Electronic device that vibrates an element for sound transmission
Provided is an electronic device that is capable of reducing sound leakage from a vibration plate vibrated by a piezoelectric element. An electronic device 1 of the present invention includes: a piezoelectric element 30 ; and a vibration plate 10 configured to be vibrated by the piezoelectric element 30 . Vibration sound is transmitted by the vibration plate vibrating a part of a human body. The piezoelectric element 30 is vibrated using a processed sound signal in which at least a part of frequency components of a sound reproduction signal that are higher than a predetermined threshold value is cut or attenuated.
1. An electronic device configured for positioning in contact against a portion of a human body comprising:
a housing including an interior and an exterior;
a piezoelectric element positioned in the interior of the housing; and
a vibration plate including a back surface facing the interior of the housing and a front surface positioned to face the portion of the human body, the vibration plate configured to be vibrated by the piezoelectric element and to be joined to the housing such that vibration of the vibration plate by the piezoelectric element is higher in an upper portion thereof including a joining portion with the piezoelectric element than in a lower portion thereof,
wherein sound is transmitted by bending the vibration plate with the piezoelectric element such that a portion of the vibration plate directly above the piezoelectric element protrudes to a greater extent than all neighboring portions of the vibration plate adjacent to a long side of the piezoelectric element and by vibrating a contacting part of a human body that is in contact with the bent vibration plate, the protruding portion of the vibration plate located directly above the piezoelectric element and including a portion of the front surface positioned in nonoverlapping relationship with the housing in a direction normal to the front surface extending towards the exterior to expose the nonoverlapping portion of the front surface to the exterior,
wherein the piezoelectric element is vibrated using a signal in which at least a part of frequency components that are higher than a predetermined threshold value is cut or attenuated, and
wherein the piezoelectric element is directly attached to the back surface of the vibration plate via a joining member.
2. The electronic device of claim 1 , wherein an attenuation rate of the signal is increased gradually or stepwise at higher frequencies.
3. The electronic device of claim 1 , wherein the cutting or the attenuation of the at least the part of the frequency components higher than the predetermined threshold value is performed by a filter.
4. The electronic device of claim 1 , wherein the predetermined threshold value is set to be any one of the frequencies of from 0.4 kHz to 3.4 kHz.
5. The electronic device of claim 1 , wherein frequency components lower than or equal to the predetermined threshold value are not cut or attenuated.
6. The electronic device of claim 1 , wherein the vibration plate is larger than an ear.
7. The electronic device of claim 1 , wherein the vibration plate comprises a panel for display.
8. The electronic device of claim 7 , wherein the piezoelectric element is disposed outside of a display area provided for a display function.
9. An electronic device configured for positioning in contact against a portion of a human body, comprising:
a piezoelectric element;
a vibration plate to which the piezoelectric element is joined for vibration; and
a housing to which the vibration plate is joined such that vibration of the vibration plate by the piezoelectric element is higher in an upper portion thereof including a joining portion with the piezoelectric element than in a lower portion thereof, the housing including an interior and an exterior and the piezoelectric element positioned in the interior of the housing, the vibration plate including a back surface facing the interior of the housing and a front surface positioned to face the portion of the human body, the front surface including an area positioned directly opposite and corresponding to an extent of the piezoelectric element, at least a portion of the area of the front surface being free from overlap with the housing in a direction normal to the front surface extending towards the exterior to expose the portion of the area free from overlap to the exterior,
wherein sound is transmitted by bending the vibration plate with the piezoelectric element such that a portion of the vibration plate directly above the piezoelectric element protrudes to a greater extent than all neighboring portions of the vibration plate adjacent to a long side of the piezoelectric element and by vibrating a pressed part of a human body that is pressed against the bent vibration plate, and
wherein the piezoelectric element is directly attached to the back surface of the vibration plate via a joining member.
10. The electronic device of claim 9 , wherein, with the vibration plate pressed with force greater than or equal to 3 N, and the pressed part of the vibration plate is vibrated, sound is transmitted by the vibration plate.
11. The electronic device of claim 9 , wherein, with the vibration plate pressed with force greater than or equal to 5 N, and the pressed part is vibrated, sound is transmitted by the vibration plate.
12. The electronic device of claim 9 , wherein, with the vibration plate pressed with force less than or equal to 10 N, and the pressed part is vibrated, sound is transmitted by the vibration plate.