JPS6424796A - Powder-applying printer - Google Patents

Abstract

PURPOSE:To enable a powder to be supplied onto an arbitrary viscous ink image speedily and effectively, by arranging a plurality of powder-applying elements in a dot matrix form to constitute a powder-supplying region over the entire width of an ink image printing area on a paper, and selectively driving the powder-applying elements. CONSTITUTION:An electromagnet group 52 disposed on the lower side of a paper-feeding passage opposite to a magnetic brush roller 42 comprises first and second arrays 54, 56, which altogether cover the entire part of a power-supplying region extending over the width of a paper. The top surface 58 of an attracting part of the electromagnet proximate to the paper is rectangular in shape, and each of the electromagnets takes control of one dot in a dot matrix. In due consideration of the movement of the paper, each of the electromagnets takes control of one dot column. By arranging the electromagnets 50 in a staggered form and combining the arrangement with the feed of the paper, it is possible to form a dot matrix over the entire surface of the paper. The electromagnet 50 attracts a magnetic powder with a magnetic force stronger than the magnetic force with which a magnetic powder layer is attracted onto a sleeve 46, whereby the powder is selectively applied to the surface of the paper according to an impressed signal. Since the powder can be speedily applied to the paper by attracting the powder by the electromagnets 50, there is no need to intermittently feed the paper, and the paper can be continuously fed.