Abstract: There is described an amplitude-controlled electronic device (1) intended to generate at an output (11; 11a) an alternating output signal (S1; Sosc) of substantially constant amplitude. This electronic device includes a measuring branch (20; 20*; 201) for generating a measuring voltage (Vout) representative of the amplitude of the output signal (S1; Sosc) and means for generating a reference voltage (Vref) including a reference branch (40; 40*; 400) matched with the measuring branch and at the input (A) of which a voltage reference (U0) is selectively switched. A comparator (30; 300) is arranged for comparing the measuring and reference voltages and generating in response a control signal (Sc) which is applied on a control terminal (12) of the electronic device. According to the invention, the matching of the measuring and reference branches allows the sensitivity of the control signal to temperature and manufacturing process variations to be substantially cancelled.

Abstract: The structure described forms a PIFA antenna (10) and a shield container (11) which can contain electric circuits, particularly a transceiver associated with the antenna. It is arranged to be incorporated in a portable electronic apparatus of small volume, for example a wristwatch. In order to be as far away as possible from a body located under the apparatus and capable of absorbing or disturbing part of the radiation, the antenna (10) is arranged in the top part of the structure. The cover (14) of the case (11) includes a substantially plane external surface and an indentation (17) in a peripheral zone of the cover. The radiating element (20) of the antenna extends in the plane of said external surface, above said indentation whose bottom surface (18) forms the antenna's ground plane.

Abstract: The invention concerns a non acoustic alarm device, intended to be fitted to a unit worn in contact with the body, such as a timepiece or a portable telephone, including a case, a moving mass within said case intended to transmit vibrations thereto, a coil (L) electromagnetically coupled to said moving mass to cause it to oscillate, and an excitation circuit of said coil. According to the invention, the device includes means for measuring the instantaneous oscillation frequency of the coil-moving mass unit during the oscillation in progress, as well as means for generating a series of excitation pulses for said coil during the following oscillation, whose characteristics are a function of the measurement of said instantaneous oscillation frequency. Due to its high yield and low energy consumption, this device is particularly suitable for watches.

Abstract: The inductive micro-sensor includes a flat micro-coil (2) formed on an integrated circuit (4) by long conductive segments Si with a high aspect ratio, each segment Si being arranged along a perpendicular direction with respect to the next segment Si+1 to form a spiral type structure with an overall square or rectangular contour. It is characterised in that each long segment Si is connected to the next long segment Si+1 by means of a short segment si forming, with the two long segments Si, Si+1, angles &agr; and &agr;′ greater than 90°.

Abstract: The invention concerns a mixer, in particular for an dual conversion receiver. The mixer includes a first variable transconductance stage (A) controlled by a high frequency carrier signal, this first stage including first (37) and second (38) terminals delivering a first signal; and a second stage (B) connected to said first terminal of the first stage including, in parallel, first (T32) and second (T33) switching means respectively controlled by first (in2) and second (in2b) phase opposition control signals at a first intermediate frequency (IF1), these first and second switching means being powered by a substantially equal current supplied by polarisation means (34). The mixer according to the invention is characterised in that it further includes means (T36) for modulating said first signal delivered by said first stage by means of a third control signal (in3) at a second intermediate frequency (IF2).

Abstract: An optical device (20) is provided using at least one film (23) of cholesteric liquid crystal to reflect at least one predetermined wavelength band from an incident light. This device is characterized in that a non zero birefringence gradient is present in a portion or the entire thickness of said film. The gradient may be obtained in particular by superposing layers (24a-24j) having increasing or decreasing respective birefringence coefficients. The birefringence gradient has the effect of removing the lateral bands of the reflection spectrum, hence making the color of the reflected light more brilliant and more saturated. The effect is particularly advantageous in the case of the color red, for which the lateral band located on the yellow side is perceived strongly by the human eye.

Abstract: The dual-modulus prescaler circuit for a frequency includes several dividers-by-two of the asynchronous type, connected in series, a phase selector unit (11) inserted between two of the dividers-by-two (10, 12a) and a control unit for supplying first control signals(S0, S1, S2, C1, C2) to the selector unit as a function of a selected mode. Said control unit receives four signals phase shifted by 90° with respect to each other from a first master-slave divider and supplies a selected one of the four phase shifted signals. The selector unit includes a first amplifying branch (21) receiving two first phase shifted signals (F2I, F2Ib), a second amplifying branch (22) receiving two second phase shifted signals (F2Q, F2Qb), and a selection element (23) connected to each branch. The first control signals (S0, S1, S2) are supplied to the first and second branches, and to the selection element for selecting one of the four phase shifted signals (F2) at one output in a determined division period.

Abstract: An optical device, for homogenising the lighting in an image plane, defined by a digital optical sensor wherein the optical device is formed of a block made of transparent homogenous filtering material, this block having a substantially uniform absorption coefficient for all the wavelengths of the visible optical spectrum which pass through it, and having a variable thickness suited to a determined absorption profile.

Abstract: The present invention concerns a piezoelectric motor of the type including:

Abstract: A display assembly includes two superposed, respectively upper (24) and lower (26) display devices, characterized in that the upper display device (24) includes a display cell (28) arranged above an optical valve (30), said double structure being arranged so as to be transparent in a first state to make the lower display device visible (26), and so as to display item of data in a second state, control circuits supplying a control voltage to the cell (28) to cause it to switch from the first state to the second state and vice versa, characterized in that the cell (28) is a display cell of the type including a diffusing or reflective liquid crystal in the second state.

Abstract: Generator of the clockwork type including a rotor formed of two flanges 8 supporting magnets 9 and arranged at the end of shaft 5 having a diameter D at its centre. The stator is formed of three coils 11a, 11b, 11c carried by a support made in two parts 21 and 22 allowing the coils to be mounted in a separate manner between the rotor flanges upon the assembly of the rotor with the stator. Accordingly, the distance separating two adjacent coils can be less than the diameter D of the rotor shaft after the assembly of the generator. This allows the magnet-coil coupling to be increased by increasing the dimensions of the coils so that the overlapping surface between the flanges 8 which carry the magnets 9 is optimum.

Abstract: The case (2) includes means (4a, 4b; 24, 25) for attaching a wristband (3) to a wrist and means for connecting a flexible support (11) of a keyboard (13, 23) with keys (14, 15) connected inside the case (2) to a data processing unit (29) controlling a display device (16, 16a, 16b) allowing characters, supplied by the processing unit (29), to be displayed on a dial (7) of the case (2), the electric power for the electronic components of the assembly being provided by a power source (10). The case is characterized in that the flexible support (11) for the keyboard (13, 23) is connected on one side of the case (2) and its length substantially corresponds to the size of the wrist outline, and in that the wristband (3) totally covers the keyboard (13, 23) while being provided with fixed attachment means (4b, 24) diametrically opposite the means for connecting the keyboard (13, 23) and removable attachment means (4a, 25) located in proximity to said connection to the keyboard.

Abstract: Analog display horological piece, comprising at least a step by step motor (18, 20) driving hands (MN, H) for displaying a time keeping information; means of controlling said step by step motor; position detectors (51-62) providing in angular sector defined on the piece, the activation of each of said position detectors enabling the selection of a predetermined digital piece of information (0-9, ×, ÷, +, −, =); means (36, 40) for inputting said selected digital piece of information; and means (22) for processing said digital information. The control means are adapted so that at least one of said hands (MN, H) is driven so that it indicates the angular sector corresponding to the position detector (51-62) which is activated so as to confirm the selection of the digital piece of information (0-9, ×, ÷, +, −, =).

Abstract: There is described a colored photovoltaic cell (1) with a semiconductor, preferably silicon, which has high efficiency and a pleasing colored appearance, allowing it to be used as a dial for a watch or another electronic apparatus powered by the cell. The cell includes a reflective metal substrate (2) serving as the bottom electrode, a stack of hydrogenated amorphous silicon layers forming p-i-n junctions (8), and a transparent top electrode (9). The latter may be coated with a layer (16) of slightly diffusing lacquer, which may be colorless or colored. The respective thicknesses e1 of the top electrode and e2 of the silicon are combined as a function of the refractive indices of the materials so as to produce an interferential reflection in a predetermined reflection spectrum.

Abstract: A first (5) of the indicators and a first pipe (1) form part of an angular position indicating moving part (MR1) carrying a plate (9) co-operating with a first sensor (11) for generating a position signal for said indicator as a result of discontinuities in the material of said plate. A second display indicator (6) coaxial to said first indicator is coupled to a second angular position indicating moving part (MR2). The latter, which is mounted at a distance from the first moving part, is in a meshing relationship with a second pipe (2) carrying said second indicator. This second moving part carries a second plate (18) co-operating with a second sensor (20), for generating a position signal for said second indicator as a result of discontinuities in the material of said second plate.

Abstract: The method for hermetically encapsulating microsystems in situ consists, in a first phase, of mounting on a common substrate (1), several microsystems (6) surrounded by a metal adhesion layer (4) deposited on the substrate (1). In a second phase, in a common deposition step a first metal layer (7) is deposited by electrolytic means on each microsystem (6) and on an annular zone (7a) of the adhesion layer (4) surrounding each microsystem (6), so as to completely cover each microsystem by overlap. Subsequently a second metal layer (9) is deposited by electrolytic means on the first metal layer (7) and on the adhesion layer so as to cover most of the first layer with the exception of at least one passage (10) per microsystem (6), providing access to the first layer (7). The metal of the first layer is different from the metals of the adhesion layer, the second layer and the microsystem.

Abstract: Solid optical guide (10) with microprisms (20) of refractive index n, for uniformly illuminating a surface (4) in grazing incidence at an angle &thgr;1 in which a plane angle &dgr; of the cross-section develops with respect to the surface (4) a substantially perpendicular face (15) and a substantially parallel face (14), in which microprisms (20) are structured in hollows, one facet (21) of said microprisms oriented towards the face (15) has its edge (22) formed with the parallel face (14) inclined at an angle {right arrow over (&agr;)} with respect to the axis of the guide and its edge (23) formed with the perpendicular face (15) inclined at an angle {right arrow over (&ggr;)} with respect to the perpendicular to the surface to be illuminated, the values {right arrow over (&agr;)} and {right arrow over (&ggr;)} being determined from characteristics n, &thgr;1 and &dgr; of the guide.

Abstract: The invention concerns a liquid crystal display cell including two close substrates (2), separated by a sealing frame which delimits a sealed enclosure in which the liquid crystal molecules (4) are confined, and spacers (8) intended to maintain a constant spacing between said substrates (2), characterised in that the sealing frame and/or the spacers (8) are formed of an anisotropic polymer which is used to align and orient the liquid crystal molecules.

Abstract: The present invention concerns a portable object such as, in particular, a timepiece (1) including means for controlling at least an electronic function such as an horological function, these control means including at least a touch-sensitive key (16) for selecting the desired electronic function, characterized in that the control means further include a strain gauge (22) allowing the selection of the desired electronic function to be confirmed and/or the electronic function to be activated, the confirmation and/or activation of said electronic function being effected by applying pressure to the portable object via the effect of which the strain gauge (22) generates a control signal which will be applied to an electronic data processing circuit, said portable object also being able to include means able to emit an acoustic signal to indicate to a user that the desired function has actually been switched on.

Abstract: The present invention concerns chiral doping agents allowing a modification to be induced in the spiral pitch of a cholesteric liquid crystal, said doping agents including a biactivated chiral unit at least one of whose functions allows a chemical link to be established with an isomerisable group, for example by radiation, said group possibly having a polymerisable or co-polymerisable end chain.