US3779166A — Electrostatic printing system and method using io…

Claim 1

Independent Claim 205 words

Apparatus for electrostatic printing using marking particles impacted by ions propelled along a path comprising: means for generating a substantially uniform ion stream; means for supporting a print receiving medium in spaced relation to the generating means and in line with the path of the ion stream; particle propelling electrical field means effective at least between the means for generating and the print receiving medium for propelling ions of the stream along the path toward the print receiving medium; electrically controlled apertured means in the path between the generating means and the print receiving means for modulating the cross-sectional flow density of the ions in the stream along the path in accordance with a pattern to be reproduced to convert the ion stream into a modulated ion stream propelled toward the print receiving means by said field means; and means for introducing a cloud of marking particles, in which cloud the particles carry as low a charge as possible, into the path of the modulated ion stream between the print receiving medium and the apertured means so that the modulated ion stream selectively impinges upon and charges marking particles in the cloud and the field means propels the so-charged particles to the print receiving medium.

Claim 2

Dependent Claim 205 words

Apparatus for electrostatic printing using marking particles impacted by ions propelled along a path comprising: means for generating a substantially uniform ion stream; means for supporting a print receiving medium in spaced relation to the generating means and in line with the path of the ion stream; particle propelling electrical field means effective at least between the means for generating and the print receiving medium for propelling ions of the stream along the path toward the print receiving medium; electrically controlled apertured means in the path between the generating means and the print receiving means for modulating the cross-sectional flow density of the ions in the stream along the path in accordance with a pattern to be reproduced to convert the ion stream into a modulated ion stream propelled toward the print receiving means by said field means; and means for introducing a cloud of marking particles, in which cloud the particles carry as low a charge as possible, into the path of the modulated ion stream between the print receiving medium and the apertured means so that the modulated ion stream selectively impinges upon and charges marking particles in the cloud and the field means propels the so-charged particles to the print receiving medium.

Claim 3

Dependent Claim 194 words

Apparatus for electrostatic printing comprising: means for generating and directing a substantially uniform ion stream along a path; apertured means interposed in the ion stream for modulating the cross-sectional flow density of ions in the stream along the path in accordance with a pattern to be reproduced to convert the ion stream to a modulated ion stream directed along said path away from said modulating means; means for supporting a print receiving medium in the path of the modulated ion stream; said means for directing comprising electrical field means establishing an electrical field between the means for generating and the supporting means; and means for introducing a cloud of marking particles into the path of the modulated ion stream between the print receiving medium and the means for modulating whereby ions of the modulated ion stream selectively impinge upon and charge marking particles in the cloud which are thereby directed by the electrical field toward, and deposited on, the print receiving medium in accordance with said pattern to be reproduced, said cloud of marking particles when so introduced being in a substantially uncharged state relative to the charge imparted to them by the ions.

Claim 4

Dependent Claim 194 words

Apparatus for electrostatic printing comprising: means for generating and directing a substantially uniform ion stream along a path; apertured means interposed in the ion stream for modulating the cross-sectional flow density of ions in the stream along the path in accordance with a pattern to be reproduced to convert the ion stream to a modulated ion stream directed along said path away from said modulating means; means for supporting a print receiving medium in the path of the modulated ion stream; said means for directing comprising electrical field means establishing an electrical field between the means for generating and the supporting means; and means for introducing a cloud of marking particles into the path of the modulated ion stream between the print receiving medium and the means for modulating whereby ions of the modulated ion stream selectively impinge upon and charge marking particles in the cloud which are thereby directed by the electrical field toward, and deposited on, the print receiving medium in accordance with said pattern to be reproduced, said cloud of marking particles when so introduced being in a substantially uncharged state relative to the charge imparted to them by the ions.

Claim 5

Dependent Claim 146 words

Apparatus for electrostatic printing as set forth in claim 2, wherein the modulating means comprises: a line printing modulator comprising a layer of insulating material, and layers of conductive material coated on the sides respectively of the insulative layer, the modulator having at least one row of apertures formed therethrough and at least one of said conductive layers segmented into isolated segments each including at least one aperture opening; said segments together with portions of the insulating laYer covered thereby and the conductive layer on the side of the insulating layer opposite said opening supporting a plurality of separately controllable electric fields within said apertures for modulating the stream of ions by selectively controlling the passage of ions through the apertures, and means for applying electric potentials to each of said segments of the segmented layer of conductive material to establish said separately controllable electric fields.

Claim 6

Dependent Claim 87 words

Apparatus for electrostatic printing as set forth in claim 2, wherein the modulating means comprises a multilayered apertured screen formed with a two-dimensional array of apertures therethrough, the screen having at least a conductive layer and insulative layer overlaying the conductive layer, means for applying a potential to the conductive layer and means for establishing an electrostatic latent image on the insulative layer for establishing electrostatic lines of force within the apertures across the screen for controlling passage of ions in accordance with the electrostatic latent image.

Claim 7

Independent Claim 228 words

A system for electrostatic printing comprising: means for generating a directed stream of ions including an ion source and an electrode spaced from said ion source; means interposed in the ion stream for modulating the ion flow comprising a multilayered apertured modulating element spaced between said ion source and said electrode having at least a conductive layer and an insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the element for controlling passage of ions to form a modulated ion stream in accordance with a pattern to be reproduced; means for supporting and positioning a print receiving medium spaced from said modulating element between said modulating element and said electrode; means for establishing an electrical field between said ion source and said electrode encompassing said modulating element and the print receiving medium; and means for introducing a cloud of marking particles into the path of the modulated ion stream in the space between said modulating element and the positioned print receiving medium whereby the modulated ion stream selectively impinges upon and charges marking particles in the cloud which are propelled by said electrical field and deposited on the print receiving medium in accordance with the pattern to be reproduced; said marking particles when so-introduced being substantially uncharged relative to the charge imparted to them by the ions.

Claim 8

Independent Claim 228 words

A system for electrostatic printing comprising: means for generating a directed stream of ions including an ion source and an electrode spaced from said ion source; means interposed in the ion stream for modulating the ion flow comprising a multilayered apertured modulating element spaced between said ion source and said electrode having at least a conductive layer and an insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the element for controlling passage of ions to form a modulated ion stream in accordance with a pattern to be reproduced; means for supporting and positioning a print receiving medium spaced from said modulating element between said modulating element and said electrode; means for establishing an electrical field between said ion source and said electrode encompassing said modulating element and the print receiving medium; and means for introducing a cloud of marking particles into the path of the modulated ion stream in the space between said modulating element and the positioned print receiving medium whereby the modulated ion stream selectively impinges upon and charges marking particles in the cloud which are propelled by said electrical field and deposited on the print receiving medium in accordance with the pattern to be reproduced; said marking particles when so-introduced being substantially uncharged relative to the charge imparted to them by the ions.

Claim 9

Dependent Claim 96 words

Apparatus for electrostatic printing as set forth in claim 5, wherein said modulating means comprises a multilayered apertured screen formed with a two-dimensional array of apertures having at least said conductive layer and insulative layer, means for applying a potential to said conductive layer and means for establishing an electrostatic latent image on said insulative layer for establishing electrostatic lines of force within said apertures across the screen for controlling passage of ions therethrough in accordance with the electrostatic latent image; and means for establishing relative motion between said ion generating means and said modulating element.

Claim 10

Dependent Claim 42 words

A system for electrostatic printing as set forth in claim 6, wherein the multilayered apertured screen is formed in the configuration of a hollow cylinder and wherein said ion source is positioned within the cylinder and said electrode is outside the cylinder.

Claim 11

Dependent Claim 69 words

A system for electrostatic printing as set forth in claim 5, further comprising means for establishing an air pressure differential from one side of said modulating element to the other with the lower pressure on the side adjacent the print receiving medium whereby a small air flow is established through the apertures of the modulating element to prevent the marking particles from entering the apertures of said modulating element.

Claim 12

Dependent Claim 38 words

A system for electrostatic printing as set forth in clAim 5, further comprising means for projecting air streams along the surfaces of said modulating element and positioned print receiving medium to provide air boundaries around said introduced cloud.

Claim 13

Dependent Claim 102 words

Apparatus for electrostatic printing as set forth in claim 5, wherein said modulating means comprises a line printing modulator comprising a layer of insulating material, and layers of conductive material coated on the sides of the insulative layer respectively, said modulator having at least one row of apertures formed therethrough and at least one of said conductive layers segmented into isolated segments; and means for applying electric potentials to each of said segments of the segmented layer of conductive material for establishing a plurality of separately controllable electric fields within said apertures for modulating a stream of ions passing through the aperatures.

Claim 14

Dependent Claim 48 words

A system for electrostatic printing as set forth in claim 5, further comprising means for imparting a lateral component of motion relative to the modulated stream to the cloud substantially parallel to the plane of the print receiving medium where the print receiving medium receives charged marking particles.

Claim 15

Independent Claim 130 words

A method of electrostatic printing comprising: generating an ion stream; modulating the cross-sectional flow density of ions in the stream in accordance with a pattern to be reproduced to produce a modulated stream of ions; establishing an ion projection field for propelling the ions of the ion stream for modulation and propelling the ions of a modulated stream thus formed toward the print receiving medium; and introducing a cloud of marking particles into the path of the modulated ion stream whereby the modulated ion stream selectively impinges upon and charges marking particles in the cloud which are deposited on the print receiving medium by said projection field in accordance with a pattern to be reproduced; said marking particles when so-introduced being in as low a state of charge as possible.

Claim 16

Independent Claim 130 words

A method of electrostatic printing comprising: generating an ion stream; modulating the cross-sectional flow density of ions in the stream in accordance with a pattern to be reproduced to produce a modulated stream of ions; establishing an ion projection field for propelling the ions of the ion stream for modulation and propelling the ions of a modulated stream thus formed toward the print receiving medium; and introducing a cloud of marking particles into the path of the modulated ion stream whereby the modulated ion stream selectively impinges upon and charges marking particles in the cloud which are deposited on the print receiving medium by said projection field in accordance with a pattern to be reproduced; said marking particles when so-introduced being in as low a state of charge as possible.

Claim 17

Dependent Claim 55 words

A method of electrostatic printing as set forth in claim 12 further comprising the additional steps of translating the print receiving medium; and imparting a velocity component to the cloud parallel to the surface of the print receiving medium receiving the charged marking particles and in the direction of translation thereof and substantially synchronized therewith.

Claim 18

Independent Claim 201 words

A method for electrostatic printing comprising: generating and propelling a stream of ions from an ion source toward an electrode spaced from said ion source; modulating the ion flow by interposing in the ion stream a multilayered apertured grid having at least a conductive layer and an insulative layer supporting charge potentials of differing magnitude on either side of the insulative layer respectively establishing electrostatic lines of force therebetween within the apertures to control passage of ions therethrough and thereby to modulate the ion stream in accordance with a pattern to be reproduced; propelling the modulated ion stream exiting from the grid; supporting and positioning a print receiving medium in the space between the grid and electrode; introducing a cloud of marking particles into the path of the modulated ion stream in the space between the grid and the positioned print receiving medium whereby ions of the modulated ion stream selectively impinge upon and charge marking particles in the cloud, said particles so-introduced carrying substantially no charge relative to the charge imparted to them by said ions; and moving the so-charged particles in the direction of the print receiving medium for deposit thereon in accordance with the pattern to be reproduced.

Claim 19

Independent Claim 201 words

A method for electrostatic printing comprising: generating and propelling a stream of ions from an ion source toward an electrode spaced from said ion source; modulating the ion flow by interposing in the ion stream a multilayered apertured grid having at least a conductive layer and an insulative layer supporting charge potentials of differing magnitude on either side of the insulative layer respectively establishing electrostatic lines of force therebetween within the apertures to control passage of ions therethrough and thereby to modulate the ion stream in accordance with a pattern to be reproduced; propelling the modulated ion stream exiting from the grid; supporting and positioning a print receiving medium in the space between the grid and electrode; introducing a cloud of marking particles into the path of the modulated ion stream in the space between the grid and the positioned print receiving medium whereby ions of the modulated ion stream selectively impinge upon and charge marking particles in the cloud, said particles so-introduced carrying substantially no charge relative to the charge imparted to them by said ions; and moving the so-charged particles in the direction of the print receiving medium for deposit thereon in accordance with the pattern to be reproduced.

Claim 20

Dependent Claim 54 words

A system for electrostatic printing as set forth in claim 14, further comprising means for establishing an electrostatic latent image on the insulative layer of the modulating screen in accordance with the pattern in the form of electrostatic lines of force in the apertures; and means for applying a potential to the conductive layer.

Claim 21

Independent Claim 299 words

A system for electrostatic printing comprising: means for generating a stream of ions comprising row corona source means and electrode means comprising an electrode spaced from said row corona source means; means interposed in the ion stream for modulating the ion stream comprising a multilayered apertured screen formed with a two-dimensional array of apertures spaced between the ion corona source and the electrode; said screen having at least a conductive layer and an insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the screen for controlling passage of ions in accordance with a pattern to be reproduced; means for translating said screen across the stream of ions for modulating the stream in accordance with the pattern of electrostatic lines of force within the apertures of the screen; said electrode means moving the ions in the ion stream toward the modulating means and moving the ions exiting from the modulating means toward the electrode in the form of a modulated ion stream; means for supporting and positioning a print receiving medium between the modulating screen and the electrode in the path of the modulated ion stream; means for transporting said print receiving medium across the modulated ion stream at substantially the same rate as the modulating screen is translated across the stream of ions; and channel means for introducing a cloud of marking particles in a state of charge as low as possible into the path of the modulated ion stream in the space between the modulating screen and the positioned print receiving medium whereby the modulated ion stream selectively impinges upon and charges marking particles in the cloud which are deposited on the print receiving medium by the electrode means in accordance with the pattern to be reproduced.

Claim 22

Independent Claim 299 words

A system for electrostatic printing comprising: means for generating a stream of ions comprising row corona source means and electrode means comprising an electrode spaced from said row corona source means; means interposed in the ion stream for modulating the ion stream comprising a multilayered apertured screen formed with a two-dimensional array of apertures spaced between the ion corona source and the electrode; said screen having at least a conductive layer and an insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the screen for controlling passage of ions in accordance with a pattern to be reproduced; means for translating said screen across the stream of ions for modulating the stream in accordance with the pattern of electrostatic lines of force within the apertures of the screen; said electrode means moving the ions in the ion stream toward the modulating means and moving the ions exiting from the modulating means toward the electrode in the form of a modulated ion stream; means for supporting and positioning a print receiving medium between the modulating screen and the electrode in the path of the modulated ion stream; means for transporting said print receiving medium across the modulated ion stream at substantially the same rate as the modulating screen is translated across the stream of ions; and channel means for introducing a cloud of marking particles in a state of charge as low as possible into the path of the modulated ion stream in the space between the modulating screen and the positioned print receiving medium whereby the modulated ion stream selectively impinges upon and charges marking particles in the cloud which are deposited on the print receiving medium by the electrode means in accordance with the pattern to be reproduced.

Claim 23

Dependent Claim 69 words

A system for electrostatic printing as set forth in claim 16, wherein the multilayered apertured screen is formed with the insulative layer comprising a layer of photoconductive insulating material adjacent the conductive layer, means for uniformly charging the photoconductive layer, and means for optically imaging a pattern to be reproduced onto the photoconductive layer for selectively dissipating the uniform charging to form an electrostatic latent image of the pattern.

Claim 24

Dependent Claim 153 words

A system for electrostatic printing as set forth in claim 16, wherein said system has multiple copy capability, said screen formed in the configuration of an elongate web; and a plurality of spaced apart printing stations provided along the web; each printing station comprising a source of ions on one side of the web, a print receiving medium on the other side of the web, means for translating each of said last mentioned print receiving mediums in synchronism with the web, means for introducing marking particles between the web and each of said last mentioned print receiving mediums, and means for propelling ions from the last mentioned sources toward said last mentioned print receiving mediums selectively via the web for charging marking particles by impact therewith whereby the so-charged marking particles are deposited on the last mentioned print receiving mediums by the propelling means to print multiple copies in accordance with said pattern.

Claim 25

Dependent Claim 52 words

A system for electrostatic printing as set forth in claim 16, further comprising means for imparting a component of motion to said cloud in the direction of translation of the screen and transporting of the print receiving medium, said component of motion having substantially the same velocity as said print receiving medium.

Claim 26

Independent Claim 303 words

A system for electrostatic printing employing ions for charging marking particles comprising: a screen for modulating a flow of ions comprising a multilayered apertured screen having at least a conductive layer and an insulative layer capable of supporting cHarge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the screen for controlling passage of ions in accordance with a pattern to be reproduced, said screen formed in the configuration of a hollow cylinder; means for electrostatically charging the screen in accordance with said pattern; means for generating a stream of ions, comprising a row corona source positioned inside the cylindrical screen and electrode means comprising an electrode spaced from said row corona source outside the cylindrical screen; electric field means for propelling charged particles including ions, said field means effective between the row corona source and the electrode; means for rotating the cylindrical screen through said field means thereby to modulate the ion flow in accordance with the pattern of electrostatic lines of force within the apertures across the screen; means for supporting and positioning a print receiving medium spaced from the screen between the screen and electrode; means for transporting said print receiving medium across the path of the modulated ion flow from the row corona source at a rate synchronized with the rotation of the cylindrical screen; and channel means for introducing a cloud of marking particles in substantially uncharged state relative to the charge imparted to them by the ions in the path of the modulated ion stream in the space between the screen surface and the positioned print receiving medium whereby the modulated ion stream selectively impinges upon and charges particles in the cloud; said field means propelling the so-charged particles to the print receiving medium in accordance with the pattern to be reproduced.

Claim 27

Independent Claim 303 words

A system for electrostatic printing employing ions for charging marking particles comprising: a screen for modulating a flow of ions comprising a multilayered apertured screen having at least a conductive layer and an insulative layer capable of supporting cHarge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the screen for controlling passage of ions in accordance with a pattern to be reproduced, said screen formed in the configuration of a hollow cylinder; means for electrostatically charging the screen in accordance with said pattern; means for generating a stream of ions, comprising a row corona source positioned inside the cylindrical screen and electrode means comprising an electrode spaced from said row corona source outside the cylindrical screen; electric field means for propelling charged particles including ions, said field means effective between the row corona source and the electrode; means for rotating the cylindrical screen through said field means thereby to modulate the ion flow in accordance with the pattern of electrostatic lines of force within the apertures across the screen; means for supporting and positioning a print receiving medium spaced from the screen between the screen and electrode; means for transporting said print receiving medium across the path of the modulated ion flow from the row corona source at a rate synchronized with the rotation of the cylindrical screen; and channel means for introducing a cloud of marking particles in substantially uncharged state relative to the charge imparted to them by the ions in the path of the modulated ion stream in the space between the screen surface and the positioned print receiving medium whereby the modulated ion stream selectively impinges upon and charges particles in the cloud; said field means propelling the so-charged particles to the print receiving medium in accordance with the pattern to be reproduced.

Claim 28

Dependent Claim 85 words

A system for electrostatic printing as set forth in claim 20, wherein the insulative layer of the modulating screen comprises a photoconductive layer on the outer surface of the cylindrical screen; and, wherein the means for charging the screen establishes substantially uniform charge on the photoconductive layer and optically images the pattern to be reproduced on the photoconductive layer for selectively dissipating the charge and establishing an electrostatic latent image, and further comprising means for applying a potential to the conductive layer of said screen.

Claim 29

Dependent Claim 25 words

A system for electrostatic printing as set forth in claim 20, wherein said means for supporting and positioning a print receiving medium comprises a drum.

Claim 30

Dependent Claim 293 words

An electrostatic printing head employing ions for charging marking material particles comprising: a multilayered apertured modulating grid element having at least a conductive layer and an insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the element for controlling passage of ions through the apertures in accordance with a pattern to be reproduced; means for generating and propelling a stream of ions comprising a corona source positioned on one side of the modulating grid element and electrode means spaced from the modulating grid element on the other side thereof; means for supporting and positioning a print receiving medium spaced from the modulating element between the modulating element and electrode means; first channel means arranged between the modulating element and print receiving medium adjacent the modulating element for introducing a cloud of dry toner marking particles in substantially uncharged state relative to the charge imparted to the particles by the ions in the space between the modulating element and the positioned print receiving medium whereby the modulated ion stream passing through the modulating element selectively impinges upon and charges toner particles in the cloud which are thereby moved by the propelling means and deposited on the print receiving medium in accordance with the pattern to be reproduced; second channel means arranged between the modulating element and print receiving medium adjacent the surface of the positioned print receiving medium for delivering pulsed air against the print receiving medium at the location of dry toner particles deposited on the medium in the pattern determined by said modulating element; and means for initiating an air pulse in said second channel means in order to erase a pattern of toner deposited on the paper prior to fixing.

Claim 31

Dependent Claim 293 words

An electrostatic printing head employing ions for charging marking material particles comprising: a multilayered apertured modulating grid element having at least a conductive layer and an insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the element for controlling passage of ions through the apertures in accordance with a pattern to be reproduced; means for generating and propelling a stream of ions comprising a corona source positioned on one side of the modulating grid element and electrode means spaced from the modulating grid element on the other side thereof; means for supporting and positioning a print receiving medium spaced from the modulating element between the modulating element and electrode means; first channel means arranged between the modulating element and print receiving medium adjacent the modulating element for introducing a cloud of dry toner marking particles in substantially uncharged state relative to the charge imparted to the particles by the ions in the space between the modulating element and the positioned print receiving medium whereby the modulated ion stream passing through the modulating element selectively impinges upon and charges toner particles in the cloud which are thereby moved by the propelling means and deposited on the print receiving medium in accordance with the pattern to be reproduced; second channel means arranged between the modulating element and print receiving medium adjacent the surface of the positioned print receiving medium for delivering pulsed air against the print receiving medium at the location of dry toner particles deposited on the medium in the pattern determined by said modulating element; and means for initiating an air pulse in said second channel means in order to erase a pattern of toner deposited on the paper prior to fixing.

Claim 32

Dependent Claim 104 words

A system for electrostatic printing as set forth in claim 23, wherein the modulating grid element comprises a line printing modulator comprising a layer of insulating material, and layers of conductive material coated on each side of the insulative layer, said multilayered modulator having at least one row of apertures formed therethrough and at least one conductive layer segmented into isolated segments for establishing a plurality of separately controllable electric fields respectively within said apertures for modulating the stream of ions directed toward the grid element, and means for applying electric potentials to each of said segments of the segmented layer of conductive material.

Claim 33

Dependent Claim 197 words

An ion flow electrostatic typewriter printing head comprising: a first housing having an opening for positioning adjacent a print receiving medium; second housing means supported within said first housing means, said first and second housing means defining a channel for delivering air pulses to the surface of the print receiving medium through said opening, said second housing means also formed with an opening in substantial alignment with the opening in said first housing means; third housing means positioned within said second housing means, said second and third housing means defining a channel for introducing a cloud of dry toner marking particles in which the particles carry as low charge as possible in the space inside the opening in the second housing means; an apertured modulating grid element for controlling flow of ions through the apertures of the modulating grid element, said element positioned within said third housing means so that the apertures thereof are in substantial alignment with the openings from said first and second housing means; and a corona discharge source within said third housing means substantially in alignment with the apertures of said modulating grid and the openings in said first and second housing means.

Claim 34

Dependent Claim 197 words

An ion flow electrostatic typewriter printing head comprising: a first housing having an opening for positioning adjacent a print receiving medium; second housing means supported within said first housing means, said first and second housing means defining a channel for delivering air pulses to the surface of the print receiving medium through said opening, said second housing means also formed with an opening in substantial alignment with the opening in said first housing means; third housing means positioned within said second housing means, said second and third housing means defining a channel for introducing a cloud of dry toner marking particles in which the particles carry as low charge as possible in the space inside the opening in the second housing means; an apertured modulating grid element for controlling flow of ions through the apertures of the modulating grid element, said element positioned within said third housing means so that the apertures thereof are in substantial alignment with the openings from said first and second housing means; and a corona discharge source within said third housing means substantially in alignment with the apertures of said modulating grid and the openings in said first and second housing means.

Claim 35

Dependent Claim 210 words

An electrostatic typewriter printing head for erasable electrostatic printing on a print receiving medium using ions for charging dry toner marking particles comprising: means for generating ions; means for propelling charged particles including said ions in a stream toward the print receiving medium; an electrically modulatable grid element interposed in the ion stream for modulating the cross-sectional flow density of ions in the stream in accordance with a selected typewriting pattern for exiting a modulated stream of ions; means for introducing a cloud of dry toner marking particles carrying substantially no charge relative to the charge imparted to them by the ions into the path of the modulated ion stream in the space between the modulating grid element and the print receiving medium whereby the modulated ion stream selectively impinges upon and charges toner particles in the cloud; said means for propelling charged particles propelling the so-charged toner particles to the print receiving medium in accordance with the selected pattern to be reproduced; and means for delivering pulses of air to the surface of the print receiving medium at the location of toner particles, deposited on the print receiving medium in a pattern determined by the modulating grid, thereby to permit dispersal of the deposited toner pattern prior to fixing.

Claim 36

Dependent Claim 210 words

An electrostatic typewriter printing head for erasable electrostatic printing on a print receiving medium using ions for charging dry toner marking particles comprising: means for generating ions; means for propelling charged particles including said ions in a stream toward the print receiving medium; an electrically modulatable grid element interposed in the ion stream for modulating the cross-sectional flow density of ions in the stream in accordance with a selected typewriting pattern for exiting a modulated stream of ions; means for introducing a cloud of dry toner marking particles carrying substantially no charge relative to the charge imparted to them by the ions into the path of the modulated ion stream in the space between the modulating grid element and the print receiving medium whereby the modulated ion stream selectively impinges upon and charges toner particles in the cloud; said means for propelling charged particles propelling the so-charged toner particles to the print receiving medium in accordance with the selected pattern to be reproduced; and means for delivering pulses of air to the surface of the print receiving medium at the location of toner particles, deposited on the print receiving medium in a pattern determined by the modulating grid, thereby to permit dispersal of the deposited toner pattern prior to fixing.

Claim 37

Independent Claim 131 words

A method of erasable electrostatic printing employing ions for charging marking particles comprising: generating an ion stream in the direction of a print receiving medium; modulating the cross-sectional density flow of ions in the strEam in accordance with a pattern to be reproduced; introducing a cloud of toner marking particles in which the particles carry substantially no charge relative to the charge imparted to them by the ions into the path of the modulated ion stream adjacent the print receiving medium whereby the modulated ion stream selectively impinges upon and charges toner particles in the cloud; depositing the so-charged toner particles on the print receiving medium in accordance with a pattern to be reproduced; and blowing the so deposited pattern of toner particles off the print receiving medium to achieve erasing.

Claim 38

Independent Claim 131 words

A method of erasable electrostatic printing employing ions for charging marking particles comprising: generating an ion stream in the direction of a print receiving medium; modulating the cross-sectional density flow of ions in the strEam in accordance with a pattern to be reproduced; introducing a cloud of toner marking particles in which the particles carry substantially no charge relative to the charge imparted to them by the ions into the path of the modulated ion stream adjacent the print receiving medium whereby the modulated ion stream selectively impinges upon and charges toner particles in the cloud; depositing the so-charged toner particles on the print receiving medium in accordance with a pattern to be reproduced; and blowing the so deposited pattern of toner particles off the print receiving medium to achieve erasing.

Claim 39

Independent Claim 211 words

A method of electrostatically controlled printing employing ions for charging marking material for deposition on a print receiving medium comprising the steps of: generating the ions; forming a stream of ions; interposing apertured modulator means in the path of the stream to define portions of a plurality of electrically selectable paths for the generated ions to the print receiving medium, said modulator means comprising at least a conductive layer overlaying an insulative layer with the layers having coinciding apertures defining said portions of the paths; at least partially opening and closing said paths at the modulator means in accordance with a pattern to be reproduced on the print receiving medium; introducing a cloud of marking material particles into said paths between the modulator means and the print receiving medium, said particles so-introduced carrying substantially no charge relative to the charge imparted to them by said ions; propelling the ions along said paths selectively via the modulator means into the cloud for charging marking material impacted by the ions and propelling the so-charged marking material directly to the print receiving medium; and establishing relative movement of the paths to the print receiving medium in synchronization with the opening and closing of said paths at the modulator means in accordance with said pattern.

Claim 40

Independent Claim 211 words

A method of electrostatically controlled printing employing ions for charging marking material for deposition on a print receiving medium comprising the steps of: generating the ions; forming a stream of ions; interposing apertured modulator means in the path of the stream to define portions of a plurality of electrically selectable paths for the generated ions to the print receiving medium, said modulator means comprising at least a conductive layer overlaying an insulative layer with the layers having coinciding apertures defining said portions of the paths; at least partially opening and closing said paths at the modulator means in accordance with a pattern to be reproduced on the print receiving medium; introducing a cloud of marking material particles into said paths between the modulator means and the print receiving medium, said particles so-introduced carrying substantially no charge relative to the charge imparted to them by said ions; propelling the ions along said paths selectively via the modulator means into the cloud for charging marking material impacted by the ions and propelling the so-charged marking material directly to the print receiving medium; and establishing relative movement of the paths to the print receiving medium in synchronization with the opening and closing of said paths at the modulator means in accordance with said pattern.

Claim 41

Dependent Claim 226 words

An electrostatically controlled printing process employing ions for charging marking material for deposition on a print receiving medium, comprising in combination; a source of ions for generating an ion stream; apertured modulator means disposed in the path of the stream to define portions of a plurality of electrically selectable paths between the source and the print receiving medium; said modulator means comprising at least a conductive layer overlaying an insulative layer with the layers having coinciding apertures to comprise said portions of the selectable paths; means for selectively at least partially opening and closing said paths at the modulator means in accordance with a pattern to be reproduced on the print receiving medium; means for introducing a cloud of marking material particles into the space between the modulator means and the print receiving medium, said particles so-introduced carrying substantially no charge relative to the charge imparted to them by said ions; means for propelling ions along said selectable paths and selectively via the modulator means into the cloud for charging marking material impacted and for propelling the so-charged marking material directly to the print receiving medium; and, means for establishing relative movement of the selectable paths to the print receiving medium in synchronization with the opening and closing of said paths by the means for selectively opening and closing the paths in accordance with said pattern.

Claim 42

Dependent Claim 226 words

An electrostatically controlled printing process employing ions for charging marking material for deposition on a print receiving medium, comprising in combination; a source of ions for generating an ion stream; apertured modulator means disposed in the path of the stream to define portions of a plurality of electrically selectable paths between the source and the print receiving medium; said modulator means comprising at least a conductive layer overlaying an insulative layer with the layers having coinciding apertures to comprise said portions of the selectable paths; means for selectively at least partially opening and closing said paths at the modulator means in accordance with a pattern to be reproduced on the print receiving medium; means for introducing a cloud of marking material particles into the space between the modulator means and the print receiving medium, said particles so-introduced carrying substantially no charge relative to the charge imparted to them by said ions; means for propelling ions along said selectable paths and selectively via the modulator means into the cloud for charging marking material impacted and for propelling the so-charged marking material directly to the print receiving medium; and, means for establishing relative movement of the selectable paths to the print receiving medium in synchronization with the opening and closing of said paths by the means for selectively opening and closing the paths in accordance with said pattern.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-12-17	1977-06-18	1977-12-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-12-17	1981-06-18	1981-12-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-12-17	1985-06-18	1985-12-18	$7700.00	Window Closed / Lapsed

Electrostatic printing system and method using ions and toner particles

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