Piezoelectric audio device and method for sound production

(19)

(11)

EP 1 051 058 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	29.09.2004 Bulletin 2004/40

(43)	Date of publication A2:
	08.11.2000 Bulletin 2000/45

(21)	Application number: 00106906.1

(22)	Date of filing: 31.03.2000

(51)	International Patent Classification (IPC)⁷: H04R 17/00

(84)	Designated Contracting States:
	AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
	Designated Extension States:
	AL LT LV MK RO SI

(30)

Priority:

07.05.1999 FI 991061

(71)	Applicant: Nokia Corporation
	02150 Espoo (FI)

(72)	Inventor:
	Backman, Juha 02140 Espoo (FI)

(74)	Representative: Lamberg, Samu Petteri
	Nokia Corporation IPR Department P.O. Box 226 00045 Nokia Group 00045 Nokia Group (FI)

(54)	Piezoelectric audio device and method for sound production

(57) An arrangement (1) to improve the sound quality of a piezoelectric element actuating element (AE). A sensing element (ME) is attached to the piezoelectric element to supply an electric response to movement of the element when the plate vibrates producing a sound. The response is electrically filtered in order to compensate said mechanical resonance frequency band for stabilisation of said first signal. The filtered response is inverting summed by a summation node (SN) with the audio signal to be reproduced in order to compensate the otherwise exaggerated amplitude at these resonance frequencies.

Search report