Browse Prior Art Database

Mesh Supported Ferrofluid Display

IP.com Disclosure Number: IPCOM000089404D
Original Publication Date: 1977-Oct-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Scranton, RA: AUTHOR [+2]

Abstract

A wettable mesh carrier sheet is coated with an opaque ferrofluid. Application of a magnetic field makes it easy to puncture a thin meniscus of ferrofluid, filling the holes of the mesh in a desired pattern. Punctured holes permit light to pass through the holes in the mesh to provide a display. Removal of the field thickens the fluid in the unpunctured areas.

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Mesh Supported Ferrofluid Display

A wettable mesh carrier sheet is coated with an opaque ferrofluid. Application of a magnetic field makes it easy to puncture a thin meniscus of ferrofluid, filling the holes of the mesh in a desired pattern. Punctured holes permit light to pass through the holes in the mesh to provide a display. Removal of the field thickens the fluid in the unpunctured areas.

This is a ferrofluid display or printer involving ferrofluid droplets in combination with a mesh or compartmented carrier sheet. A mesh or grid belt 10 is wetted by a ferrofluid 11. There is no local containment of the fluid required, and it may be free to redistribute itself on the belt 10. Belt 10 is coated with ferrofluid in reservoir 12, bridging the holes, so that it is completely opaque. It has been observed that this situation is stable indefinitely. However, if a magnetic field is applied by pole pieces 13, for example, perpendicular to the mesh of belt 10, the fluid surface becomes highly distorted. It thickens in the vicinity of the grid intersections (particularly if they are magnetic, i.e., nickel mesh). It thins to an extremely thin meniscus over the holes.

Ferrofluid is extremely opaque, so the thickness can be less than about three microns. In this state it is very easily punctured.

Mechanical puncturing can be used, but a laser beam 14 from scanned laser beam source 15 is a preferred means of puncturing the meniscus. Others include acoustic, thermal, air jet...