Loudspeaker

Abstract

A loudspeaker is disclosed. The loudspeaker includes a frame; a vibration system accommodated in the frame, a voice coil for driving the voice diaphragm and a support installed at one end of the voice coil away from the voice diaphragm. The vibration system includes a voice diaphragm, and the support is connected to the frame for providing elastic support to the voice coil. The loudspeaker further includes a magnetic circuit system for driving the vibration system. The magnetic circuit system includes a yoke, a first magnet portion, and a second magnet portion. The second magnetic portion includes an auxiliary magnet and an auxiliary pole plate overlapped with the auxiliary magnet. A light source installed on the auxiliary pole plate and opposite to the support, and a photosensitive sensor arranged on the support and being within the irradiation scope of the light source are further provided.

Dependencies are inferred from the claim text.