Electret transducer cartridge and case

Claim 2

An electroacoustic transducer comprising: a. a cartridge, said cartridge comprising a pair of plates mounted in confronting relation, a first of said plates comprising an electret having a dielectric surface confronting a second of said plates and an opposed metallized surface, and being imperforate and flexible to serve as a diaphragm, said second plate comprising a relatively rigid dielectric body pierced for acoustic airflow to serve as a backplate and having on the surface thereof confronting said dielectric surface a peripheral ridge extending to the peripheral region of said dielectric surface and a supporting element extending from said confronting surface within and spaced from said peripheral ridge to said dielectric surface for making contact with and supporting said first plate in spaced relation from said second plate, a metallic coat on said confronting surface of said body within said ridge and conductor means extending through said body for making electrical contact to said coat from the opposed side of said body, the surface of said ridge confronting said peripheral region of said dielectric surface being free of said coat, and means effecting a dielectric-todielectric bond between said surface of said ridge and said peripheral region; b. a tubular housing having at one end electrically conductive means at least partially closing said one end, said cartridge being disposed in said housing with said metallized surface of said first plate facing to said one end; c. an electrically conductive belt-like contact member in electrical contacting relation to said metallized surface of said first plate in a peripheral region thereof opposed to said peripheral ridge of said second plate and bearing against said closing means; d. a rigid third plate disposed within said housing at the other end to serve as a closure for said housing; e. an electronic signal transducing circuit formed on the surface of said third plate within said tubular housing, said circuit having a first terminal on said surface, and a second terminal on the opposed surface of said third plate, and resilient electrical conductor means comprising resilient dielectric material loaded with electrically conductive material held under compression between said second and third plates making connection between said first terminal and said electrical contact to said coat on said second plate; f. resilient belt-like means in said housing under compression between the respective peripheries of said third plate and said opposed side of said body of said second plate; and g. means holding said third plate fast in said housing, the space between said first and third plates providing a compression chamber for said diaphragm.

Claim 3

An electroacoustic transducer according to claim 1 wherein said electrically conductive belt-like member comprises a a dielectric body coated with an electrical conductor.

Claim 4

An electroacoustic transducer comprising: a. a cartridge, said cartridge comprising a pair of plates mounted in confronting relation, a first of said plates comprising an electret having a dielectric surface confronting a second oF said plates and an opposed metallized surface, and being imperforate and flexible to serve as a diaphragm, said second plate comprising a relatively rigid dielectric body pierced for acoustic airflow to serve as a backplate and having on the surface thereof confronting said dielectric surface a peripheral ridge extending to the peripheral region of said dielectric surface and a supporting element extending from said confronting surface within and spaced from said peripheral ridge to said dielectric surface for making contact with and supporting said first plate in spaced relation from said second plate, a metallic coat on said confronting surface of said body within said ridge and conductor means extending through said body for making electrical contact to said coat from the opposed side of said body, the surface of said ridge confronting said peripheral region of said dielectric surface being free of said coat, and means effecting a dielectric-to-dielectric bond between said surface of said ridge and said peripheral region; b. a tubular housing having at one end electrically-conductive means at least partially closing said one end, said cartridge being disposed in said housing with said metallized surface of said first plate facing to said one end; c. an electrically conductive belt-like contact member in electrical contacting relation to said metallized surface of said first plate in a peripheral region thereof opposed to said peripheral ridge of said second plate and bearing against said closing means; d. a rigid third plate disposed within said housing at the other end to serve as a closure for said housing; e. an electronic signal transducing circuit formed on the surface of said third plate within said tubular housing, said circuit having a first terminal on said surface, and a second terminal on the opposed surface of said third plate, and resilient electrical conductor means held under compression between said second and third plates making connection between said first terminal and said electrical contact to said coat on said second plate, said resilient conductor comprising an electrically conductive elastomeric ring affixed at its periphery to said first terminal with its axis of revolution substantially parallel to said surface of said third plate within said tubular housing, whereby when placed under compression said ring is distorted in a direction transverse to said axis; f. resilient belt-like means in said housing under compression between the respective peripheries of said third plate and said opposed side of said body of said second plate; and g. means holding said third plate fast in said housing, the space between said first and third plates providing a compression chamber for said diaphragm.

Claim 5

An electroacoustic transducer comprising: a. a cartridge, said cartridge comprising a pair of plates mounted in confronting relation, a first of said plates comprising an electret having a dielectric surface confronting a second oF said plates and an opposed metallized surface, and being imperforate and flexible to serve as a diaphragm, said second plate comprising a relatively rigid dielectric body pierced for acoustic airflow to serve as a backplate and having on the surface thereof confronting said dielectric surface a peripheral ridge extending to the peripheral region of said dielectric surface and a supporting element extending from said confronting surface within and spaced from said peripheral ridge to said dielectric surface for making contact with and supporting said first plate in spaced relation from said second plate, a metallic coat on said confronting surface of said body within said ridge and conductor means extending through said body for making electrical contact to said coat from the opposed side of said body, the surface of said ridge confronting said peripheral region of said dielectric surface being free of said coat, and means effecting a dielectric-to-dielectric bond between said surface of said ridge and said peripheral region; b. a tubular housing having at one end electrically-conductive means at least partially closing said one end, said cartridge being disposed in said housing with said metallized surface of said first plate facing to said one end; c. an electrically conductive belt-like contact member in electrical contacting relation to said metallized surface of said first plate in a peripheral region thereof opposed to said peripheral ridge of said second plate and bearing against said closing means; d. a rigid third plate disposed within said housing at the other end to serve as a closure for said housing; e. an electronic signal transducing circuit formed on the surface of said third plate within said tubular housing, said circuit having a first terminal on said surface, and a second terminal on the opposed surface of said third plate, and resilient electrical conductor means held under compression between said second and third plates making connection between said first terminal and said electrical contact to said coat on said second plate, said resilient conductor comprising an electrically conductive elastomeric ring affixed at its periphery to said first terminal with its axis of revolution substantially parallel to said surface of said third plate within said tubular housing, whereby when placed under compression said ring is distorted in a direction transverse to said axis; f. resilient belt-like means in said housing under compression between the respective peripheries of said third plate and said opposed side of said body of said second plate; and g. means holding said third plate fast in said housing, the space between said first and third plates providing a compression chamber for said diaphragm.

Claim 6

An electroacoustic transducer according to claim 3, wherein said electrically conductive belt-like member comprises a dielectric body coated with an electrical conductor.

Claim 7

An electroacoustic transducer comprising: a. a cartridge, said cartridge comprising a pair of plates mounted in confronting relation, a first of said plates comprising an electret having a dielectric surface confronting a second of said plates and an opposed metallized surface, and being imperforate and flexible to serve as a diaphragm, said second plate comprising a relatively rigid dielectric body pierced for acoustic airflow to serve as a backplate and having on the surface thereof confronting said dielectric surface a peripheral ridge extending to the peripheral region of said dielectric surface and along the opposed side thereof away from said diaphragm at least one groove extending to the periphery of said rigid body providing an air leak for permitting air communication from one side of said diaphragm to the other, a metallic coat on said confronting surface of said body within said ridge and conductor means extending through said body for making electrical contact to said coat from the opposed side of said body, the surface of said ridge confRonting said peripheral region of said dielectric surface being free of said coat, means effecting a dielectric-to-dielectric bond between said surface of said ridge and said peripheral region, and means to make electrical contact to said metallized surface of said first place; b. a tubular housing having at one end closure means at least partially closing said one end; c. means supporting said cartridge in said housing with said diaphragm facing to said closure means and spaced therefrom; and d. air passage means between the inner-side walls of said housing and the confronting outer peripheral walls of said cartridge communicating with said air leak for permitting air passage from said opposed side of said cartridge to the region between said diaphragm and said closure means.

Claim 8

An electroacoustic transducer comprising: a. a cartridge, said cartridge comprising a pair of plates mounted in confronting relation, a first of said plates comprising an electret having a dielectric surface confronting a second of said plates and an opposed metallized surface, and being imperforate and flexible to serve as a diaphragm, said second plate comprising a relatively rigid dielectric body pierced for acoustic airflow to serve as a backplate and having on the surface thereof confronting said dielectric surface a peripheral ridge extending to the peripheral region of said dielectric surface and along the opposed side thereof away from said diaphragm at least one groove extending to the periphery of said rigid body providing an air leak for permitting air communication from one side of said diaphragm to the other, a metallic coat on said confronting surface of said body within said ridge and conductor means extending through said body for making electrical contact to said coat from the opposed side of said body, the surface of said ridge confRonting said peripheral region of said dielectric surface being free of said coat, means effecting a dielectric-to-dielectric bond between said surface of said ridge and said peripheral region, and means to make electrical contact to said metallized surface of said first place; b. a tubular housing having at one end closure means at least partially closing said one end; c. means supporting said cartridge in said housing with said diaphragm facing to said closure means and spaced therefrom; and d. air passage means between the inner-side walls of said housing and the confronting outer peripheral walls of said cartridge communicating with said air leak for permitting air passage from said opposed side of said cartridge to the region between said diaphragm and said closure means.

Claim 9

An electroacoustic transducer according to claim 5 in which a transverse dimension of said cartridge is smaller than the corresponding inner transverse dimension of said housing, to provide said air passage means.

Claim 10

An electroacoustic transducer according to claim 6 including spacer means between said diaphragm and said closure means for locating said cartridge relative to said closure means, a third rigid plate disposed within said housing at the other end to serve as a back closure plate for said housing, resilient belt-like means in said housing under compression between the respective peripheries of said closure plate and said opposed side of said body of said second plate, said resilient belt-like means forming a seal for establishing a sole fluid communication passage from one side of said diaphragm to the other through said groove, and means holding said closure plate fast in said housing, the space between said first and third plates providing a compression chamber for said diaphragm.

Claim 11

An electroacoustic transducer according to claim 5 in which said housing closure means at said one end has an aperture which extends over the major portion of said metallized diaphragm surface.

Claim 12

An electroacoustic transducer according to claim 5 in which said housing closure means at said one end overlies substantially all of said metallized diaphragm surface, said closure means having an aperture of which the area is a minor fraction of the area of said metallized surface, thereby defining a substantially fully enclosed volume of air between said housing closure means and said diaphragm.

Claim 13

An electroacoustic transducer according to claim 5 having a tubular conduit extending laterally from said housing into the region between said housing closure means at said one end and said metallized diaphragm surface, said closure means fully closing said one end of said housing and covering entirely said metallized diaphragm surface, thereby defining a substantially fully enclosed volume of air between said housing closure means and said diaphragm.

Claim 14

An electroacoustic transducer comprising an electrically conductive housing having a front end, a back end, and side walls, a substantially imperforate and flexible electret diaphragm supported in the front end of said housing, electrostatic shield means overlying said diaphragm in said front end, closure means for said back end, said closure means including electrostatic shield means along one surface thereof electrically connected to said housing, power terminal means overlying said shield means, an insulating film covering a portion of said shield means separating said power terminals and said shield means, and ground terminal means engaging said shield means.

Claim 15

An electroacoustic transducer comprising an electrically conductive housing having a front end, a back end, and side walls, a substantially imperforate and flexible electret diaphragm supported in the front end of said housing, electrostatic shield means overlying said diaphragm in said front end, closure means for said back end, said closure means including electrostatic shield means along one surface thereof electrically connected to said housing, power terminal means overlying said shield means, an insulating film covering a portion of said shield means separating said power terminals and said shield means, and ground terminal means engaging said shield means.