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.

The invention disclosed fast start-up single-pin crystal oscillation apparatus and operation method thereof. The apparatus comprises a comparator, an envelope detector, a trigger, a crystal, a finite state machine, an amplifier gain module, a load capacitor module and a bias resistor. Compared to prior arts, the invention uses a single-pin oscillator structure to remove two external load capacitors, reduces start-up time, increase negative resistance, reduce load capacitor, and uses fast start-up algorithm to make the oscillation circuit operating at optimal power-consumption.

The invention relates to a watch, in particular a wristwatch, comprising an electro-optical converter, an opto-electrical converter, a light wave guide, a useful signal generating device and a watch display device. The electro-optical converter is formed to generate and feed a clocked light signal into the light wave guide. A reflector is arranged at a reflector end of the light wave guide, through which the clocked light signal is reflectable back into the light wave guide. A decoupling device is arranged at a feeding end of the light wave guide and is formed to decouple the reflected clocked light signal into the opto-electrical converter. The opto-electrical converter is formed to generate an electrical signal based on the reflected clocked light signal. The watch comprises an electrical signal path between the opto-electrical converter and the electro-optical converter, wherein the electro-optical converter is controllable for generating the clocked light signal based on the electrical signal of the opto-electrical converter. The useful signal generating device is formed to generate a useful signal based on a frequency of the electrical signal, wherein the watch display device is formed to display the time based on the useful signal.

A method for manufacturing a resonator in a substrate, including: a) modifying a structure of at least one region of the substrate to make the at least one region more selective; b) etching the at least one region to selectively manufacture the resonator.

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.

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.