Patent ID: 7052116
Filing Date: 2006-05-30
Classification: B41J

Abstract:
1. A Thermal ink jet printhead comprising a reservoir containing ink, a die, a slot etched in said die and fluidly connected with said reservoir, and a plurality of ejectors each of which in turn comprises a nozzle having an outer edge, and a chamber, said ink forming a meniscus on said outer edge, and each of said ejectors presenting a time constant τ, wherein each of said chambers is fluidly connected with said slot through a plurality of elementaiy ducts each having width g determined by means of the formula where v is the viscosity of the ink and τ is the time constant assigned to each of said ejectors, and the number N of said elementary ducts is determined by means of the formula where R′ and L′ represent respectively the hydraulic resistance and the hydraulic resistance of a single elementary duct, and Cm represents the hydraulic compliance of said meniscus, whereby said meniscus presents a critical damping with whatever value is assigned to τ.