Abstract: A control device for controlling the display of an electronic watch capable of providing two different types of information. The control device enables selection of the information to be displayed and differentiation between the two types of display available.

Abstract: An electronic timepiece havng an integrated electronic circuit including a quartz crystal oscillator, connected to a multi-stage divider, which divider supplies various outputs of various frequencies to corrector circuits, a logic circuit and a motor control circuit. The motor control circuit includes a switch to allow the timepiece to be stopped by resetting at least one stage of the divider. One of the terminals of the motor is connected to one of the stages of the divider to allow the control of the frequency of the signal issued from this stage, and, therefore, the frequency of the quartz oscillator.

Abstract: The chronograph comprises a device allowing to memorize at least two lapses of time and a subtraction device to effect the absolute difference between two lapses of time or time intervals which are memorized and preselected. The subtraction device includes:(a) a first array of complete subtractors which effect a first difference between the decimals, converted in binary numbers, forming two lapses of time memorized and selected, by taking in account an eventual carry over.(b) a second array of complete subtractors adapted to take the complement of the said first difference if the subtrahend is greater than the minuend, the carry over issued from the difference between the decimals of the greatest weight being used to form the complement number, this carry over being further used as discrimination element between the said first difference and the complementary number.

Abstract: An electronic timepiece, wherein an oscillator drives a frequency divider and the output of the frequency divider controls via a driver circuit a display device.A short-circuit between an output of the driver circuit and a pole of the power supply causes a selector inserted between two of the stages of the frequency divider to feed to the stage following the selector, not as normally, the frequency delivered by the preceeding stage but a higher frequency. This serves for speeding up circuit testing.

Abstract: It is known that an electro-luminescent display increases its light emitting efficiency with the current through it. Such a display in a watch run from a small battery, is fed by short impulses of high-intensity current by means of discharges from two capacitors which are alternately charged and discharged by transistor switches opened and closed by externally supplied impulses. The battery current is thus kept substantially constant and low. A series of digits or segments thereof, if used, may be fed in sequence with the impulses.

Abstract: A device for maintaining constant the amplitude of the oscillation of an electro-magnetically driven balance wheel of a timepiece, whereby a first voltage is generated of an amplitude proportional to the amplitude of oscillation of the wheel. This is compared with a reference voltage and a signal is derived corresponding in amplitude and sign with the difference. This signal is then used to control the application of driving pulses to the balance wheel. The said driving pulses are preferably much shorter than one half-period of the balance wheel.

Abstract: An electronic timepiece including a time-keeping circuit having serially connected counters generating day, hour, minute and second signals; a four digit display connected to the counters; a selecting circuit coupled to the counters and having one mode for the display of two units of real time, and a plurality of other modes for the selection and display of each single unit of time for correction; a first switch connected to the selecting circuit and actuable to sequentially advance the selecting circuit from one mode to another; and a second switch coupled to the selecting circuit and the counters for causing the display of a different two units of real time when the selecting circuit is in the first mode, and for correcting each individually selected unit of time when the selecting circuit is in one of its other modes.

Abstract: A device for correcting running of an electronic watch comprises two contactors acting on respective bistable circuits in turn acting on a combinatory circuit controlling a counter which provides binary correction information to an inhibitor circuit. The latter is arranged to inhibit a number of pulses of a pulse generator having a predetermined nominal frequency above a given value, to set the frequency at said given value prior to division to provide accurate clock pulses fed to a device for indicating the time. Successive actuation of respective contactors corresponds to increasing or decreasing the number of inhibited pulses from an approximate number stored in a programmable memory.