Abstract: An arteriosclerosis diagnostic device according to various embodiments is a simple device, resistant to an external factor, such as an error resulting from a skin surface, and capable of measuring the degree of hardness of an artery. The arteriosclerosis diagnostic device detects a heart sound and a pulse wave at least one location of a living body, the pulse wave propagating through an artery in relation to the heart sound, converts detected signals thereof into respective frequency signals, specifies the peak frequency of each of the frequency signals, and determines the degree of arteriosclerosis on the basis of the difference between the peak frequency of the heart sound and the peak frequency of the pulse wave. Accordingly, the degree of arteriosclerosis can be determined by comparison between the frequency signals.

Abstract: An ultrasonic sensor includes a cylindrical outer case with a bottom and a piezoelectric element fixed to the inner side of the bottom portion of the outer case. A ring-shaped inner case having a central hole extending in the axial direction in the central portion thereof is disposed inside the sidewall portion of the outer case. A flat or substantially flat portion is provided around the central hole of the inner case, and a viscoelastic filler is arranged so as to extend from the central hole to the flat or substantially flat portion of the inner case. A tabular member is disposed on the flat or substantially flat portion so as to face the flat or substantially flat portion with the filler interposed therebetween. When the inner case vibrates, shear deformation occurs in the filler interposed between the flat or substantially flat portion and the tabular member since the tabular member is not substantially deformed, and the vibration is reduced by the viscoelastic damping effect.

Abstract: A piezoelectric device is attached to an inner bottom surface of the outer case having a tubular shape including a bottom, and an inner case is disposed within the outer case. In an ultrasonic vibration acting surface of the inner case that is arranged to face the bottom surface of the outer case, a mass of the inner case is arranged to restrain vibration of the outer case, which is generated by the piezoelectric device. A first cutout is provided in a portion of the ultrasonic vibration acting surface and arranged to face the piezoelectric device so as to flatten an ultrasonic beam generated by vibrations of the piezoelectric device and the outer case. Second cutouts are provided at locations on the ultrasonic vibration acting surface spaced away from the first cutout in a line symmetrical relationship with a long axis of the first cutout defining a symmetrical axis.

Abstract: An ultrasonic transducer includes a piezoelectric resonator including a pair of electrodes sandwiching a piezoelectric body and provided with the backing layer in contact with one of the electrodes of the piezoelectric resonator and having the same acoustic characteristic impedance as the piezoelectric body. A method includes the step of driving the ultrasonic transducer so as to satisfy a condition: 2Th?Td?6Th where Th is a propagation time of an ultrasonic wave in the piezoelectric body sandwiched by the pair of electrodes, and Td is a pulse width of a drive pulse driving the piezoelectric resonator.

Abstract: A piezoelectric device is attached to an inner bottom surface of the outer case having a tubular shape including a bottom, and an inner case is disposed within the outer case. In an ultrasonic vibration acting surface of the inner case that is arranged to face the bottom surface of the outer case, a mass of the inner case is arranged to restrain vibration of the outer case, which is generated by the piezoelectric device. A first cutout is provided in a portion of the ultrasonic vibration acting surface and arranged to face the piezoelectric device so as to flatten an ultrasonic beam generated by vibrations of the piezoelectric device and the outer case. Second cutouts are provided at locations on the ultrasonic vibration acting surface spaced away from the first cutout in a line symmetrical relationship with a long axis of the first cutout defining a symmetrical axis.

Abstract: An ultrasonic sensor includes a cylindrical outer case with a bottom and a piezoelectric element fixed to the inner side of the bottom portion of the outer case. A ring-shaped inner case having a central hole extending in the axial direction in the central portion thereof is disposed inside the sidewall portion of the outer case. A flat or substantially flat portion is provided around the central hole of the inner case, and a viscoelastic filler is arranged so as to extend from the central hole to the flat or substantially flat portion of the inner case. A tabular member is disposed on the flat or substantially flat portion so as to face the flat or substantially flat portion with the filler interposed therebetween. When the inner case vibrates, shear deformation occurs in the filler interposed between the flat or substantially flat portion and the tabular member since the tabular member is not substantially deformed, and the vibration is reduced by the viscoelastic damping effect.

Abstract: An ultrasonic transducer includes a cylindrical cap member having a bottom. A piezoelectric element is bonded to the inner side of a bottom portion of the cap member using a conductive adhesive or other suitable adhesive. An inner frame made of a material having an acoustic impedance greater than that of the cap member is fitted into the cap member so as to be in contact with a side portion, including the end portion, of the cap member. Through-holes are provided in the side portion of the inner frame. Lead wires are connected to the piezoelectric element and the inner frame, respectively. A sound absorber and a damper are inserted into the inner frame. The damper is in direct contact with the side portion of the cap member via the through-holes of the inner frame.

Abstract: An ultrasonic transducer includes a cylindrical cap member having a bottom. A piezoelectric element is bonded to the inner side of a bottom portion of the cap member using a conductive adhesive or other suitable adhesive. An inner frame made of a material having an acoustic impedance greater than that of the cap member is fitted into the cap member so as to be in contact with a side portion, including the end portion, of the cap member. Through-holes are provided in the side portion of the inner frame. Lead wires are connected to the piezoelectric element and the inner frame, respectively. A sound absorber and a damper are inserted into the inner frame. The damper is in direct contact with the side portion of the cap member via the through-holes of the inner frame.

Abstract: An ultrasonic transmitting/receiving device that effectively suppresses ringing during emission of ultrasonic waves and improves time resolution when measuring a sonic velocity includes a pair of ultrasonic transducers. Each of the ultrasonic transducers has a piezoelectric vibrator including a first electrode and a second electrode that are separated by a piezoelectric body and a backing disposed in contact with the first electrode and composed of the same material as a material of the piezoelectric body. The ultrasonic transducers are connected by a support so as to face each other and have a substantially rectangular U-shape as a whole when viewed from the side.

Abstract: An ultrasonic transducer includes a piezoelectric resonator including a pair of electrodes sandwiching a piezoelectric body and provided with the backing layer in contact with one of the electrodes of the piezoelectric resonator and having the same acoustic characteristic impedance as the piezoelectric body. A method includes the step of driving the ultrasonic transducer so as to satisfy a condition: 2Th?Td?6Th where Th is a propagation time of an ultrasonic wave in the piezoelectric body sandwiched by the pair of electrodes, and Td is a pulse width of a drive pulse driving the piezoelectric resonator.

Abstract: A method for quickly screening piezoelectric transformer apparatuses having low mechanical strength and latent defects is performed by connecting a load impedance to a generator of a piezoelectric transformer apparatus and applying a stress signal to an actuator to vibrate the piezoelectric transformer apparatus. Latent-defect transformer apparatuses having low mechanical strength are damaged during this process and therefore can be easily identified.

Abstract: A method for selecting a piezoelectric transformer characteristic includes the steps of connecting a primary-side driving section of a piezoelectric transformer to a high-frequency generator while leaving a secondary-side generating section thereof in an open state, causing the high-frequency generator to sequentially generate and sweep a high-frequency signal over a predetermined frequency range, measuring a resonant frequency of an input-impedance-versus-frequency characteristic of the piezoelectric transformer, and selecting the characteristic of the piezoelectric transformer based on the value of the measured resonant frequency.

Abstract: An ultrasonic transmitting/receiving device that effectively suppresses ringing during emission of ultrasonic waves and improves time resolution when measuring a sonic velocity includes a pair of ultrasonic transducers. Each of the ultrasonic transducers has a piezoelectric vibrator including a first electrode and a second electrode that are separated by a piezoelectric body and a backing disposed in contact with the first electrode and composed of the same material as a material of the piezoelectric body. The ultrasonic transducers are connected by a support so as to face each other and have a substantially rectangular U-shape as a whole when viewed from the side.

Abstract: A piezoelectric transformer includes a piezoelectric unit. The piezoelectric unit includes a plurality of driver units divided by at least one groove extending in the longitudinal direction of the piezoelectric unit from one end thereof, and also includes a plurality of generator units, opposing the driver units, divided by at least one groove extending in the longitudinal direction of the piezoelectric unit from the other end thereof. Opposing pairs of the driver units and the generator units constitute a plurality of transformer units. The transformer units differ in length from one another.

Abstract: A method for selecting a piezoelectric transformer characteristic includes the steps of connecting a primary-side driving section of a piezoelectric transformer to a high-frequency generator while leaving a secondary-side generating section thereof in an open state, causing the high-frequency generator to sequentially generate and sweep a high-frequency signal over a predetermined frequency range, measuring a resonant frequency of an input-impedance-versus-frequency characteristic of the piezoelectric transformer, and selecting the characteristic of the piezoelectric transformer based on the value of the measured resonant frequency.

Abstract: A piezoelectric transformer includes a piezoelectric unit. The piezoelectric unit includes a plurality of driver units divided by at least one groove extending in the longitudinal direction of the piezoelectric unit from one end thereof, and also includes a plurality of generator units, opposing the driver units, divided by at least one groove extending in the longitudinal direction of the piezoelectric unit from the other end thereof. Opposing pairs of the driver units and the generator units constitute a plurality of transformer units. The transformer units differ in length from one another.

Abstract: The output impedance of a piezoelectric transformer defined as a value obtained by dividing the output current at a load resistance of about zero into the output voltage at a load resistance of about infinity is set to be larger than about one-third of the maximum impedance of a discharge tube during discharging. Further, the absolute value of the gradient of the characteristic curve of the piezoelectric transformer is set to be smaller than the absolute value of the gradient of the output characteristic curve of a discharge lamp.

Abstract: A monolithic piezoelectric transformer includes a piezoelectric substrate and input electrodes which include internal electrodes disposed in the piezoelectric substrate alternately and between piezoelectric ceramic layers and external electrodes provided on the corresponding upper and lower surfaces of the piezoelectric substrate. The length of the external electrodes is about 50% of an overall length L of the piezoelectric substrate. The length of the internal electrodes is longer than approximately 50% of the overall length L.

Abstract: A piezoelectric transformer includes a piezoelectric plate in which a pair of cuts are formed in the piezoelectric plate at a position corresponding to a nodal point of the piezoelectric plate. The pair of cuts form a cut-out projection. Connection electrodes electrically connected to input electrodes are respectively formed on input-side cut-out projections. In this piezoelectric transformer, the desired support and electrical connection are made through the cut-out projections.