US3851318A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal information storage and read-out system
Assignee: INT LIQUID XTAL CO
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Filing: 1973-10-11
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Granted: 1974-11-26
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Expires: 1993-10-11
Abstract
Abstract The unique properties of the Smectic C-phase of a liquid crystal are used to store information represented by the bistable orientation directions of molecular axes. Groups of molecules contained between transparent surfaces which are treated in a particular manner to develop optical homogeneity are used as storage elements. The information state of the storage element is set by causing the molecular axes within the element to assume either a first or a second stable orientation of the axes. Various methods for reading, writing, and erasing information stored in this manner are disclosed.
Inventors
- 👤 T Taylor
- 👤 J Fergason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:05
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13781; G02F3/00; G02F3/02; G02F3/022; G11; G11C; G11C13/00; G11C13/04; G11C13/048; G11C13/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
126 words
An information storage and read-out system comprising a liquid crystal memory element selected to have first and second stable molecular axis orientations, means for producing a high intensity beam of electromagnetic wave energy and for directing said beam to selected molecular groups comprising storage elements in said liquid crystal memory element, said high intensity beam of electromagnetic wave energy acting to change the molecular orientation of the liquid crystal molecules in said selected molecular groups from a first stable orientation to a second stable orientation, and means for establishing a low intensity electromagnetic wave energy reading source polarized so as to cause birefringent rotation through said selected molecular groups whereby electromagnetic wave energy will pass through only those selected molecular groups in said first molecular orientation.
Claim 2
Dependent Claim
126 words
An information storage and read-out system comprising a liquid crystal memory element selected to have first and second stable molecular axis orientations, means for producing a high intensity beam of electromagnetic wave energy and for directing said beam to selected molecular groups comprising storage elements in said liquid crystal memory element, said high intensity beam of electromagnetic wave energy acting to change the molecular orientation of the liquid crystal molecules in said selected molecular groups from a first stable orientation to a second stable orientation, and means for establishing a low intensity electromagnetic wave energy reading source polarized so as to cause birefringent rotation through said selected molecular groups whereby electromagnetic wave energy will pass through only those selected molecular groups in said first molecular orientation.
Claim 3
Dependent Claim
13 words
The system of claim 1 wherein said electromagnetic wave energy comprises light energy.
Claim 4
Dependent Claim
15 words
The system of claim 2 wherein said liquid crystal is of the semectic C-phase type.
Claim 5
Dependent Claim
31 words
The system of claim 2 wherein said high intensity beam comprises polarized light having an electric field vector parallel to said second stable orientation and normal to said first stable orientation.
Claim 6
Dependent Claim
53 words
The system of claim 2 including means for producing a beam of electromagnetic wave energy for erasing information stored in said liquid crystal memory element, said latter-mentioned beam acting to change the molecular orientation of all molecular groups in said liquid crystal memory element from said second to said first stable molecular orientation.
Claim 7
Dependent Claim
25 words
The system of claiM 5 wherein said high intensity beam and said erase beam are directed onto opposite sides of said liquid crystal memory element.
Claim 8
Dependent Claim
51 words
The system of claim 2 wherein said reading source comprises a beam of polarized light at right angles to said high intensity beam, said liquid crystal memory element comprising a layer of liquid crystal material disposed at an angle of about 45* with respect to said high intensity and reading beams.
Claim 9
Dependent Claim
80 words
The system of claim 1 wherein said low intensity reading source comprises a low intensity light beam directed along and parallel to said second stable orientation, a first read polarizer through which said low intensity beam passes and having a plane of polarization substantially parallel to said first stable molecular axis orientation, the direction of polarization within said first read polarizer causing birefringent rotation of polarized light through those molecular groups having axes oriented parallel to said first stable orientation.
Claim 10
Dependent Claim
49 words
The system of claim 8 including a second read polarizer on the side of said memory element opposite said first read polarizer, said second read polarizer having a plane of polarization parallel to said first read polarizer and a polarization direction crossed with respect to said first read polarizer.
Claim 11
Dependent Claim
34 words
The system of claim 9 including means for scanning light and dark spots on the surface of said second read polarizer to develop information output signals corresponding to the states of said molecular groups.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |