Patents by Inventor PRASANNA SHRESTHA

PRASANNA SHRESTHA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11256185
    Abstract: A photoconductive drum includes an elongated support element with a shaped charge generation layer. The layer extends from the support element at various thicknesses along a length thereof. Thicker charge generation portions provides denser optical densities compared to thinner portions allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. A charge transport layer overcoats the charge generation layer. Optionally, an oxidation layer underlies the charge generation layer as does a protective overcoat overlying the charge transport layer. Various thicknesses and shapes of the charge generation layer are also disclosed.
    Type: Grant
    Filed: May 19, 2020
    Date of Patent: February 22, 2022
    Assignee: LEXMARK INTERNATIONAL, INC.
    Inventors: Matthew David Heid, Laura Lee Kierstein, Weimei Luo, Prasanna Shrestha
  • Patent number: 11249406
    Abstract: Shaping a photoconductive drum includes preparing a dispersion having a charge generation composition and dipping an elongated support element into the dispersion. Withdrawing from the dispersion portions of the support element at different speeds results in different thicknesses of charge generation composition on the support element. Faster withdrawal results in thicker charge generation composition than does slower withdrawal. Portions with thicker composition provide denser optical densities compared to thinner composition allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. Coating the support element with a charge transport layer occurs next, then curing. Oxidation of the support element may occur prior to application of the charge generation composition. A protective overcoat may also exist over the charge transport layer.
    Type: Grant
    Filed: May 19, 2020
    Date of Patent: February 15, 2022
    Assignee: LEXMARK INTERNATIONAL, INC.
    Inventors: Matthew David Heid, Laura Lee Kierstein, Weimei Luo, Prasanna Shrestha
  • Publication number: 20220026820
    Abstract: A photoconductive drum includes an elongated support element with a shaped charge generation layer. The layer extends from the support element at a single thickness along about two-thirds of a length thereof. Thicker charge generation portions provides denser optical densities compared to thinner portions allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. A charge transport layer overcoats the charge generation layer. Optionally, an oxidation layer underlies the charge generation layer as does a protective overcoat overlying the charge transport layer.
    Type: Application
    Filed: October 11, 2021
    Publication date: January 27, 2022
    Inventors: MATTHEW DAVID HEID, LAURA LEE KIERSTEIN, WEIMEI LUO, PRASANNA SHRESTHA
  • Publication number: 20210124277
    Abstract: Shaping a photoconductive drum includes preparing a dispersion having a charge generation composition and dipping an elongated support element into the dispersion. Withdrawing from the dispersion portions of the support element at different speeds results in different thicknesses of charge generation composition on the support element. Faster withdrawal results in thicker charge generation composition than does slower withdrawal. Portions with thicker composition provide denser optical densities compared to thinner composition allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. Coating the support element with a charge transport layer occurs next, then curing. Oxidation of the support element may occur prior to application of the charge generation composition. A protective overcoat may also exist over the charge transport layer.
    Type: Application
    Filed: May 19, 2020
    Publication date: April 29, 2021
    Inventors: MATTHEW DAVID HEID, LAURA LEE KIERSTEIN, WEIMEI LUO, PRASANNA SHRESTHA
  • Publication number: 20210124278
    Abstract: A photoconductive drum includes an elongated support element with a shaped charge generation layer. The layer extends from the support element at various thicknesses along a length thereof. Thicker charge generation portions provides denser optical densities compared to thinner portions allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. A charge transport layer overcoats the charge generation layer. Optionally, an oxidation layer underlies the charge generation layer as does a protective overcoat overlying the charge transport layer. Various thicknesses and shapes of the charge generation layer are also disclosed.
    Type: Application
    Filed: May 19, 2020
    Publication date: April 29, 2021
    Inventors: MATTHEW DAVID HEID, LAURA LEE KIERSTEIN, WEIMEI LUO, PRASANNA SHRESTHA