Electrostatic transducer having narrowed directional characteristic

An electrostatic sonic transducer comprising a relatively inflexible support plate having at least one major surface thereof formed of conductive material so as to provide a first conductive layer, a relatively flexible layer of conductive material forming a second conductive layer stretched across said one major surface with a layer of insulative material disposed between said second conductive layer and said one major surface, said major surface being formed so that portions thereof in contact with said insulative material define a generally convex curvature to provide reliable contact between layers, said one major surface being defined by a plurality of projections spaced apart by intervening grooves, with the configuration of said projections and grooves being optimized for maximum output at a given frequency near the center of said one major surface and varied from said optimum near the periphery thereof so as to reduce the side lobe radiation of said transducer.

An electrostatic sonic transducer comprising a relatively inflexible support plate having at least one major surface thereof formed of conductive material so as to provide a first conductive layer and a relatively flexible layer of conductive material forming a second conductive layer stretched across said one major surface with a layer of insulative material disposed between said second conductive layer and said one major surface, said one major surface being defined by a plurality of projections spaced apart by intervening grooves, and the crest of said projections include substantially uniform surface variations formed by substantially uniform striations.

An electrostatic sonic transducer comprising a relatively inflexible support plate having at least one major surface thereof formed of conductive material, a relatively flexible layer of conductive material stretched across said one major surface with a layer of insulative material disposed between said flexible conductive layer and said one major surface, said major surface being formed so that portions thereof in contact with said insulative material define a generally convex curvature to provide reliable contact between said layers, said one major surface being defined by a plurality of projections spaced by intervening grooves, the crest of one said projection deviating from said convex curvature as compared to an adjacent or next adjacent projection to define an undulating convex curvature of said one major surface.

An electrostatic sonic transducer comprising a relatively inflexible support plate having at least one major surface thereof formed of conductive material so as to provide a first conductive layer, a relatively flexible layer of conductive material forming a second conductive layer stretched across said one major surface with a layer of insulative material disposed between said second conductive layer and said one major surface, said major surface being formed so that portions thereof in contact with said insulative material define a generally convex curvature to provide reliable contact between said layers, said one major surface being defined by a plurality of projections spaced by intervening grooves, and the crests of said projections include sequentially uniform scribing.

An electrostatic transducer comprising a relatively inflexible support plate having at least one major surface thereof formed of conductive material, a relatively flexible layer of conductive material tightly stretched across said one major surface with a layer of insulative material disposed between said conductive material and said one major surface, said major surface being defined by a series of projections spaced apart by intervening grooves, and the configuration of said projections and grooves being optimized for maximum output at a given frequency near the center of said one major surface and varied from said optimum near the periphery thereof so as to reduce the side lobe radiation of said transducer.

An electrostatic transducer comprising a relatively inflexible support plate having at least one major surface thereof formed of conductive material, a relatively flexible layer of conductive material tightly stretched across said one major surface with a layer of insulative material disposed between said flexible layer of conductive material and said one major surface, said major surface being defined by a series of projections spaced apart by intervening grooves, and the crests of said projections having substantially uniform striations.