Patent ID: 6412920
Filing Date: 2002-07-02
Classification: B41J

Abstract:
A liquid jet printing head having a plurality of electrothermal transducers, each having a driving voltage, for creating a bubble in liquid upon electric energy supply thereto from an electric energy supply and ejecting the liquid by pressure produced by creation of the bubble, comprising:a first electrothermal transducer having a first heat generating resistor with a first area and wiring electrically connected with said first heat generating resistor; and a second electrothermal transducer having a second heat generating resistor with an area which is different from the first area of said first heat generating resistor so that said first and second electrothermal transducers eject different amounts of liquid relative to each other for application of a given amount of electric energy, and wiring electrically connected with said second heat generating resistor; wherein each of said first and second electrothermal transducers have a threshold voltage for generating a bubble in the liquid and those said threshold voltages are the same, and said first and second electrothermal transducers are supplied with the driving voltage from a same voltage source, wherein said first heat generating resistor has a first length and said second heat generating resistor has a second length, and wherein the first and second lengths of said respective first and second heat generating resistors, measured in the wiring direction, are substantially the same.