Method and apparatus for delivery of high solids content toner cake in a contact electrostatic printing system

Claim 2

A toner cake layer delivery apparatus for delivery of a toner cake layer having a high solids content to a receiving member surface on a receiving member, the apparatus being operable in a contact electrostatic printing engine, comprising: a supply of liquid developing material, the liquid developing material being a mixture of toner particles in a liquid carrier medium, the mixture exhibiting a percentage level of solids content that is less than the percentage level of solids content in the desired toner cake layer; a liquid developing material applicator connected to the supply of liquid developing material and operable for receiving a quantity of liquid developing material and for providing therefrom a layer of liquid developing material; a layer concentrator operable for receiving the layer of liquid developing material and for removing at least a portion of the liquid carrier medium present in the layer of liquid developing material so as to increase the percentage level of solids content in the layer of liquid developing material, thus transforming the layer of liquid developing material into the desired toner cake layer; and a movable member aligned with the liquid developing material applicator and the layer concentrator, the movable member having a first surface for receiving thereon the layer of liquid developing material, the movable member being movable for: (1) transporting the layer of liquid developing material received on the first surface to the layer concentrator, whereby the layer of liquid developing material is transformed into the desired toner cake layer, and (2) for transporting the resulting toner cake layer into engagement with the receiving member surface for subsequent delivery of the toner cake layer to the receiving member surface.

Claim 3

The apparatus of claim 1, wherein the low solids content liquid developing material is characterized as having percentage level of solids content in the range of less than approximately 10 percent solids content.

Claim 4

The apparatus of claim 1, wherein the toner cake layer is characterized as having a percentage level of solids content of approximately 10 percent solids content or greater.

Claim 5

The apparatus of claim 1, wherein the toner cake layer is characterized as having a uniform thickness in the range of 1 to 15 microns.

Claim 6

The apparatus of claim 1, wherein the toner cake layer is characterized as having an accurately metered mass per unit area of approximately 0.1 mg per cm 2 .

Claim 7

The apparatus of claim 1, further comprising a toner cake layer cleaning unit operable with respect to the first surface for removal of a remnant of the toner cake layer from the first surface subsequent to the delivery of the toner cake layer to the receiving member surface.

Claim 8

An imaging system for effecting contact electrostatic printing of an output image, comprising: an imaging assembly having an imaging member, the imaging member having an image bearing surface for receiving an electrostatic latent image thereon, the electrostatic latent image being representative of the desired output image; a development assembly for developing the electrostatic latent image, the development assembly having a receiving member for receiving a toner cake layer of high solids content and engaging the electrostatic latent image on the image bearing surface for development of the electrostatic latent image; and a toner cake layer delivery apparatus operable for delivery of the toner cake layer to a receiving member surface on the receiving member, the toner cake layer delivery apparatus having: (a) to a supply of liquid developing material, the liquid developing material being a mixture of toner particles in a liquid carrier medium, the mixture exhibiting a percentage level of solids content that is less than the percentage level of solids content in the toner cake layer, (b) a liquid developing material applicator connected to the supply of liquid developing material and operable for receiving a quantity of the liquid developing material and for providing therefrom a layer of liquid developing material, (c) a layer concentrator operable for receiving the layer of liquid developing material and for removing at least a portion of the liquid carrier medium present in the layer of liquid developing material so as to increase the percentage level of solids content in the layer of liquid developing material, thus transforming the layer of liquid developing material into the desired toner cake layer, and (d) a movable member aligned with the liquid developing material applicator and the layer concentrator, the movable member having a first surface for receiving thereon the layer of liquid developing material, the movable member being movable for: (1) transporting the layer of liquid developing material received on the first surface to the layer concentrator, so as to transform the layer of liquid developing material into the toner cake layer, and (2) for transporting the toner cake layer into engagement with the receiving member surface for subsequent delivery of the toner cake layer to the receiving member surface; wherein the development assembly is operable for engaging the toner cake layer with the electrostatic latent image on the imaging member so as to develop the latent image into a developed image representative of the output image.

Claim 9

An imaging system for effecting contact electrostatic printing of an output image, comprising: an imaging assembly having an imaging member, the imaging member having an image bearing surface for receiving an electrostatic latent image thereon, the electrostatic latent image being representative of the desired output image; a development assembly for developing the electrostatic latent image, the development assembly having a receiving member for receiving a toner cake layer of high solids content and engaging the electrostatic latent image on the image bearing surface for development of the electrostatic latent image; and a toner cake layer delivery apparatus operable for delivery of the toner cake layer to a receiving member surface on the receiving member, the toner cake layer delivery apparatus having: (a) to a supply of liquid developing material, the liquid developing material being a mixture of toner particles in a liquid carrier medium, the mixture exhibiting a percentage level of solids content that is less than the percentage level of solids content in the toner cake layer, (b) a liquid developing material applicator connected to the supply of liquid developing material and operable for receiving a quantity of the liquid developing material and for providing therefrom a layer of liquid developing material, (c) a layer concentrator operable for receiving the layer of liquid developing material and for removing at least a portion of the liquid carrier medium present in the layer of liquid developing material so as to increase the percentage level of solids content in the layer of liquid developing material, thus transforming the layer of liquid developing material into the desired toner cake layer, and (d) a movable member aligned with the liquid developing material applicator and the layer concentrator, the movable member having a first surface for receiving thereon the layer of liquid developing material, the movable member being movable for: (1) transporting the layer of liquid developing material received on the first surface to the layer concentrator, so as to transform the layer of liquid developing material into the toner cake layer, and (2) for transporting the toner cake layer into engagement with the receiving member surface for subsequent delivery of the toner cake layer to the receiving member surface; wherein the development assembly is operable for engaging the toner cake layer with the electrostatic latent image on the imaging member so as to develop the latent image into a developed image representative of the output image.

Claim 10

The imaging system of claim 7, further comprising: an electrostatic latent image including image areas defined by a first voltage potential and non-image areas defined by a second voltage potential; and a process nip formed by operative engagement of the imaging member and the receiving member for positioning the toner cake layer in pressure contact with the image bearing surface, wherein the electrostatic latent image on the second imaging member generates imagewise electric fields across the toner cake layer in the process nip; wherein the process nip being defined by a nip entrance and a nip exit, and having a preestablished nip gap, the toner cake layer developed in the nip gap to have imagewise separation of the toner cake layer to create a developed image corresponding to the electrostatic latent image and a background image, the developed image and the background image each having a thickness greater than one half the nip gap.

Claim 11

The imaging system of claim 8 wherein the toner cake layer is defined by a yield stress threshold in a range sufficient to allow the toner cake layer to behave substantially as a solid at the nip entrance and in the nip gap, while allowing the toner cake layer to behave substantially as a liquid along the image/background interfaces at the nip exit.

Claim 12

The imaging system of claim 8, wherein the yield stress threshold of the toner cake layer is sufficient to prevent lateral movement of toner particles therein in presence of the compressive stress forces exerted at the nip and nip entrance, and the yield stress threshold is sufficient to permit lateral movement of the toner particles therein in presence of the tensile stress forces exerted at the nip exit.

Claim 13

The imaging system of claim 7, wherein the image bearing surface includes a photosensitive imaging substrate.

Claim 14

The imaging system of claim 7, wherein the toner cake layer has a thickness of approximately 1 to 15 microns.

Claim 15

The imaging system of claim 7, wherein the low solids content liquid developing material is characterized as having percentage level of solids content in the range of less than approximately 10 percent solids content.

Claim 16

The imaging system of claim 7, wherein the toner cake layer is characterized as having a percentage level of solids content of approximately 10 percent solids content or greater.

Claim 17

The imaging system of claim 7, wherein the toner cake layer is characterized as having an accurately metered mass per unit area of approximately 0.1 mg per cm 2 .

Claim 18

An imaging system for effecting contact electrostatic printing of an output image, comprising: an imaging assembly having an imaging member, the imaging member having an image bearing surface for receiving an electrostatic latent image thereon, the electrostatic latent image being representative of the desired output image, and for receiving a toner cake layer adjacent the electrostatic latent image on the imaging member; a charging source for selectively delivering charges to the toner cake layer in an image-wise manner responsive to the electrostatic latent image on the image bearing member to form a secondary latent image in the toner cake layer having image and non-image areas corresponding to the electrostatic latent image on the imaging member; and a development assembly for developing the electrostatic latent image, the development assembly having a separator member for selectively separating portions of the toner cake layer in accordance with the secondary latent image in the toner cake layer to create a developed image corresponding to the electrostatic latent image formed on the image bearing member, so as to develop the electrostatic latent image; and a toner cake layer delivery apparatus operable for delivery of a toner cake layer of high solids content to the image bearing surface on the imaging member, the toner cake layer delivery apparatus having: (a) to a supply of liquid developing material, the liquid developing material being a mixture of toner particles in a liquid carrier medium, the mixture exhibiting a percentage level of solids content that is less than the percentage level of solids content in the desired toner cake layer, (b) a liquid developing material applicator connected to the supply of liquid developing material and operable for receiving a quantity of liquid developing material and for providing therefrom a layer of liquid developing material, (c) a layer concentrator operable for receiving the layer of liquid developing material and for removing at least a portion of the liquid carrier medium present in the layer of liquid developing material so as to increase the percentage level of solids content in the layer of liquid developing material, thus transforming the layer of liquid developing material into the desired toner cake layer, (d) a movable member aligned with the liquid developing material applicator and the layer concentrator, the movable member having a first surface for receiving thereon the layer of liquid developing material, the movable member being movable for: (1) transporting the layer of liquid developing material received on the first surface to the layer concentrator, so as to transform the layer of liquid developing material into the desired toner cake layer, and (2) for transporting the resulting toner cake layer into engagement with the image bearing member surface for subsequent delivery of the toner cake layer to the image bearing surface; wherein the development assembly is operable for engaging the toner cake layer with the electrostatic latent image on the imaging member so as to develop the latent image into a developed image representative of the output image.

Claim 19

An imaging system for effecting contact electrostatic printing of an output image, comprising: an imaging assembly having an imaging member, the imaging member having an image bearing surface for receiving an electrostatic latent image thereon, the electrostatic latent image being representative of the desired output image, and for receiving a toner cake layer adjacent the electrostatic latent image on the imaging member; a charging source for selectively delivering charges to the toner cake layer in an image-wise manner responsive to the electrostatic latent image on the image bearing member to form a secondary latent image in the toner cake layer having image and non-image areas corresponding to the electrostatic latent image on the imaging member; and a development assembly for developing the electrostatic latent image, the development assembly having a separator member for selectively separating portions of the toner cake layer in accordance with the secondary latent image in the toner cake layer to create a developed image corresponding to the electrostatic latent image formed on the image bearing member, so as to develop the electrostatic latent image; and a toner cake layer delivery apparatus operable for delivery of a toner cake layer of high solids content to the image bearing surface on the imaging member, the toner cake layer delivery apparatus having: (a) to a supply of liquid developing material, the liquid developing material being a mixture of toner particles in a liquid carrier medium, the mixture exhibiting a percentage level of solids content that is less than the percentage level of solids content in the desired toner cake layer, (b) a liquid developing material applicator connected to the supply of liquid developing material and operable for receiving a quantity of liquid developing material and for providing therefrom a layer of liquid developing material, (c) a layer concentrator operable for receiving the layer of liquid developing material and for removing at least a portion of the liquid carrier medium present in the layer of liquid developing material so as to increase the percentage level of solids content in the layer of liquid developing material, thus transforming the layer of liquid developing material into the desired toner cake layer, (d) a movable member aligned with the liquid developing material applicator and the layer concentrator, the movable member having a first surface for receiving thereon the layer of liquid developing material, the movable member being movable for: (1) transporting the layer of liquid developing material received on the first surface to the layer concentrator, so as to transform the layer of liquid developing material into the desired toner cake layer, and (2) for transporting the resulting toner cake layer into engagement with the image bearing member surface for subsequent delivery of the toner cake layer to the image bearing surface; wherein the development assembly is operable for engaging the toner cake layer with the electrostatic latent image on the imaging member so as to develop the latent image into a developed image representative of the output image.

Claim 20

The imaging system of claim 16, wherein the toner cake layer has a thickness of approximately 2 to 15 microns in the nip gap.

Claim 21

The imaging system of claim 16, wherein the low solids content liquid developing material is characterized as having percentage level of solids content in the range of approximately 1 to 10 percent solids content.

Claim 22

The imaging system of claim 16, wherein the toner cake layer is characterized as having a percentage level of solids content of approximately 10 percent solids content or greater.

Claim 23

The imaging system of claim 16, wherein the toner cake layer is characterized as having a uniform thickness in the range of 1-5 microns.

Claim 24

The imaging system of claim 16, wherein the toner cake layer is characterized as having an accurately metered mass per unit area of approximately 0.1 mg per cm 2 .

Claim 25

The imaging system of claim 16, further comprising a biased member for inducing air breakdown to create an electrical discharge in the vicinity of the toner cake layer on the latent image, wherein the electrical discharge selectively delivers charged ions to the toner layer in response to the electrostatic latent image on the image bearing member to form a secondary latent image in the toner layer having image and non-image areas corresponding to the electrostatic latent image on the image bearing member; and wherein the separator member is operable for selectively separating and transferring portions of the toner layer thereto in accordance with the secondary latent image in the toner layer to create a developed image corresponding to the electrostatic latent image formed on the image bearing member.