Thin film resistor type thermal ink pen using a form storage ink supply

A printhead and orifice plate assembly which comprises:

• a. a thin film resistor type of thermal ink jet substrate member having a plurality of openings therein for receiving different colors of ink,
• b. a barrier layer mounted on said substrate member and having a geometry defining a plurality of ink reservoirs which receive ink from said openings,
• c. a nozzle plate disposed on said barrier layer and having a plurality of ink ejection orifices which receive different colors of ink from said reservoirs, whereby multiple colors of ink may be ejected from a single plane in which said orifices lie,
• d. a multi-compartment housing adjacent to and supporting said substrate member,
• e. ink storage means within each compartment of said housing for supplying ink to said substrate member and directly through openings in said housing, said ink storage means being a foam material compressible to reduce the pore size therein and increase its density, so that the desired capillarity of said foam material can be controlled and the capillary force of said foam increased, thereby rendering said foam material especially well suited for feeding ink to a thin film resistor type of thermal ink jet printhead, and
• d. tab means extending into contact with said foam material for providing a desired amount of compressive force to said foam.