Patent ID: 9143871
Filing Date: 2015-09-22
Classification: H04R

Abstract:
1. An electro-acoustic micro-converter for generating sound from an electronic input signal, in particular for a device worn in an ear of a user, comprising a device housing with a sound output in which a membrane assembly is suspended with freedom of movement, the membrane assembly comprising an acoustic membrane and a coil element connected thereto, wherein the coil element is provided with connecting means for receiving the electronic input signal and extends in a coil gap, and wherein the device housing comprises magnet means which maintain a magnetic field in the coil gap, the magnet means comprising a permanently magnetic magnet body, wherein the magnet body is located within an at least substantially rectangular first contour around which the coil gap with the coil element therein extends while at least substantially following the contour, the device housing comprises adjacently of the coil gap at least one magnetically conductive wall part extending along an at least substantially rectangular second contour which surrounds the first contour, and the membrane extends over the whole magnet body at least substantially parallel to a main plane formed by the first contour, and on a side remote from the magnet body is in open communication with a hollow sound chamber which is bounded by magnetically non-conductive chamber walls and of which a chamber wall oriented substantially transversely of the membrane is provided with the sound output.