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US 4,646,872 AGranted
Earphone
AssigneeSony Corporation
InventorsYoshiyuki Kamon, Makoto Yamagishi, Shingo Watanabe
Life of this patent
Estimating the term…
Abstract
An earphone having a housing, a speaker unit accommodated in the housing and a duct formed in the housing to pass sound emanated from the rear surface of the speaker unit and in which a mesh subjected to water repellent treatment is provided within the duct.
Claims4
An earphone comprising:
- a housing having a front facing opening,
- a speaker unit having front and rear portions mounted in said housing with the front of the speaker positioned in said opening;
- a back cavity in said housing formed between a rear portion of said speaker unit and said housing, and a duct acoustically coupled to said back cavity to imprive the lowest resonance frequency, said duct comprising an opening through said housing by which said back cavity and the rear outside of said housing communicate with each other, said duct being provided with a mesh thereacross which passes acoustical sounds but limits passage of water.
Dependencies are inferred from the claim text.