DE2402820C3 - Electronic clock - Google Patents

Description

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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 «o the time is displayed via electromechanical devices, for example by a stepper motor, the drives a gear train, either by an ordinary motor or by a balance wheel with a spiral spring. Around To use the high accuracy that can be achieved with a quartz oscillator, an automatically operating correction circuit can be used for this ensures that the mechanical time display device with the time signals derived from the quartz oscillator in Is brought into line. With a watch like the one in that US-PS 35 53 957 is described, this is done in that periodically the rotational position of one of the gear train the clock driven disk is scanned and in the event that the disk has been moving since the last Check has rotated too far or too little, drive pulses for the time display device can be added or omitted.

However, the high accuracy of a quartz-controlled watch that can be achieved in this way is often achieved by the user not used because the clock was readjusted at the f> o relatively small time deviations, which can occur after a long period of time, usually cumbersome and is complicated. Therefore, the watch user usually refrains from using the watch in the event of small deviations, the take less than half a minute to readjust. '■ The high accuracy of the watch is due to this Reason mostly 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 1 and advantageous in the dependent claim further educated

An advantage of the clock according to the invention is that if 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 move the time display device of the watch into the time display to run according to the time of actuation of the switch crown. Is particularly advantageous that regardless of whether the clock goes before or after a similar actuation of the switch crown sufficient so that a really simple and uncomplicated adjustment device is created.

If the electronic clock is further developed according to the dependent claim, it can be simply pressed on further switch crown or by a different actuation of the first switch crown at the time which the time display device passes through the display value 00. Correspondence between the time display device and the pulse counter can be achieved.

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

F i g. 1 a switch device for readjusting the clock in the event of small time deviations;

F i g. Fig. 2 shows an embodiment of the invention for an electronic watch which is driven by a stepping motor.

In Fig. 1, a pusher 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, so the pusher returns to its rest position under the action of a spring 13. The switch is between a current 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 that counts up to 30 and thus divides by 30 and one counter 25 that counts up to two and thus divides by two. The starting 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 thus runs synchronously with the motor 13 and the display of the time. The status of counter A can be brought into agreement with the position 00 of the second hand using a switch "Reset counter A".

Like counter B, counter A consists of one counter 10 that counts up to 30 and thus divides by 30 and one that counts up to two and thus divides by two 11. The mutual phase position of counters A and B is determined by a comparator 26 (a well-known electronic Unit) and by NOXOR

Circuits (27 and 28) determined which indicate the state A <B or A> B. This circuit device is applied to the gate 29 a such that it is closed when A> B, that is A to B voreilL The 2-Hz pulses 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 get to MotGrteiler 12 and counter A Since this frequency is twice that of the ι ο Counter B is supplied frequency, the counter A advances the counter B until A = B. So the counters A and B 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 state of equilibrium, counter A counter B and the indication of the time are synchronized with each other, that is, when the second hand moves past 00, the two counters to 0 steven.

Have the two counters A and B and the second hand z. B. the value 45 and if the switch "Reset the counter" 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, to Λ = B.

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 B, for example at the moment of a time signal, the clock is 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 setting 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 which feeds a frequency divider circuit, a motor driver circuit and a correction circuit automatically synchronizing the time display device with the time signal coming from the frequency divider circuit, characterized in that the correction circuit has an electronic pulse counter operating synchronously with the time display device ( A) , which is fed from the frequency divider circuit (22) via a gate circuit (29), that a reference pulse counter fZJJ fed by the frequency divider circuit is provided, that a comparison device (26-28; 35-37), the gate (29) so as to change at different count of the two counters (A, B) the frequency of the pulse counter (A) supplied to count pulses in such a direction that at equal counts of both pulse counters (A, £ t) are acted upon, and that the reference counter (B) can be reset by means of a switch which can be operated by 2ί outside the watch case (»resetting the counter Bv) 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 J "switch (" reset the counter An) is resettable