Abstract: A piezoelectric device that includes a substrate defining an opening therein; a piezoelectric layer arranged above the substrate such that at least part of the piezoelectric layer extends over the opening and forms a membrane part that is not superimposed with the substrate; a lower electrode arranged below the piezoelectric layer in at least the membrane part; and an upper electrode that is arranged above the piezoelectric layer so as to face at least part of the lower electrode with the piezoelectric layer interposed therebetween in the membrane part. A heater is arranged above the piezoelectric layer so as to be separate from the upper electrode or at least part of the upper electrode doubles as a heater.

Abstract: An electroacoustic transducer includes an ultrasonic element that includes a diaphragm and a support frame, a case body that accommodates the ultrasonic element, and fixing portions that join the support frame portion to a bottom plate portion of the case body. First and second main surfaces of the diaphragm face top and bottom plate portions of the case body, respectively, and a sound hole is provided in the case body. The fixing portions are partially provided along the circumferential direction of the support frame such that a space between the second main surface and the bottom plate portion communicates with a space around the ultrasonic element, and an acoustic path connecting the first main surface and the second main surface and the sound hole is provided in the case body. The fixing portions are defined by a die bonding agent including spherical spacers.

Abstract: An electroacoustic transducer includes an ultrasonic element that includes a diaphragm and a support frame, a case body that accommodates the ultrasonic element, and fixing portions that join the support frame portion to a bottom plate portion of the case body. First and second main surfaces of the diaphragm face top and bottom plate portions of the case body, respectively, and a sound hole is provided in the case body. The fixing portions are partially provided along the circumferential direction of the support frame such that a space between the second main surface and the bottom plate portion communicates with a space around the ultrasonic element, and an acoustic path connecting the first main surface and the second main surface and the sound hole is provided in the case body. The fixing portions are defined by a die bonding agent including spherical spacers.

Abstract: A piezoelectric device that includes a substrate defining an opening therein; a piezoelectric layer arranged above the substrate such that at least part of the piezoelectric layer extends over the opening and forms a membrane part that is not superimposed with the substrate; a lower electrode arranged below the piezoelectric layer in at least the membrane part; and an upper electrode that is arranged above the piezoelectric layer so as to face at least part of the lower electrode with the piezoelectric layer interposed therebetween in the membrane part. A heater is arranged above the piezoelectric layer so as to be separate from the upper electrode or at least part of the upper electrode doubles as a heater.

Abstract: A speaker box and a speaker device that can be manufactured at low cost and that provide a sound-absorbing effect. A speaker box of a speaker device includes a baffle, four intermediate plates, and a rear plate. The baffle plate has a speaker mount hole at the center. Each intermediate plate has a hole. The intermediate plates are stacked such that they are alternately reversed or rotated so that the holes in the adjacent intermediate plates communicate with each other while the holes are shifted from with each other. A hollow space with a sound-absorbing effect is formed by the holes in the speaker box.

Abstract: A speaker box and a speaker device that can be manufactured at low cost and that provide a sound-absorbing effect. A speaker box of a speaker device includes a baffle, four intermediate plates, and a rear plate. The baffle plate has a speaker mount hole at the center. Each intermediate plate has a hole. The intermediate plates are stacked such that they are alternately reversed or rotated so that the holes in the adjacent intermediate plates communicate with each other while the holes are shifted from with each other. A hollow space with a sound-absorbing effect is formed by the holes in the speaker box.

Abstract: A transformer includes a bobbin having a cavity, a primary winding wound around the bobbin, and a secondary winding wound around the bobbin and magnetically coupled with the primary winding. In the transformer, at least one of the primary winding and the secondary winding is divided into at least two portions which include a portion wound at an inside region of the transformer and a portion wound at an outside region of the transformer. Also, at least a portion of the other one of the primary winding and the secondary winding is wound between said at least two portions obtained by dividing the one of the primary winding and the secondary winding, and at least a portion of the cavity of the bobbin is used as a space to dispose another member therein.

Abstract: A speaker includes a disk-shaped base. A substantially hemispherical surface vibrator is fitted into a substantially circular groove formed in the base to be bonded therein. Terminals are attached to electrodes located on both surfaces of the vibrator. The edge portion of the vibrator is bonded with a first adhesive, and further, its circumference is bonded with a second adhesive. The first adhesive has a sufficient bonding strength between the vibrator and the base. The second adhesive has a lower elastic modulus than the first adhesive.

Abstract: A speaker includes a disk-shaped base. A substantially hemispherical surface vibrator is fitted into a substantially circular groove provided in the base and bonded therein. Terminals are attached to electrodes provided on both surfaces of the vibrator. The terminals, passing through the terminal grooves provided in the base, are led out in a direction that is substantially perpendicular to the plane of the base. Further, a horn as a separate member may be attached to the outer surface side of the vibrator.