SPLIT LEVEL CHANNELS FOR IMPROVED BUBBLE JET PERFORMANCE
Original Publication Date: 1991-Aug-31
Included in the Prior Art Database: 2004-Apr-05
Xerox Disclosure Journal
A recent advance in bubble jet performance has come about as a result of addition of the "pit layer", as disclosed in U.S. Patent 4,638,337. In that patent, the pit layer puts the bubble jet resistor in a recess, so that the force of the bubble is directed vertically upward. The roof of the channel is very far from the resistor, however, as a result of the combined depth of the pit and height of the roof. Operational improvement may be achieved by changing the etching process for formation of the channels to lower the roof. The channel 12 of printhead 10 should be divided in two portions 14,16 as shown in the figure below. The lower roof 18 should increase drop velocity and frequency response.