Abstract: A photovoltaic cell (1) including a first front collector layer (4), an amorphous silicon layer (6) on the first layer (4) and a second conductive layer (8) on the amorphous silicon layer (6). Electrical connection of the second conductive layer (8) to the first layer (4) is made through the amorphous silicon layer (6) at the periphery of the photovoltaic cell, the electrically conductive layer (8) comprising a positive peripheral bus (8?), which is connected to the TCO first layer (4) and to at least one positive connection terminal at one end of the positive peripheral bus, and a negative peripheral bus, which is connected to a negative connection terminal, and the positive and negative peripheral buses being asymmetrical relative to one another, with the positive peripheral bus being longer than the negative peripheral bus.

Abstract: A rotary piezoelectric motor (1), in particular for a timepiece, including a rotor (3) configured to rotate and actuate a mechanical device, and a stator (2) configured to rotate the rotor (3), the stator (2) including a piezoelectric actuator provided with a resonator (29) arranged to perform an oscillatory motion, and a fixed element (4). The resonator in a movable element (5) arranged at a distance from the fixed element (4) and connected to the fixed element (4), the piezoelectric actuator being configured to move the movable element (5) against the rotor (3) to make it rotate, the movement of the movable element (5) making the rotor (3) rotate in a first direction.

Abstract: A piezoelectric balance spring (3) for a circuit (10) for self-regulating an oscillation frequency of an oscillating mechanical system (2, 3), or an energy recovery circuit or a motor circuit for actuating the movement or for the automatic maintenance thereof. The piezoelectric balance spring (3) includes at least one piezoelectric layer (7, 7?, 17, 17?, 27, 27?) provided on a top face (20) or bottom face of a certain number of coils of the spring in a plane, and at least two pairs of electrodes (8a, 8b, 8c, 8d), whereby the electrodes of each pair are provided on two opposing faces of the same piezoelectric layer or respectively two piezoelectric layers so as to apply a reverse bias voltage on each pair of electrodes.

Abstract: A horological movement includes an analogue time display, a gear train, a barrel driving the analogue display via the gear train, and an oscillator formed of a resonator, including a balance and a piezoelectric spring, and a mechanical escapement coupling the balance to the gear train. This horological movement further includes an electric energy source which is associated with the electronic control circuit, which is arranged to be able to control the application of an electrical supply voltage to the piezoelectric spring to excite the oscillator to obtain a functional oscillation of the resonator and then to maintain this functional oscillation. The mechanical escapement is an escapement for counting the alternations of the functional oscillation, to pace the running of the horological movement, without the resonator being able to receive from the barrel via this mechanical escapement enough mechanical energy to maintain the functional oscillation.

Abstract: An horological movement includes an analogue time display, a geartrain, a barrel and an electromechanical oscillator, which is formed of a resonator, including a balance and a piezoelectric balance-spring, and a mechanical escapement, and further includes an electronic control circuit connected to an electrical energy source and arranged to be able to control the application of an electrical voltage on at least one electrode of the piezoelectric balance-spring so as to generate driving electrical pulses for the oscillator. The horological movement is configured such that the barrel is capable, in a first main state, of maintaining alone a functional oscillation of the oscillator with a first amplitude, while in a second main state, the electronic control circuit powers the piezoelectric balance-spring to maintain, partially or fully, the oscillation of the resonator with a second amplitude greater than the first amplitude for any spatial orientation, the second amplitude being preferably constant.

Abstract: A photovoltaic cell (1) including a first front collector layer (4), an amorphous silicon layer (6) on the first layer (4) and a second conductive layer (8) on the amorphous silicon layer (6). Electrical connection of the second conductive layer (8) to the first layer (4) is made through the amorphous silicon layer (6) at the periphery of the photovoltaic cell, the electrically conductive layer (8) comprising a positive peripheral bus (8?), which is connected to the TCO first layer (4) and to at least one positive connection terminal at one end of the positive peripheral bus, and a negative peripheral bus, which is connected to a negative connection terminal, and the positive and negative peripheral buses being asymmetrical relative to one another, with the positive peripheral bus being longer than the negative peripheral bus.

Abstract: A piezoelectric resonator, in particular for a rotary piezoelectric motor, the resonator including a stationary base and an oscillating mass extending about a longitudinal axis, the oscillating mass being provided with at least one inertia-block, preferably two opposing inertia-blocks, wherein the resonator includes a flexible blade guide connecting the oscillating mass to the base, so that the oscillating mass can be oscillated about a centre of rotation in a pendulum movement, the flexible guide including at least one first flexible blade connected to the base and/or to the oscillating mass to allow the displacement of the oscillating mass relative to the base, the flexible blade guide including a spiral spring connected to the base and/or to the oscillating mass, the spiral spring including at least partially an electrically actuatable piezoelectric material to deform the spiral spring and oscillate the oscillating mass.

Abstract: A piezoelectric resonator, in particular for a rotary piezoelectric motor, the resonator including a stationary base and an oscillating mass extending around a longitudinal axis, the oscillating mass being provided with at least one flyweight, preferably two opposing flyweights, wherein the resonator includes a flexible guide connecting the oscillating mass to the base, so as to be able to cause the oscillating mass to oscillate about a centre of rotation in a pendulum movement, the flexible guide comprising at least a first flexible blade connecting the base to the oscillating mass, the first flexible blade comprising at least in part an electrically actuatable piezoelectric material for deforming the first flexible blade and causing the oscillating mass to oscillate.

Abstract: A piezoelectric resonator for a rotary motor, the resonator including a stationary base and an oscillating mass extending around a longitudinal axis, the oscillating mass having an inertia-block. The resonator includes a flexible blade guide connecting the oscillating mass to the base, so as to be able to cause the oscillating mass to oscillate about a centre of rotation in a balance movement, the flexible guide including a first RCC-type pivot provided with an intermediate moving element, a first pair of flexible blades connecting the base to the intermediate moving element, and a second pair of flexible blades forming a second RCC-type pivot connecting the intermediate moving element to the oscillating mass, the piezoelectric resonator including a first flexible blade connecting the intermediate moving element to the base, the first flexible blade including at least in part a piezoelectric material that can deform the first flexible blade and cause the oscillating mass to oscillate.

Abstract: A rotary piezoelectric motor, in particular for a timepiece, the motor including: a rotor configured to rotate and actuate a mechanical device, a stator configured to rotate the rotor, the stator including a piezoelectric actuator, the piezoelectric actuator including a moving element whose movement causes the rotor to rotate in a first direction, the piezoelectric actuator including only two electrically actuatable resonators, the two resonators being connected to the moving element to move it against the rotor to cause it to rotate, the two resonators being arranged relative to the moving element so as to cause the moving element to oscillate in first and second directions different from each other, each resonator including a centre of rotation, the two resonators being disposed relative to the moving element so that, around each centre of rotation, the torque resulting from all the acceleration forces being applied in the plane of each resonator is zero.

Abstract: A rotary piezoelectric motor (1), in particular for a timepiece, including a rotor (3) configured to rotate and actuate a mechanical device, and a stator (2) configured to rotate the rotor (3), the stator (2) including a piezoelectric actuator provided with a resonator (29) arranged to perform an oscillatory motion, and a fixed element (4). The resonator in a movable element (5) arranged at a distance from the fixed element (4) and connected to the fixed element (4), the piezoelectric actuator being configured to move the movable element (5) against the rotor (3) to make it rotate, the movement of the movable element (5) making the rotor (3) rotate in a first direction.

Abstract: The piezoelectric balance spring (3) is provided for a circuit (10) for self-regulating an oscillation frequency of an oscillating mechanical system (2, 3), or an energy recovery circuit or a motor circuit for actuating the movement or for the automatic maintenance thereof. The piezoelectric balance spring (3) comprises at least one piezoelectric layer (7, 7?, 17, 17?, 27, 27?) disposed on a top face (20) or bottom face of a certain number of coils of the spring in a plane, and at least two pairs of electrodes (8a, 8b, 8c, 8d), whereby the electrodes of each pair are disposed on two opposing faces of the same piezoelectric layer or respectively two piezoelectric layers so as to apply a reverse bias voltage on each pair of electrodes.

Abstract: An horological movement includes an analogue time display, a geartrain, a barrel and an electromechanical oscillator, which is formed of a resonator, including a balance and a piezoelectric balance-spring, and a mechanical escapement, and further includes an electronic control circuit connected to an electrical energy source and arranged to be able to control the application of an electrical voltage on at least one electrode of the piezoelectric balance-spring so as to generate driving electrical pulses for the oscillator. The horological movement is configured such that the barrel is capable, in a first main state, of maintaining alone a functional oscillation of the oscillator with a first amplitude, while in a second main state, the electronic control circuit powers the piezoelectric balance-spring to maintain, partially or fully, the oscillation of the resonator with a second amplitude greater than the first amplitude for any spatial orientation, the second amplitude being preferably constant.

Abstract: A horological movement includes an analogue time display, a gear train, a barrel driving the analogue display via the gear train, and an oscillator formed of a resonator, including a balance and a piezoelectric spring, and a mechanical escapement coupling the balance to the gear train. This horological movement further includes an electric energy source which is associated with the electronic control circuit, which is arranged to be able to control the application of an electrical supply voltage to the piezoelectric spring so as to excite the oscillator to obtain a functional oscillation of the resonator and then to maintain this functional oscillation. The mechanical escapement is configured so as to be an escapement for counting the alternations of the functional oscillation, so as to pace the running of the horological movement, without the resonator being able to receive from the barrel via this mechanical escapement enough mechanical energy to maintain the functional oscillation.