Browse Prior Art Database

MULTIPLE PULSE RECORDING

IP.com Disclosure Number: IPCOM000025429D
Original Publication Date: 1985-Jun-30
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 68K

Publishing Venue

Xerox Disclosure Journal

Abstract

In magnetography, magnetic latent images are produced on a magnetic recording medium representing information such as that from an original document. The latent image is developed with magnetic toner particles and transferred in image configuration to a record sheet, such as paper, whereat the developed image is permanently fixed thereto, producing a final hard copy. The magnetic latent image is generally formed by reversing the magnetic polarity of relatively small areas representing picture elements or pixels in a premagnetized DC magnetic field placed on a recording medium such, for example, chromium dioxide. Fringe fields are developed between the opposite magnetic polarities or flux reversals which attract and hold magnetic toner particles.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 66% of the total text.

Page 1 of 2

Proposed Classification
U.S. CI. 340/174 Int. CI. C08c 7/12

In magnetography, magnetic latent images are produced on a magnetic recording medium representing information such as that from an original document. The latent image is developed with magnetic toner particles and transferred in image configuration to a record sheet, such as paper, whereat the developed image is permanently fixed thereto, producing a final hard copy. The magnetic latent image is generally formed by reversing the magnetic polarity of relatively small areas representing picture elements or pixels in a premagnetized DC magnetic field placed on a recording medium such, for example, chromium dioxide. Fringe fields are developed between the opposite magnetic polarities or flux reversals which attract and hold magnetic toner particles.

It has been found that if the areas of flux reversal are too small, the fringe field is too weak to provide adequate strength to hold the appropriate quantity of toner particles, thus providing poor copy quality for the hard copies. For adequate resolution and toner development, a spatial wavelength of 70 microns (i.e., 35 microns between flux reversals) are required. However, page width magnetic recording bars are generally created by a linear array of several thousand thin- film heads, each with a gap of 10 microns. The recorded spot size or flux reversal region provided by each head is on the order of 10 microns or less, well below that required for magnetogra...