Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Detector for Optical Memory

IP.com Disclosure Number: IPCOM000080213D
Original Publication Date: 1973-Nov-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 3 page(s) / 52K

Publishing Venue

IBM

Related People

Ii, LB: AUTHOR

Abstract

An optical memory system utilizing a ferroelectric optical memory 10 is provided with a dynamic threshold tracking detector capability to prevent erroneous readouts.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Detector for Optical Memory

An optical memory system utilizing a ferroelectric optical memory 10 is provided with a dynamic threshold tracking detector capability to prevent erroneous readouts.

Memory 10 stores digital information in three dimensions. Information is stored spatially along the X and Y axes, and by color along the Z axis. Each memory element or bin is thus capable of storing the information selectively in several discrete different colors. Collimated light passing through memory 10 is collected, integrated and focused by optical system 11 onto various light detectors, there being one detector for each discrete color. Only one detector 12 is shown for sake of simplicity. At any given time, the number of memory elements storing the same color can thus vary from a minimum of one to the maximum number of elements in the memory. Moreover, the feedthrough light from any memory element not selected for decoding is approximately 1%. Thus, the feedthrough could vary an input light intensity from: Minimum: 0.01E, where E = element intensity

Maximum: 0.01xExB, where B = bins (i.e., memory elements). For example, for 10 bins, the threshold could be 1000E. Hence, if one bin was turned "ON", the detection required is 1E in 1000E.

To resolve any ambiguities which may result from these possibilities, programmed trackers for all the color thresholds are provided. For sake of simplicity, only one tracker 13, which is associated with detector 12, is described and shown. By continuously tracking the particular color threshold, an incremental increase or decrease is detected for a selected bin for that color. Light L1 is the feedthrough light from the optical scarner, not shown, incident to the storage elements of memory 10...