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. 13, 1981
Filed:
Nov. 08, 1978
Gary L Fillmore, Boulder, CO (US);
Arthur R Hoffman, Longmont, CO (US);
Thomas Young, Boulder, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An inner cylindrical tube has its outer cylindrical surface spaced from an inner cylindrical surface of outer means to have an ink cavity therebetween from which ink is supplied through one or more ink jet nozzles. At least the inner tube is a piezoelectric material so that the inner tube vibrates radially when electrically excited to produce vibrations at a desired operating frequency whereby a stream of ink droplets is supplied from each of the ink jet nozzles. The spacing between the inner surface, which has its longitudinal axis coaxial with the longitudinal axis of the inner cylindrical tube, of the outer means and the outer surface of the inner cylindrical tube is selected so that the ink cavity is resonant at the operating frequency of the inner cylindrical tube. To maintain the lowest frequencies of perturbations in the axial direction of the inner cylindrical tube substantially greater than the operating frequency, the inner cylindrical tube can be formed of a plurality of longitudinal segments acoustically isolated from each other in the axial direction. In another form, the outer means is a body formed with a membrane providing acoustical communication from a liquid cavity between the inner tube and the body and each ink cavity, which has ink jet nozzles at its end. The liquid cavity preferably has a liquid of substantially the same density as the ink. This enables each of the ink cavities to have a different colored ink if desired.