Browse Prior Art Database

Scanning Arrangement

IP.com Disclosure Number: IPCOM000090461D
Original Publication Date: 1969-Apr-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Greiner, JH: AUTHOR

Abstract

In a beam-addressable data storage method which utilizes a rotary cylindrical data storage medium in conjunction with a nonrotatable mirror on the axis of the cylinder, the rapidity with which the stored data can be accessed by the scanning beam reflected from the mirror is limited by the rotational speed of the cylinder. This arrangement maintains the cylinder stationary while rotating the mirror, which, being more compact and lighter in weight, can be rotated at much higher speed than the cylinder, thus affording quicker access to the stored data. All bit positions in storage are readable by a single light source and a single detector.

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Scanning Arrangement

In a beam-addressable data storage method which utilizes a rotary cylindrical data storage medium in conjunction with a nonrotatable mirror on the axis of the cylinder, the rapidity with which the stored data can be accessed by the scanning beam reflected from the mirror is limited by the rotational speed of the cylinder. This arrangement maintains the cylinder stationary while rotating the mirror, which, being more compact and lighter in weight, can be rotated at much higher speed than the cylinder, thus affording quicker access to the stored data. All bit positions in storage are readable by a single light source and a single detector.

Drawings 1A and 1B show two alternative arrangements. Each utilizes a rotatable mirror 3A or 3B that can be shifted axially for deflecting the axially directed light beam onto a selected scanning track of the cylindrical storage medium 4, only a portion of which is shown. In 1A, the incident light is directed along the cylinder axis through diagonal half-silvered mirror 5 and lens 6 to the diagonal reflecting surface of rotary mirror 3A. This deflects the incident beam so that it impinges normally upon the selected scanning track on medium 4. The light returning from medium 4 then is deflected by mirror 3A through lens 6 to mirror 5. This deflects it to detector 7 where any significant change in the return beam is sensed to determine its digital significance. In 1B, the incident beam is directed by lens 8 and...