Browse Prior Art Database

Electro Optic Read Only Store

IP.com Disclosure Number: IPCOM000094144D
Original Publication Date: 1966-Jun-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

McDonnell, JA: AUTHOR

Abstract

This storage unit provides very fast response times and the facility of replacing or advancing one memory document while another is being read.

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Electro Optic Read Only Store

This storage unit provides very fast response times and the facility of replacing or advancing one memory document while another is being read.

CRT 1 contains photoemissive cathode 2 onto which binary-coded indicia is projectable selectively from either of two memory documents such as film strip negatives 3 and 4. At any bit position where a 1 is desired, 3 and 4 are transparent to transmit light. Otherwise the negative is opaque. Thus, to read data from 3, switch 5 is closed to cause lamp 6 and lens 7 to project collimated light through 3 to produce on 2 an image corresponding to the entire frame on the negative. Plate 2 emits electrons only where light strikes it. Any desired bit position can be addressed by using deflection plates X and Y to deflect the desired stream of electrons through a hole in mask 8 that collects the unwanted electrons corresponding to unselected bits. Output signal 9 is provided only if the addressed bit on 3 is a transparency i.e., a 1.

While 3 is being read, 4 can be replaced or, if a reel of film, can be advanced to another frame. After 3 is read, 5 is opened and switch 10 is closed to cause lamp 11 and lens 12 to project collimated light through 4 onto 2. Then an output signal 9 is provided in the same manner as explained above by use of X and Y and 8.

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