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. 06, 1982
Filed:
Oct. 22, 1979
Gerald L Pressman, Cupertino, CA (US);
Robert A Moore, Amherst, NH (US);
Jeffrey B Brooks, Keene, NH (US);
Robert W Sengstaken, Jr, Harrisville, NH (US);
Markem Corporation, Keene, NH (US);
Abstract
An improved electrostatic print head is disclosed comprising a corona source, an aperture mask, a slotted focus plane, and a back plane electrode for supporting a moving dielectric print medium. The aperture mask includes two rows of staggered circular apertures which are surrounded by individual aperture electrodes on the side of the mask facing away from the corona source. The side of the aperture mask facing the corona source has a continuous conductive layer thereon which is biased at a fixed potential. The aperture electrodes are selectively pulsed with a control potential to control the flow of ions from the corona source through the two staggered rows of apertures and the slotted focus plane to form any desired dot-matrix latent image on the moving dielectric print medium. The center line of the slotted focus plane is parallel to the center line between the two staggered rows of apertures to focus the ion beams defined by the individual apertures toward the center line of the slot while intensifying the electric field in the imaging region. The slotted focus plane also compresses the cross section of the ion beams defined by the individual apertures into ellipses having their minor axes parallel to the direction of motion of the dielectric print medium, permitting higher ion densities to be deposited on a moving dielectric print medium for a given final dot size and an improved resolution of the final dot-matrix image.