Control device for an electronic wrist-watch
BACKGROUND OF THE INVENTION 
     The present invention relates to a control device for electronic watches, comprising a push button. 
     In order to increase the possibilities offered by the use of a push button to initiate various operations in a watch, the present invention envisages a device where one can obtain two different effects according to whether the actuation of the push button is of short or of long duration. 
     SUMMARY OF THE INVENTION 
     The device in accordance with the invention comprises a push button switch for providing a control signal delay means actuated by said control signal, first and second flip-flop circuits controlled by said delay means, inputs of the flip-flops being supplied with said control signal, the device having outputs formed by a Q output of the first flip-flop circuit and a Q output of the second flip-flop circuit, a return-to-zero of the device being effected by setting the first flip-flop circuit to zero and setting the second flip-flop circuit to one. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be described further, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 illustrates an embodiment of a device in accordance with the present invention; and 
     FIGS. 2 and 3 show diagrams illustrating the functioning of the device of FIG. 1. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     In FIG. 1 a push button 1 actuates a switch 2 which, when it is closed, connects the input of a monostable circuit 4 and the input of an inverter 9 to earth G corresponding to a logic potential &#34;0&#34;. When the switch 2 is open, the push button 1 being in the rest position, these inputs are connected to a terminal of voltage +V corresponding to a logic potential &#34;1&#34;, via a resistance 3. The output of the inverter 9 is connected to inputs D6 and D7 of two D flip-flops 6 and 7, so that when the switch 2 is open, the inputs D6 and D7 are at the logic potential  0  and when the switch 2 is closed the input D6 and D7 are at the logic potential  1 . The monostable circuit 4 has a delay time τ. The output of the monostable circuit 4 is connected via an inverter 5 to the control inputs T6 and T7 of the flip-flops 6 and 7. The outputs of the device are provided, on the one hand, by the output Q6 of the flip-flop 6 and, on the other hand, by the output Q7 of the flip-flop 7. 
     Before circuit operation, the device must be placed in adequate initial conditions which correspond to the normal functioning of the watch. In our case, the two outputs Q6 and Q7 of the device must be set at zero. To do this, the flip-flop 6 will be returned to zero by its input RAZ 6 and the flip-flop 7 returned to one by its input RAU 7 so that its out-put Q7 is at zero. (For resetting) flip-flops 6 and 7, a timing circuit 8 is provided which may be a monostable circuit. 
     FIGS. 2 and 3 illustrate two cases of actuation of the push button 1. In the first case (FIG. 2), the actuation is short, which provides a control signal SC which is relatively short. In the second case (FIG. 3), the actuation of the push button is long, providing a relatively long signal SC. 
     The monostable 4 changes state at the beginning of this control signal SC, and after a period τ, the inputs T6 and T7 receive a positive going edge which causes the information present at the input D6 of flip-flop 6 and for the flip-flop circuit 7 the reverse of the information present at the input D7 to be conveyed to the outputs of the device. Thus, for a signal SC of short duration at the instant of transfer of information by the flip-flop circuits 6 and 7, the outputs Q6 and Q7 will be in the state 
     
             0,1                                                                   
 
    
     and for a signal SC of long duration the condition will be: 
     
             1,0                                                                   
 
    
     Thus, there is obtained a coding of output information in accordance with the duration of pressure on the push button 1. 
     The terms &#34;long duration&#34; and &#34;short duration&#34; are defined with respect to the time lapse τ. The actuation time t is considered as short if: 
     
             t &lt; τ                                                             
 
    
     and it is considered as long if: 
     
             t &gt; τ                                                             
 
    
     FIGS. 2 and 3 also illustrate the return-to-zero impulse of the device. This can be furnished in different manners in accordance with the use to which the device will be put. The timing circuit 8 is set at the same time as monostable circuit 4, whereby the delay time T of timing circuit 8 is longer than that of monostable circuit 4. In this case, the duration of the operation or of the chosen function will last T - τ. 
     One could replace the monostable circuits 4 and 8 by a delay counter-actuated by the control signal SC and fed by a train of impulses derived from the watch circuit. 
     One can envisage multiple applications of this device, however, we will call attention to only a few by way of example. 
     In watches having liquid crystal displays only indicating the hour and the minute during normal working one could actuate display of either the dates (short manipulation) or the seconds (long manipulation). If the watch has a display having light-emitting diodes, such a display is not permanent, for reasons of power consumation and if the display only comprises four digits with which one can only have two pieces of information (hour and minute or date and second) the choice could be made with the aid of the duration of manipulation of a single push button. If there is provided, in a watch, besides it absolute time indicating circuit, normally and permanently displayed, another circuit, for example a chronographic circuit or a calculating circuit, these circuits can be operated in two different manners. One can choose the type of operation that the annexed circuit is going to effect by an application of adequate time on a single push buttom. In that case, the return-to-zero impulse of the device in accordance with the invention will only be given at the moment when the user decides to return to normal operation, that is to say by another push button or another appropriate means.