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:
Jan. 28, 1997
Filed:
Sep. 07, 1993
Ulrich E Hess, Corvallis, OR (US);
James W Grace, Los Altos Hills, CA (US);
James R Hulings, Fort Collins, CO (US);
Jaime H Bohorquez, Escondido, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A bipolar ink jet driver circuit includes a plurality of individual driver cells having a common collector and a resistive heater element. A common collector obviates the need for any isolation between adjacent driver cells. The driver cells each include two bipolar transistors configured as a Darlington pair, which drive an associated resistive heater element. The cells are grouped together to form individual driver circuits each having a control line for enabling each driver circuit. The cells within each driver circuit are individually addressable via address lines which are coupled to each of the driver elements. The resistive heater elements are actuated by enabling a driver circuit and addressing a driver cell within the enabled driver circuit.