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:
Mar. 09, 1993
Filed:
Oct. 29, 1990
Hartmut Fuhrmann, Karlsfeld, DE;
Alfred Hirt, Munich, DE;
Man Roland Druckmaschinen AG, Offenbach am Main, DE;
Abstract
To provide an electrically controllable printing form, on which the printing image is retained even upon repeated application of printing toner or printing ink formed of toner suspended in a carrier liquid, the printing form (10) has a surface layer (12) of ferroelectric material or, if a gravure form (40), the cells (31) have a bottom (32) of ferroelectric material. The form is programmed under control of a control unit (13, 13') by an electrode (14, 14') which selectively polarizes the ferroelectric material. Upon application of electrically charged toner or ink, the ink or toner particles which are charged oppositely to the polarization of the ferroelectric layer or bottom will be retained, the equally charged particles repelled, so that, by selective positive or negative polarization, two-color printing can be effected at one pass of a printing substrate over the form.