EP 1094686 A1 20010425 - Mobile telephone loudspeaker
Title (en)
Mobile telephone loudspeaker
Title (de)
Lautsprecher für mobile Telefon
Title (fr)
Haut-parleur de téléphone mobile
Publication
Application
Priority
FR 9912996 A 19991019
Abstract (en)
The transducer has a main winding (2) fixed to a diaphragm (3) as normal, but also has an additional winding (9) placed around the central pillar (4) of the permanent magnet (1). This auxiliary winding is connected in series such that movement due to currents induced by the on-off switching of the transmitter tends to be cancelled out. The ends of the transducer windings are preferably adhered to the back surface of the diaphragm. Both windings are of e.g. 40 - 50 turns and can be arranged in several ways, e.g. they may be fixed together or can be separated by a surface permitting them to slide relative to each other. The second winding may be stationary, e.g. adhered to the central pillar of the permanent magnet, or it can be placed outside the field of the magnet.
Abstract (fr)
Pour réduire les effets de champs électromagnétiques perturbateurs intenses sur un haut-parleur d'un téléphone mobile, on munit le haut-parleur d'une bobine de compensation en sus d'une bobine d'excitation. La bobine de compensation est montée en série avec la bobine d'excitation. Elle est toutefois dispensée d'un rôle moteur en la collant contre l'aimant permanent du haut-parleur. On montre qu'on réduit les effets néfastes sans empêcher le haut-parleur de fonctionner. <IMAGE>
IPC 1-7
IPC 8 full level
H04R 9/06 (2006.01)
CPC (source: EP US)
H04R 9/063 (2013.01 - EP US)
Citation (search report)
- [YA] US 5937076 A 19990810 - TANABE KEI [JP], et al
- [A] WO 9416536 A1 19940721 - VELODYNE ACOUSTICS INC [US]
- [YA] PATENT ABSTRACTS OF JAPAN vol. 017, no. 125 (E - 1332) 16 March 1993 (1993-03-16)
Designated contracting state (EPC)
DE ES FR GB IT
DOCDB simple family (publication)
EP 1094686 A1 20010425; EP 1094686 B1 20030514; DE 60002649 D1 20030618; DE 60002649 T2 20040401; ES 2193925 T3 20031116; FR 2799919 A1 20010420; FR 2799919 B1 20021011; US 2004208337 A1 20041021; US 6901150 B1 20050531
DOCDB simple family (application)
EP 00402728 A 20001004; DE 60002649 T 20001004; ES 00402728 T 20001004; FR 9912996 A 19991019; US 69168400 A 20001018; US 84277404 A 20040511