Abstract: An ink jet head includes a plurality of liquid flow paths for ejecting the ink; and a plurality of heat generating resistors for the respective liquid flow paths, the heat generating resistor being independently drivable; wherein adjacent ones of the heat generating resistors are spaced by not more than 8 microns.

Abstract: A method for producing a substrate for an ink jet recording head comprises preparing a substrate with plural heat generating resistors for applying heat to the ink, plural wirings electrically connected thereto, and plural heat generating areas formed by the heat generating resistors exposed from the wirings, coating the heat generating resistors and the wirings on the substrate with a first insulating protective film, removing the first insulating protective film by wet etching in portions on the heat generating areas, and coating thus etched first insulating protective film with a second insulating protective film, wherein the etched portion of the first insulating protective film, in the longitudinal direction of the heat generating area, is positioned inside from the end of the heat generating area, by at least 1/2 of the thickness of the first and second insulating protective films covering the wirings.

Abstract: An ink jet recording apparatus includes an orifice for ejecting ink; a heater for generating thermal energy to produce a bubble to eject the ink; an ink passage for supplying ink to the orifice, the ink passage being provided with the heater; an ink container for containing ink to be supplied to the ink passage, the ink container retaining the ink, using capillary force; wherein the following is satisfied:V.sub.OH >[(R'+P)/(F'+R'+P).times.(F+R)/R+1 ]Vdwhere V.sub.OH is a volume of the ink passage from the orifice to an edge of the heater adjacent the orifice, Vd is a volume of ink ejected from the orifice, F is a flow resistance from a center of the heater to the orifice; R is a flow resistance from a center of the heater to the ink container; F' is a flow resistance from a maximum bubble produced on the heater to the orifice; R' is a flow resistance from a maximum bubble produced on the heater to the ink container, and P is a flow resistance of the ink container.

Abstract: An ink supply mechanism, which supplies ink from an ink container for storing ink to an ink jet recording unit which discharges ink, comprises a first filter member provided in an ink outlet section of the ink container; an ink supply passage which conductively connects the ink jet recording unit and the ink container for supplying ink from the ink container to the ink jet recording unit; and a second filter member provided in the ink supply passage between ink discharging ports of the recording unit and the first filter member. The second filter member is provided with holes which create the capillary force greater than the negative pressure in the ink container.