Abstract: A power generation device is provided. A weight may vibrate in one direction as an axial direction in response to an external vibration. A beam may be arranged in at least one side with respect to the weight in the axial direction of the weight, and vibrate together with the weight. A piezoelectric element may be mounted on the beam. A guide may include a hollow guiding a movement of the weight in the axial direction. A stopper may be included in the weight. The stopper may restrict an amount of the movement of the weight in the axial direction within a predetermined amount. A stopper wall may stop the movement of the weight in the axial direction by contacting with the stopper.

Abstract: A rotary system mounted piezoelectric generator has a folded beam structure in which the whole or part of a spring is formed with a piezoelectric generation element, in which one end is provided in a drive rotation system and in which a weight is attached to the other end, the degree of freedom of motion of the weight is two or more-dimensional and thus it is possible to easily change the locus thereof. The beam has a spiral structure such that when the drive rotation system is rotated, a centrifugal force applied to the weight is efficiently modulated by a second force other than the centrifugal force. A self-powered wireless communication terminal is operated with an extremely small amount of power consumption by use of a wireless connection control means and a modulation scattering response antenna which perform multilevel phase-shift keying (MPSK).

Abstract: A power generation device is provided. A weight may vibrate in one direction as an axial direction in response to an external vibration. A beam may be arranged in at least one side with respect to the weight in the axial direction of the weight, and vibrate together with the weight. A piezoelectric element may be mounted on the beam. A guide may include a hollow guiding a movement of the weight in the axial direction. A stopper may be included in the weight. The stopper may restrict an amount of the movement of the weight in the axial direction within a predetermined amount. A stopper wall may stop the movement of the weight in the axial direction by contacting with the stopper.

Abstract: An electrostatic induction-type vibration power generation device and method for improving a power generation amount, and extracting an external electric field from a spontaneous polarization electret. A pair of conductive plates is disposed with a gap therebetween. A charged body formed of a spontaneous polarization electret having predetermined thickness has a positively charged lower surface and negatively charged upper surface. The charged body is between conductive plates in contact with one conductive plate. The gap between the conductive plates is displaced in a direction vertical to the surfaces of the spontaneous polarization electret, whereby an electrostatic capacitance changes and electric power is generated. The other conductive plate is disposed at a position where an absolute value of an external electric field emitted outside from the charged body is between 2.7×107 V/m and 1.5×1010 V/m. Moreover, the thickness of the spontaneous polarization electret is between 1 mm and 60 mm.

Abstract: A sensor device for sensor networks capable of saving power and securing accuracy and a method for transmitting data to a sensor network. The device includes: an oscillation-type sensor that oscillates with a mechanical vibrator; a data processor and communicator that processes a signal output from the oscillation-type sensor and transmits data to an external apparatus; a power supply that supplies electric power to the oscillation-type sensor and the data processor and communicator; and a power supply control unit that controls connection of a power supply line between the power supply and the oscillation-type sensor and connection of a power supply line between the power supply and the data processor and communicator. The power supply control unit connects the power supply line between the power supply and the oscillation-type sensor and then connects the power supply line between the power supply and the data processor and communicator.

Abstract: A rotary system mounted piezoelectric generator has a folded beam structure in which the whole or part of a spring is formed with a piezoelectric generation element, in which one end is provided in a drive rotation system and in which a weight is attached to the other end, the degree of freedom of motion of the weight is two or more-dimensional and thus it is possible to easily change the locus thereof. The beam has a spiral structure such that when the drive rotation system is rotated, a centrifugal force applied to the weight is efficiently modulated by a second force other than the centrifugal force. A self-powered wireless communication terminal is operated with an extremely small amount of power consumption by use of a wireless connection control means and a modulation scattering response antenna which perform multilevel phase-shift keying (MPSK).

Abstract: An electrostatic induction-type vibration power generation device for improving a power generation amount, and extracting an external electric field from a spontaneous polarization electret and method of manufacturing the same. A pair of conductive plates is disposed with a gap therebetween. A charged body formed of a spontaneous polarization electret having predetermined thickness has a positively charged lower surface and negatively charged upper surface. The charged body is between conductive plates in contact with one conductive plate. The gap between conductive plates is displaced in a direction vertical to the surfaces of the spontaneous polarization electret, whereby an electrostatic capacitance changes and electric power is generated. An absolute value of an external electric field generated by the spontaneous polarization electret is between 2.7×107 V/m and 1.5×1010 V/m at a position where the other conductive plate is present.

Abstract: Novel fire detection method and apparatus for positively detecting a fire in the stage of initial smoldering fire or smokeless burning with a high sensitivity. A sensor apparatus disposed in an area i makes gas detection and gas recognition using an existing pattern recognition method such as principal component analysis. If no gas is detected, flag f.sub.i =0 is set. If a gas is detected and recognized as a water vapor, f.sub.i =1 is set. If it is not recognized as a water vapor, f.sub.i =0 is set. Monitoring N areas as above, J=f.sub.1 +f.sub.2 + . . . +f.sub.N is calculated, if 0<J<N, an area of f.sub.i =1 is recognized as highly possible to be a fire. When J=0 or J=N, it is recognized as a non-fire since it is highly possible as due to detection of a gas other than a water vapor such as alcohol or an ordinary humidity change.