Abstract: A piezoelectric speaker has a piezoelectric element and vibration plate. The piezoelectric element has a base body with a mounting surface, as well as first and second terminals that are formed on the mounting surface with a distance between them. The vibration plate has a conductive body joined to the piezoelectric element and having a principle surface facing the mounting surface, as well as a first hole with or without a bottom which is formed on the principle surface in a region facing the first terminal to form a space between the body and first terminal. The piezoelectric speaker is capable of preventing the external electrodes of the piezoelectric element from shorting to each other.

Abstract: A piezoelectric speaker has a piezoelectric element and vibration plate. The piezoelectric element has a base body with a mounting surface, as well as first and second terminals that are formed on the mounting surface with a distance between them. The vibration plate has a conductive body joined to the piezoelectric element and having a principle surface facing the mounting surface, as well as a first hole with or without a bottom which is formed on the principle surface in a region facing the first terminal to form a space between the body and first terminal. The piezoelectric speaker is capable of preventing the external electrodes of the piezoelectric element from shorting to each other.

Abstract: A mass flow rate-controlling apparatus including a mass flow rate-detecting mechanism 8 a flow rate-controlling valve mechanism 10 and a mechanism 44 for controlling the flow rate-controlling valve mechanism based on a flow rate-setting signal S0 input from outside and a flow rate signal S1, the flow path being provided with a pressure-detecting mechanism 42 for detecting the pressure of the fluid to output the detected pressure signal, so that the controlling mechanism selectively switches a first control mode for controlling the mass flow rate based on the flow rate signal and the flow rate-setting signal without using the detected pressure signal, and a second control mode for controlling the mass flow rate based on the detected pressure signal, the flow rate signal and the flow rate-setting signal, based on a pressure variation obtained from the detected pressure signal.

Abstract: Electrode layers 22A-22C, 24A-24C are formed on both main surfaces of each of piezoelectric layers 20A, 20B. Voltages of different polarities are respectively applied to the electrode layers next to each other on the same main surface and to the electrode layers opposing to each other via the piezoelectric layer. Projection forms 30, 32 are formed in respective edges of the second electrode layers 22B, 24B, each of which extends into the opposite area. Through-holes are formed in the piezoelectric layer 20A, 20B, in positions off a division line 38. The electrode layers 22A-22C are connected together by the through-holes 26A, 26B and the projection form 30, to have an equal potential. Those are lead from the diaphragm to the outside, thus reducing the overall thickness.

Abstract: A piezoelectric electroacoustic transducer capable of uniformly adhering the periphery of a piezoelectric diaphragm to an annular holding part of the holding body over the whole circumference is provided. The piezoelectric electroacoustic transducer includes a pair of piezoelectric elements having external electrodes on one main surface, a piezoelectric diaphragm provided between the piezoelectric elements and adhered to both main surfaces of an insulation substrate and a holding body having an annular holding part along the periphery of the edge of the piezoelectric diaphragm. The diaphragm is provided with a aperture conductor in an inner area enclosed by the annular holding part to interconnect the connection electrodes on both main surfaces of the diaphragm. A pair of extracted parts respectively connected to the connection electrodes is formed on the periphery of the edge of the other main surface.

Abstract: A mass flow rate-controlling apparatus comprising a mass flow rate-detecting means 8 for detecting a mass flow rate to output a flow rate signal, and a flow rate-controlling valve mechanism 10 for changing a valve-opening degree in response to a valve-operating signal to control the mass flow rate in a flow path 6 for a fluid, and further comprising a means 44 for controlling the flow rate-controlling valve mechanism based on a flow rate-setting signal S0 input from outside and a flow rate signal S1, the flow path being provided with a pressure-detecting means 42 for detecting the pressure of the fluid to output the detected pressure signal, so that the controlling means selectively switches a first control mode for controlling the mass flow rate based on the flow rate signal and the flow rate-setting signal without using the detected pressure signal, and a second control mode for controlling the mass flow rate based on the detected pressure signal, the flow rate signal and the flow rate-setting signal, based

Abstract: Electrode layers 22A-22C, 24A-24C are formed on both main surfaces of each of piezoelectric layers 20A, 20B. Voltages of different polarities are respectively applied to the electrode layers next to each other on the same main surface and to the electrode layers opposing to each other via the piezoelectric layer. Projection forms 30, 32 are formed in respective edges of the second electrode layers 22B, 24B facing to each other, each of which extends into the opposite area. Through-holes are formed in the piezoelectric layer 20A, 20B, in positions off a division line 38. The electrode layers 22A-22C are connected together by the through-holes 26A, 26B and the projection form 30, to have an equal potential. Those are lead from the diaphragm to the outside, thus reducing the overall thickness. This can reduce the thickness of a piezoelectric sounding body thus obtained and achieves lead reliability improvement, manufacturing process simplification and material diminishing.

Abstract: An enclosure of a cellular phone is formed with a plurality of sound releasing holes. The inside of a portion where the sound releasing holes are provided defines an air chamber formed with a receiving portion for mounting a piezoelectric sounding element. The piezoelectric sounding element is of bimorph structure formed by adhering piezoelectric elements on both surfaces of a diaphragm, and serves as a speaker by hermetically fixing a peripheral edge of the diaphragm to the receiving portion. Acoustic characteristics of such a piezoelectric sounding body relates to the total sum S of side surface areas of the sound releasing holes. Therefore, by setting the total sum to a value from 1.5 mm to 60 mm2, variations in resonant frequency and lowering of the sound pressure are prevented, and hence the required acoustic characteristics can be secured while realizing reduction of the thickness of the wall of the enclosure.

Abstract: A flow rate sensor capable of increasing a range where fluid flow rate can be detected with a high accuracy. The flow rate sensor includes: a sensor pipe; a resistor group; a reference resistor group; a constant current source; a first differential circuit; and a flow rate decision unit. The flow rate sensor further includes: a dummy sensor pipe where no fluid is flown; a dummy resistor group changing their resistance value according to the temperature and attached in the longitudinal direction, a dummy reference resistor group, a for-dummy constant current source, switch means for selectively connecting the resistor group with the dummy resistor group in series, a flow rate range increasing differential circuit for detecting a potential difference, and a third flow rate decision unit for obtaining the flow rate of the fluid flowing in the fluid passage according to the potential difference.

Abstract: A flow rate sensor capable of increasing a range where fluid flow rate can be detected with a high accuracy. The flow rate sensor includes: a sensor pipe; a resistor group; a reference resistor group; a constant current source; a first differential circuit; and a flow rate decision unit. The flow rate sensor further includes: a dummy sensor pipe where no fluid is flown; a dummy resistor group changing their resistance value according to the temperature and attached in the longitudinal direction, a dummy reference resistor group, a for-dummy constant current source, switch means for selectively connecting the resistor group with the dummy resistor group in series, a flow rate range increasing differential circuit for detecting a potential difference, and a third flow rate decision unit for obtaining the flow rate of the fluid flowing in the fluid passage according to the potential difference.

Abstract: A mass flow controller having a shut off valve in a flow path body as an integral part. The mass flow controller minimize a dead space between the shut off valve and a mass flow control valve to reduce the amount of entrapped gas therein, thereby avoiding occurrence of overshoot in the initiation of the next mass flow control operation. In another aspect, a bypass passage is provided in the flow path body. The bypass passage bypasses a sensor flow path, a bypass flow path and a mass flow control valve which increase a flow resistance, and therefore, a large amount of purge gas can be passed through the bypass passage in a short time. In still another aspect, a sealing surface of a valve seat is made into coplanar with the top surface of the flow path body, thereby making the sealing surface and the top surface of the body possible to be simultaneously subjected to lapping finish.