Patent ID: 9004639
Filing Date: 2015-04-14
Classification: B41J

Abstract:
1. A system for identifying changes in drop mass in an inkjet printer, the system comprising: an image receiving member configured to rotate about an axis; an optical sensing device configured to generate image data of a surface of a rotating image receiving member; a printhead assembly having a plurality of printheads that eject fluid towards a surface of the rotating image receiving member; and a controller operatively connected to the optical sensing device, the image receiving member, and the printhead assembly, the controller being configured to operate at least one of the printheads in the printhead assembly to eject a first line of fluid drops across the image receiving member in a cross-process direction as the image receiving member rotates in a process direction, to displace each at least one printhead that ejected the first line of fluid drops by a predetermined distance in a direction that is perpendicular to the cross-process direction and the process direction, to eject a second line of fluid drops across the image receiving member in the cross-process direction as the image receiving member rotates in the process direction, the second line being generated to be placed on the first line of fluid drops, to identify a distance between a first portion of the first line of fluid drops and a first portion of the second line of fluid drops, to compare the identified distance between the first portions of the first and second lines to a distance stored in association with the at least one printhead that ejected the fluid drops in the first portion of the first line of fluid drops and the first portion of the second line of fluid drops, and to modify a printer parameter in response to the identified distance being greater than or less than the distance stored in association with the at least one printhead that ejected the fluid drops in the first portion of the first line of fluid drops and the first portion of the second line of fluid drops by a predetermined amount.