Electrostatographic image-forming apparatus and method

Abstract

Electrostatographic recording method and apparatus that includes a primary image-forming member (PIFM) which moves along a closed path at high-speed. The PIFM may be in the form of an endless belt, which has a row of image frame synchronizing indicia. The indicia are spaced from each other in the direction of movement of the PIFM. The indicia are not all uniformly spaced from one another so that an interframe area larger than other smaller interframe areas on the PIFM can exist. During a production run toner images are formed on the image frames by sensing the image frame synchronizing indicia. The larger interframe area is provided preferably at a splice or seam area to provide sufficient time for a change in a process element for which sufficient time is not available at a smaller interframe area. As an example, the process element may be a transfer roller which is switched in polarity at the larger interframe area to reduce toner contamination of the transfer roller due to presence of the seam or placement of toner at process control patches at such area. The endless belt may contain a single row of indicia that are used to synchronize two respective different series of image frame sizes.