Patent ID: 8870341

Claim:
An ink jet printhead comprising: a nozzle plate having an underside and comprising one or more nozzles in the underside configured to dispense drops of fluid in a dispensing direction; a multi-level maintenance structure coupled to the nozzle plate such that a gap exists between a portion of the maintenance structure and the underside of the nozzle plate, the maintenance structure comprising: a first portion having a first upper surface suspended at a first distance from the underside of the nozzle plate; and a second portion that is coupled to the first portion, the second portion having a second upper surface suspended at a second distance from the underside of the nozzle plate, which is greater than the first distance, the second upper surface laterally displaced relative to the first upper surface, wherein each of the first and second portions of the maintenance structure defines one or more openings extending in the dispensing direction, the one or more openings aligned with the one or more nozzles in the dispensing direction and configured to allow the drops of fluid dispensed by the one or more nozzles to pass through the maintenance structure, wherein the one or more nozzles comprise an array of nozzles arranged in ordered columns, and wherein the one or more openings defined by the second portion of the maintenance structure comprise a plurality of closed shape openings, each of the closed shape openings aligned with a respective nozzle of the array; and a maintenance fluid source in fluid communication with the gap, the maintenance fluid source being configured to inject a flow of maintenance fluid into the gap, the flow in a direction substantially perpendicular to the dispensing direction, the maintenance fluid comprising a vapor carrying a solvent, wherein a solvent concentration of the vapor is sufficient to maintain a non-drying environment in the gap.