Abstract: A control method of presented information in a control device, having first and second sensor sections and that is connected to a network, is provided. The method includes acquiring information concerning a human activity detected by first and second sensor sections during first and second periods. The method also includes a first control operation of (i) determining content that is to be output by the first output section during the second period, based on the information concerning a human activity detected during the first period by the first and second sensor sections, and then (ii) causing the first output section to output the determined content in a case where it is determined that a human activity is performed during the second period in a space in which the first sensor section is disposed, based on the information concerning a human activity during the second period acquired from the first sensor section.

Abstract: A sound presentation device including: a casing; an electroacoustic transducer that is installed in such a way that a space inside the casing is divided into a first empty chamber and second empty chamber that are acoustically isolated, and that receives an electrical signal and vibrates; and a vibration plate that makes contact with a body surface of a human body when the sound presentation device is mounted on the body surface, and causes vibration of the electroacoustic transducer to be propagated to the human body via the first empty chamber, the second empty chamber suppressing sound waves produced by the vibration of the electroacoustic transducer from being emitted to outside of the sound presentation device via the second empty chamber.

Abstract: An earphone includes: a loudspeaker unit; a sound conductive tube which is connected to a front surface having a diaphragm included in the loudspeaker unit, and has a hole through which a sound generated from the loudspeaker unit is emitted; a housing which is connected to a back surface of the loudspeaker unit so that a space is formed between the housing and the back surface of the loudspeaker unit, and has a first air hole connecting the space to external air; a first braking part which closes a sound hole of the loudspeaker unit; and a second braking part which closes the first air hole.

Abstract: A sound presentation device including: a casing; an electroacoustic transducer that is installed in such a way that a space inside the casing is divided into a first empty chamber and second empty chamber that are acoustically isolated, and that receives an electrical signal and vibrates; and a vibration plate that makes contact with a body surface of a human body when the sound presentation device is mounted on the body surface, and causes vibration of the electroacoustic transducer to be propagated to the human body via the first empty chamber, the second empty chamber suppressing sound waves produced by the vibration of the electroacoustic transducer from being emitted to outside of the sound presentation device via the second empty chamber.

Abstract: A control method of presented information includes acquiring information concerning a human activity detected by first and second sensor sections during first and second periods; and a control device of presented information controlling a first output section and the first and second sensor sections, the control device of presented information performing, in the controlling, a first control operation of (i) determining content that is to be output by the first output section during the second period based on the information concerning a human activity detected during the first period by the first and second sensor sections and then (ii) causing the first output section to output the determined content in a case where it is determined that a human activity is performed during the second period in a space in which the first sensor section is disposed based on the information concerning a human activity during the second period acquired from the first sensor section.

Abstract: A loudspeaker is provided which includes: a magnetic circuit including a magnet having at least one hole, a plate fixed to one of a pair of polar surfaces of the magnet, and a box-shaped yoke having an inner bottom surface fixed to the other polar surface of the magnet; a voice coil vertically vibratably provided in a magnetic gap formed by the plate and the yoke; a diaphragm having a peripheral edge connected to an upper end of the voice coil; and a magnetic fluid filled in at least one of a gap between the voice coil and the plate and a gap between the voice coil and the yoke. The loudspeaker includes at least one means for uniformly distributing the magnetic fluid.

Abstract: A loudspeaker includes: a frame; a yoke fixed to the frame; a magnet fixed to the yoke; a plate fixed to an upper surface of the magnet which is opposite to a surface of the magnet which is fixed to the yoke; a vibratable voice coil arranged in a first magnetic gap formed between the yoke and the plate; a diaphragm having an outer-edge portion joined to the voice coil; and a support member supporting the diaphragm in a vibratable manner, and composed of edges, one end of each edge being fixed to the frame. The plate is composed of: a flat-plate part fixed to the upper surface of the magnet, and having, at an upper surface thereof, a planar portion extending from the outer-edge portion up to a predetermined distance; and a protruding part disposed on the flat-plate part excluding the planar portion, and protruding toward the diaphragm.

Abstract: A piezoelectric acoustic transducer (1) of the present invention includes a lower frame (78), a lower speaker circuit (20), an upper frame (77), an upper speaker circuit (10), and a surround (76). The upper speaker circuit (10) has a piezoelectric diaphragm (14) in which piezoelectric elements (16, 17), each having a structure that flat plate electrodes are disposed on top and bottom of a piezoelectric member, are mounted on top and bottom surfaces of a board (15). The lower speaker circuit (20) has a piezoelectric diaphragm (24) in which piezoelectric elements (26, 27), each having the same structure, are mounted on a top surface and a bottom surface of a board (25). The piezoelectric diaphragms (14, 24) are coupled to each other via coupling members (74, 75). At an application of a voltage, the piezoelectric diaphragms (14, 24) are caused to curve in directions opposite to each other.

Abstract: A piezoelectric speaker is a piezoelectric speaker which radiates acoustic waves by vibrating according to an applied voltage, including (i) a substrate which includes a first region having first bending stiffness against bending of a plane perpendicular to a vibration direction and a second region having second bending stiffness against bending of the perpendicular plane, the second bending stiffness being different from the first bending stiffness, (ii) a first piezoelectric element which is mounted on the first region and to which a voltage of a first frequency band is applied, and (iii) a second piezoelectric element which is mounted on the second region and to which a voltage of a second frequency band different from the first frequency band is applied.

Abstract: A loudspeaker is provided which includes: a magnetic circuit including a magnet having at least one hole, a plate fixed to one of a pair of polar surfaces of the magnet, and a box-shaped yoke having an inner bottom surface fixed to the other polar surface of the magnet; a voice coil vertically vibratably provided in a magnetic gap formed by the plate and the yoke; a diaphragm having a peripheral edge connected to an upper end of the voice coil; and a magnetic fluid filled in at least one of a gap between the voice coil and the plate and a gap between the voice coil and the yoke. The loudspeaker includes at least one means for uniformly distributing the magnetic fluid.

Abstract: A loudspeaker includes: a frame; a yoke fixed to the frame; a magnet fixed to the yoke; a plate fixed to an upper surface of the magnet which is opposite to a surface of the magnet which is fixed to the yoke; a vibratable voice coil arranged in a first magnetic gap formed between the yoke and the plate; a diaphragm having an outer-edge portion joined to the voice coil; and a support member supporting the diaphragm in a vibratable manner, and composed of edges, one end of each edge being fixed to the frame. The plate is composed of: a flat-plate part fixed to the upper surface of the magnet, and having, at an upper surface thereof, a planar portion extending from the outer-edge portion up to a predetermined distance; and a protruding part disposed on the flat-plate part excluding the planar portion, and protruding toward the diaphragm.

Abstract: An earphone includes: a loudspeaker unit; a sound conductive tube which is connected to a front surface having a diaphragm included in the loudspeaker unit, and has a hole through which a sound generated from the loudspeaker unit is emitted; a housing which is connected to a back surface of the loudspeaker unit so that a space is formed between the housing and the back surface of the loudspeaker unit, and has a first air hole connecting the space to external air; a first braking part which closes a sound hole of the loudspeaker unit; and a second braking part which closes the first air hole.

Abstract: A piezoelectric acoustic transducer achieves both space-saving and high sound quality without increasing the number of parts. In order to achieve this, the transducer includes a piezoelectric element constructed of a piezoelectric material interposed between two surface electrodes and a diaphragm of which at least one principal surface is provided with a print wiring and at least one principal surface is bonded to the piezoelectric element. The diaphragm includes a frame section, a vibrating section which is bonded with the piezoelectric element and which vibrates, and at least one supporting section which connects the frame section and the vibrating section and which supports the vibrating section. Either the frame section or the at least one supporting section includes at least one electrical resistance which is integrally formed to the print wiring and which constructs, in combination with the piezoelectric element, a series-RC circuit.

Abstract: Provided is a piezoelectric type loudspeaker capable of reproducing a high sound pressure in a limited space, without increasing a voltage applied to a piezoelectric element in a bass range. A plurality of piezoelectric diaphragms are disposed in parallel, and coupled to one another in a thickness direction of the diaphragms via a coupling member, and a polarity of the piezoelectric element and the applied voltage are defined so as to cause deformations in opposite directions from each other. One diaphragm includes an edge on a periphery, and operates as a sound wave radiation surface. At least one diaphragm is fixed to a housing side via a fixing member. Series resistance is connected to the piezoelectric element on the piezoelectric diaphragm fixed to the housing side.

Abstract: A piezoelectric speaker includes: a chassis having a wall surface including an opening; a plurality of diaphragms including at least a first piezoelectric diaphragm and second piezoelectric diaphragms which vibrate in phases opposite to each other when a voltage is applied; and a joint member which connects the first and second piezoelectric diaphragms in a positional relationship such that the diaphragms are located at positions different from each other in a thickness direction. One of the diaphragms is provided, in the opening of the chassis, to have one surface facing an outside of the chassis and another surface facing an inside of the chassis. The diaphragm functions as a radiation plate which radiates a sound wave by vibrating at an amplitude generated by synthesizing amplitudes of the first and second piezoelectric diaphragms.

Abstract: A speaker device includes a plurality of speaker units arranged in a line when seen from the front side of the speaker device. At least one of intervals between effective vibration regions of adjacent speaker units is set to a predetermined length. The predetermined length is a length that is set such that a difference between a distance from an end of one of the effective vibration regions, which form the at least one of intervals therebetween, to a listening position, and a distance from an end of the other of the effective vibration regions to the listening position can be less than half the shortest wavelength of a reproduced sound of each of the speaker units.

Abstract: The speaker system according to the present invention is a speaker system in which a sound is emitted into a closed space from the back surface of a speaker unit, and has characteristic that gas in the closed space is physically adsorbed by a gas adsorber obtained by adding a binder to a porous material including a plurality of grains so as to perform molding. The speaker system according to the present invention is capable of reproducing, even when a small cabinet is used, low frequency sound while suppressing reduction in sound pressure level as compared to a conventional art.

Abstract: A piezoelectric speaker is a piezoelectric speaker which radiates acoustic waves by vibrating according to an applied voltage, including (i) a substrate which includes a first region having first bending stiffness against bending of a plane perpendicular to a vibration direction and a second region having second bending stiffness against bending of the perpendicular plane, the second bending stiffness being different from the first bending stiffness, (ii) a first piezoelectric element which is mounted on the first region and to which a voltage of a first frequency band is applied, and (iii) a second piezoelectric element which is mounted on the second region and to which a voltage of a second frequency band different from the first frequency band is applied.

Abstract: Provided is a piezoelectric type loudspeaker capable of reproducing a high sound pressure in a limited space, without increasing a voltage applied to a piezoelectric element in a bass range. A plurality of piezoelectric diaphragms are disposed in parallel, and coupled to one another in a thickness direction of the diaphragms via a coupling member, and a polarity of the piezoelectric element and the applied voltage are defined so as to cause deformations in opposite directions from each other. One diaphragm includes an edge on a periphery, and operates as a sound wave radiation surface. At least one diaphragm is fixed to a housing side via a fixing member. Series resistance is connected to the piezoelectric element on the piezoelectric diaphragm fixed to the housing side.

Abstract: A piezoelectric acoustic transducer (1) of the present invention includes a lower frame (78), a lower speaker circuit (20), an upper frame (77), an upper speaker circuit (10), and a surround (76). The upper speaker circuit (10) has a piezoelectric diaphragm (14) in which piezoelectric elements (16, 17), each having a structure that flat plate electrodes are disposed on top and bottom of a piezoelectric member, are mounted on top and bottom surfaces of a board (15). The lower speaker circuit (20) has a piezoelectric diaphragm (24) in which piezoelectric elements (26, 27), each having the same structure, are mounted on a top surface and a bottom surface of a board (25). The piezoelectric diaphragms (14, 24) are coupled to each other via coupling members (74, 75). At an application of a voltage, the piezoelectric diaphragms (14, 24) are caused to curve in directions opposite to each other.