Browse Prior Art Database

Drum Recording

IP.com Disclosure Number: IPCOM000091471D
Original Publication Date: 1968-Feb-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Cole, JN: AUTHOR

Abstract

This system for writing on the surface of a rotating drum comprises metallic rotatable drum 2 on whose outer surface 4 are located discrete spots 5 of insulation, such as plastic, and discrete spots of metal or selenium 6. In effect, each discrete spot acts as a capacitive element.

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Drum Recording

This system for writing on the surface of a rotating drum comprises metallic rotatable drum 2 on whose outer surface 4 are located discrete spots 5 of insulation, such as plastic, and discrete spots of metal or selenium 6. In effect, each discrete spot acts as a capacitive element.

Galvanometer 8 has capacitive or contact probe 10 associated with it. Signals applied to the deflection coil of galvanometer 8 cause probe 10 to sweep along drum 2 in the direction of the arrow, starting at one end of drum 2 and moving toward the other end as a function of the analog signal applied to the deflection coil. Each analog signal can be the output of a binary-to-analog electrical converter. As probe 10 moves across spots 6, an electrical charge is applied to such spots. After such charging step, electrostatic ink, drawing D is applied at station 12. Such ink adheres only to those spots 6 that are charged. Such charged ink is transferred to paper 14, giving a pictorial representation of the signal applied to the galvanometer 8 coil. Surface 4, before completing one rotation and making contact with probe 10, is discharged at station 16.

Where selenium strips are used over the discrete spots of insulation instead of metal strips, galvanometer 8, drawing C, has mirror 1 attached to it so that signals sent to the deflection coil of galvanometer 8 deflect mirror 18 that is constantly reflecting a beam of light 20 coming from source 22. The light path along the drum...