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:
Jul. 27, 1993
Filed:
Mar. 12, 1992
Richard G Sweet, Palo Alto, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
An apparatus for a Nozzleless Droplet Projection System (10) is disclosed. The invention employs a novel geometry for producing a thin film of ink (26) having a constant depth traveling at a constant velocity across a tubular transducer head (16a, 16b). The head includes a smooth exterior perimetrical surface (18) that faces toward a sheet of paper (14) and a laminar flow regulator (28) that resembles a knife-edge. An array of electro-acoustic transducers (15) submerged beneath the transducer head support surface (17) generates tone bursts (20) of acoustic energy which are focused by a corresponding array of acoustic lenses (19) inscribed along the length of the transducer head (16a, 16b). A constant thickness and constant velocity fluid film (26) is generated by forcing pre-regulated, pressurized fluid (33) through a narrow slit (30) and across the smooth perimetrical surface (18) of the transducer head (16a, 16b). The dimensions of the slit (30) are defined by the space separating the laminar flow regulator (28) and the smooth exterior surface (18) of the print head. The ink film (26) is maintained at the acoustic focus of the lenses (19) to control the size of droplets of ink (12) that are ejected from the print head toward a sheet of paper (14). A pattern of droplets (12) is ejected by pulsing the appropriate electro-acoustic transducers (15) as the paper (14) is moved across the apparatus at a constant velocity. The cooperative action of the knife-edge shaped laminar flow regulator (28) and the smooth surface (18) of the print head (16a, 16b) provides a stable, fixed-depth, non-undulating film down stream from slit (30). The elastic action of a meniscus (46, 48) of fluid formed in slit (30) regulates the fluid velocity and depth along smooth exterior surface (18) during operation of the apparatus (10).