (intermediate) position is one in which rotation of the stem in one direction effects date correction and rotation in the opposite direction effects hour correction; and the third (outermost) position is used for setting the hour hand and the minute hand (allowed to be added to control the second hand). However this way of effecting time correction in a mechanical watch is not satisfactorily applicable to an electronic watch because of the numerous and complex mechanical parts which are necessary.Their provision in an electronic watch would make it undesirably expensive and, because parts for the correction of time are additional, the mechanism necessary could only be accommodated in an electronic watch of relatively great thickness, which is very undesirable especially in the case of a wrist watch. Moreover the method is not applicable to a watch giving a display of both date and day. To overcome this limitation it would be necessary to provide the stem with four positions (instead of only three) but this would still further complicate the mechanism necessary as well as make the watch less convenient for the user. There is a further reason whey the mechanical watch time correction method above described is not satisfactorily practical for an electronic watch.In normal practice in an electronic watch there is a date dial and a day star with a dial disk which are rotated mechanically in only one direction. So, if the hour hand has to be rotated backwards (i.e. in the direction reversed relatively to the direction of rotation of the date dial) and the position of the day star is to be changed, the indications of date and day will not be correctly synchronized with the hour hand.

There is another known method of effecting displayed time correction which is sometimes used in an electronic watch. This method is to effect time correction electrically by driving the motor with a quicker than normal stepping action. For example, in a watch in which the motor is driven normally by timekeeping pulses which cause its stepping rate to be one step per second, it is possible, by pressin-g a button, to supply it with higher frequency pulses so that it steps at 32 Hz. But, as. will be apparent, with this method it takes two minutes ta change the displayed time by sixty minutes assuming the quick feed to be 32. Hz.

If, as may happen, the displayed time has to be changed by a large amount-say several hours-it takes toa long to do so to be practically convenient. In some arrangements of this nature the motor is required to be made to run, during time correction, either forward or in the reverse direction and this is an additional disadvantage. It has been proposed, in a timepiece provided only with minute and hour hands, but no second hand to correct the hours display mechanically by means of a knob activated stem and to correct the minutes display electrically by providing a quick- pulse input to the motor. Such an arrangement is disclosed in Japanese Patent 39584/75 as laid apen to inspection and Fig.

2 shows, sufficiently for an understanding thereof, a block diagram of the circuitry used for obtaining the quick pulse input when required. In Fig. 2, 1 is a crystal controlled time standard oscillator feeding a frequency divider 2a providing, normally, timekeeping pulses to a drive circuit 3 driving a stepping motor 4. There is a switch 35, actuated by a push button (not shown) and it will be seen that, by changing over the position af the switch, the drive circuit 3 can be supplied, for time correction, with pulses at a frequency higher than the normal timekeeping frequency, 2band-2cbeing also frequency di-viders.

Reference may also be made to Japanese Patent No. 123668/77 as laid open to public inspection and which proposes another method of time correction for a timepiece having only hour and minute hands but no second hand. However the proposal in that.

Patent, like all the other prior proposals. mentioned above does not provide a really satisfactory solution of the problem of making provision, in a resonably cheap and easily manufactured electronic timepiece having hour, minute and second hands and also date and day displays and which can be made of sufficiently small size and thickness to be satisfactory for a wrist watch, for convenient quick and accurate time correction.

According ta this invention there is provided an electronic analog timepiece having displayed time correction means comprising manually operable means for correcting the hour and minute hand positions and stopping the advance of the second hand during such correction, means for memorising the time taken for such correction, manually operable means, operable after such correction, for causing the second hand to advance again and means for automatically causing the last mentioned advance of the second hand to be at.a rate which is high relative to the normal timekeeping rate for a time corresponding with the memorised time and thereafter to advance at the normal timekeeping rate.

The invention is illustrated in and further explained in connection with the accompanying drawings, in which: Figure 1 which is provided for purposes of preliminary explanation, illustrates the way in which provision for displayed time correction by external operation of a stem is made in many conventional electronic watches; Figure 2 which is also provided for purposes of preliminary explanation is a simplified block diagram of a conventional wrist watch having provision for time correction with quick advance, electrically, of the second hand; Figure 3 illustrates the way in which dis played time correction is effected by operation of a stem in one embodiment of this invention; Figure 4 is a simplified block diagram of one embodiment of this invention;; Figure 5shows circuitry used in an embodi ment as illustrated by the block diagram of Fig. 4, and Figure 6 is a waveform timing chart explanatory of the operation of Fig. 5.

Fig. 3 illustrates how the knob ended stem is operated when carrying out time correction in one embodiment of this invention. The stem has three positions indicated in Fig. 3 by the encircled numerals 1, 2 and 3. The in -wards position, 1, is a neutral position. The intermediate or second position 2 is the position in which the date can be corrected by rotating the stem in one direction and the day corrected by rotating the stem in the opposite direction. The outwards or third position, 3, is the position used for time setting. For correct ing displayed time by using the stem to adjust the hour hand and minute hand but without (finally) disordering the position of the second hand, the operating method used is as fol lows.

As a first operation, the stem is pulled as quicly as possible from position 1 or from position 2, to position 3. This should take only a quite short time from nearly zero to a second or thereabouts. This operation leaves the hour, minute and second hands in a condition to be corrected without disordering the second hand. After this first operation, the operation is the same as in a conventional watch, position 1 being a neutral position, position 2 being a position for correcting day and/or date and position 3 being a position for correcting the hour and minute hands as already stated. Just after the stem is pushed fom position 3 to position 1 to the second hand is automatically caused to be advanced quickly by the time which was taken for the correction of the hour and minutes hands.

When the second hand has been thus quickly advanced to the correct position, its normal timekeeping advance is resumed.

Fig. 3 will assist in an understanding of the foregoing. Fig. 3A shows the first operation mentioned above. In Fig. 3B the stem is pulled out to position 3, after the first operation, at the time of 35 minutes 10 seconds past 9 o'clock. In Fig. 3C the displayed time has been advanced for one hour and changed into 35 minutes 10 seconds past 10 o'clock the stem being in position 3 so that the second hand is still in the position indicating 10 seconds. At this time, the minute hand has been rotated through one revolution on the watch dial and occupies the same position it had before the correction. After this operation, the stem is pushed back to the first or neutral position.

Suppose the time taken for the correction was 20 seconds. Then the second hand is quickly advanced by a signal of 1 6 Hz and is set to the correct time within one second or so, and then returns to the normal timekeeping step advance (see Fig. 3D). Usually, the time required for this quick advance of the second hand for correction of the time difference is, at most, one to two minutes and therefore the extra load imposed on the battery for this quick advance is acceptably small.

The positions of the second hand and of the minute hand must exactly correspond to each other. The minute hand is correctly set to the position it had before the correction for the time difference. During this operation, the second hand itself is controlled and stopped.

The minute hand position, as measured by eye along the scale of minutes will be in correct correspondence with the position of the second hand from the 1 2 o'ciock position.

Thus correct synchronization of the minute and second hands is achieved and made the same as it was before correction.

As will now be seen the whole operation of time correction is quite different from that of time correction in a conventional watch and the invention has the considerable merit that the hour and minute hands can be set without disordering the position of the second hand.

Further, the invention has the advantage of not involving any serious extra cost for the time correcting means which, ordinarily, are not used very often and the additional advantage of not interfering with the means for indicating the date and the day. Furthermore time correction is easily and conveniently effected by the user who has merely to rotate the stem to correct the positions of the hour and minute hands, the directions of rotation of the stem for this purpose being the same as in time setting in a conventional watch and therefore presenting no special problems or difficulties to the user. If, in any case time correction involves moving the hour and minute hands backward and getting the indications of the date and the day out of position, the date and day indications can easily be made correct by rotating the stem when in position 2 as in a conventional watch.

Fig. 4 is a block diagram of one embodiment of the invention, Fig. 5 shows the circuitry thereof and Fig. 6 is an explanatory waveform timing chart.

Referring to Fig. 4, 1 represents a relatively high frequency time standard oscillator such a quartz crystal controlled oscillator generating a frequency of, for example, 32768 Hz. This frequency is fed to a multi-stage frequency divider 2, preferably of integrated circuit (IC) construction of the MOS IC type, providing a timekeeping output to a drive circuit 3 driving a stepping motor represented by block 4 which drives through a gear wheel train 5, a display arrangement represented by block 6 and comprising hour, minute and second hands, a date dial and a day star with a day dial disk.

As so far described, the diagram of Fig. 4 is the same aS that of a conventional quartz crystal timepiece. However, as will be more clearly understood in detail later, an output signal provided by operation of an externally operable member 7 (a stem operated switch) is fed to a timer 8 which decides whether to reset stages in the divider 2 or to wait and prepare an up-down counter 9 for counting.

While the hour and minute hands are being corrected the up-down counter 9 counts up timekeeping signals. When the stem is pushed from position 3 into position 1 after the hour and minute hands have been set, the counter 9 counts down the signal and a quick feeding signal obtained from the divider 2 quickly advances the second hand.

Usually, in time setting, the stem is in position 3 for a relatively long time-more than 1 second and this is set in the timer 8.

However, stages in the divider 2 are reset if the stem is in position 3 for a time shorter than one second, and a preparatory signal is sent to the counter 9. As soon as the stem is in the position for time setting, the counter 9 begins to count timing signals from the drive circuit 3.

In Fig. 5, 22 is the quartz crystal in the time standard oscillator 20, 21 is a NOT gate and 23 to 25 are D-type flip-flops (FF) in a multi-stage divider each stage of which divides by two. The stage referenced 25-actu- ally it is the eighth stage of the divider-pro- vides an output of 1 28 Hz. There is a changeover switch with a switch arm 35 and one contact 36 connected to the positive supply and the other one earthed. Switch arm 35 is coupled with or incorporated in the normally provided second setting lever of the watch.

62 is an anti-chatter circuit which prevents undesired chatter effects due to operation of the switch and which includes a flip-flop to which a frequency of 64 Hz is supplied from stage 26 of the divider by a circuit connection not shown. 37 is a one second counting timer, and 38 is a gate for re-setting, via a futher gate 38', the divider stages 26, 27, 28 (which gives an output of 1 6 Hz) and the remaining stages of the divider (stages 29 and 30 give outputs of 1 Hz and > Hz respectively).Gates 39, 41 and 43 co-operate to provide a signal for making an up/down counter 44 count up; 40 is a D-type FF providing a < division; gates 46, 47, 48 are for making the counter 44 count down; flipflop 52 (to which a clock signal of 1 28 Hz is applied from divider stage 25) and gates 52 and 58 are circuit elements in the motor driving circuit; and 59 is the energising coil and 60 the stator of a stepping motor with a permanently magnetised rotor 61 with poles as indicated by the letters N and S.

If the switch arm connects with the contact 36 for a time longer than one second, the time 37 puts out a HIGH signal during the one second interval which starts from when the switch arm 35 becomes HIGH and puts out a LOW signal at the end of this 1 second interval. At this time, the output signal from the gate 38 is HIGH, which causes the output from the gate 38' to be HIGH, and the divider stages 26 and 30 inclusive are reset. While the timer 37 is performing this operation, the second hand is not moved because the gear wheel train is controlled to prevent this. After the wheel train is released from this control, The second hand is not rotated by an output signal in the same direction, but starts to be rotated by an inverted output signal after the interval of one second has passed.

If the switch arm 35 connects with the contact 36 for a time which is shorter than one second and which is set in the timer 37, the output signal from the gate 38 is LOW and the divider stages 26 and 30 are not reset. However, if the switch arm contacts with 36 for less than 1 second, the output from timer 37, acting through gate 39 makes the Q output from FF 40 HIGH and establishes a waiting condition ready to await the next operation of the switch arm 35 and the said 0 output from 40 causes the output from gate 41 to become HIGH, and the counter 44 begins to count up the 1 Hz signal from divider stage 29 supplied to its through gate 43.

In this period, the divider stage 30 is not reset and its 0 output signal is supplied via the gate 51 NOT gate 51' and the motor drive circuit to the coil 59 of the motor.

However the second hand does not rotate because the gear train is so controlled as not to move the second hand while the hour hand and the minute hand are mechanically corrected (for example as shown in Fig. 3 by one hour) by rotation of the stem. When the switch arm 35 is again released to connect with earth, the output from gate 42 resets the FF 40 and also causes a HIGH signal to appear at the output from gate 46. This causes, via the cross-connected gates 47, 48, the NOT gate 49' and the gate 49, the counter 44 to count down. During the down count, counter 44 counts the 1 6 Hz output from the stage 28 so that the 1 Hz up count made, during the operation of mechanically correcting the hours and minutes hands is quickly counted down.When the Q outputs from counter 44 all become LOW, the output from gate 50 causes the gates 47, 48 to switch over, the output from gate 49 ceases, and the second hand returns to its normal time-keeping stepping operation controlled by the output from the divider stage 30.

Fig. 6 shows the wave forms occurring at Q5 outputs of the divider stages 25, 29 and 30, from the switch arm 35, from the output of the timer 37, from the gates 38, 39, 41, 42, 49, 51', 57 and 58, from the timer 37, from the Q terminal of the flip-flop 40, and from the 0M terminal of the flip-flops 52 during the indicated periods la, Ila, Ib, llb, Ic, llc, Illa, Id It also shows the pulses in the motor coil 59.The coil pulses marked X are those in which the motor rotor does not rotate the second hand, The periods are period la normal timekeeping condition period Ila condition of regulation and setting of the circuitry as in a usual time setting operation period lb condition after regulation and release of resetting period llb condition of regulation in short time period Ic waiting condition after regulation in a short ime period Ile condition in which the time taken to set the displayed hours and minutes to correct for a displayed time error is memorized period Illa condition in which quick feeding and correction of the second hand occurs during a time after the stem is pushed in to position 1 period Id condition in which normal timekeeping is resumed.

The invention is not limited to the arrangements described with reference to Figs. 3 to 6. For example various different modifications may be made to the circuitry used for counting the time during which the second hand stops. For example, the circuitry may be so made as to count the time only in the period between two successive operations of pulling out or pushing in the stem.

In the embodiment so far described and illustrated, the stem is used not only as a switching control member for establishing (when desired) an operating condition in which a time difference can be corrected but also for the purpose of effecting the time difference correction itself. This, however, is not essential to the invention and other arrangements are possible. Thus, in another way of carrying out the invention a separate push button is provided in addition to the stem and is used as a switching control member for establishing the operating condition in which a time difference can be corrected, the actual correction being effected by the stem.

Such a modification needs little further description having regard to the description of the illustrated embodiment already given. The additional button and the stem could be arranged to effect the required control switching of the timer 8 and the up/down counter 9 (Fig. 4), in any convenient way, for example by connecting switching means controlled by said additional button directly with said timer and counter. The adoption of such a modification would involve changes in the circuitry described with reference to Fig. 5 but it is thought that those skilled in the art will have no difficulty in making suitable changes in the circuitry so that detailed description of the modified circuitry is unnecessary.

If an additional separate push button is provided it can be arranged to effect several functions. For example it could control switching means producing or stopping quick advance of the second hand of the timepiece. In the case of a timepiece fitted with an alarm, the button operated switch means could be also arranged to stop the alarm. In the case of a timepiece which was a combined timekeeper and chronograph (stop watch), the additional button could be also used to start and stop chronograph operation.

In one arrangement in which a push button is provided additionally to the stem, time setting is effected by pulling the stem out to its middle position and is then operated to set the time. When the stem is pushed in again to its initial position, the second hand again starts to move in the normal time-keeping manner. For time correcting, operation of the button prepares the electronic circuitry for correction of the time difference i.e. puts the circuitry in a state for time correction to be effected. For example, if the button is pushed once the circuitry is put into a state for time correction to be effected. After this operation, the stem is pulled out to its outermost position and a count of the seconds starts. When the stem is again returned to its initial position, a count down of seconds starts in order to advance the second hand quickly towards the correct time.

It is possible to resort to a more complex arrangement. For example, the button may be used to control means for regulating the second hand, the stem being used for time setting and for correcting the time and the time difference, and the circuitry being arranged to memorize the time taken from the beginning of the operation to the end thereof.

When the button is released, the second hand is quickly advanced to overtake the correct time.

It is possible to adopt yet another arrangement which will now be described. In this arrangement, after the stem is pulled out to its outermost position and then pushed previously to the correction of a time difference, the circuitry receives a signal for advancing the timer for a certain predetermined period, for example 30 seconds. During this period, the drive signal is stopped in order to stop movement of the second hand. When the hour hand and the minute hand are set and the time difference is corrected to within 30 seconds and the stem is pushed, the timer becomes OFF after the passage of 30 seconds regardless of the time required for correction and the second hand is then quicly advanced for 30 seconds and overtakes the correct time.

The function of quick advance of the second hand for time correction may be performed in yet another way which will now be described it now being supposed that the manual control means consists of the stem only. When the stem is pulled out and pushed in twice in a short time, the second hand advances for 5 seconds. If the time required for setting the hour hand and the minute hand is longer than a certain period, the second hand is quickly advanced during the time in which the second hand is stopped and is set to the correct time as soon as the stem is pushed. Thus, the second hand can be caused to operate in three ways in dependence on the position of the stem.

In normal practice the circuity of a timepiece in accordance with this invention will be integrated circuit (I.C.) construction. As will be at once appreciated such a timepiece is quite different from and imposes problems quite different from those which arise in a conventional mechanical timepiece in which difference in time is corrected by only the hour hand. The present invention provides electronic timepieces which do not require extra mechanical parts to be added to the mechanism and therefore the watch can be made thin-an important practical advantage. The resent pin which comes into use when the stem is in its third (outermost) position and which is customarily provided in a quartz crystal watch may be used when carrying out this invention. This militates against increase in the cost of manufacture.Furthermore a timepiece in accordance with this invention and having an alarm may be provided with a conventional reset release function which is brought into operation when the reset pin is moved coincidentally with the time alarm. The time of the timepiece can be correctly set in a conventional manner. It will be comparatively rare in practice to require the stem to be pulled out and pushed in in a short time so that there will be practically no occasion for missing the operation. Further, once the operation of making the timepiece memorize the time during which the second hand is stopped is appreciated, the user can easily remember what he has to do, for it is so simple. Indeed, when the watch is used always in one country, the user has virtually nothing to remember and can use his timepiece in the ordinary way.In a conventional timepiece on the other hand, there is always the risk that the hour hand may be by mistake incorrectly handled with the possibility that the date display is put into a condition for correction when the stem is in its middle position. This risk can be avoided with a timepiece in accordance with the present invention.

Problems and disadvantages arise with hitherto proposed methods for correcting time difference in conventional timepieces. For example, if time is corrected only by means of electrical signals applied to the motor driving the hands, the time taken to effect correction can easily be too long to be acceptable. If provision is made for the time to be corrected over intervals of one hour by reversing the drive to the motor, it is necessary to provide a reversable motor. As will already have been seen, however, in a watch embodying this invention the hour and minute hands can be rotated manually (by the stem) and this operation takes at most, 20 seconds, the second hand being then quickly advanced by the quick feed signals (16 Hz in the illustrated embodiment) and this operation needs only 1 to 2 seconds to advance the displaced time to the correct time.Thus, a difference in time is easily corrected in an acceptably short time.

Known mechanical and electronic timepieces have various merits and demerits. They are never perfect. A user is apt to suppose that the time is correctly set when only the hour hand is corrected. But when time correction involves setting the displayed time backwards and this is done during the period in which the date and the day display is being changed, the result may well be to display an incorrect date and day, for a date dial and a day star with a dial disk which are rotated only in one direction can easily be put out of correct co-operation with the time.

In the preferred embodiments of this invention, the hour hand and the minute hand are corrected in the third (outermost position) of the stem and the date and day are corrected in the second (middle) position of the stem.

So erroneous displays due to the user thinking that the time has been. correctly set when only the positions of the hour and minute hands have been corrected will not arise. Of course, if the user is informed e.g. by an announcement from the captain of an aircraft in which he is travelling, that the date and the day are not correctly displayed he can immediately and easily make the appropriate correction of date and day displayed. In embodiments of the invention in which the externally operable member consists only of the stem, with no additional button, the general design and appearance of the timepiece may be made very atractive indeed with a simple casing structure of good waterproof or moisture proof qualities.In an independent timpiece constructed to have an l.C. circuit block, an oscillator and a trimmer condenser the means provided by this invention, for correcting the time difference may be readily incorporated in said circuit block there being no need to use other than normal mechanical parts such as the motor and so on.

With this invention, as will now be appreciated, the correction of the time difference by merely rotating the hour and minute hands to their correct positions, and then causing the second hand to be quickly fed until synchronism with the minute hand is obtained, results in the three hands being in their correct relative positions when the operation of correction is completed. Furthermore, if the hour and minute hands are manipulated by the stem when in its third position, the operation with which the user is faced is an operation which is conventional and familiar to him.

Claims (11)

1. An electronic analog timepiece having displayed time correction means comprising manually operable means for correcting the hour and minute hand positions and stopping the advance of the second hand during such correction, means for memorising the time taken for such correction, manually operable means, operable after such correction, for causing the second hand to advance again and means for automatically causing the last mentioned advance of the second hand to be at a rate which is high relative to the normal timekeeping rate for a time corresponding with the memorised time and thereafter to advance at the normal timekeeping rate.

2. A timepiece as claimed in claim 1 wherein said manually operable means is constituted by a rotatable stem which has a plurality of selectable longitudinal positions.

3. A timepiece as claimed in claim 1 wherein the manually operable means comprise a rotatable stem and an externally operable switch button.

4. A timepiece as claimed in claim 2 or 3 in which the stem has three longitudinal positions in the outermost one of which rotation corrects the hour and minute hand positions and in the middle one of which rotation corrects the displayed day and/or date.

5. A timepiece as claimed in any of the preceding claims wherein the memorising of time is effected by up/down counting means counting up pulses at one frequency while the advance of the second hand is stopped and counting down pulses at a higher frequency when the manually operable means, operable after correction, are operated, means for quickly advancing the second hand during count down by said counting means and means, operated when the count down is completed, for restoring normal timekeeping advance of the second hand.

6. A timepiece as claimed in claim 5 wherein the up/down counter is controlled by a timer which sets the counter to count up pulses if the advance of the second hand is stopped for not less than 1 second.

7. A timepiece as claimed in claim 5 or 6 and including a time standard crystal controlled oscillator, a multi-stage frequency divider driven thereby, and a stepping electric motor normally driving the second hand at a normal timekeeping rate, wherein the pulses counted by the counting means and for driving the motor are derived from stages in said divider.

8. A timepiece as claimed in claim 4 wherein rotation of the stem when in its intermediate pull-out position effects adjustment of the day when rotated in one direction and adjustment of the date when rotated in the other direction.

9. A timepiece as claimed in any of the preceding claims having a stepping motor normally driving the second hand through a train of gear wheels wherein the means for stopping advance of the second hand during correction of the hour and minute hand positions include means for interrupting the gear wheel drive.

10. Electronic timepieces substantially as herein described with reference to Figs. 3 to 6 inclusive of the accompanying drawings.

11. A correcting means for an electronic timepiece with an external operating member, an electronic circuit, a motor driven by a signal put out from said electronic circuit, a wheel train, and an indicating portion having at least an hour hand and a minute hand, comprising a stepping means for controlling a part of said motor or said wheel train during said correction of the hour hand and minute hand, memorising means for memorising the time in which said motor or said wheel trains is stopped, and a means for resupplying the time in which said motor or said wheel train was stopped after said hour hand and minute have been corrected.

1 2. Correcting means as claimed in claim 11 wherein the external operating member is a stem.

1 3. Correction means as claimed in claim 1 2 wherein the stem is a rotatable stem with three longitudinal positions of which the first is a neutral position, the second is a position for correcting the date and the day, and the third is a position or correcting the time.