公开(公告)号：US3573400A

公开(公告)日：1971-04-06

申请号：US3573400D

申请日：1968-08-14

Applicant: BELL TELEPHONE LABOR INC

Inventor： SESSLER GERHARD M ,  WEST JAMES E

IPC: H04R1/38 ,  H04R1/32

CPC classification number: H04R1/38

Abstract: A directional microphone with toroidal sensitivity characteristics which can be selectively distorted is constructed with an arrangement of acoustic tubes which sample an acoustic field at a number of separated points on an inner circle and at separated points on a concentric outer circle. The acoustic signals from the inner points are summed in a first acoustic cavity and the signals from the outer points are summed in a second cavity. The first and second cavities are separated by a foil electret or other electroacoustic transducer which produces a signal proportional to the difference in sound pressure between them. Several of the acoustic tubes may be adjusted to alter the shape of the microphone''s sensitivity pattern in the plane of maximum sensitivity and the entire acoustic system is selectively dimensioned to equalize the system''s inherent frequency response.

公开(公告)号：US3118979A

公开(公告)日：1964-01-21

申请号：US12962961

申请日：1961-08-07

Applicant: BELL TELEPHONE LABOR INC

Inventor： SESSLER GERHARD M ,  WEST JAMES E

IPC: H04R19/00

CPC classification number: H04R19/00

公开(公告)号：US3118022A

公开(公告)日：1964-01-14

申请号：US19667062

申请日：1962-05-22

Applicant: BELL TELEPHONE LABOR INC

Inventor： SESSLER GERHARD M ,  WEST JAMES E

IPC: H01G7/02 ,  H04M1/03 ,  H04R19/01

CPC classification number: H04R19/016 ,  H01G7/02 ,  H01G7/025 ,  H04M1/03 ,  H04R19/01 ,  Y10S55/39

公开(公告)号：US3644605A

公开(公告)日：1972-02-22

申请号：US3644605D

申请日：1969-02-11

Applicant: BELL TELEPHONE LABOR INC

Inventor： SESSLER GERHARD M ,  WEST JAMES E

IPC: H01G7/02 ,  H04R7/00 ,  H04R19/00

CPC classification number: H01G7/023 ,  Y10S55/39 ,  Y10S522/912 ,  Y10T29/49002

Abstract: STABLE THIN FILM ELECTRETS ARE PRODUCED BY DIRECTING AN ELECTRON BEAM ON A DIELECTRIC MATERIAL IN A CONTROLLED FASHION. ELECTRON ABSORPTION IN THE FILM AND INDUCED SECONDARY EMISSION, BOTH FROM THE FILM AND FROM AN ADJACENT DIELECTRIC SURFACE, AID IN PRODUCING STABLE ELECTRETS WITH SUPERIOR CHARGE CHARACTERISTICS AND VERY LONG LIFETIMES.

公开(公告)号：US3573399A

公开(公告)日：1971-04-06

申请号：US3573399D

申请日：1968-08-14

Applicant: BELL TELEPHONE LABOR INC

Inventor： SCHROEDER MANFRED R ,  SESSLER GERHARD M ,  WEST JAMES E

IPC: H04R1/40

CPC classification number: H04R1/406

Abstract: A directional microphone with toroidal or truncated toroidal sensitivity characteristics is constructed from a plurality of concentric transducer elements, the outputs of which are combined in accordance with a predetermined formula.

公开(公告)号：US3496461A

公开(公告)日：1970-02-17

申请号：US3496461D

申请日：1967-05-25

Applicant: BELL TELEPHONE LABOR INC

Inventor： SESSLER GERHARD M ,  WEST JAMES E

IPC: G01N27/04 ,  G01R27/02

CPC classification number: G01N27/041