Patent ID: 6234612
Filing Date: 2001-05-22
Classification: B41J

Abstract:
An inkjet printing apparatus comprising:a first print cartridge including a first resistive heating element in a first ink-containing chamber having a first orifice, said first heating element having first longitudinal and transverse dimensions and a first resistance, a ratio of said first longitudinal dimension to said first transverse dimension is from about 0.8:1.0 to about 1.2:1.0;a second print cartridge including a second resistive heating element in a second ink-containing chamber having a second orifice, said second heating element having second longitudinal and transverse dimensions and a second resistance, a ratio of said second longitudinal dimension to said second transverse dimension being greater than or equal to about 1.5:1.0, wherein a ratio of said second resistance to said first resistance is greater than or equal to 1.2:1; anda driver circuit, electrically coupled to said first and second print cartridges, for selectively applying to one of said first and second heating elements a firing pulse, said firing pulse to said first heating element causing a vapor bubble to be produced in said first chamber such that a droplet of ink of a first size is ejected from said first chamber orifice and said firing pulse to said second heating element causing a vapor bubble to be produced in said second chamber such that a droplet of ink of a second size which is smaller than said first size is ejected from said second chamber orifice.