Abstract: An electronic device (1) has a substrate (2) of monocrystalline silicon on which is an integrated circuit (3). The integrated circuit is an oscillator containing a resonator, a maintenance circuit to cause the vibration of the resonator, and a frequency division chain. The maintenance circuit as well as the division chain are manufactured as CMOS circuits. The resonator is an integrated resonator (4) formed of a body cut out in a delimited surface part of reduced thickness (14) of the substrate (2), of a thin layer of piezoelectric material (10) deposited on at least a part (6) of the body, and of a thin metallic layer (11) deposited on the piezoelectric layer (10) so as to form an electrode.

Abstract: A multitasking controller comprising task storage means (2) for storing up to N tasks (P0,P1,P2,P3) each comprising a sequence of instructions, a microprocessor for processing, by time-sharing, a plurality of such N tasks, and a random access memory (12) for storing variable data created and used by said microprocessor. The microprocessor further comprises a scheduler (7) realized in hardware for controlling the use of said microprocess or by such processes, and program counter storage means for storing N program counters (Pc0,Pc1,Pc2,Pc3) each for use by the scheduler (7) is able select a different one of the program counters (Pc0,Pc1,Pc2,Pc3) when the task processed by the microprocessor is changed without the transfer of data from the random access memory (12). FIG.

Abstract: A watch (31) comprises an horological movement (32) associated with a liquid crystal display arrangement (34) located under the crystal (8) of such watch. The watch (31) comprises an active display arrangement (36) located within the watch case (4). In addition, the watch comprises a mirror (40) arranged in the back cover (6) of the watch and an enlarging lens (38) arranged under the crystal (8). The optical elements are arranged so that the light coming from the active display arrangement (36) is reflected by the mirror (40) in the direction of the enlarging lens (38).

Abstract: The piezoelectric resonator (1) comprises two plates (5,6) and at least two parallel bars (2 to 4) connecting the plates (5,6) to each other. The orientation of the quartz wafer in which the resonator (1) is cut and the arrangement of the electrodes (9 to 11, 15 to 17) on the bars (2 to 4) are such that these bars (2 to 4) vibrate in an elongation mode. The elongation mode of the bars is coupled to a plate and bar flexure mode to improve the thermal properties of the resonator. This resonator can be used in devices in which the dimensions of the resonator have to be as small as possible and/or in which its resonance frequency has to be as low as possible.

Abstract: The present invention relates to a reference voltage source in CMOS technology. The reference voltage source is based on the use of two compatible bipolar transistors (T1) and (T2) working at different current densities. A transresistance amplifier (1) connected as a negative feedback between the collectors and bases of (T1) and (T2) delivers the reference voltage (V.sub.ref). A conductor block (4) allows sufficient current to be drawn through the resistors (2) and (3) to render neglible the base current of (T1).

Abstract: The invention concerns an amplifier comprising means for compensating for the input drift voltage. During a preparation phase, the input signal of the amplifier (10) is nullified by short-circuiting the inputs (12) and (13) by means of the change-over switch (30) and the output (15) is connected to a capacitor (40) and to a secondary input (14) of the amplifier. The secondary input has a substantially lower gain than the gain relative to the main input (13), which makes it possible substantially to reduce the effect of charge injection caused by opening of the switch (60). In the amplification phase, the input (13) receives an input signal (V1) and the input drift voltage (.alpha.V) is compensated by means of the value stored in the capacitor (40).

Abstract: A method for manufacturing a device with micro-shutters, e.g., a light modulating device, includes the following steps: producing a first grid presenting cells; providing a plane support by depositing a layer of organic material on the grid filling the cells; producing a second grid on the layer of organic material; depositing a fine metallic layer on the second grid; cutting shutters and shutter attachments in the fine metallic layer; and removing the organic material layer in the cells to free the shutters.

Abstract: There is disclosed a differential amplifier which comprises bipolar transistors which may be produced using MOS technology and wherein the amplifier is particularly useful when the transistors have a poorly defined current gain. The amplifier includes a first pair of transistors having emitters connected in common and having bases forming the inputs to the differential amplifier. A second pair of transistors identical to the first pair are coupled such that the emitters and bases of said second pair are connected respectively to the emitters and bases of the first pair. The collectors of the second pair of transistors are connected to a current generator and to the input of a transconductance amplifier such that the transconductance amplifier causes the sum of the emitter currents of the first and second pairs of transistors to be controlled by the current supplied by the current generator.

Abstract: A display device comprising an insulating carrier (1) and shutters (V) which are capable of rotating under the effect of an electrical field (E) which is perpendicular to the plane of the carrier. The shutters (V) are grouped in pairs and are controlled by applying a voltage between a shutter and a counter-electrode (c). The control may be multiplexed if the shutters of the same pair have different potentials applied thereto.

Abstract: Axes X', Y' and Z' of a resonator are established from the axes X, Y and Z of a quartz crystal by virtue of two rotational movements through angles .phi. and .theta., respectively. The resonator is energized to vibrate in accordance with the fundamental torsional mode. The angles of cut .phi. and .theta. are such that the first-order temperature coefficient is zero. The torsional mode may be coupled to a flexural mode in order to render the second-order temperature coefficient zero. The fork tines extend in the X' direction. In other embodiments the tines extend in the Y' direction and the rotation .phi. and .theta. are about the X and Z' axes, respectively.

Abstract: Integrated accelerometers comprising a flap (2) fixed to a carrier (1) by two attachment means (3) which are disposed symmetrically and in line with one side of the flap. An electrode (5) deposited on a plate (4) permits acceleration to be measured by measuring the corresponding variation in capacitance between the flap (2) and the electrode (5).

Abstract: A ZT-cut quartz crystal resonator comprises two thin rectangular plates connected together by at least one resonant arm which itself is connected to a support zone by a linking bar. A pair of electrodes is provided on the quartz resonator for receiving alternating electrical signals of opposite polarity for effecting in-phase contour-mode vibration of the plates while making the arms to vibrate in opposite phase to the plates.

Abstract: 44A pressure transducer which uses the principle of a variation in the resonance frequency of a membrane when it is subjected to a variable pressure. The transducer comprises a vibrating membrane which is fixed on a support member forming a cavity, and a cover member forming a second cavity. Excitation of the membrane is facilitated since it is made of a piezoelectric material and is provided with electrodes. An object of the invention is to provide a digital output pressure transducer which can be minaturized and which has low power consumption.

Abstract: A dynamic amplifier comprises two complementary MOS transistors T1 and T2 which are connected in series, the gates G1 and G2 of which are connected to each other and to an input node by way of capacitors C1 and C2. The gate of T1 is connected to its drain by a switch means S1. The input node is connected to an input terminal and a reference voltage terminal by switch means S4 and S3 respectively and an output node between T1 and T2 is connected to an output terminal by switch means S5. The gate of T2 is connected by way of a switch means S2 to a bias voltage source.

Abstract: Each segment of a display device, e.g., a seven-segment display comprises at least one shutter normally obturating a cavity in a carrier on a base plate. Each shutter is suspended by two resilient attachments and can turn about a torsion axis established by these attachments under the influence of an electric field applied between a common electrode on a transparent cover plate and an electrode, individual to the shutter at the bottom of its cavity. An optical contrast is provided by light reflection or absorbance caused by a shutter remaining in a rest obturating position or rotating to an open position to allow light absorption in an absorbing layer backing the base plate which is transparent. A selective light transmission (light valve) construction is equally possible. The shutters themselves may be used as one electrode of each pair, with the torsion axis along a shutter edge.

Abstract: A device is provided for the rapid and easy introduction of data into an apparatus, e.g., for setting a digital watch. A binary decision device continuously tests the state of a plurality of finger responsive sensors A, B, C and D and produces control signals for a operational unit. The operational unit comprises an up-down counter which can be incremented or decremented by signal F1 to F8 at different frequencies. An inertia effect is produced by maintaining counting of the up-down counter between two successive actuations of the sensors. Touching sensor B or C stops the counter. Sweeping A, B, C, D speeds the incrementing rate (up to a top rate) or slows the decrementing rate while sweeping D, C, B, A acts conversely. Touching A and D alone, respectively, single-steps the counter down and up. The amount by which the rate is speeded or slowed can be made to depend on the speed of sweeping the sensors as well as the number of times they are swept.

Abstract: An electronic filter circuit is described having first and second selective circuits each of said selective circuits having an input terminal for receiving an input voltage, each of said selection circuits comprising a first capacitor, an integrator means providing an output signal, switching means for connecting said capacitor alternatively between said input terminal and said integrator output, respectively between a common input-output terminal and said integrator input, in response to a switching signal, further comprising means for providing first and second switching signals to said first and second selection circuits, said signals having the same frequency but differing in phase whereby each of said first and second selective circuits provides for alterate sampling of an input signal and means for combining said integrator means output signals.

Abstract: A reference voltage source implemented in silicon-gate CMOS transistor technology comprises a pair of reference transistors of the same conductivity type, the gates of which are made of polycrystalline silicon and differ from each other by the type of doping. The reference voltage can be temperature-compensated by adding an auxiliary compensation voltage source or by establishing a predetermined ratio of current densities in the pair of reference transistors operating in weak inversion.

Abstract: The resonator according to the invention comprises at least one quartz crystal in the form of a rectangular thin plate, of which the length l is directed along an axis X', the width w along an axis Y' and the thickness t along an axis Z', and which vibrates in a contour mode. The axis Z' is situated in the plane of the electrical axis X and optical axis Z of the crystal and forms with the axis Z an angle .phi. such that16.degree.<.phi.<36.degree.and the axis Y' forms with the mechanical axis Y of the crystal an angle .theta. such that10.degree.<.theta.<30.degree.This resonator presents a zero temperature coefficient of the first order and is not dependent to any critical extent on the dimensional ratio between the sides w and l of the plate; the temperature coefficients of higher order are very small. The piezo-electric coupling is such that the optimized mode of oscillation is the only one excited in practice.

Abstract: An integrated control device for controlling a device such as a LED display or a miniature stepping motor for an electronic watch comprises at least one insulated-gate field effect transistor for controlling the supply of current to the element. The gate of the F.E.T. is connected to a control circuit including a voltage multiplier comprising a series-connected chain of rectifiers and a plurality of capacitors connected between the respective junctions between rectifiers and alternate inputs. High frequency signals of opposite phase are supplied to the inputs under control of an input control signal. Circuit means are provided for starting the action of the voltage multiplier at the beginning of an input control signal and for short-circuiting the output of the control circuit at the end of an input control signal.