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US4807187A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and device of memory using liquid crystal

Assignee: Kureha Corp
•
Filing: 1987-03-06
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Granted: 1989-02-21
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Expires: 2007-03-06
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Abstract

Abstract A memory comprises a viologen which shows liquid crystalline properties, and a voltage more than 0.7 V is applied to the viologen so that the electric conductivity of the viologen is changed and the resultant state of said viologen in which the electric conductivity has been changed is used as a memorized state.

Inventors

  • 👤 Iwao Tabushi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 12:15
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/22

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 93 words
A memory method comprising: (a) arranging a voltage sensitive element consisting of a viologen which has liquid crystalline properties between a pair of electrodes so that a voltage may be applied thereto; (b) applying to said electrodes a voltage sufficient to change electric conductivity of said voltage sensitive viologen element from a first state to a second state; and (c) measuring the electric conductivity state of said element, a measurement indicating said first conductivity state representing a first memory state and a measurement indicating said second conductivity state representing a second memory state.
Claim 2
Dependent Claim 93 words
A memory method comprising: (a) arranging a voltage sensitive element consisting of a viologen which has liquid crystalline properties between a pair of electrodes so that a voltage may be applied thereto; (b) applying to said electrodes a voltage sufficient to change electric conductivity of said voltage sensitive viologen element from a first state to a second state; and (c) measuring the electric conductivity state of said element, a measurement indicating said first conductivity state representing a first memory state and a measurement indicating said second conductivity state representing a second memory state.
Claim 3
Dependent Claim 14 words
A method according to claim 1, wherein said viologen is a halide of viologen.
Claim 4
Dependent Claim 20 words
A method according to claim 2, wherein said viologen is one selected from N,N'-bis(3,6,9-trioxatridecyl)-4,4'-dipyridinium diiodide, N,N'-bis(3,6,9,12-tetraoxadecyl)-4,4'-dipyridinium diiodide and N,N'-bis(3,6,9-trioxatridecyl)-4,4'-dipyridinium dibromide.
Claim 5
Dependent Claim 14 words
A method according to claim 1, wherein said viologen is at liquid crystalline state.
Claim 6
Dependent Claim 20 words
A method according to claim 1, wherein said viologen is at sintering state in which liquid crystalline properties are maintained.
Claim 7
Dependent Claim 59 words
A memory method according to claim 1, wherein said first conductivity state is a low conductivity state, said second conductivity state is a conductivity state of substantially higher conductivity than said low conductivity state, and said applied voltage is of a level such as to change electric conductivity of said viologen rapidly between said first and second conductivity states.
Claim 8
Dependent Claim 17 words
A memory method as recited in claim 6 where said applied voltage is more than 5 V.
Claim 9
Dependent Claim 78 words
A memory method according to claim 1 wherein said first conductivity state is a low conductivity state, said voltage applied to said electrodes is of a level such as to change the low conductivity state of said element to a second conductivity state of substantially higher conductivity over a substantial period of time, and said measurement of electric conductivity of said second conductivity state is representative of the length of time said voltage is applied to said electrodes.
Claim 10
Dependent Claim 19 words
A memory method as recited in claim 8 wherein said applied voltage is between 0.7 V and 5 V.
Claim 11
Dependent Claim 17 words
A memory method as recited in claim 1 wherein said applied voltage is more than 0.7 V.
Claim 12
Dependent Claim 97 words
A memory device comprising: a pair of electrode means; a viologen having liquid crystalline properties disposed between said electrode means in constant contact therewith; condition sensing means connected to said electrodes for applying a voltage to said electrode means upon occurrence of a condition, such that an electrical conductive state of said viologen is changed by application of said voltage to store in memory an indication of occurrence of said condition; and detecting means connected to said electrode means for measuring a change in the electrical conductive state of said viologen as representing occurrence of said condition.
Claim 13
Dependent Claim 97 words
A memory device comprising: a pair of electrode means; a viologen having liquid crystalline properties disposed between said electrode means in constant contact therewith; condition sensing means connected to said electrodes for applying a voltage to said electrode means upon occurrence of a condition, such that an electrical conductive state of said viologen is changed by application of said voltage to store in memory an indication of occurrence of said condition; and detecting means connected to said electrode means for measuring a change in the electrical conductive state of said viologen as representing occurrence of said condition.
Claim 14
Dependent Claim 15 words
A memory device according to claim 11, wherein said viologen is a halide of viologen.
Claim 15
Dependent Claim 21 words
A memory device according to claim 12, wherein said viologen is one selected from N,N'-bis(3,6,9-trioxatridecyl)-4,4'-dipyridinium diiodide, N,N'-bis(3,6,9,12-tetraoxadecyl)-4,4'-dipyridinium diiodide and N,N'-bis(3,6,9-trioxatridecyl)-4,4'-dipyridinium dibromide.
Claim 16
Dependent Claim 29 words
A memory device according to claim 11, wherein said condition is the magnitude of voltage applied, and a source of voltage to be measured is connected to said electrodes.
Claim 17
Dependent Claim 48 words
A memory device as recited in claim 11, wherein said condition is one of an occurrence of a power failure and a duration of a power failure in an electric machine, and said voltage is applied to said electrode means only during the time said power failure occurs.

References Cited (Backward Citations)

US3652149A Cited
US3712709A Cited
US3854794A Cited
US4088393A Cited
US4300138A Cited
JPS54143783A Cited
JPS57137814A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-02-21 1992-08-22 1993-02-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-02-21 1996-08-22 1997-02-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-02-21 2000-08-22 2001-02-21 $7700.00 Window Closed / Lapsed

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