Electrophotography – Image formation – Development
Reexamination Certificate
1999-09-28
2001-02-27
Braun, Fred L (Department: 2852)
Electrophotography
Image formation
Development
C399S249000
Reexamination Certificate
active
06195520
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is generally directed to coating processes and coating conditioning processes for improved coating layers. More specifically, the present invention relates to improved coating processes and methods for improving or altering the properties of the resulting coating layer. The present invention can be applied to, for example, liquid development processes and imaging processes thereof providing, for example, improved coating and image cake forming processes, improved imaging processes, and improved imaging apparatuses.
There are certain prior art liquid toner development processes that use a thin layer or thin coating of high concentration toner materials as its development input. A problem associated with these prior art coating systems generally, and liquid development processes using a thin liquid toner layer specifically, particularly for highly viscous coating formulations such as certain liquid developers, is the inability to reliably form thin layers from high solids content coating formulations or developers. The problem is particularly evident for developer materials which are slightly to highly non-Newtonian and or strongly shear thinning. Additionally, paste or slurry-like materials can present other complications attributable to their strong yield stress and viscoelastic properties. In contrast, forming coatings of relatively dilute solutions or slurries, for example, with solids content of from about 1 to about 10 weight percent, is rather straight forward and uncomplicated. However, these dilute developers are disadvantaged and complicated by the need to remove a large excess of carrier fluid.
These and other problems are solved in embodiments of the present invention. The present invention provides in embodiments an apparatus and processes for forming very thin coatings with highly uniform thicknesses and high solids contents from either relatively dilute or relatively concentrated coating formulations or liquid developers.
PRIOR ART
In commonly owned and assigned U.S. Pat. No. 5,826,147, issued Oct. 20, 1998, to Liu, et al., there is disclosed a novel image development method and apparatus, wherein an imaging member having an imaging surface is provided with a layer of marking material thereon, and an electrostatic latent image is created in the layer of marking material. Image-wise charging of the layer of marking material is accomplished by a wide beam ion source such that free mobile ions are introduced in the vicinity of an electrostatic latent image associated with the imaging member having the layer of marking material coated thereon. The latent image associated with the imaging member causes the free mobile ions to flow in an image-wise ion stream corresponding to the latent image, which, in turn, leads to image-wise charging of the toner layer, such that the toner layer itself becomes the latent image carrier. The latent image carrying toner layer is subsequently developed and transferred to a copy substrate to produce an output document.
In U.S. Pat. No. 5,596,396, issued Jan. 21, 1997, to Landa, et al., there is disclosed an imaging apparatus including a first member having a first surface having formed thereon a latent electrostatic image, the latent electrostatic image including image regions at a first voltage and background regions at a second voltage, a second member charged to a third voltage intermediate the first and second voltages and having a second surface adapted for resilient engagement with the first surface and a third member adapted for resilient contact with the second surface in a transfer region. The imaging apparatus also includes apparatus for supplying liquid toner to the transfer region thereby forming on the second surface a thin layer of liquid toner containing a relatively high concentration of charged toner particles and apparatus for developing the latent image by the selective transfer of portions of the layer of liquid toner from the second surface to the first surface.
In commonly owned and assigned U.S. Pat. No. 5,937,248, issued Aug. 10, 1999, to Liu, et al., there is disclosed a printing machine and method for efficiently forming toner images such that a quantity of unused toner applied to a photoreceptor of the machine is significantly diminished. The printing machine and method include a movable photoreceptor having a photoconductive surface for supporting electrostatic charge; a first charging device for selectively charging only scattered portions of the surface of the photoreceptor; a liquid developer material supply and application apparatus for applying a coat of charged toner solids having a single polarity onto each charged selected scattered portion, thereby forming an image area patch of toner; an exposure device for image-wise exposing each charged selected scattered portion to form a first latent image therein; and a contact electrostatic printing (CEP) assembly including a conductive (CEP) roll and a bias source coupled thereto, for applying compressive and tensile forces to the image area centered patches of toner moving through an image processing nip formed by the photoconductive surface of the photoreceptor and the conductive CEP roll, wherein the bias source cooperates with a charge pattern of the image area centered patches of toner to generate image-wise electric fields within the image processing nip, and the image-wise electric fields together with the compressive and tensile forces, enable easy separation of background area toner solids from image area toner solids of the image area centered patches of toner, and onto the CEP roll; thereby resulting in an efficiently produced, quality toner image with significantly reduced non-development marking material generated and requiring removal.
In commonly owned and assigned U.S. Pat. No. 5,937,243, issued Aug. 10, 1999, to Liu, et al., there is disclosed a novel image development method and apparatus, whereby image-wise charging of a toner layer is accomplished by induced air breakdown electrical discharge such that free mobile ions are introduced in the vicinity of an electrostatic latent image coated with a layer of developing material. The latent image causes the free mobile ions to flow in an image-wise ion stream corresponding to the latent image, which, in turn, leads to image-wise charging of the toner layer, such that the toner layer itself becomes the latent image carrier. The latent image carrying toner layer is subsequently developed and transferred to a copy substrate to produce an output document.
The disclosures of the above mentioned patents are incorporated herein by reference in their entirety.
SUMMARY OF THE INVENTION
Embodiments of the present invention, include:
A process comprising:
forming a first coating layer on a first movable substrate surface with a liquid developer; and
contacting the resulting first coating layer on the first substrate with a second movable substrate surface to produce a thin uniform second coating layer on the first movable substrate surface, wherein the directional movement of the first movable substrate surface opposes the directional movement of the second movable substrate surface, and wherein at least one of the first substrate surface and the second substrate surface conforms to an opposing surface; and
A printing machine comprising:
a coater adapted for depositing a liquid developer on the surface of a first movable substrate to form a first toner layer;
a second movable substrate adapted for contacting the first toner layer on the first substrate to form a uniformly thin second toner layer on the first substrate, wherein the directional movement of the first movable substrate surface is contrary to the directional movement of the second movable substrate surface, and wherein at least one of the first substrate surface and the second substrate surface conforms to an opposing surface; and
a photoactive member adapted for receipt and formation of latent image information thereon and further adapted for receipt of a toner layer to permit development of
Chinnici John
Liu Chu-heng
Morehouse Jr. Paul W.
Proulx Rodney B.
Wallace Anthony M.
Braun Fred L
Haack John L.
Xerox Corporation
LandOfFree
Method and apparatus for forming a uniform layer of liquid... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for forming a uniform layer of liquid..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for forming a uniform layer of liquid... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2558548