Browse Prior Art Database

Magnetic Duplication of Recording Belts

IP.com Disclosure Number: IPCOM000075772D
Original Publication Date: 1971-Nov-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 4 page(s) / 100K

Publishing Venue

IBM

Related People

Klein, WF: AUTHOR [+2]

Abstract

This audio belt recording system and process permits rapid and mass reproduction of magnetic records: Machine type and recording pattern.

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Magnetic Duplication of Recording Belts

This audio belt recording system and process permits rapid and mass reproduction of magnetic records: Machine type and recording pattern.

The machines used with the magnetic records produced from this process may be the magnetic recording belt machines, such as those presently marketed by IBM for dictation. The recording pattern is helical, with the exception of one wide circular track which is used here for the aligning process and belt assembly. Master magnetic belt and machine -.

The "Master" magnetic belt is a magnetic coated medium with magnetic properties of high coercivity and retentivity, that differ from the "copy" material properties so as to be effective with magnetic passive transfer. See C. L. Gardner et al patent 3,536,855.

The machine to produce the master belt must be capable of generating helical recorded tracks on the belt in such a fashion that when a passive transfer "copy" is made, it can be played on a "standard belt machine". This means that the mirror image caused by "copying" is to be compensated for by recording the "Master" with a reverse helix. Copy magnetic belt and machine -.

The "copy" magnetic belt or sheet (flat prior to assembly into a belt) is a magnetic medium coated on a polyester and/or plastic substrate. This material, when used for a passive transfer copy of a "master" recording, has the potential to reproduce speech frequencies (200 Hz to 3K Hz) of a quality equal to a direct recording process, provided the proper equalization is used during the record and playback modes. Belt reproduction -.

Belt reproduction can be accomplished in several ways. Two approaches - single-and continuous - are discussed. A. Single - Fig.
1. See also Gardner et al patent 3,536,855

1) Master belt is produced on the master recording machine,

checked, and then unspliced to be used in flat sheet.

2) Flat sheet master (magnetic side up) is positioned in copy

device cavity on the two locating pins.

3) Flat (unspliced) "copy" sheet (oxide down) is placed on top

of master and located on same pins as the master.

4) Pressure plate is placed on top of the two media and clamped

into place to insure good intimate contact between the two

magnetic surfaces.

5) Copy device is turned over, the permanent magnet roller

placed on the rack and rotated and translated over the

entire length of the copy device. This rotation and

translation is accomplished through the use of rack and

pinion combination. This effects duplication of magnetic

information on master onto copy.

6) Top plate is unclamped and copy material removed.

7) Sheet is spliced together using splicing tape and the

positive alignment device. See belt assembly description.
B. Continuous - Fig. 2

1

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1) Master belt is produced on the master recording machine

checked, and then placed on an expandable drum on the

continuous belt copying machine.

2) Copying is accomplished by rolling the copy stock in contact

with the master...