Electrostatic speaker with foam stator

An electrostatic speaker device, comprising:

• a foam stator having opposing exterior surfaces and acoustic transparency over an operating frequency range of the device;
• said exterior surfaces including electrically conductive cellular structure sufficiently small in cell size to develop a substantially continuous electrostatic charge dispersion across the respective exterior surfaces;
• at least one diaphragm disposed adjacent each exterior surface, said diaphragm including an electrically conductive layer responsive to electrostatic forces developed by the stator;
• means for providing an electrical charge on the at least one diaphragm;
• and
• electrical contacts coupled to the foam stator for attachment to a signal source operable to supply voltage at the exterior surfaces of the stator to provide a push-pull drive configuration for the at least one diaphragm as an active speaker element.

An electrostatic speaker device, comprising:

• a first rigid grid which is substantially acoustically transparent;
• a second rigid grid spaced from an interior surface of the first grid;
• a first foam stator supported at the interior surface of the first grid;
• a second foam stator supported at an interior surface of the second grid and facing the interior surface of the first grid, at least one of said first and second foam stators being acoustically transparent;
• said first and second foam stators including electrically conductive cellular structure at respective faces of each foam stator most proximate to the diaphragm wherein the cellular structure is sufficiently small in cell size to develop a substantially continuous electrostatic charge dispersion across the respective first and second foam stators;
• at least one diaphragm disposed between the first and second foam stators, said diaphragm including an electrically conductive layer responsive to electrostatic forces developed on the respective first and second stators;
• means for providing an electrical charge on the at least one diaphragm;
• and
• electrical contacts coupled to the first and second foam stators for attachment to a signal source operable to supply voltage at the respective first and second stators to provide a push-pull drive configuration for the diaphragm as an active speaker element.

An electrostatic speaker device, comprising:

• a first rigid grid which is substantially acoustically transparent;
• a second rigid grid spaced from an interior surface of the first grid;
• a first foam stator supported at the interior surface of the first grid;
• a second foam stator supported at an interior surface of the second grid and facing the interior surface of the first grid;
• at least one of said first and second foam stators being acoustically transparent and including electrically conductive cellular structure at respective faces of each foam stator most proximate to the diaphragm wherein the cellular structure is sufficiently small in cell size to develop a substantially continuous electrostatic charge dispersion across the respective first and second foam stators;
• at least one diaphragm disposed between the first and second foam stators, said diaphragm including an electrically conductive layer responsive to electrostatic forces developed on the respective first and second stators;
• means for providing an electrical charge on the at least one diaphragm;
• and
• electrical contacts coupled to the first and second foam stators for attachment to a signal source operable to supply voltage at the respective first and second stators to provide a push-pull drive configuration for the diaphragm as an active speaker element.

An electrostatic speaker device, comprising:

• a first compressible foam stator which is substantially acoustically transparent;
• a second compressible foam stator having an electrically conductive interior surface spaced from an electrically conductive interior surface of the first stator;
• an insulative frame portion extending around an interior perimeter at the respective interior surfaces of the first and second rigid grids;
• at least one electrostatic diaphragm having a conductive layer sandwiched between the first and second foam stators and having a diaphragm perimeter positioned for push-pull operation between respective insulative frame portions of the grid, said diaphragm including an insulative layer between the conductive layer and the interior conductive surfaces of the first and second grids;
• gripping structure attached to the first and second grid for maintaining the spaced orientation and supporting the diaphragm therebetween;
• and
• electrical contacts positioned on the respective first and second rigid grids and the conductive layer of the diaphragm for coupling to a signal source for providing an audio signal capable of imposing a push-pull electrostatic force field on the diaphragm to drive audio output from the diaphragm between the respective first and second grids.

An electrostatic speaker device, comprising:

• a first foam stator having an interior conductive surface;
• a second foam stator positioned adjacent to the first stator at least one of said first and second foam stators being acoustically transparent;
• a first rigid grid which is substantially acoustically transparent;
• a second rigid grid having an electrically conductive interior surface in substantially juxtaposed orientation and spaced a preselected distance from an electrically conductive interior surface;
• at least two electrostatic diaphragms sandwiched between the first and second rigid grids and having a diaphragm perimeter positioned for push-pull operation between respective insulative frame portions of the grids, said diaphragms including conductive surfaces which are juxtapose from each other and separated from the conductive surfaces of the first and second grids by an insulative layer of the diaphragm;
• gripping structure attached to the first and second grid for maintaining the parallel and spaced orientation and supporting the diaphragm therebetween;
• a damping member inserted between the two electrostatic diaphragms, said damping member being fully surrounded by open diaphragm space to enable interdependent modification of resonant frequency of the surrounding diaphragm through 360 degrees;
• and
• electrical contacts positioned on the respective first and second rigid grids for coupling to a signal source for providing an audio signal capable of imposing a push-pull electrostatic force field on the diaphragm to drive audio output from the diaphragm between the respective first and second grids.