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:
Apr. 02, 2002
Filed:
Nov. 30, 2000
Chien-Hua Chen, Corvallis, OR (US);
Kenneth M. Kramer, Corvallis, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
Described herein is a monolithic printhead formed using integrated circuit techniques. Thin film layers, including a resistive layer, are formed on a top surface of a silicon substrate. The various layers are etched to provide heater resistors and conductors. The thin film layers are also etched to expose portions of the upper surface of the substrate where ink feed holes leading into ink chambers are to be formed. A trench is etched in the bottom surface of the substrate while leaving a relatively thin membrane of the substrate underlying the thin film layers. After the trench is formed and using a backside etch, ink feed holes are formed in the substrate membrane leading from the trench to the ink chambers. Ink channels are also formed in the substrate membrane leading to sides of the ink feed holes. These channels preferably have widths smaller than the widths of the ink feed holes. Ink particles or other particles which may clog an ink feed hole opening do not block the narrower channels leading to the sides of the ink feed holes. Various examples of such channels and ink feed holes are described to form a particle-tolerant printhead for use in an inkjet printer.