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High Speed Read Write Optical Memory

IP.com Disclosure Number: IPCOM000094765D
Original Publication Date: 1965-May-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Harris, TJ: AUTHOR

Abstract

An X-Y memory array is formed by a plurality of bistable circuits. Each circuit includes a resistor, a tunnel diode TD and a light emitting diode LD. Assuming that each of the bistable circuits is in its on state, a positive voltage applied by the Y driver to any one of the Y lines causes each of the bistable circuits in that line to shift from point 1 to point 1'. If a negative voltage is now applied by the X driver to one of the- X lines, the bistable circuit at the junction of the two lines is shifted to point 0''. The other circuits connected to the X line are shifted to point 1'.

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High Speed Read Write Optical Memory

An X-Y memory array is formed by a plurality of bistable circuits. Each circuit includes a resistor, a tunnel diode TD and a light emitting diode LD. Assuming that each of the bistable circuits is in its on state, a positive voltage applied by the Y driver to any one of the Y lines causes each of the bistable circuits in that line to shift from point 1 to point 1'. If a negative voltage is now applied by the X driver to one of the- X lines, the bistable circuit at the junction of the two lines is shifted to point 0''. The other circuits connected to the X line are shifted to point 1'.

Removal of the voltages on both lines results in a return of the junction circuit to point 0. The other circuits return to point 1. The junction circuit can be returned to its on state by applying voltages of reversed polarity to the X-Y lines intersecting at the junction. This causes the bistable circuit to shift from point 0 to point 1'' and then to point 1 when the voltages are removed.

When any one of the bistable circuits is in its 0 state, no light is emitted by its diode LD. Light is emitted, however, from each diode when its circuit is in the 1 state. A digital light deflector is caused to scan the diodes LD and to deflect any light that may be emitted by the selected diode to a photodetector. The presence of light indicates the positions in memory at which 1's are stored. The locations of these positions are indicated by the switching re...