Abstract: A micro vibration body includes a curved surface portion, which has an annular curved surface, and a recessed portion, which is recessed from the curved surface portion. A mounting substrate includes an inner frame portion and electrode portions, which surround an inner frame portion. A joining member is provided in an inner region of the mounting substrate surrounded by the inner frame portion. The recessed portion of the micro vibration body has a bottom surface defining a mounted surface located in the inner region and joined to the mounting substrate via the joining member. The curved surface portion has a rim that includes an end portion of the curved surface portion on an opposite side to the recessed portion. The rim has a rim lower surface located on a same plane as the mounted surface or a tip end portion of the mounted surface.

Abstract: A semiconductor device includes a pulse generation circuit which generates a pulse control signal for selectively supplying currents to the coils with the coil phases of the brushless DC motor, a selector circuit which selects arbitrary two signals, from detection signals corresponding to currents flowing respectively to the coils and a reference signal, a comparator circuit which compares the two signals selected by the selector circuit, timer counter, and a control circuit. The control circuit repeatedly controls an operation for the pulse generation circuit to output a pulse control signal for supplying electricity to one of the coil phases in a state where the rotor is stopped, an operation for the selector circuit selects the reference signal and one of the detection signals, from the detection signals.

Abstract: A semiconductor device includes a pulse generation circuit which generates a pulse control signal for selectively supplying currents to the coils with the coil phases of the brushless DC motor, a selector circuit which selects arbitrary two signals, from detection signals corresponding to currents flowing respectively to the coils and a reference signal, a comparator circuit which compares the two signals selected by the selector circuit, timer counter, and a control circuit. The control circuit repeatedly controls an operation for the pulse generation circuit to output a pulse control signal for supplying electricity to one of the coil phases in a state where the rotor is stopped, an operation for the selector circuit selects the reference signal and one of the detection signals, from the detection signals.

Abstract: When electricity is supplied sequentially one by one to coils with a plurality of coil phases provided in a stator of a brushless DC motor, detection is made on a difference of signals corresponding to currents flowing respectively to coils with another plurality of coil phases coupled to the electrically conductive coil phases due to an effect of a magnetic flux of a stopped rotor. A stop position of the rotor with respect to the stator is determined, based on the relationship between a result of the detection operation and a coil phase in association with each other.

Abstract: When electricity is supplied sequentially one by one to coils with a plurality of coil phases provided in a stator of a brushless DC motor, detection is made on a difference of signals corresponding to currents flowing respectively to coils with another plurality of coil phases coupled to the electrically conductive coil phases due to an effect of a magnetic flux of a stopped rotor. A stop position of the rotor with respect to the stator is determined, based on the relationship between a result of the detection operation and a coil phase in association with each other.