The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 1999
Filed:
Nov. 04, 1996
Masao Mitani, Hitachinaka, JP;
Kenji Yamada, Hitachinaka, JP;
Katsunori Kawasumi, Hitachinaka, JP;
Osamu Machida, Hitachinaka, JP;
Kazuo Shimizu, Hitachinaka, JP;
Hitachi Koki Co, Ltd., Tokyo, JP;
Abstract
In an ink ejection type recording device in which expansion of bubble ejects an ink droplet from a nozzle toward a recording medium, a heater formed in an ink channel is applied with a pulse of voltage by a driver circuit. The pulse of voltage is determined so that the surface of the heater in direct contact with the water-based ink is rapidly heated to a temperature causing to invoke caviar-wise nucleation of the ink that is in direct contact with the surface of the heater. Expanding bubbles resulting from the caviar-wise nucleation ejects an ink droplet from the nozzle, wherein the heater is heated at a heating speed in a range from 1.times.10.sup.8 .degree. C./sec to 5.times.10.sup.8 .degree.C./sec, and the surface of the heater is heated up from a room temperature to a temperature substantially equal to 320 C within a period of time ranging from 0.6 to 3 .mu.sec. By heating the heater under these conditions, the ink in contact with the heater starts boiling with a high boiling pressure, the generated bubble has a large volume, and thus the bubble can generate pressure sufficiently large to eject the ink droplet.