The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 26, 2008
Filed:
Dec. 02, 2002
Claus Erdmann Fürst, Roskilde, DK;
Lars Jorn Stenberg, Roskilde, DK;
Jens Kristian Poulsen, Hedehusene, DK;
Henrik Thomsen, Søborg, DK;
Claus Erdmann Fürst, Roskilde, DK;
Lars Jorn Stenberg, Roskilde, DK;
Jens Kristian Poulsen, Hedehusene, DK;
Henrik Thomsen, Søborg, DK;
Sonion A/S, Roskilde, DK;
Abstract
In a first aspect the present invention provides a compact high efficiency driver suitable for driving a loudspeaker, such as a miniature loudspeaker for mobile phones or hearing aids. The driver comprising an interface for receiving an input signal, a three-level modulator, and a three-level H-bridge. The interface may be adapted to receive a digital input signal. In a preferred embodiment of the driver the H-bridge is controlled by a correction circuit which is operated by a Return-To-Zero scheme. In a further preferred embodiment the driver comprises a supply voltage step-up circuit for increasing a voltage supplied to the H-bridge. In a second aspect the present invention provides a miniature loudspeaker assembly having a built-in driver. In a third aspect the present invention provides a mobile device with a built-in miniature loudspeaker assembly.