Browse Prior Art Database

MAGNETIC TAPE CLEANER

IP.com Disclosure Number: IPCOM000025199D
Original Publication Date: 1984-Feb-29
Included in the Prior Art Database: 2004-Apr-04
Document File: 4 page(s) / 141K

Publishing Venue

Xerox Disclosure Journal

Abstract

A single-step, magnetic tape cleaner 10 shown in Figure 1 consists of a fixed mag-net arrangement 12 inside a rotating drum 14, a scraper blade 16 fixed at about 250' from the tangent line 11 formed by a magnetic tape 18 and the drum 14 (or nearest point therebetween) and a bin 20 for receiving the magnetic toner 13 re-moved from the drum by the blade and for storing the same as reusable toner. Arrows 22 and 24 show the direction of movement of the tape and drum respec-tively. The magnet arrangement is positioned in the drum such that there isoa magnetic flux of approximately 2000 gauss at the tangent line or zero degree (Oo) reference point. The flux steadily decreases to zero gauss at approximately 235 . The magnets 15 in the fixed arrangement are positioned so that the poles alternate as shown in Figure 1. A flux density gradient between 2000 gauss diminishing to zero can be generated by a number of alternative ways, &or example, by decreasing the size of the magnets as the magnets progress from 0 towards to 235' position, by increasing the distance from the magnets to the drum surface as shown in Figure 1, by a combination of the two, or by equivalent electromagnetic arrang-ment. The surface of the rotating drum 14 is roughened so that it will carry the toner even though the magnetic field is decreasing to zero prior to its removal by the blade 16.

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XEROX DISCLOSURE JOURNAL

MAGNETIC TAPE CLEANER Proposed Classification Almon P. Fisher US. C1. 118/637

Int. C1. B05b 5/02

-240 FIG. 2

Volume 9 Number 1 January/February 1984 3

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MAGNETIC TAPE CLEANER (Cont'd)

A single-step, magnetic tape cleaner 10 shown in Figure 1 consists of a fixed mag- net arrangement 12 inside a rotating drum 14, a scraper blade 16 fixed at about 250' from the tangent line 11 formed by a magnetic tape 18 and the drum 14 (or nearest point therebetween) and a bin 20 for receiving the magnetic toner 13 re- moved from the drum by the blade and for storing the same as reusable toner. Arrows 22 and 24 show the direction of movement of the tape and drum respec- tively. The magnet arrangement is positioned in the drum such that there isoa magnetic flux of approximately 2000 gauss at the tangent line or zero degree (Oo) reference point. The flux steadily decreases to zero gauss at approximately 235 . The magnets 15 in the fixed arrangement are positioned so that the poles alternate as shown in Figure 1. A flux density gradient between 2000 gauss diminishing to zero can be generated by a number of alternative ways, &or example, by decreasing the size of the magnets as the magnets progress from 0 towards to 235' position, by increasing the distance from the magnets to the drum surface as shown in Figure 1, by a combination of the two, or by equivalent electromagnetic arrang- ment. The surface of the rotating drum 14 is roughened so that it will carry the toner even though the magnetic field is decreasing to zero prior to its removal by the blade 16.

In operation, the magnetic field of the cleaner simultaneously demagnetizes the tape and then lifts the toner off of the tape as the tape passes under the cleaner drum about 1 mil away. The cleaner drum rotates carrying the toner through a decreasing magnetic field to the scraper where there is no magnetic field. The decreasing magnetic field allows the toner to be moved out of a high flux area to a lower flux so that there will not be a toner buildup at the tape. At the scraper, the toner is removed and stored in a bin.

In order to remove toner completely from the tape, a high magnetic field is needed. Because high magnetic fields may polarize toner, changing its handling properties, magnetic removal of toner can be divided into two steps:

1) Removal of a large percentage of the toner...