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US 4,544,805 AGranted
Plane speaker
OwnerTadashi Sawafujiinventor
Life of this patent
Estimating the term…
Abstract
A plane speaker comprises a frame having an opening; a diaphragm facing said opening and having secured its peripheral edge portion to the frame; an actuating plate attached perpendicularly to the back of said diaphragm; a coil mounted on the surface of said actuating plate; and magnets attached to the frame opposite to each other in relation to said coil.
Claims1
A plane speaker comprises a frame having an opening portion;
- a plane diaphragm which has its peripheral edge portion secured to said frame facing said opening portion of the frame and has been provided with a number of parallel cone-shaped projections;
- a folded actuating plate which is formed separately from said diaphragm and attached perpendicularly to the back only of said diaphragm;
- a coil printed on both surfaces of the actuating plate;
- and a magnet disposed on the frame oppositely to said coil, said actuating plate made by repeatedly folding a piece of flexible web zigzag in the longitudinal direction and attaching one edge thereof to the back of the diaphragm.
1 more element
Dependencies are inferred from the claim text.