公开(公告)号：US10684577B1

公开(公告)日：2020-06-16

申请号：US16207512

申请日：2018-12-03

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： Christopher Michael Bennett ,  Matthew David Heid ,  Gina Marie Johns ,  Michael Craig Leemhuis ,  Christopher David Strack

IPC: G03G15/16

Abstract: An imaging device has first image transfer from photoconductive drums to an intermediate transfer member (ITM) and second image transfer from the ITM to media. Transfer rolls oppose the drums from an opposite side of the ITM and electrically ground to a frame of the imaging device by mechanical connection. The rolls may be laterally offset from the drums. The ITM has relatively low surface and volume resistivity. An imaging subassembly may include the frame, the ITM, and the transfer rolls grounded to the frame.

公开(公告)号：US10782627B1

公开(公告)日：2020-09-22

申请号：US16443985

申请日：2019-06-18

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： Andrew Pryse Dale ,  Matthew David Heid ,  Christopher David Strack

IPC: G03G15/02 ,  G03G15/08 ,  G03G15/00 ,  G03G15/06

Abstract: An imaging device includes a photoconductive drum charged by a charge roll and opposed by developer roll. The developer roll adds toner to the drum to develop a latent image on the drum for transfer to media. One or more high voltage power supplies communicate with a controller to set voltages on the rolls. The controller determines whether imaging of the media is to occur at a time when the drum is rotating. If not, a laser beam discharges the drum and the voltage on the charge roll is decreased to reduce the charge on the drum, but the controller maintains the voltage differential between the drum and the developer roll.

公开(公告)号：US11249406B2

公开(公告)日：2022-02-15

申请号：US16877795

申请日：2020-05-19

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： Matthew David Heid ,  Laura Lee Kierstein ,  Weimei Luo ,  Prasanna Shrestha

IPC: G03G5/00 ,  G03G5/05 ,  G03G5/047 ,  G03G5/06 ,  G03G5/10 ,  G03G5/147

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.

公开(公告)号：US10719026B2

公开(公告)日：2020-07-21

申请号：US16032273

申请日：2018-07-11

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： Christopher Michael Bennett ,  Andrew Pryse Dale ,  Matthew David Heid

IPC: G03G15/01 ,  G03G15/16

Abstract: An imaging device prints in color and monochromatically, such as black-only. It has a plurality of photoconductive drums, one each for black toner and at least one colored toner. The drums contact and rotate with an intermediate transfer member (ITM) to transfer images at a first transfer. During black-only imaging, the photoconductive drum for the black toner rotates with the ITM at process speed while the drum for the at least one colored toner rotates at less than process speed, often substantially less. The technique reduces consumption of colored toner during black-only imaging and minimizes charge build-up on the drum for the colored toner.

公开(公告)号：US11256185B2

公开(公告)日：2022-02-22

申请号：US16877783

申请日：2020-05-19

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： Matthew David Heid ,  Laura Lee Kierstein ,  Weimei Luo ,  Prasanna Shrestha

IPC: G03G5/00 ,  G03G5/05 ,  G03G5/047 ,  G03G5/06 ,  G03G5/10 ,  G03G5/147

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.

公开(公告)号：US10809641B1

公开(公告)日：2020-10-20

申请号：US16518215

申请日：2019-07-22

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： Douglas Anthony Able ,  Andrew Pryse Dale ,  Jared Kuohui Lin ,  Matthew David Heid ,  Christopher David Strack

IPC: G03G15/02 ,  G03G15/16 ,  G03G15/06

Abstract: An imaging device includes a photoconductive drum charged by a charge roll and opposed by developer roll. The developer roll adds toner to the drum to develop a latent image on the drum for transfer to media or an intermediate transfer member at a transfer roll. One or more high voltage power supplies communicate with a controller to set voltages on the rolls. During times of non-imaging, but rotation of the drum, the charge roll charges the drum to less than a Paschen breakdown voltage of the drum. A voltage of the transfer roll is determined that corresponds to a temperature and relative humidity of an operating environment of the imaging device and the developer roll is charged based thereon. The charge of the transfer roll is set close to the charge of the drum, but higher in magnitude. A laser may also discharge the drum.