Headphone

Abstract

A headphone in which a housing containing a drive unit is provided with a window hole formed therein and the window hole is covered with a diaphragm providing acoustic transmissibility therethrough.

What is claimed is:  
     
       1. A headphone comprising: 
       a housing;  
       a drive unit contained in said housing;  
       a first window hole formed in said housing;  
       a first diaphragm attached to said drive unit and covering said first window hole, whereby acoustic transmissibility between an inside space of said housing and an outside space thereof is provided, wherein said inside space of said housing is divided by partition means including said drive unit and said first diaphragm into a front chamber having a sound emitting opening and a rear chamber and wherein a section of said housing enclosing said front chamber has a second window hole formed therein connecting the front chamber with an exterior of said housing, a second diaphragm covering said second window hole; and  
       said second window hole being operatively provided with a lid member for opening and shutting said second window hole, whereby said second window hole can be shut by a user of said headphone.  
     
     
       2. A headphone comprising: 
       
         a housing having an opening at an end thereof for communicating with an ear of a user;  
       
       
         a baffle plate mounted within the housing for dividing the housing into a front acoustic chamber and a rear acoustic chamber;  
       
       
         an active diaphragm mounted on the baffle plate and having a drive unit; and  
       
       
         a passive diaphragm mounted over a window hole of the rear acoustic chamber of the housing, wherein  
       
       
         the active diaphragm is provided between the opening and the passive diaphragm and is respectively spaced apart therefrom such that the active diaphragm substantially overlaps the passive diaphragm. 
       
     
     
       3. A headphone according to claim  2 , wherein the window hole is provided with a lid member for opening and shutting the window hole by action of the user. 
     
     
       4. A headphone according to claim  2 , wherein the baffle plate has a through hole therein through which the front acoustic chamber and the rear acoustic chamber are in communication. 
     
     
       5. A headphone according to claim  4 , wherein the through hole is covered by an acoustic resistance member.