PANEL-ACOUSTIC TRANSDUCER COMPRISING AN ACTUATOR FOR ACTUATING A PANEL, AND SOUND-GENERATING AND/OR RECORDING DEVICE

• US 20090034776A1
• Filed: 07/21/2005
• Published: 02/05/2009
• Est. Priority Date: 08/06/2004
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Scholte, Rick, La Grange, Martijn Roger, Den Hamer, Abram Jan, Koevoets, Marco Adrianus Hendrikus, Roozen, Bert, Angelis, Georgo Zorz
• Application Number:
  US11/573,011
• Publication Number:
  US 20090034776A1
• Time in Patent Office: Days
• US Class Current: 381/386
• CPC Class Codes: H04R 2440/05 Aspects relating to the positioning and way or means of mounting of exciters to resonant bending wave panels
• CPC Class Codes: H04R 7/045 using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion

Abstract

A panel-acoustic transducer comprises a plate-like actuator (4) and a panel (5). The panel (5) has two substantially perpendicular axes of symmetry (A_S,A_l). The plate-like actuator (4) is coupled to the panel in such a way that: —the actuator (4) is coupled to the panel substantially symmetrically with respect to both symmetry axes (A_S,A_l) of the panel (4); the plate-like actuator (4) is so arranged that, in operation, at least the first five odd excitation modes ((1,1), (3,1), (1,3), (3,3), (5,1)), in order of increasing frequency, are actuated with alternating signs. Cusps in the power spectrum of the transducer are thereby prevented.

Claims

1. A panel-acoustic transducer comprising a plate-like actuator (4) for actuating a panel (5), which panel has two substantially perpendicular axes of symmetry (A_s, A_l), wherein the actuator (4) is coupled to the panel (5) substantially symmetrically with respect to both symmetry axes (A_s,A_l) of the panel (5), and the actuator (4) is so arranged that, in operation, at least the first five odd excitation modes ((1,1),(3,1),(1,3),(3,3),(5,1)), in order of increasing frequency, are actuated with alternating signs.

2. A panel-acoustic transducer as claimed in claim 1, wherein the plate-like actuator is so arranged that, in operation, at least the first six odd excitation modes ((1,1),(3,1),(1,3),(3,3),(5,1),(1,5)), in order of increasing frequency, are actuated with alternating signs.

3. A panel-acoustic transducer as claimed in claim 1, wherein the plate-like actuator (4) is a piezoelectric actuator.

4. A panel-acoustic transducer as claimed in claim 1, wherein the plate-like actuator is a single actuator.

5. A panel-acoustic transducer as claimed in claim 1, wherein the panel has an elongated shape and comprises a central part (C), an east (E), west (W), north (N), south (S), northeast (NE), northwest (NW), southeast (SE) and southwest (SW) part, where the east-west axis corresponds to the shorter one of the symmetry axes of the panel, and the north-south axis corresponds to the longer one of the symmetry axes, and wherein the coupling of the plate-like actuator to said parts is as follows:

F(E)≈

F(W)=A*F(C), where 0≦

A<sup>−

1</sup>≦

1 where F(E) is the coupling in the east part, F(W) is the coupling in the west part and F(C) is the coupling in the central part, and

the coupling in the other parts is substantially smaller than the coupling in the east part.

6. A panel-acoustic transducer as claimed in claim 5, wherein 0.25≦

A<sup>−

1</sup>≦

1.

7. A panel-acoustic transducer as claimed in claim 5, wherein 0.25≦

A<sup>−

1</sup>≦

0.75.

8. A panel-acoustic transducer as claimed in claim 5, wherein the actuator has a dumbbell shape.

9. A panel speaker comprising the panel-acoustic transducer as claimed in claim 1.

10. A sound-generating and/or sound-recording device comprising a panel-acoustic transducer as claimed in claim 1.