DE2402820B2 - Electronic clock - Google Patents

Description

The invention relates to an electronic watch according to the preamble of claim 1.

Because of their high accuracy, electronic quartz watches are increasingly being used in which the time is displayed using electromechanical devices, for example a stepper motor that drives a gear train, an ordinary motor or a balance wheel with a spiral spring To make use of the high accuracy achievable with a quartz oscillator, an automatically operating correction circuit can be used which ensures that the mechanical time display device is brought into harmony with the time signals derived from the quartz oscillator. In a clock as described in US Pat. No. 3,553,957, this is done by periodically scanning the rotational position of a disk driven by the clockwork mechanism and in the event that the disk has moved too far since the last check or rotated too little, Vi drive pulse c for the time display device can be added or deleted.

The high accuracy of a quartz-controlled clock that can be achieved in this way is often not exploited by the user, since adjusting the clock with the ^{h ()} relatively small time deviations, which can occur after a long period of time, is usually laborious and complicated. Therefore, the watch user usually refrains from adjusting the watch in the event of small deviations of less than half a minute. *> ^r ' For this reason, the high accuracy of the watch is usually not used.

The object of the present invention is therefore

for an electronic watch of the type required, a very easy-to-use and accurate one To make time setting device available for the correction of small time deviations.

The solution to this problem is characterized in claim I and advantageous in the dependent claim further educated

A Voneil of the clock according to the invention is that when the time display deviates from the real time that is less than half a minute, a single press on, for example, an am The switch crown attached to the watch case is sufficient to display the time display device of the watch to run according to the time of actuation of the switch crown. Is particularly advantageous that regardless of whether the clock is before or after goes, a similar actuation of the switch crown is sufficient, so that a really simple and uncomplicated Adjusting device is created.

If the electronic clock has been developed according to the dependent claim, you can simply press a further switching crown or by a different actuation of the first switching crown at the point in time which the time display device passes the display value 00, correspondence between the time display device and the pulse counter.

The invention is explained in more detail below with reference to embodiments. In the drawing shows

1 shows a switch device for readjusting the clock in the event of small time deviations;

F i g. Figure 2 shows an embodiment of the invention for an electronic watch driven by a stepping motor will.

In Fig. I a trigger 11 acts on a switch 12, which consists of two contact tongues 12 'and 12 ". If the finger pressure on the trigger 11 is released, see the pusher returns under the action of its spring 13 in its rest position back. The switch is between a power source 14 and a terminal 15 of a Circuit 16.

According to the embodiment of FIG. 2, a quartz oscillator 21 is followed by a frequency divider 22 which outputs pulses with a frequency of 2 Hz. These pulses are fed to a counter 23 dividing by two, then a reference counter B, which consists of a counter 24 counting up to 30 and thus dividing by 30 and one counting up to two and thus dividing by two counter 25. The output period of this counter is 60 seconds.

When the gate 29 is open, the pulses coming from the frequency divider 22 are fed to a counter A and also to a motor driver 12 which emits drive pulses to the motor 13. For each pulse applied to the motor by motor driver 12, the motor is advanced by one step. The counter A runs synchronously with the motor 1.3 and the display of the time. The state of the counter A can be brought into agreement with the position 00 of the second hand with a switch "Reset counter A".

The counter A , like the counter ö, consists of one counter t0 that counts up to 30 and thus divides by 30 and one to two counting and thus divides by two counters 11. The mutual phase position of counters A and B is determined by a comparator 26 (a known electronic unit ) and through NOXOR

Circuits (27 and 28) determined which indicate the state A <B or A> B. This circuit device is applied to the gate 29 so a that it is closed when A> B, that is A to B leads the 2-Hz ImpuIse are locked and then go> neither to the motor driver 12 still to counter A, the counter B , however, receives 1 Hz pulses via counter 23. It advances until A = B. Conversely, if A <B, the 2 Hz pulses go to motor divider 12 and counter A. Since this frequency is double that of the motor Counter B is supplied frequency, the counter A advances the counter B until A = B. So the counters A and β are synchronized. Since the counter A is already synchronized with the motor 13 and the display of the time, it can be said that In this equilibrium state, counter ι> A, counter B and the indication of the time are synchronized with one another, that is to say that the two counters are at 0 when the second hand moves past 00.

Have the two counters A and B and the second hand z. B. the value 45 and if the switch m »reset of the counter Bn is operated, the counter B jumps to position 00. The comparator 26 between A and B therefore causes the frequency 2 Hz. The motor 13 and the counter A then move twice faster, until Λ = Ä

If, however, the counters A and B and the second hand are e.g. B. at 15 and if the counter B is reset, it jumps to 00. The comparator reacts in such a way that it stops the motor 13 and the counter A until B = A

By resetting the counter β, for example at the moment of a time signal, the clock has been set to the exact time in both cases. This setting is stored in counter B and forwarded to counter A and motor 13

So you can correct small deviations with a simple pressure and a; Pointer adjustment without using the usual means, which are difficult to manage.

For this purpose 2 sheets of drawings

Claims (2)

Patent claims: 1. Electronic clock with a motor-driven electromechanical time display device, an oscillator that feeds a frequency divider circuit, a motor driver circuit and a die Time display device automatically with the time signal from the frequency divider circuit synchronizing correction circuit, characterized in that that the correction circuit has an electronic pulse counter (A) which operates synchronously with the time display device and which is fed from the frequency divider circuit (22) via a gate circuit (29), that a reference pulse counter (B) fed by the frequency divider circuit is provided,
that a comparison device (26-28; 35-37) controls the gate circuit (29) in such a way that if the counts of the two counters (A, B) differ, the frequency of the counting pulses supplied to the pulse counter (A) changes in such a direction that on equal counts of both pulse counters (A. £ tyhin is acted, and that the reference counter (B) can be reset by means of a switch which can be operated from outside the watch case ("resetting the counter ß"). 2. An electronic watch according to claim 1, characterized in that also the pulse counter (A) by means of an actuatable from outside of the watch case switch ( "reset the counter A") is resettable. jo