Vibration generating device and display apparatus including the same
A display apparatus includes a display panel configured to display an image and a plurality of vibration generating devices on a rear surface of the display panel, the display panel being at least one of a vibration plate configured to output sound and a vibration plate configured to output a haptic vibration. Each of the plurality of vibration generating devices includes a first electrode under the display panel, a piezoelectric member under the first electrode, a damping member in a periphery the piezoelectric member, and a second electrode under the piezoelectric member.
1. A vibration generating apparatus, comprising:
a plurality of piezoelectric members;
a damping member configured between the plurality of piezoelectric members, the damping member comprising a piezoelectric ceramic fiber;
a first electrode on a first surface of the plurality of piezoelectric members and a first surface of the damping member; and
a plurality of second electrodes on a second surface of the plurality of piezoelectric members,
wherein the first electrode contacts the first surface of the plurality of piezoelectric members and the first surface of the damping member.
2. The vibration generating apparatus of claim 1 , wherein each of the plurality of piezoelectric members includes a curved surface portion to face a first electrode.
3. The vibration generating apparatus of claim 2 , wherein the damping member includes a portion between the first electrode and the curved surface portion of each of the plurality of piezoelectric members.
4. The vibration generating apparatus of claim 2 , wherein an angle between the first electrode and a virtual normal line with respect to an intersection point between the curved surface portion and a side surface of each of the plurality of piezoelectric members is within a range from 40 degrees to 60 degrees.
5. The vibration generating apparatus of claim 1 , wherein the damping member further comprises an elastomer, and
wherein the damping member has an elastic modulus that is lower than an elastic modulus of the piezoelectric member.
6. The vibration generating apparatus of claim 1 , further comprising a third electrode on a second surface of the damping member.
7. The vibration generating apparatus of claim 6 , wherein the third electrode surrounds at least one of the plurality of second electrodes.
8. The vibration generating apparatus of claim 1 , further comprising a third electrode configured to vibrate the damping member.
9. A display apparatus, comprising:
a display panel configured to display an image; and
a vibration generating apparatus at a rear surface of the display panel, the vibration generating apparatus being configured to vibrate the display panel,
wherein the vibration generating apparatus comprises:
a plurality of piezoelectric members;
a damping member configured between the plurality of piezoelectric members;
a first electrode on a first surface of the plurality of piezoelectric members and a first surface of the damping member; and
a plurality of second electrodes on a second surface of the plurality of piezoelectric members, and
wherein the first electrode contacts the first surface of the plurality of piezoelectric members and the first surface of the damping member.
10. The display apparatus of claim 9 , wherein each of the plurality of piezoelectric members includes a curved surface portion to face a first electrode.
11. The display apparatus of claim 10 , wherein the damping member includes a portion between the first electrode and the curved surface portion of each of the plurality of piezoelectric members.
12. The display apparatus of claim 10 , wherein an angle between the first electrode and a virtual normal line with respect to an intersection point between the curved surface portion and a side surface of each of the plurality of piezoelectric members is within a range from 40 degrees to 60 degrees.
13. The display apparatus of claim 9 , wherein each of the plurality of piezoelectric members includes a piezoelectric material, a binder, and a surface treatment agent.
14. The display apparatus of claim 9 , wherein the damping member comprises an elastomer, or
wherein the damping member has an elastic modulus that is lower than an elastic modulus of the piezoelectric member.
15. The display apparatus of claim 9 , wherein the damping member comprises an elastomer and a piezoelectric ceramic fiber.
16. The display apparatus of claim 9 , wherein the vibration generating apparatus further comprises a third electrode on a second surface of the damping member.
17. The display apparatus of claim 16 , wherein the third electrode surrounds at least one of the plurality of second electrodes.
18. The display apparatus of claim 9 , wherein the vibration generating apparatus further comprises a third electrode configured to vibrate the damping member.
19. The display apparatus of claim 9 , wherein each of the plurality of piezoelectric members is configured to output a sound or a haptic vibration having different frequency ranges.