Browse Prior Art Database

Fabrication of Erasable, Write/Read Optical Storage Device

IP.com Disclosure Number: IPCOM000036239D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Kim, J: AUTHOR [+4]

Abstract

Disclosed is a conceptual structure of a digital erasable, write/read optical storage device (Figs. 1 and 2).

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Fabrication of Erasable, Write/Read Optical Storage Device

Disclosed is a conceptual structure of a digital erasable, write/read optical storage device (Figs. 1 and 2).

Writing information is accomplished by applying an electrical potential externally (Fig. 1) or internally using a photoconductive layer (layer C in Fig. 2) to the transparent electrode (layer E) which polarizes the hard ferroelectric material (layer F) and induces liquid crystals (layer L) to rotate for light penetration through the perpendicular and parallel polarizer (layer P). Those spots which were not charged electrically do not have liquid crystals rotated for light penetration. Upon removing the electrical potential, remanent polarization of hard ferroelectric material acts as a permanent electrical source to ensure the stability of the liquid crystals which has been a major problem with current liquid crystal memory disk technology.

Information reading is achieved simply by a detection of the laser beam, either reflected from the common ground electrode (layer G) through the polarizer in case of reflected mode or transmitted laser beam in case of transmission scheme.

Erasing the information is done either by local heating of the ferroelectric material (layer F) and liquid crystal (layer L) by laser to a temperature where they lose ferroelectricity and smectic orientation or by applying a negative potential to the electrode so that the ferroelectric material can lose its remanent polarizati...