Reducible metal salt-dry electrographic visible image recording process

Claim 2

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of at least about 1×10 10 ohm-cm and containing at least one reducible metal salt, said process comprising the steps of: (a) applying an electric potential to selected portions of said recording element of a magnitude and for a sufficient period of time to produce in said portions a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 said charge density forming a developable pattern of latent image sites; and (b) heating the entire recording element substantially uniformly in the presence of a reducing agent until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 3

The process of claim 1 wherein said potential applying step comprises disposing one surface of said recording element in electrical connection with a conductive member and contacting portions of the opposite surface of said recording element with an electrode in an imagewise pattern while maintaining an electric field strength of at least about 1×10 5 volts/cm between said electrode and said conductive member.

Claim 4

The process of claim 1 wherein said recording element is heated to a temperature in a range of about 80° C. to about 250° C.

Claim 5

The process of claim 1 wherein said recording element is heated to a temperature in a range of about 100° C. to about 160° C.

Claim 6

The process of claim 4 wherein the time of heating said recording element ranges from about 0.1 second to about 120 seconds.

Claim 7

The process of claim 4 wherein said heating step is performed while said recording element is in face to face contact with an element containing a reducing agent for said metal salt.

Claim 8

The process of claim 4 wherein said recording element contains at least one reducible metal salt of an organic fatty acid and a reducing agent therefor.

Claim 9

The process according to claim 7 wherein said metal salt is selected from the group consisting of salts of silver, lead, nickel and copper.

Claim 10

The process according to claim 7 wherein said metal salt is a silver salt of an organic acid.

Claim 11

The process according to claim 9 wherein said silver salt is selected from the group consisting of silver behenate, silver stearate, silver oleate, silver hydroxystearate, silver laurate, silver palmitate, silver caprate and silver myristate.

Claim 12

A dry electrographic recording process for producing a visible image in a charge-sensitive recording layer element having an ohmic resistivity of at least about 1×10 10 ohm-cm and containing at least one reducible metal salt in a binder, said process comprising the steps of: (a) applying an electric potential having a field strength of at least about 1×10 5 volts/cm to selected portions of said recording element for a sufficient period of time to produce in said portions a storable latent image; and (b) heating the entire recording element substantially uniformly in the presence of a reducing agent until a sufficient quantity of said metal salt is reduced in said portions to form a visible image.

Claim 13

A dry electrographic recording process for producing a visible image in a charge-sensitive recording layer element having an ohmic resistivity of at least about 1×10 10 ohm-cm and containing at least one reducible metal salt in a binder, said process comprising the steps of: (a) applying an electric potential having a field strength of at least about 1×10 5 volts/cm to selected portions of said recording element for a sufficient period of time to produce in said portions a storable latent image; and (b) heating the entire recording element substantially uniformly in the presence of a reducing agent until a sufficient quantity of said metal salt is reduced in said portions to form a visible image.

Claim 14

A dry electrographic recording process comprising the steps of: (a) imagewise altering the conductivity of a photoconductive layer in accordance with a pattern which is to be recorded; (b) positioning the imagewise altered photoconductive layer adjacent a charge-sensitive recording layer having an ohmic resistivity of at least about 1×10.sup. ohm-cm and containing at least one reducible metal salt; (c) applying an electric potential across said photoconductive and recording layers of a magnitude and for a sufficient period of time to produce in the areas of said recording layer corresponding to the imagewise altered portions of said photoconductive layer a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 , such charge density forming in said areas a developable pattern of latent image sites; and (d) heating the entire recording element substantially uniformly in the presence of a reducing agent until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 15

A dry electrographic recording process comprising the steps of: (a) imagewise altering the conductivity of a photoconductive layer in accordance with a pattern which is to be recorded; (b) positioning the imagewise altered photoconductive layer adjacent a charge-sensitive recording layer having an ohmic resistivity of at least about 1×10.sup. ohm-cm and containing at least one reducible metal salt; (c) applying an electric potential across said photoconductive and recording layers of a magnitude and for a sufficient period of time to produce in the areas of said recording layer corresponding to the imagewise altered portions of said photoconductive layer a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 , such charge density forming in said areas a developable pattern of latent image sites; and (d) heating the entire recording element substantially uniformly in the presence of a reducing agent until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 16

The process of claim 12 further including the steps of: (a) subsequently positioning the imagewise altered photoconductive layer adjacent a second charge-sensitive recording layer having an ohmic resistivity of at least about 1×10 10 ohm-cm and containing at least one reducible metal salt; (b) applying an electrical potential across said photoconductive and said second charge-sensitive recording layers of a magnitude and for a sufficient period of time to produce in the areas of said recording layer corresponding to the imagewise altered portions of said photoconductive layer a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 , said charge density forming in said areas a developable pattern of latent image sites; and (c) uniformly heating the entire second charge-sensitive recording layer in the presence of a reducing agent until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 17

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of at least about 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) positioning and recording element in face to face contact with a photoconductive element; (b) exposing said photoconductive element to an imagewise pattern of actinic radiation while simultaneously applying across said photoconductive and recording elements an electric potential of a magnitude and for a sufficient period of time to produce in the areas of said recording element corresponding to the exposed areas of said photoconductive element a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 , said charge density forming a developable pattern of latent image sites; and (c) heating the entire recording element substantially uniformly until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 18

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of at least about 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) positioning and recording element in face to face contact with a photoconductive element; (b) exposing said photoconductive element to an imagewise pattern of actinic radiation while simultaneously applying across said photoconductive and recording elements an electric potential of a magnitude and for a sufficient period of time to produce in the areas of said recording element corresponding to the exposed areas of said photoconductive element a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 , said charge density forming a developable pattern of latent image sites; and (c) heating the entire recording element substantially uniformly until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 19

The process of claim 14 wherein the impedance of said recording element differs from the impedance of said photoconductive element by no more than approximately 10 5 ohms-cm when said latent image forming electric potential is applied across said photoconductive and recording elements.

Claim 20

The process of claim 14 wherein said latent image forming electric potential produces a field strength of at least 1×10 5 volts/cm in the areas of said recording element corresponding to the exposed areas of said photoconductive element.

Claim 21

The process of claim 14 wherein said recording element is heated to a temperature of about 100° C. to about 160° C. for a time period of about 0.1 second to about 120 seconds.

Claim 22

The process according to claim 14 wherein said photoconductive element is x-ray sensitive and the conductivity of such element is imagewise altered by exposing said photoconductive element to x-ray radiation in accordance with the pattern to be recorded.

Claim 23

The process of claim 18 wherein said photoconductive element comprises a dispersion of lead oxide in an insulating binder coated on an electrically conducted, x-ray transparent support.

Claim 24

A dry electrographic recording process comprising the steps of: (a) forming a conductivity pattern on a dielectric material; (b) sequentially positioning said dielectric material containing said conductivity pattern in face to face contact with a plurality of charge-sensitive recording materials having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt in a binder and establishing a potential difference across said dielectric and recording materials of a magnitude and for a sufficient period of time to produce a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 in the area of each recording material corresponding to said conductivity pattern, said charge density being sufficient to form a latent image in said recording material; and (c) heating the recording materials substantially uniformly in the presence of a reducing agent for said metal salt to render the latent images visible.

Claim 25

A dry electrographic recording process comprising the steps of: (a) forming a conductivity pattern on a dielectric material; (b) sequentially positioning said dielectric material containing said conductivity pattern in face to face contact with a plurality of charge-sensitive recording materials having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt in a binder and establishing a potential difference across said dielectric and recording materials of a magnitude and for a sufficient period of time to produce a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 in the area of each recording material corresponding to said conductivity pattern, said charge density being sufficient to form a latent image in said recording material; and (c) heating the recording materials substantially uniformly in the presence of a reducing agent for said metal salt to render the latent images visible.

Claim 26

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) positioning said recording element on an electrically conducting backing member; (b) modulating a corona ion current flow to the recording element by an electrostatic field established imagewise between an image grid comprising an electrically conductive core sequentially connectable to sources of different potential relative to said backing member and completely covered with a coating of a photoconductive insulating material and a control grid that is electrically conductive and sequentially connectable to sources of different potential relative to said backing member, said current flow being of a magnitude sufficient to produce a charge density of approximately from 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 in selected portions of said recording element which charge density forms a latent image therein; and (c) heating the recording element substantially uniformly to render the latent image visible.

Claim 27

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) positioning said recording element on an electrically conducting backing member; (b) modulating a corona ion current flow to the recording element by an electrostatic field established imagewise between an image grid comprising an electrically conductive core sequentially connectable to sources of different potential relative to said backing member and completely covered with a coating of a photoconductive insulating material and a control grid that is electrically conductive and sequentially connectable to sources of different potential relative to said backing member, said current flow being of a magnitude sufficient to produce a charge density of approximately from 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 in selected portions of said recording element which charge density forms a latent image therein; and (c) heating the recording element substantially uniformly to render the latent image visible.

Claim 28

A dry electrographic process for recording and updating information on a charge-sensitive, heat developable recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) producing an electric current in selective portions of the recording element sufficient to produce therein a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 which charge density forms a first latent image therein; (b) heating the entire recording element substantially uniformly to produce a visible image corresponding to said first latent image; (c) subsequently producing an electric current in additional selective portions of the recording element sufficient to produce therein a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 which charge density forms a second latent image therein; and (d) uniformly heating the entire recording element to produce a visible image corresponding to said second latent image.

Claim 29

A dry electrographic process for recording and updating information on a charge-sensitive, heat developable recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) producing an electric current in selective portions of the recording element sufficient to produce therein a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 which charge density forms a first latent image therein; (b) heating the entire recording element substantially uniformly to produce a visible image corresponding to said first latent image; (c) subsequently producing an electric current in additional selective portions of the recording element sufficient to produce therein a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 which charge density forms a second latent image therein; and (d) uniformly heating the entire recording element to produce a visible image corresponding to said second latent image.

Claim 30

A dry electrographic process for recording and updating information on a charge and light sensitive, heat developable recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) exposing said recording element to an imagewise pattern of light to form therein a first latent image; (b) heating said recording element substantially uniformly to produce a visible image corresponding to said first latent image; (c) subsequently producing an electric current in selected portions of said recording element to produce therein a charge density of from approximately 1 microcouloumb/cm 2 to approximately 1 millicouloumb/cm 2 which charge density forms a second latent image; and (d) heating said entire recording elements substantially uniformly to produce a visible image corresponding to said second latent image.

Claim 31

A dry electrographic process for recording and updating information on a charge and light sensitive, heat developable recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor in a binder, said process comprising the steps of: (a) exposing said recording element to an imagewise pattern of light to form therein a first latent image; (b) heating said recording element substantially uniformly to produce a visible image corresponding to said first latent image; (c) subsequently producing an electric current in selected portions of said recording element to produce therein a charge density of from approximately 1 microcouloumb/cm 2 to approximately 1 millicouloumb/cm 2 which charge density forms a second latent image; and (d) heating said entire recording elements substantially uniformly to produce a visible image corresponding to said second latent image.

Claim 32

A dry electrographic process for recording and updating information on a charge and light sensitive, heat developable recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor and a binder, said process comprising the steps of: (a) producing an electric current in selected portions of said recording element sufficient to produce therein a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 which charge density forms a first latent image; (b) heating said recording element substantially uniformly to produce a visible image corresponding to said first latent image; (c) subsequently exposing said recording element to an imagewise pattern of light to form therein a second latent image; and (d) heating said recording element substantially uniformly to produce a visible image corresponding to said second latent image.

Claim 33

A dry electrographic process for recording and updating information on a charge and light sensitive, heat developable recording element having an ohmic resistivity of at least 1×10 10 ohm-cm and containing at least one reducible metal salt and a reducing agent therefor and a binder, said process comprising the steps of: (a) producing an electric current in selected portions of said recording element sufficient to produce therein a charge density of from approximately 1 microcoulomb/cm 2 to approximately 1 millicoulomb/cm 2 which charge density forms a first latent image; (b) heating said recording element substantially uniformly to produce a visible image corresponding to said first latent image; (c) subsequently exposing said recording element to an imagewise pattern of light to form therein a second latent image; and (d) heating said recording element substantially uniformly to produce a visible image corresponding to said second latent image.

Claim 34

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of from about 1×10 10 ohm-cm to about 1×10 15 ohm-cm and comprising an electrically conductive support having thereon an emulsion comprising at least one reducible metal salt and a reducing agent therefor in a polymeric binder, said process comprising the steps of: (a) contacting portions of the emulsion surface of said recording element with an electrode while a potential difference of at least 3 kilovolts is maintained between said electrode and said conductive support, said potential difference being maintained until a charge density of approximately 1 microcoulomb/cm 2 is achieved in the contacted portions of said recording element which charge density forms an imagewise pattern of developable latent image sites; and (b) heating said recording element substantially uniformly until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 35

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of from about 1×10 10 ohm-cm to about 1×10 15 ohm-cm and comprising an electrically conductive support having thereon an emulsion comprising at least one reducible metal salt and a reducing agent therefor in a polymeric binder, said process comprising the steps of: (a) contacting portions of the emulsion surface of said recording element with an electrode while a potential difference of at least 3 kilovolts is maintained between said electrode and said conductive support, said potential difference being maintained until a charge density of approximately 1 microcoulomb/cm 2 is achieved in the contacted portions of said recording element which charge density forms an imagewise pattern of developable latent image sites; and (b) heating said recording element substantially uniformly until a sufficient quantity of said metal salt is reduced at said image sites to form a visible image.

Claim 36

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of from about 1×10 10 ohm-cm to about 1×10 15 ohm-cm and comprising an electrically conductive support having thereon an emulsion comprising at least one reducible metal salt and a reducing agent therefor in a polymeric binder said process comprising the steps of: (a) placing the emulsion surface of said recording element in face to face contact with a photoconductive element; (b) exposing said photoconductive element to an imagewise pattern of actinic radiation while simultaneously maintaining a potential having an electric field strength of approximately 1×10 5 volts/cm between said photoconductive element and said conductive support, said potential difference being of a magnitude sufficient to produce in the areas of said recording element corresponding to the exposed areas of said photoconductive element a charge density of approximately 1 microcouloumb/cm 2 which charge density forms an imagewise pattern of developable latent image sites; and (c) heating said recording elements substantially uniformly until a sufficient quantity of said metal salt is reduced at said image sites to form a latent image.

Claim 37

A dry electrographic recording process for producing a visible image in a charge-sensitive recording element having an ohmic resistivity of from about 1×10 10 ohm-cm to about 1×10 15 ohm-cm and comprising an electrically conductive support having thereon an emulsion comprising at least one reducible metal salt and a reducing agent therefor in a polymeric binder said process comprising the steps of: (a) placing the emulsion surface of said recording element in face to face contact with a photoconductive element; (b) exposing said photoconductive element to an imagewise pattern of actinic radiation while simultaneously maintaining a potential having an electric field strength of approximately 1×10 5 volts/cm between said photoconductive element and said conductive support, said potential difference being of a magnitude sufficient to produce in the areas of said recording element corresponding to the exposed areas of said photoconductive element a charge density of approximately 1 microcouloumb/cm 2 which charge density forms an imagewise pattern of developable latent image sites; and (c) heating said recording elements substantially uniformly until a sufficient quantity of said metal salt is reduced at said image sites to form a latent image.