Ebauches S.a.

Eta Sa Fabriques D'ebauches

Eta S.a. Fabriques D'ebauches Eta 13

Rene Besson

Yves Guerin

Alphonse Bron

Fridolin Wiget

Ali Schneiter

Igor Scherrer

Roberto Zafferri

Jean-Luc Breguet

The purpose of the invention is the realization of a motor assembly formed from a stepping motor and its control circuit capable of operating at a maximum speed substantially greater than that obtainable with comparable existing assemblies. This is effected by substituting for the single coil or for each coil of a known motor two or more windings and adopting a control circuit which connects the windings in series or parallel according to whether motor drive pulses of low or high frequency are applied thereto. The total number of winding turns and the sum of the resistances of the windings are preferably chosen to be equal respectively to the number of turns and the resistance of the coil which they replace in order to avoid basic modification of the characteristics and performances of the motor when operating at low speed. When the windings are connected in parallel their resistance and equivalent self-inductance are less than that of a single coil. The energy transfer from the voltage source to the rotor of the motor is increased and facilitated and the maximum speed of the motor is considerably increased.

Stepping motor assembly

A watch comprising at least a minute hand, an hour hand and a knobbed shaft which can occupy an extended axial position known as a correcting position. Minute-by-minute correction or correction by whole time zones is operated with the knobbed shaft in the same extended position by the selection of the speed at which the knob is rotated. Time zone correction always uses as point of reference the real time at the moment of actuation of the knob into the extended position, and the watch includes means operative to cancel any step-by-step correction of the minute hand which may have preceded the time zone correction.

Electronic time piece comprising a device for adjusting the time display

The invention provides an electronic watch having an analog display with time indicating hands, a digital display and control means including a crown adapted to act on contacts arranged so as to provide signals representing rotary and axial displacements of said crown to an electronic selection and correction circuit. Responding to movements of the crown, the electronic circuit determines the operating mode of the watch and modifies the indications given by the displays. In a special synchronizing mode the two displays are set to indicate the same information and the analog form thereof may be adjusted to coincide with the digital form.

Watch having an analog and digital display

The device includes two driving circuit (C.sub.1, C.sub.2) each of which includes six power transistors (T.sub.11 -T.sub.16, T.sub.21 -T.sub.26) that are connected in pairs into three parallel circuit branches. A first coil (B.sub.11) of one of the motors and a first coil (B.sub.21) of the other are, on the one hand, both connected to the junctions of the transistors of one of the branches of one of the driving circuits (C.sub.1) and, on the other hand, respectively connected to the junctions of the transistors of the two other branches of this circuit. The same applies for the second coils (B.sub.12, B.sub.22) of the motors and the other driving circuit (C.sub.2). The various transistors are controlled so that the two coils of the same motor simultaneously receive the current pulses which are needed to make it turn but by preventing the simultaneous application of current pulses to a coil from one of the motors and to a coil from the other. This arrangement makes it possible to save four transistors and two output terminals on the integrated circuit used to control the motors.

Control device for two bidirectional step motors

For performing a very precise detection of the position of at least one hand, the watch is provided with an electro-optical detection device. The detection device comprises a wheel 8 carrying a mirror 26. The wheel 8 is intermittently driven by the driving member 6 for defining n angular positions of the mirror 26. The member 6 is meshing with the gear train 12 of the watch. It further comprises a light emitter 30 and a light receiver 32 which receives a light beam when the mirror 26 is in an angular position corresponding to the reference position of the hand. The number n is inferior to the number of steps performed by the hand during a complete revolution of said hand.

Electronic watch with means for detecting the movement of a hand through

A watch which comprises movable analog display members, a dial and a digital display cell surrounded by said dial. The watch is further provided with means that can be controlled by the user of the watch, for making the digital display device visible or invisible, as desired. The digital display cell is of the twist nematic type. A liquid crystal layer 60a is positioned between two polarizers 60b and 60c. Polarizer 60c can be rotated about an axis 12 perpendicular to its plane by actuating means 13a, 14, 15, 17 which is accessible from the outside of the casing of the watch. The cell can be made substantially invisible by rotating the movable polarizer 60b in order to position its polarizing plane either parallel or perpendicular to the polarizing plane of the other polarizer 60c, depending on whether the color of the dial around the cell is dark or light respectively. Other optical arrangements are disclosed for causing the display device to take selectively the color of the dial and a second color different from the dial's color.

Watch having an analog display and a digital display

An electronic watch comprising a stepping motor for driving a mechanism for displaying the time information, a quartz oscillator, a frequency divider with an adjustable division factor, a circuit for adjusting the division factor, a memory containing data relating to the magnitude of said adjustment and a logic circuit which, in response to an interrogation signal, produces a measuring signal which is supplied to the coil of the stepping motor and which comprises pulses whose distribution is representative of the division factor and the frequency of the oscillator and whose duration is sufficiently short so as not to cause the motor to turn and sufficiently long to cause a magnetic stray field of the coil of the motor which can be detected by an external apparatus for measuring the rate of the watch.

Analog-display electronic timepiece comprising a divider with an

Reduces the consumption of an electronic time piece equipped with a motor 4 driving a display unit 5. A quartz oscillator 1 feeds a supply circuit 3 through a frequency divider 2. The supply circuit 3 of the motor and its control circuit 9 periodically decrease the pulse energy supplied to the motor in response to a reference signal 8.2 provided by a reference counter say every 60 seconds. The energy then supplied to the motor is regulated as a function of the presence or absence of a signal delivered by a detection switch 7 operated by the display unit. If the detection switch does not close, compensating pulses are fed to the motor to catch up the lost seconds and the pulse energy is stepped up.

Reduction of energy consumption of electronic timepiece

A resilient member for connecting a crystal to a watch casing in which the crystal is used for generating acoustic signals. The member is of generally annular configuration with an inner portion rigidly connected to the circumference of the crystal, an outer peripheral portion connected to a supporting member of the watch casing, and a free portion extending between the inner portion and the outer peripheral portion. The free portion has a width and a thickness which permits flexing in a direction normal to the plane of the crystal so that the crystal can vibrate in a direction normal to its plane and act as an acoustical transmitting member.

Watch

Touch sensitive key switches of an electronic watch which control functions of the watch such as time setting, are gated to reduce the power consumption of the watch. The key switches are capacitive and are fed signals derived from the time standard oscillator of the watch. A change in the key switch signals when the switches are touched by the user activate the time setting functions. Gates are provided coupling the signals derived from the oscillator to the key switches so that the signals are applied to the key switches either under control of the user or during repetitive time periods, reducing the time the signals are applied to the key switches and the power necessary to continuously supply such signals to the key switches.

Electronic watch with touch-sensitive keys

A method for the display of information by means of a multi-element passive display device, the elements being separately activated, matrixially arranged and at least two elements required to be activated for display of information. The type of display involves use of a liquid crystal cell formed of electrodes and counter-electrodes carried by two glass plates respectively and the said elements are parts of said electrodes and counter-electrodes. The method comprises the election for activation of elements which are adjacent in any direction, that is, either those superposed, or side by side or diagonally arranged. This method enables use of conventionally shaped characters of greater individual size than heretofore available and is useful for display of dates and/or days of the week on electro-optic watches.

Method for the display of information

An electro-mechanical watch for advancing the uncorrected watch indicating members to their correct time indicating positions, after a correction period during which one of the indicating members is adjusted and the advancement of the uncorrected members is interrupted. In regular operation, a pulsed signal at a normal frequency from a watch frequency divider drives a stepping motor to advance the indicating members. At the beginning of the correction period, the pulsed signal is switched from the stepping motor to a pulse counter which counts the pulses occurring during the correction period. After the correction period, the pulsed signal is switched back to the stepping motor and a number of signal pulses at a higher than normal frequency, equal to the count of the pulse counter are applied to the stepping motor to advance rapidly the uncorrected indicating members to their correct time indicating positions.

Electro-mechanical watch

A device for automatically correcting the date indicator of an electro-mechanical timepiece to the first date of the next month at the end of each month. A pulse driven motor advances the date indicator one date in response to a plurality of pulsed drive signals with the motor advancing one step for each drive signal pulse, and at a speed corresponding to the drive signal frequency. A fixed number of drive signal pulses are applied to the motor each month to advance the date indicator through the dates of each month to the first date of the next month. A predetermined number of the drive signal pulses, corresponding to the number of dates of each month, are applied to the motor at a normal advance frequency normally to advance the date indicator. The remaining number of the drive signal pulses, for each month having less than 31 days are applied to the motor at a rapid advance frequency which is greater than the normal advance frequency, rapidly to advance the date indicator and indicate the first date of the next month.

Electro-mechanical calendar timepiece

An apparatus for advancing a date indicator of an electromechanical calendar watch. An hour indicator is driven through two normal operating revolutions of twelve hours each while keeping the date indicator fixed. The hour indicator then is driven through at least one more revolution at a speed much greater than the two normal operating revolutions to advance quickly the date indicator one day through a gearing connecting the hour indicator to the date indicator.

Electro-mechanical calendar watch

A capacitive adjusting device for a quartz crystal oscillator utilizing one of the metallization provided on the quartz crystal as a common electrode for a plurality of capacitors, the second electrodes of which are provided as metallized strips on a portion of a ceramic base member forming part of the casing containing the quartz crystal.

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Neuchatel, Switzerland

Rene Besson