An ultrasonic generator includes an ultrasonic wave source and a converging portion. The converging portion includes a first reflecting portion which reflects the ultrasonic wave generated by the ultrasonic wave source on its first reflecting surface, a second reflecting portion which reflects the ultrasonic wave reflected by the first reflecting surface on its second reflecting surface, and a waveguide serving as a transmission path for the ultrasonic wave. The waveguide is disposed such that the ultrasonic wave reflected by the second reflecting surface is introduced through an introduction portion thereof. The focal point of the second reflecting surface and the focal point of the first reflecting surface are disposed such that the ultrasonic wave reflected by the second reflecting surface becomes a plane wave.

The invention relates to an enclosure for diffusing sound by reverberation comprising: —a loudspeaker comprising a fixed frame, a cylindrical support and a membrane connected to an upper bearing surface of the frame; and—a wave guide mounted on the upper bearing surface, the wave guide being substantially in the form of a truncated pyramid with a long wall forming a front face, a short wall and lateral uprights; the wave guide comprising at least one acoustic wall fastened to the lateral uprights, the acoustic wall extending tangentially relative to the generatrix line of the cylindrical support closest to the front face.

An ultrasonic sensor which includes a substrate where an opening section is formed, a vibration plate that is provided on the substrate so as to close the opening section, and a piezoelectric element that is layered on a surface of the vibration plate on an opposite side to the opening section and includes a first electrode, a piezoelectric element, and a second electrode, includes a reflection layer that is provided in a space around the piezoelectric element on the surface of the vibration plate on an opposite side to the opening section, to reflect other ultrasonic waves which are transmitted in a different direction from a transmitted ultrasonic wave transmitted to a measuring target side on an interface between the piezoelectric element and the reflection layer, and has a thickness so as to superimpose other ultrasonic waves on the transmitted ultrasonic wave.

An ultrasonic sensor which includes a substrate where an opening section is formed, a vibration plate that is provided on the substrate so as to close the opening section, and a piezoelectric element that is layered on a surface of the vibration plate on an opposite side to the opening section and includes a first electrode, a piezoelectric element, and a second electrode, includes a reflection layer that is provided in a space around the piezoelectric element on the surface of the vibration plate on an opposite side to the opening section, to reflect other ultrasonic waves which are transmitted in a different direction from a transmitted ultrasonic wave transmitted to a measuring target side on an interface between the piezoelectric element and the reflection layer, and has a thickness so as to superimpose other ultrasonic waves on the transmitted ultrasonic wave.

This speaker system includes: a speaker device that is disposed outside a region of a projection surface on which a display surface of a display is projected, the speaker device functioning as a real sound source; and a reflector that has a reflection surface reflecting a sound output from the speaker device, the reflector localizing a sound image of a virtual sound source within the region of the projection surface. The reflector has an elliptical reflection surface in at least a part of the reflection surface. With this configuration, the sound output from the speaker device disposed outside the region of the projection surface is reflected on the reflector, and a sound image thereof is localized within the region of the projection surface, whereby it is possible to bring a display position of a video into alignment with an output position of the sound. Thus, a comfortable viewing state can be ensured for a viewer.

This speaker system includes: a speaker device that is disposed outside a region of a projection surface on which a display surface of a display is projected, the speaker device functioning as a real sound source; and a reflector that has a reflection surface reflecting a sound output from the speaker device, the reflector localizing a sound image of a virtual sound source within the region of the projection surface. The reflector has an elliptical reflection surface in at least a part of the reflection surface. With this configuration, the sound output from the speaker device disposed outside the region of the projection surface is reflected on the reflector, and a sound image thereof is localized within the region of the projection surface, whereby it is possible to bring a display position of a video into alignment with an output position of the sound. Thus, a comfortable viewing state can be ensured for a viewer.

A catheter that fits within a blood vessel wall includes electrodes aligned along a longitudinal axis of the catheter that produce unfocused shock waves that propagate radially toward the blood vessel wall for treatment.

A catheter that fits within a blood vessel wall includes electrodes aligned along a longitudinal axis of the catheter that produce unfocused shock waves that propagate radially toward the blood vessel wall for treatment.

A waveguide assembly for guiding sound includes a chassis that provides a cavity configured to receive sound propagating in a forwards direction along a primary axis of the waveguide assembly; a fixed waveguide that is fixed with respect to the chassis and positioned on the primary axis of the waveguide assembly, wherein the fixed waveguide is spaced apart from the chassis and is configured to guide sound received by the cavity through at least one opening formed between the fixed waveguide element and the chassis; a moveable waveguide that is moveable with respect to the chassis between: a standby position in which the moveable waveguide is configured to obstruct the at least one opening and form a forward-facing surface of the waveguide assembly; an operational position in which the moveable waveguide is configured to allow sound to exit the cavity through the at least one opening.

A waveguide assembly for guiding sound includes a chassis that provides a cavity configured to receive sound propagating in a forwards direction along a primary axis of the waveguide assembly; a fixed waveguide that is fixed with respect to the chassis and positioned on the primary axis of the waveguide assembly, wherein the fixed waveguide is spaced apart from the chassis and is configured to guide sound received by the cavity through at least one opening formed between the fixed waveguide element and the chassis; a moveable waveguide that is moveable with respect to the chassis between: a standby position in which the moveable waveguide is configured to obstruct the at least one opening and form a forward-facing surface of the waveguide assembly; an operational position in which the moveable waveguide is configured to allow sound to exit the cavity through the at least one opening.