Wet-wiping technique for inkjet printhead

Abstract

A service station for use with an inkjet printer is described. The service station includes a sled that is mounted to the printer's chassis. Caps and wipers can be mounted on the sled for each of the printer's movable carriage-mounted printheads. The sled and the chassis, and the sled and carriage, are each cam-coupled so that movement of the carriage produces slight vertical and lateral movement of the sled out of a nominal position to automatically place the sled in one of three primary positions relative to the carriage: an elevated position for capping the printheads, an intermediate position for wiping the printheads and a lowered position for free reciprocal movement of the carriage without interference between the printheads and either the caps or the wipers. In one embodiment of the invention, prior to wiping the printhead of a print cartridge, the print cartridge is spitted to wet the printhead. Such spitting is particularly beneficial for a print cartridge that dispenses a pigmented ink (frequently a black ink), since the pigmented ink tends to crust on the printhead more than inks that are dyes. Preferably, a plurality of drops of ink are spit from the print cartridge at each of a plurality of frequencies. The method according to the invention is applicable to printers including one or more print cartridges.