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Photoemitter for Recording Information

IP.com Disclosure Number: IPCOM000092887D
Original Publication Date: 1967-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Halter, EA: AUTHOR

Abstract

This photoemitter controls the placement as well as the width of bits of information recorded on magnetic tape. Emitter disk 1 is on shaft 3 which drives magnetic tape 5. Disk 1 has transparent slots 7 emanating from its center portion and directed outwardly towards the circumference. Slots 7 are centered on and parallel to radial lines 8 which are spaced at a constant angular distance from one another. The angular width of slots 7 progressively varies radially to the circumference of disk 1.

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Photoemitter for Recording Information

This photoemitter controls the placement as well as the width of bits of information recorded on magnetic tape. Emitter disk 1 is on shaft 3 which drives magnetic tape 5. Disk 1 has transparent slots 7 emanating from its center portion and directed outwardly towards the circumference. Slots 7 are centered on and parallel to radial lines 8 which are spaced at a constant angular distance from one another. The angular width of slots 7 progressively varies radially to the circumference of disk 1.

Located on one side of disk 1 is light source 9. On the other side is phototransistor 11. Both are mounted on slidable bracket 13.

The latter slides on rod 14 so that source 9 and phototransistor 11 can be moved radially along disk 1. As the latter rotates, phototransistor 11 produces an output on line 15 each time one slot 7 exposes it to source 9. This output gates data signals on line 17 through gating circuit 19 and causes information bits to be recorded on tape 5 by head 21.

The time duration during which head 21 records information and, hence the width of the recorded bit of information, is dependent upon the width of slots 7 and the distance from the center of disk 1 that phototransistor 11 is located. The width of the recorded bits is reduced as phototransistor 11 and source 1 are moved toward the circumference of disk 1 and increased when they are moved toward the center of disk 1. This is because the angular width of slots 7 p...