Magnetic display erasing apparatus including a plurality of magnets
US5979774A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 1996 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Nov 26, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09F9/375
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic display erasing apparatus is provided in which an ideal erasing magnetic field can be realized by using a small-sized magnet. A magnet is formed by bending a rectangular plate-like magnet, having the N-pole on the surface and the S-pole on the back face, into a U-shape so that the N-pole of one end of the magnet confronts the N-pole of the other end thereof symmetrically with respect to a magnetic display sheet. The magnetic display sheet is conveyed by a conveying apparatus, which is not shown, in the U-shaped gap space which is formed by the magnet. Because the magnetic field is symmetrical with respect to the plane of the magnetic display sheet, an ideal planar magnetic field is attained on the disposition plane of the magnetic display sheet. There is no point where the strength of the magnetic field is zero. Therefore, the whole region of the empty space can be used for erasure and the space utilization efficiency of the magnet is enhanced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.