Lexmark : Patent Issued for Method for Increasing Useful Life In Toner

Toner News Mobile Forums Toner News Main Forums Lexmark : Patent Issued for Method for Increasing Useful Life In Toner

Date: Monday September 15, 2014 11:09:37 am
Viewing 1 post (of 1 total)
  • Author
    Posts

  • Anonymous
    Inactive

    Lexmark : Patent Issued for Method for Increasing Useful Life ( in a Toner ) of an Image Forming Apparatus

    By a News Reporter-Staff News Editor at Journal of Engineering — A patent by the inventors Campbell, Alan Stirling (Lexington, KY); Langer, David Brian (Lexington, KY); Pickett, Peter Brown (Lexington, KY); Schneider, David Anthony (Lexington, KY), filed on July 19, 2010, was published online on September 2, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

    Patent number 8824929 is assigned to Lexmark International, Inc. (Lexington, KY).
    http://i.ytimg.com/vi/LlGWtHza68c/0.jpg

    The following quote was obtained by the news editors from the background information supplied by the inventors: "The present invention relates generally to an image forming apparatus and, more particularly, to a system and method for reducing the churning of toner in the image forming apparatus.

    "An image forming apparatus, such as a color printer typically includes four image forming stations associated with four colors, black, magenta, cyan, and yellow. Each image forming station includes a laser to expose a latent image on the charged surface of a photoconductive drum. The latent image on each photoconductive drum is developed with the appropriate color toner and is then transferred to either an intermediate transfer medium or directly to a media (such as paper) that travels past the photoconductive drums. The un-fused toner on the media is then fused to the media by application of heat and pressure in a fuser assembly.

    "In the process of printing a sequence of pages, the image forming station runs for a short time before printing the first page (run in) and runs for a short period of time after printing the last page (run out). The run in and run out processes are required to prepare the various components of the image forming station before printing and to clean the image forming station after completion of printing, respectively. When a print job includes a small number of pages, the overhead time consumed during run in and run out is more than the time required for actual printing of the pages. Excessive amount of time spent during run in and run out results in a degradation of print quality due to recycling of toner in the image forming stations of the image forming apparatus. Toner that is not used in the printing process is re-circulated many times before it is used for printing. This repeated recycling of the toner is known as churn and results in print quality defects such as starvation, grainy print, and poor transfer to the media.

    "In the image forming apparatus, the photoconductive drums that print each color are arranged in tandem and typically all the photoconductive drums start rotating at the same time. This is done to provide a stable motion quality of the photoconductive drums within the image forming apparatus, however since the upstream image forming stations are used before the downstream stations, the downstream stations experience toner churn that is not productive at the beginning of a print job. Similarly during the completion of the print job, the upstream stations experience toner churn until the downstream station complete the image transfer process.

    "Further, the photoconductive drum transfers its image to an intermediate transfer member that accumulates the images from each of the four imaging forming stations. The intermediate transfer member then transfers the accumulated image to a media at a second transfer point. In the prior art system, the photoconductive drums continue to rotate until the intermediate transfer member completes transfer of the image to the media at the second transfer point. This linkage between the running of the photoconductive drums and the intermediate transfer member is done to improve motion quality and reduce slippage that might cause damage to the photoconductive drums or the intermediate transfer member. However, this process also results in toner churn that is undesirable.

    "Therefore, it is desirable to increase the useful life of the image forming apparatus by reducing excess toner churn."

    In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "Embodiments of the present invention overcome the shortcomings of prior imaging systems and thereby satisfy a significant need for an improved image forming system, generally by sequencing the running of each image forming station such that the station does not start running until at or near the latest possible opportunity to do so, and stops running at or near the earliest opportunity to stop at the end of a print job.

    "Disclosed herein is an image forming apparatus including an intermediate transfer member; a plurality of photoconductive drums in contact with the intermediate transfer member, the plurality of photoconductive drums transferring an image to the intermediate transfer member during a print operation; a plurality of charging rollers positioned in contact with the plurality of photoconductive drums; and a controller providing instructions to the image forming stations that sequentially starts and then ramps the speed of the photoconductive drums so that the controller can control the start of imaging on an upstream image forming station while preparing the components of a downstream image forming station, and then after completing the imaging process at an image forming station, the controller then sequentially starts decelerating each photoconductive drum from the print speed towards a stationary position after completing the printing operation.

    "In some embodiments, a photoconductive drum begins rotating after an immediately upstream photoconductive drum begins accelerating but prior to the laser exposing the upstream photoconductive drum. Further, a photoconductive drum begins deceleration after image transfer is completed by an immediately downstream photoconductive drum. By controlling run-in and run-out for the photoconductive drums individually, the revolutions of each photoconductive drum may be limited to substantially only include the time necessary to perform run-in and run-out functions for the drum. Reduction in photoconductive drum revolutions substantially reduces toner churn which thereby extends cartridge life.

    "Additional features and advantages of the invention will be set forth in the detailed description which follows and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description, which follows, the claims, as well as the appended drawings.

    "It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention."

    URL and more information on this patent, see: Campbell, Alan Stirling; Langer, David Brian; Pickett, Peter Brown; Schneider, David Anthony. Method for Increasing Useful Life of an Image Forming Apparatus. U.S. Patent Number 8824929, filed July 19, 2010, and published online on September 2, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8824929.PN.&OS=PN/8824929RS=PN/8824929

    Keywords for this news article include: Lexmark International, Lexmark International Inc.

    Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC
    http://www.laserservicesinc.com/images/lexmark_logo.gif

Viewing 1 post (of 1 total)
  • You must be logged in to reply to this topic.