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:
Oct. 17, 2000
Filed:
Aug. 13, 1999
Frank R Bryant, Denton, TX (US);
John E Turner, Corvallis, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A thin-film print head is provided that includes at least one MOSTFT transistor, at least one resistor, a conductive line between the transistor and resistor. External interconnects between the internal circuitry of print head and external driver circuitry are provided. The thin-film print head device is adjacent to an ink barrier and an orifice plate that together define the firing chamber. Each firing chamber has associated with it a respective thin-film resistor of the print head that is selectively driven by a respective transistor. The transistor includes a source, a gate, a channel, and a drain, wherein the source, channel, and drain are formed by a first polysilicon layer. The MOSTFT transistor selectively drives the resistor with sufficient current to vaporize ink in the chamber and eject ink therefrom. The MOSTFT transistor allows the print head to be manufactured on a relatively inexpensive, non-silicon substrate or a less expensive silicon substrate, due to the less restrictive criteria for the substrate material required by MOSTFT transistors. The substrate may also comprise a material that provides enhanced thermal conductivity to act as a substantial heat sink for the print head.